Motor

Abstract

An outboard propulsion unit ( 10 ) mountable on a watercraft structure ( 3 ) such as a transom comprises a main body ( 12, 14 ) and a propulsion leg ( 16 ) carrying a thrust generator ( 18 ) and being rotatable relative to the main body for steering. The propulsion unit ( 10 ) comprises a helical actuator ( 32 ) for rotating the propulsion leg relative to the main body. This provides for a more compact motor with a lower body, which allows the motor to be tilted horizontally aft of the transom and facilitates towing.

1 . An outboard propulsion unit mountable on a watercraft structure, the outboard propulsion unit comprising a main body and a propulsion leg carrying a thrust generator, the main body for mounting to a watercraft structure, the propulsion leg being rotatable relative to the main body for steering when submerged, wherein the propulsion unit comprises a helical actuator coupled with the propulsion leg and controllable to cause rotation of the propulsion leg relative to the main body. 
     
     
         2 . The outboard propulsion unit according to  claim 1 , wherein the helical actuator has a holding torque larger than a propulsion torque of the thrust generator. 
     
     
         3 . The outboard propulsion unit according to  claim 1 , wherein the helical actuator is controlled by a hydraulic system. 
     
     
         4 . The outboard propulsion unit according to  claim 1 , wherein the helical actuator is configured to control rotation of the propulsion leg relative to the main body within a range of no less than 170 degrees. 
     
     
         5 . The outboard propulsion unit according to  claim 4 , wherein the helical actuator is configured to control rotation of the propulsion leg relative to the main body within a range of no less than 180 degrees. 
     
     
         6 . The outboard propulsion unit according to  claim 1 , wherein the helical actuator is configured to control rotation of the propulsion leg relative to the main body within a range of no more than 220 degrees. 
     
     
         7 . The outboard propulsion unit according to  claim 1 , wherein the main body comprises a motor arranged to drive the thrust generator via a drive shaft extending from the main body to the propulsion leg. 
     
     
         8 . The outboard propulsion unit according to  claim 7 , wherein the helical actuator is arranged coaxially with the drive shaft. 
     
     
         9 . The outboard propulsion unit according to  claim 8 , wherein the helical actuator is of annular configuration comprising an axial passage, the drive shaft extending through the axial passage. 
     
     
         10 . The outboard propulsion unit according to  claim 1 , wherein the helical actuator is located in the main body. 
     
     
         11 . The outboard propulsion unit according to  claim 1 , wherein the main body comprises a trim pivot located at a top end of the main body. 
     
     
         12 . The outboard propulsion unit according to  claim 1 , wherein the main body comprises a head and a transom attachment for mounting the main body aft of a plane of a transom, the main body comprising a pivot joint configured to allow the motor to be pivoted between a deployed position and a non-use position, wherein the pivot joint is located relative to the head such that the head is aft of the plane in the non-use position. 
     
     
         13 . The outboard propulsion unit according to  claim 12 , wherein the transom attachment is provided by a transom bracket integral with the main body. 
     
     
         14 . The outboard propulsion unit according to  claim 12 , wherein the transom attachment is provided by a transom bracket assembly comprising a first bracket subassembly and a second bracket subassembly mountable to the first bracket subassembly, the first bracket subassembly being detachable from the second bracket subassembly for installation to a transom without the main body, the second bracket subassembly being part of or connected with the main body for mounting to the first bracket subassembly. 
     
     
         15 . The outboard propulsion unit according to  claim 1 , wherein the outboard propulsion unit is pivotable about a trim axis in the cowl region of the main body. 
     
     
         16 . The outboard propulsion unit according to  claim 15 , wherein the outboard propulsion unit is pivotable about a trim axis in the upper half of the cowl region. 
     
     
         17 . The outboard propulsion unit according to  claim 15 , wherein the outboard propulsion unit is pivotable about a trim axis at the top of the cowl region.