Calade pump and motor-pump unit

Abstract

The invention relates to a Calat pump for conveying a fluid from an inlet pump chamber of the Calat pump connected to an inlet to an outlet pump chamber of the Calat pump connected to an outlet, the Calat pump having: a rotatable outer rotor; a rotatable inner rotor disposed radially inside the outer rotor, where the inner rotor and the outer rotor have different axes of rotation from each other; a housing having a housing space in which the outer rotor and the inner rotor are received; and a plurality of radially displaceable pressure elements which are arranged on the outer circumference of the outer rotor and which lie against the housing during operation in such a way that a pressure chamber which is fluidically connected to the inlet pump chamber and / or the outlet pump chamber is formed between the outer rotor and the housing and / or between the outer rotor and the pressure elements. The invention also relates to a motor-pump unit having a Geite pump.

Description

[0001] The invention relates to a gerotor pump for conveying a fluid and a motor-pump unit having the gerotor pump.

[0002] Conventional Gerotor pumps (also known 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. In this case, 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, with the help of which the fluid is conveyed.

[0003] The conventional axial compensation of gerotor pumps with the aid of compensation plates is described in “Fundamentals of Designing Hydraulic Gear Machines” by Jaroslaw Stryczek (ISBN: 978-83-01-21226-1) and “Axial clearance compensation in the gerotor pump” by Jaroslaw Stryczek and Slawomir Bednarczyk (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 lead to so-called tooth tip gaps between the teeth of the inner rotor and the outer rotor. As a result, there are gaps, in particular, between the teeth of the inner rotor and the outer rotor that face each other. This tooth tip gap is already present when the pump is in the rest state, i.e., when the pump is not yet in operation. When the pump is in operation, the pressure increases and the gap between the inner rotor and the outer rotor further expands, thus causing internal leakage and reducing the efficiency of the pump.

[0005] The object of the present invention is to provide a gerotor pump which can reduce the tooth tip gap between the inner rotor and the outer rotor during operation by radial compensation and thus has high efficiency. In addition, the object of the present invention is to provide a motor-pump unit which also has high efficiency.

[0006] This object is achieved by the features of the independent claims. The dependent claims contain advantageous embodiments 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 of the gerotor pump connected to an inlet to an outlet pump chamber of the gerotor pump connected to an outlet. Here, the gerotor pump has a rotatable outer rotor and a rotatable inner rotor. The inner rotor is arranged radially inside the outer rotor. The inner rotor and the outer rotor have different rotation axes from each other. In addition, the gerotor pump has a housing having a housing space in which the outer rotor and the inner rotor are accommodated. In addition, the gerotor pump has a plurality of radially movable pressure elements. The pressure elements are arranged on the outer circumference of the outer rotor. When the gerotor pump is in operation, the pressure elements abut against the housing, so that a pressure chamber is formed between the outer rotor and the housing and / or between the outer rotor and the pressure elements. The pressure chamber is fluidically connected to the inlet pump chamber and / or the outlet pump chamber.

[0008] During operation of the pump, pressure chambers are formed between the outer rotor and the housing and / or between the outer rotor and the pressure element. During operation of the pump, forces are generated by these pressure chambers, which press the outer rotor radially against or against the inner rotor. This effect is also known as "radial compensation". As a result, the gap between the outer rotor and the inner rotor is reduced, especially when the pressure increases during operation of the pump, thus increasing efficiency.

[0009] The pressure chambers are advantageously defined as corresponding pressure zones of the fluid to be conveyed, which are separately or additionally to the pressure zones between the outer rotor and the inner rotor, which mainly convey the fluid. For the purpose of distinction, the pressure zone formed between the outer rotor and the inner rotor, which is mainly used for fluid conveyance, is also referred to as the "main pressure zone", and the pressure chambers defined above for radial compensation and generated by the pressure element are also referred to as the "secondary pressure zone".

[0010] In a particular embodiment, the gerotor pump has at least two pressure elements. Particularly preferably, the gerotor pump has at least three to seven, further preferably at least eight pressure elements. Particularly preferably, the gerotor pump has exactly eight pressure elements or exactly six pressure elements.

[0011] In an advantageous embodiment, the housing has a plurality of housing openings along its inner circumference, in each of which the pressure element is at least partially arranged. The housing openings (hereinafter also referred to as "openings") are advantageously slots and / or holes. Advantageously, the pressure element rests against the housing in the housing openings in the circumferential direction of the housing. The pressure element rests against the outer circumference of the outer rotor or is placed or prestressed against the outer circumference of the outer rotor.

[0012] The housing opening is advantageously fluidically connected to the inlet pump chamber and / or the outlet pump chamber, respectively. In other words, the fluid to be conveyed reaches the opening. This has the advantage that during operation of the gerotor pump, the pressure element rests on the outer rotor due to the hydraulic pressure in the opening, so that a secondary pressure zone is thus formed. The arrangement of the pressure element in the housing opening also has the advantage that the inner rotor or the outer rotor does not necessarily need to be adjusted, thereby simplifying the manufacture of the gerotor pump.

[0013] Advantageously, the Gerotor pump has a plurality of spring elements, wherein each spring element is arranged in one of the housing openings. The spring elements preload the corresponding pressure element (in the same housing opening) toward the outer rotor. In other words, the spring elements press the pressure element toward the outer rotor.

[0014] The spring element is advantageously a helical spring or a leaf spring, wherein different types of spring elements can be arranged in different housing openings. In addition, a plurality of spring elements can be arranged in a housing opening. For example, two helical springs can be arranged in one housing opening. Alternatively or in other housing openings, a (single) leaf spring can be arranged in the housing opening.

[0015] In an advantageous embodiment, the outer rotor has a plurality of openings along its outer circumference, in each of which pressure elements are at least partially arranged. The openings are advantageously slots and / or holes. The openings are respectively connected to the inlet pump chamber and / or the outlet pump chamber fluid. In other words, the fluid to be conveyed reaches the openings. This has the advantage that the pressure elements between the outer rotor and the housing can be at least partially accommodated by the outer rotor. This advantageously reduces the structural dimensions of the Gerotor pump.

[0016] The pressure element is radially movable and is advantageously arranged at least partially in the above-mentioned opening / housing opening. In the case of a pressure element arranged in an opening of the outer rotor, the pressure element can, for example, be arranged completely inside the corresponding opening in the rest state of the pump and, during operation of the pump, be moved radially outwards due to the acting centrifugal forces so as to be arranged only partially in the corresponding opening. During operation of the pump, the pressure elements can all emerge from their corresponding openings to the same or similar extent or to different extents from each other.

[0017] When the pressure element is arranged in the housing opening, the pressure element can be arranged completely in the corresponding opening in the rest state of the pump. When the pump is running, the hydraulic pressure of the inlet pump chamber and / or the outlet pump chamber connected to the opening fluid makes the corresponding pressure element lean against the outer rotor.

[0018] In another example, the pressure element can also be resting or prestressed against the outer rotor in the idle state of the pump by means of a spring element.

[0019] In an advantageous embodiment, the housing has a housing cover and a housing bottom, between which the inner rotor and the outer rotor are arranged (in the axial direction). In the axial direction, there are spacings between the housing cover, the inner rotor and the outer rotor and between the housing bottom, the inner rotor and the outer rotor, which spacings form parts of the inlet pump chamber and the outlet pump chamber, so that the fluid to be conveyed axially surrounds the inner rotor and the outer rotor.

[0020] In a preferred embodiment, the housing cover and / or the housing bottom advantageously have grooves, which together with the gap between the inner rotor and the outer rotor form an inlet pump chamber and an outlet pump chamber. The groove advantageously extends at least partially in the circumferential direction of the outer rotor. In a top view (defined as a cross section looking at the outer rotor and the inner rotor perpendicular to the axis of rotation), the grooves are arranged on both sides of the inlet and / or the outlet in the circumferential direction and extend away from the inlet and / or the outlet in the circumferential direction. The volume of the inlet pump chamber and / or the outlet pump chamber between the housing cover / the housing bottom and the outer rotor and / or the inner rotor is advantageously increased by the grooves, thereby reducing the viscous friction with the fluid, and therefore the surface with the necessary small gap / tolerance can be reduced, and the efficiency of the pump is thereby improved.

[0021] In a preferred design, the pressure element is a rotary slide. Here, the pressure element designed as a rotary slide is preferably substantially rectangular and plate-shaped. Advantageously, the rotary slide has rounded corners.

[0022] It is further advantageous that at least one side surface of the rotating slide arranged in the opening of the outer rotor, in particular the side surface of the rotating slide in contact with the outer rotor, is rounded. This reduces the friction between the rotating slide and the housing. It is further advantageous that at least one side surface of the rotating slide arranged in the opening of the outer rotor, in particular the side surface of the rotating slide in contact with the outer rotor, is rounded. This reduces the friction between the rotating slide and the outer rotor.

[0023] Advantageously, the height of the rotating slider in the axial direction of the outer rotor is less than the height of the outer rotor or less than the height of the housing in the axial direction. In other words, the depth of the opening or slot or hole in the outer rotor or housing in the axial direction is advantageously greater than the height of the corresponding rotating slider. This has the advantage that the fluid to be conveyed can flow from the inlet pump chamber along the rotating slider into the housing space or housing opening between the outer rotor and the housing with particularly low viscous friction. By adjusting the height of the rotating slider, the amount of fluid flowing on the rotating slider as described above can be controlled, and therefore the pressure between the pressure chambers generated by the rotating slider can be controlled. In a special design, the rotating sliders have different heights, or they all have the same height.

[0024] In some special embodiments, the height of the rotary slide is 90%, preferably 95%, more preferably 98% of the height of the outer rotor or the height of the housing. Preferably, the height difference between the outer rotor or the housing and the rotary slide is greater than the height difference caused (only) by manufacturing tolerances. In this way, a particularly good effect of the rotary slide can be achieved and friction is reduced. Alternatively, the height of the rotary slide can be about 50% of the height of the outer rotor or the height of the housing.

[0025] The height is to be understood in particular to mean the (axial) length of the side surface on the housing side or of the side surface on the outer rotor side.

[0026] In an advantageous design, the rotating slide separates the housing space at least partially in the circumferential direction of the outer rotor. During operation, a pressure chamber is formed at least in the circumferential direction between the rotating slides. Preferably, these pressure chambers are formed in addition to the main pressure zone (between the inner rotor and the outer rotor) described above. These pressure chambers are advantageously formed in the circumferential direction between the rotating slides and in the radial direction between the outer rotor and the housing. When the pump is running, the fluid pressure in the pressure chamber is advantageously not axisymmetric with respect to the axial direction or with respect to the axis of rotation of the outer rotor and / or the inner rotor. In other words, the pressure generated in the pressure chamber is different between at least some of the pressure chambers. As a result, a force is advantageously generated that places the outer rotor against the inner rotor, so that the gap therebetween is reduced and the efficiency is thereby improved.

[0027] In an advantageous design, the pressure element is a piston. Advantageously, the respective opening is designed as a hole in which the respective piston is arranged radially displaceably. The opening is fluidically connected to the inlet pump chamber and / or the outlet pump chamber.

[0028] In the case where the piston is arranged in the outer rotor, when the pump is running, the piston moves radially inwards, thereby applying pressure to the fluid located in the opening. This pressure in turn applies a force to the outer rotor, which forces the outer rotor against the inner rotor and reduces the gap, thereby improving efficiency. In the case where the piston is arranged in the housing, when the pump is running, the piston is moved radially inwards by the pressure filled in the inlet pump chamber or the outlet pump chamber, so that the piston presses the outer rotor against the inner rotor and reduces the gap, thereby improving efficiency.

[0029] Advantageously, the corresponding piston seals the radial housing-side end of the opening in the outer rotor or the radial outer rotor-side end of the opening in the sealing housing. In other words, each opening in the outer rotor in which such a piston is arranged has a radially inner (inner rotor side) end and a radially outer (housing side) end, wherein the piston is movably at least partially extended from the housing-side end. The radial inner side of the opening in the outer rotor forms a piston pressure chamber with the piston, which is the inner side of the opening on its radial inner end and is connected to the inlet pump chamber and / or the outlet pump chamber fluid. In the case where the piston is arranged in the opening of the housing, the radial inner end of the opening is arranged on the outer rotor side of the housing, and the radial outer end of the opening is arranged radially more outward in the housing. Here, the piston pressure chamber is formed between the radial outer end of the housing opening and the piston, which is arranged between the housing and the outer rotor.

[0030] In other words, the piston and the opening together form a piston-cylinder assembly. The piston pressure chamber advantageously exerts the above-mentioned bearing force on the outer rotor, thereby increasing the efficiency of the pump.

[0031] The radially inner end of the opening in the outer rotor or the radially outer end of the housing opening is preferably connected to the gap between the outer rotor and the housing cover or, depending on the axial orientation of the opening, to the gap between the outer rotor and the housing bottom, so that the fluid in this gap can flow into the opening.

[0032] Advantageously, the design of the pressure element as a rotating slide and as a piston can be combined. For example, at least one pressure element is designed as a rotating slide and at least one pressure element is designed as a piston. Furthermore, the pressure element can be designed functionally as a rotating slide and a piston at the same time, for example by designing the rotating slide as a piston, which has an exemplary height in the axial direction, which is at least 50% or 90% of the height of the outer rotor or one of the other values ​​mentioned above with respect to the rotating slide. Advantageously, such a piston here at least partially separates the housing space in the circumferential direction of the outer rotor and forms a further pressure chamber between the outer rotor and the housing in the circumferential direction in addition to the piston pressure chamber.

[0033] In an alternative design, the outer rotor and the housing space have different center point axes that are perpendicular to the radial direction. In this case, the center point axis of the housing space and the rotation axis of the outer rotor are particularly different. In other words, the outer rotor is not arranged centrally in the housing space. This has the advantage that the secondary pressure chambers are asymmetrical and the forces generated by these pressure chambers press the outer rotor against the inner rotor, thereby improving efficiency. Due to the different center point axes, the angular position or circumferential position of the maximum pressure generated in the secondary pressure chambers changes accordingly when the pump is running, so that the pressure force of all secondary pressure chambers offsets the pressure force of the main pressure chamber that presses the outer rotor against. If the pressure from the main pressure chamber is more than compensated (more than completely offset), the gap between the outer rotor and the inner rotor is reduced, thereby further improving efficiency.

[0034] Preferably, the outer rotor has at least one, in particular a plurality of outer rotor grooves distributed in the circumferential direction. The outer rotor grooves are formed in particular between the above-mentioned openings in the circumferential direction. The outer rotor grooves advantageously reduce the viscous friction with the fluid between the outer rotor and the housing cover and / or the housing bottom. The outer rotor grooves can be formed on one or both axial sides (housing bottom side and / or housing cover side) of the outer rotor. The outer rotor grooves are formed in particular as recesses in the outer rotor that are elongated in the circumferential direction and deepened in the axial direction. Preferably, the inner rotor can also have such corresponding grooves (inner rotor grooves).

[0035] Preferably, the housing has at least one, in particular a plurality of housing grooves distributed in the circumferential direction. The housing grooves are in particular formed between the above-mentioned housing openings in the circumferential direction. The housing grooves advantageously reduce the viscous friction with the fluid between the housing and the housing cover and / or the housing bottom. The housing grooves can be formed on one or both axial sides of the housing (the housing bottom side and / or the housing cover side). The housing grooves are in particular formed as recessed portions in the housing that are elongated in the circumferential direction and deepened in the axial direction. Preferably, the inner rotor and / or the outer rotor can have such a groove.

[0036] In some embodiments, the gerotor pump further comprises at least one compensation plate (English: "compensation plate"), which is arranged in the axial direction between the housing cover and / or the housing bottom and the inner rotor and / or the outer rotor (respectively) and can realize axial compensation of the gerotor pump. As a result, the gerotor pump advantageously has radial compensation and axial compensation, which makes it particularly efficient.

[0037] The present invention also relates to a motor-pump unit. The motor-pump unit has a gerotor pump according to the preferred design scheme described above. In addition, the motor-pump unit has a motor, which is connected to the inner rotor and is configured to rotate the inner rotor to drive the gerotor pump. The motor is mechanically connected to the inner rotor, in particular by means of a shaft. The motor-pump unit has an improved efficiency.

[0038] Gerotor pumps and motor-pump units also have the following advantages. Due to the compensation tolerances (radial compensation or radial compensation and axial compensation), their components can be manufactured at significantly lower costs, since the manufacturing tolerances can be significantly increased. Due to the higher efficiency, they can be used in higher pressure ranges. In addition, the radial compensation increases the performance stability at different pressures. Furthermore, no additional control device is required for the radial compensation described above, since the radial compensation operates in an autonomous manner via a hydraulic operating principle.

[0039] The preferred embodiments and effects described above are independent of the direction of rotation of the outer rotor or the inner rotor.

[0040] Further details, advantages and features of the invention will be apparent from the following description of exemplary embodiments with the aid of the accompanying drawings. In the drawings:

[0041] Figure 1 A schematic cross-sectional view showing a gerotor pump according to a first embodiment of the present invention;

[0042] Figure 2 A schematic top view of a gerotor pump according to a first embodiment of the present invention is shown;

[0043] Figure 3 A perspective detail view showing the outer rotor of a gerotor pump according to a first embodiment of the present invention;

[0044] Figure 4 A perspective detail view showing the outer rotor and the rotating slide of a gerotor pump according to a first embodiment of the present invention;

[0045] Figure 5 A schematic cross-sectional view showing a gerotor pump according to a second embodiment of the present invention;

[0046] Figure 6 A schematic cross-sectional view showing a gerotor pump according to a third embodiment of the present invention;

[0047] Figure 7 Another schematic cross-sectional view showing a gerotor pump according to a third embodiment of the present invention; and

[0048] Figure 8 A schematic block diagram of a motor-pump unit according to an embodiment of the present invention is shown.

[0049] Figure 1 A schematic cross-sectional view of a gerotor pump 1 according to a first embodiment of the invention is shown.

[0050] A Gerotor pump 1 for conveying fluid (hereinafter referred to as "pump 1") has a rotatable inner rotor 7 and a rotatable outer rotor 6. The inner rotor 7 is designed as a gear and the outer rotor 6 is designed as a ring gear.

[0051] The inner rotor 7 and the outer rotor 6 are accommodated in a housing space 11 of a housing 10 . In this case, the inner rotor 7 is arranged in a radial direction 15 inside the outer rotor 6 .

[0052] The inner rotor 7 can rotate about the inner rotor rotation axis 8, and the outer rotor 6 can rotate about the outer rotor rotation axis 9. Figure 1 It can be seen that the axes of rotation 8, 9 are arranged different from each other, that is, parallel to each other. When the pump 1 is in operation, the rotation of the inner rotor 7 causes the rotation of the outer rotor 6. Figure 2 The operation of pump 1 is explained.

[0053] As from Figure 1 It can further be seen that in the present embodiment, the outer rotor 6 is not arranged centrally in the housing space 11, at least in the rest state of the pump 1. In other words, the center point axes of the housing space 11 and the outer rotor 6 are different from each other. The inner rotor 7 is arranged centrally in the housing space 11, so that the center point axis of the housing space 11 coincides with the inner rotor rotation axis 8. In the present case, the center point axis of the outer rotor 6 coincides with the outer rotor rotation axis 9.

[0054] The outer rotor 6 has at least two, here eight, openings 16 on its outer circumference 13. Figure 3 and Figure 4 As explained, the openings 16 are slots. In the present case, the openings 16 are preferably evenly distributed, i.e. symmetrically arranged on the outer circumference 13 of the outer rotor 6. In an alternative special design, the openings 16 can be arranged asymmetrically along the outer circumference 13, so that different spacings are formed between at least two pairs of openings 16 along the outer circumference 13.

[0055] A rotating slide 12 serving as a pressure element is arranged in each opening. The rotating slide 12 can move radially inside the corresponding opening 16. When the outer rotor 6 rotates, the centrifugal force generated by the rotation causes the rotating slide 12 to extend from the corresponding opening 12 and abut against the housing 10.

[0056] As explained below (see Figure 2 ), when the pump 1 is running, the fluid to be conveyed is partially still located in the housing space 11 between the outer rotor 6 and the inner rotor 7. When the outer rotor 6 rotates, the rotating slide 12 forms a pressure chamber 14. Here, the pressure chamber 14 is formed between the outer rotor 7 and the housing 10 in the radial direction 15, and between the rotating slides 12 in the circumferential direction 18.

[0057] Due to the eccentric rotation of the outer rotor 6 in the housing space 11, the pressure chambers 14 are formed with different fluid pressures. These different fluid pressures at different circumferential positions around the outer rotor 6 produce a combined force that presses the outer rotor 6 against the inner rotor 7. In the present case, the combined force advantageously causes the outer rotor 6 to press against the inner rotor 7 in the marked y direction. As a result, the gap between the opposing tips 19 of the outer rotor 6 and the inner rotor 7 is advantageously reduced. The reduction of the gap between the outer rotor 6 and the inner rotor 7 at the position of the opposing tips 19 has the most advantageous effect on reducing internal leakage and increasing the efficiency of the pump 1. With the help of Figure 2 To further elaborate on this point.

[0058] In addition, part of the fluid is radially further inwards than the corresponding rotating slide 12 inside the corresponding opening 16. Here, the fluid is located in the opening space 24 between the radial inner side 17 of the opening 16 and the rotating slide 12, thus forming an opening space pressure chamber 25. The opening space pressure chamber 25 provides elasticity of the rotating slide 12 and, as explained below with reference to the second embodiment, provides (further) support of the outer rotor 6. Alternatively or in addition thereto, a spring element can be arranged in the corresponding opening space 24, which makes the rotating slide 12 elastic or radially preloads / supports it.

[0059] Figure 2 A schematic top view of a gerotor pump 1 according to a first embodiment of the present invention is shown. Figure 2 In particular, the housing cover 20 is shown, which covers the outer rotor 6, the inner rotor 7 and the housing space 11. The components covered by the housing cover 20 are shown here with dashed lines. Figure 2 The rotary slide 12 is not shown.

[0060] More precisely, the pump 1 has a housing cover 20 and a housing bottom 21, wherein the housing bottom 21 is not (directly) visible in the present view. The inner rotor 7 and the outer rotor 6 are arranged between the housing cover 20 and the housing bottom 21 in an axial direction 30 of the outer rotor 6, which coincides with the outer rotor rotation axis 9 (here in the z direction). In this case, a spacing (axial gap) is formed in the axial direction 30 between at least the housing cover 20 (and / or at least the housing bottom 21), the outer rotor 6 and the inner rotor 7, so that the fluid surrounds the outer rotor 6 and the inner rotor 7.

[0061] Openings for the inlet 2 and the outlet 4 are formed in the housing bottom 21. The fluid is delivered by the pump 1 from the inlet 2 to the outlet 4. Figure 2It can be seen that the housing cover 20 has grooves 22, which extend in the circumferential direction 18 and are connected to the inlet 2 or the outlet 4, respectively. The grooves 22 together with the gaps 23 (hereinafter referred to as "volumes 23") between the teeth of the inner rotor 7 and the outer rotor 6 define the inlet pump chamber 3 and the outlet pump chamber 5 of the pump 1. The inlet pump chamber 3 and the outlet pump chamber 5 of the pump 1 also include the above-mentioned fluid or fluid volume between the housing cover 20 and / or the housing bottom 21, the outer rotor 6 and the inner rotor 7 in the axial direction 30.

[0062] When the pump 1 is in operation, the fluid is conveyed in the circumferential direction 18 from the inlet 2 to the outlet 4. Figure 2 It can be seen that the volume 23 of the gap first increases from the inlet 2 in the circumferential direction 18 (clockwise here), so the fluid is sucked in from the inlet 2. Subsequently, at the end of the groove 22 in the circumferential direction 18, the volume 23 first remains almost constant, and then the volume 23 decreases on this basis. Since the volume 23 decreases toward the outlet 4, the fluid is pressurized and the fluid is discharged from the outlet 4. The pressure zones of the fluid thus formed are also called "primary pressure zones", by means of which the fluid is mainly transported between the inlet 2 and the outlet 4, and the pressure zones formed by the above-mentioned rotating slide 12 are also called "secondary pressure zones".

[0063] At the location of the opposite tip 19, due to the smaller bearing surface of the tooth, the separation of the volume 23 and therefore the efficiency of the pump 1 at high fluid pressures is particularly sensitive to manufacturing tolerances and the bearing of the outer rotor 6. By bearing the outer rotor 6 against the inner rotor 7, the outer rotor 6 is formed by the outer rotor 6. Figure 1 The described rotating slide 12 , which reduces the gap between the opposing tips 19 , increases the efficiency of the pump 1 .

[0064] Figure 3 A perspective detail view of the outer rotor 6 of a Gerotor pump 1 according to a first embodiment of the present invention is shown. Figure 3 It can be seen that the outer rotor 6 is substantially a ring gear which has a slot as an opening 16 for receiving the rotating slide 12 .

[0065] Furthermore, the outer rotor 6 has a plurality of outer rotor grooves 26 which are formed between the openings 16 in the circumferential direction 18. The outer rotor grooves 26 reduce the viscous friction with the fluid between the outer rotor 6, the housing cover 20 and / or the housing bottom 21.

[0066] Figure 4 A perspective detail view of the outer rotor 6 and the rotating slide 12 of a Gerotor pump 1 according to a first embodiment of the present invention is shown. Figure 4 The housing bottom 21 is also shown.

[0067] As from Figure 4As can be seen in FIG, the rotary slide 12 rests on the housing bottom 21. The height 27 of the rotary slide 12 relative to the axial direction 30 is smaller than the height 28 of the outer rotor 6. In a special embodiment, the height 27 of the rotary slide 12 is between 90% and 98% of the height 28 of the outer rotor 6.

[0068] Due to the smaller height 27 of the rotating slide 12, the fluid indicated by the fluid flow 29 can flow from the inlet pump chamber 3 along the rotating slide 12 into the housing space 11 between the outer rotor 6 and the housing 10 particularly easily. In this case, the above-mentioned fluid between the housing cover 20, the outer rotor 6 and the inner rotor 7 (in the axial gap) can flow into the housing space 11 particularly easily, that is, with low viscous friction.

[0069] In this case, the rotary slide 12 also has a rounded housing-side side surface 31 , as a result of which the friction between the rotary slide 12 and the housing 10 is reduced.

[0070] Figure 5 A schematic cross-sectional view of a gerotor pump 1 according to a second embodiment of the invention is shown.

[0071] In the present embodiment, the pressure element is designed as a piston 32. Here, the Gerotor pump 1 has at least two, in the present case six pistons 32. The openings 16 are designed as radial holes in the outer circumference 13 of the outer rotor 6. The pistons 32 are radially movable and seal the radial housing-side ends 34 of the respective openings 16. Furthermore, the openings 16 are fluidically connected to the inlet pump chamber 3 and / or the outlet pump chamber 5. For this purpose, as Figure 5 As shown, the opening 16 has an additional axial hole ( Figure 5 The axial hole is connected to the radial hole (in the depth direction in the outer rotor 6). As a result, a substantially L-shaped hole is obtained in the outer rotor 6, wherein the corresponding piston 32 is arranged in the radial hole. As a result, the fluid between the housing cover 20 and the outer rotor 6 (in the axial gap) can flow into the opening 6 through the axial part of the hole. In other words, the axial hole is connected to the axial gap fluid.

[0072] As a result, a piston pressure chamber 33 is formed between the radial inner side 17 of the opening 16 and the corresponding piston 32. When the outer rotor 6 rotates, the piston 32 is pressed radially into the opening 16, wherein pressure is exerted on the fluid by the piston 32. The resulting pressure exerts a force on the radial inner side 17 of the opening 16 and thus on the outer rotor 6, thereby pressing the outer rotor against the inner rotor 7. The piston pressure chamber 33 is a secondary pressure region similar to the pressure chamber 14 generated by the rotating slide 12.

[0073] like Figure 5 and Figure 1A comparison of 2 and 3 shows that the piston 32 can also generate a pressure chamber 14 in the housing space 11 between the outer rotor 6 and the housing 10 . For this purpose, the piston 32 can have a corresponding height 27 of the rotary slide 12 .

[0074] In the above-described embodiment, the outer rotor 6 is not arranged centrally in the housing space 11 at least in the rest state of the pump 1. Alternatively, however, the outer rotor 6 can be arranged centrally in the housing space 11 in the rest state of the pump 1. Here, the pressure difference between the inlet 2 and the outlet 4 (primary pressure zone) causes the outer rotor 6 to lean against each other when the pump 1 is in operation. Especially at high pressures, this leaning also causes the outer rotor 6 to be arranged non-centrally in the housing space 11, so that in this case, secondary pressure zones are also formed during the operation of the pump 1. However, these secondary pressure zones at least partially offset the leaning caused by the primary pressure zones, so that the gap between the outer rotor 6 and the inner rotor 7 is reduced at least during the operation of the pump 1 and the efficiency of the pump is improved.

[0075] Figure 6 and Figure 7 Schematic cross-sectional views of a gerotor pump 1 according to a third embodiment of the present invention are respectively shown.

[0076] In the current embodiment, in particular, Figure 6 It can be seen that the housing 10 has a plurality of, here four, openings 37 (also referred to as housing openings 37) along its inner circumference 36. A radially displaceable pressure element is arranged as a rotary slide 35 in each of these housing openings 37. In this case, each rotary slide 35 rests against at least one inner surface 41 of the housing 10 or of the housing opening 37 in the circumferential direction 18, especially during operation of the gerotor pump 1.

[0077] Each rotary slide 35 protrudes from the radial inner side 39 of the housing opening 37 and is arranged on the outer rotor 6. Figure 7 It can be seen that each rotary slide 35 is resting or prestressed against the outer rotor 6 via a spring element 38 , here a leaf spring.

[0078] As from Figure 7 It can also be seen that the height 27 of the rotating slide 35 relative to the axial direction 30 is smaller than the height 42 of the housing 10. In this case, the height 27 of the rotating slide 35 is in particular smaller than the height 28 of the outer rotor 6. As in the first embodiment, the fluid can thus flow from the housing space 11 between the housing cover 20 and the housing 10 into the housing opening 37 particularly easily, i.e. with low viscous friction.

[0079] Preferably, the housing cover 20 or the housing bottom 21 can have recesses which guide the fluid into the housing opening 37. In this case, the spring element 38 can be functionally replaced at least partially by the fluid in the housing opening 37 which bears against the outer rotor 6.

[0080] As an alternative or in addition to the recess in the housing cover 20 or the housing bottom 21, the housing 10 may have a recess in the housing cover 20 or the housing bottom 21. Figure 6 One or more housing grooves 43 are shown in dashed lines in the figure. The housing groove 43 is an axial depression in the housing 10 and connects the two openings 37 to each other, so that they are fluidically connected to each other. In addition, the housing groove 43 shown connects the two openings 37 to the housing space 11, so that the openings 37 are fluidically connected to the housing space. As a result, the hydraulic pressure exerted by the fluid from the inlet pump chamber 3 and / or the outlet pump chamber 5 can cause the rotary slide 35 to rest on the outer rotor 6.

[0081] Furthermore, a plurality of housing recesses 43 may be arranged in the housing 10. In the present example of four openings 37, in particular two housing recesses 43 may be formed, which respectively connect two of the four openings 37 to one another. Thus, for example, two of the openings 37 may be fluidically connected to the inlet pump chamber 3, and the other two of the openings 37 may be fluidically connected to the outlet pump chamber 5, without causing these openings (in pairs) to be fluidically short-circuited.

[0082] The rotary slide 35 of the present embodiment brings the same advantages as the rotary slide 12 of the first embodiment. In other words, the rotary slide 35 radially generates a pressure chamber 14 in the housing space 11 between the outer rotor 6 and the housing 10, thereby causing the outer rotor 6 to come into contact.

[0083] The gerotor pump 1 according to the present embodiment can be combined with the gerotor pump 1 according to the first embodiment and / or the second embodiment. In this case, in particular, the rotary slide 35 of the present embodiment, in addition to being arranged in the housing 10, has a configuration similar to or identical to the pressure elements 12, 32 and the openings 16 of the first two embodiments with its associated openings 37. For example, the present rotary slide 35 can also be designed as a piston, which places the outer rotor 6 against the inner rotor 7. This combination can be combined particularly advantageously with the above-described configuration, in which the housing 10 has one or more housing recesses 43 in addition to or instead of possible recesses in the housing cover 20 or the housing bottom 21.

[0084] The present invention also relates to a motor-pump unit 100. Figure 8 The motor-pump unit is illustrated in , which shows a schematic block diagram of a motor-pump unit 100 according to one embodiment of the present invention.

[0085] The motor-pump unit 100 has a motor 101 and the gerotor pump 1 according to the above-described embodiment. The motor 101 is configured to rotate the inner rotor 7 to drive the gerotor pump 1. Here, the motor 101 is driven by a shaft 102 (see also Figure 2 ) is mechanically connected to the inner rotor 7.

[0086] The motor-pump unit 100 has a particularly high efficiency and is not subject to tolerances.

[0087] 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.

[0088] List of Reference Numerals

[0089] 1 Gerotor Pump

[0090] 2 Entrance

[0091] 3 Inlet pump room

[0092] 4. Export

[0093] 5 Outlet pump room

[0094] 6 Outer rotor

[0095] 7 Inner rotor

[0096] 8 Inner rotor rotation axis

[0097] 9 Outer rotor rotation axis

[0098] 10 Housing

[0099] 11 Shell space

[0100] 12 Rotate Slider

[0101] 13 Outer circumference of outer rotor

[0102] 14 Pressure Chamber

[0103] 15 Radial direction

[0104] 16 Opening

[0105] 17 radial inside

[0106] 18 Circumferential direction

[0107] 19 Opposite Tips

[0108] 20 Housing cover

[0109] 21 Shell bottom

[0110] 22 grooves

[0111] 23 Void / Volume

[0112] 24 Open Space

[0113] 25 Open Space Pressure Chamber

[0114] 26 Outer rotor groove

[0115] 27 Height of the rotating slider

[0116] 28 Height of outer rotor

[0117] 29 Fluid Flow

[0118] 30 Axial direction

[0119] 31 Side

[0120] 32 Piston

[0121] 33 Piston pressure chamber

[0122] 34 Open radial housing side end

[0123] 35 Rotate Slider

[0124] 36 Inner circumference of the shell

[0125] 37 Shell opening

[0126] 38 Spring element

[0127] 39 Radially inside the housing opening

[0128] 40 Radially outer side of the housing opening

[0129] 41 Inner surface of the shell

[0130] 42 Height of the housing

[0131] 43 Housing groove

[0132] 100 Motor-Pump Unit

[0133] 101 Motor

[0134] 102 Axis

Claims

1. A gerotor pump (1), the gerotor pump being used to transfer a fluid from an inlet pump chamber (3) of the gerotor pump (1) connected to an inlet (2) to an outlet pump chamber (5) of the gerotor pump connected to an outlet (4), the gerotor pump comprising: A rotatable outer rotor (6); a rotatable inner rotor (7) which is arranged radially inside the outer rotor (6), wherein the inner rotor (7) and the outer rotor (6) have different axes of rotation (8, 9) from one another; A housing (10), the housing having a housing space (11), the outer rotor (6) and the inner rotor (7) being received in the housing space; as well as A plurality of radially movable pressure elements (12, 32, 35) are arranged on the outer circumference (13) of the outer rotor (6) and bear against the housing (10) during operation, so that pressure chambers (14, 25, 33) are formed between the outer rotor (6) and the housing (10) and / or between the outer rotor (6) and the pressure elements (12, 32, 35) and are fluidically connected to the inlet pump chamber (3) and / or the outlet pump chamber (5).

2. The gerotor pump (1) according to claim 1, wherein the housing (10) has a plurality of housing openings (37), in particular slots and / or holes, along its inner circumference (36), in which a pressure element (35) is at least partially arranged.

3. The gerotor pump (1) according to claim 2 further comprises a plurality of spring elements (38), which are respectively arranged in housing openings (37) and are configured to preload the corresponding pressure element (35) toward the outer rotor (6).

4. A gerotor pump (1) according to claim 1, wherein the outer rotor (6) has a plurality of openings (16), in particular slots and / or holes, along its outer circumference (13), in which pressure elements (12, 32) are at least partially arranged, respectively, wherein the openings (16) are respectively fluidically connected to the inlet pump chamber (3) and / or the outlet pump chamber (5).

5. A gerotor pump (1) according to one of the preceding claims, wherein the housing (10) has a housing cover (20) and a housing bottom (21), between which the inner rotor (7) and the outer rotor (6) are arranged, and wherein the housing cover (20) and / or the housing bottom (21) have a groove (22), which together with the gap (23) between the inner rotor (7) and the outer rotor (6) forms the inlet pump chamber and the outlet pump chamber (3, 5).

6. The gerotor pump (1) according to claim 1, wherein the pressure element (12, 32, 35) is in each case a rotating slide (12, 35).

7. The gerotor pump (1) according to claim 6, wherein a height (27) of the rotating slider (12, 35) in the axial direction (30) of the outer rotor (6) is smaller than a height (28) of the outer rotor (6) or a height (42) of the housing (10) in the axial direction (30).

8. A gerotor pump (1) according to claim 6 or 7, wherein the rotating slide (12, 35) at least partially separates the housing space (11) along the circumferential direction (18) of the outer rotor (6), and during operation, a pressure chamber (14) is formed at least between the rotating slides (12, 35) along the circumferential direction (18).

9. The gerotor pump (1) according to claim 2, wherein the pressure element (12, 32, 35) is in each case a piston (32).

10. A gerotor pump (1) according to claim 9 in combination with claim 4 or 5, wherein the corresponding piston (32) seals the radial housing-side end (34) of the opening (16) and forms a piston pressure chamber (33) with the radial inner side (17) of the opening (16) during operation, the opening being fluidically connected to the inlet pump chamber (3) and / or the outlet pump chamber (5).

11. The gerotor pump (1) according to claim 1, wherein the outer rotor (6) and the housing space (11) have center point axes which are different from one another and which are perpendicular to the radial direction (15).

12. 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 (7) and configured to rotate the inner rotor (7) to drive the gerotor pump (1).

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