To provide a hydraulic cylinder improved in durability by suppressing or preventing deterioration of a seal member resulting from cavitation.
The hydraulic cylinder includes a cylinder 31 having a shaft hole, a piston 32 inserted in the shaft hole in such a manner that a clearance is defined between the piston and an inner peripheral surface of the shaft hole, and seal members disposed in annular grooves formed in the inner periphery of the shaft hole so as to seal annular gaps between the inner periphery of the shaft hole and the piston. The cavitation occurs at the clearance when the piston 32 moves. In the hydraulic cylinder, an extension part is formed by extending a part of an inner peripheral end of a side wall surface of each annular groove to the outside of an arrangement region of each seal member, so that a distance from the position where the cavitation occurs to the seal member is increased by a length of a space defined by the extension part.
| JP2004028160A | 2004-01-29 | |||
| JP2002181198A | 2002-06-26 | |||
| JP2002310303A | 2002-10-23 |
Mayuko Wakuda
Koichiro Sakai