Motion Control Elements

Motion Control

Machine systems require control whenever the speed or the direction of the motion of one or more components is to be changed. When a device is started initially, it must be accelerated from rest to the operating speed. As a function is completed, the system must frequently be brought to rest. In continuously operating systems, changing speeds to adjust to different operating conditions is often necessary. Safety sometimes requires motion control, for example when a load being lowered by a hoist or an elevator.

The machine elements most frequently used for motion control are

    1. Clutch

    2. Brake

Types of Brakes and Clutches

  1. Internal expanding type

  2. External contracting type

  3. Band type

  4. Thrust type

  5. Cone type

1. Internal expanding 2. External contracting 3. Band type 4. Thrust type 5. Cone type

Three basic requirements in design of brakes and drums

  1. The required friction torque must be produced by an acceptable actuating force.

  2. The energy converted to friction heat (during braking or during clutch engagement) must be dissipated without producing destructively high temperatures.

  3. The wear characteristics of the friction surfaces must be such that they give acceptable life.