The Black Bearing is a product developed by CBC in conjunction with NTN Corporation of Japan in order to provide a bearing with enhanced features and improved life for CBC customers in the broad-acre agriculture market.

The Black Bearing range stocked by CBC is the Wide Inner Ring (WIR) series. This particular series of single row ball bearings incorporates an eccentric collar lock. The WIR series in most cases features a spherical outside diameter which fits into a housing with a spherical seat to provide misalignment capability.

In developing the Black Bearing CBC undertook considerable research with end users (primarily farmers) via attendance to regional field days, trade nights and trade breakfasts. Some feedback regarding harvester bearing issues included:

• The bearing runs dry of grease and is often mounted in a press metal housing without any provision for re-lubrication, which inevitably results in premature bearing failure as lubricant cannot be replenished, seals are damaged, and contaminants cannot be excluded.
• Many users of broadacre agricultural harvesting equipment (headers) commented that the purchase cost of this machinery is now in excess of $500,000. It was therefore perceived that there was little value in not using the best parts and paying slightly more for a higher performance bearing to match the machine capability & performance made good sense.

A further consideration to the criticality of bearing performance on harvester applications was revealed at regional field days in discussions with local insurance assessors. These assessors confirmed claims have resulted from high value crop losses due to header fires caused by bearing failures.

Others commented that the issue of bearing failures where often compounded by the fact that the bearing corrodes and freezes on the shaft.

This not only makes replacement difficult but also more time consuming (often when the harvester is needed most). When a failure occurs in the process of harvesting the crop the farmer is understandably reluctant to use oxy acetylene equipment for fast removal of the frozen bearing anywhere near his crop.

This often means removal of components to a workshop environment as the least risky option to undertake the repair.

Finally many comments were also noted about harvester bearing failures due to ingress of contaminants. Wheat husks are abrasive and along with the moisture and dust in the operating environment these factors combine to rapidly break down standard bearing sealing arrangements.

CBC started negotiations with NTN Corporation Bearing Engineering Centreto produce a bearing that incorporates design features to overcome these issues and provide extended service life. These features are summarised as follows;

1. The Black Bearing is black in colour because it undertakes a process where the inner and outer rings are coated with black oxide. While this gives the bearing improved corrosion and fretting resistance over normal high carbon bearing steel finishes. The major advantage is it provides a layer of oxide between the bearing inner ring and the shaft facilitating easy removal. This technology has been proven by NTN with agricultural OEM’s.
2. The sealing on the bearing was the next area of attention and in this case it was decided to incorporate NTN’s “Trashguard” seal into the Black Bearing. This seal is again proven technology with agricultural OEM’s and features a heavy duty seal plate with a wide land seal lip to keep out contaminants. This seal design is also manufactured by the Timken Bearing Company (USA) formerly Fafnir Bearing Company for the same advantages in Agricultural applications.