CN205806305U - Multidimensional can be harmonized zero stiffness vibration-isolating platform - Google Patents

Abstract

The utility model discloses a kind of multidimensional can harmonize zero stiffness vibration-isolating platform, including moving platform, base, vibroshock and adjusting means, vibroshock is to be connected with moving platform, and adjusting means is to be connected with base and vibroshock, and is used for regulating the initial position of vibroshock.Base includes that with moving platform be the silent flatform being oppositely arranged and the support means being arranged on silent flatform and being connected with adjusting means.Multidimensional of the present utility model can be harmonized zero stiffness vibration-isolating platform, and rigidity can easy regulate, it is adaptable to wide frequency domain vibration isolation, has good engineering adaptability；While having higher support stiffness, also having the lowest motion rigidity, static deformation amount is little, and dynamic natural frequency is low, and vibration isolating effect is good；By rigidity, the flexible of damping, it is possible to resolve the intrinsic contradictions of restriction tradition vibrating isolation system, i.e. low-frequency vibration transport and the contradiction of dither attenuation rate.

Description

Multi-dimensional adjustable zero-stiffness vibration isolation platform

technical field

The utility model belongs to the technical field of shock absorbers. Specifically, the utility model relates to a multi-dimensional adjustable zero-stiffness vibration isolation platform.

Background technique

High-precision machine tools and precision instruments and equipment, high-level scientific laboratory equipment, missile transport vehicles, etc., put forward higher performance requirements for the vibration isolation platform. Prominent vibration isolation platform.

Utility model content

The utility model provides a quasi-zero-stiffness vibration-isolation platform which has high static stiffness and low dynamic stiffness and can realize wide-frequency vibration isolation with adjustable stiffness.

In order to achieve the above purpose, the technical solution adopted by the utility model is: a multi-dimensional adjustable zero-stiffness vibration isolation platform, including:

moving platform;

A shock absorber, which is connected to the moving platform;

an adjustment device, which is connected to the shock absorber and is used to adjust the initial position of the shock absorber; and

The base includes a static platform opposite to the moving platform and a supporting device arranged on the static platform and connected with the adjustment device.

One end of the shock absorber is rotatably connected to the moving platform, and the other end is rotatably connected to the adjusting device.

The supporting device is movably arranged on the static platform, the adjusting device is movably arranged on the supporting device, and the moving direction of the supporting device when moving on the static platform is the same as that of the adjusting device moving on the supporting device The direction of movement is perpendicular to the time.

A plurality of adjustment devices are distributed circumferentially around the moving platform, and each adjustment device is connected to the moving platform through the shock absorber, and among two adjacent adjustment devices, one of the adjustment devices is connected to the moving platform. The distance between the static platforms is greater than the distance between the other adjusting device and the static platforms.

The shock absorber and the adjusting device are evenly distributed around the moving platform with the axis of the moving platform as the centerline.

The support device includes a support plate arranged on the static platform and connected with the adjustment device, and a sliding piece that is slidably connected with the static platform and connected with the support plate.

A plurality of support plates are evenly distributed along the circumference of the static platform with the axis of the static platform as the center line.

The sliding part is a bolt embedded in a chute provided on the static platform, the support plate has a hole for the bolt to pass through, and the bolt is provided with a nut for fastening the support plate.

The adjustment device includes an adjustment seat that is rotatably connected with the shock absorber and connected with the support plate through a fastener. The support plate has a slideway for the fastener to pass through. The length direction of the slideway is the same as that of the adjustment seat. parallel to the direction of movement.

The support plate has a first chute and a second chute located on the same straight line, and the second chute is located between the first chute and the static platform.

The multi-dimensional adjustable zero-stiffness vibration isolation platform of the utility model has the following advantages:

1. The vibration isolation platform not only solves the problem of traditional linear vibration isolation systems in isolating low-frequency or ultra-low-frequency vibrations, but also avoids the shortcomings of active and semi-active control vibration isolators with complex structures, high manufacturing costs and high energy consumption;

2. Within a certain deformation range of the vibration isolation platform, the three vibration damping springs at the upper end are used as positive stiffness elements and the three vibration damping spring elements at the lower end are used as negative stiffness vibration damping spring elements in parallel, which can realize the vibration isolation platform near its equilibrium position. nonlinear stiffness;

3. The vibration isolation platform can adjust the initial position of the shock absorber through the adjustment device to achieve wide frequency domain vibration isolation. It can be widely used in precision instruments and equipment that require strict vibration isolation, and has good engineering practicability.

4. The vibration isolation platform not only has high support stiffness, but also has very low motion stiffness, small static deformation, and vibration isolation effect with low dynamic natural frequency.

Description of drawings

This manual includes the following drawings, the contents shown are:

Fig. 1 is the structural representation of the vibration isolation platform of the present utility model;

Fig. 2 is the structural representation of moving platform;

Fig. 3 is the assembly diagram of moving platform and shock absorber;

Fig. 4 is the structural representation of base;

Fig. 5 is the structural representation of static platform;

Labeled in the figure:

1. Shock absorber; 11. Pin hole; 12. Damping spring; 2. Base; 21. Static platform; 22. Support plate; 23. First chute; 24. Second chute; 25. Third chute Groove; 26, sliding member; 27, first nut; 3, adjusting device; 31, adjusting seat; 32, bolt; 33, second nut; 4, moving platform; 41, bearing plate; 42, mounting seat; 43, The fourth chute; 44, bolt; 45, the third nut.

detailed description

Next, with reference to the accompanying drawings, through the description of the embodiments, the specific implementation of the present utility model will be further described in detail, the purpose is to help those skilled in the art to have a more complete, accurate and in-depth understanding of the concept and technical solutions of the present utility model , and contribute to its implementation.

As shown in Figures 1 to 5, the utility model provides a multi-dimensional adjustable zero-stiffness vibration isolation platform, including a moving platform 4, a base 1, a shock absorber and an adjustment device 3, and the shock absorber is connected to the moving platform 4 Connection, the adjustment device 3 is connected with the base 1 and the shock absorber, and is used to adjust the initial position of the shock absorber. The base 1 includes a static platform 21 opposite to the moving platform 4 and a supporting device arranged on the static platform 21 and connected to the adjustment device 3 . The multi-dimensional adjustable zero-stiffness vibration isolation platform of the utility model sets certain structural parameters, and the vibration isolation platform can realize quasi-zero stiffness at the equilibrium position and non-linear stiffness near the equilibrium position, which can solve the problem of the traditional linear vibration isolation system. Difficulties in isolating low-frequency or ultra-low-frequency vibrations; stiffness can be easily adjusted, suitable for wide-frequency vibration isolation, and has good engineering applicability; while having high support stiffness, it also has very low motion stiffness and small static deformation , the dynamic natural frequency is low, and the vibration isolation effect is good; through the flexible adjustment of stiffness and damping, it can solve the inherent contradiction that restricts the traditional vibration isolation system, that is, the contradiction between low-frequency vibration transmission rate and high-frequency vibration attenuation rate. The multi-dimensional adjustable zero-stiffness vibration isolation platform proposed by the utility model is a new type of vibration reduction and vibration isolation platform, which has good economy and practicability, and can be extended to various fields.

Specifically, as shown in Figure 1, one end of the shock absorber is rotatably connected to the moving platform 4, and the other end is rotatably connected to the adjustment device 3. perpendicular to each other. The center line of the shock absorber is perpendicular to the axis of the rotating connection points at both ends of the shock absorber. The adjustment device 3 is used to adjust the initial angle between the center line of the shock absorber and the horizontal plane, that is, to change the initial position of the shock absorber , thereby changing the initial preload of the damping spring on the shock absorber.

As shown in Fig. 1, Fig. 4 and Fig. 5, the static platform 21 of the base 1 is arranged opposite to the moving platform 4, and the supporting device is movably arranged on the static platform 21, and the position of the supporting device on the static platform 21 can be adjusted. The adjustment device 3 is movably arranged on the support device, the position of the adjustment device 3 on the support device can be adjusted, and the movement direction of the support device when moving on the static platform 21 is the same as the movement of the adjustment device 3 when it moves on the support device. direction perpendicular to each other. The static platform 21 is a disc-shaped member, and a plurality of support devices are arranged on the static platform 21 along the circumferential direction with the axis of the static platform 21 as the center line. The support device includes a support plate 22 arranged on the static platform 21 and connected with the adjustment device 3 and a sliding member 26 which is slidingly connected with the static platform 21 and connected with the support plate 22. The support plate 22 is vertically arranged on the top surface of the static platform 21 Above, the length direction of the support plate 22 is parallel to the axis of the static platform 21, and correspondingly on the top surface of the static platform 21 there is a third chute 25 extending radially, and the end of the slider 26 is embedded in the third chute 25, realize the sliding connection with static platform 21.

As shown in FIG. 4 and FIG. 5 , the third chute 25 is a T-shaped chute arranged on the static platform 21 with a T-shaped cross section. The length direction of the third chute 25 is perpendicular to the axis of the static platform 21 . The sliding part 26 is preferably a bolt, and the axis of the sliding part 26 is parallel to the axis of the static platform 21. The hexagonal head of the sliding part 26 is embedded in the third chute 25, and the screw part stretches out from the third chute 25 and A first nut 27 for fastening the support plate 22 is provided on the sliding member 26 through the through hole provided on the support plate 22 . The third chute 25 forms an opening on the surface in contact with the support plate 22 on the static platform 21 to allow the slider 26 to stretch out. The angular head is always embedded in the third chute 25, and the slider 26 can only move radially relative to the static platform 21, so that the supporting device can move radially on the static platform 21 for position adjustment. By tightening the first The nuts 27 , the fasteners formed by the first nuts 27 and bolts fix the support plate 22 on the static platform 21 .

As shown in Figures 4 and 5, the end of the support plate 22 has a mounting plate that is parallel to and in contact with the static platform 21. This mounting plate is a rectangular flat plate. Specifically, the support plate 22 is connected to the static platform 21 through a plurality of fasteners composed of the first nut 27 and the slider 26, and at least two fasteners are provided. Correspondingly, on the static platform 21, two parallel third chutes 25 are respectively set at the positions corresponding to each supporting device, and the third chutes 25 are set in pairs and on the static platform 21 with the axis of the static platform 21 as the center line. Multiple groups are evenly arranged along the circumferential direction, and at least one sliding member 26 is respectively installed in the two third slide grooves 25 of each group.

In this embodiment, as shown in Figures 4 and 5, each support plate 22 is connected to the static platform 21 through four fasteners composed of first nuts 27 and sliders 26, and the four fasteners are rectangular. distribution, and two sliding pieces 26 are respectively installed in the two third sliding slots 25 of each group.

As shown in Figure 1, the adjustment device 3, the shock absorber and the support plate 22 are evenly distributed in the circumferential direction around the moving platform 4, and the number of the adjustment device 3, the shock absorber and the support plate 22 is equal, and each support plate 22 is connected to the shock absorber via an adjusting device 3 . Among the two adjacent adjustment devices 3, the distance between one adjustment device 3 and the static platform 21 is greater than the distance between the other adjustment device 3 and the static platform 21; among the three continuous adjustment devices 3 in the circumferential direction , the distance between the adjusting device 3 located in the middle and the static platform 21 is smaller than the distance between the adjusting device 3 located on both sides and the static platform 21 . In the state shown in FIG. 1 , the adjusting device 3 , the shock absorber and the support plate 22 are evenly distributed around the moving platform 4 with the axis of the moving platform 4 as the centerline. In this embodiment, as shown in FIG. 1 , there are six adjusting devices 3 , shock absorbers and supporting plates 22 respectively.

As shown in Figures 1 and 3, one end of the shock absorber is rotatably connected to the moving platform 4 through a pin shaft, and the other end is rotatably connected to the adjustment device 3 through a pin shaft. As shown in Figure 2, the moving platform 4 includes a bearing plate 41 and a mounting base 42 which is arranged on the bearing plate 41 and is rotatably connected with the shock absorber. The mounting base 42 is connected with the bearing plate 41 through fasteners, and the bearing plate 41 has a The fourth chute 43 through which the fastener passes, the length direction of the fourth chute 43 is parallel to the axis of the moving platform 4 . The position of the mounting base 42 on the bearing plate 41 is adjustable, the mounting base 42 is movably arranged on the bearing plate 41 , and the moving direction of the mounting base 42 when moving on the bearing plate 41 is parallel to the axis of the moving platform 4 . A plurality of mounting seats 42 are evenly distributed on the bearing plate 41 along the circumferential direction with the axis of the moving platform 4 as the center line, and each mounting seat 42 is respectively connected to a shock absorber in rotation.

As shown in FIG. 2 , the fourth chute 43 is a T-shaped chute disposed on the bearing plate 41 and has a T-shaped cross section. The length direction of the fourth chute 43 is parallel to the axis of the moving platform 4 . The fastener used to connect the mounting base 42 and the bearing plate 41 is composed of a bolt 44 and a third nut 45, the axis of the bolt 44 is perpendicular to the axis of the moving platform 4, and the hexagonal head of the bolt 44 is embedded in the fourth chute 43 , the screw part of the bolt 44 protrudes from the fourth chute 43 and passes through the through hole provided on the mounting base 42 , and the bolt 44 is provided with a third nut 45 for fastening the mounting base 42 . The fourth chute 43 forms an opening that allows the bolt 44 to protrude on the surface of the carrier plate 41 that is in contact with the mounting seat 42. The size of the hexagonal head of the bolt 44 is greater than the size of the opening, so that the hexagonal head of the bolt 44 Always embedded in the fourth chute 43, the bolt 44 can only move along the length direction of the fourth chute 43 relative to the bearing plate 41, so that the mounting seat 42 can be parallel to the axis of the moving platform 4 on the bearing plate 41. The direction of the mounting seat 42 is fixed on the bearing plate 41 by tightening the third nut 45 until it moves, and the fastener composed of the third nut 45 and the bolt 44 is fixed.

As shown in Figure 2, the end of the mounting base 42 has a mounting plate in contact with the surface of the bearing plate 41, the mounting plate is a rectangular flat plate, in order to improve the stability of the mounting base 42 when moving and the reliability after fixing, The mounting seat 42 is connected to the bearing plate 41 through a plurality of fasteners composed of third nuts 45 and bolts 44 , and at least two fasteners are provided. Correspondingly, two parallel fourth slide grooves 43 are respectively arranged at the positions where each mounting seat 42 is installed on the bearing plate 41, and the fourth slide grooves 43 are arranged in pairs in groups of two on the bearing plate 41 with the axis of the moving platform 4 as the centerline. There are multiple sets evenly arranged along the circumferential direction, and at least one bolt 44 is respectively installed in the two fourth sliding grooves 43 of each set.

In this embodiment, as shown in FIG. 2 , each mounting seat 42 is connected to the bearing plate 41 through two fasteners composed of third nuts 45 and bolts 44, and the two fasteners are in contact with the moving platform 4. The axes are perpendicular to each other on the same straight line, and a bolt 44 is respectively installed in the two fourth sliding grooves 43 of each group.

In this embodiment, since there are six shock absorbers, six corresponding mounting seats 42 are also provided. As shown in FIG. 4, two fourth slide grooves 43 are provided on the six sides of the bearing plate 41, and the six mounting seats 42 are connected with the bearing plate 41 by fasteners and are uniformly distributed around the bearing plate 41 in the circumferential direction.

As shown in Figures 1 and 4, the adjustment device 3 includes an adjustment seat 31 that is rotatably connected to the shock absorber and connected to the support plate 22 through a fastener. The support plate 22 has a chute for the fastener to pass through, and the chute The length direction of the adjustment seat 31 is parallel to the moving direction. An adjustment seat 31 is respectively arranged on each support plate 22, and the adjustment seat 31 is movably arranged on the support plate 22. The position of the adjustment seat 31 on the support plate 22 is adjustable, and when the adjustment seat 31 moves on the support plate 22 The direction of movement is parallel to the axis of the static platform 21. Since the two adjacent adjustment seats 31 are arranged in a manner of one far and one near relative to the static platform 21, each support plate 22 has a first chute 23 and a second chute 24 located on the same straight line, and the second chute 24 is located on the same straight line. Chute 24 is positioned between the first chute 23 and the static platform 21, the distance between the first chute 23 and the static platform 21 is greater than the distance between the second chute 24 and the static platform 21, far away from the static platform 21 The adjustment seat 31 is connected with the support plate 22 at the position of the first chute 23 by a fastener, and the adjustment seat 31 close to the static platform 21 is connected with the support plate at the position of the second chute 24 by the fastener. 22 connections.

As shown in Figures 1 and 4, the first chute 23 and the second chute 24 are long grooves extending along the length direction of the support plate 22, and the first chute 23 and the second chute 24 are parallel to the support plate 22. The thickness direction of the center is set through, and the fasteners used to connect the adjustment seat 31 and the support plate 22 are composed of bolts 32 and second nuts 33. The axis of the bolt 32 is perpendicular to the axis of the static platform 21, and is perpendicular to the axis of the bolt 44. In parallel, the size of the hexagonal head of the bolt 32 is larger than the width of the first sliding groove 23 and the second sliding groove 24 . For the adjusting seat 31 connected to the support plate 22 at the first chute 23 by a fastener, the hexagonal head of the bolt 32 is located outside the first chute 23, and the adjusting seat 31 is located inside the first chute 23, The screw part of the bolt 32 is embedded in the first chute 23 and protrudes from the first chute 23 and passes through the through hole provided on the adjustment seat 31. The bolt 32 is sleeved with the first chute for fastening the adjustment seat 31 Two nuts 33, the bolt 32 can move along the length direction of the first chute 23 relative to the support plate 22, so that the adjustment seat 31 can move on the support plate 22 along the direction parallel to the axis of the static platform 21 until the position is adjusted. Adjustment, by tightening the second nut 33 , the fastener formed by the second nut 33 and the bolt 32 fixes the adjustment seat 31 on the support plate 22 . For the adjusting seat 31 connected to the support plate 22 at the second chute 24 by a fastener, the hexagonal head of the bolt 32 is located outside the second chute 24, and the adjusting seat 31 is located inside the second chute 24, The screw part of the bolt 32 is embedded in the second chute 24 and protrudes from the second chute 24 and passes through the through hole provided on the adjustment seat 31. Two nuts 33, bolts 32 can move along the length direction of the second chute 24 relative to the support plate 22, so that the adjustment seat 31 can move on the support plate 22 along the direction parallel to the axis of the static platform 21 until the position is adjusted. Adjustment, by tightening the second nut 33 , the fastener formed by the second nut 33 and the bolt 32 fixes the adjustment seat 31 on the support plate 22 . Each support plate 22 has the same structure, and is provided with a first chute 23 and a second chute 24 at the same time, which has good versatility, but each adjustment device 3 can only be installed at the first chute 23 on the corresponding support plate 22 Or the second chute 24 places. Among the three consecutive adjustment devices 3 in the circumferential direction, the adjustment seat 31 of the adjustment device 3 in the middle is connected with the support plate 22 at the second sliding groove 24 on the support plate 22 through fasteners, and the two on both sides The adjustment seat 31 of the adjustment device 3 is connected to the support plate 22 at the first slide groove 23 on the support plate 22 through fasteners.

As shown in Figure 4, the end of the adjustment seat 31 has a mounting plate in contact with the surface of the support plate 22, the mounting plate is a rectangular flat plate, in order to improve the stability of the adjustment seat 31 when moving and the reliability after fixing, The adjustment seat 31 is connected to the support plate 22 through a plurality of fasteners composed of second nuts 33 and bolts 32 , and at least two fasteners are provided. Correspondingly, at least two parallel first sliding grooves 23 and two parallel second sliding grooves 24 are provided on the support plate 22, and at least one bolt 32 is installed in each first sliding groove 23 and second sliding groove 24 respectively. .

In this embodiment, as shown in FIG. 4 , each adjustment seat 31 is connected to the support plate 22 through two fasteners composed of second nuts 33 and bolts 32 , and the two fasteners are in contact with the static platform 21 . On the same straight line where the axes are perpendicular, two parallel first slide grooves 23 and two parallel second slide grooves 24 are arranged on the support plate 22, and the first slide grooves 23 and the second slide grooves 24 respectively Install one bolt 32 .

The main advantages of the connection between the adjusting device 3, the base 1, the moving platform 4 and the components of the above structure are as follows: 1) It is convenient to adjust and disassemble the whole vibration isolation platform, and the adjustment can make the size of the platform vibration isolation object, The weight range is expanded, and the flexible disassembly can make the platform easy to move and transport; 2) The structural design of the whole platform can easily produce a series of products, which is convenient for the modularized and serialized production of the platform.

The following describes in detail how to achieve the quasi-zero stiffness of the vibration isolation platform. The specific steps are:

Step 1: First calculate the deformation of the damping spring when the moving platform 4 is subjected to an external excitation force and reaches the static equilibrium position.

Step 2: According to the deformation of the damping spring when the placed object reaches the static equilibrium position, adjust the pre-compression amount of the shock absorber connected to the adjustment device 3 at the first chute 23 of the support plate 22 to make the vibration damping The preload of the damper is directed along the shock absorber towards the lower end cap of the spring. The damping spring on the shock absorber will produce positive stiffness when the moving platform 4 moves downward.

Step 3: Adjust the deformation of the damping spring of the shock absorber connected to the adjusting device 3 arranged at the second chute 24 of the support plate 22, thereby adjusting the pre-compression amount of the shock absorber to make the pre-compression of the shock absorber The tightening force is directed down the shock absorber. When the moving platform 4 moves downwards, the damping spring on the shock absorber will produce negative stiffness.

The positive stiffness produced by the shock absorber connected to the adjustment device 3 at the first chute 23 of the support plate 22 and the positive stiffness generated by the shock absorber connected with the adjustment device 3 at the second chute 24 of the support plate 22 Adding the negative stiffnesses in numerical values can realize the total stiffness of the entire vibration damping system to be zero, thereby realizing a quasi-zero stiffness vibration isolation platform.

The utility model has been exemplarily described above in conjunction with the accompanying drawings. Apparently, the specific implementation of the present invention is not limited by the above methods. As long as the various insubstantial improvements made by adopting the method concept and technical solution of the present utility model; within the scope of protection.

Claims (10)

1. multidimensional can be harmonized zero stiffness vibration-isolating platform, it is characterised in that including:

Moving platform；

Vibroshock, it is connected with moving platform；

Adjusting means, it is connected with vibroshock, and is used for regulating the initial position of vibroshock；And

Base, it include with moving platform be the silent flatform being oppositely arranged and be arranged on silent flatform and be connected with adjusting means Support arrangement.

Multidimensional the most according to claim 1 can be harmonized zero stiffness vibration-isolating platform, it is characterised in that described vibroshock one end with Described moving platform is rotationally connected, and the other end is rotationally connected with described adjusting means.

Multidimensional the most according to claim 1 can be harmonized zero stiffness vibration-isolating platform, it is characterised in that described support means is can Being arranged on described silent flatform of movement, described adjusting means is for be movably arranged in support means, and support means exists Moving direction when moving direction when moving on silent flatform moves in support means with adjusting means is perpendicular.

Multidimensional the most according to claim 1 can be harmonized zero stiffness vibration-isolating platform, it is characterised in that described adjusting means is in institute The circumferentially about distribution stating moving platform is multiple, and each adjusting means is connected with moving platform by described vibroshock respectively, and In two adjacent adjusting meanss, the distance between one of them adjusting means and described silent flatform is more than another adjusting means And the distance between silent flatform.

Multidimensional the most according to claim 4 can be harmonized zero stiffness vibration-isolating platform, it is characterised in that described vibroshock and described Adjusting means line centered by the axis of described moving platform is evenly distributed around moving platform.

6. can harmonize zero stiffness vibration-isolating platform according to the arbitrary described multidimensional of claim 1 to 5, it is characterised in that described support Device include the gripper shoe being arranged on described silent flatform and being connected with described adjusting means and with silent flatform for being slidably connected and The sliding part being connected with gripper shoe.

Multidimensional the most according to claim 6 can be harmonized zero stiffness vibration-isolating platform, it is characterised in that described gripper shoe is with described Centered by the axis of silent flatform, line is uniformly distributed circumferentially multiple on silent flatform.

Multidimensional the most according to claim 6 can be harmonized zero stiffness vibration-isolating platform, it is characterised in that described sliding part is for embedding The bolt in chute set on described silent flatform, described gripper shoe has the hole allowing bolt pass, and bolt is provided with for tightly Gu the nut of described gripper shoe.

Multidimensional the most according to claim 6 can be harmonized zero stiffness vibration-isolating platform, it is characterised in that described adjusting means includes The adjustment seat being rotationally connected with described vibroshock and be connected with described gripper shoe by securing member, gripper shoe has allows securing member wear The chute crossed, the length direction of chute is paralleled with the moving direction of adjustment seat.

Multidimensional the most according to claim 9 can be harmonized zero stiffness vibration-isolating platform, it is characterised in that described gripper shoe has The first chute being located along the same line and the second chute, the second chute is between the first chute and described silent flatform.