Background of the Invention: As is well known, the manufacture of permanent magnet electrical machines as abovementioned requires the assembly of permanent magnet components into the machine. This has traditionally been an operation that has been performed manually and with the advent of powerful rare earth permanent magnets, such as Sm-Co (Samarium Cobalt) and Nd-Fe-B (Neodymium Iron Boron) magnets for example, which provide opportunities for utilisation of permanent magnet machines which previously were satisfied with electromagnetic machines, a need arises to adopt a new approach.

Summary of the Invention: According to the present invention in one of its aspects, a method of assembling permanent magnets into a machine component comprises the steps of providing unmagnetized bodies of magnetic material, particularly though not exclusively a rare earth material such as Sm-Co or Nd-Fe-B abovementioned, automatically supplying said bodies sequentially to a

magnetizing station and magnetizing them at said station, and thereafter automatically moving the magnetized bodies from the magnetizing station and automatically inserting them into respective accommodating locations of said machine component.

The invention also extends to an automatic apparatus for putting the abovementioned method into effect. According to an exemplary embodiment of this aspect of the invention which will be described more fully hereinafter, unmagnetized bodies of Sm-Co or Nd-Fe-B rare earth material, which may have previously been demagnetized by use of equipment substantially as described in WO-A-9829883 and as manufactured and sold by us, are introduced into a means, for example a bowl feeder or like vibratory feeding device, which is arranged to develop a stack of the bodies comprising a predetermined number of bodies all in the same predetermined orientation.

The stacks of bodies are then processed by feeding bodies from each stack, one at a time, to a magnetizing station comprising equipment as mentioned above and substantially as described in WO-A-9829883 where the bodies are indexed from the stack, one at a time, and subjected to magnetization as described in WO-A-9829883. From the magnetizing station, the magnetized bodies are supplied one at a time to an assembly station where they are inserted into respective accommodating recesses of a rotor for a permanent magnet machine. The entire process is effected automatically and under automatic control.

The recesses abovementioned may have adhesive applied to them prior to the insertion of the magnets, so as to hold the magnets in place when the machine is in operation, if the material of the recesses is not ferromagnetic or if the machine will operate at such a high speed as to warrant the use of adhesive. Alternatively or additionally the adhesive could be applied to the magnetized bodies, and/or mechanical securing means for the magnetized bodies could be used.

The arrangement of the above-described embodiment could advantageously be such that the bodies of magnetic material are fed through the magnetizing equipment, operating in a demagnetizing mode, before they are supplied to the bowl feeder, this ensuring that, when they enter the bowl feeder, they do not carry any remanent magnetism such as might interfere with its proper operation. The equipment that is described in WO-A-9829883 has both demagnetizing and magnetizing modes, and the arrangement of the embodiment can advantageously be such that magnetic bodies received from their manufacturer are first input to a magnetizing/demagnetizing station operating in a demagnetizing mode, then go to the bowl feeder and then return to the magnetizing/demagnetizing station now operating in a magnetizing mode. Alternatively, the magnetic state of the bodies can just be checked before they are processed further.

The above and further features of the invention are set forth in the appended claims and will be well understood from consideration of the following description given with reference to the accompanying drawing.

Description of the Drawing : The single drawing figure is a schematic representation of an exemplary embodiment of the present invention.

Detailed Description of the Embodiment: Referring to the drawing, the schematically illustrated system performs the function of loading rare earth magnets into recesses formed in flywheels for use in permanent magnet electric machines such as motors, generators and motor generators. Not shown in the drawing is an input stage where demagnetized rare earth magnetic bodies are stacked and oriented automatically, for example by means of a device such as a bowl feeder.

The assembled stacks of demagnetized bodies, there being 16 bodies in each stack in this particular embodiment, are automatically supplied to a dispensing device which includes an actuator (not shown) controlled to dispense the bodies 1 one at a time from the stack 2 into the magnetizing coil 4 of a magnetizing/demagnetizing apparatus 5 as mentioned hereinbefore and substantially as described in WO-A-9829883 which is operating in its magnetizing mode. The magnetized bodies are then moved from the coil 4 by the actuator and arrive at a loading position where they are inserted into a respective recess 6 in a flywheel 7 which is positioned to receive the respective body by means of a loading station 8. As previously mentioned, an adhesive may be used to secure the bodies 1 in the recesses 6.

The loading station 8 has provision for the mounting of first and second flywheels 7-1 and 7-2 each on an indexable hub (not shown) enabling the flywheels to be controllably rotated in stepwise manner for locating their recesses successively in registry with the loading position for insertion of a magnetized body 1. The operation of the indexing mechanism in the loading station 8 is synchronized with the operation of the actuator and of the magnetizing apparatus 5 by electronic control means (not shown). The loading station 8 also provides for automatic movement of second flywheel 7- 2 into registry with the loading position once the loading of magnetized bodies into the recesses of the first flywheel 7-1 has been completed, the first filled flywheel 7-1 then being removed and replaced by an empty flywheel which will be moved automatically into loading position once flywheel 7-2 has been filled.

The operation of the invention will be clear from the foregoing and it will be appreciated that the invention proposes a fully automated system designed to accept high strength magnets, such as the rare earth Nb-Fe-B magnet material previously referred to or Sm-Co magnets for example, from their supplier/manufacturer, demagnetize them to eliminate residual effects or at least check them to determine their magnetic status, magnetize them appropriately and load them into flywheels or other components substantially without human intervention.

Recent improvements in the properties of Nd-Fe-B and Sm-Co magnets, coupled with the emergence of new designs for large motors,

generators and motor generators, has meant that the magnetization and assembly of such magnets is becoming increasingly safety critical. This is because the magnetic forces and resulting potential mechanical forces are related to the magnetic properties and the size, especially the surface area, of the magnets involved. Unless great care is taken in the machanical handling of these magnets in their magnetized state, there is a great risk to personal safety through potential uncontrolled movement of powerful magnets. The system and method of the present invention enables this problem to be overcome or at least substantially reduced.

The invention having been described by reference to a specific embodiment, it is to be well understood that the embodiment is exemplary only and that modifications and variations are possible without departure from the spirit and scope of the invention. For example, it might be possible to place the magnets in the recesses, with or without use of adhesive, and then magnetize them in situ rather than sliding in already magnetized bodies as described hereinbefore. This might be difficult and possibly impractical for large rare earth machines, but it is theoretically possible.