What are the classifications of proportional valves?

Classification by proportional valve control method refers to classification according to the electrical-mechanical conversion method in the pilot control valve of the proportional valve. The electrical control part has various forms such as proportional electromagnets, torque motors, and DC servo motors.

(1) Electromagnetic type The electromagnetic type refers to a proportional valve that uses a proportional electromagnet as an electrical-mechanical conversion element. The proportional electromagnet converts the input current signal into a force and displacement mechanical signal output. In turn, parameters such as pressure, flow and direction are controlled.
(2) Electric type Electric type refers to a proportional valve that uses a DC servo motor as an electrical-mechanical conversion element, and the DC servo motor will input an electrical signal. Converted into rotational speed, and then output force and displacement through reduction devices and conversion mechanisms such as screw nut, rack and pinion or gear cam, and further control hydraulic parameters.
(3) Electro-hydraulic type Electro-hydraulic type refers to the proportional valve that adopts the structure of torque motor and nozzle baffle as the pilot control stage. Input different electrical signals to the torque motor, and output displacement or angular displacement through the baffle connected to it (sometimes the armature of the torque motor is the baffle), change the distance between the baffle and the nozzle, and make the nozzle spray. The oil flow resistance changes, which in turn controls the small parameters.