FR2570067A1 - Rotary valve e.g. for medical fluids - Google Patents

Abstract

A rotary valve includes a rotor having at least one internal flow passageway extending between ports for providing communication between various pairs of flow passageways in the body of the valve. The rotor includes an annular surface for sealing engagement with the body, at least one of the rotor ports being disposed on the annular surface.- A continuous resilient seal is disposed between the sealing surfaces of the rotor and the body to provide static and dynamic sealing. A spherical surface disposed between the rotary drive and the rotor applies axial pressure to the rotor, the surface accommodating rocking of the rotor to insure uniform loading thereof. Loading of the seal between the rotor and body is adjustable externally of the valve

Description

FRENCH REPUBLIC Publication no .: 2,570,067 (to be used only for

  NATIONAL INSTITUTE reproduction orders) OF INDUSTRIAL PROPERTY National registration number: 84 13808 PARIS

  Int CI ': B 67 D 5/34, 5/10.

@ PATENT INVENTION APPLICATION Al

  (Filing date O: September 7, 1984. Applicant (s): ANGAR SCIENTIFIC COMPANY INC -

us. (> Priority:

(Inventor (s): Joseph Baker.

  (Date of public availability of the

  application: BOPI <Patents i n 1i1 of March 14, 1986.

  (References to other national documents appearing

  r'entés: rnéQ Holder (s): (Agent (s): Cabinet Regimbeau, Corre. Martin,

Schrimpf. Warcoin and Ahner.

- Rotary distributor.

  57L The invention relates to a rotary distributor.

  The distributor comprises a rotor 52 provided with at least one internal flow passage extending between orifices 80, 82 so as to establish communication between different pairs of flow passages formed in the body 12 of the distributor: the rotor is provided with an annular surface coming into tight contact with a corresponding surface 68 of the body 12, at least one of the orifices of the rotor being If disposed in this annular surface; a continuous elastic seal is disposed between the sealing surfaces of the rotor and the body to establish a static and dynamic seal; a spherical surface 124 placed between the rotary drive device and the rotor exerts an axial pressure on the latter and absorbs a tilting of the rotor to ensure its uniform stress; furthermore the seal between the rotor 52 and

  O the body 12 is adjustable from the outside by means of a screw 36.

  O N U E D Sale of booklets at IMPRIMERIE NATIONALE. 27. rue de la Convention - 75732 PARIS CEDEX 15 The present invention relates to a rotary distributor comprising a rotor provided with at least one internal flow passage for establishing communication between different pairs of flow passages in the body of the distributor. Known rotary distributors include rotors provided in one face with slots establishing communication between flow passages formed in the body of the distributor. Because a large separating force between the rotor and the body is created by fluid as it flows through the slots, great force is required to seal the rotor and the

body to prevent leakage.

  Typically, the rotor abuts directly against the body of the rotary distributor. Misalignment of the rotor and the body can cause uneven wear of the sealing surfaces between them. Due to irregularities in the sealing surfaces of the rotor and the body under the effect of wear, the surfaces do not fit exactly with each other and this results in leaks both during rotor rotation only during

that the rotor is stationary.

  Known rotary distributors typically include a stepping motor which rotates the rotor so as to bring it into alignment with different flow paths of the body, a positioning of the rotor being established by controlling the number of electric drive pulses applied to the engine. This process does not ensure correct positioning of the rotor relative to the body

  from the distributor and it turned out to be unreliable.

  The object of the present invention is to remedy a

  or more of the disadvantages mentioned above.

  The rotary dispenser of the present invention is compact and is in particular usable for delivering small amounts of fDide to medical equipment. According to one aspect of the invention, the rotary distributor comprises a rotor comprising at least one internal flow passage extending between two orifices to establish a communication between two flow passages formed in a body of the distributor, the rotor comprising an annular surface extending outwardly to come into tight contact with the body and at least one of the internal flow passages being disposed on the annular surface. The annular surface forms a small, precisely defined sealing surface

  between the rotor and the body so that when applying

  cation of a small axial force, we obtain a strong

  unit charge for establishing the seal.

  According to another aspect of the invention, a continuous elastic seal is arranged between the sealing surfaces of the rotor and of the body so as to establish a

  static and dynamic sealing.

  In accordance with another aspect of the invention, a spherical surface is provided for applying a

  axial pressure to the rotor, the surface adapting to a tilting

  the rotor to ensure uniform loading of

  sealing surfaces of the rotor and the body.

  According to yet another aspect of the invention, there is provided an alignment means extending through the rotor and the body of the distributor along the axis of

  rotation in order to prevent misalignment and wear-

  non-uniform sealing surfaces of the rotor and the body.

  According to yet another aspect of the invention, an adjustable joint biasing system is provided

from the outside.

  Other features and advantages of the invention

  tion will be highlighted in the following description,

  given by way of nonlimiting example, with reference to the appended drawings in which: FIG. 1 is an elevational view of the rotary distributor of the present invention; Fig. 2 is a plan view of the rotary distributor of FIG. 1; Fig. 3a shows the configuration of the rotor flow passages for a two-position, four-way rotary distributor; Fig. 3b shows the configuration of the rotor flow passages for a two-position, five-way rotary distributor; Fig. 3c shows the configuration of the rotor flow passages for a three-position, four-way rotary distributor; - Fig. 3d shows the configuration of the rotor flow passages for a four-position, five-way rotary distributor; Fig. 4 is a side sectional view of the rotary distributor, taken along line 4-4 of FIG. 2; Fig. 5 is a sectional view of the distributor body, taken along line 5-5 of FIG. 4; Fig. 6 is a plan view of the rotor shown in FIG. 5; Fig. 7 is a side sectional view of a modified rotary distributor, and FIG. 8 is a plan view of the rotor shown in the

Fig. 7.

  We will now describe the best bet mode

  of the invention. A rotary distributor 10, shown

  felt in Figures 1 and 2, comprises a body 12 of cylindrical shape in which are formed a number of internal flow passages, each passage extending between an orifice 14 disposed in the side wall of the body

  and an orifice disposed in an upper surface of the body.

  A rotor, disposed inside a casing 16, comprises at least one internal flow passage extending between the orifices arranged in a lower surface of the rotor in order to establish communication between different pairs of flow passages of the body 12. The rotor can be brought into rotation in alignment with different pairs of flow passages of the body by means of a stepping motor 18 fixed on a mounting support 20. The body 12 and the rotor casing 16 are fixed to the motor 18 by four screws which pass through holes 22 made in a mounting support 24 and through the body and the rotor housing to enter the mounting support of the motor 20. The support 24 is also provided with threaded holes 26 for fixing the rotary distributor 10 to the device in which it is to

 be used.

  The stepping motor 18 is controlled electronically by an integrated circuit so as to precisely position the rotor, the circuit being arranged below a cover 28 mounted on the motor. The circuit board comprises terminals 30 which extend through openings 32 of the cover 28 to establish connections with wires 34 starting from the motor 18. A screw 36 passes through the cover 28 in order to ensure a stress, adjustable from outside, sealing surfaces between the rotor and the body 12, as described below. A nut 38 fixes the cover 28 to the motor 18. The motor and the circuit are not part of the invention and will not be described

in detail.

  Figures 3a-3d show different configurations

  internal rotor flow passages for a

  body 12 comprising four flow passages, orifices

  these formed in the upper surface of the body being distributed at 90 'intervals on a circle, the orifices

  being designated by the numerical references 1, 2, 3 and 4.

  - Figure 3a-shows a rotary distributor with two positions and four channels having two internal curved flow passages 40 and 42 extending through the rotor so as to establish communication between adjacent pairs of orifices in the body 12 In a first

  position, the flow passage 40 establishes a communication

  tion between the orifices 1 and 2 of the body, the passage of

  Lement 42 establishing a communication between the orifices 3 and 4. By rotation of the rotor by 90 until within a second

  position, the flow passage 40 establishes a communication

  tion between the openings 2 and 3 of the body while the flow passage 42 establishes a communication between the openings 1 and 4. FIG. 3c represents a rotary distributor with three positions and four channels, having the same configuration of rotor as on the Figure 3a. By rotating the rotor 45 to a third position located

  between the first and second position, no communication

  tion is established with the flow passages of the body 12. Figure 3b shows a rotary valve with two positions and five channels for a body having a fifth flow passage extending to a

  central orifice 5 disposed on the axis of rotation of the distri-

  scorer. The rotor has three internal flow passages

  ment, two curved flow passages 44 and 46 to establish a communication between adjacent pairs of orifices of the body and a flow passage 48 extending diametrically in the rotor to establish a communication between the central orifice and two orifices opposites. In a first position, the flow passage 48 establishes communication between the orifices 1, 3 and 5 of the body. By rotation of the rotor 90 to a second position, the flow passage 44 establishes a communication between the orifices 2 and 3 while the flow passage 46 establishes a communication between the orifices 1 and 4. FIG. 3d represents a rotary distributor with four positions and five channels comprising a rotor provided with a single internal flow passage 50 as well as a body comprising five orifices 1, -2, 3, 4 and 5 similar to that indicated in Figure 3d. By rotation of the 90Q rotor, the central orifice 5 can be placed in communication with each of the

ports 1, 2, 3 and 4.

  Figure 4 shows a rotary distributor having a rotor 52 having a configuration of internal flow passages such as that shown in Figures 3a and 3c. As shown in Figures 4 and 5, the rotary distributor 10 comprises a body 12 of cylindrical profile which can be formed by plastic molding and which has four threaded holes 53, 54, 55 and 56 which are distributed at intervals of 900 in a side wall 58 of the body. Each of the threaded orifices has a conical end 59 opening into a flow passage, like the flow passages 60 and 62

  shown respectively for holes 53 and 55.

  Each of the flow passages extends between an associated orifice 53, 54, 55 and 56 of the side wall of the body and a respective orifice 63, 64, 65 and 66 formed in an upper surface 68 of the body, the orifices being distributed at 90 'intervals on a circle centered on

the axis of rotation.

  A continuous circular seal 70 formed of an elastic material is disposed between the body 12 and the rotor 52 so as to establish a static and dynamic seal. The seal 70 comprises four holes 72 arranged at 90- intervals and positioned so as to be aligned with the orifices 63, 64, 65 and 66 formed in the surface

  upper 68 of the body. The holes 72 of the seals

  tee are kept aligned with the holes in the surface

  upper body by means of four screws 74, of which only-

  two are shown, the screws extending through the mounting support 24, the body 12 and the seal 70 to penetrate the rotor housing 16 and the support

motor mounting 20.

  The rotor 52 of cylindrical shape shown in Figures 4 and 6 can be formed by plastic molding and have two internal flow passages 76, 78, as shown in Figures 3a and 3c, to establish communication between adjacent pairs orifices existing in the upper surface 68 of the body 12. The internal flow passages 76 and 78 extend between two respective adjacent orifices 80, 82 and 84, 86 arranged at 90 'intervals around a surface of seal 88 of the rotor and positioned so as to be aligned with the orifices provided in the upper surface 68 of the body 12

  and with the holes 72 of the seal 70.

  The sealing surface 88 of the rotor 52 is an annular surface extending outwards and having an inside diameter slightly smaller than the diameter of the circle on which the orifices 63 to 66 are arranged, and an outside diameter which is slightly more larger than the diameter of the circle, the width of the surface 88 being

  large enough to accommodate the corresponding holes

  dants. The annular surface 88 constitutes a small sealing surface, defined precisely, between the rotor 52 and the body 12 so that, when a small axial force is applied as will be described below, a large unit load of sealing establishment. The rotor 52, the body 12 and the seal are kept aligned around the axis of rotation by means of an alignment pin 92 which is engaged in holes 93, 94 and 96 formed respectively along the axes rotor, seal and body. The alignment pin ensures precise axial positioning of the holes in the sealing surfaces of the rotor 52 and of the body 12, and of the holes 72 in the seal 70, and it prevents misalignment which could cause wear. non-uniform seal and leakage. The hole 92 extends through the rotor 52 to a hole 96 having a larger diameter so as to

  receive a drive shaft 98. A drive spindle!

  ment 100 is disposed inside the hole 96 along a diameter of the rotor 52, this drive pin being urged by the drive shaft 98, as will be

  described below, to ensure the rotation of the rotor.

  The rotor 52 is rotated into different potions by the stepping motor 18 comprising a frame 102 mounted on the drive shaft 98 which is coupled to the rotor. The drive shaft 98 passes through a sleeve 104 to enter the collar 106 extending

  upward from the engine mounting bracket 20.

  The drive shaft 98 includes a hole 108 extending along the axis of rotation and in which is placed the spring 110 serving to push the rotor into sealed contact Against the body 12. The spring 110 is biased by the screw 36, adjustable from the outside and which extends through the cover 28 into a threaded insert 112 placed in a hole in the circuit board 114, a nut 116 abutting against the insert. A ball 118 is disposed between the spring 110 and the adjustment screw 36 comprising a spherical surface 120, the ball 118 and the surface 120 establishing between them a point contact to urge the spring along the axis of rotation. The drive shaft 98 further comprises a slot 112 extending along a diameter of the shaft at its lower end, the slot 122 receiving the drive pin 100 of the rotor 52. The spherical surface of a ball 124 placed on the axis of rotation in the slot 122 exerts an axial pressure on the drive spindle 100 while allowing the rotor to tilt in any direction during rotation to ensure a

  uniform stress on the seal.

  The motor 18 is electronically controlled in order to precisely position the rotor 52 relative to the orifices of the upper surface 68 of the body by means of an integrated circuit disposed on the wafer 114 which is mounted

  on the motor 18 by bolts 116 and 120. A position-

  effective is ensured by detecting the position of the rotor by means of detectors such as the detector 126 mounted on the lower side of the circuit board 114 and the reflector 128 which may be formed from aluminum foil or the like and which is mounted directly on the frame 102 of the motor. The detector 126 includes a light emitting diode 127 which emits radiation. The radiation, when it is reflected backwards by the reflector 128, excites a phototransistor 128 so as to signal the precise positioning of the rotor ending its rotation. A detector 126 is provided for each position of the rotor. Each of the detectors is mounted on the circuit board 114 so that it is located directly above the reflector 128 when the rotor

  is in the position associated with this detector.

  Figure 7 shows a rotary distributor

  130 comprising a rotor 132 and a body 134 having a confi

  guration of flow passages as illustrated in Figures 3b and 3d, the rotor drive being the same as that which has been described with reference to FIG. 4. The body

  134 has four internal flow passages

  dant between four threaded orifices arranged in the side wall of the body and orifices arranged in an upper surface 136 at 90 'intervals on a circle centered on the axis of rotation, only two of the passages 138 and being represented as s' extending between respective pairs of ports 142, 144 and 146, 148. The body also includes a threaded port 150 disposed along the axis of rotation and extending to a transfer tube

  152 to constitute a central orifice 154.

  The rotor 132 shown in Figures 7 and 8 includes three internal flow passages, two curved flow passages 156 and 157 extending between respective pairs of adjacent orifices 160, 162 and 164, 166 formed in the annular surface seal 88 of the rotor, as well as a flow passage 168 extending along a diameter of the rotor between a central orifice 170 and a pair

opposite ports 172 and 174.

  The rotor 132 comprises a sleeve 176 extending downward and in which the central orifice 170 extends, the sleeve 176 passing through the body 134 in sealed contact with the orifice 154 of the transfer tube 152. The sleeve 176 operates in the same way as the alignment pin 92 shown in FIG. 4 so as to maintain the body 134, the seal 70 and the rotor 132 in axial alignment. The rotor 132 of Figures 7 and 8 is shown for a rotary distributor having the configuration of flow passages shown in Figure 3b. However the

  rotor 132 can be modified to obtain the configuration

  tion of flow passages shown in Figure 3d by inserting buffers in the holes 160, 162, 164 and 166 of the rotor and also providing a buffer extending from the side wall of the rotor through the central passage 166 by covering the orifice 174 but leaving the central orifice 170 open. It should also be noted that the rotor 132 can also be modified so as to be used in a rotary distributor comprising the flow passage configurations of FIGS. 3a and 3c by plugging the ports 170, 172 and 174 with buffers so that

  only the two curved passages 156 and 158 remain open.

  We will now specify the possibilities of industrial application of the invention. In operation, the motor 18 rotates the rotor 52, 132 so as to bring it into a position determined by the detector 126, so that the orifices formed in the sealing surface 88 of the rotor are aligned with orifices formed in the upper surface 68 of the body. During rotation, the

  rotor 52, the seal 70 and the body 12 are now

  bare in axial alignment by spindle 92, as shown in Figure 4, the rotor 132 being kept in axial alignment with the seal 70 and the body 134 by the sleeve 176 as shown in Figure 7. The exact alignment the rotor, the seal and the body which is provided by the alignment pin 92 and the sleeve 176 prevents uneven wear of the sealing surfaces, which could

translate as a leak.

  During rotation, several characteristics of the rotary distributor contribute to establishing a low torque. The axial force generated by the spring 110 positioned in the drive shaft 98 along the axis of rotation is counterbalanced by the ball 118 which, due to its punctual contact with the spherical surface 120 of the screw 36 arranged along the axis of rotation, produces only a small moment likely to generate a torque. A low torque is also obtained thanks to the annular sealing surface 88, which is narrow and precisely defined on the rotor and which requires a low elastic force to establish a good seal. The elastic force necessary to establish the seal between the body and the rotor is further reduced to a minimum by using the passages

  internal flow formed in the rotor 42 and which

  affect the separation force between the body and the rotor.

  An effective static and dynamic seal is established by the continuous elastic seal 70 disposed between the body 12 and the rotor 52. The seal 70 compensates for small irregularities in the seal surface 68 of the body and in the seal surface of the rotor so to prevent a leak

  during rotation and while the rotor is stationary.

  Because the seal 70 is continuous on the upper surface 68 of the body, a seal is established when the rotor is between positions such that none of the passages are placed in communication. The continuous seal 70 furthermore prevents transverse flow during rotation of the rotor and it also ensures

  protection against accumulation of contaminating substances

  on other exposed surfaces of the rotor.

  The seal is further improved by the ball 124 placed in the slot 122 of the drive shaft 98, this ball transmitting the elastic force to the spindle

  100O rotor drive. The ball 124 provides a stress

  uniform citation of the seal allowing the rotor to tilt in any direction during rotation so that the seal surfaces of the rotor, seal and body fit exactly one

the other.

  The stress, adjustable from the outside, of the seal which is provided by the screw 36 passing through the cover 28 of the rotary distributor allows easy adjustment of the elastic force necessary for different pressures and dimensions of orifices. The adjusting screw 36 also eliminates the requirement to maintain tight tolerances that would otherwise be required to achieve a

appropriate elastic force.

  Of course, the invention is in no way limited to the embodiments described and shown, it is capable of numerous variations accessible to those skilled in the art, depending on the applications envisaged and without

  deviate for this from the spirit of the invention.

Claims (26)

  1. Rotary distributor comprising a body provided with a plurality of flow passages, a rotor for establishing communication between at least a pair of said flow passages and a drive means for   bringing said rotor into alignment with different   annular pairs of flow passages, characterized in that said body (12) comprises a plurality of orifices (1, 2, 3, 4, 5) disposed in a surface of the body along a circle, each of said orifices opening into an associated flow passage formed inside said body (12), and in that said rotor (52; 132) has at least one internal flow passage (40, 42; 60, 62; 76, 78; 156, 158) extending between a pair of orifices to establish communication between a pair of flow passages formed in the body (12), said rotor having an annular surface (88) coming into sealing contact with the corresponding surface of the body (12), at least one of the orifices of the internal flow passages   being disposed on said annular surface (88).   2. Rotary distributor according to claim 1, characterized in that the orifice formed in the annular surface (88) of the rotor (52) and the orifices formed in   the surface of the body (12) have equal diameters, the width -   the annular surface (88) of the rotor (12) being slightly larger than the diameter of the orifices in order to form a narrow sealing surface.   3. Rotary distributor according to claim 1, characterized in that the outside diameter of the annular surface (88) of the rotor (52) is slightly larger than the diameter of said circle and in that the inside diameter of the annular surface (88 ) is slightly   less than the diameter of said circle.   4. Rotary distributor according to claim 1, characterized in that it further comprises a rotating element (100) coupling to the rotor to ensure its rotation and a stationary element to exert an axial force on the rotor along the axis of rotation for sealing between the annular surface (88) of the   rotor (52) and the corresponding surface of the body (12).   5. Rotary distributor according to claim 4, characterized in that said stationary element comprises an axial bearing surface which comes into contact with an axial bearing surface of the rotor (52) at a point situated substantially on the axis of rotation , one of said surfaces   axial support being substantially spherical (124).   6. Rotary distributor according to claim 1, characterized in that said drive means comprises   a drive shaft (98) having a lower end   intended to couple with the rotor, said drive shaft (98) having a hole (108) formed along its axis, a rotating spring (110) disposed in the hole (108) of said drive shaft ( 98) so as to push the rotor (52) against the body (12) of the distributor, a stationary element (36) for biasing said spring (110) and a rotating ball (118) disposed between said biasing element (36) and said spring (110) to counterbalance   the force generated by the spring (110).   7. Rotary distributor according to claim 6, characterized in that said biasing element (36) comprises a spherical surface (120) establishing contact   punctual with the ball shift (118) along the axis of rotation.   8. Rotary distributor comprising a body provided with a plurality of flow passages, a rotor for establishing communication between at least one pair of said flow passages and a drive means for bringing said rotor into rotation with alignment with different pairs of flow passages, characterized in that said body comprises a plurality of orifices arranged in a surface of said body, each of said orifices opening into an associated flow passage inside the body (12), in that said rotor (52) includes at least one internal flow passage for establishing communication between a pair of body flow passages (12), the internal flow passage having a pair of ports disposed in a surface of said rotor (52) for establishing tight contact with said surface of the body, said orifices being positioned so as to be aligned with different orifices formed in the surface of said body, and a seal eity (70) disposed between the surface of the body (12) and the surface of the rotor (52), said seal (70) having several holes (72), each hole (72) being aligned with an orifice (63, 64, 65 , 66) formed in the surface (68) of said body (12).   9. Rotary distributor according to claim 8, characterized in that said seal (70) is continuous on the sealing surfaces of said rotor (52) and of said body (12).   10. Rotary distributor according to claim 8, characterized in that said seal (70) is formed of elastic material.   11. Rotary distributor comprising a body provided with a plurality of flow passages, a rotor for establishing communication between at least one pair of said flow passages and a means of entrainment for bringing said rotor into rotation with alignment with different pairs of flow passages, characterized in that said body (12) comprises a plurality of orifices (63, 64, 65, 66) formed in a surface (68) of the body, each of said orifices opening into an associated flow passage inside the body, in that said rotor (52) includes at least one internal flow passage for establishing communication between a pair of body flow passages, the internal flow passage comprising a pair of orifices formed in a surface of said rotor for coming into tight contact with said surface of the body, said orifices being positioned so as to be aligned with different orifices in the surface of the body, and in that provision is made means connected to said drive means for applying axial pressure to said rotor (52) to uniformly stress the surface sealing of the rotor.   12. Rotary distributor according to claim 11, characterized in that said means for exerting an axial pressure comprises a spherical surface (124) adapting   axial misalignment or tilting of the rotor (52).   13. Rotary distributor according to claim 11, characterized in that said rotor (52) comprises a drive spindle (100) extending along a diameter of the rotor and in that said drive shaft (98) comprises an ente (122) intended to receive the drive spindle (100), a ball (124) being disposed in said slot (122) along the axis of rotation, said ball (124) pressing against said spindle d 'training (100).   14. Rotary distributor comprising a body provided with a plurality of flow passages, a rotor for establishing communication between at least one pair of said flow passages and a drive means for rotating said rotor in alignment with different pairs of flow passages, characterized in that said body (12) comprises a plurality of orifices (63, 64,, 66) formed in a surface (68) of the body, each of the orifices opening into a flow passage associated partner inside the body, in that said rotor comprises at least one internal flow passage for establishing communication between a pair of body flow passages, this internal flow passage having a pair of orifices arranged in a surface of said rotor so as to come into sealing contact with said surface of the body, said orifices being positioned so as to be aligned with different orifices of the surface of the body, and in that it is provided means for exerting an axial force on said rotor in order to establish a seal between the rotor surface and the surface of   body, said means being adjustable from outside the dispenser rotary scorer.   15. Rotary distributor according to claim 14, characterized in that said means for applying an axial force comprises a spring (110) disposed along the axis of rotation and a screw (36) adjustable 'from the outside for biasing said spring (110).   16. Rotary distributor according to claim 15, characterized in that said screw (36) has a spherical surface (120) for applying the axial force along the axis of rotation.   17. Rotary distributor according to claim 15, characterized in that it further comprises a ball (118) disposed along the axis of rotation between said screw (36) and said spring (110).   18. Rotary distributor comprising a body provided with a plurality of flow passages, a rotor for establishing communication between at least one pair of said flow passages, said rotor being in sealed contact with said body, and a drive means for bringing said rotor into alignment with rotation with different pairs of flow passages, characterized in that said drive means comprises a rotating element (98) mating with the rotor to ensure its rotation, said rotating element comprising a spherical surface adapting to a tilting of the rotor (52), and a stationary element (36) for exerting an axial force on said rotor along the axis of rotation in order to establish the seal between the rotor (52) and the body (12).   19. Rotary distributor according to claim 19, characterized in that said stationary element (36) has a spherical surface (120) for establishing point contact with said rotary element (98) along the axis of rotation.   20. Rotary distributor according to claim 19, characterized in that said rotary element comprises a drive shaft (98) in which is formed a hole (108) extending along the axis of rotation and in which is disposed a spring (110), said stationary element   (36) biasing said spring (110).   21. Rotary distributor according to claim 20, characterized in that it further comprises a ball (118) disposed along the axis of rotation between the spring   (110) and the stationary element (36).   22. Rotary distributor according to claim 20, characterized in that said rotor (52) comprises a drive pin (100) extending along a diameter of the rotor (52) and in that said drive shaft (98) comprises a slot (112) formed in one end of said shaft so as to receive the drive spindle (98), a ball (124) being arranged in said slot (122) on the axis of rotation, said ball leaning against said entrainment pin (100O).   23. Rotary distributor comprising a body provided with a plurality of flow passages, a rotor for establishing communication between at least one pair of said flow passage and a drive means for rotating said rotor in alignment with different pairs of flow passages, characterized in that said body comprises a plurality of orifices formed in a surface of the body. (12), each of said orifices (63, 64,, 66) opening into an associated flow passage formed inside the body (12), in that said rotor comprises at least one internal flow passage for establishing a communication between a pair of body flow passages, said internal flow passage having a pair of orifices disposed in a surface (88) of said rotor (52) so as to come into tight contact with said surface (68) of the body, said orifices being positioned for alignment with different orifices of the surface (68) of the body (12), and in that there is provided a means extending through said rotor and   of said body along the axis of rotation with a view to aligning it   ment of the rotor (52) with the body (12).   24. Rotary distributor according to claim 23, characterized in that the rotor (52) and said body (12) each have a hole of equal diameter extending the   along the axis of rotation and in that said alignment means   ment is a pin (92) engaged in each of the aforementioned holes. 25. A rotary distributor according to claim 23, characterized in that said body (12) comprises a hole extending along the axis of rotation and in that said   alignment means comprises an outer extending element-   ment from the sealing surface (88) of said rotor along the axis of rotation, said element being received in the body hole (12). PL. I / 3 2570067 FIG. I FIG. 2 / o $ 0 / 4,122 26 = g2 4 FIG. 3a FIG. 3b 2 2 2 2 44 J 3 1 3 3 4 "4" 42 2,402 40 2 2 FIG. 3c 3 3_j - 42 42 4 4 4 FIG. 3d C3 50 2 50 3 1 31 31 3 4 4 4 4 PL. II / 3 257006? IR 8IIR ----. - 54,955 oT2777FIG. 6 FIG. 5IC / 22 i00 129 93 90 82 72 '! 7'4 -'92 24 54, 95 OO oo -..._ '] - 78 FIG. 6 FIG. 5 PL. III / 3 FIG. 7 ,, f ,,; N, H IF NI, lNI <- / 627 8 - ,. / 148 / 54-e _ X1 64o / '' 46 't S / 34 / '50/52 156 164_- "" "./66 / 58, FIG. 8