Slewing bearing (turntable bearing) selection calculation method

Slewing bearing (turntable bearing) Selection calculation method:

Static reference load Fa 'and M' calculation method

Single row four point contact ball

Single-row four-point contact ball slewing bearing selection calculation according to the bearing angle of 45 ° and 60 ° two cases.

I, a = 45 ° Ⅱ, a = 60 °

Fa '= (1.225 • Fa + 2.676 • Fr) • fs Fa' = (Fa + 5.046 • Fr) • fs

M '= 1.225 • M • fs M' = M • fS

Then find the above two points on the graph, one of which can be below the curve.

Single row crossed roller type

Fa '= (Fa + 2.05 • Fr) • fs

M '= M • fs

Double row different diameter ball

For double-row reduced-diameter ball slewing bearing selection calculation, Fr ≤ 10% Fa, Fr negligible. When Fr> 10% Fa, we must take into account changes in the pressure angle of the raceway, the calculation, please contact us.

Fa '= Fa • fs

M '= M • fs

Three-row roller

When selecting three-row roller slewing bearing, only the effect of axial roller load and overturning moment is calculated.

Fa '= Fa • fs

M '= M • fs

On January 1, 2008, the National Development and Reform Commission promulgated a new standard of slewing bearing with the participation of our company. 1. By JB / T 10837-2008 "construction machinery and equipment three rows of column slewing bearings" instead of JG / T 68-1999 "three rows of columnar construction machinery slewing ring"; 2. By JB / T 10838-2008 "Construction machinery and equipment single row cross roller (cone) slewing bearing" instead of JG / T 67-1999 "single row crossed roller bearings (construction machinery)", the new standard to cancel the original Appendix 1 "Supplement Series of specifications "; 3. By JB / T 10839-2008" construction machinery and equipment single volleyball slewing ring "instead of JG / T 66-1999" single row ball slewing ring for construction machinery ", the new standard to increase the overlap section configuration, Cancel some of the less common specifications, the new part of the specification, increased to 48; to cancel the original Appendix A "Supplementary Series Specifications"; performance curve by d0 ≤ 40,57 HRC, d0 ≥ 50,55 HRC drawing.

Three new standards have abolished product quality grading, since July 1, 2008 onwards.

ZYS High-speed Angular Contact Ball Bearings

High Precision Angular Contact Ball Bearings are our hot products. We have been engaged in research and development of High Precision Angular Contact Ball Bearings since 1958. ZYS has set up a scientific research workstation, and a strong world class experts team for High Precision Angular Contact Ball Bearings, whose main researches represent the technology developing direction of China bearing industry. So we bring you the High Precision Angular Contact Ball Bearings with best quality , high precision, reliable performance and strong durability.

1. Application of High-speed Angular Contact Ball Bearings:

•Machine tool spindle

•Robot technology

•high-frequency motor

•gas turbine

•centrifuge

•small-size automobile front wheels

•differential pinion shaft 

2. Advantages of High-speed Angular Contact Ball Bearings:

The inner ring, outer ring and rolling element of High-speed Angular Contact Ball Bearings are made in high carbon chromium bearing steel. The chamfer arc radius of rings is reasonable, which is not only convenient to install, but also guaranteed to improve the installation precision and reduce the risk of the related parts being bumped. 

•The speed performance of High-speed Angular Contact Ball Bearings is outstanding. 

•Unique heat treatment process of High-speed Angular Contact Ball Bearings allows products to achieve the best dimensional stability and rigidity, so as to reduce wear and tear. 

•Multiple pre-load levels can help to meet different requirements for speed and system stiffness, which is more reasonable to select and use the levels. 

Visit more:

http://www.zysbearing.com/precision-bearings/high-precision-angular-contact-ball-bearings.html

Key Pieces Of ZYS BEARING Make Contributions To China Aerospace

If you want to know more, please visit www.zys-bearings.com or send email to zysdong@gmail.com. 

China has successfully sent this year's first satellite into space, according to the China Aerospace Science and Technology Corporation (CASC). The Zhongxing-2D satellite was sent into space on a Long March-3B carrier rocket from the Xichang Satellite Launch Center in southwest China's Sichuan Province at 1:11 a.m. Friday, and has entered the preset orbit. This was the first launch for China and also the first for the launch center in 2019. 

On the key parts of the Zhongxing 2D satellite, it is equipped with a variety of high-precision, long-life bearing products developed by ZYS.

Among them, a certain type of bearing provided by ZYS is used in the momentum wheel of the "Zhongxing 2D" satellite attitude control system, which is a key component to determine the rotation accuracy and service life of the momentum wheel.

Satellites operating in space need to adjust the attitude according to the actual situation, so as to achieve accurate and stable signal transmission. The bearings provided by ZYS are the core to ensure the stable operation of the momentum wheel. If the stability of the bearing operation fluctuates slightly, it will affect the operation of the momentum wheel, which will lead to satellite jitter.

In addition to the bearings for the momentum wheel, ZYS also provides bearings and related components for the control system, transponder system, and antenna system for the Zhongxing 2D satellite.

As communication broadcast satellite, the Zhongxing 2D satellite requires long-life, highly reliable bearings and bearing components. For this purpose, ZYS has set up a special project team to strictly control the processing, inspection, assembly, performance testing, test verification and other aspects of high-precision bearings and components, and finally ensure the smooth delivery of the products.

Since 1958, ZYS has been developing special bearings, bearing components and momentum wheels for China's aerospace engineering. It has completed the "Dongfanghong" series of satellites, the "Shenzhou" series manned spacecraft, the "Chang’e" lunar exploration project and other supporting tasks. 

The relationship between industrial robot accuracy and bearing design

For industrial robots, accuracy is a very important factor that directly affects product quality and productivity. The main factor affecting the accuracy of industrial robots is the bearings. So what kind of bearings can make industrial robots have higher precision? 

1. Design of key structural parameters

Industrial robot bearings have the requirements of long life, high rigidity and low friction. Therefore, when designing industrial robots, not only the maximum rated dynamic load should be considered, but also the optimal value of each structural parameter should be carefully selected to improve the contact stress distribution of the bearing parts. Then it can reach the optimum contact state for the formation of the lubricating oil film and improve the service life of the bearing.

2. The raceway position

The inner and outer rings of the contact ball bearing of the industrial robot adopt the integral structure, and the general sectional area is only 20% of the bearing with the same inner diameter standard, so the radial wall thickness of the cage is very limited. If the position is designed in the middle of bearing width, the bearing becomes a symmetrical structure and the strength of the bottom of the cage and the mounting position of the sealing ring will be limited. Therefore, in order to ensure that the bearing cage has sufficient strength and the sealing ring has sufficient installation space, the groove position adopts an asymmetrical design on both end faces.

3.The height of the flange

When the contact ball bearing of an industrial robot is in working condition, it must bear a certain axial load while receiving a certain radial load. If the axial load is too large, it may cause the break of contact ellipse between the steel ball and the edge of the inner and outer rings or between the flange and the raceway. And then, stress concentration will occur and the bearing ring will be worn, which will affect accuracy.

Therefore, when the flange height is designed, the minimum flange height J of the bearing ring is calculated according to the Hertz contact stress theory according to the axial load of the bearing, and the diameter of the ring flange is calculated. In the design, the contact ball bearing cross-sectional area is considered small, and the flange height coefficient can be smaller than the deep groove ball bearing under the premise of satisfying the use requirement.

4. Sealing structure design

If the sealing property is not good, the impurities or other contaminants in the air will easily enter the bearing, thereby gradually failing the grease and resulting in bearing damage. Therefore, the sealing of the bearing is critical. When designing sealed bearing, it is necessary to consider the sealing and the specific working requirements of the bearing and the specific structural form of the bearing.

Industrial robots are moving toward miniaturization, light weight, and precision. Therefore, the lubrication of bearings for industrial robots is preferably greased by means of a lubrication method with a sealing structure.

5.The characteristics of industrial robot bearing

There are two ways to match the inner ring of the bearing and the sealing lip:

Contact seal with inner ring seal lip in contact with inner ring rib

Non-contact seal with inner ring seal lip in contact with inner ring rib

ZYS can offer the complete solution for industrial robot bearing. Any demand, please send email to zysdong@gmail.com.

The performance of lubrication-free bearing materials

The lubrication-free bearing has the characteristics of high carrying capacity, impact resistance, high temperature resistance and strong self-lubricating ability. It is especially suitable for heavy load, low speed, reciprocating or swinging, etc., which is difficult to lubricate and form an oil film. It is also not afraid of water and other acid liquids. The lubrication-free bearing products have been widely used in metallurgical continuous casting machines, rolling equipment, mining machinery, molds, lifting machinery, textile machinery, wind power generation, ships, steam turbines, hydraulic turbines, injection molding machines and equipment production lines.
Superior performance of lubrication-free bearing materials:

1. Extremely high wear resistance, very low wear rate

2. Good self-lubricating performance and low friction coefficient

3. High impact strength and good toughness.

4. Excellent chemical resistance, resistant to almost all acid-base media

5. Non-toxic, tasteless, no exudate

6. It has elasticity and shock absorption; it has good self-recovery and low water absorption.

7. Good mechanical properties, can withstand large impacts and loads, and can effectively protect other components from mechanical damage due to its excellent toughness.

8. Excellent low temperature resistance. It is not brittle even at -176 ° C.
If you have demand for bearing, please visit http://www.zysbearing.com/ or send email to zysdong@gmail.com.

Rotational accuracy of rolling bearings

Rotational accuracy of rolling bearings refers to:

1. Radial runout of the inner ring and outer ring of the bearings;

2.The runout of bearing inner ring and outer ring end face to the raceway;

3. The runout of the inner ring datum end face to the inner diameter;

4. The amount of change of the outer surface line to the inclination of the datum end face;

5.The amount of change of the thrust bearing raceway to the bottom thickness.
Symbols and definitions:
1.The radial runout of the bearing: Kia-The radial runout of the inner ring of the bearings. It means the difference between the maximum and minimum distance between the inner diameter surface and the fixed point of the outer ring when the inner ring is at different angular positions; Kea-The radial runout of the outer ring of the bearings. It refers to the difference between the maximum and minimum distances between the outer diameter surface and the fixed point of the inner ring when the outer ring is at different angular positions.
2. The runout of the bearing end face to the raceway
Sia - The runout of the bearing inner ring end face to the raceway. It means the maximum and minimum axial distances between the datum end face of the inner ring and the fixed point  of the outer ring when the inner ring is at different angular positions.
Sea-The runout of the bearing outer ring end face to the raceway. It means the maximum and minimum axial distances between the datum end face of the outer ring and the fixed point of the inner ring when the outer ring is at different angular positions.
3. Sd - The runout of the datum end of the bearing inner ring against the inner diameter.

Introduction of Bearing Ring Groove Superfinishing Machine

Bearing Ring Groove Superfinishing Machine is semi-automatic superfinishing machine for groove of ball bearing ring, which is suitable for processing inner and outer ring groove.Processing accuracy is above P5 level.
The workpiece spindle of the machine is driven by an AC- motor through belt pulley, and the variable frequency stepless speed is regulated. The oscillating mechanism is connected by a bending plate to the side of the drag plate. The feeding drag plate is installed on the top of the workpiece spindle box. The  press device is fixed on the left side of the workpiece spindle box by bending plate.The radial and axial movement of the machine's dragging plate, the radial reciprocating and end face pressing of the pressure device, the oilstone pressure are all controlled by the hydraulic system, and the order of superfining action and the frequency of oscillation are controlled by electrical system.
In order to achieve higher machining accuracy, various parameters are adjusted according to the size of the workpiece, the rough and fine superfining are finished.   Lubrication of the machine
Before running the machine, lubricate the relative motion guide and the parts with oil mark. Bearings lubricated with molybdenum disulfide shall be replaced semiannually.
Maintenance of the machine
1) The guide of the machine should be regularly lubricated, and there should be no acid and other sundries mixed in the lubricating oil.
2) Regularly check the insulation of electrical appliances of machine.
3) When the machine fails, press the total stop button immediately to stop all moving parts.
4) The pressure gauge and electromagnetic valve of each oil system shall be checked regularly to ensure the reliability of their work.
5) The coolant of the oil tank should be replaced regularly and the sediment should be removed.
6) The filter should be cleaned regularly to ensure the filtering effect.http://www.zysbearing.com/bearing-manufacturing-machines/superfinishing-machine-series.html