How Are Linear Bearings Stored?

Ⅰ. What is a linear bearing?

A linear bearing is a linear motion system used for linear travel, which is paired with a cylindrical shaft. The bearing balls come in contact with the bearing outer sleeve, allowing them to roll with minimal frictional resistance. As a result, linear bearings are characterized by low friction, relatively stable performance, and no variation in response to changes in bearing speed. This enables high sensitivity, high precision, and smooth linear motion.

Ⅱ. What is the tolerance grade of linear bearings?

The tolerance grade of linear bearings is also known as the precision grade, which is generally divided into six levels: 0, 6, 6X, 5, 4, and 2, with level 0 being the lowest and level 2 being the highest. Each level has different requirements for size, rotation, and appearance quality, with higher levels having more stringent requirements and more advanced product performance. The price of the product also increases with higher levels. Clearance is present in linear bearings to ensure smooth and unobstructed operation while maintaining stable performance. The precision grade of linear bearings and the clearance of linear bearings are not directly related. The radial clearance of radial linear bearings is generally divided into groups C2, C0, C3, C4, and C5. The range of clearance values increases from small to large.

In theory, any group of clearances can be chosen for each tolerance level of linear bearings, but the selection of clearance groups must be based on specific working conditions, temperature, load, and linear bearing configuration in order to achieve the precision functions of linear bearings.

Ⅲ. Storage of linear bearings

1. Storage location requirements. Bearings are generally stored in a warehouse, but the relative humidity in the warehouse should not exceed 60%, the room temperature should be around 25 degrees Celsius, and the temperature difference should not be too large. In addition, corrosive substances such as acids, alkalis, salts, chemical raw materials, and objects with high moisture content should not be placed in the warehouse. The storage location should avoid direct sunlight, have good ventilation, and a clean environment.

2. Storage method requirements. Different types of linear bearing products have different storage methods, and incorrect methods can have adverse effects on the bearings. Small-sized bearings are best placed flat on a shelf about 30cm above the ground, while large rolling bearings should not be placed vertically due to uneven stress, which can cause permanent deformation. Therefore, they should be stored in a horizontal position.

3. Pre-storage requirements. Before storing linear bearings, it is essential to check whether the outer packaging is intact. This is critical because even if the storage conditions are good, problems can arise if the bearing's outer packaging is damaged. If any damage is found, the bearing should be repackaged immediately.