Use these seven maintenance practices to keep mobile crushers dependable throughout their working life.

By Paul McLaren

Worn grizzly bars require hardfacing to return to optimum condition.

Today’s mobile crushers are rugged and dependable machines, but crushing and processing material can result in excessive wear on certain components, excessive vibration throughout the plant, and excessive dust in the working environment. And a hard rock application is going to require more maintenance on top of standard maintenance, as it will include more vibration, more dust, and more wear than from a softer aggregate.

From the moment a mobile crusher starts, the machine is wearing itself out and breaking itself down. Without routine, regular maintenance and repair, a mobile crusher will not be reliable, nor will it provide the material customers demand.

1. Feed the beast properly

The first area of wear on any machine is the feed system. Whether it’s a feeder with an integrated grizzly or a feeder with an independent prescreen, how the machine is fed contributes to wear.

Easy does it: Material dropped from a height deforms and wears hopper walls.

One of the major points to remember when setting up and maintaining a machine is that the machine must be level. If the machine is unlevel left to right, it will cause increased wear on all components from the feeder to the screens, crushing chambers, and conveyor belts. In addition, it reduces production and screening efficiency, as it is not effectively using the whole area of the machine. Having the machine sit high at the discharge end will have the effect of feeding the material uphill in the feeder, reducing its efficiency, and thus reducing production.

This woven wire mesh has been damaged by too large material passing over.

Another area for consideration is the equipment with which the machine is fed. If fed with a loader, the operator can’t see in the bucket and has no control over the feed size. With an excavator, the operator can see what’s inside and has more control over the feed into the hopper. Not feeding as much material all at once and controlling the size of the feed reduces wear in the impact zones of the feed hopper and eliminates material blockages due to feed size being too large to enter the chamber.

2.  Grizzlies and prescreens

Rubber on rubber: Worn rubber on this tail pulley roller needs relining or complete replacement.

The standard integrated feeder is a grizzly section that is integrated into a vibrating feeder, so the feeder and the grizzly move at the same time. It’s a set of tapered fingers that allows material less than the size of the opening of the grizzly to drop through, bypassing the crusher. This reduces wear on the crusher, as material that does not need to be crushed never enters. That material is bypassed or sent to a side conveyor, but is not screened to a classified saleable product. These grizzly fingers must be rebuilt and hardfaced to maintain the sizing of material that is being removed.

The wear plate of this crusher box has almost completely worn through (oxidized metal) and must be replaced, or the crusher box will be permanently damaged.