In recent years, due to the development of grinding wheel, control, measurement and vibration technologies, TIMKEN bearing grinding new technology and process equipment have been continuously applied, mainly in the following aspects:
1.High-speed grinding technology is generally used. The linear speed of the grinding wheel can reach 60～80m/s when grinding the inner surface; the linear speed of the grinding wheel can reach 120m/s when grinding the outer surface. We can supply Metric and Inch size TIMKEN bearings , rich stock , today share TIMKEN stock photo .
2.The increase of the grinding wheel linear velocity raises new requirements for the dynamic balance of the grinding wheel. Therefore, the grinding machine tools are all equipped with the grinding wheel dynamic balancing device to compensate for the unbalance of the grinding wheel caused by the grinding.
3.In order to meet the requirements of TIMKEN bearing ring grinding processing automation, CBN grinding wheel grinding technology has been adopted in TIMKEN bearing ring grinding. Compared with ordinary grinding wheels, the wear ratio is as high as 4000-10000, which is equivalent to 150 times of ordinary grinding wheels. The grinding efficiency is extremely high, especially suitable for automatic high-speed grinding.
4.Artificial granite, as a material for manufacturing TIMKEN bearing grinder bed, is gradually adopted by various machine tool manufacturers in the world due to its advantages of strong rigidity, good vibration resistance, low thermal conductivity and short manufacturing cycle.
5.The headstock spindle and the TIMKEN bearing grinding machine grinding wheel spindle can be adjusted steplessly by PC or CNC programming control device with the help of frequency converter to obtain maximum and sales volume, best processing quality and keep the grinding wheel linear speed constant.
6.The development of plunge grinding technology is improving day by day. The application of computer in the measurement feedback (inductive active measurement) system makes plunge grinding, dimensional measurement and feedback control a closed-loop system.
7.With the development of hydraulic components technology, the hydraulic system of TIMKEN bearing ring grinding machine has also been updated. Variable vane pumps are commonly used to control the working temperature of hydraulic oil at a level of 5℃ higher than room temperature, overcoming the hydraulic system. The influence of machine tool working precision and product processing precision.
8.The combined grinding technology of combining two processes on the same grinding machine has been applied in TIMKEN bearing ring grinding, which not only ensures higher processing accuracy, but also greatly improves the processing efficiency of the product.
9.Due to the rapid development of CNC technology and its hot components (servo motors, ultra-precision roller screws, encoders, etc.) technology, PC and CNC control technologies have been widely adopted in the control system of TIMKEN bearing ring grinders. The CNC system can program, control, store and modify the actions of each mechanism of the TIMKEN bearing ring grinder and the entire processing cycle parameters; the wheel dresser realizes the requirements of linear or arc wheel dressing and dressing through NC coordinates.
Several common destruction forms of TIMKEN bearings
The TIMKEN bearing will inevitably be damaged during operation. If abnormal heating, vibration and sudden increase in noise occur, it indicates that the TIMKEN bearing may have been damaged. It should be checked and analyzed in time. Common forms of destruction are:
1.Indentation
When the external hard particulate matter enters the TIMKEN bearing and is pressed between the body and the raceway, the surface can form an indentation. In addition, excessive impact load can also cause local plastic deformation of the contact surface to form pits. When the TIMKEN bearing is stationary, even if the load is small, due to the vibration of the surrounding environment, a uniformly distributed pit will be formed on the raceway.
2.Wear
When the TIMKEN bearing is not well sealed, dust or particulate matter enters the TIMKEN bearing, or the lubrication is poor, which will cause serious scratches or wear on the contact surface, and increase the vibration and noise of the TIMKEN bearing.
3.Corrosion
Improper selection of moisture or acids, alkalis, salts, etc. intruding into TIMKEN bearings or lubricants will cite TIMKEN bearing corrosion. Even slight corrosion of precision TIMKEN bearings will make TIMKEN bearings scrap.
4.Cracks and fractures
Material defects and improper heat treatment, too much interference fit, improper combination design, such as stress concentration caused by grooves on the bearing surface, will form ferrule cracks and fractures.
5.Current corrosion
When the current passes through the TIMKEN bearing, a small electric spark will be generated, resulting in local annealing of the contact surface and the appearance of small pits or black bright spots. In serious cases, larger pits will appear.
6.The cage is damaged
TIMKEN bearings, especially high-speed TIMKEN bearings, due to lack of lubricant, make the cage contact with the body or ferrule wear, collision, or even cause the cage to break.
7.Fatigue spalling
On the raceway or body surface of the TIMKEN bearing, the metal on the surface of the contact surface flakes off due to the effect of alternating load, and gradually expands to form pits. If it continues to operate, it will form a peeling area. Due to improper installation or the tilt of the TIMKEN bearing housing hole and the centerline of the shaft, the local area of the TIMKEN bearing will bear a large load and early fatigue damage will occur.
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