Axial piston machine with an asymmetric bearing assembly

Abstract

An axial piston machine includes at least one asymmetric bearing assembly rotatably supporting a swash plate. Rotation of the asymmetric bearing assembly off-set allows other elements of the axial piston machine to be arranged in locations that would otherwise be occupied by portions of the bearing assembly if a symmetric bearing assembly were used to support the swash plate. This configuration allows for a reduction in the overall package size of the axial piston machine in terms of bearing span and / or machine length. The axial piston machine can be an axial piston pump having a barrel defining a plurality of bores and having a respective piston arranged in each bore. The swash plate angle determines the displacement level of the machine.

Description

Technical Field

[0001] This disclosure relates generally to axial piston machines, and more particularly to axial piston machines with reduced overall package size in terms of bearing span and / or machine length. Background Technology

[0002] Axial piston machines are generally known. An axial piston machine can be an axial piston pump comprising a cylinder drum arranged rotatably within a housing and having a plurality of orifices or cylinders defined therein. A control plate connects the cylinders to a fluid reservoir. As each piston arranged in each orifice or cylinder moves, the fluid reservoir supplies fluid to the cylinder to increase the available volume of the orifice or cylinder for the fluid. A cylinder spring or plate retainer provides force to move the piston, thus increasing the volume of the cylinder. Once the cylinder drum is filled with fluid, as the cylinder drum rotates, an angled or inclined swashplate applies a compressive force to the piston, which causes the piston to reduce the available volume of the orifice or cylinder for the fluid contained therein, thereby applying force to the fluid to pressurize it, and discharging the pressurized fluid from the cylinder via the control plate. Thus, fluid is repeatedly drawn into each orifice or cylinder, the piston moves, thereby applying force to the fluid, and discharging the pressurized fluid from the orifice or cylinder via the control plate. A shaft connected to the cylinder drum drives the rotational movement of the cylinder drum.

[0003] The movement of the piston when drawing fluid into an orifice or cylinder can be called the inlet stroke, and the movement of the piston when applying force to the fluid and / or discharging the fluid can be called the outlet stroke. The lengths of the inlet and outlet strokes of each piston can be set by the angle between the cylinder roller and the angled or inclined swashplate, and this angle can vary from no angle when the piston has no movement in the cylinder to the maximum angle that provides the piston with maximum movement, and thus the piston applies the maximum possible work to the fluid in each orifice or cylinder.

[0004] One or more types of bearings are typically required to support the rotating or moving elements of an axial piston machine. For example, bearings can be implemented to adjust the angle of a swashplate. Any of these bearings can potentially significantly increase the overall package (i.e., the overall size or dimensions of the machine) of the axial piston machine in order to accommodate or accommodate the range of motion of the bearing itself and the elements it supports. Summary of the Invention

[0005] The axial piston machine according to this disclosure advantageously includes at least one asymmetric bearing assembly, which allows for a reduction in the overall package size of the axial piston machine compared to an axial piston machine having a symmetric bearing assembly. According to some embodiments, the axial piston machine includes: a housing; a roller configured to rotate within the housing, the roller defining a plurality of orifices; a plurality of pistons, each of the plurality of pistons being movably arranged within a corresponding orifice of the plurality of orifices; a swashplate configured to tilt to change the displacement level of the plurality of pistons; and at least one asymmetric bearing assembly rotatably supporting the swashplate. Attached Figure Description

[0006] Figure 1A This is a cross-sectional view of an existing axial piston machine;

[0007] Figure 1B yes Figure 1A Perspective end views of some components of existing axial piston machines;

[0008] Figure 1C yes Figure 1A Another cross-sectional view of an existing axial piston machine;

[0009] Figure 2A This is a cross-sectional view of an axial piston machine according to this disclosure;

[0010] Figure 2B Based on this disclosure Figure 2A A cross-sectional view of an axial piston machine, with the swashplate in a zero-angle position;

[0011] Figure 2C Based on this disclosure Figure 2A A cross-sectional view of an axial piston machine, with the swashplate at its maximum tilt angle.

[0012] Figure 3A Based on this disclosure Figure 2A An illustration of an axial piston machine, with the swashplate at its maximum tilt angle;

[0013] Figure 3B Based on this disclosure Figure 2A Another cross-sectional view of an axial piston machine;

[0014] Figure 4 This is a photograph of a portion of an axial piston machine according to this disclosure, showing an asymmetric bearing assembly;

[0015] Figure 5 These are photographs of a swashplate with an asymmetric bearing assembly according to this disclosure; and

[0016] Figure 6It is a cross-sectional view of an axial piston machine according to this disclosure, wherein the swashplate is in the position of maximum tilt angle. Detailed Implementation

[0017] Before proceeding with a detailed description of the various embodiments, it should be understood that the invention is not limited to the specific embodiments described. It should also be understood that the terminology used is for the purpose of describing particular embodiments only and is not intended to limit the scope of the claims of this application.

[0018] refer to Figures 1A to 1C The diagram shows a cross-sectional view of a prior art axial piston machine 100. The prior art machine 100 includes a housing 101 and a shaft 102 configured to rotate a roller 104, the roller 104 defining a plurality of bores or cylinders 106. The shaft 102 rotates about a rotation axis 103. The machine 100 also includes a swashplate 108 configured to act on a piston arranged in a roller 14 (also not shown in the prior art diagram) via a piston shoe (not shown in the prior art diagram). The swashplate 108 is rotatably supported by two bearings 110. The tilt angle of the swashplate 108 determines the level of displacement of the machine 100.

[0019] Each bearing 110 includes an inner raceway 112 and an outer raceway 114, between which a plurality of rollers 116 are arranged. Each bearing 110 may be referred to as a symmetrical roller bearing assembly because, as Figure 1C As shown, the center plane 118 of the bearing 110 is aligned with the rotation axis 103 of the shaft 112, that is, the center plane 118 of the bearing 110 is parallel to the rotation axis 103 of the shaft 102.

[0020] Partly due to the space requirements of the swashplate 108's range of motion and the size of the bearing 110, the prior art machine 100 has a bearing span 120 and a pump length 122. In the case of this prior art machine 100, the bearing span 120 is 120 mm and the pump length 122 is 219.5 mm.

[0021] refer to Figures 2A to 2CThis image shows a cross-sectional view of an exemplary embodiment of the axial piston machine 200 of this disclosure. Machine 200 is an axial piston pump. Machine 200 is similar in the sense of a prior art machine 100, which includes a housing 201 and a shaft 202 configured to rotate a roller 204 defining a plurality of bores or cylinders 206. The shaft 202 rotates about a rotation axis 203. Machine 200 also includes a swashplate 208 configured to act on a piston 224 disposed in the roller 204 via a piston shoe 226. The piston shoe 226 slides on a guide surface of the swashplate 208. The swashplate 208 is rotatably supported by one or more bearings 228 (or asymmetric bearings or asymmetric bearing assemblies). In some embodiments, the swashplate is rotatably supported by two bearings 228 (asymmetric bearing assemblies). The tilt angle of the swashplate 208 determines the displacement level of the machine 200.

[0022] Each bearing 228 includes an inner raceway 230 and an outer raceway 232, between which a plurality of rollers 234 are arranged. The inner raceway 230 rotates as the swashplate 208 moves. Unlike the prior art machine 100, the bearing(s) 228 of the axial piston machine according to this disclosure may be referred to as an asymmetric roller bearing assembly. The raceways 230, 232 are relative to (e.g., as...) Figures 1A to 1C The raceway position of the symmetrical roller bearing assembly shown is rotational. Figures 2A to 2C In the illustrated embodiment, when the swashplate 208 is at zero swashplate angle (e.g.) Figure 2B As shown), the outer raceway 232 rotates 24° clockwise, and the inner raceway 230 rotates 3.5° counterclockwise relative to the outer raceway 232. It should be understood that other degrees of relative offset in asymmetric roller bearing assemblies are within the scope of this disclosure, and embodiments of this disclosure are not limited to this combination. Figures 2A to 2C The embodiment is described and shown with precise angular offset. The center plane of bearing 228 is not aligned with the axis of rotation 203 of shaft 202.

[0023] The inner raceway 230 and / or the outer raceway 232 are rotationally offset such that one end of the inner raceway 230 and / or the outer raceway 232 does not extend beyond the guide surface of the swashplate 208, which is the surface on which the piston shoe 226 slides during operation. Figure 2B and Figure 2C As shown, the inner raceway 230 is held in place by a retaining feature arranged in a groove 209 defined by the swash plate 208. The housing 201 is configured to allow a shoe retainer to be arranged in a region 236, which will be occupied by a symmetrical bearing assembly but not by the asymmetrical bearing assembly 228 according to this disclosure.

[0024] Advantageously, the machine 200 having one or more of the asymmetric bearings 228 as described above allows for a more compact overall package. For example, and without limitation, the bearing span 220 can be reduced to 107 mm, and the pump length 222 can be reduced to 198.6 mm, both smaller than the corresponding dimensions of the prior art machine 100. Other bearing span and machine length dimensions are within the scope of this disclosure.

[0025] One or more bearings 228 are asymmetrical, allowing the area 236 near the swashplate 208, previously occupied by conventional bearing assemblies, to now be occupied by other elements. For example, and without limitation, area 236 could be occupied by a shoe retainer. This innovative configuration allows for a reduced overall machine size, such as a reduced bearing span 220 and / or a reduced pump length 222.

[0026] refer to Figure 3A and Figure 3B The diagram illustrates an asymmetric bearing assembly, showing the outer raceway rotated 24° clockwise relative to the outer raceway of a conventional bearing assembly that would house a support swashplate. Other rotational offsets are within the scope of this disclosure (e.g., rotational offsets less than or greater than 24°).

[0027] refer to Figure 4 and Figure 5 The images show photographs of portions of an axial piston machine according to this disclosure. Each of these photographs shows an asymmetric bearing assembly configured to rotatably support the swashplate in the manner described above, thereby allowing for a reduction in the overall package size of the machine.

[0028] refer to Figure 6 This image shows a cross-sectional view of an exemplary embodiment of the axial piston machine of this disclosure. The machine is similar to... Figures 2A to 2C The machine 200, however, has asymmetric bearing assemblies with sliding elements arranged between raceways instead of multiple rollers. Any bearing assembly element or mechanism is within the scope of this disclosure, provided that the outer and / or inner raceways can be rotationally offset as disclosed herein.

[0029] As will be recognized by those skilled in the art, many changes and modifications can be made to the above-described embodiments of this disclosure without departing from the spirit of the invention as defined in the appended claims. Therefore, the specific embodiments described are to be considered illustrative rather than restrictive.

Claims

1. A hydraulic axial piston machine, comprising: case; A roller configured to rotate within the housing, the roller defining a plurality of holes; A plurality of pistons, each of the plurality of pistons being movably arranged within a corresponding hole in the plurality of holes; A swashplate, which is configured to tilt to change the displacement level of the plurality of pistons; and At least one asymmetric bearing assembly that supports the swashplate in a rotatable manner.

2. The hydraulic axial piston machine of claim 1, further comprising a shaft connected to the roller and configured to rotate about a rotation axis, wherein the central plane of the at least one asymmetric bearing assembly is not aligned with the rotation axis.

3. The hydraulic axial piston machine according to claim 1, wherein, The outer raceway of the at least one asymmetric bearing assembly is rotated 24° clockwise relative to the symmetric bearing assembly in order to support the swashplate, and the inner raceway of the at least one asymmetric bearing assembly is rotated 3.5° counterclockwise relative to the outer raceway.

4. The hydraulic axial piston machine according to claim 1, wherein, The swash plate defines a groove, which is configured to accommodate the bearing retention feature of the at least one asymmetric bearing assembly.

5. The hydraulic axial piston machine according to claim 4, wherein, The at least one asymmetric bearing assembly includes the bearing retaining feature, and the bearing retaining feature is arranged within the slot of the swashplate.

6. The hydraulic axial piston machine according to claim 1, wherein, The at least one asymmetric bearing assembly includes a plurality of rollers arranged between the outer raceway and the inner raceway.

7. The hydraulic axial piston machine according to claim 1, wherein, The at least one asymmetric bearing assembly includes a sliding element arranged between the outer raceway and the inner raceway.

8. The hydraulic axial piston machine according to claim 1, wherein, Each of the plurality of pistons engages with a corresponding piston shoe on the guide surface of the swashplate.

9. The hydraulic axial piston machine according to claim 8, wherein, The at least one asymmetric bearing assembly is rotationally offset such that one end of the outer raceway and / or one end of the inner raceway of the at least one asymmetric bearing assembly does not extend beyond the guide surface of the swashplate.

10. The hydraulic axial piston machine according to claim 1, wherein, The central plane of at least one asymmetric bearing assembly is not aligned with the axis of rotation of the shaft connected to the roller.

11. A hydraulic axial piston machine, comprising: case; Swashplate, which is arranged within the housing; and An asymmetric bearing assembly that supports the swashplate in a rotatable manner.

12. The hydraulic axial piston machine of claim 11, further comprising a shaft connected to a roller and configured to rotate about a rotation axis, wherein the central plane of the asymmetric bearing assembly is not aligned with the rotation axis.

13. The hydraulic axial piston machine according to claim 11, wherein, The outer raceway of the asymmetric bearing assembly is rotated 24° clockwise relative to the symmetric bearing assembly in support of the swashplate, and the inner raceway of the asymmetric bearing assembly is rotated 3.5° counterclockwise relative to the outer raceway.

14. The hydraulic axial piston machine according to claim 11, wherein, The swash plate defines a groove, which is configured to accommodate bearing retaining features of the asymmetric bearing assembly.

15. The hydraulic axial piston machine according to claim 14, wherein, The asymmetric bearing assembly includes the bearing retaining feature, and the bearing retaining feature is arranged within the slot of the swashplate.

16. The hydraulic axial piston machine according to claim 11, wherein, The asymmetric bearing assembly includes a plurality of rollers arranged between the outer raceway and the inner raceway.

17. The hydraulic axial piston machine according to claim 11, wherein, The asymmetric bearing assembly includes a sliding element arranged between the outer raceway and the inner raceway.

18. The hydraulic axial piston machine of claim 11, further comprising a plurality of pistons arranged in a bore of the drum, wherein each of the plurality of pistons engages with a corresponding piston shoe on the guide surface of the swashplate.

19. The hydraulic axial piston machine according to claim 18, wherein, The at least one asymmetric bearing assembly is rotationally offset such that one end of the outer raceway and / or one end of the inner raceway of the at least one asymmetric bearing assembly does not extend beyond the guide surface of the swashplate.

20. The hydraulic axial piston machine according to claim 11, wherein, The central plane of the at least one asymmetric bearing assembly is not aligned with the axis of rotation of the shaft connected to the roller.

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