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| Illustration 1 | g00495005 |
Belt tensioner (PIN: 8DN620-UP1DR1401-UP7DM658-UP) (1) Accumulator (2) Bleed valve (3) Belt tension cylinder (4) Roller frame (5) Guard (6) Swing link (7) Front idler (8) Fill valve (9) Nipple | |
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| Illustration 2 | g00495011 |
Belt tensioner (PIN: 8DN1-6191DR1-14007DM1-657) | |
Reference: See Systems Operation/Testing and Adjusting, "Track - Tension/Detension" for more information about tensioning the belts and detensioning the belts.
Reference: See Systems Operation/Testing and Adjusting, "Track - Tension/Detension" for more information on checking the nitrogen pressure in the accumulator.
Each undercarriage has a self-contained belt tensioner. The belt tensioners provide a constant belt tension for each belt. The belt tensioners have the ability to recoil.
The belt tensioner consists of an accumulator (1) and a belt tension cylinder (3). Belt tension cylinder (3) pushes on swing link (6). Swing link (6) is attached to roller frame (4) .
Front idler (7) is attached to swing link (6). When front idler (7) is pivoted forward by belt tension cylinder (3), the belt is tensioned.
Accumulator (1) provides the ability for the belt tension cylinder (3) to recoil in order to maintain belt tension. Accumulator (1) is a bladder type accumulator. Accumulator (1) is charged with dry nitrogen.
In addition to the charge of dry nitrogen, belt tension is maintained by fully charging belt tension cylinder (3) with the machine's implement hydraulic system.
The hydraulic oil in belt tension cylinder (3) can be charged and released by the machine's implement hydraulic system. Nipple (9) is located on each belt tension cylinder.
A nominal tension of 93080 kPa (13,500 psi) is achieved when the belt tension cylinder is fully charged at 18960 kPa (2750 psi).
Belt tension cylinder (3) has a charge pressure that is equal to the high pressure stall for the implement hydraulic system.
The belt tension is a value that is monitored by the Electronic Monitoring Center. The EMC alerts the operator if the belt tension drops below the preset value for more than eight seconds.
A red indicator lamp that is on the EMC will illuminate if the belt tension is too low. A alarm will also sound. A F395 fault code will be logged until the fault is corrected or the engine is turned off.
Accumulator (1) and belt tension cylinder (3) cannot be serviced while the belt is under tension.
The belt tensioner is protected by guard (5). Guard (5) must be removed before servicing the belt tensioner.