IE53541B1 - A rotary hydraulic device - Google Patents

Description

The present invention relates to a rotary hydraulic device of variable capacity.

There exist devices, more or less of this type, in which the rotor is axially displaced and is found in constant contact with a fixed part [(see for example the documents FR-A-1.498.399 (OUSSOF) and FR-A-1.045.882 (EZQUERRA)].

There are devices in which the movable elements with a fixed path are in direct contact with a rotary element with an axial displacement [(see for example the documents US-A-2.628.566 (BERNER) and US-A-2.629.332 (TRIPP)].

There are devices in which the movable bosses move towards vanes with 10 a path which is or is not fixed [(see for example the documents DE-C-243.697 (INT. ROTATIONS) and FR-A-1.130.841 (COUTURIER)].

Finally, there is a device in which the vanes with a fixed path, which can be altered, co-operate with a means of diverting fluid [(see especially the document US-A-3.250.223 (KRAWACKI)].

The device according to the invention belongs to the generation of devices of the applicant having sliding vanes, sliding axially, aligned in recesses in the rotor, the said vanes each being applied in a constant and total manner to a continuous surface of the stator base, which may be a cycloidal surface, and which can be deformed to present rectilinear zones or hollows appropriate for the functioning of the device.

The space between the rotor and stator is a space with a longitudinal axis variable circularly and defined in part by the said continuous surface of the stator base which is of a constant width and unique for a particular set of vanes.

In one of the devices of this generation of devices, the axially slidable vanes are placed in pairs in rotor recesses, on both sides of a middle stator piece, the hollows being opposed back to back on both sides of the said stator middle piece and made in that piece, the vanes coming towards one another to be applied to the continuous surface of the base, at hollows in that piece.

In another device of this generation of devices, a middle stator piece, with bottom surfaces provided on both sides of an axis of symmetry, is united with a portion of a fixed shaft, the rotor being mounted in the form of a cage around the stator.

The present invention provides a rotary hydraulic device of variable capacity of the volumetric pump type having a coaxial stator and rotor and with vanes sliding axially in the rotor, the stator having at least one lower surface presenting fixed planar zones and recesses, the said vanes following the said lower surface, the said recesses each being formed by axially movable elements presenting a central plateau forming the base of the recess and on both sides of this central plateau a flank with an inclined slope relative to the central plateau, each flank being laterally recessed with respect to the width of the central plateau and being located between two fixed ramps of the stator making the junction between the flank and the adjacent fixed plane area.

Such a hydraulic device is distinguished from the subject of the patent application EP-A-0 053 544 of the applicant, lodged but not published at the priority date of the present application, by the arrangement of the flanks with inclined slopes. - 3 A control means is provided to act, as desired, in the standstill position and/or during the course of functioning, on the said movable elements of the stator and the recesses and thus on the depth of the said recesses, and because of this may vary the cylindrical capacity of the device.

Other characteristics and advantages of the present invention are apparent from the description which follows and which describes an embodiment of the invention with reference to the accompanying drawings, wherein: Figure 1 is a schematic view of a portion of a hydraulic device according to the invention; Figure 2 is a perspective view of a stator of a device corresponding to the invention having at least one stator element with an adjustable recess; and Figure 3 is a perspective view of a portion of a stator showing a stator element with an adjustable recess and the adjoining ramps of the stator.

In the form of embodiment shown, axially slidable vanes 1 sliding in housings 2 formed in a rotor 3 come to bear by at least one edge portion of their nose 4 projecting therefrom, on a bottom stator surface having deformations or recesses therein. This continuous stator surface has the distinguishing feature of being composite, in that it comprises both a stationary portion 5 and movable portions or elements 6. The stationary portion 5 comprises ramps 7 and movable elements 6 comprise recesses 8 therein.

The movable elements 6 can move in housings 9 formed in the stationary stator portion, in the standstill position and/or during the operation, under the action of a mechanical, hydraulic or magnetic outer control means 10. Watertight sealing means 11 are provided between a hub 12 and the control 10 of each movable element 6 and guiding means 13 in the respective stator housing. Channels 14 for hydraulic balance pass through each movable element 6.

In the form of embodiment shown in Figures 2 and 3, each movable element 6 having a recess 8 therein is formed with a central flat portion (i.e. a central plateau) 15 constituting the bottom of the recess, and on 93841 either side of this central flat portion, a wing, or flank, 16 having an inclined slope with respect to the central flat portion.

Each wing 16 is laterally restricted with respect to the width of the central flat portion 15 so that it can be inserted in the stator housing 9 between two stationary stator ramps 7 of the stationary part of stator 5. A planar zone 17, also laterally restricted, provides a connection between the central flat portion 15 and each wing 16.

Both ramps 7 functionally form the junction with the more or less enclosed wing 16 to ensure proper constant contact of all or part of the forward nose of the respective vane 1 (or at least of all or part of an edge portion of said nose) with the stator, when the vane 1 moves past, from the stationary stator portion 5, and over the enclosed sloping wing 16 to reach the restricted portion 17 and the central flat portion 15. The constant contact of said parts is made sometimes by means of one edge portion sometimes by the other, with an intermediate passage on a flat portion in the form of embodiment shown on the Figures 2 and 3, in which each vane is shown in an exemplfying form with a forward quadrangular nose and the movable stator portion 6 has two recesses 8 therein separated by a planar zone 18.

With reference to Figure 3, virtual lines L symbolically show mutual contact of the stator bottom surface with a vane having a forward quadrangular nose, between an edge portion of said nose and both stationary stator ramps 7, on the one hand, and then, on the other hand, between the same edge portion and a portion of the sloping wing 16 more or less enclosed, depending on the position of the movable stator element 6 in the stator housing 9. It may be noted that there is a relieving contacting line LR, commonly shared by both stator ramps 7 and the enclosed sloping wing 16. Both on the zone 18 and the restricted zone 17 and the central flat portion 15, the contact is no longer linear, but is rather made according to a surface S corresponding to the quadrangular forward nose surface of the vane.

According to a working variation schematically shown in Figure 1, low pressure BP and high pressure HP circuits pass through the stator, both in its stationary portion 5, by means of channels 19 therein and in its movable portion 6 by channels 20 therein, with the action of a vane 1 upon a fluid being shown by arrows FI and the rotor motive power by means of arrow F2. In - 5 53541 the active compression zone, the vanes are perfectly engaged with the stator bottom surface along the whole of their length.

Appropriate sealing means are provided on the lateral sides of the vanes for making them watertight.

Claims (7)

1. A rotary hydraulic device of variable capacity of the displacement pump type, having a coaxial stator and rotor and with vanes sliding axially in the rotor, the stator having at least one lower surface presenting fixed 5 planar zones and recesses, the said vanes following the said lower surface, the said recesses each being formed by axially movable elements presenting a central plateau forming the base of the recess, and on both sides of this central plateau a flank with an inclined slope relative to the central plateau, each flank being laterally recessed with respect to the width of the 10 central plateau and being located between two fixed ramps of the stator making the junction between the flank and the adjacent fixed planar zone.

2. A rotary hydraulic device according to Claim 1, wherein a control means is provided to act, as desired, in the standstill position and/or during the course of functioning, on the said movable elements of the stator and the 15 recesses and thus on the depth of the said recesses.

3. A rotary hydraulic device as claimed in Claim 1 or Claim 2, wherein a planar zone which is laterally restricted provides a connection between the central plateau and each flank.

4. A rotary hydraulic device according to any one of Claims 1 to 3 20 wherein the movable elements of the stator are hydraulically balanced.

5. A rotary hydraulic device according to any one of Claims 1 to 4 wherein low pressure and high pressure circuits pass through the stator both in its stationary position and in its movable portion through appropriate channels. 25 5. A rotary hydraulic device according to any one of Claims 1 to 5 wherein lateral sealing means are provided for the slidable vanes.

6.

7. A rotary hydraulic device substantially as hereinbefore described with reference to the accompanying drawings.