Blog
After using the electric actuator for a period of time, you may sometimes find that the control accuracy of the electric actuator is not as precise as it was at the beginning, so we need to find the reason that affects the control accuracy of the electric actuator. Heli's years of experience have summarized some reasons and solutions that affect the control accuracy of electric actuators. Let's talk about the previous one.
1. The control valve oscillates. First find the vibration source. The vibration induced by the outside should keep the regulating valve away from the vibration source; eliminate or weaken the vibration intensity of the vibration source; use a fulcrum and other methods to reduce the vibration of the control valve if it is appropriate. The oscillation caused by the flow of the medium inside should try to reduce the resistance of the regulating valve. In the adjustment of things that are allowed by experience, a bypass pipe can be added. For the rapid response control system, a logarithmic spool can be used. Butterfly valves try their best to work within the range of 10~70°, avoiding the point of change of the effect of the medium on the valve body.
2. The electric actuator brake does not work. The brake is used to eliminate the influence of the inertia of the rotor and the output shaft and the load reaction torque after the electric actuator is powered off, so that the output shaft stops correctly at the corresponding position. If the brake does not work, it will reduce the control precision of the electric actuator. Because this should do the following.
(1) Adjust the braking torque according to the load volume;
(2) The clearance between the brake wheel and the brake disc should be adjusted properly;
(3) The brake shoe must have a sufficient friction coefficient, and it is forbidden to drip oil (do not exceed the maximum position of the oil mark when filling lubricating oil).
3. There are backward links in the output of electric actuators. The main backward link exists in the connection part of the output shaft of the angular stroke electric actuator and the adjusting mechanism (butterfly valve, etc.). Because of this, there must be no slack or gaps in the installation of all connecting rods and levers. Try to use a special coupling to replace the link mechanism. The pressure control system of the coke oven gas collector pipe of our factory thinks it is appropriate and uses a special coupling, the effect is satisfactory. When processing the coupling, please pay attention to the installation situation on the spot, and ensure that the output angle of the electric actuator is 0~90° and the valve body 0~90° angle and the valve position feedback signal 4~20mA.
