Find weakness,breakthrough bearing industry

Recent years, high speed bearing Rail, automobile, ship loader bearing and engineering machine industry of China is  rapidly developing. as the industry foundation  accessory equipment demand has increased dramatically, bearing opened  huge market demand space of China bearing industry.

The current bearing  produced in China and world industrial powers of production, where still exsits a  certain  gap .It mainly displays among the high technology, high precision bearing , high value added products the proportion of low, the stability of the product needs to be further improved and improvement.
   

Common sense of Ferris wheel

The Ferris wheel bearing , a structure composed of a rotating vertical wheel multi passenger component, in such a way, the rotation of the wheels on the edge, they remain upright, usually by gravity.

  Some of the largest modern mobile crane bearing is arranged on the rim, the electric motor rotate independently, upright every car. These wheels are sometimes referred to as observation wheels, whose cars are called capsule, however these alternative name, sometimes used with conventional gravity type vehicle wheel.

  The first Ferris wheel was built by George Washington gale Ferris, as small as, signs in the 1893 Chicago World Expo Kolumb. Ferris round of the term collectively referred to as all this structure, this is the type of now rides on national exhibition in the most common American.

Crane bearing and the ship crane bearing technical characteristics comparison

Slewing bearing is bearing the heavy industry is extremely important, diameter ranging from 10cm to 10 m, almost all of the large equipment to do reciprocating circular motion.

• Wind turbine slewing bearing

  Technical features: the yaw bearing is installed on the connecting part of the tower and cabin,variable paddle bearing installed in the root and the hub of each blade connecting parts. Each wind generator with a set of yaw bearing and three sets of variable pitch bearings. Yaw, pitch bearingmaterials selected 42CrMo, heat treatment using whole quenching and tempering treatment, the raceway surface quenching. The stress situation of yaw, pitch bearing complex, but also bear theshock and vibration is relatively large, therefore, requirements of bearing can bear the impact, but also can bear larger ship loader bearing.

  Wind turbine host life requirement of 20 years, the cost of installation and bearing large, therefore asked the yaw, pitch bearing life to reach 20 years. Bearing ring matrix hardness is 240-280HB,able to withstand shock and plastic deformation does not occur at the same time, the racewaysurface quenching hardness reaches 55-62HRC, which can increase the contact fatigue life, so as to ensure the long life of use requirements of bearing.

• The ship crane slewing bearing

The crane load bearing requirements of large, flexible rotation, relatively high speed, rotation of 270 degrees, the action to be fast, so the selection of internal tooth, double row ball slewing bearings. Crane bearing and the ship crane bearing technical characteristics comparison

•  Offshore platform crane bearing

According to the requirement of the bearing capacity of different, offshore platform crane often use four point contact ball slewing and the three row roller slewing bearing inner tooth.

Slewing bearing used in the offshore platform crane requires special material, the mechanical properties of the material to be able to ensure the safety coefficient of limit load, forging samplingCharpy impact experiment can achieve the average value of 42 J@-20 degrees C or 27J @ -40 C.Bearing finished product to Norske Veritas certification CCS.

How to identify and domestic bearings Bearing

A look at the packaging
The packaging is clear: Under normal circumstances, are factory brand has its own dedicated designers external packaging design, production conditions and arrangements for clearance of the factory production of production, and therefore in terms of packaging lines to color are very clear and unambiguous .

2 Look bearings and odor

Seal word is clear: in the spherical ball bearings body will be printed with the word brand, label and so on. Font is very small, but most are factory produced using Seal technology, but without the heat treatment prior to the conduct embossing, so the font may be small, but a deep concave, very clear. The counterfeit products not only fuzzy fonts, due to printing technology rough, font floating on the surface, some of them can be easily wiped off by hand. Are there muddy surface traces of oil: It should pay particular attention to when buying imported bearings. It is easy to leave the country due to the current anti-rust when technology is not particularly home, so crossed roller bearings body rust treatment thick traces of oil, in our hands sticky sticky thick, while on foreign imported bearings almost invisible the traces of anti-rust oil, experts say it touches particularly attentive bearing smells kind of taste, certainly under the anti-rust oil, but do not see it. Chamfering is uniform: the so-called bearing chamfer, which is the junction of the transverse plane and the vertical plane, bearing counterfeit production technology due to restrictions in parts of the corners of the handle was unsatisfactory.
3 Sound

Is there a hybrid ring: left hand holding the taper bearing sleeve body, right hand to rotate toggle coat, listen to whether hybrid ring. Because most of the counterfeit products production conditions behind, completely hand-workshop-style operations in the production process will inevitably be mixed into the sand of a class of impurities, hidden in the angular contact ball bearing body, so the rotation will be issued hybrid ring. This is strictly enforced and between production standards, and with the operation of the machine are factory brand the biggest difference. If you really can not tell the sound check on the use of sound measuring device for the operation of rolling bearings of the size and sound quality, bearing even a slight peeling damage, abnormal tone and irregular tone will be issued with a sound measuring device able to distinguish

Pay attention to the use of tapered roller bearing specification to ensure its service life

The rapid development in modern society, all kinds of bearing products in the industry played a huge role, tapered roller bearing as a bearing products widely used, demand in the market is very large, our company has used the most advanced production technology to create a circular cone ball and roller combined bearing‍ with high quality, welcome everyone to come to our company to consult the purchase.

You must when using tapered roller bearings, according to the norms of operation, we will try to understand specification about its use.

1, tapered roller bearings when not in use must be properly preserved, as far as possible is placed in the original packaging, avoid contact with moist air.

2, in the assembly of thin section bearing‍, as much as possible to ensure the surrounding environment clean, reduce dust assembly environment, so as to avoid the debris into the tapered roller bearings, affect its service life.

When 3, the use of tapered roller bearings to carry out effective installation on the installation process should focus on the attention with the size of the various parts, check regularly, ensure the normal operation of the use of tapered roller bearing.

Use 4, daily, pay attention to the lubrication of tapered roller bearings, regularly to detect, guarantee the service life.‍

Installation thrust bearings loose ring

Thrust bearing assembly major axial load, its wide range of applications. Although the swing bearing installation operation is relatively simple, but the actual service is still often an error occurs, the tight and loose ring ring bearing installation location that is incorrect, the results of the miniature ball bearings out of action, the journal soon be worn. Figure 1 is a clamping ring mounted on the end surface of the stationary member, i.e., the error assembling. Tight inner ring and the journal for transition fit to drive when the shaft rotates tight ring, and the end surface friction with the stationary element, axial forces in the subject (Fx), it will appear larger than the inner diameter of the friction torque with the drag torque, resulting in tight ring and the shaft with face mandatory rotation, increased wear journal.
Therefore, the thrust ball bearing installation should note the following.
(1) distinguish between the bearing ring and tighten loose ring (according to the size of the judgment bearing diameter, pore size difference O.1 ~ O.5mm).
(2) to distinguish between stationary member institutions (ie moving parts does not occur, mainly refers to the assembly).
(3) No matter what the circumstances, the loose double direction thrust ball bearing  ring should always be against the end face of the stationary member.

A cylindrical bearing installation space

Tight fit of the bearing inner ring and the shaft, the outer ring bearing hole is relatively loose fit of the non-separation of bearings installed, can press the bearings installed in the shaft, and the shaft bearings mounted together along with the bearing hole inside, if the bearing is small, can also be used a metal hammer tap softer ferrule end face is forced into the bearing, but the striking force to be evenly distributed in the bearing rings.
Bearing outer ring and the bearing hole is a tight fit, while the inner ring and the shaft is relatively loose fit can be installed first day of the shaft bearing.
Bearing ring and shaft or housing bore are a tight fit when applied to install a special set of barrels while the rotary bearing pressed onto the shaft or bearing housing.
Separate bearing installation due to inner and outer rings, respectively, can be easily mounted to the shaft or rolling mill bearing housing, then that should be noted is that the already installed inner shaft insert has been installed when the outer ring of the bearing box try to keep it concentric to prevent abrasions rolling elements and raceways.
When the tomb bearing large scale, by the installation of days required for large or heavy duty bearings work interference with the use of larger and therefore have difficulty when cold installed, you will need to pre-heat the bearing inner ring or bearing after installation. When installing hot, the heating temperature should be strictly controlled. When heating slewing ring bearings, the maximum heating temperature should not exceed 1200C, should generally be in the 80 ~ 1000C. Bearings with shields or seals can not be heated, otherwise it will cause the loss of lubricant. Beauty can be electric induction heating oil bath heating methods.

Bearing rings precision cold rolling technology

Precision cold rolling technology is at room temperature, the ring rotational parts using extrusion and then give a cold plastic deformation method of forming the finished piece. Precision cold rolling allows workpiece size, shape, close to the theoretical maximum value of the finished piece. Its advantages are:
1 can significantly improve material utilization and processing efficiency. Compared with the traditional way of turning, precision cold rolling process allows the material saving rate increased by 10% to 15%, in order to achieve the radar bearing rings of cutting, reducing processing costs.
2. You can improve product quality. As a result of rolling manner, the internal parts of the metal flow lines continuous and complete, the metal grains more uniform and smaller, more dense tissue, so the strength of the parts can be improved. Meanwhile, due to the presence of surface residual stress finished parts, but also to the deformation after heat treatment of small parts.
3. You can save energy, improve the working environment. Compared to die, precision rolling equipment needed smaller tonnage, significantly reduces noise during processing, energy-saving effect. Compared with the turning blank, the noise, the dust is small.
When rolling a workpiece, the workpiece rotation drive roller wheel, mandrel under driven support wheel is fixedly connected with the feeding means pressing the workpiece, in order to achieve rolling of the workpiece. From the stress state of the workpiece, the forming conditions are satisfied: the horizontal direction of the work force required and the feed direction of the force exerted by the equilibrium, which is a necessary condition for a stable deformation; the force of the workpiece in the vertical direction must be greater than equal to deformation of the work arising from the introduction of force, which is to continue rolling conditions. These two forces are supported by wheels or rollers contact with the workpiece core arc normal force in the horizontal and vertical component. When the feed amount sufficient to ensure that the support wheels of plastic deformation throughout the thickness of the workpiece, deformation effectively. Moreover, depending on the amount of feed rollers wheel drive power, thrust thin bearings wheels, rolling wheels and a radius of curvature of the core roll. Feed rate determines the size of the core support wheels or rollers in contact with the workpiece length of the arc, corresponding to the deformation of the workpiece is produced by normal deformation force, the longer the contact arc, the greater the deformation force.
Due to rolling wheel, the radius of curvature of the inner and outer circle of the mandrel and the workpiece is different, every feed in and outside the workpiece deformation is not equal. The deformation of the workpiece will be greater than the outer deformation of the inner circle, as the rolling process is carried out, the difference between the amount of deformation of the inner and outer circle will decrease. Roundness of cylindrical stick used to control the workpiece. In the rolling process workpiece roundness always stick close to the cylindrical workpiece, with increasing diameter of the workpiece while back, and provides a constant full circle moment. Roundness of the stick but also to ensure the smooth adoption of the workpiece rolling process, effectively reducing the rolling vibration, thus extending the life of the mold and machine tool slewing bearings.
Currently, foreign fine rolling equipment mainly Germany BAD DUBEN of URAW series and Japanese KYOEI company CRF and TCR series. They represent the two techniques: BAD DUBEN with vertical layout, electro-hydraulic position servo control system to improve the accuracy of rolling, while KYOEI company uses a horizontal layout, rough rolling and the whole diameter of the workpiece to improve the combination of the workpiece dimensional accuracy.

After the installation of precision precision bearings

1. improve the accuracy of Law
After the bearings installed in the host, such as measuring spindle radial runout, the measured values can be found in each of its turn has some changes; continuous measurements, can be found after a certain number of revolutions, the repetition of this change will be approximately appears. Indicators to measure the extent of this change for the precision rotation cycle, approximately repeated changes in the number of revolutions required for precision rotation cycle representative "quasi-periodic" magnitude of change in the amplitude of the quasi-periodic big difference is the precision rotation cycle .
If properly pre-load on the spindle, the speed gradually increased to nearly the speed of work to implement the "run-in" effect of the bearing can improve the accuracy of spindle rotation cycle.
2. A method for improving the accuracy of dental bearing
Precision instruments factory trial, spindle 6202 / P2-bearing and its accuracy still can not meet the requirements, and after making the bold journal on which to replace the inner ring raceways and balls were waxy dense measurements to size each set of three tablets, each taking the ball close to the interval of 120 ° apart, due to the reduction of a heavy machined surface, but with a weight reduction of the surface, while improving the rigidity of the shaft-bearing system, and the maximum and minimum three tablets three equally spaced ball close grain, but also improves the accuracy of the axis of rotation, so the instrument meets the accuracy requirements.
3. Install a comprehensive calibration method precision
After the angular contact ball bearing manufacturer into the spindle mounting accuracy of calibration sequence is as follows (with a shaft diameter of 60 100mm lathe, for example?):
(1) Measure the shaft and the slewing bearing hole size to determine with precision bearings, with the following requirements:
Take the inner ring and the shaft interference fit, the amount of interference 0 ~ + 4μm (at light load, when high precision is 0); the outer ring and the bearing hole to take a clearance fit, clearance volume 0 ~ + 6μm (but at the free end of the bearing when using angular contact ball bearings, but also increase the gap); the shaft and housing bore surface roundness error 2μm or less parallel to the end face of the bearing cage used in 2μm or less, the external end face of the inner shaft shoulder end beating in 2μm or less; retaining shoulder of the housing bore axis beating 4μm below; cover the face before the end of the axis of the spindle runout at 4μm below.
(2) the fixed end of the front bearing mounted on the shaft
After the bearings were cleaned thoroughly washed with clean kerosene, grease lubrication, the first containing 3% to 5% of the grease into the bearing organic solvents for degreasing, and then quantitative grease gun oil filled bearings (accounting bearing space volume of 10% to 15%); heating bearings make heating 20 ~ 30 ℃, oil press the bearing into the shaft; the tight sets against the shaft and bearing a suitable pressure against the end face axially the spring balance tape volumes on the bearing outer ring, the pre-load starting torque measuring method prescribed check whether a substantial change (even if the bearings are correct, but the fit or maintain deformation frame, preload there; positioning change may be).
(3) the bearing? Shaft assembly into the housing bore
Heated seat hole so heated 20 ~ 30 ℃, with continuous gentle pressure on the bearing shaft assembly into the housing bore;? Before adjusting cover, tighten the amount of the front cover of 0.02 ~ 0.05μm, to the outer face of the bearing housing benchmark indicator of the conflict in the journal header surface, the axis of rotation measured beating error 10μm following requirements; the dial gauge positioned on the shaft, the first table inconsistent backseat hole surface, the axis of rotation front and rear seat to measure the thrust roller bearing bore concentricity.
(4) the free end of the bearing may be selectively placed in a position offset bias, is mounted to the support position after the bearing, as much as possible to offset the roundness and concentricity deviation deviation between each other.
4. tapered bore double row cylindrical roller bearings installed
When installing NN3000K series tapered bore double row cylindrical roller bearings, must pay attention to the shaft bearing bore and taper fit properly in the case of the production of less coloring method available contact check, but in the production of large quantities of , preferably with a precision taper gauge calibration.
In the bearing mounted on a tapered shaft, the inner ring should be transferred to the appropriate position in the axial direction, so that the radial clearance is close to zero.