Needle roller bearings consist of a ring, needle rollers, and a cage. In terms of the same load-bearing capacity, the cross-sectional size of needle roller bearings is the smallest. Suitable for situations with high speed, large load, and small bearing space. Needle roller bearings, also known as needle rollers, have a slender shape. The shapes of the two ends of the rolling needle include round head, pointed cone, and concave arc head.

The commonly used needle roller bearings have the following structural types:

1. Needle roller bearings with stamped outer rings:

This type of bearing has two types: perforated and sealed. The stamped outer ring needle roller bearing does not have an inner ring, and the needle roller directly contacts the surface of the shaft. Therefore, the machining accuracy and heat treatment hardness of the shaft should be the same as that of the bearing inner ring. Stamped outer ring needle roller bearings with retaining frames are suitable for high-speed and heavy-duty applications, and are commonly used in machine tools, automotive, motorcycle transmissions, or textile machinery. Stamped ring needle roller bearings without retaining frames are suitable for swing working conditions under heavy loads due to being filled with needle rollers. Such as the frame of an airplane, the shaft end of a missile's main wing, etc.

2. Solid ring needle roller bearing:

The commonly used solid ring needle roller bearings are NA type and RNA type. Solid ring needle roller bearings are commonly used in machine tools and automotive transmissions. Their advantages include small radial cross-sectional dimensions and high radial load capacity. Standard solid ring needle roller bearings have retainers, so the speed is high and can meet the requirements of machine tools and automotive transmissions.

3. Combination needle roller bearing:

Combination needle roller bearing is a combination of solid ring needle roller bearing, ball bearing, and roller bearing.

4. Needle roller and holder assembly:

Needle roller and cage components are actually needle roller bearings without rings, which are commonly used for the large and small ends of connecting rods in gearboxes, motorcycles, and automobiles. Due to the increase in temperature inside the cylinder, the bearings need to withstand high temperatures