Piston type hydraulic shock absorber - has drain passage starting from above base of leakage collector chamber

摘要

The hydraulic shock-absorber has external and internal cylinders coaxial to each other and forming an annular intervening space, while a piston works in the inner one equipped with a rod protruding through a head common to both. The head forms a bush with a bore having a narrower inner portion guiding the piston rod and a wider outer one forming a collector chamber for hydraulic fluid which has leaked past the narrower one from the inner cylinder. The radial face joining the two bore portions forms the base of this chamber, which is connected via a drain passage to the intervening space between the cylinders. The point where this drain passage (52) joins the chamber (34) is above the level of the base (36) of the latter, typically about 5mm.