Sealing arrangement for a shock absorber having an annular reservoir

Claim 1

A sealing arrangement for a shock absorber comprising an inner cylinder having first and second ends and defining an inner working chamber in which a piston for generating a damping force is slidably fitted, an outer cylinder having first and second ends and spaced coaxially from said inner cylinder to define a first annular oil and high pressure gas reservoir between said inner and outer cylinders, said inner cylinder having at least one hole therethrough near the second end thereof to allow fluid communication between said inner chamber and said first reservoir, a piston rod secured to said piston and extending outwardly of the first end of said inner and outer cylinders, said second end of said inner and outer cylinders being closed, a rod guide secured to the first end of said inner and outer cylinders and in sliding contact with said piston rod, an auxiliary sene and main seal arranged above said rod guide and tightly sealing the first end of said outer cylinder and in sliding contact with said piston rod, a second annular oil reservoir provided between said main and auxiliary seal, a gap defined between said main and auxiliary seals and enclosed by said piston rod, main seal, auxiliary seal, and said second reservoir to allow fluid communication between said rod and said second reservoir, and cuts formed through a bottom surface of said auxiliary seal to return oil from said second reservoir to said first reservoir when the oil pressure in said second reservoir has risen above the pressure of said high pressure gas in said first reservoir during operation of said shock absorber.