A gear inertia negative stiffness friction damping device

Abstract

The present invention relates to the technical field of structural vibration control, and in particular to a gear inertia negative stiffness friction damping device. It includes a housing, a gear inertia system, a drum brake friction system, and a spur rack that drives the gear inertia system and the drum brake friction system together, and also includes a linear bearing and a rack limiter that limit the working plane of the gear inertia system and the drum brake friction system; the gear inertia system includes two sets of mutually meshing primary gear sets and secondary gear sets, and any gear set includes two spur gears that are relatively spaced and different in size. The central axes of the two spur gears in each gear set are jointly provided with a transmission shaft and are connected by a flat key, and rotating bearings are provided at both ends of the transmission shaft and connected to the housing; the drum brake friction system includes a driving gear and a friction round steel welded concentrically with the driving gear, and a drum brake is provided on the inner side of the friction round steel. The present invention generates friction damping to dissipate energy while providing negative stiffness, thereby realizing a dual control strategy of structural displacement and acceleration.

Description

Technical Field

[0001] The invention relates to the technical field of structural vibration control, and in particular to a gear inertia negative stiffness friction damping device. Background Art

[0002] Seismic isolation technology is an important way to effectively reduce the seismic response of structures. It can effectively improve the seismic disaster reduction capabilities of structures by extending the natural vibration period of the structure so that the fundamental frequency of the structure is outside the frequency range of high-energy seismic motion.

[0003] However, in rare earthquakes, the isolation layer may cause significant displacement. Excessive displacement of the isolation layer may lead to an enhancement effect on the mechanical behavior of the isolation layer. The traditional solution is to add lead core damping to the isolation layer to control the displacement of the isolation layer. Although lead core damping can effectively control the displacement of the isolation layer, the bilinear characteristics of the lead core damping also increase the stiffness of the isolation layer, thereby further increasing the absolute acceleration response of the superstructure.

[0004] Negative stiffness damping as a shock absorbing device can effectively solve the above problems. The damping provided by negative stiffness damping can control the displacement of the seismic isolation layer. At the same time, the negative stiffness characteristics generated can reduce the acceleration response of the structure and realize the dual control strategy of displacement-acceleration. Therefore, it is urgent to propose a new negative stiffness damping technical solution to solve the problems existing in the existing technology. Summary of the invention

[0005] In view of the above-mentioned defects of the prior art, the present application provides a gear inertia negative stiffness friction damping device to solve the problem of increased superstructure response of the seismic isolation structure caused by bilinear damping.

[0006] In order to achieve the above objectives, this application provides the following technical solutions:

[0007] A gear inertia negative stiffness friction damping device comprises a housing, a gear inertia system, a drum brake friction system, and a spur rack that drives the gear inertia system and the drum brake friction system together, and also comprises a linear bearing and a rack stopper that limit the working plane of the gear inertia system and the drum brake friction system;

[0008] The gear inertia system includes two sets of mutually meshing primary gear sets and secondary gear sets, each gear set includes two spur gears of different sizes arranged at a relative interval, the central axes of the two spur gears in each gear set are jointly provided with a transmission shaft and connected by a flat key, and rotating bearings are provided at both ends of the transmission shaft and connected to the housing;

[0009] The drum brake friction system comprises a driving gear and a friction round steel welded concentrically with the driving gear, a drum brake is arranged inside the friction round steel, a transmission shaft is also arranged at the central axis of the drum brake friction system, and rotating bearings are also arranged at both ends of the transmission shaft, and the drum brake is connected to the housing through a fixed support; the driving gear and the upper part of the spur rack meshing and are in the same working plane;

[0010] The rack limiter includes three relatively spaced and symmetrically arranged rotating bearings, the central axis of which is provided with a transmission shaft, the two outer rotating bearings are connected to the housing, and the middle rotating bearing is in contact with the groove on the back of the spur rack, so as to limit the spur rack and the middle rotating bearing to be in the same working plane;

[0011] The spur rack is arranged between the primary gear set and the secondary gear set, wherein the pinion of the primary gear set is meshed with the lower part of the spur rack and is located in the same working plane, the large gear of the primary gear set and the pinion of the secondary gear set are meshed with each other and are located in the same working plane, and the working plane of the large gear of the secondary gear set and the working plane of the pinion are symmetrically arranged with the working plane of the spur rack as the symmetry plane.

[0012] Furthermore, in order to limit the synchronous rotation of the gears of each gear set in the gear inertia, the pinion and the large gear of the first-stage gear set are connected to the transmission shaft through a flat key, and the flat key is used to limit the coaxial rotation of the first-stage gear set; the pinion and the large gear of the second-stage gear set are connected to the transmission shaft through a flat key, and the flat key is used to limit the coaxial rotation of the second-stage gear set.

[0013] Furthermore, each gear in the gear inertia system is provided with a stop ring on both sides to limit the axial movement between the gear and the transmission shaft; rotating bearings are respectively arranged on both sides of the transmission shaft in the first-stage gear set and the second-stage gear set, and the rotating bearings are connected to the housing.

[0014] Furthermore, the friction round steel is coaxial with the driving gear and is welded and fixed, the friction plate of the drum brake is in contact with the inside of the friction round steel, and the drum brake is colinear with the central axis of the friction round steel.

[0015] Furthermore, a steel wire rope with adjustable length is arranged between the linkage arm of the drum brake and the limiting hole tangent to the movement direction of the linkage arm to control the opening and closing of the friction plate inside the drum brake; a stop ring is respectively arranged on the outside of the driving gear and the drum brake to limit the axial movement of the driving gear, the friction round steel and the drum brake relative to the transmission shaft; in addition, two rotating bearings are arranged at intervals on both sides of the transmission shaft in the drum brake friction system, and the rotating bearings are connected to the outer casing.

[0016] Furthermore, all the transmission shafts and the inner rings of the rotating bearings are bonded and fixed by chemical adhesive to limit the axial movement between the transmission shafts and the rotating bearings, and the outer rings and the outer shells of the rotating bearings on both sides are bonded and fixed by chemical adhesive to limit the axial movement between the rotating bearings and the outer shells.

[0017] Furthermore, the linear drive shaft is threadedly connected to the bottom of the spur rack and maintains the same axis. The linear bearing passes through the linear drive shaft and is bolted to the housing to limit the movement of the linear drive shaft and the spur rack outside the axial direction.

[0018] Furthermore, the negative stiffness characteristic of the gear inertia negative stiffness friction damping device is mainly provided by the gear inertia system, and its inertia coefficient is positively correlated with the mass of the large gear and the square of the ratio of the gear group dividing circle radii.

[0019] Furthermore, in the gear inertia system, the distance between the meshing point of the pinion in the primary gear set and the driving gear and the spur gear in the drum brake friction system should be less than the length of the spur rack to meet the stroke requirements of the gear inertia negative stiffness friction damping device.

[0020] The application of the gear inertia negative stiffness friction damping device is that the gear inertia negative stiffness friction damping device is applied as a whole in the seismic isolation layer of the seismic isolation structure.

[0021] Compared with the prior art, this application has the following beneficial effects:

[0022] The present application provides a gear inertia negative stiffness friction damping device, comprising a housing, a gear inertia system, a drum brake friction system, a rack and a linear drive shaft that jointly drive the gear inertia system and the drum brake friction system, and a linear bearing and a rack stopper that define the working planes of the two. The gear inertia negative stiffness friction damping device has the following advantages:

[0023] 1. The negative stiffness characteristics of the damping device are mainly provided by the gear inertia system. The inertia coefficient is positively correlated with the mass of the large gear and the square of the ratio of the radius of the gear group dividing circle. That is, a gear inertia system with a smaller mass or smaller size can produce a considerable negative stiffness characteristic;

[0024] 2. The damping part of the damping device is mainly generated by the drum brake friction system. The drum brake linkage arm applies displacement to the brake pad through the lever principle to rub against the friction round steel, thereby applying a small tension to the wire rope to obtain a large and stable dual-line damping force. At the same time, the structure based on the annular friction makes the damping device have no travel limit;

[0025] 3. The gear inertia system and the drum brake friction system are driven by a spur rack. The hysteresis model of the damping device is a negative stiffness bilinear damping formed by superimposing negative stiffness and a bilinear model. This type of rack parallel mode can superimpose negative stiffness characteristics with any form of damping to form negative stiffness damping. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work. It should be understood that the specific shapes and structures shown in the drawings should not usually be regarded as limiting conditions for implementing the present application; for example, based on the technical concepts and exemplary drawings disclosed in the present application, those skilled in the art are able to easily make routine adjustments or further optimizations to the increase / decrease / attribution division, specific shapes, positional relationships, connection methods, dimensional ratio relationships, etc. of certain units (components).

[0027] Figure 1 It is a schematic diagram of the three-dimensional structure of the gear inertia negative stiffness friction damping device provided by the present application in one embodiment from one viewing angle (the panel on one side of the housing is hidden);

[0028] Figure 2 It is a right perspective structural schematic diagram of a gear inertia negative stiffness friction damping device provided by the present application in one embodiment;

[0029] Figure 3 It is a schematic structural diagram of the cooperation between the gear inertia system and the rack of the gear inertia negative stiffness friction damping device provided by the present application in one embodiment;

[0030] Figure 4 It is a schematic structural diagram of the cooperation between the drum brake friction system and the rack of the gear inertia negative stiffness friction damping device provided by the present application in one embodiment;

[0031] Figure 5 It is a schematic diagram of the exploded structure of the drum brake friction system of the gear inertia negative stiffness friction damping device provided by the present application in one embodiment;

[0032] Figure 6 It is a schematic structural diagram of the coordination of a spur rack, a linear drive shaft, a linear bearing and a rack limiter of a gear inertia negative stiffness friction damping device provided by the present application in one embodiment;

[0033] Figure 7 The test results of the gear inertia negative stiffness friction damping device provided by the present application under different sinusoidal period hysteresis loading conditions with constant drum brake preload in one embodiment are shown;

[0034] Figure 8 The hysteresis loading test results of the gear inertia negative stiffness friction damping device provided by the present application under different drum brake preload forces under constant sinusoidal loading cycle conditions in one embodiment are shown.

[0035] Reference numerals:

[0036] 1. Housing; 2. Primary gear set; 3. Secondary gear set; 4. Transmission shaft; 5. Flat key; 6. Rotating bearing; 7. Stop ring; 8. Driving gear; 9. Friction round steel; 10. Drum brake; 11. Fixed support; 12. Spur rack; 13. Linear drive shaft; 14. Linear bearing. DETAILED DESCRIPTION

[0037] In the description of this application: unless otherwise specified, the meaning of "plurality" is two or more. The terms "first", "second", "third", etc. in this application are intended to distinguish the objects referred to, and do not have special meanings in terms of technical connotations (for example, they should not be understood as emphasizing the importance or order, etc.). Expressions such as "including", "comprising", "having", etc. also mean "not limited to" (certain units, components, materials, steps, etc.).

[0038] The terms such as "upper", "lower", "left", "right", "middle", etc. used in this application are usually used to facilitate intuitive understanding by comparing with the accompanying drawings, and are not absolute limitations on the positional relationship in the actual product. Without departing from the technical concept disclosed in this application, changes in these relative positional relationships should also be regarded as the scope of this application.

[0039] Example 1

[0040] The following is combined with Figure 1-8 The structure and working principle of a gear inertia negative stiffness friction damping device provided by the present invention are further explained.

[0041] like Figure 1-2 As shown, a gear inertia negative stiffness friction damping device of this embodiment includes a housing 1, a gear inertia system, a drum brake friction system, and a spur rack 12 that jointly drives the gear inertia system and the drum brake friction system, and also includes a linear bearing 14 and a rack limiter that limit the working plane of the gear inertia system and the drum brake friction system.

[0042] In this embodiment, Figure 2 As shown, the gear inertia system includes two sets of mutually meshing primary gear sets 2 and secondary gear sets 3. Each gear set includes two spur gears that are relatively spaced and have different sizes. The central axes of the two spur gears in each gear set are commonly provided with a transmission shaft 4 and are connected by a flat key 5. Rotating bearings 6 are provided at both ends of the transmission shaft and are connected to the housing 1.

[0043] Each gear in the gear inertia system has a stop ring 7 on both sides to limit the axial movement between the gear and the transmission shaft 4. Rotary bearings 6 are respectively arranged on both sides of the transmission shaft 4 in the primary gear set 2 and the secondary gear set 3, and the rotary bearings 6 are connected to the housing 1.

[0044] like Figure 1 As shown in Figures 4 and 5, the drum brake friction system includes a driving gear 8 and a friction round steel 9 welded concentrically with the driving gear 8. A drum brake 10 is arranged inside the friction round steel 9. A transmission shaft 4 is also arranged at the central axis of the drum brake friction system. Rotating bearings 6 are also arranged at both ends of the transmission shaft 4. The drum brake 10 is connected to the housing 1 through a fixed support 11. The meshing part of the driving gear 8 and the upper part of the spur rack 12 is in the same working plane.

[0045] The friction round steel 9 is coaxial with the driving gear 8 and is welded and fixed. The friction plate of the drum brake 10 is in contact with the inside of the friction round steel 9. At the same time, the central axis of the drum brake 10 and the friction round steel 9 are colinear.

[0046] like Figure 4-5 As shown, a steel wire rope with adjustable length is arranged between the linkage arm of the drum brake 10 and the limit hole tangent to the movement direction of the linkage arm to control the opening and closing of the friction plate inside the drum brake 10. A stop ring 7 is arranged on the outside of the driving gear 8 and the drum brake 10 to limit the axial movement of the driving gear 8, the friction round steel 9 and the drum brake 10 relative to the transmission shaft 4. In addition, two rotating bearings 6 are arranged at intervals on both sides of the transmission shaft 4 in the drum brake friction system, and the rotating bearings 6 are connected to the housing 1.

[0047] like Figure 6 As shown, the rack limiter includes three relatively spaced and symmetrically arranged rotating bearings 6, the central axis of which is provided with a transmission shaft 4, the two outer rotating bearings 6 are connected to the housing 1, and the middle rotating bearing 6 is in contact with the groove on the back of the spur rack 12, so as to limit the spur rack 12 and the middle rotating bearing 6 to be in the same working plane.

[0048] like Figure 3 As shown, the spur rack 12 is arranged between the primary gear set 2 and the secondary gear set 3, wherein the pinion of the primary gear set 2 meshes with the lower part of the spur rack 12 and is in the same working plane, the large gear of the primary gear set 2 meshes with the pinion of the secondary gear set 3 and is in the same working plane, and the working plane of the large gear of the secondary gear set 3 and the working plane of the pinion are arranged symmetrically with the working plane of the spur rack 12 as the symmetry plane. In order to limit the synchronous rotation of the gears of the gear sets of each level in the gear inertia, the pinion of the primary gear set 2 and the large gear are connected to the transmission shaft 4 through a flat key 5, and the flat key 5 is used to limit the coaxial rotation of the primary gear set. The pinion and the large gear of the secondary gear set 3 are connected to the transmission shaft 4 through a flat key 5, and the flat key 5 is used to limit the coaxial rotation of the secondary gear set 3.

[0049] like Figure 1 As shown in ,2,6, the linear drive shaft 13 is threadedly connected to the bottom of the spur rack 12 and maintains the same axis. The linear bearing 14 passes through the linear drive shaft 13 and is bolted to the housing 1 to limit the movement of the linear drive shaft 13 and the spur rack 12 other than the axial direction.

[0050] In this embodiment, all the transmission shafts 4 and the inner rings of the rotating bearings 6 are bonded and fixed by chemical adhesive to limit the axial movement between the transmission shafts 4 and the rotating bearings 6, and the outer rings of the rotating bearings 6 on both sides and the outer shell 1 are bonded and fixed by chemical adhesive to limit the axial movement between the rotating bearings 6 and the outer shell 1.

[0051] In this embodiment, the negative stiffness characteristics of the gear inertia negative stiffness friction damping device are mainly provided by the gear inertia system, and its inertia coefficient is positively correlated with the mass of the large gear and the square of the ratio of the radius of the dividing circle of the gear group. Among them, in the gear inertia system, the distance between the small gear in the primary gear group and the driving gear 8 and the spur gear meshing point in the drum brake friction system should be less than the length of the spur rack 12 to meet the travel requirements of the gear inertia negative stiffness friction damping device.

[0052] The test results of the gear inertia negative stiffness friction damping device provided in Example 1 under different sinusoidal period hysteresis loading conditions with constant drum brake preload are as follows: Figure 7 The hysteresis loading test results of the gear inertia negative stiffness friction damping device under constant sinusoidal loading cycle conditions with different drum brake preloads are shown in Figure 8 Its negative stiffness characteristics are significant, and it can effectively reduce the acceleration response of the structure, and generate friction damping to dissipate energy while providing negative stiffness, thus realizing the dual control strategy of displacement-acceleration.

[0053] Example 2

[0054] The gear inertia negative stiffness friction damping device provided by the present application is used as a whole in the seismic isolation layer of the seismic isolation structure in a specific application. The specific structure and composition of the gear inertia negative stiffness friction damping device is the same as that of Example 1, which will not be repeated here.

[0055] The technical features of the above embodiments can be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. These embodiments that are not explicitly written should also be considered to be within the scope of this specification.

[0056] The present application is described in more detail and in greater detail above through general descriptions and specific embodiments. It should be understood that, based on the technical concept of the present application, several conventional adjustments or further innovations may be made to these specific embodiments. However, as long as they do not deviate from the technical concept of the present application, the technical solutions obtained by these conventional adjustments or further innovations also fall within the scope of protection of the claims of the present application.

Claims

1. A gear inertia negative stiffness friction damping device, characterized in that: It comprises a housing (1), a gear inertia system, a drum brake friction system, and a spur rack (12) that drives the gear inertia system and the drum brake friction system together, and also comprises a linear bearing (14) and a rack stopper that limit the working plane of the gear inertia system and the drum brake friction system; The gear inertia system comprises two sets of mutually meshing primary gear sets (2) and secondary gear sets (3), each gear set comprises two spur gears of different sizes arranged at a relative interval, the central axes of the two spur gears in each gear set are jointly provided with a transmission shaft (4) and are connected via a flat key (5), and rotating bearings (6) are provided at both ends of the transmission shaft and are connected to the housing (1); The drum brake friction system comprises a driving gear (8) and a friction round steel (9) welded concentrically with the driving gear (8); a drum brake (10) is arranged on the inner side of the friction round steel (9); a transmission shaft (4) is also arranged at the central axis of the drum brake friction system; rotating bearings (6) are also arranged at both ends of the transmission shaft (4); the drum brake (10) is connected to the housing (1) via a fixed support (11); the driving gear (8) and the upper part of the spur rack (12) are meshed and in the same working plane; a steel wire rope with adjustable length is arranged between the linkage arm of the drum brake (10) and the limiting hole tangent to the movement direction of the linkage arm, so as to control the opening and closing of the friction plate inside the drum brake (10); The rack limiter comprises three rotating bearings (6) which are relatively spaced and symmetrically arranged, the central axis of which is provided with a transmission shaft (4), the two outer rotating bearings (6) are connected to the housing (1), and the middle rotating bearing (6) is in contact with the groove on the back side of the spur rack (12), so as to limit the spur rack (12) and the middle rotating bearing (6) to be in the same working plane; The spur rack (12) is arranged between the primary gear set (2) and the secondary gear set (3), wherein the pinion of the primary gear set (2) meshes with the lower part of the spur rack (12) and is located in the same working plane, the large gear of the primary gear set (2) and the small gear of the secondary gear set (3) mesh with each other and are located in the same working plane, and the working plane of the large gear and the working plane of the small gear of the secondary gear set (3) are symmetrically arranged with the working plane of the spur rack (12) as a symmetric plane.

2. A gear inertia negative stiffness friction damping device according to claim 1, characterized in that: In order to limit the synchronous rotation of the gears of the gear sets of each level in the gear inertia, the pinion gear and the large gear of the first-stage gear set (2) are connected to the transmission shaft (4) through a flat key (5), and the flat key (5) is used to limit the coaxial rotation of the first-stage gear set; the pinion gear and the large gear of the second-stage gear set (3) are connected to the transmission shaft (4) through a flat key (5), and the flat key (5) is used to limit the coaxial rotation of the second-stage gear set (3).

3. The gear inertia negative stiffness friction damping device according to claim 1, characterized in that: Each gear in the gear inertia system is provided with a stop ring (7) on both sides to limit the axial movement between the gear and the transmission shaft (4); a rotating bearing (6) is provided on both sides of the transmission shaft (4) in the first-stage gear set (2) and the second-stage gear set (3), and the rotating bearing (6) is connected to the housing (1).

4. The gear inertia negative stiffness friction damping device according to claim 1, characterized in that: The friction round steel (9) is coaxial with the driving gear (8) and is welded and fixed, the friction plate of the drum brake (10) is in contact with the inside of the friction round steel (9), and the central axes of the drum brake (10) and the friction round steel (9) are colinear.

5. The gear inertia negative stiffness friction damping device according to claim 4, characterized in that: A stop ring (7) is respectively arranged on the outside of the driving gear (8) and the drum brake (10) to limit the axial movement of the driving gear (8), the friction round steel (9) and the drum brake (10) relative to the transmission shaft (4); in addition, two rotating bearings (6) are arranged at intervals on both sides of the transmission shaft (4) in the drum brake friction system, and the rotating bearings (6) are connected to the housing (1).

6. A gear inertia negative stiffness friction damping device according to any one of claims 1 to 5, characterized in that: All the transmission shafts (4) and the inner rings of the rotating bearings (6) are bonded and fixed by chemical adhesive to limit the axial movement between the transmission shafts (4) and the rotating bearings (6); the outer rings of the rotating bearings (6) on both sides and the outer shell (1) are bonded and fixed by chemical adhesive to limit the axial movement between the rotating bearings (6) and the outer shell (1).

7. The gear inertia negative stiffness friction damping device according to claim 1, characterized in that: The linear drive shaft (13) is threadedly connected to the bottom of the spur rack (12) and maintains the same axis. The linear bearing (14) passes through the linear drive shaft (13) and is bolted to the housing (1) to limit the movement of the linear drive shaft (13) and the spur rack (12) outside the axial direction.

8. The gear inertia negative stiffness friction damping device according to claim 1, characterized in that: The negative stiffness characteristic of the gear inertia negative stiffness friction damping device is mainly provided by the gear inertia system, and its inertia coefficient is positively correlated with the mass of the large gear and the square of the ratio of the gear group dividing circle radius.

9. The gear inertia negative stiffness friction damping device according to claim 1, characterized in that: In the gear inertia system, the distance between the meshing point of the small gear in the primary gear set and the driving gear (8) and the spur gear in the drum brake friction system should be smaller than the length of the spur rack (12) to meet the travel requirement of the gear inertia negative stiffness friction damping device.

10. An application of a gear inertia negative stiffness friction damping device according to any one of claims 1 to 9, characterized in that: The gear inertia negative stiffness friction damping device is used as a whole in the seismic isolation layer of the seismic isolation structure.

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