Tensioner

Chain tensioner on a single-speed bicycle
Hydraulic bolt tensioner

A tensioner is a device that applies a force to create or maintain tension. The force may be applied parallel to, as in the case of a hydraulic bolt tensioner, or perpendicular to, as in the case of a spring-loaded bicycle chain tensioner, the tension it creates. The force may be generated by a fixed displacement, as in the case of an eccentric bicycle bottom bracket, which must be adjusted as parts ware, or by stretching or compressing a spring, as in the case of a spring-loaded bicycle chain tensioner; by changing the volume of a gas, as in the case of a marine riser tensioner; by hydraulic pressure, as in the case of a hydraulic bolt tensioner; or by gravity acting on a suspended mass, as in the case of a chair lift cable tensioner.

Applications

  • Bolt tensioners are devices designed to apply a specific tension to a bolt. The device may be either removed once the actual nut is threaded into place, or left in place, in the case of a hydraulic nut.[1]
  • The belt or chain tension on a single-speed bicycle can be maintained by either setting the fixed horizontal position of the rear sprocket or the front chainring horizontally, or by a separate tensioner that pushes perpendicular to the chain with either a fixed position or spring tension.[2]
  • The chain tension of a chainsaw may be adjusted with a chain tensioner.[4]
  • A marine riser tensioner is a device used on an offshore drilling vessel which provides a near constant upward force on the drilling riser independent of the movement of the floating drill vessel.
  • A guideline tensioner is a hydropneumatic device used on an offshore drilling rig that keeps a positive pulling force on the guidelines from the platform to a template on the seabed.
  • Overhead electrical wires may be kept in tension by springs or weights.
  • Certain wood trusses, such as the beam tensioner truss picture below.[5][6]
  • Fencing made of wire, such as electric fences, barbed-wire fences, and chainlink fences often include tensioning devices to keep them taut.
  • Belt sanders have a mechanism, often a spring loaded idler drum, to apply the proper tension to the sanding belt, which can be released to allow for changing belts.[7]

Gallery

See also

References

  1. "How Hydraulic Tensioners Work". Hydraulics Technology, Inc. 2014. Retrieved 2014-12-29.
  2. Brown, Sheldon. "Chain Tensioner". Sheldon Brown. Retrieved 2014-12-29.
  3. "Your Engine 101: Belts and Tensioners". Gates Corporation. 2009. Retrieved 2014-12-29.
  4. "Homelite 18″ Gas Chain Saw Review". Gadget Review. September 1, 2011. Retrieved 2014-12-29.
  5. "Timber Connectors". MiTek. 2011. Retrieved 2014-12-29.
  6. "Strap Brace Tensioners". Pryda. 2014. Retrieved 2014-12-29.
  7. "Belt Sander". ShopSmith. Retrieved 2013-12-30.

External links