TABLE OF CONTENTS Demand within the automotive industry has led to strong competition among driveshaft manufacturers. For each application the strength and life must meet the specifications, while the weight and price must be kept as low as possible.
The useful life of a driveshaft is determined mainly by the joints. For this reason the other component parts will not be discussed here; they can in any case be de-signed using the general principles of strength of materials.
With good lubrication and sealing the life is limited by fatigue [1] of the material after millions of reversals. With bad sealing the life is limited by corrosion and, if there is contamination, by the resultant increase in wear. In order to calculate the life the first case is assumed.
The role of joints and driveshafts is to transmit torques between shafts which are not in line. These transmitted loads are limited by the capacity of the materials used. Hence in assessing the capacity of the joints it is most important to determine the pressure between the rolling bodies and their tracks. To this end (3.54) and (3.57) in Chap. 3 were derived using Hertz's theory. It must however be decided whether short or long term loading is involved:
for short term loading the stress state is quasi-static. The joint is then designed so that excessive plastic deformation does not occur,
for long term loading the stress state is dynamic. The joint must be designed for many millions of...
