Rotating fluid machine

Abstract

At a contact point, a spherical projecting portion of a piston presses a spherical recessed portion of a swash plate due to a working medium supplied to an operating chamber. The contact point is located on a cross line, on which a plane including a center of curvature of the spherical recessed portion and an axis Ls of the swash plate intersects the spherical recessed portion. Therefore, even if the piston forcefully presses the swash plate, the spherical projecting portion and the spherical recessed portion at the contact point are prevented from slipping in a circumferential direction, a radial direction and the like. Thus, the phases of a rotor and the swash plate are prevented from being displaced and causing vibration and noise. A large side thrust is prevented from acting on the piston and causing heat due to twisting and sliding friction between the piston and the cylinder.

1 . A rotating fluid machine comprising: 
 a casing;    a rotor rotatably supported by the casing;    an axial piston cylinder group annularly disposed in the rotor to surround an axis of the rotor;    a swash plate rotatably supported on an axis inclined with respect to the axis of the rotor; and    a rotary valve for controlling supply and discharge of a working medium to and from an operating chamber formed between a piston and a cylinder of the axial piston cylinder group;    a spherical projecting portion formed at a tip end of the piston abutting against a spherical recessed portion annularly disposed in the swash plate to surround the axis of the swash plate;    the rotor being rotationally driven by a reaction force which the spherical projecting portion of the piston receives from the spherical recessed portion of the swash plate, the piston advancing by pressure of the working medium supplied to the operating chamber,    wherein a contact point at which the spherical projecting portion of the piston presses the spherical recessed portion of the swash plate is located on a cross line on which a plane including a center of curvature of the spherical recessed portion and the axis of the swash plate intersects the spherical recessed portion.    
   
   
       2 . The rotating fluid machine according to  claim 1 , wherein the contact point at a moment when the working medium is supplied to the operating chamber is located on the cross line.  
   
   
       3 . The rotating fluid machine according to  claim 2 , wherein the working medium is a compressible fluid.  
   
   
       4 . The rotating fluid machine according to  claim 1 , wherein the spherical projecting portion and the spherical recessed portion at the contact point are prevented from slipping in the circumferential direction and the radial direction.  
   
   
       5 . The rotating fluid machine according to  claim 4 , wherein a phase of the rotor and the swash plate are prevented from being displaced to cause vibration, noise and abnormal abrasion and seizure due to sliding friction and heat generation.  
   
   
       6 . The rotating fluid machine according to  claim 2 , wherein at a moment when the pressure of the working medium supplied from to the operating chamber increases, slip between the spherical projecting portion and the spherical recessed portion at the contact point is prevented.  
   
   
       7 . The rotating fluid machine according to  claim 1 , wherein the contact point wherein the spherical projecting portion of the piston abuts against the spherical recessed portion of the swash plate is an arc-shaped cross line for preventing slipping therebetween.  
   
   
       8 . The rotating fluid machine according to  claim 7 , wherein a side thrust is prevented from acting on the piston to avoid twisting and sliding friction between the piston and the cylinder to avoid abrasion and seizure.  
   
   
       9 . The rotating fluid machine according to  claim 1 , wherein the contact point is located on the cross line at the time of start of an intake stroke of the piston.  
   
   
       10 . The rotating fluid machine according to  claim 1 , wherein an axis of the rotor is inclined at a predetermined angle relative to the axis of the swash plate and wherein the piston cylinder group are located on an oval to be equidistantly positioned to surround the axis of the rotor.  
   
   
       11 . A rotating fluid machine comprising: 
 a rotor rotatably supported within a casing;    a plurality of pistons annularly disposed in the rotor to surround an axis of the rotor;    a swash plate rotatably supported on an axis inclined with respect to the axis of the rotor; and    a rotary valve for controlling supply and discharge of a working medium to and from an operating chamber formed between a piston and a cylinder of each of the plurality of pistons;    a spherical projecting portion formed at a tip end of the piston abutting against a spherical recessed portion annularly disposed in the swash plate to surround the axis of the swash plate;    the rotor being rotationally driven by a reaction force which the spherical projecting portion of the piston receives from the spherical recessed portion of the swash plate, as each piston advances in reaction to pressure of the working medium supplied to the operating chamber,    wherein a contact point at which the spherical projecting portion of the piston presses the spherical recessed portion of the swash plate is located on a cross line on which a plane including a center of curvature of the spherical recessed portion and the axis of the swash plate intersects the spherical recessed portion.    
   
   
       12 . The rotating fluid machine according to  claim 11 , wherein the contact point at a moment when the working medium is supplied to the operating chamber is located on the cross line.  
   
   
       13 . The rotating fluid machine according to  claim 12 , wherein the working medium is a compressible fluid.  
   
   
       14 . The rotating fluid machine according to  claim 11 , wherein the spherical projecting portion and the spherical recessed portion at the contact point are prevented from slipping in the circumferential direction and the radial direction.  
   
   
       15 . The rotating fluid machine according to  claim 14 , wherein a phase of the rotor and the swash plate are prevented from being displaced to cause vibration, noise and abnormal abrasion and seizure due to sliding friction and heat generation.  
   
   
       16 . The rotating fluid machine according to  claim 12 , wherein at a moment when the pressure of the working medium supplied from to the operating chamber increases, slip between the spherical projecting portion and the spherical recessed portion at the contact point is prevented.  
   
   
       17 . The rotating fluid machine according to  claim 11 , wherein the contact point wherein the spherical projecting portion of the piston abuts against the spherical recessed portion of the swash plate is an arc-shaped cross line for preventing slipping therebetween.  
   
   
       18 . The rotating fluid machine according to  claim 17 , wherein a side thrust is prevented from acting on the piston to avoid twisting and sliding friction between the piston and the cylinder to avoid abrasion and seizure.  
   
   
       19 . The rotating fluid machine according to  claim 11 , wherein the contact point is located on the cross line at the time of start of an intake stroke of the piston.  
   
   
       20 . The rotating fluid machine according to  claim 11 , wherein an axis of the rotor is inclined at a predetermined angle relative to the axis of the swash plate and wherein the plurality of pistons are located on an oval to be equidistantly positioned to surround the axis of the rotor.