Assembly Method of Plain Bearings
The plain shaft bearing is a kind of sliding friction bearing, which is characterized by stable operation, reliability, low noise, and can withstand heavy loads and large impact loads. According to different structural forms, it can be divided into integral type, split type and inner column outer cone type Wait.
1. Assembly method of integral plain shaft bearing
Integral plain shaft bearings, commonly known as bushings, are also the simplest form of plain shaft bearings. They are mainly assembled by pressing and hammering. Hot-loading is used in special occasions. Most bushings are made of copper or cast iron. Care should be taken when assembling, and it can be assembled by hitting with a mallet or a hammer block. Whether it is knocked in or pressed in, it must be prevented from tilting. After assembly, the oil groove and oil hole should be in the required position.
(1) Remove the burrs from the bushing and the bearing seat hole, and apply lubricating oil in the bearing seat hole after cleaning.
(2) According to the size of the bushing and the size of the overflow during matching, the bushing is inserted into the bearing seat hole by the knock-in method or the press-in method and fixed.
(3) After the shaft sleeve is pressed into the bearing seat hole, it is prone to change in size and shape. The inner hole should be trimmed and inspected by reaming or scraping to ensure a good clearance fit between the journal and the shaft sleeve.
Bearings deformed after assembly should be trimmed for inner holes. Smaller ones can be cut with a reamer, while larger ones can be scraped. At the same time, pay attention to control the matching clearance with the shaft within the tolerance range. In order to prevent the shaft sleeve from rotating during operation, the contact surface between the shaft sleeve and the box body is equipped with positioning pins or seam screws. Due to the different hardness of the box body and the shaft sleeve material, when drilling, it is easy to make the drill bit deviate from the soft material. The rigidity of the drill bit when the hole is made.
2. Assembly method of split plain shaft bearing
Split plain shaft bearing, also known as split bearing, has the characteristics of simple structure, convenient adjustment and disassembly. Split plain shaft bearing assembly sequence:
(1) The upper and lower bearing shells should be in good contact with the bearing seat and cover, and the shoulders of the bearing shell should be close to both ends of the bearing seat.
(2) In order to improve the matching accuracy, the bearing bush hole and the shaft should be ground and scraped.
3. Assembly method of inner column outer tapered plain shaft bearing
(1) Press the bearing shell into the hole of the box and ensure the matching requirements.
(2) Grind the points with a mandrel, repair and scrape the inner tapered hole of the bearing casing, and ensure the coaxiality of the front and rear bearing holes.
(3) Drill oil holes on the bearing, which correspond to the oil holes of the casing and the bearing shell, and are connected to the oil groove of the bearing.
(4) Take the inner hole of the bearing shell as the benchmark, and match the outer conical surface of the bearing to scrape the outer conical surface of the bearing to make the contact accuracy meet the requirements.
(5) Put the bearing into the hole of the bearing casing, screw the nuts at both ends, and adjust the axial position of the plain shaft bearing.
(6) Based on the main shaft, the inner hole of the scraping bearing is equipped to make the contact accuracy qualified, and ensure that the coaxiality of the front and rear bearing holes meets the requirements.
(7) Clean the journal and bearing hole, re-install the spindle, and adjust the clearance.