JPH0214237B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to transmissions, and more particularly to overdrive transmissions for marine equipment and the like.

As the horsepower of marine propulsion systems, such as outboard motors and stern drives, increases, the use of overdrive systems becomes more desirable due to fuel costs, engine life, undercarriage life, and overall performance improvements. There is. A low pitch propeller can be used for acceleration, and once the ship is designed, an overdrive device can reduce engine speed without reducing propeller speed. The high speed operation of the driveshaft, enabled by overdrive mode operation, creates a low torque load between the drive gear on the driveshaft and the pinion gear on the propeller shaft, allowing for improved lower equipment life and fuel costs. do. An example of a device with multiple speeds is U.S. Pat. No. 1,795,135;
1979077, 2466318, 2861461, 3129602, 3372601,
It is shown in each specification of No. 3884097 and No. 4173939.

The present invention includes a first drive gear attached to rotate together with the input shaft, a first driven gear attached to rotate together with the drive shaft, and a first driven gear attached to rotate together with the input shaft. A gear train including a second driven gear that meshes with the drive gear, and a second drive gear that meshes with the first driven gear and is selectively drivably connected to the second driven gear. a first position in which the power or input shaft is driveably coupled directly to the output or drive shaft; and a second position in which the drive shaft is driven at a rotational speed higher than the rotational speed of the input shaft. The present invention provides a marine propulsion system, such as an outboard motor or stern drive, having an overdrive transmission capable of converting between the two.

More specifically, the present invention provides a rotatable input shaft drivably connected to a power source, a drive shaft drivably connected to a propulsion shaft housed in a bottom device and supporting a propeller, and an input shaft. A marine propulsion device includes a transmission drivingly coupled to a drive shaft. The transmission includes a first drive gear mounted to rotate together with the input shaft, and a first drive gear mounted to rotate together with the drive shaft and independently of the input shaft on the same axis. The first driven gear, the input shaft and the drive shaft are connected to one
The input shaft is rotated in unison in two rotational directions, and such that the drive shaft rotates with respect to the input shaft when the drive shaft is driven in said rotational direction at a higher rotational speed than the first drive gear. a clutch device drivingly coupled to the drive shaft, a second driven gear meshing with the first drive gear, and a second driven gear mounted for rotation relative to and coaxially with the second driven gear. a first position operatively coupled between the second driven gear and the second drive gear and in which the second driven gear and the second drive gear rotate freely relative to each other; an actuator operable between a second position drivingly coupling between the second driven gear and the second drive gear. Each gear has a gear ratio such that the drive shaft is driven at a higher rotational speed than the input shaft when the second drive gear and second driven gear are drivably coupled.

In one embodiment, the transmission has a rotatable countershaft spaced apart from the input shaft and the driveshaft and having an axially extending bore and configured to rotate integrally with the countershaft. A second driven gear is mounted on the countershaft, and a second drive gear is mounted on the countershaft for rotation relative to the countershaft. an actuator including a selector shaft supported in the counterbore and axially movable between first and second positions;
a device for drivingly coupling the countershaft with a second drive gear upon movement of the selector shaft to the second position; and a device for selectively moving the selector shaft between the first and second positions. Includes equipment for moving.

In one embodiment, the transmission includes an axially extending sleeve member coupled to the second drive gear for rotation therewith and surrounding the countershaft; a plurality of circumferentially arranged recesses in the inner surface of the sleeve member; a plurality of circumferentially spaced radially extending passageways in the countershaft aligned with the recesses; A coupling element drivingly engages a recess disposed therein and is movable between a retracted position away from the recess and an extended position drivingly engages the recess. Further, the coupling element is moved to an extended position in response to movement of the selector shaft to the second position, and the coupling element is moved to a retracted position in response to movement of the selector shaft to the first position. A selector shaft is provided for return to position.

One of the main features of the invention is a marine propulsion system having an inexpensive and compact overdrive transmission that is removable after the design of the vessel and provides high propeller speeds in low torque conditions without increasing engine speed. It is provided by.

Another feature of the invention is an overdrive transmission that is particularly suitable for marine propulsion systems and has a simple structure that allows the output, or rotational speed of the drive shaft, to be easily varied without increasing the speed of the input shaft. It is provided by.

Although the present invention is described as being used for outboard motors,
Can be used for stern drives or other similar applications.

Illustrated in FIG. 1 is an outboard motor 1 that includes a power head 12 housing an internal combustion engine 14 and an undercarriage 16 having a gear case 18 that is normally submerged.
It is 0. A propeller shaft 20 is rotatably mounted within the gear case 18 and supports a propeller 22 at its outer end. Inside the gear case 18 is the propeller shaft 2.
A pair of axially spaced opposed bevel gears 24 and 26 are supported at the propeller shaft 20 and driveably connected to the propeller shaft 20.

Propeller shaft 20 through lower unit 16
Extending at right angles to are gears 24 and 26.
A rotatably mounted drive shaft 28 supports a drive bevel gear 30 meshing with the drive shaft 28 . The drive shaft 28 is connected to the engine 1 by an overdrive transmission, indicated generally at 32.
4 and is drivably connected to.

The transmission 32 is connected to the engine 14.
It includes a power shaft or input shaft 34 which is drivably connected to the drive shaft 28 and rotatably mounted in the housing 35 via a bearing 36 coaxially with the drive shaft 28 . The transmission 32 also includes a first drive gear 38 mounted to rotate integrally with the input shaft 34;
The input shaft 3 is mounted on the spline portion 42 of the drive shaft 28 so as to rotate together with the input shaft 3.
4 includes a first driven gear 40 adapted to rotate independently of and coaxially therewith.

The input shaft 34 is driveably coupled to the drive shaft 28 by a wedge acting one-way overrun clutch 44. Said clutch 4
4 includes a clutch hub 46 which is mounted on a spline 48 on the drive shaft 28 to rotate together with the drive shaft 28; The clutch drum 50 is disposed between the drive gear 38 of the clutch drum 50 and the clutch drum 50, which is mounted to rotate integrally with the drive gear 38 of the clutch drum 50. The clutch 44 allows the input shaft 32 to drive the drive shaft 28 in one rotational direction, and furthermore, if the rotational speed of the drive shaft 28 exceeds the rotational speed of the input shaft in said rotational direction, i.e. the drive shaft 28 When the input shaft 34 is overrun, the drive shaft 28 is allowed to rotate freely relative to the input shaft 34. The transmission 3
2 further includes a countershaft 52 radially spaced from drive shaft 28 and input shaft 34 and rotatably supported by a pair of bearings 54 and 56. A second driven gear 58 meshing with the first drive gear 38 is mounted on the countershaft 52 for rotation therewith. A second drive gear 60 meshing with the first driven gear 40 is rotatably mounted to the countershaft 52 via a bearing 62 . The first drive gear 38 , the second driven gear 58 , the second drive gear 60 and the first driven gear 40 are connected to the second driven gear 58
The gear ratio is such that the drive shaft 28 is driven at a higher rotational speed than the input shaft 34 when the and second drive gear 60 are drivably connected to each other.
In the illustrated embodiment, the first drive gear 38 has a greater number of teeth than the second driven gear 58.

In normal operation, the wedge acting overrun clutch 44 causes the input shaft 34 to drive the drive shaft 28 at the same speed as the input shaft 34, and the first drive gear 38 Since the second driven gear 58 has a larger number of teeth than the second driven gear 58, the second driven gear 58 has a larger number of teeth.
First drive gear 38 drives countershaft 52 at a higher rotational speed than input shaft 34 . At the same time, the countershaft 52 is connected to the first driven gear 4
The second drive gear 60 is rotated by
It rotates independently.

The countershaft 52 is connected to a second shaft such that the drive shaft 28 is driven at a higher rotational speed than the input shaft 34.
An actuator is provided for selectively drivingly coupling the drive gear 60 of the drive gear 60 . In the illustrated embodiment, there is a longitudinally or axially extending hole 64 in the countershaft 52;
4 and includes a plurality of circumferentially spaced holes or passageways 66 extending radially toward each passageway 4 and a coupling element in the form of a ball 68 disposed within each passageway 66. Mounted for rotation with the second drive gear 60 and for rotation with respect to the countershaft 52 via bearings 69 surrounds the countershaft 52 and is spaced a short distance apart. 7. A sleeve member 70 having an inner surface 72 that has an inner surface 72. The inner surface of sleeve member 70 is aligned with countershaft passageway 66 and is aligned with ball 68.
It has circumferentially arranged indentations or recesses 74 capable of receiving. Countershaft 52 is drivably coupled to second drive gear 60 by ball 68 moving radially outwardly into and engaging recess 74 of sleeve member 70 .

Apparatus is provided for selectively placing and drivingly engaging the ball 68 into the recess 74. In the embodiment shown, a device is provided having a plunger or selector shaft 76 supported in a countershaft bore 66 for relative axial movement. The selector shaft 76 has a reduced diameter tip 78 and a frustoconical section 80 proximate the reduced diameter tip 78.

When the selector shaft 76 is in the first or uncoupled position shown in FIGS. 2 and 3, the ball 68 is supported on the small diameter tip 78 of the selector shaft 76 and retracted inside the passageway 66. and does not engage with the sleeve member recess. selector·
As the shaft 76 moves axially (downward in FIG. 2) toward the second or coupled position, the frustoconical portion 80 captures the ball 68 and forces it radially outwardly into the sleeve member recess 74 in a driving force. engage.

The selector shaft 76 includes a link 83 which is pivotally connected to the outer end 84 of the selector shaft.
is moved between an uncoupled position and a coupled position by the pivoting reciprocation of a bell crank 82 which is pivotally connected to the bell crank 82 . Bell crank 8 about pivot point 85
The pivoting of 2 may be accomplished by any suitable electrical, mechanical, or hydraulic device. In this manner, selector shaft 76 moves from the uncoupled position shown in FIG. Move up to. When this state is reached, the drive shaft 28 is
First driving gear 38 and second driven gear 58
, a second driving gear 60 , and a first driven gear 4
0, the input shaft is driven at a higher rotational speed than the input shaft. When selector shaft 76 returns to the uncoupled position, clockwise movement of bell crank 82 causes drive shaft 2
8 is driven at the same rotational speed as the input shaft by the action of the overrun Spragg clutch 44 mentioned above.

Alternatively, the second driven gear 58 may include a sleeve member 70 and be mounted for rotation with respect to the countershaft 52, and the second drive gear 60 may be mounted for rotation with respect to the countershaft 52. It is also possible to provide a selector shaft 56 for selectively coupling the countershaft 52 to the second driven gear 58.

[Brief explanation of drawings]

FIG. 1 is a side elevational view of an outboard motor incorporating various features of the present invention. 2 is an enlarged cross-sectional view of the overdrive transmission of the outboard motor shown in FIG. 1; FIG. FIG. 3 is a cross-sectional view taken approximately along line 3--3 in FIG. 2. DESCRIPTION OF SYMBOLS 10... Outboard motor, 12... Power head, 14... Internal combustion engine, 16... Lower device, 20... Propeller shaft, 22... Propeller, 28... Drive shaft, 32... Transmission, 34... Input shaft, 38... First driving gear, 40...first driven gear, 44...clutch, 52...counter shaft, 58...second driven gear, 60...second driving gear, 64...hole,
66... Passage, 68... Ball, 70... Sleeve member, 74... Recess.

Claims (1)

[Claims] 1. An input shaft rotatably connected to a power source so as to transmit power; a lower device housing a drive shaft; and a propeller rotatably mounted in the lower device. a supporting propeller shaft; a device for power transmittably coupling the drive shaft to the propeller shaft; and a transmission power transmittably coupling the input shaft to the drive shaft; is attached to rotate integrally with the input shaft.
a first driven gear mounted to rotate integrally with the drive shaft and coaxially rotate independently of the input shaft; The drive shaft rotates relative to the input shaft when the drive shaft is driven in the rotation direction at a rotation speed higher than the rotation speed of the input shaft. a clutch device that connects the input shaft to the drive shaft so as to transmit power; a second driven gear that meshes with the first drive gear; a second driven gear mounted for relative rotation and meshing with the first driven gear;
drive gears, and the gear ratio of these gears is such that when the second driven gear and the second drive gear are connected to each other so as to be able to transmit power, the drive shaft is lower than the input shaft. the transmission is selected to rotate at a high rotational speed, and the transmission is operatively coupled between the second driven gear and the second drive gear and a first drive gear in which the second drive gear rotates freely relative to each other;
a marine propulsion system, the marine propulsion system having an actuator that moves between a position and a second position that connects the second driven gear and the second drive gear in a power transmitting manner. 2. A marine propulsion system according to claim 1, wherein the clutch device comprises a one-way overrun clutch. 3. The apparatus of claim 1, wherein the transmission further includes a countershaft having an axially extending hole spaced radially from the input shaft and the drive shaft; a driven gear is attached to the countershaft so as to rotate together with the countershaft, and the second drive gear is attached to the countershaft so as to rotate relative to the countershaft. and the actuator further includes a selector shaft supported in the aperture and axially movable between the first and second positions, the transmission further including a selector shaft that is axially movable between the first and second positions. a device for power transmittably coupling the countershaft with the second drive gear when moving the selector shaft to the second position; and a device for selectively moving the selector shaft between the first and second positions. A marine propulsion system that includes equipment for 4. The device according to claim 3, wherein the device for connecting the countershaft to the second drive gear in a power transmitting manner,
an axially extending sleeve member coupled to the second drive gear for rotation therewith and having an inner surface surrounding the countershaft with a small clearance; a plurality of circumferentially spaced recesses in the inner surface of the member; and a plurality of circumferentially arranged recesses extending radially toward and aligned with the bore in the countershaft. a retracted position in which each passageway is in driveable engagement with one of said recesses and disposed within a respective one of said passageways and disengaged from engagement with said recess within said passageway; a plurality of coupling elements movable between a protruding position driveably engaging one of the recesses and over the selector shaft for movement of the selector shaft to the second position; a device for moving the coupling element outwardly to the extended position in response to movement of the selector shaft to the first position and returning the coupling element to the retracted position in response to movement of the selector shaft to the first position; A marine propulsion system including: 5. An input shaft that is rotatably attached, a drive shaft that is attached to rotate independently and coaxially with the input shaft, and a drive shaft that is attached to rotate integrally with the input shaft. a first driven gear attached to rotate integrally with the drive shaft; and a first driven gear attached to rotate integrally with the input shaft and the drive shaft such that the input shaft and the drive shaft rotate integrally in one rotation direction. Further, the input shaft and the drive shaft are connected to each other so that power can be transmitted so that the drive shaft rotates relative to the input shaft when the drive shaft rotates in the rotational direction at a higher rotational speed than the input shaft. a clutch device and a second drive gear meshing with the first drive gear;
a second driven gear that meshes with the first driven gear and is attached to coaxially and relatively rotate with the second driven gear; The gear ratio is selected such that the drive shaft is driven at a higher rotational speed than the input shaft when the second driven gear and the second drive gear are coupled to each other so as to transmit power. and further includes a second driven gear operatively connecting the second driven gear and the second driving gear, and allowing the second driven gear and the second driving gear to rotate freely relative to each other. an actuator movable between a first position and a second position for power transmittably coupling the second driven gear and the second drive gear. 6. The transmission according to claim 5, further comprising a countershaft having an axially extending hole rotatably mounted on a shaft different from the input shaft and the drive shaft, The second driven gear is mounted to rotate together with the countershaft, and the second drive gear is mounted to the countershaft to rotate relative to the countershaft. the actuator further includes a selector shaft supported in the bore and axially movable within the bore between the first and second positions; a transformer including means for drivingly coupling said countershaft with said second drive gear when moved to a position; and means for selectively moving said selector shaft between said first and second positions; Mitssion. 7. The transmission of claim 5, wherein said clutch device is a one-way overrun clutch. 8. The transmission according to claim 6, wherein the device for drivably coupling the countershaft and the second drive gear is integral with the second drive gear. an axially extending sleeve member coupled to the second drive gear for rotation relative to the countershaft and having an inner surface surrounding the countershaft with a small clearance; a plurality of recesses arranged circumferentially in the inner surface of the sleeve member; and a plurality of recesses circumferentially spaced within the countershaft so as to be aligned with the holes and with the recesses. movable between a plurality of elongated passageways, a retracted position disposed in the passageway, drivingly engaged with the recess, and disengaged from the recess, and a protruding position drivingly engaged one of the recesses; a plurality of connecting elements of the selector shaft, the connecting element being moved outwardly toward the protruding position in response to movement of the selector shaft into the second position; - a device for returning the coupling element to a retracted position in response to movement of the shaft to the first position.