Support bodies and method for improving wear and tear on support bodies in large scale grinders

Abstract

The invention relates to a method for improving wear and tear on support bodies (54) for plates or grinding belts in large-scale grinders (1). The support body (54) has a base body (18), onto which an abrasion-resistant primary layer of at least 0.3 mm thickness is applied using a thermal spraying process. This is configured as an inhomogeneous layer with an oxide entrapment of a specific porosity. If the support body (54) is a roll for the forward feed unit (20, 28), the roll body is roughened and a primer and the primary layer are applied using a thermal spraying process. Approximately 50% of the primary layer consists of chromium steel, in particular 13% chromium steel and an abrasion-resistant hard material and said primary layer provides a coarse surface with good grip that is resistant to wear and tear. If the support body (54) is a grinding-belt contact roll (9, 9'), the latter is polished after the thermal spraying process. If the support body (54) is a grinding belt shoe (50), the base body (18) is roughened and an adhesive layer and then the primary layer are applied in a thermal spraying process. The wear-resistant primary layer is polished to create a smooth surface and the layer construction is configured to produce a high degree of slip.

Description

[0001] The invention relates to a method for improving wear performance of support bodies in wide-belt sanding machines particularly at least as regards the drive rollers of the in-feed unit and / or the abrasive-belt contact rollers, and / or the opposing sanding shoe and / or backing roller. The invention relates further to support bodies for platens or abrasive belts in wide-belt sanding machines that are designed as either drive rollers of the in-feed unit and / or as abrasive-belt contact rollers and / or as opposing sanding shoes and / or backing roller.PRIOR ART[0002] Over the past decades, wide-belt sanding machines have developed into a class of their own. They are sanding machines of considerable size reaching 1.5 to 3 meters in height and one to several meters in length depending on the sanding heads used. Typical for these machines is their width which can reach from one to more than three meters. As a rule, the wide-belt sanding machine is adapted to the specific conditions, partic...

AI Technical Summary

Benefits of technology

"The invention relates to improving the wear performance of support bodies in wide-belts sanding machines, particularly the drive rollers of the in-feed unit and the abrasive-belt contact rollers. The technical effects include reducing wear and tear on the support bodies, increasing the stability and precision of the machine stand, and improving the adhesion and abrasion resistance of the abrasive belts. The invention also involves restoring the surface of the rollers and addressing the issue of unre-machined rollers in the machine."

Problems solved by technology

This also involves a considerable amount of thrust.

The operating means, although tougher and stronger than the work piece to be processed, sustains nonetheless irreversible wear.

The slip between the roller knobs and the work piece results in abrasion of the roller surface.

This strips 1-3 mm and results in a smaller roller diameter after re-knurling so that a machined roller can no longer be mounted in line with the other rollers.

In practical terms, the re-machined rollers cannot be used again.

A certain degree of slip is unavoidable here because of the tremendous amount of force that must be transmitted.

The situation here is twice as difficult in comparison to the drive roller of the in-feed unit.

However, in practice the plasma spray process has not been proven worthwhile except in very special cases.

In spite of the very expensive plasma application method, there were some cases in which local damage to the roller surface destroyed the enhanced surface after a certain operating period.

Still, from time to time, a complete replacement of the opposing sanding shoe, and in the case of the abrasive-belt contact roller, a relatively expensive re-machining, becomes necessary.

Wide-belt sanding machines must be overhauled more frequently and defective parts such as bearings, motors, etc. replaced.

It is a drawback that the individual components have different service lives since when their maintenance falls between two big overhaul cycles, it can cause the machine's operation to be interrupted.

Images