FR3066789A1 - HYDRAULIC APPARATUS COMPRISING AN IMPROVED DISTRIBUTOR - Google Patents

Abstract

A distributor (40) for a hydraulic apparatus, comprising a core (50) and a timing ring (60), the core (50) having a plurality of internal grooves (50A, 50B), the timing ring (60) having a plurality of grooves external (60A, 60B) said internal (50A, 50B) and external (60A, 60B) grooves being configured to be fluidly communicating and form fluid flow conduits, the core (50) including a plurality of segments; seal (52) configured to isolate said fluid flow conduits, the core (50) having an outer section decreasing from a distal end (50D) to a proximal end (50P), the dispenser (40) being characterized in that that the distribution ring (60) comprises a stop (65) configured to limit the movement of the core (50) relative to the distribution ring (60) in a direction defined by the axis (A).

Description

FIELD OF THE INVENTION

The present presentation relates to hydraulic machines, and more precisely distributors for hydraulic machines.

STATE OF THE PRIOR ART

Several applications are known for hydraulic machines arranged on vehicle axle stub axles, in particular for driving the vehicle wheels.

During the assembly of the hydraulic machine, a recurring problem arises for the assembly of the distributor. Indeed, the operator must then handle the dispenser comprising a core and a dispensing ring in order to position it. However, there is then a risk of sliding of the core in the distribution crown which can cause a fall of the sealing segments.

Indeed, the different forms and conduits layouts arranged in the core and in the distribution ring allow a relative movement of the internal distributor relative to the distribution ring which can lead to the fall of sealing elements.

The present presentation thus aims to respond at least partially to this problem.

PRESENTATION OF THE INVENTION

To this end, the present disclosure relates to a distributor for a hydraulic device, comprising a core and a distribution crown mounted rotating around the core along an axis defining a proximal end and a distal end, the distribution crown and the core being slidably mounted relative to each other along the axis, the core having a plurality of internal grooves opening into an external periphery of the core, the distribution ring having a plurality of external grooves opening into an internal periphery of the ring distribution, said internal and external grooves being configured to be placed in fluid communication and to form fluid circulation conduits, the core comprising a plurality of sealing segments configured so as to isolate each of said fluid circulation conduits from each other core with decreasing outer section from one end distal to a proximal end, the dispenser being characterized in that it comprises a stopper configured so as to limit the displacement of the core relative to the dispensing ring in a direction defined by the axis.

According to one example, said stopper is configured so as to limit the displacement along the axis of the core with respect to the distribution ring, from the distal end towards the proximal end.

Said stopper is then typically integral with the distribution ring, and is configured so as to come into contact with a wall of the core.

Alternatively, said stopper is integral with the core, and is configured so as to come into contact with a wall of the distribution ring.

According to one example, the distal end of the core is configured so as to be able to slide beyond the proximal end of the distribution ring, the stop being configured so that the portion of the core which can slide at beyond the proximal end of the distribution ring has a dimension measured along the axis strictly less than the distance between the proximal end of the core and the sealing segment closest to the proximal end of the core. The present description also relates to a hydraulic device with radial pistons and multi-lobe cam, comprising a distributor as defined above, in which there is a non-zero clearance along the axis between the stop of the distributor and a surface of the core arranged in stopper look.

The present description also relates to a method of assembling a hydraulic device on a wheel spindle, in which a first set of components of the hydraulic device is positioned around an axis of the wheel spindle, a distributor is supplied as defined above, the distributor is positioned in abutment against components of the first set of components, so as to define a non-zero clearance along an axis of the wheel stub between the distributor stop and a surface of the core disposed opposite the stop, the core is secured to a component of the first set of components, a second set of components of the hydraulic device is positioned, so as to define an internal volume of casing in which the distributor is positioned.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention and its advantages will be better understood on reading the detailed description given below of different embodiments of the invention given by way of non-limiting examples. This description refers to the pages of appended figures, in which: - Figure 1 shows an overview of a hydraulic machine comprising a distributor according to one aspect of the invention, - Figures 2, 3 and 4 are views detailed embodiments of the dispenser, - Figures 5 to 9 are alternative embodiments of the dispenser.

In all of the figures, the elements in common are identified by identical reference numbers.

DETAILED DESCRIPTION OF EXAMPLES OF EMBODIMENT

Figure 1 shows a hydraulic system comprising a housing 10 in which is disposed a hydraulic device 12, a shaft 14 engaged in the housing 10 and a sealing device 16 between the shaft and the housing. The shaft 14 and the casing 10 are mounted mobile in rotation relative to each other about an axis A. The shaft 14 is typically a spindle wheel of a vehicle, the hydraulic device 12 then typically carrying out the rotational driving of a vehicle wheel.

The hydraulic device 12 as shown comprises a cylinder block 12A, a cam 12B and a distributor 40 of fluid. The cam 12B can be a multi-lobe cam. It is therefore, with the housing, a hydraulic motor or a pump. This hydraulic device 12 can be in particular with radial pistons.

In a manner known per se, the cylinders of the cylinder block 12A are supplied with fluid from a fluid distributed by the distributor 40, via grooves that will be described later.

The distributor 40 is itself connected to main lines 1 and 2, respectively for the supply and the exhaust of the hydraulic device 12. In this case, the hydraulic device 12 can be of the type cylinder block 12A fixed and with casing 10 rotating, and the supply and exhaust pipes 1 and 2 pass through the shaft 14 of the wheel stub, in which they are oriented axially, that is to say parallel to the axis A of rotation, axis along which the shaft 14 is oriented. In the example shown, another pipe 3 is pierced axially in the shaft 14. It is a fluid supply pipe, which serves to bring the fluid to the interior space 11 of the housing. 10, in particular to put this space under pressure so as to favor the disengagement of the pistons from the hydraulic device, and to evacuate this fluid when the pistons and the cam 12B come into contact.

More precisely, the pipe 3 makes it possible to produce a fluid in the interior space 11 of the casing so as to cause a rise in pressure therein resulting in a retraction of the pistons in the cylinders of the cylinder block 12A so that the pistons are no longer in contact with the cam 12B, thus operating what is called a declutching of the hydraulic device 10 and making it possible to put the engine in freewheeling configuration. Conversely, the fact of bringing the pistons into contact with the cam 12B is called a dog clutch or a displacement of the hydraulic device 10. The fluid supplied by the pipe 3 reaches between the opposite faces of the distributor 40 and from the shaft 14 and flows towards the interior space 11 of the casing 10, for example by a dedicated connection, or else by a clearance made on a part of the splines between the shaft 14 and the cylinder block 12A.

It is thus seen that the shaft has only three axial sections of fluid line, namely two main sections which form all or part of the main supply and exhaust pipes 1 and 2 and an auxiliary section which forms all or part of the casing pressure line 3. This auxiliary section typically forms a pipe for draining the internal volume 11 of the casing 10 when the hydraulic device 12 is in operation.

The cam 12B forms a part of the casing 10, which also includes a cover 10A situated around the distributor 40, and a part 10B forming, for example, a flange for connection with a member driven by the motor, for example the hub of 'a wheel. On the side opposite to the hydraulic device 12, the casing 10 is extended by a part 10C, which can for example be engaged in the hub of a wheel. The housing 10 and the shaft 14 are mounted in relative rotation. For this reason, they cooperate with each other via bearings 18A and 18B, housed in this case in part 10C of the casing. In known manner, these bearings 18A and 18B can be bearings with tapered bearings. The system can be used to drive a vehicle wheel, in which case the shaft 14 can be a wheel spindle axle.

The dispenser 40 comprises a distribution ring 60 and a core 50, the distribution ring 60 and the core 50 are in relative displacement in rotation. The distribution ring 60 has a relative displacement in rotation relative to the cylinder block 12A.

Figures 2 and 3 are detailed views of the dispenser 40 shown in Figure 1.

We define for the distributor 40 a proximal end 40P and a distal end 40D, the proximal end 40P being defined arbitrarily as being the end of the distributor 40 closest to the shaft 14. In the same way, we defines for the core 50 and for the distribution crown 60 a proximal end 50P, 60P and a distal end 60P, 60D. In the example shown in the figures, the proximal end 50P of the core 50 forms the proximal end 40P of the distributor 40, and the distal end 60D of the distribution crown 60 forms the distal end 40D of the distributor 40.

The core 50 is inserted via its proximal end 50P into the distribution ring 60 from the distal end 60D, and slides in an internal volume of the distribution ring 60 in the direction of the proximal end 60P, for example up to 'to project from its proximal end 60P. The core 50 thus has a decreasing external section from its distal end 50D towards its proximal end 50P, while the distribution ring 60 defines an internal housing delimited by an internal section whose section decreases from the distal end 60D towards the end proximal 60P. These shapes typically make it possible to obtain an axial thrust, and therefore the support of the surface 60P of the timing ring 60 on the cylinder block 12A, when the grooves 60A and 60 B are put under hydraulic pressure. The distributor 40 comprises supply conduits 41 and 42 arranged in the core 50, which are only primed in the figures, and which, on the one hand, open onto the radial face of the internal distributor 50 facing the shaft 14 , so as to be opposite the ends of the pipes 1 and 2 located at this end of the shaft 14 and which, on the other hand, are connected to distribution grooves arranged in the core 50 and in the distribution ring 60. Distribution conduits open radially on the face forming the proximal end 60P of the distribution crown 60 so as to connect the external grooves 60A and 60B to the cylinder block 12A of the hydraulic device 12, so as to selectively supply each chamber of the cylinder block 12A of the hydraulic device 12 during its rotation.

The core 50 thus has internal grooves 50A and 50B opening into its external periphery, and connected to the supply conduits 41 and 42. The distribution ring 60 has external grooves 60A and 60B opening into the internal periphery of the distribution ring 60, and configured so as to each be placed in fluid communication with at least one internal groove of the core 50.

The external grooves 60A and 60B arranged in the distribution ring 60 are connected to conduits opening out on the radial face of the distribution ring 60 facing the cylinder block 12A, so as to supply and discharge fluid.

The communication between the main lines 1 and 2 and the supply lines 41 and 42 is sealed vis-à-vis the rest of the system by any suitable sealing means, for example by annular seals 31 and 32 arranged between the facing faces of the core 50 and the shaft 14, or of the segments, or even of the compositions of joints and segments.

In known manner, the core 50 comprises a plurality of grooves 51 in which are arranged segments 52 ensuring a sealed contact between the core 50 and the distribution ring 60, and thus making it possible to isolate the various conduits produced in the distributor 40 relative to each other, and relative to the environment outside the grooves. Each groove of the distributor 40 is therefore surrounded by segments. In the example shown, each internal groove 50A and 50B of the core 50 is surrounded by two pairs of grooves 51 and segments 52.

The sealing means 52 are typically placed for mounting in the grooves 51 by stretching them to increase their diameter. Then they are placed in the grooves 51. Next, the core 50 is placed in the crown 60, and the sealing means 52 are supported on the internal wall of the crown 60. This allows movement, in particular an essentially axial sliding along the axis AA between the. core and crown, while obtaining the watertightness of the grooves 50A and 50B.

As indicated in the preamble to this patent application, a recurring problem during the assembly of the hydraulic device is the maintenance in position of the segments 52 in the grooves 51. Indeed, it is understood that if the core 50 slides in the distribution crown 60 during its manipulation to place it in position, there is a risk that segments come out of the internal volume defined by the distribution crown 60, and disengage, in particular at the end proximal 50P of the nucleus 50.

In order to respond to such a problem, the dispenser 40 as proposed comprises a stop 65 which can be formed in or carried by the core 50 or by the distribution crown 60, configured so as to limit the displacement of the core relative to the distribution ring in a direction defined by the axis A. Reference will be made hereinafter generally to a stop 65. It is understood that the distribution ring 60 may have a single stop, several similar stops arranged around the axis A, or even an annular, the operation then remaining unchanged.

This stop 65 extends from the internal surface of the distribution ring 60, so as to come into contact with a wall of an internal groove 50A or 50B of the core 50 and thus limit the displacement of the core 50 by relative to the distribution ring 60 according to Tax A in a direction going from the distal end 40D towards the proximal end 40P of the distributor 40.

The stop 65 is typically a rib or a shoulder extending from the internal surface of the distribution ring 6.

The stop is typically an insert, such as a pin, inserted in an internal groove of the core 50 as will be seen below with reference to the various embodiments.

In the example shown in Figures 2 and 3, the stop 65 is a shoulder formed in the inner wall of the distribution ring 60, configured to extend in the internal groove 50B when the core 50 is inserted in the timing ring 60.

The stop 65 is configured so as not to come into contact with the core 50 once the hydraulic device is assembled. More precisely, the stop 65 is thus configured so as to be able to come into contact with the core 50 only during the assembly of the hydraulic device comprising the distributor 40.

Figure 2 is thus a detailed view of the distributor 40 shown in Figure 1, while Figure 3 is a view of the distributor 40 taken in isolation.

As seen in Figure 2, a non-zero functional clearance J remains between the stop 65 and the surface of the core 50 opposite the stop 65, here a wall of the internal groove 50B. This functional clearance results from the different contact surfaces of the core 50 and of the distribution ring 60 with the other elements of the hydraulic device 12, in particular with the shaft 14 and the cylinder block 12A.

Conversely, when the distributor 40 is taken in isolation as shown in Figure 3, the core 50 is no longer limited in translation by its contact with the shaft 14. The stop 65 then allows to limit the movement of the core 50 relative to the distribution crown 60 in a direction going from the distal end 60D towards the proximal end 60P of the distribution crown 60.

The stop 65 is configured so as to limit the displacement of the core 50 relative to the distribution ring 60 in order to prevent a segment 52 of the core 50 from passing beyond the proximal end 60P of the distribution ring 60. More specifically, the stop 65 is configured so that the length (measured along the axis A) of the portion of the core 50 which can protrude from the proximal end 60P of the distribution ring 60 is strictly less than the distance (measured along axis A) between the proximal end 50P of the core 50 and the segment 52 closest to said proximal end 50P of the core 50. In fact, when the distributor 40 is mounted against the shaft 14 and against the cylinder block 12A, the user will hold the distributor 40 by its distal end 40P so as to come to rest it against the shaft 14 and against the cylinder block 12A. The user thus prevents disengagement via the distal end 40D, while the stop 65 prevents disengagement via the proximal end 40P. The user can then secure the core 50 to the shaft 14, for example by bolting, which fixes the distributor 40 and then prevents any subsequent risk of falling before positioning the remaining elements of the system. In this way, the segments 52 are held sandwiched between the core 50 and the timing ring 60, which prevents any risk of loss or accidental fall of a segment.

FIG. 4 shows a variant of the embodiment shown in FIG. 3.

The stop 65 is here a shoulder extending from a radial wall of an outer groove 60A. As for the embodiment described with reference to FIG. 3, the stop 65 comes into contact with a radial wall of an internal groove, here the internal groove 50A in order to limit the displacement of the core 50 relative to the crown of distribution 60 in a direction going from the distal end 60D towards the proximal end 60P of the distribution crown 60.

Figures 5 to 9 are alternative embodiments of the dispenser.

5 shows a variant in which the stop 65 is formed by a shoulder extending from the outer periphery of the core 50 of the distributor 40. This shoulder forming stop 65 then comes into abutment against a radial surface of the crown of distribution 60, in order to limit the displacement of the core 50 relative to the distribution crown 60 in a direction going from the distal end 60D towards the proximal end 60P of the distribution crown 60. The shoulder as shown is formed adjacent to the internal groove 50B, it is understood that it can also be formed adjacent to the internal groove 50A, the function then being performed identically.

6 shows another variant in which the stop 65 is formed at the proximal end 60P of the distribution ring 60. This stop 65 thus limits the movement of the core 50, a radial wall of which comes into contact with the stop 65. The operation remains unchanged.

FIG. 7 shows another variant in which the stop 65 is formed by a screw inserted in a bore 66 formed in the distribution ring 60. The bore 66 is produced so that the screw forming the stop can be inserted into an internal groove, here the internal groove 50B. The end of the screw entering the internal groove here defines a limited axial clearance of the core 50 relative to the distribution ring 60 in both directions of the axis A. In such an embodiment, once the distributor 40 positioned, the screw can be held in position or be removed by the operator, and the hole 66 is then closed. This variant is particularly advantageous in that the distributor 40 cannot be disassembled, in particular in the case of use as a spare part which has been assembled before its transport, which then facilitates mounting on the hydraulic machine. Sealing elements such as seals (not shown) are typically provided between the screw and the bore 66. A functional clearance is typically provided radially between the free end of the screw forming the stop 65 and the axial wall of the groove associated.

Figure 8 shows another variant in which a shoulder extends from the distal end 50D of the core 50. This shoulder forms the stop 65, and is configured to come into abutment against a radial surface of the distribution ring 60 forming its distal end 60D, or close to the distal end 60D.

Figure 9 shows another variant in which the stop 65 is formed by an insert positioned in a housing 67 formed in an internal groove, here the internal groove 50B. The insert is for example a circlip, a ring, ring segment or half-ring, a pin or any other suitable element. In the embodiment shown in Figure 9, the stop 65 is formed by a pin. As for the embodiments described above, this insert forms a stop 65 making it possible to limit the displacement of the core 50 relative to the distribution crown 60 in a direction going from the distal end 60D towards the proximal end 60P of the crown distribution 60. A functional clearance is provided radially between the free end of the insert forming the stop and the axial wall of the associated groove.

It is understood from reading the above that the stop 65 is only operated during the assembly of a hydraulic device. Once the hydraulic device has been assembled, the stop 65 is no longer in contact with the core 50 in order to avoid generating additional friction between the core 50 and the timing ring 60.

To assemble a hydraulic device as shown in Figure 1, an operator will first position the bearings 18A and 18B and the housing segment 10C around the shaft 14, then the housing segment 10B. If the operator assembles directly on a vehicle, the preceding elements are already assembled and constitute a wheel spindle on a hub. The operator will then place the cylinder block 12A and the cam 12B. It will then bring the distributor 40 in order to position it in abutment against the shaft 14 and against the cylinder block 14A as indicated previously, the stop 65 then ensuring a position-keeping function of the segments 52 by keeping them sandwiched between the core 50 and the distribution ring 60. The operator then positions cover 10A which will hold the distributor 40 in position.

The distributor 40 as proposed thus makes it possible to facilitate the operations of assembling a hydraulic device comprising such a distributor, and thus avoids the risks of loss of time or damage to the distributor 40 resulting from a loss of segment 52 linked to an excessive displacement of the core 50 relative to the distribution ring 60. These advantages also apply more generally for any transport operation, or involving manipulation of the distributor 40 before its assembly.

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

It is also obvious that all the characteristics described with reference to a method can be transposed, 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 (7)

1. Distributor (40) for a hydraulic device, comprising a core (50) and a distribution ring (60) mounted to rotate around the core (50) along an axis (A) defining a proximal end (40P) and a distal end ( 40D), the distribution ring (60) and the core (50) being slidably mounted relative to each other along the axis (A), the core (50) having a plurality of internal grooves (50A, 50B) opening into an external periphery of the core (50), the distribution ring (60) having a plurality of external grooves (60A, 60B) opening into an internal periphery of the distribution ring (60), said internal grooves (50A , 50B) and external (60A, 60B) being configured to be placed in fluid communication and to form fluid circulation conduits, the core (50) comprising a plurality of sealing segments (52) configured so as to isolate each of said said fluid circulation ducts, the core ( 50) having a decreasing external section from a distal end (50D) to a proximal end (50P), the distributor (40) being characterized in that the distributor 40 comprises a stop (65) configured so as to limit the displacement of the core (50) relative to the distribution ring (60) in a direction defined by the axis (A). 2. Distributor (40) according to claim 1, wherein said stop (65) is configured so as to limit the displacement along the axis (A) of the core (50) relative to the distribution ring (60), the distal end (60D) toward the proximal end (60P). 3. Distributor according to claim 2, wherein said stop (65) is integral with the distribution ring (60), and is configured so as to come into contact with a wall of the core (50). 4. Dispenser according to claim 2, wherein said stop (65) is integral with the core (50), and is configured so as to come into contact with a wall of the dispensing ring (60). 5. Distributor (40) according to one of claims 2 to 4, wherein the distal end (50D) of the core (50) is configured so that it can slide beyond the proximal end (60P) of the distribution crown (60), the stop being configured so that the portion of the core (50) which can slide beyond the proximal end (60P) of the distribution crown (60) has a dimension measured according to l axis (A) strictly less than the distance between the proximal end (50P) of the core (50) and the sealing segment (52) closest to the proximal end (50P) of the core (50). 6. Hydraulic apparatus with radial pistons and multilobe cam, comprising a distributor (40) according to one of the preceding claims, in which there is a non-zero clearance (J) along the axis (A) between the stop (65) of the distributor (40) and a core surface (50) disposed opposite the stop (65). 7. A method of assembling a hydraulic device on a wheel spindle, in which a first set of components of the hydraulic device is positioned around an axis (14) of the wheel spindle, a distributor is provided ( 40) according to one of claims 1 to 5, the distributor (40) is positioned in abutment against components of the first set of components, so as to define a non-zero clearance (J) along an axis (A) of the rocket wheel between the stopper (65) of the distributor and a core surface (50) disposed opposite the stopper (65), the core (50) is secured to a component of the first set of components, a second set of components of the hydraulic device, so as to define an internal volume of the casing in which the distributor (40) is positioned.