Characteristics And Maintenance Of Cylindrical Roller Bearings

Time：2020.05.08  Source：Roller Bearings Suppliers

The internal structure of the cylindrical roller bearing adopts rollers arranged in parallel, with spacers or spacers installed between the rollers, which can prevent the tilting of the rollers or the friction between the rollers, which effectively prevents the increase of the rotating torque.

Introduction of cylindrical roller bearings

Cylindrical rollers and raceways are linear contact bearings. Load capacity, mainly bear radial load. The friction between the rolling element and the ferrule is small, suitable for high-speed rotation. According to the presence or absence of ribs, it can be divided into NU, NJ, NUP, N, NF and other single-row cylindrical roller bearings, and NNU, NN and other double-row cylindrical roller bearings. The bearing has a separable inner ring and outer ring structure.

Cylindrical roller bearings with no ribs on the inner or outer ring can move axially relative to the inner and outer rings, so they can be used as free-end bearings. Cylindrical roller bearings with double ribs on one side of the inner ring and outer ring and a single rib on the other side of the ring can withstand a certain degree of axial load in one direction. Generally, a steel stamping cage or a copper alloy solid cage is used. But some also use polyamide shaped cages.

Characteristics of cylindrical roller bearings

1. The roller and the raceway are in line contact or underline contact. The radial load capacity is large, which is suitable for bearing heavy loads and impact loads.

2. The friction coefficient is small, suitable for high speed, and the limit speed is close to the deep groove ball bearing.

3. The N-type and NU-type can move axially, can adapt to the change of the relative position of the shaft and the casing caused by thermal expansion or installation error, and can be used as a free end support.

4. The processing requirements of the shaft or the seat hole are relatively high. The relative deflection of the outer ring axis after the bearing is installed must be strictly controlled to avoid contact stress concentration.

5. The inner or outer ring can be separated for easy installation and removal.

Product characteristics of cylindrical roller bearings

Cylindrical rollers are in line contact with the raceway and have a large radial load capacity. It is not only suitable for bearing heavy load and impact load, but also suitable for high-speed rotation.

Cylindrical roller bearing raceways and rolling elements are geometrically shaped. After the improved design, it has higher bearing capacity. The new structural design of the rib and roller end face not only improves the axial bearing capacity of the bearing, but also improves the lubrication conditions of the contact area between the roller end face and the rib edge. Bearing performance.

Types of cylindrical roller bearings

Cylindrical roller bearings are separate bearings, which are very convenient for installation and disassembly. Cylindrical roller bearings can withstand large radial loads and are suitable for use in high-speed operations.

This type of bearing allows a small angular error (inclination) between the axis of the inner ring and the axis of the outer ring, only 2′—4 ′. Therefore, the machining accuracy of the shaft and the bearing seat is relatively high. Otherwise, uneven load or stress concentration may easily occur at the contact portion of the raceway. However, the correction of roller or raceway contact bus can reduce the occurrence of stress concentration.

Cylindrical roller bearings can be divided into single-row, double-row and multi-row cylindrical roller bearings and other structures according to the number of rows of rolling elements installed. Bearings of different structures are also expressed in the design of the position of the rib. Among the commonly used cylindrical roller bearings are the following forms:

Single-row cylindrical roller bearings: Single-row cylindrical roller bearings are separable bearings, which are easy to install and remove. Both rings can use tight fit, and the contact line between the modified roller and the raceway can reduce stress concentration.

Double-row cylindrical roller bearings : Double-row cylindrical roller bearings are swimming bearings, and their separability makes installation and disassembly very convenient. Both ferrules can be fitted tightly. Double row cylindrical roller bearings are almost not allowed to have a tilt angle.

Application of cylindrical roller bearings

Large and medium-sized motors, rolling stock, machine tool spindles, internal combustion engines, generators, gas turbines, reduction gearboxes, steel rolling mills, vibrating screens, and lifting and transportation machinery.

Maintenance of cylindrical roller bearings

Bearing disassembly

The disassembly of the bearing is a regular maintenance, carried out when the bearing is replaced. After disassembly, if you continue to use it, or if you need to check the condition of the bearing, the disassembly should be carried out as carefully as when it was installed. Be careful not to damage the parts of the bearing, especially the disassembly of the interference fit bearing, which is difficult to operate.

It is also very important to design and produce disassembly tools as needed. When disassembling, study the disassembling method, sequence, and survey the matching conditions of the bearing according to the drawings to obtain foolproof operation.

Disassembly of the outer ring The outer ring of the interference fit is provided with several screws for squeezing the screw of the outer ring on the circumference of the housing in advance, and the screw is evenly tightened on one side while being removed. These screw holes are usually covered with blind plugs, tapered roller bearings, and other separate bearings. Several cuts are provided in the housing to block the shoulders. Use pads to disassemble with a press or gently tap to disassemble. Need bearing WSBC 22332CC/W33, click here.

It is easiest to remove the inner ring with a press. At this time, pay attention to the inner ring to withstand its pulling force. Furthermore, the pull-out clips shown are mostly used, no matter which type of clips, they must be firmly stuck on the side of the inner ring. To this end, it is necessary to consider the size of the shaft shoulder, or study the processing of the upper groove at the shoulder, in order to use the pulling fixture.

The hydraulic method is used to disassemble the inner ring of large bearings. Oil pressure is applied through the oil hole provided in the bearing to make it easy to pull. Bearings with large widths are used in combination with the drawing method for disassembly.

The inner heating of cylindrical roller bearings can be dismantled by induction heating. The method of heating the local area in a short time to make the inner ring expand and pull. Where a large number of such bearing inner rings need to be installed, the induction heating method is also used.