Deck crane slew bearing rocking tests

A number of incidents have occurred recently involving failure of the slew bearings of ships’cargo deck cranes, resulting in crane losses and serious injury to personnel. These failures have been caused by undetected excessive wear in the slew bearings.Rocking tests deck crane bearing manufacturers generally recommend that ‘rocking tests’ are carried out every six months in accordance with their instructions, and that the results are recorded and monitored in order to ensure the wear tolerances remain within the limits permitted by the designers.Cranes which are particularly at risk are those with single ball race slew bearings. Cranes fitted with this type of slew bearing must have rocking tests carried out, in accordance with manufacturer’s instructions, to determine that the amount of wear in the bearing races is within permitted limits.

Super Precision Bearings & high precision bearings

Machine tools and other precision applications bearings need to have excellent performance. It includes an extensive speed capacity to maintain a high rotational accuracy, high system rigidity, low heat generation, low noise, low vibration, and so on. Rolling general industrial applications can only meet part of the requirements. Therefore, our company to create a full range of high precision bearings. Super precision bearings can help further optimize performance parameters of their equipment and applications OEMs and end customers. And depending on the bearing series and applications, with the advantage different, but always include high speed and carrying capacity, bearing a long service life, maintenance intervals long time, low energy consumption.
Typical applications include super precision bearings:
1.Metal cutting and woodworking machinery Spindle
2.Other mechanical spindles (such as dynamic balancing machine)
3.High speed rolling bearing machine
4.Printing Equipment
5.Precision Ball
6.Machining Center
7.High speed turbocharger
8.Vacuum pump
9.Racing
10.Ship anti-rolling gyro system
11.Mechanical Components Semiconductor Industry

The relative movement between the shaft and the bearing sliding bearings

The relative movement between the shaft and the bearing sliding bearings, linear plain bearings called. Bearing basic structure is divided into the bush and the journal. Rolling bearing on the most essential difference and that a point contact, one face Contacts, will have advantages and disadvantages in nature. Plain bearings can be used lubricating oil, grease, water, lubrication, etc..
Compared with the rolling bearings, sliding bearings advantages: 1, high carrying capacity; large contact area causes; 2, simple structure, easy manufacturing, processing, demolition; 3, good impact resistance and good vibration performance, smooth operation, high rotational accuracy. Disadvantages: 1, the maintenance complex, demanding lubrication conditions; 2 boundary lubricated bearings, friction and wear bigger. (This is also the disadvantage of a large contact area)

Compared with plain bearings, roller bearings.

Compared with plain bearings, roller bearings.What is the difference between the two? It is what strengths and weaknesses?Bearing in accordance with the different nature of friction was divided into Rolling and plain bearings, it is apparent definitely better than plain bearings Rolling friction is small, start fast, high efficiency, which is the advantage of rolling bearings. Compared with plain bearings,Rolling radial dimension is large, poor damping capacity, high speed, low life, the sound is large, which is its shortcoming. The rolling elements are not limited to the shape of the ball, as well as cylindrical roller, tapered roller, shares of the roller, and needle. According to different rolling elements, bearing into ball bearings and roller bearings. In other conditions, flexible operation roller bearings for high speed, but relatively low carrying capacity; roller bearings running better than ball bearings and flexible, but high load carrying capacity, strong impact.

Cranes bearing and marine gram make hanging bearing and other more technical features

4 m harbor cranes usually use internal or external gear teeth diameter three row roller slewing bearing to withstand high overturning moment. All kinds of cranes bearing, bucket wheel bearing, marine cranes and crane bearing usher bearing repair peak, the failure rate frequently, in order to save costs and improve the utilization of the bearing, slewing bearing repair, repair of wheel bearings business growing. About deck crane bearing appears sound, sometimes accompanied by vibrations, which may be for the following reasons:
1. Bearing heavy loss, fragmentation caused by the ball portion;
2. Ball isolation block (nylon or metal material) crushed, causing blockage;
3. bearing channel layer fatigue hardness loss, pitting, pits, pitting, bearing operation is not flexible;
4. bearing long-term stress and deformation, ovality tolerance
5. seal failure, bearing lubrication channel not long, into the channel of debris blockage.

wind power bearing technical characteristics

wind power bearing technical characteristics: a yaw bearing mounted on a tower and the cockpit of the connecting portion, the pitch bearing mounted in the hub and connected to the root portion of each blade. Each wind turbine with a yaw bearing and three pitch bearings. Yaw, pitch bearing rings of material selection 42CrMo, heat treatment with the overall quenching, raceway surface hardening. Yaw, pitch bearing force situation is complex, and to withstand shock and vibration is relatively large, and therefore, requires both bearings to withstand the impact, and can bear a greater load. Wind turbines host life requirements of 20 years, a larger bearing installation costs, thus requiring yaw, pitch bearing life expectancy should reach 20 years. Bearing rings substrate hardness 240-280HB, able to withstand impact without plastic deformation, while the raceway surface hardening hardness 55-62HRC, increase contact fatigue life, thus ensuring long life bearing requirements. Wind power bearing parts cleaning because cross, three row roller slewing bearing inner ring special technology: To prevent cross, after three-row roller slewing bearing inner heat deformation, must be working in pairs when turning, the race back to back processing, do not be cut off before the heat treatment, heat, cut molding.

Rotary classification and application of Slewing bearings

Slewing bearings are extremely important in today's heavy industry large bearing diameter ranging from 10cm to 10 meters, almost all of the large equipment reciprocating circular motion is essential, it is able to withstand a large-scale integrated load bearing, can bear large axial, radial load and overturning moment. Slewing ring bearings are generally installed with a hole, the internal gear or the external gear, lubricants holes and sealing devices, which enable the host compact design, the guide is simple, easy to maintain. Slewing bearings commonly used classification of a single row of five four-point angular contact ball slewing bearings, Single row crossed roller slewing bearing, double-row ball slewing bearing, three-row roller combination slewing bearings and slewing bearings light. Slewing ring bearings are widely used for lifting machinery, mining machinery, construction machinery, port machinery, ship equipment and high-precision radar and missile launchers and other mechanical equipment of large rotary device. But also according to the user's specific requirements and design, development and production of special structures slewing ring bearings.

Analysis of wind power bearing load zones

In roller bearings generally run only part withstand the load, and the area where this part of the roller bearing area we call the bearing. The bearing load size, running clearance will have an impact on the size of the load zone. If the bearing area is too small, the roller in the actual operation is prone to slippage. For wind power gear box, if the spindle is designed with double bearing support program, then theoretically only torque is transmitted to the gearbox. In this case, through simple mechanical analysis, we find that the planet carrier supporting the bearing load is relatively small, so the bearing area of the bearing often relatively small, roller prone to slippage. In the wind turbine gearbox design carrier support bearings generally use two single row tapered roller bearings or cylindrical bearings two full programs. We can appropriately preloaded tapered roller bearings or cylindrical roller bearings reduce clearance methods to improve the bearing area.

Wheel bearing performance

Developed on the basis of the hub bearing unit is the standard angular contact ball bearings and tapered roller bearings on, it will be two sets of bearings as a whole, with good assembly performance, you can omit clearance adjustment, light weight, compact, load capacity large, sealed bearings can be pre-loaded for the grease, hub seals and maintenance, etc. are omitted from the external wheel, have been widely used in cars, the truck also has a tendency to gradually expand the application. Car wheel bearings are used in pairs in the past most of single row tapered roller or ball bearings.