High efficiency hydraulic machine with radial cylinders

Abstract

The hydraulic machine with radial cylinders ( 3, 4, 5, 6 and 7 ) comprises pistons ( 8 ) with radial stroke, arranged in contact with an outer cam ( 13 ) and coplanar with said group of cylinders, each equipped with a roller on the path ( 12 ) of said cam, and it has, in each piston ( 8 ), a rolling bearing ( 9, 10, 11 ), arranged with the inner ring coupled or coinciding with the pin ( 9 ) for supporting said roller ( 10 ) and the outer ring ( 10 ) coupled or coinciding with the roller ( 10 ) itself; moreover, it has the roller ( 10 ) and the corresponding rolling bearing ( 9, 10, 11 ) with a small size such as to also allow, in the alternating motion of the piston ( 8 ), introduction steps of said roller in the respective liner of the cylinder ( 3, 4, 5, 6 and 7 ). It comprises, in a further embodiment, in each piston ( 21 ), an anti-friction ferrule ( 23 ) placed in contact with the pin ( 22 ) or with an inter-positioned and coupled support element ( 25 ) for said roller ( 20 ); said ferrule being coupled with the inner diameter of the roller ( 20 ) itself. Finally, in a more complete embodiment, it comprises both the static and dynamic O-rings each consisting of a metal ring ( 28, 31 ) mounted with interference in the coupling on the sealing diameter (D) and housed in a throat ( 29, 36 ) with slight axial clearance.

1 ) A hydraulic machine with radial cylinders of the type comprising pistons with radial stroke, arranged in contact with an outer cam and coplanar with said cylinders, each equipped with a roller on a path of said cam, characterised in that it has, in each piston, a rolling bearing, arranged with a inner ring coupled or coinciding with a pin for supporting said roller and an outer ring coupled or coinciding with the roller itself.  
   
   
       2 ) A hydraulic machine according to the previous  claim 1 , characterised in that it has the roller and the corresponding rolling bearing with a small size such as to also allow, in the alternating motion of the piston, introduction steps of said roller in the liner of the cylinder.  
   
   
       3 ) A hydraulic machine according to the previous  claim 1 , characterised in that it has said rolling bearing of a so-called full complement type.  
   
   
       4 ) A hydraulic machine according to the previous  claim 1 , characterised in that it has said rolling bearing with rollers with an annular cage.  
   
   
       5 ) A hydraulic machine according to the previous claims  4 , characterised in that it has said bearing with the annular cage in the middle of the bearing.  
   
   
       6 ) A hydraulic machine according to the previous  claim 1 , characterised in that it has said bearing with the pin and the outer ring treated with setting heat treatments on steel of the type with minimised inclusions.  
   
   
       7 ) A piston for a hydraulic machine with radial cylinders with the pistons with radial stroke, as claimed in previous  claim 1 , arranged in contact with an outer cam and coplanar with said group of cylinders, equipped with a roller on the path of said cam, characterised in that it has said roller coupled in rotation with said piston with a rolling bearing.  
   
   
       8 ) A hydraulic machine with radial cylinders of the type comprising pistons with radial stroke, arranged in contact with an outer cam and coplanar with said cylinders, each equipped with a roller on a path of said cam, characterised in that it has, in each piston, an anti-friction ferrule placed in contact with a pin or with an inter-positioned and coupled support element for said roller; said ferrule being coupled with a inner diameter of the roller itself.  
   
   
       9 ) A hydraulic machine according to the previous  claim 8 , characterised in that it has said support element positioned between the pin and the anti-friction ferrule consisting of a spacer sleeve mounted with interference on said pin; an anti-friction surface of the ferrule is in sliding contact on an outer surface of said sleeve.  
   
   
       10 ) A hydraulic machine according to the previous  claim 8 , characterised in that it has said ferrule in planar iron material, wound inside said roller, on which there is a layer of anti-friction plastic material anchored in a stable way on it through a layer of sintered metal.  
   
   
       11 ) A hydraulic machine according to the previous  claim 10 , characterised in that it has the thickness of the support element in iron material of said bearing between 0.4 and 4% of the sliding diameter.  
   
   
       12 ) A hydraulic machine according to the previous  claim 8 , characterised in that it has thrust blocks at the sides of said roller resting upon shoulders of the piston, equipped with, at least one face, a layer of anti-friction plastic material and a sintered anchoring layer thereof.  
   
   
       13 ) A hydraulic machine according to the previous  claim 10 , characterised in that it has the thickness of said layer of anti-friction plastic material advantageously between 1 and 12 1/100 of a millimetre and the thickness of a sintered metal anchoring layer between 10 and 40 1/100 of a millimetre.  
   
   
       14 ) A piston for a hydraulic machine with radial cylinders with the pistons with radial stroke, as claimed in previous  claim 8 , arranged in contact with an outer cam and coplanar with said cylinders, equipped with a roller on the path of said cam, characterised in that it has said roller coupled in rotation with said piston with an anti-friction ferrule and relative support pin.  
   
   
       15 ) A hydraulic machine with radial cylinders of the type comprising pistons with radial stroke, arranged in contact with an outer cam and coplanar with said cylinders, each equipped with a roller on a path of said cam, characterised in that it has both static and dynamic O-rings each consisting of a metal ring mounted with interference in the coupling on a sealing diameter and housed in a throat with slight axial clearance.  
   
   
       16 ) A hydraulic machine according to the previous  claim 15 , characterised in that it has a large depth of said throat with respect to its width and that of the ring.  
   
   
       17 ) A hydraulic machine according to the previous  claim 16 , characterised in that it has the side shoulder of each O-ring with a width slightly greater than the depth of the throat.  
   
   
       18 ) A hydraulic machine according to the previous  claim 15 , characterised in that it has the roller supported by a pin with a rolling bearing, arranged with a inner ring coupled or coinciding with the pin for supporting said roller and the outer ring coupled or coinciding with the roller itself.  
   
   
       19 ) A hydraulic machine according to the previous  claim 15 , characterised in that it has the roller supported by a pin with a sliding friction bearing with an anti-friction ferrule, placed in contact with the pin or with an inter-positioned and coupled support element for said roller; said ferrule being coupled with a inner diameter of the roller itself.