Page 138 - Servo Motors and Industrial Control Theory -

8.2 Some Possible Applications of ER Fluid 133

Fig. 8.3 Cross section of a ER Fluid
disc type clutch

Wi
W0

Fig. 8.4 An axial type ER ER Fluid
clutch

Wi W0

Fig. 8.5 Cross section view
of a typical variable damper Xi
ER Fluid

V+
V0

X0

This exercise is left to the reader to investigate. In the axial type, the shear stress can
be assumed to be constant over the gap and the torque capability can be obtained
by multiplying the shear stress by the contact area and multiplying the result by the
radius.

8.2.3 Variable Dampers Based on ER Fluid

Dampers are usually made of two parts, a moving piston in a cylinder. With ER
fluid, a variable damper can be made. This is shown schematically in Fig. 8.5.