Apparatus and method for surface hardening of steel balls for a ball bearing

摘要

The apparatus comprises a rotatable driven container (1) with internal radial protrusions (4) extending in the longitudinal direction of the container, and counter-rotatable driven carrier shaft (2) with radial protrusions (5) also extending in the longitudinal direction of the container. The protrusions (4) of the container carry steel balls (3) from the lower region of the container upwards until they run off the protrusions and fall back into the lower region. The protrusions (5) of the counter-rotating shaft collide with falling balls. The claimed method includes loading of the container with balls to be surface hardened, and setting the container and the carrier shaft in rotation in opposite directions, so compressive stresses are built up in the ball surface as a result of multiple impacts.