Drive Belt System Description: Notes

The drive belt system consists of the following components:

• The drive belt
• The drive belt tensioner
• The drive belt idler pulley
• The crankshaft balancer pulley
• The accessory drive component mounting brackets
• The accessory drive components
  • The power steering pump
  • The generator
  • The A/C compressor
  • The engine cooling fan
  • The water pump, if belt driven

Fig 1: Identifying Drive Belt

Courtesy of GENERAL MOTORS CORP.

The drive belt system may use 2 belts. The drive belt (1) is thin so that it can bend backwards and has several ribs to match the grooves in the pulleys. The drive belts are made of different types of rubbers - chloroprene or EPDM - and have different layers or plies containing either fiber cloth or cords for reinforcement.

Both sides of the drive belt may be used to drive the different accessory drive components. When the back side of the drive belt is used to drive a pulley, the pulley is smooth.

The drive belt is pulled by the crankshaft balancer pulley across the accessory drive component pulleys. The spring loaded drive belt tensioner keeps constant tension on the drive belt to prevent the drive belt from slipping. The drive belt tensioner arm will move when loads are applied to the drive belt by the accessory drive components and the crankshaft.

The drive belt system has an idler pulley, which is used to add wrap to the adjacent pulleys.