How to Improve Its Accuracy When Installing IKO Bearings

SKF 6219-2Z/VA201 bearing

After the angular contact ball bearing is installed in the main shaft of the IKO bearing, the verification sequence of the installation accuracy is as follows (taking an ordinary lathe with a shaft diameter of 60-100 mm as an example):

(1) Measure the size of the shaft and bearing housing holes to determine the matching accuracy of the bearing. The matching requirements are as follows: the inner ring and the shaft adopt an interference fit, and the interference amount is 0 ~ +4μm (0 at light load and high precision) ; The outer ring and the bearing seat hole adopt a clearance fit, and the amount of clearance is 0 ~ +6μm (but the clearance at the free end of the bearing can also increase the clearance); the roundness error of the shaft and the seat hole surface is less than 2μm, the bearing The parallelism of the end face of the spacer used is less than 2μm, and the runout of the inner end of the shoulder facing the outer end is less than 2μm; the runout of the bearing seat shoulder against the axis is less than 4μm; the inner end of the front cover of the spindle facing the axis is less than 4μm.

(2) Installation of the front bearing at the fixed end on the shaft: the bearing is thoroughly cleaned with clean kerosene. For grease lubrication, an organic solvent containing 3% to 5% grease is first injected into the bearing for degreasing and cleaning, and then used The oil gun fills a certain amount of grease into the bearing (10% to 15% of the bearing space volume); heat the bearing to increase the temperature by 20 to 30°C, install the bearing into the shaft end with an oil press; press the adapter sleeve on the shaft And with a suitable pressure against the bearing end face to axially position; wrap the spring scale tape on the outer ring of the bearing, and use the method of measuring the starting torque to verify whether the specified preload has a large change (even if the bearing is correct) However, due to the deformation of the fitting or cage, the preload may also change).

(3) Install the imported bearing-shaft assembly into the seat hole: heat the seat hole to increase the temperature by 20 to 30°C, and install the bearing-shaft assembly into the seat hole with continuous gentle pressure; adjust the front cover to make the front cover The tightening amount is 0.02～0.05μm, with the outer end surface of the bearing seat as the reference, the dial head of the dial gauge is pressed against the surface of the journal, and the shaft is rotated to measure its runout. The error is required to be below 10μm; locate the dial gauge at On the shaft, the meter head touches the inner surface of the rear seat hole, and the shaft is rotated to measure the coaxiality of the front and rear seat holes of the bearing seat.

(4) Put the free-end bearing selectively in the position that may offset the deviation, and install it in the bearing position behind the bearing seat, as far as possible to offset the mutual roundness deviation and coaxiality deviation.