Abstract: The invention relates to a pressure-limiting device designed to be installed in a system comprising a first line (11) and a second line (12) that can comprise pressurised oil, as well as comprising a discharge and/or booster line (10). The device also comprises a pressure selector (130, 150) in the form of a cage defining two seats (132, 134) and two pressure relief valves (160, 180). The limiting device is characterised in that it further comprises at least one means (170, 172; 190, 192) for regulating a pressure relief valve, disposed on the outside of an axial end of the pressure selector (150), in the form of a cage that allows the loading of the associated pressure relief valve to be regulated.

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: The invention relates to a device (10) for controlling the displacement of a machine (20) with axial pistons comprising a case (23) that houses a control unit comprising a displacement control spool (110) adapted to be switched between two positions by a control pressure (Ps) according to an axis of sliding (?): a working position wherein the control spool (110) provides a connection between at least one inlet (103, 104) that receives a supply pressure and an outlet (105, 106) connected to a cylinder for adjusting the inclination of said machine (31a, 31b), and an idle position wherein the control spool (110) interrupts the connection between said inlet (102, 104) and said outlet (101, 103), and comprising means for switching adapted to vary the position of the adjusting cylinder (31a, 31b), a spring (140), characterised in that: said means of communication comprise a second switching spool (130), coaxial to the control spool (110), a switching pressure (Pm) exerts an axial force on the second spool (130) in

Abstract: The invention relates to a device comprising a first hydraulic apparatus (M1) and a second hydraulic apparatus (M2), the two motors (M1, M2) being connected by a first line (11) and a second line (12) enabling the admission or discharge of the oil in said motors (M1, M2), a booster pump (30), arranged between a tank and a booster line, the booster line communicating with at least one of said lines (11, 12), characterized in that the pump (30) is configured to be able to suck oil into the booster line in order to allow the decompression of said first and second lines (11, 12). The invention also relates to a method for evacuating a device of the type described above, in which the booster pump (30) is activated in suction mode in the booster line to enable the disengagement of the machines (M1, M2).

Abstract: A hydraulic machine (1) comprising first and second brake elements (92, 93), a spring washer (65) tending to urge the first and second brake elements (92, 93) in a braking direction, and a brake release piston (61) configured to act on the spring washer (65) in a direction opposing the braking direction, the hydraulic machine being characterized in that the brake release piston (61) comprises a primary brake release piston (61a) associated with a primary brake release chamber (62a), and a secondary brake release piston (61b) associated with a secondary brake release chamber (62b), said primary and secondary chambers (62a, 62b) extending radially around the shaft (2) in such a manner that projections of the primary brake release chamber (62a) and of the secondary brake release chamber (62b) onto a plane perpendicular to a longitudinal axis (X-X) defined by the axis of rotation of the hydraulic machine (1) are superposed, at least in part.

Abstract: The invention relates to a vehicle hydraulic assistance method comprising: two hydraulic devices connected therebetween by a supply line, a return line, a power boost source, and a tank, the power boost source being connected to the supply line and return line via a power boost line and taking the oil from the tank; and a vacuum valve including an input port, connected to the supply line and return line, and an output port connected to the tank. The vacuum valve has a first passing state and a second blocking state. The method includes the steps of: (E1) activating the power boost source when the vehicle fulfills at least one predetermined requirement, the vacuum valve being in the first passing state; and (E2) switching the vacuum valve from the first passing state to the second blocking state when hydraulic assistance is required, thus making it possible to boost power to the supply system and return system.

Abstract: According to the method, transmission apparatus of a vehicle, the apparatus comprising a drive engine (18), a mechanical transmission (16) connected to the drive engine, and a hydraulic transmission (20) having a pump (24) and n hydraulic motors (26A, 26B), where n is greater than or equal to 1, the pump being suitable for being driven by the drive engine for feeding fluid to the hydraulic motors. The method consists in performing a “low-speed” assistance stage, during which, when the vehicle is driven by the mechanical transmission, the method consists in establishing a setpoint pressure for the pressure difference between the feed and the discharge of each of the hydraulic motors, in feeding the hydraulic motors by the pump, in detecting the pressure difference between the feed and the discharge (28A, 28B) of each of the hydraulic motors (26A, 26B), and in adjusting the delivery rate of the pump so that said pressure difference is substantially equal to said setpoint pressure.

Abstract: A braking circuit including at least an auxiliary right valve (200) and an auxiliary left valve (300) suitable to allow braking on both sides, right and left of a vehicle, when this is required, but allowing to apply a pressure braking only on one of the two sides, right or left, when this is required to provide a steering function, characterized in that the circuit further comprises a master valve (400) having two positions: a first position when the vehicle has a velocity under a threshold wherein separate and selective right or left braking is authorized and a second position when the vehicle has a velocity above said threshold wherein said master valve (400) connects both a right braking line (204, 1205) and a left braking line (304, 1305) to an output braking line (110) so that if a braking is requested both right braking line (204, 1204) and left braking line (304, 1305) are under pressure and selective right or left braking is forbidden.

Abstract: Hydraulic transmission apparatus (20) including a pump (24) having a variable cylinder capacity and feeding one or more hydraulic motors (26A, 26B), and a control unit (50). In the apparatus, the feed and discharge orifices of the motors are arranged in such a manner that, when the pressures at said orifices are equal, the outlet torque from the motors is zero. To make the apparatus inactive, without physically bypassing the motors, the control unit is suitable for operating the apparatus in a “torque-free” mode by regulating the cylinder capacity of the pump in such a manner that the pressures at said feed and discharge orifices remain substantially equal.

Abstract: An assembly (20) comprising a radial piston hydraulic motor (10), comprising a fixed housing (15), a shaft (14) that can be driven in rotation by the hydraulic motor (10), a wheel hub (30) comprising a hub barrel (31) that engages on the shaft (14), a bearing (40), a bearing support (41), in which the bearings (40) are housed between the hub barrel (31) and the bearing support (41) of the hydraulic motor (10), the bearing support (41) forming part of the housing (15), such that the bearing function is carried out by the housing (15), the shaft (14) supporting only the weight of same and having only a torque function.

Abstract: A selection system, comprising: a sheath defining an internal housing extending in a longitudinal direction; a link rod disposed in said internal housing, and extending in the longitudinal direction; and a selection slide mounted to slide in the internal housing, about the link rod; the link rod being held stationary relative to the sheath against movement in translation in the longitudinal direction by stop means; the system being characterized in that the stop means comprise: a base that is a body of revolution and includes a conical portion; and a shell comprising two shell portions each including a conical portion configured to come to bear in plane manner against the conical portion of the base.

Abstract: The invention relates to a hydraulic transmission device for a vehicle, said device comprising a first pump and a second pump, a first hydraulic apparatus and a second hydraulic apparatus, a first supply circuit connecting the first pump to the first apparatus, and a second supply circuit connecting the second pump to the second apparatus and wherein a non-return valve between the supply circuits, the valve having a direction for passing from the first to the second supply circuit, a first return circuit connecting the first apparatus to said pumps, a second return circuit the second apparatus to the admissions to said pumps so that the return circuits are in permanent fluidic communication with each other through a junction.

Abstract: According to the method, transmission apparatus of a vehicle, the apparatus comprising a drive engine (18), a mechanical transmission (16) connected to the drive engine, and a hydraulic transmission (20) having a pump (24) and n hydraulic motors (26A, 26B), where n is greater than or equal to 1, the pump being suitable for being driven by the drive engine for feeding fluid to the hydraulic motors. The method consists in performing a “low-speed” assistance stage, during which, when the vehicle is driven by the mechanical transmission, the method consists in establishing a setpoint pressure for the pressure difference between the feed and the discharge of each of the hydraulic motors, in feeding the hydraulic motors by the pump, in detecting the pressure difference between the feed and the discharge (28A, 28B) of each of the hydraulic motors (26A, 26B), and in adjusting the delivery rate of the pump so that said pressure difference is substantially equal to said setpoint pressure.

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: The present invention relates to a hydraulic-assistance system for motor vehicles, comprising a primary motor (M) and two hydraulic machines (140; 240, 250) connected by a hydraulic circuit such that when a first hydraulic machine (140) operates as a pump, the second hydraulic machine (240, 250) operates as a motor.

Abstract: A hydraulic transmission apparatus having at least one declutchable hydraulic motor having radial pistons and connected via two motor ducts, and a casing duct connected to the inside of the casing. The apparatus further has clutching means that, in order to perform the clutching of the motor, are suitable for bringing a first one of the motor ducts to a “clutching” first pressure that is higher than the pressure in the casing while also making it possible to remove fluid via the casing duct. Disposed on the casing duct, the apparatus further has means for limiting the flow of fluid in said casing duct, in a manner such as to cause the pressure inside the casing to increase during the clutching operation. This apparatus enables clutching to take place gently.

Abstract: A hydraulic apparatus comprising a casing (1) having arranged therein a hydraulic machine (2), a shaft (4) mounted to rotate relative to the casing (1) by means of a bearing (5), a braking system (3) having a plurality of brake disks (31, 34) configured to prevent the shaft (4) rotating relative to the casing (1) in selective manner, and a control system (6, 7) for controlling said braking disks (31, 34), the hydraulic system including an irrigation system adapted to cool said brake disks (31, 34) by means of a fluid, the irrigation system including a fluid inlet (81) and a fluid outlet (82), the hydraulic system being characterized in that the fluid inlet and outlet (81, 82) of the irrigation system define a fluid flow within the casing in which the braking system (3) is downstream from the hydraulic machine (2).

Abstract: A selection system, comprising: a sheath defining an internal housing extending in a longitudinal direction; a link rod disposed in said internal housing, and extending in the longitudinal direction; and a selection slide mounted to slide in the internal housing, about the link rod; the link rod being held stationary relative to the sheath against movement in translation in the longitudinal direction by stop means; the system being characterized in that the stop means comprise: a base that is a body of revolution and includes a conical portion; and a shell comprising two shell portions each including a conical portion configured to come to bear in plane manner against the conical portion of the base.

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 the motors having first and second enclosures for feed/discharge. 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 invention relates to a flow control valve adapted for use as a flow-dividing and flow-combining valve in hydraulic devices, comprising: a valve body having a first longitudinally extending bore, an outer spool slidably positioned within the bore, the outer spool having an axially extending passageway, a pair of axially extending inner spools slidably positioned within the passageway, the valve body having a first port and a pair of second ports, the outer spool having at least a first opening communicating with the first port and with the passageway, and at least two pairs of second openings therethrough. At least one second opening of each pair is of non-constant longitudinal section narrowing from the outer face of the outer spool on at least a part of the thickness of the second opening, so that a lateral side of the second opening offers an obstacle where a part of the fluid flow entering the second opening crashes before entering the inner spool.