Windshield Wipers Working Mechanism

In the past, the windshield wipers are operated manually, inside the car by moving lever back and forth. Today, these are operating with electric power. By moving back and forth, they are sweeping water away across the windshield countless times and keep clear. We can find the windshield wipers car windshields, on some cars headlights, airplanes and space shuttles. Now we will discuss in detail about them.

• Inside of the wipers: To perform the task, the wipers combine two mechanical technologies. Those are a combination of worm gear and electric motor, and a neat linkage. Worm gear reduction and electric motor provides power. The linkage converts the rotational output of motor into back and forth motion.
• Gear reduction and motor: To accelerate the wiper blades across windshield back and forth quickly, a lot of force is required. To generate this type of force, worm gear is used. It multiplies the motor torque by about fifty times. An electric circuit inside the gear assembly or motor senses when the wipers are at their down position. Until the wipers parked at bottom of the windshield, circuit maintains the power, after that it cuts the power to motor.
• Linkage: A short can, which is attached to gear reduction’s output shaft, spins around as wiper motor turns. This cam connects to a long rod. It moves the rod back and forth as the cam spins. Long rod connected to a short rod actuates wiper blade on the driver's side. Another long rod transmits force to the passenger side wiper blade from driver side.

• Blades: The thin rubber strips of the wiper clear the water across windshield. When the blades are new, the rubbers are clean and no cracks or nicks, without leaving any streaks it wipe away the water. When these are old, cracks or nicks build up on the edge from road grime. It do not make tight a seal and leaves streaks.

• Control: Most of the windshield wipers have a high, a low speed setting, and an intermittent setting. When the wipers are on high or low speed setting, the motor is continuously works. On the intermittent setting, the wipers stop between each type.

In the past automakers tried either to control the wipers speed automatically or to eliminate the wipers. Some of those are detecting the vibrations, which are caused by individual raindrops hitting windshield. These are need not wiped at all. When they sensed automatically they wipe. However, this system was failed due to inconvenience of drivers. The new system uses the optical sensors to detect the moisture. The sensor mounted near rear view mirror projects into the windshield an infrared light at forty-five degree angle. If there are any water droplets, the less light makes back into the sensor. When the amount of the light is less than the preset level, the software and the electronics turn on the wipers.