NTN one-way bearings for routine maintenance comprehensive calibration method

Measuring the size of the shaft and bearing hole and the precision of mutual cooperation, to make them fit for: the inner ring and the shaft to interference fit, 0 ~ + 4 um interference ( Under the condition of light load and high precision of 0) ; Outer ring and bearing hole should take clearance fit, the interval 0 ~ + 6 um ( But on the free end bearing using one-way bearing, should increase clearance) ; Shaft and hole surface roundness error in under 2 um, NTN bearing the face of baffle used parallelism in under 2 um, shaft shoulder end foreign face beat in under 2 um; Bearing hole block shoulder beating under 4 um of axis; The spindle axis inside the front cover end face fluctuations should be under 4 um. Fixed end before the installation of the bearings on the shaft position: clean with clean kerosene bearing, and to the bottom of the test. For grease lubrication, first will contain 3% ~ 5% of organic solvent injection one-way bearing grease for degreasing cleaning, then put the oil gun will fill in the NTN bearing grease quantitative ( Account for about 10% ~ 15%) of the bearing space ; Heating bearing to 20 ~ 30 ℃, bearing load shaft end with the hydraulic press, Will set casing pressure on the shaft and with appropriate pressure against bearing face makes its axial positioning; The lace will spring balance volume on the bearing outer ring, use the method of measuring start torque check is the preload of the regulation for substantial changes ( Even if the bearing is correct, as a result of improper or cage deformation, preload may change) 。 We need to bearing - Shaft assembly into the hole: heating holes make up 20 ~ 30 ℃, with a continuous gentle pressure of one-way bearing - Shaft assembly into a hole; Adjust the front cover, make the front cover of fastening is 0. 02 ~ 0. 05 um to bearing outer end face as a benchmark, the dial gauge meter resistance on shaft neck surface, will beat measuring the rotation axis, request error under 10 um. Will be located on the shaft, dial gauge meter resistance in the back seat hole surface, the axis of rotation to measure before and after bearing hole of the alignment. Inspect, clean NTN bearing will be removed, with photography method such as first and then record the appearance. In addition, to confirm the amount of residual lubricant and lubricant sampling, and then clean the bearing. A, a one-way bearing cleaning divided into rough washing and fine washing, can be put in use at the bottom of the container and on the metal frame. B, rough washing, oil using a brush to remove grease or adhesive. If at this time in oil turn the NTN bearing, pay attention to the rolling surface due to foreign bodies such as damage. C, fine cleaning, slowly rotating bearings in the oil, must be carefully. Commonly used cleaning agent for neutral aqueous diesel or kerosene, according to the need to sometimes use warm lye, etc. No matter use which kinds of detergent, often should filter clean. After cleaning, immediately on the NTN bearing coating anticorrosive oil or antirust grease. 2, examination and judgment to judge removed a one-way bearing can be reused, to inspect the dimension precision, rotating accuracy, internal clearance and mating surface, raceway surface, cage and seal rings etc. About the test results that can be used by NTN bearing or master of bearing.