How to effectively maintain mobile crushers

Mobile crushers can remain dependable throughout their working life when proper maintenance practices are followed.

Crushing and processing material can result in excessive wear on certain components, excessive vibration throughout a plant, and excessive dust in the working environment.

Some applications, of course, are more aggressive than others. A hard rock application, for example, requires more maintenance on top of standard maintenance, as there will be more vibration, more dust and more wear compared to a softer aggregate.

Due to the nature of its purpose, a mobile crushing plant begins to wear from the moment its starts. Without regular maintenance and repairs, a mobile crusher will not be reliable nor provide the material customers demand.

Crusher feed

The first area of wear on any machine is the feed system.

Whether it’s a feeder with an integrated grizzly or one with an independent prescreen, how the machine is fed contributes to wear.

When setting up and maintaining a machine, the machine must be level. A machine that is unlevel left to right will experience increased wear on all components, including the feeder, the screens, the crushing chambers and the conveyor belts. In addition, an unlevel machine reduces production and screening efficiency, as the whole area of the machine is not effectively used.

Also, having a machine sit high at the discharge end will have the effect of feeding material uphill in the feeder and reduce its efficiency, thus reducing production.

Dust management

Dust is a problem in its own right – and especially for mobile crushing plants.

In a very dusty application, it is easy to plug the radiator and have engine-overheating problems. High dust levels cause increased maintenance intervals on air filters and, if not controlled properly, dust can enter the diesel tank and cause problems with the fuel system.

Additionally, dust that gets inside the crusher increases wear. But if systems are put in place to remove dust, these should keep dust from getting into the machine in the first place.

Inside the crusher

The major wear part for a mobile crushing plant is the crusher itself.

In a jaw crusher, the major wear parts are very limited – only a fixed jaw and a swing jaw, and two or four side or cheek plates.

An impact crusher, on the other hand, has a number of wear items. The blow bars, which hit the rock and make it explode inside the machine, take a majority of the wear.

There are also impact aprons against which the rock is thrown. These see high wear.

There are side plates or wear sheets on the sides of the machine.

The highest wear area is around the impact crusher itself – around the circumference of the rotor. If not maintained, wear items will wear through and compromise the structure of the crusher box.

Best practices

Be sure to conduct a daily visual check of a mobile crushing plant.

The jaw is simple: Just stand up on the walkway and take a look down inside. A crusher’s jaw plate can be flipped, so there are two sides of wear on them. Once half the jaw is worn, flip it. Once that other is worn, change it.

An impact crusher will have an inspection hatch to see inside. Check to see how much material is left on the blow bars and how much is left on the wear sheets on the side of the crusher box. If half the bar is worn out after one week, change the blow bars in another week. The frequency of changes depends entirely on the application and the rock that is being crushed.

Information for this article adopted from Pit & Quarry University, which is available at pitandquarry.com.