Page 223 - Industrial Power Engineering and Applications Handbook

Transmission of load and suitability of bearings 8/203

Input
shaft

Figure 8.9(a) Eddy current drive (Courtesy: Dynodrive)
(a) Oil in reservoir, circuit empty, drive is disengaged

Input . output
shaft shaft

(b) Circuit partly filled, drive is partly engaged

@ DC-excitation voltage regulator.
@ Speed setting rheostat.
@ Speed comparator.
@) Excitation coil.
@ Tacho-generator.
output
shaft NR - Required speed possible up to 7-1 0% of N,.
A NA - actual speed.
AN - Speed error.
Figure 8.9(b) A general scheme illustrating speed control by
feedback control system using an eddy current coupling

Flat belts
V-belts
The flat belt is a friction drive transmitting load through
(c) Oil in circuit, drive is fully clutched
the friction between the belt and the pulley while the V-
Figure 8.8 Illustration of clutching of a scoop control variable belt is a positive drive which is flat on one side and has
fluid coupling a projection like a geartooth on the other. These