Beyond DU® - From Revolution to the Evolution of Metal-Polymer Plain Bearings and Bushings
Next year marks the 60th anniversary of GGB Bearing Technology’s iconic DU® bearings. In 1956 Glacier Metal Company, GGB’s predecessor revolutionized the bearing industry with the introduction of the world’s first self-lubricating metal polymer plain bearings.
Their success lies in the unique composite bearing structure comprised of a steel backing for mechanical strength and a porous sintered bronze interlayer impregnated with PTFE and lead for high wear resistance and extremely low friction properties.
This structure provides the following benefits:
- Improved energy efficiency due to low friction of PTFE-enriched overlay
- Extended service life with a strong wear-resistant bronze layer
- Zero maintenance as self-lubricating bearings can operate perfectly dry
- Greater reliability with lubricant to avoid potential shaft/bearing seizure under boundary conditions
- Compact, lightweight designs with a thin-wall bearing construction
- Reduced noise due to no metal-to-metal contact
- Quick, simple assembly without expensive mounting tools
Since this initial breakthrough development, GGB has gained years of experience in polymer processing and compositional formulations which has led to a series of self-lubricating metal-polymer bearing products optimized for greater performance.
These advances have resulted in a range of stronger, more durable and environmentally friendly lead-free bushings and bearings (in accordance with EU directives such ELV, RoHS and WEEE) that perform excellently under extreme conditions in both dry and lubricated applications.
For example, originally developed for use in high performance automotive shock absorbers and other heavy duty hydraulic applications, DP4 and bronze-backed DP4-B metal-polymer bushings are now used in a wide range of both automotive and for industrial applications.
In addition to automotive shock absorbers, DP4 bearings are used in braking systems; clutches; gearboxes and transmissions; door, hood and trunk hinges; convertible tops; pedal systems; pumps; seating mechanisms; steering systems; and wiper systems.Available in wide range of standard sizes and shapes (cylindrical and flanged bushings, thrust washers and sliding plates), industrial applications include aerospace, agricultural and construction equipment; food and beverage; marine; material handling; office equipment; packaging equipment; pneumatic and hydraulic cylinders; railroad and tramways, textile machinery; and valves.
In lubricated applications DP31 PTFE bushings provide superior performance low friction and resistance to wear, fatigue, flow erosion and cavitation. Typical applications include fuel injection pumps, power steering pumps, compressors, engine valve-train bearings, struts and shock absorbers, hydraulic cylinders, transmission bearings, and hydraulic pumps and motors.
Additionally, DP10 bearings are recommended for marginally lubricated applications and DP11 bearings for dry applications. In particular, DP11 performs excellently in applications with high frequency, low amplitude oscillating movements such as pulley dampers, belt and chain tensioners, twin mass flywheels, clutches, solenoids and others.