Clutches with adjustable friction are rotary hardware devices used in all types of small drives, such as light power drives, pumps and small generators. They help to protect people and equipment and are most commonly used where a shaft or machine must be started and stopped frequently.
The construction of clutches with adjustable friction is simple. Pressure is loaded onto the plates and friction rings by an adjuster which acts through a spring and pressure plate. The load can be connected to either the steel inner hub or the aluminium alloy housing.
The three main characteristics to bear in mind are breakaway torque, torque decay and speed related torque fluctuations. Breakaway torque occurs when an already installed screw is rotated or loosened further. With torque decay, the slipping torque reduces as the power causes the clutch temperature to rise. Clutches behave more consistently at high speed and low torque.