Positive clutches

Positive clutches

Positive clutches are used when positive (no slip) drives are required. These clutches transmit power from the drive shaft to the driven shaft by the interlocking of jaws or teeth. They are rarely used as compared to friction clutch.

There are two types of positive clutches:

Square jaw clutch
Spiral jaw clutch

Application of positive clutch

They have very limited use. However, they have some application where the synchronous drive is required.

Advantages

Disadvantages

They do not slip.
They can transmit large torque.
Develop no heat during engagement and disengagement because of rigid interlocking (no friction).

Engagement of clutch cannot be possible at high speed.
While starting some relative motion may be required to engage.
Difficult to disengage under load.