Patent ID: 7649293

Claim:
A rotor ( 1 ) of an electrical machine ( 10 ), having at least one permanent magnet ( 3 ), which is embodied as a hollow cylinder ( 5 ) and which has axial smooth contact faces ( 20 ) that cooperate with corresponding axial clamping faces ( 22 ) of at least one retaining element ( 4 ), with which element the permanent magnet ( 3 ) is secured to the rotor ( 1 ), wherein at least one of the clamping faces ( 22 ) has a knurling ( 46 ) extending in the radial direction, wherein the retaining element ( 4 ) has a spring element ( 30 , 32 ) which presses the clamping face ( 22 ) against the contact face ( 20 ) with a contact pressure, and wherein the radial knurling ( 46 ) is configured so that under an action of an axial clamping force it digs into an element selected from the group consisting of the smooth contact faces ( 20 ) of the magnet, and a smooth surface coating of the magnet, wherein the knurling ( 46 ) has radial grooves ( 50 ) and axially pointed raised areas ( 48 , 52 ) which extend in the radial direction, wherein the axially pointed raised areas ( 48 , 52 ) have sharp edges ( 52 ) with wedge-shaped points ( 54 ) and are composed of a high-strength material, penetrating more easily into the smooth contact faces ( 20 ) that are softer.