In the process of customizing automotive bearings, in order to ensure safety, product quality, and stable equipment operation, safety protection measures need to be taken from multiple aspects such as design, material selection, processing, assembly, testing, and daily maintenance. The specific measures are as follows:
1. Safety protection measures in the design stage
Load and speed calculation: Accurately calculate the radial load, axial load, and composite load that the bearing bears to avoid early failure caused by overload design. Determine the maximum bearing speed based on engine speed, transmission system speed, and working conditions (such as high temperature and high speed) to prevent lubrication failure or material fatigue caused by excessive speed. Sealing design: Choose the sealing form (such as rubber sealing ring, metal dust cover) according to the working environment (such as mud, water) to prevent foreign objects from entering. When designing the lubricating oil passage, ensure that the oil hole position is reasonable to avoid lubricating oil leakage or uneven distribution.
Clearance matching: Select the appropriate clearance according to the working conditions to avoid bearing loosening or "locking" faults caused by cold shrinkage and thermal expansion.
. For example, in the winter environment of -30 ℃ in the north, C3 large clearance bearings may loosen internally due to cold shrinkage, resulting in abnormal vibration; In a high-temperature workshop (150 ℃), the clearance of C2 small clearance bearings may return to zero after thermal expansion, which may cause a "lock up" fault.II. Safety protection measures during material selection and processing
Material selection: Choose high-strength, wear-resistant, and corrosion-resistant bearing steel (such as GCr15) to ensure that the chemical composition of the material meets the standard (such as C content of 0.95%~1.05%).
. Strictly inspect the raw materials of bearing steel to avoid internal defects that may cause cracks, damages, or breakage of bearing parts. Heat treatment process: Strictly control the quenching temperature (840 ℃~860 ℃), tempering temperature (150 ℃~180 ℃), and cooling rate to avoid uneven hardness caused by quenching cracks or insufficient tempering. Overheating during heat treatment of metal materials can reduce toughness and increase brittleness, and the rolling elements of bearings may experience brittle cracking or even breakage during operation.Machining accuracy: Ensure the machining accuracy of bearing parts and avoid bearing assembly failure due to dimensional deviations.
. Regularly calibrate measuring tools (such as micrometers and dial indicators) to ensure measurement accuracy.III. Safety protection measures during assembly
Cleaning and lubrication: Before assembly, thoroughly clean the bearing parts with gasoline or specialized cleaning agents to remove oil sludge, iron filings, and rust proof oil.
. After cleaning, dry it with compressed air or soak it in rust proof oil and let it air dry naturally to prevent residual moisture from causing rust. When lubricating with grease, the filling amount should be controlled at 1/2~2/3 of the internal cavity of the bearing to avoid excessive heating or leakage. Pre tightening force adjustment: Adjust the pre tightening force according to design requirements, use a torque wrench or hydraulic device to ensure uniform pre tightening force, and prevent bearing jamming caused by vibration due to insufficient pre tightening or excessive pre tightening.Assembly tools and methods: Use specialized press in tools or hot sleeve devices to assemble bearings, avoiding direct tapping that may cause cracking of the inner ring or deformation of the outer ring.
. During assembly, ensure that there is no gap between the inner ring of the bearing and the shoulder of the shaft, and that the outer ring contacts the bearing seat evenly to prevent early failure caused by unbalanced load.IV. Safety protection measures during the testing phase
Bench test: Before the test, check whether the fixture on the bench is firm to prevent the bearing specimen from flying out and injuring people.
. During the experiment, personnel need to stay away from rotating parts and record speed, temperature, and vibration data through a remote monitoring system.Road test: The test route should choose a closed road or low traffic flow area to avoid high-risk testing on highways or in urban areas.
. After the experiment, check the temperature, noise, and leakage of the bearings, record the data, and analyze the cause of any abnormalities.Fifth, safety protection measures for daily maintenance and upkeep
Regular inspection: Regularly check the use of bearings, observe whether there are abnormal noises and local rapid temperature rises in the bearing parts, timely detect bearing faults and repair or replace them.
. Lubrication management: Regularly and quantitatively add lubricating oil or grease as required to reduce bearing friction and extend its service life. According to the usage of the vehicle, thoroughly replace the lubricating oil at least every six months and carefully inspect the bearings.Dust prevention measures: Select high-quality seals (such as rubber seals, metal dust covers), regularly inspect and maintain the seals, and ensure that the bearings are always in a good sealing environment.
. Keep the driving environment clean and try to avoid prolonged driving on dusty roads.Driving habit optimization: Prohibit the axle from bearing abnormal impact loads to protect the surface of the bearing from damage.
. For example, controlling vehicle speed through complex road conditions to avoid crushing sharp stones.