Note: Descriptions are shown in the official language in which they were submitted.
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FLUID PUMP AND MOTOR
Technical Field
The present invention relates to a fluid pump and motor, and more
particularly,
to a rotary fluid pump and motor.
Background Art
A fluid pump is a device that sucks and discharges a fluid through rotation of
a
shaft thereof by use of a driving unit, and a fluid motor is a device that
receives fluid
1o discharged from a pump and causes the shaft to rotate. A fluid pump and
fluid motor
are generally the same in view of their structures.
Related art fluid pumps are classified into vane pumps with sliding parts,
gear
pumps with two engaging gears, screw pumps and the like. Among them, the vane
pump is often utilized because its structure is relatively simple. However,
the related
art vane pump should be configured such that its vane can come in and out of a
rotor.
Further, the vane pump has the following structural problems. That is,
vibration may
be produced in the vane pump because its rotating shaft is eccentric, and the
bearings
may be easily damaged due to the unbalanced load applied to the rotating
shaft.
Furthermore, pulsation may be produced because fluid is not continuously
discharged
from the vane pump.
Korean Patent No. 315954 discloses a pump having a structure different from
that of the related art rotary pump. This pump comprises a hermetic container
with
suction and discharge tubes; a transmission mechanism which is installed in
the
hermetic container to generate a driving force; a cylinder assembly which
defines an
internal space and includes a plurality of suction and discharge passages
communicating
with the internal space; a rotating shaft which is coupled to a rotor of the
transmission
mechanism and penetrates through the center of the cylinder assembly; a
partition plate
which is coupled to the rotating shaft within the cylindrical assembly to
partition the
internal space into first and second spaces; vanes which are fitted through
the cylinder
3o assembly, resiliently supported such that they are always brought into
contact with both
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sides of the partition plate and move to switch the first and second spaces
into suction
and discharge regions, respectively; and an opening/closing means which
discharges
fluid compressed in compressing regions of the first and second spaces while
opening
and closing the discharge passage of the cylinder assembly. However, the pump
disclosed in the Korean Patent No. 315954 has the problems in that the amount
of
discharge fluid is limited because a single space defined at one side of the
partition plate
becomes a compressing space, and pulsation may be produced because the width
of the
compressing region and thus the amount of discharge fluid varies over time.
Further,
since the opening/closing means (discharge valve) for discharging fluid is
essentially
provided, it is difficult to utilize the pump as a motor.
Summary of Invention
An object of the present invention is to provide a rotary fluid pump that is
configured to include a vane and not to be eccentric. Another object of the
present
invention is to provide a rotary fluid pump with a simple vane that need not
move in and
out of a rotor. A further object of the present invention is to provide a
rotary fluid
pump having an increased discharge amount. A still further object of the
present
invention is to provide a rotary fluid pump having reduced pulsation. A still
further
object of the present invention is to provide a rotary fluid pump that can
also be used as
a motor.
According to an aspect of the present invention, there is provided a fluid
pump,
comprising a rotating chamber which is defined by first and second opposite
wall
surfaces and a third cylindrical wall surface for connecting the first and
second wall
surfaces to each other; a rotor which rotates about a rotating axis passing
through the
centers of the first and second wall surfaces within the rotating chamber and
includes a
hub with an outer cireumferential surface and a vane protruding radially
outward from
the outer circumferential surface of the hub and having an outward radial tip
that is
slidably brought into close contact with the third wall surface of the
rotating chamber;
and a pair of blocking walls which cooperate with the vane and linearly move
upon
rotation of the rotor, and each of which has an opposite edge facing each
other in such a
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manner that the opposite edges of the blocking walls are slidably brought into
close
contact with both side surfaces, and the other edges of the blocking walls
adjacent the
opposite edges are slidably brought into close contact with the outer
circumferential
surface of the hub of the rotor. The vane further includes a leading end which
is
slidably brought into close contact with the first wall surface of the
rotating chamber, a
trailing end which is slidably brought into close contact with the second wall
surface of
the rotating chamber and inclines for connecting the leading and trailing
ends. A
suction port for suction of a fluid and a discharge port for discharge of the
fluid are
provided at both positions adjacent to the pair of the blocking walls which
are
1o interposed between the ports.
The pair of the blocking walls may be formed integrally with each other.
The third wall surface of the rotating chamber may be provided with suction
grooves which are positioned adjacent to the pair of the blocking walls and
connected to
the suction ports to connect both spaces separated by the vane to each other,
and
discharge grooves which are positioned adjacent to the pair of the blocking
walls and
connected to the discharge ports to connect the both spaces separated by the
vane to
each other.
The leading and trailing ends of the vane may be formed to be brought into
surface contact with the first and second wall surfaces of the rotating
chamber, and the
width of the radial tip of each of the leading and trailing ends of the vane
may be formed
to be larger than a maximum distance between the corresponding suction and
discharge
grooves.
The fluid pump may further comprise first and second pressing plates which
define the first and second wall surfaces of the rotating chamber, linearly
move along
the rotating axis and are slidably brought into close contact with the leading
and trailing
ends of the vane by an external force.
The pressing plates may be urged toward the rotating chamber by the fluid on a
high-pressure side.
The pressing plates may be urged toward the rotating chamber by an elastic
member.
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The fluid pump may further comprise a pressure-regulating device for
regulating pressure of the fluid discharged from the discharge ports and
supplied to a
load side.
Preferably, the fluid discharged from the discharge ports flows toward a
return
passage communicating with a low-pressure side and a discharge passage
communicating with the load side through first and second branched passages,
respectively, and the pressure-regulating device includes a discharge amount
regulating
unit having a moving member for moving according to the pressure of the fluid
in the
discharge passage to open and close the first passage and a check valve
provided in the
second passage.
The pressure-regulating device may further comprise an elastic member for
urging the moving member in a direction opposite to a direction in which the
pressure of
the fluid in the discharge passage is exerted on the moving member.
Preferably, two leading ends, two tailing ends and two pairs of blocking walls
are provided, and suction and discharge grooves are provided adjacent the two
pairs of
the blocking walls while being separated by the two pairs of blocking walls.
The fluid pump may fixrther comprise a pressure-regulating device for
regulating pressure of the fluid discharged from the discharge ports and
supplied to a
load side.
2o Preferably, the fluid discharged through the two discharge ports provided
at the
discharge grooves flows toward first and second passages connected to a return
passage
communicating with a low-pressure side and toward third and fourth passages
connected to a discharge passage communicating with a load side, and the
pressure-
regulating device includes a discharge amount regulating unit having a moving
member
for moving according to the pressure of the fluid in the discharge passage to
open and
close the first or second passage and first and second check valves provided
in the third
and fourth passages, respectively.
The pressure-regulating device may further comprise an elastic member for
urging the moving member in a direction opposite to a direction in which the
pressure of
the fluid in the discharge passage is exerted on the moving member.
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The pressure-regulating device may further include an accumulating portion.
The accumulating portion may include a moving member for moving by
receiving the pressure of the fluid in the discharge passage and an elastic
member for
urging the moving member in a direction opposite to a direction in which the
pressure of
5 the fluid is exerted on the moving member.
The pair of blocking walls may have contact members that are brought into
contact with both side surfaces of the vane, and each of the pair of blocking
walls may
be provided with a receiving groove for receiving the contact member and a
passage
hole for causing the receiving groove to communicate with a discharge side.
to According to another aspect of the present invention, there is provided a
fluid
motor, comprising a rotating chamber which is defined by first and second
opposite wall
surfaces and a third cylindrical wall surface for connecting the first and
second wall
surfaces to each other; a rotor which rotates about a rotating axis passing
through the
centers of the first and second wall surfaces within the rotating chamber, and
includes a
hub with an outer circumferential surface and a vane protruding radially
outward from
the outer circumferential surface of the hub and having an outward radial tip
that is
slidably brought into close contact with the third wall surface of the
rotating chamber;
and a pair of blocking walls which cooperate with the vane and linearly move
upon
rotation of the rotor, each of the blocking walls having an opposite edge
facing each
other in such a manner that the opposite edges of the blocking walls are
slidably brought
into close contact with both side surfaces and other edges of the blocking
walls adjacent
the opposite edges are slidably brought into close contact with the outer
circumferential
surface of the hub of the rotor. The vane further includes a leading end which
is
slidably brought into close contact with the first wall surface of the
rotating chamber, a
trailing end which is slidably brought into close contact with the second wall
surface of
the rotating chamber and inclines for connecting the leading and trailing
ends. An inlet
port for inflow of a fluid and an outlet port for outflow of the fluid are
provided at both
positions adjacent to the pair of the blocking walls which are interposed
between the
inlet and outlet ports.
3o The pair of the blocking walls may be formed integrally with each other.
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The third wall surface of the rotating chamber may be provided with inflow
grooves which are positioned adjacent to the pair of the blocking walls and
connected to
the inlet ports to connect both spaces separated by the vane to each other,
and outflow
grooves which are positioned adjacent to the pair of the blocking walls and
connected to
the outlet ports to connect the both spaces separated by the vane to each
other.
The leading and trailing ends of the vane may be formed to be brought into
surface contact with the first and second wall surfaces of the rotating
chamber, and the
width of a radial tip of each of the leading and trailing ends of the vane may
be formed
to be larger than a maximum distance between the corresponding suction and
discharge
l0 grooves.
The fluid motor may further comprise first and second pressing plates which
form the first and second wall surfaces of the rotating chamber, linearly move
along the
rotating axis and are brought into close contact with the leading and trailing
ends of the
vane by an external force.
The pressing plates may be urged toward the rotating chamber by the fluid on a
high-pressure side.
The pressing plates may be urged toward the rotating chamber by an elastic
member.
Brief Description of Drawings
Fig. 1 is a perspective view of a fluid pump according to a first embodiment
of
the present invention in which the interior of a main body of the pump can be
shown by
cutting away a portion of a pump housing.
Fig. 2 is a sectional side view of the main body of Fig. 1.
Fig. 3 is a sectional view schematically illustrating the interior of the main
body
and a pressure-regulating device in a state where the amount of discharge
fluid of the
fluid pump shown in Fig. 1 is 100%, in which the housing of the main body has
been cut
perpendicular to a rotating shaft.
Fig. 4 is a sectional view of the main body of Fig. 3 taken along line A-A'.
Fig. 5 is a perspective view of a linear moving object of the main body shown
in
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Fig. 1.
Fig. 6 is a perspective view of a pressing plate of the main body shown in
Fig. 1.
Fig. 7 is a perspective view of an opening/closing means of the pressure-
regulating device shown in Fig. 3.
Fig. 8 (a) to (d) is a view of an unrolled rotor of the main body of Fig. 1 in
which the rotor is shown together with the first and second blocking walls.
Fig. 9 is a sectional view schematically illustrating the interior of the main
body
and the pressure-regulating device in a state where the amount of discharge
fluid of the
fluid pump shown in Fig. 1 is 50%, in which the housing of the main body has
been cut
perpendicular to the rotating shaft.
Fig. 10 is a sectional view schematically illustrating the interior of the
main
body and the pressure-regulating device in a state where the amount of
discharge fluid
of the fluid pump shown in Fig. 1 is 0%, in which the housing of the main body
has
been cut perpendicular to the rotating shaft.
Fig. 11 is a perspective view of a fluid pump according to a second embodiment
of the present invention in which the interior of the main body of the pump
can be
shown by cutting away a portion of a pump housing.
Fig. 12 is a sectional view schematically illustrating the interior of the
main
body and a pressure-regulating device in a state where the amount of discharge
fluid of
the fluid pump shown in Fig. 11 is 100%, in which the housing of the main body
has
been cut perpendicular to the rotating shaft.
Fig. 13 (a) to (d) is a view of an unrolled rotor of the main body of Fig. 11
in
which the rotor is shown together with the first and second blocking walls.
Fig. 14 is a sectional view schematically illustrating the interior of the
main
body and the pressure-regulating device in a state where the amount of
discharge fluid
of the fluid pump shown in Fig. 11 is 0%, in which the housing of the main
body has
been cut perpendicular to the rotating shaft.
Fig. 15 is a perspective view of a main body of a fluid pump according to a
third embodiment of the present invention.
Fig. 16 is a perspective view of the housing of the main body of Fig. 15 taken
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along line C-C'.
Fig. 17 is an exploded perspective view of a linear moving object shown in
Fig.
16, in which a central portion thereof is cut away such that the discharge
side can be
seen.
Best Mode for Carrying Out the Invention
Hereinafter, preferred embodiments of the present invention will be described
in detail with reference to the accompanying drawings.
Figs. 1 to 10 are views related to a first embodiment of the present
invention.
1o Referring to Figs. 1 to 4, a fluid pump 10 includes a main body 19 and a
pressure-
regulating device 90. The main body 19 includes a housing 20, a rotor 30, a
rotating
shaft 40, first and second linear moving objects 50 and 60, and first and
second pressing
plates 70 and 80. A rotating axis 100 is the line extending along the axis of
the
rotating shaft 40. The housing 20 includes a cylindrical body portion 21, and
first and
second wing portions 28 and 29 positioned at both sides of the body portion
21. The
body portion 21 includes first and second end walls 22 and 24, and a side wall
26
connecting the two end walls 22 and 24. The first and second end walls 22 and
24 are
formed as a circular plate and face each other to be orthogonal to the
rotating axis 100.
An internal space of the body portion 21 is divided into first and second
2o pressing chambers 201 and 202 and a rotating chamber 23 by means of the
first and
second pressing plates 70 and 80 that are installed to divide the internal
space and to be
orthogonal to the rotating axis 100. The first pressing chamber 201 is a space
defined
between the first end wall 22 and the first pressing plate 70, whereas the
second pressing
chamber 202 is a space defined between the second end wall 24 and the second
pressing
plate 80. The rotating chamber 23 is a space defined between the first and
second
plates 70 and 80. The rotating chamber 23 is defined by first and second
opposite
circular wall surfaces 231 and 232 and a third cylindrical wall surface 233
connecting
the first and second wall surfaces 231 and 232. The first and second wall
surfaces 231
and 232 become surfaces facing the first and second pressing plates 70 and 80,
3o respectively, whereas the third wall surface 233 becomes a portion defined
on the inner
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surface of the side wall 26 of the body portion 21 of the housing 20 between
the first
and second pressing plates 70 and 80. Two leading ends 341 and 345 of a vane
34 of
the rotor 30 to be explained later are brought into close contact with the
first wall
surface 231 in such a manner that they can be slid while coming into surface
contact
with the first wall surface, whereas two trailing ends 343 and 347 of the vane
34 are
brought into close contact with the second wall surface 232 in such a manner
that they
can be slid while coming into surface contact with the second wall surface. A
radial
tip of the vane 34 is slidably brought into close contact with the third wall
surface 233.
The rotating shaft 40 extending along the rotating axis 100 passes through the
l0 centers of the two end walls 22 and 24 of the body portion 21. The rotating
shaft 40 is
rotatably supported by bearings 42 and 44 installed at the centers of the two
end walls
22 and 24. The rotating shaft 40 extends along the rotating axis 100 beyond
the first
end wall 22 and is connected to a driving unit (not shown).
Referring to Figs. 1 and 3, a first suction groove 261, a first discharge
groove
262, a second suction groove 263 and a second discharge groove 264 are
sequentially
disposed on the third wall surface 233 of the rotating chamber 23. Each of the
grooves
261, 262, 263 and 264 extends in parallel with the rotating axis 100. The
first and
second suction grooves 261 and 263 are arranged to be symmetrical with each
other
about the rotating axis 100. The first and second discharge grooves 262 and
264 are
also arranged to be symmetrical with each other about the rotating axis 100.
The first
suction groove 261 and the second discharge groove 264 are positioned adjacent
to each
other, whereas the first discharge groove 262 and the second suction groove
263 are
positioned adjacent to each other. The first moving object 50 is positioned
between the
first suction groove 261 and the second discharge groove 264. Further, the
second
moving object 60 is positioned between the first discharge groove 262 and the
second
suction groove 263. First and second suction ports 2611 and 2631 are provided
at
given positions (e.g., the centers) on the first and second suction grooves
261 and 263,
respectively. First and second suction tubes 15 and 17 are connected to the
first and
second suction ports 2611 and 2631, respectively. First and second discharge
ports
2621 and 2641 are provided at given positions (e.g., the centers) on the first
and second
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discharge grooves 262 and 264, respectively. First and second discharge tubes
16 and
18 are connected to the first and second discharge ports 2621 and 2641,
respectively.
However, the present invention is not limited thereto. That is, the first and
second
suction ports 2611 and 2631 and the first and second discharge ports 2621 and
2641
5 may be changed in view of their positions.
Referring to Figs. 1 to 4, the first wing portion 28 is formed to extend from
the
two end walls 22 and 24 toward the opposite directions in parallel with the
rotating axis
100. Further, the first wing portion 28 is formed to extend inward and outward
from
the side wall 26 in a radial direction. Therefore, the first wing portion 28
has a
l0 sectional shape that is a thin rectangle standing upright along the radial
direction of the
rotating axis 100 but is not formed in a space where the body portion 21 is
formed.
The first wing portion 28 is provided with a first guide passage 281 along
which the first
moving object 50 is linearly moved. The sectional shape of the first guide
passage 281
is the same as that of the first moving object 50. The first guide passage 281
extends
from the two end walls 22 and 24 of the housing 20 in a direction parallel
with the
rotating axis 100 and also beyond the side wall 26 of the housing 20 in the
radial
direction of the rotating axis 100. The first suction groove 261 and the
second
discharge groove 264 are positioned adjacent to each other with the first
guide passage
281 interposed therebetween (See Figs. 3 and 4). Passage holes 282 are formed
on
2o both longitudinal ends of the first wing portion 28, respectively. The
first guide
passage 281 is vented with the outside through passage holes 282, and thus,
the first
linear moving object 50 can be smoothly moved within the first guide passage
281. A
detailed description on the second wing portion 29 will be omitted herein
since it is
configured to be symmetrical with the first wing portion 29 about the rotating
axis 100.
The second linear moving object 60 is placed in a second guide passage 291
within the
second wing portion 29, and the first discharge groove 262 and the second
suction
groove 263 are positioned adjacent to each other with the second guide passage
282
interposed therebetween.
Referring again to Figs. 1 to 4, the rotor 30 is placed in the rotating
chamber 23
within the housing 20 and includes a cylindrical hub 32 coupled to the
rotating shaft 40
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and a vane 34 protruding from the hub 32 in a radial direction. Opposite ends
of the
hub 32 are slidably brought into close contact with the first and second wall
surfaces
231 and 232 in the rotating chamber 23, respectively. The rotating shaft 40
passes
through the centers of the opposite ends of the hub 32. The radius of the hub
32 is
sized such that its outer circumferential surface 321 is slidably brought into
close
contact with edges 541 and 561 of first and second blocking walls 54 and 56 of
the first
linear moving object 50 and edges 641 and 661 of first and second blocking
walls 64
and 66 of the second linear moving object 60. Fluid flows through a space
defined
between the outer circumferential surface 321 of the hub 32 and the third wall
surface
l0 233 of the rotating chamber 23.
Referring again to Figs. 1 to 4, the vane 34 takes the shape of a wall
protruding
from the outer circumferential surface 321 of the hub 32 in a radial direction
and
surrounds the outer circumferential surface 321 of the hub 32 such that both
side
surfaces thereof face the first and second wall surfaces 231 and 232 of the
rotating
chamber 23, respectively. Herein, one of the side surfaces 340 and 349 facing
the first
wall surface 231 of the rotating chamber 23 is referred to as a first surface
340, whereas
the other of the two surfaces facing the second wall surface 232 of the
rotating chamber
23 is referred to as a second surface 349.
Referring to Figs. 1 to 4 together with Fig. 8 (a) in which a rotor 30 is
unrolled
2o and shown, the vane 34 includes the two leading ends 341 and 345 which are
symmetrical with each other about the rotating axis 100 and have a flat
surface with a
predetermined width (an angular width) perpendicular to the rotating axis such
that it
can be slidably brought into surface contact with the first wall surface 231
of the
rotating chamber 23, the two trailing ends 343 and 347 which are symmetrical
with each
other about the rotating axis 100 and have a flat surface with a predetermined
width (an
angular width) perpendicular to the rotating axis such that it can be slidably
brought into
surface contact with the second wall surface 232 of the rotating chamber 23,
and four
inclines 342, 344, 246 and 348 which are inclined with respect to the rotating
axis 100
and connect the leading and trailing ends 341, 343, 345 and347. The vane 34 is
configured in such a manner that the leading end 341, the incline 342, the
trailing end
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343, the incline 344, the leading end 345, the incline 346, the trailing end
347 and the
incline 348 are smoothly connected with one another sequentially in a
circumferential
direction of the rotating axis 100. The outward radial tip of the vane 34 in a
radial
direction about the rotating axis 100 is slidably brought into close contact
with the third
surface 233 of the rotating chamber 23. Two opposite edges 542 and 562 of the
two
blocking walls 54 and 56 of the first linear moving object 50 and two opposite
edges
642 and 662 of the two blocking walls 64 and 66 of the second linear moving
object 60,
both of which will be described later, are slidably brought into close contact
with the
first and second surfaces 340 and 349 of the vane 34. The thickness of the
vane 34 is
to determined such that the two opposite edges 542 and 562 of the two blocking
walls 54
and 56 of the first linear moving object 50 and the two opposite edges 642 and
662 of
the two blocking walls 64 and 66 of the second linear moving object 60 are
always
slidably brought into close contact with the first and second surfaces 340 and
349 when
the rotor 30 is rotated. Preferably, the thickness of the vane 34 is
determined such that
a distance between the first and second surfaces 340 and 349 in a direction in
which the
first and second linear moving objects 50 and 60 extend is substantially kept
constant.
Due to the configuration of the vane 34, the space defined between the outer
circumferential surface 321 of the hub 32 of the rotor 30 and the third wall
surface 233
of the rotating chamber 23 is divided into first and third spaces 11 and 13,
which are
2o formed by the first wall surface 231 of the rotating chamber 23 and the
first surface 340
of the vane 34, and second and fourth spaces 12 and 14, which are formed by
the second
wall surface 232 of the rotating chamber 23 and the second surface 349 of the
vane 34.
The width of the radial tips (angular width) of the leading ends 341 and 345
and trailing
ends 343 and 347 is formed to be greater than the maximum angular distance
between
the first suction groove 261 and the second discharge groove 264 (i.e., an
angular
distance from the farthest end of the first suction groove to the farthest end
of the second
discharge groove) and the maximum angular distance between the second suction
groove 263 and the first discharge groove 262.
Referring to Figs. 1 to 5, the first linear moving object 50 takes the shape
of an
3o elongated straight thin bar and includes a base 52 located at a relatively
outer portion in
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a radial direction of the rotating axis 100 and the first and second blocking
walls 54 and
56 standing upright from the base 52 in an inward radial direction of the
rotating axis
100. The first and second blocking walls 54 and 56 define a pair of blocking
walls.
The height of the first and second blocking walls 54 and 56 is the same as
that of the
vane 34 of the rotor 30. The inner edges 541 and 561 of the first and second
blocking
walls 54 and 56 in a radial direction of the rotating axis 100 taper off and
slidably
brought into close contact with the outer circumferential surface 321 of the
hub 32 of
the rotor 30. Accordingly, friction between the hub 32 of the rotor 30 and the
first and
second blocking walls 54 and 56 can be reduced. The opposite edges 542 and 562
of
to the first and second blocking walls 54 and 56 also taper off and slidably
brought into
close contact with the first and second surfaces 340 and 349 of the vane 34 of
the rotor
30. An inner edge 521 of the base 52 between the first and second blocking
walls 54
and 56 is slidably brought into close contact with the outward radial tip of
the vane 34.
The first linear moving object 50 is placed in the first guide passage 281 of
the housing
20 and linearly moved along the first guide passage 281 by means of the vane
34 as the
rotor 30 is rotated. The second linear moving object 60 is configured to be
symmetrical with the first linear moving object 50 and placed in the second
guide
passage 291 of the second wing portion 29. Therefore, the detailed description
on the
second linear moving object will be omitted herein.
2o As shown in Fig. 8 (a) in which the vane is unrolled, when the first and
second
linear moving objects 50 and 60 are positioned at the inclines 342 and 346 of
the vane
34, respectively (or when the objects are positioned at the other inclines 344
and 348),
the first blocking wall 54 of the first linear moving object 50 divides the
first space 11
into first and second subspaces 111 and 112 and blocks the two subspaces 111
and 112.
Further, the second blocking wall 56 of the first linear moving object 50
divides the
second space 12 into first and second subspaces 121 and 122 and blocks the two
subspaces 121 and 122. Similarly, the first blocking wall 64 of the second
linear
moving object 60 divides the third space 13 into first and second subspaces
131 and 132
and blocks the two subspaces 131 and 132. Further, the second blocking wall 66
of the
3o second linear moving object 60 divides the second space 14 into first and
second
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14
subspaces 141 and 142 and blocks the two subspaces 141 and 142. On the other
hand,
as shown in Fig. 8 (a) to (d), when the first and second linear moving objects
50 and 60
are positioned at the leading ends 341 and 345 of the vane 34, respectively,
only the
second and fourth space 12 and 14 are in a state where they are divided into
two
subspaces by means of the second blocking walls 56 and 66 of the first and
second
linear moving objects 50 and 60, respectively. Although not shown in the
figure, it can
be easily understood by those skilled in the art that when the first and
second linear
moving objects 50 and 60 are positioned at the two trailing ends 343 and 347
of the
vane 34, respectively, only the first and third spaces 11 and 13 are divided
into two
to subspace by means of the first and second blocking walls 54 and 64 of the
first and
second linear moving objects 50 and 60, respectively.
Refernng to Figs. 1, 2, 4 and 7, the first pressing plate 70 takes the shape
of a
circular plate, and includes a circular through-hole 71 formed at the center
thereof, first
and second passage slits 72 and 74 extending from an outer periphery thereof
toward the
center thereof, and passage holes 76 and 78 formed adjacent to the passage
slits 72 and
74. The outer periphery 701 of the first pressing plate 70 is slidably brought
into close
contact with the side wall 26 of the housing 20. The rotating shaft 40 passes
through
the central hole 71. The first and second passage slits 72 and 74 are formed
to be
symmetrical with each other with respect to the central hole 71. Each of the
two
2o passage slits 72 and 74 has the same shape as the sectional shape of the
first blocking
wall 54 or 64 of the first or second linear moving object 50 or 60. The two
first
blocking walls 54 and 64 of the first and second linear moving objects 50 and
60 are
slidably fitted into the two passage slits 72 and 74, respectively. The two
passage
holes 76 and 78 are generally symmetrical with each other about the rotating
axis 100
and positioned at the discharge side of the rotating chamber. High-pressure
fluid at the
discharge side of the rotating chamber 23 is supplied to the first pressing
chamber 201
through the two passage holes 76 and 78. A detailed description on the second
pressing plate 80 will be omitted herein, because it has the same shape as the
first
pressing plate 70.
3o The two facing surfaces of the first and second pressing plates 70 and 80
CA 02527859 2005-11-30
become the first and second wall surfaces 231 and 232 of the rotating chamber
23.
The high-pressure fluid in the first and second pressing chambers 201 and 202
exerts a
force on the two wall surfaces to press the rotor 30 in the opposite
direction. Although
it has been described in this embodiment that the high-pressure fluid exerts a
force on
5 the first and second pressing plates 70 and 80 to press the rotor 30, the
present invention
is not limited thereto. It will be understood by those skilled in the art that
the rotor
may be pressed by an elastic member such as a compression coil spring.
Refernng to Fig. 3, the pressure-regulating device 90 includes a discharge
amount regulating unit 91 and a compressing unit 96 which are provided in a
block 900.
l0 The discharge amount regulating unit 91 includes a moving member 92, an
elastic
member 93, and first and second check valves 94 and 95. The moving member 92
and
elastic member 93 are received in a first receiving space 901. The first
receiving space
901 is cylindrically shaped, and includes circular bottom and top ends 902 and
903 and
a side wall 904 connecting the bottom and top ends 902 and 903. A first
pressure
15 supply passage 151 to be explained later, which is connected to a discharge
passage 150
and transmits discharge fluid pressure to the moving member 92 connected to a
load
side, is connected to the bottom end 902. An extension shaft 924 of the moving
member 92 to be explained later is inserted into the first pressure supply
passage 151.
A first passage hole 9033 connected to a seventh passage 107 to be explained
later is
2o formed on the top end 903. First and second inlets 9041 and 9042 connected
to first
and third passages 101 and 103 to be explained later are formed in the middle
of the side
wall 904. The first and second inlets 9041 and 9042 are positioned relatively
close to
the bottom and top ends 902 and 903, respectively. The side wall 904 is
provided with
first and second outlets 9043 and 9044 connected to fifth and sixth passages
105 and
106 to be explained later, respectively, at positions opposite to the first
and second inlets
9041 and 9042. The side wall 904 is also provided with a second passage hole
9045
connected to an eighth passage 108 to be explained later at a position
adjacent to the top
end 903.
The discharge tube 16 extending from the main body 19 of the fluid pump 10 is
branched off into the first and second passages 101 and 102. The first passage
101
CA 02527859 2005-11-30
16
communicates with the first receiving space 901 through the first inlet 9041,
and the
second passage 102 is connected with the discharge passage 150. The first
check valve
94 is provided on the second passage 102 to prevent fluid from flowing in a
reverse
direction. The second discharge tube 18 extending from the main body 19 is
branched
off into the third and fourth passages 103 and 104. The third passage 103
communicates with the first receiving space 901 through the second inlet 9042,
and the
fourth passage 104 is connected with the discharge passage 150. The second
check
valve 95 is provided on the fourth passage 104 to prevent fluid from flowing
in a reverse
direction. Although the fifth and sixth passages 105 and 106 connected with
the first
to and second outlets 9043 and 9044 of the first receiving space 901 are not
shown, they
are connected to a return passage 160 communicating with a low-pressure side
such as a
storage tank. The eighth passage 108 connects the second passage hole 9045 and
the
sixth passage 106. The seventh passage 107 connects the first passage hole
9033 and a
third passage hole 9631 provided on the top end 963 of the second receiving
space 961
of the compressing unit 96. Accordingly, the top ends of the first and second
receiving
spaces 901 and 961 are always connected to the low-pressure side.
Referring to Figs. 3 and 7, the moving member 92 includes an opening/closing
portion 921, a connection post 922, a closing portion 923 and the extension
shaft 924,
which are provided sequentially from above. The opening/closing portion 921 is
cylindrically shaped, and the radius of the opening/closing portion 921 is
determined
such that an outer circumferential surface 9211 can be slid on the side wall
904 of the
first receiving space 901. The height of the opening/closing portion 921 is
determined
such that the outer circumferential surface 9211 can close both the first and
second
inlets 9041 and 9042 and the first and second outlets 9043 and 9044 which are
provided
on the side wall 904 of the first receiving space 901. The connection post 922
is
cylindrically shaped, and the radius of the connection port 922 is less than
that of the
opening/closing portion 921 such that an outer circumferential surface 9221 is
not
brought into contact with the side wall 904 of the first receiving space 901.
Further,
the height of the connection post 922 is determined such that both the first
and second
3o inlets 9041 and 9042 and the first and second outlets 9043 and 9044, which
are provided
CA 02527859 2005-11-30
17
on the side wall 904 of the first receiving space 901, can be positioned
within an interval
of the connection post 922 when the moving member 922 is moved to an uppermost
position. The closing portion 923 takes the shape of a thin disc, and its
radius is
determined such that an outer circumferential surface 9231 can be slid on the
side wall
904 of the first receiving space 901. The extension shaft 924 takes the shape
of a thin
circular rod, and its diameter is determined such that it can be tightly
inserted into and
slid along the first pressure supply passage 151 connected with the bottom 902
of the
first receiving space 901. Fluid pressure in the discharge passage 150 is
applied to the
distal end of the extension shaft 924. Due to the fluid pressure applied to
the distal end
l0 of the extension shaft 924, the moving member 92 moves upward. The moving
member 92 can move vertically within the first receiving space 901. The
elastic
member 93 is a compression coil spring, and both ends thereof are coupled with
the top
end 903 of the first receiving space 901 and the upper end of the
opening/closing
portion 921 of the moving member 92. The elastic member 93 pushes the moving
is member 92 toward the bottom end 902 of the first receiving space 901. The
moving
member 92 is urged downward by means of the elastic member 93 such that when
the
closing portion 923 is brought into contact with the bottom end 902 of the
first receiving
space 901, the outer circumferential surface 9211 of the opening/closing
portion 921
closes both the first and second inlets 9041 and 9042 and the first and second
outlets
20 9043 and 9044, which are provided on the side wall 904 of the first
receiving space 901.
Referring to Fig. 3, the compressing unit 96 includes a moving member 97 and
an elastic member 98. The moving member 97 and elastic member 98 are received
in
the second receiving space 961. The second receiving space 961 is
cylindrically
shaped and includes circular bottom and top ends 962 and 963 and a side wall
964
25 connecting the bottom and top ends 962 and 963. A second pressure supply
passage
152, which is connected to the discharge passage 150 and transmits discharge
fluid
pressure to the moving member 97, is connected to the bottom end 962. An
extension
shaft 972 of the moving member 97 to be explained later is inserted into the
second
pressure supply passage 152. A third passage hole 9631 connected to the
seventh
30 passage 107 is formed on the top end 963.
CA 02527859 2005-11-30
18
Referring again to Fig. 3, the moving member 97 includes a piston 971 and the
extension shaft 972, which are provided sequentially from above. The piston
971 is
cylindrically shaped, and its diameter is determined such that an outer
circumferential
surface 9711 can be slid on the side wall 964 of the second receiving space
961. The
piston 971 can move vertically within the second receiving space 961. The
extension
shaft 972 is also cylindrically shaped and tightly inserted into and slid
along the second
pressure supply passage 152 connected with the bottom end 962 of the second
receiving
space 961. Fluid pressure in the discharge passage 150 is applied to a distal
end of the
extension shaft 972. The elastic member 98 is a compression coil spring, and
both
l0 ends thereof are coupled with the top end 963 of the second receiving space
961 and the
upper end of the piston 971 of the moving member 97. The elastic member 98
pushes
the moving member 97 toward the bottom end 962 of the second receiving space
961.
Hereinafter, the operation of the fluid pump according to the first embodiment
of the present invention will be described in detail with reference to Figs.
3, 8 (a) to (d),
9 and 10. First, the operating of the main body 19 is described with reference
to Fig. 8
(a) to (d). Fig. 8 (a) to (d) shows an unrolled rotor 30. In the figure, the
rotor 30 is
shown as a solid line whereas the grooves 261, 262, 263 and 264, the suction
ports 2611
and 2631 and the discharge ports 2621 and 2641 are shown as a dotted line. If
the
rotating shaft 40 is rotated clockwise by means of the driving unit (not
shown) as shown
2o in Fig. 1, the rotor 30 is also rotated clockwise. This rotation
corresponds to a leftward
linear motion of the unrolled rotor 30 shown in Fig. 8 (a). In Fig. 8 (a), the
first and
second linear moving objects 50 and 60 are placed on the two inclines 342 and
346 of
the vane 34, respectively. Referring to Fig. 8 (a), the second subspaces 112
and 142 of
the first and fourth spaces 11 and 14 communicate with each other through the
first
suction groove 261, the first subspaces 121 and 131 of the second and third
spaces 12
and 13 communicate with each other through the first discharge groove 262, the
second
subspaces 122 and 132 of the second and third spaces 12 and 13 communicate
with each
other through the second suction groove 263, and the first subspaces 141 and
111 of the
fourth and first spaces 14 and 11 communicate with each other through the
second
discharge groove 264. If the rotor 30 is rotated in such a state, the two
subspaces 112
CA 02527859 2005-11-30
19
and 142 communicating with each other through the first suction groove 261 and
the
tow subspaces 122 and 132 communicating with each other through the second
suction
groove 263 are increased. Accordingly, fluid is sucked through the first and
second
suction ports 2611 and 2631. The sucked fluid is introduced into the
respective
subspaces 112, 142, 122 and 132 communicating with one another through the
first and
second suction grooves 261 and 263. At the same time, the two subspaces 121
and
131 communicating with each other through the first discharge groove 262 and
the tow
subspaces 141 and 111 communicating with each other through the second
discharge
groove 264 are decreased. Accordingly, the fluid in the subspaces 121, 131,
141 and
l0 111 is discharged to the first and second discharge ports 2621 and 2641
through the first
and second discharge grooves 262 and 264. Fig. 8 (b) shows a state where the
first and
second linear moving objects 50 and 60 reach the two leading ends 341 and 345
of the
vane 34, respectively, while the rotor 30 is being further rotated.
Referring to Fig. 8 (b), the first and second suction grooves 261 and 263 are
placed on the inclines 342 and 346 of the vane 34, respectively, and the first
and second
discharge grooves 262 and 264 are placed on the two leading ends 341 and 345,
respectively. At this time, the first space 11 and the second subspace 142 of
the fourth
space 14 communicate with each other through the first suction groove 261, and
the
third space 13 and the second subspace 122 of the second space 12 communicate
with
each other through the second suction groove 263. The entire length of the
first
discharge groove 262 is connected with the first subspace 121 of the second
space 12,
and the whole length of the second discharge groove 264 is connected with the
first
subspace 141 of the fourth space 14. If the rotor 30 is further rotated in
such a state,
the second subspaces 142 and 122 are increased. Accordingly, fluid is sucked
through
the first and second suction ports 261 l and 2631. The sucked fluid is
introduced into
the two increased subspaces 142 and 122. At the same time, the two subspaces
121
and 141 with which the first and second discharge grooves 262 and 264 are
connected
are decreased. Accordingly, the fluid in the two subspaces 121 and 141 is
discharged
through the first and second discharge ports 2621 and 2641. Fig. 8 (c) shows a
state
3o where the first and second linear moving objects 50 and 60 reach the middle
of the two
CA 02527859 2005-11-30
leading ends 341 and 345 of the vane 34, respectively, after the rotor 30 is
further
rotated.
Refernng to Fig. 8 (c), the first suction groove 261 and second discharge
groove
264 are placed on the leading end 341, while the second suction groove 263 and
first
5 discharge groove 262 are placed on the leading end 345. At this time, the
whole length
of the first suction groove 261 is connected with the second subspace 142 of
the fourth
space 14, the entire length of the first discharge groove 262 is connected
with the first
subspace 121 of the second space 12, the entire length of the second suction
groove 263
is connected with the second subspace 122 of the second space 12, and the
entire length
l0 of the second discharge groove 264 is connected with the first subspace 141
of the
fourth space 14. If the rotor 30 is further rotated in such a state, the
subspaces 142 and
122 are increased, and fluid is accordingly sucked through the first and
second suction
ports 2611 and 2631. The sucked fluid is introduced into the two increased
subspaces
142 and 122. At the same time, the subspaces 121 and 141 are decreased, and
the fluid
15 in the two subspaces 121 and 141 is discharged through the first and second
discharge
ports 2621 and 2641. Since the first and second suction grooves 261 and 263
and the
first and second discharge grooves 262 and 264 are simultaneously placed on
the
leading ends 341 and 345, the suction grooves 261 and 263 do not communicate
with
the discharge grooves 262 and 264. Therefore, a case where the suction grooves
261
20 and 263 are connected with the discharge grooves 262 and 264 does not
occur.
Accordingly, an additional check valve (often referred to as a "discharge
valve") for
preventing the reverse flow of fluid is not needed. Fig. 8 (d) shows a state
where the
first and second linear moving objects 50 and 60 reach ending points of the
leading ends
341 and 345 of the vane 34 in an angular direction, respectively, after the
rotor 30 is
further rotated.
Refernng to Fig. 8 (d), the first and second suction grooves 261 and 263 are
placed on the two leading ends 341 and 345 of the vane 34, respectively, and
the first
and second discharge grooves 262 and 264 are placed on the inclines 344 and
348 of the
vane 34, respectively. At this time, the entire length of the first suction
groove 261 is
3o connected with the second subspace 142 of the fourth space 14, and the
whole length of
CA 02527859 2005-11-30
21
the second suction groove 263 is connected with the second subspace 122 of the
second
space 12. Further, the first space 11 and the first subspace 121 of the second
space 12
communicate with each other through the first discharge groove 262, and the
third space
13 and the first subspace 141 of the fourth space 14 communicate with each
other
through the second discharge groove 264. If the rotor 30 is further rotated in
such a
state, the subspaces 142 and 122 are increased, and fluid is accordingly
sucked through
the first and second suction ports 2611 and 2631. The sucked fluid is
introduced into
the two increased subspaces 142 and 122. At the same time, the space 11 and
subspace
121 communicating with each other through the first discharge groove 262 and
the
1o space 13 and subspace 141 communicating with each other through the second
discharge groove 264 are decreased, and the fluid therein is accordingly
discharged
through the first and second discharge ports 2621 and 2641. As the rotor 30 is
continuously rotated, the aforementioned process is repeated in such a manner
that fluid
is continuously sucked through the two suction ports 2611 and 2631 and
discharged
through the two discharge ports 2621 and 2641. At this time, since the two
spaces
separated by the vane 34 are connected with each other through the first and
second
suction grooves 261 and 263 and the first and second discharge grooves 262 and
264, a
substantially constant amount of fluid can be always sucked and discharged and
thus
pulsation can be minimized. Further, since the suction and discharge ports are
2o disposed to be substantially symmetrical with each other, rotating balance
is improved.
Accordingly, noise and vibration are reduced.
Referring to Figs. 1, 2 and 4, high-pressure fluid at the discharge side in
the
rotating chamber 23 is supplied into the first and second pressing chambers
201 and 202
through the first and second passage holes 76, 78 and 86, 88 of the first and
second
pressing plates 70 and 80, respectively. Further, the high-pressure fluid
causes the first
and second pressing plates 70 and 80 to be brought into close contact with the
rotor 30
so as to prevent the fluid from leaking out.
Due to the aforementioned operation of the main body 19, the discharged fluid
is introduced into the pressure-regulating device 90 through the first and
second
3o discharge tubes 16 and 18. Referring to Fig. 3, the moving member 92 of the
discharge
CA 02527859 2005-11-30
22
amount regulating unit 91 of the pressure regulating device 90 is pushed down
at the
lowermost position by means of a force of the elastic member 93. In such a
state, the
first and second inlets 9041 and 9042 and the first and second outlets 9043
and 9044 are
closed by the opening/closing portion 921 of the moving member 92. Therefore,
since
the fluid discharged from the main body 19 through the first and second
discharge tubes
16 and 18 is discharged through the discharge passage 150 via the second and
fourth
passages 102 and 104, the amount of discharge fluid becomes 100%. Further, the
moving member 97 of the compressing unit 96 is in a state where it is slightly
pushed
upward by means of the fluid pressure in the discharge passage 150.
If the fluid pressure in the discharge passage 150 is increased in such a
state, the
moving member 92 of the discharge amount regulating unit 91 is moved upward
against
the force of the elastic member 93 due to the increased fluid pressure, as
shown in Fig. 9.
Refernng to Fig. 9, the opening/closing portion 921 of the moving member 92 of
the
discharge amount regulating unit 91 is positioned to allow the first inlet and
outlet 9041
and 9043 to be opened and the second inlet and outlet 9042 and 9044 to be
closed.
Thus, since the fluid discharged from the main body 19 through the first
discharge tube
16 is discharged through the return passage 160 connected to the low-pressure
side and
only the fluid discharged from the main body 19 through the second discharge
tube 18 is
discharged through the discharge passage 150, the amount of discharge fluid
becomes
50%. At this time, the first check valve 94 can prevent the high-pressure
fluid in the
discharge passage 150 from flowing in a reverse direction.
If the fluid pressure in the discharge passage 150 is higher than a state
shown in
Fig. 9, the moving member 92 of the discharge amount regulating unit 91 is
moved
further upward as shown in Fig. 10. Referring to Fig. 10, the opening/closing
portion
921 of the moving member 92 of the discharge amount regulating unit 91 is
positioned
to allow the first and second inlets 9041 and 9042 and the first and second
outlets 9043
and 9044 to be opened. Thus, since all the fluid discharged from the main body
19
through the first and second outlets 9043 and 9044 is discharged through the
return
passage 160 the amount of discharge fluid becomes 0%. At this time, the first
and
3o second check valves 94 and 95 can prevent the high-pressure fluid in the
discharge
CA 02527859 2005-11-30
23
passage 150 from flowing backward into the first and second discharge tubes 16
and 18.
If the fluid pressure is lowered in such a state shown in Fig. 9 or 10, the
moving
member 92 of the discharge amount regulating unit 91 is pushed and moved by
the
elastic member 93 to deliver the fluid discharged through the first or second
discharge
tube 16 or 18 into the discharge passage 150 such that the amount of discharge
fluid can
be increased. At this time, the moving member 97 of the compressing unit 96 is
pushed downward by means of the elastic member 98 and delivers the fluid
remaining
in the second pressure supply passage 152 into the discharge passage 150.
Accordingly, the lowered pressure in the discharge passage 150 is recovered up
to a
l0 certain point.
Figs. 11 to 14 show a second embodiment of the present invention. Referring
to Figs. 11 and 12, a fluid pump l0a includes a main body 19a and a pressure-
regulating
device 90a. The main body 19a includes a housing 20a, a rotor 30a, a rotating
shaft
40a and a linear moving object SOa. A direction in which the rotating shaft
40a
extends becomes a rotating axis 100a. The housing 20a includes a cylindrical
body
portion 21a and a wing portion 28a. The body portion 21a includes first and
second
circular end walls 22a and 24a, and a side wall 26a connecting the two end
walls 22a
and 24a. A cylindrical rotating chamber 23a in which the rotor 30a is
accommodated
is provided in the body portion 21a. The rotating chamber 23a is defined by
first and
second opposite circular wall surfaces 231a and 232a and a third circular wall
surface
233a connecting the first and second wall surfaces 231a and 232a. The first
and
second wall surfaces 231a and 232a are inner surfaces of the first and second
end walls
231a and 232a of the body portion 21a, while the third wall surface 233a is an
inner
surface of the side wall 26a of the body portion 21 a. The leading end 341 a
of a vane
34a to be explained later is brought into close contact with the first wall
surface 231a in
such a manner that it can be slid while coming into surface contact with the
first wall
surface, whereas the trailing end 343a of the vane 34 are brought into close
contact with
the second wall surface 232a in such a manner that it can be slid while coming
into
surface contact with the second wall surface. The radial tip of the vane 34
about the
rotating axis 100a of the vane 34a, which will be explained later, is slidably
brought into
CA 02527859 2005-11-30
24
close contact with the third wall surface 233a. The rotating shaft 40a passes
through
the centers of the two end walls 22a and 24a of the body portion 21a. The
rotating
shaft 40a is rotatably supported by bearings 42a and 44a installed at the
centers of the
two end walls 22a and 24a, respectively. The rotating shaft 40a extends along
the
rotating axis 100a beyond the first end wall 22a and is rotatably connected to
a driving
unit (not shown).
Refernng to Figs. 11 and 12, a suction groove 261a and a discharge groove
262a, which extend straightly to the first and second wall surfaces 231a and
232a in an
extending (longitudinal) direction of the rotating axis 100a, are formed on
the third wall
to surface 233a of the rotating chamber 23a adjacent to each other. First and
second
blocking walls 54a and 56a of the linear moving object SOa to be explained
later are
positioned between the suction and discharge grooves 261a and 262a. A suction
port
2611a and a discharge port 2621a are provided at the centers of the suction
and
discharge grooves 262a and 264a, respectively. A suction tube 15a and a
discharge
tube 17a are connected to the suction and discharge ports 2611a and 2621a,
respectively.
The configuration of the wind portion 28a is the same as that of the first
wing portion 28
described in the first embodiment, except that only a single wing portion 28
is employed
in this second embodiment. Thus, a detailed description thereof will be
omitted herein.
Referring again to Figs. 11 and 12, the rotor 30a is placed in the rotating
chamber 23a within the housing 20a and includes a cylindrical hub 32a coupled
to the
rotating shaft 40a and the vane 34a protruding from the hub 32a. Opposite ends
of the
hub 32a are slidably brought into close contact with the first and second wall
surfaces
231a and 232a in the rotating chamber 23a, respectively. The vane 34a takes
the shape
of a wall protruding from an outer circumferential surface 321a of the hub 32a
in a
radial direction of the rotating axis 100a and surrounds the outer
eircumferential surface
of the hub 32a such that both side surfaces 340a and 349a of the vane face the
first and
second wall surfaces 231a and 232a of the rotating chamber 23a, respectively.
Herein,
one of the side surfaces 340a and 349a facing the first wall surface 231a of
the rotating
chamber 23a is referred to as the first surface 340a, whereas the other of the
two
surfaces facing the second wall surface 232a of the rotating chamber 23a is
referred to
CA 02527859 2005-11-30
as the second surface 349a.
Refernng to Figs. 11 and 12 together with Fig. 13 (a) in which a rotor 30a is
unrolled and shown, the vane 34a includes the flat leading end 341 a which has
a
predetermined width (an angular width) perpendicular to the rotating axis 100a
such that
5 it can be brought into surface contact with the first wall surface 231 a of
the rotating
chamber 23a, the flat trailing end 343a which has a predetermined width (an
angular
width) perpendicular to the rotating axis 100a such that it can be brought
into surface
contact with the second wall surface 232a of the rotating chamber 23a, and two
inclines
342a and 344a which are inclined with respect to the rotating axis 100a and
connect the
10 leading and trailing ends 341a and 342a. The radial tip of the vane 34a
about the
rotating axis 100a is slidably brought into close contact with the third wall
surface 233a
of the rotating chamber 23a. Due to such a configuration of the vane 34a, the
space
defined between the outer circumferential surface 321a of the hub 32a of the
rotor 30a
and the third wall surface 233a of the rotating chamber 23a is divided into a
first space
15 lla formed by the first wall surface 231a of the rotating chamber 23a and
the first
surface 340a of the vane 34a, and a second space 12a formed by the second wall
surface
232a of the rotating chamber 23a and the second surface 349a of the vane 34a.
The
leading and trailing ends 341a and 343a are arranged to be diametrically
opposite to
each other about the rotating axis 100a. The width of the radial tips (angular
width) of
20 the leading and trailing ends 341a and 343a is formed to be greater than
the maximum
angular distance between the suction and discharge grooves 261a and 262a
(i.e., an
angular distance from the farthest end of the suction groove to the farthest
end of the
discharge groove) (See Fig. 12 (c)). The two inclines 342a and 344a are
inclined with
respect to the rotating axis 100a and smoothly connect the leading and
trailing ends
25 341a and 343a. That is, the vane 34a is configured in such a manner that
the leading
end 341a, incline 342a, trailing end 343a and incline 344a are sequentially
connected to
each other and disposed on the outer circumferential surface 321a of the hub
32a across
its one revolution.
A detailed description on the linear moving object SOa will be omitted herein,
3o because it is the same as the first linear moving object 50 in view of
their configuration.
CA 02527859 2005-11-30
26
As shown in Fig. 13 (a), when the linear moving object 50a is positioned at
the incline
342a of the vane 34a (or when the object is positioned at the other incline
344a), the
first blocking wall 54a divides the first space 11 a into first and second
subspaces 111 a
and 112a and blocks the two subspaces 111 a and 112a. Further, the second
blocking
wall 56a divides the second space 12a into first and second subspaces 121a and
122a
and blocks the two subspaces 121 a and 122a. On the other hand, as shown in
Fig. 13
(b) to (d), when the linear moving object 50a is positioned at the leading end
341a of the
vane 34a, the first space l la is not divided by the first blocking wall 54a
and remains a
single space, but the second space 12a is still in a state where it is divided
into two
l0 subspaces 121a and 122a by means of the second blocking wall 56a. Although
not
shown in the figure, it can be easily understood by those skilled in the art
that when the
linear moving object 50a is positioned at the trailing end 343a of the vane
34a, only the
first space 11 a is divided into two subspaces by means of the first blocking
wall 54a.
Refernng to Fig. 12, the pressure-regulating device 90a includes a discharge
amount regulating unit 91 a and a compressing unit 96a which are provided in a
block
900a. The discharge amount regulating unit 91 a includes a moving member 92a,
an
elastic member 93a, and a check valve 94a. The moving member 92a and elastic
member 93a are received in a first receiving space 901a. An inlet 9041a
connected to a
first passage 101 a to be explained later is formed in the middle of the side
wall 904a.
The side wall 904a is provided with an outlet 9043a, which is connected to a
third
passage lOSa to be explained later, at a position opposite to the inlet 9041a.
A
discharge tube 16a extending from the main body 19a of the fluid pump l0a is
branched
off into the first and second passages lOla and 102a. The first passage lOla
communicates with the first receiving space 901a through the inlet 9041a, and
the
second passage 102a is connected with the discharge passage 150a. The check
valve
94a is provided on the second passage 102a to prevent fluid from flowing in a
reverse
direction. Although the third passage 105a connected with the outlet 9043a of
the first
receiving space 901a is not shown, it is connected to a return passage 160a
communicating with a low-pressure side such as a storage tank. The other
configuration of the pressure-regulating device 90a is the same as that of the
pressure-
CA 02527859 2005-11-30
27
regulating device 90 according to the first embodiment of the present
invention, and
thus, a detailed description thereof will be omitted herein.
Hereinafter, the operation of the second embodiment of the present invention
will be described in detail with reference to Fig. 13 (a) to (d) and Figs. 12
and 14. First,
the operation of the main body 19a will be described with reference to Fig. 13
(a) to (d).
Fig. 13 (a) to (d) shows the rotor 30a in a state where it is unrolled. If the
rotating shaft
40a is rotated clockwise by means of the driving unit (not shown) as shown in
Fig. 11,
the rotor 30a is also rotated clockwise. This rotation corresponds to a
leftward linear
motion of the unrolled rotor 30a shown in Fig. 13 (a) to (d). In Fig. 13 (a),
the linear
l0 moving object SOa is placed on the incline 342a of the vane 34a. Referring
to Fig. 13
(a), the second subspaces 112a and 122a of the first and second spaces lla and
12a
communicate with each other through the suction groove 261a, and the first
subspaces
111 a and 121 a of the first and second spaces 11 and 12 communicate with each
other
through the discharge groove 262a. If the rotor 30 is rotated in such a state,
the two
subspaces 112a and 122a communicating with each other through the suction
groove
261a are increased, and fluid is thus sucked through the suction port 2611a
connected
with the suction tube (15a, See Fig. 11). The sucked fluid is introduced into
the second
subspaces 112a and 122a through the suction groove 261a. At the same time, the
first
subspaces 111 a and 121 a communicating with each other through the discharge
groove
262a are decreased, and the fluid in the two subspaces l l la and 121a is thus
discharged
to the discharge port 2621a through the discharge groove 262a. Fig. 13 (b)
shows a
state where the linear moving object SOa reaches the leading end 341a of the
vane 34a
while the rotor 30a is being further rotated.
Referring to Fig. 13 (b), the suction groove 261a is placed on the incline
342a
of the vane 34a and the discharge groove 262a is placed on the leading end
341a. At
this time, the first space lla and the second subspace 122a of the second
space 12a
communicate with each other through the suction groove 261a. The whole length
of
the discharge groove 262a is connected with the first subspace 121a of the
second space
12a. If the rotor 30a is further rotated in such a state, only the second
subspace 122a
of the second space 12a is increased, and fluid is sucked through the suction
port 261 la
CA 02527859 2005-11-30
28
connected with the suction tube (15a, See Fig. 12). The sucked fluid is
introduced into
the increased subspace 122a through the suction groove 261 a. At the same
time, the
first subspace 121a of the second space 12a in which the discharge groove 262a
is
positioned is decreased, and the fluid in the first subspace 121a is thus
discharged
through the discharge port 2621a connected to the discharge tube (17a, See
Fig. 12).
Fig. 13 (c) shows a state where the linear moving object SOa reaches the
middle of the
leading end 341a of the vane 34a after the rotor 30a is further rotated.
Referring to Fig. 13 (c), the suction groove 261 a and discharge groove 262a
are
placed on the leading end 341a of the vane 34a. The entire length of the
suction
l0 groove 261a is connected with the second subspace 122a of the second space
12a, while
the entire length of the discharge groove 262a is connected with the first
subspace 121a
of the second space 12a. If the rotor 30a is further rotated in such a state,
the second
subspace 122a of the second space 12a is increased, and fluid is thus sucked
through the
suction port 2611a connected to the suction tube (15a, See Fig. 12). The
sucked fluid
is introduced into the increased subspace 122a of the second space 12a. At the
same
time, the first subspace 121a connected to the discharge groove 262a is
decreased, and
the fluid in the subspace 121 a is thus discharged through the discharge port
2621 a
connected to the discharge tube (16a, See Fig. 12). Since the suction groove
261a and
discharge groove 262a are simultaneously placed on the leading end 341 a, the
suction
2o groove 261 a and the discharge groove 262a do not communicate with each
other.
Therefore, a case where the suction and discharge ports 2611 a and 2621 a are
connected
with each other through the first space l la does not occur, and thus, any
losses can be
minimized. Therefore, this allows the efficiency of the pump to be improved
and also
prevents the reverse flow of fluid due to communication between the suction
and
discharge ports. Accordingly, an additional check valve (often referred to as
a
"discharge valve") is not needed. Fig. 13 (d) shows a state where the linear
moving
object 50a reaches the ending point of the leading end 341a of the vane 34a in
an
angular direction after the rotor 30a is further rotated.
Referring to Fig. 13 (d), the suction groove 261a is placed on the leading end
341a of the vane 34a and the discharge groove 262a is placed on the incline
344a of the
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vane 34a. The whole length of the suction groove 261a is connected with the
second
subspace 122a of the second space 12a. Further, the first space lla and the
first
subspace 121a of the second space 12a communicate with each other through the
discharge groove 262a. If the rotor 30a is further rotated in such a state,
the subspace
122a connected to the suction groove 262a is increased, and fluid is thus
sucked through
the suction port 2611a connected to the suction tube (15a, See Fig. 12). The
sucked
fluid is then introduced into the subspace 122a of the second space 12a. At
the same
time, the space 11 a and subspace 121 a of the second space 12a communicating
with
each other through the discharge groove 262a are decreased, and the fluid
therein is thus
to discharged through the discharge port 2621a connected to the discharge tube
(16a, See
Fig. 12).
As the rotor 30a is continuously rotated, the aforementioned process is
repeated
in such a manner that fluid is continuously sucked through the suction port
2611 a and
discharged through the discharge port 2621 a.
Due to the aforementioned operation of the main body 19a, the discharged fluid
is then introduced into the pressure-regulating device 90a through the
discharge tube
16a. Referring to Fig. 12, the moving member 92a of the discharge amount
regulating
unit 91a of the pressure regulating device 90a is pushed down at a position
closest to the
discharge passage 150a by means of a force of the elastic member 93a. In such
a state,
the inlet and outlet 9041a and 9043 9043a are closed by an opening/closing
portion 921a
of the moving member 92a. Therefore, since the fluid discharged from the main
body
19a through the discharge tube 16a is discharged through the discharge passage
150a via
the second passage 102a, the amount of discharge fluid becomes 100%. Further,
the
moving member 92a of the compressing unit 96a is in a state where it is
slightly pushed
away from the discharge passage 150a by means of the fluid pressure in the
discharge
passage 1 SOa. If the fluid pressure in the discharge passage 150a is
increased in such a
state, the moving member 92a of the discharge amount regulating unit 91a is
moved
away from the discharge passage 150a against the force of the elastic member
93a due to
the increased fluid pressure, as shown in Fig. 14. Referring to Fig. 14, the
opening/closing portion 921a of the moving member 92a of the discharge amount
CA 02527859 2005-11-30
regulating unit 91 a is positioned to allow the inlet and outlet 9041 a and
9043a to be
opened. Thus, since the fluid discharged from the main body 19a through the
discharge tube 16a is discharged through the return passage 160a connected to
the low-
pressure side, the amount of discharge fluid becomes 0%. At this time, the
check valve
5 94a can prevent the high-pressure fluid in the discharge passage 150a from
flowing in a
reverse direction. If the fluid pressure in the discharge passage 150a is
lowered in a
state shown in Fig. 14, the moving member 92a of the discharge amount
regulating unit
91a is pushed and moved by the elastic member 93a to deliver the fluid
discharged
through the discharge tube 16a into the discharge passage 150a such that the
amount of
10 discharge fluid can be increased. At this time, the moving member 97a of
the
compressing unit 96a is pushed away by means of the elastic member 98a and
delivers
the fluid remaining in a pressure supply passage 152a into the discharge
passage 150a.
Accordingly, the lowered pressure in the discharge passage 150a is recovered
up to a
certain point.
15 Although the main bodies 19 and 19a have been described as being used as
pumps in the previous two embodiments, the present invention is not limited
thereto.
It will be understood by those skilled in the art that the main bodies 19 and
19a are
constructed to be used as fluid motors. In case of the main body 19 of the
first
embodiment, when the high-pressure fluid is introduced into the rotating
chamber 23
20 through the first and second suction ports 2611 and 2631, the rotor 30
rotates and the
introduced fluid is then discharged through the first and second discharge
ports 2621
and 2641.
In the previous two embodiments, the width (angular width) of the edge of each
contact portion of the vane has been described as being larger than the
maximum
25 angular distance between adjacent two grooves. However, the present
invention is not
limited thereto. The width of the edge of each contact portion of the vane may
be
formed to be smaller than the maximum angular distance between adjacent two
grooves.
If necessary, each contact portion may be formed to be brought into line
contact with the
first or second wall surface of the rotating chamber rather than the surface
contact. In
30 this case, it will be understood by those skilled in the art that the pump
may be
CA 02527859 2005-11-30
31
constructed by mounting a check valve for preventing backflow of the fluid
within each
discharge tube.
Figs. 15 to 17 are views of a main body of a fluid pump according to a third
embodiment of the present invention. Referring to Figs. 15 to 17, a suction
tube 15b is
branched off into two passages which in turn are connected to sides of wing
portions 28
of two end walls 22b and 24b of the housing 20b. A discharge tube 16b is also
branched off into two passages which in turn are connected to sides of the
wing portion
28b of the two end walls 22b and 24b of the housing 20b. The housing 20b is
the same
as the housing 20b of the fluid pump of the aforementioned second embodiment
in their
constitutions except that the housing 20b does not have the suction groove 261
a, the
discharge groove 262a and the passage holes 282a at both ends of the wing
portion 28a.
Therefore, a detailed description thereof will be omitted.
Refernng to Figs. 16 and 17, a linear moving object SOb has a structure
substantially similar to that of the linear moving object 50 of the first
embodiment
shown in Fig. 5. The linear moving object SOb includes two contact members 58b
that
are slidably fitted at opposite positions in two blocking walls 54b and 56b,
respectively,
and slide against a vane (not shown). Each of the blocking walls 54b and 56b
is
provided with a receiving groove Sllb into which the contact member 58 is
fitted, a
passage hole 512b communicating with the receiving groove 511b, and a
connecting
2o groove 59b . The receiving grooves 51 lb are open while facing each other
at opposite
ends of the two blocking walls 54b and 56b and also open upwardly at upper
ends 541b
and 561b of the two blocking walls 54b and 56b. The passage holes 512b are
formed
on discharge sides of the blocking walls 54b and 56b to communicate with the
respective receiving grooves 511b. A high-pressure fluid on the discharge
sides is
supplied to the receiving grooves Sllb through the passage holes 512b. The
connecting grooves 59b are formed on suction sides of the blocking walls 54b
and 56b.
Each connecting groove 59b connects both ends of each of the blocking walls
54b and
56b. A low-pressure fluid on the suction sides are supplied to guide passages
281b
through the connecting grooves 59b to cause the linear moving object SOb to
move
smoothly.
CA 02527859 2005-11-30
32
Opposite one end of each of the contact members 58b fitted into the receiving
grooves 511b is tapered toward a tip thereof to form a contact end 542b or
562b that is
brought into close contact with the vane (not shown). The other side of each
of the
contact members 58b has upper and lower extensions to provide a space capable
of
receiving the high-pressure fluid introduced through the relevant passage hole
512b of
each of the blocking walls 54b and 56b. The high-pressure fluid introduced
through
the passage holes 512b of the blocking walls 54b and 56b urges the contact
members
58b so that the contact ends 542b and 562b of the contact members is slidably
brought
into close contact with the vane (not shown). Portions of the contact members
58b
I o connected to the upper ends of the blocking walls 54b and 56b also taper
toward tips
thereof to be slidably brought into close contact with the outer
circumferential surface of
a hub (not shown). Since the other operations and effects are the same as the
second
embodiment shown in Fig. 11, a detailed description thereof will be omitted.
With the structures of the present invention, all the aforementioned objects
of
the present invention can be achieved. Specifically, since the rotor is not
eccentric,
there is no vibration and bearings are not easily damaged. Further, since the
vane does
not have a structure in which it moves in and out of the rotor, its structure
is simplified.
Particularly, since all fluids in both spaces separated by the vane are
discharged contrary
to the pump disclosed in Korean Patent No. 315954, the amount of discharge
fluid is
2o doubled. Further, since the width of a compression area is kept constant, a
constant
amount of fluid per unit time is discharged, thereby minimizing pulsation and
providing
stable discharge pressure. Moreover, in case of the structure in which the
discharge
valve (check valve) is not needed, the conversion thereof into a fluid motor
can be easily
performed.
Although the present invention has been described and illustrated in
connection
with the exemplary embodiments of the present invention, it will be understood
that
various changes, modifications and additions can be made thereto without
departing
from the sprit and scope of the present invention.
