Bearings are important components of contemporary mechanical equipment. my country's bearing industry is developing rapidly. Bearing varieties range from small to large, product quality and technical level range from low to high, and industry scale ranges from small to large. A basically complete product category has been formed. Professional production system and relatively reasonable production layout. However, how much do you know about bearings? Lets learn with the editor today.
What are the functions of the 5 major parts?
①The inner ring usually fits closely with the shaft and rotates with the shaft.
②The outer ring usually cooperates with the bearing seat hole or the shell of the mechanical component to play a supporting role. However, in some applications, the outer ring rotates and the inner ring is fixed, or both the inner and outer rings rotate.
③The rolling elements are evenly arranged between the inner ring and the outer ring with the help of the cage. Its shape, size and quantity directly affect the load-bearing capacity and performance of the bearing.
④The cage evenly separates the rolling elements, guides the rolling elements to move on the correct track, and improves the internal load distribution and lubrication performance of the bearing.
⑤ Used for lubrication and sealing of mechanical friction parts. Also used on metal surfaces to fill gaps and prevent rust.
Five major parts and their composition principles(▶Bearing ring structure)
1.Inner ring
A bearing ring with raceways on its outer surface.
2. Outer ring
The raceway is located on the inner surface of the bearing ring.
3. Conical inner ring
The inner ring of a tapered roller bearing.
4. Conical outer ring
The outer ring of a tapered roller bearing.
5.Double raceway conical inner ring
The inner ring of a tapered roller bearing has double raceways.
6. Double raceway conical outer ring
Tapered roller bearings have double raceways in the outer ring.
7. Wide inner ring
A bearing inner ring that is widened at one or both ends to improve guidance of the shaft in its bore or to provide additional locations for mounting fasteners or seals.
8. Lock the inner ring
A grooved ball bearing inner ring with all or part of the shoulder removed.
9. Lock the outer ring
A grooved ball bearing outer ring with all or part of the shoulder removed.
10. Stamped outer ring
A ferrule stamped from a thin metal plate that is sealed at one end (seals the stamped outer ring) or open at both ends, generally pointing toward the outer ring of a radial needle roller bearing.
11.Flange outer ring
Flange bearing outer ring.
12. Aligning outer ring
Permanent angular displacement between axes.
13. Align the outer valve seat
The ferrule used to align the outer ring and the seat bore has a spherical inner surface that matches the spherical outer surface of the outer ring.
14.Outer sphere
The outer surface of the bearing outer ring is part of the ball surface.
15. Front rib of conical outer ring
The rib on the front of the conical outer ring raceway is used to guide the roller and bear the thrust of the large end surface of the roller.
16. Middle buckle
Double raceway bearing rings, such as the central integral rib of the double raceway conical inner ring
Making steps of bearing rings
①Forging: During the forging process, if overburning, overheating, internal cracks forming network carbides, etc. occur, the toughness and strength of the ferrule will be reduced. Therefore, processing temperature, circulating heating and post-forging heat dissipation conditions (such as spray cooling) must always be strictly controlled. Especially after final forging of larger ferrules, those with a temperature exceeding 700°C must not be stacked.
②Heat treatment: Close monitoring of heat treatment equipment is an important task in the workshop. Monitor equipment reliability. Important temperature control equipment such as instruments, thermocouples, etc. must be closely monitored to ensure accurate and reliable measurement data; any errors that are too large must be replaced in time, and work while sick is strictly prohibited.
③Monitoring of grinding process. The finished imported bearing rings are not allowed to have grinding burns and grinding cracks, especially the inner ring driving cone mating surface is not allowed to have burns. If the ferrule has been pickled, it should be thoroughly inspected to remove charred products. Those that are severely burned beyond repair or beyond repair should be scrapped. Rings with burns are not allowed to enter the assembly process.
④Identity recognition management. After the steel is put into storage and before the ferrule is ground, each process must be strictly managed, and two different materials and products, GCR15 and GCR15SIMN, must be strictly distinguished.
Installation of bearing rings
When installing bearing rings, special attention should be paid to the installation sequence. Precision bearings should also pay attention to the positive and negative ends. Reverse installation will cause dynamic imbalance and affect the performance of the bearing.
Rolling elements
Rolling elements are the core components in rolling bearings. Due to its existence, rolling friction exists between surfaces in relative motion. The types of rolling elements include steel balls, cylindrical rollers, tapered rollers, needle rollers, etc. The rolling elements of rolling bearings mainly include steel balls and rollers.
▶Basic structure of rolling bearings
Rolling bearings are developed on the basis of sliding bearings. Their working principle is to replace sliding friction with rolling friction. They generally consist of two rings, a set of rolling elements and a cage. They are highly versatile, standardized and highly serialized. High mechanical base parts. Due to the different working conditions of various machines, different requirements are put forward for rolling bearings in terms of load-bearing capacity, structure and performance. For this reason, rolling bearings need to have various structures. But the most basic structure is composed of inner ring, outer ring, rolling elements and cage.
The functions of each part in the bearing are:
For radial bearings, the inner ring usually has a tight fit with the shaft and runs with the shaft, and the outer ring usually has a transition fit with the bearing seat or the mechanical housing hole to play a supporting role. But in some cases, the outer ring is also running, and the inner ring is fixed for support, or the inner ring and outer ring run at the same time. For thrust bearings, the shaft ring and the shaft are a tight fit and move together, and the seat ring and the bearing seat or the mechanical housing hole are a transition fit and play a supporting role. The rolling elements (steel balls, rollers or needle rollers) are usually evenly arranged between the two rings in the bearing and perform rolling motion with the help of a cage. Its shape, size and quantity directly affect the load-bearing capacity and performance of the bearing. In addition to evenly separating the rolling elements, the cage can also guide the rotation of the rolling elements and improve the internal lubrication performance of the bearing.
▶Rolling bearing classification
1. Classification according to rolling bearing structure type.
1. Bearings are divided into: according to the load direction or nominal contact angle they can bear:
① Radial bearings - rolling bearings are mainly used to bear radial loads, with a nominal contact angle of 0 to 45. According to the nominal contact angle, they are divided into: Centripetal contact bearings - radial bearings with a nominal contact angle of 0; Centripetal angular contact bearings - radial bearings with a nominal contact angle greater than 0 to 45.
② Thrust bearings - rolling bearings are mainly used to bear axial loads, and the nominal contact angle is greater than 45 to 90. According to the nominal contact angle, they are divided into: axial contact bearings - thrust bearings with a nominal contact angle of 90°; thrust angular contact bearings - thrust bearings with a nominal contact angle greater than 45° but less than 90°.
Processing technology of main parts of various bearings:
①Ring processing technology: The processing of the inner and outer rings of the bearing varies according to the raw materials or blank forms. The processes before turning can be divided into the following three types. The entire processing process is: bar or pipe (some bars require forging, annealing, and normalizing) ---- turning ---- heat treatment ---- grinding ---- fine grinding or polishing ---- parts Final inspection---rust prevention----storage----(to be assembled)
② Steel ball processing technology. The processing of steel balls also varies depending on the state of the raw materials. The process before ball crushing or polishing can be divided into the following three types. The processes before heat treatment can be divided into the following three types. For the above two types, the entire processing process is: cold punching of rods or wires (some rods need to be punched and annealed after cold punching) - crimping, rough grinding, soft grinding or light balling - heat treatment - hard grinding ----Fine grinding----Fine grinding or fine grinding----Final inspection grouping----rust prevention, packaging----warehouse .
③Roller processing technology The processing of rollers varies according to different raw materials. The process before heat treatment can be divided into the following two types. The entire processing process is: bar turning or wire cold heading, then ring belt and soft grinding ---- heat treatment ---- soft points ---- rough grinding of outer diameter ---- rough grinding of end face ---- Precision grinding end face----precision grinding outer diameter----precision grinding outer diameter path----final inspection grouping----rust prevention, packaging----warehousing (to be assembled together).
④Cage processing technology The processing technology of the cage can be divided into the following two categories according to the design structure and raw materials:
Plate → Shearing [1] → Punching → Stamping → Shaping, finishing → Pickling or shot peening or string polishing → Final inspection → Rust prevention, packaging → Warehousing (complete assembly)
Processing technology of solid cage: The processing of solid cage varies according to the raw material or roughness. The blanks can be divided into the following four types before turning. The entire processing process is: bars, pipes, forgings, castings----inner diameter, outer diameter, end face, chamfering----drilling (or drawing, boring)----pickling---- Final inspection----anti-rust, packaging----warehouse .
Assembly process of rolling bearings:
After passing the inspection, rolling bearing parts such as inner rings, outer rings, rolling elements and cages enter the assembly workshop for assembly. The process is as follows:
Demagnetization and cleaning of parts → Group selection of inner and outer raceways → Assembly → Check clearance → Rivet cage → Final inspection → Demagnetization, cleaning → Rust prevention, packaging → Place in finished product warehouse (packaging and shipping).
▶Characteristics of rolling bearings
Compared with sliding bearings, rolling bearings have the following advantages:
1. The friction coefficient of rolling bearings is smaller than that of sliding bearings, and the transmission efficiency is high. Generally, the friction coefficient of sliding bearings is 0.08-0.12, while the friction coefficient of rolling bearings is only 0.001-0.005;
2. Rolling bearings have been standardized, serialized and universal, suitable for mass production and supply, and are very convenient to use and maintain;
3． Rolling bearings are made of bearing steel and heat treated. Therefore, rolling bearings not only have higher mechanical properties and longer service life, but also can save the more expensive non-ferrous metals used in manufacturing sliding bearings;
4. The internal clearance of the rolling bearing is very small, and the processing accuracy of each part is high. Therefore, the operation accuracy is high. At the same time, the rigidity of the bearing can be increased through preloading. This is very important for precision machinery;
5. Some rolling bearings can bear both radial load and axial load, so the structure of the bearing seat can be simplified;
6． Due to the high transmission efficiency and low heat generation of rolling bearings, the consumption of lubricating oil can be reduced, making lubrication maintenance easier;
7. Rolling bearings can be easily applied to uranium in any direction in space.
