To install and remove the miniature size needle bearing correctly!

The installation of miniature size needle bearing is usually carried out by using an auxiliary sleeve. At this time, the auxiliary roller or auxiliary sleeve supports the needle to prevent the needle from falling out, and the journal lifts the needle with its own chamfer. As the miniature size needle bearing moves inward on the journal, it assists The roller or auxiliary sleeve slowly withdraws until it is installed in the working position.

The outer diameter of the auxiliary roller and auxiliary sleeve should be 0.1-0.3mm smaller than the shaft diameter. When installing the miniature size needle bearing, first apply grease to the inner surface of the outer ring of the bearing, and place the needle close to the inner surface (there should be a gap when the last needle is inserted), and then replace the journal or bearing The auxiliary roller or auxiliary sleeve of the ring is pushed into the outer ring hole, and the end face is aligned with the end face of the mounting shaft or the end face of the inner ring of the miniature size needle bearing that has been installed on the shaft, and then tapped with a press or a hand hammer to apply pressure.

The miniature size needle bearing can also be installed in this way, that is, apply a thin layer of lubricant to the outer diameter of the auxiliary sleeve and insert it 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 install a needle in the annular hole . After installing the needle roller, use the working shaft to push out the auxiliary sleeve.
For the miniature size needle bearing without inner ring or outer ring, during installation, first apply a thin layer of grease to the rolling surface of the shaft or housing hole, and then close the needles to the grease on the installation site. . There should be a gap when placing the last needle. The gap should be 0.5mm on the circumference of the miniature size needle bearing.

It is not possible to hard squeeze the last needle in, or install one less needle, because the miniature size needle bearing will be stuck and unable to rotate during hard squeezing; when there is less installation, the gap is too large, which will easily cause needle rolling when the bearing is running Twisting and breaking. For needle roller bearings with a stamped outer ring, since the outer ring wall is very thin, the needle roller bearings should not be knocked and installed with a hammer, but should be pressed in with a press. Because the pressure of the miniature size needle bearing is uneven when the hand hammer is hit, it is easy to cause local deformation of the outer ring of the needle roller bearing.

How to remove the miniature size needle bearing
Percussion
The percussive force is generally applied to the inner ring of the miniature size needle bearing. The percussive force of the shielding machine room should not be applied to the rolling elements and cage of the miniature size needle bearing. This method is simple and easy, but it can easily damage the bearing. When the bearing is at the end of the shaft, Use a copper rod smaller than the inner diameter of the bearing or other soft metal materials to resist the shaft end, add a spacer under the bearing, and tap it with a hammer to remove it. In applying this method, attention should be paid to the proper placement of the cushion block and the correct focus point.

Thermal Demolition
Used to disassemble the tightly fitted miniature size needle bearing. First, pour the oil heated to about 100°C on the bearing to be dismantled with an oil pot, and after the bearing ring is heated and expand, the bearing can be pulled out with a puller.
Push method
Press the miniature size needle bearing with a press to work smoothly and reliably without damaging the machine and the bearing shielding machine room. The press has manual push, mechanical or hydraulic pressure.　
Note: The pressing point of the press should be on the center of the shaft and should not be biased.

Pull method
Using a special puller, when disassembling the miniature size needle bearing, the bearing will be slowly pulled out as long as the handle is rotated. When removing the outer ring of the bearing, the corners of the two legs of the puller should be opened outward; when removing the inner ring of the bearing, the two legs of the puller should be inward and stuck on the end surface of the inner ring of the bearing.

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