FR3057019A1 - HYDRAULIC ACTUATOR FOR TURBOMACHINE, COMPRISING A COOLING LINE SUPPLIED IN DERIVATION OF A CONTROL VALVE - Google Patents

Abstract

The invention relates to a piston (3) for a turbomachine, a housing (2) and a control valve (6) configured to control the displacement of the piston (3). The interior of the housing (2) comprises a first chamber (23) and a second chamber (25) separated from the first chamber (23) by the piston (3). The valve (6) includes a first port (C), and a second port (D) fluidly connected to the first chamber (23). According to the invention, a first branch branch (84) is located bypassing the first orifice (C) and the second orifice (D), the first branch branch (84) being fluidly connected to the cooling duct (50).

Description

DESCRIPTION

TECHNICAL AREA

The invention relates to the general technical field of aircraft turbomachines. More specifically, the invention relates to an assembly intended to supply mechanical power to turbomachine equipment.

PRIOR STATE OF THE ART

FIG. 1 represents a hydraulic assembly for a turbomachine, configured to supply mechanical power to turbomachine equipment. Such an assembly is for example known from patent application FR 2 957 999 of the company Snecma.

The assembly includes a piston 3 sliding in a casing 2. Inside the casing 2 there is a first chamber 23 and a second chamber 25 which are separated by the piston 3. The piston 3 is crossed by a channel 31 which is configured to allow a leakage flow to flow between the first chamber 23 and the second chamber 25. The channel 31 comprises a flow restrictor 32 which is for example formed by bends in the channel 31 or which has a reduced diameter relative to to the rest of channel 31.

The leakage rate is useful for cooling the assembly, in particular in the event of a fire in the turbomachine. Nevertheless, the leakage rate depends on the pressure difference between the first chamber 23 and the second chamber 25, that is to say the forces exerted on the piston 3.

There is therefore a need to cool an assembly configured to provide mechanical power to turbomachine equipment, while better controlling the leak rate and increasing the performance of the assembly.

STATEMENT OF THE INVENTION

The invention aims to at least partially solve the problems encountered in the solutions of the prior art.

In this regard, the invention relates to an assembly for a turbomachine, comprising a piston, a housing inside which the piston is configured to slide, and a control valve configured to control the movement of the piston.

The interior of the housing includes a first chamber and a second chamber separated from the first chamber by the piston. The assembly includes a cooling duct which is configured to circulate fluid to cool the first chamber and the second chamber. The valve includes a first port and a second port which is fluidly connected to the first chamber.

According to the invention, the assembly comprises a first branch branch located in branch of the first port and the second port, the first branch branch being fluidly connected to the cooling duct.

Thanks to the invention, the cooling duct comprises a fluid supply which is independent of the position of the shutter of the control valve. The cooling flow is then at least partially independent of the pressure difference between the chambers.

Furthermore, the first branch branch is located in branch of the first port and the second port of the valve, which allows to limit the mass and size of the assembly.

The invention therefore makes it possible to make the leakage flow less sensitive to the pressure difference between the chambers, while limiting the mass and size of the assembly.

The invention may optionally include one or more of the following characteristics, whether or not combined.

Advantageously, the control valve comprises a third port and a fourth port which is fluidly connected to the second chamber. The assembly includes a second branch branch located in branch of the third port and the fourth port, the second branch branch being fluidly connected to the cooling duct.

According to a particular embodiment, the valve comprises a shutter whose opening or closing position is controlled electrically and / or hydraulically.

According to an advantageous embodiment, the shutter comprises at least three positions:

a first open position in which the first port is fluidly connected to the second port, the third port being fluidly connected to the fourth port, a second open position in which the first port is fluidly connected to the fourth port, the second port being fluidly connected to the third orifice, and an intermediate position in which the orifices are not fluidly connected to each other.

According to another particular feature, the cooling duct at least partially surrounds the first chamber and the second chamber. Preferably, the cooling duct extends at least partially inside a wall of the casing.

Advantageously, the cooling duct comprises at least one flow restrictor configured to limit the flow of fluid flowing in the cooling duct.

The invention also relates to a turbomachine comprising an assembly as defined above. The assembly is in particular a hydraulic cylinder for a turbomachine.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be better understood on reading the description of exemplary embodiments, given for purely indicative and in no way limiting, with reference to the appended drawings in which:

FIG. 1 is a partial schematic representation of an assembly for a turbomachine, according to an embodiment known from the prior art, intended to supply mechanical power to turbomachine equipment r

FIG. 2 is a partial schematic representation of an assembly for a turbomachine, according to a first embodiment of the invention, in which the piston is in the "retracted rod" position;

FIG. 3 is a partial schematic representation of the assembly according to the first embodiment, in which the piston is in the “extended rod” position;

Figure 4 is a functional schematic representation of the control valve of the assembly according to the first embodiment.

DETAILED PRESENTATION OF PARTICULAR EMBODIMENTS

Identical, similar or equivalent parts of the different figures have the same reference numerals so as to facilitate the passage from one figure to another.

FIG. 2 represents a hydraulic assembly for a turbomachine 1, according to a preferred embodiment of the invention. The assembly is a mechanical actuator for a turbomachine 1, such as a hydraulic cylinder for a turbomachine. It supplies mechanical power to turbomachine equipment, for example a mechanism for changing the orientation of the stator blade blades of the turbomachine 1.

The assembly includes a piston 3 and a casing 2 in which the piston 3 is configured to slide. The displacement of the piston 3 inside the casing 2 is controlled by a control valve 6, on the order of a control system 7.

The assembly also includes a cooling circuit 5 configured to cool it by circulation of a fluid flow, in particular in the event of a fire.

The fluid circulating in the assembly is oil or fuel. It serves as a heat transfer fluid in the cooling circuit 5. It also serves to supply hydraulic power under the effect of the piston 3.

The piston 3 is connected to a rod 4 which is configured to transmit mechanical forces to the equipment of the turbomachine 1. The piston 3 and the rod 4 jointly form a single part which is substantially symmetrical of revolution around the axis of the piston 3 .

The casing 2 comprises a single side wall 20 which is substantially cylindrical of revolution around the axis of the piston 3.

The interior of the casing 2 comprises a first chamber 23 and a second chamber 25 which are surrounded by the wall 20 of the casing 2. The second chamber 25 is separated from the first chamber 23 by the piston 3.

The wall 20 is traversed by a fluid supply conduit 83 from the first chamber 23 and by a fluid supply conduit 93 from the second chamber 25. It is also traversed by a cooling conduit 50 which surrounds the first chamber 23 and the second bedroom 25.

The cooling duct 50 extends from its first end B which is located in the wall 20 to its second end G which is also located in the wall 20. The first end B is an opening which is located near the duct supply 83 from the first chamber. The second end G is an opening which is located near the supply conduit 93 of the second chamber. The cooling duct 50 extends over the majority of the periphery of the casing 2.

The cooling duct 50 comprises a flow restrictor 52 which for example takes the form of reliefs, elbows and / or narrowing of the duct

50. The flow restrictor 52 makes it possible to limit the flow of a leakage flow rate in the conduit 50.

The cooling duct 50 is used to cool at least the first chamber 23 and the second chamber 25. In the embodiment shown, it is also used to cool the wall 20 of the casing 2 and possibly other equipment of the jack, such as '' a piston displacement sensor 3.

The control valve 6 includes a shutter (not shown) and four ports C, D, H and I.

The first orifice C is connected to a first upstream conduit 81 in which fluid can flow towards a low pressure pump (not shown), via a first supply conduit 82 of the valve. This third orifice C forms a low pressure outlet of the valve 6.

The second orifice D is fluidly connected to the first chamber 23 by the supply conduit 83 of the first chamber. The second orifice D is a first port for using the valve 6. The conduit 83 extends from the second orifice D to an orifice E which opens into the first chamber 23.

The third orifice H is connected to a second upstream conduit 91 in which fluid from a high pressure pump (not shown) can flow, via a second supply conduit 92 of the valve. It is a high pressure inlet of the control valve 6.

The fourth orifice I is fluidly connected to the second chamber 25 by the supply conduit 93 of the second chamber. The fourth orifice is a second port for using the valve 6. The conduit 93 extends from the fourth orifice I to an orifice J which opens into the second chamber 25.

With reference to FIGS. 2 to 4, the valve 6 comprises at least three operating positions: a first open position for bringing out the rod 4, a second open position for bringing in the rod 4, and an intermediate position in which the piston 3 is stationary.

In the first open position, the valve 6 lets fluid flow from its first orifice C toward its second orifice D, and it lets fluid flow from its fourth orifice I towards its third orifice H The pressure of the fluid increases in the first chamber 23 relative to that in the second chamber 25. The piston 3 then tends to move in the direction of the arrow Fi to bring out the rod 4.

In the second open position, the valve 6 lets fluid flow from its third orifice H towards its second orifice D, and it lets fluid flow from its fourth orifice I towards its first orifice C The pressure of the fluid increases in the second chamber 25 relative to that in the first chamber 23. The piston 3 then tends to move in the direction of the arrow F2 in order to bring in the rod 4.

In the third position or intermediate position, the valve 6 prevents the circulation of fluid between its orifices C, D, H and I.

The valve 6 hydraulically controls the position of the piston 3 on command of the control system 7.

The control system 7 comprises a control unit 71 and an electronic regulation system 72 of the turbomachine.

The control unit 71 electrically controls the position of the shutter of the valve 6 on the order of the electronic regulation system 72.

The electronic regulation system 72 is also known by the acronym in English of "FADEC". It is a central control system with two redundant channels and with full authority of the turbomachine 1.

The electronic regulation system 72 gives orders to the control unit 71 to change the position of the piston 3, according to the mechanical power requirements of the equipment of the turbomachine 1.

The cooling duct 50 is connected at its first end B to an outlet duct 84 which is connected to the first upstream duct 81 at a node A. The node A is a node for separating the first supply duct 82 of the valve and the outlet pipe 84.

In other words, the outlet conduit 84 is located in derivation of the first supply conduit 82 of the valve and the supply conduit 83 of the first chamber.

The cooling duct 50 is connected at its second end G to an inlet duct 94 which is connected to the second upstream duct 91 at a node F. The node F is a node for separating the second duct from supply 92 of the valve and of the inlet duct 94.

In other words, the inlet conduit 94 is located in derivation of the second supply conduit 92 of the valve and of the supply conduit 93 of the second chamber.

The outlet duct 84, the cooling duct 50 and the inlet duct 94 jointly form the cooling circuit 5 of the assembly.

The first upstream conduit 81, the first supply conduit 82, the supply conduit 83 of the first chamber and the outlet conduit 84 jointly form a first fluid supply circuit 8 of the assembly.

The second upstream conduit 91, the second supply conduit 92, the supply conduit 93 of the second chamber and the inlet conduit 94 jointly form a second fluid supply circuit 9 of the assembly.

In FIG. 2, the piston 3 is in a retracted rod position in which the piston 3 is closest to the bottom of the second chamber 25.

In FIG. 3, the piston 3 is shown in the extended rod position, in which the piston 3 is closest to the bottom of the first chamber 23.

The piston 3 passes from the retracted rod position shown in FIG. 2 to the extended rod position shown in FIG. 3, when the shutter of the control valve 6 is in its first open position.

The piston 3 passes from the extended rod position shown in FIG. 3 to the retracted rod position shown in FIG. 2, when the shutter of the control valve 6 is in its second open position.

In all cases, the pressure in the first upstream circuit 81 is lower than that in the second upstream circuit 91. Fluid therefore flows continuously in the cooling circuit 5 from node F to node A, at successively through the inlet duct 94, the cooling duct 50 and the outlet duct 84. This cooling flow rate is independent of the flow rate of fluid flowing through the supply duct 83 of the first chamber and that flowing through the supply duct 93 of the second chamber.

The outlet conduit 84 being bypassed from the first supply conduit 82 of the valve and from the supply conduit 83 of the first chamber, the mass and the size of the first supply circuit 8 are limited.

Since the inlet conduit 94 is bypassed from the second supply conduit 92 of the valve and from the supply conduit 93 of the second chamber, the mass and size of the second supply circuit 9 are limited.

According to an alternative embodiment not shown, the outlet conduit 84 is not connected to the first upstream circuit 81, and the inlet conduit 94 is bypassed from the second supply conduit 92 and from the supply conduit 93 of the second bedroom.

According to another variant embodiment, not shown, the inlet conduit 94 is not connected to the second upstream circuit 91, and the outlet conduit 84 is bypassed from the first supply conduit 82 and from the supply conduit 83 of the first bedroom.

Alternatively, the cooling duct 50 can at least partially project from the cylindrical wall 20 of the casing.

As a variant, the cooling duct 50 can be formed in a jacket located between the side wall 20 and the piston 3.

As a variant, the piston 3 is fixed to the rod 4 instead of being in one piece with the

0 rod 4.

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Claims (7)

1. An assembly for a turbomachine (1), comprising: a piston (3), a housing (2) inside which the piston (3) is configured to slide, the interior of the housing (2) comprising: a first chamber (23), and a second chamber (25) separated from the first chamber (23) by the piston (3), a cooling duct (50) configured to circulate fluid to cool the first chamber (23) and the second chamber (25), a control valve (6) configured to control the movement of the piston (3), the valve (6) comprising: a first orifice (C), a second orifice (D) fluidly connected to the first chamber (23), characterized in that the assembly comprises a first branch branch (84) located in derivation of the first orifice (C) and the second orifice (D), the first branch branch (84) being fluidly connected to the cooling duct (50). 2. Assembly according to the preceding claim, in which the control valve (6) comprises a third orifice (H) and a fourth orifice (I) which is fluidly connected to the second chamber (25), the assembly comprising a second branch bypass (94) located in bypass of the third orifice (H) and the fourth orifice (I), the second branch of bypass being fluidly connected to the cooling duct (50). 3. Assembly according to any one of the preceding claims, in which the valve (6) comprises a shutter, the open or closed position of which is electrically and / or hydraulically controlled. 4. Assembly according to any one of the preceding claims, in which the valve (6) comprises at least three positions: a first open position in which the first port (C) is fluidly connected to the second port (D), the third port (H) being fluidly connected to the fourth port (I), a second open position in which the first orifice (C) is fluidly connected to the fourth orifice (I), the second orifice (D) being fluidly connected to the third orifice (H), and an intermediate position in which the orifices (C, D, H, I) are not fluidly connected to each other. 5. Assembly according to any one of the preceding claims, in which the cooling duct (50) at least partially surrounds the first chamber (23) and the second chamber (25), the cooling duct (50) extending from preferably at least partially inside a wall (20) of the housing. 6. Assembly according to any one of the preceding claims, in which the cooling duct (50) comprises at least one flow restrictor (52) configured to limit the flow of fluid flowing in the cooling duct (50). 7. Turbomachine (1) comprising an assembly according to any one of the preceding claims. S.61258 1/2