JP2013106416A - Cooling mechanism for electric motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cooling mechanism for electric motor that can securely and efficiently cool an electric motor.SOLUTION: The cooling mechanism for electric motor is characterized in that a planetary gear-side end 47c1 of a top plate 47c passes through an electric motor-side end of a planetary gear 22B, and is arranged more on the side of the planetary gear 22B than a plane F1 of rotation orthogonal to a straight line O as an axis of rotation of the planetary gear 22B, and an electric motor-side end 47c2 of the top plate 47c passes through a planetary gear-side end of a second electric motor 2B, and is arranged more on the side of the second electric motor 2B than a perpendicular plane F2 orthogonal to the straight line O as the axis of rotation of the planetary gear 22B, a position Q1 where the top plate 47c with cross the plane F1 of rotation being arranged above a position Q2 where the top plate 47c cross with the perpendicular plane F2.

Description

  The present invention relates to a motor cooling mechanism.

  As a motor cooling mechanism for cooling an electric motor, in Patent Document 1, a catch tank 182 for temporarily storing cooling oil supplied directly to the electric motor 180 is attached to an upper portion of a housing 181 that houses the electric motor 180. . In order to pump up the cooling oil mechanically connected to the drive shaft and stored in the housing 181 as the drive shaft is driven, a part of the housing 181 is immersed in the cooling oil stored in the lower part. In addition, a cooling mechanism is disclosed in which gear mechanisms (gears 160a and 160b) are disposed at positions that are substantially aligned with the supply port 184 of the catch tank 182.

JP 2005-117790 A

  However, in the motor cooling mechanism described in Patent Document 1, the gear mechanisms (gears 160a and 160b) for pumping the cooling oil stored in the housing 181 to the catch tank 182 overlap the motor 180 in the axial direction. Therefore, there is a problem that expansion in the radial direction cannot be avoided and cooling oil cannot be efficiently supplied to the electric motor.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide an electric motor cooling mechanism that can cool the electric motor reliably and efficiently.

In order to achieve the above object, the invention described in claim 1
An electric motor (for example, first and second electric motors 2A and 2B in an embodiment described later);
A housing (for example, described later) having a storage section (for example, storage section R in an embodiment described later) for storing a liquid fluid (for example, oil in an embodiment described later) for cooling the motor. Case 11) of the embodiment of
A rotating body (e.g., planetary gears 22A and 22B in an embodiment described later) that is housed in the housing and disposed in the vicinity of the electric motor, and at least a part of which is immersed in the storage unit;
A cooling mechanism for an electric motor comprising liquid introducing means for guiding the liquid fluid to the electric motor (for example, first and second baffle plates 47A and 47B in embodiments described later),
The rotation axis of the rotating body is arranged in a direction inclined with respect to the vertical direction or in a direction orthogonal to the vertical direction,
The liquid introducing means is disposed above the rotating body and the electric motor so as to face the upper end of the rotating body and the upper end of the electric motor, and extends from the rotating body side to the electric motor side (for example, A top plate 47c) of an embodiment described later,
An end portion (for example, a rotating body side end portion 47c1 of the embodiment described later) of the liquid introduction section passes through an end portion of the rotating body on the electric motor side and is orthogonal to the rotation axis (for example, Arranged on the rotating body side with respect to the rotating plane F1) of the embodiment described later,
An end portion (for example, an electric motor side end portion 47c2 of an embodiment described later) of the liquid introduction portion is a vertical plane (for example, an upper surface of an embodiment described later) passing through an end portion of the electric motor on the rotating body side. F2) is arranged closer to the electric motor than
A position (for example, a position Q1 in the embodiment described later) that intersects the plane of the liquid introducing section is higher than a position (for example, a position Q2 in the embodiment described later) that intersects the vertical plane of the liquid introducing section. It is characterized by being arranged in.

Moreover, in addition to the structure of Claim 1, the invention of Claim 2 is
The end of the liquid introduction part on the electric motor side is arranged above the electric motor in the vertical direction.

In addition to the configuration described in claim 1 or 2, the invention described in claim 3
The casing includes a partition wall (for example, partition walls 18A and 18B in the embodiments described later) that is disposed between the rotating body and the electric motor and partitions the rotating body and the electric motor.

Moreover, in addition to the structure of Claim 3, the invention of Claim 4 adds to the structure of Claim 3,
The upper end of the partition wall portion is disposed above an imaginary line connecting the uppermost end of the electric motor, the uppermost end of the rotating body, and the uppermost end of the rotation locus of the rotating body, whichever is higher,
The liquid introduction part is arranged above the upper end of the partition part.

In addition to the configuration described in claim 3 or 4, the invention described in claim 5
Bearings (for example, bearings 19A and 19B and bearings 33A and 33B in the embodiments described later) that rotatably support the electric motor and the rotating body are disposed in the partition wall.

Moreover, in addition to the structure of any one of Claims 1-5, the invention of Claim 6 is
The rotating shaft of the electric motor and the rotating shaft of the rotating body are arranged on the same straight line.

Moreover, in addition to the structure of any one of Claims 1-6, invention of Claim 7 is provided,
The liquid introducing means is a separate member formed separately from the electric motor, the rotating body, and the casing.

Moreover, in addition to the structure of any one of Claims 1-7, invention of Claim 8 is provided,
In addition to the liquid introduction part, the liquid introduction means includes a fixing part (for example, a fixing part 47h in the embodiment described later) that extends from the liquid introduction part and fixes the liquid introduction means to the housing. It is characterized by.

Moreover, in addition to the structure described in claim 8, the invention described in claim 9 includes
The fixing portion extends downward from the liquid introduction portion.

Moreover, in addition to the structure of Claim 9, the invention of Claim 10 adds to the structure of Claim 9,
The lower end of the fixed portion overlaps the rotating body or a rotation locus of the rotating body in a radial direction.

Moreover, in addition to the structure of any one of Claims 7-10, the invention of Claim 11 is
The housing includes an upper wall portion (for example, an upper wall portion 11Mu in an embodiment described later) that covers an upper portion of the electric motor and an upper portion of the liquid introduction portion.

Moreover, in addition to the structure of any one of Claims 8-11, the invention of Claim 12 is
The housing has a recessed portion that opens toward the inside of the housing (for example, a recessed portion 80 in an embodiment described later),
At least a part of the opening of the recessed portion is closed by the fixing portion, and another space is formed by the recessed portion and the fixing portion.

Moreover, in addition to the structure of Claim 12, the invention of Claim 13 is
The other space is a breather chamber (for example, a breather chamber 41 in an embodiment described later) that suppresses outflow of the liquid fluid in the housing to the outside.

Moreover, in addition to the structure of any one of Claims 1-13, the invention of Claim 14 is
The electric motor drives a vehicle wheel (for example, a rear wheel Wr in an embodiment described later),
The rotating body is disposed on a power transmission path between the electric motor and the wheel,
The rotating body supports a sun gear (for example, sun gears 21A and 21B in an embodiment described later), a plurality of planetary gears meshed with the sun gear (for example, planetary gears 22A and 22B in an embodiment described later), and the plurality of planetary gears. A planetary gear mechanism (e.g., a planetary carrier (e.g., planetary carriers 23 </ b> A, 23 </ b> B in an embodiment described later) and a ring gear (e.g., ring gears 24 </ b> A, 24 </ b> B in an embodiment described later)) meshed with the outer peripheral side of the plurality of planetary gears The first and second planetary gear type speed reducers 12A and 12B) according to the embodiments described later are characterized by any element.

Moreover, in addition to the structure of Claim 14, the invention of Claim 15 is
The planetary gear includes a large-diameter pinion (for example, first pinions 26A and 26B in an embodiment described later) and a small-diameter pinion (for example, second pinions 27A and 27B in an embodiment described later) that mesh with the sun gear. And a two-stage pinion comprising
The rotating body is the large-diameter pinion.

In addition to the structure of claim 14 or 15, the invention of claim 16
The sun gear is connected to an output shaft of the electric motor (for example, cylindrical shafts 16A and 16B in the embodiments described later).

In addition to the configuration described in any one of claims 14 to 16, the invention described in claim 17 includes:
The planetary carrier is connected to the wheel.

The invention according to claim 18
Electric motors for driving the wheels (for example, first and second electric motors 2A and 2B in embodiments described later),
A rotating body (e.g., planetary gears 22A, 22B in an embodiment described later) provided on a power transmission path between the electric motor and the wheels;
A housing that stores a liquid fluid that cools the electric motor (for example, oil in an embodiment described later) (for example, a storage portion R in an embodiment described later), and stores the electric motor and the rotating body. A body (for example, a case 11 of an embodiment described later),
At least a part of the rotating body is a cooling mechanism of an electric motor immersed in the storage part,
The housing includes a recessed portion that opens toward the inside of the housing (for example, a recessed portion 80 in an embodiment described later),
At least a part of the opening of the recessed portion is closed by a lid member provided separately from the casing and fixed to the casing,
A breather chamber (for example, a breather chamber 41 in an embodiment described later) that suppresses the liquid fluid in the casing from flowing out to the outside is formed by the recessed portion and the lid member.
The lid member and liquid introduction means (for example, first and second baffle plates 47A and 47B according to embodiments described later) for guiding the liquid fluid scattered from the rotating body to the electric motor are coupled to each other. To do.

In addition to the configuration described in claim 18, the invention described in claim 19 includes
The opening of the recessed portion is arranged facing the rotating body,
The lid is disposed between the recessed portion and the rotating body,
The lid portion overlaps the rotating body or a rotation locus of the rotating body in a radial direction.

In addition to the configuration described in claim 18 or 19, the invention described in claim 20 includes
The liquid introducing means includes a liquid introducing portion (for example, a top plate 47c in an embodiment described later) disposed above the rotating body and the electric motor,
An end portion (for example, a rotating body side end portion 47c1 of the embodiment described later) of the liquid introduction section passes through an end portion of the rotating body on the electric motor side and is orthogonal to the rotation axis (for example, Arranged on the rotating body side with respect to the rotating plane F1) of the embodiment described later,
An end portion (for example, an electric motor side end portion 47c2 of an embodiment described later) of the liquid introduction portion is a vertical plane (for example, an upper surface of an embodiment described later) passing through an end portion of the electric motor on the rotating body side. F2) is arranged closer to the electric motor than
A position (for example, a position Q1 in the embodiment described later) that intersects the plane of the liquid introducing section is higher than a position (for example, a position Q2 in the embodiment described later) that intersects the vertical plane of the liquid introducing section. It is characterized by being arranged in.

  According to the first aspect of the present invention, the rotating body and the electric motor are arranged so as to face the upper end of the rotating body and the upper end of the electric motor even when the electric motor is not positioned in the direction in which the liquid fluid is lifted up by the rotating body. The liquid fluid is guided to the electric motor by the liquid introducing means having the liquid introducing portion disposed on the upper side and extending from the rotating body side to the electric motor side, so that the electric motor can be reliably and efficiently cooled.

  According to the second aspect of the present invention, since the dropping position of the liquid fluid guided by the liquid guiding section can be set to a position where the electric motor is located, the liquid fluid guided to the liquid guiding section is dropped to the electric motor. And the electric motor can be efficiently cooled.

  According to the third aspect of the present invention, it is possible to prevent the liquid fluid lifted up by the rotating body from being scattered in the axial direction and to prevent the liquid fluid from entering the air gap of the electric motor. .

  According to the invention described in claim 4, since the height of the partition wall is higher than the trajectory of the rotating body and the uppermost end of the electric motor, it is possible to prevent the liquid fluid swirled by the rotating body from scattering in the axial direction. It is possible to prevent the liquid fluid from entering the air gap of the electric motor.

  According to the fifth aspect of the present invention, the rotating body and the electric motor can be partitioned into separate spaces while rotatably supporting the electric motor and the rotating body, and the member supporting the bearing and the partition wall portion are provided. There is no need to use separate members, and an increase in the axial direction can be prevented.

  According to the sixth aspect of the present invention, since the electric motor and the rotating body are arranged so as to overlap in the radial direction, liquid fluid is supplied from the rotating body to the electric motor while preventing expansion in the radial direction. Can do.

  According to the seventh aspect of the invention, the position and shape of the liquid introducing means can be optimally designed regardless of the electric motor, the rotating body, and the housing.

  According to the eighth aspect of the invention, the liquid introduction means can be disposed without interfering with the rotation of the electric motor and the rotating body by fixing the liquid introduction means to the housing.

  According to the ninth aspect of the present invention, since the fixing portion is disposed radially inward in the casing, it is possible to ensure a large fixing portion while preventing the casing from expanding in the radial direction.

  According to the tenth aspect of the present invention, since the fixing portion extends to a position where it overlaps the rotating body in the radial direction, the fixing portion can form another space partitioned from the rotating body in the axial direction. it can.

  According to the eleventh aspect of the present invention, the separate member forming the liquid introduction portion and the electric motor can be accommodated in the same casing.

  According to the twelfth aspect of the present invention, another space can be formed inside the housing by using the fixing portion for closing the recessed portion.

  According to the thirteenth aspect of the present invention, the pressure in the casing can be kept constant by providing the breather chamber in the casing.

  According to the fourteenth aspect of the present invention, by using the rotating body as one of the elements of the planetary gear mechanism, it is possible to perform speed change using the gear ratio of the planetary gear mechanism while cooling the electric motor.

  According to the invention described in claim 15, since the revolution locus of the large-diameter pinion has a larger radius than that of the ring gear, the liquid fluid can be scraped up using the large-diameter pinion. In other words, since the large-diameter pinion of the two-stage pinion can also be used for liquid fluid scooping, it is not necessary to provide a separate member, and the weight can be reduced.

  According to the sixteenth aspect of the present invention, when the sun gear is connected to the electric motor, an amount of liquid fluid corresponding to the number of rotations of the electric motor can be supplied.

  According to the seventeenth aspect of the present invention, when the carrier is connected to the wheel, an amount of liquid fluid corresponding to the number of rotations of the wheel can be supplied.

  According to the eighteenth aspect of the invention, the lid member that closes the recessed portion to form the breather chamber and the liquid introduction means that guides the liquid fluid from the rotating body to the electric motor are combined and integrated. The number of points can be reduced, and fixing of each member can be omitted as compared with the case of forming each independently.

  According to the nineteenth aspect of the present invention, since the rotating body and the recessed portion are partitioned by the lid member forming the breather chamber, the liquid fluid scattered from the rotating body is prevented from flowing into the recessed portion. can do.

  According to the twentieth aspect, the liquid fluid guided by the liquid introduction unit can be dropped onto the electric motor, and the supply of the liquid fluid to the electric motor can be realized without using another power.

1 is a block diagram showing a schematic configuration of a hybrid vehicle that is an embodiment of a vehicle equipped with a vehicle drive device equipped with a cooling mechanism for an electric motor according to the present invention. It is a longitudinal cross-sectional view of a rear-wheel drive device. FIG. 3 is a partially enlarged view of the rear wheel drive device shown in FIG. 2. It is a perspective view of the rear-wheel drive device attached to the frame member. It is a partial exploded perspective view of a rear-wheel drive device. FIG. 4 is a partially enlarged view of the rear wheel drive device shown in FIG. 3. It is a figure which shows the cooling mechanism of the electric motor described in patent document 1. FIG.

The motor cooling mechanism according to the present invention can be suitably used for a vehicle drive device. The vehicle drive device shown below uses an electric motor as a drive source for driving wheels, and is used in a vehicle having a drive system as shown in FIG. 1, for example. In the following description, a case where the vehicle drive device is used for rear wheel drive will be described as an example, but it may be used for front wheel drive.
A vehicle 3 shown in FIG. 1 is a hybrid vehicle having a drive device 6 (hereinafter referred to as a front wheel drive device) in which an internal combustion engine 4 and an electric motor 5 are connected in series at the front portion of the vehicle. While power is transmitted to the front wheel Wf via the transmission 7, the power of the driving device 1 (hereinafter referred to as a rear wheel driving device) provided at the rear of the vehicle separately from the front wheel driving device 6 is the rear wheel Wr ( RWr, LWr). The electric motor 5 of the front wheel drive device 6 and the first and second electric motors 2A and 2B of the rear wheel drive device 1 on the rear wheel Wr side are connected to the battery 9 to supply power from the battery 9 and to regenerate energy to the battery 9. Is possible. In FIG. 1, reference numeral 8 denotes a control device for controlling the entire vehicle.

First, the vehicle drive device of 1st Embodiment which concerns on this invention is demonstrated based on FIG.2 and FIG.3. The arrows in the figure indicate the positional relationship when the rear wheel drive device 1 is mounted on the vehicle.
FIG. 2 is a longitudinal sectional view of the entire rear wheel drive device 1, and FIG. 3 is an enlarged partial sectional view of the upper part of FIG. In the figure, reference numeral 11 denotes a case of the rear wheel drive device 1, and the case 11 is arranged on the left and right of the central case 11 </ b> M so as to sandwich the central case 11 </ b> M between the central case 11 </ b> M and the central case 11 </ b> M. It is comprised from the side cases 11A and 11B arrange | positioned, and the whole is formed in a substantially cylindrical shape. Inside the case 11 are axles 10A and 10B for the rear wheels Wr, first and second electric motors 2A and 2B for driving the axles, and first and second planets for decelerating the driving rotation of the electric motors 2A and 2B. The gear speed reducers 12A and 12B are arranged so that their rotation axes are located on the same straight line O. The axle 10A, the first electric motor 2A and the first planetary gear speed reducer 12A drive and control the left rear wheel LWr, and the axle 10B, the second electric motor 2B and the second planetary gear speed reducer 12B drive the right rear wheel RWr. Control. The axle 10A, the first electric motor 2A and the first planetary gear speed reducer 12A, and the axle 10B, the second electric motor 2B and the second planetary gear speed reducer 12B are arranged symmetrically in the vehicle width direction in the case 11. Yes.

  The side cases 11A and 11B are respectively provided with partition walls 18A and 18B extending radially inward on the central case 11M side, and the spaces surrounded by the side cases 11A and 11B and the partition walls 18A and 18B are respectively 1 and 2nd electric motor 2A, 2B are arrange | positioned. Further, first and second planetary gear speed reducers 12A and 12B are arranged in a space surrounded by the central case 11M and the partition walls 18A and 18B. In other words, the partitions 18A and 18B define a space for accommodating the first and second electric motors 2A and 2B and a space for accommodating the first and second planetary gear speed reducers 12A and 12B. A storage portion R that stores oil as a liquid fluid used for cooling the first and second electric motors 2 </ b> A and 2 </ b> B is formed at a lower portion in the vertical direction of the case 11. The upper surface of the oil stored in the storage portion R is set to be higher than the lowest point of the revolution trajectory of planetary gears 22A and 22B described later.

  As shown in FIG. 4, the case 11 is supported by support portions 13 a and 13 b of a frame member 13 that is a part of a frame that is a skeleton of the vehicle 3 and a frame of the drive device 1 (not shown). The support portions 13a and 13b are provided on the left and right with respect to the center of the frame member 13 in the vehicle width direction.

  The rear wheel drive device 1 is provided with a breather device 40 that communicates the inside and outside of the case 11 so that the air inside the case 11 escapes to the outside through the breather chamber 41 so that the air does not become excessively high temperature and pressure. Configured as follows. The breather chamber 41 is disposed in the upper part of the case 11 in the vertical direction, and includes an upper wall portion 11Mu of the central case 11M, a first cylindrical wall 43 extending substantially horizontally on the left side case 11A side in the central case 11M, A second cylindrical wall 44 extending substantially horizontally on the right side case 11B side, a left and right dividing wall 45 that connects the inner ends of the first and second cylindrical walls 43, 44, and a left side of the first cylindrical wall 43 A first baffle plate 47A attached to come into contact with the front end of the side case 11A, and a second baffle plate 47B attached to come into contact with the front end of the second cylindrical wall 44 on the right side case 11B. Consists of formed spaces.

  The first and second cylindrical walls 43, 44 and the left and right dividing walls 45 that form the lower surface of the breather chamber 41 are such that the first cylindrical wall 43 is positioned radially inward from the second cylindrical wall 44, and the left and right dividing walls 45 are A third cylinder that extends from the inner end of the second cylindrical wall 44 to the inner end of the first cylindrical wall 43 while being bent while reducing the diameter, and further extends radially inward and extends substantially horizontally. Reach wall 46. The third cylindrical wall 46 is located on the inner side of both outer end portions of the first cylindrical wall 43 and the second cylindrical wall 44 and substantially in the center thereof.

FIG. 5 is a partially exploded perspective view of the rear wheel drive device shown in FIG. In FIG. 5, only the left first baffle plate 47A and the first planetary gear speed reducer 12A are shown, but the right second baffle plate 47B and the second planetary gear speed reducer 12B have the same configuration.
Each of the first and second baffle plates 47A and 47B has a substantially annular shape in which a thin plate-like side wall 47a is opened at the lower end, and extends axially from the outer edge of the side wall 47a so as to surround the side wall 47a. Ribbed ribs 47b are provided. A fixing portion 47h extends from the side wall portion 47a to the outer diameter side above the side wall portion 47a, and two bolt holes 47f (only one is shown) are formed in the fixing portion 47h. The fixed portion 47h of the first baffle plate 47A is configured to partition the space between the first cylindrical wall 43 and the upper wall portion 11Mu of the central case 11M from the first planetary gear type speed reducer 12A. The fixing portion 47h of the plate 47B is configured to partition the space between the second cylindrical wall 44 and the upper wall portion 11Mu of the central case 11M from the planetary gear type speed reducer 12B.

  A top plate 47c extends from the upper outer edge of the fixing portion 47h so as to be inclined slightly downward from the horizontal direction. At the center of the top plate 47c, a notch 47d is provided so that the length of the top plate 47c is shortened on both sides in the circumferential direction, and the air in the case 11 passes through the notch 47d and the tip of the top plate 47c. It is configured to be introduced into the breather chamber 41. The top plate 47c is provided with recessed groove portions 47e on both sides of the notch 47d. The first and second baffle plates 47A, 47B are bolts 48 that pass through the two bolt holes 47f provided in the fixing portion 47h and the bolt holes 47f of the two attachment pieces 47g provided below the rib 47b. It is fixed to the central case 11M.

  2 and 3, an external communication path 49 that connects the breather chamber 41 and the outside is connected to the upper surface in the vertical direction of the breather chamber 41 in the central case 11M. The breather chamber side end portion 49a of the external communication passage 49 is arranged so as to be directed downward in the vertical direction. Accordingly, the oil is prevented from being discharged to the outside through the external communication passage 49.

  In the first and second electric motors 2A and 2B, stators 14A and 14B are fixed to side cases 11A and 11B, respectively, and annular rotors 15A and 15B are rotatably arranged on the inner peripheral sides of the stators 14A and 14B. Yes. Cylindrical shafts 16A and 16B as output shafts of the first and second electric motors 2A and 2B surrounding the outer periphery of the axles 10A and 10B are coupled to the inner peripheral portions of the rotors 15A and 15B. The cylindrical shafts 16A and 16B are connected to the axles. 10A and 10B are supported by end walls 17A and 17B and partition walls 18A and 18B of side cases 11A and 11B via bearings 19A and 19B so that they can rotate relative to each other coaxially. Further, the rotation position information of the rotors 15A and 15B is fed back to the control controllers (not shown) of the electric motors 2A and 2B on the end walls 17A and 17B on the outer periphery on one end side of the cylindrical shafts 16A and 16B. Resolvers 20A and 20B are provided.

  The first and second planetary gear speed reducers 12A and 12B include sun gears 21A and 21B, a plurality of planetary gears 22A and 22B meshed with the sun gear 21, and planetary carriers 23A that support these planetary gears 22A and 22B. , 23B and ring gears 24A, 24B meshed with the outer peripheral sides of the planetary gears 22A, 22B. The driving forces of the electric motors 2A, 2B are input from the sun gears 21A, 21B, and the decelerated driving forces are transmitted to the planetary carrier 23A, It is output to the axles 10A and 10B through 23B.

  The sun gears 21A and 21B are formed integrally with the cylindrical shafts 16A and 16B. Further, the planetary gears 22A and 22B have two series of first pinions 26A and 26B having large diameters directly meshed with the sun gears 21A and 21B, and second pinions 27A and 27B having smaller diameters than the first pinions 26A and 26B. The first pinion 26A, 26B and the second pinion 27A, 27B are integrally formed in a state of being coaxial and offset in the axial direction. The planetary gears 22A and 22B are supported by the planetary carriers 23A and 23B, and the planetary carriers 23A and 23B are supported so as to be integrally rotatable with the axially inner ends extending inward in the radial direction and being spline-fitted to the axles 10A and 10B. At the same time, the outer ends in the axial direction are supported by the partition walls 18A and 18B via bearings 33A and 33B. That is, the partition walls 18A and 18B support the bearings 33A and 33B that support the planetary gears 22A and 22B via the planetary carriers 23A and 23B, respectively, and the first and second electric motors 2A and 2B via the cylindrical shafts 16A and 16B. Bearings 19A and 19B are arranged.

  As the planetary carriers 23A and 23B rotate, the planetary gears 22A and 22B revolve while rotating, and at that time, the oil stored in the storage portion R located at the lower portion in the vertical direction of the case 11 is pumped up.

  The ring gears 24A and 24B have gear portions 28A and 28B that are meshed with the second pinions 27A and 27B whose inner peripheral surfaces are small diameters, and small diameters that are smaller than the gear portions 28A and 28B and that are opposed to each other at an intermediate position of the case 11. Parts 29A, 29B, and connecting parts 30A, 30B for connecting the axially inner ends of the gear parts 28A, 28B and the axially outer ends of the small diameter parts 29A, 29B in the radial direction. In the case of this embodiment, the radial outer edges of the ring gears 24A, 24B are set to be smaller than the maximum distance from the center of the axles 10A, 10B of the first pinions 26A, 26B.

  The gear portions 28A and 28B face each other in the axial direction with a third cylindrical wall 46 formed at the inner diameter side end portion of the left and right dividing wall 45 of the central case 11M. The outer diameter surfaces of the small diameter portions 29A and 29B are spline-fitted to an inner race 51 of a one-way clutch 50, which will be described later, and the ring gears 24A and 24B are connected to each other so as to rotate integrally with the inner race 51 of the one-way clutch 50. Configured.

  A space is secured between the second cylindrical wall 44 of the central case 11M constituting the case 11 and the gear portion 28B of the ring gear 24B, and a hydraulic brake 60 constituting braking means for the ring gear 24B is provided in the space. It arrange | positions so that it may overlap with the pinion 26B in radial direction, and it may overlap with the 2nd pinion 27B in an axial direction. The hydraulic brake 60 includes a plurality of fixed plates 35 that are spline-fitted to the inner peripheral surface of the second cylindrical wall 44 and a plurality of rotary plates 36 that are spline-fitted to the outer peripheral surface of the gear portion 28B of the ring gear 24B. These plates 35 and 36 are arranged to be fastened and released by an annular piston 37. The piston 37 is accommodated in an annular cylinder chamber formed between the left and right dividing walls 45 of the central case 11M and the third cylindrical wall 46, and is further provided with a receiving provided on the outer peripheral surface of the third cylindrical wall 46. The elastic member 39 supported by the seat 38 is constantly urged in a direction to release the fixed plate 35 and the rotating plate 36.

  More specifically, the working chamber S into which oil is directly introduced is defined between the left and right dividing walls 45 and the piston 37, and the pressure of the oil introduced into the working chamber S exceeds the urging force of the elastic member 39. The piston 37 moves forward (rightward), and the fixed plate 35 and the rotating plate 36 are pressed against each other and fastened. When the urging force of the elastic member 39 exceeds the pressure of the oil introduced into the working chamber S, the piston 37 moves backward (leftward movement), and the fixed plate 35 and the rotating plate 36 are separated and released. . The hydraulic brake 60 is connected to an electric oil pump 70 (see FIG. 4).

  In the case of this hydraulic brake 60, the fixed plate 35 is supported by the second cylindrical wall 44 extending from the left and right dividing walls 45 of the central case 11M constituting the case 11, while the rotating plate 36 is supported by the gear portion 28B of the ring gear 24B. Therefore, when the plates 35 and 36 are pressed by the piston 37, a braking force is applied to the ring gear 24B by the frictional engagement between the plates 35 and 36, and is fixed. When the fastening by the piston 37 is released from this state, the ring gear 24B is allowed to rotate freely. As described above, since the ring gears 24A and 24B are connected to each other, the braking force is also applied to the ring gear 24A when the hydraulic brake 60 is fastened, and the ring gear 24A is fixed when the hydraulic brake 60 is released. Free rotation is allowed.

  Also, a space is secured between the coupling portions 30A and 30B of the ring gears 24A and 24B facing each other in the axial direction, and only power in one direction is transmitted to the ring gears 24A and 24B in the space to transmit power in the other direction. A one-way clutch 50 is arranged to be shut off. The one-way clutch 50 has a large number of sprags 53 interposed between an inner race 51 and an outer race 52. The inner race 51 is connected to the small diameter portions 29A, 29B of the ring gears 24A, 24B by spline fitting. It is configured to rotate integrally. The outer race 52 is positioned by the third cylindrical wall 46 and is prevented from rotating.

  The one-way clutch 50 is configured to engage and lock the rotation of the ring gears 24A and 24B when the vehicle 3 moves forward with the power of the electric motors 2A and 2B. More specifically, the one-way clutch 50 is engaged when rotational power in the forward direction on the motors 2A, 2B side (rotation direction when the vehicle 3 is advanced) is input to the wheel Wr side. When the rotational power in the reverse direction on the electric motors 2A and 2B is input to the wheels Wr, the non-engagement state is established, and when the rotational power in the forward direction on the wheels Wr is input to the electric motors 2A and 2B, it is not engaged. The engaged state is established when the rotating power in the reverse direction on the wheel Wr side is input to the electric motors 2A, 2B while being engaged.

  Thus, in the rear wheel drive device 1 of the present embodiment, the one-way clutch 50 and the hydraulic brake 60 are provided in parallel on the power transmission path between the electric motors 2A, 2B and the wheels Wr. The hydraulic brake 60 is released, weakly engaged, or engaged by the pressure of oil supplied from the electric oil pump 70 in accordance with the running state of the vehicle and the engaged / disengaged state of the one-way clutch 50. Controlled. For example, when the vehicle 3 moves forward by powering drive of the electric motors 2A and 2B (at low vehicle speed and medium vehicle speed), the one-way clutch 50 is engaged, so that power can be transmitted but the hydraulic brake 60 is weakly engaged. Therefore, even when the input of forward rotational power from the motors 2A and 2B side temporarily decreases and the one-way clutch 50 is disengaged, the motors 2A and 2B Inability to transmit power to the wheel Wr side is suppressed. Further, when the vehicle 3 moves forward by power driving of the internal combustion engine 4 and / or the electric motor 5 (at the time of high vehicle speed), the one-way clutch 50 is disengaged and the hydraulic brake is controlled to be in a released state, so that the electric motor Over-rotation of 2A and 2B is prevented. On the other hand, when the vehicle 3 moves backward or regenerates, the one-way clutch 50 is disengaged, so that the hydraulic brake 60 is controlled to be in the engaged state, so that the rotational power in the reverse direction from the electric motors 2A and 2B is changed to the wheels Wr. Or forward rotational power on the wheel Wr side is input to the electric motors 2A and 2B.

Here, the cooling mechanism of the electric motor of the present invention will be described.
The planetary gears 22A and 22B described above function as a rotating body that scoops up the oil stored in the storage portion R, and the first and second baffle plates 47A and 47B use the first and second oils that are scooped up by the planetary gears 22A and 22B. It functions as a liquid introduction means that leads to the electric motors 2A and 2B. More specifically, when the planetary gears 22A and 22B, which are rotating bodies, revolve, the oil stored in the storage portion R is lifted up, and the oil scattered from the planetary gears 22A and 22B is the first liquid introduction means. And supplied to the first and second electric motors 2A and 2B via the second baffle plates 47A and 47B.

  At this time, the top plate 47c of the first and second baffle plates 47A and 47B functions as a liquid introduction part. The top plate 47c is disposed above the planetary gears 22A, 22B and the first and second electric motors 2A, 2B so as to face the upper ends of the planetary gears 22A, 22B and the upper ends of the first and second electric motors 2A, 2B. It extends from the 22A, 22B side to the first and second electric motors 2A, 2B side.

  Further, as shown in FIG. 6, in the second baffle plate 47B, the planetary gear side end 47c1 of the top plate 47c passes through the motor side end of the planetary gear 22B and is orthogonal to the straight line O that is the rotation axis of the planetary gear 22B. The motor-side end 47c2 of the top plate 47c is disposed on the planetary gear 22B side of the plane F1, and passes through the planetary gear-side end of the second electric motor 2B. From the vertical plane F2 orthogonal to the straight line O that is the rotation axis of the planetary gear 22B. Is located on the second electric motor 2B side, and the position Q1 that intersects the rotation plane F1 of the top board 47c is located above the position Q2 that intersects the vertical plane F2 of the top board 47c. Furthermore, the motor side end portion 47c2 of the top plate 47c is disposed above the second motor 2B in the vertical direction. The vertical plane F2 is a vertical plane passing through the planetary gear side end portion of the stator core constituting the stator 14B of the second electric motor 2B.

  Although not shown in FIG. 6, the positional relationship between the planetary gear 22A and the first electric motor 2A with respect to the first baffle plate 47A is the same, and the planetary gear side end of the top plate 47c of the first baffle plate 47A is the electric motor of the planetary gear 22A. It is disposed on the planetary gear 22A side with respect to the rotation plane orthogonal to the straight line O that is the rotation axis of the planetary gear 22A through the side end portion, and the motor side end portion of the top plate 47c passes through the planetary gear side end portion of the first electric motor 2A. The position that is disposed closer to the first electric motor 2A than the vertical plane that is orthogonal to the straight line O that is the rotational axis of the planetary gear 22A and that intersects the rotational plane of the top board 47c is greater than the position that intersects the vertical plane of the top board 47c. Arranged above. Furthermore, the electric motor side edge part of the top plate 47c is arrange | positioned in the perpendicular direction upper direction of the 1st electric motor 2A. The vertical plane is a vertical plane passing through the planetary gear side end portion of the stator core constituting the stator 14A of the first electric motor 2A.

  As a result, the oil pumped up by the planetary gears 22A and 22B is dropped onto the first and second electric motors 2A and 2B along the back surface of the top plate 47c. Therefore, even when the first and second electric motors 2A and 2B are not positioned in the direction in which the oil is lifted up by the planetary gears 22A and 22B, the first and second electric motors 2A and 2B can be reliably and efficiently operated. Can be cooled. The first and second baffle plates 47A and 47B as the liquid introducing means do not need to be provided with the side wall portion 47a, and it is sufficient if the top plate 47c as the liquid introducing portion is provided, and the fixing portion 47h is provided. It is preferable to provide.

  The first and second baffle plates 47A and 47B are fixed to the case 11 by the fixing portion 47h, so that the first and second motors 2A and 2B and the planetary gears 22A and 22B are not hindered from rotating. The baffle plates 47A and 47B can be arranged in the case 11. Further, since the fixing portion 47h extends radially inward from the top plate 47c, the fixing portion 47h can be secured large while preventing the case 11 from expanding in the radial direction. Furthermore, the lower end of the fixed portion 47h overlaps the rotation (revolution) trajectory of the planetary gears 22A and 22B in the radial direction, thereby forming another space partitioned from the planetary gears 22A and 22B in the axial direction by the fixed portion 47h. be able to.

  In this embodiment, inside the case 11, the first and second electric motors 2A, 2B are opened toward the planetary gears 22A, 22B so as to face the upper wall 11Mu of the central case 11M and the left side in the central case 11M. A first cylindrical wall 43 extending substantially horizontally on the case 11A side, a second cylindrical wall 44 extending substantially horizontally on the right side case 11B side, and the inner sides of the first and second cylindrical walls 43, 44 A recessed portion 80 composed of a left and right dividing wall 45 that connects the end portions is provided, and the opening of the recessed portion 80 is closed by the fixing portions 47h of the first and second baffle plates 47A and 47B. Thus, the breather chamber 41 is formed. Although this space does not necessarily need to be the breather chamber 41, the pressure in the case 11 can be kept constant by using the breather chamber 41.

  In other words, in this configuration, the breather chamber 41 includes a recessed portion 80 formed in the case 11, and a lid member that closes the recessed portion 80. The lid member that constitutes the breather chamber 41, the planetary gear 22A, It can also be said that the fluid introducing means for guiding the oil scattered from 22B to the first and second electric motors 2A, 2B is coupled.

  Further, the first and second baffle plates 47A and 47B are composed of separate members formed separately from the first and second electric motors 2A and 2B, the planetary gears 22A and 22B, and the case 11, and so on. Regardless, the position and shape of the first and second baffle plates 47A and 47B can be optimally designed.

  Furthermore, as described above, the partitions 18A and 18B allow the space for housing the first and second electric motors 2A and 2B and the space for housing the first and second planetary gear speed reducers 12A and 12B, particularly the planetary gears 22A and 22B. Is separated from the space for housing the oil, the oil pumped up by the planetary gears 22A and 22B can be prevented from splashing in the axial direction, whereby the air gaps of the first and second motors 2A and 2B can be prevented. It is possible to suppress the oil from entering. This effect is because the upper ends of the partition walls 18A and 18B are arranged above the imaginary line segment connecting the uppermost ends of the first and second electric motors 2A and 2B and the uppermost ends of the rotation trajectories of the planetary gears 22A and 22B. The plate 47c becomes more prominent by being disposed above the upper ends of the partition walls 18A and 18B.

  In the above embodiment, the rotating bodies are the planetary gears 22A and 22B of the first and second planetary gear speed reducers 12A and 12B. However, the rotating body is not limited to this, or in a direction in which the rotation axis is inclined with respect to the vertical direction, or It may be a rotating body arranged in an orthogonal direction (horizontal direction). For example, a normal gear or the like may be used. In this case, the rotation shaft of the gear is preferably arranged in the same straight line as the rotation shaft of the electric motor, and the upper end of the partition wall is higher than the imaginary line connecting the uppermost end of the electric motor and the uppermost end of the gear. It is preferable that the liquid introduction part is disposed above the upper end of the partition wall.

In addition, this invention is not limited to embodiment mentioned above, A deformation | transformation, improvement, etc. are possible suitably.
Further, the output shafts of the electric motors 2A and 2B and the axles 10A and 10B do not need to be arranged coaxially.
Further, the front wheel drive device 6 may use the electric motor 5 as a sole drive source without using the internal combustion engine 4.

  In the above-described embodiment, as the drive device to which the motor cooling mechanism is applied, the vehicle drive device including the first and second electric motors 2A and 2B that respectively drive and control the left and right rear wheels Wr (RWr, LWr) is illustrated. However, the present invention is not limited to this, and the present invention can also be applied to a drive device that drives and controls the left and right rear wheels with one electric motor, or a drive device that is not limited to a vehicle and includes one electric motor.

2A, 2B First and second motors (motors)
11 Case (housing)
11Mu upper wall portion 12A, 12B Planetary gear type reduction gear (planetary gear mechanism)
16A, 16B Cylindrical shaft (output shaft)
18A, 18B Partition (partition wall)
19A, 19B Bearing 21A, 21B Sun gear 22A, 22B Planetary gear (rotating body)
23A, 23B Planetary Carriers 24A, 24B Ring Gears 26A, 26B First Pinion (Large Diameter Pinion)
27A, 27B Second pinion (small pinion)
33A, 33B Bearing 41 Breather chamber (other space)
47A, 47B First and second baffle plates (liquid introducing means)
47c Top plate (liquid transfer part)
47c1 Rotating body side end portion 47c2 Electric motor side end portion 47h Fixed portion 80 Recessed portion R Reserving portion Wr Rear wheel (wheel)
F1 Rotation plane F2 Vertical plane

Claims (20)

An electric motor,
A housing for storing a liquid fluid used for cooling the electric motor, and a housing for housing the electric motor;
A rotating body housed in the housing and disposed in the vicinity of the electric motor, at least a part of which is immersed in the storage unit;
A liquid introduction means for guiding the liquid fluid to the electric motor, and a cooling mechanism for the electric motor,
The rotation axis of the rotating body is arranged in a direction inclined with respect to the vertical direction or in a direction orthogonal to the vertical direction,
The liquid introducing means includes a liquid introducing portion that is disposed above the rotating body and the electric motor so as to face the upper end of the rotating body and the upper end of the electric motor, and extends from the rotating body side to the electric motor side. ,
The end portion on the rotating body side of the liquid introduction portion is disposed on the rotating body side with respect to a plane orthogonal to the rotation axis through the end portion on the electric motor side of the rotating body,
The end portion on the electric motor side of the liquid introduction portion is disposed on the electric motor side with respect to a vertical plane passing through the end portion on the rotating body side of the electric motor,
A cooling mechanism for an electric motor, wherein a position of the liquid introduction section that intersects the plane is disposed above a position of the liquid introduction section that intersects the vertical plane.   The motor cooling mechanism according to claim 1, wherein the end portion of the liquid introduction section on the motor side is disposed vertically above the motor.   The motor cooling mechanism according to claim 1, wherein the casing includes a partition wall that is disposed between the rotating body and the electric motor and partitions the rotating body and the electric motor. The upper end of the partition wall portion is disposed above an imaginary line connecting the uppermost end of the electric motor, the uppermost end of the rotating body, and the uppermost end of the rotation locus of the rotating body, whichever is higher,
The cooling mechanism for an electric motor according to claim 3, wherein the liquid introduction part is disposed above an upper end of the partition wall part.   The motor cooling mechanism according to claim 3 or 4, wherein a bearing that rotatably supports the electric motor and the rotating body is arranged in the partition wall.   The motor cooling mechanism according to claim 1, wherein the rotating shaft of the electric motor and the rotating shaft of the rotating body are arranged on the same straight line.   The cooling mechanism for an electric motor according to any one of claims 1 to 6, wherein the liquid introducing means is a separate member formed separately from the electric motor, the rotating body, and the casing. .   The liquid introduction means includes a fixing portion that extends from the liquid introduction section and fixes the liquid introduction means to the housing in addition to the liquid introduction section. The cooling mechanism for an electric motor according to item 1.   The motor cooling mechanism according to claim 8, wherein the fixing portion extends downward from the liquid introduction portion.   The motor cooling mechanism according to claim 9, wherein a lower end of the fixed portion overlaps the rotating body or a rotation locus of the rotating body in a radial direction.   The said housing | casing is provided with the upper wall part which covers the upper direction of the said electric motor, and the upper direction of the said liquid introduction part, The cooling mechanism of the electric motor of any one of Claims 7-10 characterized by the above-mentioned. The housing has a recessed portion that opens toward the inside of the housing,
12. At least one part of opening of the said recessed part is obstruct | occluded by the said fixing | fixed part, and other space is formed by the said recessed part and the said fixing | fixed part. The cooling mechanism of the electric motor described.   13. The motor cooling mechanism according to claim 12, wherein the other space is a breather chamber that suppresses outflow of the liquid fluid in the casing to the outside. The electric motor drives the wheels of the vehicle;
The rotating body is disposed on a power transmission path between the electric motor and the wheel,
The rotating body includes any one element of a planetary gear mechanism including a sun gear, a plurality of planetary gears meshed with the sun gear, a planetary carrier that supports the plurality of planetary gears, and a ring gear meshed with an outer peripheral side of the plurality of planetary gears. The electric motor cooling mechanism according to claim 1, wherein the electric motor cooling mechanism is a motor cooling mechanism. The planetary gear is formed of a two-stage pinion including a large-diameter pinion that meshes with the sun gear and a small-diameter pinion that meshes with the ring gear.
The motor cooling mechanism according to claim 14, wherein the rotating body is the large-diameter pinion.   16. The electric motor cooling mechanism according to claim 14, wherein the sun gear is connected to an output shaft of the electric motor.   The cooling mechanism for an electric motor according to any one of claims 14 to 16, wherein the planetary carrier is connected to the wheel. An electric motor that drives the wheels;
A rotating body provided on a power transmission path between the electric motor and the wheel;
A storage section for storing a liquid fluid that cools the electric motor, and a housing that houses the electric motor and the rotating body,
At least a part of the rotating body is a cooling mechanism of an electric motor immersed in the storage part,
The housing has a recessed portion that opens toward the inside of the housing,
At least a part of the opening of the recessed portion is closed by a lid member provided separately from the casing and fixed to the casing,
A breather chamber that suppresses outflow of the liquid fluid in the housing to the outside is formed by the recessed portion and the lid member,
A cooling mechanism for an electric motor, wherein the lid member and liquid introducing means for guiding the liquid fluid scattered from the rotating body to the electric motor are coupled. The opening of the recessed portion is arranged facing the rotating body,
The lid is disposed between the recessed portion and the rotating body,
The cooling mechanism for an electric motor according to claim 18, wherein the lid portion overlaps the rotating body or a rotation locus of the rotating body in a radial direction. The liquid introducing means has a liquid introducing portion disposed above the rotating body and the electric motor,
The end portion on the rotating body side of the liquid introduction portion is disposed on the rotating body side with respect to a plane orthogonal to the rotation axis through the end portion on the electric motor side of the rotating body,
The end portion on the electric motor side of the liquid introduction portion is disposed on the electric motor side with respect to a vertical plane passing through the end portion on the rotating body side of the electric motor,
The cooling mechanism for an electric motor according to claim 18 or 19, wherein the position of the liquid introduction part intersecting with the plane is arranged above the position of the liquid introduction part intersecting with the vertical plane.

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