JP2010166709A - Cooling structure of rotating electrical machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress wasting of coolant that passes a gap or the like between conductors forming a coil end part and runs off radially to the outside of the coil end part, and nonuniformity in the radial direction of the temperature at the coil end part, relating to a cooling structure of a rotating electrical machine which cools the coil end part by jetting radially the coolant toward the coil end part from the inside of the coil end part. <P>SOLUTION: The cooling structure includes a jetting hole 3 which is provided to a rotor 10 or a member that rotates together with the rotor 10 as one body and jets radially a coolant from the inside of a coil end part 32 toward the coil end part 32, and a cover member 50 that includes a cylindrical peripheral wall part 51 that covers the outer peripheral surface of the coil end part 32. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention distributes a refrigerant to a rotating electric machine including a stator having a cylindrical stator core and a coil, and a rotor rotatably supported inside the stator in the radial direction, and protrudes from an axial end portion of the stator core. The present invention relates to a cooling structure for a rotating electric machine that cools a coil end portion of the coil.

  As a method for cooling a coil in a rotating electrical machine including a stator having a cylindrical stator core and a coil, and a rotor supported rotatably inside the stator in the radial direction, the coil is formed in an annular shape protruding from the axial end of the stator core. A technique is known in which a coolant is sprayed from the radially inner side to a coil end portion of a coil to be cooled to cool the coil end portion (see, for example, Patent Document 1 below). In the configuration described in Patent Document 1, an injection hole for spraying oil as a refrigerant to the coil end portion is provided in a plate that rotates integrally with the rotor core in a state of communicating with an axial oil passage provided in the rotor core. ing. And the oil after cooling a rotor core is supplied to an injection hole, and the oil is injected toward a coil end part from an injection hole by the centrifugal force of a rotor. The oil sprayed on the coil end part cools the coil end part by heat exchange, and then returns to the lower side of the case housing the rotating electrical machine.

  In the configuration as disclosed in Patent Document 1, since the refrigerant for cooling the rotor core is also used for cooling the coil end portion, the cooling capacity of the refrigerant after cooling the rotor core is not wasted, and the coil It can be used to cool the end. Further, since the refrigerant can be injected from the injection hole toward the coil end portion by utilizing the centrifugal force of the rotor, it is not necessary to use a pump or the like only for injecting the refrigerant, and it accompanies the rotation of the rotor. Centrifugal force can be used effectively.

JP-A-9-182375

However, in the configuration in which the coolant is jetted from the radially inner side of the coil end portion toward the coil end portion as in Patent Document 1, a part of the coolant contacts the conductor forming the coil end portion even once. Otherwise, after coming into contact with the conductor forming the coil end portion, it passes through the gap between the conductors forming the coil end portion and jumps to the outside in the radial direction of the coil end portion. In particular, when the coil end portion is formed of a linear conductor having a rectangular cross section, and the linear conductor is aligned, generally, since the gap between the conductors forming the coil end portion is wide, There is a possibility that the amount of the refrigerant that jumps out to the outside in the radial direction of the coil end portion increases. The refrigerant that has jumped to the outside in the radial direction of the coil end portion does not exchange heat with the coil end portion at all, or does not sufficiently perform heat exchange with the coil end portion, and thus still has cooling capacity. Refrigerant is included. However, in the configuration as disclosed in Patent Document 1, the refrigerant that has jumped to the outside in the radial direction of the coil end portion accommodates the rotating electrical machine in the same manner as other refrigerants that function as a refrigerant without jumping to the outside in the radial direction. Since it is returned to the lower side of the case, there is a problem that the refrigerant that has jumped out to the outside in the radial direction of the coil end portion is wasted.
Further, in the configuration in which the coolant is injected from the radially inner side of the coil end portion toward the coil end portion as in Patent Document 1, it is difficult to spray the coolant on the outer peripheral surface of the coil end portion. There was a problem that the temperature of the part became non-uniform in the radial direction.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a cooling structure for a rotating electrical machine that cools a coil end portion by injecting a refrigerant from the radially inner side of the coil end portion toward the coil end portion. In addition, it is possible to prevent the refrigerant that has passed through the gap between the conductors forming the coil end portion and jumped to the outside in the radial direction of the coil end portion from being wasted and the temperature of the coil end portion from becoming uneven in the radial direction. The object is to provide a cooling structure that can.

  In order to achieve the above object, according to the present invention, a refrigerant is circulated through a stator having a cylindrical stator core and a coil, and a rotating electrical machine including a rotor rotatably supported on the radially inner side of the stator, The characteristic structure of the cooling structure of the rotating electrical machine that cools the coil end portion of the coil protruding from the axial end portion of the stator core is provided in the rotor or a member that rotates integrally with the rotor, and is radially inward of the coil end portion. The injection hole which injects a refrigerant | coolant toward the said coil end part, and the cover member which has a cylindrical surrounding wall part which covers the outer peripheral surface of the said coil end part are provided.

  In the present application, the “rotary electric machine” is used as a concept including any of a motor (electric motor), a generator (generator), and a motor / generator functioning as both a motor and a generator as necessary.

According to said characteristic structure, the refrigerant | coolant can be injected from a radial inside with respect to a coil end part effectively using the centrifugal force accompanying rotation of a rotor, and was sprayed on the inner peripheral surface of the coil end part The refrigerant cools around the inner peripheral surface of the coil end portion. Further, the refrigerant that has passed through the gap between the conductors forming the coil end portion and jumped outward in the radial direction collides with the peripheral wall portion of the cover member and adheres to the peripheral wall portion of the cover member. And the refrigerant | coolant adhering to the surrounding wall part of a cover member receives force, such as gravity and surface tension, is supplied from a radial direction outer side with respect to a coil end part, and the refrigerant | coolant adhering to the outer peripheral surface of a coil end part is coil end part. Cooling is performed around the outer peripheral surface. Therefore, the refrigerant that has passed through the gap between the conductors forming the coil end portion and jumped radially outward can be returned to the coil end portion to cool the coil end portion, thereby forming the coil end portion. It can be suppressed that the refrigerant that has passed through the gap between the conductors and jumped to the outside in the radial direction of the coil end portion is wasted.
Furthermore, since it is possible to perform cooling by attaching a refrigerant not only to the inner peripheral surface of the coil end portion but also to the outer peripheral surface of the coil end portion, it is possible to prevent the temperature distribution of the coil end portion from becoming uneven in the radial direction. be able to.

  Here, it is preferable that the peripheral wall portion is configured to cover substantially the entire axial direction of the outer peripheral surface of the coil end portion.

  According to this configuration, most of the refrigerant that has passed through the gaps between the conductors forming the coil end portion and jumped outward in the radial direction of the coil end portion can be attached to the peripheral wall portion of the cover member. Therefore, it is possible to further suppress the waste of the refrigerant that has passed through the gap between the conductors forming the coil end portion and jumped to the outside in the radial direction of the coil end portion.

  The stator core has a plurality of slots provided at predetermined intervals along the circumferential direction, and the coil end portion extends in the axial direction from a slot conductor portion inserted in each slot. And a circumferential conductor portion that connects the two axial conductor portions by connecting different slots in the circumferential direction, and the cover members are arranged radially along the radial direction of the stator, and adjacent to each other It is preferable to have a configuration having a plurality of radial wall portions that are inserted into a gap between conductors that is a gap between two axial conductor portions.

  According to this configuration, the refrigerant passing through the interconductor gap passes through a gap formed between the stator circumferential side surface of the radial wall portion and the axial conductor portion. Therefore, when the refrigerant passes through the gap between the conductors, the rate of heat exchange by contacting the coil end portion can be increased, and the cooling performance can be improved.

  Further, it is preferable that the radial wall portion is formed integrally with the peripheral wall portion so as to protrude radially inward from the peripheral wall portion.

  According to this configuration, an increase in the number of parts can be suppressed. In addition, the radial wall portion and the peripheral wall portion can be easily formed integrally with the cover member as a cast part such as resin, and the process of manufacturing the cover member can be simplified.

  The cover member has the same number of the radial wall portions as the plurality of inter-conductor gaps arranged in the circumferential direction, and the radial wall portion is inserted into all of the inter-conductor gaps. It is preferable.

  According to this configuration, in all the inter-conductor gaps, a gap for allowing the refrigerant to pass can be formed between the stator circumferential side surface of the radial wall portion and the axial conductor portion. Therefore, the ratio of heat exchange between the refrigerant and the coil end portion in all the inter-conductor gaps can be increased, and the cooling performance can be further improved.

  In addition, it is preferable that the radial wall portion is arranged with a predetermined interval with respect to the axial end portion of the stator core.

  According to this configuration, in the region in which the radial wall portion is not inserted into the inter-conductor gap, the inter-conductor gap is large by the amount that the radial wall portion is not inserted, and conversely, the radial wall portion is the inter-conductor gap. The gap between the conductors is small in the region inserted in the. Therefore, if it is set as the structure which injects a refrigerant | coolant from the radial inside toward the area | region where the radial direction wall part is not inserted, it passes through the area | region where the said radial direction wall part is not inserted, and reaches | attains the peripheral wall part of a cover member. The ratio of the refrigerant | coolant to perform can be raised. Therefore, the refrigerant can be actively guided to the outside in the radial direction of the coil end portion, and the outer peripheral surface of the coil end portion can be cooled more reliably.

  Further, the cover member includes an end wall portion that extends radially inward from an end portion on the opposite side of the stator core side in the axial direction of the peripheral wall portion and covers the axial end portion of the coil end portion. A configuration is preferable.

  According to this structure, it can suppress that the refrigerant | coolant scattered by the collision with a cover member or a coil end part jumps out on the opposite side to the stator core side in the axial direction of a surrounding wall part. Therefore, more refrigerant can be used for cooling the coil end portion.

  Further, it is preferable that the peripheral wall part has a notch part in a circumferential direction, and the inside and the outside of the cover member are communicated with each other through the notch part.

  According to this configuration, when the refrigerant accumulates inside the cover member, the refrigerant can be discharged to the outside of the cover member. Therefore, it can suppress that a refrigerant | coolant permeates into the clearance gap formed between a rotor and a stator.

  In addition, it is preferable that the injection hole is configured to inject a refrigerant toward the axial conductor portion.

  Generally, the axial conductor portion extending in the axial direction from the slot is disposed without overlapping the axial conductor portion extending from the other slot in the circumferential direction. Therefore, according to this configuration, the coolant can be sprayed substantially uniformly onto the axial conductor portion of each slot, and the temperature of the axial conductor portion can be prevented from becoming uneven due to the slot. Therefore, for example, when a coil consists of a plurality of phases, the coils of each phase can be cooled substantially uniformly, and the cooling performance can be improved.

  Further, it is preferable that the coil is constituted by a linear conductor formed in a predetermined shape that can be wound around the stator core.

  In the case where the coil is a linear conductor formed in a predetermined shape that can be wound around the stator core, the linear conductor is generally arranged in an aligned manner, so that the gap between the conductors is generally increased. Therefore, the amount of the refrigerant that passes through the gap between the conductors forming the coil end portion and jumps outward in the radial direction increases. According to this configuration, even in such a case, it is possible to prevent the refrigerant that has passed through the gaps between the conductors forming the coil end portion and jumped to the outside in the radial direction of the coil end portion from being wasted. .

  Further, it is preferable that the cover member is made of an insulating material and is disposed in an insulating space between the case for housing the stator and the coil end portion.

  According to this configuration, since the cover member can be arranged in a space necessary for insulating between the case and the coil end portion, it is not necessary to provide a dedicated space used only for arranging the cover member. . Therefore, an increase in the size of the case that houses the rotating electrical machine can be suppressed.

It is sectional drawing along the rotating shaft of the rotary electric machine which concerns on embodiment of this invention. It is a perspective view of a stator in the state where a cover member was attached. It is radial direction sectional drawing of a stator core. It is an axial view of the stator showing the cover member in a cross section with the end wall portion removed. It is a perspective view of a cover member.

  Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view of a rotating electrical machine 1 that employs the rotating electrical machine cooling structure according to the present invention along the rotation axis. FIG. 2 is a perspective view of the stator 20 of the rotating electrical machine 1 with the cover member 50 attached. As shown in these drawings, the cooling structure of the rotating electrical machine 1 according to the present embodiment has a cylindrical peripheral wall portion 51 that covers the outer peripheral surface of the coil end portion 32 of the coil 30 protruding from the axial end portion of the stator core 21. The cover member 50 which has is provided. A cooling structure of the rotating electrical machine 1 is configured by the cover member 50, the injection hole 3 provided in the rotor 10 of the rotating electrical machine 1, and an oil passage that supplies oil to the injection hole 3. In this embodiment, oil corresponds to the refrigerant in the present invention. In addition, a refrigerant | coolant is not limited to oil, A well-known various cooling fluid can be employ | adopted. Hereinafter, regarding the cooling structure of the rotating electrical machine 1 according to the present embodiment, the configuration of the rotating electrical machine 1, the configuration of the cover member 50, and the cooling mechanism of the rotating electrical machine 1 will be described in detail in order. In the following description, the axial direction, the circumferential direction, and the radial direction are defined with reference to the central axis of the stator 20 that is also the rotational axis of the rotating electrical machine 1 unless otherwise specified.

1. As shown in FIG. 1, the rotating electrical machine 1 includes a stator 20 and a rotor 10. The stator 20 constitutes an armature of the rotary electric machine 1. On the radially inner side of the stator 20, a rotor 10 as a magnetic field provided with a permanent magnet is disposed so as to be rotatable relative to the stator 20.

1-1. Configuration of Rotor The rotor 10 has a rotating shaft 11 that is rotatably held with respect to the case 4 via a bearing 60. The rotating shaft 11 includes a connecting portion (not shown) for connecting to another transmission shaft at the axial end, and can output the driving force generated by the rotating electrical machine 1 to the outside of the rotating electrical machine 1. It is configured. In this case, the rotating electrical machine 1 functions as an electric motor. Further, the rotating electrical machine 1 is configured to be capable of generating electric power by a driving force transmitted from the outside to the rotating electrical machine 1. In this case, the rotating electrical machine 1 functions as a generator.

  The rotor 10 includes a permanent magnet (not shown) in the rotor core. An axial oil passage 6 is formed in the rotor core so that the permanent magnet can be cooled. Further, the rotor 10 includes a rotation shaft oil passage 8 inside the rotation shaft 11 and a radial oil passage 5 that communicates the rotation shaft oil passage 8 and the axial oil passage 6. Then, the oil supplied through the case oil passage (not shown) passes through the rotation shaft oil passage 8, the radial oil passage 5, and the axial oil passage 6. Are supplied to the injection holes 3 formed in

  In the present embodiment, the injection hole 3 is formed in the retainer 13 that holds the rotor core of the rotor 10 from both sides in the axial direction. That is, the injection hole 3 is provided on the radially inner side of the coil end portion 32 of the coil 30 protruding from the axial end portion of the stator core 21 of the stator 20 described later, and is configured to rotate integrally with the rotor 10. . The oil supplied to the injection hole 3 is more accurately directed toward the coil end portion 32 of the coil 30 protruding from the axial end portion of the stator core 21 due to the centrifugal force generated by the rotation of the rotor 10. Injected toward the 32 axial conductor portions 33. And the oil sprayed on the coil end part 32 cools the coil end part 32 by heat exchange. Details of the cooling mechanism will be described later.

1-2. Configuration of Stator The stator 20 includes a stator core 21 that is fixed to the inner peripheral surface of the case 4 by fastening bolts, and a coil 30 that is wound around the stator core 21. The coil 30 includes a coil end portion 32 that protrudes from the axial end portion of the stator core 21.

  The stator core 21 is configured by laminating a plurality of electromagnetic steel plates, and is formed in a substantially cylindrical shape. FIG. 3 is a radial cross-sectional view of the stator core 21. As shown in FIGS. 1 and 3, a plurality of slots 22 extending in the axial direction are provided on the inner peripheral surface of the stator core 21 at predetermined intervals along the circumferential direction. Each slot 22 has the same cross-sectional shape, and has a predetermined width and depth. In the present embodiment, the stator core 21 is provided with 48 slots 22 on the entire circumference thereof.

  As shown in FIGS. 1 and 2, the coil 30 has a plurality of slot conductor portions 31 inserted into the slots 22 of the stator core 21 and the coil end portion 32. The coil end portion 32 of the coil 30 includes an axial conductor portion 33 extending in the axial direction from the slot conductor portion 31 and a circumferential conductor connecting the two axial conductor portions 33 by connecting different slots in the circumferential direction. Part 34. The perspective view of the stator 20 shown in FIG. 2 is a view in which a part of a cover member 50 to be described later is cut away for explaining the coil end portion 32.

  In the present embodiment, the coil 30 is formed in advance in a predetermined shape that can be wound around the stator core 21, and the coil 30 is formed in each slot 22 of the stator core 21 as shown in FIGS. 1 and 2. A plurality of linear conductors to be inserted are inserted. In the present embodiment, four linear conductors are inserted in each slot 22. The linear conductor forming the coil 30 has a rectangular cross section. In the slot conductor portion 31, the four linear conductors are aligned and arranged in a line in the radial direction inside the slot 22. An axial conductor portion 33 of the coil end portion 32 is constituted by a linear conductor that extends in the axial direction continuously from the slot conductor portion 31 and protrudes from the stator core 21 in the axial direction. In the axial conductor portion 33, the four linear conductors are bent inward in the radial direction from a state substantially parallel to the axial direction while maintaining a state in which they are aligned in a row, and become substantially parallel to the radial direction. So that they are aligned. As is clear from FIG. 2, the axial conductor portions 33 are arranged without overlapping the axial conductor portions 33 in the circumferential direction. In the present embodiment, a portion of the linear conductor constituting the coil end portion 32 that has the same circumferential position as the slot conductor portion 31 is defined as the axial conductor portion 33. In the circumferential conductor portion 34, the two linear conductors arranged radially outside in the slot 22 have a diameter at a position away from the axial end of the stator core 21 by a predetermined distance outward in the axial direction. The two linear conductors arranged radially inward in the slot 22 are arranged side by side in the radial direction at a position closer to the stator core 21 than the position in the axial direction. Yes.

  Moreover, in this embodiment, the rotary electric machine 1 is a rotary electric machine driven by a three-phase alternating current, and the coil 30 is also formed in a three-phase configuration (U phase, V phase, W phase). Then, four linear conductors of the same phase are inserted into two adjacent slots. FIG. 4 is an axial view of the stator 20 showing the cover member 50 in a cross section from which the end wall portion 52 is removed for explanation. As shown in FIGS. 2 and 4, a total of four linear conductors, which are two linear conductors arranged radially outward in each of the two adjacent slots 22, are the shafts of the stator core 21. Are arranged side by side in the radial direction at a position away from the end in the axial direction by a predetermined distance in the axial direction, and radially inward in each of the two adjacent slots 22 at a position closer to the stator core 21 than the position in the axial direction. A total of four linear conductors including the two linear conductors arranged in a row are arranged in the radial direction.

  As shown in FIGS. 2 and 4, the circumferential conductor portions 34 having different phases are arranged so as to overlap in the circumferential direction. And in order to ensure the electrical insulation between the circumferential conductor parts 34 in which phases differ, the insulating sheet 36 is interposed in the overlapping part of the circumferential conductor parts 34 in which phases differ. As the insulating sheet 36, for example, a sheet formed of a material having high electrical insulation and heat resistance such as a laminate of aramid fiber and polyethylene terephthalate can be used.

  Further, as shown in FIGS. 2 and 4, the inter-conductor gap 35, which is a gap between two adjacent axial conductor portions 33, is formed at a predetermined interval along the circumferential direction, and the width in the circumferential direction is the axis. It is almost uniform in the direction. A radial wall portion 54 of a cover member 50 described later is inserted into the interconductor gap 35.

2. Configuration of Cover Member FIG. 5 is a perspective view of the cover member 50. As shown in FIG. 5, in the present embodiment, the cover member 50 includes a peripheral wall portion 51, an end wall portion 52, and a radial wall portion 54. And the surrounding wall part 51, the end wall part 52, and the radial direction wall part 54 are integrally formed, for example with insulating materials, such as resin, and the case 4 and coil end which accommodate the stator 20 are shown by FIG. It is disposed in the insulating space 2 for ensuring insulation between the portion 32.

  As shown in FIGS. 1 and 2, the peripheral wall portion 51 has a cylindrical shape that covers the outer peripheral surface of the coil end portion 32. Here, the outer peripheral surface of the coil end portion 32 is a surface along the radially outermost periphery of the plurality of axial conductor portions 33 of the coil end portion 32 in the present embodiment. Further, the peripheral wall portion 51 is formed so as to have an axial height higher than the axial height of the coil end portion 32, and is arranged so as to cover substantially the entire axial direction of the outer peripheral surface of the coil end portion 32. . Further, the peripheral wall portion 51 is disposed so that the end portion on the stator core 21 side in the axial direction is in contact with the axial end portion of the stator core 21 as shown in FIG. 1. The end portion on the stator core 21 side in the axial direction of the peripheral wall portion 51 may be configured not to contact the end portion in the axial direction of the stator core 21.

  Further, as shown in FIGS. 2 and 5, the peripheral wall portion 51 has a notch 53 in a part in the circumferential direction, and the inside and the outside of the cover member 50 communicate with each other via the notch 53. It is configured as follows. The notch 53 is for discharging the oil accumulated inside the cover member 50 to the outside. The notch 53 is desirably provided at a position where oil can be prevented from entering a gap formed between the rotor core of the rotor 10 and the stator core 21. Specifically, the cutout portion 53 is disposed so that at least a part thereof is positioned below the lowermost portion of the inner peripheral surface of the stator core 21. For example, as shown in FIG. 1, when the rotating electrical machine 1 is used, the cutout portion 53 is arranged such that at least a part of the cutout portion 53 is positioned at the lowermost portion of the peripheral wall portion 51 when the axial direction is horizontal. It is good to form.

  The end wall portion 52 is formed to extend radially inward from an end portion on the opposite side of the stator wall 21 in the axial direction of the peripheral wall portion 51 and cover the axial end portion of the coil end portion 32. Here, the end portion in the axial direction of the coil end portion 32 is an end portion on the opposite side of the stator core 21 in the axial direction of the coil end portion 32. Further, as shown in FIG. 1, the end wall portion 52 is disposed so that the end surface on one side in the axial direction is in contact with the inner wall of the case 4. In addition, it is good also as a structure which the end surface of the axial direction one side of the end wall part 52 does not contact | abut with the inner wall of the case 4. FIG.

  As shown in FIG. 5, the radial wall portion 54 is formed integrally with the peripheral wall portion 51 so as to protrude radially inward from the peripheral wall portion 51, and is arranged radially along the radial direction. Has been. Further, the radial wall portions 54 are provided in the same number as the plurality of inter-conductor gaps 35 arranged in the circumferential direction, and as shown in FIGS. Inserted radially inward. Further, as shown in FIG. 4, the radial wall portion 54 has a length in the radial direction so as not to contact the insulating sheet 36 interposed in the overlapping portion of the circumferential conductor portion 34. Yes.

  Further, as shown in FIG. 5, the radial wall portion 54 extends in the axial direction as well as in the radial direction, and the end wall has a predetermined distance from the end portion on the stator core 21 side in the axial direction of the peripheral wall portion 51. It is formed from the position away from the portion 52 side to the end portion on the end wall portion 52 side. Therefore, in the state where the cover member 50 is attached, as shown in FIGS. 1 and 2, the radial wall portion 54 is arranged at the predetermined interval with respect to the axial end portion of the stator core 21. Will be. In the present embodiment, as shown in FIG. 1, the positional relationship in the axial direction between the injection hole 3 and the radial wall portion 54 is such that the radial wall is located outside the opening portion of the injection hole 3 in the axial direction. The predetermined interval is set so that the end of the portion 54 on the stator core 21 side in the axial direction is located.

3. As described above, the rotor 10 of the rotating electrical machine 1 has the injection hole 3 that injects oil as refrigerant from the radially inner side of the coil end portion 32 toward the axial conductor portion 33 of the coil end portion 32. The oil is supplied to the injection hole 3 through the oil passage 8 in the rotation shaft, the radial oil passage 5, and the axial oil passage 6. And the cover member 50 which has the surrounding wall part 51, the end wall part 52, and the radial direction wall part 54 is arrange | positioned so that the outer peripheral surface and axial direction edge part of the coil end part 32 may be covered. The oil is supplied to the rotating electrical machine by the injection hole 3, the oil passage for supplying oil to the injection hole 3 (rotary shaft oil passage 8, radial oil passage 5, and axial oil passage 6), and the cover member 50. A cooling structure of the rotating electrical machine 1 that circulates and cools the coil end portion 32 of the coil 30 protruding from the axial end portion of the stator core 21 is configured. Hereinafter, the cooling mechanism of the rotating electrical machine 1 in the cooling structure of the rotating electrical machine 1 will be described in detail.

  The oil supplied to the rotary shaft oil passage 8 via the oil passage in the case (not shown) by operating a pump (not shown) is passed through the radial oil passage 5 by the centrifugal force generated by the rotation of the rotary shaft 11. To the axial oil passage 6. And the permanent magnet arrange | positioned in a rotor core is cooled by the heat exchange between the oil and the rotor core of the rotor 10 when oil distribute | circulates the axial direction oil path 6. FIG. The oil flow at this time is shown by solid arrows in FIG.

  The oil after cooling the permanent magnet in the rotor core is supplied to the injection hole 3 formed in the retainer 13, and the oil is fed from the injection hole 3 to the coil end portion 32 by the centrifugal force accompanying the rotation of the rotor 10. Injected toward the axial conductor portion 33. And the oil adhering to the linear conductor which forms the coil end part 32 cools the said linear conductor by heat exchange. At this time, the oil is injected from the radially inner side of the coil end portion 32 toward the axial conductor portion 33, so that cooling is performed around the inner peripheral surface of the coil end portion 32. Here, the inner peripheral surface of the coil end portion 32 is a surface along the radially innermost periphery of the plurality of axial conductor portions 33 of the coil end portion 32 in the present embodiment.

  As described above, since the axial conductor portions 33 are disposed without overlapping the axial conductor portions 33 in the circumferential direction, oil is directed from the injection hole 3 toward the axial conductor portion 33 of the coil end portion 32. By spraying, oil is sprayed substantially uniformly on the axial conductor portion 33 of each slot 22. In the present embodiment, the oil injected from the injection hole 3 is hardly sprayed on the circumferential conductor 34, but the oil adhering to the axial conductor 33 receives forces such as gravity and surface tension in the circumferential direction. When flowing through the conductor 34, the circumferential conductor 34 is cooled.

  Further, since the inter-conductor gap 35, which is a gap between two adjacent axial conductor portions 33, is formed at a predetermined interval along the circumferential direction, from the injection hole 3 to the axial conductor portion 33 of the coil end portion 32. A portion of the oil sprayed toward the conductor does not make contact with the linear conductor forming the coil end portion 32, or after contact with the linear conductor forming the coil end portion 32, the inter-conductor gap 35 Through the coil end portion 32 and protrudes outward in the radial direction of the coil end portion 32. As described above, the positional relationship in the axial direction between the injection hole 3 and the radial wall portion 54 is such that the stator core in the axial direction of the radial wall portion 54 is outside the opening portion of the injection hole 3 in the axial direction. It is set so that the end on the 21st side is located. Therefore, most of the oil traveling from the injection hole 3 toward the inter-conductor gap 35 passes radially outward in a region where the inter-conductor gap 35 where the radial wall portion 54 is not inserted is large. That is, the cover member 50 in the present embodiment is configured to positively jump out a part of the oil injected from the injection hole 3 to the outside in the radial direction of the coil end portion 32. Then, the oil that has jumped out of the coil end portion 32 in the radial direction collides with the peripheral wall portion 51 of the cover member 50 and adheres to the peripheral wall portion 51.

  The oil adhering to the peripheral wall portion 51 of the cover member 50 receives forces such as gravity and surface tension, and is supplied to the coil end portion 32 from the outside in the radial direction. And the oil adhering to the linear conductor which forms the coil end part 32 cools the said linear conductor by heat exchange. The oil movement path at this time depends on the position where the oil adheres in the circumferential direction in the usage state of the rotating electrical machine 1, the amount of oil adhering to the peripheral wall 51, and the like. On the other hand, since it is supplied from the outside in the radial direction, the cooling is performed around the outer peripheral surface of the coil end portion 32. The oil supplied from the outer side in the radial direction passes through the inter-conductor gap 35 and goes inward in the radial direction. However, in the region where the inter-conductor gap 35 where the radial wall portion 54 is not inserted is large, the oil is supplied from the inner side in the radial direction. Oil comes in. Therefore, most of the oil supplied from the outside in the radial direction passes through the region where the inter-conductor gap 35 in which the radial wall portion 54 is inserted is small and goes toward the inside in the radial direction. Therefore, in the present embodiment, the ratio of heat exchange between the oil and the axial conductor portion 33 when the oil passes through the inter-conductor gap 35 radially inward is increased. . Further, when the oil adhering to the axial conductor portion 33 receives forces such as gravity and surface tension and flows to the circumferential conductor portion 34, the oil adhering to the peripheral wall portion 51 is directly supplied to the circumferential conductor portion 34. At this time, the circumferential conductor portion 34 is cooled.

  Further, the oil splashed to the opposite side of the stator core 21 in the axial direction due to the collision with the cover member 50 and the coil end portion 32 collides with the end wall portion 52 of the cover member 50 and adheres to the end wall portion 52. The oil is prevented from jumping out to the side opposite to the stator core side in the axial direction of the peripheral wall portion 51.

  The oil injected from the injection hole 3 cools the coil end portion 32, is then discharged to the outside of the cover member 50 through the notch portion 53, and is stored in the oil storage portion through an oil passage (not shown). Then, the oil that has been deprived of heat from the coil end portion 32 and the like is then circulated through the oil cooler to be cooled and used again to cool the rotating electrical machine 1 including the coil end portion 32.

[Other Embodiments]
(1) In the above embodiment, the case where the injection hole 3 is formed in the retainer 13 that clamps the rotor core from both sides in the axial direction has been described as an example. However, the embodiment of the present invention is limited to this. is not. That is, the injection hole 3 may be provided in any member as long as it is a member that rotates integrally with the rotor 10 or the rotor 10. For example, the injection hole 3 is provided on the outer peripheral surface of the rotation shaft 11. It is also one of the preferred embodiments of the present invention to have a configuration in which it is provided in a state where it is in communication with 8.

(2) In the above embodiment, the case where the injection hole 3 is configured to inject oil toward the axial conductor portion 33 of the coil end portion 32 has been described as an example. However, the embodiment of the present invention is not limited to this. That is, it is also one of preferred embodiments of the present invention that the injection hole 3 is configured to inject oil toward both the axial conductor portion 33 and the circumferential conductor portion 34 or only to the circumferential conductor portion 34. It is.

(3) In the above embodiment, the case where the coil 30 is formed in advance in a predetermined shape that can be wound around the stator core 21 and the linear conductor forming the coil 30 has a rectangular cross section will be described as an example. did. However, the embodiment of the present invention is not limited to this. That is, it is also a preferred embodiment of the present invention that the linear conductor forming the coil 30 has a cross-sectional shape other than a rectangular cross section such as a circle. Moreover, it is also one of the preferred embodiments of the present invention that the coil 30 is not formed in a predetermined shape that can be wound around the stator core 21 in advance.

(4) In the embodiment described above, the axial conductor portion 33 of the coil end portion 32 has been described as an example in which the axial conductor portions 33 are arranged without overlapping in the circumferential direction. However, the embodiment of the present invention is not limited to this, and the shape of the coil end portion 32 can be changed as appropriate.

(5) In the above embodiment, the cover member 50 includes the end wall portion 52 and the radial wall portion 54 in addition to the peripheral wall portion 51, and the peripheral wall portion 51, the end wall portion 52, and the radial wall portion 54. The case where is integrally formed has been described as an example. However, the embodiment of the present invention is not limited to this. That is, it is one of the preferred embodiments of the present invention that the cover member 50 is formed by combining a plurality of components. Moreover, it is also one of the preferred embodiments of the present invention that the cover member 50 is configured not to include one or both of the end wall portion 52 and the radial wall portion 54.

(6) In the above embodiment, the case where the peripheral wall portion 51 is formed so as to cover substantially the entire axial direction of the outer peripheral surface of the coil end portion 32 has been described as an example. However, the embodiment of the present invention is not limited to this. That is, it is also one preferred embodiment of the present invention that the peripheral wall portion 51 is configured to cover a partial region in the axial direction on the outer peripheral surface of the coil end portion 32.

(7) In the above embodiment, the peripheral wall portion 51 has a notch 53 in a part in the circumferential direction, and the inside and the outside of the cover member 50 are communicated with each other via the notch 53. The case has been described as an example. However, the embodiment of the present invention is not limited to this. That is, it is one of the preferred embodiments of the present invention that the peripheral wall portion 51 does not have the notch portion 53.

(8) In the above embodiment, the cover member 50 has the same number of radial wall portions 54 as the inter-conductor gaps 35, and the radial wall portions 54 are inserted into all the inter-conductor gaps 35 as an example. As explained. However, the embodiment of the present invention is not limited to this. That is, for example, when the rotating electrical machine 1 is in use, a configuration in which the radial wall portion 54 is inserted only in the inter-conductor gap 35 above the center axis of the stator 20, or half of the inter-conductor gap 35 is used. A configuration in which the radial wall portion 54 is inserted is also one preferred embodiment of the present invention.

(9) In the above embodiment, in the state in which the cover member 50 is attached, the radial wall portion 54 is an example of a case where the radial wall portion 54 is arranged at a predetermined interval with respect to the axial end portion of the stator core 21. As explained. However, the embodiment of the present invention is not limited to this. That is, in a state in which the cover member 50 is attached, it is also one of preferred embodiments of the present invention that the radial wall portion 54 is in contact with the axial end portion of the stator core 21.

(10) In the above embodiment, an example is given in which the cover member 50 is formed of an insulating material and disposed in the insulating space 2 for ensuring the insulation between the case 4 and the coil end portion 32. As explained. However, the embodiment of the present invention is not limited to this. That is, it is also a preferred embodiment of the present invention that the cover member 50 is not formed of an insulating material.

(11) In the above embodiment, the case where the rotating electrical machine 1 is a rotating electrical machine driven by a three-phase alternating current has been described as an example. However, the embodiment of the present invention is not limited to this. That is, it is also one preferred embodiment of the present invention that the rotating electrical machine 1 is a rotating electrical machine driven by electric power other than three-phase alternating current.

  The present invention includes a stator having a cylindrical stator core and a coil, and a rotor rotatably supported on the radially inner side of the stator, and cools a coil end portion of a coil protruding from an axial end portion of the stator core. It can utilize suitably for the well-known various rotary electric machine which needs.

1: rotating electric machine 2: insulating space 3: injection hole 10: rotor 20: stator 21: stator core 22: slot 30: coil 31: slot conductor part 32: coil end part 33: axial conductor part 34: circumferential conductor part 35 : Inter-conductor gap 50: Cover member 51: Peripheral wall portion 52: End wall portion 53: Notch portion 54: Radial wall portion

Claims (11)

A coolant is circulated through a stator having a cylindrical stator core and a coil, and a rotating electrical machine including a rotor rotatably supported on the radially inner side of the stator, and the coil protrudes from an axial end of the stator core. A cooling structure for a rotating electrical machine that cools a coil end portion,
An injection hole that is provided in the rotor or a member that rotates integrally with the rotor, and that injects the refrigerant from the radially inner side of the coil end portion toward the coil end portion;
A cover member having a cylindrical peripheral wall portion covering the outer peripheral surface of the coil end portion;
A cooling structure for a rotating electrical machine.   The cooling structure for a rotating electrical machine according to claim 1, wherein the peripheral wall portion covers substantially the entire area in the axial direction on the outer peripheral surface of the coil end portion. The stator core has a plurality of slots provided at predetermined intervals along a circumferential direction, and the coil end portion includes an axial conductor portion extending in an axial direction from a slot conductor portion inserted in each slot; A circumferential conductor portion that connects the two axial conductor portions by connecting different slots in the circumferential direction;
The said cover member is radially arranged along the radial direction of the stator, and has a plurality of radial wall portions that are inserted into inter-conductor gaps that are gaps between two adjacent axial conductor portions. Or the cooling structure of the rotary electric machine of 2.   The cooling structure for a rotating electrical machine according to claim 3, wherein the radial wall portion is formed integrally with the peripheral wall portion so as to protrude radially inward from the peripheral wall portion.   The cover member has the same number of radial wall portions as the plurality of inter-conductor gaps arranged in the circumferential direction, and the radial wall portions are inserted into all the inter-conductor gaps. 5. A cooling structure for a rotating electric machine according to 4.   The cooling structure for a rotating electrical machine according to any one of claims 3 to 5, wherein the radial wall portion is disposed at a predetermined interval with respect to an axial end portion of the stator core.   The cover member includes an end wall portion extending radially inward from an end portion on the opposite side of the stator core side in the axial direction of the peripheral wall portion and covering the axial end portion of the coil end portion. The cooling structure for a rotating electrical machine according to any one of 1 to 6.   The said surrounding wall part has a notch part in the circumferential direction part, and the inside and the exterior of the said cover member are connected via the said notch part. Cooling structure for rotating electrical machines.   The cooling structure for a rotating electric machine according to claim 3, wherein the injection hole injects the refrigerant toward the axial conductor portion.   The cooling structure for a rotating electrical machine according to any one of claims 1 to 9, wherein the coil is configured by a linear conductor formed in a predetermined shape that can be wound around the stator core.   The rotating electric machine according to any one of claims 1 to 10, wherein the cover member is formed of an insulating material and is disposed in an insulating space between the case that houses the stator and the coil end portion. Cooling structure.

Images