GB2274882A

GB2274882A - Connecting hydraulic components

Info

Publication number: GB2274882A
Application number: GB9402299A
Authority: GB
Inventors: Ruoff Carlo; Gruener Harald
Original assignee: Vickers Systems GmbH
Current assignee: Vickers Systems GmbH
Priority date: 1993-02-06
Filing date: 1994-02-07
Publication date: 1994-08-10
Anticipated expiration: 2014-02-07
Also published as: DE4303465A1; GB9402299D0; GB2274882B; JPH07113404A

Description

2274882 HYDRAULIC ASSM2LY The present invention relates to a hydraulic

assembly comprised of at least two components in fluid communicatJon wit.h one another and, more particularly, to a hydraulic assembly which comprises, for example, a servocentroller or pilot component and a main stage or power component controlled by the servocantroller. The invention especially relates to an assembly of such components in which each component has at least one mounting surface at which the respective hydraulic medium passages open at respective mouths or orifices so that fluid communication between the components is effected by communication between orifices of corresponding passages open at mounting surfaces which are in contact with one another.

Hydraulic assemblies utilizing a combination of at least one servocontrol or pilot stag& and at least one main stage can have the fa= of distributing valve or the like which can be connected to a pump supplying the hydraulic medium and to a sink or drain for the hydraulic medium such as a reservoir.

Such units can have main stages which themselves are piston and cylinder units for controlling valve elements which 2 respond to the pilot or servoelement. The main unit can, in addition or alternatively, be used to displace the swaSh plate or control plate of an axial piston pump or =otor or some other hydraulic unit.

it is common practice to connect the control c=ponents such as the pilot valve component and the main stage at resDective mounting surfaces so that the massages of the two units can communicate with one another. For this purpose, the hydraulic channels or passages can have mouths or orifices opening at the respective mounting surfaces.

The orifices or mouths of the hydraulic passages are commonly so arranged that they register fully and flush with one another where they are intended to communicate at the interface formed between two abutting surfaces.

When the components were of different sizes so that the mouths of the passages dif!ered, it has hitherto been the practice to so select the components to be connected that the full registry of the mouths and orifices could be ensured.

As a consequence, the components of such assemblies had to be especially designed to conform to one another with respect to the sizes and orientation of the orifices opening at the abutting surfaces to ensure the requisite fluid communication. As a consequence, if one desired to change the size of one of the components, either the pilot or servocomponent or the main stage component, one had to select from stock a correspondingly dimensioned other component. That, of course, required stocking a wide variety of both types of co=m.cnents at relatIvely high cost. The inventory cc=. lexities were thereby also J ncreased and, as a rule, the selection Of precisely match-4,-g c=ponents to be assembled has been a significant problem.

it is the pri4nc-.;-zal object of the present invention to provide an improved hydraulic assembly, especially of a pilot or servocomponent and a main stage component which are to be in hydraulic communication with one another, whereby the disadvantages of earlier systems are obviated.

Another object of this invention is to provide a simplified hydraulic system including a servo or pilot stage and a main stage which can reduce significantly the inventory of matching components which are required for effective assembly of two such components into a particular hydraulic controlled unit.

it is yet another object of the invention to provide an improved hydraulic assembly in which the hydraulic components can have different sizes without detriment to mutual functioning of the two stages of the assembly.

These objects and others which will become apparent hereinafter can be attained, In accordance with the present invention in a hydraulic assembly of the type described,!.a. having two components in fluid co=unicat-,on with one another and especially a servo or pilot stage and a main stage controlled by the servo or pilot stage, where the two stages have =ount-4ng surfaces at which respective hydraulic passages open and wherein, to fo= the assembly, the orifices of two bodies of the components open and yet overlap at least in part such that for one cc=monent, all members of a set of the other components can be interchangeable with the corresponding passages opening at the resmective surface so that in all cases there is at least partial overlap of the orifices or mouths of the components.

As a consequence, to form an assembly of components of different sizes, the mouths of the hydraulic passages are so arranged at at least one of the mounting surfaces that in the assembled state of two components or upon contact and juxtaposition of two mounting surfaces, even with the use of components of'different sizes, there will always be at least local overlap of the respective mouths so that corresponding passages can cc=urUcata with one another.

Thus, It a first of the components of a given size has its mounting surface so formed that the mouths or orifices of the hydraulic passages are positioned correspondingly to the orifices of the second component, i. e. in a similar pattern to the orifices of the second component and the size relationship is such that the positions of these orifices do not correspond exactly to the positions of the orifices of the second component, nevertheless there is communication between the corresponding passages which may be laterally offset fro= one another at the interface between the abuz---4ng surfaces because cl the local overlap.

In spite of the -4.-,--ercha,-,ae cf -ne cc=pcnent fcr another of the respective set, therefcre, there will always be at least a partial overlap of the passages at the interface for=ed between the assembled =ounting surfaces.

In this manner, two components of different sizes can be combined to form the assembly while nevertheless assuring that the corresponding hydraulic passages will be in fluid communication with one another. With the invention, moreover, it is not necessary that there be precise matching of the size, namely, the center-to-center spacing of the orifices or of the areas mounting surfaces.

It has been found to be especially preferable witt the present invention to provide between the two components provided with the pilot or servostage elements and the main stage elements, respectively, an intermediate element or component which is thus interposed between the first and second component.

This intermediate component has at least two mounting surfaces. one of which abuts the mounting surface of the first component and another of which abuts the mounting surface of the second component. Throughgoing passages are formed in the intermediate element and open at mouths or orifices at the opposite mounting surfaces.

The mouths or orifices of the passages are so arranged in the mounting surfaces of the intermediate element that even with major differences in the sizes of the two co=Donents and between the two components and the -4nte=adiate element there is always a partial overlap of the cr-4-'-4--es or mouths of the passages at the two interfaces so that corresponding passages of all three bodies communicate with one another without exact alignment of those passages and their respective orifices. it is thus no longer necessary to have precisely matched sizes of-the components and the adapter fo=ed by the intermediate element.

Because the mouths or orifices of the intermediate element are offset at the opposite mounting surfaces of the intermediate element, significantly different sizes and patterns of the orifices of two hydraulic components can be interconnected.

The hydraulic assembly of the invention can thus co=prize:

a first hydraulic component having a first body formed with at least one first mounting surface, a plurality of hydraulic passages formed in the first body and opening at respective orifices at the surface with a predetermined centerto-center spacing of the orifices in a predetermined pattern, and working means on the body for operating with a hydraulic medium flowing through the passages; a second hydraulic component having a second body formed with a second mounting surface parallel to and juxtaposed with the first mounting surface, a plurality of hydraulic passages formed in the second body and opening at respective 7 orifices at the second mounting surface, and working means on the second body for cperat-4ng with a."lydrau!-Jc =edia= flowing --h-cugt the passages of the second body, at least one of the Components being one of a set of -Interchangeable cc=ponents with the orifices located on the respective mounting surface in the same pattern but with different center- to-center spacings; and means for connecting the bodies together so t.hat corresponding passages of the bodies cc---,jn.4--ate with one another, the orifices being so positioned and dimensioned that, in an interconnected state of the bodies and for all of the components of the set, there is at least partial overlap between orifices opening at respective mounting surfaces directly contacting one another.

Preferably one of the working means is a hydraulic servocontroller and the cl-,tar of the working means is a main hydraulic stage controlled by tha servocontroller, at least one of tha passages of at least one of the co=ponents being connected to a pump, at least another of the passages of the one of the components being connected to a sink for the medium.

According to a feature of the invention, the second component comprises an intermediate element formed by the second body and having on the mounting surface in contact wit2i the mounting surface of the first body and another the mounting surface in contact with a mounting surface of a third body, the intermediate element having throughgoing passages between the surfaces thereof opening at respective ones of the orifices at the respective mounting surfaces, the third body being for=ed with the mounting surface of the third body parallel to and juxtaposed with the first =ounting surface and the mounting surfaces of the intermediate element, a plurality of hydraulic passages formed in the third body and opening at respective orifices at the mounting surface of the third body, and the working means of the second component, the means for connecting holding all of the bodies together.

The first and second bodies can be connected together by the means for connecting so that the mounting surfaces of the first and second bodies are in direct contact with one another in an alternative to the embodiment previously described.

With respect to both embodiments, the bodies can be generally of rectangular parallelepipedal shape with the rectangular mounting surfaces being planar and parallel to one another.

in general the pilot stage is a pilot valve while the main control stage is controlled by the pilot valve and itself can be a piston-type distributing valve, a cartridge valve or a controller for a variable displacement pump. Cartridge valves are generally parts of control units, for example, for a press, an injection molding machine or the like. The variable displacement pump can also be used for a press, Injection molding machine or similar hydraulic unit.

The above and other objects, features, and advantages will become more readily apparent from the following description, reference being made to the accompanying drawing in which:

FIG. 1 is a schematic perspective elevat-4onal view illustrating a first embodiment of a hydraulic assembly according to the invention; FIG. 2 is a perspective view similar to FIG. 1 showing a second embodiment of the hydraulic assembly; FIG. 3 is a plan view of one of the mounting surfaces; FIG. 4 is a diagrammatic section showing the connection between a pilot component and a main component in the embodiment of FIG. 1; FIG. 5 is a detail section illustrating the use of an 0-ring seal; FIG. 6 is a section similar to FIG. 4 but wherein the second component has been replaced by one of a larger size and the same general pattern of orifice layout but different canterto-canter spacing; and FIG. 7 is a view similar to FIG. 6 but illustrating the embodiment of FIG. 2.

The tar= nhydraulic assembly is used hare to describe any combination of hydraulic components in which the working elements of one are dependent upon the working elements of another, as in the case of a pilot or servocontroller stage and a main stage which responds to the servocontroller. Particularly it is intended to refer to a distributing valve system which can be utilized to control, in turn, other hydraulic means. The unit may be a distributing valve for the piloting of valve units which are built into other apparatus or larger distributing valve stages or directly as servacontrollers for pumps and the like, i.e. for controlling a hydraulic follower of the swash plate of an axial piston pump. In that case, the main stage may be the hydraulic effector for the pump itself. The working elements of the servocontrol and main s tages have not been shown in FIGS. 1-3 and they are assumed to be built into the hydraulic bodies there shown in block form.

By way of example, the working elements can include a servo or pilot valve 50, e.g. of the spocl valve type, receiving an input at 51 which may be manual or may be a feedback from a load. The servovalve built into the first hydraulic component 10 may be connected, in turn, to a pump 52 supplying the hydraulic medium and to a hydraulic sink or reservoir 53. The main unit of the second hydraulic component 20 can be a piston and cylinder arrangement 54 whose cylinder 55 receives the piston 56 which can be displaced to follow the movement of the servovalve and can control a load 57 which may be, for example, a variable displacement pump farming part of a hydraulic system controlled by the assembly of the present invention.

FIG. 1 shows a first hydraulic assembly 1 which is comprised of a first hydraulic component 10 and a second hydraulic component 20. The first component 10 is for=ed with a rectangular mounting surface 11 while the second hydraulic component 20, has a rectangular mounting surface 21. The surfaces 11 and 21 are shown to be slightly spaced fro= one another in FIG. 1 but will be understood to bear against one another and can be matched in size and orientation. The two components are interconnected with one another by, for example, bolts represented by the axes 58 and 59 and which can pass through bares formed in the bodies constituting the components 10 and 20, respectively and described in greater detail with reference to FIG. 3. The bolts 58 and 59 can constitute the =cans for connecting.

The two components 10 and 20 bear against one another at the flat and mutually parallel surfaces 11 and 21. If desired, seals can he provided between the two components. For example, In FIG. 5 it will be apparent that the body f o=ing the component 10 and the body forming the component 20 bear against one another at the interface 59 at which the passages 10A and 20A open at respective orifices 60 and 61. The orif Ice 60 may be recessed at 62 to receive an 0-ring 63 representing appropriate seals which can be interposed between the components.

As has been alluded to in connection with FIG. 5, therefore, in the mounting surfaces 11 and 21 hydraulic passages of the components 10 and 20 open at mouths or orifices so 1 p arranged that corresponding hydraulic passages of the two comconents are in fluid connection at the respective interface. This ensures that the first component 10 which is formed, for example, has a pilot or servocontrol opening, and can be connected to the second hydraulic component which is a main stage controlled by the first component in the manner described in connection with FIG. 4.

In the embodiment of FIG. 1, the hydraulic components 10 and 20 are each provided with one such mounting surface 11 or 21 which can directly abut the other. It is also possible, however, to provide the or each component with a plurality of mounting surfaces which can be selectively oriented to abut at least one surface of the other component or mounting surfaces of a plurality of components, the connecting means being then provided to hold all of the juxtaposed mounting surfaces in abutting relationship. The plurality of mounting surfaces will then be designed to effect communication between the respective orifices or mouths of the respective passage. Preferably, however, each of the hydraulic components has only one such mounting surface.

FIG. 2 shows an embodiment of the invention in which the assembly 1 In formed from three hydraulic components. In this case, between a first hydraulic component 10 and a second hydraulic component 20, a third component or intermediate element 30 is provided. The intermediate element 30 has a first mounting surface 31 juxtaposed with the mounting surface 11 of the first hydraulic component 10 and a second mounting surface 33 juxtaposed with the mounting surface 21 of the second hydraulic component 20. The spatial configuration of these components, as was the case for the embodiment of FIG. 1, can be freely selectable.

in the first mounting surface 31 of the intermediate element 30, hydraulic passages open which extend through the intermediate element 30 and also open at the second mounting surface 33 of this element. The arrangement of the mouths or orifices of the hydraulic passages of the intermediate element 30 Is so selected that the orifices of this element at least in part overlap the orifices of the mounting surfaces 11 and 21 of the hydraulic components 10 and 20. In this manner, fluid communication. is effected not only between the first hydraulic component 10 and the intermediate element 30 and between the hydraulic component 20. and the intermediate element 30, but also between the first component as a pilot or servocontrol stage and the second component 20 as a main stage of the hydraulic assembly 1.

F10.3 shows in plan view one possible configuration of a mounting surface 40 which can correspond to any of the mounting surfaces described. At the face 41 of this mounting surface, four hydraulic passages open as Is represented by A, 3, T and P. The hydraulic passage A and the hydraulic passage 3 are connected to the main stage. The hydraulic passage T can be connected to a 14 hydraulic sink, for example, the reservoir or tank. The passage p can be connected to a pump.

At the corners of an imaginary rectangle, threaded bores 43 open at the face 41 and at the corners of a larger rectangle, threaded bores 45 open, the threaded bores 43 lying inwardly of the bores 45.

Additional openings or bores can be provided in this surface to receive aligning pin or the pins can be provided to project from the surface as may be desired. With the aid of such aligning pins and with the bolts 58 and 59 which can be threaded into the bores 43 or 45, the passages A, T, 3, P which communicate with on another of the two hydraulic components can be positioned for such communication.

The different distances between the threaded bores 43 and the bores 45 are so selected that the threaded holes will line up with the bores of hydraulic components of different sizes,!.a. so that differently sized mounting surfaces can abut the surface 40 and the two components are thus connected by a bolt or screw. This enables a hydraulic component to be affixed to the mounting surface 40.

The mounting surface 40 can form the mounting surface 21 of the second ydraulic component 20, thereby constituting a hydraulic device as shown in FIG. 1. It can, however, he part of an intermediate element in which case the mounting surface can be one of the surfaces 10, 31, 33 or 21 of the hydraulic assembly visible in FIG. 2.

When two components of the hitherto conventional construction are so connected at mounting surfaces, it has been essential to ensure that the mouths or orifices of these surfaces align and register precisely so that. "he walls of the passages are flush with one another at the surfaces.

if hydraulic cc=m-onents of different size are brought together utilizing the conventional systems, there is no overlap of the orifices of the hydraulic passages and thus no fluid communication between the components of the hydraulic assembly.

With the configuration of the present invention, the orifices or mouths of the hydraulic passages of the components shown in FIG. 1 can be disposed in similar patterns but have different canter-to-center spacing. As a consequence, the orifices of the second component 20 need not line up precisely with the orifices of the first component 10 as long as the orifices of corresponding passages overlap. It will thus be apparent that for any component 10, a component 20 may be selected from a sat of such components of different sizes as long as the orifices at the abutting mounting surfaces overlap. From a cantering point of view, therefore, the communicating orifices are offset and there is at least a partial overlap to effect hydraulic communication.

This can best be seen from a comparison of FIGS. 4 and 6. In FIG. 4, the orifices for the passages 10A and 10B of the body 10 have canter-tocenter spacing which does not correspond to the canter-to-center spacing of the orifices 10A and 20B of 16 the body 20, but the corresponding orifices for the passages A and B, therefore, partly overlap.

In FIG. 6, the first component 10 is used with a second commonent 201 of larger size and a greater center-to-center spacing of the orifices of the passages 20A1, 20BI but, since the pattern or layout of the orifices is the same for the set of components 20, 201, etc., there still is at least partial overlap (FIG. 6) so that the corresponding passages A and B maintain communication.

In principle it is not significant which of the components has the centerto-center spacing of its orifices opening at the respective surface 11 or 29 changing fro= member to member of the set. In either case it is only necessary to inventory a full set of sizes of one of the two components.

In the embodiment of FIG. 2 (sec also FIG. 7) a first hydraulic component 10 and a second hydraulic component 20 can be connected without any size matching of the components or their respective mounting surfaces. In this cast, as can be scan fro= FIG. 7, the otifices of the passages 10A and 103 and the passages 20An and 20W of the second component could not overlap and communicate with one another if their respective mounting surfaces 11 and 210 war brought into contact.

in this case, the inte=adiata element 30 has mounting surfaces 31 and 33 at which the corresponding passages 30A and 303 open at respective critic which are offset from one another on opposite sides of the intermediate component and hence the 17 orifices at the surfaces 31 and 33 can overlap the corresponding orifices at the surfaces 11 and 21". As a consequence, there is cc=unication between the passages A and B of the assembled cc=onents. The same applies to the passages T and P which are not visible in FIGS. 4-7.

It will be apparent, therefore, -%hat, with the aid of the intermediate element 20, two hydraulic components 10 and 20 of a hydraulic assembly can be connected even when there is a considerable difference in size between the components. The intermediate element 30 thus functions somewhat as an adapter to connect two components of different sizes.

With the aid of the intermediate element 30 it is possible to connect two hydraulic components 10 and 20 with one another which differ by more than the order of size. in this cast the partial overlap can be effected even where the orifices of the two components are laid out with different patterns.

it has been found that the passages in the intermediate element need not be perpendicular to the mounting surfaces 31 and 33, but rather can be inclined thereto as shown. However, one or more of the bores in the intermediate element 3 0 may also be perpendicular to the mounting surfaces 31 and 33 when the cost of the assembly Is to be reduced.

As a general matter It will be noted that the hydraulic components need not be matched In size as long as, for exa=ple, the orifices of the passages of the first component opening at the mounted surface 11 at least partially overlap the orifices 18 with which they communicate to cm=Plett the hydraulic connection. No direct size matching is required with the second hydraulic comp- onent forming the main stage of the assembly.

t 1. A hydraulic assembly compr4sing:

a first hydraulic component having a first body formed with at least one first mounting surface, a plurality of hydraulic passages formed in said first body and opening at respective orifices at said surface with a predetermined canterto-center spacing of said orifices, and working means on said body for operating with a hydraulic medium flowing through said passages; a second hydraulic component having a second body formed with a second mounting surface parallel to and juxtaposed with said first mounting surface, a plurality of hydraulic passages formed in said second body and opening at respective orifices at said second mounting surface, and working =cans on said second body ior operating with a hydraulic mad!= flowing through said passages of said second body, at least one of said components being on of a sat of interchangeable components with the orifices located on the respective mounting surface but with different canter-to-center spacings; and =cans for connecting said bodies together so that corresponding passages of said bodies co==icatt with on another, said orifices being so positioned and dizensioned that, in an interconnected state of said bodies and for all of the components of said set, there Is at least partial overlap between orifices opening at respective mounting - surfaces directly contacting one another.

2. The hydraulic assembly defined in claim 1 wherein one of said working means is a hydraulic servocontroller and tha other of said working means is a main hydraulic stage controlled by said servocontroller, at least one of the passages of at least one of said commonents being connected to a pump, at least another of said passages of said one of said components being connected to a sink for said mediuz.

3. The hydraulic assembly defined in claim 2 wherein said second component comprises an intermediate element formed by said second body and having one said mounting surface in contact with said mounting surface of said first body and another said mounting surface in contact with a mounting surface of a third body, said intermediate element having throughgoing passages between said surfaces thereof opening at respective ones of said orifices at the respective mounting surfaces, said third body being formed with the mounting surface of the third body parallel to and juxtaposed with said first mounting surface and said mounting surfaces of said intermediate element, a plurality of hydraulic passages formed in said third body and opening at respective orifices at said mounting surface of said third body, and said working means of said second component, said means f or connecting holding all of said bodies together.

4. The hydraulic assembly defined in claim 3 wherein the orifices of said passages in said intermediate element at said mounting surfaces of said intermediate element are offset from one another so that said passages in said intermediate element are inclined to the mounting surfaces thereof.

5. The hydraulic ass ly defined in claim 2 wherein said first and second bodies are connected together by said =cans for connecting with the mounting surfaces of the first and second bodies in direct contact with one another.

6. The hydraulic assembly defined in claim 2 wherein said bodies are of generally rectangular parallelepipadal shape.

7. The hydraulic assly defined in claim 2 wherein said mounting surfaces are planar and parallel to on& another.

8. The hydraulic assembly defined in claim 2 wherein said mounting surfaces are rectangular.

9. The hydraulic assembly defined in claim 1 wherein said second componentcomprises an intermediate element formed by said second body and having one said mounting surface in contact with said mounting surface of said first body and another said mounting surface in contact with a mounting surface of a third body, said intermediate element having throughgoing passages between said surfaces thereof opening at respective ones of said orifices at the respective mounting surfaces, said third body being formed with the mounting surface of the third body parallel to and juxtaposed with said first mounting surface and said mounting surfaces of said intermediate clamant, a plurality of hydraulic passages formed in said third body and opening at respective orifices at said mounting surface of said third body, and said working means of said second component, said means for connecting holding all of said bodies together.

10. The hydraulic assembly defined in claiz 9 wherein the orifices of said passages In said Intermediate clamant at said mounting surfaces of said Intermediate clamant are offset fro:a one another so that said passages In said intermediate element are inclined to the mounting surfaces thereof.

23 11. The hydraulic assembly defined in claim 1 wherein said fl=st and second bodies are connected together by said means for cc.-nect-4r.g with the -,iount--na surfaces of the first and second bodies in direct contact with one another.

12. The hydraulic assembly defined in claim 1 wherein said bodies are of generally rectangular parallelepipedal shape.

13. The hydraulic assembly defined in claim 1 wherein said mounting surfaces are planar and parallel to one another.

14. The.hydraulic assembly defined in claim 1 wherein said mounting surfaces are rectangular.

15. The hydraulic assembly substantially as herein described with reference to any one of the embodiments an shown in the accompanying drawings.