JP2017093255A - Rotor of rotary electric machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To inhibit a stator from being damaged by foreign matter in the cooling liquid in a rotary electric machine which discharges the cooling liquid toward a stator from a passage provided inside a rotor.SOLUTION: In a rotor 12, a cooling liquid passage 32 is provided which extends the inside of the rotor 12 from a radial inner side toward an outer side and discharges the cooling liquid from the outer peripheral surface of the rotor. On the inner wall surface of the cooling liquid passage 32, a foreign matter capture recess 34 is provided which is recessed in the circumferential direction of the rotor 12. The foreign matter capture recess 34 is located on the radial inner side than a permanent magnet 24. Foreign matter of the magnetic metal such as abrasion powder of gears is captured in the foreign matter capture recess 34 by a magnetic force of a permanent magnet 24.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a rotor of a rotating electrical machine, and more particularly to a rotor having a coolant flow path provided therein.

  An electric motor that converts electrical energy into rotational kinetic energy, a generator that converts rotational kinetic energy into electrical energy, and an electric device that functions as both the motor and the generator are known. Hereinafter, these electric devices are referred to as rotating electric machines. The rotating electrical machine has two members that are arranged coaxially and relatively rotate. Normally, one is fixed and the other rotates. A coil can be disposed on a fixed member (stator), and a rotating magnetic field is formed by supplying electric power to the coil. The other member (rotor) is rotated by the interaction with the magnetic field.

  The following Patent Document 1 discloses an in-rotor refrigerant flow path (22) that is formed in the rotor (16) and sends a coolant (refrigerant) toward the outer peripheral surface of the rotor (see paragraph 0024, FIG. 1, etc.). ). In addition, the code | symbol in () is used by patent document 1, and is not related with the code | symbol used by embodiment of this application.

JP 2014-230408 A

  When particulate foreign matter is mixed in the coolant, the foreign matter is discharged together with the coolant toward the stator arranged so as to surround the rotor. This discharged foreign matter may damage the stator core, for example, the insulation coating of the stator core.

  An object of the present invention is to suppress damage to a stator core caused by discharging coolant from a flow path provided in a rotor to the stator.

  The rotor of the rotating electrical machine according to the present invention is a rotor in which a permanent magnet is disposed on the outer peripheral portion, and extends inside the rotor from the radially inner side to the outer side of the rotor, and discharges the cooling liquid from the outer peripheral surface of the rotor. The flow path and the inner wall surface of the coolant flow path have a foreign matter collecting recess that is recessed in the circumferential direction of the rotor. The foreign matter collecting recess is located on the radially inner side of the rotor from the permanent magnet.

  Magnetic metal foreign matter such as gear wear powder can be collected in the foreign matter collecting recess by the magnetic force of the permanent magnet disposed on the rotor, and foreign matter discharged toward the stator can be reduced.

  By reducing the amount of foreign matter discharged toward the stator, damage to the stator core can be suppressed.

It is sectional drawing containing the rotating shaft line of a rotary electric machine. It is sectional drawing orthogonal to the rotating shaft line of a rotor. It is an enlarged view of a foreign material collection hollow. It is an enlarged view which shows the other modification of a foreign material collection hollow.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a view showing a cross section including the rotation axis C of the rotating electrical machine 10 of the present embodiment, is symmetric with respect to the rotation axis C, and the left half is omitted. FIG. 2 is a view showing a cross section orthogonal to the rotation axis C of the rotor 12 of the rotating electrical machine 10, and shows a quarter of the entire circumference. 3 is a cross-sectional view taken along line AA shown in FIG. Hereinafter, the direction along the rotational axis C is referred to as “axial direction”, and the direction perpendicular to the rotational axis C is referred to as “radial direction”. Further, the radially inner side means the side closer to the rotation axis C, and the radially outer side means the far side.

  The rotating electrical machine 10 includes a substantially cylindrical rotor 12 and a substantially cylindrical stator 14 that is concentric with the rotor 12 and is disposed so as to surround the rotor 12. The rotor 12 includes a cylindrical rotor core 16 and a rotor shaft 18 that passes through the center of the rotor core 16. The rotor 12 rotates around the rotor shaft 18. The center line of the rotor shaft 18 is the rotation axis C. The rotor core 16 is formed from laminated electromagnetic steel sheets 20. The rotor core 16 is formed with a magnet accommodation hole 22 extending in parallel with the rotation axis C, and the permanent magnet 24 is disposed in the magnet accommodation hole 22. The shape of the permanent magnet 24 is a rectangular parallelepiped, and one side thereof is arranged in parallel to the rotation axis C. The permanent magnet 24 is arranged such that one pole is radially outside the rotor and the other pole is radially inside. As is well shown in FIG. 2, the permanent magnets 24 are arranged in a V shape with two open outwards, and the two form a pair to form one magnetic pole. In FIG. 2, permanent magnets 24A and 24B are permanent magnets forming one magnetic pole. The poles of the paired permanent magnets 24A and 24B face the same direction. For example, in both cases, the S pole is arranged radially outside and the N pole is arranged radially inside. The direction of the poles of the pair of permanent magnets adjacent to the paired permanent magnets 24A and 24B is opposite. A flux barrier 26 is formed on the radially inner side of the two permanent magnets 24 (for example, the permanent magnet 24B and the permanent magnet 24C in FIG. 2) on the side close to the pair of adjacent permanent magnets. The flux barrier 26 is a gap and extends along the rotation axis C. The flux barrier 26, which is a gap, has a lower magnetic permeability than other portions of the rotor core formed of a magnetic steel plate, and the magnetic flux extends to avoid this. Thereby, the magnetic path in the rotor core 16 is defined by the flux barrier 26.

  The stator 14 includes a stator core 28 and a coil 30 attached to the stator core 28. Stator core 28 has teeth arranged in a circumferential direction on a surface facing rotor 12, and a coil 30 is formed by winding a conductive wire around the teeth. When a predetermined current is passed through the coil 30, a rotating magnetic field is formed inside the stator 14, and the magnetic field and the permanent magnet 24 of the rotor 12 interact to rotate the rotor 12.

  In the rotor core 16, a coolant channel 32 through which coolant flows is formed. The coolant channel 32 extends from the radially inner side of the rotor core 16 to the outer side, preferably along the radial direction. The coolant flow path 32 extends between the permanent magnets 24A and 24B forming a pair forming one magnetic pole. The cooling liquid flows from the flow path in the rotor shaft 18 to the cooling liquid flow path 32, is guided to the outer peripheral surface of the rotor core 16 by the cooling liquid flow path 32, and is discharged from here to the inner peripheral surface of the stator core 28.

  If the coolant contains foreign matter, the foreign matter may be discharged together with the coolant to the stator core 28, and the stator core 28 may be damaged. Examples of damage to the stator core 28 include damage to the insulation coating of the stator core 28. When the rotating electrical machine 10 is arranged integrally with the transmission, there is a possibility that the abrasion powder of the gears in the transmission becomes a foreign matter. In the case of a rotating electrical machine integrated with a transmission, the coolant of the rotating electrical machine can be used as a lubricating oil for the transmission.

  In this rotating electrical machine 10, a foreign matter collecting recess 34 is provided in the middle of the coolant flow path 32 in order to collect foreign matter in the coolant. The foreign material collecting recess 34 is provided so as to be recessed in the circumferential direction from the inner wall surface of the coolant channel 32. The left-right direction in FIG. 3 is the circumferential direction, and the foreign material collecting recess 34 is formed to have the same width as the width of the coolant channel 32 (the dimension in the axial direction). Foreign matter in the coolant, particularly foreign matter of magnetic metal such as gear wear powder, is trapped in the foreign matter collecting recess 34 by the magnetic force of the permanent magnet 24. The foreign matter collecting recess 34 is preferably located at a position closer to the rotation axis C than the permanent magnet 24, that is, radially inward of the permanent magnet 24. Outside the permanent magnet 24, the magnetic flux formed by the stator 14 is affected, and the direction of the magnetic flux changes, so there is a possibility that foreign matter cannot be collected stably. In comparison, the direction of the magnetic flux is stable at a position inside the permanent magnet 24, so that the foreign matter once captured remains in the foreign matter collecting recess 34.

  Furthermore, the foreign matter collecting depression 34 is preferably disposed at a position radially inside the flux barrier 26. On the radially inner side of the flux barrier 26, the magnetic lines of force extend in the circumferential direction. For this reason, as shown by the arrow M in FIG. 2, it extends in the direction crossing the bottom surface of the foreign material collecting dent 34 to adsorb the foreign material to the bottom surface. Thereby, a foreign material can be caught stably.

  FIG. 4 is a view showing a modification of the shape of the foreign substance collecting recess. The foreign matter collecting recess 36 is formed with a width b wider than the width a of the coolant flow path 32.

  DESCRIPTION OF SYMBOLS 10 Rotating electrical machine, 12 Rotor, 14 Stator, 16 Rotor core, 18 Rotor shaft, 20 Magnetic steel plate, 22 Magnet accommodation hole, 24 Permanent magnet, 26 Flux barrier, 28 Stator core, 30 Coil, 32 Coolant flow path, 34, 36 Foreign material Collection depression.

Claims (1)

A rotor of a rotating electrical machine in which a permanent magnet is arranged on the outer periphery,
A coolant flow path extending from the radially inner side to the outer side of the rotor to discharge the coolant from the outer peripheral surface of the rotor;
On the inner wall surface of the coolant flow path, a foreign matter collecting dent recessed in the circumferential direction of the rotor, the foreign matter collecting dent positioned on the inner side in the radial direction of the rotor from the permanent magnet,
A rotor of a rotating electric machine having

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