Working principle of wiper motor
The wiper motor is driven by the motor. The rotary motion of the motor is transformed into the reciprocating motion of the wiper arm through the connecting rod mechanism, so as to realize the wiper action. Generally, the wiper can work by connecting the motor. By selecting the high-speed and low-speed gear, the current of the motor can be changed, so as to control the motor speed and then control the speed of the wiper arm. The wiper motor adopts 3-brush structure to facilitate speed change. The intermittent time is controlled by the intermittent relay. The charge and discharge function of the return switch contact of the motor and the resistance capacitor of the relay is used to make the wiper sweep according to a certain period.
There is a small gear transmission enclosed in the same housing at the rear end of the wiper motor to reduce the output speed to the required speed. This device is commonly known as the wiper drive assembly. The output shaft of the assembly is connected with the mechanical device at the end of the wiper, and the reciprocating swing of the wiper is realized through fork drive and spring return.
The blade rubber strip of the wiper is a tool to directly remove rain and dirt on the glass. The blade rubber strip is pressed to the glass surface through the spring strip, and its lip must match the angle of the glass in order to achieve the required performance. Generally, there is a wiper control knob on the handle of the automobile combination switch, which is equipped with three gears: low speed, high speed and intermittent. The top of the handle is the key switch of the washer. When the switch is pressed, the washing water is ejected to wash the windshield with the wiper.
The quality requirements of wiper motor are quite high. It adopts DC permanent magnet motor, and the wiper motor installed on the front windshield is generally integrated with the mechanical part of worm gear. The function of worm gear and worm mechanism is to reduce speed and increase torque. Its output shaft drives the four-bar linkage, which changes the continuous rotation motion into the left-right swing motion.
