Timing Belt
 

Print Page

How the Timing Belt works:

The timing belt is used to transfer torque from the timing pulley on the servo motor to the timing pulley on the wormshaft wich drives the wormwheel that provides table rotation.

Symptoms of failure:

The servomotor is running properly but there is intermittent or no movement at the table faceplate. This indicates that the belt is either slipping or broken. If the table rotation is intermittent then the timing belt is slipping. This slipping is generally caused by two things, improper tension on the timing belt or a build up of rust on pulleys that are not made of stainless steel.

Typical causes for failure of the pressure switch:

  1. Age or exceeding the designed cycle life of the timing belt.
  2. Build up of rust on pulleys that are not made of stainless steel causes premature wear.
  3. In the event of a crash, the timing belt will be damaged or possibly broken.

Note: It is common for the bearings in the wormshaft assembly and the wormset to be damaged after a crash. Any performance issues after a significant crash of the rotary table should be thoroughly resolved.

Timing Belt replacement:

  1. Turn off machine power and disconnect all electrical cables and pneumatic lines from the rotary table.
  2. The timing belt is located inside of the black pulley cover. To gain access, free the lid by
    removing the 3 button head cap screws then pull the cover away from the pulley plate
    to reveal the pulley drive system.
  3. Loosen the four flanged hex nuts that fasten the motor enclosure to the pulley plate.
  4. If the belt is not broken but needs replaced, slide the motor enclosure box in the direction that would endues slack in the timing belt to enable it to be removed.
  5. Remove and inspect the timing belt for wear and the timing pulleys for damage.
  6. Replace the timing belt and snug flange nuts until finger tight.
  7. To properly set the belt tension, slide the motor enclosure box in the direction
    that would tighten the timing belt. Adjust tension until you are able to twist the belt
    90 deg. from the horizontal position without a lot of pressure. When this adjustment is
    achieved tighten the four flange nuts, check and clear the drain hole, replace cover and
    three button head cap screws.
  8. Reconnect electrical and pneumatic lines then turn on power to the machine control.