Mounting structure and propulsion unit for watercraft propulsion systems

Abstract

To suitably reduce oscillation of a propulsion device for water surface moving body with an electric motor as driving source.SOLUTION: A mount structure 7 of a propulsion device for water surface moving body 6 including a case 11, an electric motor 12 stored in the case 11, and a propeller supported by the case 11 and rotated by driving force of the electric motor 12 includes: a fixed member 71 fixed to a hull 4 of a water surface moving body; a supporting member 72 attached to the fixed member 71 through an attachment shaft 87 for supporting the case 11; and a plurality of mount members 73 arranged in between the supporting member 72 and the case 11. The plurality of mount members 73 are positioned on the side opposite to the hull 4, with a virtual line V, which is parallel to the attachment shaft 87 and passes through the center C of the output shaft 49 of the electric motor 12, interposed therebetween, in a top view or an underside view.SELECTED DRAWING: Figure 7

Description

Technical Field

[0001] The present invention relates to a mounting structure for a propulsion device for a watercraft, a propulsion unit for a watercraft including the propulsion device for a watercraft and the mounting structure, and a watercraft equipped with the propulsion device for a watercraft and the mounting structure.

Background Art

[0002] In recent years, efforts towards realizing a low-carbon society or a decarbonized society have become active, and research and development on electrification technologies have been conducted in propulsion devices for watercraft such as outboard motors in order to reduce CO2 emissions and improve energy efficiency.

[0003] For example, Patent Document 1 discloses a propulsion device for a watercraft (an electric outboard motor) including an electric motor and a propeller (a propeller shaft and a propeller) that rotates by the driving force of the electric motor. The above electric motor is supported by a swivel portion via a pair of upper and lower mounting portions.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In a propulsion device for a watercraft using an electric motor as a drive source, compared with a propulsion device for a watercraft using an internal combustion engine as a drive source, the vibration derived from the drive source is reduced. However, since the vibration derived from the drive source is small in this way, the vibration derived from the propeller may be felt to be large. Therefore, there is still a strong demand for vibration reduction.

[0006] In view of the above background, an object of the present invention is to preferably reduce the vibration of a propulsion device for a watercraft using an electric motor as a drive source. [Means for solving the problem]

[0007] To solve the above problems, one aspect of the present invention provides a mounting structure (7, 114, 134) for a propulsion device (6, 113, 133) for a water-based mobile body, comprising a case (11), an electric motor (12) housed in the case, and a thruster (14) supported by the case and rotated by the driving force of the electric motor, wherein the mounting structure (7, 114, 134) comprises a fixing member (71, 116, 136) fixed to the hull (4) of the water-based mobile body (3), a support member (72, 118, 138) attached to the fixing member via a mounting shaft (87, 121, 139) and supporting the case, and a plurality of mounting members (73, 74, 119, 120, 144) arranged between the support member and the case, wherein in a top view or a bottom view, the plurality of mounting members are located on the opposite side from the hull, with a virtual line passing through the center of the output shaft (49) of the electric motor and parallel to the mounting shaft.

[0008] In this embodiment, multiple mounting members are arranged on the opposite side of the hull from the ship's hull, straddling a virtual line passing through the center of the output shaft of the heavy electric motor. This allows the support member to stably support the case via the multiple mounting members. As a result, vibrations of the propulsion system for a water-based mobile vehicle can be effectively reduced.

[0009] In the above embodiment, the case comprises an upper case (21) housing the electric motor and a lower case (22) rotatably supported by the upper case and supporting the thruster, and the plurality of mounting members include an upper mounting member (73) attached to the upper surface of the upper case and a lower mounting member (74) attached to the lower end of the upper case, and in a top view, at least a portion of the upper mounting member may overlap with the electric motor.

[0010] According to this embodiment, by arranging multiple mounting members to sandwich the upper case from above and below, the support member can more stably support the case via the multiple mounting members. This further effectively reduces vibrations in the propulsion system for water-based mobile vehicles.

[0011] In the above embodiment, the upper mounting member and the lower mounting member are each provided in pairs, and the distance between the pair of lower mounting members may be wider than the distance between the pair of upper mounting members.

[0012] According to this embodiment, by widening the distance between the pair of lower mounting members that bear the load of the upper case, the oscillation of the propulsion system for water-based vehicles can be suppressed. This further effectively reduces the vibration of the propulsion system for water-based vehicles.

[0013] In the above embodiment, the upper case comprises a motor case (24) housing the electric motor and a lower bracket (25) formed separately from the motor case and attached to the lower end of the motor case, wherein the upper mounting member is attached to the motor case and the lower mounting member may be attached to the lower bracket.

[0014] In this embodiment, the lower mounting member is attached to a lower bracket that is separate from the motor case. Therefore, the mounting position of the lower mounting member can be easily adjusted without being limited by the shape of the motor case.

[0015] In the above embodiment, the support member has a base plate (81) extending in the vertical direction, an upper stay (83) extending from the upper end of the base plate toward the opposite side of the hull, and a lower stay (84) extending from the lower end of the base plate toward the opposite side of the hull, wherein the upper mounting member may be attached to the tip of the upper stay, and the lower mounting member may be attached to the tip of the lower stay.

[0016] According to this embodiment, the upper and lower mounting members can be positioned on the opposite side of the dotted line from the hull using a support member with a simple configuration.

[0017] In the above embodiment, the positions and spring constants of the plurality of mounting members may be set such that the elastic center of the propulsion device for the water-based vehicle coincides with the center of gravity of the propulsion device for the water-based vehicle.

[0018] According to this embodiment, the resonances of the six degrees of freedom—forward / backward, left / right, up / down, yaw, pitch, and roll—occur independently at each frequency without influencing one another. In other words, the resonances of the six degrees of freedom can be made uncoupled. Therefore, amplification of vibrations of degrees of freedom unrelated to the input configuration can be suppressed, and the couple force applied to multiple mounting members (a couple force generated according to the distance between the elastic center and the center of gravity) can be further reduced. As a result, vibrations of propulsion systems for water-based mobile vehicles can be further reduced. In addition, when designing vibration isolation for the mounting structure, characteristics such as spring constants can be designed separately for each direction, making it easier to design the characteristics.

[0019] In the above embodiment, the plurality of mounting members may include a pair of first side mounting members (119) attached to both sides of the case, and a pair of second side mounting members (120) attached to both sides of the case and positioned below the pair of first side mounting members.

[0020] According to this embodiment, by arranging multiple mounting members to sandwich the upper case from both sides, the support member can more stably support the case via the multiple mounting members. This further effectively reduces vibrations in the propulsion system for water-based mobile vehicles.

[0021] In the above embodiment, the center of gravity of the propulsion device for the water-based mobile body may be located within the region surrounded by the plurality of mounting members.

[0022] According to this aspect, the vibration of the propulsion device for a watercraft can be suitably reduced by the mounting structure of the center-of-gravity support method.

[0023] In the above aspect, at least a part of the plurality of mounting members may be arranged on the principal axis of inertia of the propulsion device for a watercraft.

[0024] According to this aspect, the vibration of the propulsion device for a watercraft can be suitably reduced by the mounting structure of the principal axis of inertia support method.

[0025] In the above aspect, the plurality of mounting members include a pair of side mounting members (144) attached to both side surfaces of the case, and the pair of side mounting members may be arranged on the pitch axis as the principal axis of inertia of the propulsion device for a watercraft.

[0026] According to this aspect, the vibration of the propulsion device for a watercraft can be more suitably reduced by the mounting structure of the principal axis of inertia support method.

[0027] To solve the above problems, another aspect of the present invention is a propulsion unit (1, 111, 131) for a watercraft including the propulsion device for a watercraft and the mounting structure, wherein the propulsion device for a watercraft further includes a control device (13) for controlling the electric motor, and at least a part of the control device is arranged behind the electric motor and overlaps the electric motor in a front view.

[0028] According to this aspect, by arranging the electric motor and the control device side by side in the front-rear direction, the width of the propulsion device for a watercraft in the left-right direction can be suppressed. Thereby, the propulsion device for a watercraft can be made compact.

Effects of the Invention

[0029] According to the above aspects, the vibration of the propulsion device for a watercraft using an electric motor as a drive source can be suitably reduced.

Brief Description of the Drawings

[0030] [Figure 1] Side view showing the propulsion unit according to the first embodiment. [Figure 2] Cross-sectional view showing an outboard motor according to the first embodiment. [Figure 3] Perspective view showing the motor case according to the first embodiment. [Figure 4] Perspective view showing the lower bracket according to the first embodiment. [Figure 5] Front view showing the positional relationship between the electric motor and control device according to the first embodiment. [Figure 6] Perspective view showing a support member according to the first embodiment. [Figure 7] Top view showing the propulsion unit according to the first embodiment. [Figure 8] A bottom view showing the propulsion unit according to the first embodiment. [Figure 9] (A) Cross-sectional view showing the upper mounting member and its surrounding area according to the first embodiment, (B) Cross-sectional view of (A) from IXB to IXB [Figure 10] (A) Side view showing the propulsion unit according to the second embodiment, (B) Rear view thereof, (C) Top view thereof [Figure 11] (A) Side view showing the propulsion unit according to the third embodiment, (B) Rear view thereof, (C) Top view thereof [Modes for carrying out the invention]

[0031] (First Embodiment) The following describes a propulsion unit 1 for a water-based mobile vehicle (hereinafter abbreviated as "propulsion unit 1") according to the first embodiment of the present invention, with reference to Figures 1 to 9. The arrow Fr in the figures indicates the front of the propulsion unit 1.

[0032] Referring to Figure 1, the propulsion unit 1 is attached to the hull 4 of a vessel 3 (an example of a water-based vehicle) to provide thrust to the vessel 3. The propulsion unit 1 comprises an outboard motor 6 (an example of a propulsion device for a water-based vehicle) located outside the hull 4, and a mounting structure 7 for mounting the outboard motor 6 to the hull 4. The outboard motor 6 and the mounting structure 7 will be described in order below.

[0033] <Outboard motor 6> Referring to Figure 2, the outboard motor 6 comprises a case 11, an electric motor 12 housed in the case 11, a control device 13 for controlling the electric motor 12, a thruster 14 supported by the case 11 and rotating around the propulsion shaft X1 by the driving force of the electric motor 12, a drive shaft 15 provided in the drive force transmission path R from the electric motor 12 to the thruster 14 and extending along the pivot shaft X2, a bevel gear mechanism 16 connecting the drive shaft 15 and the thruster 14, and a reduction mechanism 17 provided in the drive force transmission path R for reducing the rotation of the electric motor 12. The following explanation will be based on the state in which the propulsion shaft X1 extends in the longitudinal direction and the pivot shaft X2 extends in the vertical direction (see Figure 2).

[0034] <Case 11> Referring to Figures 1 and 2, case 11 includes an upper case 21 and a lower case 22 that is rotatably supported by the upper case 21 around a pivot axis X2.

[0035] The upper case 21 includes a motor case 24, a lower bracket 25 fixed to the lower end of the motor case 24, and a control case 26 fixed to the rear upper part of the motor case 24.

[0036] Referring to Figure 3, the motor case 24 has a cylindrical peripheral wall portion 28 extending in the vertical direction and a flat plate-shaped upper wall portion 29 that closes the upper end of the peripheral wall portion 28. The upper wall portion 29 is formed integrally with the peripheral wall portion 28. A pair of upper base portions 31 protrude upward from the upper surface of the upper wall portion 29. The pair of upper base portions 31 are spaced apart in the left-right direction. An upper fitting groove 32 extending in the front-rear direction is provided on the upper surface of each upper base portion 31. Upper engagement holes 33 are provided on both the left and right sides of the upper fitting groove 32 on the upper surface of each upper base portion 31.

[0037] Referring to Figure 4, the lower bracket 25 is formed separately from the motor case 24. The lower bracket 25 is annular in shape. A pair of lower base portions 35 protrude outward to the left and right from the lower bracket 25. The pair of lower base portions 35 are spaced apart in the left-right direction. A lower fitting groove 36 extending in the front-rear direction is provided on the lower surface of each lower base portion 35. Lower engagement holes 37 are provided on both the left and right sides of the lower fitting groove 36 on the lower surface of each lower base portion 35.

[0038] Referring to Figures 1 and 2, the control case 26 is formed separately from the motor case 24. The control case 26 is located behind the motor case 24. The control case 26 is located on the opposite side of the mounting structure 7, with the motor case 24 in between.

[0039] The lower case 22 is connected to a steering motor (not shown) and is configured to rotate around a pivot axis X2 relative to the upper case 21 by the driving force of the steering motor. The lower case 22 has a rotating part 41 and a main body part 42 located below the rotating part 41.

[0040] The rotating part 41 has a cylindrical shape centered on the pivot axis X2. The upper part of the rotating part 41 is housed in the motor case 24. The rotating part 41 is attached to the motor case 24 via a plurality of bearings 44.

[0041] The main body 42 is fixed to the rotating part 41. A bullet-shaped gear case 45 extending in the front-rear direction is provided at the lower part of the main body 42. An axial hole 46 extending in the vertical direction is provided at the upper part of the main body 42, and the internal space of the gear case 45 communicates with the internal space of the rotating part 41 through this axial hole 46.

[0042] <Electric motor 12> Referring to Figure 2, the electric motor 12 is housed in a motor case 24. The electric motor 12 has a motor body 48 and an output shaft 49 extending downward from the motor body 48.

[0043] <Control device 13> Referring to Figure 2, the control device 13 is housed in a control case 26. The control device 13 consists of a PCU (Power Control Unit). The control device 13 is connected to the electric motor 12 and a battery (not shown) and controls the power supply from the battery to the electric motor 12.

[0044] Referring to Figure 5, a portion of the control device 13 is positioned behind the electric motor 12 and overlaps with the electric motor 12 in a front view. In other embodiments, the entire control device 13 may be positioned behind the electric motor 12 and overlap with the electric motor 12 in a front view.

[0045] <Propulsion device 14> Referring to Figure 2, the thruster 14 is rotatable around the thrust shaft X1 relative to the lower case 22, and is also rotatable integrally with the lower case 22 around the pivot shaft X2. The thruster 14 includes a propeller shaft 51 extending along the thrust shaft X1, and a propeller 52 fixed to the rear of the propeller shaft 51. The front of the propeller shaft 51 is rotatably supported by the gear case 45.

[0046] <Drive shaft 15> Referring to Figure 2, the drive shaft 15 has an upper shaft 54 ​​and a lower shaft 55 positioned below the upper shaft 54. The upper end of the upper shaft 54 ​​is fixed to the output shaft 49 of the electric motor 12. This allows the upper shaft 54 ​​to rotate integrally with the output shaft 49 of the electric motor 12. The lower shaft 55 is provided so as to be rotatable relative to the upper shaft 54. The lower shaft 55 passes through the shaft hole 46 of the main body portion 42 of the lower case 22. The lower shaft 55 is rotatably supported in the lower case 22 via a plurality of bearings 57.

[0047] <Bevel gear mechanism 16> Referring to Figure 2, the bevel gear mechanism 16 includes a first bevel gear 61 and a second bevel gear 62 that engages with the first bevel gear 61. The first bevel gear 61 is fixed to the lower end of the lower shaft 55. The second bevel gear 62 is fixed to the front end of the propeller shaft 51.

[0048] <Deceleration mechanism 17> The reduction gear 17 is housed in the rotating part 41 of the lower case 22. The reduction gear 17 is composed of, for example, a planetary gear mechanism. The input part of the reduction gear 17 is fixed to the lower end of the upper shaft 54. The output part of the reduction gear 17 is fixed to the upper end of the lower shaft 55.

[0049] <Operation of Outboard Motor 6> Referring to Figure 2, when the output shaft 49 of the electric motor 12 rotates, the rotation of the output shaft 49 is transmitted to the input of the reduction mechanism 17 via the upper shaft 54, and the reduction mechanism 17 reduces the rotation of the output shaft 49. This reduced rotation of the output shaft 49 is transmitted from the output of the reduction mechanism 17 to the lower shaft 55, causing the lower shaft 55 to rotate. The rotation of the lower shaft 55 is transmitted to the thruster 14 via the bevel gear mechanism 16, causing the thruster 14 to rotate around the thrust shaft X1. This imparts thrust to the ship 3, causing the ship 3 to move.

[0050] When the motor shaft of the steering motor (not shown) rotates, the rotation of the motor shaft is transmitted to the lower case 22, causing the lower case 22 and the propeller 14 to rotate around the pivot axis X2. This imparts a turning force to the ship 3, causing the ship 3 to turn.

[0051] <Mounting Structure 7> Referring to Figure 1, the mounting structure 7 comprises a fixing member 71 fixed to the hull 4, a support member 72 attached to the fixing member 71 and supporting the case 11, and a plurality of mounting members 73, 74 positioned between the support member 72 and the case 11.

[0052] <Fixing member 71> Referring to Figures 1 and 7, the fixing member 71 has a main wall portion 76 extending in the vertical direction and a pair of mounting wall portions 77 extending forward from the upper end of the main wall portion 76. The main wall portion 76 is fixed to the aft end (transom) of the hull 4. The pair of mounting wall portions 77 are provided spaced apart in the left-right direction.

[0053] <Support member 72> Referring to Figures 1 and 6, the support member 72 includes a base plate 81 extending in the vertical direction, an arm 82 extending from the upper end of the base plate 81 toward the front (towards the hull 4), an upper stay 83 extending from the upper end of the base plate 81 toward the rear (opposite side from the hull 4), and a lower stay 84 extending from the lower end of the base plate 81 toward the rear (opposite side from the hull 4).

[0054] Referring to Figure 7, a pair of mounting pieces 86 are provided at the front end (tip) of the arm 82. The pair of mounting pieces 86 are positioned on the left-right inward side of a pair of mounting wall portions 77 of the fixing member 71. A mounting shaft 87 (tilt shaft) extending in the left-right direction passes through the pair of mounting pieces 86 and the pair of mounting wall portions 77. As a result, the support member 72 is attached to the fixing member 71 via the mounting shaft 87, and the outboard motor 6 and the support member 72 can tilt relative to the hull 4 and the fixing member 71 around the mounting shaft 87.

[0055] Referring to Figure 6, a pair of upper bosses 88 are provided at the rear end (tip) of the upper stay 83. The pair of upper bosses 88 are spaced apart in the left-right direction. An upper bolt hole 89 is provided on the rear surface of each upper boss 88.

[0056] A pair of lower bosses 91 are provided at the rear end (tip) of the lower stay 84. The pair of lower bosses 91 are spaced apart in the left-right direction. A lower bolt hole 92 is provided on the rear surface of each lower boss 91.

[0057] <Multiple mounting members 73, 74> Referring to Figures 1, 7, and 8, the multiple mounting members 73 and 74 include a pair of upper mounting members 73 attached to the upper surface of the upper case 21 and a pair of lower mounting members 74 attached to the lower end of the upper case 21. The dashed line V in Figures 7 and 8 represents a virtual line (hereinafter referred to as "virtual line V") extending horizontally parallel to the mounting shaft 87. In the top and bottom views, the virtual line V passes through the center C of the output shaft 49 of the electric motor 12.

[0058] Referring to Figure 7, the pair of upper mounting members 73 are spaced apart in the left-right direction. In a top view, the pair of upper mounting members 73 are located on opposite sides of the dotted line V from the hull 4. In a top view, the entirety of each upper mounting member 73 overlaps with the electric motor 12. In other embodiments, in a top view, only a portion of each upper mounting member 73 may overlap with the electric motor 12.

[0059] Referring to Figure 9, each upper mounting member 73 includes a mounting bolt 94 extending in the front-rear direction, a mounting body 95 positioned around the outer circumference of the mounting bolt 94, a mounting cover 96 covering the mounting body 95, and a pair of mounting washers 97 positioned on both the front and rear sides of the mounting body 95. The pair of mounting washers 97 are omitted except in Figure 9.

[0060] The front end (one axial end) of the mounting bolt 94 engages with an upper bolt hole 89 provided in each upper boss 88 of the upper stay 83 of the support member 72. This attaches each upper mounting member 73 to each upper boss 88. A tightening nut 99 engages with the rear end (the other axial end) of the mounting bolt 94. The mounting body 95 and a pair of mounting washers 97 are sandwiched between the tightening nut 99 and each upper boss 88.

[0061] The mount body 95 is cylindrical overall. The mount body 95 has an inner cylinder portion 100, an outer cylinder portion 101 positioned on the outer circumference of the inner cylinder portion 100, and an elastic portion 102 positioned between the inner cylinder portion 100 and the outer cylinder portion 101. The inner cylinder portion 100 is fitted to the outer surface of the mount bolt 94. The lower part of the outer cylinder portion 101 is fitted to an upper fitting groove 32 provided on each upper base portion 31 of the motor case 24. The elastic portion 102 is made of an elastic material such as rubber. In other embodiments, the mount body 95 is not limited to the cylindrical shape used in this embodiment, but can take on various shapes such as square or V-shape.

[0062] The left and right central portions of the mount cover 96 cover the outer cylindrical portion 101 of the mount body 95 from above. Mounting bolts 107 pass through both the left and right sides of the mount cover 96. The mounting bolts 107 engage with the upper engagement holes 33 provided in each upper base portion 31 of the motor case 24. In this way, each upper mount member 73 is attached to each upper base portion 31.

[0063] Referring to Figure 8, the pair of lower mounting members 74 are spaced apart in the left-right direction. The left-right spacing of the pair of lower mounting members 74 is wider than the left-right spacing of the pair of upper mounting members 73. In a bottom view, the pair of lower mounting members 74 are located on the opposite side of the hull 4 from the dashed line V. In a bottom view, each lower mounting member 74 does not overlap with the electric motor 12. In other embodiments, in a bottom view, part or all of each lower mounting member 74 may overlap with the electric motor 12.

[0064] Referring to Figure 1, the structure of each lower mounting member 74 is the same as that of each upper mounting member 73, except that the top and bottom are inverted. The front end (axial end) of the mounting bolt 94 of each lower mounting member 74 engages with the lower bolt hole 92 (see Figure 6) provided in each lower boss 91 of the lower stay 84 of the support member 72. In this way, each lower mounting member 74 is attached to each lower boss 91.

[0065] Referring to Figure 8, mounting bolts 108 pass through both the left and right sides of the mount cover 96 of each lower mounting member 74. The mounting bolts 108 engage with each lower engagement hole 37 (see Figure 4) provided in each lower base portion 35 of the lower bracket 25. In this way, each lower mounting member 74 is attached to each lower base portion 35.

[0066] <Setting of the positions of multiple mounting members 73, 74 and the dynamic spring constants K1, K2> Referring to Figure 1, the longitudinal positions of the pair of upper mounting members 73 and the pair of lower mounting members 74 coincide with the longitudinal position of the center of gravity G of the outboard motor 6. In other words, the longitudinal position of the elastic center of the outboard motor 6 coincides with the center of gravity G of the outboard motor 6.

[0067] Referring to Figure 1, let D1 be the vertical distance from each upper mounting member 73 (here, the center of each upper mounting member 73) to the center of gravity G of the outboard motor 6, and let D2 be the vertical distance from each lower mounting member 74 (here, the center of each lower mounting member 74) to the center of gravity G of the outboard motor 6. Also, let K1 be the dynamic spring constant of each upper mounting member 73, and K2 be the dynamic spring constant of each lower mounting member 74. The dynamic spring constants K1 and K2 of the multiple mounting members 73 and 74 are set such that the following relation (1) holds true. K1:K2=D2:D1···(1) Therefore, the elastic center of the outboard motor 6 and the center of gravity G of the outboard motor 6 are located at the same vertical position.

[0068] Referring to Figure 7, the lateral distance from one upper mounting member 73 to the center of gravity G of the outboard motor 6 is equal to the lateral distance from the other upper mounting member 73 to the center of gravity G of the outboard motor 6. Referring to Figure 8, the lateral distance from one lower mounting member 74 to the center of gravity G of the outboard motor 6 is equal to the lateral distance from the other lower mounting member 74 to the center of gravity G of the outboard motor 6. Therefore, the lateral position of the elastic center of the outboard motor 6 and the center of gravity G of the outboard motor 6 coincide.

[0069] As described above, the positions and dynamic spring constants K1 and K2 of the multiple mounting members 73 and 74 are set so that the elastic center of the outboard motor 6 coincides with the center of gravity G of the outboard motor 6. Referring to Figure 7, in this embodiment, the pair of upper mounting members 73 are arranged symmetrically in the left-right direction, and the dynamic spring constant of one upper mounting member 73 matches the dynamic spring constant of the other upper mounting member 73. On the other hand, in other embodiments, due to constraints such as the positional relationship with other parts, it may not be possible to arrange the pair of upper mounting members 73 symmetrically in the left-right direction. In such cases, the position of the elastic center of the outboard motor 6 may be adjusted by making the dynamic spring constant of one upper mounting member 73 different from the dynamic spring constant of the other upper mounting member 73 (that is, by creating a left-right difference in the dynamic spring constants of the pair of upper mounting members 73), thereby making the elastic center of the outboard motor 6 coincide with the center of gravity G of the outboard motor 6. The same applies to the pair of lower mounting members 74.

[0070] Region Y1 in Figure 1 represents the area enclosed by multiple mounting members 73 and 74. The positions of the multiple mounting members 73 and 74 are set so that the center of gravity G of the outboard motor 6 is located within region Y1. In other words, the mounting structure 7 employs a center of gravity support system.

[0071] <Effects> In a top or bottom view, the multiple mounting members 73 and 74 are located on the opposite side of the dotted line V from the hull 4. Therefore, the support member 72 can stably support the case 11 via the multiple mounting members 73 and 74. This effectively reduces vibrations of the outboard motor 6.

[0072] Furthermore, as described above, the mount structure 7 employs a center of gravity support system. This center of gravity support system reduces the moment of inertia of the outboard motor 6, making it more prone to oscillation. Therefore, in this embodiment, the lateral spacing between the pair of lower mount members 74 is made wider than the lateral spacing between the pair of upper mount members 73 to suppress the oscillation of the outboard motor 6. This effectively reduces vibrations of the outboard motor 6.

[0073] <Variation> In this embodiment, the mounting structure 7 includes only a plurality of mounting members 73, 74 located on the opposite side of the virtual line V from the hull 4. In other embodiments, the mounting structure 7 may include a plurality of mounting members 73, 74 located on the opposite side of the virtual line V from the hull 4, in addition to a plurality of mounting members located on the same side of the virtual line V as the hull 4 (see Third Embodiment).

[0074] (Second Embodiment) Next, with reference to Figure 10, a propulsion unit 111 for a water-based mobile body according to the second embodiment of the present invention (hereinafter abbreviated as "propulsion unit 111") will be described. Details similar to those of the first embodiment will be omitted as appropriate. Arrows XB and XC in Figure 10(A) indicate the line of sight in Figures 10(B) and 10(C), respectively.

[0075] The propulsion unit 111 includes an outboard motor 113 (an example of a propulsion device for a water-based mobile vehicle) located outside the hull 4, and a mounting structure 114 for mounting the outboard motor 113 to the hull 4. The configuration of the outboard motor 113 is the same as that of the outboard motor 6 according to the first embodiment, so a description is omitted.

[0076] <Mounting structure 114> The mounting structure 114 includes a fixing member 116 fixed to the hull 4, a support member 118 attached to the fixing member 116 and supporting the upper case 21, and a plurality of mounting members 119, 120 positioned between the support member 118 and the upper case 21. Note that the fixing member 116 and the support member 118 are omitted in Figures 10(B) and 10(C).

[0077] The support member 118 is attached to the fixing member 116 via a mounting shaft 121 (tilt shaft) that extends in the left-right direction. This allows the outboard motor 113 and the support member 118 to tilt relative to the hull 4 and the fixing member 116 around the mounting shaft 121. The dashed line V in Figure 10(C) represents a virtual line (hereinafter referred to as "virtual line V") that extends in the left-right direction parallel to the mounting shaft 121. In a top view, the virtual line V passes through the center C of the output shaft 49 of the electric motor 12.

[0078] The multiple mounting members 119, 120 include a pair of first side mounting members 119 attached to the upper left and right sides of the upper case 21, and a pair of second side mounting members 120 attached to the lower left and right sides of the upper case 21 and positioned below the pair of first side mounting members 119. In a top view, the pair of first side mounting members 119 and the pair of second side mounting members 120 are located on the opposite side of the hull 4, separated by a dashed line V.

[0079] Region Y2 in Figure 10(A) represents the area enclosed by multiple mounting members 119 and 120. The positions of the multiple mounting members 119 and 120 are set so that the center of gravity G of the outboard motor 113 is located within region Y2. In other words, the mounting structure 114 employs a center of gravity support method.

[0080] (Third embodiment) Next, with reference to Figure 11, a propulsion unit 131 for a water-based mobile body according to the third embodiment of the present invention (hereinafter abbreviated as "propulsion unit 131") will be described. Details similar to those of the first embodiment will be omitted as appropriate. Arrows XIB and XIC in Figure 11(A) indicate the line of sight in Figures 11(B) and 11(C), respectively.

[0081] The propulsion unit 131 includes an outboard motor 133 (an example of a propulsion device for a water-based mobile vehicle) located outside the hull 4, and a mounting structure 134 for mounting the outboard motor 133 to the hull 4.

[0082] <Outboard motor 133> The outboard motor 133 has three principal inertia axes I1 to I3. More specifically, the outboard motor 133 has a roll axis I1 (X-axis) extending in the longitudinal direction, a pitch axis I2 (Y-axis) extending in the lateral direction, and a yaw axis I3 (Z-axis) extending in the vertical direction. The configuration of the outboard motor 133 is the same as that of the outboard motor 6 according to the first embodiment, except that the upper case 21 and the lower case 22 are fixed together (the upper case 21 and the lower case 22 rotate together), so a detailed explanation is omitted.

[0083] <Mounting structure 134> The mounting structure 134 includes a fixing member 136 fixed to the hull 4, a support member 138 attached to the fixing member 136 and supporting the case 11, and a plurality of mounting members 144 to 146 positioned between the support member 138 and the case 11. Note that the fixing member 136 and the support member 138 are omitted in Figures 11(B) and 11(C).

[0084] The support member 138 has a mounting portion 140 attached to the fixing member 136 via a mounting shaft 139 (tilt shaft) extending in the left-right direction, and a support portion 142 attached to the mounting portion 140 via a swivel shaft 141 extending in the up-down direction, which supports the case 11. With this configuration, the outboard motor 133 and the support member 138 can tilt around the mounting shaft 139 relative to the hull 4 and the fixing member 136. In addition, the outboard motor 133 and the support portion 142 can rotate around the swivel shaft 141 relative to the hull 4, the fixing member 136, and the mounting portion 140. The dashed line V in Figure 11(C) represents a virtual line (hereinafter referred to as "virtual line V") extending in the left-right direction parallel to the mounting shaft 139. In a top view, the virtual line V passes through the center C of the output shaft 49 of the electric motor 12.

[0085] The multiple mounting members 144-146 include a pair of side mounting members 144 attached to the left and right sides of the upper case 21, an upper mounting member 145 attached to the front of the upper case 21, and a lower mounting member 146 attached to the front of the lower case 22. In plan view, the pair of side mounting members 144 are located on the opposite side of the hull 4, separated by a virtual line V. The pair of side mounting members 144 are arranged on the pitch axis I2. In other words, the mounting structure 134 employs an inertia principal axis support system.

[0086] The upper mounting member 145 and the lower mounting member 146 are spaced apart in the vertical direction. In a plan view, the upper mounting member 145 and the lower mounting member 146 are located on the same side as the hull 4 with respect to the imaginary line V.

[0087] <Variation> In this embodiment, a pair of side mounting members 144 are arranged on the pitch axis I2. In other embodiments, multiple mounting members may be arranged on the roll axis I1 or the yaw axis I3.

[0088] This concludes the description of specific embodiments, but the present invention is not limited to the above embodiments or modifications and can be broadly modified and implemented. [Explanation of symbols]

[0089] 1: Propulsion Unit 3: Vessels (an example of a water-based mobile object) 4: Hull 6: Outboard motor (an example of a propulsion system for a water-based vehicle) 7: Mounting structure 11: Case 12: Electric motor 13: Control device 14: Propulsion device 21: Upper case 22: Lower case 24: Motor case 25: Lower bracket 49: Output shaft 71: Fixing member 72: Support member 73: Upper mounting member 74: Lower mounting member 81: Base plate 83: Upper stay 84: Lower stay 87: Mounting shaft 111: Propulsion Unit 113: Outboard motor (an example of a propulsion device for a water-based vehicle) 114: Mounting structure 116: Fixing member 118: Support member 119: First side mounting member 120: Second side mounting member 121: Mounting shaft 131: Propulsion Unit 133: Outboard motor (an example of a propulsion system for a water-based mobile vehicle) 134: Mounting structure 136: Fixing member 138: Support member 139: Mounting shaft 144: Side mounting member C: Center of the output axis G: Center of gravity I2: Pitch axis (an example of principal axes of inertia) V: virtual line Y1: Area surrounded by multiple mounting members Y2: Area surrounded by multiple mounting members

Claims

1. The case and, The electric motor housed in the aforementioned case, A thruster supported by the aforementioned case and rotated by the driving force of the aforementioned electric motor, A mounting structure for a propulsion system for a water-based mobile vehicle, comprising a drive shaft provided in the power transmission path from the electric motor to the propulsion system, A fixing member that is fixed to the hull of a water-based moving vessel, A support member is attached to the aforementioned fixing member via a mounting shaft and supports the case, The system comprises a plurality of mounting members positioned between the support member and the case, The aforementioned mounting shaft extends along the left-right direction with respect to the direction of travel of the hull, The aforementioned case is, An upper case housing the aforementioned electric motor, The upper case is rotatably supported around a pivot axis and has a lower case that supports the thruster, In a top or bottom view with the pivot shaft extending vertically, the plurality of mounting members are located on the opposite side of the hull, with a virtual line passing through the center of the drive shaft extending along the vertical direction and parallel to the mounting shaft. The plurality of mounting members include an upper mounting member attached to the upper surface of the upper case, In the aforementioned top view, at least a portion of the upper mounting member overlaps with the electric motor, forming a mounting structure for a propulsion device for a water-based mobile vehicle.

2. The mounting structure for a propulsion device for a water-based mobile body according to claim 1, further comprising a lower mounting member attached to the lower end of the upper case.

3. The upper mounting member and the lower mounting member are each provided as a pair. Mounting structure for a water-based propulsion device according to claim 2, wherein the distance between the pair of lower mounting members is wider than the distance between the pair of upper mounting members.

4. The aforementioned upper case is A motor case housing the aforementioned electric motor, It comprises a lower bracket which is formed separately from the motor case and attached to the lower end of the motor case, The upper mounting member is attached to the motor case. The mounting structure for a propulsion device for a water-based mobile body according to claim 2, wherein the lower mounting member is attached to the lower bracket.

5. The aforementioned support member is A base plate extending in the vertical direction, An upper stay extending from the upper end of the base plate toward the opposite side from the hull, It has a lower stay extending from the lower end of the base plate toward the opposite side from the hull, The upper mounting member is attached to the tip of the upper stay. The mounting structure for a propulsion device for a water-based mobile body according to claim 2, wherein the lower mounting member is attached to the tip of the lower stay.

6. The mounting structure for a propulsion device for a water-based vehicle according to claim 1, wherein the positions and spring constants of the plurality of mounting members are set such that the elastic center of the propulsion device for the water-based vehicle coincides with the center of gravity of the propulsion device for the water-based vehicle.

7. The aforementioned plurality of mounting members are A pair of first side mounting members attached to both sides of the case, Mounting structure for a water-based propulsion device according to claim 1, comprising a pair of second side mounting members attached to both sides of the case and positioned below the pair of first side mounting members.

8. The mounting structure for a propulsion device for a water-based mobile vehicle according to any one of claims 1 to 7, wherein the center of gravity of the propulsion device for a water-based mobile vehicle is located within the area surrounded by the plurality of mounting members.

9. Mounting structure for a propulsion device for a water-based vehicle according to claim 1, wherein at least a portion of the plurality of mounting members is arranged on the principal axis of inertia of the propulsion device for a water-based vehicle.

10. The plurality of mounting members include a pair of side mounting members attached to both sides of the case, The mounting structure for a propulsion device for a water-based vehicle according to claim 9, wherein the pair of side mounting members are arranged on the pitch axis which serves as the principal axis of inertia of the propulsion device for a water-based vehicle.

11. A propulsion device for a water-based mobile body according to claim 1, A propulsion unit for a water-based mobile body comprising the mounting structure described in claim 1, The propulsion system for the water-based mobile vehicle further comprises a control device for controlling the electric motor, A propulsion unit for a water-based mobile body, wherein at least a portion of the control device is positioned behind the electric motor and overlaps with the electric motor in a front view.

12. A case and The electric motor housed in the aforementioned case, A thruster supported by the aforementioned case and rotated by the driving force of the aforementioned electric motor, A drive shaft provided in the drive force transmission path from the electric motor to the propeller, A mounting structure for a propulsion system for a water-based mobile vehicle, comprising: A fixing member that is fixed to the hull of a water-based moving vessel, A support member is attached to the aforementioned fixing member via a mounting shaft and supports the case, The system comprises a plurality of mounting members positioned between the support member and the case, The aforementioned mounting shaft extends along the left-right direction with respect to the direction of travel of the hull, The aforementioned case is, An upper case housing the aforementioned electric motor, The upper case is rotatably supported around a pivot axis and has a lower case that supports the thruster, In a top or bottom view with the pivot shaft extending vertically, the plurality of mounting members are located on the opposite side of the hull, with a virtual line passing through the center of the drive shaft extending along the vertical direction and parallel to the mounting shaft. The aforementioned plurality of mounting members are A pair of first side mounting members are attached to the left and right sides of the upper case with respect to the direction of travel of the hull, A mounting structure for a propulsion device for a water-based mobile body, comprising: a pair of second side mounting members, each attached to the side surfaces of the upper case and positioned below the pair of first side mounting members.

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