Page 120 - Analysis and Design of Machine Elements

Analysis and Design of Machine Elements
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(a) (b)
Figure 4.7 Types of pins.

Taper pins can also join a shaft and the hub of mounted power transmission elements.
The pinpreventsrotationalmotionbetween theshaft andmountedelementswhena
torque is transmitted. The torque transmission capacity of connection is limited by the
shear strength of pin. Pins are suitable for transmitting low to medium torques.
A shear pin serves as a safety or protective component, usually in couplings or
clutches, as shown later in Table 13.3. Pins are purposely made of relatively weak
materials or with deliberately small diameters to ensure the pins will break if loads
exceed acceptable operating limits, thus protecting critical or expensive components
of a machine. Therefore, the diameter of a pin is determined according to the overload
when shear occurs.
Many other types of pins are used in various machines. For example, the split cotter
pin prevents the nut from turning on the bolt in Figure 3.6b. The clevis pin has a ridge
at one end and is kept in place by a cotter pin inserted through a hole in the other end,
as shown in the chain joint connections in Figure 7.3.

References

1 Mott, R.L. (2003). Machine Elements in Mechanical Design, 4e. Prentice Hall.
2 Pu, L.G. and Ji, M.G. (2006). Mechanical Design, 8e. Beijing: Higher Education Press.
3 Oberg, E. (2012). Machinery’s Handbook, 29e. New York: Industrial Press.
4 Gere, J.M. and Timoshenko, S.P. (1996). Mechanics of Materials, 4e. CL Engineering.
5 Wen, B.C. (2015). Machine Design Handbook, 5e, vol. 2. Beijing: China Machine Press.
6 Juvinall, R.C. and Marshek, K.M. (2011). Fundamentals of Machine Component
Design, 5e. New York: Wiley.
7 Budynas, R.G. and Nisbett, J.K. (2011). Shigley’s Mechanical Engineering Design,9e.
New York: McGraw-Hill.