Parking Brakes

DP4®

BEARING APPLICATION REQUIREMENTS

GGB DP4 high-performance, metal-polymer flat thrust washers successfully replaced needle roller bearings in a rear braking system. The system combines mechanical and hydraulic functions to apply a braking force when a vehicle is parked.

Torque generated by depressing a floor-mounted pedal or pulling a lever is converted to a clamping action by a shaft immersed in brake fluid that rotates three balls into a wedge-like mechanism.

The bearings must withstand forces of up to 15 000 N / 3 300 lbs and reduce friction created by the relative movement of the shaft, rotating up to 30 degrees every second or less.

GGB AUTOMOTIVE BEARING SOLUTION

The lead-free GGB DP4 thrust washers were benchmarked, compared with alternative options and ultimately used to replace the needle roller bearings.

The structure of GGB DP4 composite bearings consists of a rigid steel backing, to which is bonded a porous bronze sinter interlayer impregnated and overlaid with a filled PTFE bearing layer. This highly resistant composite bearing structure can withstand specific loads of up to 250 MPa / 36 000 psi. 

GGB AUTOMOTIVE BEARINGS - BENEFITS

In this application, the excellent self-lubricating properties of GGB DP4 metal-polymer thrust washer bearings enable the following benefits to be obtained:

• Superior antifriction and wear performance in both dry and lubricated running conditions
• More compact and lighter weight designs with a reduced 1 mm wall thickness
• Easier mounting in the assembly with a one piece bearing design
• To date, millions of braking systems operate with GGB DP4 self-lubricating metal-polymer bearings with complete security and reliability.