Axial piston pump bearing assembly and axial piston pump

Abstract

The present invention relates to a force bearing assembly of an axial piston pump and an axial piston pump, wherein the force bearing assembly comprises a flow distribution seal axial thrust bearing, a static pressure main bearing and a large axial thrust bearing; the flow distribution seal axial thrust bearing comprises a thrust plate guide assembly, a thrust plate assembly and a flow distribution plate assembly which are coaxially arranged in sequence, and a thrust mechanism is coaxially arranged on the outer side of the thrust plate guide assembly; the static pressure main bearing comprises a static pressure inner ring and a static pressure outer ring, the outer cylindrical surface of the static pressure inner ring is provided with a static pressure pad, the outer cylindrical surface of the static pressure outer ring is provided with a high-pressure water annular groove which is connected with the static pressure pad, and a dynamic pressure support friction surface is provided at one end of the static pressure outer ring; a combined surface is provided on the large axial thrust bearing, and the combined surface comprises a wedge surface, a large bearing support surface and a convection groove; the axial piston pump adopts the force bearing assembly. The bearing assembly of the present invention can withstand greater impact, vibration and swing, and has higher reliability, so that the piston pump can operate normally in a large swing and large impact environment.

Description

Technical Field

[0001] The invention belongs to the technical field of plunger pumps, and in particular relates to a force bearing assembly of an axial plunger pump and an axial plunger pump. Background Art

[0002] The plunger pump is an important device in the water hydraulic system. It relies on the reciprocating motion of the plunger in the cylinder to change the volume of the sealed working chamber to achieve water absorption and water pressure. The plunger pump has the advantages of high rated pressure, compact structure, high efficiency and convenient flow adjustment.

[0003] Axial piston pumps (English name: Piston pump) are piston pumps in which the reciprocating motion direction of the piston or plunger is parallel to the central axis of the cylinder. Axial piston pumps work by using the volume change caused by the reciprocating motion of the plunger parallel to the transmission shaft in the plunger hole. Since the plunger and the plunger hole are both round parts, they can be matched with high precision, so the volumetric efficiency is high.

[0004] At present, the bearing support structure of the axial piston pump is a dynamic pressure support. The bearing life is short and it cannot withstand axial force. In the case of axial force, the pump will be damaged. The plunger cylinder relies on dynamic pressure support to operate, and the speed cannot be too low. Too low will cause the dynamic pressure support of the plunger cylinder to fail and tilt, which will cause the return stroke of the plunger to fail, causing irreversible damage to the pump. This bearing structure has many restrictions on the operating conditions of the pump. Improper installation and operation and maintenance will cause serious irreversible damage to the pump. This often discourages users. Summary of the invention

[0005] The object of the present invention is to provide a load-bearing bearing assembly of an axial piston pump and an axial piston pump, wherein the bearing assembly can withstand greater impact, vibration and swing, and has higher reliability, so that the piston pump can operate normally in an environment with large swing and large impact.

[0006] In order to achieve the above object, the technical solution adopted by the present invention is: a load bearing assembly of an axial piston pump, comprising a flow distribution seal axial thrust bearing, a static pressure main bearing and an axial thrust large bearing arranged along the axial direction of the piston pump;

[0007] The flow distribution seal axial thrust bearing comprises a thrust plate guide assembly, a thrust plate assembly and a flow distribution plate assembly which are coaxially arranged in sequence, the thrust plate guide assembly, the thrust plate assembly and the flow distribution plate assembly are all annular disc structures, and a thrust mechanism is coaxially arranged outside the center hole of the thrust plate guide assembly, the thrust mechanism is connected to the end face of the plunger cylinder of the axial piston pump, and the guide piece on the thrust plate guide assembly is sealed and connected to the plunger hole of the plunger cylinder; the flow distribution seal axial thrust bearing is provided with a medium channel connected to the plunger hole of the plunger cylinder;

[0008] The static pressure main bearing comprises a static pressure inner ring and a static pressure outer ring, the static pressure outer ring is supported on a support surface at the end of the static pressure inner ring, a static pressure pad is arranged on the outer circumferential surface of the static pressure inner ring, a high-pressure water annular groove is arranged on the outer circumferential surface of the static pressure outer ring, and the high-pressure water annular groove is connected with the static pressure pad through the static pressure main bearing pressure supply hole; a dynamic pressure support friction surface is arranged at one end of the static pressure outer ring, and is in friction contact with the support surface, and a plurality of Archimedean spiral convection grooves are arranged on the dynamic pressure support friction surface along its circumference;

[0009] The large axial thrust bearing is cylindrical, and a combined surface is provided on the end surface of the large axial thrust bearing facing the hydrostatic main bearing. The combined surface contacts the inner ring friction surface of the hydrostatic inner ring. The combined surface includes a wedge surface, a large bearing support surface and a convection groove connected in sequence. A plurality of the combined surfaces are arranged in sequence along the circumferential direction on the end surface of the large axial thrust bearing.

[0010] The through hole on the thrust plate guide assembly, the distribution hole on the distribution plate assembly and the valve hole on the thrust plate assembly are connected to form the medium channel.

[0011] The thrust mechanism comprises a thrust retaining ring and a plurality of springs installed on the same side of the thrust retaining ring, wherein the plurality of springs are arranged at intervals along the circumference of the thrust retaining ring.

[0012] The thrust plate assembly comprises a coaxially connected thrust plate support ring and a thrust plate wear-resistant ceramic ring. The outer circumferential surface of the thrust plate wear-resistant ceramic ring is assembled on the inner circumferential surface of the thrust plate support ring. The thrust plate support ring is a metal ring. A plurality of valve holes are arranged on the thrust plate wear-resistant ceramic ring at intervals along the circumferential direction.

[0013] The distribution plate assembly includes a distribution plate support ring and a distribution plate ceramic wear-resistant ring which are coaxially connected. The distribution plate support ring is a metal ring. The outer circumferential surface of the distribution plate ceramic wear-resistant ring is assembled on the inner circumferential surface of the distribution plate support ring. A plurality of distribution holes are arranged on the distribution plate ceramic wear-resistant ring at intervals along the circumferential direction.

[0014] The thrust plate guide assembly, the thrust plate assembly and the distribution plate assembly are connected by bolts.

[0015] The static pressure pad of the static pressure inner ring is a wedge-shaped stepped structure, including a first static pressure water pad and a second static pressure water pad. A second static pressure water pad is arranged at each axial end of the first static pressure water pad. The first static pressure water pad is lower than the two second static pressure water pads to form a stepped structure. The two second static pressure water pads are both wedge-shaped structures, and the small diameter end is connected to the first static pressure water pad.

[0016] In the combined surface of the large axial thrust bearing, the angle of the wedge surface is 1-2°, and the convection groove is an Archimedean spiral convection groove.

[0017] The large axial thrust bearing comprises a PEEK sleeve ring and an alloy inner core embedded in the PEEK sleeve ring, and the combined surface is arranged at one end of the PEEK sleeve ring.

[0018] An axial piston pump comprises a pump casing, one end of which is provided with an inlet and outlet flange, a plunger cylinder, a swash plate, a plunger and a plunger forced return assembly are arranged in the pump casing, the rotating shaft of the plunger pump is transmission-connected to the plunger cylinder, the plunger and the plunger forced return assembly are arranged between the plunger cylinder and the swash plate, and the above-mentioned force bearing assembly is also arranged in the pump casing.

[0019] The beneficial effects of the present invention are as follows: the present invention can withstand relatively large axial forces by optimizing the structure and material selection of each load-bearing bearing. Under the action of the axial force, the pump will not fail and can operate normally; at the same time, it can also improve the effect of resisting vibration, swing, and impact, and can operate normally in an environment with large swing and impact.

[0020] The present invention adopts more static pressure, dynamic pressure and damping design elements, thereby improving the reliability of the product and extending the service life of the product. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a structural schematic diagram of the present invention;

[0022] Figure 2 The flow distribution and flow distribution seal axial thrust bearing of the present invention;

[0023] Figure 3 for Figure 2 Structural schematic diagram of the middle thrust plate guide assembly;

[0024] Figure 4 for Figure 2 A schematic diagram of the structure of the pre-sealing thrust mechanism;

[0025] Figure 5 for Figure 2 Axial cross-sectional view of the middle thrust plate assembly;

[0026] Figure 6 for Figure 2 Axial cross-sectional view of the middle valve plate;

[0027] Figure 7 It is a schematic diagram of the structure of the static pressure inner ring of the static pressure main bearing in the present invention;

[0028] Figure 8 It is a cross-sectional view of the hydrostatic inner ring of the hydrostatic main bearing in the present invention;

[0029] Fig. 9 It is a schematic structural diagram of the hydrostatic outer ring of the hydrostatic main bearing in the present invention;

[0030] Fig.10It is a structural schematic diagram of a large axial thrust bearing in the present invention;

[0031] Fig.11 It is an axial cross-sectional view of the axial piston pump;

[0032] Markings in the figure: 1. Flow distribution and flow distribution seal axial thrust bearing;

[0033] 1.1. thrust plate guide assembly, 1.1.1. bolts, 1.1.2. through hole seal, 1.1.3. guide, 1.1.4. guide seal;

[0034] 1.2, pre-sealed thrust mechanism, 1.2.1, thrust retaining ring, 1.2.2, spring;

[0035] 1.3, thrust plate assembly, 1.3.1, thrust plate support ring, 1.3.2, thrust plate ceramic wear-resistant ring, 1.3.3, valve hole, 1.3.4, threaded hole;

[0036] 1.4. Distribution plate assembly; 1.4.1. Distribution plate support ring; 1.4.2. Distribution plate ceramic wear-resistant ring; 1.4.3. Distribution hole;

[0037] 2. Hydrostatic inner ring, 2.1. Inner ring friction surface, 2.2. Hydrostatic pad, 2.2.1. First hydrostatic water pad, 2.2.2. Second hydrostatic water pad, 2.3. Support surface, 2.4. Damping ring belt;

[0038] 3. Hydrostatic outer ring, 3.1. High-pressure water annular groove, 3.2. Hydrostatic main bearing pressure supply hole, 3.3. Dynamic pressure support friction surface;

[0039] 4. Large axial thrust bearing, 4.1. PEEK collar, 4.1.1. wedge surface, 4.1.2. large bearing support surface, 4.1.3. convection groove, 4.2. alloy inner core;

[0040] 5. Inclined plate, 6. Plunger and plunger return assembly, 7. Inlet and outlet flanges, 8. Rotating shaft assembly, 9. Plunger cylinder, 10. Pump casing. DETAILED DESCRIPTION

[0041] The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments, but they are not intended to limit the invention in any way.

[0042] See attached Figure 1 As shown, a load-bearing bearing assembly of an axial piston pump includes a distribution and distribution seal axial thrust bearing 1, a hydrostatic main bearing and an axial thrust large bearing 4 which are sequentially arranged along the axial direction of the piston pump. The hydrostatic main bearing includes a hydrostatic inner ring 3 and a hydrostatic outer ring 2.

[0043] like Figure 2As shown, the flow distribution and flow distribution seal axial thrust bearing 1 includes a thrust plate guide assembly 1.1, a pre-sealed thrust mechanism 1.2, a thrust plate assembly 1.3 and a flow distribution plate assembly 1.4. Figure 2 The flow distribution and flow distribution seal axial thrust bearing 1 shown is an inverted structural diagram, wherein the thrust plate guide assembly 1.1 is an annular disc structure as a whole, and is located at the bottom of the flow distribution and flow distribution seal axial thrust bearing 1; the flow distribution plate assembly 1.4 is an annular disc structure as a whole, and is located at the top of the flow distribution and flow distribution seal axial thrust bearing 1; the thrust plate assembly is an annular disc structure as a whole, and is located between the flow distribution plate assembly 1.4 and the thrust plate guide assembly 1.1; the pre-sealed thrust mechanism 1.2 is annular, and is arranged on the bottom surface of the thrust plate guide assembly 1.1. The thrust plate guide assembly 1.1, the pre-sealed thrust mechanism 1.2, the thrust plate assembly 1.3 and the flow distribution plate assembly 1.4 are all coaxially arranged, and the thrust plate guide assembly 1.1, the thrust plate assembly 1.3 and the flow distribution plate assembly 1.4 are connected by bolts.

[0044] like Figure 3 As shown, the thrust plate guide assembly 1.1 comprises an annular disc, on which through holes penetrating the upper and lower disc surfaces are arranged at intervals along the circumferential direction, and a guide member 1.1.3 is installed at the through hole mouth of the lower surface of the disc, and the guide member 1.1.3 is used to extend into the plunger hole of the plunger cylinder, and a guide seal 1.1.4, such as a sealing ring, is also installed on the outer circumference of the guide member 1.1.3 to achieve sealing between the guide member 1.1.3 and the plunger hole; the upper surface of the disc is also provided with a through hole seal 1.1.2 surrounding the through hole. Bolts 1.1.1 are installed on the disc to connect the thrust plate assembly 1.3 and the distribution plate assembly 1.4. Alternatively, other fasteners can be used to replace the bolts 1.1.1.

[0045] like Figure 4 As shown, the pre-sealing thrust mechanism 1.2 includes a thrust retaining ring 1.2.1 and a spring 1.2.2 installed on the lower surface of the thrust retaining ring 1.2.1. There are multiple springs 1.2.2, which are arranged at intervals along the circumference of the thrust retaining ring 1.2.1. In the plunger pump, the thrust retaining ring 1.2.1 is installed in the annular groove of the end face of the plunger cylinder, and a spring receiving groove is provided in the annular groove to accommodate the spring 1.2.2.

[0046] like Figure 5As shown, the thrust plate assembly 1.3 includes an inner ring and an outer ring connected coaxially, the outer ring is a thrust plate support ring 1.3.1, the thrust plate support ring 1.3.1 is made of stainless steel or other metal materials, and a threaded hole 1.3.4 is arranged on the thrust plate support ring 1.3.1 to connect with the bolt 1.1.1; the inner ring is a thrust plate wear-resistant ceramic ring 1.3.2, and a plurality of valve holes 1.3.3 are arranged at intervals along the circumferential direction on the thrust plate wear-resistant ceramic ring 1.3.2, and the valve holes 1.3.3 are waist-shaped holes. The outer circumferential surface of the thrust plate wear-resistant ceramic ring 1.3.2 is in close contact with the inner circumferential surface of the thrust plate support ring 1.3.1.

[0047] like Figure 6 As shown, the distribution plate assembly 1.4 includes an inner ring and an outer ring connected coaxially, the outer ring is a distribution plate support ring 1.4.1, made of stainless steel or other metal materials, a hole for the bolt 1.1.1 to pass through is arranged on the distribution plate support ring 1.4.1, the inner ring is a distribution plate ceramic wear-resistant ring 1.4.2, a plurality of distribution holes 1.4.3 are arranged at intervals along the circumferential direction on the distribution plate ceramic wear-resistant ring 1.4.2, and the distribution holes 1.4.3 are waist-shaped holes. The outer circumferential surface of the distribution plate ceramic wear-resistant ring 1.4.2 is in close contact with the inner circumferential surface of the distribution plate support ring 1.4.1.

[0048] After the thrust plate guide assembly 1.1, the thrust plate assembly 1.3 and the distribution plate assembly 1.4 are connected, the through hole on the thrust plate guide assembly 1.1, the distribution hole on the distribution plate assembly 1.4 and the valve hole on the thrust plate assembly 1.3 are connected. Figure 2 shown.

[0049] The static pressure inner ring structure of the static pressure main bearing is as follows: Figure 7 , 8 As shown, the hydrostatic inner ring 2 is a cylindrical structure, one end of which is provided with a radial flange. The end face of the radial flange is the inner ring friction surface 2.1, which is used to form a friction pair with the end face of the large axial thrust bearing 4. The surface of the radial flange opposite to the inner ring friction surface 2.1 is a support surface 2.3, which is used to make friction contact with the end face of the hydrostatic outer ring 3. A damping ring belt 2.4 is provided on the other end of the hydrostatic inner ring 2 relative to the radial flange. A hydrostatic pad 2.2 is provided on the outer circumferential surface of the hydrostatic inner ring 2. In order to avoid wearing the hydrostatic main bearing when no hydrostatic pressure is established, the hydrostatic pad 2.2 includes a first hydrostatic water pad 2.2.1 and a second hydrostatic water pad 2.2.2 of a wedge-shaped stepped structure to obtain good dynamic pressure characteristics. Figure 8 As shown, a second static water pad 2.2.2 is arranged at each axial end of the first static water pad 2.2.1, and the first static water pad 2.2.1 is lower than the two second static water pads 2.2.2 to form a stepped structure; at the same time, the two second static water pads 2.2.2 are both wedge-shaped structures, and the small diameter end is connected to the first static water pad 2.2.1, thereby forming the wedge-shaped stepped structure.

[0050] The structure of the static pressure outer ring 3 of the static pressure main bearing is as follows: Fig. 9 As shown, the static pressure outer ring 3 is a cylindrical structure, which is sleeved on the outer circumferential surface of the static pressure inner ring 2. One end of the static pressure outer ring 3 is provided with a dynamic pressure support friction surface 3.3, which is used for friction contact with the support surface 2.3 of the static pressure inner ring 2. The dynamic pressure support friction surface 3.3 is provided with circumferentially arranged Archimedean spiral convection grooves, which can enhance convection, enhance heat dissipation, improve dynamic pressure support, reduce friction and wear, and improve product life. A circle of high-pressure water annular grooves 3.1 are provided on the outer circumferential surface of the static pressure outer ring 3 to provide high-quality support for the static pressure main bearing made of ceramic material and reduce damage to the ceramic under cyclic load conditions. The groove is located at the position where the bearing is subjected to the maximum shear force. The static pressure main bearing pressure supply hole 3.2 is provided at the high-pressure water annular groove 3.1. After the static pressure outer ring 3 is assembled on the static pressure inner ring 2, the high-pressure water annular groove 3.1 corresponds to the first static pressure water pad 2.2.1 in the static pressure pad 2.2.

[0051] The structure of the large axial thrust bearing 4 is as follows Fig.10 As shown, the axial thrust bearing 4 is a cylindrical structure with a relatively small height, and is arranged around the swash plate in the plunger pump. The axial thrust bearing 4 includes Figure 1 The PEEK collar 4.1 and the alloy inner core 4.2 embedded in the PEEK collar 4.1 are shown. Since the present invention needs to withstand a large axial impact, PEEK material with good toughness and wear resistance is selected as the outer collar structure, and the alloy inner core 4.2 of metal material is embedded therein, which can enhance the shear resistance of the PEEK collar.

[0052] The end face of the large axial thrust bearing 4 facing the hydrostatic main bearing is provided with a plurality of combined surfaces distributed along the circumferential direction, and the combined surfaces are in contact with the inner ring friction surface 2.1 of the hydrostatic inner ring 2, and the combined surfaces include a wedge surface 4.1.1, a large bearing support surface 4.1.2 and a convection groove 4.1.3 connected in sequence, and the angle of the wedge surface 4.1.1 is 1-2°, which is used to induce the formation of dynamic pressure support, improve the dynamic pressure support, reduce the friction and wear with the hydrostatic inner ring 2, and improve the product life; the large bearing support surface 4.1.2 is a plane, which mainly plays the role of auxiliary support; the convection groove 4.1.3 adopts an Archimedean spiral convection groove, which can enhance convection, enhance heat dissipation, improve dynamic pressure support, reduce friction and wear, and improve product life.

[0053] Embodiment 2: An axial piston pump comprises a pump housing 10, one end of which is provided with an inlet and outlet flange 7, a piston cylinder 9, a swash plate 5 and the force bearing assembly described in Embodiment 1 are arranged in the pump housing 10, a rotating shaft 8 of the piston pump is transmission-connected with the piston cylinder 9, a piston and a piston forced return assembly 6 are arranged between the piston cylinder 9 and the swash plate 5, and the piston and the piston forced return assembly 6 include a piston and a forced return mechanism. The working principle of the axial piston pump of the present invention is the same as that of the conventional axial piston pump, which will not be described in detail.

[0054] The above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit the same. Those skilled in the art should understand that the specific implementation modes of the present invention may be modified or replaced by equivalents with reference to the above embodiments. Any modifications or equivalent replacements that do not depart from the spirit and scope of the present invention are within the scope of protection of the pending claims.

Claims

1. A load bearing assembly for an axial piston pump, characterized in that: It includes a flow distribution seal axial thrust bearing, a static pressure main bearing and an axial thrust large bearing arranged along the axial direction of the plunger pump; The flow distribution seal axial thrust bearing comprises a thrust plate guide assembly, a thrust plate assembly and a flow distribution plate assembly which are coaxially arranged in sequence. The thrust plate guide assembly, the thrust plate assembly and the flow distribution plate assembly are all annular disc structures, and a thrust mechanism is coaxially arranged outside the center hole of the thrust plate guide assembly. The thrust mechanism is connected to the end face of the plunger cylinder of the axial piston pump, and the guide member on the thrust plate guide assembly is sealed and connected to the plunger hole of the plunger cylinder; the flow distribution seal axial thrust bearing is provided with a medium channel connected to the plunger hole of the plunger cylinder; the thrust plate assembly comprises a thrust plate support ring and a thrust plate wear-resistant ceramic ring which are coaxially connected, the outer circumferential surface of the thrust plate wear-resistant ceramic ring is assembled on the inner circumferential surface of the thrust plate support ring, and the thrust plate support ring is a metal ring; a plurality of valve holes are arranged on the thrust plate wear-resistant ceramic ring at intervals along the circumferential direction; The static pressure main bearing comprises a static pressure inner ring and a static pressure outer ring, the static pressure outer ring is supported on a support surface at the end of the static pressure inner ring, a static pressure pad is arranged on the outer circumferential surface of the static pressure inner ring, a high-pressure water annular groove is arranged on the outer circumferential surface of the static pressure outer ring, and the high-pressure water annular groove is connected with the static pressure pad through the static pressure main bearing pressure supply hole; a dynamic pressure support friction surface is arranged at one end of the static pressure outer ring, and is in friction contact with the support surface, and a plurality of Archimedean spiral convection grooves are arranged on the dynamic pressure support friction surface along its circumference; The large axial thrust bearing is cylindrical, and a combined surface is provided on the end surface of the large axial thrust bearing facing the hydrostatic main bearing. The combined surface contacts the inner ring friction surface of the hydrostatic inner ring. The combined surface includes a wedge surface, a large bearing support surface and a convection groove connected in sequence. A plurality of the combined surfaces are arranged in sequence along the circumferential direction on the end surface of the large axial thrust bearing.

2. The load bearing assembly according to claim 1, characterized in that: The through hole on the thrust plate guide assembly, the distribution hole on the distribution plate assembly and the valve hole on the thrust plate assembly are connected to form the medium channel.

3. The load bearing assembly according to claim 1, characterized in that: The thrust mechanism comprises a thrust retaining ring and a plurality of springs installed on the same side of the thrust retaining ring, wherein the plurality of springs are arranged at intervals along the circumference of the thrust retaining ring.

4. The load bearing assembly according to claim 1, characterized in that: The distribution plate assembly includes a distribution plate support ring and a distribution plate ceramic wear-resistant ring which are coaxially connected. The distribution plate support ring is a metal ring. The outer circumferential surface of the distribution plate ceramic wear-resistant ring is assembled on the inner circumferential surface of the distribution plate support ring. A plurality of distribution holes are arranged on the distribution plate ceramic wear-resistant ring at intervals along the circumferential direction.

5. The load bearing assembly according to claim 1, characterized in that: The thrust plate guide assembly, the thrust plate assembly and the distribution plate assembly are connected by bolts.

6. The load bearing assembly according to claim 1, characterized in that: The static pressure pad of the static pressure inner ring is a wedge-shaped stepped structure, including a first static pressure water pad and a second static pressure water pad. A second static pressure water pad is arranged at each axial end of the first static pressure water pad. The first static pressure water pad is lower than the two second static pressure water pads to form a stepped structure. The two second static pressure water pads are both wedge-shaped structures, and the small diameter end is connected to the first static pressure water pad.

7. The load bearing assembly according to claim 1, characterized in that: In the combined surface of the large axial thrust bearing, the angle of the wedge surface is 1-2°, and the convection groove is an Archimedean spiral convection groove.

8. The load bearing assembly according to claim 1, characterized in that: The large axial thrust bearing comprises a PEEK sleeve ring and an alloy inner core embedded in the PEEK sleeve ring, and the combined surface is arranged at one end of the PEEK sleeve ring.

9. An axial piston pump, comprising a pump housing, an inlet and outlet flange is arranged at one end of the pump housing, a plunger cylinder, a swash plate and a plunger and a plunger forced return assembly are arranged in the pump housing, the rotating shaft of the plunger pump is drivingly connected with the plunger cylinder, and the plunger and the plunger forced return assembly are arranged between the plunger cylinder and the swash plate, characterized in that: A load-bearing bearing assembly as described in any one of claims 1 to 8 is also arranged in the pump casing.

Images