Within the bearing ring, ways to save the diameter - bearing knowledge

A, 1 center drift method, within the bearing ring, outer diameter of save first on the defects existing in the parts ( Asymmetric type) Accurate measurement size, calculate the amount of one of the most refined ( To the finished product size deviation of grinding amount) M, and then in the center of the grinding of the parts when deviation ( Offset in the direction of the increased defect grinding amount) M / 2, the maximum offset, the relative increase grinding of defect, the point grinding,. 2, inside the ring and the outer race to save the grinding of bearing ring processing design reference for the inside or the outside, namely first grinding ( ) Diameter after grinding groove, within the circle, for example, if the groove is not symmetrical type of defect, need to accurately measure the parts inside diameter size, and calculate the maximum ground M and the maximum number of grinding groove defect in M1. When the M1 < M, inner ring center offset is needed when grinding inner diameter, maximum offset for the M1/2, namely in the inner diameter machining the inner race defect first relative increase grinding amount in advance, and then grinding the inner raceway, the defect will be point grinding, waste was saved. When the M1 p M, normal grinding mill not to drop, can use 1 depending on the situation. Methods to save about 1 day. The center drift method grinding is in guarantee parts hardness and carburized layer depth, under the premise of the overall offset is not completed in a migration of grinding, grinding, generally divided into several through migration test to grind - measuring - adjust offset - try grinding process repeatedly to complete, after being defects wear off, to find, normal grinding correction ovality. The low efficiency of this method, at the same time, request the operator has a higher level of technology, but in a single machine, single production, in this way to save the success rate is higher, do not delay production schedule. It has been verified by several years of practice effect is good. Second, the method of bearing steel quenching heat treatment increase organization by quenching martensite, small amounts of secondary carbides and about 12% ~ 14% of residual austenite. Quenched martensite and retained austenite are unstable, in the process of tempering martensite decomposition to the volume shrinkage of steel, and residual austenite decomposition to the volume swell of steel. Following the increase of tempering temperature, the amount of residual austenite transformation decomposition, under the condition of ensure the technological requirements of hardness, appropriately increasing tempering temperature, the residual austenite decomposition, into a larger volume of martensite structure, can make the workpiece volume increases accordingly, namely relative diameter grinding increase, this method can be used to make bearing ring defects in normal grinding conditions was saved scrap parts. This method for larger residual austenite content of thick, heavy artifacts ( Especially for spherical roller bearing) The effect is significant. In practical production for different specifications, different size and different thickness of parts made of different tempering processes, on the premise of guarantee the hardness and distortion, which changes the organization fully, generates a rally, accordingly increase the amount of grinding, save waste. Three, chemical deposition for dimensional tolerance beyond the bearing parts of design standards, chemical deposition method can be used to save. The principle of chemical deposition is through a variety of chemical raw materials, the chemical reaction between evenly over the surface of the parts have a certain thickness of metal coating, through additional guarantee the metal layer and part of the original hardness and mechanical properties of the same. Chemical deposition to increase the size of the parts, don't change the shape of the parts of tolerance, so for the size tolerance out-of-tolerance parts, by chemical deposition is an effective method of saving at present, the largest single sedimentary thickness can reach 0. About 1 mm.