FR2524944A1 - FLUID ACTUATOR - Google Patents

Abstract

THIS INVENTION CONCERNS A ROTARY ACTUATOR 10 WHICH INCLUDES A SHAFT 12 MOUNTED IN ROTATION IN A BODY 11 AND A SERVO-DISTRIBUTOR 13 AGENCY TO CONTROL A PALLET MOTOR 14 WHICH IS USED TO SELECTIVELY TURN THE SHAFT, A PART OF WHICH PROJECTS AT THE SHAFT. EXTERIOR OF THE BODY IN RELATION TO THE BODY. SUPPLY AND RETURN PASSAGES 15, 16, 19, 20 ARE FORMED IN THE BODY AND IN THE SHAFT SO THAT PRESSURIZED FLUID SUPPLIED TO THE BODY IS SUPPLIED TO THE DISPENSER AND ALSO TO THE PROJECTING END OF THE SHAFT . TWO OR MORE ACTUATORS MAY BE ASSEMBLED BY INTERMEDIATE SUPPORTS EQUIPPED WITH SUPPLY AND RETURN PASSAGES TO FORM A MULTIAXIS ACTUATOR OF THE "WRIST" TYPE WITHOUT PIPES OR EXTERNAL DUCTS.

Description

The present invention relates, in a general manner, to the field of

  actuators driven by an ifluide and it relates more particularly to a rotary actuator that can 9 be usefully used in a "poianet" actuator capable of moving around several axes. A rotary actuator driven by a fluid is,

  essentially, a device designed to convert a

  this fluid under pressure in a rotational movement of a

  Many forms of such ac-

  have already been realized It is also known that a

  vo-electro-hydraulic distributor can be used for

  control the movement of the tree by ra Dpo-t to the body.

  In recent years, a growing interest

  It has been brought to the development of robots for the execution of mechanical acts, for example, on automobile assembly lines and the like. Such robots have been designed with degrees of freedom comparable to those of the joints of the members of the body. The man's wrist, for example, is

  capable of rotational movement around three axes

  between them and it can be selectively posi-

  tion by the extension or retraction of the arm of the per-

  The desire to make good robots has led to

  born a concomitant desire to achieve simulating actuators

human joints.

  Previous attempts to achieve

  such robots and actuators are represented in the

  United States of America: N 3 984 009; 3,739,023; 2,861,701;

  4,096,766; 4,062,455; 2,528,464; 3,954,188; 3,543,910;

  3,454,169; 2,629,876; 3,605,474 and 2,422,530.

  The present invention relates to a rotary actuator

  tative and a multi-axis actuator resembling

  wrist use, in which the supply, return and control fluid lines are all internal passages instead of

  made using external pipes and pipe fittings.

  According to one of its aspects, the invention has,

  general purpose, an improvement to a rotary actuator which comprises a body, a shaft mounted to rotate relative to the body and before a portion disposed to

  the inside of the body and another part arranged externally

  of the body, a dispenser having a

  arranged to be supplied with fluid at a feed pressure of

  nentation and selectively operable to provide a

  control and a motor that receives the pressure of com-

  and which serves to urge the shaft to rotate relative

  to the body The improvement includes a passage of food

  formed in the body and extending between a

  first step to receive the supply pressure, the dis-

  tributor and an outlet supply port that opens

  on one surface of the outer part of the tree, such

  that the pressurized fluid supplied to the body inlet port is supplied to the dispenser and is also supplied to the outer portion of the shaft at a location beyond the

body.

  According to another aspect, the subject of the invention is an improved actuator which comprises at least one rotary actuator having a servodistributor, a body, a shaft mounted to rotate relative to the body and having a portion disposed

  inside the body and another part arranged on the outside.

  a motor associated with the servo-distributor and serving to urge the shaft to rotate relative to the body and a feed passage that communicates an inlet formed on the body with the servo-distributor and with a outlet orifice formed on the outer part of the shaft, and a support member fixed to the outer part of the shaft so as to rotate with it, the support member being provided with an internal feed passage which communicates with the outlet port of the shaft, and an outlet port being formed in the support member such that the pressurized fluid supplied to the inlet port of the body is supplied to the orifice

output of the support member.

  Another object of the present invention is to provide an improved rotary actuator having a labyrinth of communicating internal passages such that supply pressure supplied to an inlet port of the body is transmitted to the dispenser and a transfer port located therein. on the interface surface between the body and the shaft, the shaft being provided with an internal passage which connects the transfer port to an outlet port formed on the outer portion of the shaft; performing an improved rotary actuator having another labyrinth of internal passages such that the return fluid supplied to an inlet port of the shaft beyond the body, in combination with the fluid

  returned from the distributor, is available at a

  return of the body; providing an improved rotary actuator which is particularly adapted for use as part of a "wrist" actuator capable of pivoting movement about any one of three mutually perpendicular axes; to make a "wrist" actuator comprising

  three rotary actuators, each of which contains a servo-dis-

  tributor and an engine in such a way that the three

  connected by two intermediate support members, the feed and return ports of the

  three servo-distributors are mounted hydraulically in

  and without the need to use

  external feeding and return to the device.

  Other features and advantages of the invention

  will emerge from the following description given in

  As a non-limitative example, and with reference to the

nexes on which:

  FIG. 1 is a vertical longitudinal sectional view

  shim of the improved rotary actuator but showing the servodistributor in elevation; Fia 2 is a horizontal sectional view of the actuator, this view being taken approximately following

  line 2-2 of FIA 1, looking in the direction of the

on the top of the body;

  the Fia 3 is a vertical cross-sectional view

  actuator shim, taken approximately as

  -ne 3-3 of the Fia l and looking in the direction of the arrows;

  Fic 4 is an exploded view of the actuator re-

  shown in FIG. 1, this view being used primarily

  in order to identify its structure without obscuring the view of the assembled actuator by an overabundance of lines and reference numerals;

  the Fia 5 is a perspective view of an action-

  neur "wrist" using three of the rotary actuators

  and two support members; Fig 6 is a view of the "wrist" actuator shown in Fig 5 but showing the "wrist" actuator

  as it occurs when deployed in the "flattened" state.

  First of all, it must be clearly understood that the same reference numerals are uniformly used to designate the same elements, structure or surfaces in

  all the figures in the drawings, since such

  elements, structure or surfaces may be more fully described or explained by the whole of the specification

  this detailed description is an integral part of the

  where they are used here, expressions such as "left", "right", "high", "low" and the like are oriented

  compared to the figure in the drawing as

facing the reader.

  Advanced Rotary Actuator (Fig 1-4) As shown in Figs. 1 to 4 to which reference will now be made, the object of the invention is, according to one of its aspects, an improved rotary actuator whose presently preferred embodiment has been appointed by

the general reference 10.

  The rotary actuator 10 is shown as a

  generally speaking, a body assembled, designated

  as a whole by the general reference 11, a

  shaft 12 rotatably mounted relative to the body, a servo

  distributor 13 and a motor 14 of the pallet type (Fig 3).

  operatively mounted so as to urge the shaft

to rotate relative to the body.

  The improvement achieved according to the invention is

  centered around the realization of food passages

  communicating 15, 16, respectively in the body and in the shaft, so that the supply pressure supplied to an inlet 18 of the feed passage

  of the body by any external source not representative

  is supplied to the distributor and is also made available at the distal end of the shaft for

  described below Preferably, these feed passages

  are accompanied by return passages from the shaft and the communicating body 19, 20, which serve to convey

  a flow of return fluid from the distribution

  and / or the distal end of the shaft to a

  outlet port 21 of the return passage through the body.

  The structure of the action will now be described.

  improved rotational neuron with particular reference to

  to the exploded view of Fig 4.

  Body 11 As more particularly shown in FIG. 4, the body is formed by a suitable assembly of a left part or element 22, a part or element

  intermediate 23 and a straight part or element 24.

  The left element 22 of the body is represented as

  including among other things; a straight vertical face

  planar wedge 25, from which an annular recess of large diameter penetrates to the left in the left element to reoewir an O-ring 26; a vertical left face awn, 1 opposite area 28 from which N is circularly evident extends to the right in the left element to receive

  an O-ring 29; and a through bore having a

  special representation which makes the

  these end and which includes, in the appropriate locations

  (from left to right in Fig 4) a part 30

  secondly threaded which extends to the right from the left face 28, an annular chanbraae 31 extending inwardly, a vertical annular shoulder 32 oriented to the left and a cylindrical bore 33 which extends to the right from the shoulder to join the right side 25.

  A bearing assembly 34 is mounted in the

  left with its right side arranged adjacent to the shoulder-

  32 and its outer bearing baaue 35 bears against the cylindrical surface facing inwards

  The inner bearing bay 36 of the wheel

is mounted on the shaft 12.

  An annular left end cap 38 is

  The end cap 38 has an annular right face 39 resting against the left face

  of the bearing assembly 34, it comprises a part 40 ex-

  laterally threaded and adapted to be screwed into the internally threaded portion of the element which extends towards the

  left from this left face and it has an over-

  annular vertical face 41 oriented to the right arranged

  in order to come into compression support against the tori-ring

  that 29 and abut against the left side 28 of the ele-

  left 22 An annular shoulder extends to

  the inside of the end cap from its cy-

  the inward facing 42 and its right face 39 to receive an annular seal 43 having a

  cross-section approximately C-shaped The sur-

  cylindrical face facing towards the inside of the gasket

  Cheetah 43 is in frictional abutment on the shaft 12.

  The intermediate portion 23 of the body is shown as having a flat vertical left face 44 arranged to compress the O-ring 26 and to abut against the right face 25 of the left element, a

  flat vertical straight face 45 and a horizontal upper face

  plane 46 against which the servo-distributor is mounted.

  The intermediate element also has a 3-step traversal.

  having a particular configuration which has an aspect a> -

  proximally C-shaped, seen in cross section (Fic 3).

  More precisely, this through bore is limited by a segment

  In this case, a relatively large diameter extends over an arc of about 280, a cylindrical surface 49 of smaller diameter which extends over an arc of about 600, and flat surfaces 50. and 51 that connect

  symmetrically between them these surfaces.

  The intermediate body furthermore comprises a se-

  In particular, a horizontal hole 52 extends through the intermediate body over its through bore and this hole is intersected by a hole 53 which is extends downwards from the upper surface 46 of the intermediate body the trunks 52 and 53 form through the body part of the return passage 19 If desired, the hole 52 of the body can communicate with an aligned hole 54 formed in

  the left side of the body to relieve pressure in the

  A horizontal hole 55 extends towards the left

  in the intermediate body from its right face and this hole is intersected by a hole 56 which extends downwards from the upper surface 46 The holes 55 and 56

  are part of the feed passage 15 of the body.

  The right part 24 of the body involved

  a plane vertical left surface 58 from which an

  annular element of relatively arand diameter extends to the right in said element to receive an O-ring

  59; ur: opposite straight vertical plane face 60 and

  flat horizontal upper and lower faces 61 and,

  The right face 45 of the intermediate body is arranged in such a way as to bear in compression against the gasket 59 and abut against the left face.

  of the right body The right body is also equipped with

  passing through limited by a cylindrical surface 63 oriented

  towards the inside and which has an annular recess

  tenard: vcrs the outside in the body to receive an elastic annular seal 64 whose cylindrical surface oriented inward is in support soft friction

on the tree 12.

  The right body is provided with a series of holes and

  recesses which form continuities of food passages

  mentation and return 15, 19 of the body More precisely, a

  horizontal hole 65 extends into the body from the ori-

  18 and this hole is intersected by a hole 66 which extends upwards from the lower surface 62 to intersect an annular recess 68 which surrounds the bore, and continues beyond a horizontal hole 69, aligned with hole 55 of the intermediate body extends into the body

  right from his left side to intersect the extension

  hole 66 The hole 66 is tapped between the inside surface

  62 A horizontal hole 71 extends to the left in the right body from the outlet port 21 and is intersected by a hole 72 which extends down from the upper surface 61 of the body to intersect

  an annular recess 73 which surrounds the bore at a location

  axially spaced from the recess 68 Hole 72 is

  raudé between the upper surface 61 of the body and the hole 71 for receiving a closure plug 74 A horizontal hole aligned with the hole 52 of the intermediate body extends

  in the right body from his left side 58 for inter-

to seize the hole 72.

  c The three body parts are assembled

  between them as shown in Fig 1 and they are now

  held in this position by means of four bolts which have all been designated by the same reference 76 (Fig 2 and 3) The assembled body is thus provided with a feed passage 15

  which has the inlet port 18, the holes 65 and 66, the

  ring 68, the extension of hole 66 and the holes

  69, 55 and 56 The return passage 19 of the body comprises the

  21, the holes 72 and 2, the recess 73 and the holes 75, 52, 53 (and the hole 54, if used) The holes 56 and 53 open on the upper surface 46 of the intermediate body to form respectively aligned orifices

  with the feed and return ports (not shown

  13) Thus, the passage of feed-

  the body is arranged to transmit the pressure of

  supplied to the inlet port 18 by an external source (not shown) at a location of the shaft and

  the alumentation orifice of the servo-distributor 13 The passage of re-

  turn 19 of the body is arranged to transport the fluid to

  firing from the return port of the dispenser, the chamber con-

  holding the bearing 34 (if the hole 54 is provided) and another

  location of the shaft to the outlet 21.

  Shaft 12 Shaft 12 is a horizontally elongated member which has an outer surface with stepped diameters and which is mounted

  functionally in the bore of the body

  door: an annular vertical left end face 78 disposed outside or outside the body; an annular vertical straight end face 79; and an outer surface that

  has (from left to right in Fig 4) a cylindrical surface

  80 which extends to the right from the left

  78, an annular groove 81, a ring protuberance

  having an annular vertical shoulder 82 oriented towards the left

  an annular groove 83, an annular vertical shoulder

  left-sided rest 84 rotatably pressing against the

  this line 25 of the left element of the body, a cylindrical surface

  drioue 85 mounted a rotation against the arcuate surface 49 of

  the intermediate element of the body (Fig 3), a vertical shoulder

  86 of the right-hand element of the body, an annular groove 83 and a cylindrical surface 89 extending to the right from this groove to join the

right side 79.

  The shaft is shown to be provided with feed and return passages 1. The feed passage 16 of the shaft has a horizontal hole 90 extending into the shaft from its left end face. 7 th The left marginal end portion of hole 90 can be threaded

  to receive a closure cap 91 The hole 90 is in-

  tersected, inside the body, by a radial hole 92 aliané with the annular figure 6 F and, outside the body, by

  a radial hole 93 adjacent to the left end face 78.

  The return passage 20 of the shaft has a horizontal hole

  94 to the right in the tree from its face of ex-

  left end 78 Left marginal end portion gaucho

  hole 94 is threaded to receive a plug 95 -

  The hole 94 is intersected, inside the body, by a hole 96 aligned with the annular recess 73 and, outside the body, by a hole 98 disposed adjacent to the end face.

  left 78 Thus, the feed passage 16 of the shaft com-

  has an inlet port that communicates with the inlet port

  of the body feed pass and is arranged to transport the fluid to a location (i.e.

  hole 93) of the shaft beyond the body.

  The shaft 12 is provided, in the vicinity of its left end, with a threaded hole 99 provided for receiving a screw of

  blocking (not shown) by means of which another structure

  further embodiment (not shown in Figs. 1 to 4) can be assembled to the shaft so as to rotate with it.

  preferred embodiment, a position sensor of

  itation, designated by the general reference 100, is mounted on the right part of the body and is connected to the shaft by a splined shaft 101 This sensor is arranged to detect the angular position of the shaft relative to the body and to produce an electrical feedback signal indicative

such a relative position.

  The combination of a rotary cylinder having a

  rotatably mounted relative to the body and a motor

  to urge the tree to rotate relative to the body, a ser-

  vo-distributor arranged to control the power of energy

  engine fluidity and a counter-reaction sensor to de-

  detect the annular position of the tree in relation to the body

constitutes a servo rotary actuator.

Distributor 13

  The distributor 13 is preferably a servo-dis

  electrohydraulic tributor which has a feed hole

  the delivery (not shown) which communicates with the hole 56 and a return port (not shown) which communicates with the hole 53 The distributor 13 also has two orifices

  C 1 and C 2 which communicate with the bore of the element

  medium through holes 102 and, respectively, 103

  (Fig 2 and 3) Since the dispenser is individual-

  "old" in this technique, it will not be described

  in a detailed way It is sufficient to indicate here that the dis-

  tributor 13 is supplied with fluid under pressure through the

  medium of the feed passages of the body and the shaft, that it communicates with the return orifice via

  return passages from the body and the tree and that it is se-

  respectively driven by an electrical control signal to produce a differential fluidic control of a polarity

  or the other between the orifices C 1 and C 2.

Engine 14.

  As more particularly shown in FIG. 3, a pallet 104 extends radially beyond the surface 85 of the shaft and is in sealing abutment against the surface 48 of the body. The pallet thus displaces the intermediate portion of the body.

  in a first chamber 105 arranged to be powered

  control pressure through the orifice C of the distributor and through the hole 102 and a second chamber 106

  supplied with control pressure through port C and by -tin-

  The difference between the pressures of

  control C 1 and C 2 which act on the opposite sides of the

  lette selectively urges the shaft to rotate in one or

* the angular difference in relation to the body, depending on the

  1 C rity of differential pressure between ports C 1 and C 2.

  Operation of the rotary actuator l C

  In the improved rotary ram, labyrinthine

  interconnected feed passages serves to connect the o-

  inlet port 18 from the body to the supply port (no

  shown) and a transfer port

  tapered by the annular cavity 68 and the hole 92 in the shaft, therefore, to the outlet port 93 of the shaft.

  transfer serves to maintain the transmission of the pressure of

  supply to the outlet of the shaft over the entire sector in rotation of the tree In the same way,

  the communicating return passage connects the

  turn 21 of the body to the return port (not shown) of the

  distributor and at the return inlet port 98, by the

  Therefore, the available fluidic energy between the feed ports and

  back 18, 21 of the body is always supplied to the servo-distri

  scorer and at the end of the shaft located beyond the body regardless of the angular position of the shaft by

  This last characteristic is considered

  particularly advantageous because the

  fluid supply is made available so that it can be

  be used to provide motor energy to another

  any canism (not shown in Figs 1 to 4) that can be attached to the end of the shaft At the same time, the feed and return passages are formed inside

  body and the tree and avoid the need for

read external flexible hoses.

  Modifications of the rotary actuator 10

  The present invention contemplates that many changes

  agements and modifications may be imported to the rotary jack, it being understood that the embodiment shown,

  although currently preferred, represents only one example

  possible that the claims are intended for

  For example, it is not necessary that the body is invariably constituted by a segmented construction in three parts and it is not necessary that the

  various coins always have the same form or function

  tion than in the preferred embodiment Although it is

  preferred that the distributor be an electric servo-distributor

  it is possible to mount other types of distributors directly on the body and the shaft can also have a different shape. In addition, the transfer orifices between the body and the shaft can be made in various forms. various such as annular cavities formed on the shaft communicating with holes formed in the body or cavities and / or holes formed in the end surface of the shaft which would communicate with each other, by

  via an interface surface formed between the

  The construction or assembly process is not considered critical and can be easily changed. For example, the various holes can be molded or

  formed in another way instead of being pierced.

  motor and / or receiver mechanisms may be used for

  position of the single pallet motor of the preferred embodiment

  The advanced actuator can be powered with various

  fluids under pressure (ie, liquids or gases)

  In some applications, it may not be necessary to

  see return passages as this is the case when the dispenser or other fluid-controlled device is

  Caused directly to the atmosphere The striking feature

  of the invention is to provide a rotary actuator perfected

  in which the fluid under pressure supplied to the body

  is transported to the distributor and also in the

  and beyond the body so as to be available for

  driving energy to an appropriate device or mechanism

mounted on the tree.

  Wrist actuator 110 (Figs 5 and 6) The improved rotary actuator 10 so far described

  can advantageously be used in a "push" actuator.

  -1 Ggnet "perfected, designated by the general reference 110

in Figs 5 and 6.

  The "wrist" actuator 110 is shown as comprising a first lower rotary cylinder 10A, a second intermediate rotary cylinder 10B and a third upper rotary cylinder 10C. The output shaft 12A (FIG. 6) of the first cylinder is arranged vertically in FIG. 5 A base 111 of a first U-shaped first support member, designated by the general reference numeral 112, is attached to the output shaft of the first actuator, with its left and right arms 113, 114 surrounding the body The base 115 (FIG. 6) of a second, approximately U-shaped, support member designated by the general reference 116 is nested on the body of the third cylinder 10 C and its right arm 117 is fixed to the second cylinder. output shaft 12 B of the second cylinder The left arm

  118 of the second support member has its marginal end portion

  The first cylinder 1 OA can be mounted on a suitable object (not shown) such as

  the end of a mobile robot arm As more

  first shown in FIG. 6, the selective operation of the first jack IOA rotates the first support member

  112 around the axis of the shaft of the first cylinder The third

  10 C cylinder can be selectively manipulated to provoke

  The output shaft 12 C of the third cylinder is designed so that a tool (not shown) or a suitable part (not shown) can be rigidly attached to it. The first and second cylinders

  A, l OB are used to position the output shaft of the third

  sth cylinder relative to an object.

  An original feature of the "push" actuator

  "110 is the way in which the feed orifices

  of the three servo-distributors are hv-

  hydraulically mounted in Daralléie this way to avoid it itself: necessary to use external pipes which could,

  otherwise, hinder the movements of the articulation of the action-

  neur "wrist" or be excessively fatigued by such

vements.

  As we have previously described, the passages of

  The feedback and return ports communicate the inlet and return ports (18, 21 in Figures 1 to 4) respectively with the outlet and return ports (93, 98 in FIGS.

  4) of the tree Thus, the supply of motive power fl u-

  between the holes in the body is available at the end

of each tree.

  The first support member 112 is rigidly fixed to the first shaft by means of a locking screw 120 received in the hole 99 of the shaft and the second support member is rigidly

  attached to the second shaft by means of a similar locking screw.

  The first support member comprises a pair of passages of

  horizontal feeding and return 121 and 122 respectively that extend to the right in the base 111 so as to communicate respectively with the feed orifices

  and return 93, 98 of the shaft The left marginal ends

  these passages 121, 122 of the base of the first

  port are closed by appropriate plugs 123, 123

  pair of feed and return passages 124, 125-

  tending downwards within the left arm 113 of the first

  the first support organ so as to intersect the passages of

  feed and return from the base The ends of these pas-

  saoes can be closed with sealing plugs

  properties which are all also designated by the reference

  123 These passages 124, 125 of the arm communicate with the

  Supply and return valves 155, 21 B of the second rotary valve. In the same way, the second member Dport 116 includes internal feed and return passages

  126, 12 S in its base 115 and in its arm 117 yes make

  connect the supply and return ports 93, 98 E of 1 (the arore of the second rotary cylinder respectively with the supply and return ports 18 C and 21 C of the body of the

trolling rotary cylinder.

  Thus, the supply and return ports of the

  three servo-distributors are mounted hydraulically in

  by means of a labyrinth of internal passages

  The feed pressure supplied to the orifice of

  18A of the body of the first rotary actuator is transmitted via the first support member to the supply port 18 B of the second rotary cylinder and

  it is also provided through the second or-

  gane support at the 18 C supply port of the third

  In the same way, the return fluid pro-

  from the return port 21 C of the third cylinder is

  transmitted via the second support member to the original

  fice back 21 B of the second cylinder and it is then

  transmitted through the first support organ to the o-

  return port 21 A of the first cylinder Each servo-dis-

  It can be operated independently of the others to articulately move the "wrist" actuator in the desired manner. In this manner, the improved "wrist" actuator avoids the need for the use of external hoses to provide the necessary connections. supply and return of each servo-distributor It should also be noted that each rotary actuator of the three-wrist set

  The axes of FIG. 5 can be equipped with a posi-

  1, rotation, as indicated in the references 100 A, 1005, ICXC so that the wrist movement is performed at

  means of multi-axis rotational position servo-cylinders.

  Modifications of the "wrist" actuator 110 As in the case of the rotary jack, it is contemplated that many changes and modifications can be made. Although the preferred embodiment is shown as three rotary cylinders and two intermediate support members, we can use a number

  superior or inferior Or can easily replace the

  specifically described by other Roman actuators

  The stresses of the support members may be similar.

  modified, for example, to establish communication with the replacement orifices formed on the shaft end faces. Various further modifications and mocifications can be made to adapt the apparatus to the application.

particular final envisaged.

  Therefore, although presently preferred embodiments of the improved rotary and wrist cylinders have been described and

  describes several modifications of each of them, the specialists

  technicians will expect that various changes and

  additional modifications can be made without

  firing from the scope of the invention as defined and specified

in the appended claims.

Claims (16)

R E V E N D I C A T IO N S   Rotary actuator (10) having a body (11), a shaft (12) rotated relative to the body and having   a first part arranged inside the body and a second   a portion (13) disposed outside the body having a supply port (18) adapted to receive a supply pressure and selectively driven to provide a control pressure and a motor (14) which receives a supply pressure; control pressure and which serves to urge the shaft to rotate relative to the body, characterized in that it comprises: a feed passage (16) of the body formed in the body, extending between the orifice of an inlet (18) arranged to receive a supply pressure, the dispenser feed port, and a feed transfer port (68, 92) exposed on a surface of said first shaft portion; and a shaft feed passage (90) formed   in said shaft and extending from the transmission port   to an outlet (93) leading to an over- face of the second tree part;   in such a way that the supply pressure   denies the body's entry port is also provided to the-   said second tree part at a location outside the in the body.   Rotary actuator according to claim 1,   characterized in that said transfer port is formed by an annular chamber (68) surrounding the shaft (12) so as to maintain communication between the body inlet (18) and the outlet (93) of the tree regardless of   the angular position of the shaft relative to the body.   Rotary actuator according to claim 1,   characterized in that the surface of the second shaft portion is   an end face of said shaft (12).   Rotary actuator according to claim 1,   characterized in that the surface of the second shaft portion is   the circumferential surface of the tree.   Rotary actuator according to claim 1, characterized in that the distributor (13) is selectively controllable to provide differential fluid control between said control pressure and a second pressure.   control, said differential fluid control being   motor (14) so that the shaft (12) can be   licit to turn in one or the other direction relative to the body   (11) in response to the polarity of the different control pressure -competitive.   Rotary actuator according to claim 5,   characterized in that the motor (14) is a motor of the type lette (104).   Rotary actuator according to claim 1,   characterized in that the dispenser comprises a recess hole   turn and in that it includes, in addition: a return passage   (94) extending between an inlet port (98) de-   clogging on a surface of the second tree part and an onr-   return transfer member (96) opening into a surface of the first shaft portion at a location spaced from the pressure transfer port and a return passage (19) of the body formed in the body and extending between the transfer port   the return orifice of the distributor (13) and an opening   this output (21) of the body, so that the motive power   fluid available between the body inlet and the opening   body exit fice is provided to said dispenser and is also provided to the second shaft portion at a location located outside the body.   Rotary actuator according to claim 7,   characterized in that the dispenser is a servo-distributor electro-hydraulic (13).   9 Actuator assembly characterized in that   comprises: a first actuator (1 OA) having a first distribution   scorer, a first body, a first shaft (12A) rotatably mounted   with respect to the body and having a first portion disposed within the first body and a second portion disposed outside the body, a first motor associated with the first valve and serving to bias the first shaft to rotate.   relative to the first body, and a feed passage   communicating a shaped inlet port on the first body with the first manifold and with an outlet port formed on the second portion of the first shaft and a first support member (112) rigidly attached to the second portion of the first shaft so as to turn with   it, the first support member being provided with a feed passage   an arrangement (121, 124) extending between an inlet port in communication with the outlet port of the first shaft and an outlet port; such that pressurized fluid supplied to the inlet port of the first body is supplied to the port of output of the first support member.   Actuator assembly according to claim 9,   characterized in that it comprises, besides a second action-   neur (1 OB) having a second distributor, a second shaft (12 B)   rotated relative to the second body and having a   first part arranged inside the second body and a second   a second motor arranged on the outside of the second body, a second motor associated with the second distributor and serving to urge the second shaft to rotate by R Dport to the second body and a second supply passage communicating an inlet formed on the second body with the second distributor and with   an outlet orifice formed on the second part of the second arm   bre, the second body being mounted on the first support member with the inlet of the second body in communication with the outlet of the first support member; in order to   that the pressurized fluid supplied to the inlet of the first   first body is supplied to the second distributor and to the second part of the second tree.   11 actuator assembly according to claim 10, characterized in that it further comprises: a second support member (116) rigidly fixed to the second portion of the   shaft (123) so as to rotate with it, the second member   port being provided with an internal feed passage (126)   extending between an inlet port in communication with the ori-   output of the second shaft and an outlet, of such   so that the pressurized fluid supplied to the orifice of   first body is supplied at the exit port of the second support member.   Actuator assembly according to claim 11,   characterized in that it further comprises: a third ac-   (OCC) having a third distributor, a third shaft (12C) rotatably rotates to the third body and before a first portion disposed within the third body and a second portion disposed outside the third body. body, a third motor associated with the third distributor and serving to urge the third shaft to rotate relative   third body and a third supply passage   communicating an inlet port formed on the third body with the third distributor, the third body being mounted on the second support member with the inlet port of the third body in communication with the outlet port of the   second support member; so that the fluid under pres-   supplied to the inlet port of the first body is provided to the third distributor.   Actuator assembly according to claim   characterized in that the axis of the second shaft (12 B) is   proximally perpendicular to the axis of the first shaft (12A).   Actuator assembly according to Claim 12,   characterized in that the axis of the third shaft (12 C) is appro-   approximately perpendicular to the axis of the second shaft (12 B).   Actuator assembly according to the claim   12, characterized in that the axis of the second shaft (12 B) is   proximally perpendicular to the axis of the first shaft (12 A)   and in that the axis of the third shaft (12 C) is approximate-   perpendicular to the axis of the second shaft (12 B).   The actuator assembly of claim 12, characterized in that the second support member (116) is provided with an internal return passage (128) between an inlet port in communication with an exit port of the third body. and an outlet port; such that the return fluid from the third distributor is supplied to the orifice output of the second support member.   Actuator assembly according to Claim 16, characterized in that the second actuator 10 C) is provided with a   passageway having an inlet formed on the second   a portion of the second shaft (12 B) in communication with the outlet port of the second support shaft (116) and in communication with the second distributor and with an outlet port formed on the second body; so that the return fluid from the second and third distributors is supplied to   the outlet orifice of the second support oraane.   Actuator assembly according to Claim 17, characterized in that the first support member (12) is   provided with an internal return passage (122, 125) extending   be an inlet port in communication with the outlet aperture   second body and an outlet, so that   that the return fluid from the second and third dis-   tributers is provided at the outlet of the first support member. An actuator assembly according to claim 18, characterized in that the first actuator (1 OA) is provided with a return passage having an inlet port formed on the second portion of the first shaft (12A) in communication with   the outlet of the first support member (112) and in   communication with the first dispenser and with an outlet port formed on the first body, such that the fluid   from the first, second and third   is provided at the outlet of the first body.   Actuator assembly according to claim 9, characterized in that it comprises a first position transducer (100A) operatively mounted between the first body and the first tree (12 A).   21 actuator assembly according to claim 10, characterized in that it comprises a second position transducer (100 A) operatively mounted between the second body and the second shaft (12 B).   Actuator assembly according to claim 1, characterized in that it comprises a third transducer   position (100 C) mounted operationally between the third   sth body and the third tree (12 C).