Hunan Xiangtan city leaders to guide the work of Timken Company
TIMKEN TIMKEN Thin bearing Company China Limited Hunan Xiangtan municipal leaders 2010.04.30 Tao , deputy inspector of new water Deputy Minister , Office Yuan Xihui City Code , City Code Office deputy researcher Wu Ming and other city leaders to Hunan Xiangtan Timken company guidance . Hunan Timken Company general manager , Mr. James Ai Gete water to guide the work of the new pottery reported Hunan TIMKEN COMPANY , and government leaders attach importance to and guide the company deeply grateful. Xiangtan City , Hunan Leading Tao fresh water to roller bearing the work of Timken Company , said: "The government will be great support from the policy , the working group at any time improve coordination of services , the company provides a good investment environment . Provide good service for the enterprise , and effectively solve problems for them . "
About Timken Company in Hunan : Hunan Timken Bearing Company is the world's largest earlier this year by the United States, one bearing manufacturer Timken Company and Xiangtan Electric Manufacturing Co., Ltd. joint venture , mainly the production of large wind turbine drive spindle Timken bearings , located in Xiangtan high-tech Zone industrial Park in Germany , is the Timken in China 's first six plants. (Timken bearings distributor in China Editor )
2013年10月9日星期三
2013年8月27日星期二
Cause bearing failure caused
According to the bearing surface grinding metamorphic layer formation mechanism, the impact grinding metamorphic layer of the main factors is the grinding heat and grinding force. The following analysis on the reasons for bearing failure.
1 bearing the grinding heat
The thin bearings grinding, the grinding wheel and the workpiece contact area, consume large amounts of energy, resulting in a large number of grinding heat, causing the local instantaneous grinding zone temperature. Use of linear motion heat transfer theory derivation, calculation or application infrared and thermocouple method measured the instantaneous temperature under experimental conditions can be found in the 0.1 ~ 0.001ms instantaneous temperature within the grinding zone up to 1000 ~ 1500 ℃. Such instantaneous temperature, a certain depth sufficient to work the surface layer of high temperature oxidation, amorphous structure, high-temperature tempering, secondary hardening, cracking and other changes or burns.
(1) the surface oxide layer
The instantaneous high temperature steel surface under the role of oxygen in the air, up into very thin (20 ~ 30nm) thin layer of iron oxide. It should be noted that the oxide layer thickness and the total thickness of the surface layer of grinding deterioration test results showed a corresponding relationship. This shows that the thickness of the oxide layer which is directly related with the grinding process, the grinding quality is an important symbol.
(2) amorphous tissue layer
Instantaneous grinding zone so that the surface temperature reaches a molten state, the molten metal molecular flow has been evenly coated on the work surface, and is the base metal at breakneck speed cooling, forming a thin layer of amorphous tissue layer. It has high hardness and toughness, but it is only about 10nm, it is easy to be removed precision grinding.
(3) high-temperature tempering layer
Instantaneous grinding zone temperature to a certain depth can (10 ~ 100nm) is heated to a temperature above the tempering heating the workpiece. Does not reach the austenitizing temperature in the case, as the heating temperature is increased, the surface layer by layer will be generated corresponding to the temperature of the heating or tempering retempered organizational changes, hardness is decreased. The higher the heating temperature, the hardness decreased also more powerful.
1 bearing the grinding heat
The thin bearings grinding, the grinding wheel and the workpiece contact area, consume large amounts of energy, resulting in a large number of grinding heat, causing the local instantaneous grinding zone temperature. Use of linear motion heat transfer theory derivation, calculation or application infrared and thermocouple method measured the instantaneous temperature under experimental conditions can be found in the 0.1 ~ 0.001ms instantaneous temperature within the grinding zone up to 1000 ~ 1500 ℃. Such instantaneous temperature, a certain depth sufficient to work the surface layer of high temperature oxidation, amorphous structure, high-temperature tempering, secondary hardening, cracking and other changes or burns.
(1) the surface oxide layer
The instantaneous high temperature steel surface under the role of oxygen in the air, up into very thin (20 ~ 30nm) thin layer of iron oxide. It should be noted that the oxide layer thickness and the total thickness of the surface layer of grinding deterioration test results showed a corresponding relationship. This shows that the thickness of the oxide layer which is directly related with the grinding process, the grinding quality is an important symbol.
(2) amorphous tissue layer
Instantaneous grinding zone so that the surface temperature reaches a molten state, the molten metal molecular flow has been evenly coated on the work surface, and is the base metal at breakneck speed cooling, forming a thin layer of amorphous tissue layer. It has high hardness and toughness, but it is only about 10nm, it is easy to be removed precision grinding.
(3) high-temperature tempering layer
Instantaneous grinding zone temperature to a certain depth can (10 ~ 100nm) is heated to a temperature above the tempering heating the workpiece. Does not reach the austenitizing temperature in the case, as the heating temperature is increased, the surface layer by layer will be generated corresponding to the temperature of the heating or tempering retempered organizational changes, hardness is decreased. The higher the heating temperature, the hardness decreased also more powerful.
2013年7月14日星期日
The use of angular contact ball bearings check
Machine shaft parts, especially the spindle, thrust ball bearings are generally assembled into one, and a high rotational speed, and sometimes it will produce very high heat. This phenomenon if not removed, will cause the angular contact ball bearing overheating, and to the corresponding parts of the machine to produce thermal deformation temperature, serious cause spindle and tailstock is not high, which not only affects the accuracy and precision machine itself and would have bearing burn.
Rating fatigue life, refers to a group of the same type of bearing, operating under the same conditions, 90% of the angular contact ball bearing does not appear rolling fatigue spalling of the total number of revolutions. At constant speed, the more the total running time to indicate the nominal fatigue life.
In the research thrust ball bearing life, you can not only consider the fatigue life, but also according to the performance of the bearing should have consolidated several usage limit to consider. For example, greased bearing grease life. Noise life, abrasion life, etc., according to different purposes, using different reference limits, and therefore, most of the experience of pre-selected limits.
Therefore, only the survey angular contact ball bearing damage, injury is difficult to know the real reason. However, if you know the thrust ball bearings using mechanical, conditions of use, bearing the surrounding structure, to understand the situation before and after the accident, combined with state of the bearing damage, and several reasons, we can prevent similar incidents from recurring.
angular contact ball bearing are available judgments, mainly on account of bearing damage, mechanical properties, importance, operating conditions, to be determined during the next overhaul. If you can not use the following defects must be replaced with new thrust ball bearings. The inner ring, outer ring, rolling elements, cage on any cracks or gaps.
Kinds of bearing wear failure is a common failure modes, can generally be divided according to wear the most common form of abrasive wear and adhesive wear.
1 film resistors diagnostic techniques
Features: for different operating conditions using the same criteria. For flaking, indentation, cracks or other abnormal diagnostic poor results.
Application: for rotary axes exposed occasions.
2 Vibration diagnostic techniques
Features: Vibration diagnostic technique widely used; allows online monitoring; diagnosis faster diagnosis theory has matured.
Applications: especially suitable for rotating machinery angular contact ball bearing fault monitoring.
3 Ferrography diagnostic techniques
Features: The machine without the disintegration; investment is low, the effect is good; able to find oil-bearing early fatigue failure; do wear mechanism.
Applications: Suitable for lubricants lubricated angular contact ball bearing fault diagnosis, for grease lubricated bearings more difficult.
4 Temperature diagnostic techniques
Features: Diagnostic simple; judgment on bearing burn better.
Applications: Suitable for machine bearing simple routine diagnosis.
5 optical monitoring and diagnosis techniques
Features: Fiber optic displacement sensor with high sensitivity; directly extract the signal from non-oil bearing surface to improve the signal to noise ratio; may directly reflect the angular contact ball bearing manufacturing quality, surface wear, load, lubrication and clearance situation.
Applications: For the sensor can be installed in the bearing seat of the machine.
6 acoustic emission diagnostic techniques
Features: Diagnostic fast, simple; available on-line monitoring.
Applications: In recent years the development of new technologies, in the bearing condition monitoring is seldom used.
Direct hands to take non-oil bearing, to fully wash hands sweat, and coated with high-quality mineral oil before, during the rainy season and summer with particular attention to rust. In some special operating conditions, angular contact ball bearings can get a longer life of the conventional calculation, especially in the case of light load. These special operating condition is, when the rolling surface (track and rolling member) by a lubricant film to effectively separate and restrictions may result in contamination of surface damage. In fact, under ideal conditions, the so-called permanent bearing life is possible
Does not allow a strong punch, does not allow a direct hit with a hammer bearing, does not allow pass through the rolling pressure.
Angular contact ball bearings a rotating inner ring and outer ring raceway, the rolling contact with the rolling body is thus running track for the dark side, running track attached to the roller surface does not belong to an exception, which can be traced load conditions, so removing oil-free bearings, please strict attention and observation raceway running track.
Rating fatigue life, refers to a group of the same type of bearing, operating under the same conditions, 90% of the angular contact ball bearing does not appear rolling fatigue spalling of the total number of revolutions. At constant speed, the more the total running time to indicate the nominal fatigue life.
In the research thrust ball bearing life, you can not only consider the fatigue life, but also according to the performance of the bearing should have consolidated several usage limit to consider. For example, greased bearing grease life. Noise life, abrasion life, etc., according to different purposes, using different reference limits, and therefore, most of the experience of pre-selected limits.
Therefore, only the survey angular contact ball bearing damage, injury is difficult to know the real reason. However, if you know the thrust ball bearings using mechanical, conditions of use, bearing the surrounding structure, to understand the situation before and after the accident, combined with state of the bearing damage, and several reasons, we can prevent similar incidents from recurring.
angular contact ball bearing are available judgments, mainly on account of bearing damage, mechanical properties, importance, operating conditions, to be determined during the next overhaul. If you can not use the following defects must be replaced with new thrust ball bearings. The inner ring, outer ring, rolling elements, cage on any cracks or gaps.
Kinds of bearing wear failure is a common failure modes, can generally be divided according to wear the most common form of abrasive wear and adhesive wear.
1 film resistors diagnostic techniques
Features: for different operating conditions using the same criteria. For flaking, indentation, cracks or other abnormal diagnostic poor results.
Application: for rotary axes exposed occasions.
2 Vibration diagnostic techniques
Features: Vibration diagnostic technique widely used; allows online monitoring; diagnosis faster diagnosis theory has matured.
Applications: especially suitable for rotating machinery angular contact ball bearing fault monitoring.
3 Ferrography diagnostic techniques
Features: The machine without the disintegration; investment is low, the effect is good; able to find oil-bearing early fatigue failure; do wear mechanism.
Applications: Suitable for lubricants lubricated angular contact ball bearing fault diagnosis, for grease lubricated bearings more difficult.
4 Temperature diagnostic techniques
Features: Diagnostic simple; judgment on bearing burn better.
Applications: Suitable for machine bearing simple routine diagnosis.
5 optical monitoring and diagnosis techniques
Features: Fiber optic displacement sensor with high sensitivity; directly extract the signal from non-oil bearing surface to improve the signal to noise ratio; may directly reflect the angular contact ball bearing manufacturing quality, surface wear, load, lubrication and clearance situation.
Applications: For the sensor can be installed in the bearing seat of the machine.
6 acoustic emission diagnostic techniques
Features: Diagnostic fast, simple; available on-line monitoring.
Applications: In recent years the development of new technologies, in the bearing condition monitoring is seldom used.
Direct hands to take non-oil bearing, to fully wash hands sweat, and coated with high-quality mineral oil before, during the rainy season and summer with particular attention to rust. In some special operating conditions, angular contact ball bearings can get a longer life of the conventional calculation, especially in the case of light load. These special operating condition is, when the rolling surface (track and rolling member) by a lubricant film to effectively separate and restrictions may result in contamination of surface damage. In fact, under ideal conditions, the so-called permanent bearing life is possible
Does not allow a strong punch, does not allow a direct hit with a hammer bearing, does not allow pass through the rolling pressure.
Angular contact ball bearings a rotating inner ring and outer ring raceway, the rolling contact with the rolling body is thus running track for the dark side, running track attached to the roller surface does not belong to an exception, which can be traced load conditions, so removing oil-free bearings, please strict attention and observation raceway running track.
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