Propulsion device for water-surface movable body

Abstract

A propulsion device for a water-surface movable body includes an upper case, a propulsion motor accommodated in the upper case, a lower case supported by the upper case so as to turn around a turning axis, a propulsor supported by the lower case, a steering motor accommodated in the upper case, and a steering deceleration mechanism configured to decelerate rotation of the steering motor. The steering deceleration mechanism includes a gear shaft arranged in parallel with an output shaft of the steering motor, an output shaft gear arranged coaxially with the output shaft of the steering motor, a ring gear arranged coaxially with the turning axis, and deceleration gears interposed between the output shaft gear and the ring gear. At least one of the deceleration gears is arranged higher than the output shaft gear in a state where the turning axis extends in a vertical direction.

1 . A propulsion device for a water-surface movable body, comprising:
 an upper case supported by a hull of the water-surface movable body;   a propulsion motor accommodated in the upper case;   a lower case supported by the upper case so as to turn around a turning axis;   a propulsor supported by the lower case and configured to rotate around a propulsion axis by a driving force of the propulsion motor;   a steering motor accommodated in the upper case; and   a steering deceleration mechanism provided on a steering force transmission path from the steering motor to the lower case and configured to decelerate rotation of the steering motor,   wherein the steering deceleration mechanism includes:   at least one gear shaft arranged in parallel with an output shaft of the steering motor;   an output shaft gear arranged coaxially with the output shaft of the steering motor;   a ring gear arranged coaxially with the turning axis; and   a plurality of deceleration gears provided on the at least one gear shaft and interposed between the output shaft gear and the ring gear on the steering force transmission path, and   at least one of the plurality of deceleration gears is arranged higher than the output shaft gear in a state where the turning axis extends in a vertical direction.   
     
     
         2 . The propulsion device for the water-surface movable body according to  claim 1 , wherein the at least one gear shaft is arranged within a lateral dimension of the ring gear in a plan view. 
     
     
         3 . The propulsion device for the water-surface movable body according to  claim 1 , wherein a contour of the steering motor is arranged within a lateral dimension of the ring gear in a plan view. 
     
     
         4 . The propulsion device for the water-surface movable body according to  claim 1 , wherein the output shaft of the steering motor and the turning axis are arranged on a same straight line extending in a front-and-rear direction. 
     
     
         5 . The propulsion device for the water-surface movable body according to  claim 1 , further comprising a brake mechanism configured to restrict turning of the lower case,
 wherein a contour of the brake mechanism is arranged within a lateral dimension of the ring gear in a plan view.   
     
     
         6 . The propulsion device for the water-surface movable body according to  claim 1 , further comprising a separator that partitions an internal space of the upper case into an oil chamber and a dry chamber,
 wherein the steering motor includes a motor body accommodated in the dry chamber, and   the plurality of deceleration gears is accommodated in the oil chamber.   
     
     
         7 . The propulsion device for the water-surface movable body according to  claim 1 , further comprising a planetary deceleration mechanism provided on a driving force transmission path from the propulsion motor to the propulsor and configured to decelerate rotation of the propulsion motor,
 wherein the lower case includes a turning portion having a cylindrical shape centered on the turning axis,   the planetary deceleration mechanism is arranged on an inner circumference of the turning portion, and   the plurality of deceleration gears is arranged at a same height as the turning portion.   
     
     
         8 . The propulsion device for the water-surface movable body according to  claim 1 , wherein the plurality of deceleration gears includes a downstream end gear that engages with the ring gear, and
 the downstream end gear is arranged highest among the plurality of deceleration gears.   
     
     
         9 . The propulsion device for the water-surface movable body according to  claim 1 , wherein the plurality of deceleration gears includes an upstream end gear that engages with the output shaft gear, and
 the upstream end gear is arranged lowest among the plurality of deceleration gears.