Influence the cause of the roller bearing inner ring channel roundness - bearing knowledge

1. Roller bearing inner ring channel of roundness is an important quality index, directly affect the work of bearing precision, stability and service life. Grinding is usually semi-finishing and finish machining process with the inner ring channel, roundness of product inner ring channel decisive, inner ring channel of grinding roundness in addition to the grinding technology of depends on the precision and dynamic characteristic, is also closely related with grinding process parameters. The former, has been attention by many scholars, and a lot of research, so as to greatly improve the grinding roundness of inner ring channel. With the improvement of precision grinding process system and the improvement of the dynamic characteristics, grinding process parameters become the main factors influencing the roundness, so the grinding process parameters on the influence law of roundness, to choose a reasonable process parameters, to ensure the bearing grinding roundness of the channel, and then realize the grinding bearing channel parameters optimization, has important significance. 2. Bearing inner ring channel usually adopts variable feed rate cut grinding method, the grinding cycle can be divided into: workpiece fast approaching, coarse feed, feed and feed grinding four stages. The main factors influencing the grinding bearing channel roundness can be summarized as: ( 1) Process system in the process of grinding accuracy, depending on the precision of the grinding machine and fixture positioning principle, structure parameters and its accuracy: ( 2) Dynamic characteristic of the process system, especially the grinding wheel balance: in the process of dressing and grinding, grinding wheel unbalance, causes forced vibration, due to the relative position of dressing of grinding wheel dresser and grinding wheel and grinding workpiece and grinding wheel of the differences in the relative position, and the two different cases of process system stiffness makes the vibration caused by grinding surface of workpiece is not round: grinding process parameters affect the contact rigidity between grinding wheel and workpiece, the grinding wheel wear process and vibration damping characteristics of the process system, which affects the vibration characteristics of grinding process, and ultimately reflected in grinding workpiece geometry ( The roundness) : (and the surface quality of the other 3) Process system caused by the elastic deformation of the workpiece original error rerun: analysis of the grinding cycle change rule, the workpiece geometry error after grinding workpiece geometry error reflected mainly depends on the process system rigidity, the grinding parameters, grinding wheel wear speed and the original error? 。 Considering the above factors, when the process system stiffness and dynamic characteristics of a certain ( Especially the grinding wheel must pass a good balance) , grinding workpiece roundness error is largely due to grinding process parameters, thus can be through the test data of grinding roundness, stepwise regression modeling, from multiple parameters in selecting the important parameters, gradually introducing the regression equation, so as to establish a relationship between grinding roundness and process parameters optimal regression equation. 3. Grinding wheel unbalance or other factors caused by machine vibration, will seriously affect the grinding workpiece roundness. Maintain good working condition and grinding wheel good balance, is applied to fitting the roundness of mathematical model in front of the premise condition. In addition, the grinding wheel hardness, different groups and the grinding abrasive and abrasive, and cooling fluid composition is different, can produce certain effect on grinding roundness.