Propulsion system for a marine vessel and a use of a slip clutch assembly

Abstract

A propulsion system for a marine vessel is presented. The propulsion system comprising a propulsion unit that is rotatably attached to the marine vessel about an axis, a rotary drive arranged to rotate the propulsion unit about the axis by applying a torque about the axis, and a slip clutch assembly operationally arranged between the propulsion unit and the rotary drive to allow a rotational motion between the propulsion unit and the rotary drive about the axis in case the propulsion unit impacts an obstacle.

1 . A propulsion system for a marine vessel, the propulsion system comprising:
 a propulsion unit that is rotatably attached to the marine vessel about an axis,   a rotary drive arranged to rotate the propulsion unit about the axis by applying a torque about the axis, and   a slip clutch assembly operationally arranged between the propulsion unit and the rotary drive to allow a rotational motion between the propulsion unit and the rotary drive about the axis in case the propulsion unit impacts an obstacle.   
     
     
         2 . The propulsion system of  claim 1 , comprising a transom bracket to rotatably attach the propulsion unit to the marine vessel about the axis, the transom bracket being adapted to be secured to the marine vessel. 
     
     
         3 . The propulsion system of  claim 1 , wherein the slip clutch assembly is configured to allow a rotational motion between the propulsion unit and the rotary drive when a torque between the propulsion unit and the rotary drive about the axis exceeds a threshold torque value. 
     
     
         4 . The propulsion system of  claim 1 , wherein the slip clutch assembly is configured to allow a rotational motion along a predetermined slip rotation angle when a torque between the propulsion unit and the rotary drive exceeds a threshold torque value at the beginning of the rotational motion, the slip clutch assembly optionally being configured to allow a stepwise rotational motion along predetermined slip rotation angles. 
     
     
         5 . The propulsion system of  claim 1 , comprising a shaft to which the propulsion unit is secured, the rotary drive being arranged to rotate the shaft, and thereby the propulsion unit, about the axis. 
     
     
         6 . The propulsion system of  claim 5 , wherein the slip clutch assembly is formed by the shaft and the rotary drive. 
     
     
         7 . The propulsion system of  claim 5 , wherein the slip clutch assembly is operationally arranged between the shaft and the rotary drive. 
     
     
         8 . The propulsion system of  claim 1 , wherein the slip clutch assembly comprises an engaging member and a receiving recess, which may be engaged or disengaged, and wherein the slip clutch assembly is configured such that the rotational motion between the propulsion unit and the rotary drive about the axis is allowed when the engaging member and the receiving recess are disengaged. 
     
     
         9 . The propulsion system of  claim 8 , wherein the engaging member is biased towards the receiving recess. 
     
     
         10 . The propulsion system of  claim 8 , comprising a plurality of engaging members and receiving recesses such that the slip clutch assembly allows a stepwise rotational motion along predetermined slip rotation angles. 
     
     
         11 . The propulsion system of  claim 5 , wherein the rotary drive and the shaft are concentric. 
     
     
         12 . The propulsion system of  claim 11 , wherein the shaft is arranged inside the rotary drive. 
     
     
         13 . The propulsion system of  claim 1 , wherein the rotary drive comprises an input interface that is adapted to engage a drive unit such that the drive unit may rotate the rotary drive, wherein the rotary drive comprises an engaging member or a receiving recess that forms part of the slip clutch assembly. 
     
     
         14 . The propulsion system of  claim 1 , wherein the rotary drive essentially has the shape of a circular cylinder. 
     
     
         15 . The propulsion system of  claim 1 , comprising a drive unit arranged to rotate the rotary drive. 
     
     
         16 . The propulsion system of  claim 15 , wherein the drive unit comprises a worm gear and the rotary drive comprises an input interface that is adapted to engage the worm gear. 
     
     
         17 . The propulsion system of  claim 15 , comprising an electric trim motor that is arranged to rotate the drive unit. 
     
     
         18 . The propulsion system of  claim 1 , wherein the propulsion unit is rotatably attached to the marine vessel about a trim axis that is essentially horizontal. 
     
     
         19 . The propulsion system of  claim 1 , wherein the propulsion unit comprises a support part and a thrust part, wherein the thrust part is rotatable with respect to the support part about a steering axis to direct the thrust of the propulsion unit. 
     
     
         20 . Use of a slip clutch assembly in a propulsion system for a marine vessel, the propulsion system comprising a propulsion unit that is rotatably connected to the marine vessel, the propulsion system being configured such that the slip clutch assembly allows the propulsion unit to rotate with respect to the marine vessel in case the propulsion unit impacts an obstacle.