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US 2024/0093666 A1Published application
Hydrostatic radial piston unit
AssigneeDanfoss A/S
InventorsChris SHRIVE, Yanjiang WAN, Ruhuan CHEN
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AssigneeDanfoss A/S
InventorsChris SHRIVE, Yanjiang WAN, Ruhuan CHEN
Estimating the term…
Hydrostatic radial piston unit comprising a front case part accommodating a drive shaft via shaft bearing means so that the drive shaft can rotate around a central axis relative to the front case part. A rear case part is attached on one side to the front case part and closed on another side in order to define an internal volume. A cylinder block is disposed in the internal volume and attached to the drive shaft in a torque proof manner. Axially disposed timing holes in the cylinder block connect radially oriented working volumes in the cylinder block with a cylinder block front face that is arranged perpendicularly to the central axis and faces away from the front case part. Integrally within the rear case part internal annular flow passages are formed and are connected to an inlet and an outlet of the radial piston unit and running basically in circumferential direction around the central axis. Internal distribution conducts configured to hydraulically connect the internal annular flow passages with the cylinder block timing holes are integrally formed within the rear case part, too.
Hydrostatic radial piston unit (1) comprising:
Hydrostatic radial piston unit (1) according to any of the preceding claims, comprising a park brake mechanism (70) located on the rear side of the internal volume, wherein the brake discs (72) of the park brake mechanism (70) are arranged within the rear case part (20) and are disposed at least partially radially inside of the internal annular flow passages (22).
Hydrostatic radial piston unit (1) according to any of the preceding claims, wherein the rear case part (20) is closed by a housing cover (18) on the side facing away from the front case (10).
Hydrostatic radial piston unit (1) according to any of the preceding claims, wherein the working volumes (36) in the cylinder block (30) are sealed by radially moveable working pistons (34) arranged in working volumes (36), and wherein, under operational conditions of the radial piston unit (1), the piston movements are guided by cam lobes (13) on an inner cam surface (14) of a cam disk (12) against which the pistons (34) abut, wherein further the cylinder bores (36) and/or the pistons (34) comprising a surface-finished surface.
Hydrostatic radial piston unit (1) according to any of the preceding claims, wherein one bearing means (16) is located in the rear case part (20) and another one is located in the front case part (10).
Hydrostatic radial piston unit (1) according to any of the preceding claims, wherein, under operational conditions of the radial piston unit (1), the opening forces exerted on the pressure force distribution plate (40) via the fluid pressure in the cylinder block timing holes (37) are balanced by pressure pistons (44) abutting against the pressure force distribution plate (40), and forced against the pressure force distribution plate (40) by means of pressure springs (48) and/or by fluid pressure.
Hydrostatic radial piston unit (1) according to any of the preceding claims, wherein the rear case part (20) is manufactured by sand casting, additive manufacturing technique or primary shaping technique with lost cores.
Hydrostatic radial piston unit (1) according to any of the preceding claims, wherein the cylinder block (30) comprises at least on one side an axial oriented recess (33) adjacent to an axial through bore (38), in which the drive shaft (3) is received, wherein the at least one recess (33) is provided for receiving part of a bearing inner or outer shell and/or at least partially the pressure force distribution plate (40).
Dependencies are inferred from the claim text.