33. Hydraulic speed reducer

a.   Principle of the hydraulic speed reducer

1- Centrifugal pump 4- Pump shaft (actuating shaft)

2- Hydraulic turbine 5- Turbine shaft (receiving shaft)

3- Nozzle ring 6- Cover

b. Features

 Hydraulic speed reducer is applied on some high speed vessels and consists of two kind: one direction and reversing speed reducer. They have some following features:

- Revolution of the pump shaft (main engine) and the turbine shaft (propeller shaft) has a relation by transmission ratio:

I = n1/n2

- Torque value on the actuating shaft when transmitting is changed.

M1/M2 =1/i

- There is a nozzle ring to change torque of actuating shaft.

- Transmission efficiency is lower than in comparison with hydraulic clutch.