| 摘要 |
FIELD: mechanical engineering. SUBSTANCE: invention relates to shutoff members designed for use in pneumohydraulic systems. Proposed valve contains hollow body with hermetically sealed covers and inlet and outlet branch pipes. Controlled sealing unit divides body into inlet and outlet sealed spaces. Axial displacement screw mechanism of sealing unit is made in form of rotary spindle with handle installed in body. Rotary spindle of axial displacement screw mechanism contains two threaded sections with threads of opposite helix: one, with right-hand thread, the other, with left- hand thread. Two step sealing unit is made in form of two similar devices of gate-seat type whose gates are pointed to each other and are mated with threaded sections of spindle for reciprocal axial displacement. Stop to prevent getting of gates close to one another is made on spindle between threaded sections. Each cover is provided with stop-limiter to prevent return movement of gate. Each seat is secured in bushing movable relative to body and is pointed to corresponding gate. Bushings are spring-loaded relative to each other by means of compression spring fitted in between. Body contains also axial parting limiters of bushings, for instance, spring rings. EFFECT: improved sealing, reliability and increased service life of valve sealing unit. 1 dwg
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