Bearing is used to support components, is also used to support shaft rotary parts, bearing type according to the nature of the friction points: sliding bearings and rolling bearings; According to the direction of the load points: there are eccentric bearings, thrust roller bearings, angular contact bearings, etc.
1, sliding bearing assembly
Sliding bearing is a kind of sliding bearing grinding quality, characteristic is stable, reliable, low noise, can withstand heavy loads and large impact load, according to different can be divided into the integral structure, split and tile type, etc.
(1) the integral sliding bearing assembly
Integral sliding bearing commonly known as the shaft sleeve, is also the most simple kind of the sliding bearing, mainly adopt the method of pressure into and hammer to assembly, special occasions with hot pack. most of the collar is made of copper or iron, should be careful when assembling, use wooden hammer or hammer cushion block and the method of assembly and interference with press pressure into the larger size tolerance. Regardless of the type or pumped must prevent tilt, after assembly, oil groove and oil hole should be in the required position.
Should be done after the deformation of the bearing assembly, inner hole, smaller reamer cut, available size larger by scraping. At the same time pay attention to control and shaft fit clearance in tolerance range, in order to prevent the collar job rotation, shaft sleeve and the contact surface with a locating pin or the place of box body is various, screws. Because of the housing and shaft sleeve material hardness is not the same as drilling, it is easy to make bit towards the soft material side. the solution: one is before drilling by punching, hard material with sample. Another is to use short bit, in order to increase rigidity of drilling bit.
(2) split bearing assembly
Split bearing is also called split bearing, has the advantages of simple structure, convenient adjustment and remove, on bearing two pieces of bearing bush, in joint with gasket to adjust the reasonable clearance.
(1), the assembly of bearing and the bearing body
Upper and lower bearing contact with the bearing hole in the body must be good, if do not conform to the requirements of thick wall bearings bearing hole in the body as the benchmark, blow grind bearing bush back, at the same time, should make the ends of the bearing bush steps close to both ends of the bearing body. Thin wall tile as long as the bearing shell split higher than the split bearing body is only 0.1 mm, not compulsory.
(2) the bearing is installed in the bearing body, no matter the radial or axial displacement, are not allowed to have usually ends with bearing bush to stop the steps of positioning or dowel locating.
(3) bearing bush faced
To open four commonly used matching shaft research point, is generally lower bearing, and then scrape on bearing, in order to improve the efficiency when scraping the lower bearing don't mount bearing bushing and the cover, the basic requirements of the bearing contact, then the bearing shell and cover pressure, scraping the research on the bearing shell, further revised lower bearing contact points. Faced the tightness of the axis can be with the increase of the number of scraping, by changing the shim thickness adjustment. After the bearing cap fastening, shaft can easily turn without obvious gap, conform to the requirements of faced to complete contact point.
(4) bearing clearance measurement
The size of the bearing clearance can be adjusted through the split of gasket, also may be achieved through direct repair scraping the bearing shell. Measurement usually USES the pressure bearing clearance lead method, take some lead wire diameter greater than the bearing clearance, in the journal and points on the surface, then tighten the nut to split pressure, then fix the nut, remove the bearing cover, carefully remove the squished lead wire, one from each section of the micrometer to measure thickness, according to the average thickness of the lead wire can know the bearing clearance. General bearing clearance should be 1.5 ‰ to 2.5 ‰ of shaft diameter (mm), the larger diameter smaller clearance value. Such as is 60 mm shaft diameter bearing clearance should be between 0.09 0.15 mm.
2, rolling bearing assembly
Rolling bearing has a small friction, small axial size, simple, easy to change and maintenance etc.
(1) the requirements of the assembly
The end face of rolling bearing with code should be in a visible direction, in order to change the check.
(2) shaft neck or hole in arc radius should be less than the bearing shell are corresponding to the arc radius.
(3) bearing assembly on the shaft and hole in the shell, should be no askew phenomenon.
(4) in the two coaxial bearing, there must be a along with the axial thermal produced when axis movement.
(5) when the rolling bearing assembly, must be strictly prevent dirt from entering the bearings.
6 after the bearing assembly, flexible operation, low noise, working temperature should not be commonly more than 65 ℃.
(2) assembly method
Bearing assembly, the most basic requirement is to make and axial force, direct role in load bearing ring on the end face of (mounted on a shaft, and axial force to direct action, circle, in a hole when make the force to act directly on the outer ring). Try not to affect the rolling body. Assembly methods have a hammer, the method of assembling press, hot pack, freezing method for assembling, etc.
1) hammer method
Purple copper bar pad with a hammer and some soft materials before hammering method, be careful not to make the end of the copper bearing raceway is foreign bodies fall into, such as drum directly with a hammer or blunt cone directly bearing inner and outer ring, so as not to affect the bearing accuracy or bearing damage.
(2) screw press or hydraulic press fitting method
For interference tolerance larger bearings, can use a screw press or hydraulic press and assembly. Before the pressure to the shaft and bearing flat, and coated with a little oil, pressed into velocity should not be too fast, bearing in place to quickly removed after pressure, preventing damage of bearing or the shaft.
(3) hot pack
Hot pack is put in the oil bearing heated to 80 ℃ to 100 ℃, the suit to the shaft after bearing inner hole is puffy, can prevent the shaft and bearing from damage. For with dust cover and sealing ring, inside has been full of grease bearing is not applicable to hot pack.
(3) the taper roller bearing clearance is adjusted after assembly, the main method useful gasket adjustment, with screw, nut, is used to adjust, etc.
(4) the assembly of thrust ball bearing, should first distinguish between tight and loose ring, locking ring inside diameter slightly smaller in diameter, after locking ring and shaft assembly at work is relatively static, it always depend on the steps of the shaft or hole end surface, otherwise will lose rolling bearing function and accelerated wear and tear.