A flexible transmission rotary friction damper

Abstract

The present invention belongs to the field of vibration control technology and discloses a flexible transmission rotary friction damper, including a support, a bearing, a rotating shaft, a flexible transmission member, a preloader, a connecting seat, a screw, a friction block, a compression spring, a sleeve and a nut. The damper converts the relative horizontal displacement between the bridge main beam and the bridge tower caused by complex and changeable environmental conditions such as earthquakes, strong winds, and vehicles into the rotational displacement of the rotor through a flexible connection transmission method. By providing a device that provides long-term stable friction force, the rotation of the rotor is prevented, the reciprocating vibration energy of the bridge structure is consumed, thereby reducing the bridge amplitude and internal force, and ensuring structural safety. The damper has the advantages of simple structure, adjustable friction energy consumption intensity, good robustness and durability, wide application range, convenient component replacement, and excellent economic performance.

Description

Technical Field

[0001] The invention belongs to the technical field of vibration control and relates to a flexible transmission rotary friction damper. Background Art

[0002] Bridges vibrate under dynamic forces such as earthquakes, wind, vehicles, and pedestrians. To effectively reduce bridge vibration and internal forces under these dynamic forces, viscous or friction dampers can be installed at the bridge's tower-beam, pier-beam, and platform-beam connections. However, because viscous dampers are typically rigidly connected to the bridge structure, there's no guarantee that the dampers will be subjected solely to axial forces during bridge vibration. Complex and changing natural environments can also subject the dampers to bending moments, posing a significant threat to damper seals and leading to severe oil leakage. This significantly reduces control efficiency, leading to damage or even complete failure in actual projects, often well before their expected service life. While installing universal joints between the dampers and the bridge structure can improve load bearing, this still doesn't completely address the problem. Furthermore, factors such as temperature and strong winds can cause significant static displacement (>2m) between the main beam and tower of (super)-long span bridges. Conventional viscous dampers can exceed their travel and fail, and excessively large dampers are expensive. In summary, large viscous dampers often suffer from complex construction, high costs, and poor durability. To generate sufficient friction and energy dissipation, traditional friction dampers require sufficient pressure on the friction plate. This pressure can be achieved by applying a physical mass or by clamping a pressure plate with bolts. Obviously, if the required pressure is too high, using a mass is less economical, and there may not be sufficient space for the mass. While using bolts and a pressure plate for pre-tightening can achieve very high pressures, the friction plate inevitably becomes thinner due to long-term wear, which inevitably leads to bolt loosening and a sharp drop or even disappearance in pressure. Therefore, traditional friction dampers struggle to maintain a relatively constant pressure and friction in complex and changing environments, ultimately hindering stable and reliable control efficiency. Therefore, there is a need to develop a damper with a simple structure, low cost, and durability to address the shortcomings of traditional viscous and friction dampers. Summary of the Invention

[0003] This invention provides a flexible transmission rotary friction damper. The specific invention and its advantages are as follows: It utilizes a flexible connection transmission method to convert the relative horizontal vibration between a bridge's main beam and tower, main beam and pier, or main beam and abutment into the rotation of a rotor fixed to the main beam or tower (pier, abutment). This rotor is equipped with a device that provides long-term, stable, and controllable friction, dissipating the energy of the bridge structure's reciprocating vibrations, reducing bridge amplitude and internal forces, and ensuring structural safety. The invention features a simple structure, adjustable friction energy dissipation intensity over a wide range, excellent durability and robustness, easy component replacement, good economic performance, and a wide range of applications.

[0004] The technical solution of the present invention:

[0005] A flexible transmission rotary friction damper comprises a support 1, a bearing 2, a rotating shaft 3, a flexible transmission member 4, a preload device 5, a connecting seat 6, a screw 7, a friction block 8, a compression spring 9, a sleeve 10 and a nut 11; the support 1 is fixed on the bridge tower crossbeam to provide stable support for the transmission energy consumption of the flexible transmission rotary friction damper; the bearing 2 is mounted on the support 1 to support the rotating shaft 3; the flexible transmission members 4 horizontally arranged on the left and right of the rotating shaft 3 are respectively wound on the exposed rotating shaft 3 in a clockwise or counterclockwise direction, one end is anchored to the rotating shaft 3, and the other end is connected to the preload device 5, thereby ensuring that when the rotating shaft 3 rotates under the drive of the flexible transmission member 4, the flexible transmission member 4 is alternately wound and tensioned and unwound and relaxed, so as to drive the rotating shaft 3 to rotate stably and reliably back and forth in the bearing 2; the preload device 5 is installed on the support 1 to support the rotating shaft 3; the flexible transmission member 4 is arranged on the left and right of the rotating shaft 3 Installed on the connecting seat 6, the preloader 5 provides preload force for the flexible transmission member 4 to prevent the flexible transmission member 4 from being in an excessively relaxed state during vibration; the connecting seat 6 is fixed to the bottom of the main beam to provide stable support for the transmission energy consumption of the flexible transmission rotary friction damper; the screw 7 is solidified with the friction block 8, and the compression spring 9 is sleeved on the screw 7; the screw 7 is inserted from the wall hole of the sleeve 10 sleeved on the outside of the rotating shaft 3 fixed between the two supports 1; the outer diameter of the compression spring 9 is larger than the diameter of the wall hole, one end is against the inner wall of the sleeve 10, and the other end is against the friction block 8, so that the friction block 8 is pressed against the outer wall of the rotating shaft 3; when the main beam undergoes horizontal displacement relative to the crossbeam, the flexible transmission member 4 drives the rotating shaft 3 to rotate, and the rotating shaft 3 rubs against the friction block 8, consuming the horizontal vibration energy of the main beam and reducing the amplitude.

[0006] Take the damper installed between the bridge tower beam and the main beam to control the axial horizontal vibration of the bridge as an example.

[0007] The support 1 should have high strength and high rigidity, and the size, form, material and quantity are not limited. The support 1 can be equipped with a universal hinge to further enhance the device's ability to adapt to offset.

[0008] The bearing 2 should have high strength and high rigidity, and its size should match the diameter of the rotating shaft 3.

[0009] The rotating shaft 3 should have high strength and rigidity, excellent wear resistance, and a high coefficient of friction. The dimensions of the rotating shaft 3 should be optimized according to the specific application. Adding a larger diameter flywheel to the rotating shaft 3 can increase the rotational displacement between the rotating shaft 3 and the sleeve 10, which will be more effective but more complex.

[0010] The flexible transmission members 4 must ensure sufficient strength and rigidity. Their material form, size, and quantity are not limited. Flexible components such as high-strength, high-rigidity polyethylene fiber belts, steel chains, and steel cables can be used. This ensures that even when vibration shifts, vibration can still be reliably transmitted between the flexible transmission members 4 and the rotating shaft 3, effectively dissipating energy and suppressing vibration. The flexible transmission members 4, arranged on both sides of the rotating shaft 3, are symmetrically arranged along the axial direction of the rotating shaft 3 to ensure uniform force on the rotating shaft 3.

[0011] The pretensioner 5 is not limited in form and material and can be designed as a modular component with an anti-loosening mechanism to facilitate installation, use and maintenance, and prevent the flexible transmission member 4 from being in a loose state.

[0012] The connecting seat 6 should have high strength and high rigidity. Its size, form, material and quantity are not limited. The connecting seat 6 can be equipped with a universal hinge to further enhance the adaptability of the device to offset.

[0013] The screw 7 should have sufficient strength, rigidity and durability to ensure that it does not break, deform or corrode during the operation of the device. Its size, material and quantity are not limited.

[0014] The material of the friction block 8 should have excellent wear resistance and high friction coefficient, and sufficient thickness to ensure durability. Its size, form, material and quantity are not limited. The more friction blocks 8 there are, the greater the pressure on the rotating shaft 3, the greater the friction energy consumption, and the more obvious the vibration control effect.

[0015] The compression spring 9 should have sufficient length, strength, rigidity, and durability, and its size, form, material, and quantity are not limited. Over long-term use, the friction block 8 inevitably wears and becomes thinner, causing the compression spring 9 to lengthen and reduce pressure. Therefore, the compression spring 9 should be of sufficient length so that changes in its length have minimal impact on pressure, thereby ensuring sufficient pressure, friction, and energy consumption.

[0016] The sleeve 10 should have high strength and high rigidity, and its size should match the rotating shaft 3, the screw 7, the friction block 8, etc.

[0017] The nut 11 should be made of high-strength material to ensure that it can withstand the huge pressure of the compression spring 9.

[0018] The screw 7, friction block 8, and compression spring 9 together form an adaptive friction device. As the friction block 8 gradually wears and becomes thinner, the friction block 8, under the action of the compression spring 9, continues to press against the rotating shaft 3, ensuring sufficient pressure and friction between the friction block 8 and the rotating shaft 3, ultimately ensuring the energy efficiency of the entire system. This adaptive friction device can be installed in a variety of ways. Here, a relatively convenient and practical installation procedure is provided: The compression spring 9 is placed over the screw 7, and the screw 7 is passed through a pre-opened hole in the sleeve 10 from the inside. The spring 7 is compressed to a predetermined position by internal pressure or external tension, and the screw 7 is temporarily fixed to the sleeve 10 with a nut 11. After the rotating shaft 3 is installed in the bearing 2 and sleeve 10, the nut 11 is removed. At this time, the compression spring 9 firmly presses the friction block 8 against the outer wall of the rotating shaft 3.

[0019] If there is insufficient vertical space between the tower crossbeam and the main beam, between the pier or the cap beam on top of the pier and the main beam, or between the abutment and the main beam, or if there is no crossbeam in the vicinity of the tower and the main beam, a bracket with sufficient strength and rigidity for supporting the bearing 1 can be added to the tower crossbeam, tower column, pier, abutment or cap beam. The specific material, structure and form are not limited.

[0020] Typically, during vibration, the length of the flexible transmission member 4 wrapped around the rotating shaft 3 is equal to the horizontal displacement between the support 1 and the connecting seat 6. To improve control efficiency, a pulley can be added to the connecting seat 6 at the bottom of the main beam, and the pretensioner 5 can be installed on the support 1. One end of the flexible transmission member 4 is connected to the pretensioner 5, passing around the pulley, and the other end is connected to the rotating shaft 3. In this way, under the same horizontal displacement between the support 1 and the connecting seat 6, the rotation angle of the rotating shaft 3 is doubled, and the friction energy consumption is basically doubled accordingly. However, the structure is more complicated.

[0021] The installation positions of the support 1 and the connecting seat 6 can be interchanged, that is, the support 1 and the components connected thereto are installed on the main beam of the bridge, and the connecting seat 6 is installed on the bridge tower crossbeam, pier cap beam or abutment.

[0022] The beneficial effects of the present invention are as follows: (1) Unlike traditional viscous dampers, the present invention does not require a viscous liquid sealing cylinder, and there is no problem of oil leakage leading to performance degradation or even failure; (2) The adaptive friction device of the present invention can ensure that the friction force state remains basically unchanged for a long time, so it has good durability; (3) Since the present invention adopts a flexible transmission method, it avoids the collision or connection transmission failure problem of the rigid transmission method under complex and changeable conditions in the natural field; (4) The present invention has a simple structure, a wide range of applications, and low cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a flexible transmission rotary friction damper;

[0024] Figure 2 It is a schematic diagram of the implementation method of the adaptive friction plate;

[0025] Figure 3 These are the steps for installing the adaptive friction plate.

[0026] In the figure: 1 support; 2 bearing; 3 rotating shaft; 4 flexible transmission member; 5 preloader; 6 connecting seat; 7 screw; 8 friction block; 9 compression spring; 10 sleeve; 11 nut. DETAILED DESCRIPTION

[0027] The specific implementation of the present invention is further described below in conjunction with the accompanying drawings and technical solutions.

[0028] The support 1 is fixed on the bridge tower crossbeam; the bearing 2 is installed on the support 1 to support the rotating shaft 3; the flexible transmission member 4 is wrapped around the rotating shaft 3, one end is anchored to the rotating shaft 3, and the other end is connected to the preloaded device 5; the preloaded device 5 is installed on the connecting seat 6; the connecting seat 6 is fixed to the bottom of the main beam; the left flexible transmission member 4 and the right flexible transmission member 4 wrapped around the rotating shaft 3 are wound in opposite directions, thereby ensuring that when the main beam undergoes horizontal displacement relative to the bridge tower, the driving shaft 3 rotates stably and reliably in the bearing 2; the screw 7 is fixed to the friction block 8; the compression spring 9 is sleeved on the screw 7; the sleeve 10 is fixed on the support 1, the screw 7 passes through the wall hole of the sleeve 10, one end of the compression spring 9 presses against the inner wall of the sleeve 10, and the other end presses against the friction block 8, so that the friction block 8 is pressed against the outer wall of the rotating shaft 3; when the main beam undergoes horizontal displacement relative to the crossbeam, the flexible transmission member 4 drives the rotating shaft 3 to rotate, and the rotating shaft 3 and the friction block 8 consume energy to control the vibration of the bridge.

[0029] The above description is merely an example of a preferred embodiment of the present invention and does not constitute any limitation on the present invention. Any equivalent changes, modifications, or variations made by a person skilled in the art using the technical solution of the present invention to the above examples shall still fall within the scope of the technical solution of the present invention.

Claims

1. A flexible transmission rotary friction damper, characterized in that: The flexible transmission rotary friction damper comprises a support (1), a bearing (2), a rotating shaft (3), a flexible transmission member (4), a preload (5), a connecting seat (6), a screw (7), a friction block (8), a compression spring (9), a sleeve (10) and a nut (11); the support (1) is fixed on the bridge tower crossbeam to provide stable support for the transmission energy consumption of the flexible transmission rotary friction damper; the bearing (2) is mounted on the support (1) to support the rotating shaft (3); the flexible transmission member (4) horizontally arranged on the left and right sides of the rotating shaft (3) is wound around the exposed rotating shaft (3) in a clockwise and counterclockwise direction respectively, one end is anchored to the rotating shaft (3), and the other end is connected to the preload (5), thereby ensuring that when the rotating shaft (3) rotates under the drive of the flexible transmission member (4), the flexible transmission member (4) is alternately wound and tensioned and unwound and relaxed, so as to drive the rotating shaft (3) to stably and reliably rotate back and forth in the bearing (2); The device (5) is installed on the connecting seat (6), and the preload device (5) provides preload force for the flexible transmission member (4) to prevent the flexible transmission member (4) from being in an excessively relaxed state during vibration; the connecting seat (6) is fixed to the bottom of the main beam to provide stable support for the transmission energy consumption of the flexible transmission rotary friction damper; the screw (7) is fixed to the friction block (8), and the compression spring (9) is sleeved on the screw (7); the screw (7) is inserted from the wall hole on the sleeve (10) sleeved on the outside of the rotating shaft (3) fixed between the two supports (1); the outer diameter of the compression spring (9) is larger than the diameter of the wall hole, one end of the compression spring is pressed against the inner wall of the sleeve (10), and the other end is pressed against the friction block (8), so that the friction block (8) is pressed against the outer wall of the rotating shaft (3); when the main beam is horizontally displaced relative to the cross beam, the flexible transmission member (4) drives the rotating shaft (3) to rotate, and the rotating shaft (3) and the friction block (8) rub against each other, consuming the horizontal vibration energy of the main beam and reducing the amplitude.

2. The flexible transmission rotation friction damper according to claim 1, characterized in that: A universal hinge is installed on the support (1) to improve the adaptive offset capability of the flexible transmission rotary friction damper.

3. The flexible transmission rotation friction damper according to claim 1, characterized in that: The size of the bearing (2) matches the diameter of the rotating shaft (3).

4. The flexible transmission rotation friction damper according to claim 1, characterized in that: A flywheel is added to the rotating shaft (3), thereby increasing the rotational displacement between the flywheel and the sleeve (10).

5. The flexible transmission rotation friction damper according to claim 1, characterized in that: The flexible transmission member (4) is made of molecular polyethylene fiber belt, steel chain, and steel wire rope with sufficient strength and rigidity; the flexible transmission members (4) arranged on the left and right sides of the rotating shaft (3) are symmetrically arranged along the axial direction of the rotating shaft (3) to ensure that the rotating shaft (3) is evenly stressed.

6. The flexible transmission rotation friction damper according to claim 1, characterized in that: The pretensioner (5) is designed as a modular component.

7. The flexible transmission rotation friction damper according to claim 1, characterized in that: A universal hinge can be installed on the connecting seat (6) to further enhance the adaptive offset capability of the flexible transmission rotary friction damper.

8. The flexible transmission rotation friction damper according to claim 1, characterized in that: The greater the number of the friction blocks (8), the greater the pressure on the rotating shaft (3), the greater the friction energy consumption, and the more obvious the vibration control effect.

9. The flexible transmission rotation friction damper according to claim 1, characterized in that: The size of the sleeve (10) matches the rotating shaft (3), the screw (7) and the friction block (8).

10. The flexible transmission rotation friction damper according to claim 1, characterized in that: The installation positions of the support (1) and the connecting seat (6) are interchangeable, that is, the support (1) and the components connected thereto are installed on the main beam of the bridge, and the connecting seat (6) is installed on the bridge tower crossbeam, the pier cap beam or the abutment.

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