In the new design of the spindle, before selecting the INA bearings, first consider the spindle performance parameters, largely determine the most critical performance, and further probe into the. (including: spindle speed, the precision of the spindle, spindle rigidity, the life of main shaft, spindle, spindle reliability)
Having decided to spindle parameters, the actual size of the spindle probe meter (shaft diameter, length, bearing span).
According to the bearing form (a ball or cylindrical roller bearings), arrangement (with the number of columns), driving mode (belt, gear, a motor, a motor arranged in), lubrication (oil, oil and gas, oil mist, spray) and other main parameters setting to determine its structure.
1, bearing radial load
INA bearings mainly bear radial load is a centripetal bearing. Nominal contact the bearing angle a0<=450. The radial load size the same roller bearings than ball bearings can bear larger.
N type and NU type cylindrical roller bearings can bear radial load, radial bearing other types can bear radial load, also can withstand the axial load.
2 of axial load, bearing
Bearing the main bearing axial load for thrust bearing, its nominal contact corner a0>450. Axial thrust bearings and thrust angular contact ball bearings according to the different structure and can bear one or two directions. When subjected to particularly high preferably thrust cylindrical roller bearings and spherical roller thrust bearings.
Spherical roller thrust bearing and a one-way thrust angular contact ball bearings can also bear the axial load and radial load, thrust bearings can only bear the axial load other.
3, bearing its own length compensation
Supporting a shaft and a bearing usually adopts the structure of combination of fixed bearing and swimming bearing. Swimming INA bearing shaft length error and compensation of thermal expansion.
NU type and N type cylindrical roller bearing is traveling bearing ideal, these bearings can themselves to compensate the length. Inner and outer rings of the bearing can be used in tight fit.
4, the sliding fit length compensation
Non separable bearings are also available for traveling bearing. A this kind of bearing rings in the two match is adopted, no axial fixed surface. Therefore, a bearing ring can be activities in its supporting surface.
After determining the precision bearing size, type, consider the specific design of the bearing.
Fully considering the bearing fatigue life, rigid, heat and other factors, the bearing clearance of the selection of the most appropriate (pre load).
Because of the bearing clearance and preload on the bearing performance, INA is the most critical, the more high speed when the more crucial, so must be carefully considered. Choose not to at that time, the early damage or sintering will occur the problems. It is necessary from the fourth step to the third step, or from the fourth step to the second step, repeated consideration.
After determining the spindle structure design, to consider the necessary conditions for the actual installation.
Confirm the high precision bearing installation shaft and bearing seat precision, tolerance and fit, fixed installation required locking nut tightening force, the actual installation after INA bearing pre load and internal clearance.