The inventive technology described herein generally relates to the field of power transmission, more particularly power transmission through a mechanical drive system. More specifically, in certain embodiments the inventive technology includes methods and apparatus for a variable coupler drive utilizing, in one embodiment a dynamic drive-ratio gearing system to transmit a drive input for application with a variety of output uses. In a preferred embodiment, such a variable coupler drive may be used to transmit a rotational drive input to a drive shaft to power, for example, a variety of commercial and industrial applications, and may be particularity suited to power rotational propeller based propulsion systems.

A method for shifting a multi-speed transmission for transmitting rotation between an input shaft and an output shaft for a marine vessel. The method includes providing a multi-speed transmission having first and second gears engaged by actuating first and second clutches, and providing first and second pressure sensors that measure first and second pressures within the first and second clutches, respectively. The method further includes performing a first shift from the first gear to the second gear by de-actuating the first clutch a first delay after the second clutch is actuated, then measuring the first and second pressures and determining a first shift pressure at which the first and second pressures are substantially equal while performing the first shift. The method further includes comparing the first shift pressure to a first pressure threshold range and adjusting the first delay when the first shift pressure is outside the first pressure threshold range.

A method for shifting a marine propulsion device transmission between first and second gears transmitting torque from a powerhead with a redline RPM. The transmission has a transition time for completing a shift. The method includes measuring an RPM of the powerhead, comparing the RPM to a first threshold, and starting a timer when the RPM exceeds the first threshold. The method includes measuring the RPM of the powerhead after the first threshold is exceeded, comparing the RPM to a second threshold, stopping the timer when the RPM exceeds the second threshold, determining an elapsed time between starting and stopping the timer, and determining a shift RPM based on the determined elapsed time, the redline RPM, and the transition time of the transmission. The method includes controlling the transmission to shift when the RPM measured for the powerhead reaches the shift RPM such that shifting completes before the redline RPM.

A method for shifting a multi-speed transmission of a marine propulsion device between a first gear and a second gear each configured to transmit torque from a powerhead to a transmission output shaft. The method includes determining an actual power level requested for operating the marine propulsion device and measuring a transmission output shaft speed in which the transmission output shaft is rotating. The method further includes comparing the actual power level to a shift threshold, the shift threshold corresponding to expected power levels for operating the marine propulsion device as a function of the transmission output shaft speed of the transmission output shaft. The method further includes controlling the multi-speed transmission to shift when the actual power is outside the shift threshold.

A method for downshifting a multi-speed transmission of a marine propulsion device to a first gear from a second gear. The method includes providing a shift schedule that indicates a shift recommendation for when to downshift from the second gear to the first gear. The method further includes configuring the transmission to downshift when the shift schedule indicates the shift recommendation, determining a requested speed of the marine propulsion device, measuring an actual speed of the marine propulsion device, calculating an error between the requested speed and the actual speed, comparing the error to an error threshold, and determining when the error exceeds the error threshold longer than a duration threshold. The method further includes controlling the transmission to downshift, despite the shift schedule indicating a non-shift recommendation, when the duration threshold is exceeded so as to reduce the error between the requested speed and the actual speed.

A set of parts for marine vessel propulsion assemblies is provided A propulsion unit includes a driveshaft, and a first connection module comprising one or more input shafts, wherein the propulsion unit and the first connection module may form at least a portion of a first propulsion assembly. A second connection module comprising one or more input shafts, wherein the propulsion unit and the second connection module may form at least a portion of a second propulsion assembly. The positions, in relation to the propulsion unit, of output shafts of the first and second connection modules, when the first and second connection modules are mounted to the propulsion unit, are the same. The first propulsion assembly may differ from the second propulsion assembly in that the position, in relation to the propulsion unit, of one or more of the one or more input shafts of the first connection module differs from the position, in relation to the propulsion unit, of any of the one or more input shafts of the second connection module.

A method for controlling a speed of a propeller of a marine propulsion device during launch of a marine vessel comprises receiving a command to initiate an enhanced launch feature of the marine vessel. The method includes increasing a speed of an engine of the marine propulsion device in response to the enhanced launch feature command. While the engine speed increases, the method includes commanding a first amount of engagement of a forward gear controlling torque transfer from an output shaft of the engine to an input shaft of the propeller. After the engine speed reaches a predetermined threshold, the method includes commanding a second, greater amount of engagement of the forward gear controlling torque transfer from the engine output shaft to the propeller input shaft.

A ship maneuvering system includes first and second propulsion devices, a shift actuator, and a controller. The shift actuator switches a shift state of each of the propulsion devices. The controller causes the shift actuator of one of the first and second propulsion devices to execute intermittent control during low-speed navigation of the ship. The intermittent control intermittently switches the shift state to a shift-in state and a shift-out state.

A method for downshifting a multi-speed transmission of a marine propulsion device to a first gear from a second gear. The method includes providing a shift schedule that indicates a shift recommendation for when to downshift from the second gear to the first gear. The method further includes configuring the transmission to downshift when the shift schedule indicates the shift recommendation, determining a requested speed of the marine propulsion device, measuring an actual speed of the marine propulsion device, calculating an error between the requested speed and the actual speed, comparing the error to an error threshold, and determining when the error exceeds the error threshold longer than a duration threshold. The method further includes controlling the transmission to downshift, despite the shift schedule indicating a non-shift recommendation, when the duration threshold is exceeded so as to reduce the error between the requested speed and the actual speed.

A method for shifting a multi-speed transmission of a marine propulsion device between a first gear and a second gear each configured to transmit torque from a powerhead to a transmission output shaft. The method includes determining an actual power level requested for operating the marine propulsion device and measuring a transmission output shaft speed in which the transmission output shaft is rotating. The method further includes comparing the actual power level to a shift threshold, the shift threshold corresponding to expected power levels for operating the marine propulsion device as a function of the transmission output shaft speed of the transmission output shaft. The method further includes controlling the multi-speed transmission to shift when the actual power is outside the shift threshold.