Abstract: An hydraulic transmission device (10,110) comprising an hydraulic motor (16, 18), an hydraulic pump (20), a fluid accumulator (22). The device has an accumulator-driven mode, an energy-recovery mode, a pump-driven mode. In the pump-driven mode, the pump supplies the motor with fluid drawn from an unpressurized reservoir; and in the energy-recovery mode, the motor is supplied by the pump drawing fluid from said reservoir. An assembly (1) comprising a device (10,110) as defined above, a shaft (11, 13), and a mass (12, 14) mounted eccentrically on the shaft.

Abstract: Hydraulic apparatus for recovering energy, said apparatus comprising a hydraulic motor, and a high-pressure fluid source and a low-pressure fluid source. The apparatus has: an energy consumption mode, in which the fluid is transferred from the high-pressure fluid source to the low-pressure fluid source while driving the motor in rotation; and an energy accumulation mode, in which, by the action of the motor operating as a pump, the fluid is transferred from the low-pressure source to the high-pressure fluid source. The apparatus further comprises a pressure reducer disposed on a duct interconnecting the two fluid sources. In energy accumulation mode, if the level of the low-pressure source is tending to become excessively low, the reducer opens, enabling fluid to reach the low-pressure fluid source via the first duct.

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.

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: The present invention relates to an assembly comprising —an axle (1), —a steering pivot (2) mounted on the axle (1), —a wheel spindle (3) mounted on the pivot (2), —a hydraulic motor and a wheel mounted on said spindle (3), such that the spindle (3) is pivotally mounted relative to the axle (1), the axle (1), the spindle (3) and the pivot (2) being provided with communicating hydraulic pipes to supply the hydraulic motor with fluid, the hydraulic pipes being arranged in the axle (1), the pivot (2) and the spindle, the pivot (2) comprising a shaft member fitted in the axle (1) about which the spindle (3) is fitted, the axle (1) and the spindle (3) each comprising grooves connected respectively to the hydraulic pipes of the axle (1) and the spindle (3) in such a way as to form the rotating joint with the hydraulic pipes of the pivot (2).

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: The present invention relates to a subassembly for forming a hydraulic motor after assembly onto an assembly including a shaft, said subassembly including a cover forming a housing element, a multilobe cam, a cylinder block opposite the cam, pistons guided so as to slide radially within the respective cylinders of the cylinder block and bearing on the lobes of the cam, and a valve intended to apply pressurized fluid to said pistons in series, wherein said subassembly includes means for temporarily attaching the cylinder block to the cover and means for accessing an element of the valve through the cover in order to enable, during installation, the angular positioning of said element with respect to the shaft, followed by the attachment thereof to the shaft. The present invention also relates to a method for assembling such a hydrobase.

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: 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: 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: 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.