1. The theoretical rotation axis of rolling imported bearings, for centripetal imported bearings is the axis of the inner ring, and for thrust imported bearings, it refers to the axis of the shaft ring.

    2. Inner ring (shaft washer) axis inner ring (shaft washer) axis

The axis line of the inscribed cylinder or inscribed cone of the basic cylindrical hole or tapered hole of the inner ring (shaft ring).

    3. outer ring (housing washer) axis

If the outer surface of the outer ring is cylindrical, the axis line of the circumscribed cylinder on the outer surface is the axis line of the outer ring. If the surface is basically spherical, then the center of the sphere circumscribed by the outer surface of the ring is vertical The line on the reference end surface of the outer ring is the axis line of the outer ring.

    4. cone (cup)axis

The axis line of the inner ring (outer ring) of a tapered roller bearing.

    5. Radial plane radial plane

The plane perpendicular to the axis line and the plane parallel to the reference end face of the ferrule or the tangent plane on the back of the gasket can be considered as radial planes.

    6. Radial radial direction

The direction passing through the axis in the radial plane.

    7. Axial plane axial plane

A plane containing the axis line.

8. Axial axial direction

Direction parallel to the axis of the bearing. The direction perpendicular to the reference end face of the ring or the tangent plane on the back of the gasket can be considered as the axial direction.

    9. Radial (axial) distance radial (axial) distance

Distance measured in radial (axial) direction.

    10. contact angle (nominal contact angle) contact angle (nominal contact angle)

The angle between the plane (radial plane) perpendicular to the axis of the bearing and the resultant line of action (nominal line of action) transmitted to the rolling elements through the bearing ring or washer.

    11. Nominal contact point nominal contact point

The point where the rolling elements contact the raceway surface when the bearing parts are in their normal relative position.

    12. reference face of a ring (a washer)

The end face of the ferrule (washer) designated by the bearing manufacturer as the datum surface can be used as the datum for measurement.

    11. Nominal contact point nominal contact point

The point where the rolling elements contact the raceway surface when the bearing parts are in their normal relative position.

    12. reference face of a ring (a washer)

The end face of the ferrule (washer) designated by the bearing manufacturer as the datum surface can be used as the datum for measurement.