High performance cylindrical roller bearings
21 May 2019
Schaeffler has extended its X-life range of high performance, premium quality cylindrical roller bearings with two additional products that offer improved performance, extended maintenance intervals and extremely high power density. The bearings are said to be ideal for machine tool applications such as high speed turning, milling and grinding machines.
The N10 (single row) and NN30 (double row) series of X-life cylindrical roller bearings, which are available with inside diameters of 30mm up to 120mm, benefit from optimised surfaces and an improved internal design. The bearing cage is made from high performance polyamide (polyphthalamide) with optimised friction characteristics. This means the lubrication groove and lubrication bore are no longer required. The bearings are also interchangeable due to their matching enveloping circles.
These design improvements result in distinct technical advantages including:
- Up to 25% increase in limiting speeds.
- Up to 19% higher dynamic load ratings.
- Up to 65% longer nominal rating life (L10).
- Running temperatures reduced by up to 12K.
- Longer grease operating life.
- Less friction.
- Reduced noise levels.
- Ideal for combining with high speed axial bearings (BAX).
In machine tool applications, the bearings provide outstanding productivity for higher cutting performance, as well as extended maintenance intervals for greater machine availability. The bearings are also cost effective with a very high power density.
Reduced Total Cost of Ownership
Users of bearings are increasingly aware that the purchase price is one of many criteria that should be considered when selecting a suitable bearing. Rating life and service requirements, as well as possible bearing failure, are also important factors. In practice, this means users are more likely to choose higher quality bearings that offer longer rating and operating life, increased reliability and extended maintenance cycles, as machines fitted with these bearings will offer a competitive advantage.
The design envelope or footprint of a machine is also important. For an OEM or machine builder, a more compact design can improve the competitiveness of a machine. At the same time, power density and performance requirements of machines are increasing. This, in turn, has resulted in increased stress on machine parts, including drive components and bearings.
Due to their increased basic dynamic load ratings, X-life bearings provide significantly longer rating and operating life. X-life bearings therefore enable machine designs to be optimised by using smaller bearings that still offer the same load ratings, but which save space and weight, resulting in increased overall efficiency of plant and machines.
By using new production technologies for rolling bearings, Schaeffler is able to optimise the contact faces between rolling elements and raceways. As a result of increased raceway accuracy and more uniform surfaces, there is also a significant reduction in the stress conditions present on the rolling elements and raceway under the same load conditions. This produces a higher dynamic load rating, a longer nominal rating life, less friction and lower bearing temperatures, as well as a reduction in the strain placed on the lubricant. As a result of reduced friction, there is a simultaneous increase in the energy efficiency of the bearings, while energy consumption and operating costs are also reduced.