Patent ID: 8143760
Filing Date: 2012-03-27
Classification: H02K,Y10T

Abstract:
1. Miniature electrical drive, in particular a rotating field drive with permanent magnet excitation, comprising a stator, a rotor and a soft-magnetic return path element, the stator including a stator core formed of stator windings, the rotor being mounted to rotate within the stator, the return path element cylindrically surrounding the stator and having a multiplicity of sheet-metal laminates in the form of annular disks and arranged in layers to form a cylindrical laminated core, whereby the sheet-metal laminates in the laminated core are held prestressed with a force fit exclusively in the radial direction in a supporting sleeve, whereby the sheet-metal laminates of the laminated core make touching contact with the supporting sleeve in the area of an external circumference of the sheet-metal laminates just at contact points distributed around the external circumference, and are therefore held with a force fit, and the sheet metal laminates in the laminated core are held axially prestressed in an interlocking manner in the axial direction, and without adhesives in the supporting sleeve which coaxially surrounds the sheet-metal laminates, whereby the layered sheet-metal laminates in the laminated core are held axially between holding embossed areas on the supporting sleeve, the holding embossed areas being distributed around the external circumference on each axial face of the laminated core and projecting radially inwards from the supporting sleeve and contacting each axial face.