Analysis on the deformation of slewing ring in machining

Slewing ring is a kind of large-size thin-walled parts, widely used in construction machinery, wind power and other fields. The slewing system of slewing ring is redundantly driven by the meshing of several circumferential distributed pinions with the inner ring teeth of slewing ring, so the deformation of slewing ring will affect the meshing condition of pinions, which makes the load transfer between the axially distributed pinions and bearings different. Under the same step control condition, it is easy to cause the eccentric load of each pair of gears, Therefore, it is necessary to discuss the circumferential deformation characteristics of bearing under load.

The overall performance of slewing ring depends on the dimensional accuracy and form position deviation of the ring to a great extent. The deformation of the ring is an important problem for designers and technologists.

1. Shrinkage of coil

After the heat treatment of the tooth surface and raceway surface, the local structure of the quenched and tempered steel of the slewing bearing ring has changed. The formation of tempered martensite makes the workpiece greatly affected by the structure stress. The structure stress makes the ring of the slewing bearing shrink. This shrinkage is not conducive to the processing of the ring of the slewing bearing, and it makes the size of the part and the blank change obviously.

2. Roundness change of ring

Due to the local induction heat treatment, the cooling of the whole ring is in an unbalanced state, which leads to the effect of thermal stress as well as the effect of microstructure stress. Because the influence of thermal stress on the ring is opposite to the organizational stress, the ring of slewing bearing not only shrinks as a whole, but also deforms locally, which increases the out of roundness of the ring.