After the mounting spindle NSK bearings, precision calibration sequence is as follows (with shaft diameter for the lathe of 60-100mm as an example):
(1) measurement of the shaft and housing bore size to determine the fitting accuracy of NSK bearings to meet the requirements are as follows:
Within ring and axis take had Ying tie, had Ying volume 0~+4 μ m (in light load, and high precision Shi for 0); outer ring and NSK bearing block hole take gap tie, gap volume 0~+6 μ m (but in free end of bearing using corner contact ball bearing Shi, also can increases gap); axis and block hole surface round degrees errors in 2 μ m following, NSKNSK bearing by with across ring of end surface parallel degrees in 2 μ m following, axis shoulder within end face outside end surface of beats in 2 μ m following; bearing block hole retaining shoulder on axis of beats in 4 μ m following ; Axis of the spindle within the front cover face of beats in 4 μ m.
(2) installation of NSK bearings on the shaft before the end
Will bearing with clean of cleaning kerosene for thoroughly cleaning, for fat lubrication, first will contains 3%~5% grease of organic solvent injected bearing for skim cleaning Hou, again with oil gun will quantitative of grease filled into bearing within (accounted for bearing space volume of 10%~15%); heating bearing make warming 20~30℃, with hydraulic machine will NSK bearing loaded into axis end; will tight will set pressure in axis Shang and to suitable of pressure arrived live bearing end surface make its axis to positioning; will spring balance of tape volume in bearing outer ring Shang, A measurement method of verification of the starting torque under load there were substantial changes (even though the bearing is correctly, but due to or variant of the cage, a change in preload).
(3) load the bearings-shaft assembly into hole
Heating block hole make warming 20~30℃, with continuous gentle of pressure will NSK bearing-axis combination body loaded seat hole; adjustment Qian cover, make Qian cover of tight solid volume for 0.02~0.05 μ m, to bearing block outside end surface for benchmark, will indicator of table head subject in axis neck surface Shang, will axis rotating measurement its beats, requirements errors in 10 μ m following; will indicator positioning in axis Shang, table head subject Hou block hole within surface, will axis rotating to measurement bearing block before and after block hole of with axis degrees.
(4) the free end may offset the bias on a selective basis where installed to the NSK bearing bearing locations, offsetting each other as much as possible the roundness and concentricity deviation.