Elastic ring dynamic stiffness testing device considering extrusion oil film characteristics under rotary excitation

Abstract

The present application belongs to the technical field of performance test of aero-engine parts, and particularly relates to an elastic ring dynamic stiffness testing device considering extrusion oil film characteristics under rotary excitation, comprising a rotary excitation driving assembly, an elastic ring assembly, a plurality of force sensor assemblies and an outer shell. An annular chamber of the extrusion oil film is formed between the inner and outer bushings of the elastic ring assembly, the elastic ring assembly is installed between the inner and outer bushings, and the outer bushing is fixed to the outer shell through the force sensor assembly; the inner bushing is used for tight fit with the bearing outer ring. The present application can accurately simulate the elastic ring extrusion oil film characteristics under rotary excitation, apply rotary excitation load by using an unbalanced rotor system with adjustable unbalance, directly measure the excitation force amplitude by cross-arranged dynamic force sensors, measure the rotor displacement response by high-precision laser displacement sensors, and further realize accurate testing of dynamic stiffness considering the elastic ring structure and oil film characteristics, thereby providing strong support for elastic ring design.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of performance test of aero-engine parts, and particularly relates to an elastic ring dynamic stiffness test device considering extrusion oil film characteristics under rotary excitation. BACKGROUND

[0002] Reasonably designing a damper at the fulcrum of a rotor of an aero-engine can effectively reduce vibration. An elastic ring type extrusion oil film damper can effectively improve the nonlinear characteristics of oil film stiffness and simultaneously has a frequency modulation function, and is widely used in various types of aero-engines. The elastic ring is used to support a high-speed rotor, and accurate determination of characteristic parameters such as elastic ring dynamic stiffness under rotor rotary excitation is the basis for the design and application thereof.

[0003] At present, the design theory and test technology of elastic ring static stiffness are relatively mature, and the static stiffness characteristics are mainly designed in engineering design. For example, the patent "Elastic ring supporting stiffness measuring device" (CN: 201220556447.3) discloses a static stiffness test scheme of an elastic ring structure without considering oil film characteristics. The dynamic characteristics considering extrusion oil film characteristics under rotary excitation are mainly verified by whole machine test, which has high test cost and difficulty, and it is difficult to study the influence of structural and load characteristics, which is not conducive to direct design guidance. The patent "Test device for dynamic characteristics of elastic ring type extrusion oil film damper" (CN: 202111627280.5) discloses a device for equivalent test by using relative motion, which converts the motion form of the inner bushing of the elastic ring into the motion form of the outer bushing, and simulates the motion characteristics of the supporting-damping structure. However, the vertical / horizontal excitation and the actual rotor precession generate high-speed rotary excitation, which still has differences in extrusion oil film characteristics, and affects the accuracy of dynamic stiffness characteristics.

[0004] In a laboratory environment, how to effectively simulate the extrusion oil film characteristics under rotary excitation and accurately test the force and deformation relationship of the elastic ring type supporting and damping structure under dynamic load excitation to obtain the dynamic stiffness and other mechanical characteristics is still a difficult problem to be solved. In addition, the experimental device for measuring the dynamic stiffness of the elastic ring also requires simple structure and convenience for use, so as to carry out repeated test experiments and realize the research on the influence of parameters. Therefore, it is of great significance to design an elastic ring dynamic stiffness test device with simple structure and considering the extrusion oil film characteristics under rotary excitation. SUMMARY

[0005] In order to solve the above technical problems, the application provides an elastic ring dynamic stiffness test device considering extrusion oil film characteristics under rotary excitation, which can simulate the real stress state of the rotor fulcrum and is used for measuring the dynamic stiffness of the elastic ring under external excitation.

[0006] The present application is achieved, providing a kind of elastic ring dynamic stiffness testing device considering the characteristics of extrusion oil film under rotary excitation, including rotary excitation drive assembly, elastic ring assembly, several groups of force sensor components and outer shell, rotary excitation drive assembly includes rotary excitation drive shaft, outer shell is annular fixed shell, elastic ring assembly is arranged in outer shell, including elastic ring, inner bushing and outer bushing, annular chamber is formed between inner bushing, outer bushing and outer shell, elastic ring is arranged in annular chamber, rotary excitation drive shaft passes through the hole in the center of outer shell, is contacted with inner bushing by bearing, several groups of force sensor components are arranged in the cavity between outer bushing and outer shell and are connected with outer bushing;

[0007] Several radial protruding outer bosses are uniformly distributed on the outer circumferential surface of the elastic ring, and the same number of radial protruding inner bosses are uniformly distributed on the inner circumferential surface of the elastic ring, each inner boss is located between two adjacent outer bosses, the surface of each outer boss is in contact with the inner surface of the outer bushing, and several outer oil film cavities are formed between the two adjacent outer bosses, the inner wall of the outer bushing and the outer wall of the elastic ring, the surface of each inner boss is in contact with the outer surface of the inner bushing, and several inner oil film cavities are formed between the two adjacent inner bosses, the outer wall of the inner bushing and the inner wall of the elastic ring, a plurality of oil infiltration holes are provided on the elastic ring, each outer oil film cavity is communicated with the inner oil film cavities on its two sides through the oil infiltration hole.

[0008] An outer bushing oil supply hole is provided on the outer bushing and communicated with one of the outer oil film cavities, and an outer bushing oil return hole is also provided on the outer bushing and communicated with another outer oil film cavity, a oil supply pipeline passes through the outer shell and is communicated with the outer bushing oil supply hole, and an oil return pipeline passes through the outer shell and is communicated with the outer bushing oil return hole.

[0009] Preferably, the force sensor component includes a force sensor, one end of the force sensor is connected to the outer bushing through a connecting rod, and the other end is connected to a metal block through a connecting rod, and the metal block is connected to the inner wall of the outer shell.

[0010] Further preferably, the force sensor component is provided with four groups, which are uniformly distributed on the outer circumferential surface of the outer bushing.

[0011] Further preferably, the rotary excitation drive assembly further includes a disc, a coupling and a motor, the motor is connected to one end of the rotary excitation drive shaft through the coupling, the disc is fixed on the rotary excitation drive shaft, and a plurality of screw holes are provided on the disc.

[0012] Further preferably, the disc and the rotary excitation drive shaft are fixedly connected through a key.

[0013] Further preferably, two mutually perpendicular laser displacement sensors are provided on the periphery of the rotary excitation drive shaft close to the outer shell, and the laser emission directions of the two laser displacement sensors are both directed to the rotary excitation drive shaft.

[0014] Further preferably, a first sealing ring is arranged between the two sides of the inner sleeve and the inner wall of the outer shell, and a second sealing ring is arranged between the two sides of the outer sleeve and the inner wall of the outer shell.

[0015] Further preferably, positioning grooves are arranged at the ends of the at least two outer bosses on the same side of the elastic ring, and a positioning pin is arranged to pass through the positioning grooves and be connected with the outer sleeve.

[0016] Further preferably, a spring retainer is arranged on one side of the bearing and the position connected with the rotating excitation driving shaft, and a round nut is arranged on the other side, and a stop washer is arranged between the round nut and the bearing.

[0017] Further preferably, the outer shell body comprises a ring-shaped shell and two ring-shaped baffles, the two ring-shaped baffles are fixed on the two sides of the ring-shaped shell through bolts, the lower end of the ring-shaped shell is fixedly connected with the base, a through hole is arranged on one of the ring-shaped baffles, and the lead wires of the force sensor assembly pass through the through hole; an outer shell oil supply hole and an outer shell oil return hole are arranged on the ring-shaped shell at positions corresponding to the outer sleeve oil supply hole and the outer sleeve oil return hole respectively, an oil supply pipe is arranged to pass through the outer shell oil supply hole and be connected with the outer sleeve oil supply hole, and an oil return pipe is arranged to pass through the outer shell oil return hole and be connected with the outer sleeve oil return hole.

[0018] Compared with the prior art, the advantages of the present application are that:

[0019] 1. The present application effectively considers the elastic ring extrusion oil film characteristics under rotating excitation, and forms an annular chamber for installing the elastic ring and generating the extrusion oil film through the inner sleeve, the outer sleeve and the sealing ring, so that the dynamic stiffness of the elastic ring structure without oil can be tested, and the stiffness of the extrusion oil film under dynamic load can be tested by introducing oil.

[0020] 2. The present application can accurately simulate the motion and deformation characteristics of the elastic ring structure and the extrusion oil film under the rotating excitation of the rotor, and accurately simulate the support point dynamic load excitation characteristics generated by the precession of the rotor under real working conditions by using the unbalanced rotor excitation device.

[0021] 3. The present application adopts four dynamic force sensors arranged in a 45º cross pattern vertically and horizontally to test the excitation force, and directly places the dynamic force sensors on the outer sleeve of the elastic ring to realize direct high-precision testing of the excitation load of the elastic ring; and applies high-precision laser displacement sensors to measure displacement responses at multiple points, thereby effectively improving the accuracy of the dynamic stiffness test of the supporting-damping structure. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 is a partial sectional view of the elastic ring dynamic stiffness test device.

[0023] Figure 2 is a sectional view of the elastic ring in the installed state.

[0024] Figure 3 is a schematic diagram of an elastic ring structure.

[0025] Figure 4 is a schematic diagram of the relative positions of the force sensor, oil supply hole, and oil return hole.

[0026] Figure 5 is a schematic diagram of the overall elastic ring dynamic stiffness testing device. DETAILED DESCRIPTION

[0027] In order to make the purpose, technical solutions and advantages of the present application clearer, the present application is further described in detail below with reference to the drawings and examples. It should be understood that the specific examples described herein are only used to explain the present application and do not limit the present application.

[0028] Reference Figure 1 , Figure 2 , Figure 3 , Figure 4 and Figure 5 , the present application provides an elastic ring dynamic stiffness testing device considering the characteristics of the extrusion oil film under rotary excitation, comprising a rotary excitation driving assembly, an elastic ring assembly, a plurality of force sensor assemblies, and an outer shell 14. The rotary excitation driving assembly comprises a rotary excitation driving shaft 21. The outer shell 14 is a ring-shaped fixed shell. The elastic ring assembly is arranged in the outer shell 14 and comprises an elastic ring 1, an inner bushing 3, and an outer bushing 2. The inner bushing 3 and the outer bushing 2 form an annular cavity with the outer shell 14. The elastic ring 1 is arranged in the annular cavity. The rotary excitation driving shaft 21 passes through a hole in the center of the outer shell 14 and is in contact with the inner bushing 3 through a bearing 4. The plurality of force sensor assemblies are arranged in the cavity between the outer bushing 2 and the outer shell 14 and are connected to the outer bushing 2.

[0029] A plurality of radially protruding outer bosses 23 are uniformly distributed on the outer circumferential surface of the elastic ring 1. The number of the outer bosses 23 is even. A plurality of radially protruding inner bosses 18, which are the same in number as the outer bosses 23, are uniformly distributed on the inner circumferential surface of the elastic ring 1. Each inner boss 18 is located between two adjacent outer bosses 23. The surfaces of the outer bosses 23 are in contact with the inner surface of the outer bushing 2. A plurality of outer oil film cavities 20 are formed between the adjacent outer bosses 23, the inner wall of the outer bushing 2, and the outer wall of the elastic ring 1. The surfaces of the inner bosses 18 are in contact with the outer surface of the inner bushing 3. A plurality of inner oil film cavities 19 are formed between the adjacent inner bosses 18, the outer wall of the inner bushing 3, and the inner wall of the elastic ring 1. A plurality of oil infiltration holes 22 are provided on the elastic ring 1. Each outer oil film cavity 20 is connected to the inner oil film cavities 19 on its two sides through the oil infiltration hole 22.

[0030] An outer bushing oil supply hole 30 is provided on the outer bushing 2 and communicates with one of the outer oil film chambers 20. An outer bushing oil return hole 33 is also provided on the outer bushing 2 and communicates with another of the outer oil film chambers 20. The oil supply pipeline passes through the outer cover shell 14 and communicates with the outer bushing oil supply hole 30. The oil return pipeline passes through the outer cover shell 14 and communicates with the outer bushing oil return hole 33.

[0031] In the dynamic stiffness test of the elastic ring 1 using the device, oil is injected into the outer oil film chamber 20 connected to the outer bushing oil supply hole 30, and the oil enters the two inner oil film chambers 19 connected to the outer oil film chamber 20 through the oil permeation holes 22 on the elastic ring 1. The oil alternately passes through the inner oil film chambers 19 and the outer oil film chambers 20, and flows out of the outer bushing oil return hole 33 below the outer bushing 2 when the oil fills the entire annular chamber. The above process realizes the oil supply and return of the elastic ring type extruded oil film damper, thereby forming an oil film. Then, the rotary excitation is provided by rotating the driving shaft 21, and the rotary excitation is transmitted to the inner bushing 3 of the elastic ring assembly through the bearing 4. When the elastic ring 1 is subjected to the rotary excitation, it deforms and starts to extrude the oil film formed in the annular chamber. The oil flows between the inner oil film chambers 19 and the outer oil film chambers 20 through the oil permeation holes 22 on the elastic ring 1 to produce a damping effect, thereby achieving the damping effect. The corresponding force is transmitted to the force sensor assembly around the outer bushing 2 through the outer bushing 2, and the force sensor assembly transmits the force acting on the elastic ring 1 to the peripheral monitoring equipment, thereby measuring the force acting on the elastic ring 1.

[0032] As an implementation of the force sensor assembly, the force sensor assembly includes a force sensor 10, one end of which is connected to the outer bushing 2 through a connecting rod, and the other end is connected to a metal block 15 through a connecting rod, which is embedded in the inner wall of the outer cover shell 14.

[0033] When the force sensor 10 is installed, it is first placed in the space between the outer surface of the outer bushing 2 and the outer cover shell 14. One end of the force sensor 10 is threadedly connected to the boss of the outer bushing 2 through a connecting rod. The other end is threadedly connected to a nut 32 through a connecting rod. After the threaded connection on the boss of the outer bushing 2 is fixed, the force sensor 10 is fastened between the outer bushing 2 and the metal block 15 on the outer cover shell 14 by rotating the nut 32. The rigidity of the connection is ensured during fixation, so that the force sensor 10 accurately measures the excitation received by the elastic ring 1.

[0034] Preferably, the force sensor assembly is provided with four sets, which are evenly distributed on the outer circumferential surface of the outer bushing 2. Specifically, vertical and horizontal 45º cross arrangement can be adopted.

[0035] As a specific implementation of the rotating excitation assembly, the rotating excitation driving assembly further comprises a disc 24, a coupling 26 and a motor 25, the motor 25 is connected with one end of the rotating excitation driving shaft 21 through the coupling 26, and the disc 24 is fixed on the rotating excitation driving shaft 21, and a plurality of screw holes are arranged on the disc 24.

[0036] The screw holes arranged on the disc 24 are used for attaching unbalanced mass on the rotor system, and the mass unbalance of the rotor generates excitation on the fulcrum. The rotor system is driven by the motor 25, and the excitation is generated by adding the screws constituting eccentric mass on the disc 24, and the number and size of the screws are adjusted to adjust the size of the excitation.

[0037] In order to support stability, a supporting bearing is further arranged on the rotating excitation driving shaft 21 between the coupling 26 and the disc 24, the rotating excitation driving shaft 21 penetrates through the supporting bearing, the supporting bearing is connected with the rotating excitation driving shaft 21 through a washer 28, and the lower end of the supporting bearing is supported through a support 29.

[0038] Preferably, the disc 24 is fixedly connected with the rotating excitation driving shaft 21 through a key 27.

[0039] In order to obtain the radial deformation degree of the elastic ring 1, two mutually perpendicular laser displacement sensors 34 are arranged on the periphery of the rotating excitation driving shaft 21 close to the outer shell 14, and the laser emission directions of the two laser displacement sensors 34 are both directed to the rotating excitation driving shaft 21.

[0040] The shaft center track of the shaft segment measured by the laser displacement sensor 34 can be approximately considered as the radial deformation of the elastic ring assembly to be measured, that is, the deformation size of the elastic ring 1 can be obtained through the above laser displacement sensor 34.

[0041] In order to prevent oil leakage, a first sealing ring 6 is arranged between the two sides of the inner sleeve 3 and the inner wall of the outer shell 14, and a second sealing ring 7 is arranged between the two sides of the outer sleeve 2 and the inner wall of the outer shell 14. The first sealing ring 6 and the second sealing ring 7 on the two sides are pressed by the inner wall of the outer shell 14, so as to ensure the airtightness of the above-mentioned annular chamber.

[0042] In order to limit the elastic ring 1, positioning grooves are arranged on at least two end portions of the outer boss 23 on the same side of the elastic ring 1, and a positioning pin 16 is arranged to pass through the positioning grooves and is connected with the outer sleeve 2.

[0043] In order to ensure the stability of the connection of the bearing 4 on the rotating excitation driving shaft 21, as an improvement, a spring retainer 5 is arranged on one side of the connection position of the bearing 4 and the rotating excitation driving shaft 21, a round nut 8 is arranged on the other side, and a stop washer 9 is arranged between the round nut 8 and the bearing 4.

[0044] The outer shell body 14 comprises an annular shell 36 and two annular baffles 13 fixed on both sides of the annular shell 36 by bolts 11, and the lower end of the annular shell 36 is fixedly connected with the base 35. In this way, when the variable parameter experiment is performed, the annular baffles 13 can be removed, and the elastic ring 1 can be taken out of the annular cavity formed by the inner sleeve 3 and the outer sleeve 2, and the elastic ring 1 can be replaced, and the dynamic stiffness of the elastic ring 1 corresponding to the variable parameters can be obtained by repeating the experiment.

[0045] The lower end of the annular baffle 13 is close to the rotary excitation drive shaft 21, and the seal between the elastic ring assembly and the inner wall of the outer shell body 14 is dynamic sealing, which inevitably causes oil leakage. The two thin shells of the annular baffle 13 extending close to the rotary excitation drive shaft 21 can avoid the pollution of the surface of the rotary excitation drive shaft 21 used for measuring displacement by the leaked oil.

[0046] A through hole 12 is arranged on one of the annular baffles 13, and the lead wire of the force sensor assembly passes through the through hole 12; the annular shell 36 is provided with a shell oil supply hole 17 and a shell oil return hole corresponding to the outer sleeve oil supply hole 30 and the outer sleeve oil return hole 33, respectively, and an oil supply pipe 31 is arranged to pass through the shell oil supply hole 17 and is connected with the outer sleeve oil supply hole 30, and an oil return pipe is arranged to pass through the shell oil return hole and is connected with the outer sleeve oil return hole 33.

[0047] The device can also test the dynamic stiffness of the oil-free elastic ring structure without oil, and the test method is consistent with that when oil is used.

Claims

1. The elastic ring dynamic stiffness test device considering the characteristics of the squeeze oil film under rotational excitation is characterized by: The invention comprises a rotary excitation drive assembly, an elastic ring assembly, several groups of force sensor assemblies and an outer cover shell (14), wherein the rotary excitation drive assembly comprises a rotary excitation drive shaft (21), the outer cover shell (14) is an annular fixed shell, the elastic ring assembly is arranged in the outer cover shell (14), and comprises an elastic ring (1), an inner bushing (3) and an outer bushing (2), an annular chamber is formed between the inner bushing (3), the outer bushing (2) and the outer cover shell (14), the elastic ring (1) is arranged in the annular chamber, the rotary excitation drive shaft (21) passes through a hole in the center of the outer cover shell (14), and contacts the inner bushing (3) through a bearing (4), and several groups of force sensor assemblies are arranged in the cavity between the outer bushing (2) and the outer cover shell (14) and connected to the outer bushing (2); A plurality of radially protruding outer bosses (23) are uniformly distributed on the outer circumferential surface of the elastic ring (1), and the same number of radially protruding inner bosses (18) as the outer bosses (23) are uniformly distributed on the inner circumferential surface of the elastic ring (1), each inner boss (18) is located between two adjacent outer bosses (23), and the surfaces of the outer bosses (23) are in contact with the inner surface of the outer bushing (2), and a plurality of outer oil film cavities (20) are formed between the two adjacent outer bosses (23), the inner wall of the outer bushing (2), and the outer wall of the elastic ring (1), and the surfaces of the inner bosses (18) are in contact with the outer surface of the inner bushing (3), and a plurality of inner oil film cavities (19) are formed between the two adjacent inner bosses (18), the outer wall of the inner bushing (3), and the inner wall of the elastic ring (1), and a plurality of oil seepage holes (22) are provided on the elastic ring (1), and each outer oil film cavity (20) is connected to the inner oil film cavities (19) on both sides thereof through the oil seepage holes (22); An outer bushing oil supply hole (30) is provided on the outer bushing (2) and is communicated with an outer oil film cavity (20). An outer bushing oil return hole (33) is also provided on the outer bushing (2) and is communicated with another outer oil film cavity (20). An oil supply line passes through the outer cover shell (14) and is communicated with the outer bushing oil supply hole (30). An oil return line passes through the outer cover shell (14) and is communicated with the outer bushing oil return hole (33). The force sensor assembly includes a force sensor (10), one end of the force sensor (10) is connected to the outer bushing (2) via a connecting rod, and the other end is connected to a metal block (15) via a connecting rod, and the metal block (15) is connected to the inner wall of the outer cover shell (14); The force sensor assembly is provided with four groups, which are evenly distributed on the outer circumferential surface of the outer bushing (2) in a vertical and horizontal 45° cross arrangement; The rotary excitation drive assembly further comprises a disk (24), a coupling (26) and a motor (25), wherein the motor (25) is connected to one end of the rotary excitation drive shaft (21) via the coupling (26), and the disk (24) is fixed on the rotary excitation drive shaft (21). A plurality of screw holes are provided on the disk (24), and the screw holes are used to add screws constituting eccentric masses to the disk (24), thereby adding unbalanced masses to the rotor system. Excitation is generated by the drive of the motor (25), and the magnitude of the excitation is adjusted by adjusting the number and size of the screws.

2. The elastic ring dynamic stiffness testing device considering the squeeze oil film characteristics under rotational excitation according to claim 1 is characterized in that: The disc (24) is fixedly connected to the rotary excitation drive shaft (21) via a key (27).

3. The elastic ring dynamic stiffness testing device considering the squeeze oil film characteristics under rotational excitation according to claim 1 is characterized in that: Two mutually perpendicular laser displacement sensors (34) are provided on the periphery of the rotary excitation drive shaft (21) near the outer cover shell (14), and the laser emission directions of the two laser displacement sensors (34) are both directed toward the rotary excitation drive shaft (21).

4. The elastic ring dynamic stiffness testing device considering the squeeze oil film characteristics under rotational excitation according to claim 1 is characterized in that: A first sealing ring (6) is provided between the two sides of the inner sleeve (3) and the inner wall of the outer cover shell (14), and a second sealing ring (7) is provided between the two sides of the outer sleeve (2) and the inner wall of the outer cover shell (14).

5. The elastic ring dynamic stiffness testing device considering the squeeze oil film characteristics under rotational excitation according to claim 1 is characterized in that: At least two ends of the outer bosses (23) on the same side of the elastic ring (1) are provided with positioning grooves, and positioning pins (16) are provided that pass through the positioning grooves and are connected to the outer bushing (2).

6. The elastic ring dynamic stiffness testing device considering the squeeze oil film characteristics under rotational excitation according to claim 1 is characterized in that: A spring retaining ring (5) is provided on one side of the connection position between the bearing (4) and the rotary excitation drive shaft (21), and a round nut (8) is provided on the other side. A stop washer (9) is provided between the round nut (8) and the bearing (4).

7. The elastic ring dynamic stiffness testing device considering the squeeze oil film characteristics under rotational excitation according to claim 1 is characterized in that: The outer cover shell (14) includes an annular outer shell (36) and two annular baffles (13), the two annular baffles (13) are fixed to both sides of the annular outer shell (36) by bolts (11), the lower end of the annular outer shell (36) is fixedly connected to the base (35), and a through hole (12) is provided on one of the annular baffles (13), and the wire of the force sensor assembly passes through the through hole (12); a shell oil supply hole (17) and a shell oil return hole are respectively provided on the annular outer shell (36) at positions corresponding to the outer bushing oil supply hole (30) and the outer bushing oil return hole (33), an oil supply pipe (31) is provided passing through the shell oil supply hole (17) and connected to the outer bushing oil supply hole (30), and an oil return pipe is provided passing through the shell oil return hole and connected to the outer bushing oil return hole (33).

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