Rotary Inertial Mass Damper

Abstract

To provide a rotational inertia mass damper which can suppress an actual rotation number of a pressure motor to an allowable rotation number or smaller while securing a large push-away capacity even if using a commercially-available motor as the pressure motor.SOLUTION: A mass damper (rotational inertia mass damper) 1 of the present invention comprises: a cylinder 2 filled with a working fluid HF; a piston 3 slidably arranged in the cylinder 2, and partitioning the inside of the cylinder 2 into first and second oil chambers 2e, 2f; a communication path 4 filled with the working fluid HF, bypassing the piston 3, communicating with the first and second oil chambers 2e, 2f, and having a plurality of parallel passage parts 4c; a plurality of gear motors 5 arranged in the parallel passage parts 4c, and converting the circulation of the working fluid in the parallel communication parts 4c to a rotational motion; and a plurality of rotating bodies 6 connected to the gear motors 5, and exerting rotational inertia mass effects by being driven by the gear motors 5. Specifications of the plurality of gear motors 5 and specifications of the plurality of rotating bodies 6 are set to be the same with respect to each other.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a rotary inertia mass damper that suppresses vibrations of a structure by utilizing the rotary inertia mass effect of a rotating mass driven by a pressure motor. [Background technology]

[0002] The applicant has disclosed this type of rotary inertia mass damper in, for example, Patent Document 1. This rotary inertia mass damper is installed between first and second parts in a system including a structure, and includes a cylinder filled with a working fluid and connected to the first part, a piston slidably provided within the cylinder, dividing the inside of the cylinder into a first fluid chamber and a second fluid chamber, and connected to the second part, and a communication passage that bypasses the piston and communicates with the first and second fluid chambers. A gear motor is provided in the communication passage as a pressure motor, and a rotating mass is connected to the gear motor.

[0003] In this rotary inertia mass damper, when the first and second parts are displaced relative to each other during an earthquake or the like, the relative displacement is transmitted to the cylinder and the piston, causing the piston to reciprocate relative to the cylinder. As a result, the working fluid in one of the first and second fluid chambers is pushed out by the piston, flows through the communicating passage, and enters the gear motor. As a result, the flow of the working fluid is converted into rotational motion by the gear motor and transmitted to the rotating mass, thereby exerting a rotary inertia mass effect due to the rotating mass. In addition, a viscous damping effect is exerted due to the viscous resistance of the working fluid as it flows through the communicating passage. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2018-127875 A Summary of the Invention [Problem to be solved by the invention]

[0005] When the gear motor type rotary inertial mass damper described above is used as a seismic isolation device between a structure and the ground, for example, the stroke and speed of the damper (magnitude and speed of relative displacement) are much larger than when it is used as a seismic control device inside the structure. In response to this tendency, it is desirable to make the gear motor's displacement volume (volume of working fluid required for one rotation of the gear) as large as possible so that the gear motor does not rotate excessively.

[0006] However, the specifications of pressure motors, including gear motors, available on the market are usually set so that the larger the displacement, the smaller the allowable rotation speed. For example, as shown in the study example below, a commercially available pressure motor has a displacement Vm of 32,000 mm. 3 The permissible speed of the 1 / rev is 6300 rpm, while the displacement volume Vm is four times that, or 128,000 mm 3 The allowable rotation speed for the damper is 4000 rpm. Therefore, if a commercially available gear motor with a large displacement is used, the actual rotation speed of the gear motor may exceed the allowable rotation speed while the damper is in operation. This poses a problem that a commercially available gear motor with a large displacement cannot be used in practice.

[0007] To solve this problem, it is conceivable to develop a gear motor with a large displacement and a large permissible rotational speed, but in that case, it is unclear whether a gear motor that satisfies the conditions such as the permissible rotational speed can be developed, and even if it can be developed, the gear motor will be expensive, including the cost, which will reduce the cost performance of the gear motor itself and, ultimately, the rotary inertia mass damper.

[0008] The present invention has been made to solve such problems, and has an object to provide a rotary inertia mass damper that can suppress the actual rotation speed of a pressure motor to below the allowable rotation speed while ensuring a large displacement volume, even when a commercially available pressure motor is used. [Means for solving the problem]

[0009] In order to achieve this object, the invention of claim 1 provides a rotary inertia mass damper that is provided between a first part and a second part that are displaced relative to one another in a system including a structure, and that suppresses vibration of the structure, comprising: a cylinder filled with a working fluid and connected to the first part; a piston slidably provided within the cylinder, dividing the inside of the cylinder into a first fluid chamber and a second fluid chamber, and connected to the second part; a connecting passage filled with a working fluid, bypassing the piston, communicating with the first and second fluid chambers, and having a plurality of parallel passage sections that are parallel to one another; a plurality of pressure motors provided in each of the plurality of parallel passage sections, converting the flow of the working fluid in the parallel passage sections into rotational motion; and a plurality of rotating masses connected to the plurality of pressure motors, respectively, and driven by the pressure motors to exhibit a rotary inertia mass effect, wherein the specifications of the plurality of pressure motors are set to be identical to one another, and the specifications of the plurality of rotating masses are set to be identical to one another.

[0010] The rotary inertia mass damper of the present invention is a pressure motor type having the cylinder, piston, communication passage, pressure motor, and rotary mass configured as described above, and is provided between a first part and a second part that undergo relative displacement in a system including a structure whose vibration is to be suppressed. In this rotary inertia mass damper, when vibration is input to the structure during an earthquake or the like, and a relative displacement occurs between the first and second parts, the relative displacement is transmitted to the cylinder and the piston, causing the piston to slide within the cylinder. As the piston moves, the working fluid in the first or second fluid chamber on both sides is pushed out by the piston and flows into the communication passage in which the pressure motor is provided. As a result, the flow of the working fluid is converted into a rotational motion by the pressure motor and transmitted to the rotary mass, thereby exerting a rotary inertia mass effect by the rotary mass, thereby suppressing the vibration of the structure.

[0011] According to the present invention, the communication passage has a plurality of parallel passage sections in parallel with each other, and each parallel passage section is provided with a pressure motor, so that the working fluid pushed out from the first or second fluid chamber into the communication passage as the piston moves is dispersed and flows into the plurality of parallel passage sections, and the plurality of pressure motors are operated simultaneously. In this case, the specifications of the plurality of pressure motors are set to be the same as each other, and the specifications of the plurality of rotating masses are set to be the same as each other, so that the operations of the plurality of pressure motors, for example, the rotation speed and the rotational inertia mass effect of the plurality of rotating masses, can be made substantially the same as each other.

[0012] Furthermore, when the number of parallel passages and pressure motors is N, the amount of working fluid flowing into each pressure motor is 1 / N and the rotation speed of the pressure motor is 1 / N under the same piston movement condition, compared to the normal case where the number of installed motors is 1. In other words, the displacement volume of the multiple pressure motors as a whole is substantially N times larger, and the rotation speed of each pressure motor is significantly suppressed. As a result, even when a commercially available pressure motor is used, the actual rotation speed of the pressure motor can be suppressed to the allowable rotation speed or less while ensuring a large displacement volume.

[0013] The invention according to claim 2 is characterized in that, in the rotary inertia mass damper according to claim 1, the passage areas of the plurality of parallel passage portions are set to be the same as one another.

[0014] According to this configuration, since the passage areas of the multiple parallel passage sections are the same, the inflow amount of working fluid to each pressure motor is the same, so that the operation of the multiple pressure motors and the rotational inertia mass effect caused by the multiple rotating masses are guaranteed, and the action according to claim 1 can be obtained more reliably and smoothly. [Brief description of the drawings]

[0015] [Figure 1] 1 is a cross-sectional view showing a mass damper according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a diagram showing a model of an additional vibration system configured with a mass damper and a support member. [Diagram 3]1 is a table showing the specifications of a mass damper used in a time history response analysis. [Figure 4] 1 is a table showing specifications of an input wave with excessive amplitude used in a time history response analysis. [Diagram 5] 1 is a table showing main results obtained by a time history response analysis. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the drawings. As shown in Fig. 1, a rotary inertia mass damper (hereinafter referred to as "mass damper") 1 according to the embodiment includes a horizontally extending cylinder 2 (inner cylinder), an outer cylinder 9 provided on the outside of the cylinder 2, a piston 3 provided slidably in the cylinder 2, a communication passage 4 bypassing the piston 3 and communicating with the inside of the cylinder 2, two gear motors 5, 5 as pressure motors arranged in parallel passage parts 4c, 4c of the communication passage 4, and a rotor 6 connected to each gear motor 5.

[0017] The cylinder 2 has a cylindrical peripheral wall 2a, and a thin plate-like first end wall 2b and a thick block-like second end wall 2c integrally provided at both ends of the peripheral wall 2a. The internal space of the cylinder 2 is defined by these three walls 2a to 2c.

[0018] The piston 3 is provided in the cylinder 2 so as to be axially slidable, and divides the internal space of the cylinder 2 into a first oil chamber 2e on the first end wall 2b side and a second oil chamber 2f on the second end wall 2c side. The first and second oil chambers 2e, 2f and the communication passage 4 are filled with hydraulic oil HF. The hydraulic oil HF is an ordinary oil having an appropriate viscosity.

[0019] A piston rod 10 is provided integrally and concentrically with the piston 3. The piston rod 10 extends only toward the first oil chamber 2e side of the cylinder 2 from the piston 3, and extends outwardly while penetrating the first end wall 2b and the first end wall 9b of the outer cylinder 9 in a liquid-tight manner. A first mounting fixture FL1 is provided to the outer end of the piston rod 10 via a universal joint.

[0020] The outer cylinder 9 surrounds the entire cylinder 2 and integrally has a cylindrical peripheral wall 9a and plate-like first and second end walls 9b, 9c provided at both ends thereof, with the first end wall 9b being in contact with the first end wall 2b of the cylinder 2. Meanwhile, a space is defined between the peripheral walls 2a, 9a of the cylinder 2 and the outer cylinder 9 and between the second end walls 2c, 9c, and this space serves as a tank chamber 12. In the tank chamber 12, hydraulic oil HF is stored with an air layer A remaining at the top. A second attachment FL2 is provided to the second end wall 9c of the outer cylinder 9 via a universal joint.

[0021] The communication passage 4 has, for example, two oil chamber communication parts 4a, a branch passage part 4b, and a parallel passage part 4c. The oil chamber communication parts 4a, 4a communicate with the first and second oil chambers 2e, 2f of the cylinder 2 at their lower ends, respectively, and extend upward through the peripheral walls 2a, 9a of the cylinder 2 and the outer cylinder 9 in a liquid-tight manner. The branch passage part 4b branches off from the upper end of each oil chamber communication part 4a to both sides and extends horizontally. The parallel passage parts 4c, 4c are provided between the ends of the branch passage parts 4b, 4b in parallel with each other and extend horizontally. The passage areas of the oil chamber communication parts 4a, 4a, the branch passage parts 4b, 4b, and the parallel passage parts 4c, 4c are set to be the same as each other.

[0022] A gear motor 5 is provided in each parallel passage section 4c. The specifications (e.g., displacement volume and allowable rotation speed) of the two gear motors 5, 5 are set to be the same. The gear motor 5 is, for example, an internal type, and has a housing 7 communicating with the communication passage 4 (parallel passage section 4c) via two inlets and outlets (not shown), a rotatable input gear and an output gear (neither shown) housed in the housing 7 and meshing with each other, and an output shaft 8 integrally provided with the output gear. A drain passage (not shown) for discharging the hydraulic oil HF is provided in the housing 7. The output shaft 8 is liquid-tightly supported by the housing 7 via a seal (not shown). Note that an external type gear motor may be used as the gear motor 5 instead of the internal type.

[0023] The rotating body 6 is attached integrally to the output shaft 8 of each gear motor 5. The rotating body 6 is formed in a disk shape from a material with a relatively large specific gravity, such as steel, and is provided coaxially and integrally with the output shaft 8. The specifications of the two rotating bodies 6, 6 (e.g. material, specific gravity, diameter, thickness, etc.) are set to be identical to each other.

[0024] Meanwhile, four communication passages are formed in the piston 3, penetrating in the axial direction and communicating with the first and second oil chambers 2e, 2f. A first pressure regulating valve 21, a first relief valve 22, a second pressure regulating valve 23, and a second relief valve 24 are provided in each of these communication passages. All of these valves 21 to 24 are configured as normally closed valves, and each include a valve body that opens and closes the communication passages, and a spring that biases the valve body in the valve closing direction.

[0025] The first pressure regulating valve 21 opens when the pressure in the first oil chamber 2e reaches a first predetermined pressure, and adjusts the pressure in the first oil chamber 2e by allowing the hydraulic oil HF to flow toward the second oil chamber 2f, and the first relief valve 22 opens when the pressure in the first oil chamber 2e reaches a second predetermined pressure (equivalent to a relief load) that is higher than the first predetermined pressure, and limits the pressure in the first oil chamber 2e to below the second predetermined pressure (when the damping coefficient after relief is set to 0) by allowing the hydraulic oil HF to flow toward the second oil chamber 2f.

[0026] Conversely to the above, the second pressure regulating valve 23 adjusts the pressure in the second oil chamber 2f by opening when the pressure in the second oil chamber 2f reaches a first predetermined pressure, and the second relief valve 24 limits the pressure in the second oil chamber 2f to below the second predetermined pressure (when the damping coefficient after relief is set to 0) by opening when the pressure in the second oil chamber 2f reaches a second predetermined pressure (equivalent to the relief load).

[0027] Further, two communication passages are formed in the second end wall 2c of the cylinder 2, penetrating in the axial direction and communicating with the second oil chamber 2f and the tank chamber 12. Each of these communication passages is provided with a third pressure regulating valve 25 and a third relief valve 26, which are configured similarly to the above-mentioned valves 21 to 24. The third pressure regulating valve 25 opens when the pressure in the second oil chamber 2f reaches a first predetermined pressure, and adjusts the pressure in the second oil chamber 2f by allowing the hydraulic oil HF to flow to the tank chamber 12 side. The third relief valve 26 opens when the pressure in the second oil chamber 2f reaches a second predetermined pressure, and limits the pressure in the second oil chamber 2f to the second predetermined pressure or less (when the damping coefficient after relief is set to 0) by allowing the hydraulic oil HF to escape to the tank chamber 12 side.

[0028] Furthermore, two communication holes penetrating in the axial direction are formed in the second end wall 2c of the cylinder 2, and these communication holes are opened and closed by a check valve 27. The check valve 27 is composed of valve bodies 27a, 27a that open and close the communication holes, and a spring 27b that urges the valve body 27a toward the communication passage side, thereby allowing the flow of the hydraulic oil HF only from the tank chamber 12 side to the second oil chamber 2f side.

[0029] One end of a drain pipe 31 is connected to a drain passage of the housing 7 of the gear motor 5. The drain pipe 31 penetrates the peripheral wall 9a of the outer cylinder 9 in a liquid-tight manner, and the other end is inserted into the tank chamber 12. The drain pipe 31 is provided with a check valve 32. The check valve 32 is configured to allow only the flow of the hydraulic oil HF from the gear motor 5 to the tank chamber 12 side.

[0030] The mass damper 1 having the above configuration is attached, for example, together with a support member for adjusting the rigidity via first and second mounting fixtures FL1 and FL2, and used as a seismic isolation device. The operation of the mass damper 1 will be described below.

[0031] First, when the structure is not vibrating, the mass damper 1 is in the initial state shown in Figure 1. When the ground vibrates from this initial state due to an earthquake or other event, the piston 3 reciprocates within the cylinder 2 in response to the relative displacement between the ground and the structure.

[0032] For example, when the piston 3 moves to the first oil chamber 2e side (when the piston rod 10 is extended), the pressure in the first oil chamber 2e increases due to the pressure of the piston 3, and when it reaches a first predetermined pressure, the first pressure regulating valve 21 opens and the hydraulic oil HF flows out to the second oil chamber 2f side. The hydraulic oil HF also flows from the first oil chamber 2e into one oil chamber communicating portion 4a of the communicating passage 4, and further flows into each of the parallel passage portions 4c, 4c via the branch passage portion 4b, and after flowing through the housing 7 of each gear motor 5, returns to the second oil chamber 2f via the other branch passage portion 4b and the oil chamber communicating portion 4a. In this case, the hydraulic oil HF insufficient in the second oil chamber 2f due to the difference in cross-sectional area between the first and second oil chambers 2e, 2f depending on the presence or absence of the piston rod 10 is replenished from the tank chamber 12 to the second oil chamber 2f by the check valve 27 opening.

[0033] On the other hand, conversely to the above, when the piston 3 moves to the second oil chamber 2f side (when the piston rod 10 is contracted), the pressure in the second oil chamber 2f increases due to the pressure from the piston 3, and when it reaches the first predetermined pressure, the second pressure adjusting valve 23 opens and the hydraulic oil HF flows out to the first oil chamber 2e side. The hydraulic oil HF also flows from the second oil chamber 2f into one oil chamber communicating portion 4a of the communication passage 4, and further flows into each of the parallel passage portions 4c, 4c through the branch passage portion 4b, and after flowing through the housing 7 of each gear motor 5, returns to the first oil chamber 2e through the other branch passage portion 4b and the oil chamber communicating portion 4a. In this case, the excess hydraulic oil HF in the second oil chamber 2f due to the difference in cross-sectional area between the first and second oil chambers 2e, 2f is discharged from the second oil chamber 2f to the tank chamber 12 by the third pressure adjusting valve 25 opening.

[0034] As described above, the pressure of the hydraulic oil HF flowing inside the housing 7 of each gear motor 5 is converted into the rotational motion of the gear motor 5, and the rotor 6 integrated with the output shaft 8 is rotationally driven, thereby exerting a rotational inertia mass effect (inertia force). In addition, a viscous damping effect (viscous force) is exerted due to the viscous resistance when the hydraulic oil HF flows through the communication passages 4, etc., thereby exerting a vibration suppression effect on the structure in addition to the rotational inertia mass effect.

[0035] According to the mass damper 1 of this embodiment, the gear motors 5 are provided in the parallel passage sections 4c, 4c of the communication passage 4, and the passage areas of the parallel passage sections 4c, 4c, the specifications of the gear motors 5, 5, and the specifications of the rotors 6, 6 are set to be the same for each other. With this configuration, compared to a normal case in which only one communication passage 4 and one gear motor 5 are installed, the overall displacement capacity of the gear motors 5, 5 is substantially doubled and the rotation speed of each pressure motor 5 is halved. As a result, even when a commercially available gear motor 5 is used, the actual rotation speed of the gear motor 5 can be suppressed to be equal to or lower than the allowable rotation speed while ensuring a large displacement volume.

[0036] Furthermore, when the pressure of the hydraulic oil HF in the housing 7 of the gear motor 5 increases due to the mass damper 1 operating for a long period of time, for example, in response to a structural response due to a long-period earthquake motion input, the check valve 32 opens. This allows the hydraulic oil HF to escape through the drain pipe 31 and the check valve 32 to the tank chamber 12, which is in atmospheric condition, thereby preventing the pressure inside the housing 7 from increasing.

[0037] Next, we will explain the response analysis performed to confirm the effects and characteristics of the mass damper 1 described above. The target of the response analysis is an additional vibration system consisting of the mass damper 1 and a support member (spring element) connected to it, and its analytical model is shown in Figure 2. That is, the mass damper 1 is a model in which (a) an inertial mass element with equivalent mass md consisting of a rotor 6 and hydraulic oil HF, which are in a parallel relationship with each other, and (b) a viscous element with damping coefficient cd consisting of hydraulic oil HF flowing through a communication passage 4, are connected to (c) viscous elements with damping coefficients c1 and c2 before and after the relief consisting of hydraulic oil HF flowing through a pressure regulating valve and a relief valve, and further, (d) a spring element with stiffness kb consisting of a support member including the compression stiffness of the hydraulic oil HF is connected in series to the viscous element (c). This is the analytical model of the additional vibration system.

[0038] In the model of Figure 2, Fd is the damper external force acting on the mass damper 1, x is the displacement of the entire additional vibration system, and Fr is the relief load of the first, second and third relief valves 22, 24, 26. xb is the displacement of the support member containing the hydraulic oil HF. xiHGD is the piston movement amount when the displacement x of the entire additional vibration system (damper external force Fd) is input (acts), and is expressed by the following equation (1) where V is the displacement flow rate of the piston 3 and Ap is the piston cross-sectional area. xiHGD = V / Ap (1) Additionally, xr is the apparent movement amount obtained by dividing the flow rate Vr of the hydraulic oil HF flowing through the pressure regulating valve and the relief valve by the piston cross-sectional area Ap, and is expressed by the following formula (2). xd is the apparent movement amount obtained by dividing the flow rate Vd of the hydraulic oil HF flowing through the communicating passage 4 to the gear motor 5 side by the piston cross-sectional area Ap, and is expressed by the following formula (3). xr = Vr / Ap (2) xd = Vd / Ap (3)

[0039] The relationship of the following formula (4) is established among V, Vr, and Vd, and the relationship of the following formula (5) is established from this formula (4) and formulas (1) to (3). V = Vr + Vd (4) x iHGD = xr + xd (5) In addition, the pressure acting on the pressure regulating valve and the relief valve installed on the piston 3 is equal to the pressure acting on the gear motor 5. (6)

[0040] From the relationships in (5) and (6) and the like, the following equations (7) to (9) hold. x = xb+xiHGD = xb+xr+xd ···(7) Condition before relief: |Fd|≦Fr, |dxr / dt|≦Fr / c1 Fd = kb xb = c1 dxr / dt = md d 2 xd / dt 2 +cd·dxd / dt ···(8) Condition after relief: |Fd|>Fr, |dxr / dt|>Fr / c1 Fd = kb xb = sgn(dxr / dt) Fr +c2·(dxr / dt-sgn(dxr / dt)·Fr / c1) = md d 2 xd / dt 2 +cd·dxd / dt ···(9) Where, c1: damping coefficient before relief c2: Damping coefficient after relief dxr / dt: xr speed dxd / dt: xd speed d 2 xd / dt 2 Acceleration of :xd sgn(dxr / dt): Sign function according to the value of dxr / dt md: equivalent mass of mass damper 1 cd: Damping coefficient of mass damper 1 kb: stiffness of support member (including the effects of the compression stiffness of the hydraulic oil HF, etc.) Of these parameters, in the example study described later, the following parameters will be used: relief load Fr = 800 kN, damping coefficient before relief c1 = 2500 kNs / m, damping coefficient after relief c2 = 169.5 kNs / m, damping coefficient of mass damper 1 cd = 500 kNs / m, and support member rigidity kb = 75000 kN / m.

[0041] Although not shown, the number of gear motors 5 is four, four parallel passage sections 4c are provided in the communication passage 4 communicating with the cylinder 2, and one gear motor 5 is installed in each parallel passage section 4c. The specifications of these four gear motors 5 (e.g., displacement volume, allowable rotation speed, and strength), the specifications of the rotor 6 (e.g., specific gravity, outer diameter, and thickness), and the specifications of the parallel passage section 4c (e.g., passage area and length) are all the same, and are set, for example, according to commercially available products, as shown in FIG.

[0042] FIG. 3 shows the specifications of four gear motors 5. For example, the displacement of one gear motor 5 (pressure motor) is 32,000 mm 3 / rev, and in Figure 3, the displacement volume of four units is converted to Vm = 32000 x 4 = 128000 mm 3 / rev is shown. Similarly, the thickness of one rotating body 6 is 10 mm, and in Fig. 3, converted to the thickness of four rotating bodies, t = 10 x 4 = 40 mm, is shown, and the equivalent mass md of the mass damper 1 is 2175.342 tons. On the other hand, for example, the allowable rotation speed nmax of the gear motor 5 (pressure motor) does not change whether there is one motor or four motors, so nmax = 6300 rpm is shown.

[0043] For this analysis model, a time history response analysis was performed by adding an excessive steady input (x = xmax·sinωt) of the natural frequency of the controlled object to x in the above formula (7). Figure 4 shows an example of this steady input wave, where the natural frequency of the controlled object is f = 0.25Hz and the excessive input amplitude xmax = 1.0m. Figure 5 shows the main analysis results.

[0044] First, for the maximum damper external force Fd_max, Fd_max = 1002.666 kN was obtained, which is greater than the relief load Fd (= 800 kN), and therefore it is estimated that the first, second and third relief valves 22, 24, 26 will operate. It was also confirmed that the maximum damper external force Fd_max was smaller than both the yield strength Fdmax_c (= 1201.659 kN) calculated from the cylinder 2 and the yield strength Fdmax_m (= 1068.142 kN) calculated from the gear motor 5.

[0045] The apparent maximum piston speed Vd_max calculated from the flow rate through the gear motor 5 was Vd_max = 397.7915 mm / s. Furthermore, the maximum motor speed n_max (= 4979.269 rpm) was lower than the motor allowable speed nmax (= 6300 rpm), and it was confirmed that even in the case of an excessively large input amplitude xmax = 1.0 m, the actual speed of the gear motor 5 (pressure motor) was suppressed and remained within the allowable range. Note that a commercially available pressure motor has a displacement volume Vm = 32000 mm 3The permissible speed of the 1 / rev is 6300 rpm, while the displacement volume Vm is four times that, or 128,000 mm 3 The permissible speed of the / rev is 4000 rpm. Therefore, the displacement volume of the latter is Vm = 128000 mm 3 When a commercially available pressure motor having a rotational speed of 4000 rpm and a rotational speed of 1000 rpm is used alone, it is not possible to handle the maximum motor rotational speed n_max (=4979.269 rpm) for the above-mentioned excessively large input amplitude, and the effectiveness of the present invention was confirmed.

[0046] The present invention is not limited to the embodiment described above, and can be implemented in various forms. For example, in the embodiment, the number of parallel passage parts 4c of the communication passage 4 and the number of gear motors 5 are set to 2 or 4, but the number is not limited to this, and can be increased or decreased to a number other than 2 or 4 depending on the required magnitude of the rotational inertia mass effect and the degree of suppression of the rotation speed of the gear motor 5.

[0047] Although a gear motor is used as the pressure motor of the mass damper 1, other types of pressure motors may be used, such as a piston motor, a vane motor, or a screw motor, as long as they convert the flow of the working fluid into rotational motion. Also, in the embodiment, it has been described that normal hydraulic oil HF is used as the working fluid of the damper, but it goes without saying that other appropriate working fluids may be used.

[0048] Furthermore, in the mass damper 1 of the embodiment, in addition to the first, second and third relief valves 22, 24 and 26, the first, second and third pressure regulating valves 21, 23 and 25 are provided in the communicating passage of the piston 3. However, these pressure regulating valves 21 and 23 may be omitted, and the damping coefficient c1 before relief in the analysis model of FIG. 2 may be set to a sufficiently large value.

[0049] The mass damper 1 of the embodiment is intended primarily for use in a seismic isolation device, in which the piston rod extends only on one side of the piston and an outer cylinder is provided on the outside of the cylinder (inner cylinder). However, the present invention is not limited to this, and it goes without saying that other suitable types of mass dampers may be used, such as those in which the piston rod extends on both sides of the piston or those without an outer cylinder.

[0050] Furthermore, the specifications of the mass damper 1 set for the time history response analysis (specifications of the piston rod, cylinder, pressure motor, pressure regulating valve, relief valve, etc.), the specifications of the stiffness of the support members, the specifications of the input sine wave, and the numerical values ​​showing the results of the response analysis (FIGS. 3 to 5) are merely examples. Other details of the configuration can be changed as appropriate within the scope of the spirit of the present invention. [Explanation of symbols]

[0051] 1 Mass damper (rotary inertia mass damper) 2 Cylinder 2e 1st oil chamber (1st fluid chamber) 2f 2nd oil chamber (2nd fluid chamber) 3 Piston 4 passages 4c Parallel passage section 5 Gear motor (pressure motor) 6 Rotating mass (rotating body) HF hydraulic oil (working fluid)

Claims

1. A rotary inertia mass damper that is provided between a first portion and a second portion that are displaced relatively in a system including a structure and suppresses vibration of the structure, comprising: a cylinder filled with a hydraulic fluid and connected to the first portion; a piston slidably disposed within the cylinder, dividing the interior of the cylinder into a first fluid chamber and a second fluid chamber, and connected to the second portion; a communication passage filled with a working fluid, bypassing the piston, communicating with the first and second fluid chambers, and having a plurality of parallel passage portions arranged in parallel with each other; a plurality of pressure motors provided in the plurality of parallel passages, respectively, for converting the flow of the working fluid in the corresponding parallel passages into rotational motion; A plurality of rotating masses are respectively connected to the plurality of pressure motors and are driven by the pressure motors to exert a rotational inertia mass effect; A rotary inertia mass damper, characterized in that the specifications of the plurality of pressure motors are set to be identical to one another, and the specifications of the plurality of rotating masses are set to be identical to one another.

2. 2. The rotary inertia mass damper according to claim 1, wherein the parallel passage sections have passage areas set to be the same as each other.

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