Rotating electric machines

Abstract

The present invention is a rotating electric machine having a brush holder for holding a brush. The rotating electric machine is provided with, on one end side in the axial direction, a first cover through which a rotor shaft passes. In the first cover, a depressed brush holder housing portion for housing the brush holder is provided in the axial direction from the outside of the first cover. The brush holder is disposed so that the distance between the lower surface of the brush holder and the inner peripheral wall of the brush holder housing portion becomes larger than the distance between the portion of the brush holder other than the lower surface thereof and the inner peripheral wall of the brush holder housing portion in the brush holder housing portion.

Description

[Technical Field]

[0001] The present invention relates to a rotating electric machine. [Background technology]

[0002] In a rotating electrical machine having a brush for supplying power to a rotor, friction between the brush and the rotor shaft generates wear particles from the brush, etc. Accumulation of such wear particles reduces the insulation performance of the rotating electrical machine.

[0003] JP2871003B discloses a rotating electric machine in which a recess is provided on the side of the brush, and the brush is worn down to the recess by the commutator, thereby wearing away the accumulated wear powder during rotation, thereby preventing short circuits between the commutators. Summary of the Invention [Problem to be solved by the invention]

[0004] The technology described in the above-mentioned patent documents does not take into consideration the effects of wear debris accumulating in the housing around the brush, etc. This raises concerns about a decrease in insulation between the brush and the housing.

[0005] In view of the above problems, the present invention has an object to provide a rotating electric machine that can suppress deterioration of insulation between the brush and the housing due to wear powder. [Means for solving the problem]

[0006] According to one embodiment of the present invention, the brush housed inside It has a brush holder that holds The rotor shaft is placed horizontally to the installation surface. The present invention is applied to a rotating electric machine having a rotor shaft. A first cover is provided at one end in the axial direction, through which the rotor shaft passes. The first cover has a brush holder accommodating portion that accommodates the brush holder, and the brush holder accommodating portion is provided in the axial direction from the outside of the first cover. , the outer shape is slightly larger than the brush holder The brush holder is recessed. a through hole through which the rotor shaft passes; Brush holder housing is located on the side ofThe brush holder is arranged so that the distance between the lower surface of the brush holder and the inner wall of the brush holder accommodating section facing the lower surface is greater than the distance between another peripheral surface of the brush holder and the inner wall of the brush holder accommodating section facing the other peripheral surface. [Effects of the Invention]

[0007] According to the present invention, the distance between the underside of the brush holder and the inner circumferential wall of the brush holder accommodating portion is set larger than the distance between other parts of the brush holder and other parts of the inner circumferential wall of the brush holder accommodating portion, thereby increasing the space below the brush holder. This makes it possible to maintain the insulating distance between the brush and the housing even if brush wear powder accumulates in this space. This prevents a decrease in the insulation between the brush and the housing. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is an explanatory diagram of a rotating electrical machine according to an embodiment of the present invention. [Figure 2] FIG. 2 is an explanatory diagram of a rotating electrical machine. [Figure 3] FIG. 3 is an explanatory diagram of the brush holder. [Figure 4] FIG. 4 is an explanatory diagram showing a state in which the rotating electric machine is mounted on a vehicle. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0010] Fig. 1 is an explanatory diagram of a drive unit 100 including a rotating electric machine 1 of this embodiment, as viewed from the axial side. Fig. 2 is an explanatory diagram of the drive unit 100, showing a state in which a second cover 22 and a bus bar cover 26 are attached.

[0011] The drive unit 100 is made up of a rotating electric machine 1 and an inverter unit 3 that supplies power to the rotating electric machine 1. The inverter unit 3 is mounted on top of the rotating electric machine 1.

[0012] The rotating electric machine 1 is configured by housing a rotor and a stator (not shown) housed in a housing 2. The rotor has a rotor shaft 11. The housing 2 is provided with a refrigerant flow path through which a refrigerant (cooling oil) for cooling circulates, and a refrigerant inlet 2a and a refrigerant outlet 2b through which the refrigerant flows in and out of the housing 2.

[0013] The rotating electric machine 1 is mounted on a vehicle and functions as an electric motor that drives the wheels. The rotating electric machine 1 also functions as a generator that receives driving force from the rotation of the wheels and generates electricity (regenerates). The rotating electric machine 1 is configured as a wound-field type electric motor.

[0014] The housing 2 has an internal cavity with an opening, and the stator and rotor are housed in the internal cavity. The opening, which opens on the axial side of the housing 2 (the front side in FIG. 1), is covered with a first cover 21. A second cover 22 and a bus bar cover 26 are attached to the outside of the first cover 21. The rotor shaft 11 protrudes to the outside from the first cover 21 and supports the rotor shaft 11 so that it can rotate freely. The housing 2, first cover 21, second cover 22, and bus bar cover 26 are formed by casting using a metal material such as an aluminum alloy.

[0015] Slip rings 12 are provided on the outer periphery of rotor shaft 11. Brushes 5 abut against slip rings 12, and the inverter unit 3 and a field winding provided on the rotor are electrically connected via brushes 5, so that DC power from inverter unit 3 is supplied to the field winding.

[0016] The brushes 5 are held by the brush holders 15 while being housed in the brush holders 15 and are fixed to the rotor shaft 11 .

[0017] FIG. 3 is an explanatory diagram of the first cover 21 with the brush holder housing portion 20 at the center.

[0018] The first cover 21 is provided with a brush holder accommodating portion 20 in which the brush holder 15 is accommodated. The brush holder accommodating portion 20 is formed in a concave shape that is recessed from the side surface of the first cover 21 (the outermost surface of the first cover 21) toward the back in the axial direction. The brush holder accommodating portion 20 is formed in a shape that is slightly larger than the outer peripheral shape of the brush holder 15.

[0019] The brush holder 15 is a case made of insulating resin that houses and holds the plurality of brushes 5. The brush holder 15 has a through hole 16 through which the rotor shaft 11 passes.

[0020] The rotor shaft 11 is provided with slip rings 12 as two electrodes, positive and negative, arranged in parallel at positions spaced apart in the axial direction.

[0021] The brush holder 15 has a pair of brushes 5 for each of the positive and negative slip rings 12. The brushes 5 have a square rod shape, and one end of the brush 5 in the longitudinal direction abuts against the slip ring 12 of the rotor shaft 11. A biasing member such as a spring is disposed on the other end of the brush 5 in the longitudinal direction, and the brush 5 is pressed against the slip ring 12.

[0022] A pair of brushes 5 fixed to a brush holder 15 abuts against the positive or negative slip ring 12. The angle between the longitudinal axes of the pair of brushes 5 is an acute angle. That is, the pair of brushes 5 are arranged in a V-shape so that they move apart as they move away from the slip ring 12. Note that, as will be described later, if the brush holder 15 is arranged offset to one side of the rotor shaft 11, the brushes 5 do not necessarily have to be arranged in a V-shape at an acute angle.

[0023] The brush holder 15 is fixed to the side surface of the brush holder accommodating portion 20 by three bolts 151 .

[0024] In the first cover 21, the brush holder accommodating portion 20 communicates with a communicating portion 23 formed at its upper portion in a shallow axial direction. The communicating portion 23 further communicates with a connecting portion 24 formed at its upper portion in an axial recess. The connecting portion 24 accommodates the tip of a field bus bar 241 to which DC power from the inverter unit 3 is supplied. Wiring 19 is connected between the field bus bar 241 and the brush holder 15. The wiring 19 is routed in the vertical direction from the connecting portion 24 to the brush holder accommodating portion 20 via the communicating portion 23. Ends of the wiring 19 are connected to the brushes 5, respectively.

[0025] As shown in FIG. 2, a second cover 22 is attached to the brush holder accommodating portion 20, the communication portion 23 and the connection portion 24 recessed in the first cover 21 to close them from the outside.

[0026] A busbar accommodating portion 25 is recessed in the axial direction above the brush holder accommodating portion 20 and to the side of the connecting portion 24. The busbar accommodating portion 25 accommodates the tips of three-phase busbars 41 for supplying three-phase power to the inverter unit 3. As shown in FIG. 2 , a busbar cover 26 is attached to the busbar accommodating portion 25 to close the recess of the busbar accommodating portion 25 from the outside.

[0027] In the rotating electrical machine 1 configured as above, measures to deal with wear powder from the brushes 5 will be described.

[0028] The brushes 5 are in sliding contact with the slip ring 12, and they gradually wear down as the rotor shaft 11 rotates. Wear debris accumulates inside the brush holder 15, but because the brush holder 15 is not sealed, the wear debris is expelled to the outside of the brush holder 15. Because the wear debris contains metal components and is therefore conductive, if the wear debris accumulates on the outside of the brush holder 15, the insulation distance between the brushes 5 inside the brush holder 15 and the first cover 21 will be shortened, which may affect the insulation properties.

[0029] Furthermore, the rotating electrical machine 1 has a liquid-cooled (oil-cooled) structure and does not have a ventilation mechanism such as a fan, etc. Therefore, it is not possible to provide a gap in the first cover 21 to allow for ventilation to discharge wear powder to the outside while preventing rainwater from entering from the outside.

[0030] Therefore, in this embodiment, the following configuration is adopted to suppress the influence of the accumulated wear particles on the insulating properties.

[0031] As shown in Figure 3, the brush holder 15 is arranged in the brush holder accommodating section 20 so that the distance (indicated by A in Figure 3) between the lower surface 15a of the brush holder 15 and the inner wall 20a of the brush holder accommodating section 20 facing the lower surface 15a is greater than the distance between the other peripheral surface 15b of the brush holder 15 and the inner wall 20b of the brush holder accommodating section 20 facing the other peripheral surface 15b.

[0032] The brush holder 15 is positioned so that the distance (shown as B in Figure 3) between the upper surface 15c of the brush holder 15 and the inner wall 20c of the brush holder accommodating portion 20 facing the upper surface 15c is smaller than the distance between the other peripheral surface 15b of the brush holder 15 and the inner wall 20a of the brush holder accommodating portion 20 facing the other peripheral surface 15b.

[0033] In the brush holder accommodating portion 20, by setting the distance between the lower surface 15a of the brush holder 15 and the inner peripheral wall 20a of the brush holder accommodating portion 20 to a large value (for example, several tens of mm), it is possible to form a sufficient space for the accumulation of wear powder below the brush holder 15. In other words, the space surrounded by the lower surface 15a of the brush holder 15, the first cover 21 (the side surface of the brush holder accommodating portion 20), and the second cover 22 constitutes the wear powder accumulation portion 29.

[0034] In this manner, in this embodiment, the wear debris accumulation portion 29 is formed with sufficient capacity below the brush holder 15, so that even if wear debris from the brush 5 falls downward and accumulates in the wear debris accumulation portion 29, a sufficient insulating distance is maintained between the brush 5 in the brush holder 15 and the first cover 21. This makes it possible to suppress the influence of the insulation between the brush 5 and the first cover 21.

[0035] Next, the configuration of the brush holder accommodating portion 20 when the drive unit 100 is mounted on a vehicle will be described.

[0036] FIG. 4 is an explanatory diagram showing a case where the drive unit 100 of this embodiment is mounted on a vehicle.

[0037] 4, three mount brackets 101 are fixed to the drive unit 100, and the drive unit 100 is supported by a suspension member 110 via these mount brackets 101. The mount brackets 101 are provided at two locations on both ends of the vehicle width direction at the front side of the drive unit 100 in the vehicle longitudinal direction, and at one location on the rear side of the drive unit 100 in the vehicle longitudinal direction, in the center in the vehicle width direction.

[0038] With this configuration, the drive unit 100 is positioned so that its center of gravity is located approximately at the center of a triangle formed by the positions of the three mount brackets 101. The suspension member 110 that supports the drive unit 100 is fixed to the vehicle body.

[0039] 1, the brushes 5 are arranged in a V-shape in the brush holder 15 on one side (the left side in the figure, the rear side of the vehicle) of the rotor shaft 11. Therefore, the brush holder accommodating portion 20 is arranged at a position biased toward the rear side (one side) of the vehicle relative to the rotor shaft 11.

[0040] In contrast, of the mount brackets 101 to which the drive unit 100 is fixed, the mount bracket 101 fixed to the right side (first cover 21 side) of the drive unit 100 is positioned further forward (on one side) of the vehicle than the rotor shaft 11.

[0041] With this configuration, the mount bracket 101 can be placed in the most suitable position in the drive unit 100, and the mount bracket 101 does not get in the way when opening and closing the second cover 22 or when attaching and detaching the brush holder 15 during maintenance or replacement of the brush holder 15.

[0042] Furthermore, a busbar accommodating portion 25 is disposed above the other side of the brush holder accommodating portion 20, i.e., above the front side of the vehicle relative to the rotor shaft 11. By disposing the brush holder accommodating portion 20 at a position offset toward the rear of the vehicle relative to the rotor shaft 11, sufficient space is created above the front side of the vehicle to accommodate a three-phase busbar 41.

[0043] By arranging the three-phase bus bar 41 above the rotor shaft 11, the inverter unit 3 can be arranged above the rotating electric machine 1 as one unit with the rotating electric machine 1. The rotating electric machine 1 is configured to include a stator and a rotor inside a highly rigid housing 2, so that even in the event of a collision, for example, the inverter unit 3 is protected by the highly rigid rotating electric machine 1, preventing the case from breaking.

[0044] As described above, this embodiment is applied to a rotating electric machine 1 having a brush holder 15 that holds brushes 5. The rotating electric machine 1 includes a housing 2 having a first cover 21 through which a rotor shaft 11 passes. The first cover 21 has a brush holder accommodating portion 20 that accommodates the brush holder 15, recessed axially from the outside of the first cover 21. The brush holder 15 is arranged in the brush holder accommodating portion 20 so that the distance (A) between the lower surface 15a of the brush holder 15 and the inner circumferential wall 20a of the brush holder accommodating portion 20 that faces the lower surface 15a is greater than the distance between the other circumferential surface 15b of the brush holder 15 and the other inner circumferential wall 20b of the brush holder accommodating portion 20 that faces the other circumferential surface 15b.

[0045] With this configuration, a wear powder accumulation portion 29 with a sufficient capacity for accumulation of wear powder can be provided below the brush holder 15. Wear powder from the brush 5 accumulates in the wear powder accumulation portion 29. This makes it possible to maintain an insulating distance between the brush 5 and the housing 2 (and the first cover 21) even if wear powder from the brush accumulates in the wear powder accumulation portion 29. This makes it possible to prevent a decrease in the insulation between the brush 5 and the housing 2.

[0046] In addition, in this embodiment, the space surrounded by the lower surface 15a of the brush holder 15, the inner wall 20a of the brush holder accommodating portion 20, the first cover 21, and the second cover 22 is configured as a wear powder accumulation portion 29 where wear powder from the brush 5 accumulates.

[0047] With this configuration, even if the brush holder accommodating portion 20 that accommodates the brush holder 15 has a sealed structure, it is possible to provide a space in which wear powder from the brush 5 can be sufficiently accumulated.

[0048] In this embodiment, the brush holder 15 holds the brush 5 so that the brush 5 abuts against the rotor shaft 11 from one side of the rotor shaft 11 .

[0049] With this configuration, by bringing the brush 5 into contact with the slip ring 12 of the rotor shaft 11 from the rear side (one side) of the vehicle, the brush holder 15 can be positioned at a position offset toward the rear of the vehicle relative to the rotor shaft 11. This makes it possible to minimize the area of ​​the first cover 21 that the brush holder 15 occupies.

[0050] In addition, in this embodiment, the rotor shaft 11 is provided with multiple electrodes (slip rings 12) at positions spaced apart in the axial direction, and the brush holder 15 holds the brushes 5 so that a pair of brushes 5 abuts against one electrode (positive electrode) and another pair of brushes 5 abuts against another electrode (negative electrode).

[0051] With this configuration, even if the rotor shaft 11 is provided with multiple electrodes (slip rings 12) as positive and negative electrodes, by abutting a pair of brushes 5 in a V-shape against each slip ring 12 from the rear side (one side) of the vehicle, the brush holder 15 can be positioned at a position biased toward the rear of the vehicle relative to the rotor shaft 11.

[0052] In this embodiment, the first cover 21 is provided with a busbar accommodating portion 25 recessed in the axial direction to accommodate a three-phase busbar 41 electrically connected to the rotating electric machine 1. In the first cover 21, the brush holder accommodating portion 20 is disposed at a position offset toward the rear of the vehicle with respect to the rotor shaft 11, and the busbar accommodating portion 25 is disposed above the brush holder accommodating portion 20.

[0053] With this configuration, brush holder 15 is positioned offset to one side of rotor shaft 11, thereby ensuring sufficient space for busbar accommodating portion 25, which accommodates three-phase busbars 41, to be positioned above rotor shaft 11. This allows inverter unit 3 and rotating electric machine 1 to be positioned close to each other, so that even in the event of a collision, for example, inverter unit 3 is protected by rotating electric machine 1, which has high rigidity, and the case is prevented from breaking.

[0054] In addition, in this embodiment, the rotating electric machine 1 is supported on the vehicle body via a suspension member 110, and a mount bracket 101 that connects the rotating electric machine 1 and the suspension member 110 is provided on the outside of the first cover 21, and the mount bracket 101 is positioned at a position that is biased toward the front of the vehicle more than the brush holder accommodating portion 20 and more than the rotor shaft 11.

[0055] With this configuration, the brush holder housing 20 is positioned at a position offset toward the rear of the vehicle relative to the rotor shaft 11, and the mount bracket 101 fixed to the side of the drive unit 100 can be positioned closer to the front of the vehicle than the rotor shaft 11, which is the optimal position relative to the drive unit 100. This allows the mount bracket 101 that supports the rotating electric machine 1 to be positioned in an appropriate position, while also being positioned so as not to interfere with the opening and closing of the second cover 22 that covers the brush holder housing 20.

[0056] In addition, in this embodiment, the brush holder 15 is arranged in the brush holder accommodating portion 20 so that the distance between the upper surface 15c of the brush holder 15 and the inner wall 20c of the brush holder accommodating portion 20 facing the upper surface 15c is smaller than the distance between the other peripheral surface 15b of the brush holder 15 and the other inner wall 20b of the brush holder accommodating portion 20 facing the other peripheral surface 15b.

[0057] With this configuration, by arranging the brush holder 15 as close as possible to the upper side in the brush holder accommodating portion 20, the distance between the lower surface 15a of the brush holder 15 and the inner peripheral wall 20a of the brush holder accommodating portion 20 can be made large.

[0058] The above describes embodiments of the present invention and their modifications. However, the above embodiments and modifications merely illustrate some of the application examples of the present invention, and are not intended to limit the technical scope of the present invention to the specific configurations of the above embodiments.

[0059] Although the present invention has been described with reference to a wound field motor as an example of the rotating electric machine 1, the invention is not limited to this and can be applied to rotating electric machines having brushes (DC motors, induction motors, etc.).

Claims

1. A rotating electric machine having a brush holder that houses and holds brushes therein, and a rotor shaft that is placed horizontally relative to an installation surface, a housing having a first cover through which the rotor shaft passes; The first cover has: a brush holder accommodating portion for accommodating the brush holder is recessed from the outside of the first cover in the axial direction to have a shape slightly larger than an outer peripheral shape of the brush holder, the brush holder has a through hole through which the rotor shaft passes, is arranged on a side surface of the brush holder accommodating portion, and is arranged so that the distance between a lower surface of the brush holder and an inner peripheral wall of the brush holder accommodating portion facing the lower surface is larger than the distance between another peripheral surface of the brush holder and an inner peripheral wall of the brush holder accommodating portion facing the other peripheral surface. Rotating electric motor.

2. 2. The rotating electric machine according to claim 1, a second cover that covers the brush holder accommodating portion; a space surrounded by a lower surface of the brush holder, an inner peripheral wall of the brush holder accommodating portion, the first cover, and the second cover is configured as a wear powder accumulation portion in which wear powder of the brush accumulates; Rotating electric motor.

3. 3. The rotating electric machine according to claim 1, the brush holder holds the brush so that the brush abuts on one side of the rotor shaft perpendicular to the axial direction of the rotor shaft. Rotating electric motor.

4. 4. The rotating electric machine according to claim 3, The rotor shaft is provided with a plurality of electrodes spaced apart in the axial direction, the brush holder holds the brushes so that one pair of the brushes abuts against one of the electrodes and another pair of the brushes abuts against another of the electrodes. Rotating electric motor.

5. 5. The rotating electric machine according to claim 3, the first cover has bus bar accommodating portions recessed in an axial direction from an outer side of the first cover to accommodate tips of three-phase bus bars electrically connected to the rotating electric machine; In the first cover, the bus bar accommodating portion is disposed above the brush holder accommodating portion. Rotating electric motor.

6. 6. A rotating electric machine according to claim 3, the rotating electric machine is supported on a vehicle body via a suspension member; a mount bracket for connecting the rotating electric machine and the suspension member is provided on the outside of the first cover; The mount bracket is disposed at a position biased toward the front of the vehicle relative to the brush holder accommodating portion in the vehicle longitudinal direction. Rotating electric motor.

7. 7. A rotating electric machine according to claim 1, The brush holder is arranged in the brush holder accommodating portion so that the distance between the upper surface of the brush holder and an inner circumferential wall of the brush holder accommodating portion facing the upper surface is smaller than the distance between another surface of the brush holder and another inner circumferential wall of the brush holder accommodating portion facing the other surface. Rotating electric motor.

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