Writer: Eric Bearing Limited
The assembly of TIMKEN bearings should be determined according to the structure, size and matching nature of the bearing components. Generally, the assembly methods of TIMKEN bearings include hammering method, pressing method, hot mounting method and cold shrinking method.
1. Preparation work before TIMKEN bearing assembly
(1) Prepare the necessary tools and measuring tools according to the bearing to be assembled. Check for defects, rust and burrs on the parts that match the bearing.
(2) Clean the parts matching the bearing with gasoline or kerosene, wipe with a clean cloth or blow dry with compressed air, and then apply a thin layer of oil.
(3) Bearings sealed with anti-rust oil can be cleaned with gasoline or kerosene; those sealed with thick oil and anti-rust grease can be heated and dissolved for cleaning with light mineral oil. After cooling, they can be cleaned with gasoline or kerosene and wiped clean for later use; Bearings with dust caps, seals or coated with anti-rust and lubricating grease do not need to be cleaned.
2. TIMKEN bearing assembly method
(1) Assembly of cylindrical bore bearings
a. Non-separable bearings (such as deep groove ball bearings, self-aligning ball bearings, spherical roller bearings, angular contact bearings, etc.) should be assembled according to the tightness of the seat ring. When the inner ring fits tightly with the journal and the outer ring fits loosely with the housing, first install the bearing on the shaft, and then install the bearing into the housing together with the shaft. When the outer ring of the bearing is in a tight fit with the housing hole, and the inner ring and the journal are loosely matched, the bearing should be pressed into the housing first; when the inner ring is tightly fitted with the shaft, the outer ring and the housing hole , The bearing should be pressed on the shaft and the housing hole at the same time. TIMKEN M88048 bearings online , pls click here :
b. Since the inner and outer rings of separable bearings (such as tapered roller bearings, cylindrical roller bearings, needle roller bearings, etc.) can be freely disengaged, the inner ring and rolling elements are mounted on the shaft together, and the outer ring is mounted on the shell. Inside the body, and then adjust the clearance between them.
If the journal size is large and the interference is large, the hot mounting method can be used to facilitate assembly, that is, the bearing is heated in oil at a temperature of 80~100~C, and then matched with the shaft at normal temperature. When the bearing is heated, it should be placed on the grid in the oil tank to prevent the bearing from contacting the bottom of the tank, which is much higher than the oil temperature, and to prevent contact with the sediment on the bottom of the tank. For small bearings, they can be hung on a hook and immersed in oil for heating. Bearings filled with lubricating grease with dust caps or sealing rings cannot be assembled by hot mounting.
(2) When the assembly interference of the tapered bore bearing is small, it can be directly installed on the tapered journal, or it can be installed on the tapered surface of the adapter sleeve or the withdrawal sleeve; for the large journal size or matching interference The large-volume and frequently disassembled tapered bore bearings are usually disassembled by hydraulic sleeves.
(3) Thrust ball bearing assembly Thrust ball bearings are divided into loose ring and tight ring. When assembling, the tight ring should be placed against the end face of the rotating part, and the loose ring should be against the end face of the stationary part, otherwise the rolling elements will lose their function. , And will accelerate the wear between mating parts.
3. TIMKEN bearing assembly error detection method
For spindle components with high precision requirements, in order to improve the rotation accuracy of the spindle, the bearing inner ring and the spindle assembly and the bearing outer ring and the box hole are often assembled by directional assembly. Directional assembly is a method of artificially controlling the direction of the radial runout of each assembly, reasonable combination, and using errors to cancel each other to improve assembly accuracy. Before assembling, it is necessary to measure the deviation of the centerline of the tapered hole of the spindle shaft and the radial runout of the inner and outer rings of the bearing, determine the error direction and make a mark.
(1) Detection of radial runout of bearing outer ring. When measuring, rotate the outer ring and press the outer ring in the direction of the dial indicator. The maximum reading of the dial indicator is the maximum radial runout of the outer ring.
(2) Detection of radial runout of bearing inner ring. When measuring, the outer ring is fixed and does not rotate. A uniform measurement load F is applied to the end surface of the inner ring. The value of F varies according to the bearing type and diameter. Then the inner ring is rotated more than one circle to measure the diameter of the inner hole surface of the bearing inner ring. The amount and direction of the circle runout.
(3) Detection of the center line of the spindle taper hole. When measuring, place the main shaft journal on the V-shaped frame, insert the measuring mandrel into the main shaft taper hole, and rotate the main shaft more than one circle to measure the deviation value and direction of the center line of the cone hole L.