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.

What is claimed is: 
     
         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.