Patent Application
20140038478
Outboard motors are typically built with a thin aluminum frame and other light weight alloys. Outboard motors are designed to run in open water with little or no expected impact to the outdrive assembly. This design restricts the boat operator from running the motor and boat along shorelines and in many waterways where impacts to the lower drive unit are likely and can damage the propeller, drive, and/or outdrive housing. Such impacts can come from rocks, logs, a waterway bottoms, or other similar obstacles. Sportsmen and others who desire to hunt, fish and travel in areas where obstacles reside in the water may avoid these areas as much as possible. Even then, what lies below the water's surface is usually a mystery, especially in muddy or murky waters.
The possibility of impact and damage to the lower end of an outboard motor is always present. As such, boaters must be constantly alert for sub-surface obstacles. When an impact to an outboard motor occurs, the boater is likely to face large motor repair bills. The inconvenience, safety hazard, threat of being stranded, and the financial losses of motor damage can be daunting for outboard motor owners.
The technology provides an outboard marine drive with an engine. The outboard marine drive can include a drive housing with an upper drive housing and lower drive housing. The drive housing can be attached to a transom of a marine craft. An upper gear drive assembly can be located in the upper drive housing. A transmission can be provided with the upper gear drive assembly in the upper drive housing. In addition, a lower gear drive assembly can be located in the lower drive housing and coupled to the upper gear drive assembly. A propeller shaft may also be coupled to the lower gear drive assembly.
Additional features and advantages of the invention will be apparent from the detailed description which follows, taken in conjunction with the accompanying drawings, which together illustrate, by way of example, features of the invention.
Reference will now be made to the exemplary embodiments illustrated in the drawings, and specific language will be used herein to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended. Alterations and further modifications of the inventive features illustrated herein, and additional applications of the principles of the inventions as illustrated herein, which would occur to one skilled in the relevant art and having possession of this disclosure, are to be considered within the scope of the invention.
A transom mounted outboard motor technology is described here. More specifically, a heavy duty marine outboard is described with an upper shifting drive assembly.
Having an outboard drive unit designed and built from thicker and stronger alloys that can sustain motor operations when the motor impacts objects at medium speeds can be an advantage to a boater. In addition to the use of strong alloys, the outboard motor can have certain structures that can allow the outboard motor to be used in taxing environments.
An upper gear drive assembly 210 can be located in the upper drive housing. A transmission 212 can also be located with or in the upper gear drive assembly in the upper drive housing. The transmission receives power from the engine and transmits power through the upper gear drive assembly. The transmission can also have a single speed or multiple speeds and the ability to change gear ratios in the upper gear drive assembly. For example, there can be multiple forward gears and multiple reverse gears in the transmission. A gear ratio selection can be provided in the transmission for forward or reverse motion of the marine craft.
In an example, the transmission can be a cone clutch that provides forward, neutral and reverse motion of the marine craft. Locating the transmission in the upper drive housing provides enough space for a transmission such as cone clutch, servo-cone clutch, multi-plate clutch, a hydraulic clutch, dog clutch, or another type of transmission. In existing outboards, transmission gearing is provided in the lower housing.
Existing marine motors have a fixed gearing that does not allow the operator to choose multiple gear ratio speeds when operating with varying boat loads. Also, when operating in obstacle ridden waterways, the benefit of gearing down to slow the forward motion of the boat is useful. A marine motor with multiple forward gears can be used in such gearing down circumstances. The ability to use multiple gear shifting for power boats of varying loads at different speeds provides flexibility for an outboard motor.
A power transfer gearing can be located between the upper gear drive assembly and the lower drive assembly with a first gear and first gearing size 232. The power transfer gearing can have a second gear 230 with a second gearing size similar to the first gearing size. The power transfer gearing can have a reduced size, as compared to existing outboard motors, due to the gears having a similar size. Since the transmission is in the upper portion of the drive housing, the power transfer gears can be smaller and similar in size. In addition, both of the gears can be strong due to their similar size and strength. A power transfer gearing is generally as strong as the smallest gear in the transfer system. So, the use of two gears of similar size can increase the strength of the power transfer gearing and avoids the use of a large gear in combination with a small gear. In one example, the gearing ratio between the upper gear drive assembly and the lower drive assembly is near a 1.20 gearing ratio as needed to match the engine size with the propeller. In another example, the lower drive housing can have gears with a reduced size due to a near 1-to-1 gearing ratio of the power transfer gearing. When there is no gear ratio change or a small gear ratio change, then the similar forces on the gears means that the gears are less likely to fail. Useful ranges of gearing in the described technology can range between a 1.1:1 to a 1.7:1 gearing ratio.
Previous outboard motors of vertical design provide changes to gear ratio in the lower drive assembly. Since the gear ratio relies on one larger gear and one smaller gear, the strength of the gear set is determined by the smaller of the two gears. In contrast, the present technology provides an outboard with the ability to run at a near one to one gear ratio in the lower drive assembly and this can allow the system to utilize a large and strong gear set while having improved external fluid drag efficiency. If a large gear ratio is used in the lower drive housing as in existing outboards, then this increases the fluid drag of the lower drive housing and increases the cross sectional area of the lower drive housing that can hit obstacles in the water. In contrast, the small gear ratio provides lower drag and a smaller cross-sectional area that is more likely to avoid obstacles in the water.
A lower gear drive 214 assembly can be located in the lower drive housing and be coupled to the upper gear drive assembly. A propeller shaft 216 and propeller 218 can also be coupled to the lower gear drive assembly. The propeller shaft can be an extended length shaft and can be more than 12 inches in length. The propeller may be located above the bottom of the marine craft.
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It is to be understood that the above-referenced arrangements are only illustrative of the application for the principles of the present invention. Numerous modifications and alternative arrangements can be devised without departing from the spirit and scope of the present invention. While the present invention has been shown in the drawings and fully described above with particularity and detail in connection with what is presently deemed to be the most practical and preferred embodiment(s) of the invention, it will be apparent to those of ordinary skill in the art that numerous modifications can be made without departing from the principles and concepts of the invention as set forth herein.
| Number | Date | Country | |
|---|---|---|---|
| 61590067 | Jan 2012 | US |
