Whether buyers or sellers are concerned, the length of the bearing life. Such as: flanged bearing mainly take radial load, but also to support radial and axial load. But for the life of the Flange Slewing Bearing are not very understanding, the following three steps teach you extend bearing life:
(1) In order to make a gap in the radial direction between the bearing retainer and the bearing ring is set larger than the eccentric amount of the internal structure has been improved;
(2) the use of FEM analysis, by the shape and thickness were optimized to improve the strength of the holder;
(3) In order to prevent reduce surface damage caused by lubricating oil in the bearing ring in the design of the guide groove.
flanged ball bearing industry , market demand for high-end bearing is growing, such as machine tool bearings , aerospace bearings, high-speed precision bearings, wind power bearings, rolling bearings , high-speed rail bearings, turbocharger bearings , and so on .
2015年11月27日星期五
2014年12月19日星期五
The difference between domestic and foreign rolling bearings
Our precision spindle bearings industry started construction in 1950, after half a century of development, has formed a relatively complete system of production and technology system, to become the world's fourth largest country rankings bearing manufacturer in Japan, the United States and Germany, and has achieved remarkable achievement. However, compared with the bearing industry developed countries, China's bearing industry, there are still a big gap. Main features:
One on varieties, different specifications of products triple row roller slewing bearing the world total of about 150,000, our total production to date only two thousand months, and mostly for generic products.
Second, the production capacity, China's current production is about bearing more than 2,000 enterprises, is 5 to 6 times in other countries around the world bearing companies combined. However, the annual output value of the country's only comparable to the United States ranked sixth TIMKEN (about 21 billion yuan); compared with the number one Swedish company, equivalent to only half of its annual output (about 40 billion yuan) of ; Compared with Japan, equivalent to only ten percent of its annual output.
Third, the dimensional tolerances and precision rotation, even though our country is close to self aligning ball bearing foreign brand-name level, but in terms of the size of the deviation of the dispersion, there are still a wide gap. In addition, the countries have already begun to study and application of "non-repeatable runout" This fine precision rotation indicators, and our research in this area is still blank.
Fourth, in the high-speed performance, the value of foreign brands of DmN 4 × 106mm · r / min, while China bearing only 2 × 106mm · r / min.
Fifth, the vibration, noise and different sound, Japan has launched a mute and ultra-quiet bearing, and our bearing vibration (acceleration) compared to the extreme levels of Japanese products, generally more than a difference of 10dB.
Sixth, in life and reliability, deep groove ball bearings, for example, foreign brands of life is generally calculated life of more than 8 times (up to 30 times), the reliability of more than 98% (or to pursue with the host and other life), and our general life of the bearing life calculation is only 3 to 5 times the reliability of about 96%.
Seven, in the special conditions of the bearing application technology, China's bearing is there is a considerable gap.
It is precisely because there are not enough of bearings from different specifications to performance quality and other aspects, therefore, not only in the export, the vast majority of low-end products, each bearing an average price of only about $ 0.4, does not have any technical competence, and In a number of important host country or areas, such as civil aviation aircraft, high-speed railway passenger cars, luxury cars, computers, air conditioners, and other major equipment imported type, essentially consists of imported bearings "domination." These industries or areas, and there is a pillar industry of the national economy or in the field.
2014年11月27日星期四
Application of ceramic ball bearings in high speed spindle unit
Ultra-high-speed cutting is high quality, efficient and characterized by advanced manufacturing technology, which can bring high-speed cutting mechanism, high-speed spindle unit, high acceleration and deceleration linear feed motor development, high-performance control systems and other related cell technology. Core support high-speed spindle unit is high-speed spindle bearings. Ceramic bearings for its resistance to high speed, light weight, long life, excellent performance, high-speed spindle unit in machine tools are widely used.
A high-speed spindle unit and the spindle slewing bearing manufacturer High-speed spindle unit is one of the key technology to achieve high-speed processing, but also a key component of high-speed machine tools. The core of the high-speed spindle unit is high-speed precision bearings, its performance directly affects the performance of work spindle unit. With increasing speed, the bearing temperature, vibration and noise increase, decrease in the life. Therefore, increasing the spindle speed on the premise that developed a superior performance, high-speed spindle bearings. Currently, high-speed spindle unit, supporting mainly uses magnetic double direction thrust ball bearing spindle, liquid hybrid bearing, ceramic ball bearings in three forms. Magnetic Bearings and good high-speed performance, high precision, easy to implement diagnostics and online monitoring. But practice shows that the bearing due to electromagnetic measurement and control system is too complex and has not been widely used. Liquid hybrid bearing combines the advantages of hydrostatic bearings and hydrodynamic bearings, but this bearing must be specifically designed according to the specific machine, a separate production,the low degree of standardization, maintenance is also difficult.
Currently, the most widely used high-speed spindle bearings or hybrid ceramic ball bearings, namely the use of the rolling elements or hot isostatic pressing Si3N4 ceramic ball bearing rings remains rims. Such a high degree of standardization of the bearings, low price, small changes to the machine for easy maintenance, especially for high-speed operation of occasions. It d · n has exceeded the value 2.7 × 106. To increase bearing life, increase the wear resistance of the raceway, the raceway of the coating treatment or other surface treatment.
2 Experimental Research
Test conditions
The ceramic ball bearings used in the test parameters as shown in Table 1. The ceramic ball material HIPSN (hot isostatic pressing Si3N4), the accuracy level is G3 level, balls and rings when assembling the required value of the fine matching. The bearings are "dense beads beads" structure, and use the thin outer cage. In the tests with the ceramic bearing ball flange bearing
steel having the same structural parameters.
Spindle tests used are two models, namely A-type and B-type. Structure schematically shown in Figure 1, the bearing installation in the form of DBB. Table 2 is the main performance parameters of the two spindle.
Table 1 Test parameters with ceramic ball bearing Model Dimensions (mm) ball diameter (mm) contact angle of the original number of balls ceramic ball material cage material ferrule material
B7007CY35 × 62 × 147.1441615HIPSN resin GCr15
The main performance parameters in Table 2 spindle
Model limit speed (r / min) spindle diameter (mm) output power (kW) Lubrication
A mist type 30000354.5
B-type 24000354.5 fat
A high-speed spindle unit structure diagram in Fig.
A high-speed spindle unit and the spindle slewing bearing manufacturer High-speed spindle unit is one of the key technology to achieve high-speed processing, but also a key component of high-speed machine tools. The core of the high-speed spindle unit is high-speed precision bearings, its performance directly affects the performance of work spindle unit. With increasing speed, the bearing temperature, vibration and noise increase, decrease in the life. Therefore, increasing the spindle speed on the premise that developed a superior performance, high-speed spindle bearings. Currently, high-speed spindle unit, supporting mainly uses magnetic double direction thrust ball bearing spindle, liquid hybrid bearing, ceramic ball bearings in three forms. Magnetic Bearings and good high-speed performance, high precision, easy to implement diagnostics and online monitoring. But practice shows that the bearing due to electromagnetic measurement and control system is too complex and has not been widely used. Liquid hybrid bearing combines the advantages of hydrostatic bearings and hydrodynamic bearings, but this bearing must be specifically designed according to the specific machine, a separate production,the low degree of standardization, maintenance is also difficult.
Currently, the most widely used high-speed spindle bearings or hybrid ceramic ball bearings, namely the use of the rolling elements or hot isostatic pressing Si3N4 ceramic ball bearing rings remains rims. Such a high degree of standardization of the bearings, low price, small changes to the machine for easy maintenance, especially for high-speed operation of occasions. It d · n has exceeded the value 2.7 × 106. To increase bearing life, increase the wear resistance of the raceway, the raceway of the coating treatment or other surface treatment.
2 Experimental Research
Test conditions
The ceramic ball bearings used in the test parameters as shown in Table 1. The ceramic ball material HIPSN (hot isostatic pressing Si3N4), the accuracy level is G3 level, balls and rings when assembling the required value of the fine matching. The bearings are "dense beads beads" structure, and use the thin outer cage. In the tests with the ceramic bearing ball flange bearing
steel having the same structural parameters.
Spindle tests used are two models, namely A-type and B-type. Structure schematically shown in Figure 1, the bearing installation in the form of DBB. Table 2 is the main performance parameters of the two spindle.
Table 1 Test parameters with ceramic ball bearing Model Dimensions (mm) ball diameter (mm) contact angle of the original number of balls ceramic ball material cage material ferrule material
B7007CY35 × 62 × 147.1441615HIPSN resin GCr15
The main performance parameters in Table 2 spindle
Model limit speed (r / min) spindle diameter (mm) output power (kW) Lubrication
A mist type 30000354.5
B-type 24000354.5 fat
A high-speed spindle unit structure diagram in Fig.
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