Dynamic balancing system for a rotating part, and turbomachinery comprising a rotating part and such a balancing system

Abstract

This dynamic balancing system (18, 20) for a rotating part comprises a plurality of cylinders (22, 22a, 22b) extending radially and distributed in the circumferential direction, each cylinder (22, 22a, 22b) being provided with a body (24), a rod (26) and a piston (28) fixed to the rod (26) and delimiting in the body (24) of the cylinder (22, 22a, 22b) a first chamber (32) and a second chamber (34), each cylinder (22, 22a, 22b) being further provided with a counterweight (30) mounted on the rod (26) of the cylinder (22, 22a, 22b) and arranged radially outside the body (24) of the cylinder (22, 22a, 22b). 22b), the system (18, 20) further comprising means for supplying fluid (36) to the first and second chambers (32, 34) of each cylinder (22, 22a, 22b). Figure for the abstract: Fig 2

Description

Title of the invention: Dynamic balancing system for a rotating part, and turbomachinery comprising a rotating part and such a balancing system technical field

[0001] The invention has as its technical field the balancing of a rotating part, in particular of a turbomachine, when an imbalance appears.

[0002] In particular, the present invention relates to a dynamic balancing system for a rotating part of a turbomachine and a turbomachine comprising at least one such balancing system. Previous techniques

[0003] An imbalance can suddenly appear in a turbomachine, particularly during a loss of blade of a fan or turbine of the turbomachine.

[0004] Document FR3001291 discloses a balancing device for a turbomachine comprising a conical shell pierced by orifices distributed radially around the entire circumference of the shell, nuts crimped into the orifices of the shell, and balancing screws of different masses screwed onto the nuts.

[0005] However, such a balancing device requires detecting the imbalance of the turbomachine, then stopping the turbomachine in order to position the balancing screws adapted to correct the imbalance of the turbomachine. Description of the invention

[0006] The present invention therefore aims to overcome all or part of the aforementioned drawbacks.

[0007] The invention relates to a dynamic balancing system for a rotating part, in particular of a turbomachine, the system comprising a plurality of cylinders extending radially and distributed in the circumferential direction, each cylinder being provided with a body, a rod and a piston fixed to the rod and delimiting in the body of the cylinder a first chamber and a second chamber.

[0008] Each cylinder is further equipped with a weight mounted on the cylinder rod and arranged radially outside the cylinder body.

[0009] According to another feature, the system further includes means for supplying fluid to the first and second chambers of each cylinder.

[0010] In the event of an imbalance occurring in a given direction, particularly during a blade loss, the counterweight of at least one cylinder of the system arranged in the given direction is capable of moving radially outwards to compensate for the imbalance, for example under the effect of a centrifugal force experienced by the counterweight during the appearance of imbalance and / or under the effect of the means of fluid supply.

[0011] Advantageously, the weights of the cylinders of the system are all of identical mass.

[0012] Advantageously, the cylinders of the system are distributed regularly in the circumferential direction.

[0013] The fluid supply means may include a fluid reservoir configured to supply fluid to the first chamber of each cylinder.

[0014] The fluid supply means may include a fluid check device configured to allow fluid to flow from the fluid reservoir to the first chamber of each cylinder, and to prevent fluid from flowing from the first chamber of each cylinder back to the fluid reservoir.

[0015] Thus, the fluid contained in said first chamber of each cylinder cannot flow back into the fluid reservoir.

[0016] Advantageously, the first chamber of each cylinder is located radially outside the second chamber of the cylinder.

[0017] The fluid reservoir may contain oil under a pressure greater than 1 bar.

[0018] Thus, the oil in the fluid reservoir is under sufficient pressure so as not to generate any unbalance.

[0019] The dynamic balancing system may include at least one pair of cylinders.

[0020] The fluid supply means may include at least one conduit fluidly connecting the first chamber of the first cylinder of said pair of cylinders to the second chamber of the second cylinder of said pair of cylinders.

[0021] Thus, the movement of the weight of the first cylinder of said pair of cylinders can set in motion the weight of the second cylinder of said pair of cylinders and contribute to reducing the imbalance.

[0022] Said fluid supply means may include an additional fluid check device configured to permit fluid flow from the first chamber of the first cylinder of said pair of cylinders to the second chamber of the second cylinder of said pair of cylinders only when the pressure difference between the fluid pressure of the first chamber of the first cylinder of said pair of cylinders and the fluid pressure of the second chamber of the second cylinder of said pair of cylinders is greater than a predetermined threshold, and to prevent fluid flow from the second chamber of the second cylinder of said pair of cylinders to the first chamber of the first cylinder of said pair of cylinders.

[0023] The predetermined threshold allows the sensitivity of the dynamic balancing system to be adjusted. In particular, in the absence of an imbalance, the fluid from the reservoir supplying the first chamber of the first cylinder of said pair cannot circulate from the first chamber of the first cylinder to the second chamber of the second cylinder of said pair.

[0024] The fluid supply means may include at least one additional conduit fluidly connecting the second chamber of the first cylinder of said pair of cylinders to the first chamber of the second cylinder of said pair of cylinders.

[0025] The additional fluid check device can be configured to allow fluid to flow from the first chamber of the second cylinder of said pair of cylinders to the second chamber of the first cylinder of said pair of cylinders only when the pressure difference between the fluid pressure of the first chamber of the second cylinder of said pair of cylinders and the fluid pressure of the second chamber of the first cylinder of said pair of cylinders is greater than the predetermined threshold, and to prevent fluid from flowing from the second chamber of the first cylinder of said pair of cylinders to the first chamber of the second cylinder of said pair of cylinders.

[0026] The first cylinder of said pair of cylinders may be radially opposed to the second cylinder of said pair of cylinders.

[0027] The fluid supply means may include a plurality of solenoid valves configured to control the fluid supply to the first and second chambers of at least one cylinder.

[0028] Thus, it is possible to dynamically control the movement of the weight of said cylinder to compensate for the imbalance of the rotating part.

[0029] Optionally, the fluid supply means may include a plurality of solenoid valves configured to control the fluid supply to the first and second chambers of each cylinder.

[0030] The present invention also relates to a turbomachine comprising at least one rotating part and at least one dynamic balancing system as defined above, the cylinders of said system being mechanically connected to said rotating part and driven in rotation at the rotational speed of said rotating part.

[0031] Advantageously, the cylinders of the system are arranged according to a balancing plane orthogonal to the axis of rotation of the rotating part of the turbomachine.

[0032] The turbomachine may include a blower, a low-pressure shaft configured to drive the blower in rotation and upstream and downstream bearings supporting the low-pressure shaft.

[0033] According to a first design, the cylinders of said system are arranged axially between the blower and the upstream bearing.

[0034] Thus, the cylinders of said system can protect the upstream bearing from a loss of blower blade.

[0035] The bodies of the cylinders of said system can each extend radially outwards from a connecting element of the blower to the low pressure shaft.

[0036] According to a second alternative design, the cylinders of said system are arranged axially between the upstream bearing and the downstream bearing.

[0037] The bodies of the cylinders of said system can each extend radially outwards from the low pressure shaft.

[0038] According to a third design, the cylinders of said system are arranged axially between the blower and the upstream bearing, and the turbomachine further comprises an additional dynamic balancing system, the cylinders of said additional dynamic balancing system being arranged axially between the upstream bearing and the downstream bearing. Brief description of the drawings

[0039] Other objects, features and advantages of the invention will become apparent from the following description, given solely by way of non-limiting example and made with reference to the accompanying drawings in which:

[0040] [Fig. 1] schematically illustrates a portion of a turbomachine comprising two dynamic balancing systems according to an example of an embodiment of the invention;

[0041] [Fig.2] is a detail view of [Fig.1];

[0042] [Fig.3] schematically illustrates an arrangement of cylinders of a system dynamic balancing according to an example of an embodiment of the invention;

[0043] [Fig.4] schematically illustrates a pair of cylinders of a balancing system dynamic according to an example of an embodiment of the invention; and

[0044] [Fig.5] schematically illustrates a cylinder of a dynamic balancing system according to another example of an embodiment of the invention. Detailed description

[0045] Fig. 1 represents a turbomachine 2 comprising a blower 4, a low-pressure compressor 6, a high-pressure compressor 8, a low-pressure shaft 10 driving the blower 4 and the low-pressure compressor 6, and upstream and downstream bearings 12, 14 supporting the low-pressure shaft 10.

[0046] The blower 4 is connected to the low-pressure shaft 10 by a linkage element 16 of the turbomachine 2.

[0047] The turbomachine 2 also includes a first dynamic balancing system 18 arranged axially between the fan 4 and the upstream bearing 12 and a second dynamic balancing system 20 arranged axially between the upstream bearing 12 and the downstream bearing 14.

[0048] The first and second dynamic balancing systems 18 and 20 are each intended to correct the imbalance of the turbomachine 2, thus enabling a correction multi-stage unbalance of the turbomachine 2. They each comprise a plurality of cylinders 22 distributed along the circumferential direction of the low pressure shaft 10.

[0049] As illustrated more clearly in [Fig.2], each cylinder 22 of the first and second dynamic balancing systems 18, 20 is provided with a body 24, a rod 26, a piston 28 fixed to the rod 26 and a weight 30 mounted on the rod 26 and arranged radially outside the body 24 of the cylinder 22. In the illustrated example, each weight 30 is disposed at the distal end of the rod 26.

[0050] The radial direction is defined as orthogonal to the axial direction of the low-pressure shaft 10.

[0051] The piston 28 of each cylinder 22 of the first and second dynamic balancing systems 18, 20 delimits in the body 24 of the cylinder 22 a first chamber 32 and a second chamber 34 located radially inside the first chamber 32.

[0052] The first and second dynamic balancing systems 18, 20 each include fluid supply means 36 (figures 4 and 5) for the first and second chambers 32, 34 of each cylinder 22.

[0053] The body 24 of each cylinder 22 of the first dynamic balancing system 18 extends radially outwards from the connecting element 16 of the blower 4 to the low pressure shaft 10.

[0054] As illustrated in [Fig. 3], the cylinders 22 of the second dynamic balancing system 20 are evenly distributed along the circumferential direction of the low-pressure shaft 10. The cylinders 22 of the second dynamic balancing system 20 here number eight. Alternatively, the second dynamic balancing system 20 may comprise a different number of cylinders 22.

[0055] The body 24 of each cylinder 22 of the second dynamic balancing system 20 extends radially outwards from the outer surface of the low-pressure shaft 10.

[0056] Fig. 4 represents a pair of cylinders 22 and fluid supply means 36 of the second dynamic balancing system 20 according to a first embodiment.

[0057] The first and second cylinders 22a, 22b of the pair of cylinders 22 are radially opposed to each other.

[0058] The fluid supply means 36 comprise a fluid reservoir 38, a first conduit 40a connecting the fluid reservoir 38 to the first chamber 32 of the first cylinder 22a of the pair, a second conduit 40b connecting the fluid reservoir 38 to the first chamber 32 of the second cylinder 22b of the pair, a third conduit 42a connecting the first chamber 32 of the first cylinder 22a of the pair to the second chamber 34 of the second cylinder 22b of the pair, and a fourth conduit 42b connecting the first chamber 32 of the second cylinder 22b of the pair to the second chamber 34 of the first cylinder 22a of the pair.

[0059] The fluid supply means 36 include a fluid check valve 44 allowing fluid to flow from the fluid reservoir 38 to the first chamber 32 of the first and second cylinders 22a, 22b of the pair, and preventing fluid from flowing from the first chamber 32 of the first and second cylinders 22a, 22b of the pair to the fluid reservoir 38.

[0060] The fluid check valve 44 comprises a first check valve 44a fitted to the first fluid line 40a and a second check valve 44b fitted to the second fluid line 40b. The first and second check valves 44a, 44b are each characterized by a minimum mechanical resistance that must be overcome to allow fluid to pass through the first and second check valves 44a, 44b.

[0061] The fluid supply means 36 include an additional fluid check device 46 allowing fluid to circulate from the first chamber 32 of the first cylinder 22a of the pair to the second chamber 34 of the second cylinder 22b of the pair only when the pressure difference between the fluid pressure of the first chamber 32 of the first cylinder 22a of the pair and the fluid pressure of the second chamber 34 of the second cylinder 22b of the pair is greater than a predetermined threshold.

[0062] The additional fluid check valve 46 also allows fluid to circulate from the first chamber 32 of the second cylinder 22b of the pair to the second chamber 34 of the first cylinder 22a of the pair only when the pressure difference between the fluid pressure of the first chamber 32 of the second cylinder 22b of the pair and the fluid pressure of the second chamber 34 of the first cylinder 22a of the pair is greater than the predetermined threshold.

[0063] In addition, the additional fluid check device 46 prevents fluid from flowing from the second chamber 34 of the second cylinder 22b of the pair to the first chamber 32 of the first cylinder 22a of the pair and prevents fluid from flowing from the second chamber 34 of the first cylinder 22a of the pair to the second chamber 34 of the first cylinder of the pair 22a.

[0064] The additional fluid check valve 46 comprises a third check valve 46a fitted to the third fluid line 42a and a fourth check valve 46b fitted to the fourth fluid line 42b. The third and fourth check valves 46a, 46b are each characterized by a minimum mechanical resistance that must be overcome to allow fluid to pass through the third and fourth check valves 46a, 46b, which is strictly greater than the minimum mechanical resistance that must be overcome to allow fluid to pass through the first and second check valves 44a, 44b of the fluid check valve 44.

[0065] The fluid reservoir 38 is sealed and contains oil under a constant pressure greater than 1 bar in order to maintain the weights 30 of the cylinders 22a, 22b in a balanced position during normal operation of the turbomachine 2. Alternatively, the fluid reservoir 38 could contain another fluid, such as air.

[0066] During normal operation of the turbomachine 2, particularly in the absence of imbalance, only the fluid from the fluid reservoir 38 supplies the first chamber 32 of the first and second cylinders 22a, 22b of the pair, the additional fluid check valve 46 then does not allow the circulation of fluid in the third and fourth conduits 42a, 42b.

[0067] During abnormal operation of the turbomachine 2, particularly when an imbalance occurs in the direction of the first cylinder 22a of the pair, for example during a loss of blade in the fan 4, the centrifugal force applied to the weight 30 of the first cylinder 22a of the pair is greater than the centrifugal force applied to the weight 30 of the second cylinder 22b of the pair. The fluid pressure in the first chamber 32 of the first cylinder 22a is no longer sufficient to hold the weight 30 of the first cylinder 22a of the pair in its position, and the weight 30 of the first cylinder 22a of the pair moves radially outwards.

[0068] Since the fluid in the first chamber 32 of the first cylinder 22a of the pair cannot circulate to the fluid reservoir 38, the pressure in the first chamber 32 of the first cylinder 22a of the pair then increases until the additional fluid check device 46 allows the fluid to circulate from the first chamber 32 of the first cylinder 22a of the pair to the second chamber 34 of the second cylinder 22b of the pair.

[0069] The pressure in the second chamber 34 of the second cylinder 22b of the pair then increases, causing the weight 30 of the second cylinder 22b of the pair to move radially outwards and reducing the imbalance.

[0070] Advantageously, the other cylinders 22 of the second dynamic compensation system are also arranged in pairs.

[0071] The paired arrangement of cylinders 22 connected together by conduits 40a, 40b, 42a, 42b gives a damping effect to the dynamic compensation system, thus limiting the shocks resulting from the appearance of the imbalance and allowing a rapid return to acceptable operation of the turbomachine 2.

[0072] Fig. 5, on which the identical elements bear the same references, represents a cylinder 22 and fluid supply means 36 of the second dynamic balancing system 20 according to a second embodiment.

[0073] The fluid supply means 36 here include a solenoid valve 48 controlling the fluid supply from the fluid reservoir 38 to the first chamber 32 of the cylinder 22.

[0074] The fluid supply means 36 also include an additional fluid reservoir 50 and an additional solenoid valve 52 controlling the fluid supply from the additional fluid reservoir 48 to the second chamber 34 of the cylinder 22.

[0075] The second dynamic balancing system 20 is capable of controlling the radial movement of the weight 30 of the cylinder 22 to reduce the imbalance, for example by means of pressure sensors measuring the fluid pressure in the first and second chambers 32, 34 of the cylinder 22.

[0076] Optionally, a dynamic balancing system equipping the turbomachine 2 may include both at least one pair of cylinders 22a, 22b according to the first embodiment of [Fig.4] and at least one cylinder 22 according to the second embodiment of [Fig.5].

[0077] In the example shown in [Fig. 1], the turbomachine 2 comprises two dynamic balancing systems. Alternatively, the turbomachine 2 may comprise a single dynamic balancing system. Or, alternatively, the turbomachine 2 may comprise more than two dynamic balancing systems.

[0078] Figures 3 to 5 illustrate examples of embodiments of the second dynamic balancing system 20. Of course, each dynamic balancing system of the turbomachine 2 can include an arrangement of cylinders 22 as shown in [Fig.3], and / or a pair of cylinders 22 and fluid supply means 36 as shown in [Fig.4], and / or a cylinder 22 and fluid supply means 36 as shown in [Fig.5].

Claims

Claims

1. Dynamic balancing system (18, 20) for a rotating part, in particular a turbomachine (2), the system (18, 20) comprising a plurality of cylinders (22, 22a, 22b) extending radially and distributed in the circumferential direction, each cylinder (22, 22a, 22b) being provided with a body (24), a rod (26) and a piston (28) fixed to the rod (26) and delimiting in the body (24) of the cylinder (22, 22a, 22b) a first chamber (32) and a second chamber (34), characterized in that each cylinder (22, 22a, 22b) is further provided with a weight (30) mounted on the rod (26) of the cylinder (22, 22a, 22b) and arranged radially outside the body (24) of the cylinder (22, 22a, 22b), the system (18, 20) further comprising means (36) for supplying fluid to the first and second chambers (32, 34) of each cylinder (22, 22a, 22b).

2. The dynamic balancing system (18, 20) of claim 1, wherein the fluid supply means (36) comprises a fluid reservoir (36) configured to supply fluid to the first chamber (32) of each cylinder (22, 22a, 22b) and a fluid non-return device (44, 44a, 44b) configured to allow fluid flow from the fluid reservoir (36) to the first chamber (32) of each cylinder (22, 22a, 22b), and to prevent fluid flow from the first chamber (32) of each cylinder (22, 22a, 22b) to the fluid reservoir (36).

3. A dynamic balancing system (18, 20) according to claim 2, wherein the fluid reservoir (36) comprises oil under a pressure greater than 1 bar.

4. A dynamic balancing system (18, 20) according to any preceding claim, comprising at least one pair of cylinders (22a, 22b), the fluid supply means (36) comprising at least one conduit (42a) fluidly connecting the first chamber (32) of the first cylinder (22a) of said pair of cylinders (22a, 22b) to the second chamber (34) of the second cylinder (22b) of said pair of cylinders (22a, 22b).

5. A dynamic balancing system (18, 20) according to claim 4, wherein said conduit (42a) of the fluid supply means (36) comprises an additional fluid non-return device (46, 46a, 46b) configured to allow circulation of fluid from the first chamber (32) of the first cylinder (22a) of said pair of cylinders (22a, 22b) to the second chamber (34) of the second cylinder (22b) of said pair of cylinders (22a, 22b) only when the pressure difference between the fluid pressure of the first chamber (32) of the first cylinder (22a) of said pair of cylinders (22a, 22b) and the fluid pressure of the second chamber (34) of the second cylinder (22b) of said pair of cylinders (22a, 22b) is greater than a predetermined threshold, and to prevent the circulation of fluid from the second chamber (34) of the second cylinder (22b) of said pair of cylinders (22a, 22b) to the first chamber (32) of the first cylinder (22a) of said pair of cylinders (22a, 22b).

6. Dynamic balancing system (18, 20) according to one of claims 4 and 5, wherein the fluid supply means (36) comprise at least one additional conduit (42b) fluidly connecting the second chamber (34) of the first cylinder (22a) of said pair of cylinders (22a, 22b) to the first chamber (32) of the second cylinder (22b) of said pair of cylinders (22a, 22b).

7. A dynamic balancing system (18, 20) according to one of claims 4 to 6, wherein the first cylinder (22a) of said pair of cylinders (22a, 22b) is radially opposite the second cylinder (22b) of said pair of cylinders (22a, 22b).

8. Dynamic balancing system (18, 20) according to any one of the preceding claims, wherein the fluid supply means (36) comprise a plurality of solenoid valves (48, 52) configured to control the fluid supply to the first and second chambers (32, 34) of at least one cylinder (22, 22a, 22b).

9. Turbomachine (2) comprising at least one rotating part and at least one dynamic balancing system (18, 20) according to any one of claims 1 to 8, the cylinders (22, 22a, 22b) of said system (18, 20) being mechanically connected to said rotating part and driven in rotation at the rotation speed of said rotating part.

10. A turbomachine (2) according to claim 9, comprising a fan (4), a low-pressure shaft (10) configured to rotate the fan (4) and upstream and downstream bearings (12, 14) supporting the low-pressure shaft (10), the cylinders (22, 22a, 22b) of said system (18) being arranged axially between the fan (4) and the upstream bearing (12), the turbomachine (2) further comprising an additional dynamic balancing system (20), the cylinders (22, 22a, 22b) of said additional dynamic balancing system (20) being arranged axially between the upstream bearing (12) and the downstream bearing (14).

Images