Introduction
It is a low-cost linear motion system used in conjunction with cylindrical shafts for infinite travel. Due to the point contact between the bearing ball and the shaft, the load is small. The steel ball rotates with minimal frictional resistance, allowing for high-precision smooth motion. Characteristic linear bearings are used in conjunction with quenched linear transmission shafts. A system that performs infinite linear motion. The load-bearing ball and quenched drive shaft are in point contact, allowing for a smaller load. However, when moving in a straight line, the friction resistance is minimized, the accuracy is high, and the movement is fast.
Classification
(1) Standard linear bearings, clearance adjustment linear bearings, open type linear bearings, extended type linear bearings, universal linear bearings
(2) The flange type linear bearings can be divided into: circular flange type, flange type, elliptical flange type, guided circular flange type, guided flange type, guided elliptical flange type, and extended circular flange type. According to the standard specifications [1]: Linear bearings are divided into two major series, namely LM and LME series. The LM series is used in Asia, Southeast Asian countries, Japan, South Korea, China, and so on. Based on metric dimensions, the outer diameter tolerance of the straight axis used is generally h7. The LME series is commonly used in Europe, the United States, Germany, Italy and other regions. Based on imperial dimensions, there are also metric dimensions, and the outer diameter tolerance of the straight axis used is generally g6. The structural characteristics of the two series are roughly the same, except for differences in size and aperture tolerances.
Example 1: LM 203242 UU OP
LM represents the first series of standards for straight lines
203242 represents the size, structure, aperture, outer diameter, length
UU represents double sealed structure, OP represents open type
Example 2: LME 203245 UU AJ
LME represents the second series of standards for straight lines
203245 represents the size, structure, aperture, outer diameter, length
UU represents double sealed structure, AJ represents adjustable gap, divided by shape:
1: Straight cylinder type (shaped like a cylinder, usually installed with a snap ring, used for smaller installation sizes) 2: flange type (with mounting flange at the end or middle, can be installed with screws, and flanges are generally divided into three types: circular, square, and trimmed)
3: Open type (shaped like a straight cylinder with axial slits on the surface, used in situations where clearance adjustment is required, divided into two types: large opening and small opening) according to performance:
1: Ordinary type (for general performance requirements)
2: Super linear bearings (for applications with long lifespan and high load performance) are increasingly being used in general or special machinery industries such as electronics, food machinery, packaging machinery, medical machinery, printing machinery, textile machinery, machinery, instruments, robots, tool machinery, CNC machine tools, and automobiles.
[2] Maintenance
Lubrication and friction: Inject anti-corrosion oil into the interior of linear bearings. If lubricating with grease, first remove the anti-corrosion oil with kerosene or organic solvent, air dry, and then add lubricating grease. (It is recommended to use lithium soap grease with a viscosity mark of N0.2.)
If oil lubrication is used, it is not necessary to remove the anti-corrosion oil. According to temperature changes, ISO viscosity grade VG15-100 lubricating oil can be selected. Shaft lubrication can be supplied from the oil supply pipe or from the oil hole on the outer bearing seat. Due to the sealing ring scraping off lubricating oil, oil lubrication is not suitable for bearings with sealing rings without holes.
Other: Linear guide rail bearings
A groove or ridge made of metal or other materials that can withstand, fix, guide moving devices or equipment and reduce their friction.
A longitudinal groove or ridge on the surface of a guide rail, used for guiding and fixing machine components, specialized equipment, instruments, etc. The application of guide rails in our daily life is also very common, such as the sliding chute of sliding doors, the railway tracks of trains, and so on, which are specific applications of guide rails