Avtodizel ???-238??, Operating Instructions Manual, Page: 76 / 254

76
Fig. 38. Fan drive
1 – leap-type seal; 2 – cover; 3 – ball-bearing; 4 – driven disk; 5 –
driving disk; 6 – gasket; 7 – back pressed spring; 8 – thrust ring; 9 –
scoop pipe; 10 – spacer bushing; 11 -piston ring; 12 – leap-type seal;
13 – union; 14 – case; 15 – roller bearing; 16 – thrust flange; 17 –
gear; 18 – driving shaft; 19 – washer; 20 – gasket; 21 – bushing; 22 –
space bushing; 23 – double-row ball-bearing; 24 – pulley; 25 –
driven shaft; 26 – ball-bearing; 27 – pressing ring; 28 – piston ring;
29 – O-ring; 30 – piston; 31 – piston stop; 32 – pressing spring.
When the coolant temperature will be close to the lowest opti-
mum level, the switch stops the oil supply. The oil there is under piston
30, due acting of centrifugal forces and springs 7, 32, travels through
drainage holes and special channels to inside cavity of the front cover 2
and pulley 24. With help of scoop pipe 9 and far through the case
channels the oil arrives engine sump.
As the cavity under piston 30 is wasting the piston will travel
under pressure of springs 7, 32. The frictional drive plates are sepa-
rated and the fan switched-off.