The present invention relates to the retainers of tapered roller bearings, and it more particularly relates to a particularly effective synthetic resin composition to be used for the retainers of tapered roller bearings.
Synthetic resin materials are widely used for the retainers or cages of antifriction bearings such as ball bearings. However, conventional synthetic resin materials still have problems when used for the retainers of tapered roller bearings, and thus need to be improved in performance. For example, polyamide resins, such as nylon 66, undergo marked dimensional variations due to hygroscopicity, rendering the inner ring assembly subject to separation. When reinforced with glass fiber or carbon fiber, nylon 66, and similar polyamide resins, exhibit reduced dimensional variations but have poorer elongation, with result that the rib portion of the retainer is prone to damage when the retainer is assembled into a bearing or during handling.