In the industrial field, we often use the scotch yoke pneumatic actuator. Do you know what the scotch yoke pneumatic actuator is? Now let's talk about what the pneumatic fork actuator is.
Stcoch Yoke Pneumatic Actuator is a piston actuator with angular stroke. It is suitable for the turn-off or metering control of valves with 90 degrees turning angle, such as ball valves, butterfly valves and cock valves.
Pneumatic fork actuator, usually refers to the structure of "single cylinder, double piston, variable torque fork" pneumatic actuator. OMAL, Italy, is the world's first manufacturer of single cylinder, double piston and variable torque fork pneumatic actuators. It has many world-leading patented technologies, leading the development direction of scotch yoke pneumatic actuator in the world.
At present, only a few companies in the world can master the technology of "single cylinder, double piston, variable torque fork" pneumatic actuator. Pull fork pneumatic actuator is also the only pneumatic actuator that has not been imitated in China at present. 
Today's fluid control equipment should be economical and affordable, with high performance, long life, safe and reliable, energy-saving and environmental protection characteristics. With less downtime and lower energy consumption, the total cost of ownership of the plant is significantly reduced. Pull fork pneumatic actuator, based on the high requirements of working conditions and industry development needs, will be the dominant era in the future.
Working principle
Pneumatic fork actuator
Compressed air enters the cylinder and drives the fork-type piston to move. The linear motion of the piston is changed into the rotary motion of the disc through the fork-type piston. The disc drives the output shaft to rotate, thus realizing the control of the valve.
Rack-and-pinion pneumatic actuator
Compressed air enters the cylinder and drives the rack piston to move in a straight line. The gear engagement between the rack and the gear shaft drives the gear shaft to rotate so as to control the valve.
Structural characteristics
Motion characteristics
Pneumatic fork actuator
When the fork type pneumatic actuator works, the friction between the fork dial and the self-lubricating rotating pin is rolling during the piston movement, and the friction between the fork dial and the rotating pin is not abrasive, and the transmission is that the friction force between the fork dial and the self-lubricating rotating pin is small.
Rack-and-pinion pneumatic actuator
The rack-and-pinion actuator is a parallel structure with teeth. In the process of piston movement, the sliding friction between racks and racks is large, and the rack is easy to wear and fracture.

Torque characteristics

1. Small Volume, Large Torque
The disc of thescotch yoke pneumatic actuator is connected with the fork, the rotating pin and the disc through pins. The size of the disc can approach the cylinder diameter, and the pin connected with the fork and the disc is close to the edge of the disc, so the larger output torque can be obtained with a smaller size.
Under the same air pressure F and piston diameter, the fork-shifting actuator can produce a longer arm L than the rack-and-pinion actuator. According to the moment M=F*L, the fork-shifting actuator can produce a larger torque than the rack-and-pinion actuator under the same volume.
2. The output torque varies with the angle, which satisfies the variation characteristics of the torque when the valve is opened or closed.
The disc structure of the fork-type pneumatic actuator is unique. It has a special curve design at the pin connection. When working, the output torque can change with the change of angle and reach the maximum at the opening and closing points. The output torque is consistent with the maximum torque required for butterfly and ball valves to open and close. It is an actuator that can really exert the valve performance and prolong the average life of the valve.
Beijing Ruito Jiangnan Automation Equipment Co., Ltd. specializes in the production of high temperature butterfly valve, tri-eccentric butterfly valve, scotch yoke pneumatic actuator and other equipment, if you need, please call.