Poclain Hydraulics Industrie

Julien Viard

Dominique Costaz

Loic Bonnard

Jean Heren

Bernard R Allart

Gilles G Lemaire

Philippe Raymond Lucienne

Gery Depierre

Antoine Desmyttere

Cécile Borgnon

Hervé Desumeur

Clément Recoura

Pierrick Prat

The assembly may include a cylinder block, a plurality of pistons, and a holding element, the holding element extending over all or part of the outer periphery of the cylinder block. The holding element may include a plurality of guide portions, each partially blocking a recess of the cylinder block so as to come into contact with a planar end of the crown of a piston to guide in the translation of each piston in their respective recesses. The holding element may include two indexing means cooperating with two indexing means of the cylinder block so as to hold the holding element under a traction force when positioned around the cylinder block.

Cylinder block comprising piston-holding means

The machine comprises distribution ducts connected to respective ones of first, second, and third enclosures (), and a cylinder-capacity selector () suitable for being caused to take up a large cylinder capacity configuration in which the second enclosure () is connected to one of the main ducts (), while the first and third enclosures () are connected to the other main duct (), and a small cylinder capacity configuration in which the second and third enclosures () are connected to said one of the main ducts (), while the first enclosure is connected to the other main duct (). The machine further comprises a safety valve () having at least a first port () connected to said one of the main ducts (), and a second port () connected to the third enclosure (). Said safety valve is suitable, when the cylinder-capacity selector () is caused to go into the large cylinder capacity, for being caused to go into a first configuration that isolates the first and second ports () from each other, and, when the cylinder-capacity selector is caused to go into its small cylinder capacity, for being caused to go into a second configuration that interconnects the first and second ports ().

Hydraulic machine having two cylinder capacities and a safety valve

The devices comprises a distributor () that presents distribution ducts opening out into a radial distribution face (A), and a distributor-counterpart engaged in each other in such a manner that two main enclosures () are provided between their opposite axially-extending faces. The device comprises a cylinder-capacity selector comprising two slides () arranged after the other in a bore () of the element engaged in the other, to which are connected the main enclosures () and at least some of the distribution ducts (). The slides are able to adopt at least three distinct configurations establishing different connections between the main ducts () and the distribution ducts via the main enclosures, in order to be able to obtain at least three distinct operating cylinder capacities.

Distribution device for a hydraulic machine and a hydraulic machine fitted with such a device

The device has an internal distributor to be disposed in a casing portion (A), and has a body () that has an outside axial face (B) provided with two grooves () respectively for feed and for discharge. The distributor has distribution ducts (A,B,C) that open out in a distribution radial face and a cylinder capacity selector that has a slide () suitable for being moved in an axial bore () for connecting the distribution ducts to one or the other of the grooves. The device further has a control chamber () provided between a first end wall (') of the bore and the first end (A) of the slide, and an opposing spring () disposed in a return chamber (&#x2032;) situated at the second end (&#x2033;) of the bore and closed, at the end closer to the distribution face (A), by a second end wall (&#x2032;) of the distributor.

Distribution device for hydraulic machine

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.

Distribution casing device for a hydraulic machine

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.

Selection system having improved axial locking

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.

Subassembly forming a hydrobase for hydraulic motors, and assembly method

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.

Hydrostatic transmission apparatus making improved braking possible

A hydraulic valve having firstly a feed 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.

Hydraulic energy recovery system

A hydraulic mechanism including a cylinder block having radial pistons and mounted to rotate in a stationary casing, and a distribution cover that forms a portion of the casing that has feed and discharge ducts that extend between an outside face and inside of face of the cover. The internal distributor has distribution ducts that are selectively connected to the feed and discharge ducts that open out into a distribution face that is perpendicular to the axis of rotation and that is disposed against the communication face of the cylinder block so as to cause the distribution ducts to communicate with the cylinder ducts. In a zone defined radially outwards by end-wall portions of the cylinders, a transverse face of the cylinder block is provided with an axial setback in which at least a portion of the distributor is disposed.

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Verberie, France

Julien Viard