Patent Number: 047572094
Section: summary

BACKGROUND OF THE INVENTION The present invention relates to a drive for a neutron chopper comprising a stator and drive rotor connected with the rotor of the neutron chopper. Known neutron choppers have been designed with successively placed rotors having radiation windows, the rotors being individually driven by means of synchronous motors with laminated rotors mounted on their shafts. The production of such braced laminated rotors is extremely involved, since the set of laminations has to be produced in several working steps with intermediate stretching by centrifugal force. SHORT SUMMARY OF THE INVENTION One object of the invention is to devise a drive of the sort noted which is extremely simple to manufacture. A further aim of the invention is to devise such a drive that makes possible the satisfactory operation of the rotors of neutron choppers. In order to attain these or other objects that may become apparent in the course of the ensuing specification, in accordance with the invention a drive for a neutron chopper takes the form of a drive rotor connected with the rotor of the said chopper, and a stator, said drive rotor being manufactured of high-tensile steel in the form of a hollow cylinder, one end of said drive rotor being connected concentrically with said chopper rotor, said stator concentrically surrounding said drive rotor. The employment of a hysteresis motor makes possible stable synchronous running, it being possible for the motor to be run up to speed asynchronously with a short and simple running up period. The hollow cylindrical drive rotor, which may be produced by cold forming or hot forming in a single operation, makes it possible for the chopper rotor shaft to be made very much shorter than in the system so far known. This and the low weight of the drive rotor make for a very much lower overall moment of inertia. The connection of the hollow cylindrical drive rotor with the chopper rotor may be preferably by way of a disk or wheel on which the one end of the drive rotor is attached by a press fit. The disk, which may be in the form of an annular disk with spokes, and is made of a non-magnetic material, may be readily attached to the end plate of the drive rotor for example. The annular stator is arranged concentrically around the drive rotor and it is embedded in a radiation resistant and electrically insulating cast composition, which is furthermore resistant to high vacuum. The stator is anchored in the housing of the neutron chopper.