Squeeze film damper and film length adjustment system for a squeeze film damper

Abstract

Provided are an extrusion oil film damper, an oil film length adjusting system, and the like. The extrusion oil film damper comprises an inner ring, a fixing member, and a sliding member. The inner ring provides a shaft hole. The fixing member is fixed on the outer surface of the first end of the inner ring. The sliding member is opposite to the fixing member and is arranged on the outer surface of the second end of the inner ring, and defines an annular oil film layer with the inner ring. The sliding member is arranged to be movable along the axial direction of the inner ring, so as to increase or shorten the length of the annular oil film layer, and further adjust the oil film length. The oil film length adjusting system is provided. The extrusion oil film damper can conveniently and effectively directly adjust the oil film length, so as to achieve the effect of actively controlling the damping.

Description

Technical Field

[0001] This invention relates to the field of aero-engines, and more specifically to the field of extrusion film dampers. Background Technology

[0002] Extrusion film dampers are widely used in the vibration reduction design of various aero-engine rotors due to their excellent vibration reduction performance.

[0003] Aero-engine rotors have multiple critical speeds within their operating speed range. The same extrusion oil film damper produces different effects at different critical speeds, resulting in underdamping or overdamping at some critical speeds. This makes it impossible to simultaneously meet the optimal damping requirements for each operating condition and effectively reduce rotor vibration within the operating speed range. Summary of the Invention

[0004] One objective of this invention is to provide a squeeze oil film damper that allows for convenient and direct adjustment of the oil film length to achieve active damping control.

[0005] To achieve the above objectives, the extrusion oil film damper includes an inner ring, a fixed member, and a sliding member. The inner ring provides a shaft hole. The fixed member is fixed to the outer surface of the first end of the inner ring. The sliding member is opposite to the fixed member and is disposed on the outer surface of the second end of the inner ring, defining an annular oil film layer with the inner ring. The sliding member is configured to move along the axial direction of the inner ring to increase or decrease the length of the annular oil film layer, thereby adjusting the oil film length.

[0006] In one or more embodiments, the slider, together with the fixing member, defines an annular interval, and the movement of the slider is configured to adjust the length of the annular interval.

[0007] In one or more embodiments, the squeeze film damper further includes a movable rod connected to the slider, for moving the slider by its own movement.

[0008] In one or more embodiments, one side of the moving rod is connected to the sliding member, and the other side is engaged with the hole shaft of the fixing member.

[0009] In one or more embodiments, the fastener includes a fixed mounting flange edge having a through hole through which the movable rod passes.

[0010] In one or more embodiments, the moving rod is electrically connected to a motor.

[0011] In one or more embodiments, the movable rod is located on the opposite side of the slider towards the fixed member.

[0012] In one or more embodiments, the slider includes a flange edge, and the moving rod is fixedly connected to the flange edge.

[0013] In one or more embodiments, one of the fixing member or the sliding member is provided with a first annular member, the first annular member and the inner ring defining an annular cavity, and the other of the fixing member or the sliding member is provided with a second annular member, the second annular member being located within the annular cavity.

[0014] In one or more embodiments, the squeeze film damper includes an expansion ring disposed between the inner ring and the fixing member, and / or disposed between the inner ring and the sliding member.

[0015] In one or more embodiments, the fastener and the inner ring define a fixed annular oil film layer.

[0016] In one or more embodiments, the fastener is provided with an oil supply hole.

[0017] Another object of the present invention is to provide an oil film length adjustment system for an oil film device, including the above-mentioned extrusion oil film damper. The extrusion oil film damper further includes a moving rod connected to the sliding member. The system also includes a displacement sensor, a motor, and a control unit. The displacement sensor is used to monitor the position of the moving member; the motor is connected to the moving rod to drive the moving member to reciprocate; the control unit is signal-connected to the displacement sensor and the motor, and is used to receive the rotational speed signal of the shaft cooperating with the extrusion oil film damper, so as to adjust the oil film length according to the rotational speed of the shaft.

[0018] The aforementioned extrusion oil film damper is based on the damping calculation method of extrusion oil film dampers with long bearings and short bearings. By moving the sliding part in the opposite direction to the fixed part, it can simply and effectively change the length of the annular oil film layer and the length of the annular interval, thereby adjusting the oil film length, actively controlling the damping, and effectively reducing the over-damping and under-damping phenomena of the rotor system. Attached Figure Description

[0019] The above and other features, properties and advantages of the present invention will become more apparent from the following description taken in conjunction with the accompanying drawings and embodiments, wherein:

[0020] Figure 1A This is a partial schematic diagram of a closed-type extrusion oil film damper;

[0021] Figure 1B This is a partial schematic diagram of an open-type extrusion oil film damper;

[0022] Figure 2 This is a schematic diagram of the external structure of an embodiment of a closed-type extrusion oil film damper;

[0023] Figure 3 This is a cross-sectional view of an embodiment of a closed-type extrusion oil film damper;

[0024] Figure 4 This is a schematic diagram of the external structure of an embodiment of an open-type extrusion oil film damper;

[0025] Figure 5 This is a cross-sectional view of an embodiment of an open-type extrusion oil film damper;

[0026] Figure 6 This is a schematic diagram of the oil film length adjustment system of the oil film generator;

[0027] Figure 7 This is a cross-sectional view of the oil film length adjustment system of the oil film generator;

[0028] Figure 8 This is a schematic diagram of the oil film length of an open-type oil film generator;

[0029] Figure 9 This is a schematic diagram of the oil film length in a closed-loop oil film generator;

[0030] Figure 10 This is the logic diagram for oil film length adjustment control.

[0031] Symbol marking explanation

[0032] 1. Inner ring of the oil film generator

[0033] 2. Outer ring of the oil film device

[0034] 3. Increase Circle

[0035] 4 Oil supply hole

[0036] 11 Inner Ring

[0037] 12 Fasteners

[0038] 13 Sliding parts

[0039] 14. Circular section

[0040] 15 Moving rods

[0041] 30 motors

[0042] 40 Displacement Sensor

[0043] 50 Control Unit

[0044] 110 shaft hole

[0045] 111 First End

[0046] 112 Second End

[0047] 120 Fixed mounting flange edge

[0048] 130 flange edge

[0049] 161 First Annular Component

[0050] 162 Second Ring Part Detailed Implementation

[0051] The present invention will be further described below with reference to specific embodiments and accompanying drawings. More details are set forth in the following description in order to provide a full understanding of the present invention. However, the present invention can obviously be implemented in many other ways different from those described herein. Those skilled in the art can make similar extensions and derivations based on actual application situations without departing from the spirit of the present invention. Therefore, the scope of protection of the present invention should not be limited by the content of this specific embodiment.

[0052] It should be noted that these and other accompanying drawings are merely examples and are not drawn to scale, and should not be construed as limiting the scope of protection of the present invention.

[0053] Aero engines have complex structural designs and high rotor speeds. Within the operating speed range, there are generally multiple critical speeds. When the rotor is in a critical state, it will generate large vibration stress, which is transmitted to the casing through the support structure. This can easily lead to increased loads on the engine's load-bearing components, insufficient structural strength, and affect the engine's lifespan.

[0054] To effectively reduce the load generated by rotor vibration in an engine, a vibration damping structure is installed between the bearing and the support structure to reduce the outward propagation of rotor vibration load. Extrusion film dampers are widely used in the vibration reduction design of various aero-engine rotors due to their excellent vibration reduction performance.

[0055] Figure 1A-1B This diagram illustrates traditional closed and open-type extrusion oil film dampers. A damper typically includes an inner ring 1 and an outer ring 2. Closed-type extrusion oil film dampers also include two expansion rings 3 to control the leakage of lubricating oil within the oil film. The bearing and shaft are located within the inner ring 1. A certain gap is created between the bearing or spring support outer ring and the support structure, and lubricating oil is introduced into the gap through the oil supply hole 4 to form an oil film. The rotor's vibration load is transmitted to the oil film through the bearing, and then to the bearing housing through the oil film. The lubricating oil in the gap can absorb most of the rotor's vibration energy, thereby reducing the outward transmission of rotor vibration energy.

[0056] However, due to the high rotor speed of aero engines, there are multiple critical speeds within the operating speed range. The damping effect of the same extrusion oil film damper varies at different critical speeds, resulting in underdamping or overdamping at some critical speeds. In addition, when the rotor operates at high speed, problems such as the inner and outer rings of the oil film damper getting stuck and the vibration damping function failing often occur. At this time, the main force transmission path changes from the spring support structure to the oil film damper.

[0057] To address the aforementioned issues, this disclosure provides a squeeze film damper that can actively control the damping of the film damper at different critical speeds, avoiding underdamping and overdamping phenomena at different critical speeds, while simultaneously reducing the vibration amplitude of the rotor at each critical speed.

[0058] Reference Figures 2 to 5 As shown, the squeeze oil film damper includes an inner ring 11, a fixing member 12, and a sliding member 13. The inner ring 11 provides a shaft hole 110 for a rolling bearing and a rotating shaft to pass through. The fixing member 12 is fixed to the outer surface of the first end 111 of the inner ring 11, and the sliding member 13 is opposite to the fixing member 12 and disposed on the outer surface of the second end 112 of the inner ring 11, defining an annular oil film layer C3 with the inner ring 11. In some embodiments, the fixing member 12 and the inner ring 11 also define a fixed annular oil film layer C1. The fixing member 12 and / or the sliding member 13 are provided with oil supply holes 3 to supply oil to the oil film layer.

[0059] exist Figure 2 and 3 In the closed-loop oil film device structure shown, the fixed member 12 and the sliding member 13 face each other and define an annular section 14. For example, the fixed member 12 has a first annular member 161, and the sliding member 13 has a second annular member 162. The second annular member 162 is located within the annular cavity 17 and on the outer periphery of the inner ring 11, thus partially sealing both ends of the annular cavity 17 and forming the annular section 14. The second annular member 162 of the sliding member 13 and the first annular member 161 of the fixed member 12 together form the outer ring of the oil film device.

[0060] exist Figure 4 and 5 In the open-type oil film device structure shown, the fixed member 12 and the sliding member 13 face each other and define an annular section 14 that is in direct contact with the air.

[0061] The fixed member 12, acting as a stator, is fixed to the support member by means of bolts, such as a fixed mounting flange 120. The sliding member 13, acting as a mover, is configured to move axially along the inner ring 11 to increase or decrease the length of the annular oil film layer C3, thereby adjusting the oil film length.

[0062] In one specific embodiment, the movement of the slider 13 can be directly adjusted by setting a moving rod 15 connected to the slider 13.

[0063] For example, in the first embodiment, the moving rod 15 is located on the opposite side of the slider 13 toward the fixing member 12, so as to pull the slider 13 to the right or push the slider 13 to the left.

[0064] For example, in the second embodiment, such as Figure 3 or Figure 5 As shown, one side of the moving rod 15 is fixedly connected to the flange edge 130 of the sliding member 13, and the other side is engaged with the hole shaft of the fixing flange edge 120 of the fixing member 12. Figure 3 As shown, the fixed mounting flange 120 has a through hole for the moving rod 15 to pass through, and the moving rod 15 is fixedly connected to the flange 130 by bolts or welding. The moving rod 15 moves by moving itself, which in turn moves the sliding member 13.

[0065] like Figure 7 In the illustrated embodiment, the driving force of the moving rod 14 is directly provided by the motor 30. The end of the moving rod 14 is connected to the motor 30, and a threaded hole is provided at the connection position between the motor connecting rod and the moving rod. During the rotation of the motor, the threaded end of the moving rod is driven to reciprocate, thereby causing the outer ring sliding member 13 of the oil film device to also be in a reciprocating left-right motion state, achieving the purpose of adjusting the oil film length. During the sliding process of the sliding member 13, the damping decreases when the sliding member 13 slides outward (to the right) and the damping increases when the sliding member 13 slides inward (to the left).

[0066] Figure 8 and Figure 9 The damping adjustment principles of open and closed oil film dampers are shown respectively. The damping C is a function of the oil film length L, F(L). The actual oil film damping C of the extrusion oil film damper consists of three parts: a fixed annular oil film layer C1, an annular oil film layer C3, and an oil film layer C2 in the region containing the annular interval 14. The damping of the extrusion oil film damper can be changed by adjusting the oil film length.

[0067] Since C = C1 + C2 + C3, which is the sum of the three types of damping, where C1 = F(L1), C2 = F(L2), and C3 = F(L3), F1 is the contact length between the fixed member 12 and the inner ring 11, F3 is the contact length between the sliding member 13 and the inner ring 11, and F2 is the length of the annular interval 14.

[0068] for Figure 8In the open-type oil film damper shown, as the slider slides to the right, the outer ring cage structure of the front oil film loses its sealing effect, so the fixed annular oil film layer C1 can be basically ignored. As the slider slides outward, the length of the annular oil film layer C3 decreases, while the length L2 of the annular interval 14 becomes longer, causing the oil film layer C2 to essentially disappear, thus effectively reducing the overall damping of the oil film damper. As the slider slides to the left, the length of the annular oil film layer C3 increases significantly, thereby increasing the damping of both the annular oil film layer C3 and the oil film layer C2.

[0069] This principle and Figure 9 The principle of the open-type oil film damper shown is similar. Within the effective length of the oil film damper, as the slider slides to the right, the radial clearance of the front oil film increases, and the oil film pressure decreases. The fixed annular oil film layer C1 can be essentially ignored. When the slider slides outward, the damping of the annular oil film layer C3 decreases significantly, and the damping of the oil film layer C2 also decreases, resulting in a decrease in total damping. When the slider slides inward, the damping of the annular oil film layer C3 increases significantly, and the damping of the oil film layer C2 also increases.

[0070] By moving the sliding member relative to the fixed member in opposite directions, the length of the annular oil film layer and the annular interval can be significantly changed, thus substantially altering the damping magnitude. It is understandable that even after the sliding member 13 disengages from the annular cavity 17, a failure mode can still be achieved, in which case the lubricating oil flows directly into the bearing cavity.

[0071] The above structure is applicable to both open-type and closed-type extrusion film dampers. Figure 2-3 and Figure 4-5 Examples of closed-type and open-type extrusion film dampers are shown respectively. In the closed-type extrusion film damper, an expansion ring 3 is provided between the inner and outer rings to control the leakage of lubricating oil in the oil film device. The outer ring of the expansion ring 3 is composed of a fixed member 12 and a sliding member 13.

[0072] The aforementioned squeeze film damper achieves variable damping by adding a sliding device to the outer ring of the damper formed by a sliding member. The movement of the sliding member is driven by the direct reciprocating motion of the moving rod, allowing for effective and significant adjustment of the oil film length and continuous change of damping. Furthermore, altering the length of the outer ring of the oil film can also effectively adjust the rotor's support stiffness, preventing resonance problems within the operating speed range.

[0073] Based on the above description of the extrusion oil film damper, an oil film length adjustment system for an oil film device can also be understood. This system includes the aforementioned extrusion oil film damper, as well as a displacement sensor 40, a motor 30, and a control unit 50, such as... Figure 7As shown. Motor 30 is connected to the moving rod 15 to drive the moving component 15 in reciprocating motion. Displacement sensor 40 is used to monitor the position of the moving component; in some embodiments, displacement sensor 40 is disposed between the connecting rod of motor 30 and the moving rod 15. The displacement sensor allows real-time monitoring of the relative position of the sliding rod, thereby determining the length of the oil film in the oil film generator.

[0074] The control unit 50 is connected to the displacement sensor and motor signal, and is used to receive the rotational speed signal of the shaft that cooperates with the extrusion oil film damper, so as to adjust the oil film length according to the shaft rotational speed. During the operation of the rotor, the rotor speed signal is transmitted to the control system. The control system adjusts the displacement of the sliding rod by controlling the motor according to the preset settings, and determines whether the adjustment meets the requirements through the displacement sensor, thereby effectively controlling the damping of the oil film device.

[0075] It should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore should not be construed as limiting the scope of protection of this application.

[0076] In the description of this application, it should be understood that the orientation or positional relationship indicated by directional terms such as "front, back, up, down, left, right", "horizontal, vertical, horizontal" and "top, bottom" is usually based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing this application and simplifying the description. Unless otherwise stated, these directional terms do not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the scope of protection of this application; the directional terms "inner" and "outer" refer to the inner and outer contours relative to the outline of each component itself.

[0077] Furthermore, this application uses specific terms to describe embodiments of the application. For example, "an embodiment," "one embodiment," and / or "some embodiments" refer to a particular feature, structure, or characteristic related to at least one embodiment of the application. Therefore, it should be emphasized and noted that "an embodiment," "one embodiment," or "an alternative embodiment" mentioned twice or more in different locations in this specification do not necessarily refer to the same embodiment. In addition, certain features, structures, or characteristics in one or more embodiments of the application can be appropriately combined.

[0078] While the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the invention. Any variations and modifications can be made by those skilled in the art without departing from the spirit and scope of the invention. Therefore, any modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention, without departing from the scope of the invention, fall within the protection scope defined by the claims of the present invention.

Claims

1. A squeeze film damper, characterized in that, include: Inner ring, providing shaft hole; The fastener is fixed to the outer surface of the first end of the inner ring; as well as A sliding member, facing the fixing member, is disposed on the outer surface of the second end of the inner ring, defining an annular oil film layer with the inner ring; The sliding member is configured to move along the axial direction of the inner ring to increase or decrease the length of the annular oil film layer, thereby adjusting the oil film length.

2. The extrusion oil film damper as described in claim 1, characterized in that, The slider, together with the fixing member, defines an annular interval, and the movement of the slider is configured to adjust the length of the annular interval.

3. The extrusion oil film damper as described in claim 1 or 2, characterized in that, The squeeze film damper also includes a movable rod connected to the sliding member, which drives the sliding member to move by its own movement.

4. The extrusion oil film damper as described in claim 3, characterized in that, One side of the moving rod is connected to the sliding member, and the other side is engaged with the hole shaft of the fixing member.

5. The extrusion oil film damper as described in claim 4, characterized in that, The fastener includes a fixed mounting flange edge, which has a through hole for the moving rod to pass through.

6. The extrusion oil film damper as described in claim 3, characterized in that, The moving rod is electrically connected to the motor.

7. The extrusion oil film damper as described in claim 3, characterized in that, The movable rod is located on the opposite side of the slider towards the fixed member.

8. The extrusion oil film damper as described in claim 3, characterized in that, The sliding element includes a flange edge, and the moving rod is fixedly connected to the flange edge.

9. The extrusion oil film damper as described in claim 2, characterized in that, One of the fixing member or the sliding member is provided with a first annular member, the first annular member and the inner ring defining an annular cavity, and the other of the fixing member or the sliding member is provided with a second annular member, the second annular member being located within the annular cavity, and a portion of the annular cavity forming the annular interval.

10. The extrusion oil film damper as described in claim 1, characterized in that, The squeeze film damper includes an expansion ring disposed between the inner ring and the fixed member, and / or between the inner ring and the sliding member.

11. The extrusion oil film damper as described in claim 1, characterized in that, The fixing element and the inner ring define a fixed annular oil film layer.

12. The extrusion oil film damper as described in claim 10, characterized in that, The fastener is provided with an oil supply hole.

13. An oil film length adjustment system for an oil film generator, characterized in that, Including the extrusion film damper as described in any one of claims 1-12, the extrusion film damper further includes a moving rod connected to the sliding member, and the system further includes: A displacement sensor is used to monitor the position of the moving part; A motor, connected to the moving rod, drives the moving component to reciprocate; and The control unit is connected to the displacement sensor and the motor signal, and is used to receive the rotational speed signal of the shaft that cooperates with the extrusion oil film damper, so as to adjust the oil film length according to the rotational speed of the shaft.

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