Rotating actuator

Abstract

A rotating actuator includes a body and a shaft jointly defining at least one operating volume consisting of a an annular cavity compartmented by at least two partitions extending between two end surfaces of the cavity, one of the radial partitions being respectively borne by the shaft and the other by the body, and both partitions being provided on the opposite free edge thereof with a sealing element. The sealing element is extended in the direction of each end surface of the annular cavity up to each end surface, whereupon it extends into the connection area of the end surface and the body or, respectively, shaft. The sealing element is fitted is in the form of a continuous linear joint provided in kilometer length and can be cut up as it develops along one edge surface to another according to a loop-shaped trajectory.

1 . Rotary actuator ( 1 ) of the type composed of a body ( 2 ) and a shaft ( 3 ) delineating between one another at least one working volume, each working volume being composed of an annular cavity compartmented by means of at least two partitions ( 4 ,  5 ) extending between two surfaces ( 19 ,  20 ), the so-called end surfaces of said cavity, one ( 4 ) of these radial partitions supported respectively by the shaft ( 3 ), the other ( 5 ) by the body ( 2 ) of the actuator, these radial partitions ( 4 ,  5 ) by their free opposite edge equipped with packing ( 6 ), coming into watertight, sliding support contact, one ( 4 ) against the inside wall ( 2 A) of the body ( 2 ), the other ( 5 ) against the outside wall ( 3 A) of the shaft ( 3 ), in such a way as to form at least two chambers ( 7 ,  8 ) of variable volume capable of being pressurized alternately by intake of fluid to generate relative rotational displacement of the body ( 2 ) and of the shaft ( 3 ), characterized in that 
 each packing ( 6 ) that equips the free edge of a partition ( 4 ,  5 ) is lengthened in the direction of each end surface ( 19 ,  20 ) of the annular cavity as far as said surface in order to extend into the connecting zone between the end surface ( 19 ,  20 ) and the body ( 2 ) or shaft ( 3 ) respectively, this packing ( 6 ) that equips the shaft ( 3 ) or body ( 2 ) being present in the form of a continuous linear seal that is available in thousand meter lengths and that can be cut to length, to come to rest on the groove of the actuator that is shaped depending on the desired arrangement of the seal, this seal developing from one end surface ( 19 ) to the other ( 20 ) following a looped trajectory, closing of the loop being obtained at least by the ends of the strip comprising the seal being brought into contact.    
   
   
       2 . Rotary actuator ( 1 ) according to  claim 1 , wherein the packing ( 6 ) at the level of the free edge of each partition ( 4 ,  5 ) has the form of two axial branches extending from one end surface ( 19 ) to the other ( 20 ) so as to form a double sealing barrier.  
   
   
       3 . Rotary actuator ( 1 ) according to  claim 1 , wherein the closing of the loop formed by each packing ( 6 ) that develops from one end surface ( 19 ) to the other ( 20 ) following a looped trajectory is obtained by simple overlapping of the ends of the strip comprising the seal.  
   
   
       4 . Rotary actuator ( 1 ) according to  claim 3 , wherein the ends of the seal are bevelled to facilitate their overlapping.  
   
   
       5 . Rotary actuator ( 1 ) according to  claim 1 , wherein the packings ( 6 ) of the shaft ( 3 ) and the body ( 2 ) extend to the level of the end surfaces ( 19 ,  20 ) opposite one another and are separated from one another by a connecting strip ( 21 ) such as a collar or washer, comprising a sliding track of each of the packings ( 6 ) and thus preventing the packings ( 6 ) from rubbing against one another.  
   
   
       6 . Rotary actuator ( 1 ) according to  claim 1 , wherein the end surfaces ( 19 ,  20 ) are composed of a supported flange of the shaft ( 3 ), the packings ( 6 ) of the body ( 2 ) and of the shaft ( 3 ) extending at the level of said surfaces into a plane orthogonal to the shaft ( 3 ), the packing ( 6 ) of the shaft ( 3 ) being positioned on the periphery of said flange, preferably opposite the packing ( 6 ) that equips the body ( 2 ) of the actuator.  
   
   
       7 . Rotary actuator ( 1 ) according to  claim 1 , wherein the shaft ( 3 ) of the actuator ( 1 ) is provided somewhere over its length with at least one supported flange ( 15 ) that is integral with the partition ( 4 ) supported by the shaft for the purpose of limiting the risks of buckling of the latter, this flange ( 15 ) dividing the body ( 2 ) into two working volumes and comprising one end surface of each working volume, said working volumes communicating between other another via openings ( 16 ) arranged in said flange ( 15 ).  
   
   
       8 . Rotary actuator ( 1 ) according to  claim 1 , wherein the part of the packing ( 6 ) turned toward a part of the actuator, such as the partition ( 4 ,  5 ), body ( 2 ) or shaft ( 3 ) with which it is integral, is capable of being exposed during operation of the actuator to a thrust force (F) that tends to keep the so-called active part of the packing ( 6 ) pushed against the wall of the body ( 1 ) or of the shaft ( 3 ) with which it is in sliding support contact.  
   
   
       9 . Rotary actuator ( 1 ) according to  claim 8 , wherein the thrust force (F) is applied via pressurized fluid that is brought into contact with the packing ( 6 ), this pressurized fluid being composed of the fluid that feeds chambers ( 7 ,  8 ) of the actuator ( 1 ).  
   
   
       10 . Rotary actuator ( 1 ) according to  claim 9 , wherein the pressurized fluid that is intended to apply a thrust force (F) to the packing ( 6 ) feeds a chamber ( 9 ), the so-called pressure chamber of the packing ( 6 ), which is arranged between the packing ( 6 ) and the part of the partition ( 4 ,  5 ) that acts as the seat for said packing ( 6 ), this chamber ( 9 ) extending preferably over the entire length of the packing ( 6 ).  
   
   
       11 . Rotary actuator ( 1 ) according to  claim 10 , wherein the pressure chamber ( 9 ) of the packing ( 6 ) is supplied with fluid via a line ( 10 ,  11 A,  11 B) that communicates selectively with one or the other of the chambers ( 7 ,  8 ) of the actuator depending on the pressure that is prevailing within said chambers ( 7 ,  8 ).  
   
   
       12 . Rotary actuator ( 1 ) according to  claim 11 , wherein the fluid feed line from the pressure chamber ( 9 ) of the packing ( 6 ), arranged in a partition ( 4 ,  5 ), comprises a first segment ( 11 A,  11 B) that establishes communication between the chambers ( 7 ,  8 ) of the actuator, this first segment ( 11 A,  11 B) ending in a second fluid feed segment ( 10 ) from the pressure chamber ( 9 ) of the packing ( 6 ), the first segment ( 11 A,  11 B) being equipped with a closing element ( 12 ) that can move depending on the pressure prevailing within the chambers ( 7 ,  8 ) of the actuator ( 1 ) in order in turn to close the part ( 11 A or  11 B) of this first segment extending between the chamber ( 7 ,  8 ) of the actuator under pressure and the discharge ( 13 ) of this first segment into the second segment ( 10 ).  
   
   
       13 . Rotary actuator ( 1 ) according to  claim 12 , wherein the closing element ( 12 ) is a ball valve ( 14 ) whose ball ( 14 ) can move between two end positions extending on either side from the discharge ( 13 ) of the first segment ( 11 A,  11 B) into the second segment ( 10 ).  
   
   
       14 . Rotary actuator ( 1 ) according to  claim 2 , wherein the movable closing element ( 12 ) is equipped with two radial elements that project through the inlets of the first segment to extend into the first or into the second chamber of the actuator, these projecting elements comprising end-of-travel stops for the actuator in the vicinity of the end positions of said radial partitions.  
   
   
       15 . Rotary actuator ( 1 ) according to  claim 2 , wherein the closing of the loop formed by each packing ( 6 ) that develops from one end surface ( 19 ) to the other ( 20 ) following a looped trajectory is obtained by simple overlapping of the ends of the strip comprising the seal.  
   
   
       16 . Rotary actuator ( 1 ) according to  claim 3 , wherein the movable closing element ( 12 ) is equipped with two radial elements that project through the inlets of the first segment to extend into the first or into the second chamber of the actuator, these projecting elements comprising end-of-travel stops for the actuator in the vicinity of the end positions of said radial partitions.