The development of carbon-carbon composite cages for rolling element bearings

摘要

This paper highlights the development of carbon matrix-carbon fiber (C-C) composite bearing cages for high temperature gas turbine applications. Benefits of C-C cages under high-speed, high-temperature conditions are documented with experimental results. The experimental results show that C-C cages offer substantial reduction in heat generation compared to metal cages at the same operating conditions, and C-C cages enable much higher DN operation in the absence of liquid lubrication. The improved performance of C-C cages over conventional metal cages is largely attributed to the inherent properties of C-C composites: 1. Low density to reduce centrifugal speed effects; 2. Excellent thermal conductivity for a non-metal; 3. Low friction under marginal lubrication conditions; 4. Low wear rates compared to other self-lubricating cage materials; and 5. Low coefficient of thermal expansion to avoid seizure in high thermal gradient conditions.