JP6270213B2 - Electric motor - Google Patents

Description

  The present invention relates to an electric motor including a DC brushless motor.

  The electric motor includes a stator and a rotor, and the rotor is rotationally driven by a magnetic field formed by the stator. For example, in the case of a DC brushless motor, the stator has a plurality of stator cores arranged around the rotation center axis of the rotor, and excitation coils formed around each stator core, and the rotor includes the stator core and the stator core. It has a plurality of permanent magnets arranged at positions that can face each other. The stator forms a magnetic circuit by energizing the exciting coil, that is, by passing a current through an insulated wire constituting the exciting coil, and rotates the rotor by the electromagnetic force.

  In such an electric motor, cooling of the stator is an important issue in order to enable output of a large torque. A large torque output requires a large current to flow through each exciting coil. However, an increase in the current causes significant heat generation due to the resistance of the wire that constitutes the exciting coil, and if the temperature of the wire exceeds the allowable range, an insulating coating is formed. There is a risk of insulation failure due to damage. In order to enable output of a large torque while avoiding such an excessive temperature rise, effective cooling of the exciting coil is essential.

  As the cooling method, there are an air cooling type as described in Patent Document 1 and a liquid cooling type as described in Patent Document 2 (generally a water cooling type). The liquid cooling type requires a special airtight structure for preventing leakage of the cooling liquid, but the stator can be cooled with higher efficiency than the air cooling type. Therefore, when the required torque is large and the heat generation of the stator is remarkable, or when the allowable temperature of the stator is low, application of the water cooling method is desired.

  8 and 9 show a structure for cooling the stator, which is a main part of the electric motor described in Patent Document 2. FIG. As shown in FIG. 8, the electric motor includes a rotating shaft 100, a rotor 110 that rotates integrally with the rotating shaft 100, a cylindrical housing 120, and a stator 130 that is fixed to an inner peripheral portion of the housing 120. And comprising. The stator 130 includes a plurality of stator cores 132 arranged around the rotating shaft 100, an excitation coil 134 formed around each stator core 132, a pair of partition walls 136, and an annular member 138.

  Both the partition walls 136 have a disc shape, and are fixed to the housing 120 with the stator cores 132 and the excitation coils 134 sandwiched between the housing 120 and the partition walls 136. Specifically, the outer peripheral portion of the partition wall 136 is fixed in close contact with the flange portion 122 protruding from the inner peripheral surface of the housing 120, and the inner peripheral portion of the partition wall 136 sandwiches the annular member 138 from both sides. To be fixed to the annular member 138. As a result, a sealed space 150 surrounded by the housing 120, the both partition walls 136, and the annular member 138 is formed.

  The rotor 110 is rotatably supported by the stator 130 together with the rotating shaft via a bearing 140 interposed between the rotor 110 and the annular member 138. The rotor 110 has magnet holding portions 112 positioned on both outer sides of the both partition walls 136, and each magnet holding portion 112 holds a plurality of permanent magnets 114. These permanent magnets 114 are arranged in the circumferential direction so as to face each stator core 132 in the axial direction through the thin portion 136a of the partition wall 136.

  In this electric motor, when each excitation coil 134 is energized, a magnetic circuit indicated by a closed curve with an arrow in FIG. 8 is formed, and an electromagnetic that rotates the rotor 110 and the rotating shaft 100 relative to the stator 130 and the housing 120. Force is generated. On the other hand, an appropriate cooling liquid is supplied to and discharged from the annular sealed space 150 surrounded by the pair of partition walls 136, the annular member 138, and the housing 120, so that the stator core 132 and the excitation coil 134 in the sealed space 150 are discharged. To be cooled.

  As shown in FIG. 9, the sealed space 150 includes an inner annular space 152 connected in the circumferential direction on the radially inner side of each stator core 132 and the excitation coil 134 and a circumferential direction on the radially outer side of each stator core 132 and the excitation coil 134. It includes an outer annular space 154 that is connected, and a gap 155 between the outer peripheral surfaces of the exciting coils 134 that are adjacent to each other.

  The housing 120 has a coolant supply / discharge portion 160 formed at a part of the outer periphery of the housing 120 in the circumferential direction. The cooling liquid supply / discharge unit 160 includes a liquid supply path 162 and a liquid discharge path 164. On the other hand, a partition material 166 that partitions the inner annular space 152 in the circumferential direction at an appropriate position and a partition material 168 that partitions the outer annular space 154 in the circumferential direction at an appropriate position are provided in the sealed space 150. It has been. The partition members 166 and 168 and the cooling liquid supply / discharge section 160 are arranged in the inner and outer annular spaces from the coolant flow path inside the housing 120, that is, from the liquid supply path 162 of the cooling liquid supply / discharge section 160. A flow path reaching the liquid discharge path 164 of the coolant supply / discharge section 160 via one space of the 152, 154, each gap 155, and the other space of the inner and outer annular spaces 152, 154. , Form.

US Pat. No. 6,720,688 US Publication 2011/0306999

  The motor shown in FIGS. 8 and 9 has a problem that it is difficult to cool the plurality of exciting coils 134 with high uniformity and high efficiency. Specifically, both the supply of the low-temperature coolant and the discharge of the high-temperature coolant are performed through the coolant supply / discharge portion 160 formed in a part of the circumferential direction in the outer peripheral portion of the housing 120. Unevenness is likely to occur. Further, the flow of the coolant in the sealed space 150 is irregular, and it is practically difficult to cool all the excitation coils 134 equally.

  In view of the above circumstances, the present invention is an electric motor including a stator and a rotor, and the stator includes a plurality of stator cores and a plurality of exciting coils formed around each stator core. An object of the present invention is to provide an electric motor capable of improving the efficiency and equalization of cooling of an exciting coil.

An electric motor provided by the present invention includes a plurality of permanent magnets arranged in a circumferential direction around a specific rotation center axis, and supports the permanent magnets while integrally supporting these permanent magnets around the rotation center axis. A rotor having a rotation support member that rotates, a rotor support member that rotatably supports the rotor around the rotation center axis, a stator that rotates the rotor by electromagnetic force, a coolant supply unit, and a coolant A discharge unit. The stator includes a plurality of stator cores arranged in a circumferential direction around the rotation center axis, a stator core support member these stator core to support the respective stator core so as to be opposed to each permanent magnet, respectively A plurality of exciting coils arranged around each of the plurality of stator cores to have an outer peripheral surface and forming a magnetic circuit for rotating the rotor by being energized, and a periphery of each of the plurality of exciting coils And a flow path forming member that forms a flow path for the coolant. Of the flow path forming member, at least a portion located between adjacent stator cores is non-magnetic. The flow path forming member, as a flow path of the cooling liquid, and an outer flow passage located radially outward of said plurality of excitation coils, and an inner passage which is located radially inward of said plurality of exciting coils A plurality of cooling channels communicating the outer channel and the inner channel along the outer peripheral surface of each of the plurality of exciting coils, and one of the outer channel and the inner channel A flow path that allows the flow of the cooling liquid from each flow path to the other flow path of the outer flow path and the inner flow path through each of the plurality of cooling flow paths . The coolant supply unit is connected by supplying a cooling fluid in the flow path of prior SL hand the coolant to the one flow path to flow in each of the plurality of cooling passages. The cooling liquid discharger is connected to the other flow path so as to discharge the cooling liquid from the one flow path to the other flow path through each of the plurality of cooling flow paths. Is done .

  According to this electric motor, it is possible to regularly flow a cooling liquid in the radial direction along the outer peripheral surface of each excitation coil, thereby efficiently cooling each excitation coil with high uniformity. it can. Specifically, the cooling liquid is supplied to one of the outer flow path and the inner flow path by the cooling liquid supply unit, and from the one flow path to the outer peripheral surface of each exciting coil. Along the other flow path, and is discharged from the other flow path by the coolant discharge section. Therefore, the coolant can flow regularly along the outer peripheral surface of each excitation coil in the radial direction and simultaneously, which enables uniform and efficient cooling of each excitation coil.

  Regarding the supply and discharge of the cooling liquid, when the cooling liquid supply part and the cooling liquid discharge part arranged on the radially inner side include a pipe for circulating the cooling liquid, the rotor has a diameter of the pipe. What is arranged to rotate in the region outside in the direction is preferred. This arrangement makes it possible to supply and discharge the cooling liquid through the piping with respect to the flow path of the cooling liquid without hindering the rotation of the rotor.

  Specifically, the rotor support member is a support shaft that extends along the rotation center axis, and an annular rotor that is interposed between the support shaft and the rotor and allows the rotation of the rotor relative to the support shaft. It is preferable that the pipe is disposed so as to pass inside the rotor bearing in the radial direction and the other pipe is arranged outside the rotor in the radial direction.

  In addition, when the cooling liquid supply unit has the pipe, the cooling liquid supply unit distributes the cooling liquid supply pipe as the pipe and the cooling liquid fed through the cooling liquid supply pipe to each excitation coil. Thus, it is preferable to include a distribution channel formed in the stator core support member. The formation of the distribution flow path makes it possible to use the stator core support member as a member for distributing the cooling liquid to the respective excitation coils, thereby simplifying the structure of the flow path forming member.

  It is preferable that the flow path forming member constitutes at least one partition wall that surrounds the exciting coil, and the coolant flow path is formed inside the partition wall. In this case, the flow path forming member may constitute a partition wall that collectively surrounds all the excitation coils, or may constitute a plurality of partition walls that individually surround each of the excitation coils. Also good.

  The flow path forming member may constitute the entire partition wall, or may constitute a part of the partition wall. For example, each of the stator cores has a facing surface that can face each of the permanent magnets, and the facing surface is in close contact with the flow path forming member in a state where the facing surface is exposed toward the permanent magnet of the rotor. If the partition member constitutes the partition wall together with the forming member, for example, the counter surface as compared with the conventional motor in which the partition wall is interposed between the stator core facing surface and the permanent magnet of the rotor as shown in FIG. And the permanent magnet can be kept small, which makes it possible to suppress the magnetic resistance in the magnetic circuit and perform highly efficient operation.

  As described above, according to the present invention, the electric motor includes a stator and a rotor, and the stator includes a plurality of stator cores and an excitation coil formed around each stator core. An electric motor capable of improving the efficiency and equalization of cooling of the coil can be provided.

It is a section perspective view showing the electric motor concerning a 1st embodiment of the present invention. It is a cross-sectional front view which shows the said electric motor. It is sectional drawing to which the principal part of FIG. 2 was expanded. It is a disassembled perspective view of the stator and rotor of the electric motor. It is sectional drawing along the VV line of FIG. It is sectional drawing along the VI-VI line of FIG. It is a perspective view which shows the principal part of the electric motor which concerns on the 2nd Embodiment of this invention. It is a cross-sectional front view which shows the principal part of the conventional electric motor. It is a cross-sectional side view of the electric motor shown in FIG.

  Preferred embodiments of the present invention will be described with reference to the drawings.

  1 and 2 show the overall configuration of the electric motor according to the first embodiment of the present invention. The electric motor houses the rotor 10, a support shaft 20 that is a rotor support member that rotatably supports the rotor 10, a stator 30 that generates electromagnetic force that rotates the rotor 10, and the rotor 10 and the stator 20. An unillustrated housing.

  In this embodiment, the support shaft 20 extends in the horizontal direction, and both ends thereof are fixed to the housing. The stator 30 is fixed to an intermediate portion in the axial direction of the support shaft 20. The rotor 10 is distributed on both sides of the stator shaft direction, which is a direction parallel to the support shaft 20, and is rotatable about the center axis of the support shaft 20 as a rotation center axis. It is supported by the support shaft 20.

  The rotor 10 includes a pair of rotation support members 14 and a plurality of permanent magnets 12 supported by the rotation support members 14.

  Each of the rotation support members 14 has a substantially disk shape extending in a rotation radial direction that is a direction orthogonal to the rotation center axis, and the rotor 30 is interposed via a rotor bearing 16 at a position sandwiching the stator 30 from both sides in the stator axis direction. It is connected. The rotor bearing 16 has an annular shape and is disposed around the support shaft 20. The rotor bearing 16 is disposed between the rotation support member 14 and the support shaft 20 so as to allow the rotation support member 14 to rotate relative to the support shaft 20 around a central axis (rotation center axis). Intervene in.

  The rotation support member 14 holds the permanent magnets 12 at a plurality of positions arranged in the circumferential direction on the outer peripheral portion thereof, more specifically, a plurality of positions arranged on a circle around the rotation center axis. Each rotation support member 14 has a stator facing surface 15 that faces the stator 30 in the stator axial direction, and the permanent magnets 12 are arranged on the stator facing surface 15. That is, the rotation support member 14 supports the permanent magnets 12 so that the permanent magnets 12 can face the stator 30 in the stator axial direction. These permanent magnets 12 are arranged so that a magnetic circuit for rotating the rotor 10 is formed by the operation of the stator 30, specifically, N poles and S poles are alternately arranged in the circumferential direction. Yes.

  The stator 30 includes a plurality of stator cores 32 arranged in the circumferential direction of the rotor 10, a plurality of exciting coils 36 provided for each stator core 32, a stator core support plate 34, and a pair of flow path forming members 40. .

  The stator core support plate 34 constitutes a stator core support member that supports each of the stator cores 32, and has a substantially disk shape that extends in the rotational radius direction of the rotor 10 in the same manner as the rotation support member 14 of the rotor 10. A through hole 34a through which the support shaft 20 can pass is formed in the center portion of the stator core support plate 34, and the stator core support plate 34 is fixed to the axial central portion of the support shaft 20 in the through state. ing. Specifically, a flange portion 22 having a larger diameter than other portions is formed at a specific portion of the support shaft 20, while a similar portion is formed on the opposite side of the flange portion 22 with the stator core support plate 34 interposed therebetween. A cylindrical fixing sleeve 26 having a flange portion 24 is disposed around the support shaft 20. Then, the flange portions 22 and 24 are fastened together with the flange portions 22 and 24 sandwiching the stator core support plate 34 from both sides in the stator axial direction, so that the stator core support plate 34 is mounted on the support shaft 20. It is fixed to.

  That is, in this embodiment, the stator core support plate 34 and the support shaft 20 constitute a stator core support member that supports each stator core 32. In other words, the support shaft 20 according to this embodiment serves as both a rotor support member and a stator core support member.

  The stator core support plate 34 supports the stator cores 32 at a plurality of stator core support positions arranged in the circumferential direction on the outer periphery thereof. Specifically, as shown in FIG. 5, a notch 34b opened radially outward is formed at each stator core support position, and the stator core 32 is inserted into each notch 34b. Is possible.

  The stator core 32 is supported by the stator core support plate 34 while being circumferentially arranged around the rotation center axis. Specifically, the stator core support plate 34 is supported at each stator core support position.

  Each stator core 32 has a columnar shape having a uniform cross-sectional shape in the stator axial direction parallel to the rotation center axis, and end faces on both sides in the stator axial direction are opposed to the permanent magnets 12 of the rotor 10 in the stator axial direction. A possible facing surface 33 is constructed. In other words, the radial positions of the stator core 32 and the permanent magnet 12 are set so that the facing surfaces 33 and the permanent magnets 12 of the rotor 10 can face each other in the stator axial direction. In this embodiment, each stator core 32 has a cross-sectional shape that decreases in width from the outside in the stator radial direction orthogonal to the rotation center axis, and the intermediate portion in the stator axial direction is the stator core support plate. The stator core support plate 34 is inserted into each notch 34b from the outside in the radial direction and fixed. That is, each stator core 32 is supported by the stator core support plate 34 so as to have a pair of projecting portions that project from the stator core support plate 34 to both sides in the stator axial direction.

  Each stator core 32 may be, for example, a laminated core made of a plurality of electromagnetic steel plates laminated together, but is preferably constituted by a so-called dust core. This dust core is made of iron powder coated with an electrical insulating film, and is formed by solidifying these iron powders. The dust core is higher in airtightness than the laminated core, and the laminated core. The generation of eddy currents can be effectively suppressed as in the case of. Further, the so-called dust core has a high degree of freedom in shape, and has an advantage that a preferable shape can be easily held in order to constitute a partition wall described later together with the flow path forming member 40.

  The plurality of stator cores according to the present invention are not limited to those independent from each other. For example, the electric motor according to the present invention may include a single stator core constituting member, and the stator core constituting member may include a plurality of stator core constituting portions arranged in the circumferential direction.

  Each exciting coil 36 is provided around each protruding portion of each stator core 32 and generates an electromagnetic force that rotates the rotor 10 when energized. Specifically, each excitation coil 36 is constituted by a winding wound around each protruding portion, and forms a magnetic field line that causes the current flowing through the winding to rotate the rotor 10. This line of magnetic force is a closed curve including a portion of the stator core 32 where the exciting coil 36 is wound on the outside thereof and a portion penetrating the permanent magnet 12 opposed thereto in the stator axial direction.

  In the present invention, the exciting coil is not limited to being individually arranged on both axial side portions of the stator coil. For example, one excitation coil may be provided for one stator coil. Similarly, the rotor according to the present invention may be disposed only on one side in the stator axial direction with respect to the stator.

  In this embodiment, the support shaft 20 has a groove 28 for wiring and piping related to the stator 30. The groove 28 has a shape that extends from the outside of one rotation support member 14 to the inside of the stator 30 through the inside of the rotation support member 14 and the rotor bearing 16 that supports the rotation support member 14 in the radial direction. Through this groove 28 and a through hole formed in the fixed sleeve 26, wiring for electrically connecting an external circuit and each exciting coil 36 and piping for cooling described later are performed.

  The pair of flow path forming members 40 are joined to each other so that the stator core support plate 34 and the stator cores 32 and the excitation coils 36 supported by the stator core support plate 34 are sandwiched from both sides in the stator axial direction. In addition to forming a partition wall that encloses a sealed space in which these are accommodated, cooling fluid passages are formed around the exciting coil 36.

  Specifically, each flow path forming member 40 according to this embodiment has an annular shape arranged around the support shaft 20, and each includes an inner peripheral portion 42, an outer peripheral portion 44, and an exciting coil housing portion. 46 in an integrated manner.

  The inner peripheral portion 42 has a flat plate shape surrounding a circular through hole at the center. Each inner peripheral portion 42 is fixed to the side surface of the stator core support plate 34 with a bolt 43 in the radially inner region of each excitation coil 36.

  The outer peripheral portion 44 is joined to the outer peripheral portion 44 of the counterpart flow path forming member 40 by a bolt 45 in the radially inner region of each excitation coil 36. Both outer peripheral portions 44 have a shape surrounding the outer peripheral space 50 between the outer peripheral portions 44 in a state where the outer peripheral portions 44 are joined to each other. The outer circumferential space 50 has an annular shape that surrounds the stator cores 32 on the outer side in the radial direction of the stator cores 32.

  The exciting coil housing part 46 has an annular shape located between the inner peripheral part 42 and the outer peripheral part 44. The exciting coil housing portion 46 has a shape bulging outward from the inner peripheral portion 42 and the outer peripheral portion 44 in the stator axial direction so as to accommodate each of the exciting coils 36 and the stator core 32 inside thereof. Have. Specifically, the excitation coil housing portion 46 includes cylindrical inner peripheral walls 46a and outer peripheral walls 46b that cover the respective excitation coils 36 on the inner side and the outer side in the radial direction thereof, and the respective excitation coils 36 in the stator axial direction. And an outer wall 46c that covers the outside of the outer wall.

  As shown in FIGS. 4 and 6, the inner peripheral wall 46 a and the outer peripheral wall 46 b have inner surfaces that have a shape that substantially matches the outer peripheral surface of each excitation coil 36. However, the shape of each inner surface is set such that an inner gap 52 and an outer gap 54 are formed between the outer peripheral surface of the exciting coil 36 and the inner surfaces of the inner peripheral wall 46a and the outer peripheral wall 46b, respectively. ing. As will be described later, the inner gap 52 constitutes an inner flow path of the cooling liquid flow path, and the outer gap 54 together with the outer peripheral space 50 is located outside the cooling liquid flow path. Configure the flow path. As shown in FIG. 6, gaps 56 extending in the radial direction are also secured between the outer peripheral surfaces of the exciting coils 36 adjacent to each other, and these gaps 56 form the inner gap 52 and the outer gap 54. A cooling flow path communicating in the radial direction along the outer peripheral surface of the exciting coil 36 is formed.

  The pair of outer walls 46c have inner peripheral surfaces that surround a circular through hole at the center thereof. The diameter of the inner peripheral surface, that is, the inner diameter of the outer wall 46 c corresponds to the outer diameter of the peripheral wall portion 38, and the outer diameter of the outer wall 46 c corresponds to the inner diameter of the outer peripheral wall 42. Each outer wall 46c covers each exciting coil 36 from both sides in the stator axial direction while being joined to the outer peripheral surface of the peripheral wall portion 38 and the inner peripheral surface of the outer peripheral wall 42.

  Further, the outer wall 46c according to this embodiment has a plurality of windows 48 that communicate with the inside and outside. Each window 48 is formed at a position corresponding to the position of each stator core 32 and has a shape that matches the shape of the stator core 32. The outer peripheral surface of the outer wall 46c and the opposing surface 33 of each stator core 32 are aligned on the same plane, and the inner peripheral surface surrounding each window 48 in the outer wall 46c and the stator core 32 corresponding thereto. The outer peripheral surface is in close contact. That is, both end portions in the stator axial direction of each stator core 32 constitute a partition wall that surrounds the sealed space together with the flow path forming member 40 in a state where the opposing surfaces 33 are exposed outward in the stator axial direction.

  The exposure of each facing surface 33 enables the facing surface 33 to directly face each permanent magnet 12 without a partition. In this direct facing, the dimension of the gap between the facing surface 33 and the permanent magnet 12 is within a range in which contact between the facing surface 33 and each permanent magnet 12 in the stator axial direction can be reliably prevented. It is possible to set small.

  However, the exposure of the facing surface 33 is not essential in the present invention. For example, the outer wall 46c of the flow path forming member 40 may cover the facing surface 33 from the outside. The specific material of each flow path forming member 40 is not limited. The material can be appropriately set as long as the condition that at least a portion of the flow path forming member 40 located between adjacent stator cores has nonmagnetic properties is satisfied. Each flow path forming member 40 according to this embodiment is entirely made of non-magnetic and highly insulating synthetic resin, is transparent to the alternating magnetic flux generated by the exciting coil 36, and has an eddy current loss. It is low. These flow path forming members 40 can be formed as a single member around the stator body (each stator core 32, each exciting coil 36 and the stator core support plate 34 that supports them).

  On the other hand, in this embodiment, the stator core support plate 34 forms a flow path for supplying the cooling liquid, specifically, a distribution flow path for distributing the cooling liquid to the excitation coils 36. Used as Specifically, a distribution groove 60 as shown in FIG. 6 is formed in the stator core support plate 34 according to this embodiment. The distribution groove 60 is a bottomed groove that opens toward one side in the stator axial direction, and includes an annular portion 62, a liquid supply portion 63, and a plurality of distribution portions 64.

  The annular portion 62 has a circular shape having a center that coincides with the rotation center axis, and is continuous over the entire circumference in a region further inside than the inner end of each stator core 32. In other words, each stator core 32 has a radius smaller than the radius of the inscribed circle.

  The liquid supply part 63 extends radially inward from a specific position in the circumferential direction of the annular part 62. The terminal end, that is, the radially inner end forms a circular pipe insertion hole 66 having a diameter larger than the groove width of the other part of the liquid supply part 63.

  Each distribution portion 64 extends radially outward from the annular portion 62 toward each stator core 32 in the radial direction. The terminal end or outer end of each distribution portion 64 is located immediately inside the corresponding stator core 32, in other words, the position sandwiched by the radially inner portions of the exciting coils 36 on both sides in the stator axial direction as shown in FIG. It is in. At the end of these distribution portions 64, through holes 68 are formed through the stator core support plate 34 in the thickness direction (stator axial direction). Each through hole 68 has a circular shape having a diameter larger than the groove width of each distribution portion 64.

  An appropriate coolant supply / discharge for cooling each exciting coil 36 is performed on the coolant flow path formed in this way. Specifically, the electric motor further includes a coolant supply unit that supplies a coolant to the flow path, and a coolant discharge unit that discharges the coolant from the flow path.

  The coolant supply unit according to this embodiment includes a distribution groove 60 formed in the stator core support plate 34 and a coolant supply pipe 70 as shown in FIGS.

  The cooling liquid supply pipe 70 is a pipe that allows the flow of the cooling liquid supplied to the flow path forming member 40. The coolant supply pipe 70 according to this embodiment is provided so as to extend along the rotation center axis, that is, the center axis of the support shaft 20, but in the middle of the coolant supply pipe 70, a bearing bypass portion 72 is provided. Is formed. The bearing bypass portion 72 has a shape that bypasses the rotor bearing 16 so as to pass through the inner side of the rotor bearing 16 that supports the rotor 10 and the rotor 10 through the groove 28 formed in the support shaft 20. That is, it has a shape that wraps inward in the radial direction from the other part of the coolant supply pipe 70.

  The coolant supply pipe 70 has an upstream end (not shown) and a downstream end 74. The upstream end is connected to a coolant supply pump (not shown), and the downstream end 74 is connected to a flow path formed in the stator core support plate 34. Specifically, the downstream end 74 is inserted into the pipe insertion hole 66 of the stator core support plate 34 and is fixed to the stator core support plate 34 in a liquid-tight state.

  The coolant discharge section according to this embodiment has a coolant discharge pipe 76 as shown in FIGS. The coolant discharge pipe 76 is a pipe that allows the coolant discharged from the flow path forming member 40 to flow. The coolant discharge pipe 76 according to this embodiment is linear, and is piped so as to extend along the central axis of rotation, that is, the central axis of the support shaft 20, in a radially outer region of the rotor 30. The coolant discharge pipe 76 has an upstream end 78 and a downstream end (not shown). The upstream end 78 is joined to one outer peripheral portion 44 in a liquid-tight state so as to communicate with the outer peripheral space 50 formed by the outer peripheral portion 44 of the pair of flow path forming members 40, and the downstream end is not shown. Connected to the tank.

  The coolant used in the present invention is not limited. The coolant is preferably excellent in electrical insulation, heat transfer and nonflammability, and for example, hydrocarbon oil is suitable.

  The present invention also includes an aspect in which the coolant discharge pipe 76 is omitted and the coolant in the flow path forming member 40 flows out of the flow path forming member 40 directly. In this embodiment, for example, the effluent coolant can be collected by an oil pan installed at the lower part of the electric motor and circulated by a pump. In this aspect, the coolant discharge part according to the present invention is configured by only the coolant discharge port provided in the flow path forming member 40, for example.

  Next, the operation of this electric motor will be described.

  As described above, the exciting coils disposed around the both side portions of each stator core 32 in the stator axial direction in a state where the opposing surfaces 33 of the stator cores 32 and the permanent magnets 12 in the rotor 10 face each other in the stator axial direction. When 36 is energized, a magnetic circuit including a portion penetrating the stator core 32 and the permanent magnet 12 facing the stator core 32 in the stator axial direction is formed, and an electromagnetic force for rotating the rotor 10 is generated. Thereby, each rotation support member 14 constituting the rotor 10 and the plurality of permanent magnets 12 supported by the rotation support member 14 maintain a minute gap between the permanent magnet 12 and the facing surface 33 of each stator core 32. However, it is driven to rotate about the rotation center axis that is the center axis of the support shaft 20.

  At this time, the temperature of the excitation coil 36 increases due to the energization of the excitation coil 36, and the supply and discharge of the coolant to and from the flow path formed inside the partition wall surrounding them causes the excitation coil 36 to The temperature rise of 36 is suppressed. This means that the current that flows through each exciting coil 36 is increased while avoiding an excessive temperature rise of the exciting coil 36 and further the stator core 32 inside thereof, thereby increasing the rotational driving force of the rotor 10 and higher temperatures. Allows the use of electric motors under circumstances.

  Specifically, in this embodiment, coolant discharged from a coolant supply pump (not shown) is supplied to the stator core support plate 34 through the coolant supply pipe 70, and the distribution groove 60 formed in the stator core support plate 34. The liquid supply portion 63, the annular portion 62, each distribution portion 64, and each through hole 68 located at the end thereof are distributed to each excitation coil 36. This cooling liquid flows between the inner gaps 52 (gap between the outer peripheral surface of the excitation coil 36 and the inner peripheral portion 42 of the flow path forming member 40) located on both sides of the through hole 68, and between the outer peripheral surfaces of the excitation coils 36 adjacent to each other. To the outer peripheral space 50 through a gap 56 between them, and further an outer gap (a gap between the outer peripheral surface of the exciting coil 36 and the outer peripheral portion 44 of the flow path forming member 40) 54, and an external drain tank through the coolant discharge pipe 76. To be discharged.

  Since the flow of the coolant is a regular flow in one direction from the radially inner region of each exciting coil 36 to the radially outer region through the gap 56 between adjacent exciting coils 36, The cooling liquid allows each exciting coil 36 to be cooled efficiently and uniformly. In addition, since the rotor 10 is supported by the rotor bearing 16 so as to be rotatable in the region between the coolant supply pipe 70 and the coolant discharge pipe 76, the presence of the pipes 70 and 76 is not limited. It is possible to drive the rotor 10 without any trouble.

  Further, the flow path for distributing the coolant, for example, the distribution groove 60 shown in FIG. 6, is formed in the stator core support plate 34 by using the stator core support plate 34 as a flow path forming member. This makes it possible to distribute the coolant to each exciting coil 36 with a simple structure.

  On the other hand, in this electric motor, the facing surface 33 of each stator core 32 is exposed outwardly in the stator axial direction through each window 48 partially formed in the flow path forming member 40, and the facing surface 33 is formed on the rotor 10. Since it is possible to directly face the permanent magnet 12, it is possible to reduce the magnetic resistance by reducing the distance in the stator axial direction between the facing surface 33 and the permanent magnet 12 as compared with the conventional electric motor, Thereby, energy loss can be reduced.

  The flow path forming member according to the present invention is not limited to one that forms a single partition wall that collectively covers all the exciting coils 36 as described above. For example, the flow path forming member may constitute a plurality of partition walls which are provided for each of the excitation coils 36 and individually cover them, or all the excitation coils 36 are grouped into a plurality of groups. It may be divided and constitute partition walls provided for each group.

  An example of the former is shown in FIG. 7 as a second embodiment. The electric motor according to the second embodiment includes a plurality of flow path forming members 80 instead of the flow path forming member 40 described above. Each flow path forming member 80 has a capsule shape that individually covers each excitation coil 36. Each flow path forming member 80 has a peripheral wall 81 that covers the outer peripheral surface of the corresponding excitation coil 36 from the outside, and a pair of side walls 82 that covers both side surfaces of the excitation coil 36 in the stator axial direction from the outside, of which A window 84 similar to the window 48 according to the first embodiment is formed on the outer side wall 82 of the outer surface of the stator core 32 to expose the facing surface 33 of the stator core 32.

  The peripheral wall 81 has an inner peripheral surface having a shape corresponding to the shape of the outer peripheral surface of the exciting coil 36, and a gap 85 is secured over the entire periphery between the outer peripheral surface and the inner peripheral surface. Among the gaps 85, a gap located inside the exciting coil 36 in the radial direction constitutes an inner flow path, and a gap located outside the radial direction of the exciting coil 36 constitutes an outer flow path. A gap between the path and the outer flow path forms a cooling flow path.

  In FIG. 7, for the sake of convenience, the gap 85 is shown as a lump and is provided with a mesh, but it is actually a space in which the coolant can flow.

  The electric motor further includes a plurality of coolant supply pipes 86 and a plurality of coolant discharge pipes 88, which are provided for each stator core 32. Each cooling liquid supply pipe 86 is connected to the radially inner ends of the pair of flow path forming members 80 provided to the common stator core 32, and is piped so as to supply the cooling liquid to the respective inner flow paths. . Similarly, each of the coolant supply pipes 88 is connected to the radially outer ends of the pair of flow path forming members 80 provided to the common stator core 32, and is piped so as to discharge the coolant from each of the outer flow paths. The

  In FIG. 7, for convenience, only a pair of excitation coils 36 provided to a specific stator core 32 and a flow path forming member 80 that covers these excitation coils 36 are shown.

  Also in the second embodiment, the cooling liquid is allowed to flow from the inside to the outside in the radial direction along the outer peripheral surface of each excitation coil 36, so that the excitation coil 36 can be efficiently and uniformly cooled. Realized. Similarly to the first embodiment, a rotor (not shown) can be driven to rotate without interfering with the pipes 86 and 88 by being arranged in the region between the pipes 86 and 88. .

  In the first and second embodiments, the coolant is supplied to the radially inner position with respect to the coolant flow path, and the coolant is discharged from the outer position, that is, each coolant is inside. Although it flows from the flow path toward the outer flow path, in the present invention, the flow of the coolant may be reversed. For example, the cooling liquid discharge pipe 76 according to the first embodiment is used as a cooling liquid supply unit, and the cooling liquid supply pipe 70 and the distribution groove 60 of the stator core support plate 34 are connected to each excitation coil 36 in reverse. It may be used as a coolant discharge unit that collects and discharges. The same applies to the second embodiment.

DESCRIPTION OF SYMBOLS 10 Rotor 12 Permanent magnet 14 Rotation support member 16 Rotor bearing 20 Support shaft (Rotor support member and stator core support member)
30 Stator 32 Stator Core 33 Opposing Surface 34 Stator Core Support Plate (Stator Core Support Member)
36 Exciting coils 40, 80 Flow path forming member 42 Inner peripheral portion 44 Outer peripheral wall 46 Exciting coil accommodating portion 48 Window 50 Outer peripheral space (outer flow path)
52 Inner clearance (Inner channel)
54 Outer clearance (outer channel)
56 Clearance (cooling flow path)
60 Distribution groove (distribution flow path)
70,86 Coolant supply piping 76,88 Coolant discharge piping 85 Clearance

Claims (8)

An electric motor,
A plurality of permanent magnets arranged circumferentially around a specific rotation center axis, and a rotation support member that rotates around the rotation center axis integrally with these permanent magnets while supporting these permanent magnets; A rotor having,
A rotor support member that rotatably supports the rotor about the rotation center axis;
A stator for rotating the rotor by electromagnetic force;
A coolant supply unit;
A coolant discharge part,
The stator includes a plurality of stator cores arranged in a circumferential direction around the rotation center axis, a stator core support member these stator core to support the respective stator core so as to be opposed to each permanent magnet, respectively A plurality of exciting coils arranged around each of the plurality of stator cores to have an outer peripheral surface and forming a magnetic circuit for rotating the rotor by being energized, and a periphery of each of the plurality of exciting coils And a flow path forming member that forms a flow path for the coolant.
Of the flow path forming member, at least a portion located between adjacent stator cores is non-magnetic,
The flow path forming member, as a flow path of the cooling liquid, and an outer flow passage located radially outward of said plurality of excitation coils, and an inner passage which is located radially inward of said plurality of exciting coils A plurality of cooling channels communicating the outer channel and the inner channel along the outer peripheral surface of each of the plurality of exciting coils, and one of the outer channel and the inner channel Forming a flow path that allows the flow of the coolant from each flow path to the other flow path of the outer flow path and the inner flow path through each of the plurality of cooling flow paths ,
The coolant supply unit is connected to supply cooling liquid to the flow path before Symbol hand the coolant to the one flow path to flow in each of the plurality of cooling passages,
The cooling liquid discharger is connected to the other flow path so as to discharge the cooling liquid from the one flow path to the other flow path through each of the cooling flow paths. ,Electric motor.   2. The electric motor according to claim 1, wherein one of the coolant supply unit and the coolant discharge unit disposed radially inward includes a pipe for circulating a coolant, and the rotor has a diameter of the pipe. An electric motor arranged to rotate in a region outside the direction.   3. The electric motor according to claim 2, wherein the rotor support member includes a support shaft extending along the rotation center axis, and is interposed between the support shaft and the rotor to rotate the rotor relative to the support shaft. An annular rotor bearing to be permitted, wherein the pipe is disposed so as to pass through a radial inner side of the rotor bearing.   4. The electric motor according to claim 2, wherein the coolant supply unit distributes the coolant supplied through the coolant and the coolant supplied through the coolant supply piping to each excitation coil. A motor including a distribution channel formed in the stator core support member.   5. The electric motor according to claim 1, wherein the flow path forming member forms at least one partition wall that surrounds the excitation coil, and forms the coolant flow path inside the partition wall. ,Electric motor.   6. The electric motor according to claim 5, wherein the flow path forming member constitutes a partition wall that collectively surrounds all the excitation coils.   6. The electric motor according to claim 5, wherein the flow path forming member constitutes a plurality of partition walls that individually surround the excitation coils.   8. The electric motor according to claim 5, wherein each stator core has a facing surface that can face each permanent magnet, and the facing surface is exposed toward the permanent magnet of the rotor. An electric motor that constitutes the partition wall together with the flow path forming member by being in close contact with the flow path forming member.

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