Slewing Bearings Suppliers Plant

1.The necessity of grinding teeth for slewing bearings

Regarding the slewing bearing or slewing ring bearing, no matter external or internal teeth, helical teeth, etc., the normal process level includes gear shaping, gear hobbing, and milling. According to the design standard, the gear accuracy is generally 9-grade or 10-grade teeth.

Here, the 9th grade teeth or the 10th grade teeth, the indicators under investigation are based on the design standard of the slewing bearing of JB/T10471, and you can also refer to JB/T2300. It mainly reflects the rotation accuracy, and the specific indicators are:
1. Number of cross teeth and length of common normal
2. Common normal deviation
3. Tooth jump (tooth jump of finished turntable bearing)
4. The tooth width, tooth thickness, tooth shape and tooth direction are generally not marked separately in the drawings.

In short, the values ​​of the 9-stage teeth or 10-stage teeth of the slewing bearing are in agreement in a pure sense. From the design concept, the common normal of the 7th grade and 8th grade teeth, the tooth jump also meets the design requirements.

However, the quenching of the tooth surface has a great influence on the accuracy level of the tooth surface, and it is generally one level backward.

This article talks about the necessity of grinding teeth and the technical indicators that can be achieved.
1. Improve meshing accuracy
2. Tooth jump 0.06-0.15mm
3. Tooth surface roughness Ra0.8
4. Reduce meshing noise
5. Reduce the wear intensity of the tooth surface
Therefore, if you want to reach this technical level, you must grind the teeth.

2.Design parameters to improve slewing bearing life and reliability

Slewing Bearings life

Under a certain load, the number of revolutions or hours that a bearing experiences before pitting occurs is called bearing life.

Due to the difference in manufacturing precision and material uniformity, even the same batch of bearings of the same material and size will have different lifespans when used under the same working conditions. If the statistical life is 1 unit, the longest relative life is 4 units, the shortest is 0.1-0.2 unit, and the ratio of the longest to the shortest life is 20-40 times.

In order to determine the standard of bearing life, the slewing bearings life and reliability are related.

Work on the following design factors:

1. Structure, choose three-row roller combination slewing bearing

2. Material, choose 42CrMo, electroslag remelting

3. Quenching and tempering hardness should be above HB280

4. High manufacturing precision

5. The height of the ferrule and the size of the roller should be matched

6. Tooth surface quenching

7. Protective measures, seals and dust baffles

8. Application of integral cage

3.What factors should be paid attention to when surveying and mapping high-precision slewing ring bearings

For surveying and mapping of high-precision slewing bearings, in addition to paying attention to the installation size, in the process of surveying and mapping most slewing bearings, we must grasp the necessary technical parameters to ensure that the surveying and mapping bearings are foolproof. So what parameters must be paid attention to? What preparations are needed for high-precision surveying and mapping points?

1. The outer dimensions of the slewing bearing are necessary

2. The gear parameters of the slewing bearing, the primary

3. The size of the mounting hole of the slewing bearing, including the number, position, size and type

4. Step size, lubricating oil hole, position, number, size, type of slewing bearing

5. Structural form, must be disassembled and viewed

6. Seal form, cage form and channel type

7. Working conditions, accuracy, horizontal, inclined and vertical use

4.What are the quality standards for large bearings of slewing ring

In short, if you have to distinguish from the selection, quality reliability and high standards of bearings, you can refer to the following:

1. Material

2. Heat treatment

3. Clearance, runout, tooth jump

4. Comprehensive indicators, roughness, grinding, depth of hardness layer, flaw detection

5. The reference life value of similar bearing operation

 

The quality inspection of slewing bearing bearings can be divided into axial clearance and radial clearance according to different detection methods. important items to check. From the perspective of bearing application, clearance is an important indicator for detection. Whether the bearing can obtain more satisfactory performance largely determines its radial clearance.

The specific tests are as follows: the high-frequency quenching hardness of the bearing surface should not be lower than 55HRC, the depth of the hardened layer should not be lower than 4mm, and the width of the soft belt should not be lower than 50mm. There are certain requirements for the quenching time and temperature of the support bearing for tempering processing. In general, it needs to be quenched at a temperature of 200 degrees, so as to ensure that the stress is completely eliminated.

In addition, the most important thing is grinding. It is necessary to select a suitable grinding wheel to complete the grinding, and strictly control the linear speed to avoid raceway burns. Then for fine grinding, it is necessary to choose a resin grinding wheel with a particle size of 46° or 60° for grinding. For the support bearing containing gears, the gear hobbing process is required after the grinding process. The requirements for the entire process are very strict, and the accuracy must exceed grade 8.