First, let’s understand how to determine whether the bearing is good or not.

1. Bearing precision

The dimensional deviation and rotational accuracy of domestic bearings have been progressing, but there is still a certain gap with imported bearings. Foreign research and application of “non-repeatable runout” such fine rotational accuracy indicators, while China’s research in this area is still blank.

2. Vibration and Noise

Japan has introduced silent and ultra-silent bearings, while the extreme level of vibration of Chinese bearings compared with Japanese bearings, generally more than 10dB difference.

3. in terms of life and reliability

The life of foreign brand-name products is generally more than 8 times the calculated life (up to 30 times more), reliability of 98% or more (or the pursuit of life with the host, etc.), while the life of Chinese bearings is generally only 3 to 5 times the calculated life, reliability of 96% or so.

NMB specializes in the production of miniature bearings with an inner diameter of 10 or less and also has an advantage inside the miniature bearings.

Has been in the leading position, good quality, long life, low noise, good oil seal performance

4. In terms of high-speed performance

DMN value of foreign brand-name products up to 4 by 106 mm r/min, while the Chinese bearing is only 2 by 106 mm r/min.

Mega Tech Fan use Jan NMB Two ball bearing, to keep the high performance with low noise.

Secondly, the main reasons for the large quality gap between domestic bearings and imported bearings are.

1: Bearing finished product quality differences

A large number of tests show that: processing quality of the cage, collar, steel ball affect a lot on bearing vibration, processing quality of bearing vibration impact is the most obvious, followed by the processing quality of the collar, the most important impact factors are the roundness of the steel ball and collar, ripple degree, surface roughness, surface bruising, etc.

The most prominent problem of Chinese steel ball products is the vibration value discrete large, serious surface defects (single point, group of points, pits, etc.), although the surface roughness, size, shape, error are not lower than the level of the outer ring, the combined set of bearing vibration value is high, and even produce a foreign sound, the main problem is the ripple degree is not controlled (no standard, no suitable test analysis instrument), while indicating that the machine tool vibration resistance is poor, grinding wheel, grinding disc, the Coolant, process parameters are problems; on the other hand, to improve the management level, to avoid bump injury, scratch, burn and other random quality problems.

For the ring, the most serious impact on bearing vibration is also the channel ripple degree and surface roughness. For example, small and medium-sized deep groove ball bearings inside and outside the channel width greater than 2μm, will have a significant impact on the bearing vibration, inside and outside the channel ripple degree greater than 0.7μm, bearing vibration value increases with the ripple degree, channel serious knocking injury can make vibration rise more than 4dBa, and even the appearance of foreign noise.

2: Production process, talent, etc. pulling apart

1: The gap in industrial technology.

Bearing the social status of skilled workers, and even engineers do not get the respect they deserve (the situation has improved greatly in recent years). China’s uneven development of the education industry, technical education has not received due attention, resulting in young people would rather do nothing as white-collar workers, rather than work in the production line. Also led to China nowadays everyone entrepreneurship, and most small and micro bearing factories, bearing companies do not have high-quality technical personnel, can only produce some uncompetitive low-end bearing products.

2, the gap in material.

Alloy steel has been the shortcomings of China’s steel industry, high-end metallurgical technology, and the developed countries are strictly confidential to us, coupled with the lack of R & D of Chinese steel enterprises, resulting in China’s bearings and even industrial technology is inherently inadequate.

3, the production process gap.

Here, I only tell a little about their own ideas. The production process is the most important link in industrial technology, is a cycle, quantitative change in the process of qualitative change. To machine tools, for example, bearings have a huge impact on the accuracy of machine tools, high-end precision bearings of the large customer base is the machine tool spindle bearings. The domestic precision bearing life, precision, and foreign bearings have a huge gap.

4, Production equipment gap.

Bearing manufacturers and application manufacturers are the relationships between fish and water. No good bearings, production of good equipment, no reliable machine tool processing do not produce high-quality bearings. As far as I know, large machining manufacturers purchase basically imported machine tools. And some of China’s strength of the smaller bearing manufacturers would rather purchase the last century of the old machine tool transformation into a special machine tool for bearing processing, but also unwilling to purchase China’s well-known brand of machine tools. This has a price factor, but also the practicality of the factors.

The future direction of bearing development in China.

Mainly reflected in four areas of improvement.

1, bearing steel cleanliness

Under the premise of considering the economy, further, improve the cleanliness of steel, reduce the oxygen and titanium content in steel, to achieve the bearing steel oxygen and titanium mass fraction of less than 6 × 10-6 and 15 × 10-6 level, reduce the content and size of inclusions in steel, improve the uniformity of distribution.

2, Tissue refinement and equalization

Through the application of alloying design and controlled rolling and cooling process, further improve the uniformity of inclusions and carbides, reduce and eliminate reticulated and banded carbides, reduce the average size and maximum particle size, to achieve the target of the average size of carbides less than 1μ m; further improve the grain size of the matrix organization, so that the grain size of bearing steel is further refined.

3, Reduce low-frequency tissue defects

Further reduce the bearing steel in the center of the sparse, center shrinkage and center component segregation, improve the uniformity of the low-frequency organization.

4, bearing steel toughness

Through new alloying, hot rolling process optimization, and heat treatment process research to improve the toughness of bearing steel. Although domestic bearings and imported bearings have a lot of gaps, after the Chinese people’s continuous affirmation of the development of more high-quality bearing products, there will be a lot of excesses