J. Couplings
When (1) the transmission shaft is too long that causes
difficulty for design and installation, (2) the shaft is separated as two non-colinear
segments, (3) the shaft is operating with two rotational speeds, or (4) the
driven shaft is expected to be able to be isolated, stopped, or connected to
the driving shaft at any time, the couplings are usually used for facilitating
such transmission. Broadly speaking, coupling is a device used to join two moving
members. The most common utilization of couplings is the one that joins the
ends of the shafts of the motor and driven mechanism, in which the motor power
can be transferred into the driven mechanism. Also, it is frequently adopted
for the motion transformation through the power devices (e.g., motors or engines),
speed reducers, and the driven mechanisms. Unlike other mechanisms, the couplings
are able to deliver motion based on very few parts. Hence it has the features
of simple design and ease for replacement.