Hybrid power unit, hybrid straddle-ride vehicle, and hybrid power unit case

Abstract

To increase assembly workability and design flexibility.SOLUTION: A hybrid power unit includes: an internal combustion engine; a power transmission shaft to which power from a crank shaft is transmitted and which is housed in a crank case; an electric motor including a motor drive shaft that protrudes from a motor housing to the lateral side and mounted on an outer surface of the crank case; a linkage extending through a passage hole of the crank case and configured to transmit power from the motor drive shaft to the power transmission shaft; and a shaft cover defining a shaft space that houses a portion of the motor drive shaft, which protrudes from the motor housing and detachably fixed to the outer surface of the crank case while overlapping the passage hole.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present disclosure relates to a hybrid power unit, a hybrid saddle-ride vehicle equipped with the same, and a case for the hybrid power unit. [Background technology]

[0002] Patent Document 1 discloses a hybrid vehicle equipped with an engine and an electric motor mounted on the top surface of the crankcase behind the engine cylinders. The crankcase has an extension located on the side of the motor housing and into which the end of the motor drive shaft is inserted. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-8214 Summary of the Invention [Problem to be solved by the invention]

[0004] The extension portion protrudes significantly from the main body of the crankcase, and in some cases the extension portion may interfere with the installation of other components during assembly, or may reduce the design freedom of the extension portion. [Means for solving the problem]

[0005] A hybrid power unit according to one aspect of the present disclosure comprises an internal combustion engine including a crankshaft and a crankcase that houses the crankshaft and has a through hole; a power transmission shaft that receives power from the crankshaft and is housed in the crankcase; an electric motor that includes a motor housing and a motor drive shaft that protrudes laterally from the motor housing and is mounted on the outer surface of the crankcase; a linkage that passes through the through hole and transmits power from the motor drive shaft to the power transmission shaft; and a shaft cover that defines a shaft space that houses the portion of the motor drive shaft that protrudes from the motor housing and is removably fixed to the outer surface of the crankcase while covering the through hole.

[0006] A hybrid saddle-ride vehicle according to one aspect of the present disclosure includes the hybrid power unit.

[0007] A case for a hybrid power unit according to one aspect of the present disclosure is a case for a hybrid power unit comprising an internal combustion engine including a crankshaft, and an electric motor including a motor housing and a motor drive shaft mounted on the outer surface of the internal combustion engine, and comprises a crankcase that accommodates the crankshaft and power transmission shaft and includes a through hole, and a shaft cover that defines an axial space that accommodates the portion of the motor drive shaft protruding from the motor housing and is removably fixed to the outer surface of the crankcase while covering the through hole. [Effects of the Invention]

[0008] According to one aspect of the present disclosure, the shaft cover prevents oil in the crankcase from splashing out through the passage hole and the linkage from being exposed to the outside, while the shaft cover is removable, making it easier to assemble other parts and increasing the design freedom of the shaft cover. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a side view of a hybrid straddle-ride vehicle according to an embodiment. [Figure 2]FIG. 2 is a schematic diagram of the power system of the vehicle of FIG. [Figure 3] FIG. 3 is a perspective view of the hybrid power unit of FIG. 1 as seen from the right rear. [Figure 4] FIG. 4 is a plan view of the upper case of the crankcase of the hybrid power unit of FIG. [Figure 5A] 5A is a perspective view of a cover body of the shaft cover of FIG. 3. FIG. [Figure 5B] FIG. 5B is a bottom view of the cover body of FIG. 5A. [Figure 6] FIG. 6 is a partial cross-sectional view of the hybrid power unit of FIG. 3 as seen from the rear. [Figure 7] FIG. 7 is a partial right side view of the hybrid power unit of FIG. 3 with the cover removed. [Figure 8] FIG. 8 is a partial perspective view of the hybrid power unit of FIG. 3 with the shaft cover removed. [Figure 9] FIG. 9 is a partial plan view of the hybrid power unit of FIG. 3 with the electric motor removed. [Figure 10A] FIG. 10A is a perspective view of a modified example of the cover body of the shaft cover of FIG. 8A. [Figure 10B] FIG. 10B is a rear view of the cover body of FIG. 10A. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, an embodiment will be described with reference to the drawings. In the following description, the concept of direction is based on the direction seen by a rider riding on a vehicle. That is, the forward direction of the vehicle is defined as the front, the opposite direction is defined as the rear, and the width direction of the vehicle, which is perpendicular to the front-to-rear direction, is defined as the left-to-right direction.

[0011] FIG. 1 is a side view of a hybrid saddle-ride vehicle 1 according to an embodiment. As shown in FIG. 1, the vehicle 1 is a motorcycle, which is an example of a saddle-ride vehicle on which a rider straddles. The vehicle 1 includes a front wheel 2, a rear wheel 3, a body frame 4, a front suspension 5, and a rear suspension 6. The rear wheel 3 is, for example, a drive wheel. The front suspension 5 connects the front wheel 2 to a front portion of the body frame 4. The rear suspension 6 connects the rear wheel 3 to a rear portion of the body frame 4. The front suspension 5 is connected to a steering shaft 7 via a bracket.

[0012] The body frame 4 has a head pipe 4a. A steering shaft 7 is inserted through the head pipe 4a so as to be angularly displaceable. A handlebar 8 that is gripped by the rider's hands is connected to the steering shaft 7. A fuel tank 9 is disposed behind the handlebar 8. A seat 10 on which the rider sits is disposed behind the fuel tank 9. The main frame 4b supports a hybrid power unit 11 disposed between the front wheel 2 and the rear wheel 3.

[0013] The hybrid power unit 11 is a parallel hybrid driving power source. The hybrid power unit 11 includes an internal combustion engine 12 as a prime mover and a motor unit 13 as a prime mover. The internal combustion engine 12 is, for example, a two-cylinder engine. The internal combustion engine 12 includes a cylinder 31, a crankcase 32, and a crankshaft 33. The cylinder 31 extends upward. The crankcase 32 is connected to the lower end of the cylinder 31 and extends rearward from the cylinder 31. The crankshaft 33 is housed in the crankcase 32 and rotates in conjunction with the piston of the cylinder 31. The crankcase 32 houses the transmission 14 to which the rotational power of the crankshaft 33 is transmitted.

[0014] A swing arm 18 that supports the rear wheel 3 and extends in the fore-and-aft direction is supported on the body frame 4 so as to be angularly displaceable. The rotational power of the output shaft 14b of the transmission 14 is transmitted to the rear wheel 3 via an output transmission member 19. The output transmission member 19 may be, for example, a chain, a belt, or a drive shaft.

[0015] FIG. 2 is a schematic diagram of the power system of the vehicle 1 of FIG. 1. As shown in FIG. 2, the transmission 14 has an input shaft 14a, an output shaft 14b, and multiple sets of transmission gears 14c with different reduction ratios. The input shaft 14a is an example of a power transmission shaft to which power from the crankshaft 33 is transmitted. The crankshaft 33, the input shaft 14a, and the output shaft 14b extend in the left-right direction of the vehicle 1. In the transmission 14, an arbitrary set of the multiple sets of transmission gears 14c is selected as a power transmission path. The power input to the input shaft 14a is transmitted to the output shaft 14b via the selected transmission gear 14c. The transmission 14 is, for example, a dog-clutch transmission. One end of the crankshaft 33 of the internal combustion engine 12 is connected to the primary gear 15 so as to be able to transmit power. The other end of the crankshaft 33 is connected to the starter generator 16 so as to be able to transmit power. A main clutch 17 is arranged coaxially with the input shaft 14a and is connected to one end of the input shaft 14a.

[0016] The primary gear 15 is disposed around the input shaft 14a between the main clutch 17 and the transmission gear 14c in the axial direction of the input shaft 14a. The primary gear 15 is rotatable relative to the input shaft 14a. The primary gear 15 transmits rotational power from the crankshaft 33 to the main clutch 17. The primary gear 15 is connected to the input shaft 14a of the transmission 14 via the main clutch 17 so as to be able to transmit power. The main clutch 17 disconnects and connects the power path from the crankshaft 33 to the input shaft 14a.

[0017] The motor unit 13 has an electric motor 41 and an inverter 42. In this embodiment, the inverter 42 is integrated with the electric motor 41, but may be disposed separately from the electric motor 41. The electric motor 41 has a motor housing 41a and a motor drive shaft 41b that protrudes laterally from the motor housing 41a. The motor drive shaft 41b extends in the left-right direction of the vehicle 1. Specifically, the motor drive shaft 41b protrudes rightward from the motor housing 41a.

[0018] The motor drive shaft 41b is mechanically connected to the input shaft 14a via a linkage 20, which is a power transmission mechanism. The linkage 20 may be, for example, a chain and sprocket mechanism, a pulley and belt mechanism, or a gear mechanism. In this embodiment, a chain and sprocket mechanism is used as the linkage 20. A sprocket 21 that co-rotates with the motor drive shaft 41b is provided on the motor drive shaft 41b. A sprocket 22 that co-rotates with the input shaft 14a is disposed around the input shaft 14a between the primary gear 15 and the transmission gear 14c. The sprocket 21 is mechanically connected to the sprocket 22 via a chain 23.

[0019] The controller 28 is an ECU having a processor and a memory. The controller 28 controls the operation of the internal combustion engine 12 and the main clutch 17. Specifically, the controller 28 controls the operation of the internal combustion engine 12 by controlling the throttle device T, the fuel injection device F, and the ignition device I. The controller 28 controls the operation of the electric motor 41 by controlling the inverter 42.

[0020] The hybrid power unit 11 includes a clutch actuator 24 capable of driving the main clutch 17. A controller 28 controls the clutch actuator 24 to operate the main clutch 17 between an engaged state and a disengaged state. The clutch actuator 24 is, for example, a hydraulic actuator including a hydraulic pump that is driven in conjunction with the operation of the internal combustion engine 12, the motor unit 13, or a combination thereof, but may also be an electric actuator.

[0021] FIG. 3 is a perspective view of the hybrid power unit 11 of FIG. 1 as seen from the right rear. As shown in FIG. 3, the motor unit 13 is disposed rearward of the cylinder 31 and above the crankcase 32, and is mounted on the upper surface of the crankcase 32. The electric motor 41 of the motor unit 13 has a motor drive shaft 41b that extends rightward. The inverter 42 is adjacent to the left side of the electric motor 41. The motor housing 41a has a cylindrical shape that is circular when viewed from the left-right direction. The motor housing 41a is fixed to the crankcase 32 from above by fasteners B1 such as bolts.

[0022] The crankcase 32 has an upper case 45 and a lower case 46 that are stacked one on top of the other in the vertical direction. The crankcase 32 has a side wall 32a (see FIG. 7) that defines a main chamber MR in which the transmission 14 is housed, and a peripheral wall 32b that protrudes from the side wall 32a to the right, i.e., outward in the vehicle width direction. A clutch space S1 surrounded by the peripheral wall 32b is part of the sub-chamber SR and houses the main clutch 17 (see FIG. 2). A clutch cover 29 is detachably fixed to the outer end face of the peripheral wall 32b in the vehicle width direction so as to close the space surrounded by the peripheral wall 32b.

[0023] A shaft cover 30 is disposed to the right of the motor housing 41a so as to cover the motor drive shaft 41b. The shaft cover 30 is detachably fixed to the top surface of the crankcase 32 with fasteners B2 such as bolts. In other words, the crankcase 32 and the shaft cover 30 form the case of the hybrid power unit 11. The shaft cover 30 has a tapered shape whose front-to-rear dimension decreases as it goes upward, and has, for example, a substantially triangular shape in side view. This allows the shaft cover 30 to be made smaller and lighter.

[0024] The axle cover 30 overlaps with the electric motor 41 when viewed in the vehicle width direction. The axle cover 30 is located more inward in the vehicle width direction than the clutch cover 29. The axle cover 30 is smaller than the clutch cover 29 when viewed in the vehicle width direction. The axle cover 30 has a cover main body 51 and a lid 52. The lid 52 is detachably fixed to the cover main body 51 from the outside in the vehicle width direction by fasteners B3 such as bolts.

[0025] The electric motor 41 is disposed rearward of the cylinder 31 and above the transmission 14. The tip of the motor drive shaft 41b of the electric motor 41 is disposed inward in the vehicle width direction from the side surface (right side surface in FIG. 3 ) of the cylinder 31 in the vehicle width direction, i.e., toward the center in the vehicle width direction. This prevents the electric motor 41 from protruding from the cylinder 31 in the vehicle width direction.

[0026] One side surface in the vehicle width direction (for example, the right side surface) of the motor housing 41a is disposed in a position retracted inward in the vehicle width direction, i.e., toward the center in the vehicle width direction, with respect to one side surface in the vehicle width direction (for example, the right side surface) of the cylinder 31. When viewed from the front-rear direction, the axle cover 30 is disposed in the space between one side surface in the vehicle width direction (for example, the right side surface) of the cylinder 31 and one side surface in the vehicle width direction (for example, the right side surface) of the motor housing 41a.

[0027] FIG. 4 is a plan view of the upper case 45 of the crankcase 32 of the hybrid power unit 11 of FIG. 3. As shown in FIG. 4, the upper case 45 has an opening 45a that is open in the vertical direction. The opening 45a connects the piston space of the cylinder 31 (see FIG. 3) with the main chamber MR (see FIG. 3) of the crankcase 32. A mating surface 45b on which the cylinder 31 (see FIG. 3) is placed is disposed around the opening 45a. The upper case 45 has an arc-shaped concave surface 45c recessed downward behind the opening 45a so as to fit along the outer peripheral surface of the motor housing 41a (see FIG. 3). The concave surface 45c accommodates the lower end of the motor housing 41a. The upper case 45 has motor bearing surfaces 45d on both the front and rear of the concave surface 45c to which the electric motor 41 (see FIG. 3) is fixed. The recessed surface 45c positions the lower end of the motor housing 41a below the motor seat surface 45d, thereby reducing the vertical distance between the upper surface of the crankcase 32 and the motor drive shaft 41b, and facilitating the reduction of the vertical dimension of the shaft cover 30.

[0028] The upper case 45 has a through hole 45e, which is open in the vertical direction, to the right of the recessed surface 45c. The through hole 45e is for connecting the shaft space S2 (see FIG. 5A) defined by the shaft cover 30 (see FIG. 3) with the clutch space S1 (see FIG. 3). A mating surface 45f on which the shaft cover 30 (see FIG. 3) is placed is arranged around the through hole 45e. The mounting surface of the crankcase 32 to which the shaft cover 30 is attached, i.e., the mating surface 45f, is formed as a plane extending parallel to the axial direction of the motor drive shaft 41b of the electric motor 41 fixed to the crankcase 32. In this embodiment, the mating surface 45f slopes downward as it moves rearward away from the cylinder 31. The mounting surface, i.e., the mating surface 45f, is arranged on the top surface of the crankcase 32. The mounting surface, i.e., the mating surface 45f, is arranged on a portion of the top surface of the crankcase 32 to the side of the portion where the electric motor 41 is arranged. The mounting surface, i.e., the mating surface 45f, is disposed behind the cylinder 31. The mounting surface, i.e., the mating surface 45f, is disposed above the main clutch 17.

[0029] A pair of fastening seats 45g having fastening holes are disposed at the bottom of the recessed surface 45c. The fastening seats 45g are located below the mating surface 45f but are adjacent to the mating surface 45f around the through hole 45e in a plan view. The mating surface 45f has a recess 45j in a portion adjacent to the fastening seats 45g in a plan view that is recessed toward the through hole 45e to avoid the fastening seats 45g. The fastening seats 45g are disposed in the recess 45j in a plan view. That is, the fastening seats 45g are disposed so as to be visible when viewed from above the upper case 45. The crankcase 32 has, at the mating surface 45f, a fastening seat 45h that protrudes away from the through hole 45e and has a fastening hole, and a fastening seat 45i that protrudes toward the through hole 45e and has a fastening hole. The fastening seat 45i is disposed adjacent to the fastening seat 45g. The fastening seat portion 45i is disposed inside the cover main body 51 in a plan view, and therefore the cover main body 51 (see FIG. 3) can be brought closer to the electric motor 41 (see FIG. 3).

[0030] 5A is a perspective view of the cover body 51 of the axle cover 30 of FIG. 3. FIG. 5B is a bottom view of the cover body 51 of FIG. 5A. As shown in FIGS. 5A and 5B, the cover body 51 of the axle cover 30 defines an axle space S2 as an internal space. The cover body 51 has a through hole H1, a shaft hole H2, and an opening H3. The through hole H1 connects the axle space S2 to the through hole 45e (see FIG. 4) of the upper case 45. The shaft hole H2 opens the axle space S2 toward the motor housing 41a (see FIG. 3), allowing the motor drive shaft 41b (see FIG. 3) to enter the axle space S2. The opening H3 opens the axle space S2 outward in the vehicle width direction and is closed by a lid 52 (see FIG. 3). The opening H3 is larger than the sprocket 21 (see FIG. 7). This allows easy access to the sprocket 21 and facilitates maintenance.

[0031] The cover body 51 has a side wall portion 51a facing the motor housing 41a (see FIG. 3) and a fitted cylindrical portion 51b protruding outward from the side wall portion 51a toward the motor housing 41a (see FIG. 3). The fitted cylindrical portion 51b defines an axial hole H2. The cover body 51 has a pair of guide supports 51c, 51d facing the axial space S2. The guide support 51c is a seat through which a fastener B5 that pivotally supports a fixed guide 60 (see FIG. 7) described later is inserted. The guide support 51d is a seat through which a support pin 62 that pivotally supports a movable guide 61 (see FIG. 7) described later is inserted. The pair of guide supports 51c, 51d are disposed at the front and rear of the cover body 51, respectively, and protrude from the inner surface of the cover body 51 toward the axial space S2.

[0032] The shaft cover 30 is made of a metal material, which increases the rigidity of the guide supports 51c, 51d. The shaft cover 30 is made of a metal material, which makes it less likely to deform, and maintains a good seal between the shaft cover 30 and the motor drive shaft 41b. However, the material of the shaft cover 30 is not limited to this, and it may be made of a resin material.

[0033] The cover body 51 has a mating surface 51e that abuts against the mating surface 45f of the upper case 45. The mating surface 51e is disposed so as to surround the passage hole H1. When viewed from a direction perpendicular to the mating surface 51e, the fitted tubular portion 51b protrudes outward beyond the mating surface 51e toward the motor housing 41a (see FIG. 3). The cover body 51 has, on the mating surface 51e, a fastening seat 51f having a fastening hole that matches the fastening seat 45h (see FIG. 4) of the upper case 45, and a fastening seat 51g having a fastening hole that matches the fastening seat 45i (see FIG. 4) of the upper case 45. The fastening seat 51f protrudes in a direction away from the passage hole H1. The fastening seat 51g protrudes toward the passage hole H1. That is, the fastening seat 51g protrudes toward the axial space S2. The fastening seat portion 51g is disposed in the middle portion of the passage hole H1 in the front-rear direction, thereby making it possible to prevent interference with the chain 23 (see FIG. 7).

[0034] Fig. 6 is a partial cross-sectional view of the hybrid power unit 11 of Fig. 3 as seen from the rear. Fig. 7 is a partial right side view of the hybrid power unit 11 of Fig. 3. Fig. 8 is a partial perspective view of the hybrid power unit of Fig. 3. Note that Figs. 6 and 7 show a state in which the cover 52 of the shaft cover 30 (see Fig. 3) and the clutch cover 29 (see Fig. 3) have been removed, and the main clutch 17 (see Fig. 2) is not shown. Fig. 8 shows a state in which the shaft cover 30 has been removed.

[0035] As shown in FIG. 6 , the upper case 45 is fastened to the lower case 46 in the vertical direction by fasteners B4 such as bolts. A bearing 57 supporting the input shaft 14a is sandwiched between the upper case 45 and the lower case 46 in the vertical direction. The side wall portion 32a of the crankcase 32 has an insertion hole 32c that connects the main chamber MR to the sub-chamber SR. The bearing 57 is disposed in the insertion hole 32c. That is, the bearing 57 is sandwiched between the upper case 45 and the lower case 46. The input shaft 14a passes through the insertion hole 32c from the main chamber MR and reaches the clutch space S1. A sprocket 22 is provided on the input shaft 14a in the clutch space S1.

[0036] 6 and 7, the shaft cover 30 is detachably fixed to the outer surface of the crankcase 32 while covering the through-hole 45e of the crankcase 32. The mating surface 51e of the cover main body 51 of the shaft cover 30 abuts from above against the mating surface 45f of the upper case 45 of the crankcase 32. The fastener B3 is inserted vertically through the fastening seats 51f, 51g of the cover main body 51 and the fastening seats 45h, 45i of the upper case 45 to fasten the cover main body 51 to the upper case 45. The fastener B3 is fastened to the fastening seats 51f and 45h outside the shaft space S2. The fastener B3 is fastened to the fastening seats 51g and 45i inside the shaft space S2. The through-hole H1 of the cover main body 51 communicates with the through-hole 45e of the upper case 45.

[0037] 6 and 8, the motor housing 41a has a housing main body 41aa and a fitting tubular portion 41ab. The housing main body 41aa houses a rotor and a stator. The fitting tubular portion 41ab protrudes from the housing main body 41aa toward the shaft cover 30. The fitting tubular portion 41ab has a cylindrical shape and opens toward the shaft cover 30.

[0038] As shown in FIG. 6, the fitting tubular portion 41ab of the motor housing 41a is fitted into the fitted tubular portion 51b of the cover main body 51 of the shaft cover 30. A seal member 55 is interposed between the outer peripheral surface of the fitting tubular portion 41ab and the inner peripheral surface of the fitted tubular portion 51b. The motor drive shaft 41b protrudes from the housing main body 41aa through the fitting tubular portion 41ab to the outside of the motor housing 41a. An annular seal member 56 is interposed in the gap between the motor drive shaft 41b and the fitting tubular portion 41ab. The motor drive shaft 41b passes through the internal space of the fitting tubular portion 41ab and the shaft hole H2 of the cover main body 51 to reach the shaft space S2. A sprocket 21 is provided on the motor drive shaft 41b in the shaft space S2.

[0039] The through hole H1 of the cover main body 51 communicates with the through hole 45e of the upper case 45. The chain 23 passes through the through holes H1, 45e and is wound around the sprocket 21 disposed in the shaft space S2 and the sprocket 22 disposed in the clutch space S1. That is, a linkage 20 including the sprockets 21, 22 and the chain 23 is disposed in the auxiliary chamber SR, which includes the clutch space S1 and the shaft space S2. The linkage 20 transmits driving force from the motor drive shaft 41b to the input shaft 14a. The chain 23 is an example of a power transmission loop, and a belt may also be used as the power transmission loop.

[0040] Of the outer surfaces of the crankcase 32, a mating surface 45f, which is a mounting surface to which the shaft cover 30 is fixed, is disposed on the top surface of the crankcase 32. Specifically, the mating surface 45f is disposed more inward in the vehicle width direction than the clutch cover 29 and is disposed in a position radially adjacent to the end of the input shaft 14a of the transmission 14. For example, the mating surface 45f is disposed more outward in the vehicle width direction than the insertion hole 32c into which the bearing 57 that supports the input shaft 14a is fitted. This makes it easier to arrange the fastener B4 that joins the upper case 45 and the lower case 46 together.

[0041] The axle cover 30 has a tapered shape in rear view, with the vehicle width direction dimension decreasing upward. Specifically, the mating surface of the cover body 51 on which the lid 52 is placed is an inclined surface that slopes upward so as to approach the electric motor 41. More specifically, the wall of the axle cover 30 facing the electric motor 41 extends along a plane perpendicular to the motor drive shaft 41b, and the lid 52, which is the wall of the axle cover 30 opposite the electric motor 41, extends obliquely with respect to an imaginary plane perpendicular to the motor drive shaft 41b and slopes upward so as to approach the electric motor 41.

[0042] 7 and 8, the hybrid power unit 11 includes a fixed guide 60 and a movable guide 61 that guide the chain 23. The fixed guide 60 and the movable guide 61 face each other so as to press the outer periphery of the chain 23 toward the inner periphery. Specifically, the fixed guide 60 abuts against the outer periphery of the chain 23 from the front, and the movable guide 61 abuts against the outer periphery of the chain 23 from the rear.

[0043] The fixed guide 60 is supported by the crankcase 32 and the cover main body 51. The upper end of the fixed guide 60 is fixed to a guide support 51c of the cover main body 51 by a fastener B5. The movable guide 61 is supported by the cover main body 51 so as to be able to swing freely. The upper end of the movable guide 61 is rotatably connected to a guide support 51d of the cover main body 51 by a support pin 62. The support pin 62 supports both the cover main body 51 and the movable guide 61, thereby reducing the number of parts. The guide supports 51c, 51d are arranged so as to be exposed through the opening H3 when the lid 52 (see FIG. 3) is removed, when viewed from the outside in the vehicle width direction.

[0044] A tensioner 63 is provided in the crankcase 32 to bias the movable guide 61 toward the chain 23 to prevent slack in the chain 23. In this embodiment, the tensioner 63 is a hydraulic piston that can press the movable guide 61 toward the chain 23, but it may also be another actuator such as a solenoid.

[0045] The electric motor 41 functions as a drive motor and also as a regenerative motor. In this case, it is assumed that the chain 23 transmits power from the electric motor 41 to the input shaft 14a, and that the chain 23 transmits power from the input shaft 14a to the electric motor 41. Therefore, a fixed guide 60 and a movable tensioner 61 may be provided on both the front and rear sides of the chain 23.

[0046] Fig. 9 is a partial plan view of the hybrid power unit 11 of Fig. 3 with the electric motor 41 removed. As shown in Fig. 9, the fitted cylindrical portion 51b of the cover main body 51 is a portion that protrudes from the side wall portion 51a toward the motor housing 41a when viewed from above. When viewed from a direction perpendicular to the mating surface 45f (see Fig. 8), the fitted cylindrical portion 51b protrudes toward the motor housing 41a beyond the mating surface 45f.

[0047] A pair of fasteners B4 fastened to the crankcase 32 from above are positioned in a plan view so as to sandwich a bearing 57 that supports the input shaft 14a. The fitted tubular portion 51b of the cover body 51 overlaps a portion of the fastener B4 when viewed from the fastening direction of the fasteners B4. The fastening direction of the fasteners B4 is, for example, a direction perpendicular to the mating surface 45f (see FIG. 8). When viewed from the fastening direction of the fasteners B4, the fitted tubular portion 51b of the cover body 51 is adjacent to the bearing 57 that is positioned between the pair of fasteners B4.

[0048] FIG. 10A is a perspective view of a cover body 151 of a modified example. FIG. 10B is a rear view of the cover body 151 of FIG. 10A. As shown in FIGS. 10A and 10B, the cover body 151 has a substantially rectangular parallelepiped shape, but is basically the same as the cover body 51 described above. The cover body 151 defines an axial space S2 as an internal space. Like the cover body 51, the cover body 151 has a passage hole H1, an axial hole H2, and an opening H3. Like the cover body 51, the cover body 151 has a side wall portion 151a and a fitted tubular portion 151b that protrudes outward from the side wall portion 151a toward the motor housing 41a (see FIG. 6). Like the cover body 51, the cover body 151 has guide supports 151c and 151d.

[0049] According to the configuration described above, the shaft cover 30 can prevent oil inside the crankcase 32 from splashing out through the passage hole 45e and the linkage 20 from being exposed to the outside. By fastening the fastener B4 to the crankcase 32 with the shaft cover 30 removed, the shaft cover 30 and the fastener B4 can be fixed to the crankcase 32 without interfering with each other. Because the shaft cover 30 is detachable, it can be designed without considering interference with the fastener B4, increasing design freedom compared to when the shaft cover 30 is designed with interference with the fastener B4 in mind. When the shaft cover 30 is cast, casting can be easily performed because the shaft cover 30 is a separate body from the crankcase 32.

[0050] By performing the fastening work of the fasteners B4 before assembling the shaft cover 30, it is possible to prevent the shaft cover 30 from interfering with the fastening work of the fasteners B4. The fitted tubular portion 51b of the shaft cover 30 can be made to protrude toward the motor housing 41a without impairing the ease of assembly. Because the fitted tubular portion 51b of the shaft cover 30 does not interfere with the fastening work of the fasteners B4, the protrusion amount of the fitted tubular portion 51b of the shaft cover 50 can be increased, and a thick seal member 55 can be used to improve sealing performance and durability.

[0051] Since the shaft cover 30 includes guide supports 51c, 51d that support the fixed guide 60 and the movable guide 61 that guide the chain 23, the guide supports 51c, 51d can be formed more easily than if the guide supports 51c, 51d were formed in the crankcase 32.

[0052] The fastening seat portion 51g of the shaft cover 50 does not protrude from the side wall portion 51a toward the motor housing 41a, but protrudes from the side wall portion 51a toward the shaft space S2, so that the motor housing 41a can be brought close to the shaft cover 30, thereby realizing a compact layout.

[0053] The shaft cover 30 may not have the lid 52, and the opening H3 may be eliminated from the cover body 51. The fasteners B4 that overlap with the fitted tubular portions 51b when viewed from the fastening direction of the fasteners B4 are not limited to bolts and may be, for example, nuts. The fasteners B4 arranged on the outer surface of the crankcase 32 may be adjacent to each other without overlapping when viewed from the fastening direction of the fasteners B4. Even in this case, by performing the fastening work of the fasteners B4 with the shaft cover 30 removed, it is possible to prevent the tools used to fasten the fasteners B4 from interfering with the shaft cover 30.

[0054] The fastener B4 may be used to fasten a component such as a bracket to the crankcase 32, in addition to fastening the upper case 45 to the lower case 46. The fastening direction of the fastener B4 and the direction perpendicular to the mating surface 45f are not limited to the up-down direction, and may be other directions.

[0055] When viewed from the fastening direction of fastener B4, the portion of shaft cover 30 adjacent to fastener B4 does not have to be the mating tubular portion 51b, as long as it is a portion that protrudes from side wall portion 51a toward motor housing 41a, and may be, for example, a portion that protrudes from side wall portion 51a for something to be placed in shaft space S2 of shaft cover 30 (e.g., fastener B5, support pin 62, guide supports 51c, 51d, etc.).

[0056] In the embodiment, the "power transmission shaft" to which the power of the crankshaft 33 is transmitted and which is housed in the crankcase 32 is the input shaft 14a of the transmission 14, but it may be a shaft that does not constitute a transmission. The crankcase 32 may not house a transmission, but may house a power transmission shaft that is interposed in the power transmission path between the crankshaft 33 and the rear wheel 3. The straddle-ride vehicle on which the hybrid power unit 11 is mounted may be a three-wheeled vehicle instead of a two-wheeled vehicle. The hybrid power unit 11 may also be mounted on a four-wheeled vehicle or a device other than a vehicle instead of a straddle-ride vehicle.

[0057] The internal combustion engine 12 may have any known internal combustion engine structure. The number of cylinders in the internal combustion engine 12 is not limited to two, but may be, for example, one or four. The hybrid power unit 11 may be a parallel hybrid type or a series hybrid type.

[0058] Although the linkage 20 has been illustrated as connecting the motor drive shaft 41b to the input shaft 14a of the transmission 14, the present invention is not limited to this. For example, the linkage 20 may connect the motor drive shaft 41b to a rotating body upstream of the main clutch 17, such as the primary gear 15. The linkage 20 may also connect the motor drive shaft 41b to the output shaft 14b of the transmission 14. In the present embodiment, the crankshaft 33 extends in the vehicle width direction, but the crankshaft 33 may extend in another direction.

[0059] The motor drive shaft 41b protrudes from only one side of the motor housing 41a, but may protrude from both sides of the motor housing 41a. In that case, both ends of the motor drive shaft 41b may be covered with shaft covers.

[0060] In addition to or instead of the guide supports 51c and 51d, the axle cover 30 may have supports for supporting other components disposed in the axle space S2. For example, the axle cover 30 may support a tensioner that applies tension to the chain 23, an injection member that injects lubricating fluid, or a sensor that is disposed in the axle space S2.

[0061] At least one of the through hole H1 and the through hole 45e needs only to have an area large enough for the lean gauge 20 to pass through, and may be structured so that the space through which the drive side of the chain 23 passes and the space through which the driven side of the chain 23 passes are blocked.

[0062] As described above, the above-described embodiments have been described as examples of the technology disclosed in this application. However, the technology of the present disclosure is not limited to these embodiments and can be applied to embodiments in which modifications, substitutions, additions, omissions, etc. are made as appropriate. Furthermore, the components described in the above-described embodiments can be combined to create new embodiments. For example, some configurations or methods in one embodiment may be applied to other embodiments, and some configurations in one embodiment may be separated from other configurations in that embodiment and extracted as desired. Furthermore, the components described in the accompanying drawings and detailed description include not only components essential for solving the problem, but also components that are not essential for solving the problem, and are used to illustrate the technology. [Explanation of symbols]

[0063] 1 Hybrid saddle-ride vehicle 11 Hybrid power unit 12 Internal combustion engine 13 Motor unit 14 Transmission 14a Input shaft 20 Linkage 23 Chain 30,130 Axis cover 32 Crankcase 33 Crankshaft 41 Electric motor 41a Motor housing 41aa Housing main body 41ab Fitting cylinder part 41b Motor drive shaft 45e Passing hole 45f mating surface 51 Cover body 51a Side wall part 51b Fitted cylinder part 51c, 51d guide support 51e Mating surface 52 Lid 55 Sealing material 60 Fixed guide 61 Movable guide B3, B4 Fasteners S2 axis space

Claims

1. an internal combustion engine including a crankshaft and a crankcase that houses the crankshaft and has a through hole; a power transmission shaft to which power from the crankshaft is transmitted and which is housed in the crankcase; an electric motor including a motor housing and a motor drive shaft protruding laterally from the motor housing, the electric motor being mounted on an outer surface of the crankcase; a linkage that passes through the through hole and transmits power from the motor drive shaft to the power transmission shaft; a shaft cover that defines a shaft space to accommodate a portion of the motor drive shaft protruding from the motor housing and is removably fixed to the outer surface of the crankcase while covering the through hole.

2. The crankcase further includes a fastener that is fastened to the crankcase. The hybrid power unit according to claim 1 , wherein a portion of the shaft cover is adjacent to the fastener when viewed from a fastening direction of the fastener.

3. the shaft cover includes a mating surface that abuts against the outer surface of the crankcase, 3. The hybrid power unit according to claim 2, wherein the portion of the shaft cover is a portion that protrudes beyond the mating surface toward the motor housing when viewed in a direction perpendicular to the mating surface.

4. the motor housing includes a housing main body and a fitting tubular portion that protrudes from the housing main body toward the shaft cover and through which the motor drive shaft is inserted, the shaft cover includes a side wall portion facing the motor housing and a fitted tubular portion protruding from the side wall portion toward the motor housing, the fitting cylindrical portion of the motor housing is fitted to the fitted cylindrical portion of the shaft cover via a seal member, The hybrid power unit according to claim 3 , wherein the portion of the shaft cover is the fitted tubular portion.

5. the linkage includes a power transmission loop that passes through the through hole and mechanically connects the motor drive shaft to the power transmission shaft; The hybrid power unit further includes a guide that passes through the through hole and guides the power transmission loop, The hybrid power unit according to claim 1 , wherein the shaft cover includes a guide support that supports the guide.

6. 6. The hybrid power unit according to claim 1, wherein the shaft cover includes a side wall portion facing the motor housing, and a fastening seat portion protruding from the side wall portion toward the shaft space and having a fastening hole into which a second fastener for fixing the shaft cover to the crankcase is inserted.

7. A hybrid straddle-ride vehicle comprising the hybrid power unit according to any one of claims 1 to 6.

8. A case for a hybrid power unit including an internal combustion engine including a crankshaft, a power transmission shaft to which power from the crankshaft is transmitted, and an electric motor including a motor housing and a motor drive shaft and mounted on an outer surface of the internal combustion engine, a crankcase that houses the crankshaft and the power transmission shaft and includes a passage hole through which a linkage that transmits power from the motor drive shaft to the power transmission shaft passes; A case for a hybrid power unit comprising: a shaft cover that defines an axial space to accommodate a portion of the motor drive shaft protruding from the motor housing, and that is removably fixed to the outer surface of the crankcase while covering the through hole.

Images