The influencing factors of bearing grinding roundness

The main factors influencing the grinding bearing channel roundness can be summarized as:

(1) in the process of grinding process system precision, it depends on the precision of the grinding machine and fixture positioning principle, structure parameters and its accuracy.

Bearing is stationary and the need to withstand continuous or intermittent load (impact);

Bearing the load at the same time in the slow oscillation or rotation.

Bearing under the load at very low speed (n < 10 revolutions per minute), and requires only a very short life (in this case, such as, according to a given load equivalent P it according to the formula to calculate the life a very low necessary basic dynamic load rating of the C, so choose according to life of Introduction Of SKF 6004 Bearing in the actual operation will be severely overloaded);

Bearing in the rotation, and in addition to the normal operating load, also have to bear heavy impact load.

In these cases, the bearing is not admissible load depends on the material fatigue, but the load to the extent of the permanent deformation caused by bearing raceway. Role in the stillness of the bearings, or slowly oscillating bearing load, or the impact of the effect on the bearing load, will create a pressing on the roller surface and concave raceway appears. The distribution of the rolling track sag may be irregular, also may correspond to the position of the roller is uniformly distributed. If the load is maintained during several rotation, then sag is evenly distributed on the whole roll. Bearing the permanent deformation will cause vibration and noise and increase the friction. And may increase the internal clearance, or change the part between the coordinate.

(2) the 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, finally reflected in grinding workpiece geometry (roundness) and other surface quality.

(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 grinding wheel must be good balance), and the roundness error of grinding workpiece depends mainly on 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 of the optimal regression equation.