Saddle-type vehicle

Abstract

Provided is a ridden vehicle in which a motor compartment and a transmission compartment can be efficiently cooled.　A ridden vehicle (10) is provided with a motor compartment (62) that houses a motor (13), and a transmission compartment (66) that houses a power transmission mechanism (67) that reduces the output of the motor (13) and transmits power to drive wheels (12), wherein the motor compartment (62) and the transmission compartment (66) are adjacent to each other across an air flow space (90) inside which air flows.

Description

Technical Field

[0001] The present invention relates to a straddle-type vehicle.

Background Art

[0002] In recent years, efforts to realize a low-carbon society or a decarbonized society have become active, and research and development on electrification technologies have been carried out in vehicles in order to reduce CO2 emissions and improve energy efficiency. As a technology related to the electrification technology of straddle-type vehicles, Patent Document 1 discloses a power unit for a battery-driven motorcycle, and discloses a so-called swing-type power unit. In Patent Document 1, a power unit is formed with a motor chamber and a transmission chamber, and a PDU (Power Drive Unit) for driving the motor in the motor chamber is integrally provided. In Patent Document 1, an air flow space for cooling the PDU is provided in the power unit.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, in technologies related to the electrification technology of straddle-type vehicles, the motor chamber and the transmission chamber are also likely to become hot, so efficiently cooling them is an issue. The present invention has been made in view of the above circumstances, and an object thereof is to provide a straddle-type vehicle that can efficiently cool a motor chamber and a transmission chamber. And by extension, it contributes to the improvement of energy efficiency.

Means for Solving the Problems

[0005] A saddle-type vehicle is a saddle-type vehicle comprising a motor chamber for housing a motor and a transmission chamber for housing a power transmission mechanism that reduces the output of the motor and transmits power to the drive wheels, characterized in that the motor chamber and the transmission chamber are adjacent to each other via an airflow space through which air flows. [Effects of the Invention]

[0006] This allows for the provision of a saddle-type vehicle that can efficiently cool both the motor and transmission compartments. Ultimately, this contributes to improved energy efficiency. [Brief explanation of the drawing]

[0007] [Figure 1] Figure 1 is a left side view of the saddle-type vehicle according to this embodiment. [Figure 2] Figure 2 is a cross-sectional view of the swingarm. [Figure 3] Figure 3 is a left side view of the main arm section. [Figure 4] Figure 4 is a perspective view of the main arm section from the left rear. [Figure 5] Figure 5 is a perspective view of the main arm section from the right rear. [Figure 6] Figure 6 is a right side view of the main arm section. [Figure 7] Figure 7 is a rear view of the main arm section. [Figure 8] Figure 8 is a cross-sectional view taken along line VIII-VIII in Figure 7. [Figure 9] Figure 9 is a cross-sectional view taken along the line IX-IX in Figure 6. [Figure 10] Figure 10 is a view in the direction of arrow X in Figure 6. [Modes for carrying out the invention]

[0008] Embodiments of the present invention will be described below with reference to the drawings. In the description, directions such as front, back, left, right, and up and down refer to directions relative to the vehicle body unless otherwise specified. In each figure, the symbol FR indicates the front of the vehicle body, the symbol UP indicates the top of the vehicle body, and the symbol LH indicates the left side of the vehicle body.

[0009] [Embodiment] Figure 1 is a left side view of the saddle-type vehicle 10 according to this embodiment. The saddle-type vehicle 10 is an electric motorcycle comprising a body frame 11, an electric motor 13 that drives the rear wheel 12 which is the drive wheel, a front fork 15 that supports the front wheel 14 in a steerable manner, a swing arm 16 that supports the rear wheel 12, and a seat 17 for the rider. The saddle-type vehicle 10 is a vehicle in which the occupant sits by straddling the seat 17. The saddle-type vehicle 10 in this embodiment is an electric scooter having a low step floor 18.

[0010] The vehicle frame 11 includes a head pipe 20 at the front end, a pair of left and right upper frames 21 extending downward and rearward from the head pipe 20, a pair of left and right down frames 22 extending downward and rearward from the head pipe 20 below the upper frames 21, a pair of left and right under frames 23 extending rearward from the lower ends of the down frames 22, and a pair of left and right side frames 24 extending upward and rearward from the rear ends of the under frames 23. The branched lower ends of the upper frame 21 are connected to the midpoint of the under frames 23 in the longitudinal direction and to the lower ends of the side frames 24.

[0011] A pair of left and right seat frames 25, extending upward and rearward, are connected to the upper frame 21 midway in the front-rear direction. The seat frames 25 are connected to the upper ends of the side frames 24. A rear subframe 26, extending upward and rearward, is connected to the side frame 24 midway in the vertical direction. The seat frames 25 are connected to the rear end of the rear subframe 26.

[0012] A pair of left and right front forks 15 are attached to the head pipe 20 so as to be steerable. A steering handle 19 is attached to the upper part of the front fork 15. A front wheel 14 is attached to the lower end of the front fork 15 via an axle 14a.

[0013] A pivot bracket 27 extending rearward is provided at the rear end of the underframe 23. A pivot shaft 28 extending in the left - right direction (vehicle width direction) is supported at the rear end of the pivot bracket 27 via a link mechanism 32. A swing arm 16 extending along the front - rear direction of the saddle - type vehicle 10 is pivotally supported on the pivot shaft 28. The swing arm 16 extends from the pivot shaft 28 to the left side of the rear wheel 12. The rear end portion of the swing arm 16 supports the rear wheel 12 via an axle 12a.

[0014] A three - phase AC electric motor 13 is incorporated in the swing arm 16. The electric motor 13 is located on the left side of the rear wheel 12. The swing arm 16 is configured as a swing - type power unit. A rear cushion 29 is connected between the rear end portion of the swing arm 16 and the left - hand seat frame 25.

[0015] The seat frame 25 supports the seat 17 from below. The seat 17 is vertically openable and closable with the front - end side as a hinge fulcrum. A battery 30 is disposed below the seat 17. In the present embodiment, the batteries 30 are arranged one by one in the front - rear direction. The battery 30 is disposed in a portion surrounded by a pair of left and right side frames 24, the seat frame 25, and the rear sub - frame 26, and is supported by the side frames 24, the seat frame 25, and the rear sub - frame 26.

[0016] In front of the battery 30, a PCU (Power Control Unit) 31 as an electronic component is supported. The PCU 31 is configured to include an inverter and the like. For example, it converts the DC power supplied from the battery 30 into AC power and supplies the converted AC power to the electric motor 13. Also, when the electric motor 13 regenerates, the PCU 31 converts the AC power generated by the electric motor 13 into DC power and charges the battery 30. Note that the arrangement positions of the battery 30 and the PCU 31 shown in FIG. 1 are just examples, and they may be arranged at other positions within the saddle-riding type vehicle 10.

[0017] The vehicle body frame 11 is covered by the vehicle body cover 40. The vehicle body cover 40 includes a front cover 41, an inner cover 42, a pair of left and right under-seat covers 43, a rear side cover 44, and the like.

[0018] The front cover 41 covers the front end portion of the vehicle body frame 11 such as the head pipe 20 from the front. The inner cover 42 is connected to the rear portion of the front cover 41 and covers the head pipe 20 and the upper frame 21 from the rear or rear upper side. The pair of left and right under-seat covers 43 cover the lower part of the seat 17 from the side. The rear side cover 44 is connected to the rear edge of the under-seat cover 43 and covers the lower part of the rear portion of the seat 17 from the side.

[0019] A main stand 50 is disposed on the swing arm 16. A side stand 51 is disposed near the left under-frame 23.

[0020] FIG. 2 is a cross-sectional view of the swing arm 16. FIG. 2 corresponds to the cross-section taken along the line II-II in FIG. 3. As shown in Figures 1 and 2, the swingarm 16 comprises a swingarm body 60 that is pivotably supported on a pivot shaft 28, and a swingarm cover 61 that is attached to the outside of the swingarm body 60 in the vehicle width direction. The swingarm body 60 is pivotably supported on the pivot shaft 28 by pivot insertion portions 60a and 60b at its front end (see Figure 2). The swingarm cover 61 is fixed to cover fixing portions 60c and 60d (see Figure 1). The swingarm cover 61 covers the swingarm body 60 from the outside in the vehicle width direction.

[0021] As shown in Figure 2, the swingarm body 60 extends from the front of the rear wheel 12 in a curved manner toward the left side of the rear wheel 12. At its front end, the swingarm body 60 extends to the left and right so as to extend beyond the centerline CL in the width direction of the saddle-type vehicle 10. At the rear of the swingarm body 60 are a motor housing chamber (motor chamber) 62 and a reduction gear housing chamber (transmission chamber) 66 located on the rear wheel 12 side of the motor housing chamber 62.

[0022] The motor housing chamber 62 houses the electric motor (motor) 13. The electric motor 13 in this embodiment is an inner rotor type motor. The electric motor 13 comprises a motor shaft 13a extending in the vehicle width direction, a rotor 13b fixed to the motor shaft 13a, and a stator 13c arranged on the outer circumference of the rotor 13b. The motor shaft 13 is rotatably supported via bearings 64a, 64b, and 64c. The rotor 13b is spline-coupled to the motor shaft 13a. The stator 13c has a coil section around which a wire is wound.

[0023] The left end (axial end) 13a1 of the motor shaft 13a is rotatably supported by the motor cover 81 via a bearing 64a. The motor cover 81 covers the electric motor 13 from the outside (left side) in the vehicle width direction. A resolver (rotation angle detection unit) 110 for detecting the rotation angle is disposed at the left end 13a1 of the motor shaft 13a. The resolver 110 has a resolver rotor 110a attached to the motor shaft 13a and a resolver stator 110b facing the resolver rotor 110a. The resolver stator 110b is fixed to the motor cover 81.

[0024] The right end (the other axial end) 13a2 of the motor shaft 13a protrudes inward (to the right) in the vehicle width direction from the motor housing 62. The right end 13a2 of the motor shaft 13a protrudes into the reduction gear housing 66, which is provided adjacent to the motor housing 62. The right end 13a2 of the motor shaft 13a is rotatably supported by the reduction gear cover 82 of the reduction gear housing 66 via a bearing 64c. An oil seal 65 is fitted to the motor shaft 13a at a position between the reduction gear housing 66 and the motor housing 62 to prevent leakage of lubricating oil from the reduction gear housing 66 to the motor housing 62.

[0025] A reduction mechanism (power transmission mechanism) 67 is arranged in the reduction mechanism housing chamber 66. The reduction mechanism 67 has a transmission shaft 67a that extends parallel to the motor shaft 13a. The transmission shaft 67a is rotatably supported at both ends via bearings 68a and 68b. A first gear 67b is supported at the right end of the transmission shaft 67a. The first gear 67b meshes with a drive gear 67c provided at the right end 13a2 of the motor shaft 13a. A second gear 67d is provided at the left end of the transmission shaft 67a. The second gear 67d meshes with a driven gear 67e supported by the axle 12a. The reduction mechanism 67 of this embodiment is composed of the transmission shaft 67a, the first gear 67b, the drive gear 67c, the second gear 67d, and the driven gear 67e. The reduction mechanism 67 reduces the rotation of the motor shaft 13a by a predetermined reduction ratio and transmits it to the axle 12a. The reduction mechanism 67 may also be configured to further include other gears and transmission shafts, and to reduce the rotation using multiple gears.

[0026] The axle 12a is rotatably supported at both ends via bearings 69a and 69b. The rear wheel 12 is supported by the axle 12a. When the axle 12a rotates, the rear wheel 12 rotates.

[0027] An electrical cable 111 extending from the PCU 31 is connected to the electric motor 13. The electrical cable 111 is electrically connected to the electric motor 13. In this embodiment, the electrical cable 111 comprises a power supply line 112, a first communication line 113, and a second communication line 114. The power supply line 112 is thicker than either the first communication line 113 or the second communication line 114.

[0028] The power supply line 112 is connected to the U-phase, V-phase, and W-phase coils of the electric motor 13 so as to be able to supply power. The power supply line 112 supplies AC power to the electric motor 13. The first communication line 113 is electrically connected to the resolver 110. The results of the rotation angle detection by the resolver 110 of the rotor 13b and motor shaft 13a are transmitted to the PCU 31 via the first communication line 113. The second communication line 114 is electrically connected to temperature sensors (not shown) corresponding to the U-phase, V-phase, and W-phase. The temperature detection results corresponding to the U-phase, V-phase, and W-phase are transmitted to the PCU 31 via the second communication line 114.

[0029] The electrical cable 111 connected to the electric motor 13 is routed out of the motor housing 62, along the outer surface of the main arm portion 70, and through the left-side conductor opening 72f into the swing arm body 60. The electrical cable 111 routed inside the swing arm body 60 is routed forward through the front conductor opening 71e and connected to the PCU 31 supported by the vehicle frame 11. The electrical cable 111 along the outer surface of the main arm portion 70 is covered by the swing arm cover 61. The PCU 31 is supplied with DC power from the battery 30 via an electrical cable (not shown). The PCU 31 controls the electric motor 13 by supplying AC power to it in response to the operation of an operating member such as the throttle of the saddle-type vehicle 10.

[0030] Figure 3 is a left side view of the main arm section 70. Figure 4 is a perspective view of the main arm section 70 from the left rear. Figure 5 is a perspective view of the main arm section 70 from the right rear. Figure 6 is a right side view of the main arm section 70. Figure 7 is a rear view of the main arm section 70. The swingarm body 60 of this embodiment has a segmented structure. As shown in Figure 2, the swingarm body 60 has a main arm portion 70 that extends front to rear on the outside in the vehicle width direction, and a sub-arm portion 80 that is positioned to the right of the front end of the main arm portion 70. The swingarm body 60 of this embodiment is constructed by bolting the sub-arm portion 80 to the right of the front end of the main arm portion 70.

[0031] As shown in Figures 3 to 7, the main arm portion 70 comprises a pivot portion 71 provided at its front end, an arm portion 72 extending rearward from the pivot portion 71, a housing portion 73 provided at the rear end of the arm portion 72, and a brake connection portion 74 extending rearward from the rear end of the housing portion 73.

[0032] The pivot portion 71 is roughly rectangular in shape, extending horizontally in its external appearance. More specifically, the pivot portion 71 has an upper wall 71a and a lower wall 71b that are positioned opposite each other vertically. An outer wall 71c is formed at the outer ends in the vehicle width direction of the upper wall 71a and the lower wall 71b. The outer wall 71c closes the outer side of the upper wall 71a and the lower wall 71b in the vehicle width direction (see Figures 3 and 4). In front of the outer wall 71c, a left-side pivot insertion portion 60a that protrudes forward is formed. The pivot shaft 28 is inserted through the left-side pivot insertion portion 60a.

[0033] An inner wall 71d is formed at the inner end in the vehicle width direction of the upper wall 71a and the lower wall 71b. In a side view of the vehicle body, the inner wall 71d forms a roughly U-shaped frame-like contact portion with an open front (see Figures 5 and 6). Therefore, a wire opening 71e opening forward is formed at the front end of the upper wall 71a and the lower wall 71b (see Figures 5 and 6). Also, due to the opening shape of the inner wall 71d, an inner front opening 71f is formed at the inner end of the upper wall 71a and the lower wall 71b (see Figures 5 and 6). As shown in Figure 2, a sub-arm portion 80 with a right-side pivot insertion portion 60b is in contact with the inner wall 71d and bolted in place. Therefore, the swingarm body 60 is supported by the pivot axis 28 with a gap between them in the left-right direction.

[0034] In the main arm portion 70, an arm portion 72 is formed behind the pivot portion 71. The arm portion 72 is integral with the pivot portion 71. The arm portion 72 has an upper wall 72a, a lower wall 72b, an outer wall 72c, and an inner wall (side wall) 72d that extend continuously rearward from the upper wall 71a, lower wall 71b, outer wall 71c, and inner wall 71d of the pivot portion 71, respectively. Here, the upper wall 72a and the lower wall 72b extend upward and rearward in a side view of the vehicle body. The upper wall 72a extends upward and rearward at a steeper angle than the lower wall 72b, and the distance between the upper wall 72a and the lower wall 72b is formed to increase towards the rear.

[0035] Furthermore, the outer wall 72c extends to the rear in a nearly straight line when viewed from above. In contrast, the inner wall 72d extends to the rear while curving outward in the vehicle width direction as it moves towards the rear. In other words, the inner wall 72d extends to the rear while curving in a way that recesses the area where the rear wheels 12 are located towards the front. Therefore, the lateral width between the upper wall 72a and the lower wall 72b decreases as it moves towards the rear.

[0036] The outer wall 72c forms a roughly rectangular, annular frame-shaped contact portion when viewed from the side of the vehicle body (see Figure 3). At the rear of the outer wall 72c, a weight-reducing section 72e is formed, which has multiple holes extending in the vehicle width direction. The weight-reducing section 72e is closed on the inside in the vehicle width direction, forming an inner end surface. The weight-reducing section 72e is formed behind the inner front opening 71f of the pivot section 71. In the outer wall 72c, a conductor opening 72f is formed in front of the weight-reducing section 72e. The main arm section 70 penetrates in the vehicle width direction through the conductor opening 72f and the inner front opening 71f.

[0037] A housing section 73 is formed behind the arm section 72. The housing section 73 is integral with the arm section 72. The housing section 73 has an upper wall 73a, a lower wall 73b, an outer wall 73c, and an inner wall (side wall) 73d that extend continuously rearward from the upper wall 72a, lower wall 72b, outer wall 72c, and inner wall 72d of the arm section 72, respectively.

[0038] Here, the upper wall 73a and the lower wall 73b of the storage section 73 extend in an arc shape when viewed from the side of the vehicle body. On the outer wall 73c side of the housing section 73, a substantially cylindrical inner circumferential surface 75 is formed by the rear surface of the weight-reducing portion 72e of the arm section 72, the inner circumferential surface of the upper wall 73a, and the inner circumferential surface of the lower wall 73b. The outer wall 73c, as the open end of the inner circumferential surface 75, constitutes a substantially annular frame-shaped contact portion when viewed from the side of the vehicle body (see Figure 3). An arrangement surface 76 is formed on the inner side of the inner circumferential surface 75 in the vehicle width direction. The arrangement surface 76 is formed on the inner wall 73d. A motor shaft hole 76a is formed at the radial center of the arrangement surface 76 through which the motor shaft 13a is inserted. An annular stator fixing portion 76b is formed on the radially outer side of the arrangement surface 76. The stator fixing portion 76b protrudes from the arrangement surface 76 in a pedestal-like manner. An annular stator 13c (see Figure 2) is fixed to the stator fixing portion 76b.

[0039] Here, a motor cover 81 (see Figure 2) is fixed to the outer wall 73c of the housing section 73 via a gasket (not shown). The motor cover 81 closes the open end of the inner circumferential surface 75 from the outside in the vehicle width direction. The space enclosed by the inner circumferential surface 75, the placement surface 76, and the motor cover 81 constitutes the motor housing chamber 62 of this embodiment.

[0040] On the inner wall 73d side of the housing section 73, a bottom surface 78 is formed that is recessed in a step-like manner relative to the inner surface (outer surface) of the inner wall 73d in the vehicle width direction. The bottom surface 78 is formed on the inner wall 73d. The bottom surface 78 is formed in the area from the motor shaft hole 76a to the rear lower part of the motor shaft hole 76a. A round hole-shaped transmission shaft support portion 78a is formed on the bottom surface 78, corresponding to the rear lower part of the motor shaft hole 76a. The transmission shaft support portion 78a is recessed outward in the vehicle width direction relative to the bottom surface 78. Behind the transmission shaft support portion 78a, an axle support portion 78b is formed. The axle support portion 78b is recessed outward in the vehicle width direction relative to the bottom surface 78. The axle support portion 78b has a larger diameter than the transmission shaft support portion 78a.

[0041] An inner circumferential wall 77 is formed on the outer periphery of the bottom surface 78 so as to protrude inward from the bottom surface 78 in the vehicle width direction. The inner circumferential wall 77 includes the area around the motor shaft hole 76a. An inner end surface 77a is formed on the inner circumferential wall 77. The inner end surface 77a constitutes an irregularly shaped frame-like contact portion when viewed from the side of the vehicle body (see Figures 4 and 5).

[0042] Here, a gearbox cover 82 (see Figure 2) is fixed to the inner end surface 77a of the inner wall 73d of the housing section 73 via a gasket (not shown). The gearbox cover 82 closes the bottom surface 78 from the inside in the vehicle width direction. The space enclosed by the inner circumferential wall 77, the bottom surface 78, and the gearbox cover 82 constitutes the gearbox mechanism housing chamber 66 of this embodiment.

[0043] Above the transmission shaft support portion 78a and the axle support portion 78b, a partition wall 77b is formed, extending rearward from the motor shaft hole 76a. The partition wall 77b is configured such that its axial length relative to the bottom surface 78, i.e., its height relative to the bottom surface 78, is the same as the height of the motor shaft hole 76a and the inner end surface 77a of the inner circumferential wall 77. The partition wall 77b divides the space vertically inside the inner circumferential wall 77. Therefore, in the reduction gear housing chamber 66, an upper space 66b is formed above the lower space 66a where the transmission shaft 67a and axle 12a are arranged, communicating with the lower space 66a and located on the bottom surface 78 side. At the top of the upper space 66b, a communication hole (transmission chamber communication hole) 78c is formed, penetrating inward in the vehicle width direction. The communication hole 78c overlaps with the inner end surface 77a in a side view of the vehicle body.

[0044] A plate-shaped brake connection portion 74 extending to the rear is formed at the lower rear end of the housing portion 73. A connection hole 74a is formed in the brake connection portion 74, penetrating in the thickness direction. The rear brake 35 (see Figure 1) is connected to the connection hole 74a.

[0045] Figure 8 is a cross-sectional view taken along line VIII-VIII in Figure 7. A hollow airflow space 90 is formed in the main arm portion 70. The airflow space 90 extends from the arm portion 72 to the rear of the main arm portion 70. The airflow space 90 is formed between the upper walls 72a, 73a and the lower walls 72b, 73b of the arm portion 72 and the housing portion 73, and is a hollow space formed inside the inner walls 72d, 73d. More specifically, the airflow space 90 is composed of the space enclosed by the upper wall 72a, the lower wall 72b, the inner wall 72d and the inner end surface of the weight-reducing portion 72e of the arm portion 72, and the upper wall 73a, the lower wall 73b, the inner wall 72d, the placement surface 76 and the bottom surface 78 of the housing portion 73. The main arm portion 70 is a casting, and the hollow airflow space 90 can be formed, for example, using a sand core.

[0046] The airflow space 90 extends in the front-rear direction along the upper walls 72a, 73a and the lower walls 72b, 73b. The airflow space 90 has a vent 91 on its front end side. The vent 91 is formed by the enclosed shape of the upper wall 72a, the lower wall 72b, the inner wall 72d, and the inner end surface of the weight-reducing portion 72e in the arm portion 72. The airflow space 90 has an exhaust port 92 on its rear upper end side. The exhaust port 92 is made up of an opening that penetrates the upper wall 73a of the housing portion 73 in the thickness direction. The airflow space 90 has a lower opening (lower communication hole) 93 on its rear lower end side. The lower opening 93 is made up of an opening that penetrates the lower wall 73b of the housing portion 73 in the thickness direction. The lower opening 93 is formed behind the constricted portion 73e (see Figure 8) where the lower wall 72b of the arm portion 72 and the lower wall 73b of the housing portion 73 are connected. The lower opening 93 has a smaller opening area than the exhaust port 92. In other words, more air is more easily discharged from the exhaust port 92 than from the lower opening 93.

[0047] A separation section 101 is positioned on the side of the vent 91 of the airflow space 90, extending linearly along the flow direction of the airflow space 90. The separation section 101 is positioned in the vertical center of the airflow space 90. In the airflow space 90, the airflow is separated vertically by the separation section 101. A rear separation section 102 is positioned above and behind the separation section 101. The separation section 102 extends more gently upward and behind than the separation section 101. The separation section 102 is spaced apart from the separation section 101. Therefore, air can pass between the separation sections 101 and 102.

[0048] A hole perimeter portion 103 is integrally formed at the rear end of the separation portion 102. A motor shaft hole 76a is formed within the hole perimeter portion 103. A rear hole perimeter portion 104 is formed behind the hole perimeter portion 103. The separation portions 101 and 102, and the hole perimeter portions 103 and 104 traverse the airflow space 90 in the vehicle width direction.

[0049] In the airflow space 90, the airflow is made to flow more easily through the interior of the airflow space 90 in a meandering manner due to the separation sections 101 and 102 and the surrounding sections 103 and 104 around the holes. Therefore, the main arm section 70 is more easily cooled by the separation sections 101 and 102 and the surrounding sections 103 and 104 around the holes.

[0050] Here, in the case where the saddle-type vehicle 10 is in a stable state traveling at a constant speed on a level road surface, the vertical line L1 is defined as the line extending vertically through the center of the shaft hole 96a, and the horizontal line L2 is defined as the line extending horizontally through the center of the shaft hole 96a. In this case, the vent 91 is formed in front of the vertical line L1 and below the horizontal line L2. The exhaust port 92 is formed behind the vertical line L1 and above the horizontal line L2. Furthermore, the lower opening 93 is formed behind the vertical line L1 and below the horizontal line L2. Therefore, the exhaust port 92 is located above the vent port 91, and even if water or foreign matter enters, only air is easily discharged from the exhaust port 92.

[0051] Figure 9 is a cross-sectional view taken along the line IX-IX in Figure 6. As shown in Figure 9, the reduction gear housing chamber 66 communicates with the airflow space 90 through the communication hole 78c. The communication hole 78c is formed behind the vertical line L1 and above the horizontal line L2. The communication hole 78c is formed between the motor shaft hole 76a and the exhaust port 92. The communication hole 78c is located in front of and below the exhaust port 92. Because the communication hole 78c is in the vicinity of the exhaust port 92, it is easily exposed to the outside air, and the pressure inside the reduction gear housing chamber 66 is suppressed through the exhaust port 92 and the communication hole 78c.

[0052] In other words, when the temperature rises inside the reduction mechanism housing chamber 66, the pressure (internal pressure) inside the reduction mechanism housing chamber 66 rises, causing the lubricating oil used in the reduction mechanism 67 to volatilize. This allows air containing gaseous or atomized lubricating oil to be discharged to the outside, thereby lowering the internal pressure of the reduction mechanism housing chamber 66. In particular, since the communication hole 78c is located at the top, liquid lubricating oil is less likely to be discharged through the communication hole 78c, making it easier to effectively lower the internal pressure.

[0053] Figure 10 is a view in the direction of arrow X in Figure 6. A covering portion 105 is formed above the communication hole 78c. The covering portion 105 is formed in a semi-circular shape along the top of the communication hole 78c. The covering portion 105 is awning-like and protrudes outward in the vehicle width direction from the inner wall 72d. Therefore, the protruding end of the covering portion 105 is spaced apart from the arrangement surface 76 on the outside in the vehicle width direction. In other words, the covering portion 105 only narrows the flow path width (left-right width) of the airflow space 90, and air can pass over the covering portion 105.

[0054] As shown in Figure 10, when the exhaust port 92 is viewed from the rear and above, the cover portion 105 is visible. The cover portion 105 covers the upper part of the communication hole 78c. Therefore, even if foreign matter such as water or dust enters the airflow space 90 from the exhaust port 92, the cover portion 105 prevents the foreign matter from entering the communication hole 78c. Foreign matter that hits the cover portion 105 is easily dropped into the airflow space 90 and can be discharged from the lower opening 93.

[0055] In Figures 1 to 10, when an operating part such as the throttle is operated on the saddle-type vehicle 10, the PCU 31 supplies power from the battery 30 to the electric motor 13, causing the motor shaft 13a to rotate. The rotational force of the motor shaft 13a is transmitted to the rear wheels 12 via the reduction mechanism 57, driving the rear wheels 12. Thus, the saddle-type vehicle 10 moves. At this time, the electric motor 13 generates heat in the motor housing 62 due to the energization. In addition, frictional heat is generated in the reduction mechanism housing 66 due to the meshing of the motor shaft 13a, axle 12a, and reduction mechanism 67. Therefore, the motor housing 62 and the reduction mechanism housing 66 are prone to overheating.

[0056] In this embodiment, when the saddle-type vehicle 10 is in motion, airflow enters the swing arm 16. Specifically, when airflow enters the swing arm 16 from the conductor opening 71e on the front end of the swing arm 16, it is drawn into the airflow space 90 through the vent 91, and while cooling the airflow space 90, the airflow is discharged from the exhaust port 92. As a result, the airflow space 90, which passes between the motor housing 62 and the reduction mechanism housing 66, facilitates the cooling of the motor housing 62 and the reduction mechanism housing 66.

[0057] As described above, according to this embodiment to which the present invention is applied, in a saddle-type vehicle 10 that includes a motor housing chamber 62 for housing an electric motor 13 and a reduction mechanism housing chamber 66 for housing a reduction mechanism 67 that reduces the output of the electric motor 13 and transmits power to the rear wheels 12, the motor housing chamber 62 and the reduction mechanism housing chamber 66 are adjacent to each other via an airflow space 90 through which air flows. This configuration allows for efficient cooling of both the motor chamber 62 and the reduction mechanism chamber 66 by forming an airflow space 90 between them. Furthermore, the electric motor 13 is less susceptible to temperature influences from the adjacent reduction mechanism chamber 66, thus preventing a decrease in driving efficiency due to high temperatures. Consequently, this contributes to improved energy efficiency.

[0058] In this embodiment, an airflow space 90 is formed, and a communication hole 78c is formed in the inner wall 73d that separates the reduction mechanism housing chamber 66 from the airflow space 90, connecting the reduction mechanism housing chamber 66 and the airflow space 90. With this configuration, the communication hole 78c can be used as a breather path, eliminating the need to separately provide components such as hoses to form a breather path for communicating the air inside the reduction gear chamber 66 to the outside. Therefore, the number of parts and costs can be reduced while forming the breather path.

[0059] In this embodiment, the airflow space 90 has a vent 91 for introducing air in front of the saddle-type vehicle 10 and an exhaust port 92 for discharging air behind the saddle-type vehicle 10 beyond the vent 91, and a cover portion 105 extending in the vehicle width direction is provided inside the airflow space 90 above the communication hole 78c. With this configuration, the cover portion 105 prevents water and dust from entering through the exhaust port 92, thus keeping the airflow space 90 clean and maintaining the cooling effect of the airflow space 90. Furthermore, since the cover portion 105 is positioned above the communication hole 78c, it prevents external water and dust from entering the reduction mechanism housing chamber 66 through the communication hole 78c, thus maintaining the smooth operation of the reduction mechanism 67 inside the reduction mechanism housing chamber 66.

[0060] A lower opening 93 is provided on the underside of the saddle-type vehicle 10 in the airflow space 90, connecting the airflow space 90 with the outside of the airflow space 90. With this configuration, even if water or dust enters the airflow space 90, it can be discharged to the outside of the airflow space 90 through the lower opening 93. Also, even if lubricating oil from the reduction gear chamber 66 flows into the airflow space 90 through the communication hole 78c, the lubricating oil can be discharged to the outside of the airflow space 90 through the lower opening 93. Therefore, the inside of the airflow space 90 can be kept clean, and the decrease in cooling efficiency due to fouling of the walls of the airflow space 90 can be suppressed, thereby maintaining the cooling effect of the airflow space 90.

[0061] [Other embodiments] The embodiments described above represent only one aspect of the present invention and can be modified and applied as needed without departing from the spirit of the invention.

[0062] In the above embodiment, a motorcycle having a front wheel 14 and a rear wheel 12 was used as an example to describe the saddle-type vehicle 10. However, the present invention is not limited thereto, and can be applied to three-wheeled saddle-type vehicles having two front or rear wheels, or saddle-type vehicles having four or more wheels.

[0063] [Configurations supported by the above embodiment] The above embodiment supports the following configuration.

[0064] (Configuration 1) A saddle-type vehicle comprising a motor chamber for housing a motor and a transmission chamber for housing a power transmission mechanism that reduces the output of the motor and transmits power to the drive wheels, wherein the motor chamber and the transmission chamber are adjacent to each other via an airflow space through which air flows. This configuration allows for efficient cooling of both the motor and transmission compartments by creating an airflow space between them. Furthermore, the motor is less susceptible to temperature fluctuations in the adjacent transmission compartment, preventing a decrease in driving efficiency due to high motor temperatures. This, in turn, contributes to improved energy efficiency.

[0065] (Configuration 2) The saddle-type vehicle according to Configuration 1, characterized in that a transmission chamber communication hole is formed in the side wall that forms the airflow space and separates the transmission chamber from the airflow space, thereby connecting the transmission chamber and the airflow space. With this configuration, the transmission chamber communication hole can be used as a breather path, eliminating the need to separately provide components such as hoses to create a breather path for circulating air from inside the transmission chamber to the outside. Therefore, the number of parts and costs can be reduced while creating the breather path.

[0066] (Configuration 3) The saddle-type vehicle according to Configuration 2, characterized in that the airflow space has a vent for introducing air in front of the saddle-type vehicle and an exhaust port for discharging air behind the saddle-type vehicle beyond the vent, and a covering portion extending in the vehicle width direction is provided inside the airflow space above the transmission chamber communication hole. With this configuration, the cover prevents water and dust from entering through the exhaust port, thus keeping the airflow space clean and maintaining the cooling effect of the airflow space. Furthermore, since the cover is positioned above the transmission chamber communication hole, it prevents external water and dust from entering the transmission chamber through the communication hole, thus maintaining the smooth operation of the power transmission mechanism inside the transmission chamber.

[0067] (Composition 4) A saddle-type vehicle according to any one of configurations 1 to 3, characterized in that a lower communication hole is provided on the lower side of the airflow space of the saddle-type vehicle, which connects the airflow space with the outside of the airflow space. With this configuration, even if water or dust enters the airflow space, it can be discharged to the outside through the lower communication hole. Also, even if lubricating oil from the transmission chamber flows into the airflow space through the transmission chamber communication hole, the lubricating oil can be discharged to the outside through the lower communication hole. Therefore, the airflow space can be kept clean, suppressing the decrease in cooling efficiency due to dirt on the walls and maintaining the cooling effect of the airflow space. [Explanation of symbols]

[0068] 10. Saddle-type vehicles 12 Rear wheels (drive wheels) 13 Electric motor (motor) 62 Motor housing (motor room) 66. Deceleration Mechanism Housing (Mission Room) 67. Reduction mechanism (power transmission mechanism) 72d Interior wall (side wall) 73d Inner wall (side wall) 78c Communication hole (communication hole for the mission chamber) 90 Airflow Space 91 Ventilation opening 92 Exhaust port 93 Lower opening (lower communication hole) 105 Covering part

Claims

1. A motor room (62) housing the motor (13), In a saddle-type vehicle, the vehicle includes a transmission chamber (66) that houses a power transmission mechanism (67) that reduces the output of the motor (13) and transmits power to the drive wheels (12), The motor chamber (62) and the transmission chamber (66) are adjacent to each other via an airflow space (90) through which air flows. The airflow space (90) is formed, and a side wall (72d, 73d) that separates the mission chamber (66) from the airflow space (90) is formed, and a mission chamber communication hole (78c) that connects the mission chamber (66) and the airflow space (90) is formed in the side wall (72d, 73d), characterized in that a mission chamber communication hole (78c) is formed in the side wall (72d, 73d) that separates the mission chamber (66) from the airflow space (90), A saddle-type vehicle.

2. The aforementioned airflow space (90) includes a vent (91) that introduces air in front of the saddle-type vehicle (10), It has an exhaust port (92) that discharges air from the rear of the saddle-type vehicle (10) beyond the vent (91), The airflow space (90) is characterized in that a covering portion (105) extending in the vehicle width direction is provided above the transmission chamber communication hole (78c). A saddle-type vehicle as described in claim 1.

3. A lower communication hole (93) is provided on the lower side of the saddle-type vehicle (10) in the airflow space (90) to connect the airflow space (90) with the outside of the airflow space (90). A saddle-type vehicle according to claim 1 or 2.

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