Robot Mechanisms and Mechanical Devices Illustrated - Profe Saul

74 Chapter 2 Indirect Power Transfer Devices
Figure 2-1 Flat, O-ring, and
V-belt profiles and pulleys
back is a slight tendency to slip over time. This slip means the computer
has no precise control of the orientation of the output shaft,
unless a feedback device is on the driveN pulley. There are several
applications, however, where some slip is not much of a problem, like
in some wheel and track drives. Figure 2-1 shows the cross sectional
shape of each belt.
In spite of the warnings on the possibility of problems using variable
speed drives, here are some examples of methods of varying the speed
and torque by using variable diameter sheaves. Figure 2-2 (from
Mechanisms and Mechanical Devices Sourcebook, as are many of the
figures in this book) shows how variable speed drives work. They may
have some applications, especially in teleoperated vehicles.
Figure 2-2
Variable Belt