EP3049671B1 - Sealing ring for a distrbution device of a hydraulic pump - Google Patents

Description

The present invention relates to a sealing ring for a hydraulic pump distributor.

We know from the teaching described in the patent EP263218 a hydraulic mechanism for motor or pump, consisting of a cylinder block having a surface of communication with the outside, a plurality of cylinders, which are formed in the cylinder block and within each of which slides a piston. The hydraulic mechanism comprises a distribution window provided with orifices corresponding to ramps of corrugations while the cylinder block is provided with feed or exhaust ports of the cylinders.

We also know from the document EP526333 a hydraulic mechanism for an engine or pump, having two distinct modes of operation corresponding, one to the periodic fluid supply under pressure of all the fluid working chambers and the other mode of operation, to the supply of only the fluid working chambers belonging to a first working chamber group, the other fluid working chambers being no longer supplied with pressurized fluid. For this, the hydraulic mechanism comprises at least two separate operating cylinders.

Axial or radial piston pumps with rotating cylinders and particularly those with variable displacement are most often constituted by a rotor in which hydraulic cylinders are arranged. In each of said cylinders, a hydraulic piston moves back and forth.

Said rotor usually has a feed face maintained in contact with the most tight possible with a distribution face - also called ice or distribution plate - arranged on the surface of a stator, the latter may be part of a pump body.

The supply face generally comprises orifices each connected to one of the hydraulic cylinders, while the distribution face comprises at least a suction lumen through which the hydraulic pistons can draw hydraulic fluid, and at least one discharge lumen through which said pistons can discharge said fluid, said orifices and said lumens constituting a hydraulic distributor.

Thus, when the rotor rotates, said orifices are alternately connected to a suction duct by the suction lumen, then with a discharge duct by the discharge lumen. It follows from this that a flow of hydraulic fluid can be established between said ducts following the movements back and forth that the hydraulic pistons, each in its hydraulic cylinder.

It is noted that hydraulic fluid leaks inevitably occur between the supply face and the distribution face. As a result, part of the hydraulic fluid passes directly from the discharge pipe to the suction pipe or vice versa, while another part of the fluid passes directly from said pipes to an inner casing. which generally comprise said hydraulic pumps on the other hand. These leaks reduce the volumetric and energy efficiency of said pumps.

In the case of axial piston hydraulic pumps, to be as tight as possible between them, the supply face and the distribution face are subjected to a force that tends to keep them in contact against each other. This effort results in particular from the reaction force that oppose a platinum force to the thrust of the hydraulic pistons, said platen may for example be an inclined plate or a plateau of rods.

Combined with the relative displacement of said faces, said reaction force results in friction losses which reduce the energy efficiency of the pumps thus designed. Note that in the particular case of axial piston hydraulic pumps, the supply face and the distribution face are each positioned on a flat circular surface.

In the case of radial piston radial piston pumps, the distributor is most often constituted by a distribution face positioned on the outer surface of a first cylinder integral with the stator, while the supply face is positioned on the inner surface of a second cylinder, which caps the first cylinder, and which is secured to the rotor. According to this particular configuration, the seal between said faces is preferably obtained from a low clearance left between the first and the second cylinder, the manufacture of the latter requiring high machining precision.

Obtaining the seal according to this strategy leads to major leaks occurring in the latter type of distributor, even if the friction losses generated by said distributor are potentially lower. In addition, unless the radial piston hydraulic pump is radially balanced with at least two suction ports and two diametrically opposite discharge ports, the pressure exerted by the hydraulic fluid on the section of the light subject to the highest pressure may subject said distributor to a potentially significant radial force and which generates significant additional friction losses.

This disadvantage can be mitigated or practically eliminated if radial force balancing grooves are provided which counterbalance the radial force of the inlet or discharge light subjected to the highest pressure. Such an arrangement is for example disclosed in the patent application relating to a motor-pump No. 1354562 as of May 22, 2013, owned by the applicant.

Taking into account what has just been said, in the current state of the art, a distributor whose seal is high tends to generate high friction losses while conversely, a distributor with low friction losses is rather inclined to have significant hydraulic fluid leaks.

It is noted that the relative decrease in energy efficiency induced by hydraulic leaks and by friction losses occurring between the supply face and the distribution face of hydraulic pumps with axial or radial cylinders with rotating cylinders and in particular those with variable displacement it is all the more important that the pressure under which said pumps operate is high on the one hand, and that said pumps are used with partial displacement on the other hand.

It is therefore particularly important to reduce as much as possible said leaks and said losses while recovering the highest possible fraction of the energy released by the hydraulic fluid during its decompression.

• A mêmes pertes par frottement, les débits de fuite survenant au niveau dudit distributeur entre les conduits d'aspiration et les conduits de refoulement sont réduits de même que les débits de fuite survenant entre lesdits conduits et le carter interne que comportent en général les pompes hydrauliques :
• A même niveau d'étanchéité, les pertes par frottement générées par ledit distributeur sont réduites.

It is to serve this set of objectives that the sealing ring for hydraulic pump distributor according to the invention provides that compared to the prior art and when - according to a particular embodiment - it equips a distributor faces cylindrical supply and distribution:

• At the same friction losses, the leakage rates occurring at the level of the distributor between the suction ducts and the discharge ducts are reduced, as are the leakage rates occurring between said ducts and the internal casing which the hydraulic pumps generally comprise. :
• At the same level of sealing, the friction losses generated by said distributor are reduced.

• De contribuer à la réalisation de pompes hydrauliques à haut rendement volumétrique et énergétique ;
• De permettre la conception et la fabrication de pompes hydrauliques ou de moteur-pompes hydrauliques pouvant favorablement constituer, avec d'autres composants, une transmission hybride hydraulique à haut rendement énergétique destinée à la propulsion de véhicules automobiles.

Consequently, the sealing ring for a hydraulic pump distributor according to the invention makes it possible in particular:

• To contribute to the realization of hydraulic pumps with high volumetric and energetic efficiency;
• To allow the design and manufacture of hydraulic pumps or hydraulic motor pumps which, together with other components, can be a favorable combination of a high-efficiency hydraulic hybrid transmission intended for the propulsion of motor vehicles.

In addition, the sealing ring for a hydraulic pump distributor according to the invention has a low cost, its manufacture does not involve any process complex or expensive material. Said ring is also designed to offer great strength and long life and can operate in the field of high hydraulic pressures. Said ring is also applicable to any hydraulic pump or hydraulic motor-pump with fixed or variable displacement, that said pump or motor-pump is in particular pallet, axial piston, radial piston, rotary cylinder or not and whatever the liquid, gaseous, or semi-liquid fluid that it operates.

The other features of the present invention have been described in the description and in the dependent claims directly or indirectly dependent on the main claim.

• Au moins une bague continue d'étanchéité logée à faible jeu axial et/ou radial dans une gorge de bague aménagée dans te stator de pompe à l'intérieur de la zone surfacique que délimite la surface d'étanchéité basse-pression coté stator, ladite bague présentant une face de bague coté stator logée à l'intérieur de la gorge de blague, et une face de bague coté rotor qui affleure la surface d'étanchéité basse-pression coté stator, tandis que les lumières d'admission-refoulement débouchent au niveau de ladite surface d'étanchéité par l'intermédiaire de ladite gorge, ladite bague étant axialement ou radialement plus large que lesdites lumières de sorte à les recouvrir et comportant, approximativement axialement ou radialement aligné avec ces dernières, au moins un évidement de distribution traversant la bague continue d'étanchéité part en part dans le sens de son épaisseur, ledit évidemment pouvant mettre en communication l'une des deux lumières d'admission-refoulement avec l'orifice d'alimentation lorsque ce dernier se trouve approximativement face à ladite lumière ;
• Au moins un bossage de contact circonférentiel aménagé axialement ou radialement de part et d'autre de l'évidement de distribution, ledit bossage présentant une ligne de contact circonférentielle pouvant entrer en contact avec la surface d'étanchéité basse-pression coté rotor ;
• Au moins une piste de compression-décompression aménagée sur un certain secteur angulaire de la face de bague coté rotor, ledit secteur étant positionné en dehors de la partie de ladite face où est placé l'évidement radial de distribution ;
• Au moins une lèvre d'étanchéité de bague solidaire ou non de la bague continue d'étanchéité et qui réalise une étanchéité axiale ou radiale entre ladite bague et la gorge de blague ;
• Au moins un joint d'étanchéité de compression-décompression qui réalise une étanchéité entre la face de bague coté stator et le fond et/ou les cotés axiaux ou radiaux de la gorge de bague et ceci, au niveau de ta zone angulaire définie par te secteur angulaire sur lequel est aménagée la piste de compression-décompression ;
• Des moyens d'arrêt en rotation qui maintiennent la bague continue d'étanchéité dans une position angulaire fixe par rapport au stator de pompe.

The sealing ring for a hydraulic pump distributor provided for a hydraulic distributor that may comprise a hydraulic pump, said distributor comprising at least one solitary pump stator distribution face of a pump stator said distribution face having a surface of low-pressure sealing on the stator side of which open at least two inlet-discharge ports arranged in the pump stator and which each communicate with at least one inlet-discharge duct of their own and which is also arranged at the said stator, said dispenser also comprising at least one rotor supply face of pump integral with a pump rotor, said supply face having a low-pressure sealing surface on the rotor side from which opens at least one orifice communicating with a supply duct arranged at the front of said rotor while the surface of the low-pressure seal on the stator side is positioned facing the low-pressure sealing surface on the rotor side so that the supply orifice is alternately facing one or the other of the two intake ports; discharge at least once per pump rotor revolution, comprises:

• At least one continuous sealing ring housed at low axial and / or radial clearance in a ring groove formed in the pump stator inside the surface area delimited by the low-pressure sealing surface on the stator side, said ring having a stator-side ring face housed inside the joke groove, and a rotor-side ring face that is flush with the low-pressure sealing surface on the stator side, while the inlet-discharge ports open at level of said sealing surface through said groove, said ring being axially or radially wider than said slots so as to cover them and having, approximately axially or radially aligned with the latter, at least one through distribution recess the continuous seal ring apart in the direction of its thickness, said obviously being able to put in communication one of the two lights ad mission-discharge with the supply port when the latter is approximately facing said light;
• At least one circumferential contact boss arranged axially or radially on either side of the dispensing recess, said boss having a circumferential contact line that can come into contact with the low-pressure sealing surface on the rotor side;
• At least one compression-decompression track arranged on a certain angular sector of the rotor-side face of the ring, said sector being positioned outside the part of said face where the radial distribution recess is placed;
• At least one ring sealing lip integral or not with the continuous sealing ring and which provides an axial or radial seal between said ring and the joke groove;
• At least one compression-decompression seal which seals between the stator-side face of the ring and the bottom and / or the axial or radial sides of the ring groove and this, at the level of the angular zone defined by you. angular sector on which is arranged the compression-decompression track;
• Rotational stop means which keep the ring continuous sealing in a fixed angular position with respect to the pump stator.

The sealing ring for hydraulic pump distributor according to the present invention comprises a ring groove which comprises a ring bearing face on its sides which are oriented perpendicularly to the low-pressure sealing surface on the stator side, said face of the ring. support cooperating with a shoulder support ring that includes the continuous seal ring.

The sealing ring for a hydraulic pump distributor according to the present invention comprises a ring groove which has a ring sealing face on its sides which are oriented perpendicularly to the low-pressure sealing surface on the stator side, said face of the ring. sealing cooperating with a ring sealing shoulder that includes the continuous sealing ring.

The sealing ring for a hydraulic pump distributor according to the present invention comprises a ring seal lifter which is a flexible metal blade integral with the ring sealing shoulder.

The sealing ring for a hydraulic pump distributor according to the present invention comprises a ring sealing lip which is positioned on, below or in the extension of the ring sealing shoulder.

The sealing ring for a hydraulic pump distributor according to the present invention comprises a ring sealing lip which is constituted by a lateral seal made of flexible material held simultaneously in contact with the ring groove and with the face of the ring. stator side ring.

The sealing ring for a hydraulic pump distributor according to the present invention comprises a compression-decompression seal which has at least one sectoral compression-decompression chamber which defines a closed and sealed volume with the stator-side face of the ring and the bottom and / or the axial or radial sides of the ring groove.

The sealing ring for a hydraulic pump distributor according to the present invention comprises a compression-decompression seal which comprises a cellular stiffening structure in which is arranged the compression-decompression sector cell, said honeycomb structure being made in a rigid material that can be directly or indirectly held in position relative to the continuous sealing ring by the rotational stop means, while said rigid material may in all or in part be coated with a flexible material that can enter into contact with the stator side of the ring face on the one hand, and / or with the bottom and / or the axial or radial sides of the ring groove on the other hand.

The sealing ring for a hydraulic pump distributor according to the present invention comprises a honeycomb stiffening structure which is integrated with the stator-side face of the ring and which is made in the same piece of material as the continuous sealing ring.

The sealing ring for a hydraulic pump distributor according to the present invention comprises a compression-decompression track which has at least one compression-decompression vector orifice through which a compression-decompression sector duct opens, which connects with the ring face. rotor side the closed and sealed volume defined by the compression-decompression sector cell, said sector orifice being positioned in such a way that the supply orifice is facing said sector orifice once per revolution of the pump rotor, said orifice sectorial then connecting the supply duct to said sealed volume via the sectoral duct compression-decompression.

The hydraulic pump distributor sealing ring according to the present invention comprises a side seal and a compression-decompression seal which form a single piece.

The hydraulic pump distributor sealing ring according to the present invention comprises a ring sealing face which is positioned approximately perpendicular to the circumferential contact line.

The hydraulic pump distributor sealing ring according to the present invention comprises a ring sealing face which is positioned approximately vertically above the circumferential contact line while the ring bearing face is further away from the bottom of the ring. the ring groove and the dispensing recess that said sealing face so that it is offset relative to the plumb line of the circumferential contact line.

The hydraulic pump distributor sealing ring according to the present invention comprises at least one of the axial faces of the ring groove which is formed by the axial face of a ring mounting ring which encloses the pump stator.

The hydraulic pump distributor sealing ring according to the present invention comprises a pump stator distribution face and a pump rotor supply face which are cylindrical while at least one of the intake-discharge ports cooperates with at least one radial force compensating light arranged in the pump stator, the latter light emerging from the pump stator distribution face and facing the pump rotor supply face, said compensation light being further located - in said stator - diametrically opposite the intake-discharge lumen with which it cooperates and being connected by a radial force compensation duct to the inlet-discharge duct to which said light is connected. intake-discharge with which it cooperates.

The sealing ring for a hydraulic pump distributor according to the present invention comprises a compensation light which opens out from the pump stator distribution face via a radial force compensation groove in which is housed at low axial play and / or tangential radial force compensation sealing plate.

The sealing ring for hydraulic pump distributor according to the present invention comprises a radial force compensation sealing plate which is traversed right through its thickness by a compensating recess which connects the conduit. radial force compensation with the pump rotor supply face,

The sealing ring for a hydraulic pump distributor according to the present invention comprises a radial force compensation groove which comprises a plate bearing face on its sides which are oriented perpendicularly to the low-pressure sealing surface on the stator side. said bearing face cooperating with a plate bearing shoulder which comprises the radial force compensation sealing plate.

The sealing ring for a hydraulic pump distributor according to the present invention comprises a radial force compensation groove which has a plate sealing face on its sides which are oriented perpendicular to the low-pressure sealing surface on the stator side. , said sealing face cooperating with a plate sealing shoulder that comprises the radial force compensation sealing plate

The sealing ring for hydraulic pump distributor according to the present invention comprises a radial force compensation sealing plate which cooperates with a sealing plate sealing lip integral or not with said plate, said lip sealing axial and / or radial and / or tangential between said plate and the radial force compensation groove.

The sealing ring for a hydraulic pump distributor according to the present invention comprises a ring sealing lip which is constituted by a flexible seal of compensation of flexible material maintained simultaneously in contact with the radial force compensation groove and with the radial force compensation sealing plate.

The sealing ring for a hydraulic pump distributor according to the present invention comprises a radial force compensation sealing plate which comprises at least one compensating peripheral contact boss arranged at its periphery, said boss having a peripheral line of contact. compensation which can come into contact with the pump rotor supply face.

The hydraulic pump distributor sealing ring according to the present invention comprises a plate sealing face which is positioned approximately perpendicular to the peripheral compensation contact line.

The hydraulic pump distributor sealing ring according to the present invention comprises a plate sealing face which is positioned approximately perpendicular to the compensating peripheral contact line while the plate bearing face is further away. the bottom of the radial force compensation groove and the compensating recess that said sealing face so that it is offset from the plumb line of the peripheral compensation contact line.

The sealing ring for a hydraulic pump distributor according to the present invention comprises a dispensing recess which comprises at least one connecting beam which interconnects the circumferential contact bosses, said beam thus defining on either side of its length. at least one sub-recess of distribution.

The sealing ring for a hydraulic pump distributor according to the present invention comprises rotation stop means which consist of at least one ring rotation stopper pin inserted in a stator stopper hole arranged in the pump stator on the one hand, and introduced into a ring stopper hole through the continuous sealing ring in the direction of its thickness on the other hand.

• Figure 1 est une vue fantôme tridimensionnelle d'une pompe hydraulique à pistons axiaux comprenant un distributeur hydraulique qui reçoit la bague d'étanchéité pour distributeur de pompe hydraulique suivant l'invention dont la bague contenue d'étanchéité est de forme générale plane et est intercalée entre une face de distribution de stator de pompe et une face d'alimentation de rotor de pompe de forme également plane.
• Figure 2 est une vue fantôme tridimensionnelle d'une pompe hydraulique à pistons radiaux comprenant un distributeur hydraulique qui reçoit la bague d'étanchéité pour distributeur de pompe hydraulique suivant l'invention dont la bague continue d'étanchéité est de forme générale cylindrique et est intercalée entre une face de distribution de stator de pompe et une face d'alimentation de rotor de pompe de forme également cylindrique.
• Figures 3 et 4 sont respectivement une vue fantôme tridimensionnelle et une vue tridimensionnelle éclatée d'un distributeur hydraulique qui reçoit la bague d'étanchéité pour distributeur de pompe hydraulique suivant l'invention dont la bague continue d'étanchéité est forme générale cylindrique, ladite bague coopérant avec quatre lumières de compensation d'effort radial placées axialement de part et d'autre de deux lumières d'admission-refoulement.
• Figure 5 est une vue tridimensionnelle de la bague continue d'étanchéité lorsqu'elle est de forme générale cylindrique, et deux joints d'étanchéité de compression-décompression et de quatre joints d'étanchéité latérale constitués d'une même pièce continue de matériau souple avec laquelle peut coopérer ladite bague, cette configuration pouvant être l'objet d'un mode particulier de réalisation de la bague d'étanchéité pour distributeur de pompe hydraulique suivant l'invention.
• Figures 6 et 7 sont respectivement une vue latérale et une coupe schématique transversale de la bague continue d'étanchéité lorsqu'elle est de forme générale cylindrique et qu'elle comprend - selon un mode particulier de réalisation de la bague d'étanchéité pour distributeur de pompe hydraulique suivant l'invention-six alvéoles sectorielles de compression-décompression et quinze sous-évidements de distribution.
• Figure 8 est une coupe schématique transversale d'un distributeur hydraulique qui reçoit la bague d'étanchéité pour distributeur de pompe hydraulique suivant l'invention, ledit distributeur comprenant un stator de pompe muni de deux lumières d'admission-refoulement qui coopère avec un rotor de pompe qui présente neuf orifices d'alimentation.
• Figure 9 est une vue en coupe tridimensionnelle de la bague continue d'étanchéité de la bague d'étanchéité pour distributeur de pompe hydraulique suivant l'invention, ainsi que des joints d'étanchéité latérale, de la gorge de bague, et du stator de pompe avec lesquels coopère ladite bague continue.
• Figure 10 est une coupe schématique partielle selon B-B de la bague continue d'étanchéité montrée en figure 8 telle que peut la prévoir la bague d'étanchéité pour distributeur de pompe hydraulique suivant l'invention, ladite coupe étant effectuée au niveau d'un sous-évidement de distribution.
• Figure 11 est une coupe schématique partielle selon C-C de la bague continue d'étanchéité montrée en figure 8 telle que peut la prévoir la bague d'étanchéité pour distributeur de pompe hydraulique suivant l'invention, ladite coupe montrant notamment comment peut être agencée une alvéole sectorielle de compression-décompression et comment cette dernière peut être reliée à la surface de la piste de compression-décompression par un conduit sectoriel de compression-décompression.
• Figures 12 et 13 illustrent en coupe schématique le fonctionnement de la bague continue d'étanchéité telle qu'il peut être prévu par la bague d'étanchéité pour distributeur de pompe hydraulique suivant l'invention lorsque l'une des deux lumières d'admission-refoulement du stator de pompe avec lequel coopère ladite bague continue est soumise à une pression élevée.
• Figure 14 est une vue en coupe tridimensionnelle de la plaque d'étanchéité de compensation d'effort radial que peut comporter la bague d'étanchéité pour distributeur de pompe hydraulique suivant l'invention, ainsi que du joint souple d'étanchéité de compensation, de la gorge de compensation d'effort radial, et du stator de pompe avec lesquels coopère ladite plaque.
• Figure 15 est une coupe schématique de la plaque d'étanchéité de compensation d'effort radial telle que peut la prévoir la bague d'étanchéité pour distributeur de pompe hydraulique suivant l'invention, ladite coupe étant effectuée au niveau de l'évidement de compensation que comporte ladite plaque.

The following description with reference to the accompanying drawings, given by way of non-limiting examples, will make it possible to better understand the invention, the characteristics it presents, and the advantages that it is likely to provide:

• Figure 1 is a three-dimensional phantom view of a hydraulic pump with axial pistons comprising a hydraulic distributor which receives the sealing ring for the hydraulic pump distributor according to the invention, the sealing ring of which is generally flat in shape and is interposed between a pump stator distribution face and a planar pump rotor supply face also flat.
• Figure 2 is a three-dimensional phantom view of a radial piston hydraulic pump comprising a hydraulic distributor which receives the sealing ring for hydraulic pump distributor according to the invention, the continuous sealing ring is generally cylindrical in shape and is interposed between a pump stator distribution face and a pump-cylindrical pump rotor supply face.
• Figures 3 and 4 are respectively a three-dimensional phantom view and an exploded three-dimensional view of a hydraulic distributor which receives the sealing ring for hydraulic pump distributor according to the invention, the continuous sealing ring is generally cylindrical, said ring cooperating with four lights radial force compensation placed axially on both sides of two inlet-discharge ports.
• Figure 5 is a three-dimensional view of the continuous sealing ring when it is generally cylindrical in shape, and two compression-decompression seals and four side seals made of one and the same continuous piece of flexible material with which may cooperate said ring, this configuration may be the subject of a particular embodiment of the sealing ring for hydraulic pump distributor according to the invention.
• Figures 6 and 7 are respectively a side view and a schematic cross section of the continuous sealing ring when it is generally cylindrical in shape and comprises - according to a particular embodiment of the sealing ring for a hydraulic pump distributor according to the invention-six sectoral compression-decompression cells and fifteen distribution sub-recesses.
• Figure 8 is a schematic cross section of a hydraulic distributor which receives the sealing ring for hydraulic pump distributor according to the invention, said distributor comprising a pump stator provided with two inlet-discharge ports which cooperates with a pump rotor which has nine feed ports.
• Figure 9 is a three-dimensional sectional view of the continuous sealing ring of the hydraulic pump distributor sealing ring according to the invention, as well as lateral seals, the ring groove, and the pump stator with which cooperates said continuous ring.
• Figure 10 is a partial schematic section along BB of the continuous sealing ring shown in FIG. figure 8 as may be expected the sealing ring for hydraulic pump distributor according to the invention, said cutting being performed at a sub-recess distribution.
• Figure 11 is a partial diagrammatic section along CC of the continuous sealing ring shown in figure 8 as may be provided by the hydraulic pump distributor sealing ring according to the invention, said section showing in particular how a sectoral compression-decompression cell can be arranged and how this can be connected to the surface of the compression track decompression by a sectoral compression-decompression duct.
• Figures 12 and 13 illustrate in schematic section the operation of the continuous sealing ring such that it can be provided by the sealing ring for hydraulic pump distributor according to the invention when one of the two inlet-discharge ports of the stator of pump with which cooperates said continuous ring is subjected to a high pressure.
• Figure 14 is a three-dimensional sectional view of the radial force compensation sealing plate that can comprise the sealing ring for hydraulic pump distributor according to the invention, as well as the flexible seal compensation sealing, radial force compensation groove, and pump stator with which said plate cooperates.
• Figure 15 is a diagrammatic section of the radial force compensation sealing plate such as may be provided by the sealing ring for a hydraulic pump distributor according to the invention, said section being made at the level of the compensation recess which comprises said plate.

DESCRIPTION OF THE INVENTION

We have shown in Figures 1 to 15 the sealing ring for hydraulic pump distributor 1.

The sealing ring for hydraulic pump distributor 1 according to the invention is provided for a hydraulic distributor 2 that may comprise a hydraulic pump 44, said distributor 2 comprising at least one pump stator distribution face 5 secured to a stator pump 3 said distribution face 5 having a low-pressure sealing surface on the stator side 12 of which open at least two inlet-discharge ports 7 arranged in the pump stator 3 and which each communicate with at least one duct d 8 which is their own and which is also arranged inside said stator 3, said distributor 2 also comprising at least one pump rotor supply face 6 integral with a pump rotor 4 said face supply 6 having a low-pressure sealing surface on the rotor side 13 from which opens at least one orifice 9 communicating with a feed duct 10 arranged the inside of said rotor 4 while the low-pressure sealing surface on the stator side 12 is positioned facing the low-pressure sealing surface on the rotor side 13 so that the supply orifice 9 is alternately facing one or other of the two intake-discharge ports 7 at least once per revolution of pumped rotor 4.

We see on Figures 1 to 13 that the sealing ring for hydraulic pump distributor 1 comprises at least one continuous sealing ring 11 housed at low axial and / or radial clearance in a ring groove 16 provided in the pump stator 3 inside the surface area delimited by the low-pressure sealing surface on the stator side 12, said ring 11 having a stator side face of the ring 23 housed inside the ring groove 16, and a rotor side ring face 22 which is flush with the low sealing surface -pressure stator side 12, while the inlet-discharge ports 7 open at said sealing surface 12 through said groove 16, said ring 11 being axially or radially wider than said lights 7 so covering them and comprising, approximately axially or radially aligned with the latter, at least one dispensing recess 21 passing through the continuous sealing ring 11 from one side to the other in the direction of its thickness, said recess 21 being able to put into communication the one of the two intake-discharge ports 7 with the supply port 9 when the latter is approximately facing said light 7, the same recess of distri Bution 21 can put only one light in communication with said orifice 9.

Note that the continuous sealing ring 11 may advantageously have a low thickness and stiffness so as to be easily deformable and to adapt to its geometric environment even when the hydraulic pressure produced by the hydraulic pump 44 is relatively low.

Also, as illustrated particularly by figures 9 and 10 , the sealing ring for hydraulic pump distributor 1 according to the invention comprises at least one circumferential contact boss 14 arranged axially or radially on either side of the dispensing recess 21, said boss 14 having a line of circumferential contact 15 which can come into contact with the low-pressure sealing surface on the rotor side 13.

Note that advantageously, the circumferential contact boss 14 and / or the low-pressure sealing surface on the rotor side 13 may be nitrided, cemented and / or coated with DLC "Diamond-like-Carbon" or any other hard coating and / or low coefficient of friction.

The sealing ring for a hydraulic pump distributor 1 also comprises at least one compression-decompression track 24 arranged on a certain angular sector of the rotor-side face of the ring 22, said sector being positioned outside the portion of said face 22 where is placed the radial distribution recess 21. Said track 24 is particularly visible in figure 5 .

As we see clearly in figure 9 , the sealing ring 1 according to the invention further comprises at least one ring sealing lip 39 integral or not with the contained sealing ring 11 and which provides an axial or radial seal between said ring 11 and the throat of ring 16.

The figure 11 in particular shows that the sealing ring for a hydraulic pump distributor 1 comprises at least one compression-decompression seal 28 which provides a seal between the face of the ring on the stator side 23 and the bottom and / or the axial sides or radial of the ring groove 16 and this, at the angular zone defined by the angular sector on which is arranged the compression-decompression track 24.

Finally, the sealing ring for a hydraulic pump distributor 1 comprises rotation stop means 36 shown in FIG. figures 4 and 5 which keep the continuous sealing ring 11 in a fixed angular position relative to the pump stator 3.

The sealing ring for a hydraulic pump distributor 1 according to the invention provides that the ring groove 16 may comprise - as illustrated in FIG. figure 9 - A ring bearing face 17 on its sides which are oriented perpendicularly to the low-pressure sealing surface on the stator side 12, said bearing surface 17 cooperating with a bearing shoulder 19 that includes ring continuous ring sealing 11.

We always notice in figure 9 that the ring groove 16 may comprise a ring sealing face 18 on its sides which are oriented perpendicular to the low-pressure sealing surface on the stator side 12, said sealing face 18 cooperating with a sealing shoulder of ring 20 that includes the continuous sealing ring 11.

As shown in figure 9 , the ring sealing lip 39 may be a flexible metal blade integral with the ring sealing shoulder 20.

Note that the ring sealing lip 39 can be positioned on, below or in the extension of the ring sealing shoulder 20.

The ring sealing lip 39 may consist of a lateral seal 27 of flexible material held simultaneously in contact with the ring groove 16 and with the stator-side face of the ring 23, which is clearly shown in FIG. figure 10 . Said flexible material may for example be rubber or an elastomer, and may be reinforced with a more rigid material such as plastic, teflon, steel or any stiffening material or structure known to those skilled in the art .

As shown in figure 11 the sealing ring for hydraulic pump distributor according to the invention provides that the compression-decompression seal 28 may have at least one compression-decompression sector cell 25 which defines a closed and sealed volume with the ring face on the stator side 23 and the bottom and / or the axial or radial sides of the ring groove 16, said cell 25 being of round, oval, oblong, square, rectangular or any geometry, without any limitation.

The compression-decompression seal 28 may comprise a cellular stiffening structure 40 in which the sectoral compression-decompression cell 25 is arranged, said cellular structure 40 being made of a rigid material 42 and able to be directly or indirectly maintained. in position relative to the continuous sealing ring 11 by the rotational stop means 36, while said rigid material 42 may in all or part be coated with a flexible material 43 which can come into contact with the ring face next stator 23 on the one hand, and / or with the bottom and / or the axial or radial sides of the ring groove 16 on the other hand.

The figures 4 , 5 , 7 , 8 , 11 , 12 and 13 show that the honeycomb stiffening structure 40 can be integrated with the stator-side face of the ring 23 and be made in the same piece of material as the continuous sealing ring 11, in this case, the sectoral compression-decompression cell (s). 25 may be hollowed out in the stator-side face of the ring 23, for example by electrochemical machining, while the lateral seal 27 and the compression-decompression seal 28 may in particular be made of a flexible material 43 overmoulded on the face of the ring on the stator side 23 and the honeycomb stiffening structure 40, said seals then having to load only to achieve the best possible seal between the continuous seal ring 11 and the ring groove 16 with which it cooperates.

According to a particular embodiment of the sealing ring for hydraulic pump distributor 1 according to the invention shown in FIG. Figures 5 to 8 and in figure 11 the compression-decompression track 24 may have at least one compression-decompression sectorial orifice 26 through which a sectoral compression-decompression duct 41 opens, the latter connecting with the rotor-side face of the ring 22 the sealed and closed volume defined by FIG. sectoral compression-decompression cell 25, said sector orifice 26 being positioned in such a way that the supply orifice 9 is facing said sector orifice 26 once per revolution of the pump rotor 4, said sector orifice 26 then connecting the supply duct 10 to said sealed volume via the sectoral compression-decompression duct 41.

Note that in this case, the pressure to which the hydraulic fluid contained in the supply conduit 10 is immediately propagated to the closed and sealed volume that defines the sector cell compression-decompression 25. Taking this into account, the area of the compression-decompression sector cell 25 on which said pressure is exerted is advantageously greater than the area of the section of the supply orifice 9 so that the compression-decompression track 24 is found naturally plated by said pressure on the low-pressure sealing surface on the rotor side 13 to which it faces, this resulting producing the desired seal between said track 24 and said surface 13.

We notice - especially in figures 4 and 5 that the lateral seal 27 and the compression-decompression seal 28 may form a single piece which may be made of various rigid and flexible materials so as to be locally resistant to deformation, and so to be locally or uniformly year and / or enhanced by any means known to those skilled in the art.

As such, as shown by the figures 10 and 11 the lateral seal 27 and / or the compression-decompression seal 28 may for example comprise a metal core 55 of rigid material 42.

Note that the ring sealing face 18 can be positioned approximately vertically above the circumferential contact line 15, while a slight offset between said face 18 and said line 15 allows - as suggested by figure 10 that the pressure in the ring groove 16 plates said line 15 on the pump rotor supply face 6 to achieve a good seal between said line 15 and said feed face 6 while generating only a few contact force between these last two and therefore, little floating losses

The figure 10 also illustrates that the ring sealing face 18 may be positioned approximately perpendicular to the circumferential contact line 15 while the ring bearing face 17 may be further away from the bottom of the ring groove 16 and the distribution recess 21 as said sealing face 18 so that it is offset relative to the plumb with the circumferential contact line 15.

According to a particular embodiment of the sealing ring for hydraulic pump distributor 1 according to the invention shown in FIG. figure 4 at least one of the axial faces of the ring groove 16 can be formed by the axial face of a ring mounting ring 34 which encloses the pump stator 3, said ring 34 allowing the mounting of the continuous ring sealing 11 and / or the compression-decompression seal 28 and / or the lateral seal 27 on the pump stator 3.

Note that said mounting ring 34 can be mounted on the pump stator 3 in particular by shrinking, by gluing, by screwing, by crimping, by roller burnishing or by welding and that it can comprise at least one solid seal or viscous lodged between him and the pump stator 3.

We notice in figures 3 and 4 that the pump stator distribution face 5 and the pump rotor supply face 6 can be cylindrical while at least one of the intake-discharge ports 7 cooperates with at least one force compensation light radial 30 arranged in the pump stator 3, the latter 30 opening out from the pump stator distribution face 5 and facing the pump rotor supply face 6. said compensation light 30 being furthermore located - in said stator 3 - diametrically opposite to the intake-discharge lumen 7 with which it cooperates and is connected by a radial force compensation duct 31 to the intake-discharge duct 8 to which said intake-discharge lumen 7 is connected. with which she cooperates.

It should be noted that the surface exposed by said pressure compensating light 30 is substantially equivalent to the surface exposed by the same pressure to the inlet-discharge port 7 with which it co-operates so that said pressure generates only a small amount of pressure. or no radial force on the pump stator 3 and the pump rotor 4. It is further noted that the compensation light 30 can be arranged inside the surface area delimited by the lowermost sealing surface. stator side pressure 12 while it can face the low-pressure sealing surface rotor side 13.

As illustrated in particular by figures 4 , 14 and 15 , the compensating light 30 can emerge from the pump stator distribution face 5 via a radial force compensation groove 29 in which is housed a low axial play and / or tangential a force compensation sealing plate radial 32 which is for example made of steel.

The figure 15 shows that the radial force compensation sealing plate 32 can be traversed right through in the direction of its thickness by a compensation recess 48 which connects the radial force compensation duct 31 with the face d pump rotor supply 6.

It is noted that the compensation recess 48 may consist of a hole of small section preserving the radial force compensation sealing plate 32 the best possible rigidity, said hole serving only to propagate to the the pump rotor supply face 6 the pressure prevailing in the radial force compensation duct 31 to which said plate 32 is connected.

The figure 14 shows that the radial force compensation groove 29 may comprise a plate support face 49 on its sides which are oriented perpendicularly to the low-pressure sealing surface on the stator side 12, said bearing face 49 cooperating with a plate support shoulder 51 that comprises the radial force compensation sealing plate 32.

The figures 14 also shows that the radial force compensation groove 29 may comprise a plate sealing face 50 on its sides which are oriented perpendicularly to the low-pressure sealing surface on the stator side 12, said sealing face 50 cooperating with a plate sealing shoulder 52 that comprises the radial force compensation sealing plate 32.

Always in figure 14 it can be seen that the radial force compensation sealing plate 32 can cooperate with a compensation plate sealing lip 45 which may or may not be integral with said plate 32, said lip 45 providing axial and / or radial sealing and / or tangential between said plate 32 and the radial force compensation groove 29 while said lip 45 may in particular be a flexible metal blade integral with the plate sealing shoulder 52 and / or be positioned on, below or in the extension of said shoulder 52.

It is noted that the ring sealing lip 39 may consist of a flexible sealing gasket 33 of flexible material held simultaneously in contact with the radial force compensation groove 29 and with the sealing plate of radial force compensation 32 said flexible material may for example be rubber or an elastomer, and may be armed with a more rigid material such as plastic, Teflon, steel or any material or stiffening structure known to the skilled in the art.

According to the particular embodiment of the sealing ring for hydraulic pump distributor 1 according to the invention shown in FIG. Figures 14 and 15 , the radial force compensation sealing plate 32 may comprise at least one peripheral compensation contact boss 46 arranged at its periphery, said boss 46 having a peripheral compensation contact line 47 able to come into contact with the face of the device. pump rotor supply 6.

It is noted that advantageously, the peripheral compensation contact boss 46 and / or the low-pressure sealing surface on the rotor side 13 with which it cooperates can be nitrided, cemented and / or coated with DLC "Diamond-like-Carbon" or any other hard coating and / or low coefficient of friction.

Also, the plate sealing face 50 can be positioned approximately perpendicular to the peripheral compensating contact line 47, while a slight offset between said face 50 and said line 47 allows the pressure in the throat of compensation of radial force 29 plate said line 47 on the pump rotor supply face 6 to achieve a good seal between said line 47 and said feed face 6 while generating little contact force between these last two and therefore, little friction losses, This configuration is clearly exposed in figure 15 .

The figure 15 also shows that the plated sealing face 50 can be positioned approximately perpendicular to the compensating peripheral contact line 47 while the plate bearing face 49 is further away from the bottom of the compensation groove of FIG. radial force 29 and the compensating recess 48 that said sealing face 50 so that it is offset from the plumb with the peripheral compensating contact line 47.

As shown by Figures 3 to 10 and 12 and 13 , the distribution recess 21 may comprise at least one connecting beam 56 which interconnects the circumferential contact bosses 14, said beam 56 thus defining on either side of its length at least one distribution sub-recess 57 said beam 56 thus partially closing the intake-discharge lumen 7 which is approximately axially or radially aligned with said recess 21 without compromising the good circulation of a hydraulic fluid or any other fluid between said lumen 7 and the orifice feeding 9 facing him.

We notice in figures 4 and 5 that the rotational stop means 36 may consist of at least one ring rotation stop pin 35 plugged into a stator stop pin hole 37 provided in the pump stator 3 on the one hand, and introduced into a ring stop pin hole 38 through the continuous sealing ring 11 in the direction of its thickness on the other hand.

Note that the ring rotation stop pin 35 can be freely mounted in the ring stop pin hole 38 and clamped in the stator stop pin hole. 37 or vice versa, said stop pin 35 being for example a metal cylinder or a split elastic pin.

OPERATION OF THE INVENTION:

From the above description and in relation to the Figures 1 to 15 the operation of the sealing ring for a hydraulic pump distributor 1 according to the present invention is understood.

To illustrate the operation of said ring 1, the configuration shown in FIG. Figures 2 to 15 applied to a hydraulic pump 44 whose hydraulic pump pistons 53 and the hydraulic pump cylinders 54 are arranged radially in the pump rotor 4 as shown in FIG. figure 2 . It is specified that according to this non-limiting embodiment, said pump 44 pumps the oil.

According to this non-limiting embodiment of the sealing ring 1 according to the invention, the pump stator distribution face 5 and the pump rotor supply face 6 are cylindrical. Said ring 1 is therefore also of predominantly cylindrical shape. As is clearly illustrated by figures 8 , 12 and 13 , the hydraulic distributor 2 comprises according to this example two inlet-discharge ports 7. This justifies that the continuous seal ring 11 has two distribution recesses 21 each radially aligned with the inlet-discharge ports 7 with which it cooperates as shown by Figures 3 to 8 and 12 and 13 .

The figure 10 is a partial section along BB of the continuous sealing ring 11 shown in FIG. figure 8 . Said cut is made at a dispensing recess 21 and more particularly at a dispensing sub-recess 57. Said cut shows in particular the circumferential contact boss 14 arranged axially on either side of said obviously 21. As shown in three dimensions figure 9 . said boss 14 has a circumferential contact line 15 intended to come into contact with the low-pressure sealing surface on the rotor side 13 so as to achieve with the latter the best possible seal.

We see Figures 3 to 10 and 12 and 13 that the dispensing recesses 21 pass through the continuous sealing ring 11 from one end to the other in the direction of its thickness and are separated from each other in the circumferential direction by a compression-decompression track 24 on the surface of which open several sector-specific compression-decompression ducts 41 via a sectoral orifice of compression-decompression 26 own. According to this non-limiting embodiment, the circumferential contact bosses 14 arranged axially on either side of the distribution recesses 21 are connected in the axial direction by connecting beams 56 which separate the distribution sub-recesses 57.

We notice - especially in figures 8 , 12 and 13 each compression-decompression sector duct 41 is connected to a sectoral compression-decompression cell 25 which defines, with the bottom of the ring groove 16, a sealed and sealed volume. The figure 11 is a partial section along CC of the continuous sealing ring 11 shown in FIG. figure 8 which shows in detail how a sectoral compression-decompression cell 25 is arranged and how it is connected to the surface of the compression-decompression track 24 by the sectoral compression-decompression duct 41 with which it cooperates.

We clearly see figures 5 , 7 , 8 , 12 and 13 that the compression-decompression sector cells 25 are arranged in a stiffening honeycomb structure 40 integrated with the stator side ring face 23, said structure 40 forming - with a flexible material 43 overmolded on said structure - the compression seal -depression 28, as shown in more detail the figure 11 .

We also see in figures 4 and 5 that according to the particular embodiment of the sealing ring 1 according to the invention taken here to illustrate the operation, the two compression-decompression seals 28 and the four side seals 27 comprise in particular of the same continuous piece of flexible material 43. For clarity, in said figures, said continuous piece is shown separate from the continuous sealing ring 11. In practice, said piece can be coated by overmolding or by gluing the face next to the stator ring 23 and the stiffening honeycomb structure 40 integrated in said ring face 23.

The figure 11 shows that the flexible material 43 partially fills the sectoral compression-decompression alveoli 25 so as to form a pocket in said alveoles 25, and makes the best possible seal between the face of the stator side ring 23 and the ring groove 16.

As we can see in figures 4 and 5 , the continuous sealing ring 11 is held in a fixed angular position relative to the pump stator 3 by the ring rotation stop pin 35 - here a simple metal cylinder - which passes through said ring 11 via the pawn hole ring stop 38, said pin 35 being free in said hole 38 while it is locked in the stator stop pin hole 37.

It is easy to deduce from figure 4 that the continuous sealing ring 11 thus configured with its compression-decompression sealing seals 28 and its lateral seals 27 could be mounted on the pump stator 3 by means of the ring mounting ring 34.

We also note in figures 3 and 4 that the pump stator 3 has four radial force compensation lights 30 placed axially on either side of the inlet-discharge ports 7. According to this particular configuration of the hydraulic pump distributor sealing ring 1 according to the invention, each intake-discharge lamp 7 cooperates with the two radial force compensation holes 30 which are arranged at its diametrical opposite in the pump stator 3, the latter slots 30 being connected by their compensation pipe. radial force 31 to the same intake-discharge duct 8 as the inlet-discharge lumen 7 with which they cooperate, as clearly shown in FIG. figure 3 .

It is noted that the total area exposed to pressure by the two so-called compensation windows 30 is substantially equivalent to the surface exposed at the same pressure to the intake-discharge port 7 with which they cooperate. Thus, the pressure in the intake-discharge port 7 generates a radial force on the pump stator 3 and the pump rotor 4 weak or zero.

It can be seen that, like the continuous sealing ring 11 which ensures the best possible seal between the inlet-winding ports 7 and the pump rotor supply face 6, the compensation sealing plate of radical force 32 that each radial force compensation light 30 also provides the best possible seal between said light 30 and said supply face 6.

As such, the radial force compensation sealing plate 32 comprises in particular a compensation plate sealing lip 45 which provides a seal between said plate 32 and the radial force compensation groove 29 with which it cooperates. . The figure 14 which is a three-dimensional section of said plate 32 and the figure 15 which is a schematic section show that, in the case taken here to illustrate the operation of the sealing ring 1 according to the invention, the compensation plate sealing lip 45 is a thin metal blade arranged in the extension of the plate sealing shoulder 52 and which cooperates with a flexible seal of compensating seal 33 of flexible material 43 such as rubber or an elastomer, said flexible material 43 being able to be overmolded under the sealing plate radial force compensation device 32 and in extension of said shoulder 52, said flexible seal 33 being held simultaneously in contact with the radial force compensation groove 29 and with the lower part of the compensation plate sealing lip 45 .

It can be stated here that the radial force compensation sealing plate 32 is relatively flexible and easily deformable so that the pressure can press the peripheral compensation contact line 47 on the low-pressure sealing surface on the rotor side. 13.

To do this, an offset is provided between the plate sealing face 50 that has the radial force compensation groove 29 and the plumb with the compensating peripheral contact line 47 that comprises - immediately above said sealing face 50 - the radial force compensation sealing plate 32. It results from said shift a weak section S1 on which the pressure is exerted, so that the radial force resulting from said section S1 remains low. This tends to achieve a good seal between the peripheral compensating contact line 47 and the low-pressure sealing surface on the side rotor 13 while generating little contact force between said line 47 and said surface 13 and therefore, little loss by floating.

To properly describe the operation of the sealing ring 1 according to the invention, it should be pointed out that the continued seal ring 11 is of small thickness and as such, it is also relatively flexible and easily deformable. Furthermore, it should also be noted that the ring groove 16 is deep enough for said continuous ring 11 to be radially offset relative to said groove 16, as shown by FIGS. Figures 12 and 13 . However, it is understood that in practice, the deformations and eccentrations to which the continuous sealing ring 11 is subjected are of the order of a few microns to a few tens of microns and that the Figures 12 and 13 which show said deformations and eccentrations strongly exaggerate them so that we can understand the impact on the operation of the sealing ring 1 according to the invention.

Thus, when the hydraulic pump 44 with radial pistons - of the type represented in FIG. figure 2 - operates, its pump rotor 4 rotates around the pump stator 3. The pump stator distribution face 5 is positioned facing the pump rotor supply face 6 while the intake-discharge ports 7 are approximately aligned with the nine feed port apertures 9 which each feed a hydraulic pump cylinder 54 via its own feed duct 10.

We notice in Figures 12 and 13 that the pressure which prevails in the upwardly located inlet-discharge lumen 7 and which we shall tentatively call "upper lumen 7", does not propagate to the inlet-discharge lumen 7 placed furthest on said Figures 12 and 13 and that we will call temporarily "lower light 7" and this, thanks to the continuous seal ring 11 and in particular to the compression-decompression seal 28 which prevents the oil from passing tangentially between the side of the ring side stator 23 and the bottom of the ring groove 16.

If, as illustrated by figure 12 it is in the upper lumen 7 that the highest pressure prevails, for example a thousand bars, while a lower pressure prevails in the lower lumen, for example ten bars, the highest pressure exerts a local radial thrust. on the side of the ring stator 23 whose intensity is stronger than that exerted on said face 23 the lower pressure at the level of the lower lumen 7.

As a result of this asymmetry of thrust, the continuous sealing ring 11 is deformed and is pressed against the low-pressure sealing surface on the rotor side 13 at the level of the upper lumen 7 while said continuous ring 11 remains at a distance a few microns or tens of microns of said surface 13 at the level of the lower lumen 7.

Note that the force corresponding to said radial thrust remains low because the pressure is exerted on the face of the stator side ring 23 only on a small section S1 of said face 23 as shown in FIG. figure 10 . Said section S1 was determined during the design of the continuous sealing ring 11 and results from the intentionally planned axial offset between the two ring sealing faces 18 that the ring groove 16 has on either side of the continuous sealing ring 11, and the plumb with the circumferential contact line 15 arranged immediately above each of said sealing faces 18 on the face of the rotor side ring 22. It is noted in this regard that as shown in FIG. figure 10 , the circumferential contact lines 15 are axially located more inside the continuous sealing ring 11 than the ring sealing faces 18 with which they cooperate in order to produce the desired radial radial thrust on the side face of the ring. stator 23.

Thus, the axial offset provided between the two ring sealing faces 18 and the plumb with the circumferential contact lines 15 and which determines the section S1 makes the pressure in the ring groove 16 actually plates said lines 15 on the pump rotor supply face 6. This tends to seal between said lines 15 and said feed face 6 while generating little contact force between said lines 15 and said face 6 and therefore, little loss by friction. It should be noted that the contact pressure between said lines 15 and the pump rotor supply face 6 depends essentially on the width of the contact made by said lines 15 with said face 6, said width also resulting from a voluntary choice made during of the design of the continuous sealing ring 11.

We see on the figure 10 that between the ring sealing face 18 that has the ring groove 16 and the ring sealing shoulder 20 that the continuous sealing ring 11 presents, the seal is formed on the one hand by the lip of the ring sealing ring 39 which remains in contact - given its elasticity - with the ring sealing face 18, and secondly, by the lateral seal 27. Thus, said lip 39 prevents said seal 27 from Extrude even under very high pressure - for example two thousand bars - while the latter ensures a perfect seal.

We have seen figure 12 that due to the deformation of the continuous sealing ring 11, at the level of the lower lumen 7, the rotor side ring face 22 has remained at a distance of a few microns or tens of microns from the lowermost sealing surface; 13. In the angular sector occupied by said lower lumen 7, the circumferential contact lines 15 do not therefore apply to the pump rotor supply face 6 and do not perform any sealing.

As a result, the seal between said lower lumen 7 and the pump rotor supply face 6 is no longer achieved only by the small clearance of a few microns or tens of microns left between the low-pressure sealing surface quoted. stator 12 and the low-pressure sealing surface on the rotor side 13. Said weak clearance is obtained in particular by virtue of a high precision machining of said surfaces 12, 13 while the leak rates passing between them remain low given the low pressure. - here, ten bars according to the example chosen - prevailing in the lower light 7. The energy loss related to said leakage rates is negligible.

We understand that the figure 13 shows the deformation of the continuous sealing ring 11 when it is in the upper lumen 7 that the weakest pressure prevails - for example ten bars - while it is in the lower lumen 7 that the highest pressure prevails - For example a thousand bars, the operation of the continuous sealing ring 11 remains unchanged.

We noticed - especially in figures 8 , 12 and 13 the sectoral compression-decompression cells 25 which ensure a good seal between the supply orifices 9 and the compression-decompression track 24 after said orifices 9 have left the angular sector occupied by the upper lumen 7, said alveoles 25 are also visible in three dimensions in figure 5 , and in schematic section figure 11 .

Indeed, according to the example taken here to illustrate the operation of the sealing ring 1 according to the invention, the hydraulic pump cylinders 54 draw oil under ten bars from the lower slot 7 to push it back under a thousand bars at the level of the upper light 7. Also, during the passage of any supply port 9 of the upper lumen 7 to the lower lumen 7 via the compression-decompression track 24, it is necessary to progressively relax the oil included in the hydraulic pump cylinder 54 and the supply ducts 10 which are connected to said supply port 9. During this expansion, the energy that has been stored by said oil during its compression - said oil being compressible - can be mechanically recovered by the hydraulic pump 44. This function is necessary to give said pump 44 a good energy efficiency.

When - as a result of the rotation of the pump rotor 4 - the supply orifice 9 leaves the upper lumen 7 to engage on the compression-decompression track 24, said orifice 9 which has hitherto blocked said upper lumen 7 in connection with the corresponding hydraulic pump cylinder 54 via its own feed duct 10 is closed by said track 24. The mechanism of the hydraulic pump 44 increasing the volume of the hydraulic pump cylinder 54, the oil contained therein relaxes and begins to mechanically yield to said pump 44 the energy stored during the compression of said oil.

The feed orifice 9 continues to engage on the compression-decompression track 24 until it encounters a first sectoral pressure-decompression orifice 26 which connects said track 24 to the sealed and sealed volume defined by the sectoral cell of compression-decompression 25 located immediately below said sector orifice 26.

So we find ourselves in the configuration that illustrates the figure 11 which has the immediate effect of propagating the pressure prevailing in the hydraulic pump cylinder 54 to said closed and sealed volume whose radial section is substantially larger than that of the supply port 9. The resulting differential radial section S2 is represented in figure 11 . We take note that S2 was determined during the design of the continuous sealing ring 11 on the basis of a compromise between sealing and friction losses.

Due to the radial differential section S2 , the compression-decompression track 24 is pressed by the pressure on the low-pressure sealing surface on the side 13 of which opens the opening of the feed port 9. This constitutes a seal around of the supply port 9 between the compression-decompression track 24 and the low-pressure sealing surface on the rotor side 13, with a plating force of said track 24 on said surface 13 which is all the more important as the pressure prevailing in the hydraulic pump cylinder 54 is high.

Also, it is understood that as and when the feed port 9 is advanced on the compression-decompression track 24, the volume of the hydraulic pump cylinder 54 increases without the amount of oil increasing. that is contained in said cylinder 54. This is imposed by the mechanism of the hydraulic pump 44. This effectively results in an expansion of said oil and a recovery of energy that had been previously stored during the compression of the latter.

When said supply port 9 encounters the sectoral compression-decompression orifice 26 following, the same principle of plating the compression-decompression track 24 on the low-pressure sealing surface on the rotor side 13 takes place, but at a lower pressure, and so on until said supply port 9 reaches the lower lumen 7.

Note that according to the non-limiting embodiment of embodiment of the sealing ring 1 according to the invention illustrated in FIG. figures 8 , 12 and 13 , the annular gap between two compression-decompression sector openings 26 and the diameter of said orifices is calculated so that a same supply orifice 9 can not be simultaneously facing two said sectoral orifices 26. To increase the number of compression-decompression sector ports 26 and therefore, the number of compression-decompression sector orifice 26, it is noted that one can provide axially oblong axial supply ports 9, which can be staggered in at least two rows, the latter configuration also being applicable to As a non-limiting example - to the sectoral compression-decompression ports 26.

Furthermore, the geometry of the sectoral cells of compression-decompression 25 presented in particular in figure 5 is non-limiting and may differ from one cell 25 to another. In practice, the choice of said geometry must be guided by the need on the one hand, to produce the best possible seal between the compression-decompression track 24 and the low-pressure sealing surface on the rotor side 13 and other on the other hand, to generate the lowest possible friction between said track 24 and said surface 13.

We notice in figure 11 the section S1 resulting from the axial offset between the ring sealing faces 18 and the plumb with the circumferential contact lines 15, said offset being provided in the angular zone of the continuous sealing ring 11 occupied by the compression track -compression 24 at the same pulling as it is provided on the remainder of the circumference of the continuous sealing ring 11. Said section S1 makes it possible to perfect the tightness in axial borders of said track 24.

Claims (26)

1. Hydraulic pump (1) comprising a hydraulic distributor (2) and a sealing ring, the said distributor (2) comprising at least one pump stator distribution face (5) secured to a pump stator (3), the said distribution face (5) having a stator-side low-pressure sealing surface (12) from which there open at least two inlet-delivery ports (7) formed in the pump stator (3) and each of which communicates with at least one inlet-delivery duct (8) specific to it and likewise formed inside the said stator (3), the said distributor (2) also comprising at least one pump rotor feed face (6) secured to a pump rotor (4), the said feed face (6) having a rotor-side low-pressure sealing surface (13) from which there opens at least one orifice (9) communicating with a feed duct (10) formed inside the said rotor (4) whereas the stator-side low-pressure sealing surface (12) is positioned facing the rotor-side low-pressure sealing surface (13) so that the feed orifice (9) alternately finds itself facing one or other of the two inlet-delivery ports (7) at least once per revolution of the pump rotor (4), characterized in that the sealing ring comprises:

   • At least one continuous sealing ring (11) housed with a small amount of axial and/or radial clearance in a ring groove (16) formed in the pump stator (3) inside the surface area delimited by the stator-side low-pressure sealing surface (12), the said ring (11) having a stator-side ring face (23) housed inside the ring groove (16), and a rotor-side ring face (22) flush with the stator-side low-pressure sealing surface (12), whereas the inlet-delivery ports (7) open onto the said sealing surface (12) via the said groove (16), the said ring (11) being axially or radially wider than the said ports (7) so as to cover them and comprising, approximately in axial or radial alignment therewith, at least one distribution opening (21) passing right through the continuous sealing ring (11) in the direction of its thickness, the said opening (21) being able to place one of the two inlet-delivery ports (7) in communication with the feed orifice (9) when the latter is approximately facing the said port (7);

   • At least one circumferential-contact boss (14) formed axially or radially on each side of the distribution opening (21), the said boss (14) having a circumferential line of contact (15) that can come into contact with the rotor-side low-pressure sealing surface (13);

   • At least one compression-decompression track (24) formed on a certain angular sector of the rotor-side ring face (22), the said sector being positioned outside of that part of the said face (22) in which the radial distribution opening (21) is situated;

   • At least one ring sealing lip (39) that may or may not be secured to the continuous sealing ring (11) and that performs axial or radial sealing between the said ring (11) and the ring groove (16);

   • At least one compression-decompression sealing gasket (28) which performs sealing between the stator-side ring face (23) and the bottom and/or the axial or radial sides of the ring groove (16) and does so in the angular area defined by the angular sector over which the compression-decompression track (24) is formed;

   • Rotation-proofing means (36) which keep the continuous sealing ring (11) in a fixed angular position in relation to the pump stator (3).
2. Hydraulic pump according to Claim 1, characterized in that the ring groove (16) comprises a ring bearing face (17) on its sides which are oriented at right angles to the stator-side low-pressure sealing surface (12), the said bearing face (17) collaborating with a ring bearing shoulder (19) that the continuous sealing ring (11) comprises.
3. Hydraulic pump according to Claim 1, characterized in that the ring groove (16) comprises a ring sealing face (18) on its sides which are oriented at right angles to the stator-side low-pressure sealing surface (12), the said sealing face (18) collaborating with a ring sealing shoulder (20) that the continuous sealing ring (11) comprises.
4. Hydraulic pump according to Claim 3, characterized in that the ring sealing lip (39) is a flexible metal blade secured to the ring sealing shoulder (20).
5. Hydraulic pump according to Claim 3, characterized in that the ring sealing lip (39) is positioned on, under or in the continuation of the ring sealing shoulder (20).
6. Hydraulic pump according to Claim 1, characterized in that the ring sealing lip (39) consists of a lateral sealing gasket (27) made of a flexible material kept simultaneously in contact with the ring groove (16) and with the stator-side ring face (23).
7. Hydraulic pump according to Claim 1, characterized in that the compression-decompression sealing gasket (28) has at least one sectorial compression-decompression cell cavity (25) which, with the stator-side ring face (23) and the bottom and/or axial or radial sides of the ring groove (16), defines a closed and sealed volume.
8. Hydraulic pump according to Claim 7, characterized in that the compression-decompression sealing gasket (28) comprises a stiffening cellular structure (40) in which the sectorial compression-decompression cell cavity (25) is formed, the said cellular structure (40) being produced in a rigid material (42) and being able to be kept in position in relation to the continuous sealing ring (11) directly or indirectly using the rotation-proofing means (36), whereas the said rigid material (42) may be coated completely or partially with a flexible material (43) that can come into contact with the stator-side ring face (23) on the one hand, and/or with the bottom and/or the axial or radial sides of the ring groove (16) on the other hand.
9. Hydraulic pump according to Claim 8, characterized in that the stiffening cellular structure (40) is incorporated into the stator-side ring face (23) and is made from the same piece of material as the continuous sealing ring (11).
10. Hydraulic pump according to Claim 7, characterized in that the compression-decompression track (24) has at least one sectorial compression-decompression orifice (26) via which a sectorial compression-decompression duct (41) opens, the latter duct connecting the closed and sealed volume defined by the sectorial compression-decompression cell cavity (25) with the rotor-side ring face (22), the said sectorial orifice (26) being positioned in such a way that the feed orifice (9) finds itself facing the said sectorial orifice (26) once per revolution of the pump rotor (4), the said sectorial orifice (26) then connecting the feed duct (10) to the said sealed volume via the sectorial compression-decompression duct (41).
11. Hydraulic pump according to Claim 6, characterized in that the lateral sealing gasket (27) and the compression-decompression sealing gasket (28) form just one single component.
12. Hydraulic pump according to Claim 3, characterized in that the ring sealing face (18) is positioned approximately plumb with the circumferential line of contact (15).
13. Hydraulic pump according to Claims 2 and 3, characterized in that the ring sealing face (18) is positioned approximately plumb with the circumferential line of contact (15) whereas the ring sealing face (17) is further away from the bottom of the ring groove (16) and the distribution opening (21) than the said sealing face (18) so that it is offset out of plumb with the circumferential line of contact (15).
14. Hydraulic pump according to Claim 1, characterized in that at least one of the axial faces of the ring groove (16) is formed by the axial face of a ring mounting band (34) that fits closely around the pump stator (3).
15. Hydraulic pump according to Claim 1, characterized in that the pump stator distribution face (5) and the pump rotor feed face (6) are cylindrical whereas at least one of the inlet-delivery ports (7) collaborates with at least one radial-load compensating port (30) formed in the pump stator (3), the latter port (30) opening from the pump stator distribution face (5) and facing the pump rotor feed face (6), the said compensating port (30) also being situated - within the said stator (3) - diametrically opposite the inlet-delivery port (7) with which it collaborates and being connected by a radial-load compensating duct (31) to the inlet-delivery duct (8) to which the said inlet-delivery port (7) with which it collaborates is connected.
16. Hydraulic pump according to Claim 15, characterized in that the compensating port (30) opens from the pump stator distribution face (5) via a radial-load compensating groove (29) in which a radial-load compensating sealing plate (32) is housed with a small amount of axial and/or tangential clearance.
17. Hydraulic pump according to Claim 16, characterized in that the radial-load compensating sealing plate (32) has passing right through it in the direction of its thickness a compensating opening (48) which places the radial-load compensating duct (31) in communication with the pump rotor feed face (6).
18. Hydraulic pump according to Claim 16, characterized in that the radial-load compensating groove (29) comprises a plate bearing face (49) on its sides which are oriented at right angles to the stator-side low-pressure sealing surface (12), the said bearing face (49) collaborating with a plate bearing shoulder (51) that the radial-load compensating sealing plate (32) comprises.
19. Hydraulic pump according to Claim 16, characterized in that the radial-load compensating groove (29) comprises a plate sealing face (50) on its sides which are oriented at right angles to the stator-side low-pressure sealing surface (12), the said sealing face (50) collaborating with a plate sealing shoulder (52) that the radial-load compensating sealing plate (32) comprises.
20. Hydraulic pump according to Claim 16, characterized in that the radial-load compensating sealing plate (32) collaborates with a compensating-plate sealing lip (45) that may or may not be secured to the said plate (32), the said lip (45) performing axial and/or radial and/or tangential sealing between the said plate (32) and the radial-load compensating groove (29).
21. Hydraulic pump according to Claim 20, characterized in that the ring sealing lip (39) consists of a flexible compensating sealing gasket (33) made of a flexible material kept simultaneously in contact with the radial-load compensating groove (29) and with the radial-load compensating sealing plate (32).
22. Hydraulic pump according to Claims 16 and 17, characterized in that the radial-load compensating sealing plate (32) comprises at least one compensating peripheral contact boss (46) formed at its periphery, the said boss (46) having a compensating peripheral line of contact (47) able to come into contact with the pump rotor feed face (6).
23. Hydraulic pump according to Claims 19 and 22, characterized in that the plate sealing face (50) is positioned approximately plumb with the compensating peripheral line of contact (47).
24. Hydraulic pump according to Claims 18, 19 and 22, characterized in that the plate sealing face (50) is positioned approximately plumb with the compensating peripheral line of contact (47) whereas the plate bearing face (49) is further away from the bottom of the radial-load compensating groove (29) and the compensating opening (48) than the said sealing face (50) so that it is offset out of plumb with the compensating peripheral line of contact (47).
25. Hydraulic pump according to Claim 1, characterized in that the distribution opening (21) comprises at least one connecting beam (56) which connects together the circumferential-contact bosses (14), the said beam (56) thus defining on either side of its length at least one distribution sub-opening (57).
26. Hydraulic pump according to Claim 1, characterized in that the rotation-proofing means (36) consist of at least one ring rotation-proofing pin (35) which on the one hand is plugged into a stator rotation-proofing pin hole (37) formed in the pump stator (3) and on the other hand is inserted into a ring rotation-proofing pin hole (38) that passes through the continuous sealing ring (11) in the direction of its thickness.

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