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, a propulsor supported by the lower case, a steering motor accommodated in the upper case, a steering deceleration mechanism configured to decelerate rotation of the steering motor, and a turning angle detection mechanism configured to detect a turning angle of the lower case. The steering deceleration mechanism includes a deceleration gear, the turning angle detection mechanism includes a detection shaft provided separately from a gear shaft of the deceleration gear, a connection unit that connects the gear shaft of the deceleration gear and the detection shaft, and a detection unit configured to detect a rotation angle of the detection shaft. A rotation speed of the detection shaft is identical to a turning speed of the lower case.

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;   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; and   a turning angle detection mechanism configured to detect a turning angle of the lower case relative to the upper case,   wherein the steering deceleration mechanism includes at least one deceleration gear,   the turning angle detection mechanism includes:   a detection shaft provided separately from a gear shaft of the at least one deceleration gear;   a connection unit that connects the gear shaft of the at least one deceleration gear and the detection shaft; and   a detection unit configured to detect a rotation angle of the detection shaft, and   a rotation speed of the detection shaft is identical to a turning speed of the lower case.   
     
     
         2 . The propulsion device for the water-surface movable body according to  claim 1 , further comprising a 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, and   the deceleration mechanism is arranged on an inner circumference of the turning portion.   
     
     
         3 . 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,
 the at least one deceleration gear is accommodated in the oil chamber, and   the turning angle detection mechanism is accommodated in the dry chamber.   
     
     
         4 . The propulsion device for the water-surface movable body according to  claim 1 , wherein the detection unit is composed of a resolver,
 the resolver includes:   a rotor configured to rotate integrally with the detection shaft; and   a stator arranged on an outer circumference of the rotor,   the connection unit includes:   a driving gear arranged on the gear shaft of the at least one deceleration gear; and   a driven gear arranged on the detection shaft and engaging with the driving gear, and   the turning angle detection mechanism further includes a rotation restricting member configured to move between an allowing position and a restricting position, the allowing position being a position where the rotation restricting member allows rotation of the detection shaft relative to the driven gear, the restricting position being a position where the rotation restricting member restricts the rotation of the detection shaft relative to the driven gear.   
     
     
         5 . The propulsion device for the water-surface movable body according to  claim 4 , wherein the turning angle detection mechanism further includes a collar arranged coaxially with the detection shaft,
 a locking protrusion is provided on an outer circumferential surface of the detection shaft,   the rotation restricting member is composed of a fastening nut that engages with the detection shaft, and   the collar and the driven gear are sandwiched between the fastening nut and the locking protrusion.   
     
     
         6 . The propulsion device for the water-surface movable body according to  claim 5 , wherein the rotor is coupled to an outer circumferential surface of the collar,
 the fastening nut and the rotor each have an annular shape, and   an outer diameter of at least a portion of the fastening nut is larger than an inner diameter of the rotor.   
     
     
         7 . The propulsion device for the water-surface movable body according to  claim 1 , wherein the lower case includes a turning portion having a cylindrical shape centered on the turning axis,
 the steering deceleration mechanism further includes a ring gear coupled to an outer circumferential surface of the turning portion,   the at least one deceleration gear includes a downstream end gear that engages with the ring gear, and   the connection unit includes:   a driving gear arranged on a gear shaft of the downstream end gear and having a smaller diameter than the downstream end gear; and   a driven gear arranged on the detection shaft and engaging with the driving gear.