JP4880559B2 - Cooling structure in rotating electrical machines - Google Patents

Description

  The present invention relates to a cooling structure in a rotating electrical machine in which an annular stator that surrounds the outer periphery of a rotor having a rotating shaft arranged substantially horizontally includes a plurality of coils arranged in a circumferential direction via a plurality of slots.

  In a rotating electrical machine in which a plurality of coils wound around the outer periphery of a stator core via an insulator are connected in the circumferential direction to form an annular stator, a slot is formed between adjacent coil windings as a refrigerant. Patent Document 1 below discloses that the stator is cooled by circulating the oil.

Also, the rotor with the rotating shaft arranged horizontally and the stator surrounding the outer periphery thereof are housed inside the motor case, and the oil discharged from the oil discharge port provided on the upper wall of the motor case is the lower part of the stator. It is known from Patent Document 2 below that the cooling is performed.
JP 2004-40924 A JP 2006-197772 A

  However, what is described in Patent Document 1 described above is that only one oil supply port and one oil discharge port for supplying and discharging oil as a refrigerant to the internal space of the stator are provided at positions facing each other. Therefore, the oil cannot be uniformly distributed through the plurality of slots, and it has been difficult to cool the entire stator uniformly.

  In addition, what is described in the above-mentioned Patent Document 2 only cools the stator with oil that flows by gravity from the upper part to the lower part of the stator arranged in a standing posture in the vertical plane. It was difficult to cool down.

  The present invention has been made in view of the above-described circumstances, and an object of the present invention is to enable uniform cooling of the entire stator disposed in a standing posture in a vertical plane.

  In order to achieve the above object, according to the first aspect of the present invention, an annular stator surrounding the outer periphery of a rotor having a rotating shaft arranged in a substantially horizontal direction is provided in a circumferential direction via a plurality of slots. In a rotating electrical machine including a plurality of coils arranged, by fixing the first plate and the second plate to both end surfaces in the axial direction of the plurality of coils, a space having the slot as a refrigerant passage is defined, A refrigerant supply port for supplying a refrigerant is provided at an upper part in the vertical direction, and a plurality of refrigerant discharge ports are formed at predetermined intervals over the entire circumferential direction of at least one of the first and second plates. A cooling structure in a rotating electrical machine is proposed, in which the opening area of the rotating machine is set to be smaller in the lower vertical direction.

  According to the invention described in claim 2, in addition to the configuration of claim 1, the plurality of refrigerant discharge ports are arranged on a predetermined circle, and the center of the circle is perpendicular to the center of the stator. A cooling structure in a rotating electric machine is proposed, which is characterized by being eccentric in the lower direction.

  According to the third aspect of the present invention, in addition to the configuration of the first aspect, the distance from the plurality of refrigerant discharge ports to the center of the stator is larger as the refrigerant discharge port is on the lower side in the vertical direction. A cooling structure in a rotating electrical machine is proposed, which is characterized by being set.

  According to the invention described in claim 4, in addition to the configuration of any one of claims 1 to 3, a refrigerant supply port that supplies the refrigerant to the space is formed in the first plate. In addition, the plurality of refrigerant discharge ports are formed in the second plate, and an opening area of the refrigerant discharge port closest to the refrigerant supply port is set smaller than an opening area of the refrigerant discharge port adjacent to the refrigerant discharge port. A cooling structure for a rotating electrical machine is proposed.

  According to the invention described in claim 5, in addition to the configuration of any one of claims 1 to 4, of the refrigerant supplied from the refrigerant supply means for supplying the refrigerant to the refrigerant supply port. A cooling structure for a rotating electrical machine is proposed, comprising: a refrigerant storage means for storing excess refrigerant; and a refrigerant supply passage for supplying the refrigerant from the refrigerant storage means to an upper outer peripheral portion of the stator. The

  According to the invention described in claim 6, in addition to the configuration of any one of claims 1 to 5, adjacent coils are axially arranged on the radially outer side and the radially inner side of the slot. A cooling structure in a rotating electrical machine is proposed, which is engaged by a convex portion and a concave portion extending in the direction.

  The first and second convex portions 27a and 27b of the embodiment correspond to the convex portions of the present invention, and the first and second concave portions 27b and 27b of the embodiment correspond to the concave portions of the present invention. The oil supply port 29a of the embodiment corresponds to the refrigerant supply port of the present invention, the oil discharge port 31a of the embodiment corresponds to the refrigerant discharge port of the present invention, and the oil pump 35 of the embodiment includes the refrigerant supply means of the present invention. The oil reservoir 38 of the embodiment corresponds to the refrigerant storage means of the present invention, and the oil passage P6 of the embodiment corresponds to the refrigerant supply passage of the present invention.

  According to the above configuration, the annular stator that surrounds the outer periphery of the rotor having the rotation shaft arranged substantially in the horizontal direction includes the plurality of coils arranged in the circumferential direction via the plurality of slots, and the plurality of coils By fixing the first plate and the second plate to both end surfaces in the axial direction, a space having a slot as a coolant passage is defined inside the stator. The refrigerant supply port for supplying the refrigerant is provided at the upper part in the vertical direction of the space, and the plurality of refrigerant discharge ports are formed at predetermined intervals over the entire circumferential direction of at least one of the first and second plates. The coil of the stator can be cooled by passing through the slot while the refrigerant supplied to the space is discharged from the plurality of refrigerant discharge ports.

  At this time, since the refrigerant pressure becomes higher due to the influence of gravity toward the lower side of the stator space in the vertical direction, the flow rate of the refrigerant discharged from the refrigerant discharge port is increased and the cooling effect is increased. Since the refrigerant pressure becomes lower due to the influence of gravity toward the upper side in the direction, the flow rate of the refrigerant discharged from the refrigerant discharge port decreases, and the cooling effect may be lowered. However, by setting the opening area of the refrigerant discharge port to be smaller in the lower vertical direction, the flow rate of the refrigerant discharged from all the refrigerant discharge ports can be made uniform, and the entire stator can be cooled uniformly.

  According to the second aspect of the present invention, the center of the predetermined circle in which the plurality of refrigerant discharge ports are arranged is decentered vertically downward with respect to the center of the stator. It can be placed close to the lower side of the slot on the upper side in the vertical direction, and the refrigerant outlet on the lower side in the vertical direction can be placed close to the lower side of the slot on the lower side in the vertical direction. Can be prevented.

  According to the third aspect of the present invention, since the distance from the plurality of refrigerant discharge ports to the center of the stator is set to be larger as the refrigerant discharge port is on the lower side in the vertical direction, the upper refrigerant discharge port is set on the upper side in the vertical direction. The refrigerant discharge port on the lower side in the vertical direction can be brought closer to the lower side of the slot on the lower side in the vertical direction, so that the refrigerant is trapped in the slot and the cooling effect is reduced. Can be prevented.

  According to the fourth aspect of the present invention, the refrigerant supply port is formed in the first plate, the plurality of refrigerant discharge ports are formed in the second plate, and the opening area of the refrigerant discharge port closest to the refrigerant supply port is defined as the refrigerant. Since the opening area of the refrigerant discharge port adjacent to the discharge port is set smaller, the refrigerant supplied from the refrigerant supply port of the first plate does not fill the space of the stator, and the refrigerant discharge port close to the refrigerant supply port It is possible to prevent a short circuit from being discharged to the outside of the space.

  According to the fifth aspect of the present invention, surplus refrigerant among the refrigerant supplied from the refrigerant supply means for supplying refrigerant to the refrigerant supply port is stored in the refrigerant storage means, and from the refrigerant storage means to the stator Since the refrigerant is supplied to the upper outer peripheral portion via the refrigerant supply passage, not only from the inside of the stator but also from the outer peripheral portion of the stator can be cooled using the surplus refrigerant, and the cooling effect can be enhanced. .

  Further, according to the configuration of the sixth aspect, adjacent coils are engaged with each other by the projecting portion and the recessed portion extending in the axial direction on the radially outer side and the radially inner side of the stator slot, so that no special seal member is provided. The space for retaining the refrigerant in the stator can be isolated from the external space to minimize the leakage of the refrigerant.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

  1 to 6 show a first embodiment of the present invention. FIG. 1 is a longitudinal sectional view of a motor, FIG. 2 is an enlarged view of a main part of FIG. 1, and FIG. 3 is a line 3-3 in FIG. 4 is an enlarged view of the main part of FIG. 3, FIG. 5 is a view taken along the line 5-5 in FIG. 1 (single view of the first plate), and FIG. 6 is a view taken along the line 6-6 in FIG. (Single product drawing of the second plate).

  As shown in FIGS. 1 to 3, the housing 11 of the DC brushless motor M is configured by connecting a first housing 12 and a second housing 13 with a plurality of bolts 14. A rotating shaft 17 is supported on the housings 12 and 13 via ball bearings 15 and 16, respectively. The rotor 18 fixed to the rotating shaft 17 includes a rotor boss 19 on the radially inner side, a rotor core 20 made of a laminated steel plate fixed on the radially outer side of the rotor boss 19, and a plurality of permanent magnets embedded in the outer periphery of the rotor core 20. 21...

  The annular stator 22 disposed on the outer periphery of the rotor 18 is configured by alternately coupling a plurality (18 in the embodiment) of U-layer, V-layer, and W-layer coils 23 in the circumferential direction. Thus, the annular holding member 24 fitted to the outer peripheral portion is fixed to the end surface of the first housing 12 with a plurality of bolts 25. Each coil 23 includes a stator core 26 made of a laminated steel plate, an insulator 27 made of synthetic resin covering the stator core 26, and a winding 28 wound around the outer periphery of the insulator 27.

  A first plate 29 made of an annular plate material is superposed on one end face of the insulators 27 of the coils 23 arranged in an annular shape, and the inner peripheral portion thereof is connected to the insulators 27 with a plurality of bolts 30. Fixed. A second plate 31 made of an annular plate is superimposed on the other end face of the insulators 27 of the coils 23 arranged in an annular shape, and the outer periphery of the second plate 31 is formed on the insulators 27 with a plurality of bolts 32. Fixed.

  As apparent from FIGS. 2 and 5, the first plate 29 has a circular oil supply port 29 a formed in the upper part in the vertical direction, and the oil supply port 29 a is an oil supply passage formed in the first housing 12. 12a is connected via a seal member 39. Further, bolt holes 29b through which the bolts 30 pass are formed in the inner peripheral portion of the first plate 29.

  As is apparent from FIGS. 2 and 6, the second plate 31 includes 18 oil discharge ports 31a arranged at equal intervals on a circle C centered on the axis L of the rotating shaft 17, and the Bolt holes 31b... Through which the bolts 32.

  As is apparent from FIGS. 3 and 4, slots 33 are formed between the windings 28 of the adjacent coils 23 to form a space extending in the direction of the axis L, and both ends of these slots 33. The first and second plates 29 and 31 are reached. The insulator 27 of each coil 23 includes a first convex portion 27a and a second convex portion 27b extending in the axis L direction on one side surface, and a first concave portion 27c and a second concave portion 27d extending in the axis L direction on the other side surface. The adjacent insulators 27 and 27 are engaged with the first convex portion 27a and the first concave portion 27c on the radially outer side of the slot 33, and the second convex portion 27b and the second concave portion 27d on the radially inner side of the slot 33. Engage. Due to the sealing effect of these concave and convex engaging portions, it is possible to minimize oil leakage from the slot 33 inward and outward in the radial direction.

  Each oil discharge port 31a formed in the second plate 31 is positioned so as to face the middle in the radial direction of each slot 33, and the oil supply port 29a of the first plate 29 faces one oil discharge port 31a. (See FIG. 4).

  As is clear from FIG. 6, the 18 oil discharge ports 31a... Of the second plate 31 have the largest diameter (opening area) in the upper side and the largest diameter (opening area) in the lower side. It is small, and the diameter continuously changes between them.

  As shown in FIG. 1, a reservoir 34 for storing oil is provided in the first housing 12 via an oil passage P1, an oil pump 35, an oil passage P2, a control valve 36, an oil passage P3, an oil cooler 37, and an oil passage P4. It is connected to the oil supply passage 12a. An oil passage P5 branched from the oil passage P4 is connected to an oil reservoir 38, and the oil reservoir 38 is connected to an internal space at the upper end of the housing 11 via an oil passage P6. The internal space at the lower end of the housing 11 is connected to the reservoir 34 via the oil passage P7. The oil passage P8 branched from the control valve 36 is connected to each hydraulic device.

  Next, the operation of the first embodiment having the above configuration will be described.

  In order to cool the stator 22 that generates heat with the operation of the motor M, the oil pump 35 pumps up the oil in the reservoir 34, the reservoir 34 → oil path P1 → oil pump 35 → oil path P2 → control valve 36 → oil path P3 → oil cooler. 37 → Supplies to the oil supply passage 12a of the first housing 12 through the oil passage P4. At this time, the pressure of the oil supplied to the motor M is adjusted to a relatively low pressure by the control valve 36.

  18 slots 33 extending in the direction of the axis L are formed in parallel inside the stator 22, and both ends thereof communicate with each other on the inner surfaces of the first and second plates 29 and 31. Further, the amount of oil leaking from the inner space of the stator 22 to the inside and outside in the radial direction is minimized by the engagement of the first and second convex portions 27a and 27b and the first and second concave portions 27c and 27d of the insulators 27 of the coils 23. It can be suppressed to the limit. Therefore, the oil as the refrigerant supplied from the oil supply port 29a of the first plate 29 fills the internal space of the stator 22 and flows through the slots 33... From the first plate 29 side to the second plate 31 side. Coil 23 located in ... can be cooled. Then, the oil having cooled the stator 22 is discharged into the housing 11 from 18 oil discharge ports 31a formed in the second plate 31, and the oil accumulated at the bottom of the housing 11 is stored in the reservoir through the oil passage P7. 34 is returned.

  On the other hand, surplus oil that could not be supplied to the oil supply passage 12a of the first housing 12 is supplied to the oil reservoir 38 through the oil passage P5, and from there, the inside of the upper end of the housing 11 through the oil passage P6 by gravity. Supplied to the space. This oil travels down the outer surface of the stator 22 by gravity, and cools the stator 22 from the outer surface side in the meantime, and cools the interior of the stator 22 to form 18 oil discharge ports formed in the second plate 31. The oil discharged from 31a... Is returned to the reservoir 34.

  The oil supplied to the inside of the stator 22 from the oil supply port 29a of the first plate 29 fills the internal space of the stator 22, but the oil pressure due to gravity increases toward the lower side of the stator 22 in the vertical direction. The oil pressure due to gravity becomes smaller as it goes upward in the vertical direction. Accordingly, a large amount of oil flows out from the oil discharge ports 31a on the lower side in the vertical direction where the diameter of the 18 oil discharge ports 31a is constant, and the flow rate of the oil in the vicinity increases to cool the oil. On the contrary, a small amount of oil flows out from the oil discharge port 31 on the upper side in the vertical direction where the pressure is low, the flow rate of the oil in the vicinity is reduced, the cooling effect is lowered, and the entire stator 22 is made uniform. It becomes difficult to cool down.

  However, according to the present embodiment, the oil discharge port 31a on the lower side in the vertical direction in which the oil pressure increases becomes smaller in diameter so that oil can be discharged uniformly from all the oil discharge ports 31a. The entire flow rate of oil flowing through all the slots 33 can be made uniform to cool the entire stator 22 evenly. In addition, since excess oil flows from the oil reservoir 38 to the outer surface of the stator 22 and is cooled, the stator 22 can be effectively cooled from both the inside and the outside.

  Next, a second embodiment of the present invention will be described with reference to FIG.

  In the first embodiment, as apparent from FIG. 4, the oil supply port 29 a of the first plate 29 and the one oil discharge 31 a of the second plate 31 directly face each other through the slot 33. Since the oil supplied from the oil supply port 29a flows through the slot 33 in the direction of the axis L and flows straight out from the oil discharge 31a, the oil supplied into the stator 22 may be wasted.

  Therefore, in the second embodiment, the diameter of the oil discharge 31a (1) closest to the oil supply port 29a is exceptional compared to the diameters of the two oil discharges 31a (2) and 31a (2) adjacent to both sides thereof. By minimizing it, wasteful oil spillage is minimized.

  Note that the number of oil discharges 31a (1) closest to the oil supply port 29a is not limited to one, and there may be two that are disposed at the same distance on both sides of the oil supply port 29a.

  Other configurations and effects of the second embodiment are similar to those of the first embodiment described above.

  Next, a third embodiment of the present invention will be described with reference to FIGS.

  In the first embodiment, the oil discharge ports 31a of the second plate 31 are disposed in the central portion in the radial direction of the slots 33 (see FIG. 3). There is a possibility that the oil stays between the oil discharge ports 31a and the bottom of the slots 33, and the temperature of the staying oil rises to reduce the cooling effect.

  Therefore, in the third embodiment, the oil discharge ports 31a are made to correspond to the positions as low as possible of the slots 33, so that the oil retention in the slots 33 is minimized and the cooling effect is enhanced.

  Specifically, the 18 oil discharge ports 31a... Are arranged on a circle C as in the first embodiment, but in the first embodiment, the center of the circle C is the center of the rotary shaft 17. In contrast to the axis L, in the third embodiment, the center of the circle C is an L ′ position eccentric from the axis L of the rotating shaft 17 by a distance E downward in the vertical direction. Therefore, at the position of the slot 33... In the vertical middle portion of the stator 22, the position of the oil discharge port 31 a of the second plate 31 is slightly moved in the circumferential direction on the circle C, and the oil discharge port is inserted into the slot 33. It is necessary to adjust so that 31a ... opposes.

  According to the third embodiment, since the oil discharge ports 31a are opened at the lower part of the slots 33, it is possible to prevent the oil from staying at the bottoms of the slots 33 and reducing the cooling effect. .

  Other configurations and effects of the third embodiment are the same as those of the first embodiment described above.

  The embodiments of the present invention have been described above, but various design changes can be made without departing from the scope of the present invention.

  For example, although the motor M has been described in the embodiment, the present invention can be applied to a rotating electrical machine including a generator.

  In the embodiment, the oil supply port 29a and the oil discharge ports 31a are provided at positions facing the slots 33, but they are arranged at positions shifted in the circumferential direction from the positions facing the slots 33. Can do.

  As a modification of the third embodiment, the distance from the axis L of the rotating shaft 17 to each oil discharge port 31a... May be set larger as the oil discharge port 31a. . Thereby, the oil discharge port 31a on the upper side in the vertical direction is brought close to the lower side of the slot 33 on the upper side in the vertical direction, and the oil discharge port 31a on the lower side in the vertical direction is placed on the lower side in the slot 33 on the lower side in the vertical direction. This makes it possible to prevent the oil from getting into the slots 33 and reducing the cooling effect.

  In the embodiment, the oil discharge ports 31a are formed only in the second plate 31, but the oil discharge ports can be provided in both the first and second plates 29 and 31.

  In the embodiment, the oil supply port 29 a is provided in the first plate 29, but the position of the oil supply port is not limited to the first plate 29.

1 is a longitudinal sectional view of a motor according to a first embodiment of the present invention. 1 is an enlarged view of the main part of FIG. 3-3 line view of FIG. 3 is an enlarged view of the main part of FIG. 1-5 arrow view (single product diagram of the first plate) 6-6 arrow view (single product view of the second plate) The figure corresponding to the said FIG. 4 based on the 2nd Embodiment of this invention. The figure corresponding to the said FIG. 3 based on the 3rd Embodiment of this invention. Figure corresponding to Fig. 6 (Single plate of the second plate)

Explanation of symbols

17 Rotating shaft 18 Rotor 22 Stator 23 Coil 27a First convex portion (convex portion)
27b Second convex part (convex part)
27c 1st recessed part (recessed part)
27d Second recess (recess)
29 1st plate 29a Oil supply port (refrigerant supply port)
31 Second plate 31a Oil discharge port (refrigerant discharge port)
33 Slot 35 Oil pump (refrigerant supply means)
38 Oil reservoir (refrigerant storage means)
C circle L axis P6 oil passage (refrigerant supply passage)

Claims (6)

A plurality of coils (23) in which an annular stator (22) surrounding the outer periphery of a rotor (18) having a rotating shaft (17) arranged in a substantially horizontal direction is arranged in a circumferential direction via a plurality of slots (33). ) Comprising:
By fixing the first plate (29) and the second plate (31) to both end faces in the axial line (L) direction of the plurality of coils (23), a space having the slot (33) as a refrigerant passage is defined, A refrigerant supply port (29a) for supplying a refrigerant is provided at an upper portion in the vertical direction of the space, and a plurality of refrigerant discharge ports are provided over at least one circumferential direction of the first and second plates (29, 31). (31a) is formed at a predetermined interval, and the opening area of the refrigerant discharge port (31a) is set to be smaller in the lower vertical direction.   The plurality of refrigerant discharge ports (31a) are arranged on a predetermined circle (C), and the center of the circle (C) is decentered vertically downward with respect to the center of the stator (22). The cooling structure for a rotating electrical machine according to claim 1.   The distance from the plurality of refrigerant discharge ports (31a) to the center of the stator (22) is set to be larger as the refrigerant discharge port (31a) on the lower side in the vertical direction. The cooling structure in the described rotating electrical machine.   A refrigerant supply port (29a) for supplying a refrigerant to the space is formed in the first plate (29), and a plurality of refrigerant discharge ports (31a) are formed in the second plate (31). The opening area of the refrigerant discharge port (31a) closest to the supply port (29a) is set smaller than the opening area of the refrigerant discharge port (31a) adjacent to the refrigerant discharge port (31a). The cooling structure in the rotary electric machine according to any one of claims 1 to 3.   Among the refrigerant supplied from the refrigerant supply means (35) for supplying the refrigerant to the refrigerant supply port (29a), the refrigerant storage means (38) for storing excess refrigerant, and the refrigerant storage means (38) The cooling structure for a rotating electrical machine according to any one of claims 1 to 4, further comprising a refrigerant supply passage (P6) for supplying a refrigerant to an upper outer peripheral portion of the stator (22).   The adjacent coils (23) are engaged with each other by the projecting portions (27a, 27b) and the recessed portions (27c, 27d) extending in the axis (L) direction on the radially outer side and the radially inner side of the slot (33). The cooling structure for a rotating electrical machine according to any one of claims 1 to 5, characterized in that:

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