BI618993
___________________________________________________Operation TENSIONING OF THE CRAWLER PAD CHAINS – TORQUE HUB TYPE During typical operation the sliding components, sprockets, etc. of the crawlers may wear or cat pads may need to be replaced. Therefore, to maintain properly functioning crawlers it is important to keep the appropriate amount of slack within the cat pad chains. Use the following procedure to maintain the proper sag in the crawler chain.
© DBT AUSTRALIA 2007
1. Raise up the BTP by using either the stab shoes, side-slew jacks or crawler lift jacks (see the “Stab Shoe”, “Side-Slew”, or “Crawler Lift Jacks” sections). If the crawler lift jacks are used, the BTP frame must have either crib blocks or some other means of support under it. This is so the crawler lift jacks can be retracted to raise the crawlers up off of the ground so that the cat chain sag can be measured. 2. With the crawlers up completely off the ground measure the sag of the crawler chain from the center of the arc of the sag perpendicularly up to the flat crawler pad running surface. The sag distance should measure 95mm or 3-3/4” and if not continue with step #3 below. 3. Remove the four bolts and side grease cylinder cover from the crawler frame to allow access to the grease-tensioning cylinder. 4. If the sag is greater than 95mm (3-3/4”) use a grease gun and pump the zerk fitting found on the tensioning cylinder input tee. Continue to pump grease until the sag has reached the proper dimension.
Do not over tension the crawler chain since the required hydraulic pressure to tram the machine will be excessive. IMPORTANT
5. Once the proper sag is reached, place the appropriate amount of shims along the tensioning cylinder rod between the cylinder barrel and the crawler frame attachment point. The shims are provided in ¼”, 3/8”, ½”, ¾”, and 1” thickness. To achieve a snug fit on the shim plates some pressure from the cylinder must be bled off. To bleed off the pressure see step five below. 6. If the sag is lesser than 95mm (3-3/4”) the crawler chain is over tensioned and needs to be slacked. It may be necessary to even apply more tension to the chain until the shims become loose so they can be removed (see step four above). To release the pressure on the tensioning cylinder turn the knob on the bleed-off valve on the input tee found on the tensioning cylinder.
WARNING
The grease may be under extreme pressure and, therefore, it may be discharged some distance. To avoid a mess it may be necessary to place a can or container near the grease spout to catch the discharged grease.
______________________________________________________________ DBT AUSTRALIA – BELT TAILPIECE © VUVA / 05 5.33
