ELECTRIC STERN DRIVES

Abstract

A stern drive is for propelling a marine vessel in a body of water. The stern drive has a powerhead, a mounting assembly configured to affix the powerhead to the transom, inside the marine vessel, and a drive assembly coupled to the mounting assembly, the drive assembly being trimmable up and down relative to the mounting assembly, the drive assembly comprising a driveshaft and an output shaft which extends transversely to the driveshaft. The drive assembly has a driveshaft housing for the driveshaft and a gearcase housing for the output shaft, wherein the gearcase housing is steerable relative to the driveshaft housing. A universal joint couples the powerhead to the driveshaft so that operation of the powerhead causes rotation of the driveshaft, which in turn causes rotation of the output shaft.

Description

CROSS REFERENCE TO RELATED APPLICATION

This application claims priority to U.S. Provisional Application No. 63/324,251, filed Mar. 28, 2022, which is incorporated herein by reference in its entirety.

FIELD

The present disclosure relates to marine drives, and in particular stern drives having a powerhead for propulsion, such as an electric motor, and also to methods for trimming stern drives out of a body of water.

BACKGROUND

The following U.S. patents are incorporated herein by reference in entirety.

U.S. Pat. No. 6,273,771 discloses a control system for a marine vessel which incorporates a marine propulsion system for attachment to a marine vessel and connection signal communication to a serial communication bus and a controller. A plurality of input devices and output devices are also connected in signal communication with the communication bus. A bus access manager such as a CAN Kingdom network is connected in signal communication with the controller to regulate the incorporation of additional devices in signal communication with the bus. The input and output devices can each transmit messages to the serial communication bus for receipt by other devices.

U.S. Pat. No. 9,334,034 discloses a system for combined control of steering and trim of a marine engine unit. The system includes a steering apparatus generating steering signals, a trim control generating trim signals, an electronic unit receiving steering trim and cylinder position signals and sending output signals. Port and starboard hydraulic cylinders are connected to port and starboard joints to provide movement of the engine unit. The port and starboard joints enable movement of the engine unit vertically and horizontally when the port and starboard hydraulic cylinders are extended and retracted to provide a full range of steering and trim movement of an engine unit.

U.S. Pat. No. 9,446,828 discloses an apparatus for mounting a marine drive to a hull of a marine vessel. An outer clamping plate faces an outside surface of the hull and an inner clamping plate faces an opposing inside surface of the hull. A marine drive housing extends through the hull. The marine drive housing is held in place with respect to the hull by at least one vibration dampening sealing member which is disposed between the inner and outer clamping plates. A first connector clamps the outer clamping plate to the outside surface of the hull and a second connector clamps the inner clamping plate to the outer clamping plate. The inner and outer clamping plates are held at a fixed distance from each other so that a consistent compression force is applied to the vibration dampening sealing member.

U.S. Pat. No. 10,800,502 discloses an outboard motor having a powerhead which causes rotation of a driveshaft, a steering housing located below the powerhead, wherein the driveshaft extends from the powerhead into the steering housing, and a lower gearcase located below the steering housing and supporting a propulsor shaft which is coupled to the driveshaft so that rotation of the driveshaft causes rotation of the propulsor shaft. The lower gearcase is steerable about a steering axis with respect to the steering housing and powerhead.

SUMMARY

This Summary is provided to introduce a selection of concepts which are further described herein 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.

In non-limiting examples disclosed herein, a stern drive is for propelling a marine vessel in a body of water. The stern drive comprises a mounting assembly for coupling the stern drive to a transom of the marine vessel, and a drive assembly which is trimmable up and down relative to the mounting assembly, the drive assembly comprising a driveshaft housing for a driveshaft. The drive assembly may comprise a gearcase housing for an output shaft for a propulsor, wherein the gearcase housing is steerable relative to the driveshaft housing.

In non-limiting examples, the stern drive comprises a mounting assembly for coupling the stern drive to a transom of the marine vessel, a powerhead configured to operate a propulsor to generate a thrust force in the body of water, a drive assembly which is trimmable up and down relative to the mounting assembly, the drive assembly comprising a driveshaft which is operably coupled to the powerhead and the propulsor, and a universal joint which couples the powerhead to the driveshaft so that operation of the powerhead causes rotation of the driveshaft, which in turn operates the propulsor, wherein the universal joint is configured to facilitate trimming of the drive assembly an amount sufficient to raise at least a majority of the drive assembly out of the body of water.

In non-limiting examples, the stern drive comprises a mounting assembly for coupling the stern drive to a transom of the marine vessel, a powerhead configured to operate a propulsor to generate a thrust force in the body of water, a drive assembly which is trimmable up and down relative to the mounting assembly, the drive assembly comprising a driveshaft housing for a driveshaft and a gearcase housing for an output shaft for the propulsor, wherein the gearcase housing is steerable relative to the driveshaft housing, a universal joint which couples the powerhead to the driveshaft so that operation of the powerhead causes rotation of the driveshaft, which in turn operates the propulsor, wherein the universal joint is configured to facilitate trimming of the drive assembly, a steering actuator configured to steer the gearcase housing relative to the driveshaft housing, and a controller configured to cause the powerhead to rotate the universal joint into a neutral position which facilitates trimming the drive assembly upwardly relative to the body of water, and also to cause the steering actuator to steer the gearcase housing relative to the driveshaft housing thereby moving an entirety of the drive assembly out of the body of water.

In non-limiting examples, methods are for operating a stern drive. The method may include: providing a drive assembly which is trimmable up and down, the drive assembly comprising a driveshaft housing for a driveshaft and a gearcase housing for an output shaft for a propulsor, wherein the gearcase housing is steerable relative to the driveshaft housing, and wherein the drive assembly comprises a universal joint which couples a powerhead to the driveshaft so that operation of the powerhead causes rotation of the driveshaft, which in turn operates the propulsor, and operating the powerhead to rotate the universal joint into a neutral position which facilitates trimming of the drive assembly upwardly relative to the stern drive, and also steering the gearcase housing relative to the driveshaft housing thereby moving an entirety of the drive assembly further upwardly relative to the stern drive.

In non-limiting examples disclosed herein, the stern drive has a mounting assembly configured to affix the stern drive to the transom inside the marine vessel, and a drive assembly coupled to the mounting assembly. The drive assembly is trimmable up and down relative to the mounting assembly and comprises a driveshaft and an output shaft which extends transversely to the driveshaft. The drive assembly has a driveshaft housing for the driveshaft and a gearcase housing for the output shaft. The gearcase housing is steerable relative to the driveshaft housing. In some examples, a universal joint couples the powerhead to the driveshaft so that operation of the powerhead causes rotation of the driveshaft, which in turn causes rotation of the output shaft. The universal joint is configured to facilitate trimming of the drive assembly an amount sufficient to raise at least a majority of the drive assembly out of the water. In other examples, dual constant velocity (CV) joints couple the powerhead to the driveshaft so that operation of the powerhead causes rotation of the driveshaft, which in turn causes rotation of the output shaft. The dual constant velocity (CV) joints are configured to facilitate trimming of the drive assembly an amount sufficient to raise at least a majority of the drive assembly out of the water.

In non-limiting examples, the stern drive has a steering housing which extends into the driveshaft housing and a torpedo housing coupled to the steering housing. The driveshaft extends through the steering housing and is operably engaged with the output shaft in the torpedo housing. An angle gearset may be located in the torpedo housing, wherein the angle gearset couples the driveshaft to the output shaft so that rotation of the driveshaft causes rotation of the output shaft. Upper and lower bearings may rotatably support the steering housing relative to the driveshaft housing.

In non-limiting examples, the stern drive may have a steering actuator which causes the gearcase housing to steer relative to the driveshaft housing. The steering actuator may include an electric motor, which may be located in the driveshaft housing.

In non-limiting examples, the universal joint may couple the powerhead to the driveshaft so that operation of the powerhead causes rotation of the driveshaft, which in turn causes rotation of the output shaft, wherein the universal joint is configured to facilitate trimming of the drive assembly an amount sufficient to raise at least a majority of the drive assembly out of the body of water.

The universal joint may be configured to pivot about at least one pivot axis when the drive assembly is trimmed relative to the mounting assembly. A controller may be configured to automatically cause the powerhead to rotate the universal joint into a neutral position in which the at least one pivot axis is parallel to the trim axis, which facilitates said trimming of the drive assembly the amount sufficient to raise the drive assembly out of the body of water. The controller may be configured to automatically cause the powerhead to rotate the universal joint into the neutral position based upon an operational state of the stern drive. The operational state may include at least one of an on/off state of the powerhead and a request provided to the controller by a user input device. The at least one pivot axis may comprise a first input pivot axis and first output pivot axis, and wherein in the neutral position the first input pivot axis and the first output pivot axis are both parallel to the trim axis.

In non-limiting examples, the universal joint may have an input member which is rotatably engaged with the powerhead, an output member which is rotatably engaged with the driveshaft, and a body which rotatably couples the input member to the output member. The input member may have an input shaft and input arms which form a U-shape, the input arms being pivotably coupled to the body along the first input pivot axis and along a second input pivot axis which is generally perpendicular to the first input pivot axis. The output member may have an output shaft and output arms which form a U-shape, the output arms being pivotably coupled to the body along the first output pivot axis and along a second output pivot axis which is generally perpendicular to the first output pivot axis.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure includes the following figures.

FIG. 1 is a starboard side perspective view of a stern drive according to the present disclosure.

FIG. 2 is a port side perspective view of the stern drive.

FIG. 3 is a starboard side perspective view of the stern drive.

FIG. 4 is a starboard side view of the stern drive.

FIG. 5 is a perspective view looking down at a universal joint of the stern drive which couples a powerhead, which in the illustrated example includes an electric motor, to a driveshaft of the stern drive.

FIG. 6 is an exploded view of the universal joint.

FIG. 7 is a starboard side sectional view of the stern drive.

FIG. 8 is a starboard side view of the stern drive in a trimmed-up position.

FIG. 9 is a starboard side sectional view of the stern drive in the trimmed-up position.

FIG. 10 is a starboard side perspective view of a mounting assembly which mounts the electric motor to the transom of a marine vessel.

FIG. 11 is a starboard side perspective view of the stern drive in the trimmed-up position and steered ninety degrees off center (straight-ahead) so that the drive assembly of the stern drive is trimmed fully out of the water.

FIG. 12 is a starboard side view of an example sound enclosure for the stern drive.

FIG. 13 is a starboard side sectional view of the example shown in FIG. 12.

FIG. 14 is a starboard sectional view of another example of the stern drive having dual constant velocity (CV) joints and center shaft instead of the universal joint shown in FIG. 5.

FIG. 15 is a closer starboard sectional view of the dual CV joints and center shaft shown in FIG. 14.

FIG. 16 is a starboard side sectional view showing the stern drive of FIG. 14 in a trimmed up position.

FIG. 17 is a perspective view of the dual CV joints.

DETAILED DESCRIPTION

FIGS. 1-8 illustrate a stern drive 12 for propelling a marine vessel in a body of water. Referring to FIG. 1, the stern drive 12 has a powerhead, which in the illustrated example is an electric motor 14, a mounting assembly 16 which affixes the electric motor 14 to and suspends the electric motor 14 from the transom 18 of the marine vessel, and a drive assembly 20 coupled to the mounting assembly 16. The illustrated powerhead is not limiting and in other examples the powerhead may include an engine and/or a combination of an engine and an electric motor, and/or any other suitable means for powering a marine drive. The mounting assembly 16 is configured so that the electric motor 14 is suspended (i.e., cantilevered) from the interior of the transom 18, above the hull of the marine vessel. As will be further explained below, the drive assembly 20 is trimmable up and down relative to the mounting assembly 16, including in non-limiting examples wherein an majority or an entirety of the drive assembly 20 is raised completely out of the water. The drive assembly 20 has a driveshaft housing 22 containing a driveshaft 24 and a gearcase housing 26 containing one or more output shaft(s) 28, e.g., one or more propulsor shaft(s). The output shaft(s) 28 extends from the rear of the gearcase housing 26 and support one or more propulsors(s) 30 configured to generate thrust in the water for propelling the marine vessel. The output shaft(s) 28 extend generally transversely to the driveshaft 24. In the illustrated example, propulsor(s) 30 include two counter-rotating propellers. However this is not limiting and the present disclosure is applicable to other arrangements, including arrangements wherein one or more output shaft(s) 28 are not counter-rotating and/or wherein the one or more output shaft(s) 28 extend from the front of the gearcase housing 26, and/or wherein the propulsor(s) 30 include one or more impellers and/or any other mechanism for generating a propulsive force in the water.

Referring to FIGS. 1 and 7, the gearcase housing 26 is steerable about a steering axis S relative to the driveshaft housing 22. The gearcase housing 26 has a steering housing 32 which extends upwardly into the driveshaft housing 22, as well as a torpedo housing 34 which depends from the steering housing 32. An angle gearset 36 in the torpedo housing 34 operably couples the lower end of the driveshaft 24 to the output shaft(s) 28 so that rotation of the driveshaft 24 causes rotation of the output shaft(s) 28, which in turn causes rotation of the propulsor(s) 30.

Referring to FIG. 7, upper and lower bearings 38, 40 are disposed radially between the steering housing 32 and the driveshaft housing 22. The upper and lower bearings 38, 40 rotatably support the steering housing 32 relative to the driveshaft housing 22. A steering actuator 42 is configured to cause rotation of the gearcase housing 26 relative to the driveshaft housing 22. In the illustrated example, the steering actuator 42 is an electric motor 44 located in the driveshaft housing 22. The electric motor 44 has an output gear 46 which is meshed with a ring gear 48 on the steering housing 32 so that rotation of the output gear 46 causes rotation of the gearcase housing 26 about the steering axis S. As further explained below, operation of the electric motor 44 can be controlled via a conventional user input device located at the helm of the marine vessel or elsewhere, which facilitates control of the steering angle of the gearcase housing 26 and associated propulsors(s) 30. This facilitates steering control of the marine vessel. The type and configuration of the steering actuator 42 can vary from what is shown and in other examples could include one or more hydraulic actuators, electrohydraulic actuators, and/or any other suitable actuator for causing rotation of the gearcase housing 26. Other suitable examples are disclosed in the above-incorporated U.S. Pat. No. 10,800,502.

Referring to FIGS. 5-7, a universal joint 50 couples the electric motor 14 to the driveshaft 24 so that operation of the electric motor 14 causes rotation of the driveshaft 24, which in turn causes rotation of the output shaft(s) 28. The universal joint 50 is also advantageously configured to facilitate trimming of the drive assembly 20 an amount sufficient to raise at least a majority of the drive assembly 20 out of the water, for example during periods of non-use. The universal joint 50 has an input member 52 which is rotatably engaged with an output shaft 54 of the electric motor 14, an output member 64 which is rotatably engaged with the driveshaft 24, and an elongated body 66 which rotatably couples the input member 52 to the output member 64. The input member 52 has an externally-splined input shaft 62 and input arms 63 which form a U-shape. The output member 64 has an output shaft 68 and output arms 70 which form a U-shape. The elongated body 66 has a first pair of arms 74 which form a U-shape and an opposing second pair of arms 76 which form a U-shape. Input pivot pins 78, 80 pivotably couple the input arms 63 of the input member 52 to the first pair of arms 74 of the elongate body 66 along a first input pivot axis 82 and along a second input pivot axis 84 which is perpendicular to the first input pivot axis 82. Output pivot pins 86, 88 pivotably couple the output arms 70 of the output member 64 to the second pair of arms 76 of the elongated body 66 along a first output pivot axis 90 and along a second output pivot axis 92 which is perpendicular to the first output pivot axis 90.

Referring to FIG. 7, an internally splined sleeve 56 is rotatably supported in the mounting assembly 16 by inner and outer bearings 58, 60. The output shaft 54 of the electric motor 14 is fixed to the splined sleeve 56 so that rotation of the output shaft 54 causes rotation of the splined sleeve 56. The externally-splined input shaft 62 of the universal joint 50 extends into meshed engagement with the splined sleeve 56 so that rotation of the splined sleeve 56 causes rotation of the input member 52. The output shaft 68 of the universal joint 50 is coupled to the driveshaft 24 by an angle gearset 72 located in the driveshaft housing 22 and configured so that rotation of the output member 64 causes rotation of the driveshaft 24. Thus, it will be understood that operation of the electric motor 14 causes rotation of the universal joint 50, which in turn causes rotation of the driveshaft 24 and output shaft(s) 28. The splined engagement between the input member 52 and splined sleeve 56 also advantageously permits telescoping movement of the input member 52 during trimming of the drive assembly 20, as will be further described below with reference to FIGS. 8-9. A flexible bellows 94 encloses the universal joint 50 relative to the mounting assembly 16 and the driveshaft housing 22.

Referring to now FIGS. 1-4, the mounting assembly 16 has a rigid mounting plate 100, a vibration dampening (e.g., rubber or other pliable or resilient material) mounting ring 102, and a rigid mounting ring 103 which is fastened to the transom 18 by fasteners 105 and a fastening ring 107 to couple the vibration dampening mounting ring 102 and rigid mounting plate 100 to the transom 18. A pair of rigid mounting arms 104 extends rearwardly from the rigid mounting plate 100 and is pivotably coupled to a rigid, U-shaped mounting bracket 108 extending forwardly from the top of the driveshaft housing 22. The pivot joint between the mounting arms 104 and mounting bracket 108 defines a trim axis T (see FIG. 2) about which the drive assembly 20 is pivotably (trimmable), up and down relative to the mounting assembly 16. The type and configuration of mounting assembly 16 can vary from what is shown. In other examples, the mounting assembly 16 is configured according to the examples disclosed in the above-incorporated U.S. Pat. No. 9,446,828.

Trim cylinders 110 are located on opposite sides of the mounting assembly 16. The trim cylinders 110 have a first end 112 pivotably coupled to the rigid mounting plate 100 at a first pivot joint 114 and an opposite, second end 116 pivotably coupled to the drive assembly 20 at a second pivot joint 118. A hydraulic actuator 120 (which in this example includes a pump and associated valves and line components) is mounted to the interior of the rigid mounting plate 100. The hydraulic actuator 120 is hydraulically coupled to the trim cylinders 110 via a least one internal passage through the mounting assembly 16 and the first pivot joint 114, advantageously so that there are no other hydraulic lines located on the exterior of the stern drive 12, or otherwise outside the marine vessel so as to be subjected to wear and/or damage from external elements. The hydraulic actuator 120 is operable to supply hydraulic fluid to the trim cylinders 110 via the noted internal passage to cause extension of the trim cylinders 110 and alternately to cause retraction of the trim cylinders 110. Extension of the trim cylinders 110 pivots (trims) the drive assembly 20 upwardly relative to the mounting assembly 16 and retraction of the trim cylinders 110 pivots (trims) the drive assembly 20 downwardly relative to the mounting assembly 16. Examples of a suitable hydraulic actuator are disclosed in the above-incorporated U.S. Pat. No. 9,334,034.

By comparison of FIGS. 7-9, it will be seen that the universal joint 50 advantageously facilitates trimming of the drive assembly 20 about the trim axis T while maintaining operable connection between the electric motor 14 and the output shaft(s) 28. In particular, as the drive assembly 20 is trimmed, the elongated body 66 is configured to also pivot about the first and/or second input pivot axes 82, 84 (via input pivot pins 78, 80), and the output member 64 is configured to also pivot about the first and/or second output pivot axes 90, 92 (via output pivot pins 86, 88). As explained above, the input shaft 62 is coupled to the internally splined sleeve 56 via a splined coupling so that the input shaft 62 is free to telescopically move outwardly relative to the internally splined sleeve 56 and mounting assembly 16 when the drive assembly 20 is trimmed up and so that the input shaft 62 is free to telescopically move inwardly relative to the mounting assembly 16 when the drive assembly 20 is trimmed down.

A controller 200 is communicatively coupled to the electric motor 14, the steering actuator 42, and the hydraulic actuator 120. The controller 200 is configured to control operation of the electric motor 14, the steering actuator 42, and the hydraulic actuator 120. More specifically, the controller 200 is configured to control the electric motor 14 to rotate the universal joint 50, the driveshaft 24 and the output shaft(s) 28, thereby controlling the thrust force generated by the propulsor(s) 30 in the water. The controller 200 is configured to control the steering actuator 42 to rotate the gearcase housing 26 about the steering axis S. The controller 200 is configured to control the hydraulic actuator 120 to extend and alternately to retract the trim cylinders 110 to trim the drive assembly 20 about the trim axis T.

The type and configuration of the controller 200 can vary. In non-limiting examples, the controller 200 has a processor which is communicatively connected to a storage system comprising a computer readable medium which includes volatile or nonvolatile memory upon which computer readable code and data is stored. The processor can access the computer readable code and, upon executing the code, carry out functions, such as the controlling functions for the electric motor 14, steering actuator 42, and the hydraulic actuator 120. In other examples the controller 200 is part of a larger control network such as a controller area network (CAN) or CAN Kingdom network, such as disclosed in U.S. Pat. No. 6,273,771. A person having ordinary skill in the art will understand that various other known and conventional computer control configurations could be implemented and are contemplated by the present disclosure, and that the control functions described herein may be combined into a single controller or divided into any number of distributed controllers which are communicatively connected.

The controller 200 is in electrical communication with the electric motor 14, the steering actuator 42, and the hydraulic actuator 120 via one or more wired and/or wireless links. In non-limiting examples, the wired and/or wireless links are part of a network, as described above. The controller 200 is configured to control the electric motor 14, the steering actuator 42, and the hydraulic actuator 120 by sending and optionally by receiving said signals via the wired and/or wireless links. The controller 200 is configured to send electrical signals to the electric motor 14 which cause the electric motor 14 to operate in a first direction to rotate the universal joint 50, the driveshaft 24 and the output shaft(s) 28 in a first direction, thereby generating a first (e.g., forward) thrust force in the water via the propulsor(s) 30, and alternately to send electric signals to the electric motor 14 which cause the electric motor 14 to operate in an opposite, second direction, to rotate the universal joint 50, the driveshaft 24 and the output shaft(s) 28 in an opposite direction which generates a second (e.g., reverse) thrust force in the water via the propulsor(s) 30. The controller 200 is configured to send electric signals to the steering actuator 42 which cause the steering actuator 42 to rotate the gearcase housing 26 in a first direction about the steering axis S and alternately to send electric signals to the steering actuator 42 which cause the steering actuator 42 to rotate the gearcase housing 26 in an opposite direction about the steering axis S. The controller 200 is configured to send electrical signals to the hydraulic actuator 120 which cause the hydraulic actuator 120 to provide hydraulic fluid to one side of the trim cylinders 110 to extend the trim cylinders 110 and trim the drive assembly 20 upwardly relative to the mounting assembly 16 and alternately to send electric signals to the hydraulic actuator 120 which cause the hydraulic actuator 120 to provide hydraulic fluid to an opposite side of the trim cylinders 110 to retract the trim cylinders 110 and trim the drive assembly 20 downwardly relative to the mounting assembly 16.

A user input device 202 is provided for inputting a user-desired operation of the electric motor 14, and/or a user desired operation of the steering actuator 42, and/or a user-desired operation of the hydraulic actuator 120. Upon input of the user-desired operation, the controller 200 is programmed to control the electric motor 14, and/or the steering actuator 42, and/or the hydraulic actuator 120 accordingly. The user input device 202 can include any conventional device which can be communicatively connected to the controller 200 for inputting a user-desired operation, including but not limited to one or more switches, levers, joysticks, buttons, touch screens, and/or the like.

Referring to FIG. 7, one or more sensor(s) 204 are provided for directly or indirectly sensing a rotational orientational position of the universal joint 50 and communicating this information to the controller 200. In non-limiting examples, the sensor 204 comprises one or more conventional magnetic pick-up coil(s), Hall-effect sensor(s), magneto-resistive element (MRE) sensor(s), and/or optical sensor(s), such as are available for purchase from Parker Hannifin Corp., among other places. The sensor(s) 204 may be configured to sense the orientational position of the universal joint 50 by sensing the rotational position of the output shaft of the electric motor 14 and/or the rotational position of the internally splined sleeve 56 and/or by sensing the rotational position of the input gear of the angle gearset 72, for example. In other examples, the sensor(s) 204 may also or alternately be configured to directly sense the orientational position of one or more rotatable component of the universal joint 50. The location of the one or more sensor(s) can vary, but preferably is located to be able to accurately sense a rotating part of the assembly for which an orientation between the splines and gears is known.

The controller 200 is configured to automatically cause the electric motor 14 to rotate the universal joint 50 into the neutral position shown in the figures (e.g., see FIGS. 5 and 7), wherein the first input pivot axis 82 and the first output pivot axis 90 are aligned with each other and generally parallel to the trim axis T. This advantageously facilitates trimming of the drive assembly 20 fully out of the water. More specifically, rotating the universal joint 50 into the neutral position with the first input pivot axis 82 and the first output pivot axis 90 oriented generally parallel to the trim axis T locates the first pair of arms 74 at a ninety degree offset from the input arms 63 of the input member 52 and thus permits the first pair of arms 74 of the elongated body 66 to pivot through a maximum allowable range about the first input pivot axis 82 within the U-shape formed by the input arms 63, as shown in FIG. 9. Similarly, rotating the universal joint 50 into the neutral position locates the output arms 70 of the output member 64 at a ninety degree offset from the second pair of arms 76 of the elongated body 66 and thus permits the output arms 70 to pivot through a maximum allowable range about the first output pivot axis 90 within the U-shape formed by the second pair of arms 76, as shown in FIG. 9.

The controller 200 is advantageously programmed to automatically operate the electric motor 14 to rotate the universal joint 50 into the neutral position as indicated by the sensor 204 based upon an operational state of the stern drive 12. The operational state can for example include change in an on/off state of the electric motor 14 (for example a key on or key off event) and/or any other designated programmed request or request input to the controller 200 via the user input device 202.

In a non-limiting example, a user can actuate the user input device 202 to command the controller 200 to control the hydraulic actuator 120 to trim the drive assembly 20 into a fully raised, storage position. Upon receiving said command, the controller 200 is programmed to automatically control the electric motor 14 to rotate the universal joint 50 into the noted neutral position. As explained above, this advantageously facilitates trimming all or at least a majority of the drive assembly 20 out of the water. For example the majority may include all of the driveshaft housing 22 and a majority of the gearcase housing 26. Referring to FIG. 11, the controller 200 can be also configured to automatically operate the steering actuator 42 to steer (i.e., rotate) the drive assembly 20 about the steering axis S, for example into the position shown, which is ninety degrees offset to either one of the port or starboard sides. This can occur prior to, during, or after the drive assembly 20 is trimmed upwardly via the universal joint 50. Steering the drive assembly 20 into the position shown (or into the 180 degree opposite position of what is shown) advantageously further elevates the lowermost point of the drive assembly 20 (which typically is on the torpedo housing 34 or skeg of the gearcase housing 26) further above the waterline W, thus ensuring that the entirety of the drive assembly 20, including all of the driveshaft housing 22 and all of the gearcase housing 26, is positioned out of the body of water. Thus the present disclosure contemplates methods for operating the stern drive 12, including the steps of operating the electric motor 14 to rotate the universal joint 50 into the aforementioned neutral position, which facilitates trimming of the drive assembly 20 upwardly relative to the rest of the stern drive 12, and optionally also steering the gearcase housing 26 relative to the driveshaft housing 26, before, during or after the trimming of the drive assembly 20, thereby moving an entirety of the drive assembly 20 further upwardly relative to the stern drive 12 and ensuring that the entirety of the drive assembly 20 is positioned out of the body of water. This advantageously locates the majority or entirety of the drive assembly 20 out of the body of water during periods of non-use, thus preventing deleterious effects of the water on the drive assembly 20.

Referring to FIG. 7, the stern drive 12 has a cooling system for cooling various components thereof, including for example the electric motor 14. In the non-limiting example shown in the drawings, the cooling system includes an open loop cooling circuit for circulating cooling water from the body of water in which the stern drive 12 is situated and then discharging the cooling water back to the body of water. The open loop cooling circuit includes an intake inlet 300 (see FIG. 1) on the gearcase housing 26 which is connected to an annular cooling channel 302 defined between a lower annular flange 304 on the lower end of the driveshaft housing 22 and an annular flange 306 on the top of the gearcase housing 26. Reference is made to the above-incorporated U.S. Pat. No. 10,800,502. A flexible conduit 308 is coupled to the driveshaft housing 22 and configured to convey the cooling water from the annular cooling channel 302 to a cooling water pump 310 mounted on the outside of the rigid mounting plate 100. The cooling water pump 310 is configured to draw the cooling water in through the intake inlet 300, see FIG. 1, through the annular cooling channel 302, and through the flexible conduit 308. The cooling water pump 310 pumps the cooling water through the mounting assembly 16 to a heat exchanger 314 and then to an outlet 315 shown in FIG. 10. In the illustrated example, the stern drive 12 further includes a closed loop cooling circuit having a pump 312 for pumping cooling fluid such as a mixture of water and ethylene glycol through the heat exchanger 314, exchanging heat with the cooling water in the open loop cooling circuit. The mixture of water and ethylene glycol is circulated past the electric motor 14, an associated inverter 316, and one or more batteries for powering the electric motor 14, thus cooling these components.

Referring to FIGS. 12 and 13, in non-limiting examples, the stern drive 12 also has a sound absorbing enclosure 400 which encloses the inboard portions of the stern drive 12 and advantageously limits noise emanating from the stern drive 12. The sound absorbing enclosure 400 can be made of foam and/or any other conventional sound absorbing material, such as a sheet molding compound (SMC). In the illustrated example, the sound absorbing enclosure 400 completely encloses the inboard components of the stern drive 12 and is fixed to the mounting assembly 16. In other examples, the sound absorbing enclosure 400 is configured to only enclose some of the inboard components of the stern drive 12.

FIGS. 14-17 depict another example of a stern drive 12, which is like the embodiments described above, except instead of having the noted universal joint 50, the stern drive 12 shown in FIGS. 14-17 has dual (inner and outer) opposed constant velocity (CV) joints 502, 504 connected by a center shaft 506. The dual opposed CV joints 502, 504 and center shaft 506 advantageously provide dual spaced apart universal pivot axes which facilitate trimming of the stern drive 12 into the position shown in FIG. 16, above the waterline W.

More specifically, the inner CV joint 502 has an input member 508 including an input shaft 510 and a retainer cup 512 which contains an input hub member 514 and a set of ball bearings 516 disposed between the retainer cup 512 and the input hub member 514. Each ball bearing 516 is seated in a slot recess formed in the inside of the retainer cup 512 and a corresponding recess formed in the outside of the input hub member 514. The outer CV joint 504 has an output member 520 including an output shaft 522 and a retainer cup 524 which contains an output hub member 526 and a set of ball bearings 528 disposed between the retainer cup 524 and the output hub member 526. Each ball bearing 528 is seated in a slot recess formed in the inside of the retainer cup 524 and a corresponding recess formed in the outside of the output hub member 526. Like the embodiments described above, the input shaft 510 is engaged with the internally splined sleeve 56 via a splined coupling configured so that the input shaft 510 is free to telescopically move outwardly relative to the internally splined sleeve 56 and mounting assembly 16 when the drive assembly 20 is trimmed up and further so that the input shaft 510 is free to telescopically move inwardly relative to the internally splined sleeve 56 and mounting assembly 16 when the drive assembly 20 is trimmed down. Like the embodiments described above, the output shaft 522 is engaged with the driveshaft 24 by via a splined coupling with the angle gearset 72 located in the driveshaft housing 22 and thus configured so that rotation of the output member 520 causes rotation of the driveshaft 24. The center shaft 506 has an inner end rotatably engaged with the input hub member 514 and an opposite, outer end rotatably engaged with the output hub member 526.

Operation of the electric motor 14 causes rotation of the dual opposed CV joints 502, 504 and center shaft 506, which in turn causes rotation of the driveshaft 24 and output shaft(s) 28. The splined engagement between the input member 508 and internally splined sleeve 56 also advantageously permits telescoping movement of the input member 508 during trimming of the drive assembly 20, as described above. As shown in FIG. 17, the dual CV joints 502, 504 and center shaft 506 are enclosed in a protective, flexible bellows 530.

During trimming of the stern drive 12, each set of ball bearings 516, 528 facilitates universal (360 degree) pivoting of the center shaft 506 and respective input/output hub members 514, 526 relative to the retainer cups 512, 524. The center shaft 506 is sized long enough so the inner and outer CV joints 502, 504 are apart from each other by an axial distance which is sufficient to permit the noted dual universal pivoting, as shown in FIG. 16, facilitating raising of the drive assembly 20 out of the water. As with the example described herein above with reference to FIG. 11, the drive assembly 20 can also be steered ninety degrees off-center in the fully trimmed up position.

It will thus be understood that the present disclosure provides novel stern drive arrangements for propelling a marine vessel in water, which in non-limiting examples can be efficiently installed as a compact and yet comprehensive package via a through-bore in the transom of the marine vessel and supported (cantilevered) from the transom of the marine vessel in an easily serviced location. The above-described examples advantageously locate the high voltage components of the stern drive inside the marine vessel, including for example the electric motor 14 and associated inverter 316. The above-described examples advantageously permit efficient service, for example permitting removal of the entire unit from the rear of the marine vessel. Examples disclosed herein have an electric motor which is fixed to the marine vessel via a mounting assembly configured so that excess exposure and/or bending of electric and hydraulic cables is achieved. In non-limiting examples, the entire drive assembly is advantageously trimmable up out of the water, which avoids corrosion of the drive assembly when the marine vessel is left dormant for a long period of time. In non-limiting examples, the stern drive is compact so for example it can fit under a swim platform while the marine vessel is underway or parked for short periods of time and still able to trim completely out of the water when not in use for longer periods of time.

In the above-described examples, which are non-limiting, rubber isolation of the mounting assembly 16 is believed to work best if the center of gravity of the sprung structure is located at the transom. Locating the drive assembly 20 on the outside and locating the electric motor 14, inverter 316, heat exchanger 314, hydraulic actuator 120, glycol pump 312, and glycol reservoir, etc., cantilevered on the inside advantageously balances the weight on either side of the transom 18.

This written description uses examples to disclose the invention, including the best mode, and to enable any person skilled in the art to make and use the invention. 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 patentable scope of the invention is defined by the claims, and may include other examples which occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have features or structural elements which do not differ from the literal language of the claims, or if they include equivalent features or structural elements with insubstantial differences from the literal languages of the claims.

Claims

1. A stern drive for propelling a marine vessel in a body of water, the stern drive comprising:

a mounting assembly for coupling the stern drive to a transom of the marine vessel, and

a drive assembly which is trimmable up and down relative to the mounting assembly, the drive assembly comprising a driveshaft housing for a driveshaft and a gearcase housing for an output shaft for a propulsor, wherein the gearcase housing is steerable relative to the driveshaft housing.

2. The stern drive according to claim 1, wherein the gearcase housing comprises a steering housing which extends into the driveshaft housing and a torpedo housing coupled to the steering housing, and wherein the driveshaft extends through the steering housing and is operably engaged with an output shaft in the torpedo housing.

3. The stern drive according to claim 2, further comprising an angle gearset located in the torpedo housing, wherein the angle gearset couples the driveshaft to the output shaft so that rotation of the driveshaft causes rotation of the output shaft.

4. The stern drive according to claim 2, further comprising upper and lower bearings which rotatably support the steering housing relative to the driveshaft housing.

5. The stern drive according to claim 1, further comprising a steering actuator which causes the gearcase housing to steer relative to the driveshaft housing.

6. The stern drive according to claim 5, wherein the steering actuator comprises an electric motor.

7. The stern drive according to claim 6, wherein the electric motor is in the driveshaft housing.

8. The stern drive according to claim 2, further comprising an angle gearset located in the driveshaft housing, the angle gearset operably coupling a powerhead to the driveshaft.

9. The stern drive according to claim 8, further comprising a universal joint which couples the powerhead to the driveshaft via the angle gearset.

10. The stern drive according to claim 1, wherein the mounting assembly comprises a rigid mounting plate which is coupled to the transom by a vibration dampening member.

11. A stern drive for propelling a marine vessel in a body of water, the stern drive comprising:

a mounting assembly for coupling the stern drive to a transom of the marine vessel,

a powerhead configured to operate a propulsor to generate a thrust force in the body of water,

a drive assembly which is trimmable up and down relative to the mounting assembly, the drive assembly comprising a driveshaft which is operably coupled to the powerhead and the propulsor, and

a universal joint which couples the powerhead to the driveshaft so that operation of the powerhead causes rotation of the driveshaft, which in turn operates the propulsor, wherein the universal joint is configured to facilitate trimming of the drive assembly an amount sufficient to raise at least a majority of the drive assembly out of the body of water.

12. The stern drive according to claim 11, wherein the universal joint is configured to pivot about at least one pivot axis when the drive assembly is trimmed relative to the mounting assembly.

13. The stern drive according to claim 12, further comprising a controller configured to cause the powerhead to rotate the universal joint into a neutral position in which the at least one pivot axis is generally parallel to a trim axis about which the drive assembly is trimmable, which facilitates said trimming of the drive assembly the amount sufficient to raise the majority of the drive assembly out of the body of water.

14. The stern drive according to claim 13, wherein the controller is configured to cause the powerhead to rotate the universal joint into the neutral position based upon an operational state of the stern drive.

15. The stern drive according to claim 14, wherein the operational state comprises at least one of an on/off state of the stern drive and/or a request provided to the controller by a user input device.

16. The stern drive according to claim 13, wherein the at least one pivot axis comprises a first input pivot axis and first output pivot axis, and wherein in the neutral position the first input pivot axis and the first output pivot axis are both parallel to the trim axis.

17. The stern drive according to claim 16, wherein the universal joint comprises an input member which is rotatably engaged with the powerhead, an output member which is rotatably engaged with the driveshaft, and a body which rotatably couples the input member to the output member.

18. The stern drive according to claim 17, wherein the input member comprises an input shaft and input arms which form a U-shape, the input arms being pivotably coupled to a body along the first input pivot axis and along a second input pivot axis which is perpendicular to the first input pivot axis, and

wherein the output member comprises an output shaft and output arms which form a U-shape, the output arms being pivotably coupled to the body along the first output pivot axis and along a second output pivot axis which is perpendicular to the first output pivot axis.

19. The stern drive according to claim 18, wherein the body comprises a first pair of arms which form a U-shape and are coupled to the input arms along the second input pivot axis.

20. The stern drive according to claim 19, wherein the body comprises a second pair of arms which form a U-shape and are coupled to the output arms along the second output pivot axis.

21. The stern drive according to claim 20, further comprising input pivot pins which couple the input member to the body along the first input pivot axis and the second input pivot axis, respectively, and output pivot pins which couple the output member to the body along the second output pivot axis and the second output pivot axis, respectively.

22. The stern drive according to claim 20, wherein the input shaft is coupled to the mounting assembly by a splined coupling so that the input shaft is telescopically moved outwardly relative to the mounting assembly when the drive assembly is trimmed up relative to the mounting assembly and so that the input shaft is telescopically moved inwardly relative to the mounting assembly when the drive assembly is trimmed down relative to the mounting assembly.

23. The stern drive according to claim 22, further comprising a flexible bellows which encloses the universal joint relative to the mounting assembly and the driveshaft housing.

24. The stern drive according to claim 11, further comprising at least one trim cylinder having a first end pivotally coupled to the mounting assembly at a first pivot joint and a second end pivotally coupled to the drive assembly at a second pivot joint, wherein extension of the trim cylinder trims the drive assembly upwardly relative to the mounting assembly and wherein retraction of the trim cylinder trims the drive assembly downwardly relative to the mounting assembly.

25. The stern drive according to claim 24, further comprising a hydraulic actuator for causing extension of the at least one trim cylinder, wherein the hydraulic actuator is coupled to the at least one trim cylinder via a passage formed through the first pivot joint.

26. A stern drive for propelling a marine vessel in a body of water, the stern drive comprising:

a mounting assembly for coupling the stern drive to a transom of the marine vessel,

a powerhead configured to operate a propulsor to generate a thrust force in the body of water,

a drive assembly which is trimmable up and down relative to the mounting assembly, the drive assembly comprising a driveshaft housing for a driveshaft and a gearcase housing for an output shaft for the propulsor, wherein the gearcase housing is steerable relative to the driveshaft housing,

a steering actuator configured to steer the gearcase housing relative to the driveshaft housing, and

a controller configured to trim the drive assembly upwardly relative to the body of water, and also to cause the steering actuator to steer the gearcase housing relative to the driveshaft housing thereby moving an entirety of the drive assembly out of the body of water.

27. The stern drive according to claim 26, further comprising a universal joint which couples the powerhead to the driveshaft so that operation of the powerhead causes rotation of the driveshaft, which in turn operates the propulsor, wherein the universal joint is configured to facilitate trimming of the drive assembly and wherein the controller is configured to cause the powerhead to rotate the universal joint into a neutral position which facilitates trimming the drive assembly upwardly relative to the body of water.

28. The stern drive according to claim 27, wherein the universal joint is configured to pivot about at least one pivot axis when the drive assembly is trimmed relative to the mounting assembly, and wherein in the neutral position the at least one pivot axis is parallel to a trim axis about which the drive assembly is trimmable, which facilitates trimming of the drive assembly.

29. The stern drive according to claim 28, wherein the controller is configured to cause the powerhead to rotate the universal joint into the neutral position based upon an operational state of the stern drive.

30. A method of operating a stern drive, the method comprising:

providing a drive assembly which is trimmable up and down, the drive assembly comprising a driveshaft housing for a driveshaft and a gearcase housing for an output shaft for a propulsor, wherein the gearcase housing is steerable relative to the driveshaft housing, and wherein the drive assembly comprises a universal joint which couples a powerhead to the driveshaft so that operation of the powerhead causes rotation of the driveshaft, which in turn operates the propulsor, and

operating the powerhead to rotate the universal joint into a neutral position which facilitates trimming of the drive assembly upwardly relative to the stern drive, and also steering the gearcase housing relative to the driveshaft housing thereby moving an entirety of the drive assembly further upwardly relative to the stern drive.

31. The method according to claim 30, further comprising automatically rotating the universal joint into the neutral position and steering the gearcase housing relative to the driveshaft housing based upon an operational characteristic of the stern drive.