Endurance and performance of a composite spherical bearing

Since the conventional spherical bearing composed of a metal-race and metal-ball journal for the elevation driving mechanism (EDM) of guns has a seizure problem between the race and ball, a composite spherical bearing (CSB) composed of a carbon-phenolic composite race and a steel ball journal has been developed to eliminate the problem and reduce frictional torque without less clearance for the EDM of future battle tanks. In this work, the reliability of composite race of the EDM under dynamic load induced during firing was investigated with respect to environmental temperature and humidity changes. Finally, the bearing clearance and frictional torque of the CSB, which affected targeting accuracy and driving force, were measured by a pneumatic bearing tester that could simulate the ball journal oscillation under compressive bearing load.