Bearings are important components in vehicles and play a vital role in the operation of vehicles. In many cases, vehicle bearings will have certain failures. China Bearing Network (referred to as: Bearing Network) will share a typical failure of vehicle bearings-peeling phenomenon. And tell everyone how to better test the quality of the bearings, so that the bearings are safer to use.

1. Typical failure of vehicle bearings - peeling phenomenon.

After decomposing the faulty bearing, it was observed that the working surface of the bearing roller was peeled off, but the edge of the roller was dropped. The working surfaces of the inner and outer rings of the bearing also had metal flakes, and pits also appeared on the working surfaces of the inner and outer rings in contact with the edge of the rollers, as shown in Figures 1 and 2. The bearing cage has also been severely damaged and broken, and plane scars have appeared on the upper plane of the cage.

2. Cause analysis of bearing failure

For the analysis of the damage characteristics of the bearing, the basic reasons for the bearing failure mainly include the following aspects:

1) Contact fatigue damage.

2) The bearing is subjected to abnormal loads such as excessive contact load or impact load. For example, when the molten iron car is subjected to a large impact load during desulfurization or hanging tank operations; The effect of the load.

3) Improper bearing assembly or too small clearance, resulting in excessive additional contact stress between components.

4) Poor lubrication. Due to the harsh maintenance environment of metallurgical enterprises, iron slag, cotton yarn, dust and other foreign matter are mixed into the lubricant during bearing maintenance.

3. Measures to improve the quality of bearing inspection

1) Appropriate selection of bearing clearance

Clearance is an important factor for the normal operation of rolling bearings, and it is divided into axial clearance and radial clearance. Choosing an appropriate clearance can make the load reasonably distributed among the rolling elements of the bearing, limit the axial and radial displacement of the shaft (or shell), and ensure the rotation accuracy of the shaft; it can make the bearing work normally under the specified temperature; Reduce vibration and noise, which is beneficial to improve the life of the bearing. Therefore, when selecting a bearing, an appropriate bearing clearance must be selected. The selection of bearing clearance should consider the working conditions of the bearing, such as load, temperature, speed, etc.

2) Improve the quality of bearing assembly

①Matching and measuring link: When assembling the bearing, making the correct matching is an important factor to ensure the reasonable bearing clearance, but the current measurement means and tools are very single, and it is impossible to accurately match the bearing. Purchasing more advanced measurement tools at present; after the bearing is assembled, it needs to go through the process of clearance measurement, but it has not yet been implemented due to the limitations of tools and measurement technology. It is recommended to add this process.

②Operation inspection link: After the bearing is installed, it should be inspected to ensure that the bearing is installed in place, the rotation is flexible, and there is no stagnation. If the bearing is installed improperly, the temperature of the bearing will rise rapidly and be damaged, and even major accidents such as bearing seizure and fracture will occur. It is recommended to increase the bearing running and inspection process.

3) Improve bearing maintenance and storage environment

① Overhaul environment: Due to the particularity of the overhaul environment of metallurgical enterprises, there are a lot of iron dust and dust in the overhaul environment, so when the bearing is overhauled, the surrounding environment should be kept clean and free from hand sweat and dirt.

②Storage environment: Bearings should not be stored directly on the ground (more than 30cm above the ground), avoid direct light and cold walls. In order to prevent rust, store in an environment with a temperature of about 20°C and a humidity of less than 65%. Bearings placed in acidic air are prone to rust and discoloration, so it is necessary to strengthen bearing storage management to ensure that new bearings are not damaged by external factors.

4) Standardized disassembly and assembly of axle boxes

At present, the maintenance work of bearings is relatively extensive, especially in the process of disassembling and assembling the axle box. Sometimes a sledgehammer is used to strike, which may cause internal damage to the bearing and shorten the working life of the bearing. Therefore, while strengthening the management of bearing maintenance, it is necessary to Actively go deep into the front line to understand the situation, effectively improve the problems found, develop corresponding maintenance tooling, and improve the quality of bearing maintenance.

5) Eliminate the loading of inferior bearings from the source

①External packaging inspection: In general, genuine factory brands have their own dedicated designers to design the external packaging, and arrange factories that pass the production conditions to produce and produce. Therefore, the packaging is very clear from the lines to the color blocks.

②Steel printing inspection: Usually, the bearing body is printed with brand words, labels, etc., and the fonts are very small. However, most of the products produced by the original factory use steel printing technology, and the characters are embossed before heat treatment, so although the fonts are small, they are deeply concave and very clear. The fonts of counterfeit products are not only blurry, but also have rough printing techniques, floating on the surface, and can even be easily erased by hand.

③ Rotation check: hold the inner sleeve of the bearing with the left hand, turn the sleeve with the right hand to make it rotate, and listen for noise. Due to the backward production conditions of most counterfeit products, or even completely manual workshop operation, it is inevitable that sundries such as sand will be mixed into the bearing body during the production process, so there will be noise when rotating. This is the biggest difference from genuine factory brands that strictly enforce production standards and operate with machines.

④Surface quality inspection: Since the current anti-rust technology in China is not particularly qualified, it is easy to leave thick oil stains when anti-rust treatment is carried out on the bearing body, which is sticky and sticky when held in the hand. There are almost no traces of anti-rust oil on the bearings. A particularly careful expert said that the imported bearings smell a certain smell, and there must be anti-rust oil, but they cannot be seen.