How to install the needle bearing of machine tool?

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 punched outer rings, since the outer ring wall is very thin, do not use a hammer to knock and install, but use a press to press in. 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.