Sectional type centrifugal machine rotating arm

Abstract

The invention provides a sectional type centrifugal machine spiral arm. The sectional type centrifugal machine spiral arm comprises a connecting end; the load end is detachably connected with one end of the connecting end, and the load end is used for clamping an object to be measured; the counterweight end is detachably connected with the other end of the connecting end, and the counterweight end is used for placing a counterweight block. Compared with the prior art, at least one technical scheme adopted by the invention at least has the beneficial effects that through a welded box type structure and a variable-thickness section design, the bending rigidity and torsional rigidity of the rotating arm in the horizontal direction and the vertical direction are guaranteed; the structural mass of the rotating arm is effectively controlled through the design of the large-size lightening holes.

Description

Technical Field

[0001] This invention relates to the field of testing technology for aero-engines and lubricating oil systems, and specifically to a segmented centrifuge rotor. Background Technology

[0002] The lubricating oil system of an aero-engine primarily provides the necessary cooling and lubrication for friction pairs such as bearings, gears, and seals, ensuring their safe and reliable operation. However, during actual flight, the engine's operating attitude and external loads are constantly changing due to factors such as weather and aircraft usage characteristics. This is especially true for highly maneuverable aircraft like fighter jets, where these changes are not only frequent but also significant, placing stringent demands on the reliability of the lubricating oil system. Therefore, it is necessary to conduct specialized tests on the entire lubricating oil system during the design phase to verify its performance under maneuvering load conditions. Large centrifuges, as devices capable of stably providing high overloads, are widely used in civil engineering, water conservancy, electronics, and aerospace, becoming the preferred architecture for simulation testing equipment.

[0003] Considering national military standards and testing procedures, the slender rotating arms of multi-shaft centrifuges reach 15 meters. Conventional centrifuge arms have relatively low rigidity in the vertical direction and along the tangent of the plane of rotation. When the dynamic torque and impact force generated by the large mass load installed at the end of the arm acts on it, low-frequency vibrations and excessive structural deformation are likely to occur, adversely affecting equipment safety. Unlike geotextile centrifuges, the torque and impact force transmitted to the rotating arm during aero-engine lubricating oil system testing are multi-directional pulse-type disturbances, with torque impact amplitudes reaching 100,000 N·m, posing a severe test to the arm's rigidity and strength. Furthermore, the integrated rotating arm used in conventional centrifuges not only imposes stringent requirements on blank cutting, welding, heat treatment, and precision machining, but is also highly unfavorable for transportation and installation. Summary of the Invention

[0004] In view of this, the present invention provides a segmented centrifuge arm to effectively improve the structural rigidity and machinability of the arm.

[0005] The present invention provides the following technical solution: a segmented centrifuge arm, comprising: a connecting end; a load end, detachably connected to one end of the connecting end, the load end being used to clamp the object to be tested; and a counterweight end, detachably connected to the other end of the connecting end, the counterweight end being used to place a counterweight block.

[0006] Compared with the prior art, the beneficial effects that can be achieved by the above-mentioned at least one technical solution adopted by the present invention include at least the following: the present invention creates a welded box structure and a variable thickness section design, which ensures the bending stiffness and torsional stiffness of the swing arm in the horizontal and vertical directions, while the design of large-size weight-reducing holes effectively controls the structural quality of the swing arm.

[0007] By employing a redundant connection design with mutual backups, the size of the swing arm is reduced from 15 m to 5.8 m while ensuring the structural strength and rigidity. This significantly improves the machining and heat treatment processability of the swing arm, making it suitable for applications with steady-state acceleration not exceeding 115 m / s². 2 Or centrifuge applications with a capacity not exceeding 180gt. Attached Figure Description

[0008] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0009] Figure 1 This is a schematic diagram of the high-rigidity segmented rotating arm for a multi-axis centrifuge provided in an embodiment of the present invention; Figure 2 This is a cross-sectional view of the high-rigidity segmented swing arm provided in an embodiment of the present invention; Figure 3 This is a schematic diagram of the load end dimensions provided in an embodiment of the present invention; Figure 4 This is a schematic diagram of the redundant connection principle between the load end and the connection end provided in an embodiment of the present invention; Figure 5 This is a cross-sectional view of the connection between the load end and the connection end provided in the embodiment of the present invention. Figure 6 This is an enlarged schematic diagram of the connection between the load end and the connecting end flange provided in an embodiment of the present invention; Figure 7 This is a schematic diagram of the connection method between the connecting end and the drive shaft provided in an embodiment of the present invention.

[0010] The reference numerals in the figure are as follows: 1. Load end; 2. Fairing; 4. Connecting end; 6. Counterweight end; 8. Counterweight block; 9. Locking nut; 11. First connecting flange; 12. Second connecting flange; 13. First screw; 14. Second screw; 15. First nut; 16. Second nut; 17. Damping device; 18. Tensioning sleeve; 19. Drive shaft; 20. Pipeline; 21. Limiting groove; 22. Limiting pin. Detailed Implementation

[0011] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0012] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0013] The segmented centrifuge arm of this invention aims to solve the problems of insufficient rigidity and inconvenient processing and transportation of traditional integrated centrifuge arms. Its core structure includes a connecting end 4, a load end 1, and a counterweight end 6. The three are assembled by a detachable connection method, which not only ensures structural strength and rigidity, but also significantly improves the convenience of processing, assembly and transportation.

[0014] The load end 1 is used to clamp the object to be tested, such as the lubricating oil system of an aircraft engine. The counterweight end 6 achieves static balance adjustment of the entire rotating arm by placing counterweights. The connecting end 4, as an intermediate connecting component, is detachably connected to the load end 1 and the counterweight end 6, and its center is fixed to the drive shaft 19, providing power support for the rotation of the rotating arm. The load end 1, connecting end 4, and counterweight end 6 all adopt a box-type structure formed by welding plates, with multiple integral reinforcing ribs inside, which ensures structural rigidity and controls the overall weight through reasonable structural design.

[0015] The load end 1 has a tapered U-shaped structure. One end, used to clamp the object under test, is equipped with a circular assembly. This assembly consists of two opposing annular plates, forming a cavity with a diameter of 1000mm to accommodate the installation requirements of the object under test. The distance from the cavity centerline to the parallel section of the fork lugs of the load end 1 is L1, the distance to the inner bottom surface of the tapered U-shape is L2, the distance to the interface between the load end 1 and the connecting end 2 is L3, and the fork lug spacing is L4. Therefore, L1 = 1700mm, L2 = 4000mm, L3 = 5000mm, and L4 = 3100mm.

[0016] The ring assembly has two opposing inner sidewalls. A limit component is provided on one of the inner sidewalls. The limit component adopts an elastic claw structure and is fixed to the ring plate by bolts. When the object to be tested is loaded into the cavity, the elastic claw can press against the outer circumference of the object to be tested, restricting the relative rotation of the object to be tested during rotation and ensuring the stability of the clamping.

[0017] A damping device 17 is provided inside the load end 1. In this embodiment, the damping device 17 is a hydraulic damper. The connection method is as follows: the hydraulic damper is fixed to the load end 1 by high-strength bolts. This damping device can effectively absorb the vibration energy generated by the test object during the test, reduce the impact of pulse disturbance on the slewing arm structure, and improve the stability of the slewing arm operation.

[0018] Large rectangular weight-reduction windows are provided on the box-type structure and internal stiffeners of load end 1. The size of the weight-reduction windows allows operators to enter and exit, facilitating the installation of pipelines and maintenance work inside load end 1. At the same time, a removable cover plate is provided at the weight-reduction window. The cover plate is fixed to the wall panel of load end 1 by bolts. The weight-reduction window can be closed when the swing arm is in operation to ensure the swing arm has a simple shape and reduce wind resistance.

[0019] The counterweight end 6 has a T-shaped structure. The horizontal width of the part farther from the connecting end 4 is B1, and the horizontal width of the part closer to the connecting end 4 is B2, and B1 / B2=1.5. This structural design can provide sufficient installation space for the counterweight block 8 while ensuring the structural stability of the counterweight end 6.

[0020] The portion of the counterweight end 6 away from the connecting end 4 has a rectangular cavity for accommodating the counterweight block. Multiple sets of screws are arranged horizontally within the cavity, and these screws are welded and fixed to the wall plate of the counterweight end 6. The counterweight block has through holes adapted to the screws, and the counterweight block 8 is fitted onto the screws through these through holes and locked in place by a locking nut 9. In this embodiment, multiple sets of counterweight blocks 8 with different thicknesses are provided, allowing for flexible adjustment of the counterweight mass according to the mass of the object being measured, ensuring the static balance of the rotating arm during rotation.

[0021] Similar to the load end 1, the box-type structure and internal stiffeners of the counterweight end 6 also have large rectangular weight reduction windows, which take into account both structural lightweighting and internal maintenance convenience.

[0022] The connecting end 4 is a box-shaped structure formed by welding sheet metal, with an integral reinforcing rib plate inside. A through hole is provided in its center for connection with the drive shaft 19, and the center line of this through hole is the rotation center of the rotary arm. The connecting end 4 and the drive shaft 19 are fixedly connected by a tensioning sleeve. The tensioning sleeve is fitted between the through hole of the connecting end 4 and the drive shaft 19. Tightening the bolts of the tensioning sleeve causes it to elastically deform, achieving an interference fit between the connecting end 4 and the drive shaft 19. This connection is reliable and easy to disassemble.

[0023] It should be noted that the upper surface of the swing arm is horizontal, and the lower surface adopts a variable thickness structure design with a thicker middle and thinner ends. The maximum thickness of the upper and lower surfaces of the connecting end 4 is H1, and the minimum thickness of the upper and lower surfaces of the load end 1 and the counterweight end 6 is H2, and H2 / H1=1.2 is satisfied. This design can significantly improve the bending stiffness coefficient and bending modal frequency of the swing arm in the vertical direction, and avoid low-frequency vibration during the test.

[0024] The box-type structure and internal stiffeners of the connection end 4 are also provided with large rectangular weight-reducing windows, and the windows are equipped with removable covers, which not only reduces the structural weight, but also facilitates the layout and maintenance of internal pipelines.

[0025] The load end 1 and one end of the connection end 4 are detachably connected through the first connection component, and the counterweight end 6 and the other end of the connection end 4 are detachably connected through the second connection component. The first connection component and the second connection component have the same structure. The first connection component will be used as an example for detailed explanation below.

[0026] One end of the connecting end 4, corresponding to the end of the load end 1, is provided with multiple connecting through holes, including a large-diameter through hole for installing the first screw 13 and a small-diameter through hole for installing the second screw 14. There are two large-diameter through holes, which are symmetrically arranged along the vertical bisector of the connecting end face, and the line connecting the axes of the two large-diameter through holes is located on the horizontal bisector of the connecting end face; there are multiple small-diameter through holes, which are distributed in an array around the outer periphery of the two large-diameter through holes.

[0027] The specific parameters are as follows: the diameter of the large-diameter through hole is 180mm, the horizontal distance between two large-diameter through holes is 1900mm, and the vertical distance between the large-diameter through hole and the upper surface of the load end 1 is 54% of the vertical height of the contact surface; the small-diameter through holes are arranged in 7 rows along the vertical direction, and 6 holes are equally spaced in each row along the horizontal direction. The diameter of the small-diameter through holes is 46mm, and the distance between adjacent small-diameter through holes in both the vertical and horizontal directions is 150mm.

[0028] The other end of the connecting end 4, which corresponds to the counterweight end 6, is also provided with a connecting through hole that is completely consistent with the above specifications, to ensure the installation compatibility of the second connecting component.

[0029] The first connecting assembly includes two first screws 13, multiple second screws 14, a first connecting flange 11, and a second connecting flange 12.

[0030] The first screw 13 is a high-strength screw, which passes through the large-diameter through holes corresponding to the connecting end 4 and the load end 1, and is locked and fixed by a large screw nut with a tightening torque of not less than 1200 Nm to ensure the tightness of the connection. The two first screws 13 are symmetrically arranged along the vertical bisector of the connecting end face, and the line connecting their axes is located on the horizontal bisector, which can effectively withstand the axial and radial forces generated during the rotation of the rotating arm.

[0031] The second screw 14 is also made of high-strength bolt, which passes through the small-diameter through holes corresponding to the connecting end 4 and the load end 1, and is locked in place by a small bolt and nut. Multiple second screws 14 are arranged in an array around the outer periphery of the two first screws 13, further enhancing the structural strength and stability of the connection, and sharing the load with the first screws 13.

[0032] The first connecting flange 11 and the second connecting flange 12 have identical structures, both having a U-shaped groove along their length, with two rows of bolt holes on both sides of the groove. The first connecting flange 11 is located on the upper end face of the connection between the load end 1 and the connecting end 4, and the second connecting flange 12 is located on the lower end face. Flange edges protrude from the connection between the load end 1 and the connecting end 4, and the contacting flange edges are inserted into the corresponding U-shaped grooves. Then, bolts are passed through the bolt holes on both sides of the grooves to fix the first connecting flange 11 and the second connecting flange 12 to the load end 1 and the connecting end 4, respectively.

[0033] The aforementioned connections of the first screw 13, the second screw 14, and the connecting flange serve as backups for each other, forming a triple-redundant connection structure. Even if one connection fails, the other two connections can still ensure connection reliability, guaranteeing the safe and stable operation of the boom under a 180gt load. It should be noted that the first screw 13 is paired with a first nut 15, and the second screw 14 is paired with a second nut 16.

[0034] The second connecting assembly is installed in the same way as the first connecting assembly. It reliably connects the counterweight end 6 and the connecting end 4 through two first screws 13, multiple second screws 14, and corresponding connecting flanges. This will not be described in detail here.

[0035] Both the load end 1 and the connecting end 4 have multiple pipeline through holes, which are symmetrically arranged along the perpendicular bisector of the connecting end face. The number and diameter of the pipeline through holes are determined according to the actual pipeline layout requirements. A pipeline channel is pre-reserved inside the drive shaft 19. After the pipeline 20 passes through this channel, it sequentially passes through the corresponding pipeline through holes on the connecting end 4 and the load end 1, connecting to the object under test placed on the load end 1 to achieve the transmission of test signals, hydraulic oil, coolant, etc. A tensioning sleeve 18 is also provided on the outside of the drive shaft 19.

[0036] The location of the pipeline through-holes is designed to avoid the stress area of ​​the connecting components, which ensures the rationality of the pipeline layout without affecting the structural strength of the connection parts.

[0037] The side walls of the load end 1, the connection end 4 and the counterweight end 6 are all equipped with fairings 2. The fairings 2 are made of lightweight and high-strength composite materials. There are two sets of fairings 2 for each component, which are symmetrically arranged on both sides of the component.

[0038] The fairing 2 is detachably connected to the wall panels of each component via bolts. Its streamlined design effectively reduces aerodynamic drag during the rotation of the rotor arm, thereby reducing wind noise and energy consumption. Furthermore, the fairing 2 can be further disassembled into smaller units. When maintenance of the internal structure of the rotor arm is required, the corresponding fairing unit can be removed without dismantling the entire structure, making maintenance convenient.

[0039] The present invention also includes a limiting component. At least one limiting component for limiting is provided on the inner end face of the load end 1. In this embodiment, the limiting component includes an arc-shaped limiting groove 21 and a limiting pin 22 that can slide in the limiting groove 21. The limiting component can prevent the object to be tested from flipping.

[0040] Installation and debugging steps Component pretreatment: Perform flaw detection on the welded structures of load end 1, connection end 4, and counterweight end 6 to ensure there are no welding defects; clean each connection end face and connection through hole to remove burrs and impurities; Assembly of the connecting end and the drive shaft: Place the tensioning sleeve into the center through hole of the connecting end 4, then insert the drive shaft 19 into the tensioning sleeve, and tighten the fixing bolts of the tensioning sleeve to fix the connecting end 4 and the drive shaft 19. Load end and connection end assembly: Align and fit the flange edge of load end 1 with the flange edge of one end of connection end 4, ensuring that the connection through holes correspond one-to-one; pass the two first screws 13 through the large diameter through holes and screw on the large screw nuts, initially tightening (not reaching the specified torque); pass the multiple second screws 14 through the small diameter through holes and screw on the small bolt nuts, initially tightening; install the first connecting flange 11 and the second connecting flange 12 on the upper and lower end faces of the connection, respectively, so that the flange edges are inserted into the U-shaped groove, and fix the connecting flange with bolts; tighten all the first screws 13, second screws 14 and fixing bolts of the connecting flange in sequence according to the specified torque; Assembly of counterweight end and connecting end: The other end of the counterweight end 6 is fixedly connected to the other end of the connecting end 4 by the second connecting component; Installation of damping device 17 and limiting component: Fix the hydraulic damper to the load end with bolts; fix the limiting component (elastic claw) to the inner wall of the ring component with bolts; Fairing installation: Fix each fairing 2 to the side wall of the load end 1, the connecting end 4 and the counterweight end 6 with bolts to ensure that the installation is firm and tight. Pipeline layout: Pipeline 20 is passed through the internal channel of drive shaft 19, the pipeline through hole of connection end 4 and load end 1, and connected and fixed to the object to be tested; Counterweight adjustment and balance test: Based on the mass of the object to be tested, select appropriate counterweights and install them in the rectangular cavity of counterweight end 6, and fix them with lock nuts; install the rotating arm on the centrifuge frame and perform a static balance test. If it is unbalanced, adjust the number or position of the counterweights until the balance requirements are met. Trial run: Start the centrifuge, gradually increase the speed, test the stability of the rotating arm, the tightness of the connection parts, and various performance parameters. Once it is confirmed that it meets the design requirements, it can be put into formal use.

[0041] The above description is merely a specific embodiment of the present invention and should not be construed as limiting the scope of the invention. Therefore, any substitution of equivalent components or equivalent changes and modifications made within the scope of protection of this patent should still fall within the scope of this patent. Furthermore, the technical features, technical features and technical solutions, and technical solutions in this invention can be freely combined and used.

Claims

1. A segmented centrifuge arm, characterized in that, include: Connection end (4); The load end (1) is detachably connected to one end of the connection end (4), and the load end (1) is used to clamp the object to be measured; The counterweight end (6) is detachably connected to the other end of the connecting end (4), and the counterweight end (6) is used to place the counterweight block.

2. The segmented centrifuge arm according to claim 1, characterized in that, The load end (1) is connected to one end of the connection end (4) through a first connection component, and the counterweight end (6) is connected to the other end of the connection end (4) through a second connection component.

3. The segmented centrifuge arm according to claim 2, characterized in that, One end of the connecting end (4) and the end corresponding to the load end (1) are provided with multiple connecting through holes at corresponding positions. The other end of the connecting end (4) and the end corresponding to the counterweight end (6) are provided with multiple connecting through holes at corresponding positions.

4. The segmented centrifuge arm according to claim 3, characterized in that, The first connecting component and the second connecting component have the same structure. The first connecting component includes: Two first screws (13) are symmetrically arranged along the vertical bisector of the connecting end face, and the line connecting the axes of the two first screws (13) is located on the horizontal bisector of the connecting end face; Multiple second screws (14) are arranged in an array around the two first screws (13).

5. The segmented centrifuge arm according to claim 4, characterized in that, The first connection component also includes: The first connecting flange (11) is located on the upper surface of the connection between the load end (1) and the connecting end (4). The two sides of the first connecting flange (11) are respectively connected to the load end (1) and the connecting end (4). The second connecting flange (12) is located on the lower end face of the connection between the load end (1) and the connecting end (4). The two sides of the second connecting flange (12) are respectively connected to the load end (1) and the connecting end (4).

6. The segmented centrifuge arm according to claim 4, characterized in that, Multiple pipeline through holes are provided at one end of the load end (1) and the connection end (4), and the multiple pipeline through holes are provided along the vertical bisector of the connection end face.

7. The segmented centrifuge arm according to claim 6, characterized in that, The connecting end (4) is connected to the drive shaft (18), and a pipeline (19) is provided in the drive shaft (18). The pipeline (19) passes through the corresponding pipeline through hole and is connected to the object to be tested placed at the load end (1).

8. The segmented centrifuge arm according to claim 1, characterized in that, The side walls of the connecting end (4), the load end (1) and the counterweight end (6) are all equipped with fairings (2).

9. The segmented centrifuge arm according to claim 1, characterized in that, A damping device (17) is provided inside the load end (1), and the damping device (17) is fixed to the load end (1) by bolts.

10. The segmented centrifuge arm according to claim 1, characterized in that, The load end (1) is provided with a ring assembly for passing through a rotating shaft at one end for holding the object to be tested. The ring assembly has two opposing inner sidewalls, and at least one inner sidewall is provided with a limiting component for limiting the rotation of the object to be tested.

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