Two-piece axle bushing and marine propeller using same

Abstract

A two-piece axle bushing for marine propeller includes a first transmission member including an accommodation chamber and longitudinal inner ribs spaced around an inner perimeter of the accommodation chamber, and a second transmission member, which includes a tube shaft that includes a first transmission segment inserted into the accommodation chamber and including longitudinal outer ribs spaced around the outer perimeter thereof and respectively movably inserted into one respective buffer space of the first transmission member and selectively engageable with one respective longitudinal inner rib and a second transmission segment connected to the first transmission segment, and a shock absorber fixedly surrounding the outer perimeter of the second transmission segment. Thus, the two-piece axle bushing of the present invention can generate power hysteresis effects when the engine starts up, reducing vibration due to a sudden high torque and further enhancing marine propeller start-up stability and smoothness.

What is claimed is: 
     
         1 . A two-piece axle bushing for marine propeller, comprising:
 a first transmission member comprising an accommodation chamber, at least two longitudinal inner ribs equiangularly spaced around an inner perimeter of said accommodation chamber and radially projecting toward the inside of said accommodation chamber at a predetermined distance, and a buffer space defined inside said accommodation chamber between each two adjacent said longitudinal inner ribs; and   a second transmission member comprising a tube shaft and a shock absorber, said tube shaft comprising a first transmission segment and a second transmission segment connected to said first transmission segment, said first transmission segment being inserted into said accommodation chamber of said first transmission member, said first transmission segment comprising at least one longitudinal outer rib located at an outer perimeter thereof and respectively movably inserted into one respective said buffer space of said first transmission member and selectively engageable with one said longitudinal inner rib, said shock absorber fixedly surrounding the outer perimeter of said second transmission segment.   
     
     
         2 . The two-piece axle bushing as claimed in  claim 1 , wherein each said longitudinal inner rib of said first transmission member comprises at least one first sloping surface; each said longitudinal outer rib of said second transmission member comprises at least one second sloping surface; when each said longitudinal outer rib of said second transmission member is engaged with one respective said longitudinal inner rib of said first transmission member, one said second sloping surface of each said longitudinal outer rib is abutted against one respective said first sloping surface of one respective said longitudinal inner rib. 
     
     
         3 . The two-piece axle bushing as claimed in  claim 1 , wherein said second transmission segment of said tube shaft comprises a plurality of bearing portions equiangularly spaced around the outer perimeter thereof and embedded in said shock absorber. 
     
     
         4 . The two-piece axle bushing as claimed in  claim 1 , wherein said first transmission member and said shock absorber of said second transmission member are peripherally kept in flush. 
     
     
         5 . The two-piece axle bushing as claimed in  claim 1 , wherein each two adjacent said longitudinal inner ribs define therebetween a contained angle in the range of 21˜25 degrees. 
     
     
         6 . The two-piece axle bushing as claimed in  claim 1 , wherein the outer perimeter of said first transmission member consists of a plurality of first planes connected to one another; said shock absorber comprises an outer perimeter consisting of a plurality of second planes that are connected to one another and respectively disposed in line with said first planes of said first transmission member in a flush manner. 
     
     
         7 . The two-piece axle bushing as claimed in  claim 1 , wherein said first transmission member is made from metal. 
     
     
         8 . The two-piece axle bushing as claimed in  claim 1 , wherein said tube shaft of said second transmission member is made from metal. 
     
     
         9 . The two-piece axle bushing as claimed in  claim 1 , wherein said shock absorber of said second transmission member is made from rubber. 
     
     
         10 . A marine propeller, comprising:
 a propeller hub comprising an axle hole;   a plurality of propeller blades equiangularly and radially extended from an outer perimeter of said propeller hub; and   a two-piece axle bushing as claimed in  claim 1 , said two-piece axle bushing being mounted in said axle hole of said propeller hub.   
     
     
         11 . The marine propeller as claimed in  claim 10 , wherein each said longitudinal inner rib of said first transmission member comprises at least one first sloping surface; each said longitudinal outer rib of said second transmission member comprises at least one second sloping surface; when each said longitudinal outer rib of said second transmission member is engaged with one respective said longitudinal inner rib of said first transmission member, one said second sloping surface of each said longitudinal outer rib is abutted against one respective said first sloping surface of one respective said longitudinal inner rib. 
     
     
         12 . The marine propeller as claimed in  claim 10 , wherein said second transmission segment of said tube shaft comprises a plurality of bearing portions equiangularly spaced around the outer perimeter thereof and embedded in said shock absorber. 
     
     
         13 . The marine propeller as claimed in  claim 10 , wherein said first transmission member and said shock absorber of said second transmission member are peripherally kept in flush. 
     
     
         14 . The marine propeller as claimed in  claim 10 , wherein the outer perimeter of said first transmission member consists of a plurality of first planes connected to one another; said shock absorber comprises an outer perimeter consisting of a plurality of second planes that are connected to one another and respectively disposed in line with said first planes of said first transmission member in a flush manner. 
     
     
         15 . The marine propeller as claimed in  claim 10 , wherein each two adjacent said longitudinal inner ribs define therebetween a contained angle in the range of 21˜25 degrees. 
     
     
         16 . The marine propeller as claimed in  claim 10 , wherein said first transmission member is made from metal. 
     
     
         17 . The marine propeller as claimed in  claim 10 , wherein said tube shaft of said second transmission member is made from metal. 
     
     
         18 . The marine propeller as claimed in  claim 10 , wherein said shock absorber of said second transmission member is made from rubber.