Bi-directional mechanical gerotor pump

Abstract

A bi-directional mechanical gerotor pump can have an inner rotor and an outer rotor disposed within a housing having an internal contour profile. The outer rotor can switch between a forward rotation profile in the internal contour profile and a reverse rotation profile in the internal contour profile. The pump can pump fluid in the same direction regardless of whether the pump is being rotated in a clockwise direction or a counterclockwise direction.

Description

BI-DIRECTIONAL MECHANICAL GEROTOR PUMPINCORPORATION BY REFERENCE TO ANY PRIORITY APPLICATIONS

[0001] Any and all applications for which a foreign or domestic priority claim is identified in the Application Data Sheet or PCT Request as filed with the present application are hereby incorporated by reference under 37 CFR 1.57, and Rules 4.18 and 20.6. The present application claims priority to U.S. Provisional Patent Application Nos. 63 / 567,109, filed March 19, 2024, the disclosures of which are incorporated herein by reference in their entirety and for all purposes.BACKGROUNDField

[0002] The present disclosure relates generally to pumps, particularly gerotor pumps in drive train environments for vehicles. Other possible applications include gerotor pumps in windmills, conveyor belt drive trains, and heat transfer systems.Description of the Related Art

[0003] Mechanical positive displacement gerotor pumps are used in various automotive applications such as thermal management and drive train environments to move fluid from one point to another as a simple and cost-effective solution. However, when coupled to the vehicle drive train, the design needs to function in all driving conditions to ensure optimal performance of the system.SUMMARY

[0004] For purposes of summarizing the disclosure and the advantages achieved over the prior art, certain objects and advantages of the disclosure are described herein. Not all such objects or advantages may be achieved in any particular embodiment. Thus, for example, those skilled in the art will recognize that the invention may be embodied or carried out in a manner that achieves or optimizes one advantage or group of advantages as taughtherein without necessarily achieving other objects or advantages as may be taught or suggested herein.

[0005] All of these embodiments are intended to be within the scope of the invention herein disclosed. These and other embodiments will become readily apparent to those skilled in the art from the following detailed description of the preferred embodiments having reference to the attached figures, the invention not being limited to any particular preferred embodiment(s) disclosed.

[0006] In some aspects, the techniques described herein relate to a mechanical gerotor pump including a housing having an internal contour profile. The internal profile can include a first contour curve, a second contour curve, and a transition curve. The pump can further include an outer rotor positioned in the internal contour profile and an inner rotor positioned in the outer rotor. The first contour curve tangentially connects to the transition curve, the second contour curve tangentially connects to the transition curve, and the first contour curve and the second contour curve connect transversally.

[0007] In some aspects, the techniques described herein relate to a pump, further including an inlet port and an outlet port disposed in the housing.

[0008] In some aspects, the techniques described herein relate to a pump, wherein the internal contour profile is symmetrical around a midline.

[0009] In some aspects, the techniques described herein relate to a pump, further including an inlet port and an outlet port disposed in the housing.

[0010] In some aspects, the techniques described herein relate to a pump, wherein the inlet port is symmetrical around the midline and the outlet port is symmetrical around the midline.

[0011] In some aspects, the techniques described herein relate to a bidirectional gerotor pump configured to rotate in a clockwise direction and in a counterclockwise direction. The gerotor pump includes a housing having an internal contour profile comprising a plurality of curves defined by a plurality of centers, an outer rotor positioned in the internal contour profile and configured to rotate about a first center of the plurality of centers in the clockwise direction and about a second center of the plurality of centers in the counterclockwise direction, and an inner rotor positioned in the outer rotor and configured to drive the outer rotor.

[0012] In some aspects, the techniques described herein relate to a pump, further including an inlet port and an outlet port disposed in the housing.

[0013] In some aspects, the techniques described herein relate to a pump, wherein the inlet port and the outlet port are symmetrically positioned around a midline of the pump.

[0014] In some aspects, the techniques described herein relate to a pump, wherein the inlet port and the outlet port are non-symmetrically positioned around a midline of the pump.

[0015] In some aspects, the techniques described herein relate to all embodiments described and discussed above.BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Embodiments of the present disclosure are described with reference to the accompanying drawings, in which like reference characters reference like elements, and wherein:

[0017] FIG. 1 is a flow chart illustrating a bi-directional mechanical gerotor pump and drive unit positioned within a hydraulic circuit.

[0018] FIG. 2A is a perspective view of a bi-directional mechanical gerotor pump according to an exemplary embodiment of the present disclosure.

[0019] FIG. 2B is an exploded view of the pump from FIG. 2A.

[0020] FIG. 3A is a perspective view of a bi-directional mechanical gerotor pump according to another exemplary embodiment of the present disclosure.

[0021] FIG. 3B is an exploded view of the pump from FIG. 3A.

[0022] FIG. 3C is a section view of the pump from FIG. 3 A illustrating a fluid flow path through the pump.

[0023] FIG. 4 is a section view of a bi-directional mechanical gerotor pump according to an exemplary embodiment of the present disclosure.

[0024] FIG. 5 is an illustration of an internal contour profile of a housing of a bidirectional mechanical gerotor pump.

[0025] FIG. 6A is a section view of a bi-directional mechanical gerotor pump according to an exemplary embodiment of the present disclosure from FIG. 1.

[0026] FIG. 6B is a section view of a bi-directional mechanical gerotor pump according to an exemplary embodiment of the present disclosure from FIG. 1.

[0027] FIG. 7 is an illustration of a transition from clockwise operation to counterclockwise operation of a mechanical gerotor pump.

[0028] FIG. 8A is an illustration of an unsymmetric inlet port and outlet port layout within a housing of a bi-directional mechanical gerotor pump.

[0029] FIG. 8B is an illustration of a symmetric inlet port and outlet port layout within a housing of a bi-directional mechanical gerotor pump.

[0030] FIG. 8C is an illustration of another unsymmetric inlet port and outlet port layout within a housing of a bi-directional mechanical gerotor pump.

[0031] FIG. 8D is another illustration of a symmetric inlet port and outlet port layout within a housing of a bi-directional mechanical gerotor pump.

[0032] FIG. 9A is chart of flow rate vs. pump speed for a bi-directional mechanical gerotor pump running forward as compared to a unidirectional mechanical gerotor pump and as compared to the bi-directional mechanical gerotor pump running backwards.

[0033] FIG. 9B is a chart of overall efficiency vs. pump speed for a bi-directional mechanical gerotor pump running forward as compared to a unidirectional mechanical gerotor pump and as compared to the bi-directional mechanical gerotor pump running backwards.DETAILED DESCRIPTION

[0034] The circulation of oil within the drive unit of an electric vehicle is critical for adequate oil cooling and lubrication of the traction motor and gearbox. Oil is often circulated with pumps which are packaged within the drive unit, creating a compact system. These pumps are often mechanically driven by the geartrain of the drive unit. Because the geartrain drives the pump, the flow direction of oil through the pump can be coupled to the direction the geartrain is turning. Decoupling the direction of oil flow from the geartrain drive direction is important for proper oil circulation through the system. It is vital to design a simple and compact pump which decouples the oil flow direction from the direction of the geartrain to decrease the cost and complexity of the drive unit system in a vehicle.

[0035] The disclosed devices, systems, and methods offer an improved system that assures that oil circulates in the same flow direction through the drive unit during both forwardand reverse operation of the vehicle, maintaining high reliability of the system by sufficiently lubricating the geartrain and traction motor in all conditions. This also prevents reverse flow of the fluid. Reverse flow can cause debris from the upstream filter to flow back into the sump or even pump internals. Eliminating reverse flow advantageously reduces the risk of gearbox failure and pump stalls. Further, in an architecture with multiple seals in the hydraulic circuit, it can be advantageous to decouple the pump flow direction from the geartrain direction as it can eliminate a risk of seal failure caused by vacuum pressures in reverse operation. Benefits also extend to consistent priming of the pump by preventing evacuation of the oil from the pressurized circuit and pump internals in the reverse operation. The pump structure advantageously enables a lower part count and a lower bill-of-materials cost by eliminating multiple valves, seals, or additional parts that conventional pump or system designs utilize.

[0036] Described herein are examples of a bi-directional mechanical gerotor pump, and systems and methods of using a bi-directional mechanical gerotor pump. The mechanical gerotor pump can advantageously transition automatically between two positions to maintain the same pump flow direction when driven clockwise or counterclockwise.

[0037] FIG. 1 is a flow chart illustrating a bi-directional mechanical gerotor pump 10 positioned within a hydraulic circuit 60. As illustrated, oil is pulled from the sump 50 into the pump 10. The oil is pumped through the pump 10 and flows through a filter 20. Next, the oil passes through a heat exchanger 30 and into the drive unit 40, which can include the motor, gearbox, and other drive unit components. The oil then returns to the sump 50. This oil circulation is driven primarily by the pump 10, and the pump 10 can be driven by the motor or gearbox in the drive unit 40. Although the embodiments described herein are in the context of an oil-based system, other fluids or lubricants may be used (e.g., coolant in heat transfer applications).

[0038] FIG. 2A is a perspective view of an exemplary embodiment of a bidirectional mechanical gerotor pump 100 which includes a housing 110, a housing cover 112, an inlet 150, an outlet 160, and a drive shaft 170.

[0039] FIG. 2B is an exploded view of the bi-directional mechanical gerotor pump 100 illustrated in FIG. 2A. As shown in FIG. 2B, the housing 110 can have an internal contour profile 120. An inner rotor 140 and an outer rotor 130 can be housed or disposed within the housing 110. The inner rotor 140 can be attached to the drive shaft 170 and the outer rotor 130can be positioned around the inner rotor 140. The cover 112 can be positioned over the internal contour profile 120 of the housing 110.

[0040] FIG. 3 A is a perspective view of another exemplary embodiment of a bidirectional mechanical gerotor pump 200 which includes a housing 210 and a pump gear 272. The housing 210 includes an inlet housing 214 and an outlet housing 216.

[0041] FIG. 3B is an exploded view of the bi-directional mechanical gerotor pump 200 illustrated in FIG. 3 A. As shown in FIG. 3B, the inlet housing 214 has an inlet 250 which can be covered by a fluid permeable screen 254. The inlet housing 214 has an internal contour profile 220. An inner rotor 240 and an outer rotor 230 are housed or disposed within the inlet housing 214. The inner rotor 240 is attached to the drive shaft 270 which can be driven by the pump gear 272. The pump gear 272 is keyed to the drive shaft 270 and affixed with a clip 274. The pump gear 272 drives the gerotor pump 200. The outer rotor 230 is positioned around the inner rotor 240. The outlet housing 216 is positioned over the internal contour profile 220 of the housing 210 to hold the inner rotor 240 and outer rotor 230 in place. An outlet 260 is formed in the outlet housing 216.

[0042] FIG. 3C is a section view of the pump 200 illustrated in FIG. 3 A illustrating the flow path through the pump 200. As illustrated, fluid flows from the sump 50 through the screen 254 and into the inlet 250. The fluid is pulled through an inlet port 252 by the inner rotor 240 and the outer rotor 230. The fluid is pushed out the pump outlet port 262 by the inner rotor 240 and the outer rotor 230. Next, the fluid is pushed out of the outlet 260 and flows into the filter 20.

[0043] FIG. 4 is a section view of a bi-directional mechanical gerotor pump 300. The operation of bi-directional mechanical gerotor pump 300 is exemplary and the structure and functionality of the pump 300 can be applied to each bi-directional mechanical gerotor pump described herein. As shown in FIG. 4, the bi-directional mechanical gerotor pump has an inlet port 352 and an outlet port 362. The inlet port 352 can allow fluid to flow into the housing 310 and the outlet port 362 allows fluid to flow out of the housing 310. As shown, an inner rotor 340 can be driven by the drive shaft 370. The inner rotor 340 can have one less tooth than an outer rotor 330. The inner rotor 340 can eccentrically drive the outer rotor 330 so that both the inner rotor 340 and the outer rotor 330 rotate in the same direction. The outer rotor 330 is positioned against the contour profile 320 of the housing 310.

[0044] In this example, the drive shaft 370 is rotating in a clockwise direction 382. However, the drive shaft 370 could alternatively rotate in a counterclockwise direction. During operation, the eccentricity of the movement of the inner rotor 340 and outer rotor 330 cause gaps 342 to open between the outer rotor 330 and a trailing edge 344 of the inner rotor 340 over the inlet port 352 which creates a vacuum and pulls the fluid into the gaps 342. The eccentric movement of the inner rotor 340 and outer rotor 330 also causes gaps 342 to close between the outer rotor 330 and a leading edge 346 of the inner rotor 340 which creates fluid pressure and pushes the fluid out of the gaps 342 and out of the outlet port 362. This concept can be referred to as gerotor meshing. The gerotor meshing pulls fluid from the inlet port 352 towards the outlet port 362 and pushes fluid towards and out of the outlet port 362. This concept can be referred to as gerotor fluid transfer.

[0045] FIG. 5 is an illustration of the shape of the contour profile 120. The contour profile 120 is an exemplary contour profile that can be applied to any embodiment of the bidirectional gerotor pump described herein. In certain embodiments, the contour profile 120 can consist of three contour curves: a forward contour curve 124, a reverse contour curve 126, and a transition contour curve 128. The forward contour curve 124 can have a circular shape and a curve length ‘AB’. The forward contour curve 124 can locate the outer rotor 130 of the pump 100 for a clockwise rotation. X is the center of the forward contour curve 124. ‘XY’ is the eccentricity distance between outer rotor 130 and inner rotor 140. The reverse contour curve 126 can have a circular shape and a curve length ‘AC’. The reverse contour curve 126 can locate the outer rotor 130 of the pump 100 for counterclockwise rotation. Z is the center of the reverse contour curve 126. ‘YZ’ is the eccentricity distance between the outer rotor 130 and the inner rotor 140. The transition contour curve 128 can have a circular shape and a curve length ‘BC’. The transition contour curve 128 can provide a clearance path for the outer rotor 130 to transition from the forward contour curve 124 to the reverse contour curve 126 and vice versa. Y is the center of the transition contour curve 128. The transition contour curve 128 is tangentially connected on one end to the forward contour curve 124 and the transition contour curve 128 is tangentially connected on a second end to the reverse contour curve 126. The forward contour curve 124 connects transversally to the reverse contour curve 126 creating a notch 122 in the contour profile 120 where the forward contour curve 124 connects to the reverse contour curve 126. The notch 122 can retain the outer rotor 130 in the forward contourcurve 124 during clockwise rotation. The notch 122 can retain the outer rotor 130 in the reverse contour curve 126 during counterclockwise rotation. This contour profile can also be flipped and forward and reverse direction can be defined based on the position of the pump with respect to the gear train (e.g., the forward direction may correspond to counterclockwise rotation and the reverse direction may correspond to clockwise rotation).

[0046] The forward contour curve 124 can be symmetric with the reverse contour curve 126. The curve radius of each of the forward contour curve 124 and the reverse contour curve 126 can be equal to the radius of the outer rotor 130. The curve radius of each the forward contour curve 124 and the reverse contour curve 126 can be equal to the radius of the outer rotor 130 plus additional radial clearance to advantageously improve smooth operation and reduce the mechanical losses in the pump. In some examples, the radius of the outer rotor 130 and the radius of the forward contour curve 124 can be substantially the same. The radius of the outer rotor 130 and the rearward contour curve 126 can be substantially the same.

[0047] The transition contour curve 128 can have a non-circular curve shape or can be non-tangential to the forward contour curve 124 and the reverse contour curve 126. The contour profile 120 may include disruptions (e.g., notches or divots) between the transition contour curve 128 and the forward contour curve 124 and the transition contour curve 128 and the reverse contour curve 126. Each of these features may advantageously improve efficiency or debris collection while allowing the outer rotor 130 to freely transition from the forward contour curve 124 to the reverse contour curve 126 and vice versa.

[0048] FIG. 6A is a section view of a bi-directional mechanical gerotor pump 100 according to an exemplary embodiment of the present disclosure from FIG. 1. As shown, FIG. 6A depicts the operation of the pump 100 in a clockwise direction 182. In the clockwise direction 182, the outer rotor 130 is positioned in the forward contour curve 124 and the center of the outer rotor 130 is located at X. At this position, the eccentricity of the movement of the inner rotor 140 and the outer rotor 130 cause gaps 142 to open between the outer rotor 130 and a trailing edge 144 of the inner rotor 140 on the same side as the forward contour curve 124 near the inlet port 152. The eccentric movement of the inner rotor 140 and outer rotor 130 also causes gaps 142 to close between the outer rotor 130 and a leading edge 146 of the inner rotor 140 proximate to the outlet port 162. This gerotor transfer causes fluid to flow in direction 180 from the inlet 150 towards the outlet 160. When the outer rotor 130 is positioned in the forwardcontour curve 124, there is clearance between the reverse contour curve 126 and the outer rotor 130.

[0049] FIG. 6B is a section view of a bi-directional mechanical gerotor pump 100 according to an exemplary embodiment of the present disclosure from FIG. 2A. As shown, FIG. 6B depicts the operation of the pump 100 in a counterclockwise direction 184. In the counterclockwise direction 184, the outer rotor 130 is positioned in the reverse contour curve 126 and the center of outer rotor 130 is located at Z. At this position, the eccentricity of the movement of the inner rotor 140 and outer rotor 130 cause gaps 142 to open between the outer rotor 130 and a trailing edge 144 of the inner rotor 140 on the same side as the reverse contour curve 126 and near the inlet port 152. The eccentric movement of the inner rotor 140 and outer rotor 130 also causes gaps 142 to close between the outer rotor 130 and a leading edge 146 of the inner rotor 140 proximate to the outlet port 162. This gerotor transfer causes fluid to flow in flow direction 180 from the inlet 150 towards the outlet 160. When the outer rotor 130 is positioned in the reverse contour curve 126, there is clearance between the forward contour curve 124 and the outer rotor 130.

[0050] As illustrated, the notch 122 is oriented at the top of the profile 120. The notch 122 can be rotated to any other position around the profile 120. Gravity can impact where debris collects in the profile 120, such as where there is clearance between the profile 120 and the outer rotor 130. The orientation of the notch 122 can be adjusted to bias debris to collect where the debris will not impact forward operation of the pump 100. Depending on the pump application, it may be advantageous to adjust the notch 122 orientation for debris to collect in other locations.

[0051] FIG. 7 is an illustration of a transition from clockwise operation to counterclockwise operation of a mechanical gerotor pump 400. Starting in box 1, the pump 400 is operating with the drive shaft 470 rotating in a clockwise direction 482 and the outer rotor 430 is positioned in the forward contour curve 424. In boxes 2-4, the drive shaft 470 starts to rotate in the counterclockwise direction 484 and the outer rotor 430 rotates through the transition contour curve 428 around the inner rotor 440. In box 5, the outer rotor 430 is positioned in the reverse contour curve 426.

[0052] When the pump starts to rotate in the clockwise direction 482 again, it follows the transition contour curve 428 and returns to the forward contour curve 424 position.This way the pump 400 provides flow in direction 480 from the inlet 450 to the outlet 460 irrespective of the direction of rotation of gerotor. This beneficially assures that oil traverses the fluid circuit 60 as described in FIG. 1 regardless of whether drive unit is operating in forward or reverse. This can advantageously limit the amount of debris captured by the filter which can reenter the fluid circuit 60.

[0053] Electric vehicle drive systems can spend the vast majority of their operating time in forward operation. Therefore, it can be advantageous to optimize the arrangement of a bi-directional mechanical gerotor pump to maximize the efficiency of the pump for clockwise driveshaft rotation for this system. One way to improve the efficiency of the pump for clockwise driveshaft rotation is to bias the inlet and outlet ports to one side. The unsymmetric port designs as shown in FIGS. 8A and 8C can improve pump volumetric efficiency for pump flow when operating in a forward direction. In other embodiments, it can be advantageous to optimize efficiency for both clockwise and counterclockwise operation. The symmetric port design as shown in FIGS. 8B and 8D can help achieve the same volumetric efficiency for both forward and reverse operation.

[0054] FIGS. 8A-8D illustrate exemplary embodiments of inlet and outlet port layouts. Each layout described can be applied to any of the bi-directional gerotor pumps described herein.

[0055] FIG. 8A is an illustration of an unsymmetric inlet port and outlet port layout within a housing of a bi-directional mechanical gerotor pump 500 A. As shown, the inlet port 552A and outlet port 562A are wider and closer together proximal to the forward contour curve 524 and narrower and further apart proximal to the reverse contour curve 526. The pump housing 510A with unsymmetric port design shown improves volumetric efficiency in the clockwise direction of rotation by reducing internal leakage.

[0056] FIG. 8B is an illustration of a symmetric inlet port and outlet port layout within a housing of a bi-directional mechanical gerotor pump. As shown, the inlet port 552B and outlet port 562B are equally spaced between the forward contour curve 524 and the reverse contour curve 526. The pump housing 510A with a symmetric port design helps achieve the same volumetric efficiency in both clockwise and counterclockwise rotation.

[0057] FIG. 8C is an illustration of another exemplary embodiment of an unsymmetric inlet port and outlet port layout within a housing of a bi-directional mechanicalgerotor pump. There is an angle E defined by a horizontal axis BC and the end of the outlet port 562C on the same side as the forward contour curve 524. There is an angle F defined by the horizontal axis BC and the end of the outlet port 562C on the same side as the reverse contour curve 526. There is an angle G defined by the horizontal axis BC and the end of the inlet port 552C on the same side as the reverse contour curve 526. There is an angle H defined by the horizontal axis BC and the end of the inlet port 552C on the same side as the forward contour curve 524. As shown, the inlet port 552C and outlet port 562C are wider on the same side as the forward contour curve 524 and narrow towards the reverse contour curve 526. Angle E can be 18 degrees, angle F can be 20 degrees, angle G can be 20 degrees, and angle H can be 18 degrees. These angles and profile can be optimized based on the application and size of the gerotor to increase the volumetric efficiency and maximize the output flow rate.

[0058] FIG. 8D is an illustration of another exemplary embodiment of a symmetric inlet port and outlet port layout within a housing of a bi-directional mechanical gerotor pump. There is an angle J defined by a horizontal axis BC and the end of the outlet port 562D on the same side as the forward contour curve 524. There is an angle K defined by the horizontal axis BC and the end of the outlet port 562D on the same side as the reverse contour curve 526. There is an angle L defined by the horizontal axis BC and the end of the inlet port 552D on the same side as the reverse contour curve 526. There is an angle M defined by the horizontal axis BC and the end of the inlet port 552D on the same side as the forward contour curve 524. As shown, the inlet port 552D and outlet port 562D are the same width on the forward contour curve 524 side and the reverse contour curve 526 side. In certain embodiments, the angle J can be 18 degrees, the angle K can be 18 degrees, the angle L can be 18 degrees, and the angle M can be 18 degrees. These angles and profile can be optimized based on the application and size of the gerotor to increase the volumetric efficiency and maximize the output flow rate.

[0059] In other embodiments angle E can be 10 degrees, angle F can be 30 degrees, angle G can be 30 degrees, and angle H can be 10 degrees. In other embodiments, angle E can be 30 degrees, angle F can be 30 degrees, angle G can be 30 degrees, and angle H can be 30 degrees. Different angles can be applied to improve the volumetric efficiency of the pump for different use cases.

[0060] In other embodiments angle J can be 30 degrees, angle K can be 30 degrees, angle L can be 30 degrees, and angle M can be 30 degrees. Different angle can be applied to improve the volumetric efficiency of the pump for different use cases.

[0061] In some embodiments the axis BC is oriented horizontally relative to a ground plane. In other embodiments, the axis BC is oriented relative to the notch 522 orientation. Axis BC can be perpendicular to an axis passing through the notch 522 and the midpoint Y.

[0062] FIGS. 9A-9B are charts depicting the results of Proof of Concept testing results for the bi-directional mechanical gerotor pump. FIG. 9A is chart of pump speed vs. flow rate for a tested bi-directional mechanical gerotor pump running forward as compared to a tested unidirectional mechanical gerotor pump and as compared to the bi-directional mechanical gerotor pump running in reverse. FIG. 9B is a chart of pump speed vs. overall efficiency for a tested bi-directional mechanical gerotor pump running forward as compared to a tested unidirectional mechanical gerotor pump and as compared to the bi-directional mechanical gerotor pump running in reverse.

[0063] The testing results show that bi-directional mechanical gerotor pump system operates successfully across vehicle operating in all speeds, temperatures and pressure ranges. The results highlight that bidirectional pump in forward direction (unsymmetric port design) can provide comparable performance to conventional unidirectional pump systems when tuned appropriately. Based on the application, fluid type, and operating temperature conditions, mechanical and volumetric efficiency can be tuned to provide the maximum overall efficiency.

[0064] Port geometry, eccentric shift, and radial and axial clearances can be optimized to get the desired performance and high efficiency from the system including debris accumulation risk mitigation.

[0065] For explanatory purposes, the term “forward operation” or “forward running” as described herein with respect to gerotor pumps is defined as the main operational state of the pump. The term “reverse operation” or “reverse running” as described herein is defined as the secondary operational state of the pump.

[0066] While the embodiments and examples described herein describe the drive shaft rotating in a clockwise direction for the forward operation of the pump and the drive shaftrotating in a counterclockwise direction for the reverse operation of the pump, those skilled in the art will understand that the drive shaft may rotate in a counterclockwise direction for the forward operation and the drive shaft may rotate in a clockwise direction for the reverse operation.

[0067] In the foregoing specification, the disclosure has been described with reference to specific embodiments. However, as one skilled in the art will appreciate, various embodiments disclosed herein can be modified or otherwise implemented in various other ways without departing from the spirit and scope of the disclosure. Accordingly, this description is to be considered as illustrative and is for the purpose of teaching those skilled in the art the manner of making and using various embodiments of the disclosed gerotor pump. It is to be understood that the forms of disclosure herein shown and described are to be taken as representative embodiments. Equivalent elements, materials, processes or steps may be substituted for those representatively illustrated and described herein. Moreover, certain features of the disclosure may be utilized independently of the use of other features, all as would be apparent to one skilled in the art after having the benefit of this description of the disclosure. Expressions such as "including", "comprising", "incorporating", "consisting of', "have", "is" used to describe and claim the present disclosure are intended to be construed in a non-exclusive manner, namely allowing for items, components or elements not explicitly described also to be present. Reference to the singular is also to be construed to relate to the plural.

[0068] For expository purposes, the term “horizontal” as used herein is defined as a plane parallel to the plane or surface of the floor of the area in which the device being described is used or the method being described is performed, regardless of its orientation. The term “floor” can be interchanged with the term “ground.” The term “vertical” refers to a direction perpendicular to the horizontal as just defined. Terms such as “above,” “below,” “bottom,” “top,” “side,” “front,” “rear,” “lateral,” “higher,” “lower,” “upper,” “over,” and “under,” are defined with respect to the horizontal plane, in use.

[0069] Conditional language used herein, such as, among others, “can,” “might,” “may,” “e.g.,” and the like, unless specifically stated otherwise, or otherwise understood within the context as used, is generally intended to convey that some embodiments include, while other embodiments do not include, certain features, elements, and / or states. Thus, suchconditional language is not generally intended to imply that features, elements, blocks, and / or states are in any way required for one or more embodiments or that one or more embodiments necessarily include logic for deciding, with or without author input or prompting, whether these features, elements and / or states are included or are to be performed in any particular embodiment.

[0070] Further, various embodiments disclosed herein are to be taken in the illustrative and explanatory sense and should in no way be construed as limiting of the present disclosure. All joinder references (e.g., attached, affixed, coupled, connected, and the like) are only used to aid the reader's understanding of the present disclosure, and may not create limitations, particularly as to the position, orientation, or use of the systems and / or methods disclosed herein. Therefore, joinder references, if any, are to be construed broadly. Moreover, such joinder references do not necessarily infer that two elements are directly connected to each other. Additionally, all numerical terms, such as, but not limited to, "first", "second", "third", "primary", "secondary", "main" or any other ordinary and / or numerical terms, should also be taken only as identifiers, to assist the reader's understanding of the various elements, embodiments, variations and / or modifications of the present disclosure, and may not create any limitations, particularly as to the order, or preference, of any element, embodiment, variation and / or modification relative to, or over, another element, embodiment, variation and / or modification.

[0071] It will also be appreciated that one or more of the elements depicted in the drawings / figures can also be implemented in a more separated or integrated manner, or even removed or rendered as inoperable in certain cases, as is useful in accordance with a particular application.

Claims

WHAT IS CLAIMED IS:

1. A mechanical gerotor pump comprising: a housing having an internal contour profile comprising: a first contour curve; a second contour curve; and a transition curve; an outer rotor positioned interior to the internal contour profile; and an inner rotor positioned interior to the outer rotor, wherein the first contour curve tangentially connects to the transition curve, the second contour curve tangentially connects to the transition curve, and the first contour curve and the second contour curve connect transversally.

2. The pump of Claim 1, further comprising an inlet port and an outlet port disposed in the housing.

3. The pump of Claim 1 , wherein the internal contour profile further comprises a notch positioned between the first contour curve and the second contour curve.

4. The pump of Claim 1, wherein the internal contour profile is symmetrical around a midline.

5. The pump of Claim 4, further comprising an inlet port and an outlet port disposed in the housing.

6. The pump of Claim 5, wherein the inlet port is symmetrical around the midline and the outlet port is symmetrical around the midline.

7. The pump of Claim 5, wherein the inlet port is asymmetrical around the midline and the outlet port is asymmetrical around the midline.

8. The pump of Claim 4, further comprising a drive shaft connected to the inner rotor.

9. The pump of Claim 1, wherein the radius of the outer rotor and the radius of the first contour curve and the second contour curve are substantially the same.

10. The pump of Claim 6, wherein the outer rotor is configured to transition between the first contour curve and the second contour curve.

11. The pump of Claim 8, wherein the outer rotor is configured to be positioned in the first contour curve when the drive shaft rotates in a first direction and the outer rotor isconfigured to be positioned in the second contour curve when the drive shaft rotates in a second direction.

12. The pump of Claim 11, wherein the outer rotor is configured to transition between the first contour curve and the second contour curve.

13. The pump of Claim 12, wherein the outer rotor is configured to transition between the first contour curve and the second contour curve in less than one rotation of the inner rotor.

14. A bidirectional gerotor pump configured to rotate in a clockwise direction and in a counterclockwise direction, the gerotor pump comprising: a housing having an internal contour profile comprising a plurality of curves defined by a plurality of centers; an outer rotor positioned in the internal contour profile and configured to rotate about a first center of the plurality of centers in the clockwise direction and about a second center of the plurality of centers in the counterclockwise direction; and an inner rotor positioned in the outer rotor and configured to drive the outer rotor.

15. The pump of Claim 14, further comprising an inlet port and an outlet port disposed in the housing.

16. The pump of Claim 15, further comprising a drive shaft connected to the inner rotor.

17. The pump of Claim 16, wherein the gerotor pump is configured to pump a fluid receive from the inlet port out of the outlet port when the drive shaft rotates in a clockwise direction and a counterclockwise direction.

18. The pump of Claim 17, wherein the outer rotor is configured to transition from rotating about the first center to rotating about the second center when the outer rotor transitions from being rotated clockwise to being rotated counterclockwise.

19. The pump of Claim 15, wherein the inlet port and the outlet port are symmetrically positioned around a midline of the pump.

20. The pump of Claim 15, wherein the inlet port and the outlet port are non- symmetrically positioned around a midline of the pump.

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