Roller type one-way clutch

Roller type one-way clutch is composed of periphery, roller, spring and inner ring. The number of rollers is usually 6-8. During operation, if the outer ring of the one-way clutch rotates counterclockwise relative to the inner ring, the roller moves to the big end in the open groove with cam profile and compresses the spring. At this time, the one-way clutch will not lock, but allows the outer ring to rotate, that is, the one-way clutch allows its outer ring to rotate counterclockwise relative to the inner ring at any time. In other words, the inner ring is allowed to rotate clockwise relative to the outer ring.
However, in the working process, if the outer ring of the one-way clutch tries to rotate clockwise relative to the inner ring, the roller will move to the small end in the open groove and wedge between the inner and outer rings to lock them. At the same time, torque can be transmitted between them. At this moment, the function of the spring is to improve the initial wedging action of the roller. Once the roller wedges into the small end of the open groove, the one-way clutch will lock, so that its outer ring is not allowed to rotate clockwise relative to the inner ring, or the inner ring rotates counterclockwise relative to the outer ring.
The contact surface between the outer ring and the roller is made into a cam profile surface with a certain wedge angle. In the existing structure, this angle is generally 6-8 degrees. Considering the influence of machining error and wear in use, in order to maintain the constant wedge angle in the contact section, the cam surface profile of the open groove is often processed into logarithmic helix.
When the roller type one-way clutch works, the contact stress occurs at the contact between the roller and the inner and outer rings. Strictly speaking, because the forces on both sides of the roller are equal, and its contact area with the convex surface of the inner ring is less than that with the concave surface of the outer ring, the contact stress occurs on the contact surface between the roller and the inner ring. Here, the most prone is surface fatigue wear, and the typical failure form is pitting and spalling. The metal materials for manufacturing one-way clutch rollers and inner and outer rings are generally the same as those of rolling bearings.