Select Year: Select Make:

How does a Wiper Motor work?
We need wiper motors to make windshield wipers work. A windshield wiper removes water and debris from the windshield of motor vehicles, so that the operator can have a clear view of where he is going. They are required on most motor vehicles, and these include aircraft, sea-crafts, and trains.

A wiper is on an arm, turning on one end, with a rubber blade attached to the other end. They push water, and debris from the windshield's surface, as the rubber blades move in a back and forth motion. The speed is adjustable, with several settings including an intermittent setting.

How does it work?
The first wipers operated by moving a lever that was in the vehicle back and forth manually. The wipers of today are electrical, and move at different speeds. They are much more effective at clearing water and debris off the windshields.

  • Wipers have an electric motor, that works with a worm gear reduction. This provides the power needed to move the wipers.
  • The back and forth motion of the wiper occurs when a neat linkage converts the rotational output of the electric motor.
  • The motor by itself cannot create the high level of force that is needed to move the blades quickly. A worm gear is therefore used on the output of the motor.
  • There is an electric circuit inside the motor and gear assembly. This senses when the wipers are in a down position. Only when the circuit senses the wipers are down will the power of the motor be cut. The circuit also stops the wipers in between wipes when they are on the intermittent setting.
  •  The worm gear reduction is an important element because it can multiply the torque of the motor by about 50 times. It can also slow down the output speed by 50 times also. The output of the gear reduction is what operates the linkage that makes the wipers move back and forth.
  • As the wiper motor turns, a cam attached to the output shaft of the gear reduction spins. This cam is also attached to a rod, and when the cam spins, the rod moves back and forth. This rod is also connected to a shorter rod that activates the blade on the driver's side of the vehicle. On the passenger side, the wiper blade activates when another long rod sends the force from the driver's side to the passenger side.