What is the current technological status of Rack&Pinion pneumatic actuators?

Rack&Pinion  pneumatic actuators  are a common device that is often used in conjunction with valves. Let's take a look at the current technology status of Rack&Pinion Pneumatic Actuators.

The working principle of traditional electric/pneumatic valve positioners using mechanical locators and Pneumatic Actuators is shown in Figure 1. When a current is input into the coil, the iron core is magnetized. Under the action of a permanent magnetic field, the iron core rotates around the O axis. The balance spring on lever 1 is used to adjust the initial distance between the baffle and the nozzle, ensuring that the baffle and nozzle are at the optimal distance when there is no current in the coil. When the input current causes lever 2 to rotate counterclockwise by a small angle, the baffle approaches the nozzle, and the pressure in the compressed chamber increases, pushing the valve stem downward and driving the eccentric cam to rotate counterclockwise, pushing the roller to the left. The spring on lever 2 pulls lever 2 to the left, and the baffle moves away from the nozzle, reducing the pressure in the compressed chamber. This is the negative feedback effect, ensuring adjustment. The valve opening is proportional to the input signal, which is the positioning function. In the early 1970s and 1980s, this type of locator accounted for about 85% to 90% of its usage in China. The disadvantages of the mechanical force balance structure were poor environmental resistance, susceptibility to temperature and external vibrations, wear and tear, time-consuming manual adjustment, and the need to interrupt the control circuit. But due to its low price, it is still used in traditional enterprises. 1. Balance spring; 2 magnets; 3 leverage 1; 4. Leave a constant mouth; 5 Pneumatic amplifier; 6 nozzles; 7 baffles; 8 leverage 2; 9 eccentric cam; 10 rollers; 11 regulating valve; 12 tablets
Through the above content, I believe everyone has already understood the current technical status of Rack&Pinion  pneumatic actuators .