JP2014033491A - Rotary electric machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To cause a ventilation fin 14 to blow cooling air Wconcentrically to brushes 7a, 7b, 7c and slip rings 6a, 6b, 6c thereby improving the efficiency of cooling of the brushes 7a, 7b, 7c and the slip rings 6a, 6b, 6c and removal of abrasion powder of the brushes 7a, 7b, 7c.SOLUTION: A rotary electric machine 101 includes: a housing 1; a rotation shaft 4 rotatably supported by the housing 1; slip rings 6a, 6b, 6c which are provided so as to rotate with the rotation shaft 4; brushes 7a, 7b, 7c which are provided so as to contact with the slip rings 6a, 6b, 6c; brush holders 8a, 8b, 8c which fix the brushes 7a, 7b, 7c to the housing 1; air blower fins 14 provided on the rotation shaft 4; and a fan shroud 16 which is provided facing the ventilation fins 14 in the radial direction.

Description

  The present invention relates to a rotating electrical machine, and more particularly, to a rotating electrical machine including a plurality of brushes for supplying electric power to a rotor.

  A rotating electrical machine such as a motor generally has a stator fixed to a casing, a rotor that can rotate relative to the stator, and a brush that supplies electric power to the rotor. The brush is in sliding contact with a slip ring provided on the outer periphery of the rotating shaft, and electric power is supplied to the slip ring via the brush. Here, a portion including the brush and the slip ring in the rotating electrical machine is a feeding portion. In the power feeding portion, the brush and the slip ring rub against each other, so that the brush is shaved and wear powder is generated, and the power feeding efficiency to the slip ring may be reduced. Further, the brush and the slip ring generate heat due to the power supply to the slip ring via the brush and the friction between the brush and the slip ring. If the brush or slip ring is left heated, the durability of the device may be reduced.

In view of the above problem, Patent Document 1 includes a blowing blade 114 for sending the cooling air W ₀ to at least one of the brush 107 or the slip ring 106 when the rotating shaft 104 rotates as shown in FIG. A rotating electrical machine is described. Blast vanes 114 is provided on the rotary shaft 104, to remove the abrasion powder of the brush 107 by the cooling air _{W 0,} to cool the brushes 107 and the slip ring 106.

JP 2011-205815 A

However, in the rotating electrical machine disclosed in Patent Document 1, a part of the cooling air W ₀ generated by the rotation of the blowing blade 114 does not directly hit the brush 107 or the slip ring 106 but diffuses in the radial direction of the blowing blade 114. End up. For this reason, the blowing blade 114 cannot efficiently blow the air to the brush 107 and the slip ring 106, and the efficiency of cooling the brush and the slip ring and removing the abrasion powder of the brush is reduced.

  The present invention has been made to solve such a problem, and the blowing blades blow cooling air intensively to the brush and slip ring, thereby cooling the brush and slip ring and removing the abrasion powder of the brush. An object of the present invention is to provide a rotating electrical machine capable of improving the above.

A rotating electrical machine according to the present invention includes a housing, a rotating shaft that is rotatably supported by the housing, a slip ring that is provided to rotate together with the rotating shaft, and a brush that is provided so as to be in contact with the slip ring. And a brush holder for fixing the brush to the housing, a blowing blade provided on the rotation shaft, and a wind guide member provided to face the blowing blade in the radial direction.
As described above, by providing the air guide member around the blowing blade, the cooling air can be efficiently blown toward the plurality of brushes and the slip ring without diffusing.

  In the rotating electrical machine according to the present invention, the air guide member may be cylindrical. Furthermore, a plurality of brushes are provided, and when the plurality of brushes are viewed along the length direction of the rotation axis, the position of the brush may be shifted along the circumferential direction around the rotation axis. Good.

  According to the present invention, in the rotating electrical machine, the blowing blades intensively blow cooling air to the brush and the slip ring, and the efficiency of cooling the brush and the slip ring and removing the abrasion powder of the brush can be improved.

It is sectional drawing which shows typically the mode of the electric power feeding part of the rotary electric machine which concerns on Embodiment 1 of this invention. It is a figure which shows typically a mode when the electric power feeding part of the rotary electric machine of FIG. 1 is seen along the length direction X of a rotating shaft. It is a figure which shows typically the mode of the cross section which cut the electric power feeding part of the rotary electric machine of FIG. 1 along II. It is sectional drawing which shows typically the mode of the electric power feeding part of the rotary electric machine which concerns on Embodiment 2 of this invention. It is a figure which shows typically a mode when the electric power feeding part of the rotary electric machine of FIG. 4 is seen along the length direction of a rotating shaft. It is a figure which shows typically the mode of the cross section which cut the electric power feeding part of the rotary electric machine of FIG. 4 along I'-I '. It is a side view which shows typically the mode of the electric power feeding part of the conventional rotary electric machine.

Embodiments of the present invention will be described below with reference to the accompanying drawings.
Embodiment 1 FIG.
FIG. 1 shows a cross-sectional view of a power feeding portion in rotating electric machine 101 according to Embodiment 1 of the present invention. This power feeding portion is electrically connected to a motor (not shown) of the rotating electrical machine 101. The motor includes a rotor (not shown) and a stator (not shown), and the rotating electrical machine 101 includes a housing 1 that houses the rotor and the stator. The stator is fixed to the housing 1 and the motor is integrally attached to a rotating shaft 4 that is rotatably supported by the housing 1 so as to be rotatable relative to the stator.

  In the rotating electrical machine 101, the rotating shaft 4 is rotatably supported by the housing 1 and protrudes from the power feeding portion. The rotating shaft 4 is connected to an engine (not shown) of the rotating electrical machine 101 and the rotor described above, and rotates in the circumferential direction A. Further, a substantially L-shaped plate-like support portion 1 a is integrally formed on the outside of the housing 1 on the power feeding portion side. That is, the support part 1 a constitutes a part of the housing 1. Here, the outer periphery of the rotating shaft 4 is covered with an insulator 15 made of resin inside the substantially L-shape of the support portion 1a. The insulator 15 is attached so as to be rotatable together with the rotating shaft 4. Further, three annular slip rings 6 a, 6 b, 6 c are arranged at equal intervals on the outer periphery of the insulator 15, and are fixed so as to be integrally rotatable with the rotary shaft 4. And brush 7a, 7b, 7c is provided in the position corresponding to slip ring 6a, 6b, 6c, respectively inside support part 1a. The brushes 7a, 7b, and 7c are in sliding contact with the slip rings 6a, 6b, and 6c, respectively. The brushes 7a, 7b, and 7c are fixed to the inside of the support portion 1a through the brush holders 8a, 8b, and 8c so as not to rotate. Each of the brush holders 8a, 8b, and 8c is a plate-like member having a shape obtained by cutting a semicircle from a rectangle (see FIG. 2). Further, gaps 11a, 11b, and 11c are formed between the brush holders 8a, 8b, and 8c and the slip rings 6a, 6b, and 6c, respectively. The brushes 7a, 7b and 7c are made of copper or carbon, and the slip rings 6a, 6b and 6c are made of gunmetal, brass, stainless steel or copper.

As shown in FIGS. 1 and 2, three bus bars 12 are attached to the end portion of the rotating shaft 4 that is opposite to the motor side. The bus bar 12 is a copper plate curved along the outer peripheral surface of the rotating shaft 4. A part of the bus bar 12 is sandwiched between the rotating shaft 4 and the insulator 15 and is electrically connected to the slip rings 6a, 6b, 6c, and the remaining part is exposed from the insulator 15 and is separated from the insulator 15. The exposed portion constitutes the blower fin mounting portion 12a. Two substantially trapezoidal plate-like blowing fins 14 are fixedly attached to the blowing fin attachment portion 12a. That is, a total of six blowing fins 14 are fixed to the outer periphery of the rotating shaft 4 via the bus bar 12 so as to be integrally rotatable with the rotating shaft 4. The blowing fins 14 are arranged at an angle inclined with respect to the length direction of the rotating shaft 4, that is, the direction X. The blowing fins 14 are formed of the same material as the bus bar 12, that is, copper, but are not limited thereto, and a material having higher thermal conductivity than the bus bar 12 may be used.
Each bus bar 12 is connected to an electrical wiring 13 that is electrically connected to a rotor (not shown) on the motor side.
In addition, the ventilation fin 14 comprises the blade | wing for ventilation.

  The six fan fins 14 attached to the bus bar 12 are surrounded by a cylindrical fan shroud 16. That is, the fan shroud 16 is provided to face the radial direction of the blower fins 14. Here, the length of the fan shroud 16 in the direction X is configured to be long enough to cover the entire blowing fin 14. The fan shroud 16 is fixed and attached to the end of the support portion 1a so as not to rotate. Further, the fan shroud 16 is formed of the same material as the insulator 15, that is, an appropriate resin material. The fan shroud 16 constitutes an air guide member.

The arrangement of the brushes 7a, 7b, and 7c will be described in detail with reference to FIG.
The brush 7a is attached to the center of the brush holder 8a. That is, it is configured to be in sliding contact with the slip ring 6a at a position directly above the rotation shaft 4. Further, the brush 7b is attached to the brush holder 8b at a position shifted by about 40 degrees in the direction opposite to the circumferential direction A from the center. Further, the brush 7c is attached to the brush holder 8c at a position shifted by about 40 degrees in the circumferential direction A from the center. That is, the brushes 7a, 7b, and 7c are arranged so that the positions of the brushes 7a, 7b, and 7c are shifted from each other along the circumferential direction A when the brushes 7a, 7b, and 7c are viewed along the direction X. ing.

Next, the operation of the rotary electric machine 101 according to Embodiment 1 of the present invention will be described.
The power supplied from a power source (not shown) is supplied to the slip rings 6a, 6b, 6c through the brushes 7a, 7b, 7c, so that the rotary shaft 4 rotates in the circumferential direction A. Each of the slip rings 6a, 6b, 6c rubs against the brushes 7a, 7b, 7c. Here, since the brushes 7a, 7b, and 7c are softer than the slip rings 6a, 6b, and 6c, the brushes 7a, 7b, and 7c are scraped and wear powder is generated. The brushes 7a, 7b, and 7c generate heat due to friction between the brushes 7a, 7b, and 7c and the slip rings 6a, 6b, and 6c, and power supply from the power source to the brushes 7a, 7b, and 7c. On the other hand, the cooling air W ₁ is generated by the blowing fins 14 rotating in the circumferential direction A together with the rotating shaft 4. Some of the cooling air _{W 1,} the inner brush 7a of the support portion 1a, 7b, 7c and the slip rings 6a, 6b, blown directly towards 6c. On the other hand, the remaining part of the cooling air W ₁ is blown out so as to diffuse in the radial direction of the blower fins 14. However, the cooling air W ₁ blown out in the radial direction of the air blowing fin 14 immediately hits the fan shroud 16 around the air blowing fin 14, changes the flow path, and blows toward the inside of the support portion 1 a. It becomes like this.

The cooling air W ₁ blown to the inside of the support portion 1 a circulates along the rotation shaft 4. First, the cooling air _{W 1} is sprayed onto the brush 7a and the slip rings 6a. Then, the cooling air W ₁ is to cool the brushes 7a and the slip rings 6a, removed blown off abrasion powder generated on the sliding surface between the brush 7a and the slip ring 6a. Then, the cooling air W ₁ after passing through the gaps 11a, blown into the brush 7b and the slip rings 6b, performs the same function as those in the brush 7a and the slip rings 6a. Furthermore, after the cooling air _{W 1} is passing through the gap 11b, blown brush 7c and the slip rings 6c, brushes 7a, 7b and the slip rings 6a, it performs the same function as those in 6b.

  As described above, by installing the fan shroud 16 around the blower fin 14, the cooling air can be intensively sent to the brushes 7a, 7b, 7c and the slip rings 6a, 6b, 6c. Therefore, the removal of abrasion powder generated on the sliding surfaces of the brushes 7a, 7b, 7c and the slip rings 6a, 6b, 6c and the cooling of the brushes 7a, 7b, 7c and the slip rings 6a, 6b, 6c are more efficiently performed. It can be carried out.

Further, the brush 7a, 7b, the position of 7c, by being displaced along the circumferential direction A, the brush 7a, 7b, the cooling air _{W 1} of each of the 7c sent from the blower fins 14, the upstream side brush You can hit directly without being blocked. That is, the air of approximately the same temperature comes into contact with the brushes 7a, 7b, and 7c. Therefore, the cooling efficiency of the entire brushes 7a, 7b, and 7c can be increased, and variations in the cooling efficiency of the brushes 7a, 7b, and 7c can be suppressed.
Furthermore, by attaching the blowing fins 14 to the bus bar 12, heat generated in the slip rings 6 a, 6 b, 6 c is transmitted to the blowing fins 14 through the bus bars 12 and is radiated from the blowing fins 14. Therefore, the slip rings 6a, 6b, 6c can be cooled more efficiently.

Embodiment 2. FIG.
Next, a rotating electrical machine 102 according to Embodiment 2 of the present invention will be described with reference to FIGS. In the second embodiment, the same reference numerals as those in FIGS. 1 to 3 are the same or similar components, and detailed description thereof is omitted.
FIG. 4 shows a cross-sectional view of a power feeding portion in rotating electric machine 102 according to Embodiment 2 of the present invention. The rotating electrical machine 102 has a housing 1 ′ that houses a motor (not shown), and a rotating shaft 4 is rotatably supported by the housing 1 ′. In addition, a substantially cylindrical power supply side casing 1b, which is disposed so as to cover the entire power supply portion, is integrally formed outside the housing 1 '. That is, the power supply side casing 1b constitutes a part of the housing 1 ′. In addition, a circular opening 2a is formed on the end surface of the power supply side casing 1b opposite to the motor side, and the rotating shaft 4 protrudes outside the power supply side casing 1b through the opening 2a. Moreover, the rotating shaft 4 is coat | covered with the insulator 15 'inside the electric power feeding side casing 1b. The insulator 15 'also covers a portion of the rotating shaft 4 that protrudes outside the power supply side casing 1b, and a portion of the insulator 15' that protrudes outside the power supply side casing 1b is a blower fin. A mounting portion 15a ′ is formed.

  A bus bar 12 ′ is attached to the rotating shaft 4 so as to be integrally rotatable outside the motor side of the power supply side casing 1 b. In addition, slip rings 6 a, 6 b, 6 c are attached to the outer periphery of the insulator 15 ′ so as to be integrally rotatable with respect to the rotary shaft 4 inside the power supply side casing 1 b. Further, at positions corresponding to the slip rings 6a, 6b, 6c, brushes 7a ', 7b', 7c 'are provided on the power supply side casing 1b via substantially annular brush holders 8a', 8b ', 8c', respectively. Attached fixed inside.

Three brushes 7a ′, 7b ′, and 7c ′ are attached to the brush holders 8a ′, 8b ′, and 8c ′, respectively. That is, three brushes 7a 'are fixed to the brush holder 8a', three brushes 7b 'are fixed to the brush holder 8b', and three brushes 7c 'are fixed to the brush holder 8c'. . Then, three brushes 7a 'are in sliding contact with the slip ring 6a, three brushes 7b' are in sliding contact with the slip ring 6b, and three brushes 7c 'are in sliding contact with the slip ring 6c (see FIG. 6). Further, gaps 11a ', 11b', 11c 'are formed between the brush holders 8a', 8b ', 8c' and the slip rings 6a, 6b, 6c.
As in the first embodiment, the insulator 15 ′ is formed of resin, and the brushes 7a ′, 7b ′, and 7c ′ are formed of copper or carbon.

Next, with reference to FIGS. 4 and 5, the shape of the power supply side casing 1b around the blower fins 14 ′ and the fan shroud 16 will be described.
Six blower fins 14 'are arranged at equal intervals and attached to the outer periphery of the blower fin mounting portion 15a' of the insulator 15 '. The blowing fins 14 ′ are arranged at an angle inclined with respect to the direction X. The blower fins 14 'are formed of the same resin as the insulator 15'. And the circumference | surroundings of blowing fin 14 'are enclosed by the fan shroud 16 provided facing the radial direction of blowing fin 14'. The fan shroud 16 is fixed and attached to the power supply side casing 1b so as not to rotate so as to be fitted into the opening 2a of the power supply side casing 1b. Further, in the power supply side casing 1b, three substantially elliptical ventilation holes 18 are formed at equal intervals along the circumferential direction A around the opening 2a. One of the ventilation holes 18 is formed so as to be positioned directly above the rotation shaft 4, and the other two are arranged with the ventilation holes 18 spaced about 120 degrees from each other around the rotation shaft 4. It is formed to be.
The air blowing fins 14 ′ constitute air blowing blades.

Moreover, with reference to FIG. 6, the shape of brush holder 8a ', 8b', 8c 'and arrangement | positioning of brush 7a', 7b ', 7c' are demonstrated in detail.
The brush holder 8a ′ is a substantially annular plate material. Cutouts 19a are formed in the outer peripheral portion of the brush holder 8a 'at intervals of about 120 degrees. Similarly, notches 19b and 19c are formed in the brush holders 8b 'and 8c'. The brush holders 8a ′, 8b ′, and 8c ′ are arranged so that the positions of the ventilation holes 18 and the notches 19a, 19b, and 19c of the power supply side casing 1b are seen to overlap each other when viewed from the direction of the rotation shaft 4. Then, it is attached to the inner peripheral surface of the power supply side casing 1b.

  Three brushes 7 a ′ are attached to the brush holder 8 a ′ toward the rotating shaft 4, respectively, just inside the notch 19 a. Similarly, three brushes 7b ′ are attached to the brush holder 8b ′ toward the rotary shaft 4, but each of the brushes 7b ′ is approximately 40 in the circumferential direction A with respect to the position of the brush 7a ′. It is arranged to deviate. Furthermore, three brushes 7c ′ are attached to the brush holder 8c ′ toward the rotary shaft 4, but each of the brushes 7c ′ is about 40 degrees in the circumferential direction A with respect to the position of the brush 7b ′. It is arranged so as to be displaced. That is, when the brushes 7a ', 7b', and 7c 'are viewed along the direction X, the brushes 7a', 7b ', and 7c' are arranged so as to be seen without overlapping each other.

Next, the operation of the rotating electrical machine 102 according to the second embodiment of the present invention will be described.
Similar to the rotating electrical machine 101, the rotating electrical machine 102 also needs to remove the abrasion powder of the brushes 7a ′, 7b ′, 7c ′ and cool the brushes 7a ′, 7b ′, 7c ′ and the slip rings 6a, 6b, 6c. Arise. Therefore, blowing fins 14 that rotates together with the rotary shaft 4 'cooling air _{W 2} which is to be generated, the interior of the brush 7a of the feed casing 1b' blowing, 7b ', 7c' and the slip rings 6a, 6b, towards 6c. Further, a part of the cooling air W ₂ blows out so as to diffuse in the radial direction of the blower fin 14, but immediately hits the fan shroud 16 around the blower fin 14 ′, changes the flow path, and the power supply side casing. It sprays on the inside of 1b.

Cooling air W ₂ blown onto the inside of the power supply casing 1b is distributed along the rotation axis 4, firstly, blown onto the brushes 7a 'and the slip ring 6a. Then, the cooling air W ₂ is 'to cool the and the slip rings 6a, brushes 7a' brushes 7a is removed by blowing off the abrasion powder generated on the sliding surface between the slip ring 6a. Then, the cooling air W ₂ is' passed through the brush 7b 'gap 11a is blown in and the slip ring 6b, performs the same function as those in the brush 7a' and the slip ring 6a. Furthermore, the cooling air _{W 2} is 'passed through the brush 7c' gap 11b blown in and the slip rings 6c, brushes 7a ', 7b' and the slip rings 6a, performs the same function as those in 6b. Further, the brush 7a ', 7b', 7c 'and the slip rings 6a, 6b, the cooling air _{W 2} which has finished cooling 6c, change the channel to the outside collides with the wall of the feed casing 1b, the brush holder 8a The notches 19a, 19b and 19c of ', 8b' and 8c 'are distributed in sequence. Then, the cooling air _{W 2} which has flowed notches 19a, 19b, a 19c is blown from the ventilation holes 18 to the outside of the power supply casing 1b.

  As described above, by surrounding the fan fin 14 'with the fan shroud 16, the air is concentrated on the brushes 7a', 7b ', 7c' and the slip rings 6a, 6b, 6c as in the first embodiment. can do. For this reason, in the rotating electrical machine 102, wear components generated on the sliding surfaces of the brushes 7a ′, 7b ′, 7c ′ and the slip rings 6a, 6b, 6c are removed, and the brushes 7a ′, 7b ′, 7c ′ and the slip rings 6a, The cooling of 6b and 6c can be performed more efficiently.

  Further, when the brushes 7 a ′, 7 b ′, and 7 c ′ are viewed along the direction X, the positions of the brushes 7 a ′, 7 b ′, and 7 c ′ are shifted along the circumferential direction A. Therefore, even when there are a plurality of brushes 7a ′, 7b ′, and 7c ′, the cooling air sent from the air blowing fins 14 ′ is not directly blocked by the upstream brush, but directly brushes 7a ′, 7b ′, 7c ′, It comes into contact with the slip rings 6a, 6b, 6c. Therefore, it is possible to prevent variations in the efficiency of removing abrasion powder and cooling by the blower fins 14 ′, and the efficiency of removing wear and cooling as a whole increases.

  The power supply side casing 1b is provided with a ventilation hole 18, and the brush holders 8a ', 8b', 8c 'are provided with notches 19a, 19b, 19c. Are arranged so as to overlap each other. Therefore, even when the power supply side casing 1b covers the brushes 7a ', 7b', 7c 'and the slip rings 6a, 6b, 6c as a whole, the flow of air becomes smooth, and the efficiency of removing wear powder and cooling is increased.

In the first and second embodiments, the brushes 7a, 7b, 7c or the brushes 7a ′, 7b ′, 7c ′ are made of copper or carbon, and the slip rings 6a, 6b, 6c are gunmetal, brass, stainless steel, or copper. However, it is not limited to this.
In addition, the bus bar 12 or 12 ′ is formed of a copper plate, but is not limited to this as long as the material has good thermal conductivity.
Furthermore, regarding the arrangement of the brushes 7a, 7b, and 7c or the arrangement of the brushes 7a ′, 7b ′, and 7c ′, the displacement of the position of each brush is not limited to the first or second embodiment, and the cooling air hits appropriately. Any arrangement may be used.

  101, 102 Rotating electric machine, 1, 1 ′ casing, 1a casing (supporting part), 1b casing (power supply side casing), 4 rotating shaft, 6a, 6b, 6c slip ring, 7a, 7b, 7c, 7a ′ , 7b ', 7c' brush, 8a, 8b, 8c, 8a ', 8b', 8c 'brush holder, 14, 14' blower fin (fan blade), 16 fan shroud (wind guide member).

Claims (3)

A housing,
A rotating shaft rotatably supported by the housing;
A slip ring provided to rotate with the rotating shaft;
A brush provided in contact with the slip ring;
A brush holder for fixing the brush to the housing;
A blowing blade provided on the rotating shaft;
A rotary electric machine comprising: an air guide member provided facing the radial direction of the blowing blade.   The rotating electrical machine according to claim 1, wherein the air guide member has a cylindrical shape. A plurality of the brushes are provided,
The position of the said brush has shifted | deviated mutually along the circumferential direction centering on the said rotating shaft when the said several brush is seen along the length direction of the said rotating shaft. Rotating electric machine.

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