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CN-121993375-A - Sealing part and sealing concept of hydraulic axial piston machine

CN121993375ACN 121993375 ACN121993375 ACN 121993375ACN-121993375-A

Abstract

The invention relates to a thrust pad for a port flange of a hydraulic axial piston machine. Thrust pads are used to improve the sealing concept of hydraulic axial piston machines. The thrust pad includes a top surface, a side surface, and a bottom surface. Furthermore, the thrust pad includes a curved shape configured to be at least partially disposed between the port flange and a port plate of the hydraulic axial piston machine. The thrust pad extends in a first direction, a second direction, and a third direction. The second direction is defined to be orthogonal to the first direction, and the third direction is defined to be orthogonal to the first direction and the second direction. Further, the thrust pad has an extension in the third direction that is less than the extension in the first direction and the second direction, wherein the thrust pad has an extension in the first direction that is greater than the extension in the second direction. The thrust pad includes a through bore, wherein the through bore is configured to fluidly connect a first port of the port flange to a control aperture of the port plate. Furthermore, the invention relates to a port flange, an assembly and a hydraulic axial piston machine.

Inventors

  • Paul Eric Hansen
  • Frank Holm Iverson
  • Akutan Babu

Assignees

  • 丹佛斯有限公司

Dates

Publication Date
20260508
Application Date
20250812
Priority Date
20241107

Claims (14)

  1. 1. A thrust pad (1) for a port flange (101) of a hydraulic axial piston machine (1000), Wherein the thrust pad (1) comprises a top surface (2), a side surface (3) and a bottom surface (4), Wherein the thrust pad (1) comprises a curved shape configured to be at least partially arranged between the port flange (101) and a port plate (103) of the hydraulic axial piston machine (1000), Wherein the thrust pad (1) extends in a first direction (X), a second direction (Y) and a third direction (Z), wherein the second direction (Y) is defined to be orthogonal to the first direction (X) and the third direction (Z) is defined to be orthogonal to the first direction (X) and the second direction (Y), Wherein the thrust pad (1) has a smaller extension in the third direction (Z) than in the first direction (X) and in the second direction (Y), wherein the thrust pad (1) has a larger extension in the first direction (X) than in the second direction (Y), Wherein the thrust pad (1) comprises a through hole (9), and Wherein the through hole (9) is configured to fluidly connect a first port (109) of the port flange (101) to a control hole (102) of the port plate (103).
  2. 2. Thrust pad (1) according to claim 1, wherein the lateral surface (3) is provided partly by an inner curved profile (7) and partly by an outer curved profile (8) extending between a first end portion and a second end portion, and wherein the inner curved profile (7) and the outer curved profile (8) meet at a first end point (5) and a second end point (6) of the respective end portions, respectively, and/or wherein the thrust pad (1) comprises a half-moon curved shape.
  3. 3. Thrust pad (1) according to any one of the preceding claims, wherein the through hole (9) extends partly along the curved shape of the thrust pad (1), and wherein the through hole (9) extends in the first direction (X) by a greater amount than in the second direction (Y).
  4. 4. Thrust pad (1) according to any one of the preceding claims, wherein the through hole (9) is a curved slot.
  5. 5. Thrust pad (1) according to any one of the preceding claims, wherein the thickness of the thrust pad (1) is defined by an extension of the thrust pad along the third direction (Z), wherein the thickness is smaller than the extension of the thrust pad (1) in the first direction (X) and is at most one tenth of the extension of the thrust pad (1) in the first direction (X).
  6. 6. A port flange (101) for a hydraulic axial piston machine (1000), Wherein the port flange (101) extends along a longitudinal axis (XL) between a cylinder side surface (105) and an opposite surface (106), Wherein the port flange (101) comprises a first port (109) and a second port (110), each of the first and second ports being configured to fluidly connect the port flange (101) to a cylinder (111) of a cylinder (107) of a hydraulic axial piston machine (1000), Wherein the cylinder side surface (105) of the port flange (101) further comprises a groove (112) at least partially surrounding the first port (109), wherein the groove (112) is configured to at least partially receive the thrust pad (1) according to any one of claims 1 to 5, Wherein, when the thrust pad (1) is received in the recess (112) of the port flange (101), the through hole (9) of the thrust pad (1) at least partially overlaps the first port (109) such that when the port flange (101) is fluidly connected to the cylinder (111) of the cylinder barrel (107) of the hydraulic axial piston machine (1000), the first port (109) is fluidly connected with the through hole (9) of the thrust pad (1).
  7. 7. The port flange (101) of claim 6, wherein the groove (112) comprises a groove (114) extending orthogonal to the longitudinal axis (XL), wherein the groove (114) is configured to receive a sealing element, and wherein the sealing element is configured to abut a lateral surface (3) of the thrust pad (1) when the thrust pad (1) is at least partially received within the groove (112).
  8. 8. The port flange (101) according to claim 6 or 7, wherein the first port (109) provides a high pressure port configured to supply a fluid containing high pressure to the cylinder (111) of the cylinder (107) of the hydraulic axial piston machine (1000) or to drain a fluid containing high pressure from the cylinder (111) of the cylinder (107) of the hydraulic axial piston machine (1000).
  9. 9. An assembly (100) comprising a port plate (103), a thrust pad (1) according to any one of claims 1 to 5 and a port flange (101) according to any one of claims 6 to 8, Wherein the thrust pad (1) is at least partially received in a groove (112) of the port flange (101) such that the third direction (Z) of the thrust pad (1) is parallel to a longitudinal axis (XL) of the port flange (101), Wherein the cylinder side surface (105) of the port flange (101) is arranged to abut the port plate (103) and/or the port plate (103) is arranged to abut the thrust pad (1) such that the thrust pad (1) is at least partially arranged between the port flange (101) and the port plate (103) when the thrust pad (1) is received in the recess (112).
  10. 10. The assembly (100) of claim 9, wherein the recess (112) of the port flange (101) forms a stepped portion having a contact surface (113) offset along the longitudinal axis (XL) with respect to a cylinder side surface (105) of the port flange (101), and wherein an offset between the contact surface (113) and the cylinder side surface (105) is greater than an extension of the thrust pad (1) along the third direction (Z).
  11. 11. The assembly (100) according to claim 9 or 10, wherein the assembly (100) further comprises a sealing element arranged inside a groove (114) of a groove (112) of the port flange (101).
  12. 12. A hydraulic axial piston machine (1000), comprising: the assembly of any one of claims 9 to 11; -a cylinder tube (107) having at least one cylinder (111) with a piston (116); A retainer plate (119) plate coupled to a piston (116) of the cylinder (107), and -A drive shaft (120), the drive shaft (120) being mechanically coupled to the cylinder (107).
  13. 13. The hydraulic axial piston machine (1000) of claim 12, wherein the hydraulic axial piston machine (1000) further comprises a pressure plate (108) and at least one spring (120), the at least one spring (120) being configured to press the pressure plate (108) against the port plate (103), thereby providing a seal between the port plate (103) and a cylinder side surface (105) of the port flange (101).
  14. 14. The hydraulic axial piston machine (1000) according to claim 12 or 13, wherein, when the drive shaft (120) is rotated by a drive motor, the hydraulic axial piston machine (1000) is configured to draw low pressure fluid into the at least one cylinder (111) of the cylinder tube (107) via the second port (110) of the port flange (101) and to discharge high pressure fluid via the first port (109) of the port flange (101), Wherein, when the drive shaft (120) rotates due to the rotation of the cylinder tube (107), the hydraulic axial piston machine (1000) is configured to supply high pressure fluid to the at least one cylinder (111) of the cylinder tube (107) via a first port (109) of the port flange (101) and to discharge low pressure fluid via a second port (110) of the port flange (101).

Description

Sealing part and sealing concept of hydraulic axial piston machine Technical Field The invention relates to a thrust pad for a port flange of a hydraulic axial piston machine. Furthermore, the invention relates to a port flange, to an assembly of a port plate, a thrust pad and a port flange, and to a hydraulic axial piston machine. Background Hydraulic axial piston machines are well known in the art. In a hydraulic axial piston machine, the piston is guided in a cylinder of a cylinder tube and rotates about a drive shaft of the hydraulic axial piston machine. Furthermore, each piston is coupled to a sliding shoe which is held in a retainer plate, wherein the piston performs a full stroke every one revolution of the cylinder barrel. The term "hydraulic axial piston machine" refers to both hydraulic axial piston pumps and hydraulic axial piston motors. The hydraulic axial piston pump converts mechanical energy into hydraulic energy, and the hydraulic axial piston motor converts hydraulic energy into mechanical energy. In this respect, therefore, hydraulic axial piston machines are often used in hydraulic systems such as construction machines, agricultural machines and factories. Excellent reliability, high power density and precise controllability make hydraulic axial piston machines the preferred choice for hydraulic systems. Typically, the hydraulic axial piston machine is thus integrated into a complex hydraulic fluid system and is fluidly connected to pipes, tubes, channels, tubes etc. which deliver fluid at high pressure or fluid at low pressure to and from the hydraulic axial piston machine. Leakage in hydraulic fluid systems, in particular in the transition region between the fluid delivery device and the cylinder barrel of, for example, a hydraulic axial piston machine, can lead to energy losses. Thus, hydraulic axial piston machines known in the art are equipped with a sealing concept to allow high pressure fluid to enter or leave the hydraulic axial piston machine, preferably without leakage, however there is typically limited leakage, which reduces the efficiency of the hydraulic axial piston machine. In other words, leakage during the supply of fluid into and the discharge of fluid from the cylinders of the cylinder tube may lead to a loss of efficiency of the hydraulic axial piston machine. In order to prevent excessive leakage, it is therefore known to arrange sealing elements in hydraulic axial piston machines. However, known sealing concepts often require alternating seals (i.e., sealing elements or sealing surfaces alternate between the high pressure side and the low pressure side), have larger dimensions, require many parts, are complex, heavy, or are not suitable for use with high pressures at all. In particular, handling high pressures that deform sealing surfaces such as the sealing surfaces of port flanges or port plates of hydraulic axial piston machines can present difficulties. Disclosure of Invention Thus, there is a need for an improved sealing concept for hydraulic axial piston machines. It is therefore an object of the present invention to improve the sealing concept of a hydraulic axial piston machine. In particular, it is an object of the present invention to provide an improved sealing concept for a hydraulic axial piston machine, which concept allows to operate the system at e.g. higher pressures and higher flows while reducing leakage. The above object is achieved by a thrust pad, an assembly or a hydraulic axial piston machine according to the invention. Typically, hydraulic axial piston machines include a port plate (also referred to as a valve plate, a distributor plate, or a control plate). The port plate comprises control holes allowing fluid to flow from the port flange into the cylinder of the cylinder barrel of the hydraulic axial piston machine, for example via the port plate. The thrust pad according to the invention is suitable for use with a port flange of a hydraulic axial piston machine, and in other words, the thrust pad is configured for use with a port flange in order to improve tightness. The thrust pad includes a top surface, a bottom surface, and side surfaces. The top surface may be disposed on an opposite side of the bottom surface. The bottom surface may face the port flange when the thrust pad may be disposed within the groove of the port flange, wherein the top surface may face the port plate. The bottom surface may include a first hole. The first aperture may be aligned with the second aperture of the port flange when the thrust pad is disposed within the groove of the port flange. In one aspect, the thrust pad includes two apertures, one at each end portion of the thrust pad. The first and second holes may be provided by blind holes. A resilient element (e.g., a spring element) may be disposed within the first aperture and the second aperture to urge the thrust pad toward the port plate. Furthermore, the top surface may be a substantially flat surfa