Note: Descriptions are shown in the official language in which they were submitted.
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TANDEM ELECTRIC PUMP
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a PCT International Application and claims benefit of
United States Patent Application No. 61/803,688 filed on March 20, 2013.
TECHNICAL FIELD
The present invention relates to a tandem electric pump combing two
independent pump chambers within the same housing.
BACKGROUND OF THE INVENTION
Generally, pumps include a stator and rotor. The rotor is in
communication with a pump element for moving a fluid. The fluid flows into
pump through an inlet when it flows past the pump element and through an
outlet in the pump. Generally, the rotor and stator are separated by a
magnetic air gap and the rotor and stator include rare earth metals so that
magnetic air gap between the rotor and stator may be bridged so that the
rotor is rotated during use and so that the rotor, the stator, or both are
isolated
from the fluids during use and continue to operate. However, the use of rare
earth metals may be damaged by the fluid such that the rare earth metals
may require additional packaging so that damage is prevented.
It would be attractive to have a pump with a reduced volume and mass
so that the pump may fit within a smaller space of a machine such as a
vehicle engine. It would be attractive to have a pump that includes fewer
components while maintaining motor efficiency, pumping efficiency, and
noise, vibration, and harshness characteristics. It would be attractive to
have
a pump arrangement for dissipating heat. It would be attractive to have a
pump that includes a family of standardized components across platform(s).
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SUMMARY OF THE INVENTION
A tandem pump with a pump housing that includes a first pump portion
with a first pump inlet and first pump outlet. The pump housing further
includes a second pump portion having a second pump inlet and a second
pump outlet. Within the pump housing is a rotatable common shaft that
extends between the first and second pump portions.
The first pump portion has a first pump chamber that includes a first
pump element with a first pump outer rotor surrounding a first pump inner
rotor. The first pump inner rotor is connected to a first end of the common
shaft. A second pump chamber of the second pump portion has a second
pump element operationally connected to a second end of the common shaft
located opposite the first end of the common shaft.
A stator is positioned in the first pump portion of the pump housing and
circumscribes the first pump outer rotor. The stator and the first pump outer
rotor are magnetically coupled so that energization of the stator causes the
first pump outer rotor to rotate and pump a first fluid through said first
pump
chamber, between the first pump inlet and the first pump outlet. Rotation of
the first pump outer rotor causes rotation of the first pump inner rotor,
which is
translated to the second pump element through the common shaft. The
second pump element rotates causing a second fluid to pump through the
second pump chamber between the second pump inlet and the second pump
outlet.
Further areas of applicability of the present invention will become
apparent from the detailed description provided hereinafter. It should be
understood that the detailed description and specific examples, while
indicating the preferred embodiment of the invention, are intended for
purposes of illustration only and are not intended to limit the scope of the
invention.
BRIEF DESCRIPTION OF THE DRAWINGS
Fig. 1 is a cross-sectional view of a tandem pump in accordance with a
first embodiment of the present invention;
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Fig. 2 an exploded perspective view of the tandem pump of Fig. 1 in
accordance with a first embodiment of the present invention;
Fig. 3 is a cross-sectional side plan view of a tandem pump in
accordance with the second embodiment of the present invention;
Fig. 4 is a cross-sectional side plan view of a tandem pump in
accordance with a third embodiment of the present invention;
Fig. 5A is a cross-sectional side plan view of a tandem pump in
accordance with a fourth embodiment of the present invention;
Fig. 5B is a cross-sectional side plan view of a tandem pump in
accordance with a fifth embodiment of the present invention;
Fig. 6 is a cross-sectional side plan view of a tandem pump in
accordance with a sixth embodiment of the present invention; and
Fig. 7 is a side perspective view of the tandem pump in accordance
with the sixth embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The following description of the preferred embodiment(s) is merely
exemplary in nature and is in no way intended to limit the invention, its
application, or uses.
Referring now to Figs. 1 and 2, a first embodiment of the invention is
shown which includes a tandem pump 10 that has two electric oil pumps
contained within a pump housing 12. Inside the pump housing 12 is a first
pump portion 14 having a first pump inlet 16 and first pump outlet 18. A
second pump portion 20 has a second pump inlet 22 and second pump outlet
24 disposed through the pump housing 12. In the present embodiment of the
invention, the first pump portion 14 of the tandem pump 10 is a main oil pump,
while the second pump portion 20 of the tandem pump 10 is a transmission
fluid pump. It is within the scope of this invention for the first pump
portion 14
and second pump portion 20 to be other types of pumps; examples include a
pump that moves oil, air, water, anti-freeze, coolant or a combination
thereof.
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Additionally, with regard to all other embodiments of the invention described
herein, the two pumps can also include the aforementioned various types of
applications. In all embodiments of the invention, the first pump portion 14
pumps a first fluid, while the second pump portion 20 pumps a second fluid,
that may be same or different from the first fluid. Thus, the tandem pump 10
can be used in place of two separate pumps.
A common shaft 26 is rotatably positioned in the pump housing 12 and
extends between first pump portion 14 and second pump portion 20. The first
pump portion 14 includes a first pump chamber 28 and has a first pump
element 30 that includes a first pump outer rotor 32 surrounding a first pump
inner rotor 34. The first pump inner rotor is rotatably connected to a first
end
of the common shaft 26.
A second pump portion 20 has a second pump chamber 36 that
contains a second pump element 38 having components connected to a
second end of the common shaft 26. The second pump element 38 includes
a second pump outer rotor 40 circumscribing a second pump inner rotor 42.
The tandem pump 10 further includes a stator 44 contained within the
pump housing 12. In the present embodiment of the invention, shown in Fig.
1, the stator 44 is located in the first pump portion 14, circumscribes and is
magnetically coupled to the first pump outer rotor 32 so that energization of
the stator 44 causes the first pump outer rotor 32 to rotate. Rotation of the
first pump outer rotor 32 causes the first fluid to pump through the first
pump
chamber 28 between the first pump inlet 16 and first pump outlet 18. The
rotation of the first pump outer rotor 32 about the first pump inner rotor 34
causes the first pump inner rotor 34 to rotate because the first pump inner
rotor 34 is in meshed engagement with the first pump outer rotor 32. In the
present embodiment of the invention, the first pump outer rotor 32 and first
pump inner rotor 34 are gerotor or gears. As the first pump inner rotor 34
rotates, the common shaft 26 will also rotate thereby translating the rotation
of
the first pump inner rotor 34 through the common shaft 26 to the second
pump element 38. More specifically, the rotation of the common shaft 26
causes the second pump inner rotor 42 to rotate which causes the second
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pump fluid to pump through the second pump chamber 36 between said
second pump inlet 22 and the second pump outlet 24.
In the present embodiment of the invention, the second pump outer
rotor 40 and second pump inner rotor 42 are also two gears which form a
gerotor type pump. However, it is within the scope of this invention for the
first pump element 30 and second pump element 38 to be another type of
pump element. For example, it is within the scope of this invention for the
first
pump element 30 and second pump element 38 to be a vane pump or any
other major pump category including but not limited to a screw pump,
progressing cavity pump, gear pump, roots-type pump, parastolic pump,
plunger pump, impulse pump and centrifugal pump. It is also within the scope
of this invention for all other embodiments to have pump elements that include
one of the aforementioned specific types of pumps.
With regard to the pump housing 12, it is a single housing, meaning a
single housing containing two pumps that is formed of several pieces
including a first pump portion housing 13, second pump portion housing 15.
The pump housing also has a stator sleeve 17 and divider 21 positioned
between the first pump portion housing 13 and the second pump portion
housing 15. Additionally, the pump housing 12 in accordance with the present
embodiment of the invention further includes an electronics cover 19 that
connects to the second pump portion housing 15.
The tandem pump 10 in accordance with the present invention further
includes a single electronics controller 46 that is connected to the
electronics
cover 19 and is mounted to the external side of the first pump portion housing
13. The single electronics controller 46 is in heat sink contact with the
electronics cover 19 in order to remove heat from the single electronics
controller 46. The single electronics controller 46 controls the energization
of
the stator 44. The single electronics controller 46 includes one or more
insulated-gate bipolar transistors which is capable of providing a rapid
voltage
signal to the stator 46 if required by a particular application. It is within
the
scope of this invention for all embodiments of the present invention to
include
a single electronics controller 46 which may include one or more insulated
gate bipolar transistors.
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Referring now to Fig. 3, a second embodiment of the invention is
shown where a tandem pump 10' includes a combination of an oil pump and
water pump. Similar or identical reference numerals from Figs. 1 and 2 have
been carried forward to Fig. 3 while new or different structures are
identified
with new reference numerals or using prime numbers. In the present
embodiment of the invention, the first pump portion 14 is similar or nearly
identical to the first pump portion 14 shown in Fig. 1. The first pump portion
14 includes a first pump chamber 28 with a first pump outer rotor 32 and first
pump inner rotor 34 circumscribed by the first pump outer rotor 32. The first
pump inner rotor 34 is connected to the common shaft 26 which extends to a
second pump portion 20'. The second pump portion 20' has a second pump
chamber 36' that is defined by a wet sleeve 48 and volute 50. The volute 50
has a second pump inlet (not shown) and a second pump outlet 24' formed
through the volute 50. The second pump chamber 36' is a wet area where a
second fluid moves through the second pump chamber 36', therefore the wet
sleeve 48 and volute 50 are connected to the pump housing 12' using seals
52 that prevent leakage of the second fluid in the second pump chamber 36.
The present embodiment of the invention also includes a second pump
element 38' that includes a magnetic rotor 54 having magnets 56 attached to
the magnetic rotor 54. The magnetic rotor 54 is rotatably positioned within
the
wet sleeve 48 and volute 50.
The second pump element 38 in the present embodiment of the
invention also includes a magnetic coupling 58 connected to an end of the
common shaft 26, where the magnetic coupling 58 has magnets 59 that
circumscribe a portion of the wet sleeve 48 and are magnetically coupled to
the magnets 56 on the magnetic rotor 54.
The tandem pump 10' shown in Fig. 3 operates in a manner similar to
the tandem pump shown in Fig. 1 in that the stator 44 is energized and
causes the rotation of the first pump outer rotor 32 about the first pump
inner
rotor 34 in order to pump fluid through the first pump portion 14. The
rotation
of the first pump outer rotor 32 causes the first pump inner rotor 34 to
rotate
and cause rotation of the common shaft 26. Rotation of the common shaft 26
causes rotation of the magnetic coupling 58 of the second pump portion 20'
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through the connection between the magnetic coupling 58 and the common
shaft 26. Rotation of the magnetic coupling 58 causes rotation of the
magnetic rotor 54 by a magnetic connection through the wet sleeve 48
between magnets 56 and magnets 59. Rotation of the magnetic rotor 54
causes the second fluid to pump through the second pump chamber 36'
defined by the wet sleeve 48 and the volute 50 so that the second fluid moves
between the second pump inlet (not shown) and the second pump outlet 24'.
The second pump inlet (not shown) cannot be seen in Fig. 3 because it
is formed in a portion of the volute 50 that is perpendicular to the plane of
the
cross-section view shown in Fig. 3. However, Fig. 4 shows a second pump
inlet 22' in the volute 50, which is the same type of volute 50 and inlet 22'
that
is used in the embodiment shown in Fig. 3.
Referring now to Fig. 4, a cross-sectional of a third embodiment of a
tandem pump 10" is shown. Similar reference numerals having the same or
equivalent structures shown in the previous drawings are carried forward to
Fig. 4. Fig. 4 shows an embodiment having the same first pump portion 14 as
Figs. 1-3 and the same second pump portion 20' shown in Fig. 3, which is a
gerotor pump. The main difference between the tandem pump 10' shown in
Fig. 3 and the tandem pump 10" shown in Fig. 4 is that a stator 44' is
positioned in an area of the pump housing 12 where the stator 44'
circumscribes a magnetic coupling 58' of a second pump element 38". The
second pump element 38" includes the magnetic coupling 58' and magnetic
rotor 54. The magnetic coupling 58' has magnets 60 connected to the outside
surface of the magnetic coupling 58' adjacent the stator 44'. The magnetic
coupling 58' also has magnets 59 located on an inside surface of the
magnetic coupling 58' which are coupled in a manner similar to Fig. 3. In the
present embodiment of the invention shown in Fig. 4, energization of the
stator 44' causes the magnetic coupling 58' to rotate, which in turn causes
the
magnetic rotor 54 of the second pump element 38" to rotate and pump fluid
through the second pump chamber 36'. Rotation of the magnetic coupling 58'
also causes rotation of the common shaft 26 because the magnetic coupling
58' is connected to the common shaft 26. Rotation of the common shaft 26
causes second pump portion 20' to operate in a slightly different manner than
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the operation of second pump portion 20 in Figs. 1-3. In the present
embodiment of the invention shown in Fig. 4, the rotation of the common shaft
26 causes an inner rotor 42' of the second pump chamber 36' to rotate which
causes fluid to pump through the second pump chamber 36'.
In the embodiment shown in Fig. 4, a single electronics controller 46' is
positioned between the first pump chamber 28' and second pump chamber
36'. This eliminates the presence of the electronics cover 19 shown in Figs.
1-2.
Referring now to Fig. 5a and 5b, a fourth and fifth embodiment of the
present invention is shown. In the embodiments shown in Figs. 5a and 5b,
the tandem pumps provide variable control of the two pump elements of the
tandem pump using a single controller.
Fig. 5a shows a variable tandem pump 100 that includes a pump
housing 112 containing a first pump portion 114 that is an engine oil pump
and a second pump portion 120 that is a transmission oil pump.
The first pump portion 114 has a first pump inlet 116 and a first pump
outlet 118. The second pump portion 120 has a second pump inlet (not
shown) and a second pump outlet 124.
A first shaft 126 is rotatably positioned in the pump housing 112 in the
first pump potion 114 and a second shaft 127 is rotatably positioned in the
pump housing 112 and extends into the second pump portion 120. The first
pump portion 114 includes a first pump chamber 128 and has a first pump
element 130 that includes a first pump outer rotor 132 surrounding a first
pump inner rotor 134. The first pump inner rotor is rotatably connected to a
first end of the first shaft 126.
The second pump portion 120 has a second pump chamber 136 that
contains a second pump element 138 having components connected to a
second end of the second shaft 127. The second pump element 138 includes
a second pump outer rotor 140 circumscribing a second pump inner rotor 142.
The tandem pump 100 further includes a stator 144 contained within
the pump housing 112. The stator 144 has a first coil 146 and a second coil
148. The first coil 146 circumscribes and is magnetically coupled to the first
pump outer rotor 132 and the second coil 148 circumscribes and is
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magnetically coupled to a magnetic coupling element 150 formed on an end
of the second shaft 127. When the first coil 146 is energized the first pump
outer rotor 132 will rotate causing fluid to pump through the first pump
chamber 130. The first pump outer rotor 132 and second pump inner rotor
134 are gears, which form a gerotor type pump.
When the second coil 148 is energized the magnetic coupling element
150 rotates, which causes the second shaft 127 to rotate. The second shaft
137 is connected to the second pump inner rotor 142, which causes fluid to
pump through the second pump chamber 136. The second pump inner rotor
142 and the second pump outer rotor 140 are gears, which form a gerotor
type pump.
The tandem pump 100 in accordance with the present invention further
includes a single electronics controller 152 that independently controls the
energization of the first coil 146 and second coil 148. The single electronics
controller 152 includes one or more insulated-gate bipolar transistors which
is
capable of providing a rapid voltage signal to the stator 144 if required by a
particular application. This allows for the first pump portion 114 and second
pump portion 120 to be variable in that their output is independent of the
other.
Fig. 5b shows a variable tandem pump 200 that includes a pump
housing 212 containing a first pump portion 214 that is a water pump and a
second pump portion 220 that is a transmission oil pump. However, as
indicated above the pump portions are not limited to being a water pump and
transmission pump but can be any type of pump for moving a fluid.
The first pump portion 214 has a wet sleeve 248 and a volute 250 that
define a first pumping chamber 228. The volute 250 has a first pump inlet 216
and a first pump outlet 218. The first pump portion 214 contains a first pump
element 230 that includes a first magnetic rotor 254 connected a first shaft
226, where the first magnetic rotor 254 and first shaft 226 are rotatably
positioned in the wet sleeve 28 and extends into the first pump chamber 228
for moving a first fluid through the first pump chamber 228 between the first
pump inlet 216 and the second pump outlet 218. The first magnetic rotor 225
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has magnets 256 connected to a portion of the surface of the first magnetic
rotor 225.
The first pump element 230 also includes first magnetic coupling
element 258 that circumscribes and selectively rotates about a portion of the
wet sleeve 248 and the magnets 256 of the first magnetic rotor 254, outside of
the first pump chamber 228. The first magnetic coupling element 25 has
outside magnets 260 on an outside surface and inside magnets 259 on an
inside surface, which are magnetically coupled through the wet sleeve 248, to
the magnets 256 of the first magnetic rotor 254.
A single stator 244 is positioned in the housing 212 and has a first coil
246 and a second coil 248. The first coil 246 circumscribes the first magnetic
coupling element 258 and energization of the first coil 246 acts on the
outside
magnets 260 of the first magnetic coupling element 258, thereby causing the
first magnetic coupling element 258 to rotate about a portion of the first
magnetic rotor 254 where the magnets 256 are connected. The inside
magnets 259 of the first magnetic coupling element 258 are magnetically
through the wet sleeve 248 to the magnets 256 of the first magnetic rotor 254.
This causes the first magnetic rotor 254 to rotate when the first coil 246 is
energized and the first magnetic coupling 258 rotates. When the first
magnetic rotor 254 rotates the first fluid begins pumping through the first
pump portion 214.
The second pump portion 220 has a second pump chamber 236 that
contains a second pump element 238 having components connected to an
end of the second shaft 227. The second pump element 238 includes a
second pump outer rotor 240 circumscribing a second pump inner rotor 242.
The second coil 248 of the stator 244 circumscribes and is
magnetically coupled to a magnetic coupling element 250 formed on another
end of the second shaft 227. When the second coil 248 is energized the
magnetic coupling element 250 rotates, which causes the second shaft 227 to
rotate. The second shaft 237 is connected to the second pump inner rotor
242, which causes fluid to pump through the second pump chamber 236. The
second pump inner rotor 242 and the second pump outer rotor 240 are gears,
which form a gerotor type pump.
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The tandem pump 200 in accordance with the present invention further
includes a single electronics controller 252 that independently controls the
energization of the first coil 246 and second coil 248. The single electronics
controller 252 includes one or more insulated-gate bipolar transistors which
is
capable of providing a rapid voltage signal to the stator 244 if required by a
particular application. This allows for the first pump portion 214 and second
pump portion 220 to be variable in that their output is independent of the
other. In the present embodiment of the invention the single electronics
controller 252 is positioned adjacent to and in heat sink contact with the wet
sleeve 248 so that fluid flowing through the first pump chamber 228 will cool
the single electronics controller 252 through the heat sink. It is also within
the
scope of this invention for the single electronics controller in the other
water
pump embodiments shown in Figs. 3 and 4 to be in positioned adjacent to and
in heat sink contact with the wet sleeve.
Referring now to Figs. 6-7 a sixth embodiment of a tandem pump 300
is shown. The tandem pump 300 has a pump housing 312 defining a first
pump portion 314 with a first pump inlet 316 and first pump outlet 318
disposed thought the pump housing 312. The tandem pump 300 also has a
second pump portion 320 having a second pump inlet 322 and a second
pump outlet 324 disposed through the pump housing 312.
Within the pump housing 312 is a first pump chamber 328 of the first
pump portion 314. The first pump chamber 328 is in fluid connection to the
first pump inlet 316 and the second pump inlet 318. The first pump portion
314 also includes a first pump element 330 that includes a first pump outer
rotor 332 surrounding a first pump inner rotor 334. The first pump inner rotor
is connected to a first end of a first shaft 326. The first shaft 326 is
rotatably
positioned in the pump housing 312.
Within the pump housing 312 is a second pump chamber 336 of said
second pump portion 320. The second pump chamber 336 is in fluid
connection with the second pump inlet 322 and the second pump outlet 324.
The second pump portion 320 includes a second pump element 338 within
the second pump chamber 336. The second pump element 338 has a
second pump outer rotor 340 circumscribing a second pump inner rotor 342.
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The second pump inner rotor 342 is connected to a second shaft 327 and
rotatable within the second pump chamber 336.
Between the first pump portion 314 and second pump portion 320 is a
single rotor 354 rotatably positioned inside of the pump housing 312. The
single rotor 354 connects to the first shaft 326 and the second shaft 327. The
single rotor 354 also has a magnetic coil 355 wound on its outside surface.
Within the single rotor 354 is a first clutch member 356 coupled between the
single rotor 354 and first shaft 326. There is also a second clutch member
358 coupled between the single rotor 354 and the second shaft 327. The first
clutch member 356 and the second clutch member 358 are one way clutches
with their outer housing mounted to the single rotor 354 and an inner sleeve
connected to one of the first shaft 326 or second shaft 327 with a needle
bearing positioned between the inner sleeve and outer housing. When the
single rotor 354 is rotated in a clutch engaging direction torque from the
single
rotor 354 will be applied to the first shaft 326 or second shaft 327. When the
single rotor 354 is rotated in clutch disengaging direction the first clutch
member 356 or second clutch 358 member are disengaged and the first shaft
326 or second shaft 327 will rotate freely and not be driven by the rotation
of
the single rotor 354. While the present embodiment of the invention has
needle bearing clutch members it is within the scope of this invention for
virtually any other type of clutch mechanism to be used.
The tandem pump 300 also has a stator 344 with a stator coil 346
circumscribing the magnetic coil 355 of the single rotor 354. The stator coil
346 is energized in one of a first manner or a second manner where
energization in said first manner causes the single rotor 354 to rotate in a
first
direction causing the second clutch element 358 to disengage and the first
clutch element 356 to engage. When this occurs the first shaft 326 rotates the
first pump member 330. Energization of the stator coil 346 in a second
manner causes the single rotor 354 to rotate in a second direction causing the
first clutch 356 to disengage and the second clutch 358 to engage and drive
the second shaft 327 to rotate the second pump member 338.
The energization of the stator 344 is controlled by a single electronics
controller 352 located in the pump housing 312 and is covered by a
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removable pump cover 319, where the single electronics controller 352 is
connected in contact with the pump cover 319 for better heat conductivity.
The single electronics controller 352 also includes one or more insulated-gate
bipolar transistors.
The tandem pump 300 of the present embodiment provides an
advantage of being able to pump a single fluid over a wide range of flow and
pressure requirements by using a single stator and two different sized
pumping elements. In particular the tandem pump can use one side of the
pump to provide high pressure and low flow based on the small displacement
of the pump, while the second side can be used to provide high flow and low
pressure under similar motor speeds and resultant torque with a larger
displacement pump. It is also within the scope of this embodiment of the
invention to be used to pump the same type of fluid or different fluids
depending on the needs of a particular application.
The description of the invention is merely exemplary in nature and,
thus, variations that do not depart from the gist of the invention are
intended
to be within the scope of the invention. Such variations are not to be
regarded
as a departure from the spirit and scope of the invention.
