Calade pump and motor pump unit
By adopting a pre-tight compensation plate design in the Gallout pump, the leakage and high starting torque problems caused by axial clearance in conventional pumps are solved, and more efficient and lower wear pump performance is achieved.
Patent Information
- Application Number
- CN202410438691.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Priority Date
- 2023-08-18
- Filing Date
- 2024-04-12
- Publication Date
- 2025-02-21
AI Technical Summary
The conventional Gelaut pump has internal leakage in the axial clearance problem caused by manufacturing tolerances, which reduces the efficiency of the pump, and the compensation plate applies force to the rotor in a rest state, increasing the starting torque and wear.
A Gelaut pump is designed with a pre-tight compensation plate arranged in the axial direction to ensure that it is spaced from the outer and inner rotors in a resting state, reduce friction and leakage, and compensate by pressurized fluid during operation plate, reduce axial clearance.
Effectively reduce the axial clearance, improve the efficiency and operating stability of the pump, reduce wear and starting torque, and maintain efficient operation within a lower pressure range.
Smart Images
Figure CN119491818A_ABST
Abstract
Description
[0001] The invention relates to a gerotor pump for conveying fluid and a motor pump unit having the gerotor pump.
[0002] Conventional Gerotor pumps (also referred to as "ring gear pumps" or "Eaton pumps") have a rotatable outer rotor and a rotatable inner rotor, wherein the inner rotor is arranged radially inside the outer rotor. Conventionally, the inner rotor is driven by a motor. Here, the inner rotor is designed as a gear and the outer rotor is designed as a ring gear, wherein the inner rotor and the outer rotor have different axes of rotation from one another. As a result, the outer rotor runs eccentrically on the outer teeth of the inner rotor. Due to the change in volume between the tooth gaps between the inner rotor and the outer rotor, pressure zones (also referred to as pump chambers) are formed, by means of which the fluid is conveyed.
[0003] Conventional axial compensation in gerotor pumps by means of compensation plates (English: "compensation plates") is described in "Fundamentals of Designing Hydraulic Gear Machines" by Jaroslaw Stryczek (ISBN: 978-83-01-21226-1) and in "Axial clearance compensation in the gerotor pump" by Jaroslaw Stryczek and Slawomir Bednarczyk from the "19th International Conference on Hydraulics and Pneumatics, Prague, September 29-October 1, 2008".
[0004] However, conventionally known Gerotor pumps have the following disadvantages: manufacturing tolerances can lead to so-called axial clearances between the inner and outer rotors and the housing, in particular the housing cover or the housing bottom. Such axial clearances can lead to internal leakage ("Innenleckage") of the fluid to be conveyed, which reduces the efficiency of the pump. The above-mentioned conventional compensation plate also has the following disadvantages: the compensation plate applies a certain force to the moving parts, i.e. to the inner and outer rotors, when the pump is in a rest state, which causes the rotors to be braked when the pump is started. This is also called "normally closed". Therefore, the pump requires a higher starting torque and therefore a greater power. In addition, the axial clearance compensated in a conventional manner can lead to a sharp drop in the efficiency of the pump, especially at lower temperatures, because the fluid to be conveyed usually has a higher viscosity at lower temperatures. The wear on the pump caused by the friction between the rotor and the compensation plate is also disadvantageous.
[0005] The object of the present invention is to provide a gerotor pump which can reduce the axial clearance and at the same time has a higher efficiency and lower wear in a lower pressure range.
[0006] This object is achieved by the features of the independent claim. The dependent claims contain advantageous refinements of the invention.
[0007] This object is achieved in particular by a gerotor pump according to claim 1. The gerotor pump is designed and suitable for conveying a fluid from an inlet pump chamber connected to an inlet of the gerotor pump to an outlet pump chamber connected to an outlet. The gerotor pump has a rotatable outer rotor and a rotatable inner rotor. The inner rotor is arranged radially inside the outer rotor. The gerotor pump also has a housing with a housing cover and a housing bottom. The outer rotor and the inner rotor are arranged between the housing cover and the housing bottom. In addition, the gerotor pump has at least one compensation plate, which is arranged axially between the outer rotor and the inner rotor and the housing cover or the housing bottom, respectively. For example, the gerotor pump has: at least one compensation plate, which is arranged axially between the outer rotor and the inner rotor and the housing cover, and / or at least one compensation plate, which is arranged axially between the outer rotor and the inner rotor and the housing bottom. In this case, the at least one compensation plate is axially spaced apart from the outer rotor and the inner rotor due to preload in the rest state of the gerotor pump.
[0008] Since the at least one compensating plate is spaced apart from the outer rotor and the inner rotor in the rest state of the Gerotor pump by means of preload, wear of the pump can be reduced and the efficiency of the pump can be increased, even in the lower pressure range. This is also referred to as "normally open".
[0009] In the following description, the term "rotor" or the like should be understood as a general term for "inner rotor and outer rotor". In addition, in this context, for example, an element "arranged between the inner rotor and the outer rotor and the housing (cover / bottom)" should be understood as an element that is arranged between the housing (cover / bottom) and the inner rotor and / or between the housing (cover / bottom) and the outer rotor, especially in the axial direction.
[0010] In an advantageous embodiment, the gerotor pump has an upper compensating plate and / or a lower compensating plate as the at least one compensating plate. In this case, the upper compensating plate is arranged axially between the outer rotor and the inner rotor and the housing cover. In this case, the lower compensating plate is arranged axially between the outer rotor and the inner rotor and the housing bottom. Preferably, the gerotor pump has only an upper compensating plate. Alternatively, the gerotor pump has only a lower compensating plate. Further alternatively, the gerotor pump has an upper compensating plate and a lower compensating plate.
[0011] In an advantageous embodiment of the invention, the gerotor pump has at least one spring element which preloads the upper compensation plate axially toward the housing cover and / or the lower compensation plate axially toward the housing bottom. The at least one compensation plate is thereby preloaded such that it is axially spaced apart from the outer rotor and the inner rotor in the rest state of the gerotor pump ("normally open").
[0012] The spring element is preferably a helical spring. Advantageously, the at least one compensating plate has at least one retaining structure for the respective spring element. For example, the at least one compensating plate has at least one recess for the at least one spring element as a helical spring ("spring element recess"), in which one end of the helical spring is received. Alternatively or in addition thereto, the compensating plate has a retaining lug as retaining structure, which retaining lug can receive one end of a leaf spring and keep it clamped. This makes it possible for the at least one spring element to be held radially by the compensating plate.
[0013] In an advantageous embodiment in which the gerotor pump has an upper compensation plate and a lower compensation plate, the at least one spring element is arranged axially between the upper compensation plate and the lower compensation plate. In other words, the spring element is clamped axially between the upper compensation plate and the lower compensation plate and preloads the compensation plates in the axial direction. Here, the spring element extends axially from the upper compensation plate to the lower compensation plate and is preferably in direct contact with both.
[0014] Advantageously, the at least one compensating plate has at least one inlet through-hole connected to the inlet fluid. Furthermore, the at least one compensating plate has at least one outlet through-hole connected to the outlet fluid. As a result, pressure equalization can be achieved between the housing side and the rotor side of the compensating plate. As a result, the manufacturing tolerances of the Gerotor pump can also be increased, thereby simplifying manufacturing.
[0015] In an advantageous embodiment, the at least one compensating plate has at least one first groove, which extends at least along the circumference of the compensating plate on the housing cover-side end face or the housing bottom-side end face of the compensating plate. The groove advantageously promotes pressure compensation between the housing side and the rotor side of the compensating plate. The axial pressure acting on the compensating plate is advantageously reduced or minimized by the pressure compensation.
[0016] Advantageously, the upper compensating plate has a first groove on the end face on the housing cover side. Further advantageously, the lower compensating plate has a first groove on the end face on the housing bottom side. Alternatively or additionally thereto, the lower compensating plate has a first groove on the end face on the housing cover side and / or the upper compensating plate has a first groove on the end face on the housing bottom side. In the exemplary case in which at least one of the compensating plates has a first groove on both of its end faces (on the housing bottom side / on the housing cover side), these first grooves can be fluidically connected to one another via axial grooves.
[0017] Advantageously, the at least one groove is formed radially in at least one radial section of the compensating plate(s) from the circumference of the compensating plate towards the radial center. In other words, the groove advantageously extends in at least one radial section of the compensating plate from the circumference of the compensating plate towards the radial center. As a result, it can be advantageously achieved that a fluid entering the above-mentioned groove of the compensating plate can reach the shaft and thus return to the inner rotor or the outer rotor. Furthermore, the corresponding groove(s) can extend in a plurality of radial sections of the corresponding compensating plate(s), for example at radial sections opposite with respect to the radial center, respectively towards the radial center of the compensating plate.
[0018] In an advantageous embodiment of the gerotor pump, the gerotor pump has an upper compensating plate and a lower compensating plate, wherein the first groove of the upper compensating plate extends on the end face on the housing cover side and the first groove of the lower compensating plate extends on the end face on the housing bottom side. In other words, both the upper compensating plate and the lower compensating plate have the first groove on their end face on the housing side and not on their end face on the rotor side.
[0019] The first groove has the advantage in particular that the gap between the compensation plate and the housing (housing bottom or housing cover) is reduced due to the above-mentioned pressure compensation, even at higher fluid pressures. In addition, leakage of the fluid can be directed back to the rotor.
[0020] Advantageously, the at least one compensating plate has at least one pump chamber recess. Here, the respective pump chamber recess extends on the rotor-side end face of the respective compensating plate and defines, together with the gap between the inner rotor and the outer rotor, an inlet pump chamber or an outlet pump chamber. Advantageously, the respective compensating plate has a first pump chamber recess for the inlet pump chamber and a second pump chamber recess for the outlet pump chamber. Advantageously, each of the compensating plates has the aforementioned first pump chamber recess and the aforementioned second pump chamber recess.
[0021] Further advantageously, the gerotor pump has at least one compensating seal. The at least one compensating seal is arranged on the end face of the at least one compensating plate on the housing cover side or on the end face of the housing bottom side. The corresponding compensating seals enclose a compensating surface, which is axially opposite to the pump chamber groove. Here, the surface enclosed by the pump chamber groove is smaller than the above-mentioned compensating surface. Due to the different sizes of the (directly) opposite surfaces, to which the fluid reaches at the same pressure via the inlet / outlet through-holes, a directional force is generated, which overcomes the preload and presses the (multiple) compensating plates toward the rotor side, thereby reducing the axial clearance during operation of the pump.
[0022] The pump chamber groove in particular generates a pressure surface which can be larger than the pump chamber groove during operation of the pump. In such a case, the pressure surface generated by the pump chamber groove is preferably smaller than the above-mentioned compensation surface. In other words, the above-mentioned compensation surface is at least larger than the pump chamber groove, preferably larger than the pressure surface generated by the pump chamber groove.
[0023] In particular, the compensating seal surrounds the respective inlet passage opening(s) or outlet passage opening(s).
[0024] In the example of a gerotor pump, the gerotor pump has four such compensating seals, namely, two on the upper compensating plate and two on the lower compensating plate. Each of these compensating seals is axially opposite to the pump chamber groove of the corresponding compensating plate. Since the surface surrounded by the pump chamber groove or the pressure surface generated by it is smaller than the compensating surface of the compensating seal, a directional force is generated, which reduces the distance between the at least one compensating plate and the outer rotor or the inner rotor. As a result, during the operation of the pump, especially at higher pressures, the axial clearance is reduced, thereby improving efficiency. When the pump is closed to the rest state, the directional force is weakened, so that the "normally open" state appears again. In other words, the axial clearance is reduced due to the hydraulic pressure.
[0025] The invention also relates to a motor pump unit. The motor pump unit has a gerotor pump according to one of the above-mentioned preferred designs. In addition, the motor pump unit has a motor, which is preferably connected to the inner rotor and is configured to rotate the inner rotor so as to operate the gerotor pump. The motor is mechanically connected to the inner rotor, in particular by means of a shaft. The motor pump unit has higher efficiency and lower wear. Alternatively, the motor is connected to the outer rotor of the gerotor pump and operates it.
[0026] The gerotor pump and motor pump unit according to the invention also have the following advantages. (Volume) efficiency is improved, wear is reduced, starting torque is reduced, the pump operates more efficiently at low temperatures or higher fluid viscosities, and the power requirement is reduced. In addition, the gerotor pump can be operated at higher pressures. Expanded manufacturing tolerances are also achievable.
[0027] Further details, advantages and features of the invention will emerge from the following description of exemplary embodiments with the aid of the accompanying drawings.
[0028] In the figure:
[0029] Figure 1 A schematic cross-sectional view showing a gerotor pump according to an embodiment of the present invention;
[0030] Figure 2 A perspective view showing a compensation plate of a gerotor pump according to an embodiment of the present invention;
[0031] Figure 3 A schematic cross-sectional view showing a gerotor pump according to an embodiment of the present invention; and
[0032] Figure 4 A schematic block diagram of a motor pump unit according to another embodiment of the present invention is shown.
[0033] Figure 1 A schematic cross-sectional view of a gerotor pump 1 according to a first embodiment of the invention is shown.
[0034] The gerotor pump 1 is configured and designed to convey a fluid from an inlet pump chamber connected to an inlet 2 to an outlet pump chamber connected to an outlet 3 of the gerotor pump 1 .
[0035] exist Figure 1 In FIG. 1 , arrows 28 show an exemplary fluid flow for the purpose of illustration. The Gerotor pump 1 has a rotatable outer rotor 4 and a rotatable inner rotor 5 , wherein the inner rotor 5 is arranged radially inside the outer rotor 4 . Figure 1 2 shows the radial direction 26. The inner rotor 5 is connected to a shaft 25 which drives the inner rotor 5 during operation of the pump 1. The rest state is defined as the shaft 25 applying no torque.
[0036] Furthermore, the Gerotor pump 1 has a housing 8 having a housing cover 6 and a housing bottom 7, wherein the inner rotor 5 and the outer rotor 4 are arranged axially between the housing cover 7 and the housing bottom 7. Figure 1 The axial direction 27 is drawn in FIG.
[0037] The gerotor pump 1 in this embodiment has two compensation plates 9. Here, the gerotor pump 1 has an upper compensation plate 10 between the outer rotor 4 and the inner rotor 5 and the housing cover 6, and a lower compensation plate 11 between the outer rotor 4 and the inner rotor 5 and the housing bottom 7. However, the gerotor pump 1 of the present invention is not limited thereto, but may have only the upper compensation plate 10 or only the lower compensation plate 11.
[0038] The compensation plates 10, 11 are prestressed by spring elements 12, which are coil springs in this case. The upper compensation plate 10 is prestressed toward the housing cover 6, while the lower compensation plate 11 is prestressed toward the housing bottom 7. In the exemplary case in which only one of the compensation plates 10, 11 is present, the spring element 12 rests against the housing cover 6 or the housing bottom 7 which is located opposite.
[0039] By means of the spring element 12, the compensating plates 10, 11 are axially spaced apart from the outer rotor 4 and the inner rotor 5 in the rest state of the gerotor pump 1 due to the prestressing of the spring element 12. As a result, the friction between the compensating plates 10, 11 and between the rotors 4, 5 is reduced, so that the gerotor pump 1 requires a lower starting torque.
[0040] In particular, in the rest state of the gerotor pump 1, the spring element 12 brings about the above-mentioned axial spacing between the compensation plates 10, 11 (or respectively the compensation plates 10, 11 from the opposite housing bottom 7 or the housing cover 6). When the gerotor pump 1 is in operation, in particular at higher pressures, the compensation plates 10, 11 are pressed toward each other by the pressurized fluid. In other words, when the gerotor pump 1 is in operation, the upper compensation plate 10 is pressed toward the housing bottom 7 and / or the lower compensation plate 11 is pressed toward the housing cover 6. This is explained below.
[0041] Figure 2 A perspective view of the compensation plate 9 of the gerotor pump 1 according to the present embodiment is shown. Figure 2 In particular, an upper compensation plate 10 is shown, wherein the following description may describe a lower compensation plate 11 (in particular flipped with respect to the axial direction 27) instead of or in addition thereto. Furthermore, the above and below descriptions relate to a bidirectionally operable recovery gerotor pump. However, the invention is also applicable to unidirectional gerotor pumps. In this case, the axial compensation is preferably carried out only on one side, the high-pressure side or the low-pressure side, in particular only on the high-pressure side. In other words, only the high-pressure side is used. Figure 1 The left half of the illustrated Gerotor pump 1 can have the described structure, while the right half (low-pressure side or tank pressure side) can be designed according to a conventional Gerotor pump. Figure 2 The compensation plate 10 shown can also be approximately halved with respect to its circumference. In other words, as an alternative to the 360° design shown (circular), the compensation plate 10 can be approximately 160° or more, preferably approximately 180° or more, further preferably 190° or more, preferably not more than 270° (partial circle). Of course, geometric shapes other than circular can also be selected depending on the specifications.
[0042] like Figure 2 As shown, the compensation plate 10 has an end face 16. For the upper compensation plate 10, the end face 16 is the end face 16 on the housing cover side (see Figure 1The compensating plate 10 has a groove 15 which extends along the circumference 18 of the compensating plate 10 on the end face 16 on the housing cover side. Figure 2 and Figure 1 As shown in the comparison of FIG. 1 and FIG. 2 , the lower compensation plate 11 has a first groove 15 on the end surface 17 on the bottom side of the housing. Figure 2 It can be seen in FIG. 1 that the groove 15 extends radially in a radial section 19 of the compensating plate 10 from the circumference 18 of the compensating plate 10 to the radial center 20 . Figure 1 The illustrated axis 25 extends through the radial center 20 of the compensation plate 10 .
[0043] This makes it possible to achieve that pressurized fluid that reaches the area between the upper compensating plate 10 and the housing cover 6 or between the lower compensating plate 11 and the housing bottom 7 can return to the shaft 25 and thus to the inner rotor 5 or the outer rotor 4. In this case, the radial center 20 of the compensating plate 10 can accommodate the shaft 25 with a clearance fit, so that the fluid can flow (radially) through the radial center 20 between the shaft 25 and the compensating plate 10 in the axial direction 27.
[0044] Furthermore, the compensating plate 10 in this embodiment has two inlet through-openings 13 which are fluidically connected to the inlet 2. Furthermore, the compensating plate 10 in this embodiment has two outlet through-openings 14 which are fluidically connected to the outlet 3.
[0045] Figure 2 The recess 29 of the illustrated compensating plate 10 is configured for receiving a locking pin (not illustrated) which prevents the compensating plate 10 from synchronously rotating during operation of the pump 1 .
[0046] exist Figure 2 Also shown are spring element recesses 40 which each receive a spring element 12 .
[0047] The (upper and / or lower) compensating plate(s) 10 may also have a plurality of the above-mentioned grooves 15, for example one groove on each end face 16, 17 of the (multiple) compensating plate(s) 10. In such an exemplary case, the two grooves 15 may be fluidly connected via at least one axially extending groove of the (multiple) compensating plate(s) 10. As a result, a pressure balance may be achieved between the two sides of the (multiple) compensating plate(s) 10 in an advantageous manner, thereby reducing or minimizing the axial pressure on the compensating plate(s).
[0048] exist Figure 1 In FIG. 1 , for the upper compensation plate 10 , the inlet through-hole 13 and the outlet through-hole 14 are shown with dotted lines.
[0049] Figure 3 A schematic cross-sectional view of the gerotor pump 1 according to the present embodiment is shown. Figure 3 The sectional view of FIG. 2 shows in particular a plan view in the axial direction 27 , with the housing cover 6 being transparent.
[0050] like Figure 3 As shown, the gerotor pump 1 according to the present embodiment has a pump chamber groove 21 for the inlet pump chamber and a pump chamber groove 21 for the outlet pump chamber. The pump chamber groove 21 is formed in the rotor-side end face 22 of the compensation plate 10 (shown in dotted lines). The lower compensation plate 11 can also have a pump chamber groove 21. The pump chamber grooves 21 (each) together with the gap between the inner rotor 5 and the outer rotor 4 define the inlet pump chamber and the outlet pump chamber.
[0051] like Figure 1 As shown in the cross-sectional illustration of , the pump chamber grooves 21 are arranged axially opposite, in particular directly axially opposite, the compensating seal 23 (or the surface enclosed by the compensating seal). Figure 3 The illustrated compensation seal 23 encloses a compensation surface which is axially opposite the corresponding pump chamber recess 21. The compensation surface enclosed by the compensation seal 23 and the pump chamber recess 21 are fluidically connected via the corresponding inlet through-opening 13 or outlet through-opening 14.
[0052] The pressurized fluid flows from the inlet pump chamber (from the corresponding pump chamber recess 21) through the inlet through-hole 13 into the compensation chamber 30 surrounded by the compensation seal 23 in the housing cover 6 or the housing bottom 7. Figure 1 Displayed in.
[0053] Especially Figure 1 and Figure 3 As shown in the comparison of , the compensation surface surrounded by the compensation seal 23 is larger than the surface surrounded by the pump chamber groove 21. Since the pressure of the fluid in the pump chamber groove 21 is the same as the pressure of the fluid in the compensation cavity 30, and the compensation surface is larger than the surface surrounded by the pump chamber groove 21, the pressurized fluid exerts a greater force on the compensation surface than on the pump chamber groove 21 (P=F / A; F=P*A). Therefore, a combined force is generated that overcomes the preload generated by the spring element 12.
[0054] In other words, the compensating plates 10, 11 are pressed axially against the inner rotor 5 and the outer rotor 4 during operation of the pump 1, so that the axial play is reduced at higher pressures. As a result, the efficiency of the gerotor pump 1 at higher pressures is increased. At lower pressures, the prestressing of the compensating plates 10, 11 reduces the viscous friction and thus also reduces the starting torque of the gerotor pump 1. These advantages are achieved in particular by suitable adjustment of the compensating surfaces.
[0055] Figure 4 A schematic block diagram of a motor pump unit 100 according to an embodiment of the present invention is shown.
[0056] The motor pump unit 100 has a motor 101 and a gerotor pump 1 according to the present invention. The motor 101 is configured to rotate the inner rotor 5 so as to operate the gerotor pump 1. Here, the motor 101 is driven by a shaft 25 (see also Figure 1 ) is mechanically connected to the inner rotor 5. The motor pump unit 100 has particularly good efficiency and a particularly long service life.
[0057] In addition to the above written description of the invention, explicit reference is hereby made to the illustrations of the invention in the accompanying drawings for supplementary disclosure.
[0058] List of Reference Numerals
[0059] 1 Gerotor Pump
[0060] 2 Entrance
[0061] 3. Exit
[0062] 4 Outer rotor
[0063] 5 Inner rotor
[0064] 6 Housing cover
[0065] 7 Shell bottom
[0066] 8 Housing
[0067] 9 Compensation plate
[0068] 10 Upper compensation plate
[0069] 11 Lower compensation plate
[0070] 12 Spring element
[0071] 13 Inlet through hole
[0072] 14 Exit hole
[0073] 15 Grooves
[0074] 17 End face
[0075] 18 Circumference
[0076] 19 Radial Segments
[0077] 20 Radial Center
[0078] 21 Pump chamber groove
[0079] 22 Rotor side end face
[0080] 23 Compensating seal
[0081] 25 Axis
[0082] 26 Radial direction
[0083] 27 Axial direction
[0084] 28 Fluid Flow
[0085] 29 Notch
[0086] 30 Compensation cavity
[0087] 40 Spring element notch
Claims
1. A gerotor pump (1), the gerotor pump being used to transfer a fluid from an inlet pump chamber connected to an inlet (2) of the gerotor pump (1) to an outlet pump chamber connected to an outlet (3), the gerotor pump comprising: A rotatable outer rotor (4); a rotatable inner rotor (5), the inner rotor being arranged radially inside the outer rotor (4); a housing (8), the housing having a housing cover (6) and a housing bottom (7), the outer rotor (4) and the inner rotor (5) being arranged between the housing cover and the housing bottom; and At least one compensating plate (9, 10, 11) is arranged axially between the outer rotor (4) and the inner rotor (5) and the housing cover (6) or the housing bottom (7), respectively. The at least one compensating plate (9, 10, 11) is axially spaced apart from the outer rotor (4) and the inner rotor (5) due to preload in the rest state of the gerotor pump (1).
2. The gerotor pump (1) according to claim 1, wherein the gerotor pump has an upper compensation plate (10) and / or a lower compensation plate (11) as the at least one compensation plate (9, 10, 11), wherein the upper compensation plate is axially arranged between the outer rotor (4) and the inner rotor (5) and the housing cover (6), and the lower compensation plate is axially arranged between the outer rotor (4) and the inner rotor (5) and the housing bottom (7).
3. The gerotor pump (1) according to claim 2, wherein the gerotor pump has at least one spring element (12), which preloads the upper compensation plate (10) axially toward the housing cover (6), and / or the at least one spring element preloads the lower compensation plate (11) axially toward the housing bottom (7).
4. The gerotor pump (1) according to claim 3, comprising the upper compensation plate (10) and the lower compensation plate (11), wherein the at least one spring element (12) is arranged axially between the upper compensation plate and the lower compensation plate (10, 11).
5. The gerotor pump (1) according to one of the preceding claims, wherein the at least one compensating plate (9, 10, 11) has at least one inlet through-hole (13) fluidically connected to the inlet (2) and at least one outlet through-hole (14) fluidically connected to the outlet (3).
6. A gerotor pump (1) according to one of the preceding claims, wherein the at least one compensating plate (9, 10, 11) has at least one first groove (15), which extends at least along the circumference (18) of the compensating plate (9, 10, 11) on the end face (16) on the housing cover side or the end face (17) on the housing bottom side.
7. A gerotor pump (1) according to claim 6, wherein the at least one first groove (15) extends radially from the circumference (18) of the compensating plate (9, 10, 11) towards the radial center (20) in at least one radial section (19) of the compensating plate (9, 10, 11).
8. A gerotor pump (1) according to one of the preceding claims, wherein the at least one compensating plate (9, 10, 11) has at least one pump chamber groove (21), the at least one pump chamber groove extending on the end face (22) on the rotor side, and the at least one pump chamber groove together with the gap between the inner rotor (5) and the outer rotor (4) defines the inlet pump chamber or the outlet pump chamber.
9. The gerotor pump (1) according to claim 8 has at least one compensating seal (23), which is arranged on the end face on the housing cover side or the end face (16, 17) on the housing bottom side of the at least one compensating plate (9) and forms a compensating surface, and the compensating surface is axially opposite to the pump chamber groove (21), wherein the surface surrounded by the pump chamber groove (21) is smaller than the compensating surface.
10. A motor pump unit (100), comprising: A gerotor pump (1) according to any one of the preceding claims; and a motor (101) connected to the inner rotor (5) and configured to rotate the inner rotor (5), thereby operating the gerotor pump (1).