US 3703642 A
An outboard motor unit for use on small boats and having a primary propulsion engine connected through a clutch to the propeller shaft and an electric motor aligned with and connected to the propeller shaft. The electric motor is connected to a battery through a switch operatively connected to the engine throttle to complete the power connection for the electric motor when the throttle is at a selected proportion of full throttle. The electric motor operates as a motor when the engine is stopped and as a generator when the engine is running.
Claims available in
Description (OCR text may contain errors)
United States Patent Balaguer  OUTBOARD MOTOR UNIT  Inventor: Rodolfo Rodriguez Balaguer, 2607 Grace Drive, Harbor Beach, Fort Lauderdale, Fla. 33316 22 Filed: 0a. 28, 1911 21 Appl.No.: 193,353
52] -U.S. c1 ..290l43,290/46,115/l8 A, 115/18 E, 290/54 511 1111.0 ..F03b 13/10  Field of Search ..1 15/18 A, 18 E; 290/42, 43,
 References Cited UNITED STATES PATENTS 3,619,632 11/1971 Labombarde 1290/43 3,411,013 ll/l968 Vogelsang ..290/43X 1451 Nov. 21, 1972 1,898,973. 2/1933 Lansing ..290/54X Primary Examiner-G. R. Simmons Attorney-Charles B. Smith [57 ABSTRACT An outboard motor unit for-use on small boats and having a primary propulsion engine connected through a clutch to the propeller shaft and an electric motor aligned with and connected to the propeller shaft. The electric motor is connected to a battery through a switch operatively connected to the engine throttle to complete the power connection for the electric motor when the throttle is at a selected proportion of full throttle. The electric motor operates as a motor when the engine is stopped and as a generator when the engine is running.
6 Claims, 3 Drawing Figures TO BATTERY OUTBOARD MOTOR UNIT I BACKGROUND OF THE INVENTION The present invention relates to: outboard motors used for the propulsion of small boats. Such engines,.in
a variety of styles and sizes, have been used for many years for propelling small boats used for fishing, plea sure boating and otherpurposes.
In general, the size of outboardmotor, in terms of horsepower, selected fora particular boat is determined by the size and weight of the boat and the use to be made of the boat. Whena boat is to be used for fishing, it is customary to select a motor of sufficient size to propel the boat at asubstantial speed to permit rapid travel to and from afishing area. However, while actually engaged in fishing, and especially when trolling, the motor is generally far larger'than is necessary for movement of the boat and much noisier than is desirable. This problem is sometimes accommodated by providing a boat with two outboard motors, a large one for principal propulsion and a small one for trolling or moving in the fishing area.
Small auxiliary outboard motors are also used on occasion for reliability in the event of failure of the principal propulsion motor.
The use of an additional small outboard motor, whether for fishing or for reliability, represents a substantial extra initial expense and substantial additional maintenance problems.
' The principal object of the present invention has been to provide an outboard motor unit which, in one unit, provides a principal propulsion motor and a relatively small auxiliary propulsion motor.
Another object of the invention has been the provision of such an outboard motor unit which is only slightly more expensive than a conventional outboard motor of equal horsepower and which requires little or no maintenance beyond that of'a conventional out- BRIEF DESCRIPTION OF THE INVENTION The outboard motor unit of the invention comprises a conventional outboard engine which may be of the two cycle or four cycle type and may be powered by any desired fuel, e.g., gasoline or diesel oil. The engine is coupled through a clutching arrangement to a propeller shaft on which is mounted the propeller. The propeller shaft is extended beyond the usual end thrust bearing and is directly coupled to-an electric motor. The electric motor is connected to a battery through a cam operated switch which is arranged to be closed only when the engine throttle is at or beyond a selected proportion of its full on position, e.g. three-fourths throttle. When the engine is operating at the selected speed of rotation of the propeller shaft will be sure,
ciently high that the 7 electric motor operates as a generator to charge the battery. At lower engine speeds, the cam operated switch will be open and the electric motor will not produce any. output.
When the engine is not running, turning the engine throttle toor beyond the selected position will connect the'electric motor to the battery so as to powerthe electric motor and in turn to rotate the propeller shaft. At this time the engine clutch will be in its disengaged position so that the electric motor will not be required to turn over the engine.
DETAILED DESCRIPTION OF THE INVENTION The invention will now be described in greater detail with reference to the appended drawings in which:
FIG. 1 is a perspective view of an outboard motor nection arrangement useful in operating the outboard motor unit of the invention.
Referring now to the drawings and more particularly to FIG. 1, there is shown an outboard motor of conventional design comprising an internal combustion engine located within a housing 10, a lower drive unit 11 and a shaft housing 12 intercoupling the engine and the lower drive unit. I
A combined steering and throttle handle 13, shown more or less diagrammatically, is provided to steer the boat and to control the engine speed in the usual way. This is to say, when a rotatable hand grip 14 at the end of handle 13 is rotated, an internal shaft 15 is. rotated which, through gears 16 and 17, rotates throttle shaft 18 to speed up or slow down the engine, depending on the direction of rotation. v
The engine power is delivered through a drive shaft 19 and bevel gears 20 and 21 (or 20 and 22) to a propeller shaft 23 on which is mounted a propeller 24 for driving the boat. A clutch mechanism 25 is provided to engage bevel gears 20 and 21 or 20 and 22 or to disengage gear 20 from both gears 21 and 22 to provide forward motion, reverse motion or no motion (neutral). The lower unit 11 is filled with oil to provide lubrication for the gears.
What has been described so far is a preferably conventional outboard motor. For this reason most of the parts of the outboard motor have not been illustrated in detail and some have been omitted for simplicity, e.g., the starting cord and the mounting brackets.
As is best shown in FIG. 2, at the rear of the lower unit 1 1 the propeller shaft 23 is journalled for rotation in a bearing 26, as is customary. The adjacent rear end of the propeller shaft is hollowed out to accommodate has threaded openings which accept peripherally.
spaced bolts 33 which act in holes provided in annular plate 29 and serve to attach motor 32 to plate 29.
Seal ring 30 is compressed between collar 31 and plate 29 by the action of bolts 29 and serves to keep water from penetrating between collar 31 and plate 29. However, seal ring 30. preferably does not prevent oil from lower unit 11 and which is present at bearing 26 from seeping along the surface of shaft 27. This oil is however kept away from the electric motor 32 by means of O-rings 34 and 35 located in internal annular grooves in collar 31.
It should be understood that the electric motor housing may be made integral with the rear wall 28 of the lower unit 11. in such case, the O-rings 34 and 35, or similar devices, would still be provided to keep oil from the lower unit out of the electric motor.
The electric motor 32 is preferably of the permanent magnet rotor type with the rotor unit mounted on shaft 27. One of the motor brushes is grounded to the motor housing, as indicated diagrammatically at 36. The ground connection is made also to the outboard engine proper through bolts 33 and plate 29. The other of the motor brushes is connected to one terminal of a microswitch 37 through a conductor 38 which passes through aligned openings in collar 31, seal ring 30, plate 29 and rear wall 28 and then up through shaft housing 12.
The other terminal of micro-switch 37 is connected through a conductor 39 to one terminal of a battery (not shown) which may be the starting battery commonlyprovided for outboard engines or may be a separate battery provided for auxiliary propulsion. Typically the battery will be 12 volts. The other terminal of the battery is grounded to the outboard engine through a conductor 40. The battery connections for outboard engines are commonly made through plug and socket units or binding posts, and connectors such as these, while not shown, would normally be used for convenience.
The micro-switch 37 mounted on the engine housing and is provided with an operating arm 41 located in the path of a cam 42 carried by a collar 43 which in turn is carried by outboard engine throttle shaft 10. The arrangement is such that at a predetermined throttle setting, e.g., 75 percent of full throttle, cam 42 will actuate arm 41 and close microswitch 37 thereby completing the electrical connection between the electric motor 32 and the battery. The cam 42 is so shaped as to maintain the micro-switch 37 closed for all throttie settings above the selected value and to open the micro-switch for all throttle settings below the selected value.
.When the outboard engine is running and the clutch is engaged, shaft 23 will be turned over by the engine. When the throttle setting is sufficient to close microswitch 37, the shaft 23, and hence also motor shaft 27,
will be turning at an RPM'substantially higher than the normal RPM resulting from electric motor operation. Hence the electric motor 32 will act not as a motor but rather as a generator and will charge the battery. The value of throttle setting at which switch 37 is closed should be selected to insure the generator type of operation while the engine itself is running. Three.- quarters throttle has been found typically to be a satisfactory value for this purpose.
If the engine is running and the clutch is disengaged, opening the throttle sufficiently to close switch 37 will cause motor 32 to be operated and to turn over shaft 27 and hence also propeller 24. However, since it is generally considered quite harmful to run an engine at high speed with the clutch disengaged, this situation is not likely to be continued for long enough to present any real problem.
When switch 37 is closed with the engine stopped, electric motor 32 will be operated to turn shaft 27 and hence also shaft 23 and propeller 24 and thus to propel the boat to which the outboard motor unit is attached. With an electric motor of reasonable horsepower relative to the size andweight of the boat, the boat will be propelled at a relatively slow speed suitable for trolling. And since an electric motor is inherently quiet, a low noise level will be maintained. 7
Should the clutch 25 inadvertently be in engaged position and with the engine stopped at the time the motor 32 is powered, the electric motor will generally stall since its torque output is well below that necessary to turn over the engine against compression. in this connection it will be realized that an electric motor suitable for use as a starting motor would draw far too much power to be practical for propulsion purposes.
By way of example, for an outboard engine of 6 horsepower, an electric motor 32 which drew 10 amperes at 12 volts (about one-sixth horsepower), was found satisfactory for trolling purposes. In this case, the electric motor, when operated as a motor, turned over at about 500 RPM (under load) and when operated as a generator turned over at about 2,800 RPM or more. When rotated at 3,200 RPM the motor (generator) yielded a charging rate of 2 amperes. The same motor 32 has been found usable with a 25 horsepower engine, although a larger motor can be used to advantage.
Very small outboard engines, e.g., those of Ht to 39% horsepower commonly arebuilt without clutches. To use the invention with such engines a one-direction clutch may be added to the engine drive train so as to disengage the enmne from the propeller shaft when torque is supplied from the electric motor rather than the engine. By way of example, a one-direction clutch was installed in the lower unit of a 1%. horsepower outboard engine to disengage the engine from the propeller shaft when the electric motor was operated. The lower unit was provided with a factory installed 2:1 reduction gear. An electric motor 32 of about onetwelfth horsepower was coupled to the propeller shaft through a planetary gear train providing a 7:1 reduction between the electric motor and the propeller shaft.
When the outboard motor engine runs at @000 RPM the propeller shaft turns at 2,000 RPM yielding anelectric motor RPM of 14,000 RPM. At this speed, the
electric motor operates as a generator. With the engine off and the electric motor powered, the motor operates at 10,000 RPM, yielding a propeller rotational speed of 1,400 RPM (atno load, i.e., out of the water). It should be understood that a lower gear ratio than 7:1 would be preferable. I
In accordance with a further'aspect of the invention, the electric motor 32may be of the type which will operate at either of two voltages, e.g., 6 volts .or 12 volts. Normally the electric motor will be operated at 12 volts since this is the usual storage battery voltage. To operate at a decreased speed but for a longer period on the same storage battery charge, the battery may be connected as shown inFIG. 3.
In FIG. 3 thereis shown a storage battery 44 which is of the type with connections for cells accessible. The battery has series connected cells 45, 46 and 47 providing 6 volts and series connected cells 48, 49 and 50 providing 6 volts. The usual connection between cells 47 and 48 is removed.
The'positive terminal of cell 45 is connected to conductor 39 and to a contact 51 of a double pole-double throw switch 52. The negative terminal of cell 47 is connected to an armature 53 of switch 52. The negative terminal of cell 50 is connected to conductor 40 and to contact 54 of switch 52. The positive terminal of cell 48'is connected to contact 55 of switch 52 and, through a conductor 56, to armature 57 of switch 52.
With switch 52 in the right hand position of FIG. 3
and with arrnatures 53 and 57 made with contacts 54 and 51, respectively, 6 volts will be available at conductors 39 and 40 but with cell groups 45-47 and 48-50 connected in parallel to afford the combined ampere hour capacity of the two groups. With switch 52 in the left hand position of FIG. 3 and with armature 53 made with contact 55, the cell groups 45-47 and 48-50 will be connected in series to provide 12 volts at conductors 39 and 40. o
The arrangement of FIG. 3 can, of course, be used with two separate batteries rather than two groups of cells of the same battery.
While the invention has been described in connection with specific embodiments thereof and in a specific use, various modifications thereof will occur to those skilled in the art without departing from the spirit and scope of the invention as set forth in the appended claims. I
What is claimed is:
1. An outboard motor unit, for use on small boats, comprising:
a. a primary propulsion engine having a throttle control for adjusting the speed of said engine;
b. a lower unit adapted to be immersed in water and having a propeller arranged to be rotated to propel a boat to which said outboard motor unit is attached;
c. a propeller shaft in said lower unit and on which said propeller is mounted;
d. means including a drive shaft and a gear mechanism operatively intercoupling said propeller shaft and said engine for rotating said propeller shaft and said propeller when said engine is operating;
. clutch means for disengaging said engine from said propeller shaft to permit rotation of said propeller shaft and said propeller independently of operaf. 39312211? :1?) i' liaving a rotor shaft aligned with and operatively coupled to said propeller shaft and arranged to be rotated when said propeller shaft rotates and to rotate said propeller shaft when said rotor shaft is rotated;
. an electrical power connection for said electric motor, said connection including an operable switch mechanism for opening and closing saidpower connection; and
h. means operatively interconnecting said throttle control and said'switch mechanism and arranged to close said switch mechanism and thereby to close said power connection for throttle settings at and above a selected value and to open said switch mechanism and thereby to open said power connection for throttle settings below said selected value.
2. An outboard motor unit as setforth in claim 1 in which said electric motor is constructed to rotate said propeller shaft at a relatively low speed when said motor is powered through said'electrical power connection and in which said selected value of throttle setting corresponds to an engine speed sufficient, when said clutch mechanism is engaged with said engine operating, to rotate said propeller shaft at a speed higher than said relatively low speed whereby said electric motor acts as a generator.
3. An outboard motor unit as set forth in claim 2 in which said lower unit is filled with lubricant oil, in which communication between said lower unit and the forward end of said rotor shaft exposes the latter to lubricant oil from said lower unit, and in which means is provided to exclude said oil from the interior of said electric motor.
4. An outboard motor unit as set forth in claim 2 in which said throttle control includes a rotatable throttle shaft and in which said means operatively intercoupling said throttle control and said switch mechanism includes a cam mounted on said throttle shaft and arranged to contact said switch mechanism.
5. An outboard motor unit as set forth in claim 2 in' which said selected value of throttle setting is approximately 14 full throttle.
6. An outboard motor unit as set forth in claim 2 in which saidelectrical power connection includes a multicell battery and in which switch means is provided selectively to connect all of said cells in series and two groups of said cells in parallel.
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