taper roller bearing for car 30308

The dimensional parameters of the 30308 bearing are: 90 mm × 40 mm × 25.25 mm, which is a tapered roller bearing.

1. Application of bearing materials in automobiles

As we all know, bearings are composed of four parts: outer ring, inner ring, rolling elements (ball, cylindrical, tapered or needle roller, etc.) and cage. Some have sealing rings. In addition to sealing rings and part of the cage, the rest The manufacturing material is mainly bearing steel.

When selecting the type and model of automobile bearings, it is mainly based on the nature, direction, size of the load, the working environment of the actual location, as well as the requirements for the bearing's rigidity, limit speed, life, accuracy, etc., and is generally completed by the designer. Bearings are widely used in vehicles and vary with vehicle type, installation location and manufacturer, as shown in Figure 1.

The author has visited some important domestic automotive bearing suppliers, such as Shanghai Renben, Zhejiang Wanxiang Precision, Hubei New Torch, Changzhou Guangyang, Luoyang Dongsheng, Chongqing Yangtze, etc. The following only combines the automotive power system (alternator in the engine) , air-conditioning electromagnetic clutch, tensioner pulley, idler pulley and other bearings), drive system (shaft teeth in the gearbox, differential, clutch and other bearings), wheel hub bearings and other related products are briefly introduced.

(1) Power system bearings

The engine is the heart of the car, continuously providing power to other components. The internal bearings were previously dominated by sliding bearings. Nowadays, most of them use sealed ball bearings on the premise of improving bearing performance. Figure 2 shows several typical bearings in engines.

The alternator bearing is a single-row sealed ball bearing, which is mainly affected by centripetal force and is required to operate reliably when the speed exceeds 2000r/min and the temperature exceeds 180°C. The rings and rolling elements are made of high-purity GCr15, and the hardness after heat treatment is required to be 58 ~64HRC, the cage is generally made of nylon PA46, and the sealing ring is generally made of acrylic rubber ACM. The reference standard is JB/T8167-2006.

The electromagnetic clutch bearing of the air-conditioning compressor is a double-row angular contact ball bearing. The outer ring rotates. The speed of the air-conditioning pulley can reach 7000~13000r/min. The maximum temperature is 160°C. The material is the same as above. The cage is changed from a part of an ordinary single spherical pocket. Cylindrical surface, the reference standard is JB/T10531-2005.

The tensioner and idler bearings are high-performance sealed ball bearings. The former acts on the loose edge of the synchronous transmission belt, and the latter acts on the tight edge of the synchronous conveyor belt. The materials are basically the same as above. The cage can be made of engineering plastics, 08 steel or 10 steel. Manufactured, the sealing ring is made of ACM or FPM (fluorine rubber), and the reference standard is JB/T10859-2008.

Water pump shaft bearings are generally double row ball bearings, and their radial dimensions are smaller than ordinary bearings. It is essentially a double bearing system with a simplified structure. The two supported bearings do not have inner rings. The raceways of the rolling elements are directly formed on the shaft. The outer rings of the two supported bearings are made into a whole. Both sides are sealed with seals. Its rollers are usually made of high-chromium bearing steel. The materials of the shaft and outer ring are made of carburized steel or high-chromium bearing steel. The reference standard is JB/T8563-2010.

(2) Drive system bearings

The typical representative of the transmission system is the gearbox, which can be divided into manual (MT), automatic (AT), continuously variable transmission (CVT), and dual clutch (DCT). It is also the part where most bearings are used. There are often several bearings in the gearbox to match different gears. The main types are ball bearings, cylindrical roller bearings, tapered roller bearings, needle roller bearings, etc. The gearbox can be regarded as a gearbox. Grease and anti-rust oil often contain impurities (iron filings, burrs, sand inclusions, etc.). The bearings rotate at a high speed during operation, resulting in a greatly shortened service life.

Figure 3 is a schematic diagram of the bearing position of our company's MA manual transmission (see the blue marked part in the picture). The first gear of the first shaft is a deep groove ball bearing 25D52E15, and the fifth gear of the first shaft is a deep groove ball bearing 25D62E17. The first gear of the second axis is a cylindrical roller bearing 32D62E16, and the fifth gear of the second axis is a deep groove ball bearing 22D57E17.