Two Installation Methods of Cylindrical Roller Bearings

Two Installation Methods of Cylindrical Roller Bearings

Cylindrical roller bearings are bearings with line contact between the cylindrical rollers and the raceways. They have a large load capacity and mainly bear radial loads. The friction between the rolling elements and the rib of the ring is small, making them suitable for high-speed rotation. According to whether the rings have ribs or not, they can be classified into single-row cylindrical roller bearings such as NU, NJ, NUP, N, NF, etc., and double-row cylindrical roller bearings such as NNU, NN, etc. This kind of bearing has a separable structure for the inner ring and the outer ring. Common models include: NJ2216ECM/C3, INA SL1818/500-E, INA LSL192334-TB, and so on.

For cylindrical roller bearings without ribs on the inner ring or the outer ring, the inner ring and the outer ring can move axially relative to each other, so they can be used as free-end bearings. Cylindrical roller bearings with double ribs on one side of the inner ring and the outer ring and a single rib on the ring of the other side can bear a certain degree of axial load in one direction. Generally, steel plate stamping cages or solid cages made of copper alloy by turning are used. However, some also use polyamide formed cages.

There are commonly two correct installation methods for cylindrical roller bearings: one is cold installation, and the other is hot installation.

1. Cold Installation

When installing small bearings with a not-too-tight fit, a sleeve can be used, and the bearing can be gently tapped into place by hammering. When tapping, the force should act as evenly as possible on the ring of the cylindrical roller bearing to prevent the bearing from tilting or skewing. Most cylindrical roller bearings are installed using the press-in method. If the inner and outer rings of the cylindrical roller bearing are to be installed onto the shaft and the bearing housing simultaneously, it is necessary to ensure that the same pressure acts on the inner and outer rings at the same time, and the contact surface with the installation tool must be on the same plane.

2. Hot Installation

Under normal circumstances, for the installation of larger bearings, it is impossible without heating the bearing or the bearing housing, because as the size increases, more force is required during installation. The temperature difference between the cylindrical roller bearing ring and the shaft or the bearing housing required for hot installation mainly depends on the interference amount and the diameter of the bearing fit. The heating temperature of open bearings should not exceed 120°C. It is not recommended to heat cylindrical roller bearings with seals and dust covers to above 80°C (it should be ensured that the temperature does not exceed the temperature allowed by the seals and the lubricating grease). When heating cylindrical roller bearings, they should be heated evenly, and there should never be a situation of local overheating. 

By following these steps, you can easily purchase the right slewing bearing for your excavator, ensuring smooth operations and minimal downtime.