Question

For the transmission of power, a direct drive is only preferred when:
1. the slip is negligible
2. the speed of the driven machine equals the motor speed
3. the high speed motor is to drive a low speed machine
4. a noiseless, slipless and smooth operation is required

Answer 1

Correct Answer - Option 2 : the speed of the driven machine equals the motor speed

Direct drive motor:

A direct drive motor is any motor (rotary or linear) in which the load is connected directly to the motor, without mechanical transmission elements such as gearboxes or belt and pulley systems. In other words, the motor directly drives the load.

As the motor is directly connected to load, the speed of the driven machine must be equal to the motor speed.

Important Points:

• Rotary direct drive motors are often referred to as torque motors because of their ability to produce high torque at low speeds, even when stalled.
• Torque motors tend to be brushless, permanent magnet synchronous motors much like a traditional servo motor, but with a large number of poles.
• They’re often provided as frameless designs, meaning they don’t include a housing, bearings, or feedback device, with these components being purchased separately and integrated by the user.