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Rolling bearing finish, vibration reduction, noise reduction, progress life
Source: Bearing network time: 2013-05-31
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Based on the investigation of the level of the roll product, the level of quality, the level of the leveling instrument and the detection method, and the condition of the abrasives, tooling and grinding fluids; The method of tackling and adopting the skills required for the rollover.
2. Improve the life and reliability of the rolling body
2.1 The status of domestic and international rollover life The impact of the rolling body on the bearing life is theoretically second only to the inner ring; in the middle of the national bearing quality supervision and inspection in the past three years;
The share of rollover damage in the number of bearing failure sets is: 80% in 2000; 36% in 2001; 31% in 2002; although it is gradually decreasing; but the share is still appropriate; and foreign brand-name products are damaged due to rollover The share of failure is low; even in some experiments it is zero.
At the end of 2002, the national bearing quality supervision and inspection center; the life test results of several types of bearings at home and abroad: the experimental results of the deep groove ball bearings 6208, 6304, 6307, 6311; the four types of nine sets of bearings There is a type better than foreign (SKF, NSK) samples; three types of life is lower than foreign samples, domestic 6208, 6304, 6307 reliability Re less than 90%; in the 77 sets of domestic bearings tested; steel ball failure 8 sets of bearings; 73 sets of foreign bearings in the experiment; steel ball did not attack failure. A total of nine groups of 63/28 bearings for motorcycles tested together; K from 1 to 25; 4 groups of K>12; Re >90%. The experimental tapered roller bearing K is 1.33 ~ 3.65; the reliability Re is 90 ~ 99. 99%. It can be seen that the domestic rolling body life and reliability are still far from abroad; Together; through the tumbling career continues to do their best; also has a certain level of quality.
2.2 The primary factor affecting the life of the rolling body is analyzed from the cause of the rollover damage; the first is:
(1) The composition, noisy and loose arrangement and quality of the original data steel,
(2) Roller hardness,
(3) Metallographic microscopic arrangement of the rolling body,
(4) tumbling the surface and quality of the external surface,
(5) Rolling the external surface stress state,
(6) Tumble the extracorporeal invasive and smooth membrane,
(7) Rolling the external surface to grind burns and soft spots,
(8) Rolling body accuracy grade,
(9) The roller convexity and convexity values ​​do not meet the drawing requirements.
(10) Roller group difference.
2.3 Measures to improve the life of the rolling body Align the elements that affect the life of the rolling body; arrange the professional production companies, research institutes, universities and affiliates of the rolling body; plan for the implementation of the "10th Five-Year" technology of the rolling body profession On the basis of; the quality of the original rolling material steel; the leading tumbling heat treatment process; the handling of the rolling mill hardness, metallographic micro-arrangement and other hot processing quality; the development of efficient tumbling external surface strengthening machine; discuss the strengthening mechanism and methods; Deepen the implementation of the tumbling external surface strengthening process; optimize and improve the rolling body processing technology; strengthen the tumbling external surface description and grinding cutting mechanism analysis; strengthen the tumbling external surface stress analysis and related research.
Key points for the following joint research on key skills closely related to the number of rollovers:
(1) Research on the quality and related skills of the original tumbling body data,
(2) Research on optimization and quality control of roll heat treatment process,
(3) Development of high-efficiency tumbling external surface strengthening machine,
(4) Optimization and implementation of the tumbling external surface strengthening process,
(5) Optimization and implementation of the grinding process of resin grinding wheel,
(6) The study of the effect of tumbled external surface on the function of bearing life,
(7) Analysis and discussion of external tumbling stress
(8) Study on the mechanism of infiltration and smooth membrane formation of tumbling external body,
(9) Discussion on the control theory and shortcomings of the external control of the external surface of the tumbling,
(10) Discussion and discussion on experimental methods for the life of rolling bodies,
(11) Discussion on the quantitative processing technology of roller crown.
3, progressive roller public service level; reduce the vibration and noise reduction of the roller oscillating ball bearing; after the bearing professional "Ninth Five-Year" skills research; achieved a significant role. Roller bearing vibration and noise reduction; first in the motor occupation Then, the demand for automobiles and other occupations is becoming more and more severe; it is getting more and more urgent. But compared with ball bearings; the vibration reduction and noise reduction of roller bearings has always been thinner; the quality level has always been low; the distance from foreign famous brands Larger; since 2000, the national bearing quality supervision and inspection of the tapered roller bearing oscillation test in the middle; 2000 inspection a total of 20 types; oscillation pass rate of 55%; 2001 a total of 20 types; oscillation pass rate of 70 %; In 2002, a total of 14 types were examined; the oscillation pass rate was 64%; but the oscillation acceleration and oscillation speed were in Z, Z1 and V groups; compared with foreign SKF products; the oscillation acceleration was one level; the oscillation speed was two. Sub-precision domestically spreads at level III; some grade II; foreign roller public service grades are grade 0, grade I; domestic roller accuracy is at least two grades abroad; in roller production skills; to ensure process stability There are still a lot of work to be done to improve the accuracy of the roller.
3.1 The primary problem of domestic roller production and the distance from foreign leading level
3.1.1 Roller product description and process preparation Our country in the aspects of roller depiction, tooling depiction, process preparation and testing procedures; bound by linear thinking; distance in depicting thinking and depicting ideas; lack of innovation Changed understanding, careful and detailed discussion and systematic inductive analysis; the depiction of roller products stayed at the level of the 50s and 60s; the constraints of equipment, tooling, original materials, management level, process quality control ability and traditional habits The production process is long; the processing capacity is large; the processing times are large; the auxiliary processes are numerous; the number of loading and unloading is many. Many companies depict specifications and grinding specifications for many years; the tooling has not improved for many years. The product formation is relatively backward; Data is ruined; production costs are added; process rationality is poor.
3.1.2 Roller production equipped with domestic roller needle roller equipment and process level is the most backward in the bearing profession; fundamentally the level of 50-60 years; the formation of cylinders, cones and spherical rollers with a diameter of φ24mm or less Basically still use the general Z31-25, Z31-13 cold heading machine; use the disk material or straight strip material; from the open type cutting material; the cutting material deformation is large; the one-time forming shape is large in public service and scale; the appearance quality is poor There are also manufacturers that use general press molding and single-axis or multi-axis active lathe turning. However, foreign countries use high-speed double-click cold heading machine; close the cutting material; the original data is disk material or bar material; domestic disk material diameter is below φ10mm; Foreign countries are below φ21mm.
The outer diameter grinding process of tapered roller is equipped with domestic special grinding machine of M1080 and XF004 tapered roller. The comparison of grinding machine parameters with foreign equipment is shown in Table 1.
The outer diameter of foreign tapered roller is high-speed and high-precision full-active grinding machine; such as MT85/VS of coarse grinding outer diameter and MT85/LS grinding machine of refined outer diameter produced by German MODLER company.
The cylindrical roller outer diameter grinding equipment has made great progress; the domestic MGT10100 and MGT1050 centerless grinding machines are satisfied with the cylindrical roller production demand; but the cylindrical roller final grinding end grinding processing equipment and lapping processing equipment can not satisfy the demand; especially in the end face circular beating The roughness of the surface is difficult to reach the specification of the class I roller.
Spherical roller outer diameter grinding equipment; 3M4020, 3M6825, 3M6850 outer diameter grinding machine produced by Xinxiang Risheng Company and Wuxi Machine Tool Plant; processing precision and scale precision are close to foreign equipment; but the support method is different; domestic fixed support Foreign countries are floating support.
In the super-finishing of the outer diameter of the roller; further development and optimization of the drawing of the super-precision roller and the development of the logarithmic curve super-precision roller grinder. At present, the Luo axis, the tile axis and the Luo axis have done a lot of work; Still need to be improved.
There is an urgent need to improve the level of domestic equipment.
3.1.3 Test instruments and testing methods The current domestic testing instruments are relatively backward; the quality management concepts and methods are still very primitive; in quality management, quality inspection, quality control; the primary reference is to check the inspection; some full-time inspection personnel adopt the tradition The inspection methods and methods are used for quality control; the quality products are inspected; not manipulated. The testing instruments and testing skills do not have informational conditions; the quality information feedback is delayed during the production process; the quality information is not true or even lost; End quality control.
3.2 The primary factor affecting roller oscillation and noise
(1) Roller appearance roughness,
(2) Roller appearance waviness,
(3) Roller roundness,
(4) Roller batch diameter variation,
(5) The characteristics of the roller surface,
(6) Tapered roller ball base surface balance.
3.3 Countermeasures for Vibration and Noise Reduction of Roller Bearings China's roller is superior to foreign leading level in terms of quality level, process level and leveling detection method; there is still a long distance; followed by high precision and longevity of roller bearings The demand for number, low noise and high reliability is getting higher and higher; the demand is based on the current domestic roller quality level; the item is compared with the international leading level; the related countermeasures are formulated; the key skills are coordinated; the innovation is strengthened; Accelerate the structural adjustment of specialization arrangements; quickly train a group of specialized roller production backbone companies with certain planning; adjust the skill structure; advance the skills; increase the skill innovation and input; develop roller professional production companies, research institutes Institutes, colleges and universities, as well as equipment, testing equipment, raw materials, abrasives, tooling and other related companies, scientific and technological cooperation; implementation of new processes, new skills, new equipment, leading management methods; improve and implement roller connection Processing technology, logarithmic curve process; arc end face process, glazing process, shot peening process, controllable atmosphere heat treatment process Looks to strengthen crafts; develop efficient fine machining with roller; staffing levels near to the level of foreign countries; strive after the "fifth" research skills to reach the following guidelines:
(1) Roller public service level: fine roller reaches level I; stable batch reaches level II.
(2) Carrying out roller standardization work; including drawing standardization, process standardization, and tooling standardization.
(3) Roller specialization production roller coverage rate reaches 50%; convexity rate is 70%; outer diameter super-fine penetration rate is 50%; ball base surface non-magnetic grinding penetration rate is 60%; tapered roller public service level Above level II reaches 60%; cylindrical roller has reached 75% above grade II; needle roller G2 reaches 60%.
(4) Disposal of roller key production skills; greatly improve the overall quality of the roller.
3. 4 Roller "Tenth Five-Year" skill research direction and project based on the domestic roller production level of slow conditions; advocate the arrangement of roller production companies and affiliates to carry out the following key skills joint research.
3.4.1 Process skills
(1) Development of the skills of the roller and tooling depicting system,
(2) Development of roller technology system skills,
(3) Development and stability of batch processing of Class I and II grade rollers,
(4) Development of roller joint processing skills,
(5) Research on the processing technology of roller logarithmic curve,
(6) The implementation of roller exterior lighting and shot peening skills,
(7) The implementation of the roller controllable heat treatment process,
(8) Comparative analysis of the roller crowning process,
(9) Discussion on the strengthening skills of roller appearance,
(10) Analysis of the influence of the external appearance of the roller on the function of the roller bearing,
(11) Analysis of the comparison of roller oscillations.
3. 4 2 equipped with skills
(12) Development of high-speed and high-precision cold heading machines,
(13) Development of a centerless grinder for high-speed fine tapered rollers,
(14) Development of R300 to R600 tapered roller ball base grinding machine,
(15) Development of fine double-face grinding machines,
(16) Development of fine end face superfinishing machine,
(17) Development of spherical roller end surface grinders,
(18) Development of self-aligning roller outer diameter superfinishing machine,
(19) Development of roller crown super-precision machine and process skills,
(20) Development of roller logarithmic curve super-precision roller grinder.
3.4.3 Detection skills and specifications
(21) Roller quality ensures system skill development,
(22) Unification and publicity of the roller inspection specification,
(23) Roller leads the implementation of quality management system,
(24) Development of roller online detection skills and network skills,
(25) Development of roller eddy current flaw detectors,
(26) Development of the roller appearance meter,
(27) Development of roller crown measuring instrument.
3.4.4 Related skills
(28) Development of new mold materials,
(29) Development of new grinding fluids,
(30) Development of roller cleaning demagnetization and dry oiling equipment
(31) Development of roller efficient finishing machine,
(32) Development of the roller exterior strengthening machine,
(33) Development of roller efficient shot peening machine tool.
4 Summarize that China's rolling body is superior to foreign leading level in terms of quality level, technological level and leveling detection method; there is still distance; followed by the demand for high precision, longevity, low noise and high reliability of rolling bearings High; demand is based on the current domestic quality level of the rolling body; item by item and international leading level; formulate related countermeasures; joint research on key skills; increase innovation; accelerate the adjustment of specialization structure; The planned professional rollover production backbone company; the disposal of the tumbler key production skills; a substantial improvement in the overall quality of the rolling body; to the end of the roll bearing damping and noise reduction progress life dedication.
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