GB1435185A - Driving device for rotary machine - Google Patents

Abstract

1435185 Variable-speed gear TSUKISHIMA KIKAI CO Ltd 25 July 1973 [28 July 1972] 35484/73 Heading F2D [Also in Division B1] Mechanism for driving a rotary machine such as a centrifugal separator comprises a reversible motor, a planetary gear system, one-way drive means so arranged that when the motor rotates in one direction it drives the machine at reduced speed through the planetary gear system and when it rotates in the opposite direction it drives the machine directly at high speed, and means providing a controlled reaction force on the planetary gear system to limit the transmitted torque during reduced speed operation. The high speed is suitable for centrifugal separation and the reduced speed for discharging separated solid material. In one embodiment, a hollow shaft 16, Fig. 2, connected to the motor M through a centrifugal or a fluid clutch (not shown) is connected by oneway clutches 11, 12 with a planetary gear housing 14 and an output shaft 7. Planetary wheels 23, 24 fixed to a shaft 25 rotatable in the housing mesh respectively with a sun wheel 17 fixed to the shaft 7 and a sun wheel 19 fixed to a sleeve 20 which is rotatable in the housing and on the shaft 7 and carries a disc 15 braked by elements 27. Rotation of the shaft 16 in one direction engages the clutch 11 to rotate the housing 14 which, due to the stationary wheel 19, causes the wheel 17 and shaft 7 to be driven at reduced speed, whilst rotation of the shaft 16 in the other direction engages the clutch 12 for direct drive of the shaft 7. The braking pressure applied by the elements 27 to the disc 15 to limit the transmitted torque during reduced speed operation is determined by a solenoid-operated air valve 30 governed by means 33 subject to control by a presetting device 32 and a motor overload protection device 31. The means 33 may also control the radial position of the braking elements relatively to the disc to extend the braking range. Eddy current braking may be employed instead of the friction arrangement. A modification, with an upwardly extending output shaft 7, Fig. 6, has a belt drive 42 from the motor (not shown) to a sleeve 16 which carries a sun wheel 57 in mesh with a planetary wheel 56 on a carrier 52 formed with a second sun-wheel 53 in mesh with a second planetary wheel 61 which has a one-way clutch connection 60 with an arm 58 projecting from the output shaft 7. A rotatable casing 14 with brake discs 15 is formed with internal ring gears 45, 46 in mesh with the wheels 56, 61. Rotation of the input shaft in one direction results in the wheel 61 attempting to turn in the direction in which rotation is prevented by the clutch 60 so that the entire planetary train is locked and, with the brake(s) 10 released, direct drive is transmitted. With the brake(s) 10 applied and the input shaft driven in the opposite direction the one-way clutch 60 allows the wheel 61 to rotate so that reduced-speed drive is established. A further modification has two belt drives from the motor, one driving the output shaft directly through a one-way clutch when the motor rotates in one direction and the other providing a reduced-speed drive through a second oneway clutch and planetary gearing when the motor rotates in the other direction.