Valve actuator for slide exhaust brake systems

摘要

Herein disclosed is a valve actuator which is to be used with a slide exhaust brake system. The valve actuator includes a cylinder casing which is constructed of: a shortened cylinder body having a length substantially equal to the sliding distance of a piston member fitted therein; and a cylindrical wall fixed on the inner side of the bottom wall of the cylinder body such that the cylinder body has its lower end merging around its circumference into the circumference of the upper end of the cylindrical wall. The heat to be transferred from the exhaust brake system to the actuator is effectively reduced by a thermal impulse at the fixing portion between the cylinder body and the cylindrical wall to exert less thermal influences upon the packing of the piston member. Moreover, the cylinder casing of the actuator can be formed simply by cutting an elongated cylinder member having its inner circumference subjected to a necessary treatment and by fixing the cut cylinder member to the cylindrical wall having its inner circumference left untreated.