About bearing

Bearing steel grade Feature Application G20CrMo Low alloy carburized steel, the surface hardness after carburizing is relativelyHigh, good wear resistance, low core hardness, toughnessit is good. Suitable for making bearings resistant to impact loads andParts.  It is often used as the impact resistance of cars and tractors.Impact load roller bearings, also used as steamCar gears, piston rods, bolts, etc.  G20CrNiMo Have good plasticity, toughness, and strength, carburizing orAfter carbonitriding, the surface has quite high hardness and resistanceGood grind ability, contact fatigue life is obviously better thanGCr15 steel, the core carbon content is low, there is enoughToughness to withstand impact loads.  Good material for making impact-resistant bearingsMaterial, which can be used as steam to withstand impact loadCar bearings and small and medium-sized bearings are also availableMake automobile, tractor gears, and cone drillsThe claws and cones of the head.  G20CrNi2Mo After carburizing, the surface hardness is high, the wear resistance is good, and it hasModerate surface hardening, good heart toughness, and resistanceImpact load, the cold and hot working plasticity of steel is better,It can be processed into rods, plates, strips, and seamless steel pipes.  Rollers used to withstand higher impact loadsBearings, such as railway freight car bearing rings andRollers, also used as car gears and pistonsRods, universal joint shafts, and round head bolts, etc.  G10CrNi3Mo After carburizing, the surface has high carbon content and high hardness,Good wear resistance, the low carbon content in the heart, good toughness,Can withstand impact loads.  Used for large-scaleRoller bearings. Such as rolling mill bearings.  G20Cr2Ni4A Common carburized structural steel is used to make bearings.The carbon back surface has quite high hardness, wear-resistance andHigh contact fatigue strength, good heart toughness, and resistanceStrong impact load. Medium weldability, with temperingTendency to brittleness, more sensitive to the formation of white spots.  Making large bearings resistant to impact loads,Such as rolling mill bearings, etc., but also used for otherLarge carburized parts, such as large gears, shaftsEtc., it can also be used for manufacturing requirements of toughnessHigh tempered parts.  G20Cr2Mn2MoA After carburizing, the surface hardness is high, the core toughness is good, and it can beResistant to strong impact load, phase with G20Cr2Ni4ACompared with the carburizing speed, the carburized layer is easier to form a coarseLarge carbides are not easy to diffuse and eliminate.  Used to work under high impact load conditionsExtra-large and medium-sized bearing parts and shaftsAnd gears, etc. 

A: The internal clearance of the bearing is closely related to the life, temperature rise, vibration, and noise of the bearing. Including radial oil gap and axial oil gap. The radial oil clearance is divided into five groups of 2, 0, 3, 4, and 5. Group 0 is the basic clearance, and its value increases sequentially. 

A: Traditional automobile wheel bearings are composed of two sets of tapered roller bearings or ball bearings.The hub bearing unit is developed on the basis of standard angular contact ball bearings and tapered roller bearings. It combines two sets of bearings as a whole. It has good assembly performance, can omit clearance adjustment, light weight, compact structure, and load capacity. Large, sealed bearings can be pre-loaded with grease, omit external wheel hub seals, and are free from maintenance. They have been widely used in cars, and there is a trend to gradually expand their applications in trucks.

A: The sliding contact surface of plain bearings is an inner sphere and an outer sphere, which can rotate and swing at any Angle when moving. (1) GE...E type: single-faced outer ring, without lubricating oil groove. It can bear radial load and small axial load in any direction.(2) GE...ES type: single-slit outer ring with lubricating oil groove. It can bear radial load and small axial load in any direction.(3) GE...ES-2RS type, GEEW...ES-2RS type: single-slit outer ring with lubricating oil groove and sealing rings on both sides. It can bear radial load and small axial load in any direction.(4) GE...ESN type: single-slit outer ring, GE...XSN type: double-slit outer ring (split outer ring), with lubricating oil groove, the outer ring with stop groove. It can bear radial load and small axial load in any direction. However, when the axial load is borne by the stop ring, its ability to withstand the axial load is reduced.(5) GE...HS type: The inner ring has a lubricating oil groove, and the outer ring is double-half. The clearance can be adjusted after wear. It can bear radial load and small axial load in any direction.(6) GE...DE1 type: the inner ring is hardened bearing steel, and the outer ring is bearing steel. When the inner ring is assembled, it is extruded and formed with lubricating oil grooves and oil holes. Bearings with an inner diameter of less than 15mm have no lubricating oil grooves and oil holes. It can bear radial load and small axial load in any direction.(7) GE...DEM1 type: the inner ring is hardened bearing steel, and the outer ring is bearing steel. When the inner ring is assembled, it is extruded and formed. After the bearing is installed in the bearing seat, the end groove is pressed out on the outer ring to fix the bearing axially. It can bear radial load and small axial load in any direction.(8) GE...DS type: the outer ring has an assembly groove and lubrication groove. Only limited to large-size bearings. It can bear radial load and small axial load in any direction (one side of the assembly groove cannot bear axial load).

A: The self-aligning ball bearing can bear a large radial load, but also can bear a certain axial load. The outer ring raceway of this type of bearing is spherical, so it has self-aligning performance. When the shaft is bent or tilted so that the centerline of the inner ring and the centerline of the outer ring is not more than 1°～2.5°, the bearing can still work.

First, because ceramics are almost not afraid of corrosion, ceramic rolling bearings are suitable for operation under harsh conditions full of corrosive media.Second, because the density of the ceramic rolling ball is lower than that of steel, and the weight is much lighter, the centrifugal effect of the outer ring during rotation can be reduced by 40%, and the service life is greatly extended.Third, ceramics are less affected by thermal expansion and contraction than steel, so when the bearing gap is constant, the bearing can be allowed to work in an environment where the temperature difference changes more drastically.Fourth, since the elastic modulus of ceramic is higher than that of steel, it is not easy to deform when subjected to force, so it is beneficial to increase the working speed and achieve higher accuracy.

A: The advantages of needle roller bearings:1. The friction resistance is small, the power consumption is small, the mechanical efficiency is high, and it is easy to start.2. The size is standardized, interchangeable, easy to install and remove, and easy to maintain.3. Compact structure, light weight, and reduced axial size. High precision, high speed, low wear and long service life.4. Some bearings have self-aligning performance, which is suitable for mass production, with stable and reliable quality and high production efficiency.5. The transmission friction torque is much lower than that of hydrodynamic bearings, so the friction temperature rise and power consumption are lower;6. The starting friction torque is only slightly higher than the rotating friction torque;7. The sensitivity of bearing deformation to load changes is less than that of hydrodynamic bearings;8. Only a small amount of lubricant is needed for normal operation, and it can provide lubricant for a long time during operation;9. The axial size is smaller than the traditional hydrodynamic bearing;10. It can bear combined radial and thrust loads at the same time;11. In a large load-speed range, the unique design can obtain excellent performance;12. Bearing performance is relatively insensitive to fluctuations in load, speed and operating speed.

A: 1. Insufficient bearing lubrication will cause high temperature discoloration of the bearing.2. Bearings are prone to scratches and peeling under high load and low speed applications or continuous high temperatures. This phenomenon is due to the thin or insufficient lubricating oil film that will accelerate the problem.3. The bearing rollers are overheated. The rupture of the lubricating film will cause direct contact between the parts and cause local scratches. Thermal damage to the tapered roller caused by metal-to-metal contact.4. The bearing is completely locked. Insufficient lubrication can lead to extreme local heating, and then produce metal flow in the bearing, changing the original material and geometric structure of the bearing.

A: Excessive lubrication of bearings, especially high-speed equipment, will generate excessive heat due to oil agitation, chemically degrade the lubricating oil, and cause bearing damage.Correct lubrication and regular maintenance can avoid bearing damage caused by lubrication problems. 

A: Rolling element bearings developed on the basis of bearings. Its working principle is to replace sliding friction with rolling friction. It is generally composed of two ferrules, a set of rolling elements, and a cage. It is highly versatile, standardized, and serialized basic mechanical parts.

A: If the bearing is in a good state of continuous rotation, it will emit a low whining or buzzing sound. If there is a sharp hiss, squeak and other irregular sounds, it often indicates that the bearing is in a poor continuous rotation condition. The sharp squeaking noise may be caused by improper lubrication. Inappropriate bearing clearance can also cause metallic noise.The dents on the bearing outer ring track will cause vibration and cause a smooth and crisp sound.If there is intermittent noise, it means that the rolling parts may be damaged. This sound occurs when the damaged surface is rolled over, and if there are contaminants in the bearing, it will often cause a hissing sound. Severe bearing damage will produce irregular and loud noises.If it is caused by knocking scars during installation, noise will also be generated, and this noise will vary with the speed of the bearing.

A:Wear and rust of partsThe wheel hub bearing is poorly lubricated. If the lubricating grease between the roller and the raceway is insufficient, the two will have dry friction, resulting in abnormal noise of metal friction.

A: The hub bearing unit is developed on the basis of standard angular contact ball bearings and tapered roller bearings. It combines two sets of bearings as a whole. It has good assembly performance, can omit clearance adjustment, lightweight, compact structure, and has load capacity. Large, sealed bearings can be pre-loaded with grease, omit external wheel hub seals, and are free from maintenance. They have been widely used in cars, and there is a trend to gradually expand their applications in trucks.

A: The choice of bearing material is determined by the designer based on the bearing working conditions and the functional requirements of the bearing parts.Rolling bearings are mainly composed of rings, rolling elements, cages and other parts. The materials of the parts can be divided into:(1) Ferrule and rolling element materials;(2) Cage material;(3) Other parts such as rivets, dust cover, sealing ring and other materials.There are many kinds of materials used in the above parts, and because of their different physical, chemical and mechanical properties, each has different characteristics to meet the requirements of working under various working conditions and environments. The selection of bearing material is directly related to whether it can meet the function and use requirements of the mechanism, and has a decisive influence on the working performance and fatigue life of the bearing. Generally, when the material is selected correctly, as long as the fit and installation, lubrication and maintenance are normal, the bearing will obtain good working performance and meet the reliability requirements.