System for driving hydraulic member

Abstract

A system for driving a component (10) by means of a hydraulic circuit is disclosed, comprising: a hydraulic energy source (100) adapted to supply pressure in the hydraulic circuit; a drive member (200) comprising a crankcase (210) having a first orifice (212) and a second orifice (214), a main hydraulic machine (230) housed in the crankcase (210), and a supercharger (300) integrated in the crankcase (210), the supercharger (300) being adapted to selectively boost pressure, in this way, the pressure difference between the two orifices (232, 234) in the main hydraulic machine (230) is greater than the pressure difference between the two orifices (212, 214) in the crankcase (210).

Description

Technical Field

[0001] The present invention relates to a system for driving a hydraulic member, in particular for driving a shaft, a moving member, a jack, or for driving the rotation of more general equipment such as a winch, a crusher, a drill, etc. Background Art

[0002] A hydraulic system generally consists of a power converter that converts the mechanical energy provided by a main motor (e.g., a heat engine or an electric motor) into hydraulic energy, which is distributed by a high-pressure pipeline network to one or more hydraulic members, such as a jack or a hydraulic motor for driving a wheel or a shaft.

[0003] However, such a transmission solution has some limitations, especially in the following aspects:

[0004] - Torque density: The pressure of commonly used pipelines is limited to a value less than 450 bar, and the maximum transmissible torque limit is the product of this pressure and the displacement value of the hydraulic actuator (usually a hydraulic motor). However, the displacement value directly affects the size and cost of the motor.

[0005] - Speed: For a given pump displacement and the maximum rotational speed of the main motor, a maximum flow rate is defined. In the case of applying a transmission, this limits the speed of the vehicle.

[0006] In the case of hydrostatic transmission, two distinct operating modes are usually distinguished:

[0007] - An operating mode called the "working" mode: The load is large and the speed is low, and at this time, the best obstacle-crossing ability (for a vehicle) or in any case the maximum torque (for more general rotating equipment) is sought. This specific condition is decisive for determining the size of the motor displacement.

[0008] - An operating mode called the "road" mode (for a vehicle) or the "normal" mode (for more general rotating equipment), especially for the movement of a vehicle or a machine between two working positions: In this mode, the load is low and the speed is high. At this time, the fastest speed is sought, and this fastest speed is limited by the size and volume of the pump and / or the motor driving the pump.

[0009] Therefore, it can be understood that these two operating modes constrain the size of the hydraulic circuit; the size of the components must be too large to provide a power margin that the driver will never use.

[0010] More generally, for the drive of hydraulic members, different drive modes may be required, which involves various requirements in terms of hydraulic power supply. Summary of the Invention

[0011] To at least partially solve these problems, the present invention relates to a system for driving a member by means of a hydraulic circuit, comprising:

[0012] A hydraulic energy source adapted to provide pressure in the hydraulic circuit;

[0013] A drive member, comprising:

[0014] - A housing having a first housing orifice and a second housing orifice, the first housing orifice and the second housing orifice being adapted to define a suction port and a discharge port of the housing;

[0015] - A main hydraulic machine adapted to be supplied by the hydraulic energy source, the main hydraulic machine being accommodated in the housing and having a first hydraulic machine orifice and a second hydraulic machine orifice,

[0016] The system is characterized in that the drive member includes a booster integrated in the housing, the booster being adapted to selectively increase the pressure such that the pressure difference between the two orifices of the main hydraulic machine is greater than the pressure difference between the two orifices of the housing.

[0017] According to one example, the booster is integrated in the housing such that the booster is connected to the first orifice and the second orifice of the main hydraulic machine via a conduit formed in the housing.

[0018] According to one example, the booster is configured to be activated when the pressure difference between the two orifices of the main hydraulic machine exceeds a threshold.

[0019] The system may further include at least one valve connecting the booster to the first orifice and / or the second orifice of the housing, the at least one valve being configured to: deactivate the booster when the pressure difference between the two orifices of the housing is less than or equal to a pressure threshold.

[0020] The system may further include at least one valve connecting the booster to the first orifice and / or the second orifice of the housing, the at least one valve being configured to: deactivate the booster when the rotational speed of the main hydraulic machine is greater than a threshold.

[0021] The system may further include at least one valve connecting the booster to the first orifice and / or the second orifice of the housing, the at least one valve being configured to: deactivate the booster when the rotational speed of the main hydraulic machine exceeds a specific threshold.

[0022] According to one example, the booster is adapted to obtain a flow rate Q1 and a pressure P1 from the first orifice or the second orifice of the housing and provide a flow rate Q2 and a pressure P2 to the first orifice or the second orifice of the main hydraulic machine such that Q2 < Q1 and P2 > P1.

[0023] According to one example, the main hydraulic press can be a hydraulic press of axial technology, such as, in particular, a hydraulic press having an inclined plate on which a piston slides.

[0024] According to one example, the main hydraulic press can be a hydraulic press of radial technology, such as, in particular, a hydraulic press having a multi-lobe cam in sliding contact with a piston.

[0025] According to one example, the main hydraulic press can have a fixed displacement.

[0026] According to one example, the main hydraulic press can have a multi-displacement.

[0027] According to one example, the main hydraulic press can have a variable or continuously variable displacement.

[0028] According to one embodiment, the supercharger employs oscillating linear technology.

[0029] According to one example, the supercharger includes a first hydraulic press and a second hydraulic press that are rotationally fixed, the first hydraulic press and the second hydraulic press having the same displacement, and the first hydraulic press and the second hydraulic press being configured such that one hydraulic press operates as a pump while the other hydraulic press operates as a motor.

[0030] According to one example, the supercharger includes a first hydraulic press and a second hydraulic press that are rotationally fixed, the first hydraulic press and the second hydraulic press having different displacements, and the first hydraulic press and the second hydraulic press being configured such that one hydraulic press operates as a pump while the other hydraulic press operates as a motor.

[0031] According to one example, the supercharger includes a first hydraulic press and a second hydraulic press that are rotationally fixed, the first hydraulic press and the second hydraulic press having different displacements, and the first hydraulic press and the second hydraulic press being configured such that one hydraulic press operates as a pump while the other hydraulic press operates as a motor. The machine can be a hydraulic press of radial technology, particularly a hydraulic press of multi-lobe cam radial technology.

[0032] According to one example, the supercharger includes a first hydraulic press and a second hydraulic press that are rotationally fixed, and the first hydraulic press and the second hydraulic press are configured such that one hydraulic press operates as a pump while the other hydraulic press operates as a motor. The hydraulic press can have a fixed displacement, a multi-displacement, or a variable displacement.

[0033] According to one example,

[0034] - The first hydraulic press has a first orifice and a second orifice, the first orifice being selectively connected to the housing orifice having the highest pressure among the two housing orifices, and the second orifice being selectively connected to the housing orifice having the lowest pressure among the two housing orifices.

[0035] - The second hydraulic machine has a first orifice and a second orifice. The first orifice is connected to the housing orifice with the lowest pressure among the two housing orifices, and the second orifice is connected via a conduit arranged in the housing to the orifice with the highest pressure in the main hydraulic machine.

[0036] According to one example, the supercharger includes a first hydraulic machine and a second hydraulic machine that are rotationally fixed. The displacement of the first hydraulic machine is greater than the displacement of the second hydraulic machine.

[0037] The system is configured such that, for a first operating mode, the first hydraulic machine operates as a motor, and the second hydraulic machine operates as a pump. The second hydraulic machine supplies the main hydraulic machine.

[0038] According to one example,

[0039] - The first hydraulic machine has a first orifice and a second orifice. The first orifice is selectively connected to the housing orifice with the highest pressure among the two housing orifices, and the second orifice is selectively connected to the housing orifice with the lowest pressure among the two housing orifices.

[0040] - The second hydraulic machine has a first orifice and a second orifice. The first orifice is connected to the second orifice of the first hydraulic machine, and the second orifice is connected via a conduit arranged in the housing to the inner orifice with the highest pressure in the main hydraulic machine.

[0041] According to one embodiment, the second orifice of the second hydraulic machine is connected to the first orifice and the second orifice of the main hydraulic machine via a high-pressure selector.

[0042] According to one example,

[0043] The first orifice of the first hydraulic machine is connected to a first calibration valve. The first calibration valve is connected on the one hand to the first orifice of the housing and on the other hand to the second orifice of the housing. The first calibration valve is configured to: when the pressure difference between the orifices of the housing exceeds a first calibration threshold, connect the first orifice of the first hydraulic machine to a connection member connected to a hydraulic energy source with the highest pressure.

[0044] The second orifice of the first hydraulic machine is connected to a second calibration valve. The second calibration valve is connected on the one hand to the first orifice of the housing and on the other hand to the second orifice of the housing. The second calibration valve is configured to: when the pressure difference between the orifices of the housing exceeds a second calibration threshold, connect the first orifice of the first hydraulic machine to a connection member connected to a hydraulic energy source with the lowest pressure.

[0045] According to one example, the supercharger includes a first hydraulic machine and a second hydraulic machine that are rotationally fixed. The displacement of the first hydraulic machine is greater than the displacement of the second hydraulic machine.

[0046] The system is configured such that, for a first operating mode, a first hydraulic press operates as a motor while a second hydraulic press operates as a pump, and the second hydraulic press supplies a main hydraulic press.

[0047] Wherein:

[0048] - The first hydraulic press has a first orifice and a second orifice. The first orifice is connected to a first orifice of the housing, and the second orifice is connected to a second orifice of the housing.

[0049] - The second hydraulic press has a first orifice and a second orifice. The first orifice is connected to a second orifice of the main hydraulic press, and the second orifice is connected to a first orifice of the main hydraulic press.

[0050] The system includes a valve adapted to selectively isolate the first orifice of the housing from the first orifice of the main hydraulic press, and a valve adapted to selectively isolate the second orifice of the housing from the second orifice of the main hydraulic press.

[0051] According to one example, the first hydraulic press and / or the second hydraulic press is a radial piston and multi-lobe cam hydraulic press.

[0052] According to one example, at least one of the first hydraulic press and the second hydraulic press is a variable displacement hydraulic press.

[0053] According to one example, the system further includes a first valve and a second valve. The first valve is adapted to selectively connect or isolate the first orifice of the housing from the first orifice of the main hydraulic press, and the second valve is adapted to selectively connect or isolate the second orifice of the housing from the second orifice of the main hydraulic press.

[0054] According to one example, the pressure amplification is pilot-controlled by a command external to the drive member.

[0055] According to one example, the main hydraulic press is a radial piston and multi-lobe cam hydraulic press.

[0056] The invention also relates to a rolling machine (e.g., a vehicle, construction machinery, or agricultural machinery) that includes at least one moving member and at least one system as defined above, and the at least one system is adapted to selectively drive the rotation of the moving member.

[0057] The invention also relates to a drive member as defined above with reference to the system. Thus, the invention specifically relates to a drive member adapted to selectively drive the rotation of a member, and the drive member includes:

[0058] - A housing having a first housing orifice and a second housing orifice, and the first housing orifice and the second housing orifice are adapted to define a suction port and a discharge port of the housing.

[0059] - A main hydraulic press, adapted to be supplied by a hydraulic energy source, the main hydraulic press being housed in a housing and having a first hydraulic press orifice and a second hydraulic press orifice, the system being characterized in that the drive member includes a booster integrated in the housing.

[0060] The booster is adapted to selectively increase the pressure such that the pressure difference between the two orifices of the main hydraulic press is greater than the pressure difference between the two orifices of the housing. Description of the Drawings

[0061] The present invention and its advantages will be better understood after reading the following detailed description of different embodiments of the present invention given as non - limiting examples.

[0062] Figure 1 Figure 1 is a schematic diagram of an example of a system according to one aspect of the present invention.

[0063] Figure 2 Figure 2 represents an exemplary embodiment of a system embodiment according to one aspect of the present invention.

[0064] Figure 3 Figure 3 represents an exemplary embodiment of a system according to one aspect of the present invention.

[0065] Figure 4 Figure 4 represents another exemplary embodiment of a system according to one aspect of the present invention.

[0066] Figure 5 Figure 5 represents another exemplary embodiment of a system according to one aspect of the present invention.

[0067] Figure 6 Figure 6 represents another exemplary embodiment of a system according to one aspect of the present invention.

[0068] Figure 7 Figure 7 represents another exemplary embodiment of a system according to one aspect of the present invention.

[0069] Figure 8 Figure 8 represents Figure 6 a specific configuration of

[0070] Figure 9 Figure 9 represents Figure 6 a specific configuration of

[0071] Figure 10 ​​​​​​​​​​​​​​​​​​​​Figure 10 Represents another exemplary embodiment of a system according to one aspect of the present invention.

[0072] Figure 11 Figure 11 Represents Figure 10 a specific configuration of the system shown.

[0073] Figure 12 Figure 12 Represents Figure 10 another specific configuration of the system shown.

[0074] Figure 13 Figure 13 Represents Figure 10 another specific configuration of the system shown.

[0075] Figure 14 Figure 14 Represents another exemplary embodiment of a system according to one aspect of the present invention.

[0076] Figure 15 Figure 15 Represents Figure 14 a specific configuration of the system shown.

[0077] Figure 16 Figure 16 Represents Figure 14 another specific configuration of the system shown.

[0078] Figure 17 Figure 17 Represents Figure 14 another specific configuration of the system shown.

[0079] Figure 18 Figure 18 Represents another exemplary embodiment of a system according to one aspect of the present invention.

[0080] Figure 19 Figure 19 Represents another exemplary embodiment of a system according to one aspect of the present invention.

[0081] In all the figures, common elements are identified by the same reference numerals. Detailed Description

[0082] ​​​​​​​​​​​​​​​​​​The system according to one aspect of the present invention will be described below with reference to the accompanying drawings. The presented circuit is a simplified diagram. Thus, different elements such as boost means and calibration means are not represented in the figures. However, those skilled in the art understand that these figures are not restrictive and that the circuit may include such well-known elements. In particular, in the described embodiment, the member 10 is represented as a hydraulic motor for driving the rotation of an element such as a wheel. However, the present invention is applicable to other types of drive members, in particular translational drive members such as hydraulic jacks.

[0083] Figure 1 is a general schematic diagram of a system according to one aspect of the present invention. This figure shows the member 10, for example a member for moving a vehicle or machinery (e.g., a wheel, a machine shaft or an excavator turret ring). The member 10 is driven by a hydraulic circuit.

[0084] The represented hydraulic circuit includes a hydraulic energy source 100 (e.g., a pressure source such as a pump or an accumulator) and a drive member 200. The hydraulic energy source 100 is adapted to supply the drive member 200 such that the drive member drives the member 10 to rotate or translate (depending on the type of member selected). The circuit may be an open-loop circuit or a closed-loop circuit. In the case of an open-loop hydraulic circuit, the hydraulic energy source 100 generally includes an ambient pressure tank, a hydraulic pump or an accumulator, and valves or valve elements that ensure hydraulic connection according to the operating mode.

[0085] It can be understood that the system may be reversible. The description generally presents the operation of driving the member 10 to rotate. The hydraulic member has a reversible operation, especially during the braking phase, reverse operation can be performed; then the member 10 performs a driving function, allowing energy recovery.

[0086] The hydraulic energy source 100 is generally a hydraulic pump, such as a variable displacement hydraulic pump 110 driven by a main motor 120 (e.g., a heat engine or an electric motor). The hydraulic energy source may also include a fixed displacement hydraulic pump 110 and a main motor 120 adapted to drive the fixed displacement hydraulic pump 110 to rotate at a variable speed. Figure 2 An exemplary embodiment (with a variable displacement pump) is shown.

[0087] The drive member 200 includes a housing 210 in which a main hydraulic machine 230 is accommodated. The main hydraulic machine 230 is generally adapted to perform motor operation in order to drive the member 10 to rotate. The drive member also includes a booster 300 accommodated in the housing 210.

[0088] The booster 300 is configured to selectively perform a pressure increase or amplification function. Thus, for an initial pressure P1 at the suction port of the booster 300, the booster 300 will provide a pressure P2 such that P2 > P1.

[0089] Figure 3 and Figure 4 represent two exemplary embodiments of the supercharger 300.

[0090] The housing 210 defines a first orifice 212 and a second orifice 214, and the first orifice 212 and the second orifice 214 form a fluid suction port and a fluid discharge port according to the circulation direction of the fluid. Similarly, the main hydraulic machine 230 defines a first orifice 232 and a second orifice 234, and the first orifice 232 and the second orifice 234 form a fluid suction port and a fluid discharge port according to the circulation direction of the fluid. Within the framework of the specification, for the motor operation of the main hydraulic machine 230, it will be considered that the first orifice 212 forms a fluid suction port, thereby forming a high-pressure pipeline, and the second orifice 212 forms a fluid discharge port, thereby forming a low-pressure pipeline. Unless otherwise specified, the described operations will be considered to correspond to the operations in the traction forward gear.

[0091] For example, the main hydraulic machine 230 can be a rotary machine, typically a radial piston and multi-lobe cam hydraulic machine, or an axial piston hydraulic machine. For example, the hydraulic machine can be used as a motor for driving components such as wheels or shafts, tow hooks or tools.

[0092] The main hydraulic machine 230 can also be a jack, and then the two orifices 232 and 234 are usually connected to the two chambers of the jack to apply opposite forces. In this case, the system usually includes means suitable for restricting the pressure in the hydraulic circuit, such as a pilot calibration valve element.

[0093] The supercharger 300 generally includes a first hydraulic machine 310 and a second hydraulic machine 320. The first hydraulic machine 310 and the second hydraulic machine 320 are rotationally fixed and are configured such that one hydraulic machine performs a pumping operation while the other hydraulic machine performs a motor operation. It should be understood that such components are reversible, and the hydraulic motor can perform a pumping operation, and vice versa. In the illustrated example, the first hydraulic machine 310 performs a motor operation, while the second hydraulic machine 320 performs a pumping operation. By rotationally fixed, it means here that the first hydraulic machine 310 and the second hydraulic machine 320 are rotationally coupled and thus rotate together. For example, this rotational coupling can be achieved by coupling the two hydraulic machines on the same shaft or by connecting the two hydraulic machines through a rigid mechanical link.

[0094] The first hydraulic machine 310 and the second hydraulic machine 320 are generally formed by the same hydraulic machine including two different components.

[0095] In Figure 3In the example shown, the first hydraulic press 310 has a first orifice 312 and a second orifice 314. The first orifice 312 is connected to the first orifice 212 of the housing 210 (that is, here it is connected to the orifice in the housing 210 with the highest pressure), while the second orifice 314 is connected to the second orifice 214 of the housing 210 (that is, it is connected to the orifice in the housing 210 with the lowest pressure). The second hydraulic press 320 has a first orifice 322 and a second orifice 324. The first orifice 322 is connected to the second orifice 314 of the first hydraulic press 310 and the second orifice 214 of the housing 210 (that is, it is connected to the orifice in the housing 210 with the lowest pressure), while the second orifice 324 is connected to the first orifice 232 of the main hydraulic press 230 via a conduit arranged in the housing (that is, its suction port, so the orifice with the highest pressure). In this embodiment, the displacement C1 of the first hydraulic press 310 is greater than the displacement C2 of the second hydraulic press 320. Such an embodiment is called a 3-line common return supercharger. For example, the first hydraulic press 310 and / or the second hydraulic press 320 can have a fixed displacement or a variable displacement. For example, one hydraulic press can have a fixed displacement while the other can have a variable displacement, or both hydraulic presses can have a fixed displacement, or both hydraulic presses can have a variable displacement. Using at least one variable displacement hydraulic press enables the pressure amplification or elevation ratio to be changed by varying the displacement ratio between the first hydraulic press 310 and the second hydraulic press 320. Then, the system can include, for example, a controller that is adapted to pilot control the change in the displacement ratio according to a setpoint or operating conditions, thereby pilot controlling the change in the pressure elevation ratio.

[0096] The first hydraulic press 310 and the second hydraulic press 320 are generally identical or similar in all respects and are asymmetric in appropriate cases except for the displacement. The first hydraulic press 310 and the second hydraulic press 320 each generally have a single shaft output member, and these two shaft output members are mechanically connected.

[0097] In operation, the supercharger 300 is supplied by a hydraulic energy source 100. Therefore, high pressure is applied to the suction port 312 of the first hydraulic press 310. The first hydraulic press 310 performs the function of driving the second hydraulic press 320 to rotate. The second hydraulic press is supplied through the discharge port of the first hydraulic press 310. However, due to the difference in displacement, the second hydraulic press 320 will provide a higher pressure (described as a very high pressure) to supply the main hydraulic press 230. Therefore, in this embodiment, the pressure elevation specifically depends on the ratio between the displacements C1 and C2.

[0098] More generally, the supercharger 300 can thus obtain a flow rate Q1 and a pressure P1 from an orifice of the housing 210, here the first orifice 212 of the housing 210, and supply a flow rate Q2 and a pressure P2 to the suction port of the hydraulic press 230, here its first orifice 232, such that Q2 < Q1 and P2 > P1.

[0099] In Figure 4 In the example shown, the first orifice 312 of the first hydraulic press 310 and the first orifice 322 of the second hydraulic press 320 are both connected to the first orifice 212 of the housing 210 (that is to say, here connected to the orifice in the housing 210 having the highest pressure).

[0100] The second orifice 314 of the first hydraulic press 310 is connected to the second orifice 214 of the housing 210 (that is to say, connected to the orifice in the housing 210 having the lowest pressure).

[0101] The second orifice 324 of the second hydraulic press 320 is connected via a conduit arranged in the housing to the first orifice 232 of the main hydraulic press 230 (that is to say, its suction port, and thus the orifice having the highest pressure). Such an embodiment is called a 3 - line common supply booster.

[0102] In this embodiment, the displacement C1 of the first hydraulic press 310 can generally be equal to or substantially equal to the displacement C2 of the second hydraulic press 320.

[0103] In operation, the supercharger 300 is supplied by a hydraulic energy source 100. Thus, a high pressure is applied to the suction port 312 of the first hydraulic press 310. The first hydraulic press 310 performs the function of driving the second hydraulic press 320 to rotate. The second hydraulic press 320 is also supplied by the hydraulic energy source 100; thus the second hydraulic press 320 will perform a pressure amplification function.

[0104] For the previous embodiment, the supercharger 300 can thus obtain a flow rate Q1 and a pressure P1 from an orifice of the housing 210, here the first orifice 212 of the housing 210, and supply a flow rate Q2 and a pressure P2 to the suction port of the hydraulic press 230, here its first orifice 232, such that Q2 < Q1 and P2 > P1.

[0105] More generally, the supercharger 300 enables the transformation of a high pressure at the suction port of the housing 210 into a very high pressure at the inlet of the main hydraulic press 230.

[0106] In the system according to the invention, as described above, the connection between the main hydraulic press 230 and the second hydraulic press 320 is formed by a conduit arranged in the housing 210 of the drive member 200. Thus, such a structure can limit the area of very high pressure to a reduced space inside the housing 210 and avoid a pressure increase in the entire circuit.

[0107] Thus, the proposed structure enables the pressure supplied to the main hydraulic press 230 to be increased without the need to oversize the various components of the hydraulic circuit.

[0108] In particular, this function can be implemented on demand, for example to overcome an obstacle. When the conditions are met, the booster 300 can be selectively activated.

[0109] Figure 5 A variant of the invention is schematically represented, in which the booster 300 is rotationally connected by a first hydraulic press 310 and a second hydraulic press 320, wherein the supply and discharge pipes of the first hydraulic press 310 and the supply and discharge pipes of the second hydraulic press 320 are by default isolated from each other. Such a booster can be referred to as a "4-line lifter" to distinguish it from other variants of the boosters described as including "3 lines"; in particular, the Figure 4 "3-line common supply" booster shown and Figure 3 , Figures 6 to 9 the "3-line common return" booster shown are distinguished.

[0110] In Figure 5 the example shown, the valves allow the fluid to pass or not pass through the ducts depending on the activation or non-activation of the booster. This makes it possible to activate or deactivate the booster in one or the other rotational direction in a traction or restraint state (for example, for a machine equipped with a system according to the invention).

[0111] The first hydraulic press 310 has a first orifice 312 and a second orifice 314, the first orifice 312 being connected at the level of the hydraulic connection A to the duct joining the first orifice 212 of the housing 210 to the first orifice 232 of the main hydraulic press 230. The second orifice 314 is connected at the level of the hydraulic connection B to the duct joining the second orifice 214 of the housing 210 to the second orifice 234 of the main hydraulic press 230.

[0112] The second hydraulic press 320 has a first orifice 322 and a second orifice 324, the first orifice 322 being connected at the level of the hydraulic connection D to the duct joining the second orifice 214 of the housing 210 to the second orifice 234 of the main hydraulic press 230. The second orifice 324 is connected at the level of the hydraulic connection C to the duct joining the first orifice 212 of the housing 210 to the first orifice 232 of the main hydraulic press 230.

[0113] The valve 243 is located between the first orifice 312 of the first hydraulic press 310 and the hydraulic connection A.

[0114] The valve 245 is located between the second orifice 314 of the first hydraulic press 310 and the hydraulic connection B.

[0115] The valve 247 is located between the second orifice 324 of the second hydraulic press 320 and the hydraulic connection C.

[0116] The valve 249 is located between the first orifice 322 of the second hydraulic press 320 and the hydraulic connection D.

[0117] The valve 251 is located on the conduit joining the first orifice 212 of the housing 210 to the first orifice 232 of the main hydraulic press 230 between the connection A and the connection C.

[0118] The valve 253 is located on the conduit joining the second orifice 214 of the housing 210 to the second orifice 234 of the main hydraulic press 230 between the connection D and the connection B.

[0119] Each of these valves 243, 245, 247, 249, 251 and 253 can be pilot-controlled to switch from an open state to a closed state or from a closed state to an open state. Thus, the valves 243, 245, 247, 249, 251 and 253 enable the first hydraulic press 310 and / or the second hydraulic press 320 to be isolated from or not isolated from each other, and the first hydraulic press 310 and / or the second hydraulic press 320 to be isolated from or not isolated from the main hydraulic press 230.

[0120] It should be noted that the system can have a smaller number of valves. Thus, the system includes the valves 251 and 253, and at least one pair of valves from the pair of valves 243 and 245 on the one hand and the pair of valves 247 and 249 on the other hand.

[0121] These valves 243, 245, 247, 249, 251 and 253 can be pilot-controlled hydraulically or electrically from inside or outside the housing 210.

[0122] An example of a traction operation in the circulating direction, which can be called the forward gear, will now be described.

[0123] Consider the initial situation where the supercharger 300 is deactivated (e.g., deactivated by the user or the system control unit based on captured data). Thus, the valves 251 and 253 are open. The valves 243, 245, 247 and 249 are closed.

[0124] In this case, the first orifice 212 of the housing 210 is supplied by the pressure source 100 and thus defines a high-pressure suction port, while the second orifice 214 of the housing 210 defines a low-pressure discharge port. The main hydraulic press 230 operates as a motor in traction mode without a pressure increase. In addition, the fluid does not circulate in the supercharger 300.

[0125] When the supercharger 300 is activated (e.g., activated by the user or the control unit of the system based on the captured data), valves 251 and 253 are switched to the non-conductive configuration, while valves 243, 245, 247, and 249 are conductive.

[0126] As previously described, the first orifice 212 of the housing 210 is supplied by the pressure source 100, thus defining a high-pressure suction port, and the second orifice 214 of the housing 210 defines a low-pressure discharge port. However, in this case, valve 251 is non-conductive, while valve 243 is conductive, and the high-pressure fluid flows to the first orifice 312 of the first hydraulic machine 310 instead of flowing to the first orifice 232 of the main hydraulic machine 230. The second orifice 214 of the housing 210 is connected to the low pressure, and valve 253 is in the non-conductive configuration, while valve 245 is in the conductive configuration, and a low pressure is established in the pipeline from the second orifice 214 of the housing 210 through the hydraulic joint B to the second orifice 314 of the first hydraulic machine 310.

[0127] The pressure difference at the terminals of the first hydraulic machine 310 causes the first hydraulic machine 310 to generate a rotational movement. The second hydraulic machine 320 rotatably fixed to the first hydraulic machine 310 will operate as a pump to generate a pressure difference at its terminals, thereby generating a very high pressure (i.e., a pressure greater than the pressure supplied by the pressure source to the first orifice 212 of the housing 210) in the hydraulic pipeline from the second orifice 324 of the second hydraulic machine 320 to the first orifice 232 of the main hydraulic machine 230, and valve 247 is in the conductive state. In the hydraulic pipeline from the first orifice 322 of the second hydraulic machine 320 to the second orifice 234 of the main hydraulic machine 230, a low pressure has been established, and the valve 249 on this pipeline is in the conductive state.

[0128] The pressure difference at the terminals of the main hydraulic machine 230 is greater than when the supercharger is deactivated, and the member 10 rotated by the main hydraulic machine 230 can apply a greater torque (e.g., to allow a machine equipped with such a device to cross an obstacle).

[0129] Now, an example of the suppression operation in the same cycle direction as previously described, which can be called the forward gear, will be described.

[0130] When the supercharger 300 is deactivated (e.g., deactivated by the user or the control unit of the system based on the captured data), valves 251 and 253 are conductive. Valves 243, 245, 247, and 249 are non-conductive.

[0131] In this case, although the machine is in the forward gear (e.g., driven by its inertia), the machine is in the inhibition mode (e.g., the so-called hydrostatic brake), and the hydraulic circuit is designed to generate a resistance torque opposite to the rotation direction of the member 10. In this case, the second orifice 214 of the housing 210 is at high pressure, while the first orifice 212 of the housing 210 is at low pressure. Due to the inhibition state, the main hydraulic machine 230 performs a pumping operation, and there is no pressure increase due to the fluid not circulating in the booster 300.

[0132] When the booster 300 is activated (e.g., activated by the user or the control unit of the system based on the captured data), the valves 251 and 253 are non-conductive, while the valves 243, 245, 247, and 249 are conductive.

[0133] The main hydraulic machine 230 performs a pumping operation in the inhibition state, and a very high pressure is established in the pipeline connecting the second orifice 234 of the main hydraulic machine 230 to the first orifice 322 of the second hydraulic machine 320. The valve 249 is conductive, while the valve 253 is in the non-conductive state. The pipeline connecting the first orifice 232 of the main hydraulic machine 230 to the second orifice 324 of the second hydraulic machine 320 is at low pressure (the valve 247 is conductive). The pressure difference at the terminals of the second machine 320 generates its motor operation. The second machine 320 rotatably fixed to the first hydraulic machine 310 causes the first hydraulic machine 310 to work as a pump, so as to apply a mechanical inhibition state to the machine equipped with the system according to the present invention by establishing a high pressure in the pipeline. This pipeline passes from the second orifice 314 of the machine 310 through the conductive valve 245, through the hydraulic joint B, through the second orifice 214 of the housing 210 (the valve 253 is in the non-conductive state) and engages with the pressure source 100. The pipeline passing from the first orifice 312 of the first hydraulic machine 310 through the valve 243 (which is conductive), through the hydraulic joint A, through the first orifice 212 of the housing 210 and engaging with the pressure source 100 is at low pressure.

[0134] The system is reversible and has a similar operation in the reverse direction, which generally corresponds to the operation in reverse gear, whether in the traction state or the inhibition state, regardless of whether the booster 300 is started.

[0135] The presented embodiment is particularly advantageous due to its structural symmetry, which enables operation without difference in the inhibition state and the traction state in the forward and reverse gears when the booster 300 according to the present invention is started or deactivated.

[0136] Figure 6 Schematically represents Figure 3 a variant, in which actuators such as valves are added to pilot-control the activation or deactivation of the booster 300. As Figure 3 shown, this is a 3-wire common return booster.

[0137] In this figure, the first orifice 232 of the main hydraulic press 230 is connected via a calibration valve element 240 to the first orifice 212 of the housing 210. When the pressure at the first orifice 212 of the housing 210 exceeds the calibration value, the calibration valve element 240 is conductive in the direction of the first orifice 212 of the housing 210 towards the first orifice 232 of the main hydraulic press 230.

[0138] It should be noted that the calibration valve element 240 can also be a pilot calibration valve element, that is to say, it is a valve element whose opening degree can be controlled by an external command (for example, a hydraulic command or a pneumatic command).

[0139] This figure also shows the different possible positions of the pilot valve for pilot - controlling the activation or de - activation of the booster 300. It can be understood that, depending on the desired pilot control, the different positions indicated can be used individually or in combination in the same embodiment.

[0140] According to a first example, the system includes a valve 242 located between the first orifice 212 of the housing 210 and the first orifice 312 of the first hydraulic press 310, that is to say, upstream of the suction port of the hydraulic motor of the booster according to the operation considered. Thus, when the valve 242 is non - conductive, the booster 300 is not supplied and is therefore deactivated. By deactivated here it means that the booster 300 is inoperable, that is to say, in particular, it means that the pressure difference between the two orifices 232 and 234 of the main hydraulic press 230 is equal to the pressure difference between the two orifices 212 and 214 of the housing 210, excluding head loss.

[0141] According to a second example, the system includes a valve 244 located between the second orifice 324 of the second hydraulic press 320 and the first orifice 232 of the main hydraulic press 230. When the valve 244 is non - conductive, the discharge port of the second hydraulic press 320 is sealed and the first hydraulic press 310 and the second hydraulic press 320 have zero effective displacement.

[0142] According to a third example, the system includes a valve 246 located between, on the one hand, the second orifice 314 of the first hydraulic press 310 and the first orifice 322 of the second hydraulic press 320 and, on the other hand, the second orifice of the housing 214 and the second orifice 234 of the main hydraulic press 230. This valve 246 is generally used in combination with one of the above - mentioned valves 242 and / or 244. When the booster 300 is started, the valve 246 is conductive. When the booster 300 is deactivated, the valve 246 and, if applicable, one or both of the valves 242 and / or 244 are non - conductive.

[0143] Figure 7Shows an exemplary embodiment of a system according to an aspect of the present invention. This figure represents the different elements that allow the system to operate in both rotational directions of the main hydraulic press 230, whether in traction mode or in inhibition mode. The particularity and focus of such a circuit is that it enables the user to be provided with an operation called 4-quadrant operation, in which the booster does not have a symmetric mode. In this exemplary embodiment, the booster 300 is of the 3-wire common return type, similar to the booster already referred to Figure 3 described booster.

[0144] In the example shown, different pilot valves are integrated to pilot-control the enabling or disabling of the booster 300. These different pilot valves described below may or may not be integrated into the housing 210.

[0145] For example, the pilot valve can be configured to: enable the booster when the pressure difference between the first orifice 212 and the second orifice 214 of the housing 210 exceeds a threshold, and disable the booster when the pressure difference between the first orifice 212 and the second orifice 214 of the housing 210 is below the said threshold. This type of activation corresponds, for example, to crossing an obstacle. As a variant, the pilot valve can be configured, for example, to: disable the booster when the fluid flow rate at the orifice forming the fluid suction inlet of the housing 210 exceeds a flow rate threshold (which reflects high-speed movement). Alternatively or additionally, the system can include a sensor of the rotational speed of the member 10 or of the rotational speed of the shaft driven by the main hydraulic press 230, which sensor is associated with a controller (e.g., an electronic control unit or ECU (according to the common abbreviation)), such that when the speed measured by the sensor exceeds a specific threshold, the pilot valve is pilot-controlled to disable the booster.

[0146] The presented system includes two breaker valves 410 and 420, denoted as the first breaker valve 410 and the second breaker valve 420. These valves are generally on / off type valves and can be conductive or non-conductive. For example, these valves can be solenoid valves that are default conductive, that is, they can also be solenoid valves that are default non-conductive in the absence of pilot control.

[0147] The first breaker valve 410 is located between the first orifice 212 of the housing 210 and the first orifice 232 of the main hydraulic press 230. The second breaker valve 420 is located between the second orifice 214 of the housing 210 and the second orifice 234 of the main hydraulic press 230.

[0148] The system also includes two calibration valves or amplification valves, namely 430 and 440 respectively. In the example shown, these valves 430 and 440 are independent. As a variant, these valves 430 and 440 can be mechanically connected.

[0149] The first amplification valve 430 is typically a spool valve adapted to selectively connect the first port 312 of the first hydraulic machine 310 to the first port 212 of the housing 210 or to the second port 214 of the housing 210, typically to the port among ports 212 and 214 having the highest pressure. The first amplification valve 430 is default in a non-conducting configuration. The first amplification valve 430 is calibrated such that it conducts only when the pressure difference between the first port 212 of the housing 210 and the second port 214 of the housing 210 exceeds a calibration value or a threshold value.

[0150] The second amplification valve 440 is typically a spool valve adapted to selectively connect the second port 314 of the first hydraulic machine 310 and the first port 322 of the second hydraulic machine 320 to the first port 212 of the housing 210 or to the second port 214 of the housing 210, typically to the port among ports 212 and 214 having the lowest pressure. The second amplification valve 440 is default in a non-conducting configuration. The second amplification valve 440 is calibrated such that it conducts only when the pressure difference between the first port 212 of the housing 210 and the second port 214 of the housing 210 exceeds the calibration value or the threshold value.

[0151] The second port 324 of the second hydraulic machine 320 is connected to the first port 232 and the second port 234 of the main hydraulic machine 230 via a high-pressure selector 450, and the high-pressure selector 450 is adapted to connect the second port 324 of the second hydraulic machine 320 to the port having the highest pressure in the main machine 230.

[0152] This structure of the system allows for reversible operation, as described below.

[0153] Describe the first operation mode of the system, corresponding to a traction mode in the first cycle direction which can be referred to as a forward gear. In this embodiment, the first port 212 of the housing 210 is supplied by a hydraulic energy source 100, thus defining a high-pressure suction port, while the second port 214 of the housing 210 defines a low-pressure discharge port. The main hydraulic machine 230 operates as a motor. The breaker valves 410 and 420 are conducting; thus the main hydraulic machine 230 is directly supplied by the hydraulic energy source 100. When the pressure difference between the first port 212 of the housing 210 and the second port 214 of the housing 210 is less than the calibration value or the threshold value, the booster 300 is deactivated.

[0154] When the pressure difference between the first orifice 212 and the second orifice 214 of the housing 210 exceeds a calibrated value, the amplification valves 430 and 440 are actuated. Then, the first orifice 312 of the first hydraulic press 310 is connected to the first orifice 212 of the housing 210, while the second orifice 314 of the first hydraulic press 310 and the first orifice 322 of the second hydraulic press 320 are connected to the second orifice 214 of the housing 210. Then, the breaker valve 410 is switched so that it is no longer conducting. This configuration is shown in Figure 8 as shown.

[0155] In this configuration, the operation presented in reference Figure 3 can then be observed; the high-pressure selector 450 ensures that the pressure provided by the second hydraulic press 320 is supplied to the suction port of the main hydraulic press 230 (i.e., here its first orifice 232). Since the breaker valve 410 is switched to its non-conducting configuration, the pressure P2 is isolated from the hydraulic circuit.

[0156] When the pressure difference between the first orifice 212 and the second orifice 214 of the housing 210 drops below the calibrated value or the starting value, or when, for example, the flow rate at the first orifice 212 or the second orifice 214 of the housing 210 exceeds a threshold value, or when the rotational speed of the main hydraulic press 230 exceeds a threshold value, the breaker valves 410 and 420 are then pilot-controlled to switch to their conducting configuration, which deactivates the booster 300.

[0157] In the case of operation in the same direction, but in the case of a braking or damping state, the high-pressure and low-pressure branches of the hydraulic circuit are reversed.

[0158] The high-pressure branch of the circuit is established at the second orifice 234 of the main hydraulic press 230, so the second orifice 234 of the main hydraulic press 230 is connected via the high-pressure selector 450 to the second orifice 324 of the second hydraulic press 320.

[0159] If the pressure difference between the first orifice 212 and the second orifice 214 of the housing 210 is less than the calibrated value or the starting value, the amplification valves 430 and 440 are non-conducting and the booster is deactivated.

[0160] If the pressure difference between the first orifice 212 and the second orifice 214 of the housing 210 is greater than or equal to the calibrated value or the starting value, the amplification valves 430 and 440 are conducting. Then, the first orifice 312 of the first hydraulic press 310 is connected to the second orifice 214 of the housing 210, while the second orifice 314 of the first hydraulic press 310 and the first orifice 322 of the second hydraulic press 320 are connected to the first orifice 212 of the housing 210. Then, the breaker valve 420 is switched so that it is no longer conducting. This configuration is shown in Figure 9 as shown.

[0161] In this operation, the first hydraulic press 310 is supplied with pressure P1 at the second orifice 214 of the housing 210. The first hydraulic press 310 drives the second hydraulic press 320, and the second hydraulic press 320 provides pressure P2 such that, due to the ratio between the displacements of the two hydraulic presses 310 and 320, P2 > P1 at the second orifice 324 of the second hydraulic press 320. This pressure P2 is applied to the second orifice 234 of the main hydraulic press 230, which enhances the suppression effect. Since the breaker valve 420 is switched to its non-conducting configuration, this pressure P2 is isolated from the rest of the hydraulic circuit.

[0162] The presented system is fully reversible and can thus also be operated in the opposite direction, for example driven in reverse gear, whether in the traction state or the suppression state, regardless of whether the supercharger 300 is activated.

[0163] Figure 10 Another example of a system according to an aspect of the present invention is shown.

[0164] In this embodiment, the supercharger 300 is associated with a plurality of valves and components such that the automatic activation of the supercharger 300 can be ensured when the pressure in the hydraulic circuit exceeds a pressure threshold.

[0165] In this embodiment, the supercharger 300 has a structure similar to the structure that has been specifically referred to Figure 3 and described.

[0166] In this embodiment, the valves 410 and 420 (previously presented in Figure 7 , Figure 8 and Figure 9 ) are replaced by a calibrated check valve flap having a pilot chamber.

[0167] The first orifice 212 and the second orifice 214 of the housing 210 are connected in parallel to a high-pressure selector 460 and a low-pressure selector 470.

[0168] The low-pressure selector 470 is connected to the second orifice 314 of the first hydraulic press 310 and the first orifice 322 of the second hydraulic press 320.

[0169] The high-pressure selector 460 is connected to a pilot valve 480, a sequence valve element 485, and a first restrictor 488. The first restrictor 488 is connected to a pressure relief valve element 490 adapted to relieve pressure when the pressure exceeds a pressure relief threshold, is also connected to the hydraulic pilot line of the sequence valve element 485, and is connected to the hydraulic pilot line of the pilot valve 480 via a second restrictor 492.

[0170] The sequence valve element 485 connects the high-pressure selector 460 to the first orifice 312 of the first hydraulic press 310 of the supercharger 300.

[0171] The pilot valve 480 is connected on the one hand to the pilot chambers of the calibration check valve plates 410 and 420 and on the other hand to the second orifice 324 of the second hydraulic press 320.

[0172] The second orifice 324 of the second hydraulic press 320 is also connected to the high-pressure selector 450 and the pressure limiter 495. The high-pressure selector 450 is connected to the two orifices 232 and 234 of the main hydraulic press 230. The high-pressure selector 450 is adapted to connect the second orifice 324 of the second hydraulic press 320 to the orifice in the main unit 230 having the highest pressure.

[0173] The pilot valve 480 is configured to selectively connect the pilot chambers of the calibration check valve plates 410 and 420 to the high-pressure selector 460 or to the high-pressure selector 450 connected to the second orifice 324 of the second hydraulic press 320. By default, the pilot valve 480 connects the pilot chambers of the calibration check valve plates 410 and 420 to the second orifice 324 of the second hydraulic press 320. When the pressure at the level of the high-pressure selector 460 exceeds the pressure value at the level of the second restrictor 492 on the side of the pilot chamber 480 by a specific threshold value (determined by the stiffness of the elastic return means of the pilot valve 480), the pilot chamber 480 switches to its configuration in which it connects the pilot chambers of the calibration check valve plates 410 and 420 to the high-pressure selector 460.

[0174] The sequence valve element 485 is by default non-conductive. When the difference between the pressure at the suction port of the sequence valve element 485 and the pressure in the pilot line provided to the sequence valve element 485 at the outlet of the first restrictor 488 exceeds the sequence threshold, the sequence valve element 485 becomes conductive. When the pressure relief valve element 490 becomes conductive, this sequence threshold is reached (since the flow then passes through the first restrictor 488, thereby creating a pressure difference at its terminals, with the lowest pressure at the terminal connected to the pressure relief valve element 490). Thus, the pressure relief valve element 490 determines, by its calibration (usually by means of a calibration spring), the pressure value according to which the sequence valve element is enabled, and thus the pressure value from which the booster 300 is supplied. The calibration of the pressure relief valve element 490 can be adjustable or fixed.

[0175] Now, the first operating mode of the system is described, which corresponds to the operating mode in the first operating direction without pressure increase. This operating mode corresponds to Figure 10 the configuration shown.

[0176] The hydraulic energy source 100 supplies a supply pressure P1 to the first orifice 212 of the housing 210.

[0177] Then, the high-pressure selector 460 connects the pilot valve 480, the first restrictor 488, and the sequence valve element 485 to the first port 212 of the housing 210. The low-pressure selector 470 connects the second port 314 of the first hydraulic press 310 and the first port 322 of the second hydraulic press 320 to the second port 214 of the housing 210.

[0178] The pressure P1 considered here is lower than the calibration pressure of the pressure relief valve element 490. The sequence valve element 485 is in its non-conducting configuration.

[0179] The pilot valve 480 is in its default configuration. The pilot valve 480 connects the pilot chambers of the calibration check valve disks 410 and 420 to the second port 324 of the second hydraulic press 320, the pressure limiter 495, and the high-pressure selector 450.

[0180] Therefore, the booster 300 is not put into operation.

[0181] The pressure P1 provided by the pressure source 100 is supplied to the main hydraulic press 230 via the first port 232 of the main hydraulic press 230. In addition, the pressure P1 pilot-controls the pilot chambers of the calibration check valve disks 410 and 420 via the high-pressure selector 450. Therefore, the calibration check valve disk 420 is conducting to allow the main hydraulic press 230 to discharge towards the second port 214 of the housing 210.

[0182] Figure 11 A second operating mode of the system is now described, corresponding to the operating mode in the first operating direction with increasing pressure. The differences from the first operating mode are described below.

[0183] In this second operating mode, the pressure P1 provided by the hydraulic energy source 100 is greater than the calibration pressure of the pressure relief valve element 490.

[0184] Therefore, the pressure relief valve element 490 is conducting and releases the excess pressure into the tank R, so that fluid flow passes through the valve element 490. This fluid flow creates a head loss in the first restrictor 488, thereby creating a pressure difference at its terminals (the lowest pressure is at the level of the pressure relief valve element 490).

[0185] Then, when the difference between the pressure at the suction port of the sequence valve element 485 and its pilot pressure exceeds the calibration value applied by the return element (usually about a few bars, e.g., 4 bars), the sequence valve element 485 switches to its conducting configuration.

[0186] Similarly, when the pressure difference between the pressure P1 provided by the hydraulic energy source 100 and the pilot pressure at the level of the second restrictor 492 exceeds the calibrated value (usually about a few bars, for example 4 bars) applied by the elastic return device to the pilot valve 480, the pilot valve 480 switches to its configuration that connects the pilot chambers of the calibrated check valve disks 410 and 420 to the high-pressure selector 460.

[0187] The booster 300 is supplied via the first orifice 312 of the first hydraulic machine 310. The first hydraulic machine 310 operates as a motor and drives the second hydraulic machine 320 to rotate. The suction port 322 of the second hydraulic machine 320 is connected to the discharge port 314 of the first hydraulic machine 310. As already described above, due to the ratio between the displacements C1 and C2 of the first hydraulic machine 310 and the second hydraulic machine 320, the pressure provided by the second hydraulic machine 320 to its second orifice 324 is the pressure P2, such that P2 > P1. The pressure limiter 495 defines the maximum pressure P2max, beyond which the excess pressure will be returned to the return line of the hydraulic circuit.

[0188] The pressure P2 is supplied to the main hydraulic machine 230 via the high-pressure selector 450. The high-pressure selector 450 is configured to connect the second orifice 324 of the second hydraulic machine 320 to the first orifice 232 of the main hydraulic machine 230 due to the pressure increase, as described above.

[0189] The calibrated check valve disk 410 is non-conductive, its pilot chamber is at the pressure P1, while the pressure P2 is applied to the first orifice 232 of the main hydraulic machine 230.

[0190] The main hydraulic machine 230 discharges the flow and supplies it to the second orifice 214 via the second orifice 234 of the main hydraulic machine 230. This flow passes through the calibrated check valve disk 420, which is itself conductive due to the pressure P1 applied to its pilot chamber.

[0191] Therefore, it can be understood here that when the pressure provided by the hydraulic energy source 100 exceeds the pressure threshold, the proposed system automatically switches to the operating mode enabling the booster 300.

[0192] When the pressure provided by the hydraulic energy source 100 decreases and drops below the said pressure threshold, the system switches to its first operating mode as described above.

[0193] The presented system is reversible. Therefore, referring to Figure 10 and Figure 11 the two operating modes described can also be applied to the operation in the opposite direction. The high-pressure selector 450, the high-pressure selector 460, and the low-pressure selector 470 allow the system to be reversed while maintaining the operating principle unchanged.

[0194] The proposed system also allows operation in a hydrostatic braking or inhibition state. This operation is represented in Figure 12 and Figure 13 and shows, respectively, the case where the supercharger 300 is not started and the case where the supercharger 300 is started. Figure 12 and Figure 13

[0195] Figure 12 shows a configuration similar to the one already described with reference to Figure 10 but in which the high-pressure and low-pressure branches of the hydraulic circuit are reversed. In inhibition or braking operation, the main hydraulic machine 230 performs a pumping operation; its suction port 232 is at low pressure and its discharge port 234 is at high pressure. Similarly, the first orifice 212 of the housing 210 is at low pressure and the second orifice 214 of the housing 214 is at high pressure. Compared with the system already described with reference to Figure 10 the operation of this system remains unchanged. The high-pressure selector 450, the high-pressure selector 460 and the low-pressure selector 470 ensure the reversal of the hydraulic connections to maintain the operation already described with reference to Figure 10

[0196] More specifically, in this operating mode, the hydraulic energy source 100 no longer provides power. The main hydraulic machine 230 performs a hydraulic pump function. The main hydraulic machine 230 provides a pressurized flow that is applied via the high-pressure selector 450 to the pilot chambers of the calibrated check valve plates 410 and 420 to make them conductive.

[0197] The high-pressure selector 460 and the low-pressure selector 470 ensure that the high-pressure line is connected in particular to the first restrictor 488. As long as the pressure remains below the calibrated pressure of the pressure relief valve element 490, the supercharger 300 is deactivated, as already described with reference to Figure 10

[0198] Figure 13 shows the configuration of the inhibition operation in the case where the supercharger 300 is in the operating state. As already described with reference to Figure 11 the supercharger is enabled as long as the pressure at the level of the pressure relief valve element 490 exceeds its calibrated pressure and the difference between the pressure at the suction port of the sequence valve element 485 and the pressure between the first restrictor 488 and the second restrictor 492 exceeds the calibrated value defined by the elastic return means of the sequence valve element 485.

[0199] Then, the sequence valve element 485 becomes conductive, which allows the first hydraulic machine 310 and the second hydraulic machine 320 of the supercharger 300 to rotate by allowing the circulation of the fluid at the first orifice 312 of the first hydraulic machine 310. The valve 480 changes position to connect the highest system pressure P1 to the pilot chambers of the pilot valve plates 410 and 420.

[0200] ​​​Temporarily, the first hydraulic press 310 is driven to rotate by sucking oil from its orifice 312 and discharging the oil to the orifice 314. The orifice 314 of the first hydraulic press 310 drives the second hydraulic press 320 to rotate during motor operation, and the second hydraulic press 320 starts to operate as a pump, discharging its oil to the orifice 324. This discharge causes a pressure increase at the level of the second orifice 234, and the conduit at the level of this orifice sees the two hydraulic presses 230 and 320 discharging towards it in pump mode. The pilot chamber of the valve plate 420 has been set to the highest system pressure P1 by means of the high-pressure selector 460, and the valve plate 420 closes and becomes non-conductive. Since the pilot chamber is connected to the pressure P1, the valve plate 410 remains in its conductive position.

[0201] Due to the closing of the valve plate 420, the second hydraulic press 320 is supplied with pressure provided by the main hydraulic press 230 via the second orifice 324 of the second hydraulic press 320. The second hydraulic press 320 drives the first hydraulic press 310 to rotate, and the first hydraulic press 310 performs an additional braking function due to its larger displacement. This braking will cause a pressure increase at the second orifice 324 of the second hydraulic press 320 (where its suction port is formed), thereby causing a pressure increase at the second orifice 234 of the main hydraulic press 230 (where its discharge port is formed), which amplifies the pressure difference at the terminals of the main hydraulic press 230, thereby amplifying the braking or inhibiting effect.

[0202] Then, the fluid provided by the first hydraulic press 310 is supplied to the second orifice 214 of the housing 210 via the high-pressure selector 460.

[0203] Therefore, the traction operation or the inhibition operation enables the booster 300 to be automatically started as long as the pressure difference at the terminals of the main hydraulic press 230 exceeds the threshold value.

[0204] Regarding the traction operation, it can be understood that the braking operation or the inhibition operation is reversible. Therefore, referring to Figure 12 and Figure 13 The two operating modes described can also be applied to operations in the opposite direction, and the high-pressure selector 450, the high-pressure selector 460, and the low-pressure selector 470 allow the system to be reversed while maintaining the operating principle unchanged.

[0205] As a variant, the pressure relief valve element 490 can be an electric pilot valve. Therefore, the calibration of the pressure relief valve element 490 can be monitored and modified, and the opening degree of the pressure relief valve element 490 can be pilot-controlled. As a variant, it is optional that the calibration of the pressure relief valve element 490 can be adjusted by hydraulic or mechanical action.

[0206] As a variant, the pressure relief valve element 490 can be connected at its outlet to a 2-position - 2-port distributor, which makes it possible to block the connection to the low-pressure housing (shell or tank) and prevent any activation of the supercharger 300 when this connection is severed.

[0207] As a variant, the 2-position - 2-port distributor can be installed in parallel with the pressure relief valve element 490 in order to be able to force the activation of the supercharger 300 by forced leakage.

[0208] As described above, the opening of the pressure relief valve element 490 pilot-controls the activation of the supercharger 300. Thus, for example, using an electrical command to pilot-control the pressure relief valve element 490 makes it possible to pilot-control the activation of the supercharger 300.

[0209] Figure 14 Another exemplary embodiment of a system according to an aspect of the present invention is shown.

[0210] Unlike the variant described above with reference to Figures 10 to 13 which is a pilot-control variant, for example using an electrical command or an actuator. Thus, the activation or deactivation of the supercharger 300 can here be selected by the user or via a controller.

[0211] In this embodiment, there are valves 410 and 420, which are here solenoid valves for example. It will be understood that this embodiment is not restrictive and that the valves presented as solenoid valves (in particular valves 410, 420 and / or 500) can be hydraulic pilot valves, typically displacement sliders.

[0212] The orifices 212 and 214 of the housing 210 are both connected on the one hand to the low-pressure selector 470 and on the other hand respectively to one of the valves 410 and 420.

[0213] The valve 410 is able to connect the first orifice 212 of the housing 210 and the low-pressure selector 470 to the first orifice 232 of the main hydraulic press 230, or to the first orifice 312 of the first hydraulic press 310 of the supercharger 300. In its default configuration, the valve 410 connects the first orifice 212 of the housing 210 to the first orifice 232 of the main hydraulic press 230.

[0214] The valve 420 is able to connect the second orifice 214 of the housing 210 and the low-pressure selector 470 to the second orifice 234 of the main hydraulic press 230, or to the first orifice 312 of the first hydraulic press 310 of the supercharger 300. In its default configuration, the valve 420 connects the second orifice 214 of the housing 210 to the second orifice 234 of the main hydraulic press 230.

[0215] The low-pressure selector 470 connects the second orifice 314 of the supercharger 300, in particular the first hydraulic press 310, and the first orifice 322 of the second hydraulic press 320 to the orifice with the lowest pressure among the first orifice 212 and the second orifice 214 of the housing. The low-pressure selector 470 is also connected to the pressure limiter 495, which is adapted to perform a pressure limiting function in the circuit. The two orifices 232 and 234 of the main hydraulic press 230 are connected to the pressure limiter 495 via the high-pressure selector 450, which ensures the safety function in the ultra-high pressure branch.

[0216] The selection slider 500 connects the second orifice 324 of the second hydraulic press 320 to the first orifice 232 or the second orifice 234 of the main hydraulic press 230, so that the terminal in the main hydraulic press 230 whose pressure is to be increased can be selected.

[0217] Now refer to Figure 14 Describe the first operating mode, for example corresponding to the traction operation in the forward gear, without enabling the supercharger 300.

[0218] The hydraulic energy source 100 supplies the supply pressure P1 to the first orifice 212 of the housing 210.

[0219] The valves 410 and 420 are in their default configuration. Therefore, the pressure P1 is supplied to the first orifice 232 of the main hydraulic press 230. The fluid at the discharge orifice 234 of the main hydraulic press 230 reaches the second orifice 214 of the housing 210 through the valve 420.

[0220] The supercharger 300 is connected to the second orifice 214 of the housing 210 and is not supplied. Therefore, the main hydraulic press 230 is directly supplied by the hydraulic energy source 100.

[0221] Now refer to Figure 15 Describe the second operating mode, for example corresponding to the traction operation in the forward gear, in which the supercharger 300 is enabled.

[0222] In this operating mode, the command of the valve 410 is actuated. Therefore, the pressure P1 provided by the hydraulic energy source 100 is supplied to the first orifice 312 of the first hydraulic press 310. The first hydraulic press 310 operates as a motor and drives the second hydraulic press 320 to rotate. The second hydraulic press 320 is supplied via the discharge orifice of the first hydraulic press 320, and due to the ratio between the displacements, a pressure P2 > P1 can be provided.

[0223] The pressure P2 is applied to the first orifice 232 of the main hydraulic press 230 via the selection slider 500, and the command of the selection slider 500 is actuated. The discharge of the main hydraulic press 230 passes through its second orifice 234 and via the valve 420. The excess fluid from the second orifice 314 of the first hydraulic press 310 of the supercharger 300 in the circuit reaches the second orifice 214 of the housing 210 through the low-pressure selector 470.

[0224] Therefore, it can be understood that the start of the supercharger is accomplished by activating the valve 410. Conversely, the supercharger 300 can be deactivated by stopping the pilot control valve 410.

[0225] The presented system can also perform a suppression function or a braking function. Refer to Figure 16 for a detailed description of the operation.

[0226] In this operation, the main hydraulic press 230 is driven to rotate; thus, the main hydraulic press 230 performs a pumping operation. The main hydraulic press 230 supplies the pressure P1 to its second orifice 234, and the pressure P1 is discharged through the second orifice 214 of the housing 210 via the valve 420.

[0227] The selection slider 500 is actuated such that the orifice 324 of the supercharger is connected to the orifice 232 of the main hydraulic press, such that the pump section of the supercharger discharges to the orifice 232 and supplies the main hydraulic press 230 through the orifice 232.

[0228] For the suppression operation, the pressure increase function can be enabled by passing through the pilot control valve 420 and returning the selection slider 500 to its default configuration. This configuration is as Figure 17 shown.

[0229] Therefore, the valve 420 seals the discharge through the second orifice 234 of the main hydraulic press 230. The flow passes through the selection slider 500 to supply the second hydraulic press 320 through the second orifice 324 of the second hydraulic press 320. The second hydraulic press 320 operates as a motor and drives the first hydraulic press 310 to rotate. Then, the first hydraulic press 310 operates as a pump, and due to the difference in displacement from the second hydraulic press 320, the pressure at the orifice 324 of the second hydraulic press 320 is amplified, and thus the pressure at the discharge port at the level of the orifice 234 of the main hydraulic press 230 is amplified. This pressure increase amplifies the pressure deviation at the terminals of the main hydraulic press 230, and thus amplifies the braking or suppression torque.

[0230] As mentioned above, the pilot control of the valve 420 enables switching to the operating mode without pressure increase.

[0231] The proposed system is reversible, whether in the traction state or the suppression state. The operation is similar to the reference Figures 14 to 17Operation is described in which the high-pressure branch and the low-pressure branch are reversed at the orifices 212 and 214 of the housing 210.

[0232] Figure 18 Another embodiment of a system according to an aspect of the present invention is shown.

[0233] In this embodiment there is a particular reference to Figures 10 to 13 The different elements described.

[0234] In this embodiment, the booster 300 is of the 4-wire type, as has been specifically mentioned. Figure 5 as described.

[0235] This 4-wire booster 300 structure requires doubling the sequence valve element 485. Thus, two sequence valve elements 485a and 485b are connected to the first orifice 312 and the second orifice 314 of the first hydraulic machine 310, respectively, and these two sequence valve elements 485a and 485b have the same operation as the sequence valve element 485 described above. The two sequence valve elements 485a and 485b generally have the same calibration. The calibration can be fixed or can be modulated by means of a command (e.g., an electrical command).

[0236] This operation is basically similar to the one already mentioned Figures 10 to 13 The operation described.

[0237] When the pressure provided by the hydraulic energy source 100 is lower than the calibrated pressure of the pressure relief valve element 490 , the two sequence valve elements 485 a and 485 b are non-conductive, thus deactivating the pressure intensifier 300 .

[0238] The main hydraulic machine 230 is supplied via valves 410 and 420 which are conducting due to the circulation direction of the fluid or due to the pilot control of its pilot chamber.

[0239] When the pressure provided by the hydraulic energy source 100 is higher than the calibrated pressure of the pressure relief valve element 490 , the pressure relief valve element 490 becomes conductive and relieves pressure into the tank R.

[0240] The opening of the pressure relief valve element 490 allows the flow to pass through the restrictor 488, thereby creating a head loss and a pressure difference at the terminals of the restrictor 488; the pressure is lowest downstream of the restrictor, allowing the sequence valve elements 485a and 485b to open, and the sequence valve elements 485a and 485b then conduct, thereby allowing the first hydraulic machine 310 of the supercharger 300 to supply and discharge fluid. As previously described, the first hydraulic machine 310 then operates as a motor to drive the second hydraulic machine 320, which operates as a pump, and due to the displacement ratio between the first hydraulic machine 310 and the second hydraulic machine 320, the second hydraulic machine 320 can provide a pressure P2 > P1. Then, the pressure P2 is supplied to the main hydraulic machine 230.

[0241] The operation in the braking or inhibiting mode is also similar to the operation already referred to Figure 12 and Figure 13 described, except that the two sequence valve elements 485a and 485b are pilot-controlled simultaneously.

[0242] Figure 19 Another embodiment of a system according to an aspect of the present invention is shown.

[0243] This variant is a pilot control variant, where the supercharger 300 is of the 4-wire type.

[0244] As with Figures 14 to 17 the same, this embodiment shows valves 410 and 420, which are here, for example, solenoid valves, and which enable the main hydraulic machine 230 to be connected to the hydraulic energy source 100 or the supercharger 300.

[0245] Thus, the system can isolate the supercharger 300, for example, by positioning the supercharger 300 in a closed loop such that the supercharger 300 is in a freewheel configuration.

[0246] The valves 410 and 420 can be pilot-controlled such that the hydraulic energy source 100 supplies the first hydraulic machine 310 with pressure P1. The first hydraulic machine 310 drives the second hydraulic machine 320 to rotate and discharges low pressure towards the hydraulic energy source 100. Due to the displacement ratio between the first hydraulic machine 310 and the second hydraulic machine 320, the second hydraulic machine 320 provides a pressure P2 > P1, which is supplied to the main hydraulic machine 230. Then, the second hydraulic machine 320 forms a closed circuit with the main hydraulic machine 230, so that the very high pressure P2 is confined within the housing 210.

[0247] The proposed system can also perform an inhibiting or braking operation, whether or not the supercharger 300 is enabled via the pilot control valves 410 and 420, in a manner particularly similar to the embodiment referred to Figure 16 and Figure 17 described.

[0248] Thus, the systems presented in the various examples are capable of achieving an increase or boost in pressure at the terminals of the main hydraulic machine 230 without the need for an oversized hydraulic circuit or an increase in the pressure of the entire circuit. The presented booster 300 is capable of creating a pressure differential between the two orifices 232 and 234 of the main hydraulic machine 230 that is greater than the pressure differential between the two orifices 212 and 214 of the housing 210.

[0249] Thus, this local pressure amplification in the circuit enables various advantages as follows.

[0250] The main hydraulic machine 230 can have a lower displacement for the same torque provided, without the need to size the entire hydraulic circuit to withstand higher pressures. Thus, the obstacle-crossing ability can be improved without the need for an oversized circuit.

[0251] To obtain the same pressure and for a given displacement of the main hydraulic machine, the size of the hydraulic energy source 100 can be smaller compared to a circuit without the booster 300.

[0252] Furthermore, using the main hydraulic machine 230 as a motor with reduced displacement has a beneficial effect on efficiency, whether or not the pressure boost function is activated.

[0253] For example, the proposed system can be used in machinery, vehicles, construction machinery, agricultural machinery, or any other equipment that can be equipped with the proposed hydraulic drive components.

[0254] For example, such machinery can be equipped with such a system on all or part of the moving components, e.g., on each wheel or on one or more axles, to drive several wheels of the same axle using a single system, e.g., equipped with such a system only on the rear axle, only on the front axle, or even on each wheel of the front axle or on each wheel of the rear axle.

[0255] Such machinery can have a circuit that allows the booster to automatically operate on the moving component or wheel that requires additional torque. For example, this automatic activation can be pilot-controlled by an electronic control unit that can determine the activation based on data captured on the machine, or this automatic activation can be derived from the design of the hydraulic machine that allows activation through an appropriate hydraulic circuit.

[0256] Such machinery can have a circuit that allows the booster to perform a controlled operation on the wheel that requires additional torque. The command is issued by the user.

[0257] By considering a machine or machinery that includes several drive components according to the present invention, different drive components can be activated independently or in combination to initiate a pressure increase on all drive components of the same part of the machine.

[0258] Although the present invention has been described with reference to specific exemplary embodiments, it will be apparent that modifications and changes can be made to these examples without departing from the general scope of the invention as defined in the claims. In particular, the various features of the different embodiments shown / mentioned can be combined into additional embodiments. Accordingly, the specification and drawings are to be regarded as illustrative rather than restrictive.

[0259] It is also apparent that all features described with reference to a method can be transformed, individually or in combination, into an apparatus, and conversely, all features described with reference to an apparatus can be transformed, individually or in combination, into a method.

Claims

1. A system for driving a member (10) by means of a hydraulic circuit, comprising: A hydraulic energy source (100), adapted to provide pressure in the hydraulic circuit; A drive member (200), comprising: - A housing (210) having a first housing orifice (212) and a second housing orifice (214), the first housing orifice (212) and the second housing orifice (214) being adapted to define an inlet and an outlet of the housing (210); - A main hydraulic press (230), adapted to be supplied by the hydraulic energy source (100), the main hydraulic press (230) being received in the housing (210) and having a first hydraulic press orifice (232) and a second hydraulic press orifice (234), The system is characterized in that the drive member (200) comprises a booster (300) integrated in the housing (210), The booster (300) is adapted to selectively increase the pressure such that the pressure difference between the two orifices (232, 234) of the main hydraulic press (230) is greater than the pressure difference between the two orifices (212, 214) of the housing (210).

2. The system according to claim 1, wherein, The booster (300) is integrated in the housing (210) such that the booster (300) is connected to the first orifice (232) and the second orifice (234) of the main hydraulic press (230) via ducts formed in the housing (210).

3. The system according to any one of the preceding claims, wherein, The booster (300) is configured to be activated when the pressure difference between the two orifices (212, 214) of the main hydraulic press (230) exceeds a threshold.

4. The system according to any one of the preceding claims, wherein, The booster (300) is configured to be activated when the pressure difference between the orifice of the housing of the hydraulic press and the internal pressure of the housing exceeds a threshold.

5. The system according to any one of the preceding claims, further comprising at least one valve (242, 244, 246, 430, 440) connecting the booster (300) to the first orifice (212) and / or the second orifice (214) of the housing (210), the at least one valve (242, 244, 246, 430, 440) being configured to: deactivate the booster (300) when the pressure difference between the two orifices (212, 214) of the housing (210) is less than or equal to a pressure threshold.

6. The system according to any one of claims 1 to 5, further comprising at least one valve (242, 244, 246, 430, 440) connecting the booster (300) to the first orifice (212) and / or the second orifice (214) of the housing (210), the at least one valve (242, 244, 246, 430, 440) being configured to: deactivate the booster (300) when the rotational speed of the main hydraulic press (230) is greater than a threshold.

7. The system according to any one of claims 1 to 6, wherein, The supercharger (300) is adapted to obtain a flow rate Q1 and a pressure P1 from a first orifice (212) or a second orifice (214) of the housing (210), and supply a flow rate Q2 and a pressure P2 to a first orifice (232) or a second orifice (234) of the main hydraulic machine (230), such that Q2 < Q1 and P2 > P1.

8. The system according to any one of claims 1 to 7, wherein The supercharger (300) includes a first hydraulic machine (310) and a second hydraulic machine (320) that are rotationally fixed. The first hydraulic machine (310) and the second hydraulic machine (320) have the same displacement, and the first hydraulic machine (310) and the second hydraulic machine (320) are configured such that one hydraulic machine performs a pumping operation while the other hydraulic machine performs a motor operation.

9. The system according to claim 8, wherein: - The first hydraulic machine (310) has a first orifice (312) and a second orifice (314). The first orifice (312) is selectively connected to the orifice of the housing (210) having the highest pressure among the two orifices of the housing, and the second orifice (314) is selectively connected to the orifice of the housing (210) having the lowest pressure among the two orifices of the housing. - The second hydraulic machine (320) has a first orifice (322) and a second orifice (324). The first orifice (322) is connected to the orifice of the housing (210) having the lowest pressure among the two orifices of the housing, and the second orifice (324) is connected via a conduit arranged in the housing (210) to the orifice (232, 234) of the main hydraulic machine (230) having the highest pressure.

10. The system according to any one of claims 1 to 7, wherein, The supercharger (300) includes a first hydraulic machine (310) and a second hydraulic machine (320) that are rotationally fixed. The displacement of the first hydraulic machine (310) is greater than the displacement of the second hydraulic machine (320). The system is configured such that, for a first operating mode, the first hydraulic machine (310) performs a motor operation while the second hydraulic machine (320) performs a pumping operation, and the second hydraulic machine (320) supplies the main hydraulic machine (230).

11. The system according to claim 10, wherein: - The first hydraulic machine (310) has a first orifice (312) and a second orifice (314). The first orifice (312) is selectively connected to the orifice of the housing (210) having the highest pressure among the two orifices of the housing, and the second orifice (314) is selectively connected to the orifice of the housing (210) having the lowest pressure among the two orifices of the housing. - The second hydraulic machine (320) has a first orifice (322) and a second orifice (324). The first orifice (322) is connected to the second orifice (314) of the first hydraulic machine (310), and the second orifice (324) is connected via a conduit arranged in the housing (210) to the orifice of the main hydraulic machine (230) having the highest pressure among the two orifices of the housing.

12. The system according to claim 11, wherein, The second orifice (324) of the second hydraulic press (320) is connected via a high-pressure selector (450) to the first orifice (232) and the second orifice (234) of the main hydraulic press (230).

13. The system according to any one of claims 11 or 12, wherein: The first orifice (312) of the first hydraulic press (310) is connected to a first calibration valve (430) which is connected on the one hand to the first orifice (212) of the housing (210) and on the other hand to the second orifice (214) of the housing (210), the first calibration valve (430) being configured to connect the first orifice (312) of the first hydraulic press (310) to the orifice of the housing (210) having the highest pressure when the pressure difference between the orifices of the housing (210) exceeds a first calibration threshold, The second orifice (314) of the first hydraulic press (310) is connected to a second calibration valve (440) which is connected on the one hand to the first orifice (212) of the housing and on the other hand to the second orifice (214) of the housing (210), the second calibration valve (440) being configured to connect the first orifice (312) of the first hydraulic press (310) to the orifice of the housing (210) having the lowest pressure when the pressure difference between the orifices (212, 214) of the housing (210) exceeds a second calibration threshold.

14. The system according to any one of claims 1 to 7, wherein, The booster (300) comprises a first hydraulic press (310) and a second hydraulic press (320) which are rotationally fixed, The displacement of the first hydraulic press (310) is greater than the displacement of the second hydraulic press (320), The system is configured such that, for a first operating mode, the first hydraulic press (310) operates as a motor while the second hydraulic press (320) operates as a pump, the second hydraulic press (320) supplying the main hydraulic press (230), wherein - the first hydraulic press (310) has a first orifice (312) and a second orifice (314), the first orifice (312) being connected to the first orifice (212) of the housing (210) and the second orifice (314) being connected to the second orifice (214) of the housing (210), - the second hydraulic press (320) has a first orifice (322) and a second orifice (324), the first orifice (322) being connected to the second orifice (234) of the main hydraulic press (230) and the second orifice (324) being connected to the first orifice (232) of the main hydraulic press (230), The system includes a valve (251) adapted to selectively isolate the first orifice (212) of the housing (210) from the first orifice (232) of the main hydraulic press (230), and a valve (253) adapted to selectively isolate the second orifice (214) of the housing (210) from the second orifice (234) of the main hydraulic press (230).

15. The system according to any one of claims 8 to 14, wherein, The first hydraulic press (310) and / or the second hydraulic press (320) are radial piston and multi-lobe cam hydraulic presses.

16. The system according to any one of claims 8 to 15, wherein, At least one of the first hydraulic press (310) and the second hydraulic press (320) is a variable displacement hydraulic press.

17. The system according to any one of the preceding claims, further comprising a first valve (410, 251) and a second valve (420, 253), the first valve (410, 251) being adapted to selectively connect or isolate a first orifice (212) of the housing (210) from a first orifice (232) of the main hydraulic press (230), while the second valve (420, 253) is adapted to selectively connect or isolate a second orifice (214) of the housing (210) from a second orifice (324) of the main hydraulic press (230).

18. The system according to any one of the preceding claims, wherein, The main hydraulic press (230) is a radial piston and multi-lobe cam hydraulic press.

19. A rolling machine comprising at least one moving member and at least one system according to any one of the preceding claims, the system being adapted to selectively drive the moving member to rotate.

20. A drive member (200) adapted to selectively drive a member (10) to rotate, the drive member (200) comprising: - a housing (210) having a first housing orifice (212) and a second housing orifice (214), the first housing orifice (212) and the second housing orifice (214) being adapted to define an inlet and an outlet of the housing (210); - a main hydraulic press (230) adapted to be supplied by a hydraulic energy source (100), the main hydraulic press (230) being received in the housing (210) and having a first hydraulic press orifice (232) and a second hydraulic press orifice (234), The system is characterized in that the drive member (200) comprises a booster (300) integrated in the housing (210), the booster (300) being adapted to selectively increase the pressure such that the pressure difference between two orifices (232, 234) of the main hydraulic press (230) is greater than the pressure difference between two orifices (212, 214) of the housing (210).

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