Extrusion bullet for a laminated stator core

摘要

The known extrusion bullets are virtually completely surrounded with insulation and have a very small amount of play with respect to the hole in the laminated stator core. Insulation damage can occur as a result of magnetic excitation forces and a pulsating torque. This damage can develop to produce iron fires. The invention is based on the object of avoiding such damage and of detuning the natural frequency (eigen frequency) of the extrusion bullet from the excitation frequency. Centric (2) and eccentric (3) supporting elements are provided alternately on the extrusion bullet (1). These supporting elements have an external diameter which is virtually equivalent to the diameter of the hole in the laminated stator core. The diameter of the extrusion bullet is significantly smaller. The extrusion bullet (1) which is inserted into the hole in the laminated core is bent with its supporting elements (2, 3) in such a manner that a defined detuning of the natural frequency with respect to the excitation frequency is produced.