What is progression ratio? working principle of hydraulic drive, Advantage and Disadvantages of hydraulic drive

Progression ratio: The ratio of maximum speed to the minimum speed is called progression ratio. It is represented by Φ.

Machine Tool drive: The tools whice are driven by the power known as machine tools.

working principle of hydraulic drive: hydraulic drive is machine tools use the pressurized oil to transmit energy. The high viscous oil is used for this purpose. The pressurized oil from the pump is transmitted through the pipe to a hydraulic motor where the motor is set to motion. These are positive dispalcement pumps because the energy conversion takes place during the process of oil in the working chamber.

Advantages of hydraulic drive:

1. Realtively small dimension and weight

2. Quiet running and self lubricating

3. possiblity of high cutting and clamping force

4. The possiblity of simple and smooth speed reversion

Disadvantages of hydraulic drive:

1.The high accuracy of the parts and close fit of assembly leads to high cost of production

2. Any leakage of reduces the efficiency of the system

3. Absolute accuracy of working speed can not be attained easily.

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