Electric motor unit and self-propelled electric vehicle

Abstract

To provide an electric motor unit for efficiently cooling a controller for controlling the operations of an electric motor, and a self-propelled electric vehicle equipped with the electric motor unit.SOLUTION: A self-propelled electric vehicle 100 is equipped with an electric motor unit 120 in a frame 101 supporting a front wheel 103 and a back wheel 108. The electric motor unit 120 has an electric motor 121, a controller 132, and an air blower 140. In the electric motor 121, a rotor accommodation space 126 is formed in a main housing 124 and a part of the main housing 124 is covered with a second housing 130 so that a controller accommodation space 131 is formed. The air blower 140 is arranged across the rotor accommodation space 126 and the controller accommodation space 131 by the main housing 124 and the second housing 130.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a motor unit mounted on a self-propelled electric vehicle that self-propels using an electric motor as a drive source, and a self-propelled electric vehicle equipped with the motor unit.

Background Art

[0007] According to the features of the present invention configured in this way, the electric motor unit has a control device housing space formed outside the rotor housing space of the electric motor for housing a control device that controls the operation of the electric motor, and a blower is provided that generates cooling air by flowing the air outside the rotor housing space and the control device housing space, respectively, while spanning both the rotor housing space and the control device housing space. As a result, the electric motor and the control device can be efficiently cooled by this blower.

[0008] Another feature of the present invention is that, in the electric motor unit, the main housing and the second housing are made of the same material.

[0009] According to other features of the present invention configured in this way, since the main housing and the second housing of the electric motor unit are made of the same material, the difference in thermal expansion and contraction between the main housing and the second housing can be suppressed, thereby improving durability.

[0010] Another feature of the present invention is that, in the electric motor unit, the main housing and the second housing are made of different materials.

[0011] According to another feature of the present invention configured in this way, since the electric motor unit has a main housing and a second housing made of different materials, the difference in thermal expansion and contraction between the main housing and the second housing can be suppressed by cooling with a blower.

[0012] Another feature of the present invention is that, in the electric motor unit, the rotor housing space is formed below the control device housing space.

[0013] According to other features of the present invention configured in this way, since the rotor housing space of the electric motor unit is formed below the control device housing space, the heavy components such as the rotor and stator that make up the electric motor are located below the control device, thereby lowering the center of gravity of the entire electric motor unit and improving stability.

[0014] Another feature of the present invention is that, in the electric motor unit, the blower is positioned opposite the main housing and the second housing, which extend along the axial direction of the rotor.

[0015] According to other features of the present invention configured in this way, the motor unit can effectively cool the entire motor and control unit by cooling the motor along its axial direction, since the blower is positioned opposite the main housing and second housing which extend along the axial direction of the rotor.

[0016] Another feature of the present invention is that, in the electric motor unit, the control device controls the operation of the blower.

[0017] According to other features of the present invention configured in this way, the motor unit can be simplified in configuration because the control device controls the operation of the blower, eliminating the need to provide a separate control device for the blower.

[0018] Another feature of the present invention is that, in the electric motor unit, at least one of the main housing and the second housing has a curved surface on which at least a portion of the outer surface facing the blower curves in a direction away from the flow direction of the cooling air as it moves away from the blower.

[0019] According to other features of the present invention configured in this way, the electric motor unit has a curved surface in which at least one of the main housing and the second housing has a portion of the outer surface facing the blower that curves away from the blower, thereby smoothing the flow of cooling air on the outside of the rotor housing space and the control device housing space and enhancing the cooling effect.

[0020] Another feature of the present invention is that, in the electric motor unit, at least one of the main housing and the second housing has a coolant passage through which coolant flows, and the blower is positioned facing the coolant passage.

[0021] According to other features of the present invention configured in this way, the electric motor unit can efficiently cool the electric motor and / or control device by cooling the coolant, since at least one of the main housing and the second housing has a blower positioned facing a coolant passage through which the coolant flows.

[0022] Another feature of the present invention is that the electric motor unit further includes a radiator for cooling the coolant, and the radiator is located either upwind or downwind of the blower.

[0023] According to other features of the present invention configured in this way, the motor unit further includes a radiator for cooling the coolant, and since the radiator is positioned on the windward or leeward side of the blower, the cooling effect of the coolant by the radiator can be enhanced by supplying or drawing air to the radiator.

[0024] Further, another feature of the present invention is that in the electric motor unit, a cooling air regulating portion for regulating the flow of cooling air is further provided between the main housing, the second housing, and the blower.

[0025] According to another feature of the present invention configured as described above, since the electric motor unit further includes a cooling air regulating portion for regulating the flow of cooling air between the main housing, the second housing, and the blower, the cooling efficiency of the rotor accommodation space and the control device accommodation space can be adjusted or improved by regulating the flow of cooling air flowing on each surface of the main housing and the second housing.

[0026] Further, another feature of the present invention is that in the electric motor unit, the blower emits an operating sound louder than the operating sound of the electric motor.

[0027] According to another feature of the present invention configured as described above, since the blower of the electric motor unit emits an operating sound louder than the operating sound of the electric motor, it is possible to mask the unpleasant operating sound of the electric motor and to make the surrounding area recognize by the operating sound of the blower that the electric motor unit or the self-propelled electric vehicle equipped with the electric motor unit is approaching.

[0028] Further, the present invention can be implemented not only as an invention of an electric motor unit but also as an invention of a self-propelled electric vehicle.

[0029] Specifically, the self-propelled electric vehicle preferably includes a seat on which a driver sits, a handle provided opposite to the seat for steering at least one of the front wheels and the rear wheels, and an electric motor unit according to any one of claims 1 to 11 for driving at least one of the front wheels and the rear wheels. According to the self-propelled electric vehicle configured as described above, the same operational effects as those of the electric motor unit can be expected.

Brief Description of the Drawings

[0030] [Figure 1]This is a schematic side view showing the overall configuration of a self-propelled electric vehicle according to the first embodiment of the present invention. [Figure 2] Figure 1 is a perspective view showing a schematic overview of the overall configuration of the electric motor unit installed in the self-propelled electric vehicle. [Figure 3] Figure 2 shows a schematic overview of the overall configuration of the electric motor unit, as seen from the left side of the self-propelled electric vehicle shown in Figure 1. [Figure 4] Figure 1 is a schematic block diagram of the control system for a self-propelled electric vehicle. [Figure 5] Figure 2 is a cross-sectional view showing a schematic of the internal configuration of the electric motor unit. [Figure 6] This is a perspective view showing a schematic overview of the overall configuration of an electric motor unit according to a second embodiment of the present invention. [Figure 7] This is a partial cross-sectional view illustrating the schematic internal configuration of the main housing and the second housing that constitute the electric motor unit shown in Figure 6. [Modes for carrying out the invention]

[0031] <First Embodiment> Hereinafter, an embodiment of the self-propelled electric vehicle according to the present invention will be described with reference to the drawings. Figure 1 is a schematic side view showing the overall configuration of the self-propelled electric vehicle 100 according to the present invention. Figure 2 is a perspective view from the right side of the self-propelled electric vehicle 100 shown in Figure 1, showing the overall configuration of the electric motor unit 120 mounted on the self-propelled electric vehicle 100 shown in Figure 1. Figure 3 is a perspective view from the left side of the self-propelled electric vehicle 100 shown in Figure 1, showing the overall configuration of the electric motor unit 120 mounted on the self-propelled electric vehicle 100 shown in Figure 1. Figure 4 is a schematic block diagram of the control system of the self-propelled electric vehicle 100 shown in Figure 1. Figure 5 is a cross-sectional view showing the internal configuration of the electric motor unit 120 mounted on the self-propelled electric vehicle 100 shown in Figure 1. This self-propelled electric vehicle 100 is a small motorcycle (so-called scooter) driven by a driver U who is seated on the seat 110 with both feet together.

[0032] (Configuration of 100 self-propelled electric vehicles) The self-propelled electric vehicle 100 is equipped with a frame 101. The frame 101 is a component that forms the skeleton that maintains the shape of the self-propelled electric vehicle 100, and is made up of a combination of multiple iron pipes or plates. This frame 101 mainly consists of a head pipe 102, a main frame 106, and a seat rail 109, respectively.

[0033] The head pipe 102 is a cylindrical part that supports the front wheel 103 of the self-propelled electric vehicle 100 via the front fork 104. The front fork 104 is formed as a rod extending from both sides of the front wheel 103 and is a component that supports the front wheel 103 relative to the head pipe 102 so that the self-propelled electric vehicle 100 can be steered in the left and right directions, and is configured with a suspension mechanism (not shown). A handle 105 is provided at the upper end of the front fork 104. The handle 105 is a component for steering the direction of travel of the self-propelled electric vehicle 100 and is formed as a rod extending in the width direction on the left and right sides of the self-propelled electric vehicle 100. The handle 105 is made up of a pair, left and right, and one of these left and right handles constitutes an accelerator grip 105a for accelerating the self-propelled electric vehicle 100.

[0034] The main frame 106 is the central part of the frame 101, supporting the electric motor unit 120 and the secondary battery 115 respectively, and determining the strength of the frame 101. It is formed in a curved shape that extends diagonally downward from the front to the rear of the self-propelled electric vehicle 100, then extends horizontally, and then extends diagonally upward again. The main frame 106 supports the step floor 114 and the secondary battery 115 in the horizontally extending portion, and supports the swing arm 107 and the electric motor unit 120 near the portion that extends diagonally upward. The swing arm 107 supports the rear wheel 108 of the self-propelled electric vehicle 100 in a state where it can move up and down freely with the pivot 106a, which is the connection point with the main frame 106, as the pivot point.

[0035] The seat rail 109 primarily supports the seat 110, the cargo bed 112, and the taillight 113, respectively, and is formed to extend diagonally upward toward the rear of the main frame 106. The seat 110 is a component for the driver U of the self-propelled electric vehicle 100 to sit with both feet together, and is made of a cushioning material. The seat 110 is configured to be openable and closable, and a storage space 111 for accommodating small items such as a helmet is formed in a hollow shape below the seat 110.

[0036] In this case, the bottom of the storage space 111 is configured to be openable and closable, allowing access to the electric motor unit 120. The cargo bed 112 is the part for loading cargo and is constructed by forming a frame out of metal rods. The taillight 113 is a lighting device that is illuminated by the driver U's braking, turn signal operation, or the operation of the headlights at night.

[0037] The step floor 114 is a portion on which the driver U, seated in the seat 110, can place both feet together, and is formed as a flat floor surface below and in front of the seat 110, above the main frame 106.

[0038] The secondary battery 115 is a device that supplies power to the electric motor 121 and the electrical and electronic equipment of the self-propelled electric vehicle 100, and is composed of a rechargeable battery such as a nickel-metal hydride battery or a lithium-ion battery. The secondary battery 115 also stores the regenerative electrical energy generated by the electric motor 121 when the self-propelled electric vehicle 100 decelerates. This secondary battery 115 is supported by the main frame 106 below the step floor 114.

[0039] Furthermore, a cylindrical unit cover 116 that rises from the rear end of the step floor 114 towards the seat 110 and covers the motor unit 120 has a grid-like ventilation opening 117 in front of the blower 140, which will be described later. The motor unit 120 is connected to the rear wheel 108 via a reduction gear 118a and a chain 118b that reduce the rotational speed of the motor 121.

[0040] The motor unit 120 is a group of devices that constitute a power source that generates the driving force to rotate the rear wheels 108. Specifically, the motor unit 120 mainly consists of a motor 121, a control device 132, and a blower 140. In Figure 1, the motor unit 120 is located inside the self-propelled electric vehicle 100 and should be depicted with a dashed line, but it is shown with a solid line for ease of understanding.

[0041] The electric motor 121 is a drive source that generates rotational driving force to rotate the drive wheels of a self-propelled vehicle. In this embodiment, the electric motor 121 is configured as a synchronous motor that drives a self-propelled two-wheeled vehicle. It goes without saying that the electric motor 121 may also be configured as a DC motor.

[0042] The electric motor 121 is mainly composed of a stator 122, a rotor 123, and a main housing 124. The stator 122 is a component that generates a rotating magnetic field using three-phase alternating current, and is formed into a cylindrical shape with windings provided on the outer circumference of an iron core. This stator 122 is fixedly mounted inside the body 125 that constitutes the main housing 124.

[0043] The rotor 123 is a component that rotates due to the rotating magnetic field generated by the stator 122, and is constructed by attaching permanent magnets to the outer circumference of a rod-shaped shaft. This rotor 123 is positioned inside the body 125, passing through the stator 122. In this case, one end of the rotor 123 is rotatably supported, passing through the output side cover 127. In this case, an output gear 123a is provided on the portion of the rotor 123 that is exposed after passing through the output side cover 127. In other words, the rotor 123 functions as the output shaft of the electric motor 121. The other end of the rotor 123 is rotatably supported by the rear side cover 128.

[0044] The main housing 124 is a component that constitutes the outer casing of the electric motor 121 and forms the rotor housing space 126 and the control device housing space 131, respectively, and is mainly composed of a body 125, an output side cover 127, and a rear side cover 128. The body 125 is a component that forms the rotor housing space 126 and is made by forming a cylindrical shape from a non-ferrous metal such as aluminum or a non-magnetic material such as resin. This body 125 supports the stator 122 in the rotor housing space 126, which is a cylindrical internal space, and the rotor 123, which is rotatably supported by the output side cover 127 and the rear side cover 128, is positioned to pass through it.

[0045] On the other hand, the outer surface of the fuselage 125 is mainly composed of a housing space forming section 125a, a first side section 125b, and a second side section 125c. The housing space forming section 125a is the part that forms the rotor housing space 126 and the control device housing space 131, which will be described later, and is formed in a flat surface shape. The first side section 125b is the part that constitutes the side of the electric motor 121 and is formed by extending in a flat surface shape from both ends of the housing space forming section 125a that extends in the axial direction of the rotor 123. The second side section 125c is formed in a semicircular dome shape and is the part that connects the two first side sections 125b. The rotor housing space 126 is the space that houses the main parts of the stator 122 and the rotor 123, and is formed in a cylindrical shape that extends in the axial direction of the rotor 123.

[0046] The output side cover 127 is a component attached to one end of the cylindrical body 125, and is constructed from a non-ferrous metal such as aluminum or a non-magnetic material such as resin, forming a plate-like body with an upright peripheral edge. This output side cover 127 closes one end of the cylindrical body 125 and rotatably supports one end of the rotor 123. The output side cover 127 also extends to face the control device housing space 131 and forms a part of this control device housing space 131. This output side cover 127 is attached to the body 125 by bolts (not shown).

[0047] The rear side cover 128 is a component attached to the other end of the cylindrical body 125, and is made of a plate-shaped non-ferrous metal such as aluminum or a non-magnetic material such as resin. This rear side cover 128 closes the other end of the cylindrical body 125 and rotatably supports the other end of the rotor 123. This rear side cover 128 is attached to the body 125 by bolts (not shown). The outer surface of the rear side cover 128 is covered by a rear side cover 129 with a space in between, and a detection device (not shown) for detecting the rotation angle of the rotor 123 is provided in this space.

[0048] A second housing 130 is provided on a part of the outer surface of the main housing 124. The second housing 130 is a component for forming a control device housing space 131 between itself and a part of the outer surface of the main housing 124, and is formed by curving a metal plate, such as an ferrous metal like carbon steel or a non-ferrous metal like aluminum, into a semicircular dome shape extending in the axial direction of the body 125. In this case, the second housing 130 is open on the side facing the output side cover 127 and closed on the side opposite to the output side cover 127. In this embodiment, the second housing 130 is made of the same material as the main housing 124 (for example, aluminum). The second housing 130 is detachably attached to a part of the body 125 via bolts.

[0049] The control device housing space 131 is a space for housing the control device 132, and is formed by covering a part of the outer surface of the fuselage 125 with a part of the output side cover 127 and the second housing 130. In other words, the rotor housing space 126 and the control device housing space 131 are formed adjacent to each other.

[0050] The control device 132 is an electrical and electronic device that controls the operation of the electric motor 121 and also comprehensively controls the operation of the self-propelled electric vehicle 100. More specifically, the control device 132 is composed of a microcomputer consisting of a CPU, ROM, RAM, etc., and is equipped with a power control unit (PCU) consisting of an inverter, a boost converter, and a DC-DC converter for directly controlling the operation of the electric motor 121.

[0051] Here, the inverter converts the DC current output from the secondary battery 115 into AC current and outputs it to the motor 121, and also converts the AC current output from the motor 121 into DC current and outputs it to the secondary battery 115. In addition, the boost converter boosts the voltage output from the secondary battery 115 and supplies it to the motor 121. In addition, the DC-DC converter steps down the voltage output from the motor 121 and supplies it to the secondary battery 115.

[0052] The control device 132 executes a control program stored in a memory device such as ROM to control the rotational drive of the electric motor 121 and the blower 140, the operation of the instruments, and the illumination of the lights, respectively, in response to the operation of the accelerator grip 105a or other controls such as turn signals on the handle 105. The control device 132 also has an interface terminal 132a for electrically connecting to external equipment, which is exposed on the outer surface of the second housing 130.

[0053] Furthermore, the power supply unit 133 is housed within the control device housing space 131 along with the control device 132. The power supply unit 133 is an electrical device that generates three-phase alternating current to supply to the motor 121 and to the stator 122, and is configured with multiple capacitors on a circuit board. The power supply unit 133 has a power connection part 133a exposed to the outside, penetrating the second housing 130, and receives power from the secondary battery 115 of the self-propelled vehicle.

[0054] The blower 140 is a mechanical device that generates cooling air consisting of air for cooling the electric motor 121 and the control device 132, and is configured to include a propeller fan 141 whose operation is controlled by the control device 132. The blower 140 is positioned to straddle the rotor housing space 126 and the control device housing space 131 via the main housing 124 and the second housing 130. In this embodiment, the blower 140 is attached to the first side portion 125b of the main housing 124 via bolts, straddling the boundary portion between the main housing 124 and the second housing 130. In this case, the blower 140 may be installed so that the main housing 124 and the second housing 130 side is the windward side, but in this embodiment, the blower 140 is installed so that the main housing 124 and the second housing 130 side is the leeward side.

[0055] This blower 140 is constructed by integrally housing a propeller fan 141 and an electric motor (not shown) that rotates the propeller fan 141 within a cylindrical casing 142. In this case, the casing 142 has two flat mounting portions 142a that protrude from the outer surface of the casing 142, through which bolts for attaching the blower 140 to the main housing 124 pass. The casing 142 also has a notched portion 142b formed in a concave shape in the portion facing the first side portion 125b of the main housing 124, so that cool air flows smoothly over the first side portion 125b. Furthermore, this blower 140 is configured to produce an operating noise louder than the operating noise of the electric motor 121. Specifically, the blower 140 is configured so that the wind noise from the propeller fan 141 is louder than the magnetostrictive noise (high-frequency noise) produced when the electric motor 121 is operating.

[0056] In this motor unit 120, a portion of the main housing 124 is fixedly attached to the frame 101 via bolts. In this case, the motor unit 120 is mounted to the frame 101 in a position where the control device housing space 131 is located above the rotor housing space 126.

[0057] (Operation of self-propelled electric vehicle 100) Next, the operation of the self-propelled electric vehicle 100 configured in this way will be described. The driver U of the self-propelled electric vehicle 100 can activate the control device 132 via switch operation while seated on the seat 110 of the self-propelled electric vehicle 100, and then drive the self-propelled electric vehicle 100 by operating the accelerator by rotating the accelerator grip 105a.

[0058] In this case, the control device 132 starts operating the blower 140 at the same time as its own startup to begin cooling the electric motor 121 and the control device 132. Specifically, some of the cooling air generated by the blower 140 collides with the first side portion 125b of the main housing 124, while other portions collide with the second housing 130.

[0059] The cooling air W1 that strikes the first side portion 125b flows out from inside the casing 142 through the notch 142b of the blower 140, and then flows along the outer surface of the first side portion 125b. As a result, the rotor housing space 126 formed inside the main housing 124 is cooled, and the temperature rise of the electric motor 121 is suppressed.

[0060] Meanwhile, the cooling air W2 that strikes the second housing 130 flows along the outer surface of the second housing 130. As a result, the control device housing space 131 formed inside the second housing 130 is cooled, and the temperature rise of the control device 132 is suppressed.

[0061] Here, the degree of cooling effect within the rotor housing space 126 is determined by the flow rate of the cooling air W1 flowing over the first side surface 125b. The flow rate of the cooling air W1 flowing over the first side surface 125b is determined by the amount of gap between the end of the casing 142, which is determined by the amount of notch in the notch 142b formed in the blower 140, and the outer surface of the first side surface 125b. In other words, the notch 142b also functions as a cooling air regulating part according to the present invention.

[0062] Furthermore, the degree of cooling effect within the rotor housing space 126 is determined by the flow rate of the cooling air W2 flowing over the second housing 130. In this case, the second housing 130 is configured to have a curved surface that curves away from the cooling air itself as it moves away from the blower 140, so that the cooling air W2 output from the blower 140 flows smoothly over the second housing 130.

[0063] As can be understood from the above description of operation, according to the first embodiment, the self-propelled electric vehicle 100 has a control device housing space 131 that houses a control device 132 for controlling the operation of the electric motor 121, located outside the rotor housing space 126 of the electric motor 121. Furthermore, a blower 140 is provided that generates cooling air by circulating the air outside the rotor housing space 126 and the control device housing space 131, straddling both the rotor housing space 126 and the control device housing space 131. As a result, the electric motor 121 and the control device 132 can be efficiently cooled by this blower 140.

[0064] Furthermore, the present invention is not limited to the first embodiment described above, and various modifications are possible as long as they do not depart from the purpose of the present invention. In the following modified examples, the same reference numerals are used for components similar to those in the self-propelled electric vehicle 100 in the first embodiment, and their descriptions are omitted.

[0065] For example, in the first embodiment described above, the motor unit 120 is constructed with the same material for both the main housing 124 and the second housing 130. This allows the motor unit 120 to improve durability by suppressing the difference in thermal expansion and contraction between the main housing 124 and the second housing 130. However, it is also possible for the motor unit 120 to be constructed with different materials for the main housing 124 and the second housing 130. In this case, the difference in thermal expansion and contraction between the main housing 124 and the second housing 130 can be suppressed by cooling with the blower 140. This modified configuration can also be adopted in the second embodiment described later.

[0066] Furthermore, in the first embodiment described above, the motor unit 120 is positioned on the frame 101 with the rotor housing space 126 located below the control device housing space 131. However, the motor unit 120 can also be positioned on the frame 101 with the rotor housing space 126 located above the control device housing space 131, as in the motor unit 120 in the second embodiment described later.

[0067] Furthermore, in the first embodiment described above, the motor unit 120 is configured such that the blower 140 is positioned opposite the main housing 124 and the second housing 130, which extend along the axial direction of the rotor 123. This allows the motor unit 120 to effectively cool the entire motor 121 and control device 132 by cooling the motor 121 along the axial direction. However, the motor unit 120 can also be configured such that the blower 140 is positioned opposite the rotor 123 in a direction other than the axial direction, for example, in a direction perpendicular to the coaxial direction (for example, towards the rear side cover 128). This modification can also be adopted in the second embodiment described later.

[0068] Furthermore, in the first embodiment described above, the blower 140 is configured to be operated and controlled by the control device 132. This simplifies the configuration of the motor unit 120, as it eliminates the need to provide a separate control device for the blower 140. However, it is obvious that the blower 140 may be operated and controlled by a control device other than the control device 132. This modification can also be adopted in the second embodiment described later.

[0069] Furthermore, in the first embodiment described above, the main housing 124 and the second housing 130 are configured in a dome shape with a curved surface on which a portion of the outer surface facing the blower 140 curves in a direction away from the blower 140. This allows the motor unit 120 to smooth the flow of cooling air on the outside of the rotor housing space 126 and the control device housing space 131, thereby enhancing the cooling effect. However, it is obvious that the main housing 124 and the second housing 130 may be configured with only flat surfaces, eliminating the curved shape for the outer surface shape through which the cooling air flows. This modification can also be similarly adopted in the second embodiment described later.

[0070] Furthermore, in the first embodiment described above, the blower 140 was configured to be attached to the main housing 124. However, the blower 140 only needs to be positioned so as to straddle the rotor housing space 126 and the control device housing space 131. Therefore, the blower 140 can be attached to the second housing 130 instead of or in addition to the main housing 124. Also, the blower 140 may be attached directly or indirectly to parts other than the main housing 124 and the second housing 130, for example, to the frame 101. Note that this modification can also be similarly adopted in the second embodiment described later.

[0071] Furthermore, in the first embodiment described above, the motor unit 120 is configured with one blower 140. However, the motor unit 120 can also be configured with two or more blowers 140. In this case, the second and subsequent blowers 140 may be mounted on the main housing 124 and / or the second housing 130 so as to straddle the rotor housing space 126 and the control device housing space 131, or they may be mounted on the main housing 124 and / or the second housing 130 so as to face only one of the rotor housing space 126 and the control device housing space 131. This modification can also be similarly adopted in the second embodiment described later.

[0072] Furthermore, in the first embodiment described above, the blower 140 is configured to blow cooling air by blowing air toward the electric motor 121 and the control device 132. However, the blower 140 can also be configured to generate cooling air by drawing air in from the electric motor 121 and the control device 132. This modification can also be adopted in the second embodiment described later.

[0073] Furthermore, in the first embodiment described above, the blower 140 is configured to emit an operating sound louder than the operating sound of the electric motor 121. This allows the electric motor unit 120 to mask the unpleasant operating sound of the electric motor 121, and also allows the surroundings to recognize the approach of the electric motor unit 120 or the self-propelled electric vehicle 100 equipped with the electric motor unit 120 through the operating sound of the blower 140. In other words, the operating sound emitted by the blower 140 is loud enough to be heard by those present around the electric motor unit 120 or the self-propelled electric vehicle 100. However, it is obvious that the blower 140 can be configured to emit an operating sound at a volume lower than or equal to the volume loud enough to be heard by those present around the electric motor unit 120 or the self-propelled electric vehicle 100. This modification can also be similarly adopted in the second embodiment described later.

[0074] Furthermore, in the first embodiment described above, the blower 140 was configured to include a propeller fan 141. However, the blower 140 only needs to be configured to generate cooling air consisting of an airflow by blowing or sucking in air. Therefore, the blower 140 can be configured not only as an axial flow fan such as a propeller fan 141 that flows air in the axial direction of a rotating body such as blades that cause air to flow, but also as a centrifugal fan that blows air in the centrifugal direction of a rotating body in which a plurality of blades are arranged to form a cylinder, or as a cross-flow fan that sucks in air from a part of the outer circumferential surface of the rotating body and blows it out from another part of this outer circumferential surface. Note that this modification can also be adopted in the second embodiment described later.

[0075] Furthermore, in the first embodiment described above, the control device housing space 131 is configured to include a power supply unit 133 in addition to the control device 132. This allows the motor unit 120 to be made compact while effectively cooling the power supply unit 133, which generates a large amount of heat, by housing it within the control device housing space 131. However, it is not always necessary to include the power supply unit 133 within the control device housing space 131; the power supply unit 133 can be located outside the control device housing space 131. This modification can also be adopted in the second embodiment described later.

[0076] <Second Embodiment> (Configuration of the electric motor unit 120) Next, a second embodiment of the electric motor unit according to the present invention will be described with reference to Figures 6 and 7, respectively. In describing this second embodiment, the parts that differ from the first embodiment will be mainly described, and common parts will be denoted by the same reference numerals and their descriptions will be omitted as appropriate. In the first embodiment described above, the electric motor unit 120 had the electric motor 121 and the control device 132 air-cooled by a blower 140.

[0077] However, the motor unit 120 according to the second embodiment differs from the motor unit 120 in the first embodiment in that, in addition to air cooling by the blower 140, the motor 121 and the control device 132 are water-cooled using a coolant such as water or oil. Specifically, the motor unit 120 is equipped with a radiator 200, a liquid supply pump 202, and a coolant tank 203.

[0078] The radiator 200 is a device for cooling the coolant (not shown) that cools the electric motor 121 and the control device 132, respectively, by heat exchange. The upstream side of the radiator 200, which introduces the coolant, is connected to the coolant passage 205 of the main housing 124 via pipe 201a, and the downstream side, which discharges the coolant, is connected to the liquid transfer pump 202 via pipe 201b. A coolant tank 203 is also connected to the radiator 200 via pipe 201c. The radiator 200 is attached to the main housing 124 and the second housing 130, respectively, via connectors 204.

[0079] The fluid transfer pump 202 is a mechanical device for circulating coolant between the main housing 124 and the radiator 200, and its operation is controlled by the control device 132. The downstream side of the fluid transfer pump 202, which discharges coolant, is connected to the coolant flow path 205 of the main housing 124 via a pipe 202a. The fluid transfer pump 202 is also attached to the radiator 200 via a connector 202b.

[0080] The coolant tank 203 is a container for storing coolant to cool the electric motor 121, the control device 132, and the power supply unit 133, respectively, and is made of resin or metal. In other words, the coolant tank 203 is a reservoir tank. This coolant tank 203 is directly attached to the main housing 124 of the electric motor 121 via bolts.

[0081] The connector 204 is a component for supporting the blower 140 and the radiator 200, respectively, at positions spaced apart from the main housing 124 and the second housing 130, and is formed by bending a strip-shaped metal plate. In this case, the connector 204 is composed of two metal plates with symmetrical shapes that sandwich the blower 140 and the radiator 200 from both sides. One end of the connector 204 is attached to the radiator 200 via bolts, and the other end is attached to the main housing 124 via bolts. The connector 204 then supports the blower 140 by bolts in the portion between its two ends.

[0082] Meanwhile, the main housing 124 has a coolant flow path 205 formed inside the cylindrical portion that constitutes the body 125. The coolant flow path 205 is a conduit for the liquid-tight and airtight circulation of coolant to cool the internal space of the main housing 124, including the rotor housing space 126, and the control device housing space 131, respectively, and is formed extending in the longitudinal and circumferential directions of the cylindrical portion. This coolant flow path 205 is formed to cover the rotor housing space 126 from the outside. That is, the coolant flow path 205 is formed substantially uniformly throughout the cylindrical portion. Furthermore, the coolant flow path 205 penetrates the body 125 in the axial direction and is blocked by the walls of the output side cover 127 and the rear side cover 128.

[0083] The blower 140 is positioned opposite the main housing 124 and the second housing 130 so as to face the coolant passage 205. In this case, the blower 140 is positioned such that the radiator 200 is located on the windward side and the motor 121 and control device 132 are located on the leeward side. The blower 140 is mounted on the main housing 124 and the second housing 130, respectively, straddling the rotor housing space 126 and the control device housing space 131. In Figure 7, for ease of understanding, the components of the motor 121, such as the stator 122 and rotor 123 housed in the rotor housing space 126, and the control device 132 and power supply unit 133 housed in the control device housing space 131 are not shown. Also in Figure 7, for ease of understanding, cross-sectional views of the main housing 124 and the second housing 130 are shown, but the blower 140 is not shown in cross-sectional view.

[0084] In the motor unit 120 configured in this way according to the second embodiment, the control device 132 starts the operation of the blower 140 and the liquid supply pump 202 simultaneously with its own startup, thereby starting to cool the motor 121 and the control device 132. As a result, the liquid supply pump 202 circulates the coolant between the main housing 124 and the radiator 200. This allows the liquid supply pump 202 to cool the rotor housing space 126 and the control device housing space 131, respectively.

[0085] Meanwhile, the blower 140 starts blowing air onto the electric motor 121 and the control device 132. In this case, the blower 140 blows the air that has passed through the radiator 200 as cooling air W1 and W2 onto the electric motor 121 and the control device 132 (including the power supply unit 133) via the main housing 124 and the second housing 130, respectively. As a result, since the blower 140 is positioned opposite the coolant flow path 205 in the main housing 124, it can cool the coolant in the coolant flow path 205. In addition, the blower 140 cools the rotor housing space 126 and the control device housing space 131, respectively, in the same manner as in the first embodiment described above.

[0086] Furthermore, when the blower 140 is in operation, the cooling air output from the blower 140 is restricted by the connector 204 to prevent the cooling air from flowing out in the axial direction of the rotor 123, thereby suppressing a decrease in flow rate in the direction perpendicular to the coaxial direction (specifically, towards the coolant tank 203 and the control device 132). In other words, the connector 204 also functions as a cooling air restricting unit according to the present invention.

[0087] In addition, various modifications are possible in this second embodiment. Specifically, in the second embodiment described above, the blower 140 is positioned opposite the coolant flow path 205. However, the blower 140 can also be positioned in a location that does not face the coolant flow path 205.

[0088] Furthermore, in the second embodiment described above, the radiator 200 was positioned on the windward side of the blower 140. However, the radiator 200 can also be positioned on the windward side of the blower 140. That is, the blower 140 can generate cooling air by drawing in air from the electric motor 121 and control device 132 side, and can also blow this cooling air onto the radiator 200.

[0089] Furthermore, in the second embodiment described above, the connector 204 also functioned as a cooling air restrictor according to the present invention by restricting the outflow of cooling air output from the blower 140 to the axial side of the rotor 123. However, the connector 204 is a component that supports the radiator 200 and the blower 140, and does not necessarily need to also function as a cooling air restrictor. In other words, it is natural that the cooling air restrictor can be omitted in the configuration, including in the first embodiment described above.

[0090] Furthermore, in the above embodiment, the electric motor unit 120 was mounted on a small motorcycle (a so-called scooter) in which the driver U sits on the seat 110 with both feet together and drives. However, the electric motor unit 120 can be widely mounted on self-propelled electric vehicles such as two-wheeled or three-wheeled motorcycles, as well as four-wheeled go-karts. In this case, for example, the electric motor unit 120 can be mounted on a saddle-type two-wheeled, three-wheeled, or four-wheeled vehicle in which the driver straddles the seat 110. In addition, the electric motor unit 120 can be mounted on a rear-wheel-drive vehicle, as well as a front-wheel-drive or all-wheel-drive vehicle. Furthermore, the electric motor unit 120 can be mounted on a self-propelled electric vehicle that steers the rear wheels 108, as well as a self-propelled electric vehicle that steers the front wheels 103. In addition, the secondary battery 115 of the self-propelled electric vehicle 100 can be placed in a location other than below the step floor 114, for example, below the seat 110 or inside the cowl. [Explanation of Symbols]

[0091] U... Driver, W1, W2... Cooling air, 100...Self-propelled electric vehicle, 101...Frame, 102...Head pipe, 103...Front wheel, 104...Front fork, 105...Handlebars, 105a...Thrust grip, 106...Main frame, 106a...Pivot, 107...Swing arm, 108...Rear wheel, 109...Seat rail, 110...Seat, 111...Storage space, 112...Cargo bed, 113...Tail light, 114...Step floor, 115...Secondary battery, 116...Unit cover, 117...Ventilation opening, 118a...Gear reducer, 118b...Chain 120...Electric motor unit, 121...Electric motor, 122...Stator, 123...Rotor, 123a...Output gear, 124...Main housing, 125...Body, 125a...Accommodation space forming section, 125b...First side section, 125c...Second side section, 126...Rotor accommodation space, 127...Output side cover, 128...Rear side cover, 129...Rear side cover, 130...Second housing, 131...Control device housing space, 132...Control device, 132a...Interface terminal, 133...Power supply unit, 133a...Power supply connection unit, 140... Blower, 141... Propeller fan, 142... Casing, 142a... Mounting part, 142b... Notch part 200...Radiator, 201a, 201b, 201c...Pipeline, 202...Liquid pump, 202a...Pipeline, 202b...Connector, 203...Coolant tank, 204...Connector, 205...Coolant flow path.

Claims

1. an electric motor having a main housing that defines a rotor accommodating space for accommodating a rotor for driving a drive wheel of a self-propelled vehicle; a second housing defining a control device accommodating space outside the rotor accommodating space for accommodating a control device that controls operation of the electric motor; an electric motor unit characterized by comprising a blower arranged across the rotor accommodating space and the control device accommodating space via the main housing and the second housing, for generating cooling air by circulating air outside the rotor accommodating space and the control device accommodating space.

2. 2. The electric motor unit according to claim 1, The electric motor unit is characterized in that the main housing and the second housing are made of the same material.

3. 2. The electric motor unit according to claim 1, The electric motor unit is characterized in that the main housing and the second housing are made of different materials.

4. 4. The electric motor unit according to claim 1, wherein: The rotor accommodating space is The electric motor unit is formed below the control device accommodating space.

5. 5. The electric motor unit according to claim 1, wherein: The blower is An electric motor unit, characterized in that the main housing and the second housing are disposed opposite each other and extend along the axial direction of the rotor.

6. 6. The electric motor unit according to claim 1, The control device An electric motor unit that controls the operation of the blower.

7. 7. The electric motor unit according to claim 1, At least one of the main housing and the second housing is An electric motor unit, characterized in that at least a portion of an outer surface facing the blower has a curved surface that curves in a direction away from the flow direction of the cooling air as the outer surface becomes farther away from the blower.

8. 8. The electric motor unit according to claim 1, At least one of the main housing and the second housing is A coolant flow path is provided through which the coolant flows. The blower is An electric motor unit disposed facing the coolant flow path.

9. The electric motor unit according to claim 8, further comprising: a radiator for cooling the cooling liquid; The radiator is The electric motor unit is arranged on the upwind side or the downwind side of the blower.

10. The electric motor unit according to any one of claims 1 to 9, further comprising: a cooling air regulating portion for regulating the flow of the cooling air between the main housing and the second housing and between the blower and the fan;

11. 11. The electric motor unit according to claim 1, The blower is An electric motor unit that produces an operating sound louder than the operating sound of the electric motor.

12. A seat on which the driver sits, a handle provided opposite the seat for steering at least one of front wheels and rear wheels; A self-propelled electric vehicle comprising: an electric motor unit according to any one of claims 1 to 11 for driving at least one of the front wheels and the rear wheels.

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