Inverse cam type pneumatic actuator

Abstract

The invention relates to an inverse cam type pneumatic actuator. The pneumatic actuator comprises a cylinder body, a cylinder cover, a piston and a transmission shaft, wherein the inverse cam type pneumatic actuator is mainly characterized in that a cylindrical piston is adopted as the piston, two symmetrical inner guide grooves are formed in the inner circular wall of the cylindrical piston, the upper end and the lower end of each inner guide groove have radians in the circumferential direction of the cylindrical piston; guide rods matched with the inner guide grooves are arranged on the upper end of the transmission shaft, and a positioning plate is arranged on the lower end of the transmission shaft; two symmetrical outer guide grooves are formed in the outer circular wall of the cylindrical piston, guide pins matched with the outer guide grooves are arranged on the cylinder body, the outer guide grooves and the inner guide grooves form mirror symmetry on the circumferential surface of the cylindrical piston, the radian of the upper end and the lower end of the outer guide grooves in circumferential direction is 45 degrees, and the radian of the upper end and the lower end of the inner guide grooves in circumferential direction is 45 degrees. The inverse cam type pneumatic actuator has a simple structure, is low in manufacturing cost, large in output torque under the same pressure, and small in gas consumption. The inverse cam type pneumatic actuator is applicable to right-angled rotating valve pneumatic actuators.

Description

technical field [0001] The invention belongs to valve actuators, in particular to a pneumatic valve actuator. The invention is suitable for pneumatic actuators of quarter-turn valves. Background technique [0002] The pneumatic valve actuator generally consists of a cylinder, a piston and a piston rod. The piston rod is connected to the valve stem. For example, the utility model patent number is CN201420421459.4, the double-cylinder cryogenic valve pneumatic actuator consists of a lower cylinder body, an upper cylinder body, and a cylinder head. The upper cylinder body and the lower cylinder body form a closed body. There is a piston in the closed body. The cavity is provided with a spring, the lower end of the piston is connected with the upper end of the transmission shaft, and the lower end of the transmission shaft is connected with the valve stem. Pneumatic valve actuators of this structure are only suitable for actuators of straight-stroke valves such as globe valves...

AI Technical Summary

Problems solved by technology

Its main disadvantages are complex structure and high product cost; during the whole process of valve opening and closing, the air pressure pushes the valve stem to rotate at the same speed, and a large air pressure is required at the initial stage of valve opening and when it is fully closed, and the piston rod occupies a large area in the piston plane. The area of ​​the air pressure is reduced, the conversion efficiency of the air pressure and the output torque is low, and the air consumption is large.

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