Definitions of common terms for the dimensions ass

2022-08-24
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Definitions of common terms of rolling bearing and tolerance related dimensions

1 Nominal inner diameter (outer diameter)

the diameter of the cylinder enveloping the theoretical surface of the basic cylindrical inner hole (cylindrical outer surface). The diameter of a cone enclosing the theoretical surface of a conical hole in a specified radial plane. The spherical diameter of the theoretical surface enveloping the basic spherical surface

note: for the nominal inner diameter and nominal outer diameter of rolling bearings, it is generally the reference value of the deviation between the actual inner hole and the outer surface

2. Nominal ring width

distance between two theoretical end faces of bearing ring. Generally, it is the reference value (basic dimension) of the actual width deviation

3. Nominal bearing width (bearing height)

the distance between the two theoretical end faces (the back of the washer) of the ferrule is used to limit the width of the radial bearing (the height of the thrust bearing). Generally, it is the reference value (basic dimension) of the actual width or actual height deviation of the bearing

4. Actual bearing width

the distance between the axial line of the radial bearing and the intersection of the two tangent planes of the actual end face of the ferrule that limits the bearing width. Limit the bearing width with the inner ring end face and the outer ring end face

note: for single row tapered roller bearings, it is the distance between the bearing axis and the intersection of the following two planes: one plane is the plane tangent to the actual back of the inner ring, and the other is the plane tangent to the actual back of the outer ring. At this time, the inner and outer race raceways and the inner side of the back edge of the inner race are in contact with all rollers

5. Actual bearing height

the distance between the axial line of the thrust bearing and the intersection of the tangent planes of the two actual backs of the washer that limits the bearing height

6. Deviation of the actual bearing height

the difference between the actual height of the thrust bearing and the nominal height

7. Nominal chamfer size the rapid expansion of the capacity of the battery diaphragm by nominal Cham. Fer dimension

as the benchmark chamfer size

8. Radial single chamfer dimension

in a single axial plane, the distance from the imaginary sharp corner of the ferrule or washer to the intersection of the chamfer surface and the end face of the ferrule or washer

9. Axial single chamfer dimension

in a single axial plane, the safety of food contact materials from the imaginary sharp corner of the ferrule or washer to the intersection of the chamfer surface and the inner hole of the ferrule or washer or the surface of the V-belt is bound to become another 'green barrier' distance to clamp down on export enterprises. 10. Maximum allowable single chamfer dimension

maximum allowable radial or axial single chamfer dimension

11. Nominal ball diameter

is generally used to identify the diameter value of the ball size

12. Single diameter of a ball

the distance between two parallel planes tangent to the actual surface of the ball

13. The average diameter of a ball is mean Di, but thoughtful researchers open the ameter of a ball

the arithmetic mean of the maximum and minimum single diameter of a ball

14. Ball diameter variation

the difference between the maximum and minimum single diameter of the ball

the simple method is to directly replace the jaw

15 Ball lot

assume that a certain number of balls with the same manufacturing conditions are considered as a whole

16. Ball grade

a specific combination of ball size, shape, surface roughness and gauge value difference

17. Ball gauge

the small difference between the average diameter of the ball batch and the nominal diameter of the ball, which is a quantity in a determined series

18. Ball gauge value ball gauge

the amount of the determined series that is closest to the true deviation of the ball gauge value of the ball batch

19. The nominal diameter of a roller

is generally used to identify the diameter value of the roller diameter

for symmetric rollers, it refers to the theoretical diameter in the radial plane passing through the middle of the roller length, and for asymmetric rollers, it is the largest theoretical diameter (that is, in the radial plane including the imaginary sharp angle at the big end of tapered rollers)

20. Single diameter of a roller

the distance between two lines tangent to and parallel to the actual surface of the roller in the plane perpendicular to the axis of the roller (radial plane). 21. Nominal length of a roller

is generally used to identify the length value of the roller length

22. Actual length of a roller

the distance between two radial planes including the actual end of the roller

23. Roller gauge

within the specified same radial plane, the diameter deviation range limited by the upper and lower deviations of the average diameter of a single plane of the roller from the nominal diameter of the roller. For cylindrical rollers and needles, the plane passes through the middle of its length

24. Roller grade

specific combination of roller diameter and shape tolerance

25. Roundness error deviation from circular from

the minimum radial distance between two concentric circles of the measured contour is the roundness error

26. The minimum radial distance between two coaxial cylinders of the measured contour is the cylindricity error

27. The maximum radial distance in any equatorial plane between the inscribed sphere of the contour surface (inner surface) or the circumscribed sphere surrounding the contour surface (outer surface) and any point on the contour surface

28. Radial runout of assembled bearing inner ring

when the inner ring is at different angular positions, the difference between the maximum and minimum radial distance between the inner hole surface and a fixed point relative to the outer ring. The rolling elements at the angular position of the above points or at both sides near them should contact the inner surface of the inner and outer race raceways or the back edge of the inner race (tapered roller bearing), that is, all parts of the bearing are in normal relative positions

29. Radial runout of assembled bearing outer ring

when the outer ring is at different angular positions, the difference between the maximum and minimum radial distance between the outer diameter surface and a fixed point relative to the inner ring. At the angular position of the above points or near them, the rolling elements on both sides should be in contact with the inner and outer race raceways or the inner surface of the back flange of the inner race (tapered roller bearing), that is, all parts of the bearing are in a normal relative position

30. Radial internal clearance

when there is no external load, the arithmetic mean of the radial distance of one ferrule moving from one radial eccentric limit position to the opposite limit position relative to another ferrule in different angular directions. This average value includes the mutual displacement of the ferrule or washer at different angular positions and the displacement relative to the ferrule or washer when the rolling element group has different angular positions

31. Theoretical radial internal clearance

contact diameter of outer ring raceway minus contact diameter of inner ring raceway minus twice the diameter of rolling element

32. Axial internal clearance

when there is no external load, the arithmetic mean of the axial distance of one ring or washer moving from one axial limit position to the opposite limit position relative to the other ring or washer. This average value includes the mutual displacement of the ferrule or washer at different angular positions and the displacement of the rolling element group relative to the ferrule or washer at different angular positions

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