JP2017147878A - Cooling structure of motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cooling structure of a motor, which is applied to a transverse motor using an insulation bobbin, is capable of efficiently cool a coil of a stator by cooling oil dropped from an upper portion of a housing and is capable of improving output of the motor.SOLUTION: In a coil 31 of a stator 9, a lead wire 35 is wound around an insulation bobbin 34 in a laminated state. Oil holes 70, 71 dropping and supplying cooling oil to the inside of a housing 8 are formed on an upper section of the housing 8. The insulation bobbin 34 has a lead wire winding section 34a, an outer diameter side flange section 34b and an inner diameter side flange section 34c. Oil introduction notches 37 opened on the outer diameter side of a motor diameter direction are formed on the outer diameter side flange section 34b and outer diameter side guide grooves 38 connected to the oil introduction notches 37 are formed on a lower surface of a section 34ba on which the lead wire 35 is laminated in the outer diameter side flange section 34b.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a cooling structure for a motor such as an in-wheel motor.

  Motors are widely used in vehicles, industrial machines, etc., and are required to be small, light, high efficiency, and high output. On the other hand, the output of the motor is limited by the temperature of the motor. Therefore, in order to improve the output of the motor, it is important to suppress the temperature rise of the motor, in particular, the temperature rise of the stator coil as a heat source.

As a method for cooling the coil, for example, the following proposals have been made.
(1) Patent Document 1
In this proposal, a notch portion is provided in an insulating bobbin that covers the periphery of the stator core and is wound with a conducting wire, and an impregnating material is dropped between the conducting wire exposed in the notch portion and the winding surface of the insulating bobbin. That is, the cooling performance is improved by spreading the impregnating material over the entire coil instead of cooling with oil.

(2) Patent Document 2
In this proposal, the coil end portion is sealed by a bobbin, and a through hole communicating with the coil end portion is provided in the upper portion of the bobbin, and the cooling medium is allowed to flow through the through hole so that the cooling medium is spread over the coil end portion.

Japanese Patent No. 5463696 JP 2010-239775 A

  In motors such as in-wheel motors, the cooling performance of the stator coil, which is the main heat source, greatly affects the physique of the motor. If the cooling performance is poor, it is necessary to increase the physique, and the cost increases as the weight increases. Various proposals have been made regarding the cooling of the coil, including Patent Documents 1 and 2.

  When the winding method of the conductive wire is distributed winding, it is common to use insulating paper for insulation between the coil and the stator core. Since no bobbin is used, the coil is exposed in the internal space of the housing. For this reason, in a horizontally mounted motor, the coil end portion can be cooled by dropping cooling oil from above the coil end portion.

  On the other hand, when the winding method of the conducting wire is concentrated winding, the bobbin is used to ensure insulation between the coil and the stator core. For this reason, even if the cooling oil is dropped from above the coil end portion, there is a problem that the bobbin gets in the way and the cooling oil does not reach the coil.

  As a countermeasure for the above problem, Patent Document 2 has been proposed. This proposal uses a bobbin to seal the coil end portion and fill the periphery of the coil end portion with a cooling medium. However, this structure is difficult to seal.

  In general, in order to improve the cooling performance of the motor, it is only necessary to supply sufficiently cooled cooling oil to the motor. However, when the motor is an in-wheel motor used for the underbody of the vehicle, it is indispensable to reduce the size and weight, and it is difficult to install a pipe for guiding cooling oil to the motor outside the motor.

  Therefore, an in-wheel motor employs an internal circulation system that circulates cooling oil inside the motor as shown in FIG. 14 (for example, Japanese Patent Application No. 2014-216886). FIG. 14 shows a motor drive device in which the motor 101, the speed reducer 102, and the wheel bearing 105 are combined.

  The internal circulation system is configured to cool the stator core 130 and the coil 131 of the stator 109 by diffusing cooling oil from the rotating shaft 106 of the rotor 110 into the housing 108 of the motor 101. In addition, as an internal circulation system, there is a configuration in which the stator core 130 and the coil 131 of the stator 109 are cooled by scooping up or splashing the cooling oil with a centrifugal force accompanying the rotation of the rotor 110. In any configuration, it is unclear whether all of the diffused cooling oil or the cooling oil that has been scraped up or splashed reaches the stator core 130 and the coil 131 of the stator 109.

  Further, in the configuration of FIG. 14, in addition to the supply of cooling oil from the rotating shaft 106, oil holes 170 and 171 are provided in the upper portion of the housing 108, and the cooling oil supplied by the built-in pump 150 is supplied to the oil holes 170 and 171. The cooling oil is supplied to the coil end portion of the stator 109. As shown in FIG. 15, a cooling oil guide plate 172 is provided between the oil holes 170 and 171 and the coil end portion of the stator 109. The cooling oil guide plate 172 has communication holes 173 formed at a plurality of locations at intervals in the circumferential direction. The cooling oil dropped from the oil holes 170 and 171 is dispersed and supplied to the coil end portion of the stator 109. To do. As described above, when the cooling oil is dropped from above the coil end portion, the coil 131 can be cooled also from the outer diameter surface side of the stator 109, and the cooling effect is high.

  However, when the method of dropping cooling oil from above the coil end portion is applied to cooling the stator using the bobbin, the dropped cooling oil is blocked by the bobbin and does not reach the coil end portion. The coil end portion may not be sufficiently cooled.

  In Patent Document 1, it is described that the varnish is spread over the entire stator including the gap of the coil by providing a groove in the bobbin and utilizing the capillary phenomenon. However, there is no mention of cooling using a cooling medium such as oil or water.

  The object of the present invention is applied to a horizontal motor using an insulating bobbin, and the stator coil can be efficiently cooled by cooling oil dropped from the upper part of the housing, so that the output of the motor can be improved. It is to provide a cooling structure for a motor.

The cooling structure of the motor of the present invention includes a rotating shaft arranged sideways, a rotor integrally fixed to the rotating shaft, a stator arranged on the outer periphery of the rotor, and covering and fixing the stator. A housing that rotatably supports the rotating shaft via a plurality of bearings, the stator including a stator core and a coil, and the stator core having a plurality of teeth arranged radially around the axis of the rotating shaft. In addition, the coil includes a plurality of individual coils provided on each tooth portion, and the individual coils include an insulating bobbin that surrounds the outer periphery of the tooth portion, and a conductive wire wound in a laminated state on the insulating bobbin. Applied to the motor.
In the cooling structure of the motor, an oil hole is provided in the upper part of the housing to supply cooling oil by dropping into the housing.
Each of the insulating bobbins includes a cylindrical wire winding portion in which a through hole into which the tooth portion of the stator core is inserted is formed, and a motor radial direction outer side in the radial direction with respect to the rotating shaft in the wire winding portion. An outer diameter side flange portion and an inner diameter side flange portion projecting from the diameter end and the inner diameter end respectively along the lamination direction of the conducting wire,
The insulating bobbin of the individual coil located in the upper part of the plurality of individual coils has a coil end upper part extending in the motor axial direction that is the axial direction of the rotating shaft from the conductor winding part in the outer diameter side flange part. An oil introduction notch that opens on the outer diameter side in the motor radial direction is formed on the lower surface of the portion where the conductor wire is laminated in the coil end upper portion of the outer diameter side flange portion, and the oil introduction notch An outer diameter side oil guide groove that communicates is formed.

  According to this configuration, the cooling oil is supplied dropwise from the oil hole provided in the upper portion of the housing to the inside of the housing. The cooling oil dripped from the oil hole is introduced into the oil introduction notch of the insulating bobbin of the individual coil located at the upper part, and further enters the outer diameter side oil guide groove from the oil introduction notch. The outer diameter side oil guide groove is located on the lower surface of the portion where the conducting wire is laminated in the outer diameter side flange portion, and faces the upper surface of the coil end portion of the individual coil, so that the cooling that has entered the outer diameter side oil guide groove The coil end portion is efficiently cooled by the oil. Thereby, the output of a motor can be improved. In addition, the said coil end part says the part which does not oppose the rotor in the conducting wire wound around the insulation bobbin.

In this invention, the coil end upper part of the outer diameter side flange portion protrudes in the motor axial direction from the conductive wire wound around the conductive wire winding portion, and the oil introduction notch is formed in the protruding portion. Good to have been.
In this case, there is no oil introduction notch on the outer diameter side of the coil end portion of the individual coil, and the outer diameter side of the coil end portion is completely shielded by the outer diameter flange portion. Insulation performance with the stator core can be ensured.

In this invention, it is preferable that a plurality of the oil introduction notches and the outer diameter side oil guide grooves are provided side by side in a direction orthogonal to the motor shaft direction.
If a plurality of oil introduction notches and oil guide grooves on the outer diameter side are provided side by side, the cooling oil can be efficiently distributed over a wide area of the upper surface of the coil end portion of the individual coil, and the coil end portion can be further expanded. It can be cooled efficiently.

In this invention, the oil introduction notch has a slit shape that communicates from the outer diameter side to the inner diameter side in the motor radial direction, and the insulating bobbin of the individual coil located at the upper part of the plurality of individual coils includes: A coil end lower part extending in the motor axial direction from the conductive wire winding portion in the outer diameter side flange portion protrudes in the motor axial direction from the conductive wire wound in the conductive wire winding portion, and the coil An inner diameter side oil that receives the cooling oil falling through the slit-like oil introduction notch on the outer diameter surface of the lower end portion of the end and guides it to the lower side of the conductor wound around the conductor winding portion. A guide groove may be formed.
In this case, a part of the cooling oil dropped from the oil hole and introduced into the oil introduction notch enters the outer diameter side oil guide groove as described above, and most of the remaining cooling oil is slit-shaped. Fall through the oil introduction notch. The dropped cooling oil is received by the inner diameter side flange portion, and is guided by the inner diameter side oil guide groove formed in the inner diameter side flange portion and enters the lower side of the coil end portion of the individual coil. As a result, the coil end portions of the upper and lower sides are cooled by the cooling oil that has entered the upper side of the conducting wire through the outer diameter side oil guide groove and the cooling oil that has entered the lower side of the conducting wire through the inner diameter side oil guide groove. Both can be cooled at the same time.

In the present invention, the oil introduction notch may have a groove shape in which an outer diameter side in the motor radial direction is open and an inner diameter side is closed.
In this case, it is possible to receive the cooling oil dropped from the oil hole and introduced into the oil introduction notch, and allow a large amount of cooling oil to enter the outer diameter side oil guide groove.

In the present invention, a base end is located in the vicinity of the upper side of a communication portion between the oil introduction notch and the outer diameter side oil guide groove in the outer diameter side flange portion, and extends from the base end into the oil introduction notch. You may have a protruding oil introduction member.
In this case, the cooling oil dropped from the oil hole adheres to the oil introduction member, and is guided to the outer diameter side oil guide groove through the oil introduction member. For this reason, much cooling oil can be guide | induced to the outer diameter side oil guide groove.

In this invention, the outer diameter side oil guide groove may have a deeper groove depth as it approaches the oil introduction notch.
Thus, when the groove depth of the outer diameter side oil guide groove becomes deeper as it approaches the oil introduction notch, the cross-sectional area of the inlet portion communicating with the oil introduction notch in the outer diameter side oil guide groove becomes wider. A lot of cooling oil can be taken into the outer diameter side oil guide groove. Also, since the bottom surface of the outer diameter side oil guide groove is located at the bottom, the cooling oil adhering to the vicinity of the inlet of the outer diameter side oil guide groove travels along the bottom surface of the outer diameter side oil guide groove. Easy to enter the outer side of the outer diameter side oil guide groove.

  The cooling structure of the motor of the present invention includes a rotating shaft arranged sideways, a rotor integrally fixed to the rotating shaft, a stator arranged on the outer periphery of the rotor, and covering and fixing the stator. A housing that rotatably supports the rotating shaft via a plurality of bearings, the stator including a stator core and a coil, and the stator core having a plurality of teeth arranged radially around the axis of the rotating shaft. In addition, the coil includes a plurality of individual coils provided on each tooth portion, and the individual coils include an insulating bobbin that surrounds the outer periphery of the tooth portion, and a conductive wire wound in a laminated state on the insulating bobbin. An oil hole is provided in the upper portion of the housing to drop and supply cooling oil to the inside of the housing, and each of the insulating bobbins is provided on the stator core. A cylindrical lead wire winding part in which a through hole into which a toothed part is inserted is formed, and the lead wire from the outer diameter end and the inner diameter end in the motor radial direction that is the radial direction with respect to the rotating shaft in the lead winding part. The insulating bobbin of the individual coil located at the upper part of the plurality of individual coils has the outer diameter side flange portion and the inner diameter side flange portion protruding along the stacking direction of the outer diameter side flange portion. An oil introduction notch that opens to the outer diameter side in the motor radial direction is formed in an upper portion of the coil end that extends in the motor shaft direction, which is the axial direction of the rotating shaft, from the conductive wire winding portion, and the outer diameter side flange Since the outer diameter side oil guide groove communicating with the oil introduction notch is formed on the lower surface of the portion where the conducting wire is laminated in the upper part of the coil end of the part, it is applied to a horizontally mounted motor using an insulating bobbin If the the coil of the stator effectively it can be cooled by the cooling oil to be dropped from the top of the housing, it is possible to improve the output of the motor.

It is sectional drawing of the motor drive device provided with the cooling structure of the motor which concerns on 1st Embodiment of this invention. It is II-II sectional drawing of FIG. It is the III section enlarged view of FIG. It is the IV section enlarged view of FIG. It is the V section enlarged view of FIG. It is a top view of a part of individual coil of the stator in the motor of the motor drive device. It is a perspective view of a part of the individual coil. It is sectional drawing of the reduction gear used as the VIII-VIII cross section of FIG. It is the elements on larger scale of FIG. It is sectional drawing of a part of individual coil of the stator in the motor of the motor drive device provided with the cooling structure of the motor which concerns on 2nd Embodiment of this invention. It is a XI arrow line view of FIG. It is sectional drawing of a part of individual coil of the stator in the motor of the motor drive device provided with the cooling structure of the motor which concerns on 3rd Embodiment of this invention. It is a XIII arrow directional view of FIG. It is sectional drawing of the conventional motor drive device. It is XV-XV sectional drawing of FIG.

A motor drive apparatus having a motor cooling structure according to a first embodiment of the present invention will be described with reference to FIGS.
As shown in FIG. 1, the motor drive device includes a motor 1 that drives wheels, a speed reducer 2 that decelerates the rotation of the motor 1, and an input shaft 3 of the speed reducer 2 (referred to as a speed reducer input shaft 3). And a wheel bearing 5 rotated by a coaxial output member 4 and an oil cooling device R. A reduction gear 2 is interposed between the wheel bearing 5 and the motor 1, and a wheel hub, which is a driving wheel supported by the wheel bearing 5, and the rotating shaft 6 of the motor 1 are connected coaxially. is there. This motor drive device is an in-wheel motor drive device that is partly or wholly disposed in a wheel.

  A suspension (not shown) in the vehicle is connected to the reduction gear housing 7 that houses the reduction gear 2. In this specification, the side closer to the outer side in the vehicle width direction of the vehicle with the motor drive device provided in the vehicle is referred to as the outboard side, and the side closer to the center in the vehicle width direction of the vehicle is referred to as the inboard side. Call it.

  The motor 1 includes a stator 9 fixed to the motor housing 8 and a rotor 10 fixed to the rotating shaft 6. The motor 1 is an IPM motor (so-called embedded magnet type synchronous motor) in which a radial gap is provided between a stator 9 and a rotor 10. The rotating shaft 6 of the motor 1 is disposed sideways and is rotatably supported by a pair of rolling bearings 11 and 12. The pair of bearings 11 and 12 are at positions separated from each other in the motor shaft direction. The motor shaft direction is the axial direction of the rotating shaft 6.

  The rotor 10 includes a rotor core 10 a, a magnet (not shown) disposed in an opening inside the rotor core 10 a, and a fixed body 13 that fixes the rotor core 10 a to the rotating shaft 6. The fixed body 13 of this embodiment is formed integrally with the rotating shaft 6. Specifically, the fixed body 13 includes a base portion 13a that is a connection portion with the rotary shaft 6, a cylindrical portion 13b that extends from the outer diameter end of the base portion 13a to the outboard side and the inboard side, and the outboard of the cylindrical portion 13b. It consists of a pair of flanges 13c, 13c extending from the side end and the inboard side end to the outer diameter side. The rotor core 10a is fixed between the pair of flange portions 13c, 13c of the fixed body 13.

  The stator 9 has a stator core 30 and a coil 31. The stator core 30 is made of, for example, a soft magnetic material. As shown in FIG. 2 which is a II-II cross-sectional view of FIG. 1, the stator core 30 includes an annular portion 30a fitted to the inner peripheral surface of the motor housing 8, and a plurality of protrusions protruding from the annular portion 30a toward the inner diameter side. Tooth portion 30b. The plurality of tooth portions 30 b are arranged radially around the axis of the rotation shaft 6. The shape of the cross section obtained by cutting the tooth portion 30b along a plane perpendicular to the motor radial direction is, for example, a rectangle. The motor radial direction is the radial direction with respect to the rotating shaft 6.

  The coil 31 has a concentrated winding type and includes a plurality of individual coils 33 wound around the respective tooth portions 30 b of the stator core 30. Each individual coil 33 includes a plurality of insulating bobbins 34 provided so as to surround the outer periphery of the tooth portion 30 b and a conductive wire 35 wound around the insulating bobbin 34. The insulating bobbin 34 is made of an insulating material such as a resin material. The conducting wire 35 is wound around the insulating bobbin 34 in a laminated form.

  FIG. 3 is an enlarged view of part III in FIG. The insulating bobbin 34 includes a cylindrical wire winding portion 34a in which a through hole 36 into which the tooth portion 30b of the stator core 30 is inserted is formed, and an outer diameter end and an inner diameter end in the motor radial direction of the wire winding portion 34a. Each has an outer diameter side flange portion 34 b and an inner diameter side flange portion 34 c that protrude along the stacking direction of the conductive wires 35 (see FIG. 7).

  In FIG. 3, a coil end upper side portion 34bA extending in the motor axial direction from the conductor winding portion 34a is illustrated as the outer diameter side flange portion 34b. Similarly, a coil end lower part 34cA extending in the motor axial direction from the conductor winding part 34a is illustrated as the inner diameter side flange part 34c. The coil end upper part 34bA of the outer diameter side flange part 34b and the coil end lower part 34cA of the inner diameter side flange part 34c protrude in the motor axial direction from the stacking range of the conducting wires 35 on both the outboard side and the inboard side. Yes. The coil end portion 33 a of the individual coil 33 is a portion of the conducting wire 35 wound around the insulating bobbin 34 that does not face the rotor 10.

  As shown in FIG. 4, which is an enlarged view of the IV part of FIG. 3, the coil end upper part 34 b </ b> A of the outer diameter side flange part 34 b is composed of a conductor laminated part 34 ba in which the conductor 35 is laminated, and the conductor laminated part 34 ba. It consists of a protruding portion 34bb protruding in the motor shaft direction. An oil introduction notch 37 that opens to the outer diameter side in the motor radial direction is formed in the protruding portion 34bb. The oil introduction notch 37 of this embodiment has a slit shape that communicates from the outer diameter side to the inner diameter side in the motor radial direction. An outer diameter side oil guide groove 38 that communicates with the oil introduction notch 37 is formed on the lower surface, which is the inner diameter side surface of the conductor laminated portion 34ba. The outer diameter side oil guide 38 of this embodiment has a shape with a deeper groove as it approaches the oil introduction notch 37.

  5 is an enlarged view of a portion V in FIG. 2, FIG. 6 is a plan view of a part of the individual coil, and FIG. 7 is a perspective view of a part of the individual coil. As shown in each of these drawings, the protruding portion 34bb of the outer diameter side flange portion 34b is composed of a plurality of column portions 39 extending in the motor axial direction from the conductor laminated portion 34ba. A portion between the column portions 39 is an oil introduction notch 37. The cross section of the column portion 39 has a protrusion shape, for example, a mountain shape, in which the outer diameter side portion 39a in the motor radial direction becomes narrower in the circumferential direction toward the outer diameter side.

  As shown in FIGS. 4, 6, and 7, the inner diameter side flange portion 34 c protrudes larger in the motor shaft direction than the outer diameter side flange portion 34 b. A plurality of inner diameter side oil guide grooves 41 extending in the motor shaft direction are formed on the outer diameter surface of the coil end lower portion 34cA of the inner diameter side flange portion 34c. The inner diameter side oil guide groove 41 is formed from the proximal end to the distal end in the motor axial direction on the outer diameter surface of the coil end lower portion 34cA of the inner diameter side flange portion 34c.

  In FIG. 1, the rotating shaft 6 is a shaft that transmits the driving force of the motor 1 to the speed reducer 2. The rotating shaft 6 has a cylindrical shape, and the inboard side portion of the speed reducer input shaft 3 is fitted to the outboard side portion thereof. The rotary shaft 6 and the speed reducer input shaft 3 are spline-fitted (including serration fitting; the same applies hereinafter). The reduction gear input shaft 3 is rotatably supported by rolling bearings 14a and 14b on the same axis as the rotary shaft 6. The rolling bearing 14a is fitted in the cup portion of the output member 4, and the rolling bearing 14b is fitted in the cylindrical connecting member 4a. The cup portion of the output member 4 and the connecting member 4 a are connected via an inner pin 22.

  Eccentric portions 15 and 16 are provided on the outer peripheral surface of the speed reducer input shaft 3. These eccentric portions 15 and 16 are provided with a 180 ° phase shift so that the centrifugal force due to the eccentric motion cancels each other. The speed reducer 2 is a cycloid speed reducer having curved plates 17 and 18, a plurality of outer pins 19, and a counterweight 21.

  FIG. 8 is a cross-sectional view of the speed reducer portion taken along the line VIII-VIII in FIG. In the speed reducer 2, two curved plates 17 and 18, each of which is formed by a wavy trochoid curve having a gentle outer shape, are mounted on the eccentric portions 15 and 16 via rolling bearings 85, respectively. A plurality of outer pins 19 for guiding the eccentric movements of the curved plates 17 and 18 on the outer peripheral side are respectively provided inside the reduction gear housing 7, and the plurality of inner pins 22 are provided inside the curved plates 17 and 18. The plurality of circular through holes 89 provided are engaged with each other in an inserted state.

  As shown in an enlarged view in FIG. 9, needle roller bearings 92 and 93 are attached to each outer pin 19 and each inner pin 22. The outer pins 19 are supported at both ends by needle roller bearings 92, the outer rings 92a of these needle roller bearings 92 are fixed to the reducer housing 7, and the outer pins 19 are rotatably supported. In contact with the outer peripheral surface of the curved plates 17 and 18, respectively, to reduce the contact resistance with the outer periphery of each of the curved plates 17, 18. In each inner pin 22, the outer ring 93 a of the needle roller bearing 93 reduces the contact resistance between the inner periphery of each through-hole 89 of each curved plate 17 and 18 and each inner pin 22.

  Therefore, as shown in FIG. 1, the eccentric motion of the curved plates 17 and 18 can be smoothly transmitted to the inner member (rotating wheel) 5a of the wheel bearing 5 as a rotational motion. When the rotating shaft 6 rotates, the curved plates 17 and 18 provided on the speed reducer input shaft 3 that rotates integrally with the rotating shaft 6 perform an eccentric motion. At this time, the outer pin 19 is engaged so as to be in rolling contact with the outer peripheral surface of each curved plate 17, 18 that moves eccentrically, and each curved plate 17, 18 is connected to the inner pin 22 and the through hole 89 (FIG. 8). Due to the engagement, only the rotational motion of the curved plates 17 and 18 is transmitted as rotational motion to the output member 4 and the inner member 5a of the wheel bearing 5. The rotation of the inner member 5a is decelerated with respect to the rotation of the rotating shaft 6.

  The wheel bearing 5 is a double-row angular contact ball bearing in which a ball is incorporated between the inner member 5a and the outer member 5b. The outer member 5b is bolted to the speed reducer housing 7 by a flange 5c. The inner member 5a is spline-fitted (including serration fitting) to the output member 4. The rotational motion transmitted to the inner member 5a is transmitted to the tire from a wheel mounting flange 5d provided on the outer peripheral surface of the inner member 5a on the outboard side.

Next, the oil cooling device R will be described with reference to FIG.
The oil cooling device R combines cooling of the motor 1 and the speed reducer 2 and lubrication of the bearings 11, 12, 14 a and 14 b that support the speed reducer 2 and the rotating shaft 6. The oil cooling device R is provided at each part of the motor 1 and the speed reducer 2, the pump 50 provided at the boundary between the speed reducer housing 7 and the motor housing 8, the oil sump 51 provided at the bottom of the speed reducer housing 7. Oil passages 52-60.

  The pump 50 is a cycloid pump, for example. The pump 50 sucks the cooling oil in the oil reservoir 51 through the suction oil passage 52 and sends it out to the delivery oil passage 53. The delivery oil passage 53 is provided in the motor housing 8 and extends upward. The upper end of the delivery oil passage 53 communicates with the outboard side end of the axial oil passage 54. The axial oil passage 54 extends along the axial direction inside the upper portion of the motor housing 8. The axial oil passage 54 is provided with oil holes 70 and 71 (described later) communicating with the inside of the motor housing 8 at two locations.

  The inboard side end of the axial oil passage 54 communicates with the upper end of a communication oil passage 55 provided in the motor cover 8 a of the motor housing 8. The lower end of the communication oil passage 55 extends to the position of the motor shaft center, and the lower end thereof communicates with the motor shaft oil supply passage 56. The motor shaft oil supply path 56 extends from the inboard side to the outboard side along the axis of the rotating shaft 6. The lower end of the communication oil passage 55 communicates with the inboard side of the motor shaft center oil supply passage 56.

  The motor shaft center oil supply passage 56 communicates with the speed reducer shaft center oil supply passage 57 in the reducer input shaft 3 at the outboard side end, and also communicates with the discharge oil passage 60 at the axial intermediate portion thereof.

  The reducer shaft center oil supply passage 57 is provided in the reducer input shaft 3 along the shaft center, and extends from the inboard side to the outboard side. A speed reducer supply oil path 58 extends into the speed reducer housing 7 from the axial position where the eccentric portions 15 and 16 are provided in the speed reducer axial center oil supply path 57. Further, the inside of the reduction gear housing 7 and the oil reservoir 51 are communicated with each other through a drain oil passage 59.

  The discharge oil passage 60 includes a radial hole 61, a gap 62, an oil groove 63, and an oil discharge hole 64. The radial hole 61 is provided in the motor radial direction across the rotating shaft 6 and the base portion 13 a of the fixed body 13, the inner diameter end communicates with the motor shaft center oil supply passage 56, and the outer diameter end opens into the gap portion 62. ing. The gap 62 is a space formed between the cylindrical portion 13b of the fixed body 13 and the inner peripheral surface of the rotor core 10a. The oil groove 63 is provided along the inner surface of the flange 13c of the fixed body 13 that is in contact with the end surface of the rotor core 10a, and the inner diameter end in the motor radial direction communicates with the gap 62. The oil discharge hole 64 extends obliquely from the outer diameter end of the oil groove 63 in the motor radial direction toward the outer side in the motor axial direction and the outer diameter side in the motor radial direction, and the tip opens into the internal space S of the motor housing 8. Yes.

  As shown in FIG. 3, the oil holes 70, 71 provided in the axial oil passage 54 are located above the insulating bobbin 34 of the individual coil 33 located above the stator 9 among the plurality of individual coils 33. ing. More precisely, the two oil holes 70 and 71 are respectively located directly above the protruding portion 34bb on the outboard side and the inboard side in the outer diameter side flange portion 34b of the insulating bobbin 34.

  As shown in FIGS. 2 and 3, a cooling oil guide plate 72 is provided between the oil holes 70 and 71 and the outer diameter side flange portion 34 b of the insulating bobbin 34. The cooling oil guide plate 72 is an arc-shaped plate along the inner periphery of the upper portion of the motor housing 8, and communication holes 73 are formed at a plurality of locations at intervals in the circumferential direction. The communication hole 73 is at the same position in the motor axial direction as the oil holes 70 and 71. In the case of the example in the figure, the cooling oil guide plate 72 is provided in a range that covers the two insulating bobbins 34 positioned above.

  In FIG. 1, an oil drain groove 65 is provided at the bottom of the motor housing 8 that is the lower end of the internal space S of the motor housing 8. The oil drain groove 65 communicates with the oil reservoir 51.

  The cooling oil delivered from the pump 50 flows through the delivery oil passage 53, the axial oil passage 54, and the communication oil passage 55 in order, and then flows into the motor shaft oil supply passage 56. In the middle of this, a part of the cooling oil is supplied to the inside of the motor housing 8 by dropping from the oil holes 70 and 71. A part of the cooling oil that has flowed to the motor shaft oil supply passage 56 flows to the reduction gear shaft oil supply passage 57, and the rest flows to the discharge oil passage 60.

  The cooling oil that has flowed into the reduction gear shaft center oil supply passage 57 is supplied to the inside of the reduction gear housing 7 through the reduction gear supply oil passage 58 by the pressure of the pump 50 and the centrifugal force accompanying the rotation of the reduction gear input shaft 3. The Each part in the speed reducer 2 is lubricated and cooled by this cooling oil. The cooling oil used for lubrication and cooling moves downward due to gravity and is returned to the oil sump 51 via the discharge oil passage 59.

  The cooling oil that has flowed into the discharge oil passage 60 is discharged into the motor housing 8 through the radial hole 61, the gap 62, the oil groove 63, and the oil discharge hole 64 in this order. When the cooling oil passes through the gap 62 and the oil groove 63 in contact with the rotor core 10a, the rotor core 10a is cooled. The cooling oil discharged from the oil discharge hole 64 is diffused to the outer diameter side by the pressure at the time of discharge and the centrifugal force due to the rotation of the rotor 10, and cools the coil 31 of the stator 9.

The cooling oil dropped from the oil holes 70 and 71 into the motor housing 8 cools the coil 31 of the stator 9 through the following path.
In FIG. 3, the cooling oil dropped into the motor housing 8 is temporarily received by the cooling oil guide plate 72 and falls directly from the respective communication holes 73 of the cooling oil guide plate 72, or the respective communication holes. The cooling oil guide plate 72 that has passed through 73 is dispersed from each part of the lower surface of the cooling oil guide plate 72 and falls downward. The cooling oil dropped from the cooling oil guide plate 72 is introduced into the oil introduction cutout 37 of the insulating bobbin 34 of the individual coil 33 located at the upper part. As shown in FIG. 5 and FIG. 7, the outer diameter side portion 39a of the column portion 39, which is the portion between the oil introduction notches 37, has a mountain-shaped protrusion shape, so that the cooling oil hitting the column portion 39a is not easily rebounded and is cooled. Oil is easily guided downward along the outer diameter side portion 39 a of the column portion 39. Thereby, the cooling oil is smoothly introduced into the oil introduction notch 37.

  4 and 7, part of the cooling oil introduced into the oil introduction notch 37 enters the outer diameter side oil guide groove 38 communicating with the oil introduction notch 37. The outer diameter side oil guide groove 38 has a shape in which the groove depth becomes deeper as the oil introduction notch 37 is approached, and the cross-sectional area of the inlet portion communicating with the oil introduction notch 37 is large. For this reason, most of the cooling oil introduced into the oil introduction notch 37 can be taken into the outer diameter side oil guide groove 38. In addition, since the bottom surface (downward surface) of the outer diameter side oil guide groove 38 is positioned downward as it goes back, the cooling oil adhering to the vicinity of the inlet of the outer diameter side oil guide groove 38 becomes outer diameter side oil guide groove 38. It is easy to enter the outer side of the outer diameter side oil guide groove 38 along the bottom surface.

  The outer diameter side oil guide groove 38 is provided on the lower surface of the conductor laminated portion 34ba of the outer diameter side flange portion 34b, and faces the upper surface of the coil end portion 33a of the individual coil 33. The outer diameter side oil guide grooves 38 communicate with each other through a gap 74 (FIG. 7) formed between the conducting wires 35 having a circular cross section. For this reason, the cooling oil that has entered the outer diameter side oil guide groove 38 spreads well over the entire upper surface of the coil end portion 33a through the gap 74, and the coil end portion 33a is efficiently cooled.

  Of the cooling oil smoothly introduced into the oil introduction notch 37, the remaining cooling oil that has not entered the outer diameter side oil guide groove 38 passes through the oil introduction notch 37 having a slit shape and falls. The dropped cooling oil is received by the inner diameter side flange portion 34c, and is guided by the inner diameter side oil guide groove 41 formed in the inner diameter side flange portion 34c to enter the lower side of the coil end portion 33a. The inner diameter side oil guide grooves 41 communicate with each other via a gap 75 (FIG. 7) formed between the conductive wires 35. For this reason, the cooling oil that has entered the oil guide groove 41 on the inner diameter side spreads well over the entire lower surface of the coil end portion 33a through the gap 75, and the coil end portion 33a is efficiently cooled.

  Thus, both the upper surface and the lower surface of the coil end portion 33a of the individual coil 33 are simultaneously cooled by the cooling oil that has entered the outer diameter side oil guide groove 38 and the cooling oil that has entered the inner diameter side oil guide groove 41. be able to. The cooling oil that has cooled the upper individual coil 33 travels through the gaps 74 and 75 to the individual coil 33 located in the lower part, and cools the individual coil 33 located in the lower part. Thereby, the output of the motor 1 can be improved.

  As shown in FIG. 1, cooling oil discharged from the oil discharge hole 64 of the discharge oil passage 60 and used for cooling the motor 1, and cooling dropped from the oil holes 70 and 71 and used for cooling the motor 1. The oil is collected in the oil drain groove 65 at the bottom of the motor housing 8, and returned from the oil drain groove 65 to the oil reservoir 51.

10 and 11 show a second embodiment of the present invention. Only the part from which the structure differs compared with 1st Embodiment shown in FIGS. 1-9 is shown in figure. About the location which is not illustrated, it is the same structure as 1st Embodiment.
In the second embodiment, a shielding plate 43 is provided between the inner diameter ends of each column portion 39, and the oil introduction notch 37A is formed in a groove shape in which the outer diameter side in the motor radial direction is opened and the inner diameter side is closed. ing. The groove-shaped oil introduction notch 37 </ b> A communicates with the outer diameter side oil guide groove 38. Thus, if the oil introduction notch 37A has a groove shape, the cooling oil that has fallen from the cooling oil guide plate 72 and introduced into the oil introduction notch 37A is received, and a large amount of cooling oil is guided to the outer diameter side oil guide. The groove 38 can be penetrated. Thereby, especially the upper surface of the coil end part 33a can be efficiently cooled.

  12 and 13 show a third embodiment of the present invention. Only the part from which the structure differs compared with 1st Embodiment shown in FIGS. 1-9 is shown in figure. About the location which is not illustrated, it is the same structure as 1st Embodiment.

  In the third embodiment, an oil introduction member 44 is provided on the outer diameter side flange portion 34 b of the insulating bobbin 34. The base end of the oil introduction member 44 is located in the vicinity of the upper side of the communication portion between the oil introduction notch 37 and the outer diameter side oil guide groove 38 in the outer diameter side flange portion 34 b, and the oil introduction notch 37 extends from the base end. It extends to. In the illustrated example, the oil introduction member 44 has a circular cross-sectional shape, but may have other shapes. When the oil introduction member 44 is provided, the cooling oil falling from the cooling oil guide plate 72 adheres to the oil introduction member 44 and is guided to the outer diameter side oil guide groove 38 through the oil introduction member 44. For this reason, a lot of cooling oil can be guided to the outer diameter side oil guide groove 38.

  As mentioned above, although the form for implementing this invention based on embodiment was demonstrated, embodiment disclosed this time is an illustration and restrictive at no points. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

DESCRIPTION OF SYMBOLS 1 ... Motor 6 ... Rotating shaft 8 ... Motor housing 9 ... Stator 10 ... Rotor 11, 12 ... Bearing 30 ... Stator core 30b ... Tooth part 31 ... Coil 33 ... Individual coil 33a ... Coil end part 34 ... Insulating bobbin 34a ... Conductor winding Part 34b ... Outer diameter side flange part 34bA ... Coil end upper part 34c ... Inner diameter side flange part 34cA ... Coil end lower part 34ba ... Conductor lamination part (part where conductors are laminated)
34bb ... projecting portion 35 ... conducting wire 36 ... through hole 37, 37A ... oil introduction notch 38 ... outer diameter side oil guide groove 41 ... inner diameter side oil guide groove 44 ... oil introduction member 70, 71 ... oil hole

Claims (7)

A rotating shaft arranged in a lateral direction, a rotor integrally fixed to the rotating shaft, a stator arranged on the outer periphery of the rotor, and covering the stator and fixing the rotating shaft via a plurality of bearings And the stator is composed of a stator core and a coil, the stator core has a plurality of teeth arranged radially around the axis of the rotation shaft, and the coil includes the teeth. Comprising a plurality of individual coils provided in the part, and these individual coils are a cooling structure of a motor comprising an insulating bobbin surrounding the outer periphery of the tooth part and a conductive wire wound in a laminated state on the insulating bobbin,
An oil hole is provided in the upper part of the housing to supply cooling oil by dropping into the housing.
Each of the insulating bobbins includes a cylindrical wire winding portion in which a through hole into which the tooth portion of the stator core is inserted is formed, and a motor radial direction outer side in the radial direction with respect to the rotating shaft in the wire winding portion. An outer diameter side flange portion and an inner diameter side flange portion projecting from the diameter end and the inner diameter end respectively along the lamination direction of the conducting wire,
The insulating bobbin of the individual coil located in the upper part of the plurality of individual coils has a coil end upper part extending in the motor axial direction that is the axial direction of the rotating shaft from the conductor winding part in the outer diameter side flange part. An oil introduction notch that opens on the outer diameter side in the motor radial direction is formed on the lower surface of the portion where the conductor wire is laminated in the coil end upper portion of the outer diameter side flange portion, and the oil introduction notch A cooling structure for a motor, characterized in that a communicating outer diameter side oil guide groove is formed.   2. The motor cooling structure according to claim 1, wherein the coil end upper part of the outer diameter side flange portion protrudes in the motor axial direction from the conductor wound around the conductor winding portion. A motor cooling structure in which the oil introduction notch is formed.   3. The motor cooling structure according to claim 1, wherein a plurality of the oil introduction notches and the outer diameter side oil guide grooves are provided side by side in a direction orthogonal to the motor shaft direction. Construction.   4. The motor cooling structure according to claim 1, wherein the oil introduction notch has a slit shape communicating from the outer diameter side to the inner diameter side in the motor radial direction, and a plurality of the oil introduction notches The insulating bobbin of the individual coil located at the upper part of the individual coil has a coil end lower part extending in the motor axial direction from the conductor winding part in the outer diameter side flange part wound around the conductor winding part. Projecting in the motor axial direction from the conductive wire, and receiving the cooling oil falling through the slit-like oil introduction notch on the outer diameter surface of the coil end lower portion, the conductive wire winding A motor cooling structure in which an inner diameter side oil guide groove is formed to be led to the lower side of the conducting wire wound around the turning portion.   4. The motor cooling structure according to claim 1, wherein the oil introduction notch has a groove shape in which an outer diameter side in the motor radial direction is open and an inner diameter side is closed. 5. .   6. The motor cooling structure according to claim 1, wherein the motor cooling structure is based on a vicinity of an upper side of a communication portion between the oil introduction notch and the outer diameter side oil guide groove in the outer diameter side flange portion. A motor cooling structure having a protruding oil introduction member having an end positioned and extending from the base end into the oil introduction notch.   The motor cooling structure according to any one of claims 1 to 6, wherein the outer diameter side oil guide groove has a groove depth that becomes deeper as the oil introduction notch is approached. .

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