JP2011250500A - Rotary electric machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rotary electric machine that allows sufficient cooling of a field coil even in a structure where there is no space between claw-like outer magnetic poles.SOLUTION: A spiral inner groove 15 is formed in an outer circumferential surface of an inner yoke portion 7a that is positioned opposite to a field yoke 13. Also, a spiral outer groove 16 is formed in a surface of an inside diameter side of each of outer magnetic poles 7c that is positioned opposite to the field yoke 13 and a field coil 14. The inner groove 15 is configured in such a manner that cooling air is moved in an axial direction by rotation of a rotator 7. The outer groove 16 is configured in such a manner that the cooling air is moved in the opposite direction of the inner groove 15 by the rotation of the rotator 7.

Description

  The present invention relates to a rotating electrical machine such as a vehicular AC generator or a vehicular AC electric motor, and more particularly to a cooling structure for a rotating electrical machine having a field coil.

  For example, a vehicular AC generator using a large Landell rotor has been used for several decades as a generator for large automobiles such as buses and trucks. In the vehicle alternator using such a Landel rotor, a structure in which the field coil is attached to the fixed side and the slip ring is not used is employed in consideration of the life of the slip ring.

  Moreover, in the conventional large-scale Landell type vehicle alternator, the field coil is cooled by the cooling air flowing through the gaps between the claw-shaped magnetic poles (see, for example, Patent Document 1). However, if a magnet or the like is inserted between the claw-shaped magnetic poles to improve the output, the cooling air flowing between the claw-shaped magnetic poles disappears, the field coil cooling performance is lowered, and the temperature rises ( For example, see Patent Document 2). Such a decrease in cooling performance is also observed in other Landell type structures (see, for example, Patent Document 3).

  On the other hand, as a method for improving the cooling performance, a method of cooling a power generation coil by providing a centrifugal fan inside the rotor has been proposed (for example, see Patent Document 4).

JP 2001-128397 A JP 2002-335660 A JP-A-6-22482 JP 59-35547 A

  As described above, in the conventional rotating electrical machines shown in Patent Documents 2 and 3, since there is no gap between the claw-shaped magnetic poles, there is no cooling air flowing through the gap between the claw-shaped magnetic poles, and the field coil cooling performance is reduced. . On the other hand, as shown in Patent Document 4, the cooling performance cannot be sufficiently improved in the structure in which the centrifugal fan is provided inside the rotor.

  The present invention has been made to solve the above-described problems, and is capable of sufficiently cooling a field coil even when there is no gap between the claw-shaped outer magnetic poles. The purpose is to obtain an electric machine.

  The rotating electrical machine according to the present invention includes a housing, a cylindrical inner yoke portion, an outer magnetic pole portion facing the outer peripheral surface of the inner yoke portion, and an end magnetic pole portion provided between the inner yoke portion and the outer magnetic pole portion. A rotor provided rotatably in the housing, a stator fixed in the housing and surrounding the rotor, a space fixed between the inner yoke portion and the outer magnetic pole portion A field yoke that is inserted in the field yoke, and a field coil that is supported by the field yoke and forms a magnetic pole at the outer magnetic pole portion by the generated magnetic flux. A spiral inner groove that moves the cooling air in the axial direction is formed, and a spiral inner groove that moves the cooling air in the direction opposite to the inner groove by the rotation of the rotor is formed on the inner diameter side surface of the outer magnetic pole part. An outer groove is formed.

  In the rotating electrical machine of the present invention, the inner groove and the outer groove are formed in the rotor, and the cooling air is caused to flow around the field coil by the rotation of the rotor, so there is no gap between the claw-shaped outer magnetic poles. Even with such a structure, the field coil can be sufficiently cooled.

It is sectional drawing which follows the axis line of the rotary electric machine by Embodiment 1 of this invention. It is a side view which shows the 1st example of the inner side yoke part of FIG. It is a side view which shows the 2nd example of the inner side yoke part of FIG. It is sectional drawing which follows the axis line of the Landell type rotary electric machine by Embodiment 2 of this invention. It is sectional drawing which follows the axis line of the Landell type rotary electric machine by Embodiment 3 of this invention. It is sectional drawing which follows the axis line of the Landell type rotary electric machine by Embodiment 4 of this invention.

Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.
Embodiment 1 FIG.
FIG. 1 is a cross-sectional view taken along the axis line of a Landell type rotary electric machine according to Embodiment 1 of the present invention. In the figure, a disc-shaped first bracket 2 is fixed to one axial end portion of a cylindrical frame 1. A disc-shaped second bracket 3 is fixed to the other axial end of the frame 1. The frame 1 and the brackets 2 and 3 constitute a housing.

  A shaft (rotating shaft) 4 is penetrated through the centers of the first and second brackets 2 and 3. The shaft 4 is rotatably supported by the first and second brackets 2 and 3 via bearings 5 and 6.

  A Landel type rotor 7 is fixed to the shaft 4. The rotor 7 includes a cylindrical inner yoke portion 7a fixed to the shaft 4, an end magnetic pole portion 7b protruding radially outward from an end portion of the inner yoke portion 7a on the first bracket 2 side, and an end magnetic pole portion. And a plurality of claw-shaped outer magnetic pole portions 7c protruding from the radially outer end portion of 7b toward the second bracket 3 side.

  The outer magnetic pole portions 7c are arranged at intervals in the circumferential direction. In addition, inter-magnetic pole members (not shown) are arranged between the outer magnetic pole portions 7c adjacent in the circumferential direction. For example, a permanent magnet (not shown) magnetized in the circumferential direction, a nonmagnetic material, or the like is used as the member between the magnetic poles.

  The outer magnetic pole portion 7c faces the outer peripheral surface of the inner yoke portion 7a. First cooling fins 8 are fixed to the end portions of the outer magnetic pole portions 7c facing the first bracket 2. A plurality of second cooling fins 9 are fixed at intervals in the circumferential direction at the radially outer end portion of the surface of the end magnetic pole portion 7b facing the second bracket 3.

  A stator 10 is fixed to the inner peripheral surface of the frame 1. The stator 10 is opposed to the outer peripheral surface of the rotor 7 via a certain air gap. The stator 10 includes a cylindrical stator core 11 that surrounds the rotor 7, and a stator coil 12 that is wound around the stator core 11.

  A base end portion of a cylindrical field yoke 13 serving as a magnetic path is fixed to the second bracket 3. The tip of the field yoke 13 is inserted into the space between the inner yoke portion 7a and the outer magnetic pole portion 7c. A field coil 14 is fixed to the outer periphery of the tip of the field yoke 13. That is, the field coil 14 is supported by the field yoke 13 and is disposed between the inner yoke portion 7a and the outer magnetic pole portion 7c.

  A magnetic pole is formed on the outer magnetic pole portion 7c by the magnetic flux generated by the field coil. Further, an alternating current is generated in the stator coil 12 due to a change in magnetic flux from the field coil 14 as the rotor 7 rotates.

  A spiral inner groove (first groove) 15 is formed on the outer peripheral surface of the inner yoke portion 7 a facing the field yoke 13. A spiral outer groove (second groove) 16 is formed on the inner diameter side surface of the outer magnetic pole portion 7 c facing the field yoke 13 and the field coil 14.

  2 is a side view showing a first example of the inner yoke portion 7a in FIG. 1, and FIG. 3 is a side view showing a second example of the inner yoke portion 7a in FIG. In the second example, the width of the inner groove 15 is larger than in the first example. The inner groove 15 is configured to move the cooling air in the axial direction when the rotor 7 rotates. By forming the inner groove 15 in the right-handed screw direction or the left-handed screw direction, the flow direction of the cooling air when the rotor 7 rotates in the same direction can be changed.

  The outer groove 16 has the same structure as the inner groove 15 except for the formation position. The outer groove 16 is configured to move the cooling air in the direction opposite to the inner groove 15 by the rotation of the rotor 7. Further, the outer groove 16 is also formed continuously on the inner diameter side surface of the member between the magnetic poles.

  The first bracket 2 is provided with a plurality of first bracket vents 2 a for taking cooling air into the frame 1. The first bracket vents 2a are arranged on the same circumference centered on the shaft 4 with a predetermined interval in the circumferential direction.

  The second bracket 3 is provided with a plurality of second bracket vents 3 a for taking cooling air into the frame 1. The second bracket vents 3a are arranged on the same circumference around the shaft 4 with a predetermined interval in the circumferential direction. Further, the second bracket vent 3 a is disposed radially inward from the fixed portion of the field yoke 13.

  In the vicinity of the first bracket 2 of the frame 1, a plurality of first frame vent holes 1 a for discharging the cooling air mainly taken in from the first vent holes 2 a are provided. The first frame vents 1a are arranged at a predetermined interval in the circumferential direction.

  In the vicinity of the second bracket 3 of the frame 1, a plurality of second frame vent holes 1 b for mainly discharging the cooling air taken in from the second vent holes 3 a are provided. The second frame vents 1b are arranged at a predetermined interval in the circumferential direction.

  Next, the operation will be described. What is indicated by an arrow in FIG. 1 is the flow of the cooling air. The cooling air taken into the frame 1 from the first bracket vent 2a by the first cooling fin 8 cools the stator core 11 and the stator coil 12, and then passes through the first frame vent 1a. To be released out of the frame 1.

  In addition, the cooling air taken into the frame 1 from the second bracket vent 2a by the second cooling fin 9 passes between the inner yoke portion 7a and the field yoke 13 by the inner groove 15 in the left direction in the figure. Sucked into. At this time, the field yoke 13 is cooled by the cooling air, and the field coil 14 is also cooled by heat conduction.

  Further, the cooling air sucked between the inner yoke portion 7a and the field yoke 13 is moved to the right in the drawing between the field yoke 13 and the field coil 14 and the outer magnetic pole portion 7c by the outer groove 16. Released. At this time, the field coil 14 and the field yoke 13 are cooled by the cooling air.

  The cooling air discharged from between the rotor 7 and the field yoke 13 further cools the stator core 11 and the stator coil 12, and then releases to the outside of the frame 1 through the second frame vent hole 1b. Is done.

  In such a Landell type rotary electric machine, the inner groove 15 and the outer groove 16 are formed in the rotor 7, and the cooling air is caused to flow around the field coil 14 by the rotation of the rotor 7. Even if the structure has no gap between the outer magnetic poles, the field coil 14 can be sufficiently cooled. Thereby, a temperature rise can be reduced and an output can be improved.

Embodiment 2. FIG.
Next, FIG. 4 is a cross-sectional view taken along the axis of the Landell type rotary electric machine according to Embodiment 2 of the present invention. In the figure, the field yoke 13 is provided with a plurality of field yoke vent holes 13a for communicating cooling air from the inside space to the outside. The field yoke vent holes 13a are arranged at a predetermined interval in the circumferential direction. Other configurations are the same as those in the first embodiment.

  Next, the operation will be described. What is indicated by an arrow in FIG. 4 is the flow of the cooling air. The cooling air taken into the frame 1 from the first bracket vent 2a by the first cooling fin 8 cools the stator core 11 and the stator coil 12, and then passes through the first frame vent 1a. To be released out of the frame 1.

  Further, the cooling air taken into the frame 1 from the second bracket vent 2a by the second cooling fin 9 is sucked between the inner yoke portion 7a and the field yoke 13 by the inner groove 15, It is separated from the portion passing through the field yoke vent hole 13a. The field yoke 13 is cooled by the cooling air sucked between the inner yoke portion 7a and the field yoke 13, and the field coil 14 is also cooled by heat conduction.

  Further, the cooling air sucked between the inner yoke portion 7a and the field yoke 13 is moved to the right in the drawing between the field yoke 13 and the field coil 14 and the outer magnetic pole portion 7c by the outer groove 16. Released. At this time, the field coil 14 and the field yoke 13 are cooled by the cooling air.

  Furthermore, the field yoke 13 is also cooled by the cooling air flowing radially outward through the field yoke vent hole 13a, and the field coil 14 is cooled by heat conduction.

  The cooling air that has cooled the field yoke 13 further cools the stator core 11 and the stator coil 12, and then is discharged out of the frame 1 through the second frame vent hole 1b.

  Even with such a configuration, the field coil 14 can be sufficiently cooled, and the stator core 11 and the stator coil 12 which are heating elements can be sufficiently cooled, further reducing the temperature rise. The output can be improved.

Embodiment 3 FIG.
Next, FIG. 5 is a cross-sectional view taken along the axis of a Landell type rotary electric machine according to Embodiment 3 of the present invention. In the figure, a good heat conducting member 17 is disposed on the inner peripheral surface of the field yoke 13 (the surface facing the inner yoke portion 7a). The good heat conducting member 17 is made of a material having a higher thermal conductivity than the field yoke 13, such as copper or aluminum. Other configurations are the same as those in the first embodiment.

  In such a Landell type rotary electric machine, the flow of the cooling air is the same as that of the first embodiment, but the good heat conduction member 17 is provided on the inner peripheral surface of the field yoke 13, so that the heat conduction is further promoted. Thus, the field coil 14 can be efficiently cooled. Thereby, the temperature rise can be further reduced and the output can be improved.

In FIG. 5, the good heat conducting member 17 is provided on the entire inner peripheral surface of the field yoke 13. Also in this case, the temperature rise can be reduced and the output can be improved as compared with the case where the good heat conducting member 17 is not provided.
Further, the field yoke 13 of the third embodiment may be provided with the field yoke vent hole 13a shown in the second embodiment.

Embodiment 4 FIG.
Next, FIG. 6 is a cross-sectional view taken along the axis of the Landell type rotary electric machine according to Embodiment 4 of the present invention. In the drawing, a plurality of auxiliary fins 18 are provided on an end surface of the inner yoke portion 7a facing the second bracket 3. The auxiliary fins 18 are disposed in the vicinity of the radially outer end of the end face of the inner yoke portion 7a with a predetermined interval in the circumferential direction. Other configurations are the same as those in the first embodiment.

  In such a Landell type rotary electric machine, the flow of the cooling air is the same as that in the first embodiment, but the cooling air is pushed between the inner yoke portion 7 a and the field yoke 13 by the auxiliary fins 18. For this reason, the amount of cooling air flowing between the inner yoke portion 7a and the field yoke 13 increases, and the field coil 14 can be efficiently cooled. Thereby, the temperature rise can be further reduced and the output can be improved.

The field yoke 13 of the fourth embodiment may be provided with the field yoke air vent 13a shown in the second embodiment, or the good heat conducting member 17 shown in the third embodiment.
Moreover, in Embodiment 1-4, although the field yoke 13 was fixed to the 2nd bracket 3, you may fix to the flame | frame 1 and there exists the same effect.
Further, in the first to fourth embodiments, the Landell type rotary electric machine has been described. However, the present invention can be applied to other types of rotary electric machines as long as the rotary electric machine has a similar structure, and the same effects are achieved.

  1 frame (housing), 2 first bracket (housing), 3 second bracket (housing), 7 rotor, 7a inner yoke portion, 7b end magnetic pole portion, 7c outer magnetic pole portion, 10 stator, 13 field Yoke, 13a Field yoke vent, 14 Field coil, 15 Inner groove, 16 Outer groove, 17 Good heat conducting member, 18 Auxiliary fin.

Claims (4)

housing,
A housing having a cylindrical inner yoke portion, an outer magnetic pole portion facing the outer peripheral surface of the inner yoke portion, and an end magnetic pole portion provided between the inner yoke portion and the outer magnetic pole portion; A rotor provided rotatably inside,
A stator fixed in the housing and surrounding the rotor;
A field yoke fixed in the housing and inserted into a space between the inner yoke portion and the outer magnetic pole portion, and supported by the field yoke, and a magnetic flux generated on the outer magnetic pole portion by the generated magnetic flux. A field coil forming
A spiral inner groove that moves the cooling air in the axial direction by the rotation of the rotor is formed on the outer peripheral surface of the inner yoke portion.
A rotating electrical machine characterized in that a spiral outer groove for moving cooling air in a direction opposite to the inner groove by rotation of the rotor is formed on the inner diameter side surface of the outer magnetic pole portion.   2. The rotating electrical machine according to claim 1, wherein the field yoke is provided with a plurality of field yoke vent holes communicating with the inside and outside of the field yoke.   The surface of the field yoke facing the inner yoke portion is provided with a good heat conduction member made of a material having a higher thermal conductivity than the field yoke. 2. The rotating electrical machine according to 2.   2. A plurality of auxiliary fins for injecting cooling air between the inner yoke portion and the field yoke are provided in the vicinity of the radially outer end portion of the end face of the inner yoke portion. The rotating electrical machine according to any one of claims 1 to 3.

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