How Marine Wiper Motors Work
The windscreen wipers are powered by a small electric wiper motor, much like wipers for other specifications. The motor activates a linkage that moves the wiper arms forwards and backwards. Furthermore, the wipers combine two mechanical technologies to perform their role. The combination of an electric motor and worm gear provide power to the wipers. Subsequently, a neat linkage converts the rotational output of the motor into the back and forth motion of the wipers.
What do Linkages do?
Linkages are used in mechanical control systems to allow forces and motion to be transmitted to where they are needed. They consist of a series of levers which can change the direction of a movement, alter the size of a force or make things move in a particular way. Linkage mechanisms are incorporated into systems to produce rotating, oscillating or reciprocating motion from the rotation created from a crankshaft or a moving mechanical part.
How to know if a wiper motor is faulty?
Signs that a wiper motor is about to fail include slow or intermittent operation, wipers that will operate at only one speed, or arms that stop in the middle of the windshield when turned off. If your wipers don’t work, the fault could also lie with other parts of the wiper system.
Other possible causes are the interior switch that controls the wipers failing, wires in the system being damaged, or the linkage that pushes and pulls the wiper arms breaking. Moving parts in the linkage may also be stuck from corrosion and/or gunk and need lubrication.
What role do worm gears play in the Wiper Motor?
It takes a lot of force to accelerate the wiper blades back and forth across the windshield so quickly. In order to generate this type of force, a worm gear is used on the output of a small electric motor.
The worm gear reduction can multiply the torque of the motor by about 50 times, while slowing the output speed of the electric motor by 50 times as well. The output of the gear reduction operates a linkage that moves the wipers back and forth. Inside the motor/gear assembly is an electronic circuit that senses when the wipers are in their down position. The circuit maintains power to the wipers until they are parked at the bottom of the windshield, then cuts the power to the motor. This circuit also parks the wipers between wipes when they are on their intermittent setting.
To see the different wiper systems that are on a variety of ships, you can visit our newsletter page and subscribe for the latest updates.