The methods of improving the precision for INA bearing installation

INA bearings of the most common method of replacement has two kinds: one kind is with acetylene oxygen of INA bearings directly heating; The other is for small INA bearings used in oil heating, achieve expansion, expand the INA bearing inside diameter, so that the assembly. These methods in the long term has been widely used in equipment maintenance, basic content and solves the INA bearing assembly problems in equipment maintenance. But these two methods to ensure the INA bearing in the process of heating temperature of heated area is uniform, it is difficult to determine. Because traditional acetylene oxygen heating is a single burner gas, and heating process only by experience, by heating the INA bearing temperature added to what is right is very difficult to master. Temperature is too high, can produce annealing of INA bearing, reduce the mechanical properties of INA bearings; Temperature is too low, the thermal expansion values is not enough, difficult to assemble. In equipment repair, the repairman is sometimes not enough because of INA bearing heating, INA bearing is less than the right position, have forced to take down heavy, thus increasing the intensity of labor. To this end, we put forward a new method of change tradition of INA bearings heating assembly. 1. Electricity heating replace acetylene oxygen heating. Will become a cylindrical furnace, electric furnace design in his plane named INA bearings, electric heater, according to the different INA bearing inner diameter can be designed into different power and specification of INA bearings electric heater ( Best scope in the INA bearing inside diameter phi 300 mm/above) 。 The heating device has the following advantages: uniformity and stability of thermal radiation, by heating the INA bearing surface dust, clean, clean, convenient for measurement and control INA bearing temperature. 2. Using infrared thermometer on the heating surface of INA bearings temperature monitoring. INA bearing controlling the heating value of general assembly in 100 ℃ ~ 120 ℃ advisable. Within this temperature, thermal expansion value maximum INA bearing steel, facilitate INA bearing assembly, the temperature does not change the mechanical properties of INA bearings, and high reliability. To sum up, INA bearing electric heater is superior to the traditional heating, acetylene oxygen is to increase the INA bearing assembly precision and work efficiency, reduce labor intensity of effective method. 1. A method for increasing accuracy of INA bearings manufacture delicate instruments in one power plant, the type 6202 / P2 INA bearing spindle and its precision is still cannot meet the requirements, the bold shaft neck and on the race to replace the inner ring, and the steel ball precision measurement, to size every three grain of a group, each group of steel ball in the interval of close to 120 °, because added a heavy machining surface, and added the weight with the surface, at the same time improve the stiffness of shaft and INA bearing system, and the three largest grain and minimum three grain of steel ball nearly equidistant spread, and improves the precision of drive shaft rotation, thus satisfying the requirements of the precision of the instrument. 2. Accuracy improving method of INA bearings after completion of installation in the host, such as the measurement of spindle radial runout, can be found that the each measured value of a certain change; Continuous measurement, can be found that after a certain number of revolution, this change will approximately duplicated. Measure for cyclic rotation accuracy degree of the change, change the approximately duplicated the revolution, on behalf of cyclic rotation accuracy 'cycle', the value of the amplitude changed in quasi cycle, is the cycle rotation accuracy is poor. Such as the proper preload on the spindle, the speed decreases gradually to close to compulsory rotation speed, in order to practice the INA bearing 'break-in' effect, can improve the circulation of the spindle rotation accuracy.