The More You Know: How Windshield Wipers Work
Did you know that the first windshield wipers were operated manually by a lever in your car that drivers had to move back and forth? Now, all we have to do is turn a knob and the wipers move on their own. I am going to be looking at how the electric wipers we use today work.
The wipers combine two different mechanisms in order to work. Those two are an electric motor and a worm gear. To get your wipers to accelerate and decelerate the worm gear is used. The worm gear is connected to the small motor and helps channel the force from the motor to the blades. The worm gear reduction can multiply the torque by about 50 times, while slowing the output speed of the electric motor by 50 times as well. The output of the gear reduction controls a linkage that moves the wipers back and forth.
There is an electric circuit within the motor that senses when the wipers are in their down position. This circuit makes sure that the wipers return to the down position after they have been in use.
The wiper blades themselves act like a squeegee. There is a rubber strip at the end of them that wipes away any water on your windshield. When your wiper blades get old or worn they can develop cracks in them that will cause them to leave streaks of water across your windshield as they move back and forth.
There are four main ways windshield wipers move. They are a tandem system, opposed system, single arm (controlled), and single arm. Each type is show below: