Technology Center
Technology Trends Analysis bearing spindle user
Published:2014-7-24 17:50:35
Nowadays, the demand for machine tools to support efficient production system is the sophistication, complexity development. Rolling a rotating part of the machine, it is not negligible part, its performance directly affects the performance of the machine.
Machine developments
Machine is currently the several major changes in the direction, the first is an increase in 5-axis machining and composite machining applications. 5-axis machining and complex machine on the market beginning in the second half of 1990 or so, are now widely available in the market, the features are in addition to cutting, also added a grinding processing, testing and workpiece handling robots and other functions. In addition, there is still further increase the number of axes to control the movements of a more complex tendency. Followed by the machine easier to operate. Like setting in the machine automatically correct processing of mechanical thermal displacement function; check the wheel and the workpiece interfere with each other's functions; intelligent and equipment; function to monitor the running state of the spindle. These changes will make it easier to operate the machine. Then is the high-precision machine tools, microfabrication development. This improves the DD motors or linear motors and other components of performance, the level of the sub-precision positioning accuracy as possible. The other is to become more space-saving machine. Currently, the high-performance requirements of high-volume production line of compact machines are also very significant. In order to further suppress the width of equipment to improve its maintenance, equipment width 1000mm 5-axis machining is now available. The last point is the machine is to reduce the environmental impact direction. Oil lubricated air flow is reduced and the oil lubrication to grease lubrication switching, there have been many aware of the environmental problems and the design of the machine on the market.
Technology Trends spindle bearings
1. High-speed and high rigidity of coexistence
In the context of the machine to the complex development of this multi varieties of small batch production, batch production and a tendency to change varieties project sum becomes higher. The total workpiece machining multiple synthesis on multiple machines on a single machine, or multiple projects roughing, finishing and other total synthesis few projects to improve performance and save space and make contributions. Therefore, for the spindle, with heavy cutting start from low rotational speed to high-speed rotation of light cutting and processing a wide range of development needs, as bearings, require high-speed and high rigidity coexist. For high-speed, single bearing dmn value, to realize the angular contact ball bearing 400 to 5,000,000, cylindrical roller bearings for the 200 to 300 million and to adapt to the machine requirements. However, the emphasis on speed, it would be detrimental for rigidity. To this end the spindle design, have at the same time pay attention to a lot of high speed and high rigidity. Can also be seen from here, to maintain high speed, and has the necessary rigidity in heavy cutting side is a problem in the future development of the bearing.
2. New lubrication
Lubricating roughly divided into oil lubrication and grease. Usually pay attention to high-speed processing of the case using oil lubrication, low speed and attention to cost, usability and reducing the environmental impact of the occasion lubricated with grease. But as the machine advances, desirable to have a process can satisfy both occasions lubrication.
As bearing manufacturers, oil lubrication make improvements to maintain high-speed processing while saving energy and improving environmental performance, or improve grease lubrication technology development is underway. That is, the lubrication technology is a big influence on bearing performance elements, there are a lot of issues need to expand in the future.
3. bearing design
Machine tool spindle bearings, according to the high speed, high rigidity and reduce the environmental impact and other performance requirements, JTEKT now offers R, C, D, F four models of high-performance angular contact ball bearing series. R type ball diameter ball a few more, to pay attention to the rigid design; C type large diameter ball, ceramic ball, as attention to the design of life; D-type method of supplying oil to the importance of efforts to design a high speed; F type is Consider the centrifugal force, than D-type can adapt to high-speed design. Users can select the most appropriate model based on the use, each bearing the main dimensions are in accordance with ISO standards, the minimum design changes shaft or housing alternative products in the past, but also a corresponding increase existing equipment performance.
High-performance bearing performance compared to the original high-speed bearings, bearing speed limit R increased to about 1.3 times the original bearing temperature rise reduced by 20% to 30% rolling using ceramic materials bearing R, C-type bearing the same, compared to the original bearings have the same tendency to make based on the rotation speed of the attention when using rigid design and attention to R load capacity of C-type design choices as possible. According to enhance high performance bearing high-speed performance and reducing the effect of temperature rise, high-speed rotation of the spindle rigid excellent position pretension has become possible.
In grease lubrication, the use of ceramic rolling element bearings R and oil lubrication conditions and compare the test results of original bearing temperature characteristic is that in the field of high performance bearing original bearings need oil lubrication grease lubrication can be used to confirm, to prevent environmental impact resulting decline in oil scattering, cost reduction and other effects caused by waste lubricating device. About R models, pay amount of grease sealed ring type also gradually raise standards.
These R, C-type bearings and bearing equally able to use the original grease or oil lubrication lubricate the two standard methods, but can be used in special type D, F two kinds of oil lubrication have more high-speed rotation, which is the use of considering the impact of these wind barriers occur when high-speed rotation of the bearing and the development of bearing shape.
D-type bearings and bearing the comparison result R, it has been confirmed that D-type bearing R bearings about 1.1 times the high-speed performance, and the temperature is decreased by 5% to 10% due to the bearing inner ring side of D-type bearing groove He began to rail portion of the direct supply of oil lubrication structure, less susceptible to wind barrier, and compared to the original oil lubrication can make the air flow is reduced by 20%. Furthermore, the reduction ball in the wind also made possible by these good features for energy saving and low noise make a greater contribution. F-type bearings are mounted on the side of the original bearing the oiling zone, starting from the injection nozzle disposed to the outer surface of the cage guide oil and gas supply high-speed rotary bearing. Cage-guided sliding contact surfaces to maintain the operation of aircraft in the acceleration or deceleration or when ultra high speed rotation may not be stable. However, through the supply of oil and gas from the outer nozzle stable operation of the cage.
And the current high-performance cylindrical roller bearings compared confirm increased about 1.5 times the high-speed performance and a decrease of about 15 percent of the temperature rise. Advantages of cylindrical roller bearings to bring high-speed spindle configuration can be simplified. Typically, the back side of the spindle support structure according to temperature changes need to be able to absorb the telescopic shaft. Cylindrical Roller Bearings, although suitable for this role, but so far since the cylindrical roller bearings, high-speed performance is not very complete, in high-speed spindle support on the rear side of the general or the use of "angular contact ball bearings + Vice-shell" configuration. But the development of new high-performance cylindrical roller bearings due to the high-speed spindle may also correspond, it is possible to greatly simplify the structure around the bearing.
The current high-performance cylindrical roller bearings, rotating at high speed, damage will occur cage to limit the high-speed performance, but as long as this defect can make to improve high-speed performance is more improved. First, with regard cage materials, and compared to the original polyamide resin with a high-speed rotation for lightweight, high-strength resin improves the strength. Furthermore, high-speed become similar structure is rotated in contact with the neck of the cage and the roller, so that the cage pocket hole roller contact form most appropriate, to achieve a reduction in friction and low temperature rise. In addition, the ferrule same material as the original product, using easy to start bearing steel, high-speed rotation by suitable interior design improves high-speed performance.
4. High reliability
In order to improve the reliability of the machine, must be improved bearing reliability. To do this based on the detected bearing temperature or vibration, to establish bearing life, so predicting technology is indispensable. Furthermore, if the detected load on the bearing, then self-control based on the processing status of the most appropriate preload and lubrication, such a result, but also has high-speed performance and high rigidity corresponding to the width of a large processing area becomes possible. Based on this, JTEKT has developed a pay increase based on the speed of the bearing preload the most appropriate mechanism alone, this agency from low speed to high speed have sufficient rigidity, and high output built-in motor combination enables high-load processing more efficiently get on. The original position preloading way, as the speed increases to increase spindle rigidity, but use the occasion of this institution, especially to increase drastically rigid spindle low speed high torque rotation occurs when the field is suitable for high-load processing preload the way. Mold industry is the rise of a tech boom, to further accelerate the promotion of China's mold industry technical updates. China's mold industry is facing, "Ebb Tide" period, many new companies will expose scientific and technological revolution in Ngau Tau, but more small businesses hanging by a thread.
Modern mold industry is technology, capital-intensive industries. In recent years, China's mold industry accelerated restructuring, mainly as follows: large-scale, sophisticated, complex, long-life mold and mold standard growth rate than the overall growth rate of the industry; plastic mold and die casting mold larger proportion; market-oriented professional mold manufacturers to increase the number and rapid development capability.
With the deepening of economic reform, the development of "funded" and private enterprise quickly. According to the International Association Secretary-General Luo Baihui mold research shows that domestic mold manufacturing enterprises above designated size 1314, employing 244,155 people, the annual industrial output value of 55.561 billion bald. Sales revenue and profit 53.958 billion yuan and 4.675 billion yuan, exports $ 1 billion. Imports amounted to $ 1.47 billion.
January 13, 2013, total imports and exports of mold $ 1.538 billion, an increase of 12.59 percent, of which exports amounted to $ 938 million, an increase of 17.25 percent, showing a steady growth momentum. Secretary of Guangzhou Die Industry Association Wangxiang Yan said that the current mold industry as a whole to grow steadily, with the technology and brand advantages of business situation will be better, while small enterprises are facing the risk of being eliminated gradually increased. Dongguan is some small mold companies are eliminated more.
With the increasing development of domestic mold industry, mold increasingly large-scale, mainly due to the high productivity demands and decisions. In order to improve production efficiency and developed "a multi-cavity mold" technology is more widely used until.
Obviously, the same can be made once the injection process more than one product at the same time, the production efficiency of natural doubled. And another reason is also increasingly large parts, but also a direct result of this mold must be large.
Faced with this phenomenon, how large molds and parts to meet increasingly high surface accuracy has been plagued by domestic mold industry. In Luo Baihui view, to break through this bottleneck, it is necessary to break through the troubled talent, technology and capital. Qualified enterprises to invest in sophisticated new CNC equipment, while also actively organized various training courses, actively training professionals, lay a foundation for the development of mold industry.