HOME Bearing Knowledge

Contact

Knowledge

Major impact on the life of the bearing installation aspects


Decision bearing length of life of many factors, but can be broadly divided into two types , one is internal ( bearing its own factor ) , the other is external TIMKEN bearings .
Bearing factors are mainly including structural design , quality manufacturing processes and materials , such as three factors .
Manufacture of bearings generally through forging , heat treatment, turning, grinding and assembly of multi- channel processing . However, the reasonableness of the processing technology , advanced, will also affect the stability of the bearing life . KOYO bearings which affect the quality of the finished heat treatment and grinding processes normally associated with bearing failure have a more direct relationship.
Bearing materials metallurgical quality of early bearing failure was the main factor . As metallurgical techniques ( such as bearing steel vacuum degassing, etc. ) progress, improve the quality of raw materials . Raw material quality factors in bearing failure analysis in the proportion has decreased significantly, but it is still bearing failure is one of the main factors . Appropriateness of the selection is still bearing failure analysis must be considered.
( A ) a fixed circle to take a small interference fit condition that matches the shape of the surface of both sides are very high precision and a smaller roughness , or cause installation difficulties removal more difficult , in addition, also need to consider the impact of the spindle thermal elongation .
( 2 ) using the pair of angular contact ball bearing spindle , mostly lighter loads , the amount of interference , such as too large, then the internal axial preload amount will be significantly larger , resulting in adverse effects . Using double row bearing shaft and the bearing spindle , which load is relatively large, so the interference with the relatively larger .
( 3 ) shaft and housing bore roundness and verticality of the shoulder block in accordance with the appropriate INA bearings precision requirements.
( 4 ) it is necessary to accurately calculate the rotation of the ferrule with the amount of interference , but also suitable for accurate calculation of the amount of the fixed ring .
Interference amount rotatable collar may also wish to obtain a smaller range . As long as the operating temperature and ensure the effect of thermal expansion , and the maximum speed of the centrifugal force , resulting in a tight fit so as not to creep or sliding surfaces . Fixed ring size according to the work load and bearing size, select small clearance fit or interference fit , too loose or too tight is not conducive to maintaining the original shape exactly .
( 5 ) under the conditions of bearings, such as in high-speed operation , and higher operating temperature , special attention should be rotating rings can not be too loose to prevent eccentric , as well as non- fixed ferrule with a gap to prevent ferrule deformation under load and excited vibrational
A dimensional accuracy tolerance
Diameter, outer diameter in the finished product inspection in tolerance possible, mainly due to :
1 before the process of product undetected .
(2) Check the ambient temperature changes assembly .
3 standard ferrule thermostat is not enough.
4 grinding using standard parts and finished products inspection failed .
SKF bearings diameter size is too large, should be judged as substandard products , the inner scrapped. Diameter size is too small, should be judged as substandard products , but you can rework grinding , making it qualified. Bearing diameter size is too large, can be re- grinding , making it qualified. But the outer diameter is too small, to be rejected bearing outer ring scrapped.
B. Rotate the accuracy tolerance
Generating rotational accuracy tolerance reasons:
1 ring in the grinding process , the channel center plane of the base end equal degree exceeded poor.
Two inner and outer surface of the channel is injured, there is dirt .
3 inner and outer rings datum injury .
4 large outside diameter variation channel .
5 installed last ball , makes the outer ring deformation, the surface of the ball card or injury .
6 may be mixed with the ball , the ball diameter is too large .
7 cage deformation.
8 groove shape deformation.
Kia Kea ultra poor and less scrap , even if there is due to a single ring on the inner or outer diameter of the channel thickness variation tolerance. But Sia and Sea -tolerance scrapped more . To reduce losses , often through the demolition of parts re- assembled , a certain improvement . Sd and SD -tolerance can only be scrapped .
C. Flexibility bad bearings
FAG Bearings flexibility is not good, its two main reasons:
1 riveting timely internal bearing into dirt.
2 riveting timely too much pressure , so that the cage deformation.
3 Die uneven force , the retainer pressure uneven deformation.
4 rivet diameter tolerance, length ultra- poor, so riveting timely same cage rivet deformation range, the retainer deformation.
5 cage ball size tolerance , so that turning the ball without sufficient radial clearance .
6 sets when combined radial clearance is too small.
7 individually mixed with big ball , you can not turn the other .
D. radial clearance tolerance
By radial clearance requirements together sets of radial clearance tolerance occurs for two main reasons :
1 ring size sorting values are not accurate, because of the selected accidental error , the measurement system error caused .
2 -channel ring radius of curvature tolerance.
3 measuring axial clearance , ball decile uneven location is incorrect , hands thrust inconsistent.
4 bearing cleanliness is not enough .
5 ferrule channel geometry deviation is too large .
6 cage center circle of tolerance is too large.
E. bearing corrosion
NSK Bearings corrosion for the appearance of inferior quality. Its cause is improper preservation bearing parts rust ; assembly process implementation of strict anti-rust process ; especially the rainy season the operator does not work with gloves ; assembly operations room air relative humidity is too large ; cleanliness so poor .
There is no message.
Online Messagess
Company:
Email:
Message:
ValidateCode: click refresh <--Not see, click refresh