Lubrication mechanism
In a lubrication mechanism including a rotating shaft, the rotating shaft includes an external member and an internal member housed inside the external member, the internal member having an internal space extending in an axial direction, a horizontal hole is formed in the internal member, the horizontal hole for communicating between the internal space and an outer peripheral surface of the internal member, the horizontal hole communicates with a lubrication flow passage for communicating with a prescribed lubrication target portion, and the external member and the internal member are made of materials with a different hardness.
1 . A lubrication mechanism comprising a rotating shaft that includes an external member and an internal member, wherein
the external member has a first internal space inside the external member, and is disposed so that an axial direction of the external member extends along a vertical direction,
the internal member has a second internal space inside the internal member, and is disposed so that an axial direction of the internal member extends along the vertical direction, the internal member is housed inside the first internal space of the external member, wherein
a plurality of lateral holes are formed in the internal member, each of the plurality of lateral holes extending in a direction perpendicular to the axial direction and communicating between the second internal space and an outer peripheral surface of the internal member,
the plurality of lateral holes are arranged at positions spaced apart from each other along the axial direction of the internal member, and each of the plurality of lateral holes communicates with a lubrication flow passage for communicating with a predetermined lubrication target portion, and
the external member and the internal member are made of materials with different hardnesses.
2 . The lubrication mechanism according to claim 1 , wherein the internal member is made of a material having a lower hardness than a material of the external member.
3 . The lubrication mechanism according to claim 1 , wherein
the plurality of lateral holes is formed with different sizes.
4 . The lubrication mechanism according to claim 3 , wherein flow passages by the plurality of lateral holes are formed such that a flow passage by an upper one of the plurality of lateral holes is larger than a flow passage by a lower one of the plurality of lateral holes, the upper one of the lateral holes being at an upper side of the lower one of the lateral holes in the vertical direction.
5 . The lubrication mechanism according to claim 4 , wherein the lubrication flow passage for communicating with respective ones of the plurality of lateral holes is arranged upward than the predetermined lubrication target portion in the vertical direction.
6 . The lubrication mechanism according to claim 1 ,
the internal member includes, at the outer peripheral surface, a plurality of entire circumferential grooves which are provided in the axial direction of the internal member and each of which is a groove in which an entire periphery of the outer peripheral surface is recessed radially inward of the internal member,
the plurality of lateral holes communicate between the second internal space and respective ones of the plurality of entire circumferential grooves.
7 . The lubrication mechanism according to claim 6 ,
in the axial direction of the internal member, a length dimension of an upper one of the plurality of entire circumferential grooves is larger than a length dimension of a lower one of the plurality of entire circumferential grooves, the upper one of the plurality of entire circumferential grooves being at an upper side of the lower one of the plurality of entire circumferential grooves in the vertical direction.
8 . The lubrication mechanism according to claim 6 ,
in the axial direction of the internal member, length dimensions of the plurality of entire circumferential grooves are formed so as to increase in order from a lower end side toward an upper end side of the internal member in the vertical direction.
9 . An outboard motor comprising the lubrication mechanism according to claim 1 .
10 . A ship hull comprising the outboard motor according to claim 9 , wherein
the axial direction of the external member and the axial direction of the internal member are arranged substantially along an up-down direction with respect to a traveling direction of the ship hull.