Bearings Want To Be Assembled, These Foundations Need To Be Remembered!

Sliding bearing is a sliding friction bearing, characterized by smooth work, reliable noise, can withstand heavy load and large impact load, according to the different structure can be divided into integral, split type and tile type.

(1) the integral sliding bearing assembled monolithic commonly known as the sliding bearing collar, a kind of form is also the most simple 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, When the interference size tolerance is large, press in. No matter knocking or pressing, tilting must be prevented. After assembly, oil groove and oil hole should be in the required position.

The bearing deformed after assembly should be trimmed for inner holes. The smaller size can be cut with a reamer, and the larger size can be scraped. At the same time, attention should be paid to the clearance between the shaft and the control within the tolerance range. In order to prevent the rotation of the shaft sleeve when working, the contact surface of the shaft sleeve and the box is equipped with positioning pins or riding screws. Because the box and shaft sleeve material hardness is not the same when drilling, it is easy to make the drill bit biased to the soft material side, the solution: one is before drilling with a sample of hard material side punching, the other is to use a short drill bit, in order to increase the rigidity of the drill bit when drilling.

(2) Assembly of split bearing

Split bearing, also known as split bearing, has the characteristics of simple structure, convenient adjustment and disassembly. Two bearing bushes are inlaid on the bearing bush, and a reasonable gap is adjusted by gasket at the joint.

(1) The assembly of bearing and bearing body the contact between the upper and lower bearing and bearing body hole must be good, if not meet the requirements with the bearing body hole of thick wall bearing bush as the benchmark, scraping the back of the bearing bush, and the two ends of the steps should be close to the bearing body at the same time. As long as the thin wall tile makes the middle surface of the bearing bush is about 0.1mm higher than the middle surface of the bearing body, it is not required to repair and scrape.

(2) The bearing bush is installed in the bearing body regardless of radial or axial displacement is not allowed, usually with the steps at both ends of the bearing bush to stop positioning or positioning pin positioning.

(3) the 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. The tightness of the shaft can be adjusted by changing the thickness of the gasket as the number of scraping increases. When the bearing cover is tightened, the shaft can rotate easily without obvious clearance, and the scraping is completed when the contact point meets the requirements.

The size of the bearing clearance can be adjusted by the gasket at the parting, and can also be obtained by directly repairing and scraping the bearing bush. 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. Generally, the clearance of bearings should be 1.5‰-2.5‰ (mm) of the shaft diameter, and the smaller clearance value should be taken when the diameter is larger. If the shaft diameter is 60mm, the bearing clearance should be between 0.09-0.15mm.

Rolling bearing has the advantages of small friction, small axial size, convenient replacement, simple maintenance and so on.

(1) Technical requirements for assembly ① The end face of rolling bearing marked with code should be installed in the visible direction, so as to check when replacing. ② The circular radius at the step of the journal or shell hole should be less than the corresponding circular radius on the bearing. ③ After the bearing is assembled on the shaft and in the hole of the shell, there should be no skew phenomenon. (4) in the two coaxial bearings, there must be one with the thermal expansion of the shaft shaft movement. ⑤ When assembling rolling bearings, dirt must be strictly prevented from entering the bearing. ⑥ After assembly, the bearing must operate flexibly, the noise is low, and the working temperature should not exceed 65℃.

(2) Assembly method When assembling bearings, the most basic requirement is to make the added axial force act directly on the end face of the bearing ring (when mounted on the shaft, the added axial force should act directly on the inner ring, and when mounted on the hole, the added force should act directly on the outer ring).

Try not to affect the rolling body. The methods of assembly include hammering, press assembly, hot assembly, freezing assembly and so on.

(1) Hammering method with hammer cushion purple copper rod and some soft materials and then hammering method, we should pay attention to not make the copper end and other foreign matters fall into the bearing raceway, do not directly hammer or punch cylinder directly beat the inner and outer ring of the bearing, so as not to affect the bearing matching accuracy or cause bearing damage.

② Assembly method of screw press or hydraulic press For bearings with large interference tolerance, can be assembled by screw press or hydraulic press. Before pressing, the shaft and bearing should be flat, and coated with a little lubricating oil. The speed of pressing should not be too fast. After the bearing is in place, the pressure should be removed quickly to prevent damage to the bearing or shaft.

The hot loading method is to heat the bearing in oil to 80℃-100℃, so that the inner hole of the bearing is enlarged and fitted to the shaft, which can prevent the shaft and bearing from damage. For the bearing with dust cover and sealing ring, the bearing with grease inside is not suitable for hot loading.

(3) The clearance of tapered roller bearings is adjusted after assembly. The main methods are gasket adjustment, screw adjustment, nut adjustment, etc.

(4) When assembling thrust ball bearings, the tight ring and loose ring should be distinguished first. The inner diameter of the tight ring is slightly smaller. After assembly, the tight ring and the shaft remain relatively static at work, and it always depends on the step or hole end face of the shaft.