Watercraft steering device and electric assist device

Abstract

A watercraft steering device includes: a steering rotatably provided on a hull; a helm mechanism configured to convert a rotational operation of the steering into a linear motion and adjust a traveling direction of the hull; and an electric assist device configured to generate a torque depending on a rotation amount of the steering. The electric assist device is couplable to the helm mechanism, and the electric assist device includes: a coupling shaft portion that is coupled to a helm shaft portion that is a rotation shaft of the helm mechanism; an electric motor that generates a torque by being energized and transmits the generated torque to the coupling shaft portion; and a control device that controls the electric motor to generate a predetermined torque based on a magnitude of the torque generated by rotation of the steering.

1 . A watercraft steering device comprising:
 a steering rotatably provided on a hull;   a helm mechanism configured to convert a rotational operation of the steering into a linear motion and adjust a traveling direction of the hull; and   an electric assist device configured to generate a torque depending on a rotation amount of the steering, wherein   the electric assist device is couplable to the helm mechanism, and   the electric assist device includes: a coupling shaft portion that is coupled to a helm shaft portion that is a rotation shaft of the helm mechanism; an electric motor that generates a torque by being energized and transmits the generated torque to the coupling shaft portion; and a control device that controls the electric motor to generate a predetermined torque based on a magnitude of the torque generated by rotation of the steering.   
     
     
         2 . The watercraft steering device according to  claim 1 , wherein
 the coupling shaft portion includes a steering coupling portion coupled to a steering shaft portion that is a rotation shaft of the steering.   
     
     
         3 . The watercraft steering device according to  claim 2 , wherein
 the steering coupling portion is provided between the helm mechanism and the steering.   
     
     
         4 . The watercraft steering device according to  claim 1 , further comprising:
 a speed reducer configured to reduce the torque generated by the electric motor and transmit the reduced torque to the coupling shaft portion, wherein   the speed reducer is a worm gear speed reducer, and includes a worm that rotates as a rotation shaft of the electric motor rotates, and a worm wheel that is provided coaxially with the coupling shaft portion and meshes with the worm to transmit a torque to the coupling shaft portion.   
     
     
         5 . The watercraft steering device according to  claim 1 , further comprising:
 a housing that houses the electric motor, the speed reducer, and the control device, and is attachable to the hull.   
     
     
         6 . The watercraft steering device according to  claim 1 , further comprising:
 a position sensor configured to detect a position of the hull, wherein   the control device controls output of the electric motor based on position information received by the position sensor.   
     
     
         7 . An electric assist device, wherein
 the electric assist device is couplable to a helm mechanism configured to adjust a traveling direction of a hull,   the electric assist device is configured to generate a torque according to a rotation amount of a steering, and   the electric assist device comprises:   a coupling shaft portion configured to transmit the torque to a helm shaft portion that is a rotation shaft of the helm mechanism;   an electric motor configured to generate a torque by being energized and transmit the torque to the coupling shaft portion; and   a control device configured to control the electric motor to generate a predetermined torque based on a magnitude of the torque generated by rotation of the steering.