Patent ID: 9702382
Date: 2017-07-11
CPC Classifications: F15B

Claim:
1. An oil hydraulic cylinder, comprising: a cylinder body having an inner surface, wherein the inner surface defines an opening and a space, and the space is in air communication with the opening; a spindle defining a central axis, wherein the spindle is movable in the space of the cylinder body along the central axis, and the spindle comprises: a main body having a large diameter segment and a small diameter segment integrally extended from the large diameter segment, wherein a gap exists between an outer surface of the small diameter segment and the inner surface of the cylinder body, wherein the small diameter segment has an end portion away from the large diameter segment, the end portion of the small diameter segment is arranged at the opening of the cylinder body; and a surface protecting coat being a circular ring shaped copper coat brazed on an outer surface of the large diameter segment, wherein the abrasion resistance of the surface protecting coat is greater than the abrasion resistance of the main body, and the surface protecting coat contacts the inner surface of the cylinder body; a push seat fixed on the end portion of the small diameter segment; and a covering module arranged at the opening of the cylinder body and at least partially arranged between the outer surface of the small diameter segment and the inner surface of the cylinder body, wherein the covering module abuts the outer surface of the small diameter segment and the inner surface of the cylinder body without any clearance.