A labyrinth seal active clearance adaptive mechanism

Abstract

The application provides a kind of grid seal adaptive mechanism of electric hydraulic active gap, including eddy current sensor preamplifier, current amplifier, engine main shaft and the grid seal and stationary machine case that are successively sleeved on the outside of engine main shaft;Multiple voltage eddy current sensors are provided on the grid seal, and multiple installation slots are provided on the stationary machine case, and a micro motor and a micro hydraulic pump are provided in the installation slots.The application converts the change of the rotor gap when the engine main shaft rotates eccentrically into a voltage signal, and converts the voltage signal into an electric current through the eddy current sensor preamplifier to drive the micro motor to rotate and provide support power for the micro hydraulic pump, so that the gap between the grid seal and the engine main shaft remains unchanged, achieving the self-concentric purpose of the engine main shaft and the grid seal.

Description

TECHNICAL FIELD

[0001] The present application relates to a kind of grate sealing electric hydraulic active gap self-adapting mechanism, belong to the field of sealing mechanism in aero-engine, specifically related to a kind of grate sealing electric hydraulic active gap self-adapting mechanism based on eddy current signal feedback. BACKGROUND

[0002] Aero-engine is a kind of internal combustion engine that converts the internal energy of fuel into useful work by continuously flowing gas to drive impeller high-speed rotation.The grate sealing is widely used in aero-engine, gas turbine, compressor and other turbomachinery, and plays an important role in the flow path system.It mainly prevents the leakage of high-pressure air flow compressed by the engine compressor to reduce the energy consumption of the engine.It has been shown that the leakage of the sealing system is reduced by 1%, the thrust is increased by 1-2%, the fuel consumption is reduced by 10%, and the annual savings of fuel cost is billions of dollars, while the engine thrust is increased by only 0.1% by improving the engine vibration and structural strength, and the cost of improving the sealing system is much lower than that of improving other aspects of the engine.

[0003] The current turbine temperature, main shaft speed and compressor pressure ratio of the engine have been improved to a new height, which has continuously improved the working efficiency and thrust of the engine, and other parameters that measure the performance of the engine, but it also tests the working ability of the internal components of the engine, and the working environment of the internal components deteriorates, which affects the working efficiency of the engine.

[0004] During the operation of the engine, especially during the climb stage, due to the change of flight state, the engine is in different working states, and the state switching will cause different degrees of shaft vibration and eccentric rotation of the engine, at this time, the engine rotor will collide with the grate sealing ring installed on the static casing, causing the deformation of the grate sealing ring teeth, reducing the sealing effect of the sealing ring, increasing the air loss, reducing the use efficiency of high-pressure air flow and the working power of the engine, and the clearance change between the engine main shaft eccentric rotation and the grate sealing part will cause the fluid dynamic pressure effect of the high-pressure air flow passing through the rotor.

[0005] There has been a technology that uses the magnetic attraction of an electromagnet to change the gap between the front sensor and the rotor in the circumferential direction according to the gap change, so that the gap voltage signal between the brush seal and the rotor remains unchanged, such as the active gap control brush seal structure based on magnetic attraction effect disclosed in Chinese patent CN113090339B, which is different from the present application in that:

[0006] Structural difference: this patent is to use electromagnet / permanent magnet to realize the deflection of the rotor, and the circumferential resultant force will pull the brush seal ring back to the initial position, and the installation position of the permanent magnet is located at the top of the seal ring, and the magnetic attraction force will pull the seal ring back;

[0007] This application uses an electric hydraulic pump to push the labyrinth seal ring back to the initial installation position, which is located in the mortise of the seal ring installation, instead of the spring position in the patent, reducing the weight;

[0008] Different application fields: this patent is a brush seal, which belongs to a contact seal. When the rotor is greatly deflected, the brush seal allows a large friction with the rotor, and the brush seal tends to form interference with the rotor through friction, so as to achieve a tight contact with the rotor to realize the sealing effect;

[0009] This application is applied to the labyrinth seal. Compared with the brush seal, the labyrinth seal considers the gap between the rotor more. The working principle and structure of the labyrinth seal determine that it must maintain a gap with the rotor, otherwise the labyrinth seal structure will be damaged by the rotor and lose the sealing effect, causing a major accident;

[0010] Different working principles: in this patent, the magnetic attraction force of electromagnet and permanent magnet is used. The magnetic force of electromagnet is positively related to the current size, so the current of the front end eddy current sensor needs to be amplified to make the magnetic attraction force larger;

[0011] This application uses a micro electric hydraulic pump, and the circumferential resultant force is larger, which can better ensure that the labyrinth seal maintains a gap with the rotor.

[0012] Therefore, the technical scheme of the application can actively control the gap between the engine seal ring and the rotor, and keep the initial state stable. SUMMARY

[0013] To solve the above technical problems, the present application provides a kind of labyrinth seal electric hydraulic active gap self-adapting mechanism, and the labyrinth seal electric hydraulic active gap self-adapting mechanism solves the influence of the eccentric rotation of main shaft of aero-engine under different flight states on the collision and friction of labyrinth seal.

[0014] The present application is realized by the following technical solutions.

[0015] The application provides a kind of grid seal active clearance self-adaptive mechanism of electric hydraulic, including eddy current sensor preamplifier, current amplifier, engine main shaft and the grid seal and stationary machine case that are successively sleeved in the outer engine main shaft;Multiple voltage eddy current sensors are provided on the grid seal, and multiple installation slots are provided on the stationary machine case, and a micro motor and a micro hydraulic pump are provided in the installation slot;The voltage eddy current sensor is connected in series with the eddy current sensor preamplifier and the current amplifier in turn through the wire, the micro motor is connected in series with the current amplifier and the eddy current sensor preamplifier in turn through the wire, and the micro hydraulic pump is connected with the micro motor through the transmission shaft.

[0016] The stationary machine case is milled with a T-shaped tenon groove, and the grid seal is connected with the T-shaped tenon groove through the cooperation of the T-shaped tenon and the T-shaped tenon groove.

[0017] Multiple installation strips are provided on the grid seal, and the voltage eddy current sensor is connected to the installation strip through the nut.

[0018] The installation slot is machined through the lower edge of the T-shaped tenon groove.

[0019] The installation slot is located on the left and right sides of the T-shaped tenon groove, forming a first installation slot and a second installation slot.

[0020] The first installation slot is provided with a first micro motor and a first micro hydraulic pump, and the second installation slot is provided with a second micro motor and a second micro hydraulic pump.

[0021] The first micro motor and the second micro motor are connected in parallel through the wire and connected in series with the current amplifier, the first micro motor is connected with the first micro hydraulic pump through the transmission shaft, and the second micro motor is connected with the second micro hydraulic pump through the transmission shaft.

[0022] The number of voltage eddy current sensors, micro motors, micro hydraulic pumps, eddy current sensor preamplifiers and current amplifiers corresponds one by one.

[0023] The installation position section of the grid seal is a T-shaped tenon groove.

[0024] The probe end of the voltage eddy current sensor is flush with the highest tooth of the grid seal, and the gap between the probe end and the rotor is within 0.02-0.2mm.

[0025] The beneficial effects of the application are that the change of the gap between the engine main shaft and the rotor during eccentric rotation of the engine main shaft is converted into a voltage signal, the voltage signal is converted into an electric current by the eddy current sensor preamplifier, the micro motor is driven to rotate to provide support power for the micro hydraulic pump, the gap between the grid seal and the engine main shaft is kept unchanged, and the self-concentric purpose of the engine main shaft and the grid seal is achieved. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 is a structural schematic diagram of the present application;

[0027] Figure 2 is a circumferential section structural schematic diagram of the present application;

[0028] In the figure: 1 - engine main shaft, 2 - voltage eddy current sensor, 3 - static casing, 4 - micro motor, 41 - first micro motor, 42 - second micro motor, 5 - micro hydraulic pump, 51 - first micro hydraulic pump, 52 - second micro hydraulic pump, 6 - wire, 7 - eddy current sensor preamplifier, 8 - current amplifier, 9 - mounting groove, 91 - first mounting groove, 92 - second mounting groove, 10 - labyrinth seal. DETAILED DESCRIPTION

[0029] The technical solutions of the present application are further described below, but the scope of protection is not limited to the description.

[0030] Example 1

[0031] As shown in Figure 1 and 2 A labyrinth seal electric hydraulic active gap self-adaptive mechanism, comprising an eddy current sensor preamplifier 7, a current amplifier 8, an engine main shaft 1, and a labyrinth seal 10 and a static casing 3 which are sequentially sleeved on the engine main shaft 1; a plurality of voltage eddy current sensors 2 are arranged on the labyrinth seal 10, a plurality of mounting grooves 9 are arranged on the static casing 3, and a micro motor 4 and a micro hydraulic pump 5 are arranged in the mounting grooves 9; the voltage eddy current sensors 2 are connected in series with the eddy current sensor preamplifier 7 and the current amplifier 8 through wires 6 in sequence, the micro motor 4 is connected in series with the current amplifier 8 and the eddy current sensor preamplifier 7 through wires 6, and the micro hydraulic pump 5 is connected with the micro motor 4 through a transmission shaft.

[0032] Specifically, the eddy current sensor preamplifier 7 is used to collect the eddy current generated by the coil in the voltage eddy current sensor 2, and the current amplifier 8 amplifies the collected current.

[0033] Preferably, the eddy current sensor preamplifier 7 and the current amplifier 8 can be placed in the engine control system, and the control system automatically completes the relevant control.

[0034] The static casing 3 is milled with a T-shaped tenon groove, and the labyrinth seal 10 is connected by cooperating with the T-shaped tenon and the T-shaped tenon groove.

[0035] A plurality of mounting strips are arranged on the labyrinth seal 10, and the voltage eddy current sensors 2 are connected to the mounting strips through nuts.

[0036] Preferably, the mounting strips processed on the labyrinth seal 10 are uniformly arranged 8 in the circumferential direction.

[0037] Preferably, the voltage eddy current sensor 2 is evenly arranged 8 in the circumferential direction.

[0038] The mounting groove 9 is machined by the lower edge of the T-shaped tenon groove, and 8 mounting grooves are evenly arranged in the circumferential direction.

[0039] The mounting groove 9 is respectively located on the left and right sides of the T-shaped tenon groove, forming a first mounting groove 91 and a second mounting groove 92, and a total of 16 mounting grooves.

[0040] The first micro motor 41 and the first micro hydraulic pump 51 are arranged in the first mounting groove 91, and the second micro motor 42 and the second micro hydraulic pump 52 are arranged in the second mounting groove 92.

[0041] The first micro motor 41 and the second micro motor 42 are connected in parallel through the wire 6 and connected in series with the current amplifier 8, the first micro motor 41 is connected with the first micro hydraulic pump 51 through the transmission shaft, and the second micro motor 42 is connected with the second micro hydraulic pump 52 through the transmission shaft.

[0042] The number of voltage eddy current sensor 2, micro motor 4, micro hydraulic pump 5, eddy current sensor preamplifier 7 and current amplifier 8 is one-to-one corresponding.

[0043] The installation position section of the labyrinth seal 10 is a T-shaped tenon groove.

[0044] The probe end of the voltage eddy current sensor 2 is flush with the highest tooth of the labyrinth seal 10, and the gap between the probe end and the rotor is within 0.02-0.2mm.

[0045] Specifically, the labyrinth seal 10 is installed in the static casing 3, the labyrinth seal 10 is supported by the micro hydraulic pump 5 under the T-shaped tenon head, the voltage eddy current sensor 2 is evenly arranged in the circumferential direction, and the voltage eddy current sensor 2 is connected with the eddy current sensor preamplifier 7 and the current amplifier 8 in turn, and connected with the micro motor 4 through the wire 6, to provide support power for the micro hydraulic pump 5.

[0046] Example 2

[0047] The vortex sensor preamplifier 7 is connected with the current amplifier 8 through the wire 6 to amplify the collected current, when the engine main shaft 1 occurs eccentric rotation, the gap between the voltage type eddy current sensor 2 and the rotor changes, the coil in the voltage type eddy current sensor 2 changes with the change of the gap to generate different gap voltage, the voltage signal is converted into current signal in the vortex sensor preamplifier 7, the current is amplified by the current amplifier 8 and then enters the micro motor 4 to drive it to rotate, the transmission shaft transmits the torque of the micro motor 4 into the micro hydraulic pump 5 to drive the labyrinth seal 10 to move, so that the gap between the labyrinth seal 10 and the engine main shaft 1 remains unchanged, so as to achieve the self-concentric purpose of the engine main shaft 1 and the labyrinth seal 10.

[0048] The voltage type eddy current sensor 2 is fixedly installed on the installation strip of the labyrinth seal 10, the micro motor 4 and the micro hydraulic pump 5 are placed along the T-shaped tenon groove of the static casing 3, the voltage signal of the voltage type eddy current sensor 2 is obtained through the vortex sensor preamplifier 7 and is converted into current signal, wherein the voltage signal of the voltage type eddy current sensor 2 decreases with the increase of the gap between the rotor and the voltage type eddy current sensor 2 and increases with the decrease of the gap.

[0049] In summary, the beneficial effects of the present application are:

[0050] 1. The traditional use of the voltage type eddy current sensor is only to monitor the rotor shaft vibration, and the voltage signal generated by the voltage type eddy current sensor itself is not used, the dynamic voltage signal generated by the voltage type eddy current sensor when the gap changes is converted into current signal in the present application, and the current is used to control the electric hydraulic pump;

[0051] 2. The current generated by the voltage signal fed back by the voltage type eddy current sensor generates a thrust on the labyrinth seal, and the voltage signal changes, so the thrust of the micro electric hydraulic pump also changes;

[0052] 3. The gap between the engine main shaft and the voltage type eddy current sensor changes, and the voltage signal generated in the voltage type eddy current sensor also dynamically changes, further making the converted current dynamically change, the power in the micro hydraulic pump also changes, so that the thrust of the micro hydraulic pump on the labyrinth seal dynamically changes, and active gap control is achieved.

Claims

1. A slotted seal active clearance self-adaptive mechanism of electro-hydraulic type, comprising an eddy current sensor preamplifier (7), a current amplifier (8), an engine main shaft (1), and a slotted seal (10) and a static casing (3) which are successively sleeved on the engine main shaft (1), characterized in that: The labyrinth seal (10) is provided with a plurality of voltage eddy current sensors (2), the static casing (3) is provided with a plurality of mounting grooves (9), the mounting groove (9) is provided with a micro motor (4) and a micro hydraulic pump (5); the voltage eddy current sensor (2) is connected in series with the eddy current sensor preamplifier (7) and the current amplifier (8) through the wire (6), the micro motor (4) is connected in series with the current amplifier (8) and the eddy current sensor preamplifier (7) through the wire (6), the micro hydraulic pump (5) is connected with the micro motor (4) through the transmission shaft; The static casing (3) is milled with a T-shaped tenon groove, and the labyrinth seal (10) is connected with the T-shaped tenon groove through a T-shaped tenon; the mounting groove (9) is formed by processing the lower edge of the T-shaped tenon groove, and the mounting groove (9) is located on the left and right sides of the T-shaped tenon groove, forming a first mounting groove (91) and a second mounting groove (92); The first micro motor (41) and the first micro hydraulic pump (51) are arranged in the first mounting groove (91), and the second micro motor (42) and the second micro hydraulic pump (52) are arranged in the second mounting groove (92); the first micro motor (41) and the second micro motor (42) are connected in parallel through the wire (6) and connected in series with the current amplifier (8), the first micro motor (41) is connected with the first micro hydraulic pump (51) through the transmission shaft, and the second micro motor (42) is connected with the second micro hydraulic pump (52) through the transmission shaft.

2. The slotted fence sealed electro-hydraulic active clearance adaptive mechanism of claim 1, wherein: The labyrinth seal (10) is provided with a plurality of mounting strips, and the voltage eddy current sensor (2) is connected to the mounting strip through a nut.

3. The slotted fence active clearance adaptive mechanism of claim 1, wherein: The number of the voltage eddy current sensor (2), the micro motor (4), the micro hydraulic pump (5), the eddy current sensor preamplifier (7) and the current amplifier (8) corresponds one by one.

4. The slotted fence active clearance adaptive mechanism of claim 1, wherein: The installation position section of the labyrinth seal (10) is a T-shaped tenon groove.

5. The slotted fence active clearance adaptive mechanism of claim 1, wherein: The probe end of the voltage eddy current sensor (2) is flush with the highest tooth of the labyrinth seal (10), and the gap between the probe end and the rotor is within 0.02-0.2mm.

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