HYDRAULIC VALVE Russian patent published in 2000 - IPC

FIELD: positive-displacement hydraulic drives. SUBSTANCE: invention is meant for use in hydraulic equipment with thin working fluid, for example, in systems controlling powered supports in mining industry. Objective of invention lies in design of such valve in which protecting members guard seal against flow of fluid during its reversal and increase operational reliability of valve by prevention of washing out of seal. Valve has body with stepped holes communicating with radial conduits, cylindrical guide placed uniaxially in holes and housing shut-off element in the form of seal and spring-loaded bushing with shoulder that is embraced by means acting on shut-off element when valve opens. Shuttle is mounted for movement along guide between shut-off element and means acting on shut-off element. Shuttle is fabricated in the form of tubular uniaxial bushing with circular outer recess. Inner diameter of shoulder equals diameter of smaller hole. Protecting bushing is located in hole of bigger diameter. Circular outer recess communicates with radial conduit of hole of smaller diameter when valve is shut off and with both radial conduits when valve is open. Shuttle interacts with one end with seal and with the other end - with body and means acting on shut-off element. Outer diameter of shuttle is equal to diameter of smaller hole of body and its inner diameter equals diameter of cylindrical guide. EFFECT: increased operational reliability of valve. 1 dwg