The application of bearing clearance rate and matching instrument

FANADE Industry(HongKong) Ltd,a professional distributor of Introduction Of Fag Cylindrical Roller ,owns a state-level enterprising technology center,and has developed more than 200 kinds of new products on the annual average ranging from Ball Bearing Series:Deep Groove Ball,Thrust Ball(Single Row Double-Directino/Doubel Row Single-Direction),Radial Ball,Self-aligning Ball,Filling Slot Ball,Counterbored Ball,Three/Four Point Contact Ball.Roller Bearing Series:Spherical Roller,Radial Roller,Cylindrical Roller,Tapered Roller,Needle Roller,Drawn Cup Needle Roller,Convex Roller,Concave Roller,Crossed Roller,Thrust Roller,Cylindrical Roller Thrust,Tapered Roller Thrust,Needle Roller Thrust,Spherical Thrust Roller.FANADE Bearing Seals Type include:RS,2RS,Z,2Z,2RZ,DDU,LLU,VV.Bearing Row:Single-Row,Double-Row,Four-Row etc with imported and domestic famous brands including SKF,FAG,NSK,TIMKEN,NTN,NACHI,IKO,INA,KOYO,FYH and so on from Swenden,Germany,France,Japan,India,USA,Canada,Brazil and other country in European/Asia and North America/South America.For decades,the company has established and completed the quality management system of scientific standardization which has passed the quality system certification,with the quality management system in line with international standards.In 2005 they won the title of Chinese famous brand.FANADE Bearing website provide Structure、Dimensions、Net Weight and all Parameter and Details of all kind of bearings.Here we'd like to talk about The application of bearing clearance rate and matching instrument.

One, must attach great importance to raise the importance of bearing clearance rate

When the bearing supporting radial clearance is one of main quality index. Radial clearance refers to the inner and outer channel and the roller diameter direction of the total clearance.

Bearing clearance, therefore, is not only the identification of qualified after the finished parts matching is one of the main parameters of the qualified finished products bearing, and bearing can work normally one of the important factors. Clearance value is not in conformity with the technical standards, will influence the reasonable distribution of load between the rolling element bearing rotating accuracy, vibration value, life will be affected, therefore improve and guarantee the bearing clearance rate, doubtless is very important.

Second, the analysis of the radial percent of pass of causality

The quality of the product in the process of formation, once found that the problem will be immediately look for reason. Use causal analysis form, let us to solve the problem of radial clearance partial qualified rate is low profile.

Factors influencing the quality of bearing clearance has five. If not considering material and environmental factors, can be used to analyze the main testing instrument, process method and personnel quality on the quality of the bearing clearance, bearing inner and outer ring and ball past matching method is to inside, the diameter of the outer channel deviation separation with instrument is good, and according to the standard clearance to calculate an inner ring channel diameter size value and an outer ring channel diameter size, and then select the corresponding size of copper ball, after the three assembly, with the axial clearance tester to test the axial clearance upper and lower limit value, does not meet the technical requirements, selection again. As to the value of the radial clearance of bearing with axial clearance value, it is difficult to ensure accuracy. Because the measured axial clearance value is upper and lower limit value, while the upper and lower limit value of channel curvature size and each technique varies, so in this way, matching of bearing the radial qualified rate is not stable. High low, when the number of rework more frequently, don't really have to clearance of the product quality.

Third, application supporting device, improve the radial clearance rate

In order to ensure the quality of bearing parts processing and guarantee the accuracy of the test instrument in value under the premise of using the bearing inner and outer ring form a complete set of special instrument to reasonable matching of bearing inner and outer ring, is one of the effective methods to improve the bearing radial clearance rate:

1, the necessary instrument matching principle

In the process of bearing assembly, bearing clearance must comply with the provisions of the standard, the centripetal ball bearing radial clearance error formula is:

U = X - Y - 2 z or z X - Y = U + 2

Type of U = centripetal ball bearing radial clearance without load, X = ditch outside diameter deviation, Y = inside groove diameter deviation, Z = ball diameter deviation,

The U value in the formula can consult from the national standard, the Z value has been marked in the steel ball check. With matching instrument matching task is after the bearing inner and outer ring size separation, with matching instrument one-time (x-y) value is measured, and equipped with appropriate size of the steel ball after assembling, the radial clearance value with radial clearance gauge to inspect again.

2, form a complete set of methods

First with the bearing inner and outer groove diameter size standard calibration instrument. Because matching instrument is to use two comparison measurement, so checking instrument need two standard parts namely, inner ring and outer ring groove diameter standard parts. Supporting apparatus is equipped with three dial gauge, around two dial indicator reflects the internal and external channel diameter deviation, in the middle of a dial indicator one-time reflect the value of (x, y).

For example: the actual diameter deviation of outer standard channel + 8 um, inner ring the actual diameter deviation of standard channel - 5 um, x - y = + 8 - (5) = 13 um.

Calibration, aim the channel inside and outside diameter standard parts with respective measuring points, form a complete set of instrument in the middle a dial gauge pointer should be to point to in + 13 um position, prove the instrument has been calibrated. Conversely, + 13 um dial gauge pointer is not refers to the position, you need to readjust the equipment.

Because before matching has good internal and external channel diameter size separation, so matching instrument dial gauge could save on the left and need not, simply reflect a dial indicator (x-y) among values can be equipped with a certain size of the ball. This matches the bearing radial clearance values conform to the requirements of the standards.

Need reminds is, in the process of form a complete set of inner, outer ring, to stick to frequently with standard calibration instruments, prevent the stopwatch, otherwise, the measure of (X - Y numerical value is not accurate, with the bearing clearance value will be incorrect. On the application effect, to promote the use of form a complete set of apparatus, percent of pass is up to 98-100%.

1) track bearing in rolling mill location and record. Timken can provide roll neck bearing maintenance service for the customer card, can be used to record bearing, roller, frame, the position of bearing in rolling mill, tonnage and bearing outer ring bearing zone and rolling products such as hours worked data. Card should be updated and convenience of maintenance personnel to check in, the margin can record at the bottom of the bearing measuring data and other detailed content;

2) removed from the roll bearing seat, unload bearings from the bearing seat. Away from the bearing pedestal bearing or bearing checks require special hoisting ways and tools for timken can provide customers with assembly tools and special assembly way;

3) bearing cleaning. In the process of cleaning bearing should be removed all the peel, water, residual lubricant, and any other cause the dirt of severe wear of the bearing. Cleaning bearing the cleaning method and cleaning agent is used according to the number of bearings to clean bearing size or decision, or a few small bearing bearings available kerosene, mineral oil or other commercial solvents. For large bearing or bearing in great quantities, for 22 CST viscosity when available 40 ° C (100 ° F or 100 SUS) of neutral oil in cleaning tank cleaning.

4) check the bearing, including appearance inspection and repairs. To pull down the inner ring of the roller outer surface or on the roller surface, if you find a small spalling or skin cracks, usually use the metal flake grinding machine surface edge grinding and polishing flake.

5) should be regularly check the bearing wear, can by measuring the wear of the bearing clearance to evaluate bearing conditions;

6) inspection and maintenance, according to their needs, bearing seat;

7) keep bearing bearing seat back;

8) inspection and maintenance, according to their needs, roll neck;

9) will be fitted with a bearing housings to roll.