The correct mounting of spherical roller bearings affects the service life of the bearings. Therefore, the bearings must be mounted in accordance with the operating standards. Spherical roller bearings mounting method is as follows.
A, pressed into the fit (i.e. cold mounting, the fit surface must be oiled)
Spherical roller bearings installation, installation with not too tight bearing, you can pass a sleeve and hammering method, gently knock the sleeve, the bearing installed to the appropriate location. Tap as evenly as possible on the bearing collar to prevent the bearing from tilting. Press the sleeve in, do not use a hammer and other tools to directly hit the bearing end face, so as not to damage the bearing.
Most bearings are mounted using the press-in method. If the inner and outer rings of the bearing are to be mounted on the shaft and in the housing at the same time, it must be ensured that the same pressure acts on the inner and outer rings at the same time, and the contact surface with the mounting tool must be on the same plane. When pressing in, should ensure that the outer ring end face and shell shoulder end face, the inner ring end face and shaft shoulder end face pressure, no clearance.
Second, heating installation (i.e. hot installation, the mating surface can not be coated with oil)
Usually, for larger bearing installation, not by heating the spherical roller bearings or housing is not possible, because as the size increases, the greater the force required for installation. The temperature difference between the bearing collar and the shaft or housing required for hot mounting depends mainly on the amount of interference and the diameter of the bearing mating place. When heating the bearing, it should be evenly heated, and there should never be local overheating.
When the interference is large, can use oil bath heating or inductor heating bearing method to install, heating temperature range of 80 ℃ -100 ℃, the highest can not exceed 120 ℃. At the same time, the application of nuts or other appropriate methods to tighten the bearing to prevent the bearing cooling width direction contraction and make the gap between the collar and the shoulder
Spherical roller bearings are assembled with drum rollers between the inner ring with two raceways and the outer ring with a spherical raceway. The center of curvature of the outer ring raceway surface is consistent with the bearing center, so it has the same self-aligning ball bearing alignment function. In case of deflection of shaft and housing, it can automatically adjust the load and axial load in two directions.
Radial load capacity is large, suitable for situations with heavy load and shock load. Bearings with tapered inner ring bore can be mounted directly. Or it can be mounted on cylindrical shaft by using tightening sleeve and dismantling cylinder. The cage uses steel plate stamping cage, polyamide forming cage and copper alloy turning cage.
For spherical roller bearings the use of an intermediate mounting ring prevents the outer ring from tilting and rotating when fitting the bearing with shaft into the box bore. It should be remembered that some sizes of self-aligning ball bearings have balls protruding from the side of the bearing, so the intermediate mounting ring should be recessed to prevent damage to the balls. A large number of bearings are generally mounted using mechanical or hydraulic press-in methods.
For separable bearings, the inner ring and outer ring can be installed separately, which simplifies the installation process, especially when the inner and outer rings are required for interference fit. In the inner ring has been installed in place of the shaft into the outer ring of the bearing box, must pay attention to see whether the inner and outer rings are correctly aligned to avoid scratching the bearing raceway and rolling parts.
If cylindrical and needle roller bearings use inner rings without flange retaining edge or inner rings with flange edge on one side, it is recommended to use mounting sleeves. The outer diameter of the sleeve should be equal to the inner ring raceway diameter F. The tolerance standard for mechanical processing should be d10. Drawn cup needle roller bearings are best mounted using an arbor.
Spherical roller bearings clearance.
For the installation of spherical roller bearings axial clearance, available on the journal adjustment nut, adjustment shim and bearing seat hole in the thread, or with preload spring and other methods to adjust. The size of the axial clearance, and bearing installation arrangement, bearing distance between, shaft and bearing seat material, can be determined according to the working conditions.
For high load high speed spherical roller bearing, adjust the clearance, must consider the temperature rise on the axial clearance, the temperature rise caused by the clearance reduction is estimated, that is to say, the axial clearance to be properly adjusted to a larger.
For the low speed and bear the vibration bearing, should take no clearance installation, or apply preload installation. The purpose is to make the spherical roller bearings roller and raceway to produce good contact, load uniform distribution, to prevent the roller and raceway by the vibration impact was destroyed.
After adjustment, the size of the axial clearance with a micrometer test. The method is to fix the micrometer in the body or bearing seat, so that the micrometer contact top shaft clean surface, along the axial left and right push axis, the maximum swing of the needle is the axial clearance value.
Spherical roller installation last clearance adjustment, clearance value should be based on different use conditions and with the interference size and specific determination, if necessary, should be tested to determine, bearing and pump shaft bearing in the factory has been adjusted clearance, installation without further adjustment.
Spherical roller bearings installation must be in a dry, clean environment, installation should be carefully checked before the shaft and shell with the surface, convex shoulder end, groove and connection surface processing quality, all with the connection surface must be carefully cleaned and remove burrs, casting unprocessed surface must be clean sand.
Spherical roller bearings installation should be rotating test, firstly for rotating shaft or bearing box, if there is no abnormality, then power for no load, low common operation, then depending on the operation gradually increase the rotating speed and load, and detect the noise, vibration and temperature rise, found abnormal should stop the operation and check. Only after the normal operation experiment can be used.