Hydraulic system arranged between a first and a second marine propulsion device

Abstract

System and method for providing a hydraulic system ( 1 ) arranged between a first marine propulsion device ( 2, 42 ) and a second marine propulsion device ( 3, 43 ). Each propulsion device is arranged to rotate about a respective axis ( 6, 7, 46, 47 ) at a distance from one another. The system ( 1 ) includes a first hydraulic piston-cylinder device ( 8, 50 ) and a second hydraulic piston-cylinder device ( 13, 55 ) arranged between the second propulsion device ( 2, 3, 42, 43 ) and an element ( 12, 17, 54, 59 ) fixed in relation to the axis ( 6, 7, 46, 47 ). Connecting the piston-cylinder devices ( 8, 13, 50, 55 ) to one another via a first hydraulic circuit ( 18, 60 ) and a second hydraulic circuit ( 19, 61 ) leads to rotation of one propulsion device ( 2, 3, 42, 43 ) resulting in rotation of the other propulsion device ( 2, 3, 42, 43 ). The method and arrangement afford a tie bar function.

1 . A hydraulic system ( 1 ) arranged between a first marine propulsion device ( 2 ,  42 ) and a second marine propulsion device ( 3 ,  43 ), each of which are arranged to rotate about spaced-apart, respective axis ( 6 , 7 ,  46 , 47 ), said hydraulic system ( 1 ) comprising: 
 a first hydraulic piston-cylinder device ( 8 , 50 ) having a cylinder chamber ( 9 , 10 ,  51 , 52 ) on each side of a piston ( 11 ,  53 ), said first hydraulic piston-cylinder device ( 8 , 50 ) being arranged between the first propulsion device ( 2 ,  42 ) and an element ( 12 ,  54 ) fixed in relation to said axis ( 6 , 7 ,  46 , 47 ), and a second hydraulic piston-cylinder device ( 13 ,  55 ) having a cylinder chamber ( 14 , 15 ,  56 , 57 ) on each side of said piston ( 16 , 58 ), said second hydraulic piston-cylinder device ( 13 ,  55 ) being arranged between the second propulsion device ( 3 , 43 ) and an element ( 17 , 59 ) fixed in relation to said axis ( 6 , 7 ,  46 , 47 ); and    a first hydraulic circuit ( 18 , 60 ) and a second hydraulic circuit ( 19 , 61 ) configured to connect the cylinder chambers ( 9 , 10 ,  51 , 52 ) in said first piston-cylinder device ( 8 , 50 ) to the cylinder chambers ( 14 , 15 ,  56 , 57 ) in said second piston-cylinder device ( 13 , 55 ) in order that rotation of one propulsion device ( 2 , 3 ,  42 , 43 ) results in rotation of the other propulsion device ( 2 , 3 ,  42 , 43 ).    
   
   
       2 . The hydraulic system ( 1 ) as recited in  claim 1 , wherein said first hydraulic circuit ( 18 , 60 ) and said second hydraulic circuit ( 19 , 61 ) are connected to the cylinder chambers ( 9 , 10 ,  14 , 15 ,  51 , 52 ,  56 , 57 ) so that a pressure increase occurs in at least one of said circuits ( 18 , 19 ,  60 , 61 ) when rotating the one propulsion device ( 2 , 3 ,  42 , 43 ).  
   
   
       3 . The hydraulic system ( 1 ) as recited in  claim 1 , wherein at least one of said hydraulic circuits ( 18 , 19 ,  60 , 61 ) contains a hydraulic accumulator ( 33 , 62 ) for achieving reloading in at least one of said first and said second hydraulic piston-cylinder devices ( 8 , 13 ,  50 , 55 ).  
   
   
       4 . The hydraulic system ( 1 ) as recited in  claim 1 , wherein a first hydraulic pump ( 36 , 49 ) is connected to the first hydraulic circuit ( 18 ,  60 ) and the second hydraulic circuit ( 19 , 61 ) in order to permit rotation of one propulsion device ( 2 , 3 ,  42 , 43 ) relative to the other propulsion device ( 2 , 3 ,  42 , 43 ).  
   
   
       5 . The hydraulic system ( 1 ) as recited in  claim 1 , wherein said first piston-cylinder device ( 8 , 50 ) and said second piston-cylinder device ( 13 , 55 ) are arranged on opposite sides of each propulsion device ( 2 , 3 ,  42 , 43 ) and hydraulically interconnected so that rotation of one propulsion device ( 2 , 3 ,  42 , 43 ) in one direction results in compression of the first piston-cylinder device ( 8 , 50 ) and simultaneous expansion of the second piston cylinder device ( 13 , 55 ) thereby rotating the other propulsion device ( 2 , 3 ,  42 , 43 ) in the same direction.  
   
   
       6 . The hydraulic system ( 1 ) as recited in  claim 1 , wherein at least one additional piston-cylinder device ( 31 , 32 ) is arranged between one propulsion device ( 2 , 3 ) and an element fixed in relation to said axis ( 6 , 7 ), the piston-cylinder device ( 31 , 32 ) being connected to a hydraulic pump ( 21 ) driven by a manual drive member ( 20 ) for controlling the propulsion device ( 2 , 3 ).