A composite bearing with improved frictional response

The PolyLube Glass Tape bearing is a moderate RPM bearing designed for applications with higher surface velocities or when mixed film conditions are desired.

Similar to the Fiber Series bearing, the Glass Tape bearing is manufactured by a filament winding process that results in a continuous fiberglass filament backing composition-ensuring excellent mechanical properties (especially fatigue resistance) are attained. The filament wound fiberglass structure uses a high strength, corrosion resistant epoxy resin as the matrix material. The high strength backing permits the use of a thin wall (1/16" to 1/8") bearing which can often reduce the size and weight of the finished bearing assembly. PolyLube Glass Tape bearings will support a dynamic bearing load of 7,000 PSI, while handling high radial and longitudinal stresses with a static bearing capacity of 40,000 PSI. This family of materials exhibits exceptional dimensional stability and performance predictability over wide temperature ranges (±325°F).

Applications

Applications for PolyLube Glass Tape Bearings range from guide rod bearings to linear motion components to hydraulic pumps. Swashblock mounted bearings are ideal applications for the Glass Tape bearing material as long as application considerations are consistent with a mixed film condition.

The PolyLube bearing offers a more elastic, damage tolerant structure when compared to traditional metallic bearing materials. In addition, the Glass Tape bearing exhibits good cavitation resistance when subjected to high pressure fluids during cyclic conditions.

Product Schematic

The PolyLube Glass Tape lined bearing is similar in backing construction when compared to its sister product-the Fiber Series bearing; however, the difference in the construction of the liner material drives the variations in performance. The primary performance variations between the Glass Tape and the Fiber Series bearing are that the Glass Tape bearing has a lower coefficient of friction and will handle higher surface velocities. However, the Glass Tape bearing sacrifices some capabilities with a slightly lower dynamic and static load capacity.

These differences are driven from fact that the Glass Tape bearing uses a proprietary filled PTFE resin structure as opposed to the continuous PTFE filaments used in the MRP product. Two liner thicknesses are available with the 0.015” thick liner being standard and a 0.030" thick liner being available for unique applications. The 0.030" thick liner is designed for applications where boring the inner diameter might be required in order to achieve tighter tolerances in an effort to address sizing and minor misalignment conditions.

Mechanical and Physical Properties

The PolyLube Glass Tape bearing can withstand static loads of approximately 70,000 PSI and 7,000 PSI under dynamic loading. At these loading levels, minimum distortion will occur. For dry running applications, the maximum speed is approximately 300 surface feet per minute.

This bearing’s operating temperature range is ±325°F. Maximum continuous operational surface temperature for the standard formulation is 325°F, depending upon load characteristics. The bearing has been heat stabilized at these temperatures, so that little dimensional change will occur in the bearing during operation. In a free state, the coefficient of expansion of the PolyLube Glass Tape bearing is approximately 7 x 106 in/in/°F, similar to the coefficient of expansion for steel, and actually less than some metals.