Thermal overload protective device for friction clutch - includes slip and frictional power calculators and logic for temp. comparison with threshold and warning levels

摘要

The frictional power is calculated (20) by a subtractor (15, 25) of the rotational speeds (W1, W2) of input and output shafts (1, 2), a proportional torque multiplier (26), a corrector (27) of friction coeffts. dependent on speed difference and friction lining temp., and two multipliers (28,29). The result (30) is forwarded to a temp. calculator (21) whose finding is compared (32-34) with max., min. and intermediate (warning) temps. The logic (22) produces a trigger signal (40) for the control of a proportional valve (16) supplying fluid to the clutch-operating member (6). ADVANTAGE - Clutch is protected reliably even during frequent starts or prolonged periods of slight slipping.