Safety hand wheel hand-operation and automatic-operation switching mechanism of pneumatic actuator

Abstract

The invention discloses a safety hand wheel hand-operation and automatic-operation switching mechanism of a pneumatic actuator, which comprises a hand wheel, a switching handle, a box, a box cover and a worm gear and worm transmission device, wherein the worm gear and worm transmission device is arranged in an inner cavity formed by the box and the box cover. Two ends of a worm are connected with the hand wheel and an eccentric shaft respectively, one end of the switching handle is connected to an eccentric shaft bush provided with a worm which is closed to the hand wheel, and the other end of the switching handle is connected to the eccentric shaft provided with a safety switching device. The safety hand wheel hand-operation and automatic-operation switching mechanism is characterized in that a safety protection device is integrally arranged on the eccentric shaft connected with the worm and comprises a valve, a valve spool, a valve seat, two sealing rings and a left end cap. The eccentric shaft penetrates through the left end cap and the valve so that the left end cap and the valve are fixed on the box and form a valve seat cavity used for holding the valve seat, the valve is provided with a holding cavity, and the valve spool is arranged in the holding cavity. When the safety protection device is switched to the hand-operation position manually, an air source pipeline controlled pneumatically is cut off automatically so as to protect the switching mechanism from being damaged due to the fact that air sources are put through suddenly by operation faults. Besides, the safety protection device is high in integration and safety and more reliable in working as compared with conventional safety devices.

Description

technical field [0001] The invention relates to a pneumatic actuator, in particular to a manual and automatic safety switching hand wheel mechanism of the pneumatic actuator. Background technique [0002] The handwheel mechanism in the prior art mainly consists of a box body, a worm wheel arranged inside the box body, a worm screw, an eccentric half shaft fixedly connected to the two ends of the worm screw in a cylindrical shape and non-coaxially connected with the worm screw, and a The hand wheel fixedly connected to the eccentric half shaft and the switching handle fixed on the eccentric half shaft are composed. When the switching handle is at the lower position, the worm is separated from the worm wheel; when the switching handle is moved to the upper position, the worm is combined with the worm wheel and the hand wheel is turned. , then drives the worm to rotate, and the worm then drives the worm wheel to rotate. With the handwheel mechanism of this structure, when the ...

AI Technical Summary

Problems solved by technology

As a safety component, this structure is relatively easy to reduce its reliability due to the influence of external complex working conditions, and the most important thing is that it does not have a safety switching function

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