Gas turbine engine starter

Abstract

The present invention discloses a gas turbine engine starter, comprising a cone and a nozzle body; the cone is a hollow structure, comprising a cone section and a connecting section at the front end of the cone section; a spring seat is arranged at the front end of the cone, the front end of the cone and the spring seat are inserted into the rear end of the nozzle body together, and the spring seat, the cone and the nozzle body are axially pressed and fixed by a threaded ring; a plurality of contraction and expansion nozzles are distributed at the front end of the nozzle body; a guide sleeve, a spring and a sealing valve are arranged in the inner cavity of the cone at the front end of the spring seat. The starter provided by the present invention does not require fuel, has a simple structure, is easy to use, improves the test efficiency of the gas turbine engine, and reduces the test cost.

Description

Technical Field

[0001] The present invention relates to the field of gas turbine engines, and in particular to a gas turbine engine starter. Background Art

[0002] Before the gas turbine engine starts working, it needs a certain amount of energy from the outside to rotate the rotor, drive the intake air, complete a series of combustion processes, and finally put the engine into working state. Common gas turbine starter methods include: motor start, turbine start and piston start.

[0003] Gas turbine engines only use direct-acting motor starters. Electric starters are designed to be short-term repetitive. When overloaded, they will quickly heat up to the limit value. Their own mass is too large, and the batteries used are far larger than the motor itself. They are also greatly affected by the environment. Turbine starters are mainly axial single-stage ramjet turbines, which work with compressed cold air or compressed hot air. When using cold air, the air consumption is huge, and the air expands in the turbine, and the temperature drops sharply, which may cause the turbine to freeze. Hot air needs to carry fuel separately and work alone, and the engine lasts longer. The piston starter is a two-stroke piston engine with air cooling. This starter has a small rated power and can only start low-power gas turbine engines. Summary of the invention

[0004] The object of the present invention is to provide a gas turbine engine starter which solves the starting problem of driving a gas turbine engine for ground test in an efficient, energy-saving and low-cost manner.

[0005] In order to achieve the above tasks, the present invention adopts the following technical solutions:

[0006] A gas turbine engine starter comprises a cone and a nozzle body, wherein:

[0007] The cone is a hollow structure, including a cone section and a connecting section at the front end of the cone section; a spring seat is provided at the front end of the cone, the front end of the cone and the spring seat are inserted into the rear end of the nozzle body, and the spring seat, the cone and the nozzle body are axially pressed and fixed by a threaded ring; the outer shape of the cone section on the cone is consistent with the size of the engine flow channel structure; the rear end of the cone section of the cone is provided with a stepped interface connected to the air gun, and the stepped interface includes a plurality of coaxially provided step grooves;

[0008] A plurality of converging and expanding nozzles are distributed at the front end of the nozzle body, and a plurality of mounting bosses are distributed on the outer circumference of the rear end of the nozzle body;

[0009] A guide sleeve, a spring and a sealing valve are arranged in the cone inner cavity at the front end of the spring seat, wherein:

[0010] The spring seat is designed as an annular hollow structure, with a stopper and a center hole on the inner ring of the spring seat, which respectively play the role of positioning and supporting the guide sleeve and sealing the valve;

[0011] The guide sleeve is a cylindrical structure with a small front and a large rear. There are bayonet holes at both ends of the guide sleeve, and the stopper at the inner ring of the spring seat and the front end of the stepped interface provide positioning support respectively;

[0012] The sealing valve is axially assembled inside the spring seat through a spring, and the sealing valve can slide axially in the spring seat; the sealing valve includes a shaft and a sealing plug located at the rear end of the shaft, and the spring is sleeved on the shaft. After the air start is completed, the spring plays a role in resetting the sealing valve, so that the sealing plug blocks the step groove at the front end of the stepped interface.

[0013] Furthermore, the cone and the nozzle body are both processed by high-temperature alloy forgings.

[0014] Furthermore, the outer diameter of the tapered section increases gradually from the rear to the front, and the outer diameter of the connecting section is consistent.

[0015] Furthermore, the threaded ring is sleeved on the rear end of the nozzle body and the connecting section; a plurality of grooves are distributed on the circumference of the front end of the cone, and a positioning pin is provided on the circumference of the rear end of the nozzle body, passing through the spring seat and inserted into the groove, which plays the role of circumferentially positioning the cone and the spring seat; the positioning screw is installed in the threaded hole that passes through the nozzle body and the threaded ring, which plays the role of preventing the threaded ring from rotating.

[0016] Furthermore, the thread in the thread ring is a sawtooth thread, wherein the tooth side angle of the front non-working surface is 30°, and the tooth side angle of the rear working surface is 3°.

[0017] Furthermore, in the step groove of the stepped interface, the step groove at the rear end has the largest diameter, and the diameter of the step groove decreases gradually toward the front end; side panels are distributed on the inner wall of the step groove at the rear end to form a petal-shaped structure.

[0018] Furthermore, the step groove at the rear end is used to disengage and clamp the gun head of the air gun; the step groove in the middle cooperates with the elastic sealing ring on the air gun, and the step groove at the front end cooperates with the O-ring on the air gun.

[0019] Furthermore, a limiting hole is arranged on the outer ring of the spring seat, which cooperates with the positioning pin to play a role in circumferential anti-rotation.

[0020] Furthermore, the rear end of the guide sleeve is provided with a plurality of rectangular holes along the cylinder wall, the front end surface of the guide sleeve is provided with a groove, a boss is provided on the stopper of the inner ring of the spring seat, the groove and the boss cooperate to position circumferentially to prevent the guide sleeve from circumferentially rotating.

[0021] Compared with the prior art, the present invention has the following technical features:

[0022] When a special type of gas turbine engine cannot use a traditional starting device, for example, a destructive starting method such as a gunpowder start is required, the present invention can provide a starter for ground test and effectively complete the pre-delivery test to meet the stability and reliability of the engine before leaving the factory. At the same time, the present invention can save resources and reduce test costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic axial cross-sectional view of the present invention;

[0024] Figure 2 It is a front view of the starter of the present invention;

[0025] Figure 3 It is a schematic structural diagram of an embodiment of the present invention.

[0026] Explanation of the numbers in the figure: 1 cone, 2 sealing valve, 3 spring, 4 nozzle body, 5 spring seat, 6 guide sleeve, 7 threaded ring, 8 positioning screw, 9 positioning pin, 10 stepped interface, 11 step groove, 12 side plate, 13 tapered section, 14 connecting section, 15 stopper, 16 center hole, 17 expansion nozzle, 18 mounting boss, 19 shaft rod, 20 sealing plug, 21 rectangular hole, 22 gun head. DETAILED DESCRIPTION

[0027] See also Figures 1 to 3 The present invention provides a gas turbine engine starter, comprising a cone 1 and a nozzle body 4, wherein:

[0028] The cone 1 is made of high-temperature alloy forgings. The cone 1 is a hollow structure, including a cone section 13 and a connecting section 14 located at the front end of the cone section 13; the outer diameter of the cone section 13 gradually increases from the back to the front, and the outer diameter of the connecting section 14 is consistent; the contraction-then-expansion structure is adopted to increase the outlet air flow velocity and provide reorganization kinetic energy for starting; a spring seat 5 is provided at the front end of the cone 1, and the front end of the cone 1 and the spring seat 5 are jointly inserted into the rear end of the nozzle body 4, and the spring seat 5, the cone 1 and the nozzle body 4 are axially pressed and fixed by a threaded ring 7.

[0029] The outer diameter of the connecting section 14 at the front end of the cone 1 is consistent, and the threaded ring 7 is sleeved on the rear end of the nozzle body 4 and the connecting section 14; a plurality of grooves are distributed on the circumference of the front end of the cone 1, and a positioning pin 9 is provided on the circumference of the rear end of the nozzle body 4, which passes through the spring seat 5 and is inserted into the groove, and plays the role of circumferential positioning of the cone 1 and the spring seat 5. The positioning screw 8 is installed in the threaded hole that passes through the nozzle body 4 and the threaded ring 7, and plays the role of preventing the threaded ring 7 from rotating. The outer shape of the conical section 13 on the cone 1 is consistent with the structural size of the engine flow channel. The structural design of this shape can ensure that the performance of the engine on the ground test is consistent with the performance in actual use; the internal cavity shape of the conical section 13 corresponds to the outer shape, and the volume in the cavity is guaranteed while the strength is sufficient to withstand the pressure in the cavity, which meets the air capacity of the cone.

[0030] The thread in the thread ring 7 is a serrated thread, in which the tooth side angle of the front non-working surface is 30°, and the tooth side angle of the rear working surface is 3°. This thread design has the characteristics of high transmission efficiency of rectangular thread and high root strength of trapezoidal thread. It is a thread structure designed for the thread ring to be subjected to unidirectional forward force.

[0031] A stepped interface 10 connected to the air gun is provided at the rear end of the conical section 13 of the cone 1, and the stepped interface 10 includes a plurality of coaxially arranged step grooves 11, the diameter of the step groove 11 at the rear end is the largest, and the diameter of the step groove 11 decreases successively toward the front end; side plates 12 are provided on the inner wall of the step groove 11 at the rear end to form a petal-shaped structure; the step groove 11 at the rear end is a switch-type design for disengaging and clamping the gun head 22 of the air gun, to ensure the assembly and axial positioning of the air gun, and this design can meet the stable installation of the gun head 22, and ensure that the gun head 22 can be effectively clamped at the inlet end when entering the cone 1; the step groove 11 in the middle cooperates with the elastic sealing ring on the air gun, and the step groove 11 at the front end cooperates with the O-ring on the air gun to play a sealing role. The stepped interface 10 described above serves as the air outlet of the air gun. The area of ​​the step groove 11 decreases from large to small from the back to the front, which can effectively reduce the loss along the way, reduce the retention of gas, and can stably and continuously provide power output for the gas turbine engine.

[0032] The nozzle body 4 is made of high-temperature alloy forgings. A plurality of converging nozzles 17 are distributed at the front end of the nozzle body 4. The high-pressure airflow is accelerated in the converging nozzles 17 to provide sufficient momentum for the engine to start. A plurality of mounting bosses 18 are distributed on the outer circumference of the rear end of the nozzle body 4. The nozzle body 4 is fixed to the engine through the mounting holes on the mounting bosses 18. The smooth transition between the mounting bosses 18 and the outer wall of the nozzle body facilitates the installation process.

[0033] A guide sleeve 6, a spring 3 and a sealing valve 2 are arranged in the inner cavity of the cone 1 at the front end of the spring seat 5, wherein:

[0034] The spring seat 5 is designed as an annular hollow structure, which can ensure the circulation of the space in the cavity and the high-pressure air, while ensuring the strength of use; the outer ring of the spring seat 5 is provided with a limit hole, which cooperates with the positioning pin 9 to play a circumferential anti-rotation role; the inner ring of the spring seat 5 is provided with a stop 15 and a center hole 16, which respectively play the role of positioning and supporting the guide sleeve 6 and sealing the valve 2.

[0035] The guide sleeve 6 is a cylindrical structure with a small front and a large rear, and a plurality of rectangular holes 21 are opened along the wall of the rear end. This design is mainly for the circulation of high-pressure air. A groove is opened on the front end surface of the guide sleeve 6, and a boss is set on the stopper 15 of the inner ring of the spring seat 5. The groove and the boss cooperate to position the guide sleeve 6 in the circumferential direction to prevent the guide sleeve 6 from rotating in the circumferential direction. There are bayonet holes at both ends of the guide sleeve 6, which are respectively provided with positioning support by the stopper 15 at the inner ring of the spring seat 5 and the front end of the stepped interface 10.

[0036] The sealing valve 2 is axially assembled inside the spring seat 5 through the spring 3, and the sealing valve 2 can slide axially in the spring seat 5; the sealing valve includes a shaft 19 and a sealing plug 20 located at the rear end of the shaft 19, and the spring 3 is sleeved on the shaft 19. After the air start is completed, the spring 3 plays a role in resetting the sealing valve, so that the sealing plug 20 blocks the step groove 11 at the front end of the stepped interface 10, ensuring that the air starter is closed, avoiding the influence of the air gun on the exhaust, and avoiding other destructive effects caused by gas ablation, thereby reducing the engine starting loss.

[0037] Below through Figure 2 Specific embodiments of the present invention are described.

[0038] The engine starter of the present invention needs an air gun to complete the entire starting process during implementation:

[0039] The engine starter is fixed on the gas turbine engine. When the gas turbine engine needs to be started, the gun head 22 of the air gun is inserted from the stepped interface 10 at the rear of the cone 1 to push the sealing valve 2 to compress the spring 3; the petal-shaped rib of the gun head 22 is matched with the rearmost step groove 11 of the stepped interface 10. The structural design of the air gun determines that the air gun is subjected to a backward pulling force at this time. At this time, the rotation angle of the air gun is rotated to ensure that the petal-shaped rib is aligned with the rearmost step groove 11, which plays a role in axially positioning the air gun and preventing the air gun from falling out backwards.

[0040] After the gun head 22 of the air gun is inserted into the cavity, high-pressure air is sprayed into the engine starter. The high-pressure air flows in the air starter cavity and is finally ejected through the convergent and divergent nozzle 17 on the nozzle body 4, blowing the starting impeller to rotate the engine rotor; when the specified time is reached, the braking mechanism of the air gun drives the air gun to rotate, and when the petal-shaped retaining edge of the air gun disengages from the stepped interface 10, the air gun moves backwards, the spring 3 rebounds, and the sealing valve 2 blocks the stepped interface 10, completing the entire starting process.

[0041] The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application, and should all be included in the protection scope of the present application.

Claims

1. A gas turbine engine starter, characterized in that: It comprises a cone (1) and a nozzle body (4), wherein: The cone (1) is a hollow structure, comprising a cone section (13) and a connecting section (14) located at the front end of the cone section (13); a spring seat (5) is arranged at the front end of the cone (1); the front end of the cone (1) and the spring seat (5) are inserted into the rear end of the nozzle body (4) together, and the spring seat (5), the cone (1) and the nozzle body (4) are axially pressed and fixed by a threaded ring (7); the outer shape of the cone section (13) on the cone (1) is consistent with the size of the engine flow channel structure; the cone section (13) of the cone (1) is provided with a stepped interface (10) connected to an air gun at the rear end, and the stepped interface (10) includes a plurality of coaxially arranged step grooves (11); A plurality of converging and expanding nozzles (17) are distributed at the front end of the nozzle body (4), and a plurality of mounting bosses (18) are distributed on the outer circumference of the rear end of the nozzle body (4); A guide sleeve (6), a spring (3) and a sealing valve (2) are arranged in the inner cavity of the cone (1) at the front end of the spring seat (5), wherein: The spring seat (5) is designed as an annular hollow structure, and a stopper (15) and a center hole (16) are left at the inner ring of the spring seat (5), which respectively play the role of positioning and supporting the guide sleeve (6) and sealing the valve (2); The guide sleeve (6) is a cylindrical structure with a small front and a large rear. A bayonet is left at both ends of the guide sleeve (6), and positioning support is provided by a stopper (15) at the inner ring of the spring seat (5) and the front end of the stepped interface (10). The sealing valve (2) is axially assembled inside the spring seat (5) through the spring (3), and the sealing valve (2) can slide axially inside the spring seat (5); the sealing valve includes a shaft (19) and a sealing plug (20) located at the rear end of the shaft (19), and the spring (3) is sleeved on the shaft (19). After the air start is completed, the spring (3) plays a role in resetting the sealing valve, so that the sealing plug (20) blocks the step groove (11) at the front end of the stepped interface (10).

2. The gas turbine engine starter according to claim 1, characterized in that: The cone (1) and the nozzle body (4) are both processed by high-temperature alloy forgings.

3. The gas turbine engine starter according to claim 1, characterized in that: The outer diameter of the tapered section (13) gradually increases from the back to the front, and the outer diameter of the connecting section (14) is consistent.

4. The gas turbine engine starter according to claim 1, characterized in that: The threaded ring (7) is sleeved on the rear end of the nozzle body (4) and the connecting section (14); a plurality of grooves are distributed on the circumference of the front end of the cone (1); a positioning pin (9) is provided on the circumference of the rear end of the nozzle body (4) and passes through the spring seat (5) and is inserted into the groove, so as to play the role of circumferentially positioning the cone (1) and the spring seat (5); a positioning screw (8) is installed in a threaded hole that passes through the nozzle body (4) and the threaded ring (7), so as to prevent the threaded ring (7) from rotating.

5. The gas turbine engine starter according to claim 1, characterized in that: The thread in the thread ring (7) is a sawtooth thread, wherein the tooth flank angle of the front non-working surface is 30°, and the tooth flank angle of the rear working surface is 3°.

6. The gas turbine engine starter according to claim 1, characterized in that: Among the step grooves (11) of the stepped interface (10), the diameter of the step groove (11) at the rear end is the largest, and the diameter of the step groove (11) decreases gradually toward the front end; side plates (12) are arranged on the inner wall of the step groove (11) at the rear end to form a petal-shaped structure.

7. The gas turbine engine starter according to claim 1, characterized in that: The step groove (11) at the rear end is used to disengage the gun head (22) of the air gun and clamp the gun head (22); the step groove (11) in the middle cooperates with the elastic sealing ring on the air gun, and the step groove (11) at the front end cooperates with the O-type sealing ring on the air gun.

8. The gas turbine engine starter according to claim 4, characterized in that: The outer ring of the spring seat (5) is provided with a limiting hole, which cooperates with the positioning pin (9) to play a role in circumferential anti-rotation.

9. The gas turbine engine starter according to claim 1, characterized in that: The rear end of the guide sleeve (6) is provided with a plurality of rectangular holes (21) along the cylinder wall, the front end surface of the guide sleeve (6) is provided with a groove, and a boss is provided on the stopper (15) of the inner ring of the spring seat (5), and the groove and the boss cooperate to achieve circumferential positioning to prevent the guide sleeve (6) from circumferential rotation.

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