Needle bearings are roller bearings with cylindrical rollers that are thin and long relative to their diameter. Such rollers are called needle rollers. Although it has a small cross-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 length of the roller), so The radial structure is compact, and its inner diameter size and load capacity are the same as other types of bearings, and its outer diameter is the smallest, especially suitable for support structures with limited radial installation dimensions.

Classification:

In addition to those listed in the catalog, bearings that can be used for general engineering, such as:

(1) Open drawn cup needle roller bearings

(2) Closed drawn cup needle roller bearings

(3) Needle roller bearings with an inner ring

(4) Needle roller bearings without inner ring/needle roller bearings without inner ring and without cage

(5) Needle roller bearings with and without cages

Installation method

Install full complement needle roller bearings, usually using auxiliary sleeves. At this time, the auxiliary roller or the auxiliary sleeve supports the needle roller so that the needle roller does not fall out, and the journal lifts the needle roller with its own chamfer. As the needle bearing slowly moves inward on the journal, the auxiliary roller Or the auxiliary sleeve will slowly withdraw until it is installed to the working position. The outer diameter of the auxiliary roller and the auxiliary sleeve should be 0.1-0.3mm smaller than the shaft diameter. When installing, first coat the inner surface of the outer ring of the bearing with grease, and place the needle rollers close to the inner surface (there should be a gap when putting in the last needle roller), and then put the auxiliary roller instead of the journal or the inner ring of the bearing Or the auxiliary sleeve is pushed into the hole of the outer ring, and its end face is aligned with the end face of the installation shaft or the end face of the inner ring of the bearing installed on the shaft, and then tapped with a press or a hand hammer to apply pressure. Needle roller bearings 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, and inserted 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 the needle roller is installed, use the working shaft to push out the auxiliary sleeve. For needle roller bearings without inner ring or outer ring, when installing, first apply a thin layer of grease to the rolling surface of the shaft or housing hole, and then stick the needle rollers to the grease on the installation part in turn. There should be a gap when pasting the last needle roller, and the size of the gap should be 0.5mm on the circumference of the needle roller bearing. Do not squeeze the last roller into it, or install one less needle, because the bearing will be stuck and unable to rotate when it is squeezed hard; Twisted and snapped. For needle roller bearings with only stamped outer rings, since the outer ring wall is very thin, the needle roller bearings without needle rollers should be installed by tapping with a hand hammer, and should be pressed in with a press. Because when the hand hammer hits, the pressure is uneven, and it is easy to cause local deformation of the outer ring of the needle roller bearing.