Bearing is an important component in mechanical equipment. Its main function is to support the mechanical rotating body, reduce the friction coefficient during its movement, and ensure its turning accuracy.
The main role of a wheel bearing is to support the load and provide precise guidance for the rotation of the wheel hub. It bears both axial and radial loads and is a very important component. Traditional automotive wheel bearings are composed of two sets of tapered roller bearings or ball bearings. The installation, oiling, sealing and clearance adjustment of the bearings are carried out on the automobile production line. This structure makes it difficult to assemble in a car production plant, with high cost and poor reliability, and when the car is maintained at a repair point, the bearing needs to be cleaned, oiled and adjusted. The hub bearing unit is developed on the basis of standard angular contact ball bearings and tapered roller bearings. It integrates two sets of bearings, has good assembly performance, can eliminate clearance adjustment, light weight, compact structure, and load capacity. Large, sealed bearings can be pre-installed with grease, omitting the external hub seal and maintenance-free, etc., has been widely used in cars, there is also a trend of gradually expanding the application in trucks.
Classification
Plain bearing Sliding bearings have no rolling elements regardless of the inner and outer rings, and are generally made of wear-resistant materials. Commonly used for low-speed, light-duty, lubricating, and mechanically difficult to rotate parts.
Joint bearing The sliding contact surface of the articulated bearing is spherical, which is mainly suitable for swing motion, tilt motion and rotary motion.
Rolling bearing
Deep groove ball bearing Deep groove ball bearings are the most representative rolling bearings. Compared with other types of bearings of the same size, this type of bearing has a small friction coefficient, high limiting speed, simple structure, low manufacturing cost, high accuracy, no need for frequent maintenance, and a large size range and many forms, which is the most widely used type Bearings. It mainly bears radial load and can also bear certain axial load. When it is only subjected to radial loads, the contact angle is zero.
Angular contact ball bearings Generally speaking, the six types of bearings called 36 and 46 bearings are generally used, and the angular contact is generally 15 degrees, 25 degrees, and 45 degrees.
Self-aligning ball bearings Self-aligning ball bearings are bearings equipped with spherical balls between the inner ring of two raceways and the outer ring of which the raceways are spherical. The center of curvature of the outer ring raceway surface is consistent with the bearing center, so it has the same self-aligning function as the self-aligning ball bearing. When the shaft and housing are deflected, it can be adjusted automatically without increasing the bearing load. Spherical roller bearings can support radial loads and axial loads in two directions. Self-aligning ball bearings have a large radial load capacity and are suitable for heavy and shock loads. The inner diameter of the inner ring is a bearing with a tapered bore, which can be directly installed. Or use an adapter sleeve and a disassembly cylinder for installation on a cylindrical shaft. The cage is made of steel stamping cage and polyamide molding. Self-aligning ball bearings are suitable for bearing heavy and shock loads, precision instruments, low-noise motors, automobiles, motorcycles, metallurgy, rolling mills, mining, petroleum, papermaking, cement, pressing Sugar and other industries and general machinery.
Thrust ball bearing Thrust ball bearings are divided into unidirectional and bidirectional. They can only withstand axial loads and must not withstand any radial loads. Thrust bearing is divided into two parts: tight ring and live ring. The tight ring is tightly connected with the shaft sleeve, and the movable ring is supported on the bearing seat. The rings and rolling elements are usually made of rolling bearing steel with high strength and good wear resistance. The surface hardness after quenching should reach HRC60 ～ 65. The cages are mostly made of soft steel stamping, and can also be made of copper alloy cloth bakelite or plastic.
Angular contact thrust ball bearings Thrust angular contact ball bearings generally have a contact angle of 60 °. The commonly used thrust angular contact ball bearings are generally two-way thrust angular contact ball bearings. They are mainly used for precision machine tool spindles. They are generally used in conjunction with double-row cylindrical roller bearings and can withstand bidirectional shafts. It has the advantages of high precision, good rigidity, low temperature rise, high speed, and convenient assembly and disassembly.
Thrust roller bearing Including thrust cylindrical roller bearings, thrust tapered roller bearings, thrust needle roller bearings and thrust spherical roller bearings.
Needle bearing
Spherical ball bearing The outer diameter surface of the outer ring of the spherical ball bearing is spherical, which can play the role of centering.
Spherical roller bearing
Flange bearing Flange bearings have flange flanges on the outer wheel. The feature is that it can simplify the structure of the host, reduce the size of the host, and make the bearing easier to locate.
Block bearing A component in which a radial bearing and a seat are combined, and a base plate for mounting screws is provided on a supporting surface parallel to the axis line of the bearing.
Combined bearing A set of rolling bearings composed of two or more bearing structures at the same time. Such as needle roller and thrust cylindrical roller combined bearings, needle roller and thrust ball combined bearings, needle roller and angular contact ball combined bearings, etc.
Linear Bearings Linear bearings are divided into metal linear bearings and plastic linear bearings.
In terms of its role, it should be a support, that is, the literal interpretation is used to support the shaft, but this is only part of its role, and the essence of support is to be able to bear radial loads. Can also be understood as it is used to fix the shaft. The bearing selection of quick, easy and excellent automation is included. It is to fix the shaft so that it can only achieve rotation, and control its axial and radial movement. The motor cannot work without bearings. Because the shaft can move in any direction, the shaft can only be rotated when the motor is working. In theory, it is impossible to realize the role of transmission. Not only that, the bearing will also affect the transmission. In order to reduce this effect, good lubrication must be achieved on the bearings of high-speed shafts. Some bearings already have lubrication, called pre-lubricated bearings. Most bearings must be lubricated. When running at high speeds, friction not only increases energy consumption, it is even more terrible that the bearings are easily damaged. The idea of turning sliding friction into rolling friction is one-sided, because there is something called a sliding bearing.
lubricating The lubrication of rolling bearings has the purpose of reducing internal friction and wear of the bearings and preventing sticking; extending their service life; exhausting frictional heat and cooling to prevent the bearings from overheating and preventing the lubricants from aging themselves; also preventing foreign objects from entering the bearings or preventing rust and corrosion The effect.
seal Bearing seals can be divided into two types: self-contained seals and external seals. The so-called bearing comes with a seal is to make the bearing itself into a device with sealing performance. Such as bearings with dust caps, seals and so on. This seal occupies a small space, is easy to install and remove, and has a relatively low cost. The so-called bearing plus sealing performance device is a sealing device with various properties manufactured inside the mounting end cap and the like. Bearing seals are divided into non-contact seals and contact seals. Among them, non-contact seals are suitable for high-speed and high-temperature occasions, and have different structural forms such as gap type, labyrinth type and gasket type. The contact seal is suitable for medium and low-speed working conditions. Commonly used are felt seals, leather bowl seals and other structural forms.