Door Closer

DP4®

BEARING APPLICATION REQUIREMENTS

The external arm of a door closer is fixed to a geared pinion that rotates around itself, moving a worm gear that compresses a spring as the door is opened. When the door is released, the spring returns to its original uncompressed state, thereby enabling the door to close automatically.

If the door is opened by 90 degrees, the pinion goes through 140 degrees of rotation and another 140 degrees when it is closed.

GGB industrial bushing SOLUTION

DP4 lead-free, metal-polymer bushings are fitted at the top and bottom of the rotating pinion, providing low friction bearing performance and ensure an easy and noise-free operation.

The structure of the bushings consists of a rigid steel backing to which is bonded a porous bronze sinter interlayer, impregnated and overlaid with a PTFE bushing layer with wear-resistant fillers.

GGB low friction Bushings - BENEFITS

In addition to the excellent low friction bearing performance, other benefits of metal-polymer DP4 bushings are:

• High wear resistance and long service life; GGB DP4 low friction bushings passed requested life of 500 000 cycles and routinely exceeding 1 000 000 cycles.
• Compatibility with hydraulic mineral oil and water glycol, a corrosive, non-oil-based hydraulic lubricant