JP2012075244A - Rotating electric machine and cooling mechanism - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rotating electric machine and a cooling mechanism enabling appropriate cooling of each part.SOLUTION: The rotating electric machine includes: a stator 2 forming a hollow portion on the inner side thereof; a rotor 3 arranged on the inner side of the stator 2 rotatably around a rotating axial line X1; and a medium passage 72 arranged at an end in a direction along the rotating axial line X1 of the rotor 3, allowing a medium to flow therein and having an outflow opening 72c which is arranged on an end face in the direction along the rotating axial line X1 of the rotor 3 and from which the medium can flow out. Surface treatment for repelling the medium is applied at an end of the rotor 3 in which the medium passage 72 is arranged. Therefore, this configuration allows for appropriate cooling of each part.

Description

  The present invention relates to a rotating electrical machine and a cooling mechanism.

  For example, a drive device for driving a vehicle is provided with a so-called rotating electrical machine such as an electric motor that converts electric energy into mechanical power and outputs it, or a generator that converts mechanical power into electric energy and recovers it. It has been known. Such a rotating electrical machine is mounted as a driving source for traveling in, for example, a hybrid vehicle (HV), an electric vehicle (EV), a fuel cell vehicle (FCV), and the like. And since this rotary electric machine produces | generates heat with an action | operation, it is equipped with various cooling mechanisms, for example, is cooled with cooling media, such as lubricating oil.

  As a conventional rotating electric machine, for example, in Patent Document 1, a refrigerant passage through which a refrigerant can flow is formed in an end plate provided at an axial end portion of a rotor, and a discharge hole communicating with the refrigerant passage is provided in the rotor. A rotating electrical machine located radially inward is disclosed. This rotating electrical machine is a cooling object including a permanent magnet provided in a stator by a centrifugal force accompanying the rotation of the rotor causing the refrigerant to move from the radially inner side to the outer side through the refrigerant passage and discharged from the discharge hole. The part can be cooled by the refrigerant.

JP 2009-027837 A

  By the way, as for the rotary electric machine of the above-mentioned patent documents 1, it is desired to cool each part more appropriately, for example.

  This invention is made | formed in view of said situation, Comprising: It aims at providing the rotary electric machine and cooling mechanism which can cool each part appropriately.

  In order to achieve the above object, a rotating electrical machine according to the present invention includes a stator that forms a hollow portion inside, a rotor that is rotatably provided around the rotation axis inside the stator, and the rotation axis of the rotor. And a medium passage having an outflow opening through which the medium can flow out on an end surface in the direction along the rotation axis of the rotor. The rotor is characterized in that a surface treatment for repelling the medium is applied to the end portion where the medium passage is provided.

  In the rotating electrical machine, the rotor may include an end plate in a direction along the rotation axis, the end of the medium passage being provided, and the surface treatment being performed.

  In the rotating electrical machine, the end plate may form at least a part of the medium passage between the end plate and the rotor core of the rotor.

  Further, in the rotating electrical machine, the medium passage has an inclined portion in which the outflow opening side is inclined toward the outside of the rotor with respect to a direction along the rotation axis and a direction orthogonal to the rotation axis. can do.

  In the rotating electric machine, the surface of the rotor core of the rotor facing the medium passage and the surface of the rotor core facing the medium passage facing the surface of the rotor core are provided with irregularities. be able to.

  In order to achieve the above object, a cooling mechanism according to the present invention is provided at an end portion in a direction along the rotation axis of a rotor of a rotating electrical machine, and oil can flow inside and the rotation of the rotor. A passage having an outflow opening through which the oil can flow out is provided on an end surface in a direction along the axis, and the rotor is subjected to an oil repellency treatment for repelling the oil at the end where the passage is provided. Features.

  The rotating electrical machine and the cooling mechanism according to the present invention have an effect that each part can be appropriately cooled.

FIG. 1 is a schematic schematic configuration diagram of a rotating electrical machine according to the first embodiment. FIG. 2 is a partial cross-sectional view illustrating the flow of oil in the rotating electrical machine according to the first embodiment. FIG. 3 is a partial cross-sectional view including a rotor passage of the rotating electrical machine according to the second embodiment. FIG. 4 is a diagram illustrating an example of the relationship between the rotor rotational speed of the rotating electrical machine according to the second embodiment and the amount of oil supplied to the coil end portion. FIG. 5 is a partial cross-sectional view including the rotor passage of the rotating electrical machine according to the third embodiment. FIG. 6 is a schematic diagram for explaining the contact angle of the end face of the rotor core according to the third embodiment. FIG. 7 is a schematic diagram for explaining the contact angle of the facing surface of the end plate according to the third embodiment.

  Embodiments according to the present invention will be described below in detail with reference to the drawings. In addition, this invention is not limited by this embodiment. In addition, constituent elements in the following embodiments include those that can be easily replaced by those skilled in the art or those that are substantially the same.

[Embodiment 1]
FIG. 1 is a schematic schematic configuration diagram of a rotating electrical machine according to the first embodiment, and FIG. 2 is a partial cross-sectional view illustrating the flow of oil in the rotating electrical machine according to the first embodiment.

  As shown in FIG. 1, the rotating electrical machine 1 of the present embodiment includes a stator 2 that is a stator and a rotor 3 that is a rotor. The rotating electrical machine 1 is applied as an electric motor that converts electric energy into mechanical power and outputs it, a generator that converts mechanical power into electric energy, and recovers it. The rotating electrical machine 1 is mainly used for a driving device for driving a vehicle such as a hybrid vehicle (HV), an electric vehicle (EV), and a fuel cell vehicle (FCV). Mounted as an electric machine.

  In the following description, unless otherwise specified, the direction along the rotation axis X1 that is the rotation center of the rotor 3 is referred to as the axial direction, and the direction orthogonal to the rotation axis X1, that is, the direction orthogonal to the axial direction. It is referred to as the radial direction, and the direction around the rotation axis X1 is referred to as the circumferential direction. Further, in the radial direction, the rotation axis X1 side is referred to as a radial inner side, and the opposite side is referred to as a radial outer side. In the rotating electric machine described below, since the electric motor and the generator have substantially the same structure, the electric motor (electric motor) will be mainly described here, and the description regarding the generator will be omitted as much as possible.

  Specifically, the rotating electrical machine 1 of the present embodiment includes a stator 2, a rotor 3, a case 4, and a rotor shaft 5. In the rotating electrical machine 1, for example, a stator 2, a rotor 3, a rotor shaft 5, and the like are accommodated in an internal space portion of a cylindrical case 4 whose both ends are closed. In the rotating electrical machine 1, the stator 2 is fixed and supported in the internal space portion of the case 4, while the rotor 3 is supported in the internal space portion of the case 4 so as to be rotatable about the rotation axis X <b> 1 as a rotation center. The rotating electrical machine 1 is positioned in the case 4 so that the central axes of the stator 2, the rotor 3, and the rotor shaft 5 coincide with the rotational axis X1.

  Specifically, the stator 2 is formed in a cylindrical shape and has a hollow portion inside. The stator 2 is fixed to the inner peripheral surface of the case 4 so that the cylindrical center axis coincides with the rotation axis X 1 of the rotor 3. That is, the stator 2 is formed in a cylindrical shape coaxial with the rotation axis X <b> 1, and is supported in the internal space of the case 4 so as not to rotate relative to the case 4.

  The stator 2 includes a stator core (stator iron core) 21 and a stator coil 22.

  The stator core 21 forms a cylindrical iron core of the stator 2 and is configured by laminating a plurality of electromagnetic steel plates (laminated steel plates) along the axial direction. In addition, this stator core 21 is not limited to an electromagnetic steel plate, For example, you may be comprised from a dust core.

  The stator coil 22 is provided by being wound around the stator core 21. The stator coil 22 is electrically connected to a vehicle control device (not shown) via, for example, a three-phase cable. For example, a torque command value to be output from the rotating electrical machine 1 is sent to the control device from an ECU (Electrical Control Unit) mounted on the vehicle. And this control apparatus produces | generates the control current for outputting the torque designated with the torque command value, and supplies the control current to the stator coil 22 via a three-phase cable.

  The rotor 3 is formed in a cylindrical shape. The rotor 3 is provided on the inner peripheral surface 23 side of the stator 2, that is, on the radially inner side of the stator 2 so as to be rotatable about the rotation axis X <b> 1. The rotor 3 is provided on the outer peripheral surface of the rotor shaft 5 formed in a columnar shape. The rotor shaft 5 is supported by the case 4 through a bearing so as to be rotatable about the rotation axis X1. That is, the rotor 3 is rotatably supported around the rotation axis X1 in the internal space portion of the case 4 via the rotor shaft 5 and the bearing that rotatably supports the rotor shaft 5. The rotor 3 can rotate relative to the case 4 and the stator 2 together with the rotor shaft 5 about the rotation axis X1.

  The rotor 3 includes a rotor core (rotor core) 31, a permanent magnet 32, and an end plate 33.

  The rotor core 31 forms a cylindrical iron core of the rotor 3 and is configured by laminating a plurality of electromagnetic steel plates (laminated steel plates) along the axial direction. In addition, this rotor core 31 is not limited to an electromagnetic steel plate, For example, you may be comprised from a dust core.

  A plurality of permanent magnets 32 are embedded in the rotor core 31. The plurality of permanent magnets 32 are provided, for example, at equal intervals along the circumferential direction of the rotor core 31, and the two permanent magnets 32 that are arranged in the circumferential direction are set to have different polarities. Here, the rotor 3 is an embedded magnet type permanent magnet rotor. However, the present invention is not limited to this. For example, a surface magnet type permanent magnet rotor may be used.

  The end plate 33 constitutes an end portion in the axial direction along the rotation axis X <b> 1 of the rotor 3. The end plates 33 are formed in an annular plate shape having the rotation axis line X1 as the central axis, and are provided as a pair at both ends of the rotor core 31 in the axial direction. That is, the rotor core 31 is sandwiched between the pair of end plates 33 in the axial direction. Each end plate 33 is provided in close contact with each axial end surface 31 a of the rotor core 31.

  In the stator 2 and the rotor 3, the inner peripheral surface 23 of the stator 2 and the outer peripheral surface 34 of the rotor 3 are opposed to each other in the radial direction. The length of the stator 2 and the rotor 3 along the axial direction of the stator 2 is set longer than the length along the axial direction of the rotor 3. Here, the stator 2 and the rotor 3 are set to have substantially the same length in the axial direction of the stator core 21 and the rotor core 31, but the coil end portion of the stator coil 22 that protrudes from the stator core 21 on both sides in the axial direction. The stator 2 has a shape protruding from both sides of the rotor 3 in the axial direction by 24.

  Each coil end portion 24 is formed in an annular shape along the circumferential direction at both axial end portions of the stator 2. The stator 2 may be configured to have a pair of resin-molded coil end portions at both ends by, for example, resin-molding the pair of coil end portions 24 protruding from both end surfaces of the stator core 21 in the axial direction.

  And since this rotary electric machine 1 generate | occur | produces heat with an action | operation, it is equipped with the cooling mechanism 6 and is cooled with a cooling medium, oil (lubricating oil) here. The rotary electric machine 1 is a so-called shaft oil cooling type rotary electric machine, and the cooling mechanism 6 typically introduces oil into the rotor 3 to cool the rotor 3 and the like. Specifically, the cooling mechanism 6 includes an oil passage 7 in which oil as a cooling medium can flow, and oil is supplied to the oil passage 7 from an oil supply device 8. The oil passage 7 includes a rotor shaft passage 71 and a rotor passage 72 as a medium passage.

  The rotor shaft passage 71 is provided inside the rotor shaft 5 and allows oil to flow. The rotor shaft 5 has a hollow portion formed therein, and this hollow portion forms a rotor shaft passage 71. The rotor shaft passage 71 guides oil supplied from the oil supply device 8 to the rotor passage 72. The rotor shaft passage 71 includes a main passage portion 71a and a branch passage portion 71b. The main passage portion 71a is provided in the rotor shaft 5 along the axial direction. The main passage portion 71a is formed by closing one end portion in the axial direction, and the other end portion in the axial direction is connected to the oil supply device 8 through various passages. The branch passage portion 71b is provided in the rotor shaft 5 along the radial direction by branching from the main passage portion 71a. A plurality of branch passage portions 71b are provided, and the radially inner end portion communicates with the main passage portion 71a, while the radially outer end portion communicates with a rotor passage 72 described later.

  The rotor passage 72 is provided inside the rotor 3 and allows oil to flow inside. The rotor passage 72 is provided at the end portion of the rotor 3 in the axial direction, and here, is provided in the end plate 33 constituting the end portion of the rotor 3 in the axial direction. The rotor passage 72 guides oil introduced from the rotor shaft passage 71 from the radially inner side to the outer side.

  The rotor passage 72 allows oil to flow through the vicinity of the end portion of the permanent magnet 32 in the axial direction. Here, the rotor passage 72 includes a radial passage 72a, an outflow passage 72b, and an outflow opening 72c. . The radial passage 72a is provided inside the rotor 3 along the direction intersecting the axial direction, here along the radial direction. The outflow passage 72b is provided in the rotor 3 along the axial direction. The outflow opening 72c is a discharge port through which oil can flow out.

  Specifically, the radial passages 72a are provided on both ends of the rotor 3 in the axial direction, that is, on the pair of end plates 33, and a plurality of radial passages 72a are provided so as to sandwich the permanent magnet 32 in the axial direction. For example, the plurality of radial passages 72 a are provided at equal intervals along the circumferential direction of the rotor 3 in each end plate 33. The radial passage 72 a is formed in a groove shape on the facing surface 33 a of the end plate 33, and is defined between the facing surface 33 a of the end plate 33 and the end surface 31 a of the rotor core 31. Here, the facing surface 33a is a surface of the end plate 33 on the side facing the end surface 31a in the axial direction. That is, each end plate 33 forms a radial passage 72 a as at least a part of the rotor passage 72 between each opposing surface 33 a and each end surface 31 a of the rotor core 31. Each radial passage 72a communicates with the main passage portion 71a of the rotor shaft passage 71 via the corresponding branch passage portion 71b at the radially inner end portion, while the radially outer end portion is the axis of the permanent magnet 32. Closed near the end of the direction.

  A plurality of outflow passages 72b are provided corresponding to the radial passages 72a. Each outflow passage 72b has one end communicating with the corresponding radial passage 72a, while the other end opens at the outflow opening 72c. The outflow opening 72c is provided on the end face in the axial direction of the rotor 3, here, the end face 33b in the axial direction of each end plate 33. The axial end surface 33b is a surface on the back side of the opposing surface 33a in the axial direction.

  In the rotating electrical machine 1 configured as described above, when electric power is supplied to the stator coil 22, an electromagnetic force is generated in the stator 2, and the rotor 3 is rotationally driven by the electromagnetic force. That is, in the rotating electrical machine 1, the magnetic flux from the stator coil 22 of the stator 2 passes through the rotor 3 and the rotor 3 rotates. The rotation of the rotor 3 is input from the rotor shaft 5 to the power transmission member of the vehicle, and finally transmitted to the drive wheels of the vehicle to drive the drive wheels to rotate.

  During this time, the cooling mechanism 6 cools the entire rotating electrical machine 1. That is, in the rotating electrical machine 1, cooling oil is supplied from the oil supply device 8 to the main passage portion 71 a of the rotor shaft passage 71. The oil supplied to the main passage portion 71a is branched at each branch passage portion 71b by the centrifugal force acting from the radially inner side to the outer side as the rotor 3 and the rotor shaft 5 are rotated. It is introduced into each radial passage 72a of each rotor passage 72 via the passage portion 71b. The oil introduced into each radial passage 72a is guided from the inside to the outside in the radial direction by the centrifugal force acting as the rotor 3 and the rotor shaft 5 rotate. It flows to the vicinity of the axial end of the permanent magnet 32, and flows into each outflow passage 72b and then flows out of the rotor 3 through each outflow opening 72c. During this time, the oil passes through the main passage portion 71a, the branch passage portion 71b of the rotor shaft passage 71, the radial passage 72a of the rotor passage 72, the outflow passage 72b, etc., so that the rotating electrical machine 1 such as the rotor core 31 and the permanent magnet 32 is obtained. As a result, the rotating electrical machine 1 is suppressed from excessive temperature rise.

  And the rotary electric machine 1 of this embodiment makes it possible to cool each part more appropriately by performing the surface treatment which repels oil to the edge part in which the rotor channel | path 72 of the rotor 3 was provided. Here, in the rotating electrical machine 1, an oil repellent treatment (when the cooling medium is water is used as a surface treatment in which the rotor passage 72 is provided in the end plate 33 constituting the axial end portion of the rotor 3 and the oil is repelled). Water repellent treatment).

  The end plate 33 of this embodiment is subjected to an oil repellency treatment on the entire surface including the facing surface 33a, the axial end surface 33b, the opening 33c forming the outflow opening 72c, the radially outer end surface 33d, and the like. The oil repellency treatment for the surface of the end plate 33 is typically a fluorine treatment agent (for example, fluoroalkylsilane), a fluorine resin (for example, polytetrafluoroethylene), etc., and has a surface tension of about 20 mN / m. Surface treatment using the following treatment liquid can be used. The processing method is, for example, a method in which after the end plate 33 is submerged in the above-described processing solution, the end plate 33 is pulled out while adjusting the pulling speed, and then heat treatment or the like is performed (for example, dipping processing method, sol gel For example, a processing method).

  Since the surface of the end plate 33 is subjected to an oil repellency treatment, the wettability of the surface with respect to oil is relatively lowered, and the end plate 33 has a relatively high oil repellency (property to repel oil). Thereby, the surface of the end plate 33 acts as an oil-repellent surface, and the oil easily repels on the surface.

  The cooling mechanism 6 of the rotating electrical machine 1 configured as described above has the oil repellent treatment applied to the end portion in the axial direction of the rotor 3, that is, the end plate 33, so that the oil is applied to the entire surface of the end plate 33. Since it becomes easy to repel, each part can be cooled appropriately.

  That is, the cooling mechanism 6 can suppress oil from adhering to the axial end surface 33b by facilitating oil repelling on the axial end surface 33b of the end plate 33. For example, FIG. In the region indicated by the encircled line A in FIG. Thereby, the rotary electric machine 1 can reduce the oil stirring loss in the axial end surface 33b of the end plate 33 when the rotor 3 rotates. As a result, the rotating electrical machine 1 can appropriately cool each part while improving the rotation efficiency.

  In addition, the cooling mechanism 6 makes it easy for oil to repel in the opening 33c of the end plate 33, so that the inner wall surface of the outflow passage 72b and the area of the opening 33c shown in FIG. The oil that has flowed out can be quickly ejected from the end plate 33, the oil can be prevented from adhering to the rotor 3, and the gap between the inner peripheral surface 23 of the stator 2 and the outer peripheral surface 34 of the rotor 3 can be reduced. It is possible to suppress the oil from entering the region indicated by the encircling line C in FIG. 2 and reduce the amount of oil entering. For example, even if the flow rate of the oil flowing out from the outflow opening 72c is relatively slow, the cooling mechanism 6 can repel the oil by the oil repellency of the inner wall surface of the outflow passage 72b and the opening 33c. Can be prevented from adhering to the end plate 33 or from entering between the inner peripheral surface 23 of the stator 2 and the outer peripheral surface 34 of the rotor 3. Further, in the cooling mechanism 6, the oil easily repels on the radially outer end surface 33 d together with the opening 33 c of the end plate 33, so that the oil enters between the inner peripheral surface 23 of the stator 2 and the outer peripheral surface 34 of the rotor 3. This can be suppressed more reliably. Thereby, when the rotor 3 rotates, the rotary electric machine 1 can reduce oil agitation loss at the axial end surface 33 b of the end plate 33 and oil drag loss between the stator 2 and the rotor 3. As a result, the rotating electrical machine 1 can appropriately cool each part while improving the rotation efficiency.

  Further, the cooling mechanism 6 makes it easy for oil to repel in the facing surface 33a of the end plate 33, for example, the region indicated by the encircling line D in FIG. Becomes relatively higher than the flow velocity of the oil flowing on the facing surface 33a side. As a result, the rotating electrical machine 1 increases the flow velocity of the oil flowing on the end surface 31a side. For example, as illustrated in the following formula (1), the rotating electrical machine 1 increases the flow velocity u so that the oil flows on the end surface 31a side. Since the thermal conductivity at the time of cooling by is improved, the cooling performance of the rotor core 31 and the permanent magnet 32 can be improved.

  Further, since the rotating electrical machine 1 suppresses oil flowing out from the outflow opening 72c from entering between the inner peripheral surface 23 of the stator 2 and the outer peripheral surface 34 of the rotor 3, drag resistance against rotation of the rotor 3 is achieved. And heat generation such as frictional heat due to acting as a stirring resistance can be suppressed. Thereby, since the rotary electric machine 1 can suppress heat generation due to the oil acting as drag resistance and stirring resistance against the rotation of the rotor 3, the temperature rise of the oil itself can be suppressed. It can suppress that cooling efficiency deteriorates, and can suppress reliably that the temperature of the rotary electric machine 1 rises excessively. As a result, the rotating electrical machine 1 can suppress the deterioration of the cooling efficiency of the rotating electrical machine 1 and can reliably suppress the temperature of the rotating electrical machine 1 from rising excessively. Therefore, it is possible to prevent the low permanent magnet 32 from becoming high temperature, to suppress the demagnetization of the permanent magnet 32, and to suppress the deterioration of the characteristics of the permanent magnet 32 as a magnet. Therefore, since the rotary electric machine 1 can suppress that the characteristic as the magnet of the permanent magnet 32 falls, it can suppress that motor torque reduces and motor efficiency deteriorates.

  According to the rotating electrical machine 1 according to the embodiment described above, the stator 2 that forms a hollow portion inside, the rotor 3 that is provided inside the stator 2 so as to be rotatable around the rotation axis X1, and the rotation of the rotor 3 A rotor passage 72 provided at an end portion in the direction along the axis X1 and having an outflow opening 72c through which oil can flow and at the end surface in the direction along the rotation axis X1 of the rotor 3 can flow out. The rotor 3 is subjected to a surface treatment for repelling oil at the end where the rotor passage 72 is provided. According to the cooling mechanism 6 according to the embodiment described above, the cooling mechanism 6 is provided at an end portion in the direction along the rotation axis X1 of the rotor 3 of the rotating electrical machine 1, the oil can flow inside, and A rotor passage 72 having an outflow opening 72c through which oil can flow out is provided on an end face in the direction along the axis X1, and the rotor 3 is subjected to an oil repellent treatment for repelling oil at an end portion where the rotor passage 72 is provided. Yes. Therefore, the rotary electric machine 1 and the cooling mechanism 6 can cool each part appropriately.

[Embodiment 2]
3 is a partial cross-sectional view including a rotor passage of the rotating electrical machine according to the second embodiment, and FIG. 4 is an example of a relationship between the rotor rotational speed of the rotating electrical machine according to the second embodiment and the amount of oil supplied to the coil end portion. FIG. The rotating electrical machine and the cooling mechanism according to the second embodiment are different from the first embodiment in that the medium passage has an inclined portion. In addition, about the structure, an effect | action, and effect which are common in embodiment mentioned above, while overlapping description is abbreviate | omitted as much as possible, refer FIG. 1 suitably about main structures (embodiment described below is also the same). .

  The rotating electrical machine 201 of the embodiment shown in FIG. 3 includes a cooling mechanism 206, and the cooling mechanism 206 includes a rotor passage 272 as a medium passage. The rotor passage 272 includes a radial passage 72a, an outflow passage 272b as an inclined portion, and an outflow opening 72c.

  A plurality of outflow passages 272b are provided corresponding to the radial passages 72a. Each outflow passage 272b has one end communicating with the corresponding radial passage 72a, while the other end opens at the outflow opening 72c. The outflow passage 272b of the present embodiment is provided to be inclined with respect to the axial direction along the rotation axis X1 and the radial direction perpendicular to the rotation axis X1. The outflow passage 272b is inclined on the outflow opening 72c side toward the outside of the rotor 3, that is, radially outward.

  In the rotating electric machine 201 and the cooling mechanism 206 configured as described above, when the oil flows out from the outflow opening 72c as the rotor 3 rotates, the outflow passage 272b is inclined radially outward. The outflow direction of the oil at the outflow opening 72c is directed in the radially outward direction, and the centrifugal force acting on the oil is increased, so that the flying distance of the oil flowing out of the outflow opening 72c is relatively increased. Then, as illustrated by the rotating electric machine 201, the cooling mechanism 206, and the solid line L1 in FIG. 4, the action of the inner wall surface of the outflow passage 272b and the oil repellency of the opening 33c and the action of the outflow passage 272b inclined outward in the radial direction. For example, since the amount of oil reaching the coil end portion 24 is relatively increased, it is possible to greatly suppress the oil from entering between the inner peripheral surface 23 of the stator 2 and the outer peripheral surface 34 of the rotor 3. In addition, the coil end portion 24 can be cooled more effectively. In FIG. 4, the dotted line L2 indicates that the end plate is not subjected to oil repellency and the outflow passage is along the axial direction, and the dotted line L3 indicates that the end plate is not subjected to oil repellency. The case where the channel | path is inclined toward the radial direction outer side is shown.

  According to the rotating electrical machine 201 and the cooling mechanism 206 according to the embodiment described above, the rotor passage 272 has the outflow opening 72c side of the rotor 3 with respect to the direction along the rotation axis X1 and the direction orthogonal to the rotation axis X1. It has an outflow passage 272b that is inclined outward. Therefore, the rotating electrical machine 201 and the cooling mechanism 206 can achieve both a significant reduction in oil drag loss and an improvement in cooling performance.

[Embodiment 3]
FIG. 5 is a partial cross-sectional view including the rotor passage of the rotating electrical machine according to the third embodiment, FIG. 6 is a schematic diagram for explaining the contact angle of the end face of the rotor core according to the third embodiment, and FIG. It is a schematic diagram explaining the contact angle of the opposing surface of an end plate. The rotating electrical machine and the cooling mechanism according to Embodiment 3 differ from Embodiment 1 in that irregularities are provided on a predetermined surface.

  5 includes a cooling mechanism 306, and the cooling mechanism 306 includes a rotor passage 72 as a medium passage. And the rotary electric machine 301 of this embodiment is provided with the unevenness | corrugation 335 in the surface which faces the rotor channel | path 72 of the rotor core 31, here, the end surface 31a of the rotor core 31 shown by the enclosure line E in FIG. Further, the rotating electrical machine 301 faces the end surface 31a which is a surface facing the rotor passage 72 of the rotor core 31 and is subjected to a surface treatment, here, an opposing surface 33a of the end plate 33 indicated by a surrounding line D in FIG. Concavities and convexities 336 are provided on the surface. The irregularities 335 and 336 are fine irregularities and have a so-called fractal structure. The irregularities 335 and 336 can be provided, for example, by performing an etching process or a shot blasting process on the end surface 31a and the opposing surface 33a.

  As shown in FIG. 6, the rotor core 31 is provided with irregularities 335 on the end surface 31a, so that the contact angle θ1 with the oil (medium) on the end surface 31a becomes relatively small. Here, as for the rotor core 31, the unevenness | corrugation 335 is provided in the end surface 31a so that the contact angle (theta) 1 with the oil in the end surface 31a may be less than 5 degrees ((theta) 1 <5 degrees).

  Here, the contact angle θ <b> 1 between the end surface 31 a and the oil is an angle formed by the solid surface as viewed from the liquid side, here the end surface 31 a and the oil. When the contact angle θ1 is close to 0 °, the rotor core 31 is in a state of being in surface contact with the oil on the end surface 31a, and the oil easily adheres to it, so that the wettability of the end surface 31a with respect to the oil is relatively increased. However, it has high lipophilicity, here super-lipophilicity. That is, the end surface 31a acts as a super lipophilic surface.

  As shown in FIG. 7, the end plate 33 is provided with unevenness 336 on the opposing surface 33 a and is subjected to the oil-repellent treatment described above to obtain a fluorine-based treatment agent (for example, fluoroalkylsilane), fluorine-based treatment, and the like. By forming the surface treatment film 337 with a resin (for example, polytetrafluoroethylene) or the like, the contact angle θ2 with the oil (medium) in the unevenness 336 becomes relatively large. Here, the end plate 33 is provided with irregularities 336 on the facing surface 33a (θ2> 130 °) so that the contact angle θ2 with the oil on the facing surface 33a is greater than 130 °.

  Here, the contact angle θ2 between the facing surface 33a and the oil is an angle formed by the solid surface, here, the facing surface 33a and the oil as viewed from the liquid side. When the contact angle θ2 is close to 180 °, the end plate 33 comes into a state where it almost contacts the oil on the opposing surface 33a, and the oil is easily repelled. It is relatively lowered and has high oil repellency, here, super oil repellency. That is, the facing surface 33a acts as a super oil repellent surface.

  In the rotating electrical machine 301 and the cooling mechanism 306 configured as described above, the contact surface area between the end surface 31a of the rotor core 31 and the oil becomes relatively large because the end surface 31a acts as a super-oleophilic surface. Further, in the rotating electrical machine 301 and the cooling mechanism 306, the opposing surface 33a acts as a super oil-repellent surface, so that the oil is more easily repelled on the opposing surface 33a of the end plate 33, thereby the end surface of each radial passage 72a. The effect that the flow velocity of the oil flowing on the 31a side is relatively higher than the flow velocity of the oil flowing on the facing surface 33a side becomes more remarkable.

  As a result, in the rotating electrical machine 301 and the cooling mechanism 306, for example, as illustrated in the above formula (1), the flow velocity u is further increased by the super-oleophobic action of the facing surface 33a, and the super-lipophilic property of the end surface 31a is increased. Since the length L is increased by the action, the thermal conductivity at the time of cooling with oil is further improved on the end face 31a side, so that the cooling performance of the rotor core 31 and the permanent magnet 32 can be further improved. Further, since the rotating electrical machine 301 and the cooling mechanism 306 have improved cooling performance, sufficient cooling performance can be ensured even if the amount of oil supplied to the rotor shaft passage 71 and the rotor passage 72 is relatively reduced. Thus, the amount of oil that is stirred or dragged can be reduced, and stirring loss and dragging loss can be reduced. As a result, the rotating electrical machine 301 can further improve the rotation efficiency.

  According to the rotating electrical machine 301 and the cooling mechanism 306 according to the embodiment described above, the surface (end surface 31a) facing the rotor passage 72 of the rotor core 31 of the rotor 3 and the surface facing the rotor passage 72 of the rotor core 31; Concavities and convexities 335 and 336 are provided on the surface (opposing surface 33a) subjected to the facing surface treatment. Therefore, the rotating electrical machine 301 and the cooling mechanism 306 can further improve the cooling performance.

  In addition, the rotary electric machine and cooling mechanism which concern on embodiment of this invention mentioned above are not limited to embodiment mentioned above, A various change is possible in the range described in the claim. The rotating electrical machine and the cooling mechanism according to the present embodiment may be configured by combining a plurality of the embodiments described above.

  In the above description, the rotating electrical machine has been described as being a traveling rotating electrical machine provided in a drive device for driving a vehicle, but the present invention is not limited thereto. The rotating electrical machine may be applied as a working rotating electrical machine for vehicles, an auxiliary rotating electrical machine, or the like, and may be applied not only to a vehicle but also to an electric motor or a generator of another device.

  The rotating electrical machine and the cooling mechanism described above may be configured such that a medium passage is directly provided at the axial end portion of the rotor core and a surface treatment is performed without providing an end plate. The cooling medium may be a liquid other than oil (lubricating oil), such as water.

  As described above, the rotating electrical machine and the cooling mechanism according to the present invention are suitable for application to rotating electrical machines and cooling mechanisms mounted on various vehicles.

1, 201, 301 Rotating electrical machine 2 Stator 3 Rotor 6, 206, 306 Cooling mechanism 21 Stator core 22 Stator coil 24 Coil end portion 31 Rotor core 31a End surface 33 End plate 33a Opposing surface 33b Axial end surface 33c Opening portion 33d Radial outer end surface 72 272 Rotor passage (medium passage)
72a Radial passage 72b Outflow passage 72c Outflow opening 272b Outflow passage (inclined portion)
335, 336 Uneven X1 axis of rotation

Claims (6)

A stator that forms a hollow portion inside;
A rotor provided inside the stator so as to be rotatable about a rotation axis;
Provided at an end portion of the rotor in the direction along the rotation axis, the medium can flow inside, and has an outflow opening through which the medium can flow out on an end surface in the direction along the rotation axis of the rotor. A medium passage,
The rotor is characterized in that a surface treatment for repelling the medium is applied to the end where the medium passage is provided.
Rotating electric machine. The rotor constitutes an end portion in a direction along the rotation axis, and has an end plate on which the medium passage is provided and the surface treatment is performed.
The rotating electrical machine according to claim 1. The end plate forms at least a part of the medium passage with the rotor core of the rotor.
The rotating electrical machine according to claim 2. The medium passage has an inclined portion in which the outflow opening side is inclined toward the outside of the rotor with respect to a direction along the rotation axis and a direction orthogonal to the rotation axis.
The rotating electrical machine according to any one of claims 1 to 3. The surface of the rotor core of the rotor facing the medium passage, and the surface of the rotor core facing the medium passage facing the surface of the rotor core are provided with irregularities.
The rotating electrical machine according to any one of claims 1 to 4. An outflow opening provided at an end portion of the rotor of the rotating electrical machine in the direction along the rotation axis, through which oil can flow and at the end surface of the rotor in the direction along the rotation axis. Comprising a passage having
The rotor is characterized in that an oil repellent treatment for repelling the oil is applied to the end portion where the passage is provided.
Cooling mechanism.

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