JPH0595606A - Power unit for motor-driven vehicle - Google Patents

Abstract

PURPOSE:To shorten wirings for connecting an electric motor to a driving circuit and to reduce in size the entire unit. CONSTITUTION:A power unit 50 for a motor-driven vehicle assembles an electric motor 52 in unit cases 51, 60 with at least parts of the cases 51, 60 as a motor case 60, so connects a rotational shaft 61 of the motor 52 to an output shaft 84 rotatably supported to the cases 51, 60 as to be able to transmit power, and transmits power to be output from the motor 52 from the shaft 84 to driving wheels. A heat sink 66 is provided in the case 60, and a switch element for controlling an energizing current to the motor 52 is mounted at the sink 66.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power unit for an electric vehicle, and more particularly to a power unit suitable for an electric motorcycle.

[0002]

2. Description of the Related Art As is well known, an electric vehicle uses an electric motor as a power source to transmit output power of the electric motor to drive wheels, and the electric motor drives the drive wheels to run. As an electric vehicle of this type, there are known electric motorcycles described in JP-A-54-38043 and JP-A-51-80848.

A power unit having an electric motor and a transmission mechanism assembled is indispensable for an electric vehicle as described above, particularly an electric motorcycle, and the applicant of the present invention has proposed a power unit for an electric vehicle suitable for a motorcycle. No. 181496 (submitted on July 13, 1991). A power unit for an electric vehicle according to this prior application accommodates a transmission mechanism such as a continuously variable transmission in a unit case, and a motor case of an electric motor is coupled to the unit case with a bolt or the like so that a rotating shaft of the electric motor does not exist. It is configured by connecting with a gear transmission. Then, a drive circuit connected to the electric motor by wiring is provided on the vehicle body or the like, and the electric motor is energized from this drive circuit.

[0004]

Generally, in a power unit for an electric vehicle, a relatively large output torque is required for the electric motor, and a high current must be passed through the electric motor. Therefore, in the power unit for an electric vehicle in which the drive circuit as described in the above-mentioned prior application is arranged on the vehicle body side, the drive circuit on the vehicle body side and the electric motor must be connected by a long wiring, which causes a voltage drop. Is large, and electromagnetic noise countermeasures are complicated. The present invention has been made in view of the above problems, and an object of the present invention is to provide a power unit for an electric vehicle that can reduce the voltage drop of the voltage applied to the electric motor and that can easily prevent electromagnetic noise.

[0005]

In order to achieve the above object, the invention according to claim 1 assembles an electric motor in a unit case using at least a part of the unit case as a motor case, and rotates the electric motor. A power unit for an electric vehicle in which a shaft is connected to an output shaft rotatably supported in a unit case so as to be capable of transmitting power, and the power output from the electric motor is transmitted to driving wheels from the output shaft. Is provided, and a switch element for switching the electric current supplied to the electric motor is attached to the heat sink to form a drive circuit.

According to a second aspect of the present invention, in addition to the first aspect of the invention, a cover member is attached to the heat sink to cover a portion where the switch element is attached, and the cover member and the heat sink are attached. A structure is adopted in which a resin is filled between the two and fixed to each other, and the heat sink is fixed to the motor case.

The invention described in claim 3 is the same as claim 1
Alternatively, on the premise of the configuration according to claim 2, the unit case is divided into a motor case and a case body in an axial direction of the rotary shaft between end portions of the rotary shaft, and the motor case has one end portion of the rotary shaft. A bearing that rotatably supports, a rotation sensor that detects the rotation of the rotation shaft, and the heat sink, and that this heat sink is on one side in the rotation axis axial direction of the bearing and the rotation sensor is on the other side in the rotation axis axial direction of the bearing. Add the configuration to be placed.

Further, in the invention described in claim 4, on the premise of the invention described in claim 3, the stator of the electric motor is fixed to the motor case, and the stator and the rotation sensor are arranged in the rotation axis direction. It is configured to be placed adjacent to.

Furthermore, the invention described in claim 5 is based on the invention described in claim 1, and the connection terminal is provided on the surface of the motor case on the heat sink side, and similarly, the surface of the heat sink on the motor case side. In addition to providing a power supply terminal to the motor case, a plate member is provided at a predetermined position between the motor case and the heat sink, and the power supply terminal of the heat sink and the connection terminal of the motor case are electrically connected to this plate member. A terminal was provided to connect the terminals.

[0010]

According to the first aspect of the invention, the heat sink is provided in the unit case close to the electric motor, and the switch element constituting the drive circuit is attached to the heat sink. Therefore, the wiring connecting the drive circuit and the electric motor is provided. It can be shortened, the voltage drop can be reduced, and the countermeasure against electromagnetic noise is easy. Since the switch element is attached to the heat sink provided in the unit case, a dedicated supporting member is not required to support the drive circuit, the number of parts can be reduced, and the size can be reduced.

Further, according to the second aspect of the present invention, since the portion of the heat sink to which the switch element is attached is covered with the resin, the switch element is protected without impairing the cooling property and without increasing the weight. can do. Furthermore, in the invention according to claim 3, the motor case is divided from the case body, and the heat sink, the bearing, and the rotation sensor are arranged in the motor case in the axial direction of the rotating shaft, so that further miniaturization can be achieved, and It is also possible to assemble a heat sink or the like in advance in the split case to facilitate the assembly.

Further, according to the invention of claim 4, since the stator of the electric motor is also fixedly mounted in the split case, the electric coils such as the stator coil, the rotation sensor and the drive circuit are unitized. It can be assembled, its assembly can be performed more easily, and the wiring can be simplified.

According to the present invention, the terminals of the motor case and the terminals of the heat sink are electrically connected to each other through the terminals, so that wiring is not required and the motor case and the heat sink can be easily assembled. it can.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 7 show a power unit for an electric vehicle according to an embodiment of the present invention, and FIG. 1 is a side view of an electric motorcycle equipped with the power unit for an electric vehicle.
Is a cross-sectional view of the power unit for an electric vehicle, FIG. 3 is an enlarged view in which a part of the main part is cut away, and FIG. 4 is a side view of the main part.
Is a side view of the main part, FIG. 6 is an exploded perspective view in which a part of FIG. 5 is enlarged, and FIG. 7 is an electric circuit diagram.

In FIG. 1, reference numeral 11 denotes a body frame having a substantially U-shape in side view, and the body frame 11 includes a front frame 11f, a center frame 11d and a rear frame 1.
Has 1r. The body frame 11 includes a front cover 21f, a leg shield 21a, a step floor 21.
It is covered with a synthetic resin body 21 including a rear cover 21c, a rear cover 21c, and an under cover 21d.

The body frame 11 includes a front frame 1
The head tube 12 is fixed to the front part of the 1f, and the front wheel 14 is attached to the head tube 12 via the front fork 13.
f is supported by the steering handle 15 so as to be steerable. The steering handle 15 has an accelerator grip 15a, and a potentiometer 15b for detecting an operation angle of the accelerator grip 15a is attached to the steering handle 15 (see FIG. 7).

A control box 16 is attached to the front portion of the head tube 12, and the front of the control box 16 is covered with a front cover 21f. A controller 49 including an ECU and the like is housed inside the control box 16. The potentiometer 15b described above is connected to the controller 49,
In addition, a charging circuit, a drive circuit, a battery, etc. described later are connected.

A battery box 22 is provided in the center frame 11d of the body frame 11, and a power swing unit (power unit for electric vehicle) 50 is swingably supported by a pivot shaft (not shown) at the rear portion of the center frame 11d. It The power swing unit 50 includes an electric motor 52 in a case 51 as described later.
The rear wheel 14r is rotatably supported at the rear end of the case 51. Reference numeral 99 is a cushion unit provided between the rear portion of the power swing unit 50 and the vehicle body frame 11.

The battery box 22 is mounted on a battery holder 23 fixed to the center frame 11d,
Fastened with band 24. A plurality of batteries 36 (see FIG. 7) are housed inside the battery box 22, and the batteries 36 are connected in parallel or in series and connected to a drive circuit described later, the controller 49 described above, and the like.

Although not clearly shown in the figure, the battery holder 23 is made of a plate-like member which is installed in the lower portion of the center frame 11d in the vehicle width direction, and a band is mounted on the battery box 22 mounted on the battery holder 23. The step floor 21b described above is fixed via 24.

Further, the above-mentioned rear cover 21c is fixed to the rear frame 11r of the vehicle body frame 11. The rear cover 21c has a substantially hollow cylindrical shape with an open top, and a seat 26 is supported on the top so that the opening can be closed. The seat 26 has a hinge at the front portion thereof and the rear cover 21.
Attached to the upper part of c and ready to sit (see Fig. 1)
Closes the opening of the rear cover 21c, and opens the opening of the rear cover 21c in a state of being tilted forward.

In the rear cover 21c, a trunk box 25 and a charging box 27 are housed in the front and rear directions above and diagonally above the rear wheel 14r. An upper portion of the trunk box 25 is opened, and the upper opening is covered with the seat 26 so as to be openable and closable. The trunk box 25 has a size and volume capable of accommodating a helmet.

The charging box 27 has a substantially L shape in a side view with its front portion protruding upward, and its upper front portion is open. The charging box 27 accommodates a charger or the like for charging from a commercial AC power supply inside, and a front upper opening is covered with a lid 28 so as to be openable and closable. A charging circuit 97 is provided on one surface of the lid 28, and the charging circuit 97 and the charger are connected to the battery 36 and the like.

In FIG. 1, reference numeral 88 denotes an intake duct arranged in the rear cover 21c. One end of the intake duct 88 is connected to the cooling air inlet of the power swing unit 50 and the other end is opened in the rear cover 21c. To do.

As shown in FIG. 2, the power swing unit 50 includes a case body 51 whose front end is swingably supported by the vehicle body frame 11, an electric motor 52, and a continuously variable transmission 5.
3 and the final reduction mechanism 54 are integrally assembled. The case body 51 is formed by casting an aluminum alloy or the like, and has a recess 51a on the front right side and a recess 51b on the rear left side.

In the case body 51, a motor case 60 is fixed in a recess 51a on the front right side, and an electric motor 52 is provided.
Of the motor chamber 31 that accommodates the gearbox 58 that accommodates the final reduction mechanism 54 with the bearing member 57 fixed to the recess 51b on the left side of the rear portion, and the side cover 55 is fixedly provided on the left side. A shift chamber 56 that accommodates the gear transmission 53 is defined. The above-mentioned motor chamber 31 and the shift chamber 56 communicate with the case main body 51 in a ventilable manner through a through hole 34 formed in the vicinity of the bottom surface of the recess 51a, and the shift chamber 56 is opened to the atmosphere from an exhaust port (not shown). It

The case main body 51 is shown in FIGS.
It is also possible to configure in a mode as shown in FIG. As shown in the figure, in this case body 51, a boss 51e is formed in the center of the bottom surface of the recess 51a, and a plurality of spoke-like ribs 51f are formed on the left side surface from the boss 51e outward in the radial direction. The above-mentioned through hole 51g is formed between these ribs 51f. A through hole 51h is formed in the boss 51e, and a rotary shaft 61 of an electric motor, which will be described later, penetrates through the through hole 51h. The through hole 51g is formed corresponding to a cooling fan to be described later, and the cooling air flows into the transmission chamber 56 through the through hole 51g. In addition, in FIG. 10, 51i is a rib for improving rigidity.

The motor case 60 has a bottomed cylindrical shape with one end opened, and the motor case 60 is fixed to the case body 51 with a bolt 30 so that the opening matches the opening of the recess 51a to define a motor chamber 31. A bearing 32 is provided at the bottom of the motor case 60, and a rotating shaft 61 is rotatably installed in the motor chamber 31 by the bearing 32 and a bearing 33 provided at the bottom of the recess 51 a of the case body 51.

The rotary shaft 61 has one end penetrating the bottom of the recess 51a and connected to the continuously variable transmission 53 in the transmission chamber 56, and the other end penetrating the bottom of the motor case 60. This rotating shaft 6
In FIG. 1, the cooling fan 59 is provided at a position in the motor chamber 31 that is close to the bottom of the recess 51 a and faces the through hole 34.
A rotor 63 made of a magnet is fixedly installed at the center position of the motor case 60, and a rotation sensor 70 is attached to the end portion of the motor case 60 penetrating the bottom portion. As is well known, the rotor 63 is composed of a magnet and is located inside the stator.

The cooling fan 59 rotates integrally with the rotating shaft 61 and radiates cooling air from the intake duct 88 to the motor chamber 31.
The cooling air is sent to the transmission chamber 56 from the holes 34. The rotation sensor 70 is composed of a magnet fixed to the rotation shaft 61 and a magnetic sensitive element such as an MR element attached to the bottom right surface of the motor case 60, and the magnetic sensitive element is connected to the controller 49. This rotation sensor 7
0 detects the rotational position, rotational speed, etc. of the rotary shaft 61.

In the motor case 60, the motor chamber 3
Three stator coils 62 forming a stator are fixedly provided on the left side of the first side, and a heat sink 66 is fixed to the right side. The three stator coils 62 are Y-connected (see FIG. 7), and the three terminals are connected to a drive circuit described later. The motor case 60 corresponds to a divided case and constitutes a unit case together with the case body 51.

As shown in detail in FIGS. 3 to 5, the heat sink 66 is made of an extruded material of aluminum alloy having a substantially hexagonal cross section with a hexagonal cross section, and a large number of cooling fins 67 are formed on the inner circumference. There is. This heat sink 66
Attach the three bolts 98 that penetrate in the axial direction to the motor case 60.
It is fixed to the motor case 60 by being screwed on and the periphery is covered with a cover 65 (cover member) made of resin.

The cover 65 accommodates the substrate 47 in which the gate drive circuit 48 is provided, and the heat sink 66.
It is fixed to the heat sink 66 with a resin 46 such as epoxy filled between the heat sink 66 and the outer surface of the heat sink 66. An intake port is formed in the cover 65, and the intake duct described above is connected to the intake duct 88. The heat sink 66 can also be formed by casting an aluminum alloy.

The heat sink 66 has a total of six field effect transistors (F), one on each of the six outer surfaces.
ET) 35a, 35b, 35c, 35d, 35e, 35
f (hereinafter, represented by a number without a subscript if necessary) is provided to configure the drive circuit 64, and a capacitor 68 for stabilizing the power source is arranged on the inner peripheral portion. A cooling air passage 37 communicating with the intake duct 88 is formed between the condenser 68 and the inner peripheral portion of the heat sink 66, and the above-described cooling fin 67 projects into the cooling air passage 37. As shown in FIG. 7, the capacitor 68 is connected in parallel with the drive circuit 64 between the plus and minus terminals of the battery 36. The FET 35 may be composed of a plurality of FETs each connected in parallel.

The drive circuit 64, as shown in FIG.
T35 is connected in a bridge shape, and the source of FET 35a and the drain of FET 35d, the source of FET 35b and the drain of FET 35e, the source of FET 35c and F
The drain of the ET 35f is connected in a bridge shape. In the drive circuit 64, the wiring 40 connected to the positive terminal of the battery 36 is arranged on one side of the outer circumference of the heat sink 66, and the wiring 41 connected to the negative terminal of the battery 36 is arranged on the other side of the outer circumference of the heat sink 66. , FE
The drains of T35a, 35b, and 35c are connected to the wiring 40 and F
The sources of the ETs 35d, 35e, 35f are connected to the wiring 41.

Further, as shown in detail in FIGS. 2 and 3,
Terminals 39 are connected between the source and drain of these FETs 35 and are drawn out to the case body 51 side, and the end portions of these three terminals 39 are respectively insulators 43.
And is fastened to the end surface of the heat sink 66 with the bolt 42. These bolts 42 are inserted from the case body 51 side into the inner circumference of the heat sink 66, and the end portions thereof are covered by the cover 6
5 penetrates the boss portion 65b that is provided so as to project toward the inner circumference of the heat sink 66 and projects to the outside of the cover 65. These three bolts 42, as shown in FIG.
One of them is located at the uppermost portion in the vertical direction on the inner periphery of the above, and is arranged at substantially equal intervals in the circumferential direction, and the other two are located above the lowermost portion in the vertical direction.

Each of the bolts 42 has a case body 51.
One end on the side is electrically insulated from the heat sink 66 via the insulator 43 and electrically connected to the terminal 39, and the other end is connected to the terminal 38 outside the cover 65. As shown in FIG. 6, the terminal 38 is disposed between a pair of rotation preventing ribs 65b integrally formed on the outer surface of the cover 65,
It is fixed to the bolt 42 by a nut 44 screwed to the end of the bolt 42 and electrically connected to the bolt 42. Each of these terminals 38 is connected to the stator coil 62 by a wiring 45 arranged on the inner circumference of the heat sink 66, and is connected to the bolt 42.
And the terminal 39 to connect between the source and drain of the FET 35. The FET 35, the terminal 39, and the wiring 40 for connecting to the battery 36 are covered with the above-mentioned resin 46 filled between the outer periphery of the heat sink 66 and the cover 65.

Further, the gate of each FET 35 is connected to the gate drive circuit 48 of the substrate 47. As shown in FIG. 7, the gate drive circuit 48 includes a booster circuit and the like, and is connected to the above-described controller 49 and outputs a drive signal to the FET 35 based on the output signal of the controller 49. In FIG. 7, 15b is an accelerator sensor that detects the operation angle of the accelerator grip 15a, 95 is a brake sensor that detects the actuation of the brake, 96 is a vehicle speed sensor that detects the vehicle speed, and these sensors 15b, 95, 96 are It is connected to the controller 49.

The continuously variable transmission 53 comprises a drive pulley 72 and a driven pulley 73, and a belt 74 mounted between the drive pulley 72 and the driven pulley 73. The drive pulley 72 is provided on the rotating shaft 61 of the electric motor 52, and the driven pulley 73 is provided on the input shaft 71 of the final reduction mechanism 54 so as to be rotatable.
It is attached to 8. The driven pulley 73 includes a first centrifugal clutch 75 and a second centrifugal clutch 76 on the input shaft 71.
And are connected in parallel.

The drive pulley 72 is composed of a fixed face 72a fixed to the rotating shaft 61 and a movable face 72b provided on the rotating shaft 61 so as to be movable in the axial direction.
In the drive pulley 72, the movable face 72b is driven by a governor mechanism 77 having a weight 77a to move in the axial direction, and the belt 7 moves in accordance with the rotation speed of the rotating shaft 61.
The winding diameter of 4 changes.

Similarly, the driven pulley 73 is composed of a fixed face 73a fixed to the sleeve 78 and a movable face 73b supported by the sleeve 78 so as to be movable in the axial direction. In the driven pulley 73, the movable face 73b is urged toward the fixed face 73a by a spring 80a that is compressed between the movable face 73b and the clutch outer 79 of the second centrifugal clutch 76, so that the belt winding diameter of the drive pulley 72 changes. Accordingly, the movable face 73b moves to change the belt winding diameter.

In the second centrifugal clutch 76, the clutch outer 79 is fixed to the sleeve 78, and the clutch inner 80 is provided on the clutch outer 81 of the first centrifugal clutch 75. The second centrifugal clutch 76 is the first centrifugal clutch 7
The clutch outer 81 of No. 5 is connected or disconnected according to the rotation speed. In addition, the first centrifugal clutch 75 includes the clutch outer 8
1 is fixed to the input shaft 71, and the clutch inner 82 is the second
It is provided on the clutch outer 79 of the centrifugal clutch 76, and disconnects according to the rotation speed of the clutch outer 79 of the second centrifugal clutch 76. The first centrifugal clutch 75 is connected at a rotational speed slightly lower than the maximum efficiency generating rotational speed of the electric motor 52, and the second centrifugal clutch 76 is connected at a rotational speed lower than the rotational speed to which the first centrifugal clutch 75 is connected. The detailed structure of the first and second centrifugal clutches 75 and 76 will be omitted.

The final reduction mechanism 54 has a gear 71a fixed to the input shaft 71 and gears 83a, 83 fixed to the intermediate shaft 83.
b and a gear 84a fixed to the output shaft 84, the gear 71a meshes with the gear 83a, and the gear 83b meshes with the gear 84a. The input shaft 71 is rotatably supported by the case 51 and the bearing member 57, and the left end projects into the transmission chamber 56 and is connected to the continuously variable transmission 53 as described above. The output shaft 84 projects to the right of the case 51, and the rear wheel 14 is fixed to the end of the output shaft 84.

Next, the operation of this embodiment will be described. In this electric motorcycle, the drive circuit 64 supplies the electric power of the battery 36 to the electric motor 52 of the power swing unit 50, and the electric motor 52 drives the rear wheel 14r to travel. Then, the controller 49 arithmetically processes the output signals of the accelerator sensor 94 and the vehicle speed sensor 96 to supply power to the electric motor 52, and controls the electric motor 52 based on the operation of the accelerator grip 15a and the vehicle speed.

Here, the power swing unit 50 is
A recess 51a is formed in the case body 51, a motor case 60 is joined to the recess 51a of the case body 51 to define a motor chamber 31, and a rotary shaft 61 and a stator coil 62 are housed in the motor chamber 31. To assemble the electric motor 52. Then, the heat sink 66 is fixed to the motor case 60, and the FET 35 forming the drive circuit 64 is attached to the heat sink 66. Therefore, the wiring 45 that connects the stator coil 62 and the drive circuit 64 can be shortened, and a dedicated component for mounting the drive circuit 64 is not required, and the size can be reduced.

In the power swing unit 50, the motor case 60 is formed into a bottomed cylindrical shape having a joint surface with the case body 51 at an axially intermediate portion of the rotary shaft 61, and the heat sink 66 is formed on the motor case 60. , Rotary shaft 6
One bearing 32 and the rotation sensor 70 are provided. Therefore, the number of parts as a whole can be reduced, and further downsizing can be achieved.

In order to fix the stator coil 62 constituting the stator to the motor case 60, this stator coil 62, the above-mentioned rotation sensor 70, etc. are assembled in advance in the motor case 60, and the motor case 60 is replaced by the stator coil 62, etc. It can be attached to the case body 51 in an assembled state, and the assembling becomes easy.

Furthermore, this power swing unit 50
In addition, the heat sink 66 is formed in a substantially hexagonal cross section, and the FET 35 constituting the drive circuit 64 is attached to the outer surface,
The outer surface of the heat sink 66 is covered with a cover 65, and resin is filled between the cover 65 and the heat sink 66.
The T35, the terminal 39 and the like are covered. Therefore, FE
T35 etc. can be firmly fixed, and FET3 from dust and water.
5 can be effectively protected.

Furthermore, the stator coil 60 of the electric motor 52 and the drive circuit 64 are connected to each other through three bolts 42 which are inserted into the inner circumference of the heat sink 66 at equal intervals in the circumferential direction. It is arranged so as not to be located at the lowermost vertical portion of 66. Therefore, even if water that has entered the lower part of the heat sink 66 is retained, no inconvenience such as electric contact occurs.

Since the bolt 42 is inserted into the boss portion 65b of the cover 65 and the distance between the bolt 42 and the fin 67 of the heat sink 66 is maintained, an insulating collar or the like is not required and the number of parts can be reduced. Since a rib 65b for preventing rotation of the terminal 38 is integrally formed therewith, connection work of the terminal 38 is easy.

FIG. 8 shows a power unit for an electric vehicle according to another embodiment of the present invention. Note that FIG. 8 is an enlarged cross-sectional view of a main part, and the same parts as those in the above-described embodiment are designated by the same reference numerals, and illustration and description thereof will be omitted.

As shown in the figure, in this embodiment, a heat sink 66 is formed integrally with the motor case 60. The motor case 60 has a bearing portion 60a at the center in the axial direction.
Heat sink 66 on the right and stator coil 62 on the left.
Is formed with a cylindrical portion 60b. Bearing part 60a
Is provided with a bearing 32 that supports the rotating shaft 61.
A rotation sensor 70 is provided near the left side of the bearing 32.

In this embodiment, the heat sink 66
Is integrally formed with the motor case 60, the number of parts can be further reduced and the assembly can be easily performed. Further, since the rotation sensor 70 is arranged on the side opposite to the heat sink 66, these interferences can be prevented and the size can be further reduced.

12 to 20 show still another embodiment of the present invention. FIG. 12 is an exploded perspective view of a main part, FIG. 13 is a view taken along arrow 13-13 of FIG. 12, and FIG. 14 is a cross section of a heat sink. FIG. 15, FIG. 15 is a view as seen from the arrow 15-15 of FIG. 14, FIG. 16 is a part view of main parts, FIG. 17 is a part view of other main parts, FIG. 18 is a partially enlarged view, and FIG. FIG. 19 is a sectional view taken along arrow 19-19, and FIG. Also in this embodiment, the same parts as those in the above-mentioned embodiment are designated by the same reference numerals and the description thereof will be omitted.

In this embodiment, the motor case 60 is formed into a tubular shape with both left and right ends open, and a coil 62 wound around a core 221 (see FIG. 21 of an embodiment described later) is housed in the motor case 60. And fix it. As shown in detail in the figure, the core 221 is provided with three connection terminals 521 on the right end surface thereof at regular intervals in the circumferential direction. A nut 521a (see FIG. 19) is fixed to these connecting terminals 521,
As apparent from the circuit diagram of FIG. 7 described above, the coil 62 is connected to the three terminals of the Y-connected coil 62. This connection terminal 52
1 is a fixing screw 25 to the nut 521a as described later.
5 is screwed on and the terminal 260 is fixed by the fixing screw 255.
Electrically connected to.

A mounting member 210 is fixed to the right end opening of the motor case 60, and a heat sink 66 is attached to the mounting member 210 via a terminal plate (plate member) 240.
Is attached. The mounting member 210 has a Y-shape in which three spokes 211 and a boss 212 are integrally molded, and the spokes 211 are fixedly mounted on the mounting member 210 while being positioned between the connection terminals 521. .. This mounting member 21
No. 0 has a mounting boss 211a formed with a screw hole on the tip side of each spoke portion 211, and a through hole 212a for supporting the rotating shaft is formed in the boss portion 212. This through hole 21
A rotary shaft 61 is rotatably inserted into the 2a via a bearing 32. It should be noted that, as will be described in Examples described later, FIG.
Inside, 70a is a magnetically sensitive element.

As shown in FIGS. 16 to 20, the terminal plate 240 has an annular plate shape made of an electrically insulating material, and three nut holder portions 241 are radially inwardly arranged on the inner peripheral portion thereof. Projected at intervals. The nut holder portion 241 is formed with a rectangular recess 241a having an opening on the right side, and an alignment groove 241b is formed in a side wall portion on the counterclockwise side of the recess 241a.

In the terminal plate 240, the square nuts 25 are provided in the recesses 241a of the nut holders 241 respectively.
0 is loosely fitted, and a connecting bolt 251 described later is screwed into the square nut 250 to attach the terminal 260. The recess 241 a is larger than the size of the square nut 250 and allows a predetermined rattling of each nut 250. This recess 2
41a and the square nut 250 have, for example, the recess 2
If one side of 41a is 10, one side of the square nut 250 is set to about 9.5, and in this case, the diameter of the insertion hole of the terminal 260, which will be described later, is 6 and the diameter of the connecting bolt 251 is set to be 6. Set to 5. Incidentally, the above-mentioned recess 2
It is also possible to configure 41a as a square hole penetrating therethrough.

As shown in FIGS. 17 and 18 to 20, the terminal 260 is formed by molding a conductive material such as brass into a step shape by a press or the like, and the insertion holes 26 are formed in the step portions, respectively.
0a, 260b are formed, and a projection 260c for alignment is formed on the insertion hole 260a side. This terminal 260 has a projection 260c fitted in the groove 241b, and its position is defined. The terminal bolt 260 is screwed into the square nut 250.
51 is inserted into the insertion hole 260a, and the fixing screw 255 screwed to the nut of the connection terminal 521 described above is inserted into the insertion hole 2a.
Insert through 60b. As shown in the figure, this terminal 260 is provided with a fixing screw 255 to connect the terminal 5 of the electric motor 52.
21 and is electrically connected to each other, and electrically connected to the power supply terminal 39 of the heat sink 66 by the connecting bolt 251 as described later (see FIG. 20).

As shown in FIGS. 13 to 15, the heat sink 66 has three power supply terminals 39 arranged and exposed at the left end face at equal intervals, and the connecting bolt 251 and the fixing bolt 299 are arranged from the right side. Penetrate. As shown in FIG.
The connection bolt 251 is screwed into the square nut 250 of the terminal plate 240 to connect the terminal 260 and the power supply terminal 3 to each other.
9 and 9 are electrically connected. Also, the fixing bolt 299
Is a boss portion 211a of the spoke portion 211 of the mounting member 210
The heat sink 66 is screwed into the screw hole of the mounting member 21.
0, that is, fixed to the motor case 60.

In this embodiment, the heat sink 66
When attaching to the motor case 60 of, the terminal 260 is first projected onto the right side of the terminal plate 240.
0c is locked in the groove 241b on the side wall of the recess 241a, and in this state, the fixing screw 255 is inserted through the insertion hole 260b and screwed into the nut of the connection terminal 521 of the electric motor 52.
The terminal plate 240 is sandwiched between the terminal 260 and the mounting member 210. At this time, as shown in FIG. 20, the connection terminal 521 and the terminal 260 are electrically connected and contact each other.

Thereafter, the fixing bolt 299 and the connecting bolt 251 are penetrated from the right side of the mounting member 210, the fixing bolt 299 is inserted into the screw hole of the boss portion 211a of the mounting member 210, and the connecting bolt 251 is inserted into the terminal plate. 24
The square nut 250 of 0 is screwed. Therefore, the heat sink 66 is attached to the motor case 60, that is, the mounting member 210.
Fixed to the terminal 260, as shown in the figure.
And the power supply terminal 39 contact each other while maintaining an electrical connection.

As described above, in this embodiment, the power supply terminal 39 of the heat sink 66 and the connection terminal 521 of the electric motor 32 are connected to the terminal 26 of the terminal plate 240.
With 0, electrical conduction can be achieved without using wiring. Therefore, when assembling the heat sink 66, wiring connection work and the like are unnecessary, and the assembling can be performed easily.

FIGS. 21 to 24 show still another embodiment of the present invention. FIG. 21 is a sectional view of an essential part, FIG. 22 is a right side view of the essential part, and FIG. 23 is a partially enlarged side view. 24 is a sectional view taken along the line 24-24 in FIG. In this embodiment as well, the same parts as those in the previous embodiment are designated by the same reference numerals and the description thereof will be omitted.

In this embodiment, the condenser 68 is provided on the inner peripheral portion of the heat sink 66 by a mounting stay 681.
As shown in detail in the figure, the mounting stay 681 has an annular band portion 681a and a stopper portion 681b, the annular band portion 681a fastens the outer peripheral portion of the capacitor 68 with a screw 683, and the stopper portion 681b is connected to the capacitor 68.
To the left end face of the. The attachment stay 681 is fixed to the right end surface of the heat sink 66 with screws 682 at three points, and attaches the capacitor 68 to the heat sink 66.
As shown in FIG. 21, the capacitor 68 is arranged such that its right end face is located to the left of the right end face of the heat sink 66, that is, is completely buried in the inner peripheral portion of the heat sink 66, and is also connected. The terminal 68a is located on the left side, that is, the portion where the connection terminal 68a is provided is directed to the left (see FIG. 13).

In this embodiment, as shown in FIGS. 23 and 24, in the rotation sensor 70, the magnetic sensitive element 70a is attached to the annular sensor stay 710 with the screw 712, and the sensor stay 710 is attached with the bolt 711. Then, as is apparent from FIG.
a is covered with resin and protrudes to the right at a predetermined height, and the capacitor 68 is attached with the connection terminals 68a positioned symmetrically with respect to the sensor stay 710.

In this embodiment, the capacitor 68 is arranged so that the connecting terminal 68a faces the electric motor 52 side, so that the connecting terminal 68a of the capacitor 68 can be prevented from coming into contact with other devices. And the capacitor 68 is
Since it is buried in the heat sink 66, it can be prevented from coming into contact with an external device, and its left end face is locked to the stay, so that the displacement to the left can be effectively prevented.

As shown in FIG. 25, the capacitor 6
8 can be arranged so that the right end thereof projects from the inner peripheral portion of the heat sink 66. Also in this mode, since the terminal 68a of the capacitor 68 is arranged inside, the terminal 68a of the capacitor 68 can be prevented from coming into contact with an external device or the like. Other configurations, functions and effects are the same as those of the above-described embodiment, and the description thereof will be omitted.

[0069]

As described above, according to the first aspect of the invention, the heat sink is fixed to the motor case integrally assembled with the case body, and the switch element constituting the drive circuit is attached to the heat sink. Because
The effect that the wiring connecting the drive circuit and the electric motor can be shortened and the overall size can be reduced is obtained.

According to the second aspect of the present invention, the portion of the heat sink to which the switch element is attached is covered with the cover member, and the resin is filled between the cover member and the heat sink. As a result, it is possible to firmly fix the switch element, the wiring, and the like, and to effectively protect the switch element and the like.

Further, according to the invention of claim 3,
Since the heat sink, the bearing of the rotating shaft and the rotation sensor are attached to the split case that is separated from the case body at the middle part of the rotating shaft, and the rotation sensor is arranged on the axially opposite side with respect to the heat sink, the rotation sensor It can be arranged without interfering with and further miniaturization can be achieved.

According to the invention described in claim 4,
In addition to the configuration described in claim 3, since the configuration in which the stator is attached to the split case is adopted, the stator can be assembled in advance in the split case, and the assembly thereof becomes easy.

According to the invention described in claim 5, in addition to the structure of the invention described in claim 1, terminals are provided in the motor case and the heat sink of the electric motor, respectively, and the motor case and the heat sink are combined. A plate member is interposed between the plate member and a terminal provided on the plate member to electrically connect the power supply terminal of the heat sink to the connection terminal of the motor case, so that wiring is unnecessary and the motor case and the heat sink are not connected to each other. Can be easily assembled.

[Brief description of drawings]

FIG. 1 shows a power unit for an electric vehicle according to an embodiment of the present invention, and is a side view of an electric motorcycle equipped with the power unit.

FIG. 2 is a sectional view of the power unit for the electric vehicle.

FIG. 3 is a partially cutaway sectional view showing a main part of the power unit for the electric vehicle.

FIG. 4 is a left side view of a main part of the power unit for the electric vehicle.

FIG. 5 is a right side view of a main part of the power unit for the electric vehicle.

FIG. 6 is an exploded perspective view showing an enlarged part of a main part of the power unit for the electric vehicle.

FIG. 7 is an electric circuit diagram of the power unit for the electric vehicle.

FIG. 8 is a cross-sectional view of an essential part of a power unit for an electric vehicle according to another embodiment of the present invention.

FIG. 9 is a partial cross-sectional view of a motor case of another mode of the power unit for the electric vehicle.

FIG. 10 is a partial left side view of the motor case.

FIG. 11 is a partial right side view of the motor case.

FIG. 12 is an exploded perspective view of essential parts of a power unit for an electric vehicle according to still another embodiment of the present invention.

13 is a view on arrow 13-13 of FIG.

FIG. 14 is a partially enlarged sectional view of the power unit for the electric vehicle.

FIG. 15 is a view on arrow 15-15 of FIG.

FIG. 16 is a parts diagram of main parts of the power unit for the electric vehicle.

FIG. 17 is a parts diagram of other main parts of the power unit for the electric vehicle.

FIG. 18 is a partially enlarged view of the power unit for the electric vehicle.

FIG. 19 is a sectional view of a main part of the power unit for the electric vehicle.

FIG. 20 is a sectional view of another main part of the power unit for the electric vehicle.

FIG. 21 is a sectional view of a main portion of a power unit for an electric vehicle according to yet another embodiment of the present invention.

FIG. 22 is a right side view of a main part of the power unit for the electric vehicle.

FIG. 23 is an enlarged view of a main part of the power unit for the electric vehicle.

FIG. 24 is a sectional view of the main part.

FIG. 25 is a cross-sectional view showing another mode of the power unit for the electric vehicle.

[Explanation of symbols]

11 ... Body frame, 14r ... Rear wheel (driving wheel),
30, 42 ... Bolts, 31 ... Motor room, 3
2, 33 ... Bearing, 35 ... Field effect transistor (switch element), 36 ... Battery, 45 ... Wiring,
46 ... Resin, 50 ... Power swing unit (power unit for electric vehicle), 51 ... Case body, 5
2 ... electric motor, 53 ... continuously variable transmission (transmission mechanism),
54 ... Final deceleration mechanism (transmission mechanism), 60 ... Motor case (split case), 61 ... Rotating shaft, 62 ... Stator coil (stator), 64 ... Drive circuit, 65 ...・
Cover (cover member), 66 ... Heat sink, 7
0 ... Rotation sensor.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location H02K 11/00 X 8525-5H

Claims (5)

[Claims] 1. An electric motor is assembled in a unit case using at least a part of the unit case as a motor case, and a rotary shaft of the electric motor is connected to an output shaft rotatably supported by the unit case so as to be capable of transmitting power. A power unit for an electric vehicle that transmits the power output from an electric motor from this output shaft to a drive wheel, wherein a heat sink is provided in the motor case, and a switch element for switching a current supplied to the electric motor is attached to the heat sink. A power unit for an electric vehicle, which is characterized in that 2. The power unit for an electric vehicle according to claim 1, wherein a cover member that covers a portion where the switch element is attached is assembled to the heat sink, and a resin is filled between the cover member and the heat sink. And the heat sink is fixed to the motor case together. 3. The power unit for an electric vehicle according to claim 1, wherein the unit case is divided into the motor case and the case body in the rotation axis direction between the ends of the rotation axis. A bearing that rotatably supports one end of the rotating shaft, a rotation sensor that detects rotation of the rotating shaft, and the heat sink are provided in the motor case, and the heat sink is provided on one side in the rotating shaft axial direction of the bearing. A power unit for an electric vehicle, wherein the rotation sensor is arranged on the other side of the bearing in the rotation axis direction. 4. The power unit for an electric vehicle according to claim 3, wherein the stator of the electric motor is fixed to the motor case, and the stator and the rotation sensor are arranged adjacent to each other in the rotation axis direction. A power unit for an electric vehicle, which is characterized in that 5. The power unit for an electric vehicle according to claim 1, wherein a connection terminal is exposed on a surface of the motor case on the heat sink side, and a plate member provided with the terminal is provided on the motor case. Attached at a predetermined position to electrically connect the terminal and the connection terminal, a power supply terminal connected to the switch element is provided on the heat sink, and the heat sink is attached to the motor case via the plate member. A power unit for an electric vehicle, wherein the power supply terminal and the terminal are electrically connected.