Device for preventing a shaft rotation

Abstract

A device for preventing and/or stopping rotation of a shaft coupled to a motor, of the type having a first fixed element with respect to this shaft, and a moving element, and means to constrain the moving element to the shaft in such a manner as to rotate integrally with this shaft and at the same time be able to move between a position of friction contact with the fixed element, to allow stopping of the shaft, and a position of disengagement from this fixed element, to allow release of the shaft is disclosed. The device advantageously provides that the means to constrain the moving element to the shaft include a link for movement of the moving element along a direction having a radial component with respect to the shaft.

1 . A device for preventing and/or stopping a shaft rotation coupled to at least a motor, of the type comprising at least a first fixed element with respect to said shaft, and at least one moving element, and means to constrain said at least one moving element to said shaft in such a manner as to rotate integrally with said shaft and also be able to move between a position of friction contact with said least one fixed element, for stopping of said shaft, and a position of disengagement from said at least one fixed element, for release of said shaft, wherein said means to constrain said at least one moving element to said shaft comprise at least one link for movement of said at least one moving element along a direction having at least a radial component with respect to said shaft. 
     
     
         2 . The device according to  claim 1 , wherein in said position of friction contact of said at least one moving element with said at least one fixed element, at least one inclined surface of said at least one moving element is in contact with at least one corresponding inclined surface of said at least one fixed element. 
     
     
         3 . The device according to  claim 1 , wherein said means to constrain said at least one moving element to said shaft comprise at least one contrast member to counter in a controlled manner said movement of said at least one moving element, at least along said direction having at least a radial component, toward said position of disengagement from said at least one fixed element. 
     
     
         4 . The device according to  claim 3 , wherein said least one contrast member allows temporary movement of said at least one moving element to said position of disengagement from said at least one fixed element, only after exceeding a predefined angular velocity of said shaft. 
     
     
         5 . The device according to  claim 3 , wherein said contrast member is configured to return said at least one moving element to said position of friction contact with said at least one fixed element. 
     
     
         6 . The device according to  claim 5 , wherein said at least one contrast member comprises at least one spring. 
     
     
         7 . The device according to  claim 5 , wherein said at least one spring is integral with said shaft and is also constrained to said at least one moving element. 
     
     
         8 . The device according to  claim 1 , wherein said at least one link for movement of said at least one moving element along a direction having at least a radial component with respect to said shaft is a link of sliding type for translation of said at least one moving element with respect to said shaft along said direction having at least a radial component. 
     
     
         9 . The device according to  claim 8 , wherein said link of sliding type for movement of said at least one moving element along a direction having at least a radial component with respect to said shaft comprises at least one guide arranged in radial direction with respect to said shaft and/or in a direction perpendicular to the shaft and lying in a plane parallel to a plane passing through the rotation axis of said shaft. 
     
     
         10 . The device according to  claim 1 , wherein said at least one link for movement of said at least one moving element along a direction having at least a radial component with respect to said shaft is a pivot link. 
     
     
         11 . The device according to  claim 1 , wherein said at least one moving element has a circular ring shape viewed in a plane perpendicular to the rotation axis (A) of the shaft. 
     
     
         12 . The device according to  claim 10 , wherein it comprises two moving elements having a shape substantially equal to half of an annular sector viewed in a plane perpendicular to the rotation axis (A) of the shaft. 
     
     
         13 . The device according to  claim 1 , wherein said constraining means comprise at least one frame integral with said shaft, rotatable with said shaft, said at least one moving element being constrained to said at least one frame integral with the shaft in a manner rotatable with said shaft. 
     
     
         14 . The device according to  claim 13 , wherein said at least one frame constrained to said shaft has a substantially annular shape and is constrained to the outer surface of said shaft. 
     
     
         15 . The device according to  claim 1 , wherein it comprises means for regulation of said least one contrast member to modify the action of controlled countering of movement of said at least one moving element. 
     
     
         16 . A watercraft comprising at least one motion transmission shaft from a motor to a propeller, comprising at least one device according to  claim 1 . 
     
     
         17 . The watercraft according to  claim 16 , wherein said at least one motion transmission shaft is coupled to said motor through a hydraulic transmission. 
     
     
         18 . The watercraft according to  claim 16 , wherein said propeller is of the type with adjustable blades.