Apparatus for manufacturing rotor

1 . A manufacturing apparatus for a rotor having a permanent magnet provided in a state of being embedded inside a rotor core, the permanent magnet having a folding shape being convex towards a radially inside part, the manufacturing apparatus comprising:

a magnetization apparatus that magnetizes the permanent magnet in the embedded state from outside the rotor,

wherein

the magnetization apparatus is provided with a yoke part at least disposed in an axially outside part of the rotor, the yoke part constituting a magnetic path for supplying a magnetization flux to the permanent magnet,

the yoke part includes at least one of a dust core, a laminated steel plate, and a slit having a function of suppressing eddy current occurring due to the magnetization flux,

the magnetization apparatus is provided with, as the yoke part, a first yoke disposed in a radially outside of the rotor, a second yoke disposed in an axially outside of the rotor, magnetically coupled with the first yoke and having an insertion protrusion inserted into a shaft insertion hole of the rotor, and a magnetization coil provided on magnetic paths of the first yoke and the second yoke, and

the magnetization apparatus is configured to cause, based on an energization of the magnetization coil, the magnetization flux to flow between the first yoke and the insertion protrusion of the second yoke which oppose each other in a radial direction of the rotor to magnetize the permanent magnet.

2 . The manufacturing apparatus of the rotor according to claim 1 ,

wherein

the first yoke is configured mainly of the laminated steel plate; and

the second yoke is configured mainly of the dust core.

3 . The manufacturing apparatus of the rotor according to claim 2 , wherein

the second yoke moves relatively to the first yoke;

a steel plate is attached to a contact portion of the second yoke at which the second yoke contacts with the first yoke.

4 . The manufacturing apparatus of the rotor according to claim 1 ,

wherein

the first yoke has an opposing surface that opposes an outer peripheral surface of the rotor; and

the slit is formed on the opposing surface.

5 . The manufacturing apparatus of the rotor according to claim 1 ,

wherein

the insertion protrusion of the second yoke is configured of a steel material, having an opposing surface that opposes an inner peripheral surface of the shaft insertion hole of the rotor; and

the slit is formed on the opposing surface.

6 . The manufacturing apparatus of the rotor according to claim 1 ,

wherein

the magnetization apparatus is provided with, as the yoke part, a first yoke disposed in one side of the rotor an axial direction thereof, a second yoke disposed in the other side of the rotor in the axial direction thereof and a magnetization coil provided to each of the first yoke and the second yoke; and

the magnetization apparatus is configured to cause, based on an energization of the magnetization coil, the magnetization flux with the same polarity from both side in the axial direction of a portion of the rotor core positioned inside a folding shaped part of the permanent magnet to magnetize the permanent magnet.

7 . The manufacturing apparatus of the rotor according to claim 6 ,

wherein

the first yoke and the second yoke are configured mainly of the dust core.

8 . A method of manufacturing a rotor having a permanent magnet provided in a state of being embedded in a magnet accommodation hole of a rotor core, the permanent magnet having a folding shape being convex towards a radially inside part, the permanent magnet in the embedded state being magnetized from outside the rotor using a magnetization apparatus, wherein the magnetization apparatus is provided with, as a yoke part, a first yoke disposed in a radially outside of the rotor, a second yoke disposed in an axially outside of the rotor, magnetically coupled with the first yoke and having an insertion protrusion inserted into a shaft insertion hole of the rotor, and a magnetization coil provided on magnetic paths of the first yoke and the second yoke,

the method comprising steps of:

an installation step of inserting an insertion portion of the second yoke into the shaft insertion hole of the rotor, disposing the rotor such that a radially inside part and a radially outside part of the rotor oppose the first yoke and the second yoke in a radial direction, and magnetically connecting the first yoke, the second yoke, and the rotor; and

a magnetization step of causing magnetization flux to flow inside the rotor based on energization of the magnetization coil to magnetize the permanent magnet in the embedded state.

9 . A rotor manufactured by a method of manufacturing a rotor having a permanent magnet provided in a state of being embedded in a magnet accommodation hole of a rotor core, the permanent magnet having a folding shape being convex towards a radially inside part, the permanent magnet in the embedded state being magnetized from outside the rotor using a magnetization apparatus, the magnetization apparatus being provided with, as a yoke part, a first yoke disposed in a radially outside of the rotor, a second yoke disposed in an axially outside of the rotor, magnetically coupled with the first yoke and having an insertion protrusion inserted into a shaft insertion hole of the rotor, and a magnetization coil provided on magnetic paths of the first yoke and the second yoke,

the method comprising steps of:

an installation step of inserting an insertion portion of the second yoke into the shaft insertion hole of the rotor, disposing the rotor such that a radially inside part and a radially outside part of the rotor oppose the first yoke and the second yoke in a radial direction, and magnetically connecting the first yoke, the second yoke, and the rotor; and

a magnetization step of causing magnetization flux to flow inside the rotor based on energization of the magnetization coil to magnetize the permanent magnet in the embedded state,

wherein the rotor comprises:

a rotor core and a permanent magnet provided in a state of being embedded in a magnet accommodation hole of the rotor core, the permanent magnet having a folding shape being convex towards a radially inside part and being magnetized from outside the rotor using the magnetization apparatus, wherein

a magnet pole pitch is defined as a distance on an outer peripheral surface of the rotor core between extending lines extending from inner side surfaces of respective straight parts of the permanent magnet, and an embedded depth is defined as a distance on a center line in a circumferential direction of the permanent magnet from the outer peripheral surface of the rotor core to an inner side surface of a bending portion of the permanent magnet, and

the permanent magnet has a deep folding shape in which the embedded depth is larger than the magnet pole pitch.