20 Nov Getting Technical about Windshield Wiper Bushings
Windshield wipers are the first line of defense when it comes to driver safety. Responsible for keeping debris, snow and rain from blocking the driver’s vision, wipers have a lot of responsibility.
Bushings play a role in enabling movement in windshield wipers. They can be found in the arm, motor and linkage system. The bushings are composed of either metal with PTFE material or plastic. The metal backing of the PTFE version can be zinc plated for anti-corrosion capabilities.
While end users may not realize the level detail that goes into the bushings that have an ID of 4.5 to 10 mm and a length up to 28 mm, they are engineered to meet strict requirements.
- The oscillation frequency ranges from 15 to 55 cycles per minute
- They must perform in temperatures ranging from below freezing, -22 F, to over 130 F
- Extended exposure to the elements requires corrosion resistance
- Durability is expected to be between 1.5 to 3 million cycles
Add a radial load from the tension spring and friction torque generated by the blade wiping against the windshield, it is easy to see why it is important for OEMs to have the right bushing manufacturer as a partner.