Note: Descriptions are shown in the official language in which they were submitted.
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VANE PUMP HAVING HOLLOW PIVOT PIN WITH FASTENER
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The subject application claims priority to U.S. Provisional Patent
Application No.
62/785,960, filed December 28, 2018, the subject matter of which is
incorporated herein by
reference in its entirety.
BACKGROUND
FIELD
[0002] This disclosure relates generally to a vane pump. More particularly,
the present
disclosure relates to a pivot pin and assembly of a vane pump.
DESCRIPTION OF THE RELATED ART
[0003] Vane pumps are known for use for pumping fluids or lubricants, such as
oil in
automobiles. The vane pumps include vanes that move radially with respect to
an
eccentrically mounted rotor within a housing. Movement of the rotors and the
vanes create
one or more control chambers volume within which the fluid may be pressurized
and further
discharged through an outlet of the pump. The vane pump may include a single
control
chamber or two control chambers for moving lubricant.
SUMMARY
[0004] An aspect of this disclosure provides a vane pump that includes a
housing, a pivot pin
having a hollow portion mounted within the housing, a control slide
displaceable about the
pivot pin within the housing between a first slide position and a second slide
position to
adjust displacement of the pump through an outlet, and a cover attached to the
housing via a
fastener passing through the pivot pin such that the control slide rotates
about the pivot pin
with respect to the housing and the cover. The pivot pin does not create a
fluid path through
the hollow portion.
[0005] Other aspects and features of the disclosure will become apparent from
the following
detailed description, the accompanying drawings, and the appended claims.
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BRIEF DESCRIPTION OF THE DRAWINGS
[0006] The accompanying drawings, which are incorporated in and constitute a
part of the
specification, illustrate one or more embodiments and, together with the
description, explain
these embodiments. The accompanying drawings have not necessarily been drawn
to scale.
Any values of dimensions illustrated in the accompanying graphs and figures
are for
illustration purposes only and may or may not represent actual or preferred
values or
dimensions. Where applicable, some or all features may not be illustrated to
assist in the
description of underlying features. In the drawings:
[0007] FIG. 1A is a first perspective view of a vane pump, according to an
embodiment of
this disclosure;
[0008] FIG. 1B is a second perspective view of the vane pump, according to an
embodiment
of this disclosure;
[0009] FIG. 2 is an exploded view of the vane pump of FIGs. 1A and 1B,
according to an
embodiment of this disclosure;
[0010] FIG. 3 is a view of the vane pump with cover removed illustrating a
control slide
arrangement, according to an embodiment of this disclosure;
[0011] FIG. 4 is a projection view of the vane pump illustrating assembly of a
bolt to an
engine block, according to an embodiment of this disclosure;
[0012] FIG. 5A is a projection view when seen from a cover, according to an
embodiment of
this disclosure;
[0013] FIG. 5B is a cross-section view through a section line AA of FIG. 5A;
and
[0014] FIGs. 6A, 6B, 6C, and 6D are various projection views such as a top
view, a front
view, a bottom view, and a side view, respectively, of the vane pump,
according to an
embodiment of this disclosure.
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DETAILED DESCRIPTION
[0015] The description set forth below in connection with the appended
drawings is intended
as a description of various embodiments of the disclosed subject matter and is
not necessarily
intended to represent the only embodiment(s). In certain instances, the
description includes
specific details for the purpose of providing an understanding of the
disclosed
embodiment(s). However, it will be apparent to those skilled in the art that
the disclosed
embodiment(s) may be practiced without those specific details. In some
instances, well-
known structures and components may be shown in block diagram form in order to
avoid
obscuring the concepts of the disclosed subject matter.
[0016] Reference throughout the specification to "one embodiment" or "an
embodiment"
means that a particular feature, structure, or characteristic described in
connection with an
embodiment is included in at least one embodiment of the subject matter
disclosed. Thus, the
appearance of the phrases "in one embodiment" or "in an embodiment" in various
places
throughout the specification is not necessarily referring to the same
embodiment. Further, the
particular features, structures or characteristics may be combined in any
suitable manner in
one or more embodiments. Further, it is intended that embodiments of the
disclosed subject
matter cover modifications and variations thereof
[0017] It is to be understood that terms such as "inner," "outer," and the
like that may be
used herein merely describe points of reference and do not necessarily limit
embodiments of
the present disclosure to any particular orientation or configuration.
Furthermore, terms such
as "first," "second," "third," etc., merely identify one of a number of
portions, components,
steps, operations, functions, and/or points of reference as disclosed herein,
and likewise do
not necessarily limit embodiments of the present disclosure to any particular
configuration or
orientation, or any requirement that each number must be included.
[0018] FIGs. 1A and 1B are a first perspective view (when viewed from a
housing side) and
a second perspective view (when viewed from a cover side) of a vane pump 100
in an
embodiment of this disclosure. In an embodiment, the vane pump 100 is a
variable vane
pump having multi-chambers. The vane pump 100 has a housing 12 and a cover 2
attached to
the housing 12. The cover 2 attaches to the housing 12, via for example,
fasteners 26, and 27
inserted into various fastener bores provided along a periphery of the cover 2
and the housing
12. Several internal components (e.g., vanes 7, rotor 5, pivot pin 4, etc.
shown in FIG. 2) of
the vane pump 100 are enclosed between the housing 12 and the cover 2. The
vane pump 100
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further comprises a valve controller 18 housed within the housing 12. The
internal
components of the vane pump 100 are not visible in the FIGs. 1A and 1B, but
illustrated in an
exploded view of the vane pump 100 in FIG. 2.
[0019] The housing 12 (e.g., in FIGs. 1A-1B and 2) has an inlet 28 for
receiving fluid into
the housing 12, and an outlet 29 for discharging or delivering the pressurized
fluid to a
system, e.g., an engine. The housing 12 may be made of any material, and may
be formed by
aluminum die cast, iron casting, or any other known manufacturing techniques.
The housing
12 may enclose internal chambers such as a first control chamber 126 and
possibly a second
chamber 127 between the housing 12 and a control slide 25 (shown in FIG. 3)
for selectively
receiving pressurized fluid or vent pressure via 127. In an embodiment, the
first control
chamber 126 and the second chamber 127 are on either side of the pivot pin 4
(shown in
FIGs. 2 and 3) and isolated from each other. The first chamber 126 always has
a feedback
pressure, while the second chamber 127 may have pressure or vented depending
on the valve
controller 18. In other words, the first chamber 126 and the second chamber
127 are not
fluidically connected around the pivot pin 4. The first control chamber 126
receives pressured
fluid to move the control slide 25 to decrease its eccentricity relative to
the rotor 5 for
reducing pump displacement. Another chamber 128 is connected to the outlet
portion and
outlet of the pump that allows, for example, outlet oil to pass over and/or
under the slide 25.
Yet another chamber 124 is connected to the inlet and assists in limiting
leakage from
chambers 126, 127. The housing 12 may include a chamber for housing the valve
controller
18, which may be configured to deliver the pressurized fluid from the first
chambers 126 of
the pump. The valve controller 18 may be connected to the housing 12 via a
clip 19.
[0020] The cover 2 may be made of any material, and may be formed by aluminum
die cast,
powdered metal forming, forging, or any other desired manufacturing technique.
A gasket or
other seal(s) may optionally be provided between the cover 2 and peripheral
wall of the
housing 12 to seal the internal chambers. The housing 12 and cover 2 includes
various
surfaces for accommodating movement and sealing engagement (e.g. slide seal 14
and a slide
seal support 13 in FIG. 2) of the control slide 25.
[0021] FIG. 2 is an exploded view of the vane pump 100 illustrating internal
components of
the pump disposed between the cover 2 and the housing 12. For example, the
internal
components include a dowel pin 3 (e.g., for alignment of components such as
the cover 2 and
housing 12), the pivot pin 4 coupled to the control slide 25, the rotor 5, two
vane rings 6 on
either side of the rotor 5, a plurality of vanes 7 (collectively referred as
vanes 7), the control
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slide 25 assembled with the slide seal support 13 and the slide seal 14, a
spring 15, and a
relief mechanism comprising a relief ball 11, a relief spring 10, a cup plug
9, and a circlip 8.
[0022] With reference to FIGs. 2 and 3, the control slide 25 is displaceable
within the
housing 12 and relative to the cover 2. For example, the control slide 25 may
occupy a first
slide position, a neutral/default position, and a second slide position to
adjust displacement of
the vane pump 100 through the outlet. In an embodiment, the control slide 25
is pivotally
mounted (e.g., about the pivot pin 4) and configured for pivotal displacement
within the
housing 12 between the first and second slide positions (e.g., from its
neutral position to a
minimum displacement position). More specifically, it may include any number
of positions
that is away from the first slide position, and may, in one embodiment,
include when the slide
is close to a minimum displacement position, or may be the minimum
displacement position.
The control slide 25 may be pivotally mounted relative to the first control
chamber 126 and
the second control chamber 127 within the housing 12.
[0023] The first control chamber 126 is provided in the housing 12 relative to
a first side of
the control slide 25, provided on one side of the pivot pin 4, while the
second chamber 127 is
provided on an opposite, second side of the control slide 25, provided on the
other side of the
pivot pin 4. In an embodiment, the chambers 126 and 127 are isolated from one
another and
do not communicate (e.g., fluidically) with each other. The chambers 126 and
127 are not
connected to each other and the chamber 127 is connected to the inlet. A
positive pressure of
force from the pressurized lubricant may be applied or supplied to the control
chamber 126
that may urge the slide 25 to move in a second direction opposite the first
direction towards
its second slide position (or second pivotal direction) to decrease the pump
output flow (i.e.,
by decreasing the eccentricity). That pressure may be fed back from the outlet
side of the
pump or the external system.
[0024] Specifically, in an embodiment wherein the control slide 25 pivots, the
pivot pin 4 or
similar feature may be provided to guide the pivoting action of the control
slide 25. In an
embodiment, the pivot pin 4 may be rotatably mounted to the housing 12 and
cover 2 and the
control slide 25 may be fixed to the pivot pin, so that the pivot pin 4 and
thereby the control
slide 25 are free to pivot or rotate in the cover 2 and housing 12. The
configuration of the
pivotal connection of the control slide 25 in the housing 12 is not limited.
In an embodiment,
the control slide 25 is rotationally fixed to the pivot pin 4 for pivoting
along an axis. More
specifically, in an embodiment, the pivot pin 4 is designed to be press fit
within an opening of
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the control slide 25. Outer surface(s) of the pivot pin 4 may be coupled
and/or in contact with
a surface of the control slide 25, for example.
[0025] In an embodiment, the pivot pin 4 may be fixed (e.g., by press fit)
with respect to the
housing 12 and the cover 2, while the control slide 25 is free to rotate about
the pivot pin 4.
[0026] The pivot pin 4 (shown in FIGs. 2, 3, 4, 5A-5B and 6A-6D) is a hollow
pin with open
ends to receive a fastening device (interchangeably referred as a fastener)
such as a bolt, a
shaft and a screw. The pivot pin 4 has a substantially cylindrical shape
taking a form of a
hollow tubular cylinder. In an embodiment, the pivot pin 4 provide a structure
for a fastening
device (e.g., the bolt 21) that allows, for example, an additional means for
fastening the cover
2 to the engine block in this case, or in another case the cover 2 could be
bolted to housing 12
without creating additional fastening structure such as a fastening hole on
the housing 12
and/or the cover 2. Thus, the pivot pin 4 saves space and creates a compact
vane pump
design. In an embodiment, the additional bolt 21 prevents a gap from being
formed between
the cover 2 and the housing 12, thus preventing leakage of fluid thorough the
gap. An
external surface (i.e., circumferential surface) of the pivot pin 4 may be
free of any holes or
grooves, thus fluid may not enter the hollow portion 4a (see FIG. 3) of the
pivot pin from
chambers (e.g., 126) around the pivot pin 4. In an embodiment, the hollow
portion 4a of the
pivot pin 4 may be threaded to correspond to the threading of the fastening
device (e.g., the
bolt 21).
[0027] When the fastening device (e.g., the bolt 21) is inserted through the
pivot pin 4, the
hollow portion and the open ends are substantially closed and do not provide a
fluid path
through the hollow portion of the pivot pin 4. Thus, in operation, the fluid
within or around
the vane pump 100 may not flow through the pivot pin 4. In an embodiment, the
fastening
device is not in contact with the fluid within the housing 12. In an
embodiment, the bolt 21
can be inserted through the housing 12 (see FIGs. 1A, 4, 5A, 6A, 6C-6D) into
the hollow
portion of the pivot pin 4 and further extending out from the cover 2 (see
FIGs. 1B, 5B and
6A-6D) to allow attachment of a nut. In an embodiment, a nut provides a means
for providing
variable pressure for firmly tightening (or detaching) the cover 2 to the
housing 12. Also, as
shown in a cross-section view of FIG. 5B, the pivot pin 4 partially extends
through the cover
2 and is partially enclosed within the housing 12, thus, the hollow portion is
not accessible to
fluid trapped between the housing 12 and the cover 2. As such, no fluid path
is created
through the hollow portion of the pivot pin 4.
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[0028] Furthermore, the pivot pin 4 keeps the second chamber 127 isolated from
the control
chamber 126, for example, since the pivot pin 4 does not create a fluid path
for the fluid to
pass through the hollow portion and/or to pass to either side of the pin 4
within the housing
12 where the chambers 127 and 126 are located (shown in FIG. 3), as discussed
earlier. The
pivot pin 4 also provides a location dowel for mounting pump to engine block.
[0029] In an embodiment, the control slide 25 is pivoted about the pivot pin 4
(e.g., shown in
FIG. 3) to alter the position and motion of the rotor 5 and vane(s) 7 relative
to an inner
surface of the control slide 25, thus, altering the displacement of the pump
and distribution of
fluid through the outlet without passing the fluid through the hollow portion
of the pivot pin
4. The spring 15 biases or urges the control slide 25 in the first direction
towards its first slide
position (or first pivotal direction or position, or a maximum displacement
position). While
the control slide 25 pivots from the first position to the second position,
the fluid may be
pressurized without passing through the hollow portion of the pivot pin 4.
[0030] Referring to FIG. 3, the rotor 5 has one radially extending vanes 7
mounted to the
rotor 5 for radial movement. Specifically, each vane 7 is mounted at a
proximal end in a
radial slot in a central ring 6 of the rotor 5 in a manner that allows them to
slide radially.
Centrifugal force may force the vanes 7 radially outwardly to engage and/or
maintain
engagement between distal ends of the vanes 7 and the inside or inner surface
of the control
slide 25 during rotation thereof. This type of mounting is conventional and
well known. In an
embodiment, other variations may be used, such as springs in the slots for
biasing the vanes
radially outwardly, without limiting the scope of the present disclosure.
[0031] The spring 15 (shown in FIGs. 2 and 3) may be a coil spring or a leaf
spring. In an
embodiment, the spring 15 is used for biasing and/or returning the control
slide 25 to its
default or biased position (e.g., default position for maximum eccentricity
with the rotor 5).
The control slide 25 may be moved against the spring 15 to decrease
eccentricity with the
rotor 5 based on the pressure within the outlet of the vane pump 100 to adjust
displacement
and hence output flow.
[0032] The seal 14 and the slide seal support 13 (shown in FIG. 2) assist in
movement of the
control slide 25 between its slide positions along the walls of the housing
12, while still
maintaining a seal relative to the housing 12. The seal 14 also assists in
limiting leakage from
each of the chambers 126, 127, 128 back to 124.
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[0033] A retainer 16 and a screen 17 is also included in the housing 12 (see
FIG. 2). The
screen 17 filters the inlet and the retainer 16 keeps the seal in place
[0034] In an embodiment, screws 26, 27 may be used for attaching the cover 2
to the
housing 12. The housing 12 includes corresponding threaded holes to receive
the screws 26,
27. In an embodiment, the screws 26, 27 may be attached at the periphery of
the cover 2 and
housing 12 without passing through or in contact with an internal component of
the housing
such as the control slide 25. In an embodiment, the screws 26, 27 may be flush
(i.e., does not
project from a surface) with a surface of the cover 2 when assembled with the
housing 12.
[0035] While the principles of the disclosure have been made clear in the
illustrative
embodiments set forth above, it will be apparent to those skilled in the art
that various
modifications may be made to the structure, arrangement, proportion, elements,
materials,
and components used in the practice of the disclosure.
[0036] It will thus be seen that the features of this disclosure have been
fully and effectively
accomplished. It will be realized, however, that the foregoing preferred
specific embodiments
have been shown and described for the purpose of illustrating the functional
and structural
principles of this disclosure and are subject to change without departure from
such principles.
Therefore, this disclosure includes all modifications encompassed within the
spirit and scope
of the following claims.
