Pump device and ship propulsion machine

Abstract

A first or second shaft of a pump device is provided with a first axial hole opening from one end to an inner periphery of a second or first pump portion along an axial direction and a radial hole penetrating the first or second shaft from the first axial hole in a radial direction. The first pump portion includes a first drive gear and a second driven gear. The second pump portion includes a first driven gear and a second drive gear. A switching mechanism of the pump device includes a switching operation portion provided in the first axial hole so as to be movable along the axial direction, and a switching member body configured to appear and disappear from the radial hole as the switching operation portion is displaced.

What is claimed is: 
     
         1 . A pump device comprising:
 a first shaft that is a shaft member that rotates as a drive source operates;   a second shaft that is a shaft member rotatably provided in parallel to the first shaft;   a first pump portion and a second pump portion supported on the first shaft and the second shaft and configured to send a hydraulic fluid; and   a switching mechanism configured to switch between an on mode in which the second pump portion pumps liquid and an off mode in which the second pump portion does not pump liquid,   wherein the second shaft is provided with a first axial hole opening from one end to an inner periphery of the first pump portion along an axial direction and a radial hole penetrating the second shaft from the first axial hole in a radial direction, or the first shaft is provided with a first axial hole opening from the other end to an inner periphery of the second pump portion along the axial direction and a radial hole penetrating the first shaft from the first axial hole in the radial direction,   wherein the first pump portion includes
 a first drive gear that is a gear rotating integrally with the first shaft, and 
 a second driven gear that is provided on the second shaft and that meshes with the first drive gear, 
   wherein the second pump portion includes
 a first driven gear that is a gear rotatable relative to the first shaft, and 
 a second drive gear that is a gear rotating integrally with the second shaft and meshing with the first driven gear, and 
   wherein a switching mechanism includes
 a switching operation portion provided in the first axial hole so as to be movable along the axial direction, and 
 a switching member body configured to appear and disappear from the radial hole as the switching operation portion is displaced, to be in the on mode as a part of the switching member body protrudes from the radial hole, and to be in the off mode as the switching member body is inserted into the radial hole. 
   
     
     
         2 . The pump device according to  claim 1 ,
 wherein the second shaft is provided with the first axial hole.   
     
     
         3 . The pump device according to  claim 2 ,
 wherein the switching member body has a spherical shape, and   wherein the second driven gear has a recess formed in an inner peripheral surface thereof in a concave shape such that the switching member body is to be fitted.   
     
     
         4 . The pump device according to  claim 2 , further comprising:
 a first pressure generation mechanism configured to generate a pressure inside the first axial hole and to displace the switching operation portion in a first direction that is one direction along an axis; and   a first spring provided in the first axial hole and configured to bias the switching operation portion in a second direction that is a reverse direction to the first direction.   
     
     
         5 . The pump device according to  claim 4 , further comprising:
 a second spring configured to abut against one end of the switching operation portion and to bias the switching operation portion in the second direction.   
     
     
         6 . The pump device according to  claim 5 ,
 wherein the second shaft has a second axial hole that penetrates from the other end to the first axial hole along the axial direction, and   wherein the pump device further comprises a pressure adjusting plug that is provided inside the second axial hole so as to be adjustable in position in the axial direction and that abuts against the other end of the second spring.   
     
     
         7 . The pump device according to  claim 4 , further comprising:
 a second pressure generation mechanism configured to press the second shaft in the second direction.   
     
     
         8 . The pump device according to  claim 7 ,
 wherein the first pressure generation mechanism includes a first hydraulic chamber that is provided at one end of the second shaft and that is filled with oil,   wherein the second pressure generation mechanism includes a second hydraulic chamber that is provided at the other end of the second shaft and that is filled with oil,   wherein the second shaft has a second axial hole that penetrates from the other end to the first axial hole along the axial direction, and   wherein the switching operation portion includes a seal member provided on an outer peripheral surface and configured to seal a gap between the switching operation portion and an inner peripheral surface of the first axial hole.   
     
     
         9 . The pump device according to  claim 2 ,
 wherein the switching member body has a substantially cylindrical pin shape, and   wherein the second driven gear has a recess formed in an inner peripheral surface thereof in a concave shape such that the switching member body is to be fitted.   
     
     
         10 . The pump device according to  claim 2 ,
 wherein the switching operation portion includes a small diameter portion and a large diameter portion that has a larger outer diameter than the small diameter portion,   wherein the small diameter portion and the large diameter portion are both formed at positions that face the switching member body by being continuous in an order of the large diameter portion and the small diameter portion with a distal end of the switching operation portion as a reference and being displaced, and   wherein the switching member body protrudes from the radial hole due to the large diameter portion abutting against the switching member body and is to be inserted into the radial hole when the small diameter portion is located at an inner periphery.   
     
     
         11 . The pump device according to  claim 2 ,
 wherein the switching operation portion includes a small diameter portion and a large diameter portion that has a larger outer diameter than the small diameter portion,   wherein the small diameter portion and the large diameter portion are both formed at positions that face the switching member body by being continuous in an order of the small diameter portion and the large diameter portion with a distal end of the switching operation portion as a reference and being displaced, and   wherein the switching member body protrudes from the radial hole due to the large diameter portion abutting against the switching member body and is to be inserted into the radial hole when the small diameter portion is located at an inner periphery.   
     
     
         12 . A ship propulsion machine including the pump device according to  claim 1 , the ship propulsion machine comprising:
 a ship propulsion machine body including a propeller;   a cylinder device including a cylinder, a piston configured to partition an inside of the cylinder into a first chamber and a second chamber, and a piston rod that has an end portion fixed to the piston and that extends from the cylinder; and   a tilt and trim device configured to extend and contract the cylinder device,   wherein the pump device is used in the tilt and trim device to supply a hydraulic fluid into the cylinder device.