Freewheel, Sprag and Overrunning clutches – Basic Information and Applications

Author: Michael Zhang

Freewheel Clutch:

The freewheel clutch, sprag clutches and overrunning clutches are very common and most used parts in Mechanical engineering. A Freewheel Clutch is a device which fives the fastest rotation to the shaft in automotive or mechanical engineering. Sometimes this clutch is overdrive and hence mistakenly it is called Freewheel clutch. The Freewheel Clutches are couplings of one way rotation. This clutch allowed idling in one direction and in the opposite direction transmitting the torque. Freewheel clutch is the one way clutch.

Application of Freewheel clutches:

  • The Freewheel Clutches are widely used as a protective device on engine starters.
  • This clutch is used as vehicle transmissions.
  • An Overrunning Clutches are used in agriculture equipment on hay balers.
  • Freewheel Clutches are used in rotorcrafts in helicopter. It allows independent spin.
  • In older cycle, the Freewheel clutch mechanism is used in gear assembly. In new bicycles this mechanism is known as free hub.

Overrunning Clutches:

When the driven part is rotate faster compare to driving part, then the Freewheel clutch is used as Overrunning Clutches which unlocked automatically while this process is taking place. Overrunning clutch is the major factor when selecting design suitable for each application. In overrunning clutches, during major number of over speed rotations the wear is reduces and overheating as well as increases the life of freewheel which is worked as overrunning clutch. For meeting the particular application requirements, the clutches are available without or with internal bearings, with the range of mountain flanges, couplings and covers.

Applications of Overrunning Clutches:

  • In mixers for motor protections
  • In packaging machines for freely spins down
  • In printing press for ink roller drive
  • In motorcycles for down freely spins
  • For speed compensation

Sprag Clutches:

The Sprag Clutches are designed in such a way that for required installation they maximize the torque capacity. Sprag clutches are offered with and without races, with and without keyways.

Applications of Sprag Clutch:

  • The Sprag Clutches are used in helicopter design which is transfer the power from engine to main rotor. The Sprag Clutch allows the helicopter to enter in autorotation while engine failure.
  • Used as electric starter motors in modern motorcycle engines.
  • For anti-runback and indexing on conveyor drives
  • Sprag clutch used in between engine and transmission in the primary drive.
  • Sprag clutch used in as indexing and backstopping in motorcycles.
  • Sprag clutch used in automatic transmission
  • Transmit the torque

About Author:

PS Freewheel Clutches is the expert and specialized for the manufacturer of all different design Freewheel Clutch, Overrunning Clutches,Sprag Clutches,Cam Clutches, One Way Clutches and Drawn Cup Roller Clutches.For More information visit at www.psfreewheelclutches.com