Patent Publication Number: US-11035360-B2

Title: Gerotor with spindle

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This patent application claims priority to provisional patent application 62/630,523 filed on Feb. 14, 2018, whose subject matter is hereby incorporated by reference herein in its entirety. 
    
    
     BACKGROUND 
     Field 
     This disclosure relates generally to a gerotor pump. More particularly, the present disclosure relates to a gerotor pump having a spindle coupled to a gear arrangement of the gerotor. 
     Description of the Related Art 
     A gerotor pump may be used as a positive displacement pump. Typically, a gerotor includes an inner gear (or rotor) that meshes with an outer gear (rotor). The outer gear has greater number of teeth than the inner gear. The axis of the inner gear is offset from the axis of the outer gear and both gears rotate on their respective axes. The offset creates a changing-volume space between them. During a rotation cycle, fluid may enter a suction side of the gerotor, get pressurized due to the changing-volume space and the pressurized fluid is discharged at a discharge port of the gerotor. Such gerotors can experience several mechanical and frictional losses, and may be bulky. 
     SUMMARY 
     An aspect of this disclosure provides a gerotor pump that includes an inner gear mounted on a first axis for rotation, an outer gear relative to a second axis and meshing internally with the inner gear in an offset manner, a drive shaft coupled to the internal gear to drive the internal gear about the first axis in order to pressurize the received fluid for output as the pressurized fluid, and an electrical motor including a rotor and a stator having a radial gap therebetween in a radial direction. The rotor is disposed on an outer surface of the outer gear. The gerotor pump also includes a spindle that is fixedly coupled to the outer gear to facilitate maintaining the radial gap between the rotor and the stator in the radial direction. The spindle is also configured for rotation about the second axis. 
     Another aspect of this disclosure includes a system having the above-noted gerotor pump along with an engine or transmission. 
     Other aspects and features of the disclosure will become apparent from the following detailed description, the accompanying drawings, and the appended claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate one or more embodiments and, together with the description, explain these embodiments. The accompanying drawings have not necessarily been drawn to scale. Any values dimensions illustrated in the accompanying graphs and figures are for illustration purposes only and may or may not represent actual or preferred values or dimensions. Where applicable, some or all features may not be illustrated to assist in the description of underlying features. In the drawings: 
         FIG. 1A  is a first perspective view of a gerotor pump in accordance with an embodiment of this disclosure; 
         FIG. 1B  is a second perspective view of the gerotor pump in accordance with an embodiment of this disclosure; 
         FIG. 2  is an exploded view of the gerotor pump in accordance with an embodiment of this disclosure; 
         FIG. 3A  is another exploded view of the gerotor pump illustrating components of the gerotor pump in a first orientation in accordance with an embodiment of this disclosure; 
         FIG. 3B  is another exploded view of the gerotor pump illustrating the components of the gerotor pump in a second orientation in accordance with an embodiment of this disclosure; 
         FIG. 4  is another exploded view of the gerotor pump illustrating a subset of components of the gerotor pump in accordance with an embodiment of this disclosure; 
         FIG. 5  is another exploded view of the gerotor pump illustrating another subset of components of the gerotor pump in accordance with an embodiment of this disclosure; 
         FIG. 6  is a bottom perspective view of a sub-assembly of gerotor pump components including an intermediate cover or separator in accordance with an embodiment of this disclosure; 
         FIG. 7  is a side perspective view of another sub-assembly of gerotor pump components including a spindle in accordance with an embodiment of this disclosure; 
         FIG. 8A  is a first cross-section view of the gerotor pump in accordance with an embodiment of this disclosure; 
         FIG. 8B  is a second cross-section view of the gerotor pump in accordance with an embodiment of this disclosure; and 
         FIG. 9  is a third cross-section view of the gerotor pump with a sub-set of components of the gerotor pump in accordance with an embodiment of this disclosure; 
     
    
    
     DETAILED DESCRIPTION 
     The description set forth below in connection with the appended drawings is intended as a description of various embodiments of the disclosed subject matter and is not necessarily intended to represent the only embodiment(s). In certain instances, the description includes specific details for the purpose of providing an understanding of the disclosed embodiment(s). However, it will be apparent to those skilled in the art that the disclosed embodiment(s) may be practiced without those specific details. In some instances, well-known structures and components may be shown in block diagram form in order to avoid obscuring the concepts of the disclosed subject matter. 
     Reference throughout the specification to “one embodiment” or “an embodiment” means that a particular feature, structure, or characteristic described in connection with an embodiment is included in at least one embodiment of the subject matter disclosed. Thus, the appearance of the phrases “in one embodiment” or “in an embodiment” in various places throughout the specification is not necessarily referring to the same embodiment. Further, the particular features, structures or characteristics may be combined in any suitable manner in one or more embodiments. Further, it is intended that embodiments of the disclosed subject matter cover modifications and variations thereof. 
     It is to be understood that terms such as “top,” “bottom,” “side,” “height,” “upper,” “lower,” “interior,” “exterior,” “inner,” “outer,” and the like that may be used herein merely describe points of reference and do not necessarily limit embodiments of the present disclosure to any particular orientation or configuration. Furthermore, terms such as “first,” “second,” “third,” etc., merely identify one of a number of portions, components, steps, operations, functions, and/or points of reference as disclosed herein, and likewise do not necessarily limit embodiments of the present disclosure to any particular configuration or orientation, or any requirement that each number must be included. 
     Also, the terms “fluid” and “lubricant” are used interchangeably throughout this disclosure and not intended to limit this disclosure in any way. In some embodiments, fluid or lubricant may refer to oil, e.g., such as engine oil. In other embodiments, fluid or lubricant may refer to transmission fluid. 
       FIGS. 1A and 1B  illustrate different perspective views of a gerotor pump  10  in accordance with an embodiment. The gerotor pump  10  includes a top cover  100  mounted to a bottom casing  600  to form a housing assembly  150  (also referred as a housing  150  or a gerotor housing  150  herein). The gerotor pump  10  also includes a set  400  of gerotor gears (e.g., an inner gear  401  and an outer gear  402  shown in  FIG. 3A ) enclosed in the housing  150 . The bottom casing  600  includes an input (or entry) port  601  through which fluid (e.g., oil or lubricant) may enter from a source and into the housing assembly  150 , and a discharge or outlet port  603  through which pressurized fluid may exit for delivery to a system. In operation, the gerotor gears  400  create suction at an input port  601  causing a fluid to enter the housing assembly  150 , and the gerotor gears compress or pressurize the fluid as they rotate, and discharge or output the pressurized fluid through the discharge or outlet port  603 . The pump outlet port  603  is used for discharging or delivering the pressurized fluid or lubricant to a system such as a transmission or engine, for example. 
     In an embodiment, the gerotor pump  10  may be electrically driven or mechanically driven. For example, the electrically driven gerotor pump may include a set of electric coils configured to rotate one of the gerotor gears (e.g., the outer gear  402 ). The electrical power supply may be provided through electrical wires passed through a spout  101  of the top cover  100 . Hereinafter, the discussion includes electrical drive to illustrate the concepts and working of the gerotor pump  10  and does not limit the scope of the present disclosure. The gerotor pump  10  may be modified to include mechanical drive as can be understood by a person skilled in the art. For example, in case of mechanically driven gerotor, an input shaft (not shown) may be coupled to one of the gerotor gear (e.g., the inner gear  401 ) through the bottom casing  600  of the housing to drive the gerotor pump  10 . 
       FIG. 2  is an exploded view of the gerotor pump  10  illustrating a controller having an electric circuit board  200  that may be part of the electrically driven gerotor pump  10 . The electric circuit board  200  may receive power or other communication/control signals through the electric wires passed through the spout  101 . The electric circuit board may include several electrical components such as resistors, capacitors (e.g.,  201 ,  202 ,  204 ), power circuit  203 , and/or other electrical components configured to control, for example, current and voltage, to operate the gerotor pump  10 . In an embodiment, the electrical circuit board  200  may be configured to control current or voltage through electric coils (discussed below) that create magnetic field which may be used to drive a gear (e.g. the outer gear  402 ) of the gerotor. The electric circuit board  200  may be referred to herein as printed circuit board (PCB), or a controller, as may be understood by a person skilled in the art. The PCB  200  or controller may be provided in the form of a bus bar, in accordance with an embodiment. 
       FIGS. 3A and 3B  are different exploded views of the gerotor pump  10  illustrating components of the gerotor pump in a first orientation and a second orientation, respectively. The gerotor pump  10  includes the top cover  100 , the PCB  200 , an intermediate cover or separator  300 , the set of gerotor gears  400  (including an inner gear  401  and an outer gear  402 ), a spindle  405 , a bearing  407 , a pin  410 , a motor stator  500 , and the bottom casing  600 . Alternatively or in addition, a pressure plate  610  included, for example, in the bottom casing  600  of the housing  150  to compensate for axial tolerances of the gerotor pump unit. The components of the gerotor pump  10  may be coupled together to form a compact assembly within the housing. 
     In an embodiment, the intermediate separator  300  may support the PCB/controller  200  on a first side (i.e., between the top cover  100  and a top side of the separator  300 ; see, e.g.,  FIG. 8A ) and may cover and enclose the gerotor gears  400  ( 401  and  402 ) and the motor stator  500  under the second side (i.e., between the bottom casing  600  and a bottom side of the separator  300 ; e.g., such as shown in  FIG. 8A ). In an embodiment, the separator  300  may be configured such that the first side does not include any fluid and the second side includes fluid, and thus the separator  300  serves as a wall preventing fluid to flow from the second side to the first side. That is, the side with the PCB/controller  200  is dry and devoid of fluid, and the side with the pump elements contains fluid. Hence, the separator  300  may have a dual functionality of supporting the components on either side, and also serving as a fluid obstruction or a partition. 
     On the first side (e.g., top side) of the separator  300 , the PCB  200  may be supported or coupled to the separator  300  in a removable manner, according to an embodiment. Referring to  FIGS. 3B and 8A , the separator  300  includes an annular pocket  302 , a flange  305 , and a bearing support  307  on its first side. The bearing support  307  may be a hollow shaft-like portion located at a center of the separator  300 . When viewed from a top side of the separator  300 , the shaft-like portion projects upwards towards the first side (i.e., towards the top cover  100 ) along the axial direction, and when viewed from a bottom side of the separator  300  (see  FIGS. 8A and 9 ), the hollow portion may be formed and accessible from a bottom side. The hollow portion of the bearing support  307  may be configured to support or receive a bearing  407  (further discussed below with respect to the second side of the separator  300 ). 
     Around the shaft-like portion, the annular pocket  302  may be formed to accommodate the PCB  200  and its components (e.g., the electrical components  201 , 202 ,  203 ,  204 , etc.), thus forming a compact sub-assembly on the first side of the separator  300 . Furthermore, upon assembly of the gerotor pump  10  and during its operation, the separator  300  prevents the PCB  200  from contacting the fluid on its opposite side where the pump elements are located. Preferably, electrical components include capacitors, resistors, and other heat generating elements that are in direct contact with the separator  300 , and the separator  300  is made of thermally conductive material. This enables the heat to be transferred to the fluid on the other side via conduction (i.e., it is transferred through the wall of the separator  300 ), thus effectively cooling the controller  200  and its components. 
     The flange  305  may be formed around the perimeter of the intermediate separator  300  and may be used to connect to the top cover  100  on one side and the bottom casing  600  on the second side. The shape of the flange  305  may correspond to a shape, for example, at the perimeter, of the top cover  100  and the bottom casing  600  to form a seamless assembly of the gerotor pump  10 . In the exemplary illustrated embodiment, with the exception of protrusions that are provided in each of the top cover  100 , separator  300 , and bottom casing  600 , the edges of the top cover  100 , separator  300 , and bottom casing  600  may be substantially rounded and/or substantially circular (between the protrusions). While this configuration is not intended to be limiting, it should be understood that the shapes of the perimeters/outer surfaces of the flange  305 /separator  300 , top cover  100 , and bottom casing  600  may correspond to each other, such that these parts may be aligned and joined to form the housing  150 . Furthermore, in an embodiment, the protrusions are provided in each of the top cover  100 , separator  300 , and bottom casing  600  such that these parts may be aligned for securement together. In one embodiment, the protrusions provided in each of these parts include receiving openings that are designed to be aligned (see, e.g.,  FIGS. 1B and 8A ) with each other such that the top cover  100 , separator  300 , and bottom casing  600  may be stacked together and the aligned receiving openings may receive fasteners (e.g., bolts) (not shown) therein, in order to secure these housing parts of the pump together to form the housing assembly  150 . 
     On the second side (e.g., bottom side) of the separator  300  may be the hollow shaft-like portion which may be provided to accommodate the bearing  407 , such as shown in  FIG. 8A . In an embodiment, the bearing  407  may be a ball bearing, a journal bearing or other type of bearing(s). According to the bearing type, the hollow portion of the bearing support  307  may be configured to axially fit the bearing  407 . The bearing  407  may be positioned between the spindle  405  and the separator  300  (or, more specifically, between the spindle  405  and the hollow shaft-like portion of the separator  300 ). Furthermore, a spindle shaft  406  of the spindle  405  may axially pass into the bearing  407 , and, in one embodiment, the spindle shaft  406  may further extend beyond the bearing  407  to touch or contact the bearing support  307 . As such, during operation, the spindle  405  may rotate relative to the bearing  407  and the intermediate separator  300 , while the separator  300  is stationary. Also, such arrangement of the spindle  405  within the bearing  407  enables the spindle  405  to be mounted rotatably/for rotation within the housing without the need for extra radial clearance in that region. Typically, in prior art solutions, there is need for, or there tends to be, extra radial clearance for movement of these parts, and this contributes to either a reduced ability to maintain a tight motor air gap between the fixed stator coils of stator  500  and rotor coils  403  provided on the gerotor outer gear  402  (described below), or misalignment during the operation or at the assembly of the gerotor pump  10 , or both. This disclosed design, however, does not need or leave any extra radial clearance in the spindle  405 /bearing  407  region. Instead, a radial position of the magnetic rotor may be fixed (i.e., with a tight motor air gap, or a radial gap  810 ), or substantially fixed, thereby substantially eliminating or eliminating any influence of the eccentricity of the motor performance. Thus, via the spindle  405 , a radial gap  810  (see  FIG. 8A ) between the rotor coils  403 , gerotor gears  400 , and the motor stator  500  may be maintained with tight tolerance during operation of the pump. This provides, among other things, stable magnetic flux gap and improves noise and vibration performance of the gerotor pump  10 . In addition, such configuration of the intermediate separator  300  provides for a compact assembly of the gerotor pump  10 . For example, upon assembly of the components of the gerotor pump  10  on the second side of the intermediate separator  300 , a chamber  602  (see  FIG. 9 ) may be formed between the intermediate separator  300  and the bottom casing  600 . The chamber  602  may be configured to accommodate the gerotor gears  400  and the motor stator  500  to form a compact assembly. 
     The spindle  405  may be any component configured to hold the set of gerotor gears  400  such that the radial movement of the gerotor gears  400  may be controlled or maintained with respect to the motor stator  500 . In an embodiment, the spindle  405  may be a unitary construction of the spindle shaft  406 , a flange portion  415 , a top surface  417  (see  FIG. 4 ), and a through hole  412  (see  FIG. 4 ) in the top surface  417 . In an embodiment, the spindle  405  may be substantially circular or rounded with the spindle shaft  406  at the center of top surface  417  and axially projecting upwards or towards a first side (i.e., where the top cover  100  is located) from the top surface  417 . The flange portion  415  may be formed at the perimeter of the top surface  417  and projecting downwards or towards a second side (i.e., where the bottom casing  600  is located). The flange portion  415  may be configured to grip a portion of an outer surface  425  of the outer gear  402  of the gerotor gears  400 . Furthermore, the spindle  405  may be fixedly coupled to the outer gear  402  via the pin  410  passed through the holes  412  and  413  (when spindle  405  and set of gears are stacked together; e.g., see  FIG. 8B ). The holes  412  and  413  are axially aligned with each other to allow the pin  410  to pass through the holes, as shown in  FIG. 8B , thus preventing a relative rotation between the spindle  405  and the outer gear  402  of the gerotor gears  400 . In an embodiment, the holes  412  and  413  may be offset or formed away from an axis of rotation (axis  405   a ) of the spindle  405 ; e.g., the holes  412  and  413  may be formed between the perimeters of the flange portion  415  and the outer gear  402  (e.g., outer surface  425 ) and the spindle shaft  406 . For example, the hole  413  may be formed approximately midway between the spindle shaft  406  and the flange  415 . Similarly, hole  412  may be formed at a corresponding distance to hole  413  in through the body of the outer gear  402 . In an embodiment, the hole  412  may be located offset from the axis of rotation  405   a  and between the outer surface  425  and internal teeth of the outer gear  402 . The present disclosure is not limited by a dimension, number of holes, or location of the hole  413  (and corresponding hole  412  of the outer gear  402 ). In an embodiment, the diameter of the holes  412  and  413  may be less than or substantially equal to the pin  410  to limit (or prevent) an interplay between the pin  410  and the holes  412  and  413 . 
     Thus, the spindle  405  may be fixed (e.g., via pin  410 ) to the outer gear  402  and configured to rotate together about a first axis  405   a  within the bearing  407 . According to an embodiment, the spindle  405  and the outer gear  402  (as-is conventionally known of gerotors) may rotate about axis  405   a , while the inner gear  401  may rotate about a second axis  401   a . The first axis  405   a  and the second axis  401   a  are offset from each other, allowing the internal gear  401  to rotate in an eccentric manner relative to the outer gear  402 . 
     In an embodiment, as mentioned, the set of gerotor gears  400  includes the inner gear  401  and the outer gear  402 . The inner gear  401  meshes with the outer gear  402  (also illustrated in  FIGS. 3B, 4, 5, 8A, 8B and 9 ). In an embodiment, the inner gear  401  may be coupled within an internal hollow portion of the outer gear  402  in an offset manner. For example, the inner gear  401  may be mounted on a shaft  605  (i.e., a drive shaft, such as shown in  FIG. 8A ) extending through the bottom casing  600  that rotates about axis  401   a , which is offset from the axis of rotation  405   a  of the spindle  405  (and the outer gear  402 ). The offset arrangement of the gears  401  and  402  creates a varying volume space between the inner gear  401  and the outer gear  402  that enable the pumping of fluid. In an embodiment, the inner gear  401  may rotate about the axis of the shaft  605  (i.e., the second axis  401   a ) and the outer gear  402  may rotate about the spindle  405  (i.e., a first axis  405   a ). In an embodiment, the shaft  605  may be an input shaft that may be mechanically driven which may cause rotation of the inner gear  401  (i.e., the shaft  605  drives the inner gear  401 ), which further drives the outer gear  402 , creating a pumping effect. The drive shaft  605  may be configured to be driven by a driver (not shown) such that it rotates about its axis ( 401   a ) to drive the gerotor pump  10 . Such a driver may include a drive pulley, drive shaft, engine crank, gear, or electric motor, for example. One or more support bearings may support the drive shaft. 
     The inner gear  401  has external teeth (i.e., formed on an outer side of the inner gear  401 , as shown in  FIG. 3B , for example) which meshes with internal teeth (i.e., formed on an inner side of the outer gear  402 , as shown in  FIG. 3B ) of the outer gear  402 . As the inner gear  401  rotates/meshes with outer gear  402 , crescent-like shape(s) may be formed between the teeth of the gears  401  and  402 . Within these shapes, the (input) fluid is compressed or pressurized as the gears rotate. Furthermore, in one embodiment, the outer gear  402  may have greater number of teeth than the inner gear  401 , thus the inner gear  401  may rotate at a slower speed compared to the outer gear  402 . For example, the outer gear  402  may have six (6) internal teeth and the inner gear  401  may have five (5) external teeth. In an embodiment, the gerotor pump  10  may be a crescent internal pump, for example, having involute gear and in which the number of teeth on the inner gear differs from the outer gear by more than one. In an embodiment, the gerotor pump  10  may not include crescent-like shape(s) between the inner gear  401  and the outer gear  402  during rotation. The shapes or areas formed between the gears, that receive and pressurize the fluid during rotation, are not intended to be limiting. The type, number, and shape of teeth of the inner gear  401 , outer gear  402 , the gears themselves, and parts used therewith, are also not intended to be limited. 
       FIGS. 3A and 3B  also show the (optional) pressure plate  610 , which may be provided in the bottom casing  600  (see also, e.g.,  FIG. 8A ). The inner gear  401  may be placed against the pressure plate  610  to compensate for any clearance between the inner gear  401  and the ports. In accordance with an embodiment, the drive shaft  605  may extend through the pressure plate  610  and into the housing assembly  150 . Furthermore, the pressure plate  610  may include two radial slots partially extending in a radial direction and separated from each other. In an embodiment, one radial slot may provide a fluid path from the entry port  601  to the gerotor gears  400  and a second radial slot may provide a fluid path from the gerotor gears  400  to the discharge port  603 . 
     In an embodiment, the set of gerotor gears  400  may be electromagnetically driven via the outer gear  402 . The outer gear  402  may include a series of magnets that may be magnetically coupled to the motor stator  500  thus forming an electromagnetic motor configuration. In such configuration, the rotor  403  may be referred as a motor rotor and the motor stator  500  may be referred to as a stator, or vice-versa depending on a relative rotation of the gears  400  and the motor stator  500 . The rotor  403  may be disposed on an outer surface of the outer gear  402 , as shown. In an embodiment, a rotor (i.e., the outer gear  402 ) may be four-pole-rotor, a six-pole-rotor, an eight-pole-rotor, etc. which corresponds to similar number of poles on the stator (i.e., the motor stator  500 ). For example, the rotor coils  403  may be configured to form at least two magnetic poles (a north pole and a south pole), where a first pole may be diametrically opposite to the second pole. In an embodiment, the rotor  403  may be permanent magnets having poles corresponding to the motor stator  500 . In an embodiment, the motor configuration may correspond to any other type of motors such as a reluctance motor. For example, a reluctance motor configuration where non-permanent magnetic poles on the ferromagnetic rotor may be formed on the outer gear  402 . 
     In an embodiment, the outer gear  402  may be disposed internal to the motor stator  500  with the radial gap  810  (illustrated in  FIGS. 8A and 8B ) in a radial direction, therebetween. In  FIGS. 8A and 8B , the radial gap  810  may be formed between magnets and the poles of the motor stator  500 . The radial gap  810  is desired to be small (e.g., less than approximately 0.5 mm) and must be maintained or substantially maintained such that its size/dimension is approximately and relatively consistent during operation of the pump, in order to maintain a relatively high amount of magnetic flux between the motor stator  500  and the outer gear  402 , with minimal variation, for smooth and efficient operation of the gerotor pump  10 . For example, a tolerance or variance of ±2% of a selected gap or a desired gap ( 810 ) may be maintained in the disclosed pump. If the gap  810  increases, the magnetic flux may drop exponentially, thus reducing the efficiency of the gerotor pump  10 . According to an embodiment, such radial gap  810  may be tightly maintained or controlled due to the coupling between the outer gear  402  and the spindle  405 . For example, as discussed earlier and as shown in  FIGS. 3A, 3B, 4, 5, 8A, 8B, and 9 ) the outer gear  402  may be fixedly coupled to the spindle  405  via the pin  410 , in accordance with an embodiment. More than one pin may be used in an alternate embodiment. 
     The motor stator  500  is mounted in the casing  600  and designed for rotation relative to the gerotor gears  400 . The motor stator  500  may be coupled to PCB  200 , which may be configured to activate the motor stator  500  causing the outer gear  402  to rotate. In an embodiment, the motor stator  500  may be manufactured as an overmolded stator that is supported or mounted in the casing  600 , a stator having a core with winding placed in the casing  600 , or another type of stator placed therein. An overmolded motor stator  500  may include a lamination stack held together via an overmolded resin, for example. The overmolded motor stator  500  may also help reduce vibrations during the operation of the gerotor. 
     According to an embodiment, in operation, the motor stator  500  when activated causes the outer gear  402  (and the spindle  405 ) to rotate about the axis  405   a . The rotation of the outer gear  402  further rotates the inner gear  401  about the axis  401   a  in an eccentric manner. Further, the crescent-like shape(s) between the gears  401  and  402  causes a suction when the gear teeth disengage, for example, at the suction end  601  of the housing, and a compression when the gear teeth engage at a discharge end  603  of the housing. 
     In an embodiment, one or more components of the gerotor may be manufactured from powdered material to limit frictional losses during the operation of the gerotor, thus increasing the efficiency of the gerotor. 
     The gerotor pump  10  according to the present disclosure has several non-limiting advantages, some of which have been noted previously. For example, a gap (e.g., radial gap  810 ) may be maintained approximately consistent during assembly and operation of the gerotor pump, thus providing a relatively consistent flux throughout the radial gap  810  thereby increasing operational efficiency and operating speed. According to an embodiment, by using the spindle  405  and the bearing  407  without extra radial clearances (and/or by limiting their radial clearance and/or movement, while still effectively maintaining the gap  810 ), the less-sensitive issue of radial clearance between the gear teeth tips can be managed by tolerances between the inner gear bore and the shaft  605  received in it. Furthermore, the spindle  405  and bearing  407  arrangement may reduce vibrations, for example, between the outer gear  402  and the inner gear  401 , thereby maintaining a tight gap between the motor stator  500  and the electric coils of the outer gear  402 . Also, reduced vibration enables maintaining a consistent gap  810 , allowing the gerotor gears  400  to be rotated at increased speed. The spindle  405  enables self-alignment during assembly and when the gerotor is operating. The spindle  405  (with the bearing  407 ) and the pin  410  connection with the gear set reduces the requirement of a high precise gear tip tolerances (e.g., between the engaging gear teeth) between the inner gear  401  and the outer gear  402 . 
     Furthermore, the complexity of field orientation control (FOC) may be reduced (e.g., due to reduced vibration), thus allowing driving the pump at high speeds. 
     Using the pressure plate  610  in combination with the spindle  405  also allows for compensation with regards to tolerances of the pump unit, and overcome issues with regards to integration. The frictional impact between rotating parts is dramatically reduced with the used of, for example, bearing  407  compared to use of bushings. 
     Active cooling of the controller may be implemented via the construction of the separator  300  and fluid in the housing assembly, thereby enabling better thermal measurement and control for the controller (e.g., PCB  200 ). Also, use of a PCB bus bar to replaces a conventional bus bar, in accordance with an embodiment, may further reduce the cost associated with the pump. 
     An overmolded motor stator  500  may be used to overcome seal issues. In accordance with an embodiment, the stator may be formed using a powder metal. Furthermore, in an embodiment, an overmolded rotor may be formed, e.g., by a powder metal. In an embodiment, both the stator and rotor may be overmolded. In one embodiment, a sheet mounting compound (or composite) process (SMC) may be utilized, e.g., to manufacture the outer gear  402  with the rotor coil  403 , thereby reducing the cost of manufacturing, as well as to eliminate laminations from the stator. 
     Furthermore, the gerotor pump  10  has improved overall motor (or pump) efficiency based on consistent air gap and corresponding magnetic flux, and improved pump&#39;s mechanical efficiency based on reduced friction between rotating parts. In accordance with an embodiment, up to fifty (50) percent (%) of existing friction between parts may be eliminated in the disclosed design as compared to prior art solutions. Furthermore, motor integration may be established, in accordance with an embodiment, by using sheet molding compound (SMC) material for outer rotor (e.g., rotor coils  403 ) and magnets, in accordance with an embodiment. The electric oil pump assembly process may be more robust. An intermediate ring may be used to improve hydrodynamic lubrication between the spindle and bearing. 
     As previously noted, the gerotor pump  10  may be associated with a system in accordance with an embodiment of the present disclosure. The system may be a vehicle or part of a vehicle, for example. Such a system may include a mechanical system such as an engine (e.g., internal combustion engine) and/or a transmission of an automotive vehicle for receiving pressurized lubricant from the pump  10 . The pump  10  receives (input via pump inlet) fluid/lubricant (e.g., oil) from a lubricant source and pressurizes and delivers it to the engine or transmission (output via outlet). A sump or tank may be the lubricant source that inlets to the pump  10 . The controller in the pump  10  may be designed for implementing actuation of the system and/or pump  10 . 
     While the principles of the disclosure have been made clear in the illustrative embodiments set forth above, it will be apparent to those skilled in the art that various modifications may be made to the structure, arrangement, proportion, elements, materials, and components used in the practice of the disclosure. 
     It will thus be seen that the features of this disclosure have been fully and effectively accomplished. It will be realized, however, that the foregoing preferred specific embodiments have been shown and described for the purpose of illustrating the functional and structural principles of this disclosure and are subject to change without departure from such principles. Therefore, this disclosure includes all modifications encompassed within the spirit and scope of the following claims.