Wälzlager - 2015-11-27
Concerning liquefied gas, liquefied natural gas, in particular, has less impact on the environment than coal and oil. As such, the market for liquefied natural gas is expected to greatly expand. NSK is targeting 1 billion yen in global sales for its new ceramic ball bearing in 2018, focused on the global manufacturing locations of pump makers in Japan, the U.S. and China.
Bearings for liquefied gas pumps are used with a variety of liquefied gases, each of which has different temperature levels. In recent years, as liquefied gas plants have become increasingly large scale, there has been demand for bearings that last longer and provide operational stability. In addition, nowadays inverter-type motors are being employed to improve the efficiency of the pumps, which has resulted in a demand for greater wear resistance and galvanic corrosion resistance in bearings. In response to these demands, the rolling element (the ball) of bearings is being changed from the conventional stainless steel to ceramic, which is insulated and superior in terms of wear resistance.
However, since conventional ceramic material (silicon nitride) has only one-fourth the linear expansion coefficient as the stainless steel used in the inner and outer raceways, there is a problem of clearance changing in the bearing due to temperature differences. For this reason, it has become necessary to use a bearing with an initial clearance specific to the particular liquefied gas being used.
In response to this, NSK developed a new, high-performance ceramic ball bearing that can accommodate all types of liquefied gases using the same initial clearance setting.
This new bearing employs a new ceramic ball that has a linear expansion coefficient close to that of the material used in the inner and outer raceways. As a result, clearance changes due to temperature are minimal, allowing for this new bearing to work with all manner of liquefied gases while maintaining superior wear resistance and electrolytic corrosion resistance.
Single bearing type designed to work with a variety of liquefied gases, which helps lengthen the maintenance interval and improve liquefied gas pump productivity and operational stability.
NSK is committed to expanding SPACEA™ Series, and developing other high-performance products to meet the advanced needs of a wide range of industries.