Vibration reduction system and optimization method for auxiliary power device of large wide-body passenger plane

Abstract

The invention belongs to the technical field of configuration or installation of power devices or propulsion transmission devices in airplanes, and particularly relates to a damping system and optimization method for an auxiliary power device of a large wide-body passenger plane, and the damping system comprises the auxiliary power device, a plurality of dampers and a plurality of pull rods; the shock absorber comprises a shell, a shaft body and an elastic body, the shaft body comprises a shock absorbing end and a connecting end, and the shock absorbing end is provided with a mounting disc; the elastomer is provided with a center hole, the inner diameter of the middle of the center hole is increased to form a mounting cavity, and the mounting disc is sleeved with the mounting cavity of the elastomer. The shell is provided with a containing cavity, a through hole is formed in the surface of the shell, the shaft body vibration reduction end sleeved with the elastic body is installed in the shell, and the shaft body connecting end is arranged on the outer side of the shell through the through hole of the shell. The multiple shock absorbers are installed on one auxiliary power device through the connecting ends of the shaft bodies, a shell of each shock absorber is connected with the machine body through at least one pull rod, and the auxiliary power device is fixedly installed on the machine body.

Description

Technical Field

[0001] The present application belongs to the technical field of configuration or installation of a power unit or a propulsion transmission device in an aircraft, and in particular, relates to a vibration reduction system and optimization method for an auxiliary power unit of a large wide-body passenger aircraft. Background Art

[0002] The auxiliary power unit (APU) of a large wide-body aircraft is generally installed at the tail of the aircraft. It serves as the aircraft's second power source to provide electricity and bleed air for the aircraft, and to start the main engine on the ground. Since the vibration of the aircraft body will have an adverse effect on the operation and reliability of the APU, and the vibration of the APU will also be transmitted to the aircraft body, the APU needs to be installed with vibration reduction. Summary of the invention

[0003] In order to solve the above problems, the present application provides a vibration reduction system for an auxiliary power unit of a large wide-body passenger aircraft, comprising: auxiliary power unit, multiple shock absorbers, and multiple tie rods; The vibration damper comprises: a shell, a shaft and an elastic body, wherein the shaft comprises a vibration damping end and a connecting end, and the vibration damping end has a mounting disc; the elastic body has a central hole, the inner diameter of the middle part of the central hole becomes larger to form a mounting cavity, and the mounting disc is sleeved in the mounting cavity of the elastic body; the shell has a cavity, and the surface of the shell has a through hole, the vibration damping end of the shaft sleeved with the elastic body is installed inside the shell, and the connecting end of the shaft is placed outside the shell through the through hole of the shell; A plurality of shock absorbers are installed on the auxiliary power device through the connecting end of the shaft body, and the housing of each shock absorber is connected to the machine body through at least one pull rod, so that the auxiliary power device is fixedly installed on the machine body.

[0004] Preferably, the auxiliary power unit has a left front mounting section, a right front mounting section, a left rear mounting section and a right rear mounting section, and each mounting section is respectively equipped with a shock absorber.

[0005] Preferably, the shock absorber is connected to the auxiliary power unit through a mounting base, the mounting base has a spherical mounting head at one end and a flange mounting plate at the other end, the spherical mounting head has a conical through hole, the connecting end of the shaft body has a conical section and a screw section, the conical surface of the conical section fits with the conical surface of the conical through hole, and an anti-loosening bolt is connected to the screw section to fix the connecting end of the shaft body to the mounting base.

[0006] Preferably, the elastomer and the housing cavity of the shell are both cylindrical in shape, and a plurality of axially arranged grooves are circumferentially distributed on the outer cylindrical surface of the elastomer to provide deformation space for the elastomer.

[0007] Preferably, the housing is provided with a small hole at the position of the groove for inserting a filling body into the groove, and the filling bodies with different volumes and different elastic moduli are filled to adjust the radial stiffness of the shock absorber.

[0008] Preferably, the shell includes an outer shell and a packaging base plate, the outer shell is a cylindrical body with an opening at one end, the inner surface of the opening has an internal thread, the packaging base plate has an external thread, the packaging base plate and the outer shell are threadedly connected to form the cylindrical cavity, the screw-in amount of the packaging base plate is changed to compress the elastomer, thereby adjusting the axial stiffness of the shock absorber.

[0009] A method for optimizing a vibration reduction system of an auxiliary power unit of a large wide-body passenger aircraft, for optimizing a vibration reduction system of an auxiliary power unit of a large wide-body passenger aircraft, the method comprising: Step S1: determining the static resultant force of each installation node according to the gravity of the auxiliary power device, and determining the dynamic resultant force of each installation node according to the gravity and the load spectrum of the auxiliary power device; Step S2: determining the number of tie rods, tie rod installation angles, and shock absorber installation angles of each installation section according to the static resultant force and the dynamic resultant force; Step S3: establishing a three-dimensional mechanical model of the installation angle, the number of tie rods and the installation angle of the tie rods of each shock absorber; Step S4: In combination with the optimal vibration reduction direction of the shock absorber, the vibration transmission rate of the auxiliary power unit vibration reduction system is minimized as the optimization goal, and the installation angle of the shock absorber is optimized using a genetic algorithm.

[0010] Preferably, in step S4, a genetic algorithm is also used to optimize the number of tie rods and the installation angles of the tie rods.

[0011] Preferably, a vibration spectrum of each shock absorber is obtained based on the three-dimensional mechanical model, and the axial and radial stiffness of the shock absorber is adjusted based on the vibration spectrum.

[0012] The advantages of the present application include: the vibration reduction system provided by the present application can effectively suppress the vibration of the auxiliary power device, reduce the resonance peak of the device, and improve the vibration reduction efficiency.

[0013] This application is based on the vibration excitation direction of the auxiliary power unit and combined with the optimal vibration reduction direction of the shock absorber. The vibration of the system is optimized by adjusting the installation angle of the shock absorber. After the optimization is completed, the axial and radial stiffness of the shock absorber is adjusted to further optimize the vibration of the system.

[0014] The shock absorber of the present application has the function of adjusting the axial and radial stiffness. After the installation angle of the shock absorber is determined, the stiffness can be adjusted based on the vibration spectrum or test data to reduce the resonance peak and improve the vibration reduction efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is a schematic diagram of the connection of multiple shock absorbers and multiple tie rods in a preferred embodiment of the present application.

[0016] Figure 2It is a schematic diagram of a front left mounting section shock absorber according to a preferred embodiment of the present application.

[0017] Figure 3 It is a half-section view of the front left mounting section shock absorber of a preferred embodiment of the present application.

[0018] Figure 4 This is a schematic diagram of the shaft of a preferred embodiment of the present application.

[0019] Figure 5 It is a schematic diagram of the housing of the front left mounting section shock absorber in a preferred embodiment of the present application.

[0020] Figure 6 It is a schematic diagram of a packaging base plate of a front left mounting section shock absorber in a preferred embodiment of the present application.

[0021] Figure 7 It is a schematic diagram of a mounting base for a front left mounting section shock absorber according to a preferred embodiment of the present application. DETAILED DESCRIPTION

[0022] In order to make the technical solution and advantages of the present application clearer, the technical solution of the present application will be further described in detail in detail and in detail in conjunction with the accompanying drawings. It can be understood that the specific embodiments described here are only partial embodiments of the present application, which are only used to explain the present application, not to limit the present application. It should be noted that, for the convenience of description, only the parts related to the present application are shown in the accompanying drawings, and other related parts can refer to the general design. In the absence of conflict, the embodiments in the present application and the technical features in the embodiments can be combined with each other to obtain new embodiments.

[0023] In addition, it should be noted that, unless otherwise clearly specified and limited, the words "installed", "connected", "connected" and similar terms used in the description of this application should be understood in a broad sense. For example, the 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, an indirect connection through an intermediate medium, or the internal connection of two components. Technical personnel in the field can understand their specific meanings in this application according to the specific circumstances.

[0024] The present application provides a vibration reduction system for an auxiliary power unit of a large wide-body passenger aircraft, such as Figure 1-Figure 7 As shown, including: auxiliary power unit, multiple shock absorbers, and multiple tie rods; Among them, the shock absorber is divided into a front left installation section shock absorber assembly 1, a front right installation section shock absorber assembly 2, a rear left installation section shock absorber assembly 3 and a rear right installation section shock absorber assembly 4. The entire shock absorption system is connected to the body through 8 tie rods. The bottoms of the four shock absorber assemblies are respectively connected to the four installation sections of the APU. There is a rubber body of the same configuration inside the shock absorber assembly, which serves as an elastomer 152 for vibration reduction. Taking the front left installation section shock absorber assembly 1 as an example, it includes: a shell, a shaft body 151 and an elastomer 152, wherein the shaft body 151 includes a vibration reduction end and a connecting end, and the vibration reduction end has a mounting disc; the elastomer 152 has a center hole, and the inner diameter of the middle part of the center hole becomes larger to form a mounting cavity, and the mounting disc is sleeved in the mounting cavity of the elastomer 152; the shell has a cavity, and the surface of the shell has a through hole, the vibration reduction end of the shaft body 151 sleeved with the elastomer 152 is installed inside the shell, and the connecting end of the shaft body 151 is placed outside the shell through the shell through hole; Among them, in one solution, the shell includes an outer shell 11, a packaging bottom plate 12, a stop gasket 13, and a packaging bolt 14. The outer shell 11 and the packaging bottom plate 12 form a cavity, the core shaft 15 is located in the middle of the cavity, the outer shell 11 has a flange screw hole, the packaging bottom plate 12 has a central opening 121 and a flange through hole 122, the central opening 121 is used to pass the shaft 151, and the outer shell 11 and the packaging bottom plate 12 are connected to form a whole by 4 groups of packaging bolts 14 and stop gaskets 13. The outer shell 11 has three pairs of mounting ears respectively connected to three external pull rods, and the other end of the pull rod is connected to the body structure. In another embodiment, the shell includes an outer shell 11 and a packaging base plate 12. The outer shell 11 is a cylindrical body with an opening at one end. The inner surface of the opening has an internal thread. The packaging base plate 12 has an external thread. The packaging base plate 12 and the outer shell 11 are threadedly connected to form the cylindrical cavity. The screw-in amount of the packaging base plate 12 is changed to compress the elastomer 152, thereby adjusting the axial stiffness of the shock absorber.

[0025] A plurality of shock absorbers are mounted on an auxiliary power device via the connecting end of the shaft 151, and the housing of each shock absorber is connected to the machine body via at least one tie rod, so that the auxiliary power device is fixedly mounted on the machine body.

[0026] Preferably, the auxiliary power unit has a left front mounting section, a right front mounting section, a left rear mounting section and a right rear mounting section, and each mounting section is respectively equipped with a shock absorber.

[0027] Preferably, the shock absorber is connected to the auxiliary power unit via a mounting base 16, wherein the mounting base 16 has a spherical mounting head 162 at one end and a flange mounting plate 161 at the other end, the spherical mounting head 162 has a conical through hole 163, and the edge of the conical through hole 163 has a stop boss 164.

[0028] The connecting end of the shaft body 151 has a cone section 1513 and a screw section 1511, the cone surface of the cone section 1513 is fitted with the cone surface of the conical through hole 163, the screw section 1511 is connected with an anti-loosening bolt 17 to fix the connecting end of the shaft body 151 with the mounting base 16, and the screw section 1511 also has a through hole 1512 for installing a pin to prevent the anti-loosening bolt 17 from rotating. When in use, the mounting base 16 and the housing 11 are relatively displaced to cause the elastic body 152 in the core shaft 15 to be squeezed and deformed, thereby playing a role in vibration isolation.

[0029] Preferably, the elastic body 152 and the housing cavity of the shell are both cylindrical in shape, and a plurality of axially arranged grooves 153 are circumferentially distributed on the outer cylindrical surface of the elastic body 152 to provide deformation space for the elastic body 152 .

[0030] Preferably, the housing is provided with a small hole at the position of the groove 153 for inserting a filler into the groove 153, and fillers of different volumes and different elastic moduli are filled to adjust the radial stiffness of the shock absorber.

[0031] A method for optimizing a vibration reduction system of an auxiliary power unit of a large wide-body passenger aircraft, for optimizing a vibration reduction system of an auxiliary power unit of a large wide-body passenger aircraft, the method comprising: Step S1: determining the static resultant force of each installation node according to the gravity of the auxiliary power device, and determining the dynamic resultant force of each installation node according to the gravity and the load spectrum of the auxiliary power device; Step S2: determining the number of tie rods, tie rod installation angles, and shock absorber installation angles of each installation section according to the static resultant force and the dynamic resultant force; Step S3: establishing a three-dimensional mechanical model of the installation angle, the number of tie rods and the installation angle of the tie rods of each shock absorber; Step S4: In combination with the optimal vibration reduction direction of the shock absorber, the vibration transmission rate of the auxiliary power unit vibration reduction system is minimized as the optimization goal, and the installation angle of the shock absorber is optimized using a genetic algorithm.

[0032] Preferably, in step S4, a genetic algorithm is also used to optimize the number of tie rods and the installation angles of the tie rods.

[0033] Preferably, a vibration spectrum of each shock absorber is obtained based on the three-dimensional mechanical model, and the axial and radial stiffness of the shock absorber is adjusted based on the vibration spectrum.

[0034] The advantages of the present application include: the vibration reduction system provided by the present application can effectively suppress the vibration of the auxiliary power device, reduce the resonance peak of the device, and improve the vibration reduction efficiency.

[0035] This application is based on the vibration excitation direction of the auxiliary power unit and combined with the optimal vibration reduction direction of the shock absorber. The vibration of the system is optimized by adjusting the installation angle of the shock absorber. After the optimization is completed, the axial and radial stiffness of the shock absorber is adjusted to further optimize the vibration of the system.

[0036] The shock absorber of the present application has the function of adjusting the axial and radial stiffness. After the installation angle of the shock absorber is determined, the stiffness can be adjusted based on the vibration spectrum or test data to reduce the resonance peak and improve the vibration reduction efficiency.

[0037] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application shall be based on the protection scope of the claims.

Claims

1. A vibration reduction system for an auxiliary power unit of a large wide-body passenger aircraft, characterized in that: include: auxiliary power unit, multiple shock absorbers, and multiple tie rods; The vibration damper comprises: a housing, a shaft (151) and an elastic body (152), wherein the shaft (151) comprises a vibration damping end and a connecting end, and the vibration damping end has a mounting disc; the elastic body (152) has a central hole, the inner diameter of the middle of the central hole is enlarged to form a mounting cavity, and the mounting disc is sleeved in the mounting cavity of the elastic body (152); the housing has a cavity, and the surface of the housing has a through hole, the vibration damping end of the shaft (151) sleeved with the elastic body (152) is installed inside the housing, and the connecting end of the shaft (151) is placed outside the housing through the housing through hole; A plurality of shock absorbers are mounted on the auxiliary power device via the connection end of the shaft body (151), and the housing of each shock absorber is connected to the machine body via at least one pull rod.

2. The auxiliary power unit vibration reduction system for a large wide-body passenger aircraft according to claim 1, characterized in that: The auxiliary power unit comprises a left front mounting section, a right front mounting section, a left rear mounting section and a right rear mounting section, and each mounting section is respectively provided with a shock absorber.

3. The auxiliary power unit vibration reduction system for a large wide-body passenger aircraft according to claim 2, characterized in that: The shock absorber is connected to the auxiliary power unit via a mounting base (16); one end of the mounting base (16) has a spherical mounting head (162) and the other end has a flange mounting plate (161); the spherical mounting head (162) has a conical through hole (163); the connecting end of the shaft body (151) has a conical section (1513) and a screw section (1511); the conical surface of the conical section (1513) fits the conical surface of the conical through hole (163); the screw section (1511) is connected to a locking bolt (17) to fix the connecting end of the shaft body (151) to the mounting base (16).

4. The auxiliary power unit vibration reduction system for a large wide-body passenger aircraft according to claim 1, characterized in that: The elastic body (152) and the housing cavity of the shell are both cylindrical in shape, and a plurality of axially arranged grooves (153) are circumferentially distributed on the outer cylindrical surface of the elastic body (152) to provide deformation space for the elastic body (152).

5. The auxiliary power unit vibration reduction system for a large wide-body passenger aircraft according to claim 4, characterized in that: The housing is provided with a small hole at the position of the groove (153) for inserting a filling body into the groove (153), and the filling bodies with different volumes and different elastic moduli are filled to adjust the radial stiffness of the shock absorber.

6. The auxiliary power unit vibration reduction system for a large wide-body passenger aircraft according to claim 5, characterized in that: The housing comprises an outer shell (11) and a packaging bottom plate (12); the outer shell (11) is a cylindrical body with an opening at one end, the inner surface of the opening having an internal thread, the packaging bottom plate (12) having an external thread, the packaging bottom plate (12) and the outer shell (11) being threadedly connected to form the cylindrical cavity; the screwing amount of the packaging bottom plate (12) is changed to compress the elastic body (152), thereby adjusting the axial stiffness of the shock absorber.

7. A method for optimizing the vibration reduction system of an auxiliary power unit of a large wide-body passenger aircraft, characterized in that: Used to optimize the auxiliary power unit vibration reduction system of a large wide-body passenger aircraft as described in any one of claims 1 to 6, the method comprising: Step S1: determining the static resultant force of each installation node according to the gravity of the auxiliary power device, and determining the dynamic resultant force of each installation node according to the gravity and the load spectrum of the auxiliary power device; Step S2: Determine the number of tie rods, tie rod installation angles, and shock absorber installation angles of each installation section according to the static resultant force and the dynamic resultant force; Step S3: establishing a three-dimensional mechanical model of the installation angle, the number of tie rods and the installation angle of the tie rods of each shock absorber; Step S4: In combination with the best vibration reduction direction of the shock absorber, according to the vibration excitation direction of the auxiliary power unit, with the minimum vibration transmission rate of the auxiliary power unit vibration reduction system as the optimization goal, the shock absorber installation angle is optimized using a genetic algorithm.

8. The method for optimizing the vibration reduction system of the auxiliary power unit of a large wide-body passenger aircraft according to claim 7, characterized in that: In step S4, a genetic algorithm is also used to optimize the number of tie rods and the installation angle of the tie rods.

9. The method for optimizing the vibration reduction system of the auxiliary power unit of a large wide-body passenger aircraft according to claim 7, characterized in that: A vibration spectrum of each shock absorber is obtained based on the three-dimensional mechanical model, and the axial and radial stiffness of the shock absorber is adjusted based on the vibration spectrum.

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