improved assembly structure for hydraulic machine steering yoke.

Abstract

An assembly comprising a hydraulic machine (10) and a steering yoke (200), the hydraulic machine (10) comprising a rotor and a stator movable in rotation relative to each other about an axis of rotation (XX) extending in an axial direction, the hydraulic machine (10) comprising a housing (100), the housing (100) defining a pivot axis (ZZ) distinct from the axis of rotation (XX), the steering yoke (200) being assembled onto the housing (100), characterized in that said steering yoke (200) is assembled onto the housing (100) via a plurality of assembly elements (320) extending in the axial direction. Figure for the abbreviation: Fig. 1.

Description

Title of the invention: Improved assembly structure for hydraulic machine steering yoke. Technical field

[0001] The present invention relates to hydraulic machines coupled to steering members, and presents an improved structure of such an assembly. Prior art

[0002] Hydraulic machines are commonly used for various applications, for example to drive the rotation of moving parts of vehicles or machines, in particular steering parts.

[0003] In the case where the hydraulic machine drives a steering organ, it is then necessary to couple the hydraulic machine to steering means in a reliable and robust manner, without penalizing the integration and assembly of the system.

[0004] The present invention thus aims to respond at least partially to these problems. Statement of the invention

[0005] Assembly comprising a hydraulic machine and a steering yoke, the hydraulic machine comprising a rotor and a stator movable in rotation relative to each other along an axis of rotation extending in an axial direction, the hydraulic machine comprising a casing, the casing defining a pivot axis distinct from the axis of rotation the steering yoke being assembled on the casing, characterized in that said steering yoke is assembled on the casing via a plurality of assembly elements extending in the axial direction.

[0006] According to one example, the steering yoke comprises a steering portion defining a steering axis parallel to the pivot axis.

[0007] According to one example, said assembly elements comprise a plurality of elements adapted to be screwed into the casing, the assembly comprising at least one centering element each having a first end inserted into a housing formed in the casing, and a second end inserted into a housing formed in the steering yoke.

[0008] According to one example, the centering elements are mounted constrained in the casing 100 and in the steering yoke.

[0009] According to one example, the centering elements have an external section strictly greater than a section of the housing formed in the casing and strictly greater than a section of the housing formed in the steering yoke.

[0010] According to one example, the assembly comprises two centering elements each having a first end inserted into a housing formed in the casing, and a second end inserted into a housing formed in the steering yoke.

[0011] According to one example, the hydraulic machine comprises a cam secured to the casing, the cam being secured to the casing by means of a plurality of fixing elements extending in the axial direction, the steering yoke comprising at least one drilling in the axial direction aligned with at least one of said fixing elements, said drilling having a section smaller than the maximum section of said fixing elements, in which the centering elements are positioned in line with the fixing elements.

[0012] According to one example, said centering elements have an annular shape with a central recess, each of said at least one drilling of the steering yoke being aligned with the central recess of a centering element.

[0013] According to one example, each of said at least one drilling of the steering yoke has a section strictly smaller than the section of the centering elements.

[0014] According to one example, the casing has two assembly zones adapted to receive a steering yoke, the steering yoke comprising a keying device adapted to allow the assembly of the steering yoke on a single assembly zone of the casing.

[0015] The present invention also relates to a method of assembling such an assembly, in which the steering yoke is positioned on the housing, and the steering yoke is assembled on the housing via a plurality of assembly elements extending in the axial direction of the hydraulic machine.

[0016] According to one example, prior to positioning the steering yoke on the housing, centering elements are inserted under stress into housings formed in one of the steering yoke and the housing, then the steering yoke is positioned on the housing by inserting the centering elements under stress into housings formed in the other of the steering yoke and the housing.

[0017] The present disclosure also relates to a method of disassembling an assembly as presented, in which the assembly elements are removed, then a tool is introduced into the assembly holes so as to unscrew the fixing elements of the casing until the centering elements are extracted from the housings formed in the casing.

[0018] Following said disassembly operation, the fastening elements are then typically tightened to a nominal tightening value, so as to ensure the assembly of the hydraulic machine. Brief description of the drawings

[0019] The invention and its advantages will be better understood upon reading the detailed description given below of different embodiments of the invention given as non-limiting examples.

[0020] [Fig-1] [Fig.l] shows a perspective view of an assembly according to one aspect of the invention.

[0021] [Fig.2] [Fig.2] represents a sectional view specifying the assembly of the whole.

[0022] [Fig.3] [Fig.3] shows another view showing the assembly of the whole.

[0023] Throughout the figures, the elements in common are identified by identical numerical references. Description of the embodiments

[0024] [Fig. 1] represents a perspective view of a portion of a hydraulic machine casing associated with a steering yoke. Figures 2 and 3 are views illustrating the assembly of the steering yoke on the casing.

[0025] The casing 100 is a hydraulic machine casing 10 adapted to drive in rotation a member such as a steering wheel of a vehicle or machine.

[0026] The casing 100 thus typically forms a first static assembly of a hydraulic machine relative to a second assembly mobile in rotation and comprising in particular a shaft and a cylinder block according to the well-known structure of a hydraulic machine.

[0027] We more generally define two axes: - an axis of rotation XX, corresponding to the relative axis of rotation of the shaft of the hydraulic machine with respect to the casing 100, and - a ZZ pivot axis, allowing the hydraulic machine and therefore the associated component, for example a steering wheel, to be oriented.

[0028] A fixing fork is typically coupled to the elements defining the pivot axis ZZ, so as to provide a mounting that is movable in rotation about this pivot axis ZZ. In a known manner, a rotating power supply is typically formed in this pivot.

[0029] The rotation axis XX and the pivot axis ZZ are distinct, and may for example be perpendicular or inclined at an angle of between 70° and 90° to each other. The rotation axis XX defines the axial direction of the hydraulic machine 10.

[0030] In order to control the orientation of the casing 100, and therefore of the hydraulic machine, the casing 100 is associated with a steering yoke 200. The steering yoke 200 is adapted to allow an actuator to be coupled to the casing 100 so as to control its rotation around the pivot axis ZZ.

[0031] In the illustrated example, the steering yoke 200 has a structure comprising a base 210 adapted to be fixed on the casing 100, and a control portion 220, adapted to be associated with an actuator.

[0032] In the example illustrated, the control portion 220 has the shape of a cylinder of revolution with a central through channel allowing, for example, a rod to be associated with it to define a control axis parallel to the pivot axis ZZ.

[0033] The base 210 is adapted to be fixed on the casing 100. The casing 100 thus has assembly zones, which are portions adapted to receive the base 210 of the steering yoke 200. In the example illustrated, the casing 100 has two portions forming two lugs 120A and 120B on either side of the pivot axis ZZ. The two lugs are typically symmetrical with respect to the pivot axis ZZ. The structure of one of these lugs is described below, the other lug therefore typically having an identical or similar structure. The lugs will therefore be referred to by the general designation 120, the different elements of each lug being, where appropriate, identified with the index A or B depending on the lug 120A or 120B considered.

[0034] Each ear 120 typically forms a flat base adapted to receive the base 210 of the steering yoke 200.

[0035] Each ear 120 also has a plurality of holes which are described below.

[0036] Each ear has cam holes 122, these cam holes 122 being adapted to allow the insertion of fixing elements 310 for example such as screws or bolts to assemble the casing 100 to a cam 300, typically a multi-lobe cam in the case of a radial piston hydraulic machine.

[0037] The fixing elements 310 typically have a rod and a head, the head being housed in the cam holes 122 so as not to protrude from the flat surface defined by the ear 120 in question, and therefore to be entirely housed in the cam holes 122.

[0038] The cam bores 122 are typically dimensioned so as to allow a centering element 30 to be inserted into each cam bore 122, which then overcomes the head of the fastening element 310 in question. The centering element 30 is typically a hollow tubular element, having an external diameter substantially equal to the internal diameter of the cam bore 122 so as to be able to be inserted into said cam bore 122. The centering element 30 is for example a socket; it typically has a central through-recess dimensioned so as to allow a tool to be inserted through the centering element 30 to engage or disengage the fastening element 310.

[0039] The base 210 then typically has centering holes 212, adapted to receive the centering elements 30. The centering holes 212 typically have a dimension greater than or equal to the dimension of the centering elements. 30, and are sized so that the centering elements 30 are fully seated in the centering bores 212 and the cam bores 122 when the steering yoke 200 is assembled on the housing 100. In the example illustrated, two centering elements 30 are employed.

[0040] The centering elements 30 are typically mounted tightly in the steering yoke 200 and in the casing 100, that is to say that there is an interference between the external diameter of the centering elements 30 and their housing formed in the steering yoke 200 and in the casing 100. The centering elements 30 then contract by elastic deformation. In this way, isostatic positioning without play of the steering yoke 200 on the casing 100 is guaranteed. The centering elements 30 also make it possible to transmit forces parallel to the support plane between the steering yoke 200 and the casing 100 during use of the hydraulic machine, that is to say for sliding forces between the steering yoke 200 and the casing 100.

[0041] Such a structure thus makes it possible to center and temporarily hold the steering yoke 200 in position on the casing 100. The centering holes 212 as proposed are typically through-holes. Thus, the head of the fixing elements 310 can be accessed when the steering yoke 200 is assembled on the casing 100.

[0042] The centering holes 212 of the base 210 typically have two distinct sections; a first section adapted to receive the centering element 30, and a second section strictly smaller than the first section to allow the passage of a tool. The second section typically has a section equal or substantially equal to the section of the central through-recess of the centering element 30. The through-section of the second section of the centering hole 212 as well as the section of the central through-recess of the centering element 30 typically correspond to the section required for the passage of an imprint allowing the head of the fixing element 310 to be turned with a tool, for example a hollow hexagonal imprint.

[0043] Such a structure makes it possible in particular to use the fixing elements 310 to separate the steering yoke 200 from the casing 100. It is then possible to insert a tool via the centering holes 212 to unscrew the fixing elements 310, which will then push the steering yoke 200 due to the second section of the centering holes 212 of smaller diameter against which the fixing elements 310 and the centering elements 30 then come into abutment. Such a functionality is particularly advantageous when the centering elements 30 are force-fitted into the housings thus formed in the casing 100 and in the steering yoke 200.

[0044] After using the fixing elements 310 to extract the steering yoke 200 or the centering elements 30, if the machine is to be kept assembled, the fasteners 310 are typically tightened to the prescribed torque, because these fasteners 310 participate in the assembly of the structure of the hydraulic machine.

[0045] The base 210 has a plurality of assembly holes 230 passing through for the passage of assembly elements 320, for example such as screws or bolts. The ears 120 of the casing 100 have assembly holes 130 arranged in a configuration identical to the assembly holes 230 of the base 210, so that when the steering yoke 200 is positioned bearing against the casing 100 in an assembly position, the assembly holes 230 of the base 210 and the assembly holes 130 of the casing 100 are aligned.

[0046] The assembly position typically corresponds to a position in which the centering elements 30 are interposed between the steering yoke 200 and the casing 100 and thus perform a centering function as described above. More specifically, the assembly position corresponds to the configuration in which each centering element 30 is partially inserted both into the steering yoke 200 and into the casing 100 and thus performs a function of centering and holding the steering yoke 200 in position relative to the casing 100 prior to assembly by means of assembly elements. Furthermore, depending on its structure, the centering element 30 may also perform a function of reinforcing the connection between the casing 100 and the steering yoke 200, in particular by preventing shear forces from being applied to the fixing elements 310.

[0047] The assembly holes 230 of the base 210 and the assembly holes 130 of the casing 100 thus allow the passage of assembly elements 320 to assemble the steering yoke 200 on the casing 100.

[0048] The assembly holes 130 of the casing 100 thus typically have a thread 132 with which a thread of the associated assembly element 320 will cooperate.

[0049] The assembly holes 230 of the base 210 typically have two portions having distinct sections; a rod section 232 and a head section 234 having a section strictly greater than the rod section, the change in section forming a shoulder in the assembly holes 230 of the base 210. The assembly elements 320 typically have a rod and a head, the head having a section strictly greater than the rod. Thus, when an assembly element 320 is inserted into the assembly holes 230 of the base 210 and the assembly holes 130 of the casing 100, the head of the assembly element 320 bears against the shoulder formed in the assembly holes 230 of the base 210, which ensures that the steering yoke 200 is held on the casing 100.

[0050] The assembly as presented thus comprises two types of drilling; the drillings of centering and assembly holes, which allow respectively centering and temporary holding in position of the steering yoke on the housing, then its assembly.

[0051] In the assembly as proposed, the different holes are formed so as to be parallel to the axis of rotation XX.

[0052] The various centering holes and the assembly holes as proposed all open onto the same face of the ear 120 considered of the casing 100. Thus, the assembly means 320 and the fixing elements 310 are all inserted from the same side of the casing 100.

[0053] Such a structure thus makes it possible to simplify the assembly of the steering yoke 100 on the casing 200 insofar as the assembly is carried out in the same axial direction, unlike known structures in which assemblies in multiple directions are necessary.

[0054] Depending on the desired structure, the steering yoke 200 may be a single model that can be mounted on either of the lugs 120A and 120B, or have a specific shape to be mounted only on one of the lugs 120A and 120B. In such a case, the steering yoke 200 may include a keying device, adapted to allow the assembly of the steering yoke 200 only on one or the other of the lugs 120A and 120B. In the example illustrated, the steering yoke 200 comprises a lug 240 forming a key, and adapted to come into abutment against an element of the casing 100 when the steering yoke is mounted on the wrong ear 120, so that the different orifices of the steering yoke 200 and of the casing 100 cannot then be aligned, which prevents the mounting of the steering yoke 200 and on the casing 100.

[0055] The invention as proposed thus makes it possible to optimize and simplify the assembly of the steering yoke 200 on the casing 100.

[0056] Although the present invention has been described with reference to specific exemplary embodiments, it is obvious that modifications and changes may be made to these examples without departing from the general scope of the invention as defined by the claims. In particular, individual features of the various illustrated / mentioned embodiments may be combined in additional embodiments. Therefore, the description and drawings should be considered in an illustrative rather than restrictive sense.

[0057] It is also obvious that all the characteristics described with reference to a method are transposable, alone or in combination, to a device, and conversely, all the characteristics described with reference to a device are transposable, alone or in combination, to a method.

Claims

Claims

1. Assembly comprising a hydraulic machine (10) and a steering yoke (200), the hydraulic machine (10) comprising a rotor and a stator movable in rotation relative to each other along an axis of rotation (XX) extending in an axial direction, the hydraulic machine (10) comprising a casing (100), the casing (100) defining a pivot axis (ZZ) distinct from the axis of rotation (XX) the steering yoke (200) being assembled on the casing (100), characterized in that said steering yoke (200) is assembled on the casing (100) via a plurality of assembly elements (320) extending in the axial direction, parallel to the axis of rotation (XX).

2. An assembly according to claim 1, wherein the steering yoke (200) comprises a steering portion (220) defining a steering axis parallel to the pivot axis (ZZ).

3. Assembly according to one of claims 1 or 2, in which said assembly elements (320) comprise a plurality of elements adapted to be screwed into the casing, the assembly comprising at least one centering element (30) each having a first end inserted into a housing formed in the casing (100), and a second end inserted into a housing formed in the steering yoke (200).

4. Assembly according to claim 3, in which the centering elements (30) are mounted constrained in the casing (100) and in the steering yoke (200).

5. Assembly according to claim 4, in which the centering elements (30) have an external section strictly greater than a section of the housing formed in the casing (100) and strictly greater than a section of the housing formed in the steering yoke (200).

6. Assembly according to one of claims 3 to 5, comprising two centering elements (30) each having a first end inserted into a housing formed in the casing (100), and a second end inserted into a housing formed in the steering yoke (200).

7. Assembly according to one of claims 3 to 6, in which the hydraulic machine (10) comprises a cam (300) secured to the casing (100), the cam (300) being secured to the casing (100) by means of a plurality of fixing elements (310) extending in the axial direction, the steering yoke (200) comprising at least one bore (212) in the axial direction aligned with at least one of said fixing elements (310), said bore (212) having a section smaller than the maximum section of said fixing elements (310), in which the centering elements (30) are positioned in the extension of the fixing elements (310).

8. An assembly according to claim 7, wherein said centering elements (30) have an annular shape with a central recess, each of said at least one bore (212) of the steering yoke (200) being aligned with the central recess of a centering element (30).

9. Assembly according to claim 8, in which each of said at least one bore (212) of the steering yoke (200) has a section strictly smaller than the section of the centering elements (30).

10. Assembly according to one of claims 1 to 9, in which the casing (100) has two assembly zones (120A, 120B) adapted to receive a steering yoke (200), the steering yoke (200) comprising a keying device (240) adapted to allow the assembly of the steering yoke (200) on a single assembly zone (120A, 120B) of the casing (100).

11. Method of assembling an assembly according to claim 1, in which the steering yoke (200) is positioned on the casing (100), and the steering yoke (200) is assembled on the casing (100) via a plurality of assembly elements (320) extending in the axial direction of the hydraulic machine.

12. An assembly method according to claim 11, wherein prior to positioning the steering yoke (200) on the casing (100), centering elements (30) are inserted under stress into housings formed in one of the steering yoke (200) and the casing (100), then the steering yoke (200) is positioned on the casing (100) by inserting the centering elements (30) under stress into housings formed in the other of the steering yoke (200) and the casing (100).

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