The installation
In order to play the high-precision characteristics of thin-wall bearings to achieve long service life of bearings, it is necessary to install bearings correctly in a clean environment. Cleanliness is critical to the performance of bearings. Work surfaces and tools must be free of dust, debris and burrs. Disposable wipes or non-removable cloth should be used.
In any case, bearings should not be used as measuring tools when grinding and machining mating parts. Even a small amount of abrasive particles and metal fragments (soft or hard) can seriously affect the precise geometry of the bearing, as well as the surface of the raceway and rolling body, and there is almost no way to remove them from the assembled bearing.
Shaft and bearing mounting holes must be very clean, paying special attention to small holes and crevices, which are prone to dust, debris and cutting oil. The raw surface of the casting shall be painted or otherwise covered. Bearing mounting surfaces must be carefully inspected, cleaned and lightly oiled to facilitate installation and minimize the risk of scratches. It is necessary to confirm bearing mounting aperture, axle diameter, shoulder perpendicularity and fillet size.
Do not unpack and remove the bearing until the preparation is complete and ready for installation
Interference fit of bearings with bearing mounting holes and shafts needs to pay attention to damaged bearings. For R bearings, it is recommended to use temperature differences to expand external elements to minimize or eliminate mounting forces. To calculate the required temperature difference, an expansion rate of 0.000007 inches per inch per degree Fahrenheit is used for AISI52100 steel ferrule and 0.000056 inches per inch per degree Fahrenheit for AISI440C material ferrule. For our 2-inch bore bearings of precision grade 1, when matched with steel shafts, the required temperature difference needs to estimate the interference between the upper difference of the shaft and the lower difference of the bearing. The temperature difference is 90℉. For 4-inch bore bearings, 60℉. Both dry heat and oil heat can be used. Resistance bands are suitable for large bearings. Care must be taken to avoid bearing overheating. Can't exceed 250℉.
If pressure mounting must be used, mandrel with suitable pressure ring should be used to apply pressure to the entire end face of the pressure mounting ring -- force cannot be transferred through the bearing, which will cause damage to the ball bearings and bearing rings.
All pairs of bearings have a "V" shaped mark on the inside and outside, indicating the correct relative position between the bearing inner and outer rings in the circumferential direction. The "V" mark is located at the highest point of the bearing ring eccentricity, so it should be placed at the lowest point of the shaft and bearing mounting hole eccentricity to achieve compensation effect.
After installation, bearings must continue to be protected from contamination until they are assembled.
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