Rolling bearing is a precise mechanical element that changes the sliding friction between the running shaft and the shaft seat into rolling friction, thereby reducing friction losses. Rolling bearings are generally composed of four parts: an inner ring, an outer ring, a rolling body and a cage. The role of the inner ring is to cooperate with the shaft and rotate with the shaft. The role of the outer ring is to cooperate with the bearing seat to support it. Because the cage evenly distributes the rolling elements between the inner and outer rings, its shape and quantity directly affect the service performance and life of the rolling bearing; the cage can evenly distribute the rolling elements and guide the rolling elements to rotate for lubrication.
Classification by structure type According to the structure of the rolling element and the ferrule, it can be divided into: Deep groove ball bearings, needle roller bearings, angular contact bearings, self-aligning ball bearings, spherical roller bearings, thrust ball bearings, thrust spherical roller bearings, cylindrical roller bearings, tapered roller bearings, spherical balls with seats Bearings and so on.
Rolling bearings can be divided into: Deep groove ball bearing Deep groove ball bearings have a simple structure and are easy to use. They are the type of bearings with the largest production volume and the widest application range. It is mainly used to withstand radial loads and can also withstand certain axial loads. When the radial clearance of the bearing is increased, it has the function of an angular contact bearing and can bear a large axial load. Used in automobiles, tractors, machine tools, motors, pumps, agricultural machinery, textile machinery, etc.
2. Needle bearing Needle roller bearings are equipped with thin and long rollers (the length of the rollers is 3 to 10 times the diameter, and the diameter is generally not greater than 5 mm), so the radial structure is compact, and its inner diameter and load capacity are the same as those of other types of bearings The smallest diameter, especially suitable for support structures with limited radial installation dimensions. Depending on the application, a bearing or needle roller and cage assembly without an inner ring can be used. At this time, the journal surface and the housing hole surface that match the bearing are directly used as the inner and outer rolling surfaces of the bearing to maintain load capacity and running performance. As with the bearing with the ring, the hardness of the surface of the shaft or housing raceway. The machining accuracy and surface and surface quality should be similar to the raceway of the bearing ring. This type of bearing can only support radial loads. For example: universal joint shaft, hydraulic pump, sheet rolling mill, rock drill, machine gear box, automobile and tractor gearbox.
3.Angular contact bearings Angular contact ball bearings have a higher limit speed and can support both meridional and axial loads, as well as pure axial loads. The axial load capacity is determined by the contact angle and increases with the contact angle. Mostly used: oil pumps, air compressors, various transmissions, fuel injection pumps, printing machinery.
4. Self-aligning ball bearings Self-aligning ball bearings have two rows of steel balls, two raceways on the inner ring, and the outer ring raceways are inner spherical, with automatic self-aligning performance. It can automatically compensate for the coaxiality error caused by the bending of the shaft and the deformation of the housing, and is suitable for parts where the support seat hole cannot guarantee strict coaxiality. This type of bearing mainly bears radial load. It can also bear a small amount of axial load at the same time as radial load. It is usually not used to bear pure axial load. For example, only a row of steel balls is subjected to pure axial load. It is mainly used in agricultural machinery such as combine harvesters, blowers, paper machines, textile machinery, woodworking machinery, bridge crane wheels and drive shafts.
5.Spherical roller bearings Spherical roller bearing sentences have two rows of rollers, which are mainly used to bear radial loads and can also bear axial loads in any direction. This kind of bearing has high radial load capacity, especially suitable for working under heavy load or vibration load, but can’t bear pure axial load; it has good self-aligning performance and can compensate the same bearing error. Main applications: papermaking machinery, reduction gears, railway vehicle axles, rolling mill gear box seats, crushers, reducers for various industries, etc.
6. Thrust ball bearings Thrust ball bearing is a separate type bearing, and the “washer” of the shaft washer can be separated from the components of the cage steel ball. The shaft ring is a ferrule matching the shaft, and the seat ring is a ferrule matching the bearing seat hole, and there is a gap between the shaft and the shaft. Thrust ball bearings can only bear axial loads, one-way thrust ball bearings can only bear axial loads in one direction, and two-way thrust ball bearings can bear axial loads in two directions. The thrust ball can not limit the radial displacement of the shaft, and the limiting speed is very low. One-way thrust ball bearings can limit axial displacement in one direction of the shaft and housing, and two-way bearings can limit axial displacement in both directions. Mainly used in automobile steering mechanism and machine tool spindle.
7. Thrust roller bearings Thrust roller bearings are used to support shafts that are mainly axial loads. Combined loads in the warp direction, but the warp load must not exceed 55% of the axial load. Compared with other thrust roller bearings, this type of bearing has a lower friction coefficient, higher speed, and self-aligning ability. 29000 type rollers are asymmetric spherical rollers, which can reduce the relative sliding of the stick and the raceway during work, and the rollers are long. The diameter is large, the number of rollers is large, and the load capacity is large. Oil lubrication is usually used. Individual For low speeds, grease can be used. When designing and selecting, it should be preferred. Mainly used in hydro generators, crane hooks, etc.
8. Cylindrical roller bearing The roller of a cylindrical roller bearing is usually guided by the two ribs of a bearing ring, the cage. The roller and the guide ring form an assembly, which can be separated from another bearing ring, and belongs to a separable bearing. This type of bearing is easy to install and disassemble, especially when the inner, outer ring, shaft and housing are required to have an interference fit. This type of bearing is generally only used to support radial loads, only single row bearings with ribs on the inner and outer rings can withstand small steady axial loads or large intermittent axial loads. It is mainly used for large motors, machine tool spindles, axle boxes, diesel crankshafts, and automotive, variable transformers.
9.Tapered roller bearings Tapered roller bearings are mainly suitable for bearing radial and axial combined loads, and large tapered tapered roller bearings can be used for bearing radial and axial combined loads. This bearing is a split bearing, and its inner ring (including tapered roller and cage) and outer ring can be installed separately. During installation and use, the bearing’s warp and axial clearance can be adjusted, and it can also be used for pre-interference installation for automobile rear axle hubs, large machine tool spindles, high-power reducers, axle bearing boxes, and rollers of conveyors. .
10. Outer spherical ball bearing with seat Outer spherical ball bearings with seats are composed of sealed outer spherical ball bearings on both sides and cast (or stamped steel plate) bearing housings. The internal structure of the outer spherical ball bearing is the same as that of the deep groove ball bearing, but the inner ring of this bearing is wider than the outer ring. The outer ring has a truncated spherical outer surface, which can automatically adjust when matched with the concave spherical surface of the bearing seat. Usually, there is a gap between the inner hole of the bearing and the shaft. The inner ring of the bearing is fixed on the shaft with a jack wire, an eccentric sleeve or an adapter sleeve, and rotates with the shaft. The bearing with compact structure, convenient loading and unloading, perfect sealing, suitable for simple support, often used in mining. Metallurgy. Agriculture. Chemical industry. Textile. Printing and dyeing. Conveyor machinery.
Sort by size Bearing according to its outer diameter (1) Miniature bearings-bearings with a nominal outer diameter range of 26 mm or less. (2) Small bearings-bearings with a nominal outer diameter range of 28-55mm. (3) Small and medium-sized bearings —- bearings with a nominal outer diameter range of 60-115mm. (4) Medium and large size bearings —- bearings with a nominal outer diameter range of 120-190mm. (5) Large-sized bearings —- bearings with a nominal outer diameter range of 200-430mm. (6) Extra large bearings-bearings with a nominal outer diameter range of 440-2000mm. (7) Heavy-duty bearings —- bearings with a nominal outside diameter range of more than 2000mm.
1. Small friction resistance, low power consumption, high mechanical efficiency, easy to start; 2. Standard size, interchangeable, easy to install and remove, and easy to maintain; 3. Compact structure, light weight, and smaller axial size; 4. High accuracy, large load, small wear and long service life; 5. Some bearings have self-aligning performance; 6, suitable for mass production, stable and reliable quality, high production efficiency; 7. The friction torque of the transmission is much lower than the fluid dynamic pressure bearing, so the friction temperature rise and power consumption are lower; 8. The starting friction torque is only slightly higher than the rotating friction torque; 9. Bearing deformation is less sensitive to load changes than fluid dynamic pressure bearings; 10. Only a small amount of lubricant is required for normal operation, and it can provide lubricant for a long time during operation 11. The axial dimension is smaller than the traditional fluid dynamic pressure bearing; 12, can bear radial and thrust combined load; 13. The unique design can obtain excellent performance in a large load-speed range; 14. Bearing performance is relatively insensitive to fluctuations in load, speed and running speed.