Abstract: A hydraulic circuit including: at least one primary motor comprising at least first and second distinct sub-motors, the first sub-motor having a first main orifice, and the second sub-motor having a second main orifice; and at least one secondary motor; in which circuit said first main orifice of the primary motor(s) is connected to a first main orifice of the secondary motor(s) via a first series duct, and the second main orifice of the primary motor(s) is connected to a second main orifice of the secondary motor(s) via a second series duct. This configuration of circuit makes coupling possible between the primary motor(s) and the secondary motor(s).

Abstract: Hydraulic transmission circuit with N hydraulic motors, wherein each motor comprises N sub-motors, all N2 sub-motors having the same cylinder displacement. The circuit comprises one common feed duct, adapted for receiving fluid under pressure, and to which one feed sub-motor of each motor is connected; one common exhaust duct, adapted for ejecting exhaust fluid, and to which one exhaust sub-motor of each motor is connected; N serial ducts, each serial duct connecting a feed, first sub-motor to an exhaust, N-th sub-motor via N?2 interposed sub-motors, these N connected sub-motors respectively belonging to the N motors. This circuit allows tight synchronization of the N hydraulic motors.

Abstract: A hydrostatic transmission including a main pump, two main ducts serving respectfully as feed and as discharge for first and second hydraulic motors that serve to drive disposed one after the other. A bypass valve can take up a reduced-speed position in which the feed main orifices are connected to the discharge main duct, and an increased-speed position in which one of the motors is bypassed, the feed main orifice of the motor being connected to the discharge main duct via a bypass link, while the other main orifices continue to have their respective links. The apparatus further includes a constriction suitable for being activated to restrict the flow of fluid through the bypass link.

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 circuit having at least one hydraulic motor, two main ducts for feeding or discharging the at least one motor, a low-pressure fluid source, and a high-pressure accumulator forming a high-pressure fluid source. The circuit is suitable for operating in an energy recovery mode in which the feed main duct is connected to the low-pressure fluid source and the discharge main duct is connected to the high-pressure accumulator, and in an energy delivery mode in which the connections are inverted. The low-pressure fluid source has a high-flow-rate booster pump suitable for delivering a flow-rate of fluid that is sufficient to feed fluid to the at least one hydraulic motor while the motor is at maximum speed in energy recovery mode, and an adjustable pressure limiter suitable for being controlled so as to cause the pressure of the fluid at the outlet of the low-pressure fluid source to vary.

Abstract: A hydraulic valve having firstly a feed port, a discharge port, a low-pressure link port, and a high-pressure link port, which ports are respectively connected to the feed and discharge ducts of a hydraulic motor, to a low-pressure fluid source, and to a high-pressure accumulator, and secondly an auxiliary port. The valve has a slide that can take up a neutral position for connecting together the feed, discharge, and auxiliary ports, an energy recovery position for connecting together respectively the feed and low-pressure ports, and the discharge and high pressure ports, and an energy delivery position for connecting together respectively the feed and high-pressure ports, and the discharge and low-pressure ports. The slide is caused to move from its neutral position to its other positions by control signals and the auxiliary port can be connected to a reservoir or to a clutch fluid source for clutching or declutching the motor.

Abstract: A hydraulic circuit having a brake pipe suitable for being connected to a pressurized fluid source or to a pressure-free reservoir, i.e. to a reservoir without excess pressure, via a proportional pressure reducer controlled by an electronic control unit (ECU). The circuit includes link solenoid-valve means suitable for connecting the proportional pressure reducer to the reservoir or, via a calibrated pressure reducer, to the pressurized fluid source.

Abstract: A hydraulic circuit including a first motor set, and a second motor set for driving vehicle-moving means situated one behind the other. The circuit has first, second, third, and fourth main ducts for feeding the motor sets in parallel. The device includes a selector suitable for taking up a first stable position making the feeding in parallel possible by interconnecting in pairs the feed and discharge main ducts, and for taking up a second stable position in which one of the motor sets is inactive because one of the main ducts is connected to one of main ducts of the other set. Between the stable positions, the selector can take up a temporary position, in which all four main ducts are interconnected. At least while the selector is moving in one direction between its two stable positions, the temporary position is sustained in an intermediate stage during which at least one of the interconnections between the main ducts of the first and second motor sets is constricted.

Abstract: The vehicle has two groups of displacement members (1, 2, 3, 4), one of which groups is steerable. The apparatus comprises a closed transmission circuit which includes a pump (50) and hydraulic motors (10, 20, 30, 40). A first group of motors that serves to drive two displacement members on the same axle comprises at least two double motors (30, 40), each having two operating cubic capacities forming two elementary motors (31, 32; 41, 42). The first elementary motor (31, 41) of each of the double motors is connected to the pump (50) in parallel with a motor (10, 20) of the other group, while the second elementary motor (32, 42) is connected in series with said motor of the other group. There thus exist first and second series ducts (C32, C42) between the motors.

Abstract: The vehicle has two groups of displacement members (1, 2, 3, 4), one of which groups is steerable. The apparatus comprises a closed transmission circuit which includes a pump (50) and hydraulic motors (10, 20, 30, 40). A first group of motors that serves to drive two displacement members on the same axle comprises at least two double motors (30, 40), each having two operating cubic capacities forming two elementary motors (31, 32; 41, 42). The first elementary motor (31, 41) of each of the double motors is connected to the pump (50) in parallel with a motor (10, 20) of the other group, while the second elementary motor (32, 42) is connected in series with said motor of the other group. There thus exist first and second series ducts (C32, C42) between the motors.

Abstract: The present invention relates to a vehicle equipped with wheels coupled to fluid motors, restrictions being placed on supply or exhaust conduits of the motors. According to the invention, the vehicle comprises front and rear wheels, each coupled to one of the motors, each motor being of a reversible type, while a restriction is placed on the supply conduit of each motor coupled to the rear wheels, another restriction being placed on the exhaust conduit of each motor coupled to the front wheels. One application of the invention is the production of a wheeled vehicle equipped with a simple and efficient anti-skid system for its wheels.