In: Mechanical Engineering
A dog clutch is a mechanism used to connect and disconnect two rotating shafts or machine parts. It functions by mating a set of regularly spaced teeth or protrusions on one half of the clutch mechanism to a set of identical recesses on the other, rather than using the frictionprinciple used in other clutches. This has the benefit of allowing both shafts to turn at the same speed without slipping and with minimal clutch wear. They can not, however, be used to control torque as is the case with a friction clutch. Dog clutches are commonly used in manual or stick shift automobile gearboxes, marine propeller drives, and on the drives of heavy machinery.
This type of clutch is typically made up of two round plates, one fixed to the drive shaftand one to the shaft being driven. One of the plates has a series of evenly spaced protrusions machined into its face, similar to the battlements on top of a castle wall. The other has an identically spaced series of like-sized recesses cut into its face. When the two plates are brought together, the protrusions mate or fit into the recesses, thereby effectively joining the shafts and transferring rotational motion from one to the other. This ensures a strong mechanical coupling between the two components with no slip characteristics.
Advantages
They do not slip.
They can transmit large torque.
Develop no heat during engagement and disengagement because of rigid interlocking (no friction).
Disadvantages
Engagement of clutch cannot be possible at high speed.
While starting some relative motion may be required to engage.