Bearing is one of the important parts in machining equipment. The accuracy of bearing has a great impact on the accuracy and quality of products. Therefore, according to different needs, bearing manufacturers will also provide products with different accuracy requirements. How to divide the accuracy grade of bearings is described in detail below.
The accuracy grade of rolling bearings can be divided into two types, one is dimensional accuracy, the other is rotational accuracy.
The accuracy grade standard of bearings is mainly divided into six grades: grade 0, grade 6x, grade 6, grade 5, grade 4 and grade 2. The bearing grade standard is raised from grade 0 in turn. For general workpiece processing, grade 0 can meet the requirements, but in some occasions or processing requirements, bearings of grade 5 or higher accuracy are required.
These accuracy levels are formulated according to ISO standards, but their names will change greatly due to the influence of national standards.
Dimensional accuracy of bearings
This mainly refers to the items related to the installation of shaft and housing.
1. The inner diameter, outer diameter, width and assembly width will deviate.
2. Deviation is also allowed for the inner and outer diameter of the roller set.
3. Allowable limit value of chamfer size.
4. The width also allows for variation.
Rotation accuracy of bearing
This is an item related to the runout of the rotating body.
1. The inner and outer rings can allow axial and radial runout.
2. The inner ring can have lateral runout
3. Allowable variation of inclination of outer diameter surface
4. Allowable variation of thrust bearing raceway thickness
5. Allowable deviation and allowable variation of conical hole
Selection of bearing accuracy
1. The placement body is required to have high jumping accuracy
It is mainly used for sound, affecting equipment and its main shaft; Rotation axis of radar and parabolic antenna; Machine tool spindle; Electronic computer, disk spindle; Aluminum foil roll neck; Multi stage rolling mill support bearing.
The applicable accuracy levels are: P4, P5, P2, ABEC9.
2. High speed rotation
Mainly used for supercharger; Main shaft and auxiliary engine of jet engine; Centrifugal separator; Liquefied natural gas pump; Turbine molecular pump main shaft and protective bearing; Machine tool spindle; Tension wheel.
The applicable accuracy levels are: P4, P5, P2, ABEC9.
3. Small friction and friction change are required
It is mainly used to control machines (synchronous motor, servo motor, gyro gimbal; measuring instrument; machine tool spindle.
The applicable Accuracy grades are: P4, P5, P2, ABEC9, ABMA 7p.
4. General accuracy
It can be mainly used in small motors, gear drives, cam drives, generators, low induction synchronous servo motors, pressure rotors, printers, copiers, and testing instruments.
The applicable Accuracy grades are: P0, p6.
