Electric outboard engine

Abstract

To provide an electric outboard engine with durability, anti-vibration effect, moreover easy steering while aiming for durability, anti-vibration effect, moreover easy steering, and so on under the structural condition that an electric motor is arranged behind a swivel bracket in an electric outboard engine.SOLUTION: An electric outboard engine has the structure that the outboard engine body load of an electric outboard engine is supported by the conventional type upper mount system (the upper mount system that two mount arms are fixed to the outboard engine body side via a mount bracket) and supported by the lower mount unit 30 with a vibration-proof function, where the lower mount unit with an anti-vibration function is held within the yoke assembly formed by fastening both ends of the bracket in the motor basement side integrated with the motor basement and protruding beyond the cowling in front of the motor basement, and both ends of a separate mount bracket forming a pair with that bracket.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present invention relates to an electric outboard motor, specifically an electric outboard motor in which an electric motor is disposed behind a swivel bracket and which has only one lower mount unit that supports a steering shaft from below. [Background technology]

[0002] With the increasing focus on environmental issues in recent years, electric outboard motors, which use electric motors as their power source, have been proposed and are now in use in many places to fundamentally solve the problems inherent to gasoline-powered outboard motors, such as gasoline and lubricating oil leaks and exhaust gas discharge into the water.

[0003] When placing the electric motor, which is the source of propulsion power, inside the body of an electric outboard motor, there are two types: one in which the electric motor is placed in a space called the upper section of the outboard motor body (higher in the height direction than the swivel bracket and behind the swivel bracket), just like in gasoline engine outboard motors, and another in which a control mechanism such as the electric motor controller is placed in the upper section and the electric motor is placed in a space called the middle section (at the same height as the swivel bracket and behind the swivel bracket).Of these, the type that is the subject of the present invention, which will be described in detail below, is the latter type.

[0004] Electric outboard motors in which the electric motor is disposed behind a swivel bracket are disclosed in Patent Documents 1 and 2. These two patent documents are by the same applicant and each discloses an invention related to a mounting system, with Patent Document 2 pointing out the problems with the invention disclosed in Patent Document 1 and disclosing an invention that leads to a solution to those problems.

[0005] Figure 1 of Patent Document 1 (which refers to the middle section as the "middle case" and the mechanical unit housed within the middle case as the "middle unit") discloses "an upper mount 10 and a lower mount 11 within a motor compartment 13." From the drawing alone, the upper mount 10 in this document appears to have two mount arms, typical of those found in gasoline-engine outboard motors, that are fixed to the outboard motor body. Meanwhile, the specific structure of the lower mount 11 is not immediately apparent, as its structure is not explained in the specification or drawings of the document. However, from the drawing alone, the lower mount appears to be a single unit, but it does not appear to be integrated with the "motor mounting base 29A" to form a continuous body.

[0006] Patent Document 2 positions itself as an improvement over the mounting system disclosed in Patent Document 1 by the same applicant, and points out that "the technology described in Patent Document 1 has the problem of increasing the size of the middle unit 102 because the electric motor 114, drive shaft 121, etc. are offset rearward to avoid the swivel portion 117. Furthermore, the technology described in Patent Document 1 has the problem of increasing the number of parts and weight because it requires unnecessary parts such as the motor cover 115 and mount case 111." Patent Document 2 discloses a pair of left and right upper mount portions 23 wrapped around rubber bushings 23b, and a lower mount portion 24 that is integrally molded with the lower housing 22 and has a front flange portion 24a and a pair of left and right rear flange portions 24b. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Laid-Open No. 2005-162055 [Patent Document 2] Japanese Patent Application Laid-Open No. 2016-37256 DISCLOSURE OF THE INVENTION [Problem to be solved by the invention]

[0008] However, in the lower mounts disclosed in both patent documents, no member for supporting the steering shaft from below is found at the bottom end of the hole provided in the swivel portion 40 for accommodating the steering shaft so that it can rotate in a horizontal plane. As a result, the weight of the outboard motor body when the boat is sailing and the electric line is on standby is supported by two upper mount arms fixed to two locations above the outboard motor body. However, in this case, the upper mount arms are in what is known in structural mechanics as a cantilever, and there is an inherent problem of deterioration in strength due to repeated loads caused by the up and down movement of the outboard motor body while the boat is sailing.

[0009] In the upper mount of Patent Document 2, it is said that "rubber bushings 23b are fitted around bolt holes 23a," but because there are restrictions on the space available to receive such an upper mount, the thickness of rubber bushings 23b (vibration-damping rubber members) cannot be made very large, so little vertical vibration damping effect can be expected. Furthermore, in the case of the lower mount of Patent Document 2, it does not appear that a vibration isolator is inserted between the hole provided in swivel portion 40 and the steering shaft rotatably housed therein.

[0010] Considering the above points in general, even in Patent Document 2, which is an improvement on the mount system of Patent Document 1, there is room for improvement in terms of durability, vibration damping effect, ease of steering, and the like when looking at the mount system as a whole.

[0011] Therefore, the specific problem of this invention is to reduce the number of parts and achieve the objective of making the electric outboard motor smaller and lighter, while improving durability, vibration damping effects, ease of steering, etc., under the condition that the electric motor is located behind the swivel bracket in the electric outboard motor, and the specific problem described below. [Means for solving the problem]

[0012] The present inventors have conducted extensive research to solve the various problems arising from the background circumstances described above and have developed the present invention. Specifically, the inventors have discovered that by using a mechanism in which the weight of the outboard motor body of an electric outboard motor is supported by a conventional upper mount system (an upper mount system in which two mount arms are fixed to the outboard motor body via mount brackets) and a lower mount unit with vibration isolation held in a yoke assembly formed by fastening both ends of a motor basement-side bracket that is integrated with the motor basement and protrudes beyond the cowling in front of the motor basement to both ends of a separate mount bracket that pairs with the motor basement bracket, it is possible to achieve commercially-sound levels of durability, vibration isolation, ease of steering, and the like, while maintaining a simple structure and reducing the number of parts. Based on this discovery, the present invention was developed.

[0013] That is, the first invention is: An electric outboard motor with an external power source, a main body having at least a propulsion mechanism using an electric motor therein; The device has two clamp brackets that detachably fix the main body to the hull, and a swivel bracket that is supported by the clamp bracket bolts so as to be rotatable up and down together with the two clamp brackets, a steering shaft accommodated in a steering bracket integrated with the swivel bracket and rotatable within a horizontal plane; the main body is supported by the swivel bracket via the steering shaft and a mount system connected to the steering shaft so as to be rotatable within a horizontal plane; The mount system includes two upper mount units each having an identical, generally cylindrical overall shape and including a vibration-isolating member, and one lower mount unit each having a generally cylindrical overall shape and including a vibration-isolating member, the two upper mount units are disposed at corresponding rear ends of two upper mount arms extending along the fore-and-aft direction of the electric outboard motor, the one lower mount unit is fitted to a lower end of the steering shaft in a manner that allows the lower end of the steering shaft to rotate, The central axes of the two substantially cylindrical upper mount units are parallel to each other and lie in the same plane, In the electric outboard motor, the central axis of the one substantially cylindrical lower mount unit is coaxial with the central axis of the steering shaft.

[0014] The second invention is the first invention, The lower mount unit is characterized in that a mount bracket A that is integrated with the motor basement and protrudes forward of the motor basement, and a mount bracket B that forms a pair with bracket A, are held within a yoke assembly formed by fastening the ends of the corresponding brackets together.

[0015] The third invention is the second invention, The projection is characterized in that it extends forward beyond the cowling cover.

[0016] The fourth invention is the third invention. The lower mount unit is The vibration absorbing device includes an inner tubular member, an outer tubular member, and a tubular vibration absorbing material filled and fixed between the inner tubular member and the outer tubular member, The inner surface of the tubular vibration absorbing material is fixed over its entire surface to the outer surface of the inner tubular member, and the inner surface of the outer tubular member is fixed over its entire surface to the outer surface of the tubular vibration absorbing material.

[0017] The fifth invention is the fourth invention, The tubular vibration absorbing member is characterized by having at least one hole penetrating from the top surface to the bottom surface.

[0018] The sixth invention is the fifth invention, The tubular vibration absorbing member is characterized by including a rubber material.

[0019] The seventh invention is the sixth invention, The inner tubular member and the outer tubular member are both characterized in that they are primarily made of an aluminum alloy.

[0020] The eighth invention is the seventh invention, The steering shaft is cylindrical and has an anchor piece extending downward from near the top of the lower end of the cylinder, the anchor piece having a screw hole formed on the underside.

[0021] A ninth aspect of the present invention is the eighth aspect of the present invention, The lower mount unit is a mounting washer A abutting against a lower end surface of the inner tubular member of the lower mount unit, and a mounting washer B abutting against a lower end surface of a sheath disposed below the steering shaft, the lower end surface of which is disposed between the mounting washer A abutting against an upper end surface of the inner tubular member, The inner tubular member is disposed at the lower end of the steering shaft in a state in which it is fixed between the mounting washer A and the mounting washer B, with the lower end surface of the inner tubular member abutting the upper end surface of the mounting washer A and the lower end surface of the inner tubular member abutting the lower end surface of the mounting washer B by a mounting bolt that extends upward through the center of the mounting washer B and fits into the screw hole.

[0022] A tenth aspect of the present invention is the ninth aspect of the present invention, The yoke assembly formed by the bracket A and the bracket B has a wall whose vertical cross section has a substantially U-shape facing inward of the yoke assembly around the entire periphery, The lower mount unit is held in the yoke assembly with the lower end surface of the outer tubular member of the lower mount unit abutting against the upper surface of the protruding portion of the generally U-shaped lower end of the yoke assembly. That is, the upper and lower ends of the wall of the yoke assembly have inwardly protruding portions around their entire periphery, and in this manner, the vertical cross section of the wall of the yoke assembly has a generally U-shape facing inward.

[0023] An eleventh aspect of the present invention is the tenth aspect of the present invention, The lower end of the steering shaft is characterized in that it is rotatable within a horizontal plane within the tubular member inside the lower mount unit. [Effects of the Invention]

[0024] The electric outboard motor according to the present invention has a simple structure, a small number of parts, and allows for a smaller and lighter outboard motor, while also achieving the effects of improving durability, vibration damping, and ease of steering when viewed as the mounting system as a whole. [Brief explanation of the drawings]

[0025] [Figure 1] FIG. 1 is a partial perspective view showing the appearance of an electric outboard motor according to an embodiment of the present invention when it is removably fixed to a transom board (a perspective view of the electric outboard motor 10 as seen from the front right side). [Figure 2] FIG. 2 is a longitudinal cross section of the electric outboard motor 10 in FIG. 1 taken along the longitudinal direction. [Figure 3] FIG. 3 is an enlarged partial perspective view of the main part of the mount system according to the present invention shown in FIGS. 1 and 2 (an enlarged partial perspective view as seen from the front right side of the electric outboard motor 10). [Figure 4] FIG. 4 is an enlarged partial longitudinal cross-sectional view of the main parts of the mount system (consisting of an upper mount system, a steering shaft, and a lower mount system) according to the present invention in the longitudinal cross-sectional view of FIG. 1 (a longitudinal cross-sectional view taken along the fore-and-aft direction of the electric outboard motor 10). [Figure 5] FIG. 5 is an enlarged partial longitudinal cross-sectional view of a main portion of the lower mount system of the mount system (consisting of an upper mount system, a steering shaft, and a lower mount system) according to the present invention in the longitudinal cross-sectional view of FIG. 4 (a longitudinal cross-sectional view taken along the fore-and-aft direction of the electric outboard motor 10). [Figure 6] FIG. 6 is a partially enlarged exploded perspective view of a main portion of the lower mount system of the mount system (comprised of an upper mount system, a steering shaft, and a lower mount system) according to the present invention. [Figure 7] FIG. 7 is an enlarged partial cross-sectional view of a main part along a horizontal plane illustrating the entire upper mount system. [Figure 8] FIG. 8 is a perspective view of the lower mount unit 30 according to the present invention. [Figure 9] FIG. 9(a) is a top view and FIG. 9(b) is a side view of the lower mount unit 30 according to the present invention. [Figure 10] FIG. 10 is a cross-sectional view (longitudinal cross-sectional view) taken along line BB in FIG. 8 of the lower mount unit 30 according to the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0026] Definition of Terms 1) Upper, upper, lower, lower: With regard to the components and units mounted on the electric outboard motor of the present invention, the term "upper" or "upper side" refers to the upper or upper side when the electric outboard motor is stood upright (the side farthest from the water surface when the electric outboard motor body is fastened upward along the transom board at the stern), and the term "lower" or "lower side" refers to the directly opposite lower or lower side. 2) Tip, front, Fr (Front), base, rear, Rr (Rear): The direction of thrust of the electric outboard motor body is called the tip side (forward side, Fr (Front)), and the opposite side is called the base side (rear side, Rr (Rear)). Additionally, when the electric outboard motor body is fastened facing upward along the transom board at the stern of a boat, the line or plane that passes through the center point of the electric outboard motor body and is perpendicular to the water surface is called the vertical line or vertical plane of the electric outboard motor body, and the line or plane that is perpendicular to this is called the horizontal line or horizontal plane. 3) Right side and left side refer to the right and left sides when facing in the same direction as the propulsion direction of the electric outboard motor. 4) The top face of parts, components, units, etc. shown in the drawings refers to the front side of the drawings, and the back face refers to the opposite side. 5) "Yoke assembly" refers to a group of components including a U-shaped or fork-shaped structure called a yoke. In this specification, it refers to a set of components in which two lower mount brackets are fastened to receive the lower mount unit according to the present invention and support other components. 6) In this specification, a system means a combination of multiple parts / components / units that work together to provide a single function as a whole. 7) A component with the word "part" written after its name does not mean an independent component, but rather a part that is integrated with the main body indicated by its name and forms a continuous body.

[0027] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the drawings, the same reference numerals indicate the same elements. Note that the following embodiment is merely an example, and various design modifications can be made as long as the configuration can achieve the object of the present invention.

[0028] 1 is a side view (as seen from the front right side of the electric outboard motor) showing the appearance of an electric outboard motor 10 equipped with an example of a mount system (described in detail below) according to an embodiment of the present invention. As shown in the figure, the electric outboard motor 10 is made up of an outboard motor main body 20 and other parts (hereinafter referred to as "other mechanical parts"), and an example of the mount system according to the present invention is embodied in this other mechanical part. The outboard motor main body 20 (hereinafter referred to as "main body 20") contains at least the propulsion mechanism of the electric outboard motor 10, including the electric motor, a so-called motor controller that electronically controls the electric motor, and a connection cable mechanism that connects the motor controller to an external power source, all of which are not shown in Figure 1. For ease of understanding, only a portion of the power supply cable 98 that connects to the transom board and to the power supply coupler 97 that is connected to the underside of the outboard motor connection coupler 96 is shown in the figure. It should be noted that the various mechanisms and components of the electric outboard motor mounted inside the cowling cover are not mechanically or structurally related to the lower mount system (and the entire mount system including it) of the present invention, and therefore the cowling cover is shown opaque in the drawing for the sake of convenience.

[0029] On the other hand, as shown in FIG. 1, the main components of the other mechanisms described above are a fixing and rotating mechanism represented by two clamp brackets 62a, 62b that detachably fix the main body 20 to the transom board 70, a swivel bracket (not shown in FIG. 1, with its upper end surface 64b shown instead) that supports the main body 20 so that it can rotate in a horizontal plane, a steering shaft bracket (not shown in FIG. 1) that is integrated with the swivel bracket (not shown in FIG. 1) at its rear and forms a continuous body, and a steering shaft that is housed in the steering shaft bracket (not shown in FIG. 1) so that it can rotate in a horizontal plane. The components are a yoke assembly (not shown in Figure 1: consisting of a motor basement side lower mount bracket 56 molded integrally with the motor basement, a separate lower mount bracket (not shown in Figure 1) that pairs with it, and a mounting boss 54 (not shown in Figure 1)) that supports the shaft (not shown in Figure 1) from below, a steering mechanism represented by a steering arm 47, a tiller handle 44, a throttle grip 42, a friction knob 41, a stopper 43, a lanyard 45, and a monitor window 48, and a connection cable mechanism that connects the motor controller (not shown in Figure 1) inside the main body 20 to an external power source.

[0030] To explain in more detail the propulsion mechanism of the electric outboard motor 10, including the electric motor, the electric outboard motor 10 equipped with the mount system (not visible in FIG. 1) according to the present invention has an electric motor (not visible in FIG. 1) housed in a motor housing (not visible in FIG. 1; disposed in the space behind the cowling cover 21 b) located rearward of and at approximately the same height as the swivel bracket (not visible in FIG. 1; its upper end surface 64 b is shown instead), and an electronic control mechanism (not visible in FIG. 1) that controls the motor housing (not visible in FIG. 1) is located above a compartment defined by the motor housing (not visible in FIG. 1) and in a housing (not visible in FIG. 1) that defines a compartment that is air-communicative with the compartment, and power from an external power source (not visible in FIG. 1) is supplied by a cable (not visible in FIG. 1) of the outboard motor side cable 92 a that is routed within the outboard motor main body 20 and connected to the electronic control mechanism.

[0031] 1, the power train from the electric motor to the propeller 30 is mounted through the drive shaft housing 23, the gear case housing 25, and the gear case 27, and specifically includes a coupler connected to the motor rotation shaft of the electric motor, a drive shaft connected to the lower side of the coupler, a bevel gear (drive gear) provided at the lower end of the drive shaft, a bevel gear (driven gear) that meshes with the drive gear, and a propeller shaft having the driven gear. The configuration and structural elements of this power train are basically the same as those known in the art, and a description of these mechanisms and elements will be omitted below because they are not necessary for describing the mounting system (not shown in FIG. 1) according to the present invention.

[0032] Since it is difficult to distinguish the mounting system according to the present invention from Figure 1 alone, the following explanation will be given step by step, increasing the resolution of the disclosed information.

[0033] Figure 2 shows a longitudinal cross section of the electric outboard motor 10 taken along the fore-and-aft direction, with the lanyard 45 and the connection cable mechanism (not shown in Figure 1) that connects the motor controller (not shown in Figure 1) inside the main body 20 to an external power source removed. While many different structural members and elements are shown in Figure 2, the main structural elements that are necessary for explaining the mounting system according to the present invention and that are shown in Figure 2 have been extracted from the figure, starting from the top and going from right to left, and are listed below in a corresponding list with their reference numbers. The propulsive force generated by the main body 1 of the electric outboard motor 10 is transmitted via the left and right upper mount units 35a, 35b to the left and right upper mount arm portions 58a, 58b, then to the main body portion 58 of the upper mount arm, which is continuous with the left and right upper mount arm portions, and finally to the upper part of the steering shaft 67b (see Figure 4), shown by the dashed line in Figure 2. At the same time, the torque is transmitted to the lower part of the steering shaft 67b (see Figure 4), shown by the dashed line in the figure, via a portion 56 (motor basement side bracket 56) of the motor basement that extends beyond the front of the cowling cover 21b. [Table 1] TIFF2025123084000002.tif117164

[0034] To make it easier to understand the structural elements necessary for explaining the mount system according to the present invention, an enlarged partial perspective view of the relevant portion is shown in Figure 3. From this figure, the components of the mount system according to the present invention (upper mount unit, steering shaft, lower mount unit) and their spatial arrangement relationships can be more clearly identified than from Table 1, and if listed in the same way as Table 1, they are as follows: [Table 2] TIFF2025123084000003.tif187156

[0035] The left and right upper mount units 35a, 35b are each fastened with bolts to a support portion not shown in the figure. The propulsive force generated by the main body 1 of the electric outboard motor 10 is transmitted via the left and right upper mount units 35a, 35b to the left and right upper mount arm portions 58a, 58b, then to the upper mount arm main body portion 58, which is continuous with the left and right upper mount arm portions, and then to the upper part of the steering shaft 67b (see FIG. 4), shown by a dashed line in the figure. At the same time, the propulsive force is transmitted via the motor basement portion 56 (motor basement-side bracket 56), which extends beyond the front of the cowling cover 21b, to the lower part of the steering shaft 67b (see FIG. 4), shown by a dashed line in the figure. In the drawings used to explain the present invention, even if the same structural element is integrally molded to form a continuous body, for the sake of ease of understanding, the same numerals are followed by a and b to distinguish between left and right.

[0036] FIG. 4 is a partial longitudinal cross-sectional view (a longitudinal cross-sectional view taken along the fore-and-aft direction of the electric outboard motor 10) that further enlarges a portion of FIG. 2 showing the components of the mount system (upper mount unit, steering shaft, lower mount unit) according to the present invention and their spatial arrangement relationships. Similar to the case of FIG. 3, the components of the mount system (upper mount unit, steering shaft, lower mount unit) according to the present invention and their spatial arrangement relationships can be listed as follows. The number and types of structural elements listed are the same in Table 2 and Table 3, and FIG. 4 merely makes it easier to distinguish between the diagrams in FIG. 2. [Table 3] TIFF2025123084000004.tif178155

[0037] The propulsive force generated by the main body 1 of the electric outboard motor 10 is transmitted to the lower part of the steering shaft 67b (see FIG. 4), shown by the dashed line in the figure, via a portion 56 (motor basement-side bracket 56) of the motor basement that extends beyond the front of the cowling cover 21b. Furthermore, the vertical load of the main body 1 is first transmitted to the upper end of the inner cylindrical member 31 of the lower mount unit 30, then transmitted as a shear force to the vibration-damping member that is filled and fixed between the inner cylindrical member 31 and the outer cylindrical member 34, and this shear force is transmitted to the outer cylindrical member 34, and finally transmitted as a bending moment force to the motor basement 56, which has a relatively large thickness. Therefore, compared to a conventional upper mount system that uses two mount arms, as described below, the lower mount system can be made more stable even if the number of parts constituting the lower mount system is significantly reduced.

[0038] Of the components shown in FIG. 4, FIG. 5 is a further enlarged view of the periphery of the essential parts, focusing on the lower mount unit 30 according to the present invention. Of the structural elements exposed around the periphery of the essential parts of the lower mount unit 30 shown in FIG. 5, all are the same as those shown in FIG. 4 above, except for a mounting bolt newly designated with reference number 67g and a 2A housing designated with reference number 282. Note that FIG. 5 shows that, in relation to the motor basement designated with reference number 56 in the same figure, the motor basement 56 has two functions: a function for fixing the electric motor housed in the electric motor case 263 (which is housed in the electric motor case designated with reference number 263 in FIG. 2 and is therefore not visible in FIG. 2), and a function as a motor basement-side bracket by extending beyond the front of the cowling cover 21b.

[0039] Furthermore, as shown in the figure, the vertical force (compression force) from the steering shaft 67b is first transmitted to the upper end of the inner cylindrical member 31 of the lower mount unit 30, then transmitted as a shear force to the vibration-damping member filled and fixed between the inner cylindrical member 31 and the outer cylindrical member 34, and this shear force is transmitted to the outer cylindrical member 34, and finally transmitted as a bending moment force to the motor basement 56, which has a relatively large thickness.Therefore, even if the number of parts making up the lower mount system is significantly reduced compared to the conventional case using two mount arms such as the upper mount system described below, a stable support structure can be achieved.

[0040] 6 is a partially exploded perspective view illustrating the spatial relationship between the lower end of the steering shaft 67b and the lower mount unit 30 according to the present invention, as well as the spatial relationship between the mount bracket provided by the motor basement 56 (the mount bracket visible at the tip of the cowling cover 21b protruding forward in the figure) and the mount bracket 52 that pairs with it to form the yoke assembly. As shown in the figure, the yoke assembly, which is formed by the mount bracket provided by the motor basement 56 and the mount bracket 52 that pairs with it, has a vertical cross section of its wall that is roughly U-shaped facing inward over the entire periphery, and the lower mount unit 30 is held within the yoke assembly with the lower end surface of the outer tubular member 34 of the lower mount unit 30 abutting against the upper surface of the protruding portion at the lower end of the roughly U-shaped yoke assembly. That is, the upper and lower ends of the walls of both the mount bracket provided by the motor basement 56 and its corresponding paired mount bracket 52 have portions that protrude inward around the entire periphery of the bracket, and as a result, the vertical cross section of the wall of the yoke assembly formed by the mount bracket provided by the motor basement 56 and its corresponding paired mount bracket 52 has a substantially U-shaped cross section facing inward. With this configuration, the lower end of the steering shaft is journaled rotatably within the horizontal plane within the tubular member inside the lower mount unit 30, and when the lower end of the steering shaft rotates within the horizontal plane within the tubular member inside the lower mount unit 30, the entire lower mount 30 can rotate within the above-mentioned yoke assembly in response to that rotation.

[0041] Next, a diagram illustrating the upper mount system is shown in Figure 7. The structural elements indicated with reference numbers in this figure are as follows (from right to left, starting from the top of the figure). Note that when referring to structural elements with the same function, the letter "a" after the number indicates the right side, and the letter "b" after the number indicates the left side. The present invention is characterized by the lower mount system, and in upper mount systems, the structural elements used are basically known, and the configuration for arranging the upper mount unit in a horizontal plane is also known. The steering shaft 67b extends below the main body 58 of the upper mount arm, which is continuous with the left and right upper mount arm portions, i.e., beyond the plane of the drawing. Its lower end passes downward through the cylindrical member 31 inside the lower mount unit 30 and is fastened to the anchor piece 67e. The left and right upper mount units are fixed to the main body 20 of the electric outboard motor 10, so the propulsive force of the electric outboard motor 10 is transmitted via the left and right upper mount units to the left and right upper mount arm portions (58a, 58b), and further via the upper mount arm main body portion 58 to the swivel bracket 64. Note that in the drawing, different reference numerals are used for the upper mount arm main body portion 58 and the left and right upper mount arms 58a, 58b, but this is merely for the sake of convenience, as these members are molded as a single unit that cannot be separated. [Table 4] TIFF2025123084000005.tif123155

[0042] Next, a lower mount unit 30 as an example of the present invention will be described in detail. Fig. 8 is a perspective view of the lower mount unit 30. As shown in Fig. 8, the lower mount unit 30 includes an inner cylindrical member 31, an outer cylindrical member 34, and a cylindrical vibration absorbing member 32 (hereinafter simply referred to as a "cylindrical vibration damping member") filled and fixed between them. The axes of these members are all coaxial.

[0043] The outside of the inner cylindrical member 31, above the top surface of the cylindrical vibration-damping member 32, is covered with the same vibration-damping material that is integral with the cylindrical vibration-damping member 32. Similarly, the inside of the outer cylindrical member 34, above the top surface of the cylindrical vibration-damping member 32, is covered with the same vibration-damping material that is integral with the cylindrical vibration-damping member 32. Both the part covering the outside of the inner cylindrical member 31 and the part covering the inside of the outer cylindrical member 34 form gently curved surfaces that are continuous with the top surface of the cylindrical vibration-damping member 32. In the figure, the points where these curvatures change are visible as lines. For convenience, hereinafter, when referring to the cylindrical vibration-damping member 32, this will also refer to these covering parts.

[0044] The vibration-damping member 32 and the inner cylindrical member 31, and the vibration-damping member 32 and the outer cylindrical member 34 are each fixed (or joined) over their entire surfaces with an adhesive, and a vulcanizing adhesive is preferably used as the adhesive. However, as long as it can achieve the effects required of the lower mount unit that constitutes part of the lower mount system of the present invention, it is not limited to a vulcanizing adhesive, and methods that do not use an adhesive can also be preferably employed.

[0045] The cylindrical vibration damping member 32 is also formed with a drain hole 33 that runs from top to bottom. The shape of the cylindrical vibration damping member 32 does not necessarily have to be a perfect ring, as long as it has a shape that allows seawater to drain downward when splashed by it while the electric outboard motor 10 is running. The size of the inner diameter of this drain hole can also be selected appropriately.

[0046] The cylindrical vibration damping member 32 preferably has a radial thickness of 24 mm to 30 mm, more preferably 25 mm to 29 mm, and a vertical height of 20 mm to 26 mm, more preferably 21 mm to 25 mm.

[0047] 3(b), the shape of the drainage holes 33 is an ellipse with its major axis arcing to match the arc of the cylindrical vibration damping member 32, but it does not necessarily have to be an ellipse. Similarly, the number of drainage holes 33 can also be selected appropriately as needed.

[0048] The upper end of each hole 33 is formed to flare slightly from the inside to the outside of the hole 33. The shape of the opening at the upper end of the flared region is similar to the shape of the opening at the lower end. The depth of the flared region (the distance from the start of the flare to the upper end of the hole) is not particularly limited and can be selected appropriately as needed.

[0049] The outer diameter of the inner cylindrical member 31 is preferably 29 mm to 35 mm, more preferably 30 mm to 34 mm, the inner diameter is preferably 22 mm to 26 mm, more preferably 23 mm to 25 mm, and the height in the vertical direction is preferably 32 mm to 37 mm, more preferably 33 mm to 36 mm.

[0050] The outer diameter of the outer cylindrical member 34 is preferably 60 mm to 70 mm, more preferably 63 mm to 67 mm, the inner diameter is preferably 21 mm to 27 mm, more preferably 56 mm to 63 mm, and the height in the vertical direction is preferably 23 mm to 28 mm, more preferably 24 mm to 27 mm.

[0051] The inner cylindrical member 31 and the outer cylindrical member 34 are preferably made of aluminum alloy (A5052TD), but are not limited to this. The cylindrical vibration-damping member 32 is preferably made of a rubber-like material with vibration-damping properties (commonly known as vibration-damping rubber). Rubber with either isotropic or anisotropic elasticity can be used, but in the case of the shape shown in the drawings, it is preferable that the elastic modulus in the vertical direction be greater than the elastic modulus in the radial direction. This is because the load applied from above to the lower mount unit 30 is transmitted from above to the inner cylindrical member 31 by the cylindrical vibration-damping member 32 as a shear force to the outer cylindrical member 34.

[0052] 9(a) shows a top view of the lower mount unit 30, and FIG. 9(b) shows a front view. In the front view of FIG. 9(a), it can be seen that a vibration-damping member 32 is inserted and secured between the inner cylindrical member 31 and the outer cylindrical member 34 of the lower mount unit 30. Five drainage holes 33 are formed in the vibration-damping member 32, which extend from the top to the bottom of the vibration-damping member 32. When seawater splashes on the electric outboard motor 10 while the motor is running, the seawater drains through the holes 33. The number and shape (cross-sectional shape along a horizontal plane) of the holes 33 are not particularly limited and can be selected as needed. Furthermore, as can be seen from the front view of FIG. 9(b), the height of the inner cylindrical member 31 is set higher than the height of the outer cylindrical member 34. However, this is not particularly limited, and the difference in height can be selected as needed.

[0053] 10 is a longitudinal cross-sectional view of the lower mount unit 30, taken along the longitudinal direction of the electric outboard motor 10. It should be noted that the outer surface of the inner cylindrical member 31 and the inner surface of the outer cylindrical member 34 are both covered entirely with the material of the vibration-damping member 32, with the only exposed portions being the upper and lower end faces and the outer peripheral surface of the outer cylindrical member 34. In addition, the cross-sectional shapes of the upper and lower ends of the drainage holes 33 are each flared, which allows seawater that splashes on the upper surface of the vibration-damping member 32 to flow off more easily. [Industrial Applicability]

[0054] The present invention provides an electric outboard motor that has a simple structure, a small number of parts, and is compact and lightweight, while, when viewed from the perspective of the mounting system as a whole, it is possible to expect improvements in durability, vibration damping, ease of steering, etc. Also, by positioning the motor in front of the swivel bracket of the electric outboard motor, the rearward field of view of the pilot is expanded, improving steering performance, and it is possible to provide an electric outboard motor that has a reduced number of parts and is compact and lightweight, while also improving durability, vibration damping (vibration isolation), ease of steering, etc.

[0055] The above embodiment illustrates one form of the electric outboard motor according to the present invention, and the technical scope of the present invention is not limited to the above embodiment. Therefore, various modifications may be made without departing from the spirit or scope of the general inventive concept defined by the appended claims and their equivalents. [Explanation of symbols]

[0056] 10: Electric outboard motor 20: Outboard motor body 21a: Cowling cover 21b: Cowling cover 22b: Upper end of motor room cover housing 23: Drive shaft housing 24: Lower mount 25: Gear case housing 27: Gear case 28: Skeg 30: Lower mount unit 31: Cylindrical member 32: Cylindrical vibration absorbing member 33: Drainage hole 34: Cylindrical member 35: Upper mount arm bolt 35a: Upper mount unit (right) 35b: Upper mount unit (left) 36: Outer cylindrical member of upper mount unit 36a: Outer cylindrical part of upper mount unit (right) 36b: Outer cylindrical member of upper mount unit (left) 37: Cylindrical member inside the upper mount unit 37a: Inner cylindrical part of upper mount unit (right) 37b: Inner cylindrical member of upper mount unit (left) 38: Vibration damping member for upper mount unit 38a: Vibration damping member of upper mount unit (right) 38b: Vibration damping member of upper mount unit (left) 41: Friction knob 42: Throttle grip 43: Stopper 44: Tiller handle 45: Lanyard 46: Clamp bracket (right) 47: Steering arm (main body) 47a: Steering arm (right) 48: Copilot lever 48a: Co-pilot 48b: Co-pilot support member 52: Mounting bracket 54: Mounting boss 56: Motor basement side bracket 57: Upper mount arm bolt 57a: Upper mount arm bolt (right) 57b: Upper mount arm bolt (left) 58: Upper mount arm body 58a: Upper mount arm (right) 58b: Upper mount arm (left) 59: Upper mount arm bolt connection 62a: Clamp bracket (right) 62b: Clamp bracket (left) 62c: Trim lock lever 62da: Clamp (right) 62db: Clamp (left) 63a: Clamp bracket bolt knob (right) 63b: Clamp bracket bolt knob (left) 64: Swivel bracket 64b: Upper end surface part 64ca: Swivel bracket arm (right) 64cb: Swivel bracket arm (left) 64cd: Clamp bracket (left) 66: Steering shaft bracket 67b: Steering shaft 67c: Steering shaft lower sleeve 67d: Mounting washer 67e: Anchor piece 67f: Mounting washer 67g: Mounting bolt 67h: Mounting bolt 70: Transom board 80: Carrying handle 91: Connection cable outlet 92a: Outboard motor cable 93: Cable base 94: Cable sheath 96: Outboard motor coupler 97: Power supply coupler 98: Power supply connection cable 102: Middle unit 106: 1st ECU housing cover 108: Side cover (grommet) of first ECU housing cover 224: Motor room cover housing part 226: Upper mount fixing space 228: Second ECU housing 262: Electric motor cover 263: Electric motor case 271: Coupling 282: 2nd A Housing 287: Cooling fin 322: Drive shaft 405: Propeller shaft support member 408: Bevel gear B (drive gear) 409: Bevel gear A (driven gear) 411: Propeller shaft 528: Steering shaft upper end receiving part 531: Upper mount fixing part (outboard motor body side)

Claims

1. An electric outboard motor with an external power source, a main body having at least a propulsion mechanism using an electric motor therein; The device has two clamp brackets that detachably fix the main body to the hull, and a swivel bracket that is supported by the clamp bracket bolts so as to be rotatable up and down together with the two clamp brackets, a steering shaft accommodated in a steering bracket integrated with the swivel bracket and rotatable within a horizontal plane; the main body is supported by the swivel bracket via the steering shaft and a mount system connected to the steering shaft so as to be rotatable within a horizontal plane; the mount system includes two upper mount units each having an identical, generally cylindrical overall shape and including a vibration-isolating member, and one lower mount unit each having an approximately cylindrical overall shape and including a vibration-isolating member; the two upper mount units are disposed at corresponding rear ends of two upper mount arms extending along the fore-and-aft direction of the electric outboard motor, the one lower mount unit is fitted to a lower end of the steering shaft in a manner that allows the lower end of the steering shaft to rotate, The central axes of the two substantially cylindrical upper mount units are parallel to each other and lie in the same plane, The central axis of the one substantially cylindrical lower mount unit is coaxial with the central axis of the steering shaft. An electric outboard motor characterized by:

2. The lower mount unit is held in a yoke assembly formed by fastening together the ends of a mount bracket A that is integrated with the motor basement and protrudes forward of the motor basement, and a mount bracket B that forms a pair with the mount bracket A.

2. The electric outboard motor according to claim 1.

3. The protrusion extends forward beyond the cowling cover.

3. The electric outboard motor according to claim 2.

4. The lower mount unit is The vibration absorbing device includes an inner tubular member, an outer tubular member, and a tubular vibration absorbing material filled and fixed between the inner tubular member and the outer tubular member, The inner surface of the tubular vibration absorber is fixed over its entire surface to the outer surface of the inner tubular member, and the inner surface of the outer tubular member is fixed over its entire surface to the outer surface of the tubular vibration absorber.

4. The electric outboard motor according to claim 3.

5. The tubular vibration absorbing member has at least one hole that penetrates from the top surface to the bottom surface.

5. The electric outboard motor according to claim 4.

6. The inner tubular member and the outer tubular member are both made primarily of an aluminum alloy.

6. An electric outboard motor according to claim 5.

7. The tubular vibration absorbing member includes a rubber material.

7. The electric outboard motor according to claim 6.

8. The steering shaft is cylindrical and has an anchor piece extending downward from near the upper end of the cylindrical lower end, the anchor piece having a screw hole formed on the lower side.

8. An electric outboard motor according to claim 7.

9. The lower mount unit is a mounting washer A abutting against a lower end surface of the inner tubular member of the lower mount unit, and a mounting washer B abutting against a lower end surface of a sheath disposed below the steering shaft, the lower end surface of which is disposed between the mounting washer A abutting against an upper end surface of the inner tubular member, The inner tubular member is disposed on the lower end of the steering shaft in a state in which the lower end surface of the inner tubular member abuts the upper end surface of the mounting washer A and the lower end surface of the inner tubular member abuts the lower end surface of the mounting washer B by a mounting bolt that extends upward through the center of the mounting washer B and fits into the screw hole.

9. The electric outboard motor according to claim 8.

10. The yoke assembly formed by the bracket A and the bracket B has a wall whose vertical cross section has a substantially U-shape facing inward of the yoke assembly over the entire periphery, The lower mount unit is held in the yoke assembly in such a manner that the lower end surface of the outer tubular member of the lower mount unit abuts against the upper surface of the protruding portion of the substantially U-shaped lower end of the yoke assembly.

10. The electric outboard motor according to claim 9.

11. The lower end of the steering shaft is rotatable within a horizontal plane within the tubular member inside the lower mount unit.

11. The electric outboard motor according to claim 10.

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