Abstract: Hydraulic device driving a rotating receiver such as a shaft (1) includes at least one hydraulic motor having axial pistons (7) bearing against a fixed swash-plate (9) via shoes (10), the pistons (7) being arranged in a rotating barrel (5), characterized by the fact that the motor shaft (1) carries a toothed crown wheel (2) with which it is integral whose teeth are engaged by teeth (4) provided on the periphery of the rotating barrel (5) of one or more hydraulic motors (7) arranged around the shaft (1), the axis of axes of the barrel (5) being parallel to the axis of the shaft (1).

Abstract: Hydraulic device driving a rotating receiver such as a shaft (1) includes at least one hydraulic motor having axial pistons (7) bearing against a fixed swash-plate (9) via shoes (10), the pistons (7) being arranged in a rotating barrel (5), characterized by the fact that the motor shaft (1) carries a toothed crown wheel (2) with which it is integral whose teeth are engaged by teeth (4) provided on the periphery of the rotating barrel (5) of one or more hydraulic motors (7) arranged around the shaft (1), the axis of axes of the barrel (5) being parallel to the axis of the shaft (1).

Abstract: A device enables the pumping of any kind of liquid while giving the liquid very high delivery pressure. The units that cause pumped liquid suction and then its delivery are driven exclusively by hydraulic means excluding mechanical means. So that there is no material contact between the driving units and the pumped product and that the product cannot damage the mechanical driving units, the chamber receiving the hydraulic fluid is, at the end of each compression cycle, placed again in direct communication with the hydraulic fluid reservoir.

Abstract: The casing of the high-pressure pump consists of two integral segments. The first segment comprises a cylindrical borehole receiving the pump shaft 5 and its ball bearings 4. The second segment 1b comprises another borehole receiving a swash plate 9 rigidly affixed to the pump shaft 5, a cylindrical core 11 with parallel sides 11a, 11b and crossed by a plurality of open-end boreholes 12 receiving the pistons 13, a second cylindrical core 16 bearing check-valves 17, and a plug 19 resting against a shoulder 18 of the second core 16 in such manner as to keep the cores 11 and 16 compressed against each other and resting against a circular stop 7 in the second segment 1b of the pump casing 1. The inner boreholes of the two segments 1a and 1b are separated by a seal 2 and the parts located in the second segment 1b are in contact with the injection gasoline.

Abstract: A hydraulic drive system for a battery operated portable compression tool. The tool has an electric motor. The drive system has a self-regulating variable displacement pump with a rotatable conduit frame having radial conduits, pistons reciprocally located in the conduits, and a ring bearing surrounding the conduit frame in an eccentric adjustable location. Ends of the pistons are located against the inside of the ring bearing. A valve plate located against a front end of the rotatable conduit frame to control entry and exit of fluid into and out of the conduit frame as it is rotated.

Abstract: A composite joint for a hydraulic system having two parts which rotate relative to each other is formed by the combination of a friction ring of hard material which is mechanically anchored to one of the relative rotating parts as a supporting collar around a ring of more flexible material mounted in a groove of the one part to exert a force on the ring of hard material providing with the joint a relatively large clearance between the two relatively rotating parts.

Abstract: Hydraulic piston pump driven in an alternating reciprocating motion by bearing, through a stud, against a cam carried by a drive shaft, characterized by the fact that a device acting as non-return feed valve is incorporated in each piston (14) while the discharge pressure is permanently re-injected into the interior of the stud (17) by which said stud (17) takes support on said cam (6).

Abstract: A hydraulic pump comprising at least a reciprocating piston, each piston being associated with one suction valve returned to its closing position by a return spring. The return spring is associated on the one hand with the valve and on the other hand with a push-piece cyclically actuated by a cam driven by the pump driving shaft in such manner that the action of the spring on the suction valve is cancelled during the suction phase and reestablished at the end of the suction phase.

Abstract: A hydrostatic clutch, includes coaxial driving and driven rotative members, so that when in the clutched condition rotative power is transferred from the driving to driven member. The clutch includes a plurality of pistons bearing upon an inclined cam, and move in a reciprocating motion when the cam which is coupled to either the driven or driving shaft, rotates. A second cam also driven by the driven or driving members, is adopted to be disposed with respect to the mobile member which drives it, into two positions offset by 180.degree.. The second cam acting upon a suction valve controlling the intake of hydraulic fluid, via opposing springs. At least one double stage or delivery valve is carried by the same mobile driving or driven member. A fixed casing is connected to the mobile member carrying the delivery valve or valves, through a rotating seal. The fixed casing is connected via a plurality of hydraulic channels to various hydraulic fluid regulation member.

Abstract: A hydraulic pump having spring loaded valves utilizes a spring providing a constant spring force and a spring providing a varying spring force. The varying spring force depending upon the position of the pump piston. The pump suction valve opens after a variable delay relative to the beginning of the piston suction phase when the pressure prevailing in the pump's dead chamber falls below a predetermined value. Abrupt decompression to the dead chamber is therefore avoided resulting in reduced energy consumption and noise level.

Abstract: The pump comprises a casing containing the pump shaft. The casing includes a lateral housing containing an axially slidable shaft. The slidable shaft carries a first pinion, while the pump shaft carries a second pinion which is firmly connected thereto. The slidable shaft is held in a first extreme position by a spring and can be axially displaced, against the force of the spring, to a second extreme position by pneumatic control means. The control means include a piston portion which forms part of the slidable shaft. One of the said positions is a working or pumping position in which there is a driving contact, e.g. between the sliding shaft and a driving shaft, between the first pinion and a driving pinion, or between a first and second pinion.