VANE PUMP HAVING HOLLOW PIVOT PIN WITH FASTENER

Abstract

Disclosed is a vane pump including 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. In an example, the fastener passes through to the engine mount. The pivot pin does not create a fluid path through the hollow portion.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

The subject application claims priority to U.S. Provisional Patent Application No. 62/785,960, filed Dec. 28, 2018, the subject matter of which is incorporated herein by reference in its entirety.

FIELD

This disclosure relates generally to a vane pump. More particularly, the present disclosure relates to a pivot pin and assembly of a vane pump.

BACKGROUND

Description of the Related Art

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

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.

Other aspects and features of the disclosure will become apparent from the following detailed description, the accompanying drawings, and the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

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:

FIG. 1A is a first perspective view of a vane pump, according to an embodiment of this disclosure;

FIG. 1B is a second perspective view of the vane pump, according to an embodiment of this disclosure;

FIG. 2 is an exploded view of the vane pump of FIGS. 1A and 1B, according to an embodiment of this disclosure;

FIG. 3 is a view of the vane pump with cover removed illustrating a control slide arrangement, according to an embodiment of this disclosure;

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;

FIG. 5A is a projection view when seen from a cover, according to an embodiment of this disclosure;

FIG. 5B is a cross-section view through a section line AA of FIG. 5A; and

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.

DETAILED DESCRIPTION

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.

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.

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.

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 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.

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.

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.

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 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.

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.

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.

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 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.

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.

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).

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.

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.

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.

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.

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.

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.

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

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.

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.

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.

Claims

1. A vane pump comprising:

a housing;

a tubular pivot pin having a hollow portion mounted within the housing;

a control slide mounted to the pivot pin for displacement 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,

wherein the pivot pin does not create a fluid path through the hollow portion.

2. The vane pump according to claim 1, further comprising:

a control chamber on a first side of the control slide; and

a second chamber on a second side of the control slide between the housing and the control slide,

wherein the second chamber and the control chamber are not fluidically connected around the pivot pin.

3. The vane pump according to claim 1, wherein the fastener is a bolt passing through the housing, the hollow portion of the pivot pin, and the cover, creating an attachment between components of the pump.