Pump 15 delivers fluid into chambers a and b, shifting rings 12 and 13 inward into contact with the friction surfaces of sun wheels 9 and 10. At this, sun wheel 9 is shifted to the right, out of contact with friction wheel 14 which is rigidly mounted on driving shaft 1. Sun wheel 10 is shifted to the left, out of contact with carrier 4 which is rigidly mounted on driven shaft 3. As a result, wheels 9 and 10 stop rotating. Internal sun gear 6 and planet gears 8 are also stationary. Rotation of the driving shaft is transmitted by gear 2 to planet gears 5 and carrier 4. This drives the driven shaft at minimum speed. To obtain the second speed, fluid is drained from chamber a through discharge valve 17 to the tank. Sun wheel 10 remains stationary, and wheel 9 is shifted to the left by springs 11 into contact with tapered friction wheel 14. Owing to friction, wheel 9 rotates together with wheel 14. The rotation of driving shaft 1 is transmitted by two sets of planetary gearing to driven shaft 3. The speed of the driven shaft is higher than in the first case. To obtain the third speed, valve 17 is closed and valve 16 is opened. Ring 12 is shifted by the action of fluid in chamber a and it brakes wheel 9. Wheel 10 is shifted to the right by springs 11 into contact with the friction surface of carrier 4 and rotates together with the carrier. The rotation of driving shaft 1 is transmitted by sun gear 2 and planet gears 5 to internal gear 6. From gear 6 rotation is transmitted further to planet gears 8 and sun gear 10. The speed of driven shaft 3 is higher than in the preceding case. To obtain the maximum speed, pump 15 is switched off. Wheels 9 and 10 are shifted outward by springs 11 into contact with tapered friction wheel 14 and with carrier 4. At this, sun wheel 6 rotates at the speed of the drive motor.
$4037$THP,SR$