Patent ID: 11933391
Assignee: KANZAKI KOKYUKOKI MFG. CO., LTD.
Field: Mechanical elements (Mechanical engineering)
Classification: CPC F  B | IPC F

Claim 9:
10. The HST according to claim 9,
wherein the hydraulic servo mechanism includes a pushing piston that is housed in the main plate in a manner to be reciprocally movable in a pushing direction and is operatively connected to the movable swash plate via a connecting rod so that the movable swash plate swings around the swing axial line in accordance with a movement of the pushing piston along the pushing direction, first and second hydraulic oil chambers formed in the main plate in such a manner that pressure oil supplied into the first and second hydraulic oil chambers push the pushing piston to one side and the other side in the pushing direction, respectively, a switching spool that switches supply and discharge of pressure oil to and from the first and second hydraulic oil chambers in accordance with a position in a switching direction, an operating piston that is housed in the main plate in a manner to be reciprocally movable in an operating direction parallel to the switching direction and is operatively connected to the switching spool via a connection pin, first and second operation oil chambers formed in the main plate in such a manner that pressure oil supplied into the first and second operation oil chambers push the operating piston to one side and the other side in the operating direction, and an operating valve that switches supply and discharge of pressure oil to and from the first and second operation oil chambers, and
wherein the main plate is provided with a manual operating mechanism capable of manually changing the position of the switching spool in the switching direction.