How is the needle bearing installed?

Installation of needle bearing:

The installation of fully loaded needle roller bearings is usually carried out with an auxiliary sleeve. At this time, the auxiliary roller or auxiliary sleeve holds the needle roller to prevent it from falling out, and the journal lifts the needle roller with its own chamfer. As the needle roller bearing moves inward slowly on the journal, the auxiliary roller or auxiliary sleeve will slowly withdraw until it is installed to the working position. The outer diameter of auxiliary roll and auxiliary sleeve shall be 0.1-0.3mm smaller than the shaft diameter. During installation, first coat the inner surface of the bearing outer ring with grease, stick the needle against the inner surface (there should be a gap when putting the last needle), then push the auxiliary roller or auxiliary sleeve instead of the journal or bearing inner ring into the outer ring hole, and make its end face align with the end face of the installed shaft or the end face of the bearing inner ring installed on the shaft, and then knock with a press or hammer to apply pressure. The needle roller bearing can also be installed in this way, that is, the outer diameter of the auxiliary sleeve is coated with a thin layer of lubricating oil, which is sleeved into the outer ring of the bearing, so that the auxiliary sleeve and the outer ring of the bearing form an annular hole, and then the needle roller is installed in the annular hole.

After installing the needle, push out the auxiliary sleeve with the working shaft. For needle bearing without inner ring or outer ring, when installing, apply a thin layer of grease on the rolling surface of the shaft or housing hole, and stick the needle to the grease at the installation position in turn. There should be a gap when placing the last needle roller. The size of the gap should be 0.5mm on the circumference of the needle roller bearing. Do not force the last needle roller into it, or install one less needle roller, because the bearing will be stuck and cannot rotate during hard pressing; When the bearing is installed less, the clearance is too large, which is easy to cause the rolling needle to swing and break when the bearing is running. For needle roller bearings with only stamped outer rings, since the outer ring wall is very thin, the non needle roller bearings should be hammered and installed with a hammer, and should be pressed in with a press. Because the pressure is uneven when the hammer strikes, it is easy to cause local deformation of the outer ring of the needle roller bearing.

Needlebearing is a roller bearing with cylindrical rollers. Compared with its diameter, the rollers are both thin and long. This kind of roller is called a needle roller. Although it has a small section, the bearing still has a high load bearing capacity. Needle roller bearings are equipped with thin and long rollers (roller diameter D ≤ 5mm, l/d ≥ 2.5, l is the roller length), so the radial structure is compact. When its inner diameter size and load capacity are the same as other types of bearings, its outer diameter is the smallest, which is especially suitable for supporting structures with limited radial installation size.

According to different applications, bearings without inner rings or needle rollers and cage components can be selected. At this time, the journal surface and shell hole surface matching the bearing are directly used as the inner and outer rolling surfaces of the bearing. In order to ensure that the load capacity and operating performance are the same as those of bearings with rings, the hardness, machining accuracy and surface quality of the raceway surface of the shaft or outer shell hole should be similar to that of the raceway of the bearing ring. This kind of bearing can only bear radial load.