Drive system for a marine vessel

Abstract

A drive system for a marine vessel. The drive system includes a drive shaft that is rotatable about a drive axis and a motor interconnected with the drive shaft and including a rotor that defines a motor axis that is substantially coaxial with the drive axis. The motor is operable at a motor speed to rotate the drive shaft. An engine has an output shaft interconnected with the drive shaft and is operable at an engine speed to rotate the drive shaft. The output shaft defines an engine axis that is substantially coaxial with the motor axis. A clutch is operable to inhibit the transfer of torque from the motor to the engine when the engine speed is less than a predetermined engine speed without disconnecting the output shaft from the drive shaft. A tiller arm includes a speed control. The speed control is operable to control the engine speed and to control the motor speed.

1 . A drive system for a marine vessel, the drive system comprising: 
 a drive shaft rotatable about a drive axis;    a motor including a rotor that defines a motor axis, the drive shaft rotating in response to rotation of the rotor at a motor speed;    an engine including an output shaft, the drive shaft and rotor rotating in response to operation of the engine at an engine speed;    a clutch operable to inhibit the transfer of torque from the motor to the engine and to facilitate the transfer of torque from the engine to the motor and to the drive shaft without manipulating any mechanical connection between the motor, the engine, and the drive shaft; and    a tiller arm including a speed control, the speed control operable to control the engine speed and to control the motor speed.    
   
   
       2 . The drive system of  claim 1 , wherein the motor includes a stator, and wherein the rotor is spaced axially from the stator to define an axial air gap.  
   
   
       3 . The drive system of  claim 1 , wherein the motor rotor is interconnected with the drive shaft such that the motor rotor rotates in unison with the drive shaft.  
   
   
       4 . The drive system of  claim 1 , wherein the clutch connects the output shaft and the motor rotor.  
   
   
       5 . The drive system of  claim 1 , wherein the clutch includes a clutched position and a declutched position and wherein the clutch is in the declutched position when the engine speed is below a predetermined speed and is in the clutched position when the engine speed is above the predetermined speed.  
   
   
       6 . The drive system of  claim 1 , wherein the clutch includes a centrifugal clutch.  
   
   
       7 . The drive system of  claim 1 , wherein the clutch includes a roller clutch.  
   
   
       8 . The drive system of  claim 1 , wherein at least a portion of the clutch is formed as part of the rotor.  
   
   
       9 . The drive system of  claim 1 , further comprising a switch having a first position in which the engine is operable, and having a second position in which operation of the engine is inhibited but the motor is operable.  
   
   
       10 . The drive system of  claim 9 , wherein the engine includes an engine ignition that is grounded when the switch is in the second position.  
   
   
       11 . The drive system of  claim 9 , wherein the engine operates when the switch is in the first position to rotate the motor rotor and the drive shaft, the rotation of the motor rotor delivering a flow of electrical current to an electrochemical energy source, and wherein when the switch is in the second position the electrochemical energy source delivers a flow of electrical current to the motor such that the motor operates to rotate the drive shaft.  
   
   
       12 . The drive system of  claim 9 , wherein the speed control is operable to control the engine speed when the switch is in the first position and to control the motor speed when the switch is in the second position.  
   
   
       13 . The drive system of  claim 9 , further comprising a power conditioner interconnecting the motor and an electrochemical energy source, the power conditioner operable to deliver conditioned power to the electrochemical energy source when the switch is in the first position and to deliver an amount of conditioned power to the motor when the switch is in the second position.  
   
   
       14 . The drive system of  claim 1 , wherein the speed control includes a potentiometer.  
   
   
       15 . A drive system for a marine vessel, the drive system comprising: 
 a drive shaft rotatable about a drive axis to propel the vessel;    a motor including a rotor coupled to the drive shaft, the motor operable at a motor speed to rotate the drive shaft;    an engine including an engine ignition, the engine coupled to the motor rotor and operable at an engine speed to rotate the rotor and the drive shaft;    an electrochemical energy source;    a controller operable to control the flow of electrical power between the electrochemical energy source and the motor;    a clutch disposed between the motor rotor and the engine, the clutch operable both to inhibit the transfer of torque from the motor to the engine and to facilitate the transfer of torque from the engine to the motor and to the drive shaft without decoupling the engine and the motor rotor; and    a switch having a first position in which the engine is operable, and having a second position in which the engine ignition is grounded but the motor is operable.    
   
   
       16 . The drive system of  claim 15 , wherein the motor includes a stator, and wherein the rotor is spaced axially from the stator to define an axial air gap.  
   
   
       17 . The drive system of  claim 15 , wherein the motor rotor is interconnected with the drive shaft such that the motor rotor rotates in unison with the drive shaft.  
   
   
       18 . The drive system of  claim 15 , wherein the engine includes an engine drive shaft and the clutch connects the engine drive shaft and the motor rotor.  
   
   
       19 . The drive system of  claim 15 , wherein the clutch includes a centrifugal clutch.  
   
   
       20 . The drive system of  claim 15 , wherein the clutch includes a roller clutch.  
   
   
       21 . The drive system of  claim 15 , wherein at least a portion of the clutch is formed as part of the rotor.  
   
   
       22 . The drive system of  claim 15 , wherein the engine operates when the switch is in the first position to rotate the motor rotor and the drive shaft, the rotation of the motor rotor delivering a flow of electrical current to the electrochemical energy source, and wherein when the switch is in the second position the electrochemical energy source delivers a flow of electrical current to the motor such that the motor operates to rotate the drive shaft.  
   
   
       23 . The drive system of  claim 15 , wherein the controller is operable to deliver conditioned power to the electrochemical energy source when the switch is in the first position and to deliver an amount of conditioned power to the motor when the switch is in the second position.  
   
   
       24 . The drive system of  claim 15  further comprising a tiller arm including a speed control, the speed control operable to control the engine speed when the switch is in the first position and to control the motor speed when the switch is in the second position.  
   
   
       25 . The drive system of  claim 24 , wherein the speed control includes a motor speed adjustment member that is movable between a first position and a second position to provide a signal to the controller to vary the amount of electrical power delivered to the motor.  
   
   
       26 . The drive system of  claim 25 , wherein the motor speed adjustment member includes a potentiometer.  
   
   
       27 . A drive system for a marine vessel, the drive system comprising: 
 a drive shaft rotatable about a drive axis;    a motor including a stator and a rotor that defines a motor axis, the rotor offset from the stator a distance along the motor axis to define an axial air gap, the drive shaft rotating in response to rotation of the rotor at a motor speed;    an engine including an output shaft, the drive shaft and rotor rotating in response to operation of the engine at an engine speed; and    a clutch operable to inhibit the transfer of torque from the motor to the engine and to facilitate the transfer of torque from the engine to the motor and to the drive shaft without manipulating any mechanical connection between the motor, the engine, and the drive shaft.    
   
   
       28 . The drive system of  claim 27 , wherein the motor rotor is interconnected with the drive shaft such that the motor rotor rotates in unison with the drive shaft.  
   
   
       29 . The drive system of  claim 27 , wherein the clutch connects the output shaft and the motor rotor.  
   
   
       30 . The drive system of  claim 27 , wherein the clutch includes a clutched position and a declutched position and wherein the clutch is in the declutched position when the engine speed is below a predetermined speed and is in the clutched position when the engine speed is above the predetermined speed.  
   
   
       31 . The drive system of  claim 27 , wherein the clutch includes a centrifugal clutch.  
   
   
       32 . The drive system of  claim 27 , wherein the clutch includes a roller clutch.  
   
   
       33 . The drive system of  claim 27 , wherein at least a portion of the clutch is formed as part of the rotor.  
   
   
       34 . The drive system of  claim 27 , further comprising a switch having a first position in which the engine is operable, and having a second position in which operation of the engine is inhibited but the motor is operable.  
   
   
       35 . The drive system of  claim 34 , wherein the engine includes an engine ignition that is grounded when the switch is in the second position.  
   
   
       36 . The drive system of  claim 34 , wherein the engine operates when the switch is in the first position to rotate the motor rotor and the drive shaft, the rotation of the motor rotor delivering a flow of electrical current to an electrochemical energy source, and wherein when the switch is in the second position the electrochemical energy source delivers a flow of electrical current to the motor such that the motor operates to rotate the drive shaft.  
   
   
       37 . The drive system of  claim 34 , further comprising a tiller arm including a speed control, the speed control operable to control the engine speed when the switch is in the first position and to control the motor speed when the switch is in the second position.  
   
   
       38 . The drive system of  claim 37 , wherein the speed control includes a motor speed adjustment member movable between a first position and a second position, the motor speed adjustment member providing a signal to the power conditioner to vary the amount of conditioned power delivered to the motor.  
   
   
       39 . The drive system of  claim 38 , wherein the speed adjustment member includes a potentiometer.  
   
   
       40 . The drive system of  claim 34 , further comprising a power conditioner interconnecting the motor and an electrochemical energy source, the power conditioner operable to deliver conditioned power to the electrochemical energy source when the switch is in the first position and to deliver an amount of conditioned power to the motor when the switch is in the second position.