Abstract: A squirrel-cage rotor and a production method thereof, the rotor having conductors with sufficient strength. In the invention, conductor particles are sprayed onto a core and/or conductive bars in a solid-state. As a result, in the coating material, the enlargement of the crystal grain of the conductors is significantly restricted, whereby conductive end rings are connected to the core and/or the conductive bars. Since conductor particles do not melt, a gap formed by thermal contraction when the conductor melts between different kinds of members is prevented from being formed. Therefore, the deterioration of the conductor may be limited, and the conductor may have sufficient strength. The reliability of the rotor is improved.

Abstract: A squirrel-cage rotor includes a rotor core formed having a plurality of slots, a plurality of conductor bars inserted into the slots respectively and made of copper or copper alloy, two conductor end rings joined to the plurality of conductor bars on both end faces of the rotor core and made of copper or copper alloy and a reinforcing-member end ring attached to at least one of the conductor end rings and made of material having a specific strength greater than that of either copper or copper alloy. The plurality of conductor bars are arranged so as to extend through the conductor end rings and the reinforcing-member end ring. Consequently, the rotor can be manufactured by any manufacturing method but die-casting. Further, the conductor end rings can be reinforced with an easily-obtainable material and additionally, the junction of conductor end rings can be easily viewed from an outside.

Abstract: A squirrel-cage rotor and a production method thereof, the rotor having conductors with sufficient strength. In the invention, conductor particles are sprayed onto a core and/or conductive bars in a solid-state. As a result, in the coating material, the enlargement of the crystal grain of the conductors is significantly restricted, whereby conductive end rings are connected to the core and/or the conductive bars. Since conductor particles do not melt, a gap formed by thermal contraction when the conductor melts between different kinds of members is prevented from being formed. Therefore, the deterioration of the conductor may be limited, and the conductor may have sufficient strength. The reliability of the rotor is improved.

Abstract: A squirrel-cage rotor of an induction motor and a production method thereof, wherein locating of the brazing material is not necessary in order to reduce manhours for brazing, and a bar is easily connected to an end ring. Before assembling a rotor core, a silver plated layer is formed on at least one of an end ring and a conductive bar. In order to melt the silver plated layer, the rotor is heated to a temperature which is equal to or larger than the melting point of the silver plated layer. The melted layer functions as a brazing material, whereby the end ring and the conductive bar are connected.

Abstract: A squirrel-cage rotor includes a rotor core formed having a plurality of slots, a plurality of conductor bars inserted into the slots respectively and made of copper or copper alloy, two conductor end rings joined to the plurality of conductor bars on both end faces of the rotor core and made of copper or copper alloy and a reinforcing-member end ring attached to at least one of the conductor end rings and made of material having a specific strength greater than that of either copper or copper alloy. The plurality of conductor bars are arranged so as to extend through the conductor end rings and the reinforcing-member end ring. Consequently, the rotor can be manufactured by any manufacturing method but die-casting. Further, the conductor end rings can be reinforced with an easily-obtainable material and additionally, the junction of conductor end rings can be easily viewed from an outside.

Abstract: A squirrel-cage rotor including a rotor core provided with a plurality of circumferentially disposed slot holes opened in a rotational axis direction of the rotor; a pair of end rings disposed at opposite sides of the rotor core in the rotational axis direction of the rotor, each end ring being provided with a plurality of circumferentially disposed through holes opened corresponding to the plurality of circumferentially disposed slot holes; and a plurality of bar elements respectively inserted through the plurality of slot holes and the plurality of through holes. Each of the pair of end rings is prepared by laminating a plurality of sheet members, and opposite ends of each of the plurality of bar elements and the pair of end rings are brazed together through a brazing filler metal sandwiched between adjacent sheet members in advance, the brazing filler metal being adapted to melt and flow when the rotor is heated.

Abstract: A squirrel-cage rotor including a rotor core provided with a plurality of circumferentially disposed slot holes opened in a rotational axis direction of the rotor; a pair of end rings disposed at opposite sides of the rotor core in the rotational axis direction of the rotor, each end ring being provided with a plurality of circumferentially disposed through holes opened corresponding to the plurality of circumferentially disposed slot holes; and a plurality of bar elements respectively inserted through the plurality of slot holes and the plurality of through holes. Each of the pair of end rings is prepared by laminating a plurality of sheet members, and opposite ends of each of the plurality of bar elements and the pair of end rings are brazed together through a brazing filler metal sandwiched between adjacent sheet members in advance, the brazing filler metal being adapted to melt and flow when the rotor is heated.

Abstract: A control unit for a machine tool at least one vibration detection device attached to a main shaft portion of a machine tool or a movable body; a storage device for storing a vibration signal detected by the vibration detection device being related to operation information of the machine tool; a collision judgment device for judging that a collision has occurred; and an output device for outputting the vibration signal at the time of judging the occurring of the collision. By the above constitution, the control unit is capable of grasping a specific circumstance of collision and quickly determining a cause of collision.

Abstract: A control unit (10) for a machine tool comprises: at least one vibration detection means (31 to 33) attached to a main shaft portion (30) of a machine tool or a movable body moving relative to the main shaft portion (30), for example, attached to a holding table for a workpiece; a storage means (11) for storing a vibration signal detected by the vibration detection means being related to operation information of the machine tool; a collision judgment means (12) for judging that a collision has occurred in the case where the vibration signal stored in the storage means exceeds a previously determined threshold value when comparing the vibration signal with the threshold value; and an output means (13) for outputting the vibration signal at the time of judging the occurring of the collision and also outputting the operation information stored in the storage means related to the vibration signal in the case where the collision judgment means judges that the collision has occurred.

Abstract: A method of insulating the proximal portions of the coil edges of the stator. The insulation sheet has a folding portion for folding one or more coils of the same phase and two insertion portions extending from the folding portion so that distal ends are positioned away from a centerline of the folding portion. One or more coils of the same phase are folded by the folding portion and the two inserting portions are inserted into the slot or slots from which the one or more coils project. The inserting portions are drawn from inside of the stator core so that the folding portion spreads to fold the proximal portions of the coils. The inserting portions are securely held between the wall of the slots and the coils to prevent the insulation sheet from displacement, inclination and slip off to securely insulate the coils of different phases.

Abstract: An electric motor capable of ensuring insulation of proximal portions of coil edges of a stator projecting from end of a stator core, and a method of insulating the proximal portions of the coil edges of the stator. The insulation sheet has a folding portion for folding one or more coils of the same phase and two insertion portions extending from the folding portion so that distal ends are positioned away from a centerline of the folding portion. One or more coils of the same phase are folded by the folding portion and the two inserting portions are inserted into the slot or slots from which the one or more coils project. The inserting portions are drawn from inside of the stator core so that the folding portion spreads to fold the proximal portions of the coils. The inserting portions are securely held between the wall of the slots and the coils to prevent the insulation sheet from displacement, inclination and slip off to securely insulate the coils of different phases.

Abstract: An electric motor capable of ensuring insulation of proximal portions of coil edges of a stator projecting from end of a stator core, and a method of insulating the proximal portions of the coil edges of the stator. The insulation sheet has a folding portion for folding one or more coils of the same phase and two insertion portions extending from the folding portion so that distal ends are positioned away from a centerline of the folding portion. One or more coils of the same phase are folded by the folding portion and the two inserting portions are inserted into the slot or slots from which the one or more coils project. The inserting portions are drawn from inside of the stator core so that the folding portion spreads to fold the proximal portions of the coils. The inserting portions are securely held between the wall of the slots and the coils to prevent the insulation sheet from displacement, inclination and slip off to securely insulate the coils of different phases.

Abstract: An electric motor capable of ensuring insulation of proximal portions of coil edges of a stator projecting from end of a stator core, and a method of insulating the proximal portions of the coil edges of the stator. The insulation sheet has a folding portion for folding one or more coils of the same phase and two insertion portions extending from the folding portion so that distal ends are positioned away from a centerline of the folding portion. One or more coils of the same phase are folded by the folding portion and the two inserting portions are inserted into the slot or slots from which the one or more coils project. The inserting portions are drawn from inside of the stator core so that the folding portion spreads to fold the proximal portions of the coils. The inserting portions are securely held between the wall of the slots and the coils to prevent the insulation sheet from displacement, inclination and slip off to securely insulate the coils of different phases.