Torsional Force Transmitting Apparatus

Abstract

The present invention aims to couple a propeller with a power output shaft to transmit the torsional force of the power output shaft to the propeller. The apparatus includes a first sleeve and a second sleeve that form a coupling surface between them to hold a torsional force transfer means. The torsional force transfer means is coupled with the first sleeve and the second sleeve to transmit only a selected amount of the torsional force. The first sleeve has a first outer surface and the second sleeve has a second inner surface that are engaged respectively with the propeller and the power output shaft in the rotating direction so that the power output shaft can transmit the torsional force to the propeller. In the event that the propeller is overloaded the torsional force transfer means between the first sleeve and the second sleeve slip to form a protection mechanism.

1 . A torsional force transmitting apparatus to transmit a torsional force of a power output shaft to a propeller, comprising:
 a first sleeve which has a first inner surface and a first outer surface which is engaged with the propeller in a rotational direction;   a second sleeve which has a second inner surface and a second outer surface, the second inner surface being engaged with the power output shaft in the rotational direction, the first inner surface and the second outer surface being coupled together in a rotary manner to form a coupling surface; and   a torsional force transfer means located on the coupling surface to couple the first sleeve and the second sleeve and transmit only a selected amount of the torsional force.   
   
   
       2 . The torsional force transmitting apparatus of  claim 1 , wherein the torsional force transfer means is formed by disposing an adhesive on the coupling surface; the amount of the torsional force transmittable being controlled by changing the type and bonding size of the adhesive. 
   
   
       3 . The torsional force transmitting apparatus of  claim 1 , wherein the torsional force transfer means is formed by carving at least one flute on the coupling surface between the first inner surface and the second outer surface to allow an elastic element to be wedged in, the second sleeve having two ends to hold respectively a upper pad and a lower pad that are bonded to the first sleeve to prevent the first sleeve and the second sleeve from sliding against each other to anchor the elastic element, the amount of the torsional force transmittable being controlled by changing the number of the flute. 
   
   
       4 . The torsional force transmitting apparatus of  claim 3 , wherein the elastic element includes a rubber strut coupling with a spring. 
   
   
       5 . The torsional force transmitting apparatus of  claim 3 , wherein the upper pad and the lower pad are made from rubber, and formed at a dimension slightly larger than an inner diameter of the propeller. 
   
   
       6 . The torsional force transmitting apparatus of  claim 1 , wherein the first outer surface of the first sleeve is encased by an elastic material. 
   
   
       7 . The torsional force transmitting apparatus of  claim 6 , wherein the elastic material is rubber. 
   
   
       8 . The torsional transmission apparatus of  claim 6 , wherein the elastic material is plastics. 
   
   
       9 . The torsional force transmitting apparatus of  claim 1 , wherein the first outer surface is non-circular and the propeller has a corresponding non-circular profile. 
   
   
       10 . The torsional force transmitting apparatus of  claim 1 , wherein the second inner surface has annular inner teeth and the power output shaft has annular outer teeth corresponding to the annular inner teeth to be coupled together for installation such that the annular inner teeth and the annular outer teeth are engaged to allow the power output shaft to transmit the torsional force to the second sleeve. 
   
   
       11 . The torsional force transmitting apparatus of  claim 1 , wherein the first outer surface has a plurality of ribs and the propeller has an inner hole formed in a shape corresponding to the first outer surface, the propeller and the first sleeve being interposed by a plurality of elastic struts on one side of the ribs.