Hydraulic machine with improved distribution.

Abstract

Hydraulic machine with improved distribution Hydraulic machine, in which pistons are mounted sliding in housings along a sliding axis, each housing forming with the associated piston a first chamber (60) and a second chamber (70) distinct, characterized in that, the cylinder block (4) is configured so that, in projection along a plane perpendicular to the main axis (ZZ), for at least one housing, the conduit connected to the housing in which a piston slides opens at the interface between the distributor (3) and the cylinder block (4) in a manner angularly offset by an angle A relative to the sliding axis of the piston in said housing (44). Figure for the abstract: Fig. 5.

Description

Title of the invention: Hydraulic machine with improved distribution. Technical field

[0001] The present invention relates to the field of radial piston hydraulic machines. Prior art

[0002] Hydraulic machines with radial pistons and multi-lobe cams are commonly used for various applications in the field of hydraulics. These machines are typically reversible, and can have motor or pump operation, so as to deliver torque or flow depending on the desired application.

[0003] A recurring problem in the design of such hydraulic machines concerns the size, in particular due to the integration of specific functions which must be integrated into the different components, notably in the distributor and the cylinder block.

[0004] Furthermore, the applicant has developed radial piston hydraulic machines in which the pistons and associated housings define two separate chambers.

[0005] Such an architecture is interesting in terms of functionality and compactness of the cylinder block, but poses problems in terms of the size of the distributor due to the complexity of the conduits for supplying and discharging fluid into the different chambers.

[0006] The present invention thus aims to respond at least partially to this problem. Statement of the invention

[0007] The present invention thus provides a hydraulic machine comprising: a first assembly and a second assembly, movable in rotation relative to each other along a main axis, the first assembly comprising a casing, a distributor and a multi-lobe cam comprising a plurality of half-lobes each extending along an angular sector, the second assembly comprising a cylinder block having a plurality of housings, and pistons slidably mounted in said housings and performing reciprocating movements in said housings along half-lobes of the cam, each piston being slidably mounted in a housing along a sliding axis extending radially relative to the main axis, each pair formed by a piston and a housing defines between the piston and the housing a first chamber and a second chamber distinct from the first chamber, the set of first chambers defining a first hydraulic machine, the set of second chambers defining a second hydraulic machine, in which for each pair formed by a piston and a housing, the first chamber and the second chamber are superimposed according to a sliding direction of the piston in the housing, the cylinder block has a plurality of internal conduits defining a first set of conduits opening at the interface between the distributor and the cylinder block and adapted to supply and discharge fluid to the first chambers, and a second set of conduits opening at the interface between the distributor and the cylinder block and adapted to supply and discharge fluid to the second chambers characterized in that, the cylinder block is configured so that, in projection along a plane perpendicular to the main axis, for at least one housing, the conduit of the first set of conduits connected to the first chamber of said housing in which a piston slides opens at the interface between the distributor and the cylinder block in a manner angularly offset by an angle A relative to the sliding axis of the piston in said housing. It is understood that the designations of "first chambers" and "second chambers" are arbitrary here and have no impact on the scope.

[0008] According to one example, the cylinder block is configured so that, in projection along a plane perpendicular to the main axis, for each housing, the conduit of the first set of conduits connected to said housing in which a piston slides opens at the interface between the distributor and the cylinder block in a manner angularly offset by an angle A relative to the axis of sliding of the piston in said housing.

[0009] According to one example, the angle A is between 5° and 20°.

[0010] According to one example, the cylinder block is configured so that, for each housing, a conduit of the second set of conduits connected to said housing in which a piston slides opens at the interface between the distributor and the cylinder block in a manner angularly offset by an angle B relative to the sliding axis of the piston in said housing.

[0011] According to one example, for each housing, the conduit of the first set of conduits opening into the housing is offset by an angle A relative to the sliding axis of the piston in said housing in a first direction of rotation around the main axis, and the conduit of the second set of conduits opening into the housing is offset by an angle B relative to the sliding axis of the piston in said housing in a second direction of rotation around the main axis, opposite said first direction of rotation. Angles A and B are positive angles here. Thus, the conduits are positioned on either side of the sliding axis.

[0012] According to one example, the cam comprises L lobes, and for each housing, an angular difference between the conduit of the first set and the conduit of the second set of the same housing is equal to 360° / (2L), or the cylinder block comprises N pistons, and for each housing, an angular difference between the duct of the first set and the duct of the second set of the same housing is equal to 360° / (N).

[0013] According to one example, the ducts of the first set of ducts open from the cylinder block at a first distance RI relative to the main axis, and the ducts of the second set of ducts open from the cylinder block at a second distance R2 relative to the main axis, the first distance RI and the second distance R2 being distinct.

[0014] According to one example, for each set of two consecutive housings of the cylinder block in the circumferential direction around the main axis, the conduit of the first set of one of said housings and the conduit of the second set of the other of said housings are positioned so as to be supplied by two orifices of the distributor at two different distances from the main axis along the same angular sector.

[0015] According to one example, the first chambers are the chambers closest to the axis of rotation of the hydraulic machine and the second chambers are the chambers furthest from the axis of rotation of the hydraulic machine and the conduits of the first set of conduits adapted to provide the supply and discharge of the first chambers open from the cylinder block at a first distance RI relative to the main axis, and the conduits of the second set of conduits adapted to provide the supply and discharge of the second chambers open from the cylinder block at a second distance R2 relative to the main axis, with RI > R2. The distances are measured in the radial direction relative to the main axis.

[0016] Indeed, within the framework of the invention, it may be advantageous to “cross” the conduits adapted to supply and discharge the chambers of the two sub-machines for reasons of ease of manufacturing the parts and in particular the production of the drillings.

[0017] According to one example, the first chambers are the chambers closest to the axis of rotation of the hydraulic machine and the second chambers are the chambers furthest from the axis of rotation of the hydraulic machine and the conduits of the first set of conduits adapted to carry out the supply and the discharge of the first chambers open from the cylinder block to a first distance RI from the main axis, and the conduits of the second set of conduits adapted to supply and discharge the second chambers emerge from the cylinder block at a second distance R2 from the main axis, with RI < R2.

[0018] According to one example, the distributor has a first set of conduits opening from the distributor to the interface with the cylinder block at the first distance RI relative to the main axis, and a second set of conduits opening from the distributor to the interface with the cylinder block at the second distance R2 relative to the main axis, and in which the cylinder block is configured so that for each conduit of the first set of conduits of the distributor, a conduit of the second set of conduits of the distributor is positioned along the same angular sector.

[0019] According to one example, the distributor has a first set of conduits opening from the distributor to the interface with the cylinder block at the first distance RI relative to the main axis, and a second set of conduits opening from the distributor to the interface with the cylinder block at the second distance R2 relative to the main axis, and in which the cylinder block is configured so that the conduits of the first set of conduits of the distributor are positioned in a first set of angular sectors, the conduits of the second set of conduits of the distributor are positioned in a second set of angular sectors, the first set of angular sectors and the second set of angular sectors being disjoint.

[0020] According to one example, for each set of two consecutive housings of the cylinder block in the circumferential direction around the main axis, the conduit of the first set of one of said housings and the conduit of the second set of the other of said housings are positioned in the same angular sector.

[0021] According to an example, the conduits of the first set of conduits are positioned in a first set of angular sectors, the conduits of the second set of conduits are positioned in a second set of angular sectors, the first set of angular sectors and the second set of angular sectors being disjoint.

[0022] According to one example, one of the first hydraulic machine and the second hydraulic machine having a pump operation, and the other having a motor operation.

[0023] According to one example, the ducts of the cylinder block and the distributor are configured so that in operation, for each housing, the distributor conduit providing fluid admission to the hydraulic machine operating as a pump is positioned in the same angular sector as the distributor conduit providing fluid discharge to the hydraulic machine operating as a motor, and the distributor conduit carrying out the delivery of fluid from the hydraulic machine having a pump operation is positioned in the same angular sector as the distributor conduit carrying out the admission of fluid from the hydraulic machine having a motor operation.

[0024] According to one example, each housing has a first portion having a first section S1, and a second portion having a second section S2, the first section S1 being strictly greater than the second section S2, the first portion extending from an external surface of the cylinder block, and the second portion extending from the first portion.

[0025] According to one example, the distributor comprises radial through-bores, each of said radial bores connecting both a conduit of the first set of conduits and a conduit of the second set of conduits to an internal volume of the casing.

[0026] According to another example, the distributor comprises radial through-bores, each of said radial bores connecting both a conduit of the first set of conduits and a conduit of the second set of conduits to an enclosure isolated from the internal volume of the casing. Brief description of the drawings

[0027] The invention and its advantages will be better understood upon reading the detailed description given below of different embodiments of the invention given as non-limiting examples.

[0028] [Fig-1] [Fig.l] schematically presents a hydraulic machine composed of two hydraulic sub-machines.

[0029] [Fig.2] [Fig.2] shows a cylinder block structure of a hy hydraulics composed of two hydraulic sub-machines.

[0030] [Fig.3] [Fig.3] shows an example of a hydraulic machine structure composed of two hydraulic sub-machines.

[0031] [Fig.4] [Fig.4] shows an example of a hydraulic machine structure composed of two hydraulic sub-machines.

[0032] [Fig.5] [Fig.5] shows a cylinder block structure of a hydraulic machine composed of two hydraulic sub-machines according to one aspect of the invention.

[0033] [Fig.6] [Fig.6] shows an example of application of the invention.

[0034] [Fig.7] [Fig.7] shows an example of a conventional structure.

[0035] [Fig.8] [Fig.8] shows a distributor structure of a hydraulic machine composed of two hydraulic sub-machines according to one aspect of the invention.

[0036] [Fig.9] [Fig.9] shows a distributor structure of a hydraulic machine composed of two hydraulic sub-machines according to one aspect of the invention.

[0037] [Fig. 10] [Fig. 10] shows another example of application of the invention.

[0038]

[0039] [Fig. 11] [Fig. 11] shows another example of a distributor structure of a hydraulic machine composed of two hydraulic sub-machines according to one aspect of the invention.

[0040] Throughout the figures, the elements in common are identified by identical numerical references. Description of the embodiments

[0041] [Fig.l] is a schematic representation of a hydraulic machine with several hydraulic sub-machines. In the example illustrated, a hydraulic motor M is schematized as being composed of two hydraulic sub-motors Ml and M2 (for example of equal displacements or of distinct displacements) coupled in rotation. One and / or the other of the two hydraulic sub-motors Ml and M2 can be selectively engaged, typically by controlling the intake and discharge of each of the two hydraulic sub-motors Ml and M2. It is understood that this figure can also be transposed for a hydraulic pump composed of two hydraulic sub-pumps. It is also understood that this figure can also be transposed for a hydraulic machine composed of one hydraulic sub-machine Ml (for example) being a motor and the other hydraulic sub-machine M2 (for example) being a pump.

[0042] Figures 2, 3 and 4 illustrate an embodiment of a multiple displacement hydraulic machine. The hydraulic machine may have a motor or hydraulic pump operation. Alternatively, this same hydraulic machine may have a sub-machine operating as a pump and another hydraulic sub-machine as a motor.

[0043] [Fig. 2] shows a partial view of a cylinder block 4 defining a housing 44 in which a piston 5 slides, typically adapted to be held in contact with a cam, for example a multi-lobe cam. In operation, the pistons follow the cam. Thus, the pistons perform back and forth movements in their respective housings according to the geometry of the cam, while remaining in contact with the cam. The sliding axis of each piston is designated by XX. in its associated housing. Thus, for each pair formed by a housing 44 and a piston 5, the piston 5 slides along the axis XX in the housing 44. The sliding axis XX typically extends radially relative to the main axis ZZ.

[0044] [Fig. 3] shows a more complete view, comprising a cam 2 and a casing 1. The cam 2 is positioned so as to surround the cylinder block 4 relative to the main axis ZZ. The casing 1 and the cam 2 define an internal volume in which the cylinder block 4 is housed. The cylinder block 4 is integral with a shaft 6 mounted so as to be able to rotate relative to the casing 1 by means of the bearing 7. The cylinder block 4 and the shaft 6 form an assembly which is able to rotate relative to the assembly formed by the cam 2 and the casing 1 by means of the shaft or axis 6 defining the main axis ZZ. The shaft 6 typically extends outside the casing 1, and is adapted to receive or transmit a movement and / or a rotational torque depending on whether the hydraulic machine has a hydraulic pump or hydraulic motor operation. In the example shown, cam 2 surrounds cylinder block 4.

[0045] The distributor 3 is a part housed in the casing 1 which can have a slight axial mobility along the main axis ZZ (and with a slight possibility of angular oscillation) around the main axis ZZ which can follow the axial movements of the cylinder block 4 and be pressed against the latter with a certain pressure to obtain a certain sealing, while sliding on the cylinder block 4 during the rotation of the latter, according to one example, the block 4 rotates but not the distributor 3. In [Fig. 3] the distributor 3 has substantially a shape of revolution (around the axis of rotation of the engine) and is a distributor with grooves whose grooves are on the surface radially outside the distributor 3. In the example illustrated, we see in [Fig. 3] four grooves distributed along an axial direction.

[0046] The casing 1 also comprises grooves opposing the grooves of the distributor 3 to form distribution chambers, four distribution chambers in the example of [Fig. 3], of substantially toric shape, sealed from each other and isolated from the internal volume of the casing 1.

[0047] The distributor 3 also comprises axial conduits which open onto a flat face of the distributor 3 in a plane perpendicular to the main axis of rotation ZZ, this flat face defines the interface with the cylinder block 4 which has its conduits leading to the cylinders. The holes of the distributor 3 are connected to the grooves of the distributor 3 according to the supply and discharge that one wishes to define in the hydraulic machine. As the distributor 3 is linked in rotation with the casing 1, unlike the cylinder block 4 which can rotate relative to the casing 1 and therefore to the cam 2, the distributor 3 allows the supply and discharge of the housings 44 of the cylinder block 4 according to the increasing or decreasing slope of the half-lobe of the corresponding cam 2 where the associated piston 5 is located.

[0048] In traditional hydraulic machines having a single sealed chamber per piston, each hole of the distributor 3 is associated with a rising or falling phase of a cam lobe 2 in such a way that the number of distribution holes is equal to twice the number of lobes. In other words, the number of holes of the distributor 3 is equal to the number of half-lobes of the cam 2.

[0049] [Fig.4] shows an example of a radial machine structure. This figure shows a cylinder block 4 surrounded by a multi-lobe cam 2. In this example, the cylinder block 4 comprises 9 housings and the cam 2 defines 6 lobes.

[0050] In the structure proposed by the present invention, each pair formed by a piston 5 and a housing 44 defines a first chamber 60 and a second chamber 70 which are distinct, isolated from each other by means of sealing elements 46. The first chamber 60 and the second chamber 70 are thus separate and can be at distinct pressures. Thus, the distributor 3 therefore associates two distribution holes with each half-lobe of the cam 2.

[0051] The first chamber 60 and the second chamber 70 are typically superimposed according to the sliding direction of the piston 5 in the housing 44, here the radial direction relative to the main axis ZZ.

[0052] In the example illustrated, the housing 44 has two distinct portions; a first portion 41 having a first section S1, and a second portion 42 having a second section S2, the first section S1 being strictly greater than the second section S2, the first portion extending from an external surface of the cylinder block 4 and opening opposite the cam 2, and the second portion 42 extending from the first portion 41 so as to form the bottom of the housing 44. The second portion 42 is thus typically blind in the sliding direction of the pistons 5.

[0053] The piston 5 also has a first portion 51 and a second portion 52 adapted to slide respectively in the first portion 41 and the second portion 42 of the housing 44 while ensuring the sealing of the first chamber 60 and the second chamber 70.

[0054] Such a structure makes it possible to define in a single cylinder block and on a single row of pistons coming into contact with the same cam, two distinct hydraulic machines via the first chambers 60 and the second chambers 70. The two hydraulic machines thus formed can have identical or distinct cylinder capacities, which are designated respectively by C1 and C2. The cylinder capacity is defined as being the product of the effective section of a chamber considered by the stroke of the piston, the effective section of a piston being the total surface area of ​​the piston which participates in creating a force tending to move the piston in the desired direction. A distinction is made between the cylinder capacity for a given piston and the cylinder capacity for a motor or a pump, which is equal to the sum of the displacement of the pistons for the engine or pump considered. The displacement C1 of the first chambers 60 is thus defined by the stroke of the piston multiplied by the effective section of the first chambers 60. The displacement C2 of the second chambers 70 is thus defined by the stroke of the piston multiplied by the effective section of the second chambers 70. The proposed structure thus makes it possible, for example, to produce a structure allowing multi-displacement operation with a limited number of pistons and lobes and with the same row of pistons, which is advantageous in terms of compactness and therefore integration.

[0055] For each pair formed by a housing and a piston, the first chamber 60 and the second chamber 70 thus typically have distinct effective sections. The first chamber 60 can thus have an effective section strictly greater than the second chamber 70, or conversely, the first chamber 60 can thus have an effective section strictly less than the second chamber 70.

[0056] The cylinder capacity of the hydraulic machine can thus be modulated by supplying or not the first chambers 60 and / or the second chambers 70. The hydraulic machine can thus have a cylinder capacity equal to C1, to C2, or to C1+C2 or any other combination of cylinder capacity.

[0057] Alternatively, the first 60 and second 70 chambers may define hydraulic machines having distinct operations, one having a pump operation, and the other having a motor operation. Such an embodiment makes it possible in particular to produce a pressure adapter, making it possible to amplify or reduce a pressure or a flow rate.

[0058] Conduits 62 and 72 are arranged in the cylinder block 3, these conduits extending respectively from the first chambers 60 and from the second chambers 70 and emerging from a lateral surface of the cylinder block 30. The conduits 62 and 72 are then supplied by the distributor 3. By supply, it is meant in the present text that the distributor 3 carries out a supply and a discharge of fluid via the conduits 62 and 72, as a function of the rotation of the cylinder block 4 relative to the cam 3.

[0059] The cylinder block 4 thus comprises ducts 62 and 72 opening opposite the distributor 3, making it possible to connect the first chambers 60 and the second chambers 70 to the distributor 3. The ducts 62 and 72 typically open at an interface between the cylinder block 4 and the distributor 3, the interface typically being between two surfaces, one belonging to the cylinder block 4 and the other belonging to the distributor 3, extending radially relative to the main axis ZZ. It is understood that the distributor 3 has ducts having a configuration adapted so as to cooperate with the ducts thus formed in the cylinder block 4.

[0060] the conduits 62 and 72 formed in the cylinder block 4 open at distinct positions relative to the main axis ZZ; for example the conduits connected to the first chambers 60 are centered on a circle of radius RI relative to the main axis ZZ, and the conduits connected to the second chambers 70 are centered on a circle of radius R2 relative to the main axis ZZ with RI different from R2. In the example illustrated, RI is strictly greater than R2, the first chambers 60 being located radially outside relative to the second chambers 70. The distributor 3 has internal conduits adapted to, depending on the relative rotation between the cylinder block 4 and the distributor 3, open at the interface between the distributor 3 and the cylinder block 4, opposite the conduits 62 and 72, and thus allow supply and discharge of the first chambers 60 and second chambers 70. It is thus possible to define a first set of conduits for supplying the first chambers 60, comprising conduits internal to the distributor 3 and the conduit 62 internal to the cylinder block 4.It is also possible to define a second set of conduits for supplying the second chambers 70, comprising conduits internal to the distributor 3 and the conduit 72 internal to the cylinder block 4.

[0061] The invention as proposed breaks with the conventional structure of the supply ducts of the chambers, and proposes to form ducts in the cylinder block 4 which open onto a face of the cylinder block 4 at the interface with the distributor 3 so as to be angularly offset relative to the sliding axis of the piston in the associated housing.

[0062] The invention applied to a cylinder block structure 4 as proposed achieves an angular offset of at least one conduit 62 or 72 of the cylinder block 4 connected to one of the first chambers 60 or second chambers 70.

[0063] By way of example, one or more of the ducts 62 of the cylinder block 4 connected to the first chambers 60 can thus be offset by an angle A relative to the sliding axis XX of the associated piston, the angle A here being defined relative to a center of the section of the duct 62 opening at the interface between the cylinder block 4 and the distributor 3. Such an offset can be made on one or more ducts of the cylinder block 4, typically on all of the ducts of a set of chambers of the cylinder block 4. It is understood that the choice of the ducts 62 is arbitrary, and that the offset can also be made on all or part of the ducts 72 of the cylinder block 4.

[0064] According to one example, the duct 62 of the cylinder block 4 opens at the interface between the cylinder block 4 and the distributor 3 at an angle A relative to the sliding axis XX of the associated piston, the angle A here being defined relative to a center of the section of the duct 62 opening from the cylinder block 4 to the interface between the cylinder block 4 and the distributor 3.

[0065] The angle A is typically between 5° and 30°, or for example between 5° and 25°, or between 5° and 20°, or between 5° and 15°.

[0066] According to one example, all the conduits 62 of the cylinder block 4 connected to the first chambers 60 are thus offset by an angle A relative to the sliding axis XX of the associated piston.

[0067] Alternatively and / or additionally, one or more of the ducts 72 of the cylinder block 4 connected to the second chambers 70 may thus be offset by an angle B relative to the sliding axis XX of the associated piston, the angle B here being defined relative to a center of the section of the duct 72 of the cylinder block 4 opening at the interface between the cylinder block 4 and the distributor 3, as indicated previously. According to one example, all of the ducts 72 of the cylinder block 4 connected to the second chambers 70 are thus offset by an angle B relative to the sliding axis XX of the associated piston.

[0068] The angle B is typically between 5° and 30°, or for example between 5° and 25°, or between 5° and 20°, or between 5° and 15°.

[0069] According to one example, the ducts 62 of the cylinder block 4 connected to the first chambers 60 and the ducts 72 of the cylinder block 4 connected to the second chambers 70 are angularly offset relative to the sliding axis XX of the associated piston in opposite directions of rotation relative to the main axis ZZ. Thus, the ducts 62 of the cylinder block 4 connected to the first chambers 60 and the ducts 72 connected to the second chambers 70 open at the interface between the cylinder block 4 and the distributor 3 on either side of the sliding axis XX of the associated piston.

[0070] Angles A and B may have the same absolute value or different values. Alternatively, angles A and B may be such that A = -B.

[0071] It is understood that the modification of the configuration of the conduits 62 and 72 of the cylinder block 4 involves the modification of the conduits of the distributor 3 adapted to provide a supply and a discharge of fluid into the cylinder block 4.

[0072] [Fig. 5] schematically represents an example of an embodiment in which the conduits 62 and 72 are offset relative to the sliding axis XX of the associated piston so as to be positioned on either side of this sliding axis XX.

[0073] In the illustrated example, the duct 72 is an axial duct, which opens at one end of the second chamber 70. In the illustrated example, the duct 62 comprises a radial component. Thus, the ducts 62 open at the interface between the cylinder block 4 and the distributor 3 at a radius distinct from the radius at which the first chambers 60 are formed. It is understood that this example is not limiting and that the embodiments illustrated for the ducts 62 opening into the first chambers 60 can also be applied to the ducts 72 opening into the second chambers 70, and vice versa.

[0074] Alternatively, the conduits 62 and 72 are formed in the cylinder block 4 so as to open from the cylinder block 4 to the interface between the cylinder block 4 and the distributor 3. according to the same angular sector. In other words, the conduits 62 and 72 can be formed so as to open out in a superimposed manner in the radial direction relative to the main axis ZZ. Thus, considering two consecutive housings in the circumferential direction around the main axis ZZ, the conduit 62 opening into the first chambers 60 of one is superimposed on the conduit 72 opening into the second chambers 70 of the other in the radial direction.

[0075] In such an embodiment, the conduits 62 and 72 are typically formed such that conduits of similar pressures are totally or partially superimposed.

[0076] By way of example, considering that the first chambers 60 have a motor operation and are supplied by a pressure PI and discharge a pressure P2 with PI > P2, while the second chambers 70 have a pump operation and are supplied by a pressure P3 and discharge a pressure P4 with P3 < P4, then the conduits 62 and 72 are typically formed so that for a given cam half-lobe, two superimposed conduits are at pressures P2 and P3, or PI and P4.

[0077] Such a configuration makes it possible to minimize the pressure difference between adjacent conduits, and thus makes it possible to minimize the deformations of the cylinder block 4.

[0078] Alternatively, the ducts 62 and 72 of the cylinder block 4 are formed so as to open at the interface between the cylinder block 4 and the distributor 3 according to distinct and typically disjointed angular sectors. In other words, the ducts 62 and 72 of the cylinder block 4 may be formed so as to open in a staggered manner in the radial direction relative to the main axis ZZ, typically with or without partial overlap of the angular sectors.

[0079] Alternatively, the ducts 62 and 72 of the cylinder block 4 are formed so as to open at the interface between the cylinder block 4 with an angular offset allowing the design of an associated distributor 3 having distribution ducts 36 and 37 opening from the distributor 3 to the interface with the cylinder block 4 according to typically disjoint angular sectors.

[0080] In other words, thanks to this geometry on the cylinder block 4, the conduits 36 and 37 of the corresponding distributor 3 can, for example, be formed so as to open out in a staggered manner in the radial direction relative to the main axis ZZ, typically with or without partial overlap of the angular sectors.

[0081] [Fig. 6] schematically illustrates an advantage of the invention as proposed. This figure shows an example of application in which the duct 62 of the cylinder block 4 is offset relative to the sliding axis XX. [Fig. 7] schematically shows a conventional configuration without offsetting the ducts 62 and 72. It can be seen that the offset made makes it possible to increase the quantity of material between the drilling radial of the duct 72 and the face of the cylinder block forming the distribution interface with the distributor 3, and thus makes it possible to improve the mechanical strength of the cylinder block. In addition, the further the orifices are separated from each other, the more the potential leaks between the different volumes which are not intended to be fluidically connected are limited.

[0082] [Fig.8] shows an example of a distributor structure 3 adapted 8 to cooperate with a cylinder block 4 as proposed. This figure shows a view of the distributor at the level of the plane forming the interface of the distributor 3 with the cylinder block 4. This figure shows a plurality of ducts emerging from the distributor 3. In the illustrated embodiment, two series of ducts 36 and 37 are distinguished, typically adapted to be respectively positioned opposite the ducts 62 and 72 described previously during the relative rotation between the cylinder block 4 and the distributor 3.

[0083] In the illustrated example, it can be seen that the ducts 36 and 37 are superimposed in the radial direction relative to the main axis ZZ. The ducts 36 are here centered on a circle of radius RI relative to the main axis ZZ, and the ducts 37 are centered on a circle of radius R2 relative to the main axis ZZ with RI different from R2. In the illustrated example, RI is strictly greater than R2. In other words, the ducts 36 and 37 extend along the same angular sector, but along two distinct radii. Thus, the ducts 36 which are here positioned radially further out have a mouth having a surface area greater than the mouth of the ducts 37 which are positioned radially inside relative to the ducts 36. The ducts 37 and 36 may have similar or distinct shapes.Such an example of distributor 3 is adapted to cooperate with a cylinder block 4 of a hydraulic machine described in particular with reference to figures 1 to 6 whose conduits 62 and 72 open out in a superimposed manner in the radial direction relative to the main axis ZZ at the interface with the distributor 3.

[0084] According to one embodiment, the distributor 3 may have radial through-bores, each of said radial bores connecting both a conduit 36 ​​and a conduit 37 to an internal volume of the casing of the hydraulic machine. Such an embodiment finds application in particular in the case of a hydraulic machine in which the pistons each define two chambers 60 and 70, these two chambers defining two hydraulic machines having distinct operations, one having a pump operation, and the other a motor operation. Bores thus produced may for example make it possible to connect the discharge of the chambers having a motor operation to the inlet of the pumps having a pump operation via the internal volume of the casing of the hydraulic machine.

[0085] More generally, in such an embodiment, a first set is defined of angular sectors and a second set of disjoint angular sectors, each angular sector of the first set of angular sectors and of the second set of angular sectors comprising a conduit 36 ​​and a conduit 37 superimposed. The conduits opening into the angular sectors of the first set of angular sectors can then open into an internal volume of the casing so as to be connected to each other, while the conduits opening into the angular sectors of the second set of angular sectors are connected to an inlet port of the hydraulic machine and to a discharge port of the hydraulic machine.

[0086] In such an embodiment, the conduits 36 and 37 are typically formed such that conduits of similar pressures are totally or partially superimposed.

[0087] For example, considering that the distributor supplies two hydraulic machines M1 and M2 having a pump operation, then the conduits 36 and 37 are typically configured so that for the same angular sector, the superimposed conduits either both provide a fluid intake, or both provide a fluid discharge. Thus, for the same angular sector, the two conduits 36 and 37 are at pressures of the same order of magnitude. It is understood that this also applies for two hydraulic machines M1 and M2 having a motor operation.

[0088] For example, considering that the distributor supplies two hydraulic machines M1 and M2, one of which has a pump operation and the other has a motor operation, then the conduits 36 and 37 are typically configured so that for the same angular sector, one of the conduits provides a fluid supply to one of the hydraulic machines and the other of the conduits provides a fluid discharge to the other of the hydraulic machines. Thus, for the same angular sector, the two conduits 36 and 37 are at pressures of the same order of magnitude.

[0089] the first chambers 60 have a motor operation and are supplied by a pressure PI and discharge a pressure P2 with PI > P2, while the second chambers 70 have a pump operation and are supplied by a pressure P3 and discharge a pressure P4 with P3 < P4, then the conduits 62 and 72 are typically formed so that for a given half-lobe of cam, two superimposed conduits are at pressures P2 and P3, or PI and P4.

[0090] [Fig.9] shows another variant of the distributor 3, in which the conduits 36 and 37 of the distributor 3 are here positioned in a staggered manner. The conduits 36 are here centered on a circle of radius RI relative to the main axis ZZ, and the conduits 37 are centered on a circle of radius R2 relative to the main axis ZZ with RI different from R2. In the example illustrated, RI is strictly greater than R2.

[0091] In the illustrated example, the conduits 36 and 37 of the distributor 3 are positioned according to distinct angular sectors. These angular sectors may have an overlap or be disjoint. In the illustrated example, the angular sectors are adjacent, without overlap. Such an example of distributor 3 is adapted to cooperate with a cylinder block 4 of a hydraulic machine described in particular with reference to FIGS. 1 to 6, the conduits 62 and 72 of which open out in a staggered manner in the radial direction relative to the main axis ZZ at the interface with the distributor 3. Such a staggered structure makes it possible to maximize the material between the different conduits, and thus to maximize the mechanical strength and minimize the deformations due to the pressure differences in the conduits.

[0092] [Fig. 10] schematically represents an example of a cylinder block 4 according to one aspect of the invention associated with a multi-lobe cam 2.

[0093] This figure shows the angular difference between the conduits 62 and 72, this angular difference being equal to A+B according to the notations defined previously.

[0094] The angular difference is typically defined as a function of the number of lobes of the cam 2. For example, considering a cam having L lobes, the angular difference between the ducts 62 and 72 of the same housing is typically equal to 360° / (2L). Such a configuration makes it possible to obtain an arrangement in which the ducts 62 and 72 of adjacent housings 44 are superimposed. In the example illustrated, the cam 2 has 4 lobes. The angular difference between the ducts 62 and 72 of the cylinder block 4 is thus substantially equal to an angle of 360 / (2x4) or 45°.

[0095] Alternatively, the angular difference could typically be defined as a function of the number of pistons. For example, considering a cylinder block comprising N pistons, the angular difference between the ducts 62 and 72 of the same housing could typically be equal to 360° / (N). Such a configuration makes it possible to obtain an arrangement in which the ducts 62 and 72 are formed in the areas of the cylinder block 4 having the maximum thickness of material, in particular in the case where the angles A and B have the same absolute value.

[0096] The distributor 3 has a structure adapted to cooperate with the cylinder block 4 as proposed. In particular, the distributor 3 comprises conduits adapted to carry out the supply and discharge of fluid in the conduits 62 and 72, which are positioned according to the structure of the conduits 62 and 72 of the cylinder block 4 so that the hydraulic machine as a whole can operate properly and in particular so that the supply (in the broad sense) of the chambers 60 and 70 of the pistons 5 is done at the right time relative to the position of the piston 5 relative to the half-lobe of cam 2 which it encounters.

[0097] [Fig. 11] shows another variant of the distributor 3 which can in particular be associated with the cylinder block 4 and the cam 2 as presented previously with reference to [Fig. 10]. In this embodiment, the conduits 36 and 37 are superimposed. It can be seen that the conduits 37 have a circular section while the conduits 36 have an oblong section, which results in particular from the fact that the conduits 36 are centered according to a radius RI greater than the radius R2 on which the conduits 37 are centered. This embodiment also has radial through holes 38 adapted to connect the conduits 36 and 37 superimposed according to the same angular sector to an internal volume of the casing. Such an embodiment thus makes it possible to connect these two conduits via the internal volume of the casing, and is particularly applicable for conduits conveying low pressure. According to one example, every other angular sector comprising the superimposed conduits 36 and 37 has one or more radial through holes 38.

[0098] It can be seen in particular with reference to Figures 10 and 11 that the arrangement of the conduits in the distributor 3 and in the cylinder block 4 is not necessarily identical. A configuration of conduits offset from each other in the cylinder block 4 can lead to a configuration of superimposed conduits in the distributor 3, or vice versa.

[0099] In the example of [Fig. 11] the distributor 3 is a distributor with superimposed grooves and has the particularity of having an annular shape (or toric shape) having an outer radial face (circumferential) and an inner radial face (circumferential).

[0100] At least one annular groove is made on the outer radial face and at least one annular groove is made on the inner radial face of the distributor.

[0101] This distributor is housed in a housing of the casing 1 of the hydraulic machine which has a complementary toric-shaped recess. The grooves made on the distributor 3 are adapted to cooperate with corresponding opposing grooves made in the casing 1 in order to together produce sealed distribution chambers, typically provided with sealing joints positioned axially on either side of each distribution chamber.

[0102] The different variants of distributor 3 described in the embodiments above are grooved distributors known to those skilled in the art intended to be housed in the casing 1 and cooperate with the latter to allow the supply and discharge of the different chambers 60 and 70 of the cylinder block 4. It is understood that the invention also applies to other types of distribution system, in particular distributor systems with studs well known to those skilled in the art.

[0103] Although the present invention has been described with reference to specific exemplary embodiments, it is obvious that modifications and changes may be made to these examples without departing from the general scope of the invention as defined by the claims. In particular, individual features of the various illustrated / mentioned embodiments may be combined in additional embodiments. Therefore, the description and drawings should be considered in an illustrative rather than restrictive sense.

[0104] It is also obvious that all the characteristics described with reference to a method are transposable, alone or in combination, to a device, and conversely, all the characteristics described with reference to a device are transposable, alone or in combination, to a method.

Claims

Claims

1. Hydraulic machine comprising: a first assembly and a second assembly, movable in rotation relative to each other along a main axis (ZZ), the first assembly comprising a casing (1), a distributor (3) and a multi-lobe cam (2) comprising a plurality of half-lobes each extending along an angular sector, the second assembly comprising a cylinder block (4) having a plurality of housings (44), and pistons (5) slidably mounted in said housings (44) and performing reciprocating movements in said housings (44) along half-lobes of the cam (2), each piston being slidably mounted in a housing along a sliding axis extending radially relative to the main axis (ZZ), each pair formed by a piston (5) and a housing (44) defines between the piston (5) and the housing (44) a first chamber (60) and a second chamber (70) distinct from the first chamber (60), the set of first chambers (60) defining a first hydraulic machine,the set of second chambers (70) defining a second hydraulic machine, in which for each pair formed by a piston (5) and a housing (44), the first chamber (60) and the second chamber (70) are superimposed in a sliding direction of the piston (5) in the housing (44), the cylinder block (4) has a plurality of internal conduits defining a first set of conduits opening at the interface between the distributor (3) and the cylinder block (4) and adapted to supply and discharge fluid to the first chambers (60), and a second set of conduits opening at the interface between the distributor (3) and the cylinder block (4) and adapted to supply and discharge fluid to the second chambers (70) characterized in that, the cylinder block (4) is configured so that, in projection along a plane perpendicular to the main axis (ZZ), for at least one housing,the conduit (62) of the first set of conduits connected to the first chamber of said housing in which a piston slides opens at the interface between the distributor (3) and the cylinder block (4) in a manner angularly offset by an angle A relative to the axis of cou-, smoothing of the piston in said housing (44).

2. Hydraulic machine according to claim 1, in which the cylinder block (4) is configured so that, in projection along a plane perpendicular to the main axis (ZZ), for each housing, the conduit of the first set of conduits connected to said housing in which a piston slides opens at the interface between the distributor (3) and the cylinder block (4) in a manner angularly offset by an angle A relative to the axis of sliding of the piston in said housing (44).

3. Hydraulic machine according to one of claims 1 or 2, in which the cylinder block (4) is configured so that, for each housing, a conduit of the second set of conduits connected to said housing in which a piston slides opens at the interface between the distributor (3) and the cylinder block (4) in a manner angularly offset by an angle B relative to the axis of sliding of the piston in said housing (44).

4. Hydraulic machine according to claim 3, in which for each housing (44), the conduit of the first set of conduits opening into the housing (44) is offset by an angle A relative to the sliding axis of the piston (5) in said housing (44) in a first direction of rotation around the main axis (ZZ), and the conduit of the second set of conduits opening into the housing (44) is offset by an angle B relative to the sliding axis of the piston in said housing (44) in a second direction of rotation around the main axis (ZZ), opposite to said first direction of rotation.

5. Hydraulic machine according to claim 4, in which the cam (3) comprises L lobes, and for each housing, an angular difference between the conduits (62) of the first set and the conduit (72) of the second set of the same housing is equal to 360° / (2L), or the cylinder block (4) comprises N pistons, and for each housing, an angular difference between the conduits (62) of the first set and the conduit (72) of the second set of the same housing is equal to 360° / (N).

6. Hydraulic machine according to one of claims 3 to 5, in which the conduits of the first set of conduits open from the cylinder block (4) at a first distance RI relative to the main axis (ZZ), and in which the conduits of the second set of conduits open from the cylinder block (4) at a second distance R2 relative to the main axis (ZZ), the first distance RI and the second distance R2 being distinct.

7. Hydraulic machine according to claim 6, in which for each set of two consecutive housings (44) of the cylinder block (4) in the circumferential direction around the main axis (ZZ), the conduit of the first set of one of said housings (44) and the conduit of the second set of the other of said housings (44) are positioned so as to be supplied by two orifices (36, 37) of the distributor (3) at two different distances (RI, R2) from the main axis along the same angular sector.

8. Hydraulic machine according to claim 6, wherein the distributor (3) has a first set of conduits emerging from the distributor (3) at the interface with the cylinder block (4) at the first distance RI from the main axis (ZZ), and a second set of conduits emerging from the distributor (3) at the interface with the cylinder block (4) at the second distance R2 from the main axis (ZZ), and wherein the cylinder block (4) is configured so that the conduits of the first set of conduits of the distributor (3) are positioned in a first set of angular sectors, the conduits of the second set of conduits of the distributor (3) are positioned in a second set of angular sectors, the first set of angular sectors and the second set of angular sectors being disjoint.

9. Hydraulic machine according to one of claims 1 to 8, wherein one of the first hydraulic machine and the second hydraulic machine has a pump operation, and the other has a motor operation, and wherein the conduits of the cylinder block (4) and of the distributor (3) are configured so that in operation, for each housing (44), the conduit of the distributor (3) providing the fluid intake of the hydraulic machine having a pump operation is positioned in the same angular sector as the conduit of the distributor (3) providing the fluid discharge of the hydraulic machine having a motor operation,and the conduit of the distributor (3) carrying out the delivery of fluid from the hydraulic machine having a pump operation is positioned in the same angular sector as the conduit of the distributor (3) carrying out the admission of fluid from the hydraulic machine having a motor operation.,

10. Hydraulic machine according to claim 9, in which the distributor (3) comprises radial bores (38) passing through, each of said radial bores (38) connecting both a conduit (36) of the first set of conduits and a conduit (37) of the second set of conduits to an internal volume of the casing.

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