Seismic protection platform

Abstract

FIELD: mechanical engineering.SUBSTANCE: seismic protection platform comprises a fixed base and a movable platform, which includes an upper shell for installing the protected equipment and a lower shell, designed with the possibility of forming a movable connection with the fixed base, where the movable connection is provided by at least a horizontal displacement compensation device, made in the form of rolling supports. The upper and lower shells are elastically connected to each other by a vertical displacement compensation block and are spaced from each other in the vertical plane by horizontal stabilization blocks. The vertical displacement compensation unit and horizontal stabilization units are designed to ensure the horizontal position of the upper shell when its center of gravity is displaced. Between the fixed base and the lower shell, a rollover protection device is installed, designed with the ability to limit the amount of movement of the lower shell in the vertical plane while simultaneously maintaining the mobility of the lower shell in the horizontal plane within the limits provided by the horizontal movement compensation device.EFFECT: provision of the ability to protect equipment from industrial vibration and dampen vibrations from earthquakes and seismic impacts.10 cl, 9 dwg, 1 tbl

Description

[0001] Field of technology

[0002] The proposed invention relates to equipment protection against earthquakes and man-made seismic impacts, as well as protection against industrial vibration. Seismic protection platforms are particularly suitable for protecting safety-critical equipment. Safety-critical equipment is part of a safety group, the malfunction or failure of which could lead to an unacceptable level of exposure to the population, as well as a critical loss of control and information. Such equipment includes:

[0003] - structures, systems and components, the malfunction or failure of which may lead to an unacceptable level of radioactive exposure of the population, as well as chemical, biological or other mass contamination and / or mass loss of life;

[0004] - bunkers, control centers and data centers;

[0005] - designs, systems and components that prevent disturbances in normal operation from developing into emergency conditions.

[0006] State of the art

[0007] GOST R 70925-2023 / IEC / IEEE 60980-344:2020 "Safety-Related Equipment. Seismic Qualification" states that safety-related equipment must undergo seismic qualification to confirm its operability during and after maximum seismic impacts. Seismic qualification of safety-related equipment is a lengthy and expensive process that can have negative results, especially when tested for man-made seismic shocks and extreme earthquakes. To obtain positive results of seismic qualification and further reliable operation, man-made protection means are used: - seismic protection platforms (patent RU 2750951, published on 07 / 06 / 2021), mechanical vibration damping systems (patent RU 2709273, published on 12 / 17 / 2019), damping foundations (patent RU 2753505, published on 08 / 17 / 2021).

[0008] The analogue (patent RU 2709273) provides a system for damping mechanical vibrations transmitted from the construction part of structures to the complete electrical equipment and / or software and hardware complexes of the automated control system of the NPP, including a base on which the electrical equipment and / or software and hardware complex of the automated control system of the NPP are installed and / or placed, where the base is a load-bearing and / or support unit that includes 3D compensators, characterized in that the system additionally contains at least one load-bearing beam, at least one low-frequency vibration damping unit installed between the foundation of the structure for installing the base of the structure and the load-bearing beam or beams on which or which the 3D compensators are installed, wherein the low-frequency vibration damping unit has a vertical vibration damper pre-compressed to a given value,locked by a vertical damping activator lock, and a horizontal vibration damper in the form of a movable support mounted on a support plate through spherical supports, wherein the activator is designed in such a way that the vertical vibration damper is released when the threshold value of the vertical vibration amplitude is reached.

[0009] The specified analogue allows you to protect equipment from seismic shocks and earthquakes, but it has several significant disadvantages:

[0010] 1) This protection device may allow the first half-wave of a seismic shock to penetrate safety-critical equipment if the foundation initially moves upward. This is due to the design of the analog activator, in which the latch is made of a forcibly inverted disc spring. This spring will be returned to its normal state and will not prevent the compensating compression springs from triggering after the load-bearing beam relative to the support plate has moved upward by more than the required amount. After the compression springs trigger, the load-bearing beam rises sufficiently to compensate for large, low-frequency vertical displacements caused by man-made impacts. However, if the foundation initially moves upward, the activator fails to trigger, and the first half-wave of the seismic shock impacts the equipment without compensation, which may destroy safety-critical equipment.

[0011] 2) The placement of high-frequency vibration damping devices (3D compensators) on the beam significantly increases the vertical dimensions.

[0012] The closest analogue to the claimed seismic protection platform is the damping base according to Russian patent RU 2709273. The damping base comprises a fixed base, a movable horizontal platform for mounting the protected equipment, vertical displacement compensation devices in the form of elastic elements, horizontal displacement compensation devices in the form of rolling units, and a rollover protection device. The movable horizontal platform comprises an upper shell and a support carriage, which are elastically connected to each other by a horizontal stabilization unit. The horizontal stabilization unit is designed as a rocker mechanism supported by a vertical displacement compensation unit, which is capable of only vertical movement along one or more vertical guides. The guides, in turn, are rigidly fixed to the support carriage.The rocker mechanism levers are mounted on a common axis, and the levers have upper and lower bearing supports. The upper bearing supports of the rocker mechanism levers move along horizontal guides located in the upper shell, and the lower bearing supports of the rocker arms move along horizontal guides located in the support carriage. The support carriage movably rests on the base via horizontal displacement compensation devices. The support carriage is connected to a tilt protection device in such a way that it maintains the horizontal movement of the support carriage while preventing its vertical movement. Preventing vertical movement of the support carriage prevents the protected equipment from tipping over, as it limits the lower movement of the rocker mechanism, connected to the bearing supports in the horizontal guides. The rocker mechanisms prevent emergency movement of the base of the moving platform, asThey are connected to the upper bearing supports, which have a limited range of movement within the upper horizontal guides. Thus, the upper platform, connected to the equipment via fastening elements, is protected from tipping.

[0013] The analogue according to the Russian patent RU 2709273 has significant disadvantages:

[0014] 1) The presence of a support carriage between the upper shell and the base is necessary, since the fixed carriage protects the platform from swinging, but it significantly increases the vertical dimension.

[0015] 2) The use of T-shaped anti-roll devices significantly limits the range of horizontal movements when compensating for seismic effects.

[0016] Safety-critical equipment must function under the influence of industrial vibration, earthquakes, and man-made factors affecting the foundation. The equipment's dimensions must remain within the design limits. Therefore, the external dimensions of the seismic protection platform must be comparable to those of a simple welded base, which is already included in the design and which the seismic protection platform is being installed to replace. Due to increasing regulatory requirements for the stability of safety-critical equipment in terms of large mechanical vibrations, the need arises to install the seismic protection platform beneath existing equipment, but without disconnecting the associated utilities.

[0017] There is also the task of protecting mobile equipment complexes, where there may be significant violations of the horizontality of the foundation.

[0018] There is also the task of protecting equipment installed on vehicles from strong impacts at the mounting points, while maintaining the equipment's protection from vibration and its fixation in the vehicle.

[0019] These shortcomings are overcome by using the proposed design of the seismic protection platform.

[0020] Disclosure of invention

[0021] The problem solved by the proposed invention is to protect equipment from the negative impact of industrial vibration, damping large mechanical vibrations from man-made impacts, earthquakes and seismic impacts at the equipment mounting locations, while maintaining the design dimensions of the equipment and without disconnecting the communications leading to the equipment during the installation of the seismic protection platform.

[0022] To solve this problem, the following circumstances are taken into account:

[0023] 1) Large-scale mechanical vibrations occur in the low-frequency range (1-25 Hz) and are statistically rare. A severe earthquake (SSE), an airplane crash, or an air blast wave (ASW) from an explosion are rare events, while constant industrial vibration in the 25-50 Hz frequency range is a regular process that leads to mechanical aging of equipment. Industrial vibration can be successfully damped by compensating springs built into seismic protection platforms, but they are fixed with activators to ensure the design dimensions. Therefore, it is necessary to ensure the movement of the compensating springs in the inactive position of the low-frequency vibration damping unit. In this case, the stroke of the compensating springs with the activator closed must be greater than the amplitude of vibration displacement during vibration resistance tests (usually the amplitude of vibration displacement during vibration resistance tests is no more than ±2.5 mm).

[0024] 2) Equipment often has a shifted center of gravity in the coordinates of the horizontal projection, and in the case of supplies of functionally identical equipment from different manufacturers, the location of the center of gravity can change dramatically, which leads to an imbalance of the compensating springs and can cause the equipment to sway during seismic impacts and, as a result, disrupt its operation.

[0025] 3) Equipment may be mounted on vehicles, but must be secured in the transport position and protected from strong impacts and vibrations, both vertically and horizontally. New factors arise in vehicles:

[0026] - changing the horizontal position of the base, which requires solving the problem of the platform rolling out of the working position;

[0027] - inertia of the protected equipment, which requires solving the problem of compensating for the additional kinetic energy of the protected equipment.

[0028] The technical result consists in providing the ability to protect equipment from the negative impact of industrial vibration and damping vibrations from such man-made impacts as earthquakes and seismic shocks at the equipment mounting locations.

[0029] The declared technical result is achieved by the following set of essential features.

[0030] A seismic protection platform comprising a fixed base (1) and a movable platform (2) which includes an upper shell (5) for installing protected equipment and a lower shell (6) configured to form a movable connection with the fixed base (1), where the movable connection is provided by at least a horizontal displacement compensation device (4) made in the form of rolling supports, wherein the upper shell (5) and the lower shell (6) are elastically connected to each other by a vertical displacement compensation unit (13) and are spaced from each other in a vertical plane by horizontal stabilization units (7, 8), wherein the vertical displacement compensation unit (13) and the horizontal stabilization units (7, 8) are configured to ensure the horizontal position of the upper shell (5) when its center of gravity is displaced, wherein an anti-rollover device (3) is installed between the fixed base (1) and the lower shell (6),designed with the possibility of limiting the amount of movement of the lower shell (6) in the vertical plane while simultaneously maintaining the mobility of the lower shell (6) in the horizontal plane within the limits provided by the horizontal displacement compensation device (4).,

[0031] The vertical displacement compensation block (13) is made in the form of pre-compressed compensating springs.

[0032] One of the horizontal stabilization blocks (8) is made in the form of a main rocker mechanism, and the other horizontal stabilization block (7) is made in the form of an additional rocker mechanism, wherein each main and additional rocker mechanisms are made in the form of levers movably connected to each other, having on one side of the axis of their mutual connection fixed fastening axes (9, 11), one of which is connected to the upper shell (5), and the other to the lower shell (6), while on the other side of the axis of mutual connection of the levers movable supports (10, 12) are installed, one of which ensures interaction with the upper shell (5), and the other ensures interaction with the lower shell (6) so that the possibility of moving the upper shell (5) in the vertical plane is ensured.

[0033] The rollover protection device (3) is made in the form of an upper plate (14) and a lower plate (15), the mutual arrangement of which is carried out so that in the horizontal projection they form an X-shaped element, wherein the upper plate (14) is connected to the fixed base (1) by means of the first group of spacer struts (17), and the lower plate (15) is connected to the lower shell (6) by means of the second group of spacer struts (16).

[0034] The upper shell (5) and the lower shell (6) are further connected to each other by at least one vertical activator (19) having a triggering unit from a direct seismic wave and a triggering unit from a reverse seismic wave, wherein the vertical activator (19) contains a hook (20) made with the possibility of its rotation relative to an axis (21) located on the upper shell (5), until it stops against a limiter (22) located on the upper shell (5), wherein the hook (20) is connected to a spring (23), which is made with the possibility of creating a moment that prevents the vertical activator (19) from exiting the engagement, and also contains a hook lock (24) with a locking axis (26), which in the non-activated position is connected to the hook (20), wherein the hook lock (24) is made with the possibility of its rotation relative to an axis (27) installed in the lower shell (6), wherein the hook retainer (24) is connected to the spring (25),which is designed with the possibility of creating a moment of disengagement of the activator (19) when the locking axis (26) moves upward.

[0035] The upper shell (5) and the lower shell (6) are additionally connected to each other by at least one vertical activator (19), wherein the activator (19) consists of a spring-loaded hook (20) secured to the axis of the upper shell (5), and a spring-loaded hook retainer (24) with a locking axis (26), which in the non-activated position is connected to the hook (20), wherein the hook retainer (24) is made in the form of a spring-loaded chain, and the axis (27) of the hook retainer (24) is secured to the lower shell (6), wherein the spring-loaded hook (20) has a working contact zone with the spring (23) in the form of a surface with a curvature of 0-5° with respect to the tangent passing through the contact point and the chain tension axis, and the length of the working contact zone is equal to or greater than the amplitude of the maximum vibration displacement.

[0036] Additionally contains a horizontal movement activator (18) installed between the fixed base (1) and the lower shell (6), wherein the horizontal movement activator (18) is designed with the possibility of limiting the movement of the movable platform (2) when its installation angle changes in relation to the horizontal surface.

[0037] The horizontal movement activator (18) consists of a receiving hole (31) with a rim, made in a fixed base (1), an elastic element (32) mounted on a rod (33), which contains a seat for a ball (35), movably placed in the receiving hole (31).

[0038] The receiving hole (31) is a circular barrier with a diameter that is at least twice the value of the amplitude of the maximum horizontal vibration displacement when testing the protected equipment for vibration resistance, and the height of the barrier corresponds to a value that is less than the value of the elastic stroke of the spring-loaded rod (33).

[0039] The fixed base (1) and the movable platform (2) are formed from block elements including compensation blocks (47) and horizontal stability blocks (46), which are designed with the possibility of being connected to each other to form the fixed base (1) and the movable platform (2).

[0040] Brief description of the drawings

[0041] Fig. 1. Seismic protection platform.

[0042] Fig. 2 (a) Frontal projection of the seismic protection platform.

[0043] Fig. 2 (b) Shows the operation of the roll-over protection device when subjected to an overturning moment.

[0044] Fig. 3. Vertical compensation activator.

[0045] Fig. 4. External influence compensation circuit.

[0046] Fig. 5. Operation diagram of the vertical activator from the 1st half-wave of seismic impact.

[0047] Fig. 6. Horizontal movement activator.

[0048] Fig. 7. Geometric characteristics of the horizontal displacement activator.

[0049] Fig. 8. Additional elements to soften transport impacts and excessive tilts.

[0050] Fig. 9. Block structure of seismic protection platform.

[0051] Implementation of the invention

[0052] The solution to the problem is presented in Fig. 1-9, which shows a seismic protection platform that is capable of protecting equipment from vibration along three Cartesian coordinates X, Y, Z at once by compensating for external influences.

[0053] Fig. 1 shows a seismic protection platform in axonometric view, comprising a fixed base (1), a movable platform (2), a device for preventing overturning (3), a device for compensating horizontal movements (4) in the form of rolling supports, wherein the movable platform (2) comprises an upper shell (5), on which the protected equipment is placed, and a lower shell (6), which is placed on the device for compensating horizontal movements (4), wherein the upper shell (5) and the lower shell (6) are elastically connected to each other through compensation springs (13) by horizontal stabilization blocks (7, 8), located at an angle to each other, which have fixed support axes for fastening levers (9.11) and movable bearing support axes for fastening levers (10, 12).The rollover protection device (3) is configured to limit the amount of displacement of the lower shell (6) in the vertical plane while simultaneously maintaining the mobility of the lower shell (6) in the horizontal plane within the limits provided by the horizontal displacement compensation device (4). Thus, when forces arise that displace the movable platform (2) in the horizontal plane, the horizontal displacement compensation device (4) ensures its displacement within the limits determined by the design features and parameters of the corresponding rolling supports. The rollover protection device (3) does not limit the amplitude of displacement in the horizontal plane of the rolling supports, but does limit the displacement of the movable platform (2) in the vertical plane within specified limits.

[0054] Fig. 2a) shows a frontal projection of the seismic protection platform, in which the anti-rollover protection unit (3) is detailed. The anti-rollover protection unit (3) consists of an upper plate (14) attached to the base (1) by means of spacer struts (17), and a lower plate (15) attached to the movable platform (2) by means of spacer struts (16). In this case, the mutual arrangement of the upper plate (14) and the lower plate (15) is carried out such that in the horizontal projection they form an X-shaped element, wherein the upper plate (14) is connected to the structure (55) of the fixed base (1) by means of the first group of spacer struts (17), and the lower plate (15) is connected to the structure (56) of the movable platform (2) by means of the second group of spacer struts (16).The gap between the plates (14, 15) vertically must be minimal, but ensure free movement of the upper platform (2) relative to the fixed base (1); in practice, the gap is 1-2 mm. This unit must prevent the protected equipment (cabinet) from tipping over under external impact from the installation and operating personnel (see Fig. 2 b). This function is realized when the upper plate (14) and the lower plate (15) come into contact, after which the upper plate (14) blocks the tipping of the protected equipment, which is rigidly connected to the lower plate (15) via the movable platform (2), but the contact does not interfere with the horizontal movement of the lower plate (15) to compensate for horizontal movements in the area limited by the spacers (16, 17).

[0055] In section A-A, the dotted line shows the displacement of the plate (15) of the mechanism from tipping over in the extreme positions of the movable platform (2). Fig. 2 b) shows the contact of the plates (15) and (14) under the influence of the tipping moment M опр .

[0056] In this case, the movable platform is fixed in the zone of compensation of movements from industrial vibration in the horizontal direction by a horizontal activator (18), and in the zone of vertical movements by a vertical activator (19).

[0057] As shown in Figures 1 and 2 (a, b), the seismic protection platform has design-limited dimensions. The equality of the dimensions of the horizontal projection of the seismic protection platform and equipment (28) is fixed at the attachment points (30) of the platform and equipment. The vertical dimensions of the seismic protection platform are limited by the use of vertical compensation activators (19), which fix the platform height after forced compression to the design level (usually the height of the welded base). The use of activators (19) is necessary because the range of vertical vibrations that must be compensated for under seismic impact exceeds the vertical dimension of the standard welded base. The purpose of activator (19) is to fix the design height of the seismic protection platform during normal operation and automatically deploy the platform to the required compensation height during extreme seismic vibrations.In practice, the zone of extreme seismic vibrations is determined by the vibration displacement parameters at the transition frequency during vibration resistance testing. For example, for many electrical devices, the transition frequency from tests with a constant vibration displacement of ±2.5 mm to tests with a constant vibration acceleration of 10 m / s² occurs at 10 Hz. This vibration displacement is the external stimulus parameter that triggers the activator (19). It is important that the activator (19) triggers during the first half-wave of the seismic impact, as this wave is the most destructive.

[0058] The seismic protection platform shown in Fig. 1 and Fig. 2 (a, b) is capable of protecting equipment with a shifted center of gravity along two arbitrary coordinates of the horizontal projection at once due to the installation in it of a main rocker mechanism (8), located in a block with compensation springs (13) and an additional rocker mechanism (7), located at an angle to the main rocker mechanism in such a way that the continuations of the trajectories of the movable supports (10) intersect with the continuations of the trajectories of the movable supports (12) in the horizontal projection. In this case, the supports of the axes of the rocker arms (9) and (11) are fixed on the movable platform (2), which ensures the horizontality of the upper frill (5) when the center of gravity is shifted in an arbitrary direction, since the change in the reactions of the springs (13) will be balanced by the internal stresses inside the rocker arms.Ensuring the horizontality of the upper shell allows to avoid swinging, to carry out standard compensation of vertical vibrations and to protect the equipment (28) from the negative impact of industrial vibration, to dampen large mechanical vibrations from man-made impacts, earthquakes and seismic impacts in the places where the equipment is attached (30).

[0059] Fig. 3 shows a vertical compensation activator (19) which is installed between the upper shell (5) and the lower shell (6) of the movable platform (2). The activator (19) contains a hook (20) rotating relative to the axis (21) until it stops against the limiter (22), wherein the hook (20) is acted upon by a spring (23), which creates a moment M1; the activator also contains a hook lock (24), which in the inactive position is connected to the hook (20). The hook lock (24) rotates relative to the axis (27) installed in the lower shell (6), is under the action of a spring (25), which creates a moment M2, and has a locking axis (26) which contacts the hook (20).

[0060] The activator (19) is triggered by the 1st seismic wave of any direction, both downwards and upwards. The catch retainer (24) rotates relative to the axis (27) installed in the lower shell (6), is under the action of the spring (25), which creates the moment M2, and has a locking axis (26), which contacts the catch (20). The activator (19), in the closed state, allows the seismic protection platform to compensate for vertical impacts from industrial vibration. As shown in Fig. 3, the catch (20) has a protrusion with an extreme point at a distance R1 from the center of the axis (27), and R1>Ro, where Ro is the distance from the center of the axis (27) to the point A, at which the catch (20) contacts the retainer (24); Thus, when the axis (26) is displaced downward by Δz due to industrial vibration, there is a zone of maintaining contact between the catch (20) and the axis (26). When the axis (26) is displaced upward, the same projection with its extreme point at a distance R1 from the center of the axis (27) maintains contact between the catch (20) and the axis (26) as long as the upward displacement is less than Δz.As a result, the industrial vibration compensation zone is provided within ±Δz due to the protrusion with the extreme point at a distance R1 from the center of the axis (27) when the condition R1>Ro is met.

[0061] Fig. 3 shows the design of the activator (19), which has a hook (20) open upwards and, when the structure (29) moves upwards under the action of the 1st half-wave, the axis of the lock (26) rises relative to the hook and, under the action of the moment M2, disengages. In this case, the condition for the leading rise of the axis of the lock (26) must be met:

[0062] Fc-(m1+m2)g <A*(m1+m2),

[0063] where A is the acceleration of the structure (29) under the influence of the 1st seismic half-wave upward.

[0064] Fig. 4 shows a diagram of the compensation of external impacts, which are transmitted along three Cartesian coordinates (X, Y, Z) from the external structure (29) to the platform base (1), are compensated in the rolling supports (4) and in the compensating springs (13), and then transmitted to the equipment (28) to be protected. In this case, the rolling supports compensate for external impacts in the horizontal plane along the coordinates (X, Y), and the springs (13) compensate for vertical impacts. The compensation efficiency is determined by the horizontal displacement compensation coefficient K(X, Y)=A(X, Y) / a(x, y) and the vertical displacement compensation coefficient K(Z)=A(Z) / a(z).

[0065] K(X,Y)=A(X,Y) / a(x,y), where

[0066] A(X,Y) - the vector sum of the amplitudes of horizontal accelerations of the structure (29) on which the seismic protection platform with the protected equipment (28) is located, the value of A(X,Y) is specified by the design for the placement of the equipment (28) for carrying out seismic qualification;

[0067] a(x,y) is the vector sum of the amplitudes of horizontal accelerations of the protected equipment at the attachment points to the seismic protection platform (30), this value must be less than the maximum permissible value of the impact on the equipment (28).

[0068] a(x,y)=k1*g, where

[0069] k1 - rolling resistance coefficient of ball joints (4)

[0070] g is the acceleration of gravity, - therefore

[0071] К(X,Y)=A(X,Y) / ( k1*g).

[0072] Usually the maximum permissible vibration impact on equipment is set to a(x,y)=0.5g, and external seismic or man-made impact does not exceed A(X,Y)=20g, which means that the compensation coefficient should be K(X,Y)>40, i.e. the rolling resistance coefficient of ball joints should be k1<0.04, which is quite achievable, since in practice k1<0.01.

[0073] K(Z)=A(Z) / a(z), where

[0074] A(Z) - the amplitude of vertical accelerations of the structure (29) on which the seismic protection platform with the protected equipment (28) is located, the value of A(Z) is specified by the design for the placement of the equipment (28) for carrying out seismic qualification;

[0075] a(z) is the amplitude of vertical accelerations of the protected equipment at the attachment points to the seismic protection platform (30); this value must be less than the maximum permissible value of the impact on the equipment (28). Ensuring the required compensation coefficient for vertical vibrations is achieved by using soft pre-compressed springs (13), the stiffness of which is calculated using the formula: Kc = (m1 + m2) * (g + a(z)) / (z + Δz), where

[0076] Ks - total spring stiffness coefficient (13), providing the required level of compensation;

[0077] m1 - mass of the spring part of the platform,

[0078] m2 - equipment weight (28),

[0079] g - acceleration of gravity,

[0080] a(z) - amplitude of vertical acceleration of the protected equipment,

[0081] z - compression of springs (13) under the action of (m1+m2) in a state of rest,

[0082] Δz - additional compression of springs under the action of the structure (29) at its maximum vertical vibration displacement.

[0083] Therefore, the vertical compensation coefficient is determined by the formula: K(Z)=A(Z) / a(z)=A(Z)*(m1+m2) / (Kc*(z+Δz)-(m1+m2)*g).

[0084] Fig. 5 shows the operation diagram of the vertical activator from the 1st half-wave of seismic impact.

[0085] In the rest state, the springs (13) are forcibly compressed to the design height, the activator fixes the design height, the pressure force of the overspring masses is equal to P1=(m1+m2)*g. The internal moment Ma, which exists due to the resultant of the action of the compression force of the springs (13) and the pressure force of the overspring masses (see Fig. 5), multiplied by the arm "L" (the design displacement of the axis (21) relative to the axis (27)) is less than the moment M1 from the spring (23), therefore the catch (20) is held on the axis (26) and the activator (19) is closed.

[0086] When the structure (29) moves downwards with acceleration A from the impact of the 1st seismic half-wave, the activator opens, since the pressure force of the over-spring masses decreases to P1=(m1+m2)*(g-A), the internal moment of the activator increases by the value of (m1+m2)*A*L and overcomes the moment of activator locking M1, while the hook (20) disengages from the axis of the lock (26).

[0087] When the structure (29) moves upward with acceleration A from the impact of the 1st seismic half-wave, the activator opens due to the lifting of the axis of the retainer (26) upward, provided that the acceleration A of the movement of the structure (29) exceeds the acceleration of the lifting of the upper shell with the load and the moment M2 overcomes the frictional resistance to rotation of the retainer (24).

[0088] The hook (20) is subjected to the resulting force F1, which is equal to the difference between the compression force of the springs (13) and the load P, which depends on external vertical influences: P1=(m1+m2)*g - at rest and P11=(m1+m2)*(gA), when the structure (29) moves downwards together with the 1st seismic wave with acceleration A. Thus, F1 also differs:

[0089] F10=Fc-(m1+m2)*g at rest

[0090] F11=Fc-(m1+m2)*(gA) when moving downward with acceleration A.

[0091] The activator (19) has an offset of the axis (21) of the catch (20) relative to the axis (27) of the lock (24) by the value "e". This offset causes a rotation moment Ma = F1 * e, which in the state of rest is less than the moment M1, which prevents the activator from opening, but in the state of downward movement of the structure (29) with acceleration A, the force F11> F10 by (m1 + m2) * A, the moment Ma> M1 and the activator (19) opens, as a result of which the springs (13) raise the upper shell (5) to a height sufficient to compensate for the 1st wave of seismic impact.

[0092] In one embodiment of the proposed invention, the catch retainer (24) can be made in the form of a spring-loaded chain, and the axis (27) of the catch retainer (24) is fixed to the lower shell (6), wherein the spring-loaded catch (20) has a working contact zone with the spring (23) in the form of a surface with a curvature of 0-5° with respect to the tangent passing through the contact point and the chain tension axis, and the length of the working contact zone is equal to or greater than the amplitude of the maximum vibration displacement, for mechanical design group M40 according to GOST 17516.1 the contact zone is 4-5 mm.

[0093] Fig. 6 shows a horizontal displacement activator (18) consisting of a receiving recess with a rim (31), an elastic element (32), for example a disc spring, a rod (33) with a seat for a ball (35). The activator (18) prevents the movement of the movable platform (2) when the installation angle of the seismic protection platform changes from 0o to α with respect to the horizon. The activator (18) can be equipped with an activation lock (34) for cases when it is necessary to fix the activated state of the platform (2) after the impact.

[0094] Fig. 7 shows the geometric characteristics in the activator (18), and also shows the working zone S1 in which the ball (35) can move when compensating for horizontal movements from industrial vibration and the zone S2 in which the ball (35) can move when compensating for horizontal movements from seismic vibration.

[0095] Fig. 8 shows additional elements for softening transport impacts and excessive tilts.

[0096] Transport impacts and excessive vehicle tilts have less impact energy than seismic impacts from explosions and extreme earthquakes, but their impact can displace the movable platform (2) relative to the base (1) by an unacceptable value. To prevent the negative impact of transport impacts and excessive tilts during transportation, additional elements are used - return dampers (36, 37) and a vertical friction clutch (45). The return dampers are vertical pins made of spring wire with a diameter of 5 mm, clamped in a fixed base (1) and freely installed in a 6 mm hole in the upper platform (2). There are usually 4 return dampers, one in each corner of the platform. The vertical friction clutch (45) is installed on the rocker axis to regulate the damping parameters of the free oscillations of the platform (usually the logarithmic damping decrement should be around unity).The design of the vertical clutch (45) is a package of flat washers and disc springs, which are pressed by a nut and create a friction moment between the rocker arms to ensure the required damping parameters of free vibrations.

[0097] The return dampers can be in the form of an elastic pin, clamped on one side and installed in the base (1) and the movable platform (2), or in the form of a spring element for cases with a large amplitude of rigid vibrations. The vertical friction prevents rapid vertical movements due to the adjustable moment of frictional resistance during the relative movement of the rocker mechanism levers (39, 40), rotating relative to the screw (43) and separated from each other by spacer washers (42), while the levers (39, 40) are pressed by a nut (44) through a disc washer (41).

[0098] Fig. 9 shows the block structure of the seismic protection platform in the form of compensation blocks (47) and horizontal stability blocks (46), which are pulled together with transport and installation ties (54) to the design height of the platform in the operating position. The base is removed from under the equipment (28) and blocks (46, 47) are installed in its place, which after installation are connected to each other through mounting holes (49, 50) using fasteners (51). In this case, cables, pipes and other communications (48), passing through the opening (53) in the structure (29), are not disconnected from the operating equipment (28). After completion of the installation of the seismic protection platform, the equipment is connected to it at the standard mounting points (30) using the standard fasteners (52).

[0099] The seismic protection platform can be installed at an angle to the horizontal. This is a necessary characteristic because it is necessary to specify design requirements for tilt tolerances for safety-critical equipment. Tilting resistance is achieved using a horizontal displacement activator (18), shown in Fig. 6.

[0100] The activator (18) consists of a receiving recess with a rim (31), an elastic element (32), a rod (33) with a seat for a ball (35). The activator (18) prevents the movement of the movable platform (2) when the installation angle of the seismic protection platform changes from 0o to α1 with respect to the horizon. The activator (18) does not prevent horizontal movements of the base (1) relative to the platform (2) in the S1 zone during the process of compensating for industrial vibration with a displacement amplitude of x=±х1(А1). When the base (1) is tilted by an angle α≤α1, the ball (35) shifts towards the tilt, but the elastic element (32) presses the ball (35) through the rod (33) to the base (1) and exerts such a counteraction that the movable platform cannot disengage up to an angle α1. During a seismic impact, the amplitude of the base (1) displacement exceeds x1, which means that the ball (35) moves beyond the hole (31) and leaves zone S1 onto a flat area, where it can move in zone S2.

[0101] The receiving well (31) can be a circular barrier with a diameter that is at least twice the value of the amplitude of the maximum horizontal vibration displacement when testing the protected equipment for vibration resistance (in order to maintain the possibility of compensating for horizontal oscillations during industrial vibration with an amplitude of displacement according to the mechanical design group), and the height of the barrier corresponds to a value that is less than the value of the elastic travel of the spring-loaded rod (33) - to ensure that the rod rises and disengages under a horizontal impact that exceeds the rated activation value.

[0102] The operating modes of the activator (18), providing stable compensation of external influences in accordance with Fig. 7 are presented in Table 1.

[0103] Table 1. Operating modes of the activator (18), providing stable compensation of external influences.

[0104] Mode The angle of inclination of the base to the horizon Impact The contact zone of the hole (31) and the ball (35) according to Fig. 7 Moving the contact zone Horizontal acceleration impact on the base (1) Engaging the platform (2) with the base (1) 1 α =0 Industrial vibration B20-B10… B11-B21 ±х1(А1) A≤A1 There is 2 α≤α1 Industrial vibration B30-B20-B10 ±х1(А1) A≤A1 There is 3 α =0 Seismic impact B40-B10… B11-B41 ±(2*х1(А1)+х2(А2)) A≤A2 No 4 α≤α1 Seismic impact B40-B10… B11-B41 ±(2*х1(А1)+х2(А2)) A≤A2 No

[0105] Designations given in Table 1:

[0106] α1 - permissible angle of inclination of the base to the horizon according to the passport;

[0107] A1 - amplitude of maximum acceleration when testing the platform with equipment (28) for vibration resistance;

[0108] A2 - amplitude of maximum acceleration during testing of the platform with equipment (28) for seismic resistance;

[0109] х1(А1) - maximum displacement of the base (1) during vibration resistance testing with acceleration amplitude A1 at the transition frequency;

[0110] x2(A2) - maximum displacement of the base (1) during seismic resistance testing with acceleration amplitude A2 with minimum impact frequency.

[0111] It should be noted that the number of activators (18) and (19) depends on the design composition of the seismic protection platforms. If a single seismic protection platform is used, there may be two activators per platform. If seismic protection platforms are combined into a system consisting of several platforms, there may be two activators per system.

[0112] When using seismic protection platforms on vehicles, it is necessary to consider the need to expand the S1 zone to compensate for inertial overshoot, but the mechanics of the process remain the same. However, to mitigate traffic impacts and excessive tilts, damping elements can be installed, as shown in Fig. 8.

[0113] The design of the seismic protection platform allows its installation under the equipment (28) without disconnecting the corresponding communications to the equipment. This is necessary to increase the seismic stability of the equipment already in operation. The implementation of the task is shown in Fig. 9. The seismic protection platform is delivered to the installation area in the form of compensation blocks (47) and horizontal stability blocks (46), which are pulled together with transport and installation ties (54) to the design height of the platform in the operating position. The plinth is removed from under the equipment and blocks (46, 47) are installed in its place, which after installation are connected to each other through fastening holes (49, 50) using fasteners (51). In this case, cables, pipes and other communications (48), passing through the opening (53) in the structure (29), are not disconnected from the operating equipment (28).Once the seismic protection platform is installed, the equipment is attached to it at its designated mounting points (30) using standard fasteners (52). The transport and installation ties (54) are then disconnected, and the seismic protection platform is commissioned.

Claims

1. A seismic protection platform comprising a fixed base (1) and a movable platform (2) which includes an upper shell (5) for installing the equipment to be protected and a lower shell (6) configured to form a movable connection with the fixed base (1), where the movable connection is provided by at least a horizontal displacement compensation device (4) made in the form of rolling supports, wherein the upper shell (5) and the lower shell (6) are elastically connected to each other by a vertical displacement compensation unit (13) and are spaced from each other in a vertical plane by horizontal stabilization units (7, 8), wherein the vertical displacement compensation unit (13) and the horizontal stabilization units (7, 8) are configured to ensure the horizontal position of the upper shell (5) when its center of gravity is displaced, wherein an anti-rollover device (3) is installed between the fixed base (1) and the lower shell (6),designed with the possibility of limiting the amount of movement of the lower shell (6) in the vertical plane while simultaneously maintaining the mobility of the lower shell (6) in the horizontal plane within the limits provided by the horizontal displacement compensation device (4)., 2. A seismic protection platform according to paragraph 1, characterized in that the vertical displacement compensation unit (13) is made in the form of pre-compressed compensating springs.

3. The seismic protection platform according to claim 1, characterized in that one of the horizontal stabilization blocks (8) is made in the form of a main rocker mechanism, and the other horizontal stabilization block (7) is made in the form of an additional rocker mechanism located at an angle to the main one, wherein each main and additional rocker mechanisms are made in the form of levers movably connected to each other, having fixed fastening axes (9, 11) on one side of the axis of their mutual connection, one of which is connected to the upper shell (5), and the other to the lower shell (6), while on the other side of the axis of the mutual connection of the levers movable supports (10, 12) are installed, one of which ensures interaction with the upper shell (5), and the other ensures interaction with the lower shell (6) so that the possibility of moving the upper shell (5) in the vertical plane is ensured.

4. The seismic protection platform according to paragraph 1, characterized in that the anti-rollover device (3) is made in the form of an upper plate (14) and a lower plate (15), the mutual arrangement of which is carried out so that in the horizontal projection they form an X-shaped element, wherein the upper plate (14) is connected to the fixed base (1) with the help of a first group of spacer struts (17), and the lower plate (15) is connected to the lower shell (6) with the help of a second group of spacer struts (16).

5. The seismic protection platform according to claim 1, characterized in that the upper shell (5) and the lower shell (6) are additionally connected to each other by at least one vertical activator (19) having a unit for triggering from a direct seismic wave and a unit for triggering from a reverse seismic wave, wherein the vertical activator (19) contains a hook (20) made with the possibility of its rotation relative to an axis (21) located on the upper shell (5), until it stops against a limiter (22) located on the upper shell (5), wherein the hook (20) is connected to a spring (23), which is made with the possibility of creating a moment that prevents the vertical activator (19) from coming out of engagement, and also contains a hook lock (24) with a locking axis (26), which in the non-activated position is connected to the hook (20), wherein the hook lock (24) is made with the possibility of its rotation relative to an axis (27) installed in the lower shell (6), while the hook retainer (24) is connected to the spring (25),which is designed with the possibility of creating a moment of disengagement of the activator (19) when the locking axis (26) moves upward.

6. The seismic protection platform according to claim 1, characterized in that the upper shell (5) and the lower shell (6) are additionally connected to each other by at least one vertical activator (19), wherein the activator (19) consists of a spring-loaded hook (20) secured to the axis of the upper shell (5), and a spring-loaded hook retainer (24) with a locking axis (26), which in the non-activated position is connected to the hook (20), wherein the hook retainer (24) is made in the form of a spring-loaded chain, and the axis (27) of the hook retainer (24) is secured to the lower shell (6), wherein the spring-loaded hook (20) has a working contact zone with the spring (23) in the form of a surface with a curvature of 0-5° with respect to the tangent passing through the contact point and the axis of chain tension, and the length of the working contact zone is equal to or greater than the amplitude of the maximum vibration displacements.

7. The seismic protection platform according to claim 1, characterized in that it additionally contains a horizontal displacement activator (18) installed between the fixed base (1) and the lower shell (6), wherein the horizontal displacement activator (18) is designed with the possibility of limiting the movement of the movable platform (2) when its installation angle changes in relation to the horizontal surface.

8. A seismic protection platform according to paragraph 7, characterized in that the horizontal displacement activator (18) consists of a receiving hole (31) with a rim, made in a fixed base (1), an elastic element (32) mounted on a rod (33), which contains a seat for a ball (35), movably placed in the receiving hole (31).

9. A seismic protection platform according to paragraph 8, characterized in that the receiving hole (31) is a circular barrier with a diameter that is at least twice the value of the amplitude of the maximum horizontal vibration displacement when testing the protected equipment for vibration resistance, and the height of the barrier corresponds to a value that is less than the value of the elastic travel of the spring-loaded rod (33).

10. A seismic protection platform according to claim 1, characterized in that the fixed base (1) and the movable platform (2) are formed from block elements including compensation blocks (47) and horizontal stability blocks (46), which are designed with the possibility of being connected to each other to form the fixed base (1) and the movable platform (2).

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