1、 Production machinery

Machine tool bearings

As the basic accessory of machine tools, the performance of spindle bearings directly affects the speed, rotational accuracy, rigidity, vibration resistance, cutting performance, noise, temperature rise, and thermal deformation of the machine tool, thereby affecting the accuracy and surface quality of the processed parts. Therefore, high-performance machine tools must be equipped with high-performance bearings. Especially for high-speed precision CNC machine tool bearings. The accuracy of rolling bearings is generally divided into five levels: P0, P6, P5, P4, and P2. The accuracy of bearings used on precision machine tool spindles should be P5 or higher. For spindle supports of high-speed and high-precision machine tools such as CNC machines and machining centers, P4 or higher ultra precision bearings need to be selected.

Spindle bearings for machine tools typically include six structural types: deep groove ball bearings, angular contact ball bearings, cylindrical roller bearings, bidirectional thrust angular contact ball bearings, tapered roller bearings, and thrust bearings.

Printing machinery bearings

Printing machine bearings are used for the main drum of single sheet and web printing machines. Due to the complexity of application requirements, only a small portion of printing machinery bearings can be standardized. Therefore, printing machine bearings include numerous models and sizes. In addition to typical multi row, high-precision cylindrical roller bearings NN, NNU, N4N, N4U, it also includes floating bearing units with or without eccentric rings, positioning bearing units, polygonal bearings, linear and rotational bearing combination units, and tapered roller bearing units. There are two types of bearings: with and without seals. The journals at both ends of the drum can be cylindrical or conical in design.

Textile machinery bearings

In the process of spinning, weaving, finishing, or processing, modern textile machinery is highly automated and requires uninterrupted operation in high production without faults. The so-called "good bearings" mean low friction, high accuracy, zero clearance, easy installation, less maintenance, long service life, low noise, and high reliability. These leather belt wheels are easy to lubricate and have low moments of inertia. So, they can quickly reach the operating speed. In addition, these belt tensioning wheels can achieve continuous operation and low energy consumption in up to 600 alternating rotational movements per minute. These characteristics result in a significant increase in machine production while significantly reducing costs while obtaining uniform and high-quality fabrics.

Bearings in the food and packaging industry

Food production must be both economical and efficient. Usually it is an automated production process, and extreme operating conditions often occur. This requires a high level of security and reliability. The design of high-quality machine components suitable for continuous work is an essential element here. Durable and corrosion-resistant bearings, effective sealing and lifelong lubrication under most operating conditions, suitable for reliable uninterrupted operation.

Woodworking machinery bearings

In many cases, deep groove ball bearings can well meet the high-speed and relatively low load conditions of bearing arrangement in woodworking shapers. For very high speeds, spindle bearings are usually used.

2、 Power Transmission and Railways

Railway vehicle bearings

Railway rolling stock bearings refer to bearings used in locomotives and vehicles. The bearings on locomotives include various types such as axle box bearings, traction motor bearings, transmission system bearings, power unit bearings, and cooling system bearings. The bearings on vehicles are mainly axle box bearings. Short cylindrical roller bearings are commonly used on passenger car axle boxes, and tapered roller bearings are mainly used on freight car axle boxes. The variety, structure, and performance of vehicle bearings are basically similar to those of locomotive axle box bearings.

Gearbox bearings

Modern gearboxes can transmit high power in a very small space. This requires us to carefully choose high-performance rolling bearings. In addition to bearing capacity, the reasonable design, lubrication, and sealing of adjacent structures have also become prerequisites for reliable and economical bearing arrangements. In order to consider the impact of these factors on bearing life, an extended life calculation method needs to be used for analysis.

Due to different gearbox designs and gear meshing forms, almost all types of rolling bearings can be used in the power transmission industry.

The input shaft of cylindrical gear units is often supported by self-aligning roller bearings or tapered roller bearings. At particularly high speeds, a combination of cylindrical roller bearings to withstand radial forces and four point contact ball bearings to withstand axial forces is more suitable. For intermediate and output shafts, self-aligning roller bearings are usually used as floating arrangements.

In the bevel gear unit, a small axial guide clearance is required to ensure gear engagement. Axial adjustable or paired tapered roller bearings or angular contact ball bearings can be used.

The large axial force on the worm in the turbine unit can be transmitted through paired or adjustable tapered roller bearings. For worm gears, it is required that the meshing gears can be adjusted and have small axial clearance. Deep groove ball bearings or adjustable tapered roller bearings are often used.

The planetary gears in planetary gearboxes are generally supported by single or multi row cylindrical roller bearings, and in special cases, self-aligning roller bearings can be used. For smaller planetary gears, needles or rollers can be directly installed. In this way, the rolling element runs directly on the spindle of the planetary gear. In order to ensure the load-bearing capacity and working life of the planetary gear bearing arrangement, it is necessary to ensure that the hardness curve and surface quality of the raceway meet specific requirements.

Engineering machinery bearings

Among the numerous bearing arrangements in construction machinery, the bearing arrangement of the excitation shaft in vibration equipment requires special attention. Roller, compactor, vibration motor, vibration pile driver, and vibration plate compactor work through mechanical vibration. The excitation shaft and eccentric block operate at high speed.

Here, deep groove ball bearings (used for small vibration equipment), self-aligning roller bearings, and cylindrical roller bearings (N, NU designs) have all been successfully applied. In order to compensate for the deflection of the neutral axis, the rollers and inner race of cylindrical roller bearings are shaped according to a logarithmic curve. In this way, without affecting the lifespan, if greater centering ability is required, the cross-sectional shape needs to be modified.

Industrial forklift bearings

Many specially designed bearings are used on forklifts. Sensor bearings combine rolling bearing technology with modern sensor technology for transmission, control, and monitoring.

This ready-to-use system solution greatly reduces costs and provides excellent performance.

Wind turbine bearings

At present, the power level of wind turbines has exceeded 3MW. The bearing must be able to withstand medium to high loads and be suitable for swing and vibration conditions. Low friction standard rolling bearings are suitable for use in wind turbines. The bearings are installed in standard or special bearing housings. In special circumstances, special rolling bearings can also be used.

The rolling bearings used in wind turbines must meet high-quality requirements in many cases. The main bearing arrangement can be in the form of spindle bearing arrangement or hub bearing arrangement. There are successful examples of using self-aligning roller bearings, cylindrical roller bearings, or tapered roller bearings in the fixed/floating end bearing arrangement.

In the arrangement of wheel hub bearings, two tapered roller bearings can be adjusted to each other. Another solution is to use a paired tapered roller bearing as the fixed end and a cylindrical roller bearing as the floating end. For a single bearing design, multiple rows of rolling bearings should be selected to withstand both force and torque simultaneously.

3、 Heavy industry

Bearing layout in the steel industry

Usually, the bearing arrangement in steel mills needs to withstand extremely high loads, and in most cases, it works under high operating temperatures and severe environmental pollution conditions. Therefore, in addition to using standard rolling bearings, it is also necessary to use some special bearings that are suitable for these operating conditions.

The rolling bearings used in the converter not only need to support a large weight, but also withstand high impact loads. Split or integral large self-aligning roller bearings can meet these requirements.

The rotating arm on the ladle rotating equipment in the continuous casting production line is supported by large rolling bearings. Thrust aligning roller bearings are usually used to support weight, while cylindrical roller bearings are used to withstand overturning torque.

At the inner support point of the driven roller, split roller bearings are used. In order to prevent the shaft from being affected by high-temperature steel billets, iron oxide scales, and cooling water, the bearing seat needs to be water-cooled. The seal includes a disc seal box and a labyrinth seal. For non driven rollers or the outer support of driven rollers, integral bearings can be used. Sealed self-aligning roller bearings can reduce lubricant consumption and reduce environmental hazards.

In order to withstand the large radial load on the rolling mill, double row or four row cylindrical roller bearings are often used, and thrust deep groove ball bearings, angular contact ball bearings, double row tapered roller bearings, thrust tapered roller bearings, or thrust self-aligning roller bearings are also used as thrust bearings. If double row or four row tapered roller bearings are used, additional thrust bearings are usually not required.

Self aligning roller bearings are usually used in situations where axial guidance accuracy is not high and speed is low.

Multiple row tapered roller bearings with seals are commonly used for work rolls to reduce lubricant loss and environmental impact. The pressure spindle uses thrust tapered roller bearings, which require less adjustment force due to their low friction.

Single row cylindrical roller bearings and single row or double row angular contact ball bearings are commonly used in high-speed rolling mills on bar and wire production lines.

The transmission shaft of a heavy-duty rolling mill itself weighs a considerable amount. In previous designs, sliding bearings were generally used for support. Now, the use of specially designed split cylindrical roller bearings significantly reduces wear and lubricant consumption.

The gearbox of the rolling mill often uses self-aligning roller bearings. In the new design, the shaft is supported by double row cylindrical roller bearings as floating end bearings, while double row tapered roller bearings are arranged as fixed end bearings. This arrangement results in a relatively high positioning accuracy of the shaft in both radial and axial directions.

Split cylindrical roller bearings are often used on the crankshaft of the Pilger cold rolling mill. For the bearing arrangement on the working rolls of the Pilger cold rolling mill, self-aligning roller bearings with tapered holes and special internal structural design are often used. These self-aligning roller bearings can meet the application of the special load conditions of the Pilger cold rolling mill.

The arrangement of rolling bearings for multi roll cold rolling mills must ensure that the rolled plates have high surface quality and uniform thickness. Multi row cylindrical roller bearings or tapered roller bearings can be used as support roller bearings to meet these requirements.

Layout of bearings in the paper industry

Modern large paper machines extensively use various types and size series of rolling bearings. In order to avoid expensive downtime, the bearings used must have high operational reliability.

Different paper machines and internal components have different special requirements. Special attention should be paid to corrosion prevention for wet end bearings of paper machines, while the design of dry bearings must consider high temperature conditions. For the suction roller in the wet part, tapered or cylindrical hole self-aligning roller bearings with high operating accuracy are usually used.

When the outer ring of the bearing rotates, self-aligning roller bearings with lubrication holes on the inner ring are often used.

For extremely high speed operating conditions, it is necessary to install self-aligning roller bearings with high operating accuracy and large clearance groups.

The bearings used on the central rolling roller need to have angle adjustment ability and high load-bearing capacity, so self-aligning roller bearings are used.

To prevent splashing water from entering the bearings, a labyrinth seal with a complex structure is required in the wet end. The roll sleeve of the controllable medium high roller rotates around a fixed roll axis. The roller sleeve is supported by self-aligning roller bearings, which require higher operating accuracy and larger internal clearance, and the inner ring has lubrication holes.

Three ring bearings are sometimes used in driving rollers. The shaft is supported by the bearing inner race. The rotating middle ring transfers power to the roller sleeve.

The operating characteristics of the drying area are high working temperature and thermal expansion. Self aligning roller bearings are usually used as fixed end bearings. If the working width does not exceed 5m, self-aligning roller bearings can be used as floating bearings, which can compensate for changes in length caused by thermal expansion by axial movement within the bearing seat. For larger working widths, self-aligning double row cylindrical roller bearings should be preferred in typical bearing housings. The internal clearance of the self-aligning roller bearing increases to the C4 clearance group, while the radial clearance of the cylindrical roller bearing increases to the C5 clearance group.

For the drying guide roller, it is necessary to consider the significant impact of environmental high temperature on its length change. These bearings are connected to the circulating oil system of the drying cylinder. The hot embossing roller of the finished part is usually supported by self-aligning roller bearings. Due to its high operating temperature, bearings need to have large internal clearance, sometimes with tapered inner holes. Heat can be carried away by a large flow of oil. On large, high-speed paper machines, bearings with tapered inner rings should be directly installed on the tapered journal of the roller to ensure smoother operation. The self-aligning roller bearings commonly used here have an increased radial internal clearance of C3.

Composite deep groove ball bearings combined with steel rings and ceramic balls have good applications in high-speed stretching rolls. Due to the fact that the number of steel balls in these bearings is half that of ordinary bearings, the risk of slipping is reduced.

Layout of underground and open-pit mining equipment

Machines used for underground and open-pit mining require the completion of extremely challenging tasks.

The bearing arrangement of tunnel excavator drill bits requires high load-bearing capacity, usually using cylindrical roller bearings and self-aligning roller bearings. The overturning moment generated by weight and eccentric load during operation is supported by double row cylindrical roller bearings or self-aligning roller bearings. The drilling force is supported by thrust aligning roller bearings.

In large or compact excavators, the bearing arrangement at the drill bit is a ready-to-use unit. It includes a double row tapered roller bearing or a three ring thrust/radial cylindrical roller bearing with a crown gear. This bearing unit can withstand all load combinations including axial force, radial force, and overturning torque.

The force acting on the driving pinion of the tunnel excavator is completely supported by an aligning roller bearing and a cylindrical roller bearing. In material transportation and lifting equipment, the main demand is for standardized bearings of various types, sizes, and designs.

4、 Consumer goods industry

Rolling bearings appear almost everywhere around us: at home, in the office, and even in our leisure time. However, in most cases, bearings are almost unnoticed by people. Rolling bearings are used in household appliances, communication equipment, self-made tools, as well as electrical equipment such as sports equipment and medical equipment.

Household appliances usually require low noise and low vibration during operation. In order to achieve high cost-effectiveness of bearings, it is required to have a long service life and minimal maintenance. For small equipment, simple structure deep groove ball bearings with sealed pre filled grease can meet these requirements.