January 16, 2020
Metal linear bearings are a linear motion system produced at low cost for use with cylindrical shafts with infinite travel. Widely used in sliding parts of precision machine tools, textile machinery, food packaging machinery, printing machinery and other industrial machinery.
Chinese name linear bearing characteristic for infinite linear motion classification standard type, gap adjustment linear bearing Application to electronic equipment, food machinery
table of Contents
7 Linear Guide Bearings
Linear bearing is a linear motion system, used for linear stroke and cylindrical shaft. Because the bearing ball is in point contact with the bearing shell, the steel ball rolls with minimal frictional resistance, so the linear bearing has low friction, is relatively stable, does not change with the speed of the bearing, and can obtain a stable linear motion with high sensitivity and high accuracy. Consumption of linear bearings also has its limitations. The most important thing is that the bearing's impact load capacity is poor, and the bearing capacity is also poor. Secondly, linear bearings have greater vibration and noise at high speeds. The automatic selection of linear bearings Kuaiyiyou is included. Linear bearings are widely used in sliding parts of precision machinery, textile machinery, food packaging machinery, printing machinery and other industrial machinery.
Since the load ball is in contact with the bearing point, the use load is small. The steel ball rotates with very little frictional resistance, so that it can obtain high-precision and smooth movement.
Plastic linear bearings are a kind of linear motion system with self-lubricating characteristics. The biggest difference between them and metal linear bearings is that metal linear bearings are rolling friction and the point contact between the bearing and the cylindrical shaft is suitable for low-load and high-speed motion. Plastic linear bearings have sliding friction, and there is surface contact between the bearing and the cylindrical shaft, so this is suitable for high loads at low speeds.
Common linear bearing selection
A selection of common linear bearings (20 photos)
Linear bearings are used in conjunction with hardened linear drive shafts. A system for infinite linear motion. Because the load ball and the hardened drive shaft are in point contact, the allowable load is small, but when moving in a straight line, the friction resistance is minimal, the accuracy is high, and the movement is fast.
Plastic linear bearings
Plastic linear bearings
Plastic linear bearing bearings have no special requirements for the shaft; they can withstand larger loads than metal bearings, but because the motion between the bearing and the shaft is sliding friction, the plastic linear bearings have a certain speed limit; the movement resistance is greater than that of metal The bearing is larger; but its movement noise is lower than the metal linear bearing, especially in the case of medium and high speed, the plastic linear bearing noise has a very small effect on speed. The plastic linear bearing has a chip flute design inside, so it is allowed to be used in dusty places. The dust automatically brings out the friction surface of the bearing body from the chip flute during the movement. The plastic linear bearing is also allowed to Cleaning, special sliding inner membrane can even be used in liquid for a long time.
(1) Standard type, gap adjustment type linear bearing, open type linear bearing, extended linear bearing, general purpose linear bearing
(2) Flanged linear bearings can be divided into: round flange type, method blue type, oval flange type, guide round flange type, guide method blue type, guide oval flange type, extended round flange type.
Divided by specifications:
Divided into two major series namely LM and LME series. Its code LM series is used in Asia, Southeast Asian countries, Japan, Korea, China and so on. Taking the metric size as the standard, the tolerance of the outer diameter of the linear axis used is generally h7. The LME series is mostly used in Europe, the United States, Germany, Italy and other regions. The inch size is used as the standard, and the metric size is also available. The tolerance of the outer diameter of the linear axis is generally g6. The structural features of the two series, except for different sizes and different aperture tolerances, their structures are roughly the same.
1: Straight type (shaped like a cylinder, generally installed with a snap spring, used for small installations)
2: flange type (the end or middle has a mounting flange, which can be installed with screws, flanges are generally divided into three types: round, square and trimmed)
3: Open type (shape like straight tube, with axial slits on the surface, used for clearance adjustment, divided into two types: large opening and small opening)
1: Ordinary type (for general performance needs)
2: Super type (where long life and large load performance are required)
Linear bearings are more and more widely used in precision equipment such as electronic equipment, food machinery, packaging machinery, medical machinery, printing machinery, textile machinery, machinery, instruments, robots, machine tools, CNC machine tools, automobiles, and digital three-dimensional coordinate measuring equipment. Or in the special machinery industry.
Linear bearing adjustment type, open bearing inner and outer diameter are measured before the cut, there will be some elastic deformation after the cut, and the clearance should be measured in the bearing seat (steel cage bearing, KH bearing similar situation). The adjustment direction of the adjustable bearing seat should be perpendicular to the direction of the bearing cutout to ensure uniform clearance. The linear bearing structure cannot be rotated and requires good guidance. Therefore, linear bearings generally use two shafts and four sets. The bearings or two shafts + two sets of extended bearings are used in a combination. The two shafts must be installed straight. After the entire assembly is assembled, the drive mechanism must be flexible and non-blocking by hand. The drive power must be sufficient to overcome bearing friction. Resistance, linear bearing friction resistance is approximately one thousandth of the working load.
Maintenance of metal linear bearings: Lubrication and friction: Anti-corrosion oil is injected into the linear bearings. When lubricating with grease, first remove the anti-corrosion oil with kerosene or organic solvents, and add grease after air-drying. (It is recommended to use a lithium soap grease with a viscosity of N0.2.) When lubricating with oil, it is not necessary to remove the anti-corrosion oil. According to the temperature change, an oil of ISO viscosity grade VG15-100 can be used. Shaft lubrication can be obtained from the oil supply pipe. Lubricate or lubricate from the oil hole in the outer bearing housing. Since the sealing ring will scrape off the lubricant, oil lubrication is not suitable for non-porous bearings with sealing rings.
Maintenance of plastic linear bearings: Since the sliding film inside the plastic linear bearings is made of self-lubricating plastic, they do not need additional oil supply and maintenance during use; and because the plastic linear bearings have chip grooves, even the bearings If the shaft is full of dust, there is no need to maintain it. The dust will be automatically taken out of the chip removal groove during the movement. It is only necessary to replace the internal sliding film when the sliding film is worn out. Maintenance is very convenient.
(1) After disassembling each part of the linear motion bearing series, foreign matter may enter or adversely affect the assembly accuracy of each part. Do not disassemble.
(2) Dropping or hitting the linear bush may cause damage. Please be careful. When the product is impacted, the function is still available even if the appearance is not damaged.
Can be damaged, please pay attention.
(1) Carefully wipe the anti-rust oil and seal it with lubricant before using.
(2) Avoid mixing lubricants with different properties.
Linear guide bearing editing
A groove or ridge made of metal or other material that can support, fix, guide, and reduce friction of a moving device or device.
Longitudinal grooves or ridges on the surface of the guide rail for guiding and fixing machine parts, special equipment, instruments, etc. The application of guide rails in our daily life is also very common, such as sliding door slips, train rails, etc. are specific applications of guide rails.