The present disclosure relates to outboard motors for use in propelling marine vessels. More specifically, the present disclosure relates to design of a midsection area of an outboard motor, and to devices for coupling the outboard motor to a transom of a marine vessel.
U.S. Pat. No. 7,896,304 discloses a support system for an outboard motor that uses mounts which are configured and positioned to result in an elastic center point being located closely to a roll axis of the outboard motor which is generally vertical and extends through a center of gravity of the outboard motor. The mounts are positioned so that lines which are perpendicular to their respective center lines intersect at an angle which can be generally equal to 90 degrees. The mounts are positioned in non-interfering relationship with the exhaust components of the outboard motor and its oil sump.
Unpublished U.S. patent application Ser. No. 13/688,109, filed Nov. 28, 2012, discloses a mounting arrangement for supporting an outboard motor with respect to a marine vessel extending in a fore-aft plane. The mounting arrangement comprises first and second mounts that each have an outer shell, an inner wedge concentrically disposed in the outer shell, and an elastomeric spacer between the outer shell and the inner wedge. Each of the first and second mounts extend along a axial direction, along a vertical direction that is perpendicular to the axial direction, and along a horizontal direction that is perpendicular to the axial direction and perpendicular to the vertical direction. The inner wedges of the first and second mounts both have a non-circular shape when viewed in a cross-section taken perpendicular to the axial direction. The non-circular shape comprises a first outer surface that extends transversely at an angle to the horizontal and vertical directions. The non-circular shape comprises a second outer surface that extends transversely at a different, second angle to the horizontal and vertical directions.
This Summary is provided to introduce a selection of concepts that are further described below in the Detailed Description. This Summary is not intended to identify key or essential features of the claimed subject matter, nor is it intended to be used as an aid in limiting the scope of the claimed subject matter.
One example of the present disclosure is of an outboard motor configured to be coupled to a transom of a marine vessel, the outboard motor comprising a midsection housing having a front side configured to face the transom, a back side opposite the front side, a left side, and an opposite right side. An engine having an engine block is mounted directly to and supported by the midsection housing. A driveshaft is coupled in torque transmitting relation with a crankshaft of the engine, and a portion of the driveshaft is located exterior to the midsection housing. An exhaust pipe conveys exhaust gas from an exhaust gas outlet of the engine downwardly away from the engine. The exhaust pipe is located exterior to the midsection housing.
Another example of the present disclosure is of an outboard motor configured to be coupled to a transom of a marine vessel. The outboard motor comprises an engine having an engine block having a bottom surface and midsection housing having a top surface and a bottom surface. A gearcase assembly is coupled to the bottom surface of the midsection housing. A driveshaft extends from the engine to the gearcase assembly, and a portion of the driveshaft is located exterior to the midsection housing. An exhaust pipe conveys exhaust downwardly away from the engine. The exhaust pipe is located exterior to the midsection housing. A mounting cradle is mounted directly to the midsection housing, the mounting cradle being coupled to the transom. The bottom surface of the engine block is mounted directly to the top surface of the midsection housing.
The present disclosure is described with reference to the following Figures. The same numbers are used throughout the Figures to reference like features and like components.
In the present description, certain terms have been used for brevity, clarity and understanding. No unnecessary limitations are to be inferred therefrom beyond the requirement of the prior art because such terms are used for descriptive purposes only and are intended to be broadly construed.
The outboard motor 10 further comprises a gearcase assembly 30 coupled to a lower portion of the midsection housing 16. An exhaust pipe 26 conveys exhaust gas from an exhaust gas outlet 28 of the engine 18 downwardly away from the engine 18, as shown by the arrow E and into the gearcase assembly 30. An upper end of the exhaust pipe 26 extends through a cylindrical fitting 29 provided in a stabilizing plate 56 to the exhaust gas outlet 28. A lower end of the exhaust pipe 26 extends through a rectangular fitting 33 in a plate 35 defining the lower portion of the midsection housing 16. When the engine 18 is running above idle speeds, a normal flow of exhaust is downwardly away from the engine 18, through the exhaust pipe 26, into the gearcase assembly 30, and out along an axis of a propeller hub 31 coupled to the gear case assembly 30. The exhaust pipe 26 is separate from and located exterior to the midsection housing 16 (see also
Also shown in
Now turning to
With reference specifically to
In one example, coupling of a bottom surface 72 of the engine block 20 to the top surface 44 of the midsection housing 16 is accomplished by providing a plurality of fasteners 43 that extend through apertures (not shown) surrounding a circumference of the aperture 46 through the top surface 44 of the midsection housing 16. Fastener apertures 42 are provided in the bottom of the engine block 20 for receiving the fasteners 43 that extend through the top surface 44 of the midsection housing 16. In one example, the plurality of fasteners 43 comprises threaded fasteners such as bolts; however, other fasteners known to those having ordinary skill in the art could be used.
It should be noted that the pentagonal (or other) shape of the aperture 46 in the top surface 44 of the midsection housing 16 corresponds to the shape of the bottom surface 72 of the engine block 20. This ensures a fluid-tight connection between the engine block 20 and the midsection housing 16, which as described above has an open interior that may serve as an oil sump for the engine 18.
With reference to each of
Meanwhile, as described above, the exhaust pipe 26 is also located exterior to the midsection housing 16 and proximate the back side 36 of the midsection housing 16. The outboard motor 10 is also provided with at least one plenum chamber 50a, 50b in fluid communication with an idle relief port in the exhaust pipe 26, for purposes of attenuating sound produced by idle relief gas, as will be further described herein below. As shown, the plenum chambers 50a, 50b are separate components from the midsection housing 16. In one example, first and second plenum chambers 50a, 50b are provided that at least partially flank the midsection housing 16 on the right side 40 and left side 38 thereof. In another example, the plenum chambers 50a, 50b wrap around a rear portion of the exhaust pipe 26, and optionally are combined into one large plenum chamber. In the example shown, the plenum chambers 50a, 50b are mounted to the exhaust pipe 26. In other examples, the plenum chambers 50a, 50b could be mounted to the midsection housing 16 or to a plate 56 that holds an upper portion of the exhaust pipe 26 in place and is in turn coupled to the midsection housing 16. In another example, the plenum chambers 50a, 50b are mounted to both the exhaust pipe 26 and the midsection housing 16.
With reference to
When the engine 18 is idling, exhaust gases pass directly from the exhaust pipe 26 to the plenum chamber 50a or 50b. In one example, the exhaust gases pass directly from the exhaust pipe 26 to the plenum chamber 50b by way of the idle relief port 52 (see
It should be understood that although two plenum chambers 50a, 50b are shown herein, one plenum chamber could be provided in an alternative example. Further, more than two plenum chambers could instead be provided, with interconnections between the series of plenum chambers, each plenum chamber providing further sound attenuation. In one example, the plenum chambers are made of a plastic polymer, such as HDPE or polypropylene. In fact, any non-aluminum and/or non-metallic material may be used in order to both provide strength to the plenum chambers and yet reduce weight of the outboard motor 10 as a whole.
Further, it should be understood that the idle relief port 52 may comprise a short passageway as shown herein, may be a longer pipe or tube, or may be little more than a cylindrical fitting provided between the exhaust pipe 26 and the plenum chamber 50b. In other examples, the flow path for the idle relief gas may be through the midsection housing 16, but only briefly before or after the flow path is through the plenum chamber(s) 50a, 50b. In other words, the midsection housing 16 may be used as a conduit to carry idle relief gas to or from the plenum chamber(s) 50a, 50b, but according to the present disclosure is not used as the primary sound attenuation device itself.
With reference to
Each of the arms 58a, 58b has a somewhat triangular shaped extension 62a, 62b coupled beneath the respective arm. The lower mounts 60b are provided at lower corners of the triangular shaped extensions 62a, 62b and mount the extensions 62a, 62b to lower portions of the midsection housing 16 on both sides 38, 40 of the midsection housing. The location of connection of the upper mounts 60a is shown in
Additional mounts 64a, 64b are provided for coupling the arms 58a, 58b to the swivel bracket 66 along the tilt/trim axis 68. As mentioned above, the outboard motor mounting system further comprises tilt/trim cylinders 70, the purpose and function of which are known to those having ordinary skill in the art.
It should be noted that the mounting cradle 32 and associated components could be constructed in many different ways with many different materials. Further, the shape of the mounting cradle 32 could vary from the example shown herein
The present disclosure therefore provides a creative solution to reduce weight and cost of an outboard motor 10, in contrast to prior outboard motors that have a cast aluminum adapter plates between the engine and a cast aluminum driveshaft housing. In such prior systems, the cast aluminum driveshaft housing houses the driveshaft and also provides an interior volume for sound attenuation of idle relief gas. In contrast, in the outboard motor 10 of the present disclosure, a portion (and in this example a majority) of the driveshaft 22 is located exterior to the midsection housing 16. Further, one or more separate exterior plenum chambers 50a, 50b are provided for attenuation of sound produced by the idle relief gas instead of requiring extra volume within the driveshaft housing for such attenuation. Further, the exhaust pipe 26 of the present disclosure is provided separate from and exterior to the midsection housing 16. Each of these design components being located exterior (or at least partially exterior) to the midsection housing 16 allows the midsection housing 16 to be made much smaller, as it no longer houses the exhaust pipe, driveshaft, or provides an interior volume for sound attenuation of idle relief gas. This provides a much lighter outboard motor 10 design than previously available. Further weight reduction of the outboard motor 10 is achieved by direct mounting of the engine block 20 to the top surface 44 of the midsection housing 16. Prior designs utilize an adapter plate for such mounting, which adds weight and cost to the system. By direct mounting of the bottom surface 72 of the engine block 20 to the top surface 44 of the midsection housing 16, material and weight are both reduced. Further, because the midsection housing 16 acts as an oil sump, this eliminates the need for a separate oil sump as required by prior designs.
The present disclosure therefore provides an outboard motor 10 configured to be coupled to a transom 12 of a marine vessel. The outboard motor 10 comprises an engine 18 having an engine block 20 having a bottom surface 72 (see
A driveshaft 22 extends from the engine 18 to the gearcase assembly 30, and a portion of the driveshaft 22 is located exterior to the midsection housing 16. For example, a middle portion of the driveshaft 22 may be provided exterior to the midsection housing 16 in an alcove 48 in the front side 34 of the midsection housing 16. An exhaust pipe 26 conveys exhaust downwardly away from the engine 18. The exhaust pipe 26 is also located exterior to the midsection housing 16 and may be provided proximate a back side 36 of the midsection housing 16. A sound-attenuating plenum chamber 50a or 50b may be provided exterior to the midsection housing 16. The plenum chamber 50a or 50b may be in direct fluid communication with an idle relief port 52 in the exhaust pipe 26.
A mounting cradle 32 is mounted directly to the midsection housing 16. For example, the mounting cradle 32 may have first and second arms 58a, 58b that extend along either side of the midsection housing 16 near a top portion thereof, and the midsection housing 16 may be mounted to the mounting cradle 32 via upper mounts 60a provided in the arms 58a, 58b. The mounting cradle 32 may further have two triangular shaped extensions 62a, 62b, one extension on each side of the mounting cradle 32, that extend downwardly from the arms 58a, 58b. The midsection housing 16 may be mounted to the extensions 62a, 62b via lower mounts 60b. The mounting cradle 32 is coupled to the transom 12. This may be done by a connection of the mounting cradle 32 to a swivel bracket 66, which is in turn coupled to a transom bracket 14, which is in turn coupled to the transom 12.
In the above description, certain terms have been used for brevity, clarity, and understanding. No unnecessary limitations are to be inferred therefrom beyond the requirement of the prior art because such terms are used for descriptive purposes and are intended to be broadly construed. The different systems and method steps described herein may be used alone or in combination with other systems and methods. It is to be expected that various equivalents, alternatives and modifications are possible within the scope of the appended claims. Each limitation in the appended claims is intended to invoke interpretation under 35 U.S.C. §112(f), only if the terms “means for” or “step for” are explicitly recited in the respective limitation.
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Entry |
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U.S. Appl. No. 13/688,109, filed Nov. 28, 2012. |