NSK Develops a China-Produced Tapered Roller Bearing for Construction Machinery Travel Reduction Gears

Development Background

Tapered roller bearings used in the travel reduction gears of construction machinery such as hydraulic excavators are used in very harsh conditions that include heavy loads and high-impact loads. This is even more so the case in developing countries, where construction machinery is often used continuously for long hours and over long stretches of rough roads. Developing countries also pose unique challenges in terms of the poor precision of the parts surrounding the bearing as well as the lack of experience workers have in regard to handling bearings.

In response to this situation, NSK used locally sourced materials to design an optimum bearing specification for the unique conditions in developing countries. In addition, NSK introduced state-of-the-art, high-precision machining technology to the factory in China in order to achieve the local production of high-quality bearings at a cost-competitive level with shorter lead times.

Product Features

1. Optimum crowning shape (for higher reliability and longer life)

In order to prevent a decrease in bearing life due to the harsh usage conditions in developing countries, NSK applied optimal crowning to the outer and inner raceways as well as the roller contact surface to suppress edge load from occurring. In addition, NSK created a more robust design that can withstand the bearing tilting due to poor installation accuracy. Furthermore, NSK equipped the factory with state-of-the-art equipment to ensure proper crowning machining under every condition.

2. Improved impact toughness ( Reduced the stress exerted on the ribs)

In developing countries, travel reduction gears are often exposed to high impact due to driving on rough roads. This can cause a great deal of stress to be exerted onto the rib of the bearing's inner raceway, which in turn can cause the rib to crack and eventually break. In this case, the vehicle in question will no longer be able to operate. In response to this situation, NSK optimized the shape of the roller edges to reduce by 10% the stress exerted on the ribs.

3. 100% locally sourced and produced

NSK uses high-quality locally sourced materials and components along with state-of-the-art equipment to produce bearings that satisfy the rigorous demands of construction machinery travel reduction gears in developing countries.

Product Benefits

This bearing not only provides the durability and reliability required by the harsh usage conditions in developing countries, but it also provides cost competiveness and shorter lead times through local production. NSK endeavors to leverage these benefits to expand sales of this bearing in developing countries.