New Method and Equipment for Machining “S” Profiles of Cam Shafts for Drum Brakes of Bus and Truck Axles

One of the main factors of the drum brake performance and quality is the accuracy of “S” profiles of the cam shafts. To reduce cost, most axle and brake manufacturers use cam shafts with forged “S” cams, in some cases decreasing the accuracy of “S” profile, brake performance, and quality as compared to a machined “S” profile option.

Today's highly competitive market, especially the bus market, requires the highest possible brake performance at reduced cost. This paper shows how to meet both requirements for cam shaft manufacturing, high “S” profile accuracy and low machining cost, at the same time.