Improved flushing circuit for a hydraulic machine

Abstract

Disclosed is a hydraulic machine (100) comprising an improved flushing circuit for causing a primary flushing flow (F1) to circulate from an inlet (210) successively into a proximal portion (110), a mid portion (120) and a distal portion (130) of the hydraulic machine (100), then into the mid portion (120) and the proximal portion (110) as far as an outlet (220).

Description

Technical Field

[0001] This disclosure relates to a hydraulic machine comprising an improved sweeping system. Prior art

[0002] We represent schematically on the figure 1 an example of a hydraulic machine structure, for example a hydraulic pump or a hydraulic motor.

[0003] The hydraulic machine 100 as shown schematically has a shaft 102 extending along a main axis XX. Schematically, several portions can be defined for the hydraulic machine 100: a proximal portion 110, a middle portion 120 and a distal portion 130, the proximal and distal designations being defined arbitrarily with respect to the main axis XX, and being used in the text to identify the position of different elements.

[0004] The proximal portion 110 has a distribution supply function. It comprises a distributor 112, and more generally the means ensuring a supply and a discharge of fluid, typically two conduits defining a conduit which is qualified as high pressure (HP) and a conduit which is qualified as low pressure (LP).

[0005] The middle portion 120 defines the hydrocouple of the hydraulic machine 100. It comprises a cylinder block 122 comprising a plurality of housings in which pistons 124 are slidably mounted, said pistons 124 coming into contact with a multi-lobe cam 126.

[0006] The distal portion 130 typically comprises the bearing of the hydraulic machine 100. In the example shown, the distal portion comprises two tapered roller bearings 132 forming a rolling bearing ensuring the relative rotational movement of the hydraulic machine. The distal portion 130 may also comprise other elements, for example a braking device.

[0007] We represent schematically on the figure 1 an example of a closed-loop circuit of the hydraulic machine 100, comprising a hydraulic pump 10 coupled to a primary motor M which ensures its rotational drive. The hydraulic pump 10 has two orifices defining an inlet and a discharge, which are connected respectively to a discharge and an inlet formed in the proximal portion 110 of the hydraulic machine 100, so as to form a closed hydraulic circuit having two branches which are arbitrarily designated as high pressure branch HP and low pressure branch BP.

[0008] Thus in the hydraulic machine 100, the closed-loop circuit corresponds to the circuit in which the working fluid of the hydraulic machine 100 circulates, typically oil, linked to the rotational movement of the hydraulic machine 100. The closed-loop circuit also comprises a booster pump 12, which can be coupled to this same primary motor M or driven by another element. The booster pump 12 is connected to the conduits of the hydraulic circuit via non-return valves 14 so as to ensure boostering of the hydraulic circuit.

[0009] In such a hydraulic machine 100, the closed loop circuit of the hydraulic machine 100 is distinguished with respect to its internal volume. We schematize on the figure 1 the closed loop circuit by dotted lines, and the internal volume by hatching.

[0010] The internal volume of the hydraulic machine 100 is herein defined as the space within the hydraulic machine that is not part of the closed loop, and which is typically at an internal pressure much lower than the pressure of the working fluid of the hydraulic machine, for example at a pressure close to atmospheric or ambient pressure. The closed loop circuit is typically sealed and isolated from the internal volume by means of suitable sealing elements.

[0011] The working fluid circulating in the closed loop circuit and which passes through the various components of a hydraulic circuit such as pumps, motors, conduits and various regulating components tends to heat up, in particular due to friction between the various internal elements of the hydraulic machine 100 and pressure losses.

[0012] To cool the fluid circulating in the closed loop circuit, it is known to provide an exchange function; oil that is described as "hot" is taken from the closed loop on the lowest pressure line using an exchange valve 16 to replace it with the same volume of oil that comes from a reservoir R using the booster pump 12 and the circuit elements associated with the booster, this oil being at a lower temperature and typically having been filtered. Such a function thus makes it possible to lower the temperature of the oil circulating in the closed loop.

[0013] However, as indicated previously, the internal volume of the hydraulic machine 100 is separated from the closed loop in a sealed manner, consequently, the exchange does not cool the oil contained in the internal volume of the hydraulic machine 100.

[0014] To cool the internal volume, it is therefore known to carry out a sweep of the internal volume of the hydraulic machine 100 by means of a fluid which is introduced into the internal volume (for example taken from a low pressure branch of the hydraulic circuit using the exchange valve or directly from the feed pump) then to remove this same quantity of fluid through a drain.

[0015] However, the solutions currently proposed do not allow for sweeping of the entire internal volume, or require defining dedicated sweep flows having inlet and discharge pipes distributed in the different portions of the hydraulic machine 100, for example in the proximal portion 110 and the distal portion 130, which is restrictive in terms of installation and maintenance. The addition of additional pipes in fact poses additional problems in terms of access and increases the risks of the pipes being torn off.

[0016] Another known solution consists of using the leaks from the closed loop to the internal volume of the hydraulic machine 100 in association with a drain added to the casing of the hydraulic machine 100 to carry out a sweep of the internal volume. However, it turns out that such a solution leads to insufficient sweeping not allowing the entire internal volume to be cooled and in particular the parts furthest from the zones in which the leaks occur and from the drain.

[0017] Whatever the proposed structure, when the internal volume of the engine is not sufficiently swept, the oil present in the internal volume can heat up, in particular due to friction of the various moving parts or pressure losses, and become hotter than the exchanged oil, in particular in areas of the internal volume far from the arrival of the sweeping fluid or its outlet. Document EP3480458 presents another example of a known structure of a hydraulic machine.

[0018] This presentation aims to respond at least partially to these issues. Statement of the invention

[0019] In order to at least partially address these issues, the present invention relates to an assembly comprising a hydraulic machine comprising a first assembly and a second assembly movable in rotation relative to each other along a main axis, the first assembly comprising a shaft (102) and the second assembly comprising a casing of said hydraulic machine having three portions extending successively from a proximal end to a distal end along the main axis, a proximal portion, comprising a distributor and fluid supply and discharge lines, a middle portion, comprising a cylinder block and a cam, a distal portion, comprising bearings, said hydraulic machine having an internal volume and comprising a circuit for scavenging the internal volume, said scavenging circuit having a fluid inlet orifice in the proximal portion, a fluid outlet orifice (220) in the proximal portion, said scavenging circuit being configured so as to form a primary scavenging flow circulating from the inlet orifice successively in the proximal portion, in the middle portion and in the distal portion of the hydraulic machine, then in the middle portion and in the proximal portion to the outlet orifice.

[0020] In one example, the scavenging circuit defines two flows in the internal volume of the hydraulic machine: the primary flow, and a secondary flow, the primary flow and the secondary flow being injected into the hydraulic machine through the fluid inlet port, and exiting the hydraulic machine through the fluid outlet port.

[0021] In one example, the secondary flow defines a circulation of fluid within the proximal portion, between the fluid inlet port and the fluid outlet port.

[0022] In one example, the primary flow and the secondary flow are calibrated by means of restrictions defining the maximum fluid flow rate for each of said flows.

[0023] According to one example, the distal portion of the hydraulic machine comprises a braking device.

[0024] According to one example, said assembly comprises an exchange valve, adapted to take hydraulic fluid from the line having the lowest pressure among the intake line and the discharge line of the hydraulic machine; and to inject it into the fluid inlet port of the scavenging circuit.

[0025] According to one example, said exchange valve is integrated into a distribution cover of the hydraulic machine.

[0026] According to one example, said assembly comprises a scavenging valve, adapted to take hydraulic fluid from a feed circuit associated with the hydraulic machine or from a control circuit associated with the hydraulic machine.

[0027] In one example, the scavenging circuit includes conduits formed in the distributor and / or the shaft and / or the cylinder block of the hydraulic machine, so as to convey the scavenging fluid from the inlet port to the distal portion of the hydraulic machine, and to inject the scavenging fluid into an internal volume of the distal portion of the hydraulic machine.

[0028] The distal portion then typically comprises a sleeve positioned around the shaft, bearing against the cylinder block, said bearing of the sleeve against the cylinder block being provided with a sealing element, said sleeve being configured so as to define a fluid passage along the shaft, to a distal end of the internal volume of the distal portion of the hydraulic machine. Brief description of the drawings

[0029] 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. [ Fig. 1 ] There figure 1 described above schematically represents an example of a hydraulic machine. Fig. 2 ] There figure 2 represents an example of a hydraulic machine according to one aspect of the invention. Fig. 3 ] There figure 3 represents an example of a hydraulic machine according to one aspect of the invention. Fig. 4 ] There figure 4 represents an example of a hydraulic machine according to one aspect of the invention. Fig. 5 ] There figure 5 represents an example of a hydraulic machine according to one aspect of the invention.

[0030] Throughout the figures, common elements are identified by identical numerical references. Description of the embodiments

[0031] There figure 2 presents an example of a hydraulic machine according to one aspect of the invention. This figure shows the various elements already described with reference to the figure 1 . The hydraulic machine 100 as shown diagrammatically thus has a shaft 102 extending along a main axis XX. Schematically, several portions can be defined for the hydraulic machine 100: a proximal portion 110, a middle portion 120 and a distal portion 130, the proximal and distal designations being defined arbitrarily with respect to the main axis XX.

[0032] The proximal portion 110 has a distribution supply function. It comprises a distributor 112 surrounded by a distribution cover 113, and more generally the means ensuring a supply and a discharge of fluid, typically two conduits 114 defining a conduit that is described as high pressure and a conduit that is described as low pressure, which are here formed in the distribution cover 113.

[0033] The middle portion 120 defines a portion generally referred to as the hydrocouple of the hydraulic machine 100. It comprises a cylinder block 122 comprising a plurality of housings in which pistons 124 are slidably mounted, said pistons 124 coming into contact with a multi-lobe cam 126.

[0034] The distal portion 130 typically comprises the bearing of the hydraulic machine 100. In the example shown, the distal portion comprises two tapered roller bearings 132 forming a rolling bearing ensuring the relative rotational movement of the hydraulic machine 100, as well as a braking device 134 adapted to selectively apply a friction force opposing the rotational movement of the hydraulic machine 100, and dynamic seals. The braking device 134 as shown comprises stacks of discs 135 and an actuator 137, adapted to selectively engage or disengage said stacks of discs 135 and thus apply or not apply a resistive force opposing the rotational movement of the hydraulic machine 100.

[0035] As indicated in the preamble, considering that the hydraulic connections are located in the proximal portion 110, a problem concerns the fluid sweeping of the internal volume of the middle portion 120 and the distal portion 130. By internal volume of the hydraulic machine 100, we mean a volume internal to the casing of the hydraulic machine 100, but distinct from the pipes in which the hydraulic working fluid of the hydraulic machine 100 circulates.

[0036] For the hydraulic machine 100, a first assembly and a second assembly are defined which are mounted to be mobile in rotation relative to each other around the main axis XX via the bearings 132. One of the first assembly and the second assembly is typically fixed and forms a stator of the hydraulic machine 100, while the other of the first assembly and the second assembly is mobile and forms a rotor of the hydraulic machine 100.

[0037] In the example illustrated, the shaft 102 and the cylinder block 122 form a first assembly, while the cam 126, the distribution cover 113 and more generally the casing of the hydraulic machine 100 form a second assembly, the first assembly being movable in rotation relative to the second assembly along the main axis XX.

[0038] Advantageously, but optionally, the hydraulic machine 100 according to the invention may comprise one of the following characteristics, taken alone or in any combination: the hydraulic machine 100 is a hydraulic motor; the hydraulic machine 100 has radial pistons; the hydraulic machine 100 comprises a cam provided with several lobes;the hydraulic machine 100 comprises a casing formed of two lateral casing elements framing a central annular casing element, a cam comprising a lobed cam formed on a radially internal surface of the central casing element, a cylinder block mounted for relative rotation in the casing around an axis XX, opposite the cam, a shaft linked for rotation with the cylinder block, pistons guided for radial sliding in respective cylinders of the cylinder block and bearing on the lobes of the cam by means of rollers, a flat distributor adapted to ensure a fluid connection with the cylinders of the cylinder block, so that the successive bearing of the pistons on the lobes of the cam causes the relative rotation of the cylinder block and of the elements linked to it with respect to the casing.;

[0039] The hydraulic machine 100 as proposed here comprises means defining a scanning circuit which is generally designated by the reference numeral 200, adapted to ensure scanning of the internal volume of the proximal portion 110, of the middle portion 120 and of the distal portion 130 while only having fluid inlet and outlet orifices in the proximal portion 110.

[0040] More specifically, the hydraulic machine 100 comprises an inlet orifice 210 and an outlet orifice 220 between which a scavenging circuit 200 is formed. In the example illustrated, the inlet orifice 210 and the outlet orifice 220 are formed in the distribution cover 113.

[0041] According to one example, the inlet orifice 210 is connected to an exchange valve 240, adapted to take a flow of fluid from the hydraulic circuit associated with the hydraulic machine, and to convey this flow thus taken to the inlet orifice 210. Said exchange valve 240 may or may not be integrated into the hydraulic machine 100. It may be attached to the hydraulic machine 100, for example positioned in a flange fixed to the hydraulic machine 100. The exchange valve 240 is shown schematically in the figures, connected to hydraulic pipes ensuring the circulation of hydraulic working fluid of the hydraulic machine 100.

[0042] The exchange valve 240 is thus typically configured to draw fluid from the low pressure conduit connected to the hydraulic machine 100, typically the discharge in the case of a hydraulic motor, or the intake in the case of a hydraulic pump.

[0043] Alternatively, the scanning can be done in parallel with the exchange circuit.

[0044] Alternatively, the flushing fluid that arrives at the inlet orifice 210 may come from the booster pump 12. Alternatively, the flushing fluid may come from a control circuit associated with the hydraulic machine 100. Alternatively, the flushing fluid may come from a high-pressure conduit connected to the hydraulic machine 100; it may then be brought into the flushing circuit via a pressure reducer. Alternatively, the flushing fluid may come from a high-pressure conduit internal to the hydraulic machine 100. It is understood that these embodiments are not limiting, and that the flushing fluid may be taken from any suitable fluid source. The fluid is typically oil.

[0045] The outlet 220 is typically connected to a reservoir R typically at ambient pressure of the hydraulic circuit associated with the hydraulic machine 100, typically via a filter and / or a heat exchanger.

[0046] The fluid used to carry out the sweeping within the internal volume of the hydraulic machine 100 is thus typically the same fluid as that used for actuating the hydraulic machine 100. It is understood, however, that the fluid carrying out the sweeping in the internal volume of the hydraulic machine is at a pressure significantly lower than the pressure of the fluid in the intake and discharge conduits of the hydraulic machine 100; the fluid carrying out the sweeping being at the internal pressure within the internal volume of the casing of the hydraulic machine 100, as opposed to the fluid which circulates in the hydraulic conduits of the hydraulic machine in connection with the movement of the pistons and which is referred to as the working fluid.

[0047] The scavenging circuit 200 as presented defines a primary flow F1 and a secondary flow F2 circulating in the internal volume of the hydraulic machine 100.

[0048] The distribution of the fluid between the primary flow F1 and the secondary flow F2 is for example achieved by calibrating sections, typically downstream of the inlet orifice 210, or by any other suitable means making it possible to divide a flow of fluid into two flows. For example, a maximum flow rate that can be conveyed to the secondary flow F2 is defined, the remaining flow rate then being conveyed to the primary flow F1, or vice versa. It is also possible to define a maximum flow rate that can be conveyed to the primary flow F1 and a maximum flow rate being conveyed to the secondary flow F2.

[0049] In the illustrated example, a primary flow F1 and a secondary flow F2 for scavenging are defined, represented diagrammatically by arrows F1 and F2 respectively. The primary flow F1 and the secondary flow F2 are represented here diagrammatically as being separated from the inlet orifice 210. It is understood, however, that this embodiment is not limiting, and that the separation into two flows can be carried out at any point downstream of the inlet orifice 210.

[0050] In the example illustrated on the figure 2 , the primary flow F1 takes the following route, from the inlet orifice 210 to the outlet orifice 220: The fluid enters the hydraulic machine 100 via the inlet orifice 210 formed in the distribution cover 113. The fluid passes through a conduit formed in the distribution cover 113 to an interface with the distributor 112. The fluid passes through the distributor 112 to an interface with the cylinder block 122 via a conduit formed in the distributor 112. This interface is typically a circular groove formed in the distributor 112 or in the cylinder block 122. The fluid passes through the cylinder block 122 via a conduit arranged in the cylinder block 122, then opens into a volume of the distal portion 130, between the shaft 102 and a sleeve 136, and goes to the distal end of the internal volume. The sleeve 136 is typically mounted to bear against the cylinder block 122, the interface between these elements being provided with a sealing element so that the fluid is guided in the passage between the shaft 102 and the sleeve 130.The fluid then passes through the various elements of the distal portion 130 of the hydraulic machine 100, here the braking device 134 and the bearings 132. The fluid then reaches the internal volume of the middle portion 120, here via a bore formed in the sleeve 136. The fluid passes through the middle portion 120, for example by bypassing the cylinder block 122 via a passage radially to the outside relative to the main axis XX, and reaches the proximal portion 110, from where it escapes via the outlet orifice 220.

[0051] The secondary flow F2 takes the following route: the fluid enters the hydraulic machine 100 via the inlet orifice 210 formed in the distribution cover 113; the fluid passes through a conduit formed in the distribution cover 113, which opens into an internal volume of the hydraulic machine between the cylinder block 122 and the distribution cover 113; the fluid escapes via the outlet orifice 220.

[0052] The combination of the primary flow F1 and the secondary flow F2 thus makes it possible to ensure a sweep of fluid in the internal volume of the different portions of the hydraulic machine 100, and thus to ensure cooling and lubrication of the different portions of the hydraulic machine 100 while retaining fluid supply lines grouped in the proximal portion 110 of the hydraulic machine 100.

[0053] It is understood, however, that the embodiment shown on the figure 2 is not limiting.

[0054] The following figures show various other embodiments. Only the differences from the embodiment already described with reference to the following are described. figure 2 .

[0055] In the example shown in the figure 3 , the distal portion 130 does not include a braking device 134: only the bearings 132 defining the rolling bearing for the hydraulic machine 100.

[0056] In this embodiment, the primary flow F1 takes the following path, from the inlet orifice 210 to the outlet orifice 220: the fluid enters the hydraulic machine 100 via the inlet orifice 210 formed in the distribution cover 113; the fluid passes through a conduit formed by a radial clearance between the distributor 112 and the shaft 102; the fluid passes through a conduit formed by holes in the shaft 102, and exits at the distal end of the distal portion 130 of the hydraulic machine 100; the fluid then passes through the various elements of the distal portion 130 of the hydraulic machine 100, here the bearings 132; the fluid then joins the internal volume of the middle portion 120; the fluid passes through the middle portion 120, for example by bypassing the cylinder block 122 via a passage radially to the outside relative to the main axis XX, and joins the proximal portion 110, from where it escapes via the outlet orifice 220.

[0057] We therefore find in this embodiment a scavenging circuit making it possible to ensure scavenging of fluid in the internal volume of the different portions of the hydraulic machine 100, and thus to ensure cooling and lubrication of the different portions of the hydraulic machine 100 while retaining fluid supply lines grouped in the proximal portion 110 of the hydraulic machine 100.

[0058] There figure 4 presents another embodiment.

[0059] In this example, the primary flow F1 is conveyed from the inlet orifice 210 to the distal portion 130 via conduits arranged in the distributor cover 113, in the multi-lobe cam 126 and in a distal cover 138, that is to say generally in the casing of the hydraulic machine 100.

[0060] The primary flow F1 is thus reinjected at the distal end of the internal volume of the distal portion 130. The primary flow F1 then passes through the internal volume of the distal portion 130, then the middle portion 120, for example by bypassing the cylinder block 122 via a passage radially to the outside relative to the main axis XX, and joins the proximal portion 110 to reach the outlet orifice 220.

[0061] There figure 5 presents another embodiment.

[0062] This embodiment is a variant of the figure 3 described previously, in which the conduit formed by holes in the shaft 102 has been replaced by holes formed in the cylinder block 122 and in an inner ring of one of the bearings 132.

[0063] The primary flow F1 thus opens into the distal portion 130, between the two bearings 132, then joins the middle portion by crossing one of the bearings 132, crosses the middle portion 120 and joins the proximal portion 110 to reach the outlet orifice 220.

[0064] In view of the different embodiments, it is thus understood that, in general, the invention proposes to define a primary scavenging flow F1 in the internal volume of the hydraulic machine 100, which enters and leaves the hydraulic machine via the proximal portion of the hydraulic machine 100, and which ensures a circulation of fluid in the different portions of the hydraulic machine 100, namely a circulation of the scavenging fluid which successively passes through the proximal portion 110, the middle portion 120 and the distal portion 130, then passes back through the middle portion 120 and the proximal portion 110 before exiting the hydraulic machine 100.

[0065] This primary flow F1 of scavenging fluid thus ensures lubrication and cooling of the different portions of the hydraulic machine 100. A secondary flow F2 of scavenging fluid typically ensures in parallel a flow of scavenging fluid in the proximal portion 110 and the middle portion 120 of the hydraulic machine 100, to ensure lubrication and cooling of the distribution members and the elements associated with the cylinder block 122 of the hydraulic machine 100.

[0066] The primary flow F1 and the secondary flow F2 are thus calibrated for example via sections defining a maximum flow rate for one and / or the other of these flows. The primary flow F1 and the secondary flow F2 typically meet in the middle portion 120 or in the proximal portion 110 of the hydraulic machine 100 before reaching the outlet orifice 220.

[0067] Thus, at least a portion of the flushing fluid circulates throughout the entire internal volume of the hydraulic machine 100, and reaches the components positioned in the portions of the hydraulic machine 100 furthest from the inlet orifice 210 and the outlet orifice 220 without requiring one of these orifices to be in a middle or distal portion and / or without requiring the addition of other inlet or outlet orifices for the flushing fluid.

[0068] The invention as proposed thus makes it possible to propose a hydraulic machine 100 having fluid intake and discharge conduits only in a proximal portion of the hydraulic machine 100, which thus makes it possible to maintain a minimized size and simplified integration for the hydraulic machine 100 compared to a hydraulic machine structure in which additional hydraulic conduits are added in order to define additional sweeping flows within the hydraulic machine 100.

[0069] Ensuring fluid scavenging helps prevent temperature rise and / or premature wear in the various portions of the hydraulic machine 100.

[0070] The assembly according to the invention can be applied to a hydraulic machine 100 associated with a closed-loop hydraulic circuit or an open-loop hydraulic circuit.

[0071] 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.

[0072] 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

1. An assembly comprising: a hydraulic machine (100) comprising a first assembly and a second assembly that are movable in rotation relative to each other along a main axis (X-X), the first assembly comprising a shaft (102) and the second assembly comprising a casing, said hydraulic machine (100) having three portions extending successively from a proximal end to a distal end along the main axis (X-X), - a proximal portion (110), comprising a distributor (112) and fluid supply and discharge ducts, - a middle portion (120), comprising a cylinder block (122) and a cam (126), - a distal portion (130), comprising bearings (132), said hydraulic machine (100) having an internal volume and comprising a circuit for sweeping (200) the internal volume, characterized in that said sweep circuit (200) has a fluid inlet orifice (210) in the proximal portion (110), a fluid outlet orifice (220) in the proximal portion (110), said sweep circuit (200) being configured so as to form a primary sweep stream (F1) circulating from the inlet orifice (210) successively in the proximal portion (110), in the middle portion (120) and in the distal portion (130) of the hydraulic machine (100), then in the middle portion (120) and in the proximal portion (110) up to the outlet orifice (220).

2. The assembly according to claim 1, wherein the sweep circuit (200) defines two streams in the internal volume of the hydraulic machine (100): - the primary stream (F1), and - a secondary stream (F2), the primary stream (F1) and the secondary stream (F2) being injected into the hydraulic machine (100) through the fluid inlet orifice (210), and exiting the hydraulic machine through the fluid outlet orifice (220).

3. The assembly according to claim 2, wherein the secondary stream (F2) defines a circulation of fluid within the proximal portion (110), between the fluid inlet orifice (210) and the fluid outlet orifice (220).

4. The assembly according to any of claims 2 to 3, wherein the primary stream (F1) and the secondary stream (F2) are calibrated by means of restrictions defining the maximum fluid flow rate for each of said streams (F1, F2).

5. The assembly according to any of claims 1 to 4, wherein the distal portion (130) of the hydraulic machine (100) comprises a braking device (134).

6. The assembly according to any of claims 1 to 5, comprising an exchange valve (240), adapted to take hydraulic fluid from the duct having the lowest pressure among the intake duct and the discharge duct of the hydraulic machine; and to inject it into the fluid inlet orifice (210) of the sweep circuit (200).

7. The assembly according to claim 6, wherein said exchange valve (240) is integrated into a distribution cover (113) of the hydraulic machine (100).

8. The assembly according to any of claims 1 to 5, wherein the sweep circuit is supplied from the booster circuit associated with the hydraulic machine (100) or from a control circuit associated with the machine hydraulic (100).

9. The assembly according to any of claims 1 to 8, wherein the sweep circuit (200) comprises ducts formed in the distributor (112) and / or the shaft (102) and / or the cylinder block ( 122) of the hydraulic machine (100), so as to convey the sweep fluid from the inlet orifice (210) to the distal portion (130) of the hydraulic machine (100), and to inject the sweep fluid into an internal volume of the distal portion (130) of the hydraulic machine (100).

10. The assembly according to claim 9, wherein the distal portion (130) comprises a sleeve (136) positioned around the shaft (102), bearing against the cylinder block (122), said bearing of the sleeve (136) against the cylinder block (122) being provided with a sealing element, said sleeve (136) being configured so as to define a fluid passage along the shaft (102), up to a distal end of the internal volume of the distal portion (130) of the hydraulic machine (100).

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