CN111379696A - Pump assembly with two pumps in a single housing - Google Patents

Abstract

A two-stage pump assembly has first and second pumps for pumping lubricant, both of which are integrated into a single housing. A drive shaft is provided to drive both pumps. Both the first and second pumps have gears or rotors that are rotated by a drive shaft. Each pump has an inlet disposed on the housing to receive an input from a source external to the housing and an outlet. The housing has a wall common to both pumps. The first pump is disposed on a first side of the wall and the second pump is disposed on an opposite second side. The gear or rotor of the pump may be disposed in recesses provided on the first and second sides of the wall. A drive shaft extends through the wall and is connected to each of the drive gears or rotors.

Description

Pump assembly with two pumps in a single housing

Cross Reference to Related Applications

This application claims priority from U.S. provisional patent application No. 62/786,961 filed on 31/12/2018, the entire contents of which are incorporated herein by reference.

Technical Field

The present disclosure generally relates to a two-stage pump assembly including first and second pumps housed in a single housing.

Background

Dual pump systems comprising more than one pump are generally known in the art. In some cases, these systems are designed to use one pump in some cases and another pump in other cases. Us publication No. 20170058895 and us patent No. 4,519,755 provide examples of such systems that in some cases use a second pump for pumping. In some cases, the output of the pump is variable. See, for example, U.S. publication nos. 20090041593 and 20110129359 for examples of varying the output of a pump.

Disclosure of Invention

It is an aspect of the present disclosure to provide a two-stage pump assembly. The pump assembly includes: a first pump and a second pump for pumping lubricant, both integrated into a single housing and each configured to pressurize lubricant input into the housing. A drive shaft is disposed in the housing and is configured to rotate about a drive axis and drive both the first and second pumps. The drive shaft is driven by a single input device. Both the first pump and the second pump have at least one gear constructed and arranged to be rotated by the drive shaft. The first pump has a first inlet disposed on the housing for receiving lubricant from a source external to the housing and a first outlet for directing pressurized lubricant out of the housing. The second pump has a second inlet disposed on the housing for receiving lubricant from a source external to the housing and a second outlet for directing pressurized lubricant out of the housing. The second inlet and the second outlet are different from the first inlet and the first outlet, respectively. The housing further comprises a wall (or common wall) common to both the first pump and the second pump, the first pump being arranged on a first side of the wall and the second pump being arranged on a second side of the wall, the second side being opposite to the first side. A drive shaft extends through the wall and is connected to each of the at least one gear of the first and second pumps.

Another aspect of the present disclosure provides a transmission (or other system designed to receive pressurized lubricant from a pump assembly) for the two-stage pump assembly described above. The second pump is configured to continuously pump lubricant to the transmission/system. In one embodiment, the transmission includes a clutch that selectively receives lubricant pumped from the first pump. A control valve may be provided for restricting lubricant output from the first pump to the clutch of the transmission.

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

Drawings

FIG. 1 is a perspective view of a pump assembly from a first side thereof according to an embodiment of the present disclosure.

Fig. 2 is a perspective view of the pump assembly of fig. 1 from a second side thereof.

FIG. 3 is an alternative perspective view of the pump assembly of FIG. 2 with a second cover removed from the pump assembly, showing a portion of a second pump in the pump assembly, in accordance with an embodiment.

FIG. 4A is a cross-sectional view through line 4-4 of FIG. 3, showing components of the housing, the second pump, and the first pump included in the pump assembly, according to one embodiment.

Fig. 4B is an alternative cross-sectional view through the housing shown in fig. 3, showing another view of the components within the housing.

FIG. 4C is a cross-sectional view through the first pump showing an inlet and an outlet thereof, according to an embodiment.

Fig. 5 shows the connection and drive shaft of the first and second pumps of the pump assembly and the first cover according to an embodiment.

Fig. 6 shows an exploded view of the components shown in fig. 5, without the first cover.

Fig. 7 shows an exploded view of the pump assembly of fig. 1.

Fig. 8 and 9 show perspective views of the pump assembly of fig. 1 connected with a driver according to an embodiment.

Fig. 10 shows an exploded view of the components shown in fig. 8 and 9.

FIG. 11A illustrates a cross-sectional view of the pump assembly and driver illustrated in FIGS. 8 and 9, according to an embodiment.

Fig. 11B and 11C show front and rear perspective views, respectively, of a driver including cooling fins according to an embodiment.

FIG. 12 is a schematic diagram illustrating a scheme for operating the pump assembly disclosed herein to pump lubricant to a transmission.

FIG. 13 is a schematic view of a system including a pump assembly as disclosed herein.

FIG. 14 is an underside view of a cover of one of the pumps in the pump assembly disclosed herein, the cover including a seal.

FIG. 15 is a cross-sectional view through a housing of a pump assembly having a first pump and a second pump therein according to another embodiment of the present disclosure.

Fig. 16 and 17 show exploded perspective views of components of the pump assembly of fig. 15 viewed from a first side and a second side, respectively.

FIG. 18 is a perspective view of a pump assembly having a first pump and a second pump therein, as viewed from a first side thereof, according to yet another embodiment of the present disclosure.

FIG. 19 is a perspective view of the FIG. 18 pump assembly from a second side thereof.

FIG. 20 is a top view of the pump assembly of FIG. 18.

FIG. 21 is a bottom view of the FIG. 18 pump assembly.

FIG. 22 is a first side view of the pump assembly of FIG. 18.

FIG. 23 is a second side view of the FIG. 18 pump assembly.

FIG. 24 is an alternative perspective view of the pump assembly of FIG. 18 with a second cover removed from the pump assembly, showing a portion of a second pump in the pump assembly, in accordance with an embodiment.

FIG. 25 is another perspective view from a second side of the pump assembly of FIG. 19 with a first cover removed from the pump assembly showing a portion of a first pump in the pump assembly, in accordance with an embodiment.

Fig. 26 shows an exploded view of the components of the pump assembly shown in fig. 18 and 19.

Fig. 27A is a cross-sectional view of the pump assembly shown in fig. 18 and 19, and fig. 27B is an alternative view of fig. 27A showing details of a drive shaft of the pump assembly, according to an embodiment.

FIG. 28 is a full side view of the second pump of the pump assembly shown in FIG. 24 with the second cover removed from the pump assembly, according to an embodiment.

Detailed Description

The pump assemblies described herein accommodate multiple pumps in a single housing or block. Each pump is provided with different inlets and outlets that allow selective output from one of the pumps, while the other pump regularly or continuously supplies/outputs pressurized lubricant to a system (e.g., transmission or engine) during operation. A common wall is provided in the housing between the components of the two pumps, which common wall forms part of the internal chamber for each pump.

According to one embodiment, the pump assembly disclosed herein includes a low pressure pump and a high pressure pump (i.e., two stage pressures) configured to be driven by the same drive shaft. According to one embodiment, the pump assembly disclosed herein includes a low pressure gerotor (gerotor) pump and a pressure compensated high pressure external gear pump paired together and configured to be driven by the same drive shaft.

Although the components and features of the pump assembly 10 are referred to herein as top, bottom, left, right, upper, lower, first, second, etc., it should be noted that these terms are not intended to limit the orientation, mounting, or positioning of the housing 12 and/or pump assembly 10 described herein at all. These terms are for reference only.

Fig. 1 and 2 show perspective views from both sides of a two-stage pump assembly 10 according to the present disclosure. The pump assembly 10 is used to pressurize and pump lubricant to an external system, such as a transmission (see, e.g., transmission 102 of fig. 13) or an engine. In this disclosure, "lubricant" refers to a fluid, such as transmission fluid or (engine) oil, that may be pressurized and directed to a system for cooling and lubrication purposes, for example. For illustrative purposes only, the present disclosure describes the fluid as a transmission fluid for use with a transmission. However, the design may also be used with engine oil and an engine.

In accordance with an embodiment, reference to "two-stage" in the disclosed pump assembly is a reference to the pump assembly 10 being capable of providing two pressure levels, a first, higher pressure and a second, lower pressure. That is, in some embodiments, a first pump 20 and a second pump 30 are provided for pumping lubricant (e.g., oil); each pump is configured to pressurize lubricant input into the housing. In the illustrated embodiment, first pump 20 and second pump 30 are coaxially aligned and driven using a drive (e.g., a motor or engine).

More particularly, in accordance with an embodiment, the disclosed pump assembly 10 includes a first pump 20 (see fig. 4A) and a second pump 30 (also shown in fig. 4A) integrated into a single housing 12, the first pump 20 being a "high pressure" pump designed for selective output operation, i.e., when the external system requires a higher level of pressurized lubricant, the second pump 30 being a "low pressure" pump designed for the system to pump a lower level of pressurized lubricant on a continuous basis. In general, when pump assembly 10 is operating, second pump 30 continuously outputs pressurized lubricant, while output from first pump 20 is limited. Further details regarding the high and low pressure ranges involved with the pump assembly 100 are described below. In another embodiment, the pump assembly 10B comprises a tandem pump assembly having a first pump 20B (see fig. 20 and 26) for pumping air and a second pump 30B (also shown in fig. 20 and 26) for pumping lubricant or fluid to a system integrated into a single housing 12 and with a common drive shaft and common wall (see fig. 27A and 27B). Further details regarding the tandem pump assembly 10B are also described further below.

A drive shaft 24 is disposed in the housing 12 and is configured to rotate about a drive axis a-a. Drive shaft 24 drives both first pump 20 and second pump 30. Both first pump 20 and second pump 30 have at least one gear constructed and arranged to be rotated by drive shaft 24. Drive shaft 24 may rotate each of these gears, either directly or indirectly, about drive axis a-a. In the illustrated embodiment, as shown in fig. 4A and described later with reference to fig. 4A, for example, gear 46 of first pump 20 and gear 56 of second pump 30 may be gears driven by drive shaft 24.

The housing 12 of the pump assembly 10 includes a first side 14 (see fig. 1) having a (first) cover plate 16 (covering components of one of the pumps) and a second side 18 (see fig. 2) having a (second) cover plate 36 (covering components of the other of the pumps). In one embodiment, the first cover plate 16 associated with the first pump 20 is a stationary cover plate designed for utilizing the axial clearance pressure of the pump pressure. The first cover plate 16 may be fixed to the housing 12 and thus not floating. According to an embodiment, the cover plate 16 may be removably secured to the first side 14 of the housing 12 (see fig. 1) by one or more fasteners 38 (e.g., bolts extending through corresponding openings in the housing). In one embodiment, a pressure compensating plate or spacer 50 inside the cover is configured to float in the housing 12 and be loaded into the gear set (e.g., gears 46, 48, which will be described below) by a seal (e.g., seal 43) and then by pressure on the cover side of the plate. The cover plate 36 may be removably secured to the second side 18 of the housing 12 (see fig. 2) by one or more fasteners 40 (e.g., bolts extending through corresponding openings in the housing).

Optionally, in one embodiment, the housing 12 may include openings or cutouts therein, such as shown at 27 in fig. 1 and 2, that serve as areas of reduced weight within the housing. That is, the weight-reducing cutout portion 27 in the housing 12 is designed to reduce the overall weight of the pump assembly 10. Optionally, in an embodiment, the housing 12 may include locating dowels 29, the locating dowels 29 being inserted into corresponding openings in the housing 12 and the covers 36 and/or 16 to assist in placing and securing the covers to the housing. According to one embodiment, the positioning tenon 29 may be cylindrical and hollow. Additionally, one or more bolt holes 31 may be provided in the housing for receiving fasteners/bolts therein to secure the cover and/or additional components to the housing 12.

The housing 12 also includes a top side 26 (shown at the top in fig. 1, 2, and 8), a bottom side 28 (shown at the bottom in fig. 4A and 8), a front side 32 (shown at the right in fig. 1), and a back side 34 (shown at the right in fig. 2). In the illustrated embodiment, the first side 14, the top side 26, and the front side 32 may include an inlet opening and an outlet opening for each pump 20, 30 housed in the housing 12. For example, in one embodiment, the first pump 20 may include a first inlet 60 (see fig. 4C) disposed in or on the housing 12 for receiving lubricant from a source external to the housing (e.g., see lubricant source 110 of fig. 13) and a first outlet 62 (see fig. 4C) for directing lubricant pressurized by the (first pump) out of the housing 12. A first inlet opening 64 (see fig. 1) may be provided on the housing 12 and connected to the first inlet 60, and a first outlet opening 66 may be provided on the housing 12 and connected to the outlet 62. The first inlet opening 64 may be an external connection point on the housing 12 for receiving lubricant from a source external to the housing 12. In one embodiment, the first inlet opening 64 may be disposed in a plane perpendicular to the drive axis A-A of the drive shaft 24. Lubricant may be directed into the housing 12 through the first inlet opening 64 in a manner generally parallel to the drive axis a-a. In one embodiment, such as shown in FIG. 1, the first inlet opening 64 may be disposed within the first cover plate 16 and through the first cover plate 16. As shown in fig. 4A, access to the first inlet 60 may be provided on or in the underside of the cover plate 16. In another embodiment, the first inlet 60 may include a pathway formed in the housing 12.

First outlet opening 66 may be an external connection point on housing 12 to direct pressurized lubricant from first outlet 62 of first pump 20 to the exterior of housing 12 and to a system (e.g., transmission 102). In an embodiment, the first outlet opening 66 may be disposed in a plane parallel to the drive axis A-A of the drive shaft 24. Lubricant may be directed out of the housing 12 through the first outlet opening 66 in a manner generally perpendicular to the drive axis a-a. In one embodiment, the first outlet opening 66 may be disposed on the top side 26 of the housing 12. As shown in fig. 4A, the first outlet 62 may be a path or channel disposed in a common wall (described in detail below) of the housing 12 and located adjacent the driven gear 48 and the driven drive shaft 52 of the first pump 20. In another embodiment, the first outlet 62 may include a pathway that may be disposed on or in the underside of the lid 16.

Additionally, in one embodiment, the second pump 30 includes a second inlet 68 (see fig. 4B) disposed in the housing 12 for receiving lubricant from a source external to the housing and a second outlet 70 (shown in fig. 4A) for directing lubricant pressurized by the (second pump) out of the housing 12. The second inlet 68 and the second outlet 70 are different from the first inlet 60 and the first outlet 62. That is, the pump assembly 10 includes at least two distinct inlets 60, 68 and at least two distinct outlets 62, 70.

A second inlet opening 72 (see fig. 1) may be provided on the housing 12 and connected to the second inlet 68, and a second outlet opening 74 may be provided on the housing 12 and connected to the second outlet 70. The second inlet opening 72 may be an external connection point on the housing 12 for receiving lubricant from a source external to the housing 12. In one embodiment, the second inlet opening 72 may be disposed in a plane parallel to the drive axis A-A of the drive shaft 24. Lubricant may be directed into the housing 12 through the second inlet opening 72 in a manner generally perpendicular to the drive axis a-a. In one embodiment, such as shown in FIG. 1, the second inlet opening 72 may be disposed on the top side 26 of the housing 12. As shown in fig. 4B, second inlet 68 of second pump 30 may receive input lubricant from inlet path 65 connected to inlet opening 72. As described in more detail below, the housing 12 may include a primary inlet having an opening 76 disposed in the housing 12 for receiving lubricant, the primary inlet being connected to the inlet path 65 for delivery to one or more of the pump inlets 60, 68 (e.g., shown connected to the secondary inlet 68).

Second outlet opening 74 may be an external connection point on housing 12 to direct pressurized lubricant from second outlet 70 of second pump 30 to the exterior of housing 12 and to a system (e.g., transmission 102). In an embodiment, the second outlet opening 74 may be disposed in a plane parallel to the drive axis A-A of the drive shaft 24. Lubricant may be directed out of the housing 12 through the second outlet opening 74 in a manner generally perpendicular to the drive axis a-a. In one embodiment, the second outlet opening 74 may be disposed on the top side 26 of the housing 12. As shown in fig. 4A, the first outlet 70 may be a path or channel disposed in a common wall (described in detail below) of the housing 12 and located adjacent the driven gear 58 of the second pump 30. In an embodiment, the first outlet 70 may include a pathway that may be disposed on or in the underside of the cover plate 36.

In an embodiment, both the first outlet opening 66 and the second inlet opening 72 may be disposed on a plane parallel to the drive axis a-a of the drive shaft 24. In an embodiment, the first outlet opening 66 and the second inlet opening 72 may be disposed on the same side of the housing 12. In one embodiment, the first outlet opening 66 and the second inlet opening 72 may be disposed on the top side 26 of the housing 12. In yet another embodiment, the second outlet opening 74 may be disposed on the same side of the housing 12 as the first outlet opening 66 and the second inlet opening 72. That is, according to an embodiment, such as shown in the figures, the openings 66, 72, and 74 may be disposed on the top side 26 of the pump assembly 10.

One or more seals 73 may be provided around or near the openings 66, 72, 74 to aid in sealing and securing. In one embodiment, such as shown in FIG. 7, seal 73 is a single molded seal having a plurality of openings designed for placement in grooves formed around openings 66, 72, and 74.

The pump assembly 10 may also include one or more openings in its housing 12 that connect to the aforementioned inlet path 65. In an embodiment, a primary inlet may be provided in the housing 12 that directs incoming lubricant (e.g., from a source) into one or more of the pumps 20 and/or 30. That is, the primary inlet may be fluidly connected to the first inlet 60 and/or the second inlet 68. The main inlet has an inlet opening 76 disposed in the housing 12, such as shown in fig. 1, 4A, and 4B. In one embodiment, the inlet opening 76 is disposed in a plane perpendicular to the drive axis A-A of the drive shaft 24. In one embodiment, the inlet opening 76 is located on another side of the housing 12 that is transverse to the side of the housing containing the first outlet opening 66, the second inlet opening 72, and the second outlet opening 74. In an embodiment, the first inlet opening 64 and the inlet opening 76 are disposed on the same side of the housing. In an embodiment, the inlet opening 76 is located on the first side 14 of the pump assembly 10. In a similar manner to the first inlet opening 64, lubricant may be directed into the housing 12 through the inlet opening 76 in a manner generally parallel to the drive axis a-a.

In one embodiment, as shown in FIG. 1, a passage or path 65 may be provided in the housing 12 for supplying lubricant to the second inlet 68 via an opening 76 in the housing 12. The inlet path 65 may be a contoured or drilled path in the housing 12 leading to, for example, the second inlet opening 72 and the second inlet 68 of the second pump 30. In an embodiment, although not explicitly shown in the figures, the inlet path 65 is also or alternatively connected to the inlet 60 of the first pump 20. In an embodiment, as shown in the cross-sectional view of fig. 4B, there may be another opening 78 connected to the inlet path 65. The opening 78 may be provided, for example, for manufacturing purposes. As shown in fig. 4A and 4B, the opening 78 may include a plug 33 (e.g., made of steel), which plug 33 is pressed into the opening 78 to seal a portion of the inlet path 65 or passage within the housing 12 when the pump assembly 10 is ready for use.

Referring now more specifically to each pump, in one embodiment, the first pump 20 of the pump assembly 10 may be an external gear pump that includes a gear set of two externally toothed and intermeshing gears 46, 48 disposed on two parallel shafts. In one embodiment, first gear 46 is a drive gear driven by drive shaft 24. The first gear 46 is configured and arranged to rotate about a drive axis a-a. In one embodiment, first gear 46 may be connected to second pump 30 via drive shaft 24 and configured to rotate with drive shaft 24. In another embodiment, the first gear 46 may be provided on its own shaft 44, which shaft 44 is connected to the drive shaft 24 (with or without the coupling 25) (described further below). In one embodiment, the second gear 48 is a driven gear coupled to a rotatable shaft 52 (see fig. 4A and 5) disposed on a driven axis B-B. The driven axis B-B is parallel to the drive axis a-a. The output of the first pump 20 may be selectively activated to pressurize and pump lubricant to an external system (see, e.g., fig. 12-13). In one embodiment, a valve (such as valve 114 shown in FIG. 12) may be provided to limit or selectively provide lubricant to the system. In another embodiment, the system may be designed to combine its outlet with a second pump (not shown). Alternatively, in an embodiment, the outlet of the pump may be used only for lubrication as part of a lubrication circuit or only for cooling as part of a cooling circuit.

In one embodiment, second pump 30 is an internally meshing rotor pump that includes an inner rotor 56 that acts as a drive gear that rotates relative to an outer rotor 58. Inner rotor 56 is fixedly secured to shaft 24 (or shaft 42) for rotation with drive shaft 24 about axis a-a. According to one embodiment, outer rotor 58 may be rotatably received in a portion of housing 12 (specifically, common wall 80 as described below). In another embodiment, outer rotor 58 is secured within common wall 80. Inner rotor 56 meshes with outer rotor 58 with teeth disposed on each gear (e.g., inner rotor 56 has male or external teeth disposed along its outer circumference, while outer rotor 58 has female or internal teeth on its inner circumference to receive the male teeth of inner rotor 56. outer rotor 58 has a greater number of teeth or receiving portions than inner rotor 56. the axis of inner rotor 56 is offset from the axis of outer rotor 58. in one embodiment, both rotors may rotate on their respective axes. alternatively, in another embodiment, inner rotor 56 rotates relative to outer rotor 58. As will be appreciated by one of ordinary skill in the art, rotation of inner rotor 56 also rotates outer rotor 58, according to one embodiment, with their intermeshing teeth, to pressurize input fluid received in the area between the complementary components for output from pump assembly 10, and therefore these details are not described herein. During rotational rotation, fluid may enter the suction side of the intermeshing rotor pump and be pressurized due to the volume changing space, and pressurized fluid is discharged at the discharge port of the intermeshing rotor pump. Drive shaft 24 may be configured to drive inner rotor 56, for example. In an embodiment, such as shown in fig. 3 (where cover 36 is removed from housing 12 for illustrative purposes only), outer rotor 58 may be disposed in (and rotate within) rotor recess 54, which rotor recess 54 forms part of one rotor chamber disposed in housing 12.

As shown and described herein, the housing 12 is designed such that it provides two internal chambers therein; i.e. one for the first (high pressure, external gear) pump 20 and one for the second (low pressure, internal gear) pump 30. Each of these internal chambers receives and pressurizes lubricant therein using a respective pump component. In particular, the housing 12 includes a wall 80, also referred to in this disclosure as a "common wall" 80, that is common to both the first pump 20 and the second pump 30 of the pump assembly 10, which wall forms a portion of each internal chamber. The common wall 80 may be positioned in opposite radial directions (relative to the drive axis a-a) within the pump assembly 10. The first pump 20 is disposed on a first radial side 82 of the common wall 80 and the second pump 30 is disposed on a second radial side 84 of the common wall 80 opposite the first side. As shown in fig. 4A, for example, drive shaft 24 extends through common wall 80 and is connected to each of drive gear 46 and drive gear 56 of both first pump 20 and second pump 30, respectively. In an embodiment, the gears 46, 48 of the first/external gear pump 20 may be disposed on a first side 82 of the wall 80, and the inner rotor 56 and outer rotor 58 of the second/internal gerotor pump 30 may be disposed on a second side 84 of the wall 80.

In an embodiment, the common wall 80 forms at least a portion of each internal chamber provided in the pump assembly 10, and the cover (cover plate 16 or cover plate 36) forms another portion of each internal chamber. For example, according to one embodiment, the common wall 80 may be a substantially flat wall extending between components (e.g., gears) of the pumps 20, 30. That is, each of the first and second sides of the wall 80 may be substantially flat. In the present disclosure, "substantially flat" means that one side of the common wall may be positioned flush with another portion (e.g., a cover) of the pump assembly 10 and does not include a recess or cavity for receiving a pump component therein. However, such a substantially planar wall may include a channel, path or course drilled along a portion of the wall. In such embodiments, the covers 16 and 36 may include recesses or openings in their inner radial walls that are sized to receive the gears of the pumps 20, 30 therein. When the covers 16, 36 are attached to the common wall 80, the inner radial wall of each cover 16, 36 may form a peripheral wall that extends around and surrounds each interior chamber (and the gears of the pumps 20, 30).

In another embodiment, the common wall 80 defines a pressurized interior chamber in each pump 20, 30 in which at least the drive gears 46, 56 are received. In the illustrated embodiment, for example, as shown in fig. 4A and 11A, the common wall 80 may include a first recess 86 or first rotor cavity on the first side 82 thereof to receive at least one gear of the first pump 20 (e.g., the drive gear 46) therein. A second recess 54 or second rotor cavity may be provided on a second side 84 of the wall 80 to receive at least one gear of the second pump 30 therein (e.g., a drive gear or an inner rotor 56). The common wall 80 may be positioned in a radial direction (relative to the drive axis a-a), and each recess 54, 86 may extend axially into the wall 80 and/or toward the wall 80. The recesses 54, 86 may be sized to receive at least one of the gears associated with each of the pumps 20, 30. For example, the second recess 54 may be sized to receive the outer rotor 58 of the inter-engaging rotor pump 30 therein (and optionally allow the outer rotor 58 to rotate therein). In one embodiment, the first recess 86 may be sized to receive therein both the first gear 46 and the second gear 48 of the external gear pump 20 and to allow rotation therein of both the first gear 46 and the second gear 48. That is, the recesses 86 may be sized such that when the gears 46, 48 are meshingly mounted for rotation about their respective axes, the length of the recesses may be based on the length of the stacked or intermeshing gears.

Thus, the walls of the recesses 86, 54 may define the axial sides of the interior chamber and include a peripheral wall 23 that extends circumferentially around the gear to form the interior chamber. The covers 16, 36 may be attached to the common wall 80 to help enclose the interior chamber with the common wall 80. For example, the cover 36 is not shown in fig. 3 so that some of the internal components of the wall of the second pump 30 can be seen. For example, one or more seals 43 may be provided between the common wall 80 and the covers 16, 36. In one embodiment, such as shown in FIG. 14, a single seal 43 is disposed around any opening or any connection point in the cover 16 between them. The covers 16, 36 may be made of any material and may be formed by stamping (e.g., stamping steel or another metal), aluminum die casting, powdered metal forming, forging, or any other desired manufacturing technique.

In one embodiment, the cover 16 may also include one or more recesses 53A, 53B (see fig. 7) in its inner radial wall to receive respective ends of the drive shaft 24/44 and/or the driven shaft 52 therein. As shown in fig. 7, for example, the underside or radially inner side (pump facing side) of the cover plate 16 may have a recessed channel 61 to seat a seal 43, which seal 43 separates the inlet 60 from the outlet on the back side of the spacer 50 or plate. Similarly, in one embodiment, as shown in fig. 10, the inner side (pump-facing side) of cover plate 36 may include shaded (shadow) ports for the inlet and outlet of the gear/inner ring rotor set (56 and 58) of second pump 30.

Alternatively, in another embodiment as shown in fig. 17, the underside or radially inner side of the cover plate 16 may not be provided with recessed channels 61. In such embodiments (which will be described in detail later with respect to pump assembly 10A), spacers 50 or pressure compensating plates may be disposed on opposite sides of the outer gear set, that is, at or on the inside in recess 86, and/or at or near common wall 80.

In one embodiment, a first recess 86 may be formed in the first side 82 of the common wall 80 to receive the drive gear 46 and its shaft (drive shaft 24 and/or shaft 44), and a third recess is also formed in the first side 82. The third recess may be a separate recess arranged to receive the second/driven gear 48 of the first pump and its rotating/driven shaft 52 therein. According to yet another embodiment, an auxiliary recess may be included in the first recess 86 (when formed to accommodate the length of the intermeshing gears) or in the third recess for accommodating an end of the driven shaft 52 of the external gear pump 20.

In yet another embodiment, the common wall 80 may have one side that is substantially flat and an opposite side with one or more recesses therein. The flat side of the common wall 80 may be connected to a cover plate having one or more recesses therein for receiving at least one of the gears for one of the pumps, such that when the cover is connected with the flat side of the container, an internal chamber is formed in the common wall 80. On the opposite side of the common wall, the one or more recesses may be configured to receive one or more gears of another one of the pumps, and a cover plate may be attached to the opposite side to form an additional internal chamber of the pump assembly 10.

The common wall 80 and/or the housing 12 may be formed from several materials and may be manufactured in several ways. In one embodiment, the common wall 80 is molded, such as injection molded. In another embodiment, the common wall 80 may be formed by a molding process that also includes a machining process and/or a drilling process. For example, the recesses 54, 86 or rotor chambers may be machined into the common wall 80. In one embodiment, the common wall 80 may be formed by a casting process (die casting), powdered metal forming, forging, stamping, or any other desired manufacturing technique. Other components of the housing 12 may be formed by similar techniques, i.e., stamping, casting, powdered metal forming, molding, and the like. According to an embodiment, the housing 12 and its common wall 80 may be formed using a casting technique. According to embodiments, the housing 12 and the common wall 80 may be formed of die cast aluminum or cast iron. According to an embodiment, the common wall 80 and the wall forming the recess may be a single integral and continuous part, i.e. may be integral.

Drive shaft 24 extends through wall 80 and is connected to each of drive gears 56, 46 received in first and second recesses 86, 54, respectively. In the illustrated embodiment, the drive gear of the external gear pump 20 is gear 46, which is driven by the drive shaft 24 connected to the second pump 30, while the driven gear is gear 48, which is connected to a rotatable shaft 52.

In an embodiment, one or more spacers 50, pressure compensating plates, or collars may be provided adjacent the first and second gears 46, 48 of the first pump 20 to substantially prevent sliding (axial) movement of the gears 46, 48 from the wall 80. For example, the gears 46, 48 may be placed such that one side is substantially flush with the first side 82 of the common wall 80. The spacer(s) 50, plate(s), or collar(s) may be placed on a side opposite the first side 82 of the common wall 80 and fit over the shafts 44, 52 between the gears 56, 58 and the radially inner side of the cover 16. As shown in the exploded view of fig. 6, which shows the drive shaft 24 (i.e., shafts 42 and 44), the rotating shaft 52, and the components of the gears 46, 48 and 56, 58 of the pumps 20, 30, for example, the spacer 50 may be part of a separate structure having openings 51A, 51B extending therethrough to receive the shafts 44, 52 (respectively). In addition to retaining the gears 46, 48 in the recesses 86 of the wall 80 in the housing 12 (and helping to reduce or prevent axial movement of the gears 46, 48 therein), the spacer(s) 50 or collar(s) limit the amount of wear and damage to the wall 80, housing 12, and/or cover 16.

As previously described, the drive shaft 24 that drives both the first pump 20 and the second pump 30 extends through the housing 12, as shown in fig. 4A. Accordingly, common wall 80 may also have a receiving opening 88, with receiving opening 88 extending axially through common wall 80, extending between second recess 54 and first recess 86, for receiving drive shaft 24 therethrough. The size of receiving opening 88 may be based on the diameter or size of drive shaft 24.

In one embodiment, the drive shaft 24 is a single common drive shaft for both pumps 20, 30 formed as a single shaft (or tube) and designed to extend through the housing 12 and into at least a portion of the pumps 20, 30 for driving the pumps 20, 30 when rotating about the drive axis a-a. That is, the same shaft may directly drive the first pump 20 and the second pump 30. The receiving opening 88 may have a substantially uniform diameter along its axial length from one end (e.g., at the second recess 54) to the other end (e.g., at the first recess 86).

In another embodiment, such as shown in fig. 4A, 5, and 11A, the drive shaft 24 may be formed of a first drive shaft 42 and a second drive shaft 44 coaxially connected to each other for rotation together about a drive axis a-a. In one embodiment, the first drive shaft 42 and the second drive shaft 44 are coupled by a coupling 25. In one embodiment, such as shown in the cross-section of fig. 4A, the coupling 25 has a first extended end that is inserted into an opening in the drive shaft 42 and a second end having an opening therein for receiving the first drive shaft 42 therein. In another embodiment, such as shown in the exploded view of FIG. 6, the coupler 25 has openings on either side thereof. The first drive shaft may include a connector 42A on an end thereof that is inserted (e.g., press-fit) into one opening of the coupler 25, and/or the second drive shaft may include a connector 44A on an end thereof that is inserted (e.g., press-fit) into another opening of the coupler 25. Such a coupling 25 is optional and need not be provided. The illustrated coupling is exemplary only and not intended to be limiting. For example, the shafts may be directly connected using the receiving portions and corresponding connector portions (e.g., male and female components) to form a coupling therebetween. In an embodiment, one of the drive shafts (e.g., a first drive shaft) may include a connector male portion 42a1, the connector male portion 42a1 being inserted into a receiving connector female portion 42a2 of the other drive shaft (e.g., a second drive shaft). An exemplary embodiment of such a coupling for a drive shaft (or drive shafts) is shown in fig. 27A and 27B. In some embodiments, receiving opening 88 may include additional stepped portions therein to accommodate shafts 42 and 44 and/or optional coupler 25. That is, receiving opening 88 may include multiple diameters along its axial length to accommodate components associated with drive shaft 24.

Drive shaft 24 is driven by a single input device or drive, which may be mechanical, electric, or electromechanical, such as an electric motor 90 (shown in fig. 8-10 and 11A-11C), an engine, an Internal Combustion Engine (ICE), or a prime mover. As shown in these figures, in one embodiment, the pump assembly 10 is configured for assembly with an electric motor 90. As shown in the cross-sectional view of fig. 11A, the pump assembly 10 and the electric motor 90 are axially aligned on the drive axis a-a. The electric motor 90 is housed in a housing 91 and has a motor shaft 92 configured to drive the drive shaft 24 of the pump assembly 10. In one embodiment, the motor shaft 92 and the drive shaft 24 may be a single shaft extending from the electric motor 90 into the pump assembly 10. According to another embodiment, such as shown in fig. 11A, the electric motor 90 may have its own, separate motor drive shaft 92, which motor drive shaft 92 is configured to be driven about axis a-a and still be connected to the pump assembly 10 in order to drive the pumps 20, 30 in the pump assembly 10. In one embodiment, the motor shaft 92 has an end 94 configured to connect to the connector portion 22 of the pump assembly 10. For example, the end 94 may be configured to be press-fit into an opening in the connector portion 22 for axial rotation along axis A-A.

More particularly, the connector portion 22 is provided on the second side 18 of the pump assembly 10 for connection to an input device or driver (e.g., an electric motor 90 as shown in fig. 8-9). According to one embodiment, as shown, the connector portion 22 has a receiving area or opening 21 for receiving a portion of the drive shaft (motor shaft 92) of the drive therein. In one embodiment, connector portion 22 may be integrated into an end of drive shaft 24. That is, the drive shaft 24 may extend through the housing 12 and one of its ends extends through a (second) cover plate 36 on the second side 18 of the pump assembly 10, such that the drive shaft 24 may be connected to the driver. In another embodiment, connector portion 22 may be a coupler that is attached to the end of drive shaft 24 and is placed in or on cover plate 36 when assembled.

In one embodiment, the housing 91 includes a sleeve 95 (see fig. 10) to help secure the electric motor 90 to the pump assembly 10. As shown in the exploded view of fig. 7, for example, the cover plate 36 disposed on the second side 18 of the pump assembly 10 may include a cavity 37 on a radially outer side thereof, the cavity 37 configured to receive a sleeve 95 of the electric motor 90 therein when assembled together. In a particular embodiment, as shown in FIG. 11A, the connector portion 22 is aligned with the opening 97 of the sleeve 95 and inserted into the opening 97, while the exterior of the sleeve 95 is disposed in the cavity 37. One or more seals 39 or O-rings may be provided around the connector portion 22.

The electric motor 90 may include a rotor 96 and a stator 98 (see fig. 11A) and several bearings 99 disposed on its motor shaft 92. The rotor 96 is connected to the motor shaft 92, and the motor 96 is accommodated in the housing 91 thereof together with the stator 98. The motor housing 91 is generally cylindrical (see fig. 11B), and the stator 98 may be fixed thereto. In one embodiment shown in fig. 11C, the motor housing 91 may include cooling fins 93 disposed on the outside thereof (i.e., the side opposite the side to which the pump assembly 10 is attached).

Fig. 15-17 depict another embodiment of a pump assembly 10A, the pump assembly 10A including a first pump 20 and a second pump 30 therein. For clarity and brevity, like elements and components throughout fig. 15-17 are labeled with the same reference numbers and numbering as discussed with reference to fig. 1-14. Thus, although not discussed in full detail herein, those of ordinary skill in the art will appreciate that the various features associated with the pump assembly 10 of FIGS. 1-14 are similar to those previously discussed. In addition, it should be understood that the features shown in each of the individual drawings are not meant to be limited to only the illustrated embodiments. That is, features described throughout this disclosure may be interchanged with and/or used in connection with other embodiments than those illustrated and/or described with reference to the figures. The pump assembly 10A may be driven by a driver, such as a motor 90. Much like pump assembly 10, pump assembly 10A includes a first pump 20 and a second pump 30. Disposed in the housing is a drive shaft 24, which drive shaft 24 is configured to rotate about a drive axis a-a and drive both the first and second pumps 20, 30. A coupling 25 may optionally be provided to connect drive shafts 42 and 44 to form drive shaft 24, or a single drive shaft may be provided. The first pump 20 may be a high pressure external gear pump and the second pump 30 may be a low pressure internal gerotor pump, paired together and configured to be driven by the same drive shaft. The first pump 20 has a first inlet provided on the housing for receiving lubricant from a source external to the housing and a first outlet for directing pressurized lubricant out of the housing. The second pump has a second inlet disposed on the housing for receiving lubricant from a source external to the housing and a second outlet for directing pressurized lubricant out of the housing. The second inlet and the second outlet are different from the first inlet and the first outlet, respectively. The housing also includes a wall 80 common to both the first pump 20 and the second pump 30, which can be seen in fig. 15. The first pump 20 is arranged on a first (right) side of the wall and the second pump 30 is arranged on a second (left) side of the wall opposite to the first side. The drive shaft extends through the common wall 80 and is connected to gears (e.g., gears 46 and 56) of both the first pump 20 and the second pump 30.

In the illustrated embodiment, the underside or radially inner side (pump-facing side) of the cover plate 16 may include a receiving opening 17 therein (see fig. 15 and 17) for receiving an end of each of the shafts 44 and 52 for the gears 46 and 48 of the first pump 20. In this embodiment, the spacer 50 or pressure compensating plate may be disposed on an opposite side of the outer gear set. That is, rather than being disposed adjacent to coverplate 16 as shown in FIG. 7, spacer 50 is disposed on an inner (opposite) side and within recess 86 and/or at or near common wall 80. According to one embodiment, as seen in fig. 15, for example, the recess 86 of the common wall 80 may receive the seal 43A, the spacer 50, and then the gears 46, 48 therein. Seals 43A may be received in recesses 86 to separate the sides of spacers 50 or plates from direct contact with common wall 80 while still providing support and/or pressure against the outer gear set of first pump 20. Shaft 44/drive shaft 24 extends through common wall 80 and is connected to drive shafts 42(24) of inner ring rotor gear sets 56, 58, which are received in another recess 54 on the opposite side of common wall 80.

Fig. 18-28 depict yet another embodiment of a pump assembly 10B, the pump assembly 10B including a single housing 12 having a common wall 80 and a drive shaft 24, and a first pump 20B and a second pump 30B located therein. For clarity and brevity, like elements and components throughout fig. 18-28 are labeled with the same reference numbers and numbering as discussed with reference to fig. 1-14. Thus, although not discussed in full detail herein, those of ordinary skill in the art will appreciate that the various features associated with the pump assembly 10 of fig. 1-14 and/or the pump assembly 10A of fig. 15-17 are similar to those previously discussed. In addition, it should be understood that the features shown in each of the individual drawings are not meant to be limited to only the illustrated embodiments. That is, features described throughout this disclosure may be interchanged with and/or used in connection with other embodiments than those illustrated and/or described with reference to the figures. The pump assembly 10B may be driven by a driver, such as a motor 90, for example, an electric motor, an engine, or a transmission. In an embodiment, there may be a single input device for driving the drive shaft 24 of the pump assembly 10B. The input device may be an engine, transmission or electric motor. Much like pump assembly 10, pump assembly 10B includes a first pump 20B and a second pump 30B. Disposed within the housing is a drive shaft 24, the drive shaft 24 being configured to rotate about a drive axis a-a and drive both the first pump 20B and the second pump 30B. In an embodiment, such as shown in fig. 27A and 27B, drive shaft 24 may be formed of a first drive shaft 42 and a second drive shaft 44 coaxially connected to each other for rotation together about drive axis a-a. In one embodiment, the first drive shaft 42 and the second drive shaft 44 are coupled together using a receiving portion in one end of the shaft (e.g., in the drive shaft 44, as shown in fig. 27A) and a corresponding connector or insert portion in the other end of the shaft (e.g., in the drive shaft 42, as shown in fig. 27A) (e.g., male and female components) to form a coupling therebetween. In another embodiment, the first drive shaft 42 and the second drive shaft 44 may be connected via separate couplings 25, such as described above with reference to the above embodiments.

In the illustrative embodiment of fig. 18-28, the first pump 20B may be an air pump for pressurizing air, and the second pump 30B may be an oil pump or lubricant pump configured to pressurize lubricant. First pump 20B and second pump 30B of pump assembly 10B are paired together and configured to be driven via the same drive shaft 24. The first pump 20B has a first inlet 60A disposed on the housing 12 and a first outlet 62A for directing pressurized air out of the housing 12 (see fig. 21). The first pump 20B may be connected to a closed network (e.g., a brake booster system) and configured to receive air therefrom to evacuate the connected system. According to one embodiment, the first inlet 60A has a first inlet opening 64A disposed in a plane perpendicular to the drive axis A-A of the drive shaft 24. The first outlet 62A has at least one first outlet opening 66A. In the exemplary illustrated embodiment, outlet 62A includes two outlet openings 66A.

The second pump 30B has a second inlet 68 (see fig. 27A) disposed on the housing 12 for receiving lubricant from a source external to the housing and a second outlet 70 for directing pressurized lubricant out of the housing 12. The second inlet 68 and the second outlet 70 are different from the first inlet 60A and the first outlet 62A, respectively. The second inlet 68 has a second inlet opening 72. According to an embodiment, the first outlet opening (or first outlet openings) 66A and the second inlet opening 72 are provided on the same side of the housing 12, i.e. on the same side of the common wall 80 or on an axis extending through the common wall 80, as shown in fig. 23. The second outlet 70 has a second outlet opening 74. The second outlet 70 includes an outlet path 70B that directs the output/pressurized fluid to a second outlet opening 74 in the housing. In an embodiment, the second outlet opening 74 is disposed on the same side of the housing as the first inlet opening 64A, i.e., on the same side of the common wall 80, as shown in fig. 18 and 20.

According to one embodiment, the first inlet opening 64A is disposed in a plane parallel to the drive axis A-A of the drive shaft 24. According to one embodiment, the second outlet opening 74 is disposed in a plane parallel to the drive axis A-A of the drive shaft 24.

In one embodiment, as shown in the cross-sectional view of fig. 27A, a passage or inlet path 65 may be provided in the housing 12 for supplying lubricant to the second pump 30B in the housing 12. Second pump 30B may receive input lubricant via an inlet path 65 connected to a second inlet opening 72, as described in more detail below. A lubricant source (e.g., tank, reservoir) is fluidly connected to the second inlet opening 72 and the inlet path 65 for delivery to the second pump 30B. As shown in fig. 19-22, for example, the second inlet 68 and the inlet opening 72 may be in fluid communication for directing the incoming lubricant to and through the inlet path 65 or passage. The inlet path 65 may be a contoured or drilled path in the housing 12, for example, leading to the second inlet 68 of the second pump 30 and the pumping elements (e.g., rotors, vanes) of the second pump 30B. For example, according to one embodiment, the inlet path 65 may be in the form of a tube. As shown in fig. 21 and 27A, a screen or filter 81 may be provided between the main inlet opening 72 and the inlet path 65 or the channel/second inlet 68 before any lubricant enters the inlet path 65 within the housing 12, so that any particulates may be filtered from the input lubricant before it is directed to the pumping elements of the second pump 30B. In an embodiment, the shape of the housing (e.g., conical as shown here) near the inlet opening 72 may be designed to decelerate the incoming fluid before the filter 81 to reduce the pressure drop across the filter 81. Thus, fluid is drawn through the second inlet opening 72, may expand within the (conical) housing to decelerate before it passes through the filter 81, and then enters the oil pump rotating group of the second pump 30B through the inlet path 65. More particularly, according to an embodiment, the inlet opening 72 and the housing are configured for placement within a source (e.g., a sump of an engine) such that the inlet opening 72 is located within the lubricant (oil) and at least partially submerged within the lubricant source. Thus, the screen or filter 81 can filter any undesirable particulates that may be recirculated within the system during operation of the pump assembly 10B.

As described above, in an embodiment, such as shown in fig. 18, 19, and 21, a second or primary inlet opening 72 may be provided in the housing 12 to direct input lubricant (e.g., from a source) into the second pump 30B. That is, the second inlet opening 72 may be fluidly connected to the inlet path 65 and thus the second inlet 68. In one embodiment, the inlet opening 72 is disposed in a plane perpendicular to the drive axis A-A of the drive shaft 24. In one embodiment, the inlet opening 72 is positioned on the other side of the housing 12 than the second pump 30B, i.e., the inlet opening 72 is positioned on a first side (e.g., right side) of the common wall 80 (on the same side as the first pump 20), while the second pump 30B is positioned on a second, opposite side (e.g., left side) of the common wall 80. Thus, the inlet path 65 connects the inlet opening 72 and the second inlet 68 (e.g., as shown in fig. 27A). In one embodiment, the first and second inlet openings 64A, 72 are disposed on opposite sides of the housing. In an embodiment, the second inlet opening 72 is positioned on the first side 14 of the pump assembly 10.

Housing 12 also includes a wall 80 common to both first pump 20B and second pump 30B, as shown, for example, in fig. 27A. The first pump 20B is disposed on a first (right side) of the wall and the second pump 30B is disposed on a second (left side) of the wall opposite the first side. Drive shaft 24 extends through common wall 80 and is connected to the drive rotors of both first and second pumps 20B and 30B (e.g., to rotor 48A and rotor 56A via bearings 71).

In an embodiment, the common wall 80 (see fig. 27A) forms at least a portion of each of the internal chambers provided in the pump assembly 10, and the cover (cover plate 16 or cover plate 36) forms another portion of each of the internal chambers. In one embodiment, the common wall 80 defines a pressurized internal chamber in each pump 20B, 30B in which at least the rotor/gears 48A, 56A (and bearings 71) are received. In the illustrated embodiment, for example, as shown in fig. 24, 25, and 27A, the common wall 80 may include a first recess 86 or first rotor chamber on the first side 82 thereof, the first recess 86 or first rotor chamber housing therein the bearing 71 and the driven rotor 48A of the first pump 20. A second recess 54 or second rotor chamber may be provided on the second side 84 of the common wall 80, the second recess 54 or second rotor chamber accommodating therein the at least one rotor (e.g., rotor 56A) of the second pump 30. The common wall 80 may be positioned in a radial direction (relative to the drive axis a-a), and each recess 54, 86 may extend axially into the wall 80 and/or toward the wall 80. The recesses 54, 86 may be sized to receive at least one of the rotors (or gears) associated with each of the pumps 20B, 30B. For example, the second recess 54 may be sized to receive the rotor 56A and the control slide 116 of the vane pump 30 therein; that is, the second recess 54 may be sized to allow and accommodate movement of the slider 116 relative to the inner walls of the recess 54. In one embodiment, the first recess 86 may be sized to receive the driven rotor 48A and allow the driven rotor 48A to rotate eccentrically within the pump 20.

Thus, the walls of the recesses 86, 54 may define the axial sides of the interior chamber and include a peripheral wall that extends circumferentially around the rotor/gear to form the interior chamber. The covers 16, 36 may be attached to the common wall 80 and/or the housing 12 to help enclose the interior chamber with the common wall 80. For example, the cover 36 is not shown in fig. 24 so that some of the internal components of the second pump 30B can be seen. Similarly, for example, the cover 16 is not shown in fig. 25 so that some of the internal components of the first pump 20B can be seen.

For example, one or more seals 43 may be provided between the common wall 80 and the covers 16, 36. In one embodiment, such as shown in FIG. 27A, a single seal 43 may be disposed therebetween around any opening or connection point in the cover 16.

The underside or radially inner side (pump-facing side) of the cover plate 16 of the first pump 20B may include a receiving opening 17 therein (see fig. 26) for receiving one end of the drive shaft 44 for the gear/bearing 71/rotor 48A of the first pump 20B. More particularly, an end portion of the drive shaft may be press-fit into the receiving opening 17 and may or may not include a bushing. In addition, as described later, the drive shaft 24 is received in a central hole of a fixed guide gear 46A or sprocket, which fixed guide gear 46A or sprocket serves as a bearing that supports the end of the drive shaft. Shaft 44/drive shaft 24 extends through common wall 80 and is connected to drive shaft 42(24) of bearing 71 and thereby to rotor 48A, rotor 48A being received in a first recess 86 (see fig. 25 and 27A) on the opposite side of common wall 48. In one embodiment, drive shaft 24, or at least a portion thereof, is configured to extend through a cover plate 36 of second pump 30B. More particularly, a connector portion 22 (see, e.g., fig. 18) may be provided on the second side 18 of the pump assembly 10B for connecting an input device or driver (e.g., the electric motor 90 shown in fig. 8-9) to the pump assembly 10B. According to one embodiment, the connector part 22 may have a receiving area or receiving opening 21 for receiving therein a portion of the drive shaft (motor shaft 92) of the drive, as previously described.

Referring now more particularly to each of the pumps, according to one embodiment, the first pump 20B of the pump assembly 10B may be an epicycloidal vacuum pump designed to produce an epicycloidal-like rotation of its rotor 48A within the recess 86 and the housing 12. An epicycloid is defined as a geometric or planar curve that is generated by the tracking motion of a fixed point on a radius (or extended radius) of a circle as it rolls outside/on the outside of a fixed base circle. As understood by those of ordinary skill in the art, the shape of the inner envelope of the epicycloid, which is the basis of the shape of the housing in which the rotor rotates, determines or helps to generate the shape of the rotor (i.e., the shape of the outer edge or lobe of the rotor). In the exemplary embodiment, a double-lobed rotor 48A is shown for illustration purposes and not intended to be limiting. Generally, this design improves on this principle of Wankel (Wankel) engines in vacuum pumps. According to an embodiment, the first pump 20 may be or include features of an epicycloidal pump as disclosed in U.S. patent application No. 15/946,944 filed on 6.4.2018, the entire contents of which are incorporated herein by reference. Some of the features of such an epicycloidal pump are described below.

Generally, in one embodiment, a first side of the wall or recess 86 of the epicycloidal first pump 20B defines and is part of an interior space having a epicycloidal shape. The rotor 48A of the epicycloidal vacuum pump is rotatably received within the interior space or recess 86. The rotor 48A is formed with several edges conjugate to the epicycloidal shape of the inner space, and has a guide gear portion 49 with internal teeth (see fig. 25). Drive shaft 24 is configured to drive eccentric bearing 71, thereby causing rotor 48A to rotate eccentrically within interior space or recess 86. As previously described, the externally toothed guide gear 46A (or sprocket) is connected to the drive shaft 24 for support as the rotor 48A is driven by the drive shaft 24.

In the illustrated embodiment, for example, the first pump 20B of the pump assembly 10B employs a double-lobed rotor 48A disposed in the housing 12, one inlet 60A, and at least one outlet 62A. For purposes of illustration only, the vacuum/first pump 20B is shown with two outlet holes 66A that connect to a passageway within the pump assembly that forms a single outlet 62A of the pump 20B. The openings 66A may be positioned adjacent to each other or near each other to provide another channel and a larger area for expelling air, effectively increasing the cross-sectional area of the outlet. This may also help reduce the resistance (or resistances) during dislodging, for example. A reed valve 61A (see fig. 21) may be provided on each opening 66A of the outlet 62A. According to one embodiment, the opening and closing timings of opening and closing the outlet opening 66A via its associated reed valve 61A may be configured to be the same such that they act as one outlet 62A for the housing. The second inlet port or inlet 77 (see, e.g., fig. 18-19) may be a radially positioned inlet disposed along an inlet path or inlet channel connected to the inlet 60A (radially with respect to axis a-a) and configured to direct the input air from the inlet 60 to an interior inlet port within the recess 86. The inlet port 77 may also have a reed valve 77A associated therewith. The operation of the reed valves 61A and 77A is generally understood by those of ordinary skill in the art and therefore will not be described in detail herein. An inlet port 77 in the inlet path helps prevent unwanted pressurization. The inlet port 77 is configured to provide protection against any potential consequences associated with the pump rotating backwards or other unwanted movement of the pump rotor or components; that is, if the pump (i.e., rotor 48A) is running or rotating backwards, for example, to evacuate the chamber or recess 86, the inlet port 77 and reed valve 77A may prevent undesired pressurization and/or back metering of lubricant or oil in the recess 86, as it is in close proximity to check valves in the system (e.g., associated with the engine).

The recess 86 functions as a single epicycloidal working chamber and has a chamber volume, each chamber performs two evacuation cycles per revolution of the rotor, thus, in the disclosed vacuum pump 10A, the total evacuation per revolution of the pump shaft is defined as a single chamber volume × 1 (because there is one chamber) × 2 (evacuation cycles per revolution of the rotor)/2 (rotor speed reduced to shaft speed), thus, the total evacuation is 1 × single chamber volume the surrounding wall of the recess 86 defines an interior space that is shaped (non-circular or substantially circular) by an epicycloid and has a cover 16 and a common wall 80 on the sides, the rotor 48A is rotatably received within the interior space of the chamber or recess 86, as known in the art, the chamber or recess 86 is a single working chamber that varies in size as the rotor 48A rotates and orbits around the surrounding wall, each side surface of the rotor 48A is brought closer to and then farther from the wall of the recess 86, but is not fully in contact with the wall of the recess, e.g., is guided via a sliding of the rotor 48A seal, e.g., sliding along the corners, during rotation.

According to an embodiment, the body of the rotor 48A may have a substantially oval shape with both sides having convex arcuate sides forming an outer wall or edge thereof (see, e.g., fig. 25). The rotor 48A rotates eccentrically about axis a-a and is rotated by an internally toothed opening or portion 49 integrated in the rotor, an externally toothed guide sprocket 46A, bearings 71 and drive shaft 24 (44). Fig. 26 shows an exploded view of the components of the first pump 20B, including the bearing 71, the rotor 48A, the guide sprocket 46A, and the shaft 44/24. The body of the rotor 48A may have an internally toothed opening at its center for receiving the guide sprocket 46A therein. The central opening may be defined by a plurality of radially extending recessed teeth 49 on the interior thereof. The guide sprocket 46A is received within the central opening. The guide sprocket 46A may have a plurality of radially extending lobes on the exterior thereof that engage the rotor 48A and guide the movement of the rotor 48A as the drive shaft rotates.

Drive shaft 24(44) is designed to extend through rotor 48A toward cover 16. One end of the drive shaft is received within the central bore of the guide sprocket 46A and is secured against rotation therein, for example by a bushing. An end portion of the drive shaft may be placed in the receiving opening 17. To achieve eccentric motion of the rotor 48A about the axis A-A, an eccentric rotary bearing 71 is provided (see FIG. 26). In one embodiment, a spacer is provided to axially position the eccentric bearing 71, such as during press fitting of the parts (i.e., drive shaft 44, bearing 71) together. The spacer may reduce the size and weight of the eccentric bearing 71, thereby improving the balance of the bearing. The eccentric rotary bearing 71 may have its own receiving opening for positioning the drive shaft 44 therethrough. In an embodiment, the drive shaft 44 may include a stepped configuration having a continuously increasing diameter for assembly with the rotor 48A.

The aforementioned inlet 60A may thus be a vacuum inlet for inputting air into the housing. The vacuum inlet 60A includes an input channel or passageway that revolves within the housing and receives (via vacuum pulling) air therethrough. Air is communicated and drawn through the passageway to at least one radial inlet port (not shown) provided in the surrounding wall of the recess 86. Thus, the inlet port 64A is fluidly connected to the interior of the chamber or recess 86. The inlet 60A and its port 64A selectively draw and deliver air under negative pressure (vacuum) depending on the position of the rotor 48B.

In one embodiment, the second pump 30B is a vane pump that includes an inner rotor 56A and a control slide 116 (see fig. 24 and 28), the control slide 116 having a rotor receiving space 118 that communicates to the second inlet 68 and the second outlet 70. A slide 116 (also referred to in the art as a control ring) is mounted in the housing 12 for pivotal movement in opposite displacement increasing and displacement decreasing directions. As shown in fig. 24 and 28, the control slide 116 has a pivotal connection established by a pivot pin 122. During pump operation, the control slide 116 pivots about the pivot connection/pin 122 in both a displacement increasing direction and a displacement decreasing direction (depending on the pressurized fluid therein). As shown, the rotor receiving space 118 may be a substantially cylindrical bore that extends through the thickness of the body of the control slide; that is, the control slide 116 has an interior surface or inner surface that defines a rotor receiving space 118. The rotor receiving space 118 is in direct communication with the inlet 65 and the outlet 70 for drawing oil, lubricant or another fluid through the inlet 65 at a negative suction pressure and discharging oil, lubricant or another fluid from the outlet 70 at a positive discharge pressure.

As shown in fig. 28, the rotor 56A of the second pump 30B is disposed in the rotor receiving space 118. The rotor 56A is configured for rotation within the control slide 116 and relative to the control slide 116. The rotor 56A has a central axis that is typically eccentric with respect to the central axis of the control slide 116 (and/or the rotor receiving space 118). Rotor 56A is fixedly secured to shaft 24 (or shaft 42) for rotation with drive shaft 24 about axis a-a. The rotor 56A includes a plurality of blades 120. The vanes 120 may be retractable and optionally have springs or other features (e.g., fluid passages) for biasing the vanes 120 radially outward into contact with the inner surface of the rotor receiving space 118. The rotor 56A is rotatably mounted in the rotor receiving space 118 (clockwise in the orientation shown in FIG. 28) to draw lubricant under negative pressure (e.g., from a source such as a lubricant reservoir (e.g., an oil reservoir), or from within a generally enclosed space (e.g., from within a transmission housing) into the rotor receiving space 118 via the inlet 68 and expel lubricant under positive pressure from the rotor receiving space 118 via the outlet 70. the outlet 70 expels lubricant under generally positive pressure to a device requiring lubrication, such as an oil gallery of an engine.

As is generally understood in the art, movement of the control slide 116 in the displacement increasing direction increases the eccentricity between the rotor 56A and the control slide 116 in order to increase the pressure differential between the inlet 68 and the outlet 70. Conversely, movement of control slide 116 in the opposite displacement reducing direction reduces eccentricity to reduce the pressure differential. As is well known, this working principle is based on the generation of a pressure difference between the low pressure side of the rotor receiving space 118 and its high pressure side by the volume change of the recess between the individual vanes, which volume change is regulated by the eccentricity between the control slide 116 and the rotor 116, and therefore does not need to be described in detail.

The rotor 56A may be powered in any manner. For example, in engine applications, the rotor 56A is typically coupled to a gear or pulley that is driven by a belt or chain, or may be driven directly by another element of the drive train. As another example, the pump 30B may be driven by an electric motor (particularly in electric vehicles) or have two input connections to be driven by both the engine drive element and/or the electric motor (particularly in hybrid vehicles). The driving manner of the rotor 56A is not limited and may be performed in any manner.

A resilient structure 124 is located between the housing 12 or recess 54 and the control slide 116 to bias the control slide 116 in the displacement increasing direction. In the illustrated embodiment, the resilient structure 124 is a compression spring, but may have any structure or configuration. The control slide 116 includes a radial protrusion 126 (or radially extending support structure) that opposes the pivotal connection (e.g., pin 122) of the control slide 116 to the housing 12. The radial projection 126 has a bearing surface 128, the bearing surface 128 being engaged by the resilient structure 124. In the illustrated embodiment, one end of the spring/structure 124 engages the surface 128 and an opposite end thereof engages against an opposite surface disposed in the recess 54 or housing 12. As shown, the spring 124 is held in compression between these surfaces, thereby applying a reaction force that biases the control slide 116 in the displacement increasing direction.

Control slide 116 may have one or more seals 132 that define a control chamber 130 between control slide 116 and recess 54/housing 12. Control chamber 130 communicates with a source of pressurized lubricant to move control slide 116 in the displacement reducing direction. In the illustrated embodiment, lubricant is supplied into the control chamber 130 via the inlet path 65 and the recess/chamber inlet port 65A. The inlet 30 and the outlet 40 are arranged on opposite radial sides of the rotational axis of the rotor 65A. The housing 12 has at least one inlet port 65A for drawing in fluid to be pumped from the inlet 65 and at least one outlet port 70A for discharging fluid to the outlet 70. The inlet port 65A and the outlet port 70A may each have a crescent shape, and may be formed by the same wall on one axial side or both axial sides (with respect to the rotational axis of the rotor) of the housing. The inlet port 65A and the outlet port 70A may be disposed on opposite radial sides of the rotational axis of the rotor 16. These structures are conventional and need not be described in detail. The shape of the inlet and/or outlet is not intended to be limiting. Other configurations may be used, such as different shaped or numbered ports, and so forth. Further, it should be understood that more than one inlet or outlet may be provided (e.g., via multiple ports). The chamber inlet port 65A may be in communication (directly or indirectly) with the chamber outlet port 70A, through the outlet path 70B, and to the second outlet 70 of the housing 12, and thus the source of pressurized lubricant for the control chamber 130 is lubricant discharged from the outlet 70. This is a known feedback method in which the pressure from the outlet 70 is used to help regulate the pump displacement and pressure. As the pressure fed back from the outlet 70 increases, this will cause an increase in pressure in the control chamber 130, which in turn will move the control slide 116 against the bias of the resilient structure 124 in the displacement reducing direction (and thus will also reduce the pressure differential created by the vanes 120, thereby reducing the pressure of the lubricant discharged from the outlet 70). Conversely, as the pressure fed back from outlet 70 decreases, this will cause the pressure in control chamber 130 to decrease, which in turn allows the resilient structure to move control slide 116 in the displacement increasing direction (which in turn will also increase the pressure differential created by rotor 56A, thereby increasing the pressure of the lubricant discharged from outlet 70). This technique may be used to maintain the output pressure and/or the volumetric displacement of the pump at or near equilibrium levels.

According to an embodiment, the second pump 30B may have multiple control chambers for providing different levels of control over the operation of the pump assembly 10B. In other embodiments, pump 30B may have only one control chamber.

The second pump 30B may also include several safety features associated therewith. For example, one or more fail-safe pressure relief valves 140 (e.g., ball valves, check valves, emergency valves) may be provided in the housing 12 (see fig. 26 and 27A-27B). Such a valve may be positioned in the inlet path or the outlet path of the pump assembly 10B. According to an embodiment, second pump 30B may include one or more valves, such as the valves disclosed in U.S. patent nos. 9,534,519, 9,771,935, 10,030,656, and 10,247,187 and U.S. provisional serial No. 62/799,449 filed on 31/1/2019, the entire contents of each of which are incorporated herein by reference.

Also, while the vane pump is described with respect to the above exemplary embodiment of fig. 18-28 as being used with the epicycloidal pump 20B as the second pump 30B, in another embodiment, the second pump 30B may be an inter-meshing gerotor pump (such as the inter-meshing gerotor pump shown and described above with reference to fig. 3) disposed in the same housing and pump assembly as the epicycloidal pump 20B.

In this way, the exemplary embodiment shown in fig. 18-28 provides a more compact packaging solution for including the air pump and the lubricant pump in a single housing assembly. This design reduces the number of connecting parts required to connect to the engine. This design also allows the pumps therein to be operated using a common drive shaft.

Operation of the pump assembly 10 and/or 10A will be further described with reference to fig. 12 and 13. Although fig. 12 and 13 are described with reference to the pump assembly 10, it should be understood that the pump assembly 10A can be operated and used in a similar manner as the pump assembly 10. As shown in the schematic diagram of fig. 12, for example, the second (low-pressure internal-meshing rotor) pump 30 is configured to always provide lubrication to a transmission (see the transmission 102 of fig. 13) when the electric motor 90 rotates. A flow restrictor may optionally be provided (e.g., external to the pump assembly or, if desired, built into the pump assembly or well) to limit the amount of lubricant to the transmission. The controller 104 (shown in fig. 13) is configured to operate or drive the electric motor 90 (e.g., to control the magnetic field of the stator 98 of the electric motor 90) to thereby control and drive the pump assembly 10. Optionally, second pump 30 may also be configured to selectively flow lubricant through the transmission's cooling system via operation of control valve 112, for example, if cooling is desired. The controller 104 may control the valve 112 to move to an open position, for example, to feed a cooling system. Optionally, a flow restrictor may also (or alternatively) be provided (e.g., external to the pump assembly) to limit the amount of lubricant to the cooling system. In some cases, the same restrictor may be provided before the inlet for lubrication and cooling of the transmission. In one embodiment, the second pump 30 may operate at a pressure of up to about 3.0 bar.

The first (high pressure external gear) pump 20 is not stationary even though the second pump 30 is configured to continuously pump lubricant to the transmission. According to one embodiment, due to the connection of drive shaft 24 between the two pumps 20 and 30, first pump 20 is also configured to rotate with the operation of motor 90. However, the output of the first pump 20 is generally limited in operating conditions, for example at about 3.0 bar. In some embodiments, for example, when the transmission requires a higher pressure of lubricant, such as when the clutch 108 requires lubricant for a shift operation, there are situations when the first pump 20 is selectively activated. That is, the first pump 20 may be activated to output higher pressure lubricant to the transmission. According to an embodiment, the first pump 20 is configured for outputting lubricant to the clutch 108/transmission when the desired operating pressure of the lubricant is greater than about 20 bar. In one embodiment, the first pump 20 is configured to operate when a desired pressure of the external system/transmission 102 is in a range of about 20 bar to about 60 bar, inclusive.

According to one embodiment, a control valve 114, shown schematically in FIG. 12, is provided to selectively limit (or selectively allow) output from the first pump 20 to the clutch 108/transmission 102. For example, in its first position, the valve 114 may be configured to direct output pressurized fluid from the first outlet opening 62 to the clutch 108. Otherwise, at a lower pressure (i.e., less than 20 bar), the valve 114 may be configured to be disposed in the second position such that the first pump 20 recirculates lubricant back to the tank 106, as shown in fig. 12. Alternatively, in some embodiments, the output from first pump 20 may be designed to assist second pump 30 in lubricating the transmission at low pressure.

Controller 104 is also configured to control the selective activation of this valve 114 and, thus, the use of the output from first pump 20.

The first epicycloidal pump 20B may be used to provide vacuum, i.e., negative pressure or air, to any number of systems in the vehicle (e.g., brake booster systems, pneumatic actuators, and/or valves). The second vane pump 30B may function as an oil pump to supply pressurized lubricant to another system, such as a supercharger that functions as a circuit to the engine or transmission, provides lubricant and/or cooling to the gearbox, assists clutch operation, and/or another smaller pump within the vehicle.

Accordingly, the pump assemblies 10, 10A, and 10B disclosed herein provide several features and improvements, including the two pumps (20, 30) provided in the assemblies 10, 10A, and 10B being integrated and housed in one housing and sharing a common wall 80 in the housing, thereby allowing for a more compact configuration and structure. As such, the large space required for mounting the disclosed pump assembly is not required. Further, manufacturing costs and machining costs for forming the housing 12 are reduced. In addition, both pumps (20, 30) are driven by the same shaft 24 (whether of unitary or connected construction) in the housing 12.

When used in a system with a control valve, the output of the first pump may be limited. As such, the pump assemblies 10 and/or 10A and/or 10B can operate under a range of operating conditions or phases, including the selective use of a high pressure/first pump when desired.

While the principles of the disclosure have been illustrated in the illustrative embodiments set forth above, it will be apparent to those skilled in the art that various modifications may be made in the structure, arrangement, proportions, elements, materials, and components used in the practice of the disclosure.

It will thus be seen that the features of the present disclosure have been fully and effectively accomplished. It will be understood, 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. Accordingly, this disclosure includes all modifications encompassed within the spirit and scope of the following claims.

Claims (34)

1. A two-stage pump assembly comprising:

first and second pumps for pumping lubricant to the system, both integrated into a single housing and each configured to pressurize lubricant input into the housing;

a drive shaft disposed in the housing, the drive shaft configured to rotate about a drive axis and drive both the first pump and the second pump, the drive shaft driven by a single input device;

both the first and second pumps include at least one gear constructed and arranged to be rotated by the drive shaft;

the first pump includes a first inlet disposed on the housing for receiving lubricant from a source external to the housing and a first outlet for directing pressurized lubricant out of the housing;

a second pump including a second inlet disposed on the housing for receiving lubricant from the source external to the housing and a second outlet for directing pressurized lubricant out of the housing, the second inlet and the second outlet being different from the first inlet and the first outlet, respectively;

the housing further includes a wall common to both the first and second pumps, the first pump disposed on a first side of the wall, the second pump disposed on a second side of the wall opposite the first side, the drive shaft extending through the wall and connecting to each of the at least one gears of both the first and second pumps.

2. The two-stage pump assembly of claim 1, wherein the wall includes a first recess on a first side thereof that receives the at least one gear of the first pump therein and a second recess on a second side thereof that receives the at least one gear of the second pump therein, and wherein the drive shaft extends through the wall and connects to each of the at least one gear received in the first and second recesses.

3. The two-stage pump assembly of claim 1, wherein the single input device for driving the drive shaft of the two-stage pump assembly is an engine, a transmission, or an electric motor.

4. The two-stage pump assembly of claim 1, wherein the first pump is an external gear pump comprising two gears disposed on two parallel shafts, a first of the two gears being a drive gear driven by a drive shaft connected to the second pump and a second of the two gears being a driven gear coupled to a rotatable shaft.

5. The two-stage pump assembly of claim 2, wherein the wall further includes a third recess therein disposed on the first side of the wall, wherein the first pump is an external gear pump including first and second gears disposed on two parallel shafts, wherein the second gear of the first pump is received in the third recess.

6. The two-stage pump assembly of claim 4, wherein the second pump is an inter-meshing rotor pump including an outer rotor and an inner rotor that acts as a drive gear, the inner rotor rotating relative to the outer rotor, and wherein the outer rotor of the second pump is disposed on a second side of the wall.

7. The two-stage pump assembly of claim 1, wherein the drive shaft is a single common drive shaft.

8. The two-stage pump assembly of claim 1, wherein the drive shaft comprises first and second drive shafts coaxially connected to each other for rotation together about the drive axis.

9. The two-stage pump assembly of claim 8, wherein the first drive shaft and the second drive shaft are connected via a coupling.

10. The two-stage pump assembly of claim 1, further comprising: a first cover plate connected to the housing and covering at least the at least one gear of the first pump; and a second cover plate connected to the housing and covering at least the at least one gear of the second pump.

11. The two-stage pump assembly of claim 10, wherein the first cover plate of the first pump comprises a floating cover plate.

12. The two-stage pump assembly of claim 10, wherein the first cover plate of the first pump comprises a stationary cover plate.

13. The two-stage pump assembly of claim 10 wherein the first inlet of the first pump includes a first inlet opening disposed in the first cover plate, the first inlet opening receiving lubricant from the source external to the housing, and wherein the first inlet opening is disposed on a plane perpendicular to the drive axis of the drive shaft.

14. The two-stage pump assembly of claim 13, wherein the first outlet comprises a first outlet opening, the second inlet comprises a second inlet opening, and the first outlet opening and the second inlet opening are disposed on the same side of the housing.

15. The two-stage pump assembly of claim 14, wherein the first outlet opening and the second inlet opening are disposed on a plane parallel to a drive axis of the drive shaft.

16. The two-stage pump assembly of claim 14, wherein the second outlet includes a second outlet opening, and the second outlet opening is disposed on the same side of the housing as the first outlet opening and the second inlet opening.

17. The two-stage pump assembly of claim 16 wherein the second outlet opening is disposed on a plane parallel to the drive axis of the drive shaft.

18. The two-stage pump assembly of claim 16 wherein the second pump further comprises a third inlet, the third inlet comprising a third inlet opening, and the third inlet opening being located on another side of the housing that is transverse to the side of the housing containing the first outlet opening, the second inlet opening, and the second outlet opening.

19. The two-stage pump assembly of claim 18, wherein the third inlet opening is disposed in a plane perpendicular to the drive axis of the drive shaft.

20. The two-stage pump assembly of claim 18, wherein the first inlet opening and the third inlet opening are disposed on the same side of the housing.

21. A system comprising a transmission and the two-stage pump assembly of claim 1, wherein the second pump is configured to continuously pump lubricant to the transmission, and the transmission includes a clutch that selectively receives lubricant pumped from the first pump, the system further comprising a control valve for restricting lubricant output from the first pump to the clutch of the transmission.

22. A system comprising the two-stage pump assembly of claim 1 and a driver connected to the two-stage pump assembly, wherein the driver is configured to rotate a drive shaft of the two-stage pump assembly in order to pump lubricant to the driver.

23. A pump assembly, comprising:

a first pump for pumping air and a second pump for pumping lubricant to the system, both the first pump and the second pump integrated into a single housing;

a drive shaft disposed in the housing, the drive shaft configured to rotate about a drive axis and drive both the first and second pumps, the drive shaft driven by a single input device;

both the first and second pumps include a rotor constructed and arranged to be rotated by the drive shaft;

the first pump includes a first inlet disposed on the housing for receiving air from outside the housing and a first outlet for directing pressurized air out of the housing;

a second pump including a second inlet disposed on the housing for receiving lubricant from a source external to the housing and a second outlet for directing pressurized lubricant out of the housing, the second inlet and the second outlet being different from the first inlet and the first outlet, respectively;

the housing further includes a wall common to both the first pump and the second pump, the first pump being disposed on a first side of the wall, the second pump being disposed on a second side of the wall opposite the first side, the drive shaft extending through the wall and being connected to each of the rotors of both the first and second pumps.

24. The pump assembly of claim 23, wherein the wall includes a first recess on a first side thereof that receives a rotor of a first pump therein and a second recess on a second side thereof that receives a rotor of a second pump therein, and the drive shaft extends through the wall and is connected to each of the rotors received in the first and second recesses.

25. The pump assembly of claim 23, wherein the single input device for driving a drive shaft of the pump assembly is an engine, transmission, or electric motor.

26. The pump assembly of claim 23, wherein the first pump is an epicycloidal vacuum pump, the first side of the wall defining and being part of an interior space having an epicycloidal shape in which a rotor of the epicycloidal vacuum pump is rotatably received, the rotor being shaped to have a plurality of edges conjugate to the epicycloidal shape of the interior space and comprising an internally toothed guide gear; the drive shaft is configured to eccentrically rotate the rotor within the interior space; and the epicycloidal vacuum pump comprises an externally toothed guide sprocket for meshing with and guiding the movement of the guide gear of the rotor when the rotor is driven by the drive shaft.

27. The pump assembly of claim 26, wherein the second pump is a vane pump comprising a control slide having a rotor receiving space in communication with the first inlet and the first outlet, the rotor of the second pump being disposed in the rotor receiving space, the rotor of the second pump comprising a plurality of vanes movable within the rotor receiving space, and the rotor of the second pump being rotatable in the rotor receiving space to draw lubricant into the rotor receiving space via the second inlet under negative pressure and to expel pressurized lubricant from the rotor receiving space via the second outlet under positive pressure.

28. The pump assembly of claim 23, wherein the drive shaft is a single common drive shaft.

29. The pump assembly of claim 23, wherein the drive shaft comprises first and second drive shafts coaxially connected to each other for rotation together about the drive axis.

30. The pump assembly of claim 23, wherein the first inlet of the first pump comprises a first inlet opening for receiving air from outside the housing, and the first inlet opening is disposed on a plane perpendicular to the drive axis of the drive shaft.

31. The pump assembly of claim 30, wherein the rotor of the first pump is disposed on a first side of a plane parallel to the common wall and the first inlet opening is disposed on a second side of the plane parallel to the common wall.

32. The pump assembly of claim 30, wherein the first outlet comprises a first outlet opening, the second inlet comprises a second inlet opening, and the first outlet opening and the second inlet opening are disposed on the same side of the housing.

33. The pump assembly of claim 30, wherein the second outlet comprises a second outlet opening, and the second outlet opening is disposed on the same side of the housing as the first inlet opening.

34. The pump assembly of claim 33, wherein the second outlet opening is disposed on a plane parallel to the drive axis of the drive shaft.

Images