Bearing is mass production machinery parts, and manufacturing precision is strict, technical specialization degree is high, so for most of the easy to get the bearing varieties, should be to buy more economical than repair, in addition to economy, repair of bearing and its technical, which requires the repairer fully understand the bearing corresponding technical requirements, and the bearing and its components on the structure, process, and the characteristics of the material, otherwise it is difficult to guarantee the effect of bearing repair is required.
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1)
Benchmark unchanged composite repair method.
When repair and adjust the precision of dimension chain, according to the principle of benchmark superposition, only use a datum as a benchmark, namely the design basis, and all other effect the repair surface as a benchmark.
This combination of repair benchmark, easy to check the accuracy, reduce error accumulation.
For example, the speed control type hydraulic coupler in the repair, often based on the bearing body.
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2)
Benchmark transform composite repair method.
Sometimes design benchmark deformation is too big, can't use, will choose the other side as a benchmark, at the same time to carry on the dimension chain integration.
For example, if the deformation of the bearing body is too big, should be based on rotating components, reprocessed correction bearing body, and then according to the size of reprocessed out bearing body, adjust the assembly dimension chain, and replacement of the adjusting ring method, according to the order of the dimension chain inspection repair, closed loop control precision is achieved at last.
Vacuum quenching: its biggest characteristic is no oxidation, no deformation, no crack, for my company the production of precision bearing, using the vacuum heat treatment process from the start.
Both Japan's vacuum furnace and domestic vacuum furnace are two vacuum chamber (cold and hot
Hot chamber vacuum control at 2.
Below 0 pa, cold room at nine.
Below 3 pa)
, the curve of the heating process of bearing steel, in accordance with relevant provisions of the process (
Temperature and time)
To step by step to heat up, the highest to 840 plus or minus 10 ℃;
However, oil cooled or air cooled by the cooling medium, oil temperature control in the 60-80 ℃, the highest do not exceed 100-120 ℃.
Oil tempering: according to the characteristics of the bearing ring, we adopted oil at low temperature tempering, the temperature control in the 180 plus or minus 10 ℃.
Its main purpose to reduce internal stress after quenching and brittleness, stable size, can be on the premise of keep the high hardness and high wear resistance, in order to avoid when using split or premature failure.
Hardness HRC: 60-64.
Also, for stainless steel bearing products, also must pass through such heat treatment process, of course, the curve of the quenching (
Temperature and time)
Is different, the temperature is higher,
1040±10℃）
, and time is relatively long.
And within half an hour after step quenching and cryogenic processing (
That's been done in front of the paper)
, its main function is to reduce the residual austenite in the organization, and a stable organization, improve the stability of the ring precision.
But, in cryogenic treatment is to control the content of austenite can't too little, because a certain amount of residual austenite is conducive to the improvement of bearing life.
Therefore, all future production of my company all cryogenic processing precision bearing should be.
