Linear bearings refer to linear ball bearings, also called linear ball bushings. They are the most widely used linear bearing products. Linear bearing is usually combined with a linear bearing housing and installed on a linear cylindrical shaft assembly to form the linear motion system. Linear ball bearings are generally composed of balls, cages, outer sleeves, and sealing rings at both ends. The sleeve is made of high-carbon chromium bearing steel or stainless steel. It is hardened and ground to provide safe and reliable assembly of the cage and bearing housing. The cage is generally made of engineering plastic or steel. The steel bearing balls are in contact with the sleeves, they roll in the circuit on the cage with minimal frictional resistance. Therefore, the linear bearing has small friction and is relatively stable, and will not change with the bearing speed, can obtain a smooth linear motion with high sensitivity and high precision. However, linear bearing also has its limitations. First, due to the point contact feature of bearing balls in the linear bearing, its impact load capacity and bearing capacity are poor. Secondly, linear bearings have large vibration and noise during high-speed motion. The dimensions of the linear bearing have been standardized and can be interchanged, which can save a lot of costs.
Linear ball bearings are different from plastic linear bearings. Plastic linear bearings are a kind of linear motion system with self-lubricating characteristics. The biggest difference between linear ball bushings and plastic linear bearings is that linear ball bushings are rolling friction, and the bearings are in point contact with the cylindrical shaft. This type is suitable for low-load and high-speed movement; however, plastic linear bearings are sliding friction, the surface contact between the bearings and the cylindrical shafts, so this type is suitable for high-load, medium-low speed motion.
According to the appearance and structure, linear bearings can be divided into standard linear bearings, adjustable linear bearings, open linear bearings, extended linear bearings, stamped linear bearings, and flanged linear bearings. Among them, flanged linear bearings can be divided into standard circular flange type, standard square flange type, standard oval flange type, pilot circular flange type, pilot square flange type, pilot oval flange type, long circular flange type, long square flange type, long oval flange type and long centered circular flange type, long centered square flange type and long centered oval flange type.
According to different specifications and standards, linear bearings are divided into 3 series:
Asian metric LM (SM / LB / KLM) series:
Mainly used in Southeast Asian countries, Japan, Russia, Korea, China, etc., with linear shafts of g6 and h6 outer diameter tolerances;
European metric KB (LME) series:
Mainly used in the United States, Germany, Italy, etc., with linear shafts of h6 and j6 outer diameter tolerances;
Inch SW (LMB) series:
Mainly used in the United Kingdom, the United States and so on, with linear shafts of g5 and h5 outer diameter tolerances.
The linear bearings of the above three series have the same structure except for little different diameters and tolerances.
According to a different performance, linear bearings can be divided into:
Ordinary type: General performance requirements;
Super type: Combined of engineering plastics and steel, with the adjustable feature, longer service life and larger load capacity.
At present, linear bearings are more widely used in food processing machinery, packaging machinery, medical machinery, printing machinery, textile machinery, robots, machine tools, automobiles and digital 3D coordinate measuring equipment and other precision equipment or special machinery industries. ISUTAMI can provide high-quality linear bearings with standard specifications from Chinese manufacturers, with inner diameters ranging from 3-60mm.