Wälzlager - 2010-12-08
Customised bearings and pulleys
When bearings or pulleys are used in adverse environments, standard products often fall short of the mark. NSK develops bespoke solutions for such cases, bearings are tailored precisely to the specific operating conditions – e.g. for agricultural machinery.
A manufacturer of mounted implements for agricultural machinery was working on developing a new series of rotary swathers and had identified a weak point in the rotary part during initial testing. The pulleys on these implements – used by farmers to collect crops such as grass, hay and straw – soon failed. Immediate action had to be taken, so the manufacturer turned to NSK for help.
The pulleys used are designed like a single-row deep-groove ball bearing with a reinforced outer ring. They are exposed to high mechanical loads. In addition to this, working environments in the fields are heavily contaminated, meaning that the pulleys must be carefully sealed. Following a thorough analysis of the operating conditions, NSK suggested using pulleys with reinforced outer rings and a special seal.
The lubricant also had to be optimised. Instead of standard grease, specially developed MA7 grease was used, which extends the bearings’ life by some 10% in adverse environments.
Due to the tight production schedule – new agricultural machinery has to be ready in time for harvest – the rotary swather manufacturer wanted prototypes and production models of the customised pulleys within just four weeks. NSK was able to meet this requirement as our highly flexible plant in Germany (NSK Neuweg / Munderkingen) is responsible for the production of bespoke bearings.
The two-week test phase met all requirements, so the manufacturer approved the prototypes for mass production after just six weeks. Now, the rotary swathers have completed their first harvest – and the farmers are very pleased with their performance.
NSK has extensive experience of developing and producing customised pulleys, which is one of the reasons why the company was able to complete this project so quickly. The bespoke solutions feature construction details such as special shields and packing discs which increase the components’ resistance to contamination. Cylindrical and spherical outer rings can also be added. In addition to this, the races can be designed to absorb tilting moments.