Lubricating structure for marine drive

Abstract

A lubricating structure for a marine drive includes a lubricating oil supplying system that supplies lubricating oil to a meshing portion of a driven bevel gear and a drive bevel gear by utilizing centrifugal force exerted by rotation of the bevel gears and one or more passages formed in one or both of the bevel gears.

1 . A lubricating structure for a marine drive having a drive shaft driven by an engine, a bevel gear mechanism, a propeller shaft driven by the drive shaft via the bevel gear mechanism, the bevel gear mechanism having a drive bevel gear attached to the drive shaft and a driven bevel gear attached to the propeller shaft and meshing with the drive bevel gear, and a lubricating oil supplying system for supplying lubricating oil to a meshing portion of the drive and driven bevel gears, the lubricating oil supplying system comprising an oil intake passage formed in one of the drive or driven bevel gears, the oil intake passage configured so that as the corresponding bevel gear rotates, lubricating oil is drawn through the oil intake passage by centrifugal force and delivered at or adjacent the meshing portion of the drive and driven bevel gears.  
     
     
         2 . The lubricating structure of  claim 1 , wherein the bevel gear mechanism comprises a forward driven bevel gear and a reverse driven bevel gear, and the oil intake passage is formed in at least one of the driven bevel gears.  
     
     
         3 . The lubricating structure of  claim 1 , wherein the oil intake passage formed in the bevel gear axially extends from a non-toothed-side end of the bevel gear to an opening at or adjacent a toothed face of the bevel gear.  
     
     
         4 . The lubricating structure of  claim 3 , wherein the opening of the oil intake passage at a toothed-side end is generally upstream of the opening at the non-toothed-side end in a rotational direction of the bevel gear.  
     
     
         5 . The lubricating structure of  claim 1 , wherein the oil intake passage formed in the bevel gear axially extends from a non-toothed-side end of the driven bevel gear and further radially extends to open in a surface of the gear within the meshing portion.  
     
     
         6 . The lubricating structure of  claim 5 , wherein the opening of the oil intake passage at a toothed-side end is generally upstream of the opening at the non-toothed-side end in a rotational direction of the bevel gear.  
     
     
         7 . The lubricating structure of  claim 1 , wherein the oil intake passage formed in the bevel gear is tilted further outward with respect to a rotation axis of the bevel gear from a non-toothed-side end toward a toothed face of the bevel gear.  
     
     
         8 . The lubricating structure of  claim 7 , wherein a pipe member is inserted into the opening of the oil intake passage at the non-toothed-side end such that the pipe member projects from the non-toothed side.  
     
     
         9 . The lubricating structure of  claim 8 , wherein a projection of the pipe member is formed such that an opening in the projection is substantially oriented opposed to the rotational direction of the driven bevel gear.  
     
     
         10 . The lubricating structure of  claim 8 , wherein a second pipe member is inserted into the opening of the oil intake passage at a toothed-side end, and the second pipe member has an opening generally directed toward the meshing portion.  
     
     
         11 . A marine drive comprising an engine, a drive shaft, a propeller shaft and a bevel gear mechanism, the engine driving the drive shaft, which in turn drives the propeller shaft through the bevel gear mechanism, the bevel gear mechanism having a drive bevel gear attached to the drive shaft and a driven bevel gear attached to the propeller shaft and meshing with the drive bevel gear at a meshing portion, and a lubricating oil supplying system is adapted to supply lubricating oil to the meshing portion, the lubricating oil supplying system comprising an oil intake passage formed in one of the drive or driven bevel gears, the oil intake passage configured so that as the corresponding bevel gear rotates, lubricating oil is drawn through the oil intake passage by centrifugal force and delivered at or adjacent the meshing portion of the drive and driven bevel gears.  
     
     
         12 . The marine drive of  claim 11 , wherein the bevel gear mechanism comprises a forward driven bevel gear and a reverse driven bevel gear, and the oil intake passage is formed in at least one of the driven bevel gears.  
     
     
         13 . The marine drive of  claim 12 , wherein each of the forward and reverse driven gears comprises an oil intake passage.  
     
     
         14 . The marine drive of  claim 13 , wherein each of the forward and reverse driven gears comprises an oil intake passage, and the oil intake passage in the forward driven gear has a different orientation than the oil intake passage in the reverse driven gear.  
     
     
         15 . The marine drive of  claim 12 , wherein an opening of the oil intake passage at a toothed-side end is generally upstream of an opening at a non-toothed-side end in a rotational direction of the bevel gear.  
     
     
         16 . The marine drive of  claim 12 , wherein an opening of the oil intake passage at a toothed-side end of the bevel gear is farther from a center axis of the bevel gear than is an opening at a non-toothed-side end of the bevel gear.