Improved pressure adapter for hydraulic system

Abstract

The invention relates to a pressure adapter (100) comprising: a first assembly and a second assembly which are able to rotate with respect to each other about a main axis, the first assembly comprising a casing (10) and a cam (20), the second assembly comprising a cylinder block (30) having a plurality of bores (40) in which pistons (50) slide, each piston (50) being positioned in a bore (40), characterised in that each pair formed by a piston (50) and a bore (40) defines, between the piston (50) and the bore (40), a first chamber (60) and a second chamber (70) which are separate, the first chamber (60) and the second chamber (70) defining different displacements, wherein the assembly of the first chambers (60) acts as a hydraulic motor (110), suitable for being connected to a supply supplying a first flow Q1 at a first pressure P1 and for rotating the first assembly and the second assembly relative to each other, and the assembly of the second chambers (70) acts as a hydraulic pump (120), suitable for delivering a second flow Q2 at a second pressure P2.

Description

Description Title of the invention: Improved pressure adapter for hydraulic system. Technical Field

[0001] The present invention relates to a pressure adapter for a hydraulic system, which can in particular fulfill a pressure amplifier function. Prior art

[0002] Hydraulic systems are commonly used in many applications. In such systems, a recurring desire is to reduce the size for obvious reasons of reducing the mass and volume of the assembly, and also to facilitate integration.

[0003] In the case of hydraulic machines, it is thus known to seek to adapt the pressure and flow rate of a hydraulic component in order to optimize the system. In particular, it is known to use a pressure amplifier rather than oversizing the hydraulic components, which not only allows the use of standardized elements for different applications, but also to reduce their size.

[0004] Known pressure adapters generally have a linear oscillating type structure and are complex to produce. The present invention thus aims to respond at least partially to these various problems. Statement of the invention

[0005] The present invention thus relates to a pressure adapter comprising: a first assembly and a second assembly, movable in rotation relative to each other along a main axis, the first assembly comprising a cam, the second assembly comprising a cylinder block having a plurality of housings in which pistons slide, each piston being positioned in a housing, characterized in that each pair formed by a piston and a housing defines between the piston and the housing a first chamber and a second separate chamber, the first chamber and the second chamber defining separate cylinder capacities, in which the set of first chambers performs a hydraulic motor function, adapted to be connected to a power supply providing a first flow rate Q1 at a first pressure PI and to perform a relative rotation of the first assembly and the second assembly, the set of second chambers performs a hydraulic pump function, adapted to deliver a second flow rate Q2 at a second pressure P2.Such a pressure adapter has the advantage over the prior art and in particular oscillating linear type adapters of being compact, and of being able to significantly amplify the pressure while allowing the supply of a significant flow rate. In addition, the proposed structure makes it possible to produce a homokinetic adapter, and therefore to provide a constant flow rate and not a flow rate in jerks or pulsations.

[0006] According to one example, the pressure adapter comprises a housing, the first assembly being integral with the housing.

[0007] According to one example, the pressure adapter comprises a housing, the second assembly being integral with the housing.

[0008] According to an example, for each pair formed by a piston and a housing, the first chamber defines a cylinder capacity strictly greater than the second chamber.

[0009] According to an example, for each pair formed by a piston and a housing, the first chamber defines a cylinder capacity strictly lower than the second chamber.

[0010] According to one example, 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.

[0011] According to one example, each housing has a first portion having a first section SI, and a second portion having a second section S2, the first section SI being strictly greater than the second section S2, the first portion opening out from an external surface of the cylinder block opposite the cam, and the second portion extending from the first portion.

[0012] According to one example, the set of first chambers performing a hydraulic motor function has a primary inlet and a primary discharge, the set of second chambers performing a hydraulic pump function has a secondary inlet and a secondary discharge, the primary discharge feeds at least part of the secondary inlet.

[0013] According to one example, the connection between the primary discharge and the secondary intake is made via an internal volume of the casing

[0014] According to one example, the set of first chambers performing a hydraulic motor function has a primary inlet and a primary discharge, the set of second chambers performing a hydraulic pump function has a secondary inlet and a secondary discharge, the secondary inlet and the primary inlet are common.

[0015] According to one example, the first chambers are connected to a first distributor adapted to provide fluid intake and discharge, and the second chambers are connected to a second distributor adapted to provide fluid intake and discharge.

[0016] According to one example, the cylinder block comprises conduits adapted to connect the first chambers to the first distributor, said conduits emerging from the cylinder block at a first distance R1 relative to the axis main, and the cylinder block comprises conduits adapted to connect the second chambers to the second distributor, said conduits emerging from the cylinder block at a second distance R2 relative to the main axis, the first distance R1 and the second distance R2 being distinct.

[0017] According to one example, - if Q1 > Q2, then R1 > R2, and - if Q1 < Q2, then R2 > R1.

[0018] In one example, the pistons and housings are arranged to define a movement of the pistons in a direction parallel to the main axis.

[0019] In one example, the pistons and housings are arranged to define a movement of the pistons in a radial direction relative to the main axis.

[0020] According to one example, the pressure adapter may be a multi-lobe cam.

[0021] According to one example, the set of first chambers defines a first hydraulic sub-machine which operates by the collaboration of the pistons sliding in these first chambers with a multi-lobe cam.

[0022] In one example, the set of second chambers defines a second hydraulic sub-machine which operates by the collaboration of the pistons sliding in these second chambers with a multi-lobe cam.

[0023] According to an example, the set of first chambers defines a first hydraulic sub-machine which operates by the collaboration of the pistons sliding in these first chambers with a multi-lobe cam configured in such a way that the hydraulic sub-machine is homokinetic. A hydraulic machine or sub-machine is homokinetic if, at constant rotation (of the cylinder block), the flow circulating in the sub-machine is constant. In other words, the rotation takes place smoothly. In a homokinetic machine, the fluid balance is substantially zero, that is to say that at each instant, the quantity of fluid entering the cylinders is substantially equal to the quantity of fluid leaving the cylinders.

[0024] Since a constant flow rate circulates in the different conduits for a constant rotation speed of the hydraulic machine, there is no acceleration or deceleration of the fluid in the conduits, which in particular makes it possible to reduce pressure losses and therefore increase the efficiency of the machine.

[0025] According to one example, the set of second chambers defines a second hydraulic sub-machine which operates by the collaboration of the pistons sliding in these second chambers with a multi-lobe cam configured such that said second hydraulic sub-machine is homokinetic.

[0026] According to one example, the set of first chambers defines a first hydraulic sub-machine which operates by the collaboration of the pistons sliding in these first chambers with a multi-lobe cam configured in such a way that said first hydraulic sub-machine is homogeneous. The term homogeneous means that at constant rotation (of the cylinder block) for each cam lobe, the flow circulating in the first chambers whose pistons travel through the cam lobe in question is constant. An example of a hydraulic machine with homogeneous flow is presented in patent application WO2023 / 242502A1 to which a person skilled in the art may refer.

[0027] When the hydraulic machine (or sub-machine) associates a particular distribution means for a lobe or a group of lobes of the multi-lobe cam, the fact that the hydraulic machine (or sub-machine) is homogeneous allows a constant flow rate to circulate in the conduits of this distribution means assigned to this lobe or group of lobes for a constant rotation speed of the hydraulic machine (or sub-machine).

[0028] To the extent that a constant flow circulates in the different conduits of the distribution system dedicated to a lobe or a group of lobes for a constant rotation speed of the hydraulic machine, there is no acceleration or deceleration of the fluid in the conduits of the distribution system dedicated to this lobe or this group of lobes, which in particular makes it possible to reduce pressure losses and therefore to increase the efficiency of the hydraulic machine or sub-machine.

[0029] According to one example, the set of second chambers defines a second hydraulic sub-machine which operates by the collaboration of the pistons sliding in these second chambers with a multi-lobe cam configured such that said second hydraulic sub-machine is homogeneous.

[0030] In one example, the cam profile is non-sinusoidal. The non-sinusoidal cam allows profiles that allow homokinetic or homogeneity of the hydraulic machine (or sub-machine).

[0031] According to one example, the cam profile has cam flats. What the person skilled in the art calls a cam flat is a part of the cam for which, for a given angular sector of the cam, the radius of the cam profile does not change. Consequently, a piston traveling along a cam flat does not move in its housing and does not generate flow. This makes it possible, for example, to prevent pressure peaks in the chamber from being created when passing from one distribution hole to another. This makes it possible, in particular, to space the distribution holes apart from each other to improve sealing by preventing leaks from high-pressure conduits to low-pressure conduits at the distribution face.

[0032] According to one example, the pressure adapter may have a radially outward cam, the cam then being arranged radially outwardly relative to the cylinder block.

[0033] According to one example, the first distributor and the second distributor are arranged on either side of the cylinder block in the direction defined by the main axis.

[0034] According to one example, the first distributor and the second distributor are dimensioned so that the force resulting from the supply of the first chambers and the second chambers respectively by the first distributor and the second distributor tends to move the cylinder block towards one of the first distributor and the second distributor, typically either towards the first distributor or towards the second distributor, typically by minimizing the force resulting from the supply of the first chambers and the second chambers respectively by the first distributor and the second distributor. Alternatively, the first distributor and the second distributor are sized so that the force resulting from the supply of the first chambers and the second chambers respectively by the first distributor and the second distributor tends to balance each other.

[0035] According to one example, the pressure adapter may have a radially external and rotating cam and a fixed cylinder block rotationally fixed to the casing.

[0036] According to one example, the pressure adapter can be of radial technology with internal multi-lobe cam.

[0037] For example, the pressure adapter can be radial technology with a fixed casing and rotating inner multi-lobe cam. In this case, the casing and the cylinder block can be rigidly connected.

[0038] The adapter as proposed can in particular be integrated into a hydraulic machine, for example into a hydraulic motor or into a hydraulic cylinder. Brief description of the drawings

[0039] 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.

[0040] [Fig. 1] Figure 1 is a schematic representation of a pressure adapter.

[0041] [Fig. 2] Figure 2 is a schematic representation of a pressure adapter according to an exemplary embodiment.

[0042] [Fig. 3] Figure 3 is a schematic representation of a pressure adapter according to another exemplary embodiment.

[0043] [Fig. 4] Figure 4 is a schematic representation of another example of a pressure adapter according to another exemplary embodiment.

[0044] [Fig. 5] Figure 5 is a schematic representation of a pressure adapter according to another exemplary embodiment.

[0045] [Fig. 6] Figure 6 is a schematic representation of the variant shown in Figure 5, but in another configuration.

[0046] [Fig. 7] Figure 7 is a schematic representation of another variant of a pressure adapter according to an exemplary embodiment.

[0047] [Fig. 8] Figure 8 is a view of an example of a distributor for a pressure adapter according to an example embodiment.

[0048] [Fig. 9] Figure 9 is a schematic representation of another variant of a pressure adapter according to another exemplary embodiment.

[0049] [Fig. 10] Figure 10 is a schematic representation of another variant of a pressure adapter according to another exemplary embodiment.

[0050] [Fig. 11] Figure 11 is a view of an example of a pressure adapter according to another exemplary embodiment.

[0051] [Fig. 12] Figure 12 is a schematic representation of a hydraulic member incorporating an adapter according to one aspect of the invention.

[0052] Throughout the figures, common elements are identified by identical numerical references. Description of the embodiments

[0053] Figure 1 is a schematic representation of a pressure adapter 100.

[0054] The pressure adapter 100 as shown diagrammatically has two hydraulic members coupled in rotation, one being adapted to have a motor operation, and the other being adapted to have a pump operation. Here, the reference 110 will designate the hydraulic motor, and the reference 120 will designate the hydraulic pump.

[0055] The hydraulic motor 110 has a primary inlet 112 and a primary discharge 114. The hydraulic pump 120 has a secondary inlet 122 and a secondary discharge 124. The hydraulic motor 110 is adapted to be connected to a supply providing a first flow rate Q1 at a first pressure PI, and delivers a flow rate Qm (in the embodiments presented Qm = Q1 if there are no leaks) at a pressure Pm. The hydraulic motor 110 rotates the hydraulic pump 120. The hydraulic pump 120 is supplied by a flow rate Qp (in the embodiments presented Qp = Q2 if there are no leaks) at a pressure Pp, and is adapted to deliver a second flow rate Q2 at a second pressure P2 such that P2 is different from Pl. It is known to those skilled in the art that for operation of the pump without cavitation, the pressure Pp at the inlet of the pump must be greater than a minimum boost pressure of the pump.

[0056] Depending on the desired pressure adaptation, P2 can be higher than PI or lower than PI, thus achieving a pressure booster or a pressure reducer respectively.

[0057] Such an adapter 100 comprises one or more hydraulic machines each comprising a first assembly and a second assembly, movable in rotation relative to each other along a main axis ZZ visible in particular in FIG. 2.

[0058] The first assembly includes a cam. The cam is typically a multi-lobe cam. A multi-lobe cam is a cam formed to have undulations or lobes, so that a piston in a cylinder block housing shown centered with respect to the cam and remaining in contact with the cam reciprocates in its housing during rotation.

[0059] The cam is typically non-sinusoidal. A non-sinusoidal cam profile makes it possible to create a cam profile that allows a homokinetic or homogeneous hydraulic machine (or sub-machine) to be created.

[0060] The second assembly comprises a cylinder block having a plurality of housings in which pistons slide, each piston being positioned in a housing. The adapter 100 is configured so that in operation, the pistons follow the cam. Thus, the pistons perform reciprocating movements in their respective housings depending on the geometry of the cam, while remaining in contact with the cam.

[0061] Depending on the architecture chosen, a casing can be rotationally fixed to the first assembly or the second assembly.

[0062] The hydraulic motor 110 rotates the hydraulic pump 120. However, the adapter is not intended to deliver torque. Thus, the adapter 100 typically does not have a mechanical torque input or output shaft. In other words, the adapter 100 does not have a torque input or output. Pressure and flow are applied at the input, and pressure and flow are delivered at the output.

[0063] Figure 2 shows a schematic view of components allowing the production of a pressure adapter according to one aspect of the invention.

[0064] In this example, the pressure adapter 100 according to the invention has a radial structure. By radial structure, it is meant that the pistons 50 and the housings 40 are arranged so as to define a movement of the pistons 50 in a radial direction relative to the main axis ZZ. The pressure adapter 100 then has a structure that is described as radial.

[0065] This figure shows a cam 20 and a casing 10. The cam is positioned so as to surround the cylinder block 30 relative to the main axis ZZ. The casing 10 and the cam 20 define an internal volume in which the cylinder block 30 is housed, which is mounted to be able to rotate relative to the assembly formed by the cam 20 and the casing 10, typically by means of an axis 32 defining the main axis ZZ. The axis 32 is optional. The cylinder block 30 can typically be positioned in the casing 10 without an axis 32. Support elements then typically make it possible to center the cylinder block 30 relative to the cam 20.

[0066] In the example illustrated, the cam 20 has 4 lobes, and the cylinder block 30 has 3 housings 40, each housing being provided with a piston 50. The cam 20 thus has a plurality of lobes, so that during the rotation of the cylinder block 30, a piston 50 held in contact with the cam 20 will perform back and forth movements in its housing due to the lobes of the cam 20, the maximum amplitude of the movement of the piston 50 in its housing 40 defining the stroke of the piston 50.

[0067] In the structure proposed by the present invention, each pair formed by a piston and a housing defines a first chamber 60 and a second chamber 70 which are distinct, isolated from each other by means of sealing elements, and defining distinct cylinder capacities. 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 cylinder capacity of the pistons for the motor or pump considered.

[0068] Such a structure makes it possible to define in a single cylinder block a hydraulic pump and a hydraulic motor of distinct displacements, one of the chambers 60 or 70 thus defining the hydraulic pump, and the other of the chambers 60 and 70 defining the hydraulic motor. In the remainder of the text, the term hydraulic motor will refer to all the chambers performing a hydraulic motor function, and to all the chambers performing a hydraulic pump function as a hydraulic pump.

[0069] The first chamber 60 and the second chamber 70 are typically superimposed according to the sliding direction of the piston 50 in the housing 40.

[0070] In the example illustrated, the housing 40 has two distinct portions; a first portion 41 having a first section SI, and a second portion 42 having a second section S2, the first section SI being strictly greater than the second section S2, the first portion extending from an external surface of the cylinder block 30 and opening opposite the cam, and the second portion 42 extending from the first portion 41 so as to form the bottom of the housing 40. The second portion 42 is thus typically blind in the sliding direction of the pistons 50.

[0071] The piston 50 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 40 while ensuring the sealing of the first chamber 60 and the second chamber 70.

[0072] In the illustrated example, conduits are arranged in the cylinder block 30, these conduits extending from the first chambers 60 and from the second chambers 70 and emerging from a lateral surface of the cylinder block 30. The conduits are then supplied by distributors.

[0073] An example of how this works is presented below.

[0074] In this example, it is considered that the first chambers 60 perform a hydraulic motor function adapted to rotate the cylinder block 30 and form the hydraulic motor of displacement C1 = N * S1 * C0 with C0 designating the stroke of the piston 50 and N the number of pistons (N = 3 in the illustrated example), and that the second chambers 70 perform a hydraulic pump function and form the hydraulic pump of displacement C2 = N * S2 * C0 so as to deliver a flow rate and a pressure. It is noted here that the stroke C0 is the same for the first chambers 60 and second chambers 70. It is understood that this example is only limiting, and that an inverse configuration is also possible, in which the first chambers 60 perform a hydraulic motor function adapted to rotate the cylinder block 30, and the second chambers 70 perform a hydraulic pump function.

[0075] If we consider two pistons shown in Figure 2, we designate two pistons by the letters A and B and we consider a clockwise direction of rotation of the cylinder block 30 indicated by an arrow. Considering the direction of rotation indicated, the piston A is in the exit phase of its housing, while the piston B is in the withdrawal phase in the housing. The first chamber 60 is supplied by a flow Q1 at a pressure PI which is described as high pressure and which generates a force tending to move the piston out of its housing to cause the relative rotation of the cylinder block with respect to the cam. The second chamber 70 is supplied at a supply pressure Pp which is described as low pressure.

[0076] Piston B is in the delivery phase. The first chamber 60 delivers a flow rate Qm (in this particular example Qm=Ql) at a pressure Pm which is described as low pressure, such that Pm < PI, and the second chamber 70 delivers a flow rate Q2 at a pressure P2 such that P2 > Pp.

[0077] The pressure adapter 100 is typically homokinetic; for a constant rotational speed of the cylinder block 30 relative to the cam 20, it delivers a constant or substantially constant flow rate, in contrast in particular to an oscillating linear actuator which delivers pressure in pulsations.

[0078] The set of first chambers 60 typically defines a first hydraulic sub-machine which operates by the collaboration of the pistons 50 sliding in these first chambers 60 with the multi-lobe cam 20 configured in such a way that said first hydraulic sub-machine is homogeneous. The term homogeneous means that at constant rotation (of the cylinder block) for each cam lobe 20, the flow circulating in the first chambers 60 whose pistons 50 travel through the cam lobe 20 in question is constant. An example of a hydraulic machine with homogeneous flow is presented in patent application WO2023 / 242502A1 to which those skilled in the art may refer.

[0079] When the hydraulic machine (or sub-machine) associates a particular distribution means for a lobe or a group of lobes of the multi-lobe cam 20, the fact that the hydraulic machine (or sub-machine) is homogeneous allows a constant flow rate to circulate in the conduits of this distribution means assigned to this lobe or group of lobes for a constant rotation speed of the hydraulic machine (or sub-machine).

[0080] To the extent that a constant flow circulates in the different conduits of the distribution system dedicated to a lobe or a group of lobes for a constant rotation speed of the hydraulic machine, there is no acceleration or deceleration of the fluid in the conduits of the distribution system dedicated to this lobe or this group of lobes, which in particular makes it possible to reduce pressure losses and therefore to increase the efficiency of the hydraulic machine or sub-machine.

[0081] According to one example, the set of second chambers 70 defines a second hydraulic sub-machine which operates by the collaboration of the pistons 50 sliding in these second chambers 70 with a multi-lobe cam configured such that said second hydraulic sub-machine is homogeneous.

[0082] The effect of the pressure adapter 100 will then depend in particular on the ratio between the cylinder capacities C1 and C2, and on the ratio between the intake pressures and flow rates of the first chamber 60 and the second chamber 70. Depending on the configuration of the adapter 100, the latter may in particular perform a pressure-raising or pressure-lowering function.

[0083] Since the applied torque is constant between the motor and the pump due to the single cylinder block 30 which provides the mechanical torque connection between the motor and the pump, we have the relationship (Pm-Pl) * Cl = (P2-Pp) * C2. The ratio between PI and P2 thus depends in particular on the ratio between Cl and C2.

[0084] According to a first example, if we consider that Cl > C2, and that Pp = Pm (with Pp or Pm < PI), then the second chamber 70 delivers a pressure P2 such that P2 > PI, due to the ratio of the cylinder capacities Cl and C2. The adapter 100 then performs a pressure amplifier function.

[0085] Conversely, if we consider that Cl < C2, and that Pp = Pm (with Pp or Pm < PI) then the second chamber 70 delivers a pressure P2 at a flow rate Q2 such that P2 < PI and such that Q2>Q1, due to the ratio of the cylinder capacities Cl and C2. The adapter 100 then performs a pressure reducer and flow amplifier function.

[0086] According to one example, in particular in the case where Cl > C2, the inlet of the hydraulic pump 120 can be connected to the discharge of the hydraulic motor 110. The discharge of the hydraulic motor 110 thus at least partially supplies the inlet of the hydraulic pump 120. Figure 3 shows a hydraulic diagram equivalent to such an assembly.

[0087] Thus, the pressure at the inlet of the hydraulic pump 120 is equal to the pressure at the outlet of the hydraulic motor 110.

[0088] A line 115 typically extends from the internal volume of the casing 10 to provide the boosting of the pump 120, so that the pressure Pp at the inlet 122 of the pump 120 is greater than a minimum boost pressure required for the pump 120. Alternatively, the boosting is not necessary, but the system includes means for ensuring that the pressure at the inlet 122 of the pump 120 is greater than the minimum pump boost pressure, for example a restriction made on a drain of the internal volume of the casing 10 which returns to the reservoir.

[0089] Alternatively, particularly in the case where Cl > C2, the inlet of the hydraulic pump 120 and the inlet of the hydraulic motor 110 are common. Thus, the hydraulic pump 120 is supplied at a pressure PI. Figure 4 shows a hydraulic diagram equivalent to such an assembly.

[0090] The proposed structure thus makes it possible to form a pressure adapter by means of a hydraulic machine with a single cylinder block and a single row of pistons positioned opposite the same cam, 3 pistons being sufficient, by doubling the function of each pair formed by a piston and the associated housing. One of the chambers then performs a hydraulic motor function and ensures rotational drive, while the other chamber performs a hydraulic pump function 120 to deliver a pressure P2 modulated relative to the intake pressure PI of the hydraulic motor 110. Such a structure therefore differs from a structure in which the cylinder block comprises several rows of pistons axially offset along the main axis ZZ, and which can be in contact with separate cams. The proposed structure is particularly advantageous in terms of compactness compared to such structures.

[0091] The pressure adapter 100 as proposed can in particular be integrated into a hydraulic machine, for example a hydraulic motor, or into a hydraulic component such as a cylinder.

[0092] Figures 5 and 6 show two views of an exemplary embodiment of a pressure adapter 100 according to the invention having a radial structure. In this distribution mode, the cam 20 is typically integral in rotation with the casing 10.

[0093] The adapter 100 comprises a distribution block 165 defining a first distributor 160 and a second distributor 170. The first distributor 160 is adapted to provide admission and discharge of fluid into the first chambers 60. The second distributor 170 is adapted to provide admission and discharge of fluid into the second chambers 70.

[0094] The distribution block 165 is typically a grooved distributor. The distribution block 165 is interposed between the cylinder block 30 and the casing 10, and comprises distribution orifices adapted to connect supply and discharge conduits formed in a distribution cover here forming a part of the casing 10, and conduits formed in the cylinder block 30. The distribution block 165 may for example take the form of a cylinder along the axis ZZ, provided with four grooves on its outer periphery and allows the passage of fluid from these grooves to the distribution interface of the cylinder block via conduits made from the material of the distribution block.

[0095] The first distributor 160 and the second distributor 170 are arranged so as to have distribution ducts superimposed in the radial direction relative to the main axis ZZ. In other words, the ducts formed in the cylinder block 30 open at distinct positions relative to the main axis ZZ; for example, the ducts connected to the first distributor 160 are centered on a circle of radius RI relative to the main axis ZZ, and the ducts connected to the second distributor 170 are centered on a circle of radius R2 relative to the main axis ZZ with RI different from R2.

[0096] Figure 5 corresponds to the configuration described previously with reference to Figure 2 and to piston A. The piston is in the outlet phase, and therefore in suction. The first chamber 60 is supplied with a high pressure PI at a flow rate Ql. The second chamber 70 is supplied with low pressure Pp at a flow rate Qp.

[0097] Figure 6 corresponds to the configuration described previously with reference to Figure 2 and to piston B. The piston is in the withdrawal phase, and therefore in the discharge phase. The first chamber 60 discharges a low pressure Pm at a flow rate Qm. The second chamber 70 delivers a flow rate Q2 at a pressure P2 such that P2 > Pp.

[0098] Advantageously, the first distributor 160 and the second distributor 170 are configured so that the supply of the chamber performing the motor function is carried out in conduits radially to the outside relative to the conduits supplying the chamber performing the pump function. Indeed, for a given angular sector, the internal section of the conduits increases with the radius relative to the main axis ZZ. The proposed configuration thus aims to limit the forces of the fluid on the parts by conveying the highest pressure (i.e. the discharge pressure of the pump in the case where the adapter 100 performs a pressure booster function) in the conduits radially to the inside, and therefore of smaller section.This same configuration also makes it possible to route the highest flow rate, i.e. the engine flow rate in the case where the adapter 100 performs a pressure booster function, in the radially external conduits and therefore of larger cross-section, thus limiting pressure losses. In the case where the adapter 100 performs a pressure booster function, the reverse configuration is then typically produced.

[0099] Figure 7 shows another exemplary embodiment of a pressure adapter 100 according to the invention having a radial structure. This embodiment may for example have a structure as already described with reference to Figure 2. [OlOOJOn this embodiment finds the various elements already described with reference to the previous figures. Only the differences are indicated below.

[0101] In the proposed structure, the first distributor 160 and the second distributor 170 are arranged on either side of the cylinder block 30 in the direction defined by the main axis ZZ.

[0102] The cylinder block 30 thus comprises conduits opening opposite each of the first distributor 160 and the second distributor 170, making it possible to connect the first chambers 60 and the second chambers 70 respectively to the first distributor 160 and to the second distributor 170. The conduits typically open at an interface between the cylinder block 30 and the first distributor 160 or the second distributor 170, the interface typically being between two surfaces extending radially relative to the main axis ZZ.

[0103] Such a structure with a distributor on either side of the cylinder block 30 is advantageous insofar as it makes it possible to balance the forces applied to the distributor, and therefore to reduce the load on the rolling elements compared to a structure comprising a single distributor on one side of the cylinder block 30. Thus, by balancing the forces applied on either side of the cylinder block 30, the load applied to the rolling elements is minimized.

[0104] As previously indicated, the first distributor 160 and the second distributor 170 are typically configured so that the supply to the chamber performing the motor function is carried out in conduits radially outside relative to the conduits carrying out the supply to the chamber performing the pump function.

[0105] Optionally, the first distributor 160 and the second distributor 170 are configured so that in operation, the force resulting from the supply and discharge of pressure from the first chambers 60 and the second chambers 70 tends to move the cylinder block towards one of the first distributor 160 and the second distributor 170, for example towards the first distributor 160, or alternatively to the second distributor 170.

[0106] Such a configuration thus makes it possible to determine in advance where to position the rolling element which will have to support an axial load due to the thrust of the cylinder block 30 on one of the distributors, and thus makes it possible to size the rolling elements appropriately. A stop 13 of the needle thrust type, roller thrust type or a shoulder can in particular be integrated into the adapter 100 in order to support the axial forces of the cylinder block relative to the casing 10. Alternatively, such a stop can be provided on each side of the cylinder block (on either side of the cylinder block relative to the axis of rotation).

[0107] The first distributor 160 and the second distributor 170 are typically positioned opposite the cylinder block 30 at distinct radial positions relative to the main axis ZZ. The conduits formed in the cylinder block 30 and allowing them to be selectively connected to the first chambers 60 or to the second chambers 70 therefore also open at distinct radial positions relative to the main axis ZZ. As indicated previously, the first distributor 160 and the second distributor 170 are advantageously configured so that the supply of the chamber performing the motor function is carried out in conduits radially outside relative to the conduits supplying the chamber performing the pump function.

[0108] Such a structure makes it possible in particular to simplify the internal structure of the cylinder block 30 by increasing the gap between the different conduits, and therefore making it possible to improve the mechanical strength of the cylinder block 30.

[0109] Figure 8 shows an exemplary embodiment of the second distributor 170. It is understood that the first distributor 160 can also have a similar structure.

[0110] The second distributor 170 as illustrated has a generally annular shape with a central recess. Conduits 172 and 173 are formed from an axial end of the body of the second distributor 170, these conduits being adapted to supply the second chambers 70. Annular grooves 174 are formed in the external radial surface of the body of the second distributor 170, these annular grooves 174 being adapted to provide fluid communication with grooves arranged in a distribution cover.

[0111] In the structure shown, the conduits 173 are formed so as to be connected to the groove 174. The conduits 172 are, however, isolated from the groove 174, and are connected to bores 175 opening onto an external radial surface of the body of the second distributor 170. The bores 175 are formed so as to open into an internal volume of the casing 10. Thus, the second distributor 170 as proposed makes it possible, for example, to achieve an admission of fluid taken from the internal volume of the casing 10 via the bores 175 and the conduits 172, then a discharge of fluid via the conduits 173 and the groove 174.By proposing a first distributor 160 with a similar structure, which makes it possible to carry out a fluid sampling via an inlet groove and a discharge into the casing 10 by means of holes equivalent to the holes 175, it is thus possible, for example, to produce an adapter 100 with an equivalent hydraulic diagram as presented in FIG. 3, in which the connection between the discharge of the hydraulic motor 110 and the inlet of the hydraulic pump 120 is made via the internal volume of the casing 10.

[0112] Figure 9 is a schematic view of another embodiment.

[0113] In this embodiment, the pistons 50 and the housings 40 are arranged so as to define a movement of the pistons 50 in the housings 40 in a direction parallel to the main axis ZZ. The pressure adapter 100 then has a structure that is described as axial.

[0114] In this embodiment, we find the various elements already described with reference to the previous figures. The cam 20 is here positioned opposite the housings 40 in which the pistons 50 slide. The cam 20 is typically a multi-lobe cam.

[0115] Alternatively, the cam 20 may be formed by a plate inclined relative to the main axis ZZ.

[0116] This figure schematically represents the first distributor 160 adapted to supply and discharge the first chambers 60, and the second distributor 170 adapted to supply and discharge the first chambers 70.

[0117] In the illustrated embodiment, the first distributor 160 is formed at least partially in the axis 32. In other words, the first distributor 160 is formed at least partially in a volume radially inside the cylinder block 30. Indeed, to the extent that the adapter 100 does not have a torque transmission shaft, a volume in the center of the cylinder block 30 or, where appropriate, the axis 32 can be used to at least partially perform a distributor function. The cylinder block 30 thus comprises ducts extending from the first chambers 60 and opening at the interface between the cylinder block 30 and the axis 32. These ducts extend in the axis 32 to the first distributor 160.

[0118] The second distributor 170 as shown is formed in the casing 10. The cylinder block 30 thus comprises conduits extending from the second chambers 70 and opening at the interface between the cylinder block 30 and the casing 10. These conduits extend into the casing 10 to the second distributor 170.

[0119] In this configuration, the second distributor 170 is thus positioned around the first distributor 160. Such a configuration makes it possible to use the axis 32 for the formation of the fluid circulation conduits, and is thus advantageous in that it facilitates the formation of the different conduits.

[0120] Figure 10 is a schematic view of a variant of Figure 9.

[0121] In this embodiment, the first distributor 160 and the second distributor 170 are formed at least partially in the axis 32 or in the extension of the axis 32.

[0122] In other words, the first distributor 160 and the second distributor 170 are formed at least partially in a volume radially inside the cylinder block 30. The cylinder block 30 thus comprises conduits extending from the first chambers 60 and opening at the interface between the cylinder block 30 and the axis 32, and conduits extending from the second chambers 70 and opening at the interface between the cylinder block 30 and the axis 32. These conduits extend along the axis 32 respectively to the first distributor 160 and to the second distributor 170.

[0123] In the example illustrated, the conduits formed in the axis 32 open onto the cylinder block at distinct axial positions relative to the main axis ZZ.;

[0124] Such a configuration thus makes it possible to use the axis 32 for the formation of distribution conduits, and thus minimizes the size of the adapter 100.

[0125] Figure 11 is a sectional view of a particular embodiment of the pressure adapter 100 in a variant having a radial architecture with an internal cam mounted to rotate relative to the cylinder block 30 and the casing 10. The cylinder block 30 is then typically integral in rotation with the casing 10.

[0126] In the example illustrated in Figure 11, the cam 20 has 4 lobes, and the cylinder block 30 has 3 housings 40, each housing being provided with a piston 50. The cam 20 thus has a plurality of lobes, so that during the rotation thereof, a piston 50 held in contact with the cam 20 will perform back and forth movements in its housing due to the lobes of the cam 20, the maximum amplitude of the movement of the piston 50 in its housing 40 defining the stroke of the piston 50.

[0127] As for the embodiments described previously, each pair formed by a piston 50 and a housing 40 defines a first chamber 60 and a second chamber 70 which are distinct, isolated from each other by means of sealing elements, and defining distinct cylinder capacities.

[0128] Figure 12 is a hydraulic diagram illustrating an example of integration of the adapter 100 for a hydraulic member such as a cylinder.

[0129] This figure shows a cylinder 200 supplied by a pressure source, here a hydraulic pump 210 drawing a fluid from a reservoir R, and driven by a primary motor M, typically an electric or thermal motor. The hydraulic pump 210 is connected in parallel to the adapter 100 and to a pilot valve 220. The cylinder 200 has two chambers, connected to a selector 230. The pilot valve 220 is connected to the discharge of the adapter 100 and to the selector 230. The selector 230 makes it possible to control the direction of movement of the cylinder 200, by connecting one of the chambers to a pressure source, and the other to the reservoir R. The pilot valve 220 makes it possible to connect the selector 230 and therefore to supply a chamber of the cylinder 200 via the selector 230 either directly with the hydraulic pump 210, or via the adapter 100. The proposed structure thus makes it possible to actuate the cylinder 200 with or without the adapter 100, in both directions of actuation.

[0130] This integration of the pressure adapter according to the invention in a structure 300 common to the cylinder makes it possible in particular to limit the very high pressure in a closed physical environment (which is the structure, for example, metallic, of the cylinder) making it possible to locate the very high pressure in an environment close to the actuator called upon to use it and to avoid circulating very high pressure in conduits external to this structure with all the disadvantages that this entails.

[0131] 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.

[0132] 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. Pressure adapter (100) comprising: a first assembly and a second assembly, movable in rotation relative to each other along a main axis, the first assembly comprising a cam (20), the second assembly comprising a cylinder block (30) having a plurality of housings (40) in which pistons (50) slide, each piston (50) being positioned in a housing (40), characterized in that each pair formed by a piston (50) and a housing (40) defines between the piston (50) and the housing (40) a first chamber (60) and a second chamber (70) which are distinct, the first chamber (60) and the second chamber (70) defining distinct displacements, in which the set of first chambers (60) performs a hydraulic motor function (110), adapted to be connected to a supply providing a first flow rate Q1 at a first pressure PI and to effect relative rotation of the first assembly and the second assembly,the set of second chambers (70) performs a hydraulic pump function (120), adapted to deliver a second flow rate Q2 at a second pressure P2.,

2. Pressure adapter (100) according to claim 1, in which for each pair formed by a piston (50) and a housing (40), the first chamber (60) defines a cylinder capacity strictly greater than the second chamber (70).

3. Pressure adapter (100) according to claim 1, wherein for each pair formed by a piston (50) and a housing (40), the first chamber (60) defines a cylinder capacity strictly lower than the second chamber (70).

4. Adapter (100) according to one of claims 1 to 3, in which for each pair formed by piston (50) and a housing (40), the first chamber (60) and the second chamber (70) are superimposed in a sliding direction of the piston (50) in the housing (40).

5. Adapter (100) according to one of claims 1 to 4, in which each housing (40) has a first portion (41) having a first section SI, and a second portion (42) having a second section S2, the first section SI being strictly greater than the second section S2, the first portion (41) extending from an external surface of the cylinder block (30), and the second portion (42) extending from the first portion (41).

6. Adapter (100) according to one of claims 1 to 5, in which the set of first chambers (60) performing a hydraulic motor function (110) has a primary inlet and a primary discharge, the set of second chambers (70) performing a hydraulic pump function (120) has a secondary inlet and a secondary discharge, the primary discharge feeds at least part of the secondary inlet.

7. Adapter (100) according to claim 6, in which the connection between the primary discharge and the secondary intake is made via an internal volume of the casing (10).

8. Adapter (100) according to one of claims 1 to 5, in which the set of first chambers (60) performing a hydraulic motor function (110) has a primary inlet and a primary discharge, the set of second chambers (70) performing a hydraulic pump function (120) has a secondary inlet and a secondary discharge, the secondary inlet and the primary inlet are common.

9. Adapter (100) according to one of the preceding claims, wherein: the first chambers (60) are connected to a first distributor (160) adapted to carry out an intake and a discharge of fluid, and the second chambers (70) are connected to a second distributor (170) adapted to carry out an intake and a discharge of fluid.

10. Adapter according to claim 9, in which the cylinder block comprises conduits adapted to connect the first chambers (60) to the first distributor (160), said conduits emerging from the cylinder block at a first distance RI relative to the main axis (ZZ), and the cylinder block comprises conduits adapted to connect the second chambers (70) to the second distributor (170), said conduits emerging from the cylinder block at a second distance R2 relative to the main axis (ZZ), the first distance RI and the second distance R2 being distinct.

11. An adapter (100) according to claim 10, wherein - if Ql > Q2, then RI > R2, and - if Ql < Q2, then R2 > RI. Tl

12. Adapter (100) according to one of claims 1 to 11, wherein the pistons (50) and the housings (40) are arranged so as to define a movement of the pistons (50) in a direction parallel to the main axis (ZZ).

13. Adapter (100) according to one of claims 1 to 11, wherein the pistons (50) and the housings (40) are arranged so as to define a movement of the pistons (50) in a radial direction relative to the main axis (ZZ).

14. An adapter according to claim 13, wherein the cam (20) is a multi-lobe cam.

15. Adapter (100) according to claim 13, wherein the first distributor (160) and the second distributor (170) are arranged on either side of the cylinder block (30) in the direction defined by the main axis (ZZ).

16. An adapter (100) according to claim 15, wherein the first distributor (160) and the second distributor (170) are dimensioned such that the force resulting from the supply of the first chambers (60) and the second chambers (70) respectively by the first distributor (60) and the second distributor (70) tends to move the cylinder block (30) towards one of the first distributor (160) and the second distributor (170).

17. An adapter (100) according to one of claims 1 to 16, wherein the set of first chambers (60) define a homokinetic motor, and wherein the set of second chambers (70) define a homokinetic pump.

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