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Text Book of Machine Design Part 14

Shafts | CONTENTS c H A P T E R 14 Shafts 1. Introduction. 2. Material Used for Shafts. 3. Manufacturing of Shafts. 4. Types of Shafts. 5. Standard Sizes of Transmission Shafts. 6. Stresses in Shafts. 7. Maximum Permissible Working Stresses for Transmission Shafts. 8. Design of Shafts. 9. Shafts Subjected to Twisting Moment Only. 10. Shafts Subjected to Bending Moment Only. 11. Shafts Subjected to Combined Twisting Moment and Bending Moment. 12. Shafts Subjected to Fluctuating Loads. 13. Shafts Subjected to Axial Load in addition to Combined Torsion and Bending Loads. 14. Design of Shafts on the Basis of Rigidity. 14.1 Introduction A shaft is a rotating machine element which is used to transmit power from one place to another. The power is delivered to the shaft by some tangential force and the resultant torque or twisting moment set up within the shaft permits the power to be transferred to various machines linked up to the shaft. In order to transfer the power from one shaft to another the various members such as pulleys gears etc. are mounted on it. These members along with the forces exerted upon them causes the shaft to bending. In other words we may say that a shaft is used for the transmission of torque and bending moment. The various members are mounted on the shaft by means of keys or splines. Notes 1. The shafts are usually cylindrical but may be square or cross-shaped in section. They are solid in cross-section but sometimes hollow shafts are also used. 509 CONTENTS 510 A Textbook of Machine Design 2. An axle though similar in shape to the shaft is a stationary machine element and is used for the transmission of bending moment only. It simply acts as a support for some rotating body such as hoisting drum a car wheel or a rope sheave. 3. A spindle is a short shaft that imparts motion either to a cutting tool e.g. drill press spindles or to a work piece e.g. lathe spindles . 14.2 Material Used for Shafts The material used for shafts should have the following .