The structure of the equipment, dimensions of the parts which will be assembled to the bearing, and the application environment and conditions need to be confirmed. It is necessary to take into account several conditions in order to decide the bearing part number and specification. Another important factor for selecting the part number and specification is the market.

Structure and function of the equipment

The required dimensions and performance need to be based on an understanding of the structure and function of the equipment. Although the structure limitations are becoming more severe due to downsizing of equipment, we recommend taking into account the items listed below and selecting properly to achieve the required bearing performance.

Application environment (temperature, humidity, vibration, dust, etc.)

The bearing material, retainer, and lubricants are selected based on the ranges of predicted temperature and humidity. The proper preload and lubricant are selected based on the vibration conditions. The presence of dust influences the selection of the shield or seal type. Depending on the operation conditions, bearing temperature is occasionally higher than environmental temperature.

Loads

The bearing dimension (Part Number) is selected based on the magnitude, position, and direction of loads applied to the bearing. It is necessary to review the structure of the equipment to determine if excessive loads would be applied to the bearing. If so, select a larger size bearing or decrease the loads).

Material and dimensions of the shaft and housing

The dimensions and tolerances of bore, outer diameter, and width are selected based on dimensions and material of the shaft and housing. It is necessary to take into account the change in bearing internal clearance caused by temperature change. There are differences in linear expansion coefficients between either shaft or housing material and bearing material.

RPM, Rotation Precision, Rotation Ring

Dimensional tolerance, retainer, clearance, preload, and lubricant are selected based on RPM, Rotation Precision, and rotation conditions (continuous/intermittent/back and forth/outer or inner ring rotation).

Torque

Torque can be classified into either starting torque or running torque. When low torque is required, lubricant types, fill amount, and retainer types need to be considered carefully.

Noise

When low noise level is required, it is necessary to take into account the noise characteristics, lubricants, and preloads. Care must be taken during installation because improper installation could worsen the noise level.

Life

Although rating life is defined in JIS B 1518, life can be defined by various ways because it is affected by the application and the progress of degradation in required performance level (noise, torque, runout, etc...) at each customer. The various types of life include rating life, noise life, performance life, and lubricant life.

Regulated substances

In recent years, various regulations have been established for environment, health, and safety. It is necessary to confirm if regulated substances listed in the laws are present or not because substances harmful to the environment and humans are restricted.