Tensioner & Idler Bearing

Tensioner & Idler Bearing

Based on advanced bearing technology GMB tensioner and idler bearings have met rigorous requirements from car manufactures like Hyundai Motor, Kia Motors, Volks Wagen and so on for many years. Our design concept is as follows.

  • Optimal material selection for high temperature use
  • Ideal sealing design to prevent grease leakage
  • Low torque engineering to reduce excessive seal friction
  • Grease selection for high temperature and extended use
  • Optimal clearance
  • Tolerance control to achieve correct alignment

Automatic defect detectors are installed in the process. Rigorous quality control enables us to target zero defect. We cover wide range of car makers and models with more than 500 part numbers. GMB enjoys OE reputation in global aftermarket.

Functions of Tensioner & Idler Bearing

Tensioner bearing

Belt driven outer ring mechanism is inherent in this design. Tensioner bearing is placed at slack side.(Idler bearing at tight side) There are various styles according to engine types.

· To provide belt with tension
· To transfer driving force from crankshaft
· To prevent belt slippage
· To prevent noise caused by off-line belt
· To minimize space of belt layout

Product specifications Types
Unitized type (outer ring with pulley / inner ring with shaft)
Ball bearing type (bearing / pulley / shaft)
Pulley type (inner ring unitized with shaft / pulley)
Bracket assembled type


Tensioner and idler bearing consists of basic components like inner ring, outer ring, retainer, grease and seal. Pulley may be added to adjust rotation ratio. Bracket may be added to adjust location for adding tension. Races are one of the bearing component parts. It has grooved track for balls to locate. Outer race and inner race make a set. Inner race is situated on sub-assembly unit and outer race is set on housing. Pulley may be added on outer race to provide timing belt system with designed revolution rate. Rolling element is "ball" running between races. Retainer moving along with balls separates individual ball into position. Also grease has important role to reduce friction and oil seal serves to hold grease and shut foreign particles from intrusion.

Tensioner Bearing