| 摘要 |
PURPOSE:To reliably discharge oil leaking from an oil seal into a drain tank without using any conventional vacuum pump which consumes energy waste- fully. CONSTITUTION:An oil seal 6 is attached to a rod sliding surface in a penetration 5 of a piston rod 4 of a cylinder head 2 attached to a cylinder main body 1, and a dust seal 40 provided with a dust lip 40a and an oil lip is provided on the piston rod sliding surface on the opposite side of a piston 3 in relation to the oil seal 6. And annular grooves 7, 41 are formed on the slide surface across the dust seal 40, and these annular grooves 7, 41 are communicated with a drain hole 8 opened outward through respective guide holes 42a, 42b, moreover the drain hole 8 is communicated with a drain tank 14 through a drain pipe 9, thereby oil leaking from the oil seal 6 is scraped by both lips of the dust seal 40 so as to be discharged into the drain tank 14. |
