ZYS WIND TURBINE BEARINGS

In recent years, wind power in emerging markets around the world has developed rapidly. 

Against the backdrop of national policy support and tight energy supply, China's wind power 

equipment manufacturing industry has risen rapidly, and the market demand for wind power 

equipment has grown rapidly, which has also driven the development of wind turbine bearings.

Bearings are the core components of wind turbines. Wind turbine bearings range from bearings used in blades, main shafts and yaws to high speed bearings used in gearboxes and 

generators.

Main features of wind turbine bearings:

1. Bad use environment.

2. High maintenance cost.

3. High requirement of service life.

Bearings for wind turbines mainly include yaw bearings, pitch bearings, spindle bearings, 

gearbox bearings, and generator bearings. 

Generator bearing

Bearing type: deep groove ball bearings, angular contact bearings.

Working conditions: high speed (1000-1500rpm), high temperature (90-120 °C) heavy load.

Grease requirements: excellent shear stability, good oxidation stability, good wear resistance, 

excellent low temperature start-up performance.

Spindle bearing

Bearing type: tapered roller bearing, spherical bearing.

Working conditions: low speed (<25rpm), wide temperature range, heavy load, vibration, high humidity.

Grease requirements: excellent wear resistance, good oxidation stability, excellent low 

temperature start-up performance, good water resistance and so on.

Pitch/yaw bearing

Bearing type: four point contact ball bearing

Working conditions: wide temperature range, heavy load, vibration, high humidity.

Grease requirements: excellent corrosion resistance and wear resistance, excellent low 

temperature start-up performance, good water resistance, good oxidation stability, etc.

Each wind turbine equipment has 1 set of yaw bearing and 3 sets of pitch bearing (not 

equipped for the wind turbine below MW), 3 sets of generator bearings (deep groove ball 

bearings, cylindrical roller bearings), 2 sets of spindle bearings (spheroidal roller bearings), 

totally 9 sets.

In addition, there are also gearbox bearings. The gearbox has three structural forms. The first 

type requires 15 sets of bearings, the second type requires 18 sets of bearings, and the third form requires 23 sets of bearings. Thus, the average number of wind turbine bearings is 27 sets.

The structural forms of bearings for wind turbines mainly include four point contact ball bearings, cross roller bearings, cylindrical roller bearings, spherical roller bearings, and deep groove 

ball bearings. The yaw bearing is installed at the connection between the tower and the 

cockpit, and the pitch bearing is installed at the joint of the root of each blade and the hub.

Wind power bearing production process

1. Control the forging temperature.

2. Control the modulation process to ensure the mechanical properties.

3. Control the depth of the intermediate frequency quench hardened layer on the surface.

4. Avoid micro cracks on the surface.

How much do you know about wind turbine bearing?

In recent years, wind power in emerging markets around the world has developed rapidly. Against the backdrop of national policy support and tight energy supply, China's wind power equipment manufacturing industry has risen rapidly, and the market demand for wind power equipment has grown rapidly, which has also driven the development of wind turbine bearings.
Bearings are the core components of wind turbines. Wind turbine bearings range from bearings used in blades, main shafts and yaws to high speed bearings used in gearboxes and generators
Main features of wind turbine bearings
1. Bad use environment.
2. High maintenance cost.
3. High requirement of service life.
Bearings for wind turbines mainly include yaw bearings, pitch bearings, spindle bearings, gearbox bearings, and generator bearings.
Generator bearing
Bearing type: deep groove ball bearings, angular contact bearings.
Working conditions: high speed (1000-1500rpm), high temperature (90-120 °C) heavy load.
Grease requirements: excellent shear stability, good oxidation stability, good wear resistance, excellent low temperature start-up performance.
Spindle bearing
Bearing type: tapered roller bearing, spherical bearing.
Working conditions: low speed (<25rpm), wide temperature range, heavy load, vibration, high humidity.
Grease requirements: excellent wear resistance, good oxidation stability, excellent low temperature start-up performance, good water resistance and so on.
Pitch/yaw bearing
Bearing type: four point contact ball bearing
Working conditions: wide temperature range, heavy load, vibration, high humidity.
Grease requirements: excellent corrosion resistance and wear resistance, excellent low temperature start-up performance, good water resistance, good oxidation stability, etc.
Each wind turbine equipment has 1 set of yaw bearing and 3 sets of pitch bearing (not equipped for the wind turbine below MW), 3 sets of generator bearings (deep groove ball bearings, cylindrical roller bearings), 2 sets of spindle bearings (spheroidal roller bearings), totally 9 sets.
In addition, there are also gearbox bearings. The gearbox has three structural forms. The first type requires 15 sets of bearings, the second type requires 18 sets of bearings, and the third form requires 23 sets of bearings. Thus, the average number of wind turbine bearings is 27 sets.
The structural forms of bearings for wind turbines mainly include four point contact ball bearings, cross roller bearings, cylindrical roller bearings, spherical roller bearings, and deep groove ball bearings. The yaw bearing is installed at the connection between the tower and the cockpit, and the pitch bearing is installed at the joint of the root of each blade and the hub.
Wind power bearing production process
1. Control the forging temperature.
2. Control the modulation process to ensure the mechanical properties.
3. Control the depth of the intermediate frequency quench hardened layer on the surface.
4. Avoid micro cracks on the surface.
The cleaning process of wind power bearing:
1. Inspection of forging blank
2. Rough turning
3. Finish turning
4. Molding finish turning
5. Heat treatment
6. Gear-hobbing and gear-milling processing
7. During drilling, according to customer requirements, it can be treated with blue, phosphating and vulcanization.
8. Rough grinding and fine grinding
9. Demagnetization, cleaning, assembly, surface coating, grease filling,packaging

What causes the bearing cage to break?

The cage/retainer in the rolling bearing plays the role of equidistance separating the rolling elements and preventing the rolling elements from falling, guiding and driving the rolling elements to rotate.
Although the bearing is composed of many bearing parts, the first damaged/failed part of the bearing is often the bearing cage. The cage can be said to be the bearing "blood vessel", because it can evenly distribute the inner ring, the outer ring and the rolling element. The failure or damage of bearing cage will easily shorten the life of the bearing or even damage it. What causes the bearing cage to break?

◐◑ Insufficient bearing lubrication
Lubricating oil or grease is dry without adding in time / daily maintenance, or use the wrong label of the oil or grease.
◐◑ Bearing impact load
The intense vibrations in the impact load create an impact of the rolling elements on the cage.
◐◑ Bearing cleanliness
The bearing is not well sealed in the bearing box, and then dust may enter; the friction between the rolling element and the cage may be added, thus causing damage to the cage.
◐◑ Installation problem
The bearings are not installed correctly and damage the cage during installation.
◐◑ Bearing creep
Creep mostly refers to the sliding phenomenon of the ring. Under the condition of insufficient interference of the matching surface, the load point moves in the surrounding direction due to sliding, resulting in the deviation of the ring from position of the shaft or the outer casing towards the circumference direction.
Improper installation, the inclination, and too large interference will easily cause clearance reduction, increasing friction heat production, surface softening, and the abnormal peeling occurs prematurely. As peeling spreads, the foreign matter is peeled off into the pocket of the cage, resulting in the blockage of cage operation; the generation of additional loads increased the wear of the cage, and such a deteriorating cycle can cause the cage to break.
◐◑ Bearing cage material defect
Cracks, metal inclusions, shrinkage cavities, air bubbles and riveting defects, nails, padding, severe riveting, etc. may cause the cage to break.
◐◑ Intrusion of hard foreign objects
The intrusion of foreign hard foreign objects or other foreign matter increase the wear of bearing cage.
Bearing cage performance varies with cage materials and molding technology, ZYS can supply all types of bearing cage to meet the requirements of different applications. Besides the textile laminated phenolic resin, porous polyamide and PTFE engineering plastic, and other plastic cage materials, we can also supply finished cages according to the drawings provided by customers. For more information, please send email to zysdong@gmail.com or visit our website www.zysbearing.com.

Which type of bearing is less noisy?

The noise of bearing not only affects the bearing operation, but also brings a lot of trouble to the mechanical equipment. The intrusion of foreign materials will directly cause certain noise during the operation of the bearing, and the improper lubrication and wrong bearing installation will also cause bearing noise. Which kinds of bearings have less noise?

1. The noise of the ball bearing is lower than that of the roller bearing, and the friction noise of the bearing with less sliding is lower than that of the bearing with relatively more sliding; the bearing with more balls and thick outer ring also has smaller noise.

2. The noise of bearing with solid cage is relatively lower than that of a bearing using a stamped cage.

3. The noise of bearing with the plastic cage is lower than that of the bearings using solid cage or stamped cage.

4.Bearings with high precision, especially those with higher precision rolling elements, have lower noise than low precision bearings.

5. The noise of small bearings is relatively small compared to the noise of large bearings.

In order to maintain the good performance of the bearing, daily maintenance, inspection, overhaul, and prevention must be done. For long-running equipment, the usual inspection and tracking is particularly important, including the rotation of the bearing, vibration, temperature, lubricant status, etc. According to the test results, equipment maintenance personnel can find and deal with problems in time. ZYS will carefully analyze the technical information and application of bearing offered by the customer, and then choose the right type of bearing and inform the precautions during installation and operation. If you want to know more information, please send email to zysdong@gmail.com or visit our website: www.zysbearing.com.

processing of ZYS taper roller bearing~1

Tips of changing the washing machine bearing

After the washing machine bearing is removed, first observe whether there are cracks, rust, scars on the rolling element, the inner ring and outer ring of the bearing. Then hold the inner ring of the bearing by hand and level the bearing, and rotate the outer ring of the bearing with the other hand. If the bearing is good, the outer ring should rotate smoothly and gradually decelerate to stop. There is no vibration or obvious stagnation during the rotation. After the rotation, the outer ring does not reverse. If the bearing is defective, noise and vibration will appear when it rotates. It will be abrupt like a brake when it stops, and it will reverse backwards seriously. Such bearings should be replaced.　　
The radial clearance of the washing machine bearing is 0.01 mm-0.02 mm. Push the inner ring in all directions. If the gap is felt when pushing, then the bearing wear is severe.
Before installing the washing machine bearing, it should be cleaned and checked for flexibility and smoothness, and greased. Then, ZYS washing machine bearing is placed on the journal, and a sleeve is used to hold the inner ring of the bearing. The upper end of the sleeve is iron-plated and hammered until the bearing is in place. When knocking, pay attention to the fact that the bearing can not be skewed, and the tap should be facing the axial direction.

Signs That You Need To Change Washing Machine Bearings

1. Noise

After long operation of washing machine, the bearings in the drum are eventually going to wear out. You can tell this immediately when you hear noise appearing from the drum during the operation. You can do a quick inspection of the drum. 

2. Oil stains on the clothes

If there are oil on the clothes after each washing cycle, it means that your main seal on the bearings is also worn and should be replaced. Despite this, you'd better change the bearings as well since they could collapse.

It's important to remember to put the right seal around each bearing as well. The wrong seal could end up leaking water on the new bearings, hence causing part failure once again.

Products features of Washing Machine Bearings:

· Bearing supported, shipped grease lubricated and protected against dust larger than .012" (.3mm) diameter.

· Available with additional lip seals (- 2RS) for enhanced sealing, as well as, with a keyway on the inner ring (-P) or the inner and outer ring (-PP) for additional ease of installation.

· Operating temperature: 21 to 140°F (-6 to 60°C)

· Special grease available for operating temperatures: -40 to 212°F (-40 to 100°C)

Contact Person: Mr.Dong

Address: No.1 Jilin Road, Luoyang City,Henan Province,China

Zip:471039

Tel: +86-379-6488 1209

Fax: +86-379-6488 1529

Mobile No:+86 139 3792 3793

Website: www.zys.com.cn

              www.zysbearing.com
E-mail: zysdong@gmail.com
Skype: zysdongoffice

QQ: 18937963793 

How to install the robot bearing?

The installation of robot bearing will affect the accuracy, life and performance of the robot bearing. Therefore, it is important to install the robot bearing in accordance with the operating standards. The following are the installation rules for robot bearings.

The installation of the robot bearing should be based on the structure of the robot bearing, the size and the mating nature of the robot bearing components. The pressure should be directly applied to the end face of the ring instead of transmitting through the rolling element. The robot bearing installation generally adopts the following methods: First, clean the robot bearings and related parts. For grease-lubricated robot bearings and double-sided oil seals or dust caps, the seal robot bearings do not need to be cleaned before installation. Check the size and finishing of the relevant parts.

The inner ring of the robot bearing is tightly matched with the shaft. When the outer ring and the bearing hole of the robot are loosely matched, the robot bearing can be press-fitted on the shaft by the press, and then the shaft is loaded into the hole of the robot bearing seat together with the robot bearing. On the end face of the inner ring of the robot bearing during press-fit, a mounting sleeve (copper or mild steel) made of soft metal material is used. The inner diameter of the assembled sleeve should be slightly larger than the diameter of the journal. The outer diameter should be slightly smaller than the inner ring of the robot bearing to avoid pressing on the cage.When the outer ring of the robot bearing is tightly matched with the hole of the robot bearing seat but the inner ring and the shaft are loosely fitted, the robot bearing can be first pressed into the hole of the robot bearing seat. At this time, the outer diameter of the assembling sleeve should be slightly smaller than the diameter of the seat hole. If the robot bearing ring is tightly fitted with the shaft and the seat hole, the inner ring and the outer ring should be pressed into the shaft and the seat hole at the same time. The structure of the assembly sleeve should be able to simultaneously press the end faces of the inner and outer rings of the robot bearing. 

Contact Person: Mr.Dong
Address: No.1 Jilin Road, Luoyang City,Henan Province,China
Zip:471039
Tel: +86-379-6488 1209
Fax: +86-379-6488 1529
Mobile No:+86 139 3792 3793
Website: www.zys.com.cn
              www.zysbearing.com
E-mail: zysdong@gmail.com
Skype: zysdongoffice

QQ: 18937963793 

The inspection of one-way bearing for washing machine

Although the outer cup of the clutch is accurately drawn from strip steel, it can go slightly out of round during heat treatment. When the assembly is pressed into a ring gage or properly prepared housing of correct size and wall thickness, it becomes round and properly sized. Direct measurement of the outside diameter of a drawn cup assembly is an incorrect procedure. The proper inspection procedure is as follows:

1. Press the assembly into a ring gage of the proper size.

2. Gage the bore with the specified plug gages of the proper size.

- The locking plug is rotated to insure lockup when the clutch is operated at low limit shaft and is mounted in a high limit housing strong enough to properly size the clutch. 

- The overrun plug is rotated to ensure free over-running when the clutch is operated on a high limit shaft and is mounted in a low limit housing. 

- The go plug and no go plug insure proper size of the bearings in the clutch and bearing assemblies.

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

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