Abstract—The objective of this paper is to determine the best joint design in the driveshaft of monorail drive train systems. Two of the most common joints used in these types of drive train systems are Rzeppa and Cardan joints. Constant velocity joint such as Rzeppa joint can operate at a much larger joint angle for desired torque transmission than non-constant velocity joints such as Cardan joint. However, constant velocity joints are more expensive to manufacture than more versatile Cardan joints. Therefore, there has been a constant debate in determining which joint type would be optimal. The paper utilizes typical material characteristics and common operating conditions of Rzeppa and Cardan joints. Then, the bending moment couples, which are generated during operation of these joints are analyzed with finite element analysis. This helps in determining the maximum allowable joint angle in using one joint type over the other. The paper further examines the fatigue factor of safety and provides a general guideline in determining the better option between the two. It is determined from these analyses that Rzeppa joint is a better option for general monorail drive train systems. However, Cardan joint may be adequate if the joint angle is very small.

Index Terms—Rzeppa joint, Cardan joint, Monorail train, CV joint, Non-CV joint

Cite: Sang June Oh and John T Woscek, "Analysis of Rzeppa and Cardan Joints in Monorail Drive Train System," International Journal of Mechanical Engineering and Robotics Research, Vol. 4, No. 1, pp. 1-11, January 2015.