Propulsion apparatus for ship

Abstract

This propulsion apparatus for a ship includes an upper case supported by a hull, a lower case pivotably supported by the upper case, a screw disposed in an area submerged in external water in the lower case and configured to generate propulsion power, a feeding flow channel configured to feed a fluid to the lower case from the upper case via relatively pivoting sliding parts of the upper case and the lower case, and a returning flow channel configured to return the fluid to the upper case from the lower case via the sliding parts, an annular space is provided between the sliding part on the side of the upper case and the sliding part on the side of the lower case and the annular space is partitioned into a first arc-shaped passage and a second arc-shaped passage by a plurality of partition walls, any one of the first arc-shaped passage and the second arc-shaped passage is in communication with the feeding flow channel, and the other of the first arc-shaped passage and the second arc-shaped passage is in communication with the returning flow channel.

What is claimed is: 
     
         1 . A propulsion apparatus for a ship comprising:
 an upper case supported by a hull;   a lower case pivotably supported by the upper case;   a screw disposed in an area submerged in external water in the lower case and configured to generate propulsion power;   a feeding flow channel configured to feed a fluid to the lower case from the upper case via relatively pivoting sliding parts of the upper case and the lower case; and   a returning flow channel configured to return the fluid to the upper case from the lower case via the sliding parts,   wherein an annular space is provided between the sliding part on the side of the upper case and the sliding part on the side of the lower case and the annular space is partitioned into a first arc-shaped passage and a second arc-shaped passage by a plurality of partition walls,   any one of the first arc-shaped passage and the second arc-shaped passage is in communication with the feeding flow channel, and   the other of the first arc-shaped passage and the second arc-shaped passage is in communication with the returning flow channel.   
     
     
         2 . The propulsion apparatus for a ship according to  claim 1 , wherein a plurality of pairs of the feeding flow channels and the returning flow channels are provided,
 the sliding parts are disposed on facing cylindrical surfaces of the upper case and the lower case, and   the plurality of annular spaces corresponding to the pairs of the feeding flow channels and the returning flow channels are arranged on the cylindrical surface in an axial direction.   
     
     
         3 . The propulsion apparatus for a ship according to  claim 2 , wherein two sets of the feeding flow channels and the returning flow channels are provided,
 lubricating oil that lubricates the inside of the upper case flows through the annular space disposed in the vicinity of the upper case of the cylindrical surface, and   a coolant that cools heat-generating parts disposed inside or outside the upper case flows through the annular space disposed in the vicinity of the lower case of the cylindrical surface.   
     
     
         4 . The propulsion apparatus for a ship according to  claim 1 , wherein the annular space is surrounded by an annular groove formed in one of the lower case and the upper case and a closing wall provided on the other,
 a case-side passage connected to each of the first arc-shaped passage and the second arc-shaped passage is formed in the one of the lower case and the upper case in which the annular groove is formed,   a communication port facing each of the first arc-shaped passage and the second arc-shaped passage is formed in the closing wall, and   another case-side passage in communication with each of the first arc-shaped passage and the second arc-shaped passage through the communication port is formed in the other of the lower case and the upper case having the closing wall.   
     
     
         5 . The propulsion apparatus for a ship according to  claim 4 , wherein the annular space is partitioned into two arc-shaped passages with a center angle of about 180° by a pair of partition walls, one of the passages being the first arc-shaped passage and the other being the second arc-shaped passage, and
 each of the communication ports is always in communication with one of the first arc-shaped passage and the second arc-shaped passage when a pivot angle of the lower case with respect to the upper case is within a range of substantially 90° from a central position in one direction and another direction. 
 
     
     
         6 . The propulsion apparatus for a ship according to  claim 5 , wherein the communication port facing the first arc-shaped passage and the communication port facing the second arc-shaped passage are disposed to be offset in a widthwise direction crossing a circumferential direction of the annular space, and
 the pair of partition walls are formed in shapes in which partition regions in the annular space are offset in the circumferential direction on one side and the other side in the widthwise direction.   
     
     
         7 . The propulsion apparatus for a ship according to  claim 6 , wherein the pair of partition walls are formed in crank shapes when seen from an end surface in a protrusion direction facing the closing wall. 
     
     
         8 . The propulsion apparatus for a ship according to  claim 6 , wherein the pair of partition walls are formed in inclination shapes in which a shape seen from an end surface in a protrusion direction facing the closing wall is inclined from one side toward the other side in the widthwise direction on one side in the circumferential direction. 
     
     
         9 . The propulsion apparatus for a ship according to  claim 5 , wherein the lower case is set not to pivot 90° or more in one direction and another direction about the central position with respect to the upper case.