Vehicle main motor

Abstract

To provide a main motor for a vehicle, capable of suppressing noise by suppressing an increase in the amplitude of wind noise caused by cooling air colliding with a plurality of vanes of a cooling fan.SOLUTION: At a part of an outlet side passage 28, a partition plate 29 projecting toward an outer surface of a housing peripheral wall 2a from an inner surface of a cover peripheral wall is arranged. In a flow passage through which cooling air runs from an inlet port 22 to an inlet side space 23, a fab storage space 27 at which a plurality of vanes 13 are arranged, an outside side passage 28 and an exhaust port 28a, a propagation wave of wind noise generating at a fan storage space, a partition plate reflection wave at which a propagation wave reflects on a partition plate to generate, an intake port reflection wave at which a propagation wave reflects on an intake port to generate and an exhaust port reflection wave at which a propagation wave reflects on an exhaust port to generate interfere with each other, thereby forming a first synthetic wave and a second synthetic wave with smaller amplitudes a1, a2 than an amplitude a0 of the propagation wave. The first synthetic wave and the second synthetic wave are discharged from the intake port and the exhaust port to the outside.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The present invention relates to a main electric motor for a vehicle that drives a railway vehicle.

Background Art

[0002] In a railway vehicle, a main electric motor that drives wheels is attached to a bogie disposed under the floor of the car body.

[0003] For example, the main electric motor for a vehicle described in Patent Document 1 includes a stator, a rotor fixed coaxially to a rotating shaft on the inner peripheral side of the stator, a cylindrical frame that encloses the stator and the rotor, a bracket that is arranged to close one end opening of the frame and supports the rotating shaft, a cooling fan fixed coaxially to the rotating shaft at a position closer to the bracket side than the rotor, etc. A plurality of outlet flow paths communicating from one end side to the other end side are formed in the circumferential direction on the outer periphery of the frame. The cooling fan includes a main board that partitions the space between the stator and the rotor and the space on the bracket side, a plurality of blades formed on the surface of the main board facing the bracket and extending radially at intervals in the circumferential direction, and a guide in the shape of a band ring arranged in parallel with the main board and fixing the plurality of blades with the blades sandwiched therebetween. A plurality of air inlets are formed in the bracket at predetermined intervals in the circumferential direction, and these air inlets are located within a region formed by projecting the guide of the cooling fan arranged in the inlet flow path inside the bracket onto the bracket.

[0004] Then, when the rotor and the plurality of blades of the cooling fan rotate with the rotation of the rotating shaft, the cooling air flowing into the inlet flow path from the air inlet of the bracket passes between the plurality of blades and flows to the outer peripheral side of the bracket and the main board, and is discharged to the outside through the outlet flow path of the frame, so that the rotor is cooled.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

[0006] Incidentally, the cooling air flowing into the intake channel passes through multiple intake ports that are spaced apart in the circumferential direction, so the airflow direction tends to fluctuate. When this fluctuating airflow collides with the multiple blades of the cooling fan, it generates wind noise, which is a source of noise.

[0007] Patent Document 1 describes how providing a guide at a position opposite the air intake can rectify the cooling air whose airflow direction has fluctuated, thereby suppressing wind noise and reducing overall noise.

[0008] However, Patent Document 1 describes a system in which multiple vanes, which serve as sound sources for wind noise, are positioned near the air intake (opposite the air intake) and held in a guide, and it is thought that the sound waves of the sound sources (wind noise) propagating to the outside are less likely to be attenuated.

[0009] Therefore, the present invention aims to provide a vehicle main motor that can reduce noise by suppressing the increase in the amplitude of wind noise generated when cooling air collides with multiple blades of a cooling fan. [Means for solving the problem]

[0010] To achieve the above objective, a vehicle main motor according to one aspect of the present invention comprises a cylindrical housing, a stator fixed to the circumferential wall of the housing, a rotor disposed inside the stator and fixed to a rotating shaft, a cover side wall supporting the rotating shaft and covering the stator and rotor from the outside to form an intake port, a cover circumferential wall covering the outer surface of the housing circumferential wall and forming an outlet passage having an exhaust port at its end, and a main plate fixed to one end of the rotating shaft, separating the cover side wall from the stator and the rotor, and a surface on the outer circumference of the main plate facing the cover side wall. The cooling fan has multiple blades fixed radially to a rotating shaft and an inlet space formed between the cover side wall and the main plate, which communicates with the intake port. Assuming that the airflow path through which the cooling air flows from the intake port to the inlet space, the space where the multiple blades are arranged, the outlet flow path, and the exhaust port is an acoustic mode of a straight pipe with both ends open, a propagation wave interference means is provided in a part of the straight pipe, and this propagation wave interference means interferes with the propagation waves of wind noise generated in the fan housing space, thereby forming a composite wave with an amplitude smaller than the amplitude of the propagation waves. [Effects of the Invention]

[0011] According to the vehicle main motor of the present invention, noise can be reduced by suppressing the increase in the amplitude of wind noise generated when cooling air collides with multiple blades of a cooling fan. [Brief explanation of the drawing]

[0012] [Figure 1] This is an axial cross-sectional view showing a vehicle main motor according to a first embodiment of the present invention. [Figure 2] The first embodiment shows a cooling fan that constitutes a vehicle main motor, with (a) shown from the axial direction and (b) being a view along line AA in (a). [Figure 3] This figure shows the interference state between the propagated wind noise wave, the reflected waves generated at the intake and exhaust ports, and the reflected waves generated at the partition plate, assuming that the airflow path through which the cooling air flows in the first embodiment of the present invention is a straight pipe with both ends open, as the acoustic mode. [Figure 4]This diagram shows the acoustic modes of a comparative example in which a partition plate is not provided in a portion of the straight pipe. [Figure 5] This figure shows the acoustic mode of the first embodiment according to the present invention, in which a partition plate is provided in a part of a straight pipe. [Figure 6] This is an axial cross-sectional view showing a vehicle main motor according to a second embodiment of the present invention. [Figure 7] This figure shows the acoustic mode of a second embodiment according to the present invention, in which two partition plates are provided in a straight pipe. [Modes for carrying out the invention]

[0013] Next, an embodiment of the vehicle's main motor according to the present invention will be described with reference to the drawings. In the following drawings, identical or similar parts are denoted by the same or similar reference numerals. However, it should be noted that the drawings are schematic, and the relationship between thickness and planar dimensions, the ratio of the thickness of each layer, etc., may differ from reality. Therefore, specific thicknesses and dimensions should be determined by referring to the following explanation. Furthermore, it should be noted that there are parts where the relationships and ratios of dimensions differ between drawings.

[0014] Furthermore, the embodiments described below illustrate devices and methods for realizing the technical concept of the present invention, and the technical concept of the present invention does not limit the materials, shapes, structures, arrangements, etc. of the components to those described below. The technical concept of the present invention can be modified in various ways within the technical scope defined by the claims described in the patent claims.

[0015] Please note that the terms indicating direction, such as "up," "down," "left," and "right," used in the following explanation refer to the directions shown in the attached diagram. [Vehicle main motor of the first embodiment]

[0016] A vehicle main motor according to a first embodiment of the present invention will be described with reference to Figures 1 to 5.

[0017] FIG. 1 is an axial cross-sectional view showing a main electric motor 1 for vehicles that is attached to a bogie of a railway vehicle and drives wheels.

[0018] The main electric motor 1 for vehicles includes a housing 2 formed of a metal material, a stator 3 fixed to the inner peripheral surface of the housing peripheral wall 2a of the housing 2, a rotor 5 disposed inside the stator 3 and coaxially fixed to a rotating shaft 4, a cooling fan 6 disposed so as to close one end side of the housing 2 and fixed to one end 4a side of the rotating shaft 4, and a cover 7 covering the cooling fan 6 and the housing peripheral wall 2a from the outside.

[0019] The housing 2 includes a cylindrical housing peripheral wall 2a, a ring-shaped first housing side wall 2b formed at the periphery of the opening at one end side of the housing peripheral wall 2a, and a second housing side wall 2c formed by closing the opening at the other end of the housing peripheral wall 2a.

[0020] At the center position of the second housing side wall 2c, a bearing member 21a that supports the other end 4b of the rotating shaft 4 via a bearing 21c is disposed. Inside the second housing side wall 2c, a ventilation space 2d is provided between the outer periphery of the bearing member 21a, and a disk-shaped inner wall 2e is disposed. The outer diameter portion of the inner wall 2e is slidably in contact with an opening 2f provided in the second housing side wall 2c, and the inner diameter portion of the inner wall 2e is fixed to the rotating shaft 4. The bearing member 21a is formed with ventilation holes 2g that communicate the outside with the ventilation space 2d at predetermined intervals in the circumferential direction. And on the ventilation space 2d side of the inner wall 2e, a plurality of blades 2h are disposed at predetermined intervals in the circumferential direction.

[0021] The stator 3 comprises a stator core 9 and a stator coil 10. The stator core 9 is formed in a cylindrical shape extending along the axial direction by stacking multiple annular magnetic steel plates in the axial direction. Multiple teeth (not shown) are formed on the inner circumference of the stator core 9, projecting radially inward and spaced apart in the circumferential direction. Multiple slots (not shown) are formed between the teeth, and the stator coil 10 is wound around these slots. The rotor 5 is formed in a cylindrical shape by stacking multiple annular magnetic steel plates along the axial direction.

[0022] As shown in Figure 2(a), the cooling fan 6 comprises a disc-shaped main plate 11, a band-ring shaped guide plate 12 positioned opposite to the main plate 11 on its outer circumference, and a plurality of blades 13 formed radially at circumferential intervals between the opposing surfaces of the main plate 11 and the guide plate 12. As shown in Figure 2(b), the main plate 11 comprises a disc portion 15 with a fitting hole 14 formed at its center, a cylindrical portion 16 extending in one axial direction from the outer edge of the disc portion 15, and a blade-forming plate 17 extending radially outward from the end of the cylindrical portion 16 and positioned substantially parallel to the guide plate 12.

[0023] As shown in Figure 1, the cooling fan 6 is arranged with multiple blades 13 and a guide plate 12 facing outwards from the housing 2, away from the stator 3 and rotor 5. The rotating shaft 4 is fitted into the insertion hole 14 of the disc portion 15, and the outer surface of the blade-forming plate 17 is aligned with the inner surface of the first housing side wall 2b of the housing 2, thereby closing the opening in the first housing side wall 2b and fixing the fan coaxially to the rotating shaft 4.

[0024] Furthermore, as shown in Figure 1, the cover 7 includes a disc-shaped cover side wall 18 that covers the cooling fan 6 from the outside (left side in Figure 1) and extends in a direction perpendicular to the axis of the rotating shaft 4, and a cylindrical cover side wall 19 that extends from the outer peripheral end of the cover side wall 18 in a direction along the axis of the rotating shaft 4 (left-right direction in Figure 1) and covers the outer peripheral surface of the housing side wall 2a. A shaft insertion hole 20 through which the rotating shaft 4 is inserted is formed at the center of the cover side wall 18, and a bearing member 21b is positioned between the inside of the shaft insertion hole 20 and the rotating shaft 4.

[0025] Furthermore, the cover side wall 18 is provided with a plurality of air intake ports 22 formed at predetermined intervals in the circumferential direction and communicating toward the main plate 11 of the cooling fan 6. Inside the air intake ports 22, an inlet space 23 is provided that communicates with the fan housing space 27.

[0026] Here, the space where the multiple blades 13 and guide plate 12 of the cooling fan 6 are covered by the cover side wall 18 is referred to as the fan storage space 27. The space provided between the outer surface of the housing peripheral wall 2a and the inner surface of the cover peripheral wall 19, and which has an exhaust port 28a that communicates with the outside air, is referred to as the outlet passage 28.

[0027] Furthermore, a single partition plate 29 is positioned in the outlet channel 28, projecting from the cover peripheral wall 19 toward the housing peripheral wall 2a. Although not specifically shown in the figures, this partition plate 29 is an annular member extending in the circumferential direction of the cover peripheral wall 19. The partition plate 29 is an example of the "propagating wave interference means" described in the claims.

[0028] In the above configuration, the cooling fan 6 of the vehicle's main motor 1 receives rotational force from the rotating shaft 4, causing multiple blades 13 to rotate, which in turn causes cooling air to flow into the intake space 23 from multiple intake ports 22. The cooling air that flows into the intake space 23 from the intake ports 22 flows towards the fan housing space 27 where the multiple blades 13 are located. The cooling air is then sent to the outlet passage 28 which communicates with the fan housing space 27 and released into the outside air from the exhaust port 28a. The heat from the stator core 9 of the stator 3, which has been conducted to the housing peripheral wall 2a, is absorbed by the cooling air passing through the outlet passage 28 and released to the outside from the exhaust port 28a.

[0029] Figure 3 shows the airflow path (hereinafter referred to as the airflow path) from the intake port 22 to the inlet space 23, the fan housing space 27, the outlet flow path 28 where the partition plate 29 is located, and the exhaust port 28a, as an acoustic mode of the airflow path assumed to be a straight pipe with both ends open. In the acoustic mode of this airflow path (straight pipe with both ends open), the vane 13, which is the sound source, is located in the airflow path on the left side of Figure 3 relative to the partition plate 29.

[0030] In this embodiment, the acoustic mode of the airflow path is such that the propagating waves of wind noise generated by the collision of cooling air with multiple blades 13 (sound sources) flow toward the intake port 22 and the exhaust port 28a. At the intake port 22, the propagating wind noise waves are reflected to generate intake port reflected waves, and at the exhaust port 28a, the propagating wind noise waves are reflected to generate exhaust port reflected waves. Furthermore, at the partition plate 29, the propagating wind noise waves are reflected to generate partition plate reflected waves.

[0031] Then, the propagating wind noise waves, the intake port reflected waves, the exhaust port reflected waves, and the partition plate reflected waves interfere with each other to form a composite wave of a predetermined amplitude, and this composite wave is discharged to the outside from the intake port 22 and the exhaust port 28a.

[0032] Here, Figure 4 shows the acoustic mode of the airflow channel in a comparative example where the partition plate 29 described above is not placed, and Figure 5 shows the acoustic mode of the airflow channel in this embodiment where the partition plate 29 is placed in a predetermined position. The acoustic modes of the airflow channels in Figures 4 and 5 have a fundamental resonance frequency f of approximately f = 2c / L (where c is the speed of sound and L is the length of the airflow channel), and form sound waves with a frequency four times the fundamental resonance frequency f.

[0033] In the comparative example shown in Figure 4, the acoustic mode of the airflow path is such that a propagating wave with amplitude a0 at a frequency four times the fundamental resonance frequency f is emitted to the outside from the intake port 22 and the exhaust port 28a.

[0034] On one hand, in the acoustic mode of the air flow path of the present embodiment shown in FIG. 5, a partition plate 29 is disposed at a position 0.7L (L is the length of the air flow path) from the intake port 22. When the partition plate 29 is disposed at the position of 0.7L, the frequency band of the partition plate reflected wave and the frequency bands of the propagation wave, the intake port reflected wave, and the exhaust port reflected wave interfere with each other, thereby forming a first composite wave with an amplitude a1 (a1 < a0), which is emitted from the intake port 22 to the outside. Further, a second composite wave with an amplitude a2 (a2 < a1 < a0) is formed and emitted from the exhaust port 28a to the outside.

[0035] Next, the operation and effects of the main electric motor 1 for vehicles of the first embodiment will be described.

[0036] When the main electric motor 1 for vehicles is driven, the stator core 9, the stator coil 10, and the rotor 5 become heat generating parts.

[0037] The cooling fan 6 of the main electric motor 1 for vehicles transmits the rotational force from the rotating shaft 4, and the plurality of blades 13 rotate, so that the cooling air flowing into the inlet side space 23 from the plurality of intake ports 22 passes through the fan housing space 27 and the outlet side flow path 28 and is discharged from the exhaust port 28a. Then, the heat of the stator core 9 of the stator 3 conducted to the housing peripheral wall 2a is taken away by the cooling air passing through the outlet side flow path 28 and discharged to the outside from the exhaust port 28a. <00,00148>

[0038] Here, when the cooling air collides with the plurality of blades 13, a wind cut noise is generated, and this wind cut noise is discharged to the outside from the exhaust port 28a and the intake port 22 of the outlet side flow path 28.

[0039] As shown in FIG. 5, in the acoustic mode of the air flow path of the present embodiment, a partition plate 29 is arranged at a position 0.7 L from the intake port 22, so that the frequency band of the partition plate reflected wave and the frequency bands of the propagation wave, the intake port reflected wave, and the exhaust port reflected wave interfere with each other, and a first composite wave with an amplitude a1 smaller than the amplitude a0 of the propagation wave is formed and is emitted from the intake port 22 to the outside. At the same time, a second composite wave with an amplitude a2 smaller than the amplitude a0 of the propagation wave is formed and is emitted from the exhaust port 28a to the outside (a0 < a1 < a2). Therefore, in the present embodiment, by arranging the partition plate 29 in the air flow path, the first and second composite waves with amplitudes smaller than the wind noise of the plurality of blades 13 are emitted from the exhaust port 28a and the intake port 22 to the outside, so that the noise caused by the cooling fan 6 can be reduced. [Main Electric Motor for Vehicle of Second Embodiment]

[0040] Next, FIGS. 6 and 7 show the main electric motor 30 for a vehicle according to the second embodiment of the present invention. The same parts as those in the configuration of the first embodiment shown in FIGS. 1 to 3 and FIG. 5 are denoted by the same reference numerals and the description thereof is omitted.

[0041] As shown in FIG. 6, the main electric motor 30 for a vehicle of the present embodiment includes a partition plate 29 (hereinafter referred to as the first partition plate 29) protruding from the cover peripheral wall 19 of the outlet side flow path 28 toward the housing peripheral wall 2a, and a second partition plate 31 protruding from the housing peripheral wall 2a toward the cover peripheral wall 19 at a position closer to the fan housing space 27 with respect to the first partition plate 29. The second partition plate 31 is also, although not specifically shown, an annular member extending in the circumferential direction of the cover peripheral wall 19. The first partition plate 29 and the second partition plate 31 are an example of the "propagation wave interference means" described in the claims.

[0042] Figure 7 shows the airflow path (hereinafter referred to as the airflow path) from the intake port 22 to the inlet space 23, the fan housing space 27, the outlet passage 28 where the first partition plate 29 and the second partition plate 31 are located, and the exhaust port 28a, as an acoustic mode of the airflow path assumed to be a straight pipe with both ends open. In the acoustic mode of the airflow path of this embodiment, the vane 13, which acts as a sound source, is located in the airflow path on the left side of Figure 7 relative to the second partition plate 31.

[0043] In this embodiment, the acoustic mode of the airflow path is such that propagating wind noise waves generated by the collision of cooling air with multiple blades 13 (sound sources) flow toward the intake port 22 and exhaust port 28a. At the intake port 22, the propagating wind noise waves are reflected to generate intake port reflected waves, and at the exhaust port 28a, the propagating wind noise waves are reflected to generate exhaust port reflected waves. Furthermore, at the first partition plate 29 and the second partition plate 31, the propagating wind noise waves are reflected to generate partition plate reflected waves.

[0044] Then, the propagating wind noise waves, the intake port reflected waves, the exhaust port reflected waves, and the partition plate reflected waves interfere with each other to form a composite wave of a predetermined amplitude, and this composite wave is discharged to the outside from the intake port 22 and the exhaust port 28a.

[0045] In this embodiment, the first partition plate 29 and the second partition plate 31 are also positioned at predetermined locations in an air passage of length L. As a result, the frequency band of the partition plate reflected wave and the frequency bands of the propagated wave, intake port reflected wave, and exhaust port reflected wave interfere with each other, forming a first composite wave with an amplitude smaller than the amplitude a0 of the propagated wave, which is discharged to the outside from the intake port 22, and a second composite wave with an amplitude smaller than the amplitude a0 of the propagated wave is formed and discharged to the outside from the exhaust port 28a.

[0046] Therefore, in this embodiment as well, by arranging the first partition plate 29 and the second partition plate 31 at predetermined positions in the longitudinal direction of the air passage, the combined waves of the first and second, which have an amplitude smaller than the wind noise of the multiple blades 13, are discharged to the outside from the exhaust port 28a and the intake port 22, thereby reducing the noise caused by the cooling fan 6.

[0047] In the first and second embodiments described above, examples were shown in which sound with a frequency four times the fundamental resonance frequency among the propagating waves generated by the cooling fan 6 placed in the air passage was reduced. However, the present invention is not limited to these examples. [Explanation of symbols]

[0048] 1.30 Main motor for vehicles 2 Housing 2a Housing perimeter wall 2b First Housing Side Wall 2c Second Housing Side Wall 3 stata 4 rotation axes 4a One end of the rotation axis 5 rotors 6 Cooling fan 7 Cover 9 Stator Core 10 Stator coil 11 Main plate 12 Guide plate 13 birds 14 Inset hole 15. Disc section 16 Cylindrical section 17 Wing formation plate 18 Cover side wall 19 Cover surrounding wall 20 Axis insertion hole 21 Bearing member 22 Intake port 23 Entrance space 27 Fan storage space 28 Outlet channel 28a Exhaust port 29 Partition plate (first partition plate) 31. Second partition

Claims

1. A cylindrical housing, A stator fixed to the peripheral wall of the housing, A rotor is located inside the stator and fixed to the rotating shaft, A cover side wall that supports the rotating shaft and covers the stator and rotor from the outside, forming an air intake port, A cover perimeter wall that covers the outer surface of the housing perimeter wall and forms an outlet passage having an exhaust port at its end, A cooling fan is fixed to the rotating shaft, comprising a main plate that separates the cover side wall from the stator and the rotor and is fixed to one end of the rotating shaft, and a plurality of blades that are radially fixed to the outer surface of the main plate facing the cover side wall, It comprises an inlet space formed between the cover side wall and the main plate and communicating with the air intake port, Assuming that the airflow path from the intake port to the inlet space, the fan housing space where the multiple blades are arranged, the outlet flow path, and the exhaust port is an acoustic mode of a straight pipe with both ends open, a propagation wave interference means is provided in a part of the straight pipe, The wave propagation interference means is a partition plate that protrudes from one of the inner surface of the cover peripheral wall and the outer surface of the housing peripheral wall toward the other in a part of the outlet flow path. If the length of the air passage is L, the partition plate is installed at a position of 0.7L from the air intake. The wave propagation interference means interferes with the propagating waves of wind noise generated in the fan housing space, thereby forming a composite wave with an amplitude smaller than the amplitude of the propagating waves, A vehicle main motor characterized in that, in the air passage, the propagating wave, the partition plate reflected wave generated when the propagating wave is reflected by the partition plate, the intake port reflected wave generated when the propagating wave is reflected by the intake port, and the exhaust port reflected wave generated when the propagating wave is reflected by the exhaust port interfere with each other to form a composite wave with an amplitude smaller than the amplitude of the propagating wave, which is discharged to the outside from the intake port and the exhaust port.

2. A cylindrical housing and A stator fixed to the peripheral wall of the housing, A rotor is located inside the stator and fixed to the rotating shaft, A cover side wall that supports the rotating shaft and covers the stator and rotor from the outside, forming an air intake port, A cover perimeter wall that covers the outer surface of the housing perimeter wall and forms an outlet passage having an exhaust port at its end, A cooling fan is fixed to the rotating shaft, comprising a main plate that separates the cover side wall from the stator and the rotor and is fixed to one end of the rotating shaft, and a plurality of blades that are radially fixed to the outer surface of the main plate facing the cover side wall, It comprises an inlet space formed between the cover side wall and the main plate and communicating with the air intake port, Assuming that the airflow path from the intake port to the inlet space, the fan housing space where the multiple blades are arranged, the outlet flow path, and the exhaust port is an acoustic mode of a straight pipe with both ends open, a propagation wave interference means is provided in a part of the straight pipe, The wave propagation interference means includes, in a part of the outlet flow path, a first partition plate protruding from the cover peripheral wall toward the housing peripheral wall, and a second partition plate protruding from the housing peripheral wall toward the cover peripheral wall at a position closer to the fan housing space relative to the first partition plate. The propagating wave interference means is characterized by interfering with the propagating waves of wind noise generated in the fan housing space to form a composite wave with an amplitude smaller than the amplitude of the propagating waves.

Images