Shredder maintenance: why is it an essential operation

The first thing to do when talking about the maintenance of agricultural machinery is to divide the topic between ordinary and extraordinary.

In the first case we mean a series of checks that it is advisable to carry out daily (or in any case at each shift); in the second case frequency and intervals are less defined and should be identified case by case, or machine by machine.

We see below how to operate for the ordinary and extraordinary maintenance of a shredder: a type of machine that performs extremely overuse operations from a mechanical point of view, often in conditions of very high dustiness.

How is ordinary maintenance of the shredder carried out?

At every work shift it is advisable to carry out the lubrication, cleaning and visual inspection of the shredder.

Specifically, lubrication is confirmed to be a fundamental operation that should normally be performed every time you use the machine and in any case every eight hours of operation. The objective of this practice is essentially to maintain over time the efficiency of all the "lubricatable" components, namely pins, plugs and especially rolling and sliding bearings.

The most important aspect of this machine is that it is specially designed to be able to carry out lubrication without difficulties, through grease nozzles (also called nipples).

The design and fabrication quality of a shredder can also be seen in the visibility and accessibility of the grease nozzles. Some of these can be protected by guards, but they must still offer an access point. In general, there must be a grease nozzle for each moving part of the shredder.  

Important to follow the rule: grease as much as necessary, avoiding waste or grease leaks. As an example, it is sufficient to consider that the pins used for the side shift of the shredders are certainly less stressed than the rotor bearings. The latter, due to the high rotation speeds, is certainly the component that requires the highest attention for lubrication.

Also, the rear roller - when present - must be carefully lubricated. This component in fact weighs a good percentage of the overall weight of the machine and it is essential to ensure its correct rolling to avoid clogging of the rotor.

Other components that require careful lubrication are the transmission shaft and the cruises of the cardan joint. While the gearbox - which is normally immersed in oil bath - does not need greasing, but it’s part of the extraordinary maintenance operations that we go through later in the article.

Last aspect to highlight is that the lubrication must be carried out when the shredder is stopped and making sure that the power take-off of the tractor is in neutral in order to avoid any risk of activation of the components.

Cleaning operations, which can be carried out with a common pressure washer, are also an opportunity to visually check if there are accumulations of shredded material, ropes or wrapped wires, breaks or signs of excessive wear of the components on the rotor. The space between the rotor tines tends to be filled with shredded material and also with soil residual (especially if it happens to touch up to the ground with tools) and must be cleaned carefully to maintain the functionality of the shredder.

How is extraordinary maintenance of the shredder carried out?

The period of time between an extraordinary maintenance and another one of a shredder is obviously performed less often than the ordinary. In fact, it varies in relation to the work done by the equipment and is often performed in conjunction with any repairs or in any case in periods when it is not used.

Among the typical operations of extraordinary maintenance we can list:

• tool replacement (hammers or blades),
• refilling or replacement of gearbox oil,
• belt replacement.

Replacing worn tools is crucial for two reasons. Wear and tear can unbalance the rotor resulting in vibration and bearing overload, and reduce the cutting or machine’s capacity of working, increasing consumption. The tools of the shredder to be replaced must be original or of brands recommended by the manufacturer respecting the specifications for the rotor. However, it is a very complex operation, and if you are not equipped to perform it effectively and safely, it is better to contact authorized workshops.

The tools, blades or hammers are made of hardened steel and rotate on the rotor at very high speeds; for this reason they must comply with the specifications of the machine, also the bolts and bushings are of hardened steel and they must have the right degree of resistance.

With regard to the replacement of the gearbox oil, it is important to follow the indications of the working intervals of the machine’s manual of use and maintenance or to refer to the plates normally applied near the gearbox, which also show the specifications of the lubricant to be used. The oils on the market are identified by a specific abbreviation, that is GL, followed by a number ranging from 1 to 5 and indicating the viscosity of the oil.

The belts, which transmit the motion from the transmission box to the rotor, also protect the machine from any overload by slipping on the pulleys when a certain torque limit is exceeded. This function protects the rotor from damage on the one hand, and determines a certain overuse of the belts themselves on the other hand. Consequently, the belts must be visually checked and if - despite the correct tensioning - they slip or they appear worn or frayed, they must be replaced with others of the correct size (length, section and indentation).

Forigo Roter Italia is positioned at the top of the global scene in the field of shredderes manufacturing, offering a wide range of rear and front solutions, including fixed, mobile and folding. If you would like to find out more about our shredderes, please take a look at the dedicated section on our website, or contact us for more information.

Would you like to learn more about this topic? You can do so on our blog: we have selected for an article related to shredder functioning and the different types existing on the market.