Abstract: The device comprises a casing portion that has an open axial end and that has two main holes, respectively for fluid feed and for fluid discharge. Said holes open out in an inside axial face of the casing portion, respectively via a first main orifice and via a second main orifice that are disposed in succession in the direction going away from the open axial end. The inside axial face has first, second, and third sealing inside bearing surface arrangements, respectively situated between the open axial end and the first main orifice, between the two main orifices, and beyond the second main orifice. At least two of the three arrangements are staggered inside arrangements, each of which comprises two axial bearing surfaces that are staggered relative to each other, and that are separated by a shoulder facing towards the open axial end.

Abstract: A hydraulic circuit. The circuit includes a high pressure line and a low pressure line, the pressure in the high pressure line being greater than the pressure in the low pressure line, a hydraulic machine having two ports designed to be connected to the high pressure and low pressure lines, a first of the ports being a hydraulic fluid intake port and the second of the ports being a hydraulic fluid discharge port The circuit includes a sequential connector designed to connect the ports of the hydraulic machine to the high and low pressure lines.

Abstract: A hydraulic motor is provided having radial pistons, with a cylinder block, two main ducts, a fluid distributor, one distribution valve per cylinder, and a control system for controlling the distribution valves. The motor includes at least two elementary motors, and can operate in various different states in which, in each elementary motor, each of the cylinders is connected on the rising ramps to a second main duct and on the falling ramps to a second main duct; a first elementary motor being driving in a first state, and inactive or opposing in a second state, the control system operating the remainder of the hydraulic motor in the same way in these two states. A hydraulic circuit including said motor and a method of controlling such a motor are also provided.

Abstract: Hydrostatic transmission apparatus having an elementary motor with a feed enclosure and a discharge enclosure; a displacement selector suitable for taking up a bypass position, in which the feed and discharge enclosures are interconnected via a bypass link; and constriction means for constricting said bypass link. When the selector is in the bypass position, the constriction means can be activated to restrict the flow of fluid through the bypass link when the discharge pressure in the discharge enclosure exceeds a constriction threshold, said threshold being a function of a control pressure prevailing in a control chamber.

Abstract: Hydraulic transmission apparatus including a pressurized fluid source and at least one hydraulic motor fed by said pressurized fluid source. The motor has two motor ducts for feed/discharge, and one casing duct. The motor can be operated in assisted mode, in which it generates torque or in unassisted mode in which it does not generate any torque and its pistons are maintained in the retracted position under the effect of the pressure in the casing duct. The apparatus further includes an accumulator suitable for feeding: the motor ducts during a stage of passing from the unassisted mode to the assisted mode in order to facilitate deployment of the pistons; and the casing duct during a stage of passing from the assisted mode to the unassisted mode in order to facilitate retraction of the pistons. This apparatus thus enables the motor to be positively clutched/declutched quickly.

Abstract: The present disclosure is directed to a hydrostatic transmission apparatus including a pump, a first motor, and a second motor having two elementary motors, each of them and the first motor having feed/discharge first and second enclosures. In work mode and in road mode the second enclosure of the first elementary motor of the second motor and the first enclosure of the first motor are connected together in series, the second enclosure of the first motor being connected to the second port of the pump and the second enclosure of the second elementary motor of the second motor is connected to the second port of the pump. In work mode, the first enclosure of each of the two elementary motors of the third motor is connected to the first port of the pump.

Abstract: The present invention relates to a system comprising: a shaft having a distal end and a proximal end; a casing defining a housing in which a hydraulic device is rotatably mounted on the shaft; and a sealing element comprising a low pressure dynamic sealing means and a reinforced dynamic sealing means formed by a static seal tightly mounted on a friction pad, such as to isolate the dynamic sealing means from the rotating hydraulic device, said sealing element defining a discharge chamber between the dynamic sealing means and the reinforced dynamic sealing means, which discharge chamber is connected to a drain via a pipe arranged on the surface of the shaft, between the hydraulic device and the shaft, so as to discharge the fluid located in the discharge chamber, such that said discharge chamber is not subjected to the pressure in the casing of the hydraulic device.

Abstract: A hydraulic transmission device for a machine, including a declutchable hydraulic motor having radial pistons, and including a cam that is secured to a casing, and a cylinder block and an internal fluid distributor that are disposed in the casing; a hydraulic pump including a drive member; and fluid exchange couplings; in which device the casing and the distributor are mounted to rotate relative to a stationary support about an axis of rotation, whereas the cylinder block is fastened to said support. In some embodiments, the drive member of the pump is constrained to rotate with the casing of the motor, and in that a delivery orifice of the pump is connected to one of said couplings.

Abstract: A hydraulic transmission system for a vehicle is provided. The system includes a main pump serving to feed with fluid at least one hydraulic motor for driving a vehicle mover member; an auxiliary pump, the main pump and the auxiliary pump being suitable for being actuated jointly; and a “bypass” connection between a delivery orifice of the auxiliary pump and an unpressurized reservoir. In addition, a first constriction is arranged on the bypass connection, and configured to maintain a pump protection pressure in a pump protection portion of the bypass connection. This pressure is applied to the main orifices of the main pump when said pump is actuated but is not delivering, thereby ensuring that the pump is protected.

Abstract: A hydraulic actuation unit for controlling the starting and stopping of hydraulic motors includes a first main circuit and a second main circuit, a first recirculation circuit and a second recirculation circuit, a counterbalancing valve, which includes a shuttle, and a first discharge channel and a second discharge channel. The shuttle includes a first check valve and a second check valve. The first check valve includes at least one first flow control element that can move from an open position to a closure position. The second check valve includes at least one second flow control element that can move from an open position to a closure position. The first and second check valves respectively are provided with first damping means and second damping means in order to slow down the passage movement respectively of the first flow control element and of the second flow control element.

Abstract: The present invention relates to a hydrostatic transmission closed circuit comprising a fluid tank (50), a hydraulic pump (12; 212), a first engine assembly (20; 220) and a second engine assembly (30, 40; 230), said first and second engine assemblies (30, 40; 230), each comprising at least one hydraulic engine, a booster pump (14; 214), an exchange unit (60; 260), said circuit being characterised in that it also comprises a supplementary boosting line (150; 350) which removes fluid at the outlet of the exchange unit (60; 260) and boosts the hydrostatic transmission circuit at the level of the series line (104; 204).

Abstract: The present invention relates to a double hydraulic machine (100) comprising two elementary machines (M1, M2) each having two orifices, the double hydraulic machine (100) comprising a distribution valve (7) suitable for, in a first configuration (C1), feeding both elementary machines (M1, M2) in parallel, and in a second configuration (C2), producing a short circuit of one of the elementary machines (M2). The invention also relates to a system for driving a vehicle comprising such a hydraulic machine (100) for driving the vehicle into motion.

Abstract: Cut-in-cut-out valves for hydraulic circuits. The hydraulic circuits include a hydraulic pump outputting a variable pressure controlled by a slaving line, an accumulation circuit, a return line to the reservoir, a cut in-cut-out valve. The hydraulic circuits also include a cut-in-cut-out valve having four orifices, a first orifice connected to the supply line, a second orifice connected to the slaving line, a third orifice connected to the return line leading to the reservoir, and a fourth orifice connected to the accumulation circuit. The cut-in-cut-out valve alternates between two positions as a function of the pressure in the accumulation circuit, a cut-in position in which the first, second and fourth orifices are connected to each other, and a cut-out position in which the first and fourth orifices are closed.

Abstract: A hydrostatic transmission apparatus for a vehicle having at least two wheels, the second wheel being steerable, may include a main hydraulic pump, two hydraulic motors driving respective ones of the wheels, detection means for detecting that the second wheel is turned by being steered, a first synchronization duct between the first and second motors, and re-feed means for re-feeding the first synchronization duct, and suitable for acting, while the second motor is being fed by the first motor via the first synchronization duct, and when the second wheel is turned by being steered, to inject fluid into the first synchronization duct while limiting the pressure in said synchronization duct to a pressure less than a re-feed pressure that is significantly less than the high pressure of the pump.

Abstract: A hydraulic braking valve having an inlet orifice intended to be connected to a pressure supply, an outlet orifice intended to be connected to a braking unit, a leak orifice intended to be connected to a tank, a power distributor adapted so as to connect the inlet orifice to the outlet orifice in a braking configuration, and a leak orifice to the outlet orifice in a rest configuration. The power distributor is driven by two independently driven calibrators.

Abstract: This invention discloses a hydraulic braking system (1) for a vehicle comprising: two pressure supply means (2, 3), two rear braking means (4, 5) and one front braking means (6), said hydraulic system (1) being characterised in that it comprises a rear inlet distributor (12), a front inlet distributor (13), a first brake distributor (10) and a second brake distributor (11), defining a standby configuration, three braking configurations pressurising: a first rear brake, a second rear brake, the two rear brakes and the front brake respectively, pressure for the front axle braking means (6) being applied through the front inlet distributor (13), the first brake distributor (10) and the second brake distributor (11).

Abstract: Hydrostatic transmission apparatus for a vehicle having a front group of drive members and a rear group of drive members, a pump, a front motor and a rear motor contributing to driving respective ones of the front and rear groups of drive members; a first one of the motors and a second one of the motors connected to the first motor via a series duct also being connected to the main orifices of the pump, thereby constituting a closed transmission circuit; at least one pressure-limiting valve being interposed between the series duct and a low-pressure circuit, and being suitable for connecting the series duct to the low-pressure circuit while being controlled as a function of the high pressure of the pump. The pressure in the series duct is thus effectively limited to a pressure representative of the pressure necessary for driving the vehicle.

Abstract: A braking device including a housing mounted in relative rotation relative to a shaft, braking discs, a braking piston adapted to stress the braking discs, a spring washer mounted on the brake housing on a support zone located on one of the peripheries of its first face, and having on its second face a braking support zone, which cooperate with the braking piston so as to stress the braking discs according to a braking direction. An unbraking piston is adapted to stress the washer according to a direction opposite said braking direction. The spring washer has an unbraking support zone with the unbraking piston on the other of the peripheries of the second face of the spring washer. The braking support zone is located at an intermediate position of the at least one spring washer.

Abstract: The present invention relates to a hydraulic circuit comprising: an accumulator (11) a hydraulic device (1) a primary line (12) and a secondary line (13) connecting each said accumulator (11) to the hydraulic device (1), the primary line (12) comprising a restriction (14) and a primary distributor (15) adapted to selectively connect the hydraulic device (1) to the accumulator (11) or to a tank (R), the secondary line (13) comprising a secondary distributor (16) alternating between a first configuration in which it blocks the secondary line (13), and a second configuration in which it is passing, said secondary distributor (16) being controlled via the pressure within the primary line (12) downstream of the primary distributor (15) relative to the hydraulic accumulator (11), such that switching from the first to the second configuration of the secondary distributor (16) takes place only when the pressure in the primary line (12) reaches a threshold value.

Abstract: A hydrostatic transmission apparatus having a main pump, two main ducts that are respectively a feed main duct and a discharge main duct for first and second hydraulic motors serving to drive two drive members of a vehicle that are situated one after the other. At least the first hydraulic motor is a dual motor made up of two elementary motors, a first one of which is connected via a series link to the second hydraulic motor. A link selector can take up a first position in which a series loop including said series link coexists with a direct loop for directly linking at least the second elementary motor to the two respective orifices of the main pump, and a second position in which at least one of said direct and series loops is bypassed by a bypass link having a constriction valve.