A clutch controls a machine’s power transmission or motion. Clutches can control these factors on-demand or over time. Frictional clutches transmit power by harnessing friction between two contacting surfaces. This mechanism offers specific benefits over other types of clutches. We will discuss these advantages, as well as the features and types of frictional clutches that fit certain applications.
Advantages of Frictional Clutches
Frictional clutches are one of the most popular types of clutches and for good reason. They are easy to operate, especially in situations that require frequent engagement and disengagement while the machine is running. This is possible because frictional clutches have no teeth, which smooths engagement and reduces shock.
Frictional clutches can also transmit partial power and act as a safety mechanism. For example, when torque exceeds a certain level, the frictional clutch slips and protects the machine from overloading.
Features of Frictional Clutches
These are the main types of frictional clutches:
- Centrifugal: These clutches are used in machines where the engine speed defines the clutch’s operation. An example is a chainsaw, which utilizes centrifugal force to engage the clutch if the engine’s RPM goes over a specific threshold. The clutch disengages automatically when the engine’s RPM falls below the limit.
- Cone clutch: A cone clutch is made up of a pair of male and female conical friction surfaces. The cone clutch can transfer a higher amount of torque than disk clutches because the conical taper slows the approach of the friction surfaces. This translates into more pressure and friction between the mating surfaces.
- Torque limiter: A torque limiter is also called a slip clutch or safety clutch because it slips if the machine encounters resistance that is higher than normal. A good example of this device is the clutch on lawnmowers. If the mower hits a rock or immovable object, the clutch yields and prevents the equipment from damaging itself.
Frictional Clutches From BLM
Founded in 1932, BLM Automatic Clutch has been designing and producing custom clutches for our clients. Our two main product lines are Four Block Series clutches—for chippers, concrete pumps, conveyors, refrigerators, and more—and Six Block Series clutches for large industrial and commercial machinery. These are all centrifugal clutches fit for a variety of municipal, chemical, military, and other critical applications.