Suction equipment for dynamic balance test of small turbojet engine

Abstract

The utility model discloses suction equipment for dynamic balance test of a small turbojet engine, which relates to the technical field of dynamic balance test of engines and comprises a bottom plate and a high-pressure centrifugal fan arranged on the bottom plate. The air suction pipe group is arranged at the air suction end of the high-pressure centrifugal fan; the air suction pipe set is communicated with the engine through an air suction connector. The air suction pipe set comprises a smooth pipeline and vacuum hoses arranged at the two ends of the smooth pipeline and communicated with the high-pressure centrifugal fan and the air suction connector respectively. According to the suction equipment for the dynamic balance test of the small turbojet engine provided by the utility model, the high-pressure centrifugal fan is arranged, so that enough suction force is provided for an engine with a large-diameter compressor impeller and a large-diameter turbine, and the rotating speed required by the dynamic balance test is achieved; meanwhile, the provided airflow is high in stability, and large fluctuation of the rotating speed of the engine during dynamic balance testing can be avoided; the air suction pipe set is arranged, and the two ends of the air suction pipe set are flexibly arranged to further block errors caused by vibration of the high-pressure centrifugal fan.

Description

Technical Field

[0001] The utility model relates to the technical field of engine dynamic balance testing, and more specifically, to a suction device for dynamic balance testing of a small turbojet engine. Background Art

[0002] To ensure balanced high-speed operation of the main shaft of a small turbojet engine after assembly, each engine must undergo a dynamic balancing test to eliminate any imbalances. Traditional drive methods, such as belt drives and couplings, are directly connected to the engine main shaft. During the dynamic balancing process, slight vibrations of the belt or coupling are directly transmitted to the engine body, resulting in significant errors.

[0003] To address the problem of subtle vibrations being directly transmitted to the engine body, the drive method was changed to using compressed air to directly blow the engine compressor impeller to rotate. However, when the impeller and turbine diameters are large and the test speed requirements are high, conventional devices are unable to provide the required high-flow, high-speed air to drive the engine main shaft to a speed that meets the dynamic balancing test requirements. Furthermore, the compressed air pressure is generally unstable, which directly causes large fluctuations in the engine speed during dynamic balancing, resulting in large errors in the results. For example, the ultra-precision laser automatic de-weighting dynamic balancing machine for micro-turbojet engine rotors, patented with application publication number CN110940460A, utilizes an air supply mechanism and high-pressure air drive to simulate the operating state of the entire rotor. However, it still has difficulty providing the required high-flow, high-speed air to drive the engine main shaft to a speed that meets the dynamic balancing test requirements. Furthermore, the unstable compressed air pressure results in low airflow stability, which causes large fluctuations in the engine speed during dynamic balancing, resulting in large errors in the results. Moreover, existing gas pipelines are usually made of rigid structures. When testing requires a large flow of high-speed air, the air drive device must provide a large fluid force, and its vibration will be difficult to avoid. When the air drive device and the dynamic balance test device are directly connected, the vibration generated by the air drive device is easily transmitted to the dynamic balance test device, causing errors in the test. Utility Model Content

[0004] An object of the present invention is to solve the above-mentioned problems and / or disadvantages and to provide advantages as will be described below.

[0005] In order to achieve these objects and other advantages of the present invention, a suction device for dynamic balance testing of a small turbojet engine is provided, comprising: a base plate, and further comprising: a high-pressure centrifugal fan disposed on the base plate;

[0006] An air suction pipe group arranged at the air suction end of the high-pressure centrifugal fan;

[0007] The intake pipe group is connected to the engine on the dynamic balance test device through an intake joint;

[0008] The suction pipe group includes: a smooth pipe, and vacuum hoses arranged at both ends of the smooth pipe and connected to the high-pressure centrifugal fan and the suction joint respectively.

[0009] Preferably, the high-pressure centrifugal fan is connected to the suction pipe group through a three-way joint, and a bypass valve connected to the other joint of the three-way joint is provided.

[0010] Preferably, the device further comprises: a frequency converter provided on the bottom plate and electrically connected to the high-pressure centrifugal fan to adjust the speed of the high-pressure centrifugal fan;

[0011] A distribution box provided on the base plate and electrically connected to the frequency converter to supply power thereto;

[0012] A control module electrically connected to the distribution box and communicatively connected to the frequency converter;

[0013] An operation panel that is connected to the control module for communication.

[0014] Preferably, an aluminum alloy frame is provided above the bottom plate;

[0015] A top plate is provided above the frame, and opposing side doors are provided on four sides.

[0016] Preferably, the high-pressure centrifugal fan exhaust port is provided with an exhaust pipe extending upward;

[0017] The top plate is provided with an ejector pipe sleeved on the outside of the exhaust pipe;

[0018] The upper end of the ejector pipe is higher than the exhaust pipe, and a gap is provided between the two surrounding the exhaust pipe to connect the space below the top plate and the ejector pipe.

[0019] Preferably, a protective net is provided on the exhaust port of the high-pressure centrifugal fan;

[0020] The meshes of the protective net are configured in a hexagonal honeycomb shape.

[0021] Preferably, a shock-absorbing pad is provided at the mounting position of the high-pressure centrifugal fan and the base plate;

[0022] The bottom plate is provided with adjustable shock-absorbing foot cups and a universal wheel set with brakes.

[0023] The present invention includes at least the following beneficial effects: First, by arranging a high-pressure centrifugal fan, vibration errors caused by direct connection are avoided, and at the same time, the high-pressure centrifugal fan can provide sufficiently large suction for the engine with a large compressor impeller and turbine diameter, so that it can reach the speed required by the dynamic balance test; at the same time, the airflow stability it provides is high, which can avoid large fluctuations in the engine speed during the dynamic balance test, which may cause large errors in the results; by arranging an intake pipe group, the flexible setting of the vacuum hose at both ends of the smooth pipe that is respectively connected to the high-pressure centrifugal fan and the intake joint further blocks the error caused by the vibration of the high-pressure centrifugal fan.

[0024] Secondly, by setting up an intake pipe group, vacuum hoses are set at both ends. The flexible setting can further block the error caused by the vibration of the high-pressure centrifugal fan to the test device. A smooth pipe is set in the middle section to ensure the stable flow of air in it and avoid howling and other phenomena in the pipe when a large flow of gas passes through.

[0025] Other advantages, objectives and features of the present invention will be reflected in part through the following description, and in part will be understood by those skilled in the art through research and practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a schematic structural diagram of a suction device for dynamic balance testing of a small turbojet engine in one embodiment of the present invention;

[0027] Figure 2 This is a schematic structural diagram of a suction device for dynamic balance testing of a small turbojet engine in another embodiment of the present invention;

[0028] Figure 3 This is a schematic diagram of the internal structure of a suction device for dynamic balance testing of a small turbojet engine in one embodiment of the present utility model;

[0029] Figure 4 This is a schematic structural diagram of a protective net for a suction device used for a dynamic balance test of a small turbojet engine in one embodiment of the present invention.

[0030] Markings in the figure: 1. Equipment box, 11. Bottom plate, 111. Adjustable shock-absorbing foot cup, 112. Universal wheel assembly with brake, 12. Top plate, 121. Ejector pipe, 122. Hanging bracket, 13. Side door, 2. High-pressure centrifugal fan, 21. Exhaust pipe, 22. Protective net, 23. Shock-absorbing pad, 3. Suction pipe assembly, 31. Smooth pipe, 32. Vacuum hose, 4. Suction connector, 5. T-joint, 6. Bypass valve, 7. Frequency converter, 8. Distribution box, 9. Operation panel. DETAILED DESCRIPTION

[0031] The present invention will be described in further detail below in conjunction with the accompanying drawings so that those skilled in the art can implement the invention with reference to the description.

[0032] It should be understood that terms such as “having,” “including,” and “comprising” used herein do not preclude the existence or addition of one or more other elements or combinations thereof.

[0033] It should be noted that in the description of this utility model, the orientations or positional relationships indicated by terms are based on the orientations or positional relationships shown in the accompanying drawings. This is intended solely to facilitate the description of this utility model and simplify the description. It does not indicate or imply that the devices or components referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, it should not be construed as limiting this utility model. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0034] In the description of the present invention, unless otherwise clearly specified and limited, the terms "installed", "provided with", "mounted / connected", "connected", etc. should be understood in a broad sense. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection. It can be a mechanical connection or an electrical connection. It can be a direct connection or an indirect connection through an intermediate medium. It can be the internal connection of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0035] In addition, in the present invention, unless otherwise expressly specified or limited, when a first feature is "above" or "below" a second feature, it can mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediary. Furthermore, when a first feature is "above," "above," or "above" a second feature, it can mean that the first feature is directly above or diagonally above the second feature, or simply means that the first feature is higher in level than the second feature. When a first feature is "below," "below," or "below" a second feature, it can mean that the first feature is directly below or diagonally below the second feature, or simply means that the first feature is lower in level than the second feature.

[0036] Example 1

[0037] A suction device for dynamic balance test of a small turbojet engine, the structure of which is as follows Figure 1-3 As shown, it includes: a base plate 11, and also includes: a high-pressure centrifugal fan 2 arranged on the base plate 11;

[0038] An air intake pipe group 3 is provided at the air intake end of the high-pressure centrifugal fan 2;

[0039] The intake pipe group 3 is connected to the engine on the dynamic balance test device through the intake joint 4;

[0040] The suction pipe group 3 includes: a smooth pipe 31, and a vacuum hose 32 provided at both ends of the smooth pipe 31, which is connected to the high-pressure centrifugal fan 2 and the suction joint 4 respectively.

[0041] In actual applications, when compressed air is used to directly blow the engine compressor impeller, for compressor impellers with a force of 120-160 daN and a large turbine diameter, the maximum speed can only reach 1800 rpm, which is far from the speed required for dynamic balancing testing. In order to meet the speed requirement of 5000 rpm for dynamic balancing of a 160 daN engine, after multiple tests and calculations, it was concluded that an air flow of 5000 cubic meters per hour and a full pressure of 9000 Pa are required, passing through the engine to achieve the required speed. The high-pressure centrifugal fan 2 here is model: Y180M-2. The suction connector 4 is detachably connected to the suction end of the high-pressure centrifugal fan 2 by clamping it with a clamp. During operation, only different suction connectors 4 need to be replaced to meet the requirements of quickly switching to test different engine models. When the smooth pipe 31 is set to bend as needed, the bending angle of two adjacent sections of the smooth pipe 31 should be set to an obtuse angle to ensure smooth flow through it and avoid turbulent airflow, which causes howling and generates large vibrations.

[0042] During the test, the air flow rate was too fast. In order to prevent the air from hitting the pipe and causing vibration, a stainless steel smooth pipe 31 was used. The PD vacuum hose 32 was connected to the left end of the stainless steel smooth pipe 31, and the black vacuum hose 32 was connected to the right end. The two were tightly connected with a strong clamp. The vacuum hose 32 also had to withstand the suction generated by the negative pressure and could not lose its roundness. Its flexible setting further blocked the error caused by the vibration of the high-pressure centrifugal fan 2.

[0043] Working principle: By setting a high-pressure centrifugal fan 2, the suction connector 4 at its suction end is connected to the engine on the dynamic balancing test device. The suction force generated by the high-pressure centrifugal fan 2 drives a large flow of air through the engine intake duct and the outer wall of the combustion chamber on the dynamic balancing test device, etc., into the engine, and drives the engine main shaft to rotate through the internal compressor impeller and turbine of the engine, and reaches the specified speed, avoiding vibration errors caused by direct connection. At this time, the measured engine imbalance is its true imbalance; the high-pressure centrifugal fan 2 can provide sufficiently large suction for engines with large compressor impeller and turbine diameters, so that it can reach the speed required by the dynamic balancing test; at the same time, the airflow stability it provides is high, which can avoid large fluctuations in the engine speed during the dynamic balancing test, which leads to large errors in the results; by setting an intake pipe group 3, vacuum hoses 32 are set at both ends, and its flexible setting can further block the error caused by the vibration of the high-pressure centrifugal fan 2 to the test device, and a smooth pipe 31 is set in the middle section to ensure the stable flow of airflow therein, avoiding the phenomenon of whistling in the pipe when a large flow of gas passes through.

[0044] Example 2

[0045] This embodiment 2 is a preferred embodiment of the present invention, and its specific structure is as follows: Figure 2-3 As shown, the following improvement is disclosed based on the embodiment 1: the high-pressure centrifugal fan 2 is connected to the suction pipe group 3 through a three-way joint 5, and a bypass valve 6 connected thereto is provided on another joint of the three-way joint 5.

[0046] In actual application, the bypass valve 6 is provided with an adjusting component for adjusting the valve body opening; the adjusting component is provided with a stepping motor to adjust the bypass valve 6 opening.

[0047] Working principle: In order to meet the difficult problem of testing requirements for small turbojet engines, a bypass valve 6 is added to the air inlet of the fan, and the flow rate of air entering the small turbojet engine is changed by adjusting the air intake volume of the bypass valve 6.

[0048] Example 3

[0049] This embodiment 3 is a preferred embodiment of the present invention, and its specific structure is as follows: Figure 1-2 As shown, it discloses the following improvements based on embodiment 1: it also includes: a frequency converter 7 provided on the bottom plate 11 and electrically connected to the high-pressure centrifugal fan 2 to adjust the speed of the high-pressure centrifugal fan 2;

[0050] A distribution box 8 is provided on the base plate 11 and is electrically connected to the frequency converter 7 to supply power thereto;

[0051] A control module electrically connected to the distribution box 8 and communicatively connected to the frequency converter 7;

[0052] An operation panel 9 is communicatively connected to the control module.

[0053] In actual applications, the control module is electrically connected to the distribution box 8, and is communicatively connected to the frequency converter 7 and the bypass valve 6; the operation panel 9 is provided with an operation screen and operation buttons; the operation screen of the operation panel 9 is configured as a 7-inch operation screen, which serves as the human-computer interaction interface of the equipment, and displays the operating parameters and status information of the equipment. The operator can input various operation instructions through the touch screen, such as setting the fan speed, adjusting the suction volume, etc. The operation button is used as an operating component for quick operation of some emergency situations or specific functions, such as starting and stopping, etc., which facilitates the operator to control the equipment in different situations. The frequency converter 7 is used to adjust the speed of the high-pressure centrifugal fan 2, so as to accurately control the suction volume and pressure of the fan according to actual work requirements, so as to achieve the purpose of energy saving and precise control; the control module model is: SMART200, and the operation screen model is: 8071ip;

[0054] During operation, after the equipment is activated via the operating screen or buttons, the distribution box 8 supplies power to all components. The frequency converter 7 adjusts the speed of the high-pressure centrifugal fan 2 according to preset parameters or the operator's instructions. The high-pressure centrifugal fan 2 rotates at high speed, generating a strong suction force. The bypass valve 6 can adjust the bypass air intake as needed to achieve the purpose of regulating the engine's main shaft speed. The PLC program controls the rotation of the motor and stepper motor inside the high-pressure centrifugal fan 2 and bypass valve 6, driving the bypass valve 6 opening adjustment plate to rotate, adjust the bypass air intake, and adjust the engine's main shaft speed to meet the speed requirements for dynamic balancing of different engine models. This also significantly improves the efficiency of dynamic balancing tests, increasing the number of tests per shift from 20 to 50.

[0055] Example 4

[0056] This embodiment 4 is a preferred embodiment of the present invention, and its specific structure is as follows Figure 1-2 As shown, it discloses the following improvements based on embodiment 1: an aluminum alloy frame is provided above the bottom plate 11;

[0057] A top plate 12 is provided above the frame, and side doors 13 are provided on four sides.

[0058] In actual application, the bottom plate 11, top plate 12 and side door 13 are enclosed to form an equipment box 1 that encloses the high-pressure centrifugal fan 2, the frequency converter 7 and the distribution box 8. The frame is an aluminum alloy frame, and each side door 13 is installed with a connecting rod lock to facilitate its closure. The size of the equipment box 1 is: 1300mmX1300mmX1300mm. An arc-shaped groove adapted to the suction pipe group 3 is provided at the junction of a pair of side doors 13 on the suction end side of the high-pressure centrifugal fan 2, which facilitates the installation of the suction pipe group 3. A hanger 122 for hanging the suction connector 4 is provided on the top plate 12, which is convenient for organizing and storing the suction connector 4 to prevent it from being damaged or lost due to its random placement, and is also convenient for quick access during operation.

[0059] Working principle: The side door 13 of the equipment box 1 is provided to facilitate operators to enter the interior of the equipment for maintenance, repair or cleaning, and also to protect the internal components of the equipment from foreign objects.

[0060] Example 5

[0061] This embodiment 5 is a preferred embodiment of the present invention, and its specific structure is as follows: Figure 1-3 As shown, it discloses the following improvements based on the embodiment 4: an exhaust pipe 21 extending upward is provided on the exhaust port of the high-pressure centrifugal fan 2;

[0062] The top plate 12 is provided with an ejector pipe 121 sleeved on the outside of the exhaust pipe 21;

[0063] The upper end of the ejector pipe 121 is higher than the exhaust pipe 21 , and a gap is provided between the two surrounding the exhaust pipe 21 to connect the space below the top plate 12 and the ejector pipe 121 .

[0064] In actual application, the height measured from the upper end surface of the ejector pipe 121 to the outlet of the ejector pipe 121 is 1700 mm.

[0065] Working principle: When the centrifugal fan is running, an upward high-speed airflow is generated at the opening of the exhaust pipe 21. The ejector pipe 121 uses this high-speed airflow to eject the heat inside the equipment out of the equipment box 1, ensuring that the operating temperature inside the equipment box 1 is not too high, allowing the equipment to operate for a long time, thereby increasing the service life of the equipment.

[0066] Example 6

[0067] This embodiment 6 is a preferred embodiment of the present invention, and its specific structure is as follows: Figure 3-4 As shown, it discloses the following improvements based on embodiment 1: a protective net 22 is provided on the exhaust port of the high-pressure centrifugal fan 2;

[0068] The mesh of the protective net 22 is configured as a hexagonal honeycomb shape to minimize airflow obstruction.

[0069] Working principle: The protective net 22 is set to prevent foreign matter from falling into the internal pipeline of the high-pressure centrifugal fan 2. The mesh is set to a hexagonal honeycomb shape, which ensures the safety of the device while ensuring normal air circulation.

[0070] Example 7

[0071] This embodiment 7 is a preferred embodiment of the present invention, and its specific structure is as follows: Figure 1-2 As shown, it discloses the following improvements based on embodiment 1: a shock-absorbing pad 23 is provided at the mounting position of the high-pressure centrifugal fan 2 and the bottom plate 11;

[0072] The bottom plate 11 is provided with an adjustable shock-absorbing foot cup 111 and a universal wheel set 112 with brakes.

[0073] In actual application, the shock-absorbing pad 23 is configured as a special shock-absorbing pad 23 for fans, which is a BKM type rubber shock absorber, model BKM8038M12H, which reduces the vibration and noise generated during the operation of the fan and transmits them to other components, protects the overall structure of the equipment, and reduces noise pollution.

[0074] The braked universal wheel assembly 112 includes four braked universal wheels arranged at the corners of the base plate 11, which facilitates the flexible movement of the equipment in different workplaces. The brake function can fix the equipment after it reaches the designated position to prevent accidental movement.

[0075] The adjustable shock-absorbing foot cup 111 is used to adjust the levelness of the equipment to adapt to different ground conditions, and also plays a certain shock-absorbing role to reduce the vibration impact on the ground when the equipment is running.

[0076] Compared with traditional equipment, this equipment has advanced technology, adopts automatic control, and has a wide range of applications. It makes the imbalance of the tested engine more accurate and greatly improves production efficiency.

[0077] The above solutions are only examples of preferred embodiments, but are not limited thereto. When implementing the present invention, appropriate replacements and / or modifications can be made according to user needs.

[0078] The number of devices and processing scales described herein are used to simplify the description of the present invention. Applications, modifications and variations of the present invention will be apparent to those skilled in the art.

[0079] Although the embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and exemplary embodiments. They can be applied to a variety of fields suitable for the present invention. Further modifications will be readily apparent to those skilled in the art. Therefore, the present invention is not limited to the specific details and illustrations shown and described herein without departing from the general concept defined by the claims and their equivalents.

Claims

1. A suction device for dynamic balance testing of a small turbojet engine, comprising: The bottom plate is characterized in that it further comprises: a high-pressure centrifugal fan arranged on the bottom plate; An air suction pipe group arranged at the air suction end of the high-pressure centrifugal fan; The intake pipe group is connected to the engine on the dynamic balance test device through an intake joint; The suction pipe group includes: a smooth pipe, and vacuum hoses arranged at both ends of the smooth pipe and connected to the high-pressure centrifugal fan and the suction joint respectively.

2. The suction device for dynamic balance testing of a small turbojet engine according to claim 1, characterized in that: The high-pressure centrifugal fan is connected to the suction pipe group through a three-way joint, and a bypass valve connected to the other joint of the three-way joint is provided.

3. The suction device for dynamic balance testing of a small turbojet engine according to claim 1, characterized in that: Also includes: A frequency converter provided on the bottom plate and electrically connected to the high-pressure centrifugal fan to adjust the speed of the high-pressure centrifugal fan; A distribution box provided on the base plate and electrically connected to the frequency converter to supply power thereto; A control module electrically connected to the distribution box and communicatively connected to the frequency converter; An operation panel that is connected to the control module for communication.

4. The suction device for dynamic balance testing of a small turbojet engine according to claim 1, characterized in that: An aluminum alloy frame is provided above the bottom plate; A top plate is provided above the frame, and opposing side doors are provided on four sides.

5. The suction device for dynamic balance testing of a small turbojet engine according to claim 4, characterized in that: The high-pressure centrifugal fan exhaust port is provided with an exhaust pipe extending upward; The top plate is provided with an ejector pipe sleeved on the outside of the exhaust pipe; The upper end of the ejector pipe is higher than the exhaust pipe, and a gap is provided between the two surrounding the exhaust pipe to connect the space below the top plate and the ejector pipe.

6. The suction device for dynamic balance testing of a small turbojet engine according to claim 1, characterized in that: A protective net is provided on the exhaust port of the high-pressure centrifugal fan; The meshes of the protective net are configured in a hexagonal honeycomb shape.

7. The suction device for dynamic balance testing of a small turbojet engine according to claim 1, characterized in that: A shock-absorbing pad is provided at the mounting position of the high-pressure centrifugal fan and the base plate; The bottom plate is provided with adjustable shock-absorbing foot cups and a universal wheel set with brakes.

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