| 摘要 |
The upper and lower end surfaces (67b, 67c) of a rotary piston (67) have annular sealing grooves (91) formed along the circular end surfaces (67b, 67c), respectively. An annular lip seal (92) is fitted in each sealing groove (91). Thus, lubricating oil fed through an oil feeding channel (49) in a shaft (40) does not substantially flow into a fluid chamber (65) in a cylinder (63) from clearances formed by the upper and lower end surface (67b, 67c) of the rotary piston (67), the rear head (62) and the front head (61). This eliminates shortage of lubricating oil. |
