FR3058186A1 - ROTOR MOTOR TURBOPOMPE COMPRISING A ROTOR ROTATING BLOCK DEVICE - Google Patents

Abstract

A rocket engine turbocharger (10) comprising a rotor (14) rotatable with respect to a housing (12) and a locking device (16) for rotationally locking the rotor (14) relative to the housing (12).

Description

(57) Rocket engine turbopump (10) comprising a rotor (14) movable in rotation relative to a casing (12) and a locking device (16) for locking in rotation the rotor (14) relative to the casing ( 12).

FR 3 058 186 - A1

FIELD OF THE INVENTION The present disclosure relates to a rocket engine turbopump and a rocket engine comprising such a turbopump.

STATE OF THE PRIOR ART [0002] Known turbopumps sometimes suffer damage, in particular at the level of the rotor bearings, under various circumstances. This happens for example when the rotor is rotated outside the required thermal operating conditions (for example in so-called idle mode or “tank idle mode” in English), or else during various manipulations of the turbopump during its transport or of its assembly within a rocket engine. There is therefore a need in this sense.

PRESENTATION OF THE INVENTION One embodiment relates to a rocket engine turbopump comprising a rotor movable in rotation relative to a casing and a locking device for locking in rotation the rotor relative to the casing.

It is understood that the rotor extends in an axial direction and is movable in rotation around the axial direction within the housing, the locking device being configured to block the rotor in rotation around the axial direction.

The inventors have noticed that the blocking in rotation of the rotor relative to the casing not only during the transport and the assembly of the turbopump, but also during certain phases of operation of the rocket engine such as the idle mode or "tank idle" mode ”, allows the rotor bearings to be preserved from any damage, at the very least to reduce the damage to acceptable levels.

In some embodiments, the blocking device comprises a movable blocking part between a free position in which the rotor is free to rotate and a blocking position in which the blocking part cooperates with the rotor so as to block the rotor in rotation.

It is understood that the locking of the rotor is carried out by the locking part which blocks the rotor when it is in the locking position and releases the rotation of the rotor when it is in the free position. Such blocking achieved by a moving part is particularly effective and reliable. For example, the cooperation between the rotor and the blocking piece allows mechanical blocking by cooperation by form complementarity. The inventors have found that keeping the rotor shaft in position also makes it possible to homogeneously cool all the parts of the rotor before starting the rocket engine (of course during cooling phases).

In some embodiments, the rotor extends in an axial direction, the locking piece sliding in the axial direction between the free position and the locking position.

It is therefore understood that the blocking piece is movable in the axial direction between the free position and the blocking position. Such a configuration where the rotor and the blocking device are adjacent in the axial direction makes it possible to facilitate the integration of the blocking device within the turbopump, and therefore to reduce the size of the turbopump equipped with the blocking device. For example, the locking piece comprises a toothed wheel coaxial with the rotor and configured to cooperate with a toothed wheel complementary to the rotor.

In some embodiments the locking device comprises a spring (or a first spring) tending to bring the locking piece in the free position.

This spring (or this first spring) therefore makes it possible to return the blocking part to the free position whereby the free position is the default position of the blocking part. For example, the spring tending to bring the blocking piece into the free position is a compression spring, which is compressed during the passage of the blocking piece from the free position to the blocking position. This makes the blocking device more reliable and ensures that it does not disturb the proper functioning of the turbopump, even if the blocking device fails.

In some embodiments, the blocking device comprises a spring (or a second spring) tending to bring the blocking piece into the blocking position.

This spring (or this second spring) keeps the blocking part in the blocking position, whereby the blocking part does not deviate from the blocking position even when it is subjected, via the rotor. , to stresses tending to move it away from the blocking position. For example, the spring tending to bring the blocking piece into the blocking position is a compression spring, which is compressed during the passage of the blocking piece from the blocking position to the free position.

In some embodiments, the stiffness of the spring tending to bring the blocking piece in the free position is greater than the stiffness of the spring tending to bring the blocking piece in the blocking position.

When the blocking device comprises a spring tending to bring the blocking piece into the free position and a spring tending to bring the blocking piece into the blocking position, it is thus ensured that the free position is indeed the position by default.

In some embodiments, the blocking device comprises a fixed base, the spring tending to bring the blocking piece into the free position and the spring tending to bring the blocking piece into the blocking position both cooperating with the '' fixed base.

It is understood that the fixed base is a fixed element within the blocking device relative to the blocking part. Such a fixed base forms a common reference element with which the spring tending to bring the blocking piece in the free position and the spring tending to bring the blocking piece in the blocking position cooperate. It is therefore understood that each spring cooperates directly or indirectly on the one hand with the fixed base, and on the other hand with the blocking part. Such a common fixed base for the two springs simplifies the structure of the locking device and reduces its size.

In certain embodiments, the spring tending to bring the blocking piece into the free position cooperates with the blocking part by means of a return element.

It is understood that the spring tending to bring the blocking piece in the free position cooperates with the return element while the return element cooperates with the blocking part. For example, the blocking part is coupled in the oriented direction from the blocking position to the free position with the return element. Such a structure facilitates the manufacture and assembly of the various elements of the blocking device, as well as its maintenance while allowing a reduced bulk.

In certain embodiments, the return element comprises a piston sliding in a chamber with controlled pressurization.

It is understood that by varying the pressure in the chamber is varied the position of the return element within the chamber, for example when the force generated by the pressure within the chamber is sufficient to s oppose the force generated by the first spring, or not, whereby the blocking piece is brought to the blocking position or to the free position. Thus, by controlling the pressure within the chamber, for example using a pressurized gas tank, the position of the blocking part is controlled. Such a configuration makes it possible to use proven control means which are already available within a rocket engine, thanks to which the control device is particularly reliable and easily integrated within a rocket engine.

In some embodiments, the blocking device comprises a control device configured to control a first valve for the pressurization of the controlled pressurization chamber and a second valve for the depressurization of the controlled pressurization chamber.

Such a configuration enables simple and reliable control of the pressurization within the chamber, whereby the position of the blocking piece is controlled in a simple and reliable manner.

In certain embodiments, the rotor comprises a shaft extending in an axial direction, the shaft carrying a pump wheel and a turbine wheel, the locking device being arranged opposite the wheel. pump relative to the impeller in the axial direction.

It is therefore understood that considered in the axial direction, the pump wheel and the locking device are respectively arranged on either side of the turbine wheel. Such a configuration makes it possible to limit the overall size of the turbopump, and to easily integrate the blocking device within the turbopump.

An embodiment also relates to a rocket engine equipped with a rocket engine turbopump according to any one of the embodiments described in the present description.

BRIEF DESCRIPTION OF THE DRAWINGS The invention and its advantages will be better understood on reading the detailed description given below of various embodiments of the invention given by way of nonlimiting examples. This description refers to the pages of attached figures, on which:

FIG. 1 represents a spacecraft comprising a rocket engine equipped with a turbopump,

FIG. 2 represents the turbopump of the rocket engine of FIG. 1, seen in partial axial section,

FIG. 3 is a detailed view in axial section of the blocking device of the turbopump shown in FIG. 2, shown in the free position,

FIG. 4 is a view similar to FIG. 3, where the blocking device is in the blocking position, and

- Figure 5 shows a variant of the locking device. DETAILED DESCRIPTION OF EXAMPLES OF EMBODIMENT FIG. 1 represents a spacecraft 100, equipped with a rocket motor 50 itself equipped with a turbopump 10. FIG. 2 represents a more detailed view of the turbopump 10.

The turbopump 10 comprises a rotor 14 and a casing

12. The rotor 14 comprises a shaft 14C extending in an axial direction X and supported by bearings 15 within the casing 12. The shaft 14C carries a pump wheel 13 and a turbine wheel 14B.

The turbopump 10 includes a fluid inlet 11, the fluid being pressurized by the pump wheel 13, then driven by pipes not shown to the combustion chamber (not shown). Part of the combustion products of the rocket engine are led to the turbine wheel 14B, then opens into the fluid outlet casing 17, and escapes to a fluid outlet, not shown. Note that the fluid outlet housing 17 is part of the housing 12. Thus, part of the combustion products of the rocket engine drives the turbine wheel 14B in rotation, whereby the shaft 14C and therefore the pump wheel 13 are also rotated.

To block the rotation of the rotor 14, for example when no fluid circulates in the turbopump 10 or in so-called idle mode ("tank idle-mode"), the turbopump 10 comprises a blocking device 16 which is configured to block the rotor 14 cooperating with an axial end 14C1 of the shaft 14C disposed on the side of the fluid outlet housing 17. In this example, the locking device 16 is fixed to the fluid outlet housing 17. Thus, the device blocking 16 is in this example arranged opposite the pump wheel 13 relative to the turbine wheel 14B in the axial direction X.

Referring to Figures 3 and 4, the locking device 16 comprises a housing 19, this housing 19 being fixed to the housing 12 of the turbopump 10. The housing 19 extends axially and houses a locking piece 26, a first spring 20 tending to bring the locking piece 26 in the free position, a base 22, a second spring 24 tending to bring the locking piece 26 in the locking position and a piston 18 movable in a chamber 23.

The locking piece 26 is axially movable between a free position in which it does not cooperate with the rotor 14 (see fig. 3), and a locking position in which it cooperates with the rotor 14 (see fig .4). The locking piece 26 comprises at its free end a toothed wheel 26A configured to cooperate with a corresponding toothed wheel 14D of the rotor 14, the toothed wheel 14D of course forming the end 14C1 of the rotor 14. Thus, in the locked position, the wheels 26A and 14D are meshed. It is noted that the teeth of the toothed wheels 26A and 14D have inclined faces configured to cooperate in sliding so that when the teeth are not aligned, the wheel 26A of the locking device 26 rotates the wheel 14D of the rotor 14 so to line up and mesh. To do this, it is understood of course that the rotor 14 is free to rotate around the axial direction X, while the locking piece 26 is locked in rotation around the axial direction X by any means known to those skilled in the art. . For example, the blocking piece 26 is engaged with axial grooves (ie system of axial grooves / ribs) of the casing 19 and / or of the piston 18 described later, the piston 18 being itself locked in rotation around the direction axial X with respect to the base 22 described later. According to a variant shown in FIG. 5, the blocking in rotation of the blocking piece 26 relative to the casing 19 is achieved by means of an axial cleat 19A extending within a notch 27 of the blocking piece 26. Although understood, the cleat 19A is engaged with the notch 27 both in the free position and in the locking position.

According to another variant not shown, the locking piece 26 and the rotor 14 do not have toothed wheels but complementary surfaces cooperating by friction. Thus, the blocking is achieved by friction and not by meshing with toothed wheels.

The first spring 20 cooperates indirectly with the blocking part 26 and tends to bring it into the free position shown in Figure 3. More particularly, in this example, the first spring 20 is a compression spring. A first axial end of the first spring 20 cooperates with the locking piece 26 by means of the piston 18. Thus, the first spring 20 cooperates with the piston 18 bearing on a first shoulder 18A. The piston 18 has a rod 18C extending axially through the base 22 described later. The rod 18C of the piston 18 comprises a second shoulder 18B cooperating in abutment with a shoulder 26B of the locking piece 26. In this example, the shoulder 18B is formed by a washer 21 fixed to one end of the piston 18, and more particularly of the rod 18C, in this example using a screw 21A. A second axial end of the first spring 20 opposite the first end in the axial direction X, cooperates in abutment with a shoulder 22A of the base 22, the base 22 being integral with the housing 19. Thus, the first spring 20 tends to move the shoulder 18A away from the base 22 in the axial direction X, whereby the piston 18 drives, via the washer 21, the locking piece 26 in the same direction in the free position. Of course, the piston 18 does not drive the locking piece 26 when it moves in an opposite direction in the axial direction X, that is to say in a direction tending to bring the shoulder 18A closer to the base 22. In the latter case, it simply releases the locking piece 26 by moving the washer 21 away from the shoulder 26B. Thus, the piston 18 fitted with the washer 21 forms a return element for the blocking part 26, this return element tending to return the blocking part 26 to the free position.

The second spring 24 cooperates directly with the locking piece 26 and tends to bring it into the locking position shown in Figure 4. More particularly, in this example, the second spring 24 is a compression spring. A first axial end of the second spring 24 cooperates directly with a shoulder 26C of the locking piece 26. A second axial end of the second spring 24 opposite the first end in the axial direction X, cooperates in abutment with a shoulder 22B of the base 22. Thus, the second spring 24 tends to move the shoulder 26C away from the locking piece 26 of the base 22 in the axial direction X, whereby the second spring 24 tends to bring the locking piece 26 into the same steering, in the locking position shown in Figure 4.

The stiffness of the first spring 20 being greater than the stiffness of the second spring 24, the equilibrium configuration (or at rest) of the locking device 16 is the configuration shown in Figure 3 where the locking piece 26 is in free position. Furthermore, when the blocking part 26 is in the free position, the second spring 24 is prestressed, whereby the second spring 24 brings the blocking part 26 into the blocking position when it is released from the washer 21, or, more generally, of the recall element.

The piston 18 slides in the axial direction X within the housing 19. The chamber 23 is delimited by the walls of the housing 19 and by the base 22. The piston 18 is disposed within the chamber 23, the rod 18C extending axially through the base 22. The pressure within the chamber 23 is controlled by a pressure supply system 30 comprising a source of pressurized gas not shown, a pressurization valve 32, a pressure valve depressurization 36, and a control and command unit 34. For example, the pressurization valves 32 and depressurization 36 are solenoid valves. The chamber 23 is therefore a controlled pressurization chamber. Note that a fluid connection 31 communicates with the chamber 23 to pressurize / depressurize the chamber. It is also noted that in this example the piston 18 has a seal 18D cooperating with the internal axial wall of the casing 19. According to a variant not shown, the chamber 23 is delimited by a bellows extending axially between the piston 18 and the internal wall of the casing 19 vis-à-vis in the axial direction X of the casing 19.

Thus, when the chamber 23 is at external pressure, or more generally at a pressure lower than a predetermined pressure, the locking device 16 is in the equilibrium configuration shown in Figure 3, the locking piece 26 being in the free position. When the pressure inside the chamber 23 is greater than or equal to the predetermined pressure, the piston 18 slides axially and compresses the first spring 20, thus releasing the blocking part 26 from the washer 21. The second spring 24 then brings the locking element 26 in the locking position shown in FIG. 4. Conversely, when the pressure decreases within the chamber 23 so as to be less than the predetermined pressure, the first spring 20 returns, via the piston 18 and the washer 21, the locking part 26 in the free position shown in FIG. 3.

Although the present description refers 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 claims. 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.

Claims (10)

1. Rocket engine turbopump (10) comprising a rotor (14) movable in rotation relative to a casing (12) and a locking device (16) for locking in rotation the rotor (14) relative to the casing (12 ). 2. Rocket engine turbopump (10) according to claim 1, in which the blocking device (16) comprises a blocking part (26) movable between a free position in which the rotor (14) is free in rotation and a locking position in which the locking piece (26) cooperates with the rotor (14) so as to lock the rotor (14) in rotation. 3. Rocket engine turbopump (10) according to claim 2, in which the rotor (14) extends in an axial direction (X), the locking piece (26) sliding in the axial direction (X) between the free position and blocking position. 4. Rocket engine turbopump (10) according to claim 2 or 3, wherein the locking device (16) comprises a spring (20) tending to bring the locking piece (26) in the free position. 5. Rocket engine turbopump (10) according to any one of claims 2 to 4, in which the blocking device comprises a spring (24) tending to bring the blocking part (26) into the blocking position. 6. Rocket engine turbopump (10) according to claims 4 and 5, wherein the stiffness of the spring (20) tending to bring the locking piece (26) in the free position is greater than the stiffness of the spring (24) tending bringing the blocking piece (26) into the blocking position. 7. Rocket engine turbopump (10) according to any one of claims 4 to 6, in which the spring (20) tending to bring the blocking part (26) in the free position cooperates with the blocking part (26) by means of a return element (18, 21). 8. Rocket engine turbopump (10) according to claim 7, wherein the return element comprises a piston (18) sliding in a controlled pressurization chamber (23). 9. Rocket engine turbopump (10) according to any one of 5 claims 1 to 8, wherein the rotor (14) comprises a shaft (14C) extending in an axial direction (X), the shaft (14C) carrying a pump wheel (13) and a turbine wheel ( 14B), the locking device (16) being arranged opposite the pump wheel (13) relative to the turbine wheel (14B) 10 in the axial direction (X). 10. Rocket motor (50) comprising a fused motor turbopump (10) according to any one of claims 1 to 9. 1/4