Method of and machine for grinding cams

A method of grinding to a predetermined contour each of a plurality of cams which are spaced apart from each other in the direction of a longitudinal axis of an elongated rotary workpiece, comprising the steps of rotating the workpiece about the longitudinal axis;

• and establishing a relative movement between the workpiece and a grinding tool having a material removing implement for each of the cams, including moving each implement and the workpiece relative to each other independently of each other implement and the workpiece in a predetermined direction transversely of the longitudinal axis of the rotating workpiece, the cams being angularly offset relative to each other in the direction of rotation of the workpiece, and said step of establishing said relative movement comprising simultaneously moving the workpiece and at least two implements relative to each other in said predetermined direction, said rotating step including rotating the workpiece about the longitudinal axis at different speeds during different stages of each revolution of the workpiece about said axis, and said rotating step further including establishing discrete patterns for the rotational speeds of said cams such that each of said cams is rotatable at different maximum permissible speeds during different stages of each revolution of the workpiece about said axis, said rotating step additionally including rotating the cams during each stage at least close to the lowest maximum permissible speed corresponding to the respective stage.

A machine for grinding to a predetermined contour each of a plurality of cams which are spaced apart from each other in the direction of a longitudinal axis of an elongated rotary workpiece, comprising a holder for the workpiece;

• means for rotating the workpiece in the holder about the longitudinal axis;
• a grinding tool including a discrete material removing implement for each of the plurality of cams on the workpiece in the holder;
• and means for establishing a relative movement of the rotating workpiece and each of the implements in a direction transversely of the axis of the workpiece in the holder, including means for establishing for each implement a relative movement independently of at least one other implement, said cams being angularly offset relative to each other in the direction of rotation of the workpiece, and said means for establishing a relative movement comprising means for simultaneously moving at least two of said implements relative to each other in said direction, said means for rotating including means for driving the workpiece at different speeds during different stages of each revolution of the workpiece about its axis, and said cams being rotatable at different maximum permissible speeds during different stages of each revolution of the workpiece about its axis, said means for driving comprising means for regulating the angular speed of the workpiece so that the angular speed of the workpiece during each stage is at least close to the lowest maximum permissible speed corresponding to the respective stage.