LT5883B - Mechanical quasizero stiffness vibro insulating system - Google Patents

Abstract

The invention relates to vibro insulating structural systems, especially various vibro insulating clamps with a small stiff and strong system resonance damping effects. The invention is based on the fact that in tightened elastic system consisting of horizontal and vertical interacting springs, reinserting to original position, dependence of force from displacement caused by external effects is sinusoidal. Presented mechanical quasizero stiffness vibration insulating system consists of a vertical and horizontal tightened spring, keeping the adjusting by lever deformations which inclination in the vertical and the horizontal plane is close to 0 °.

Description

1. Technical field to which the invention relates

The present invention is an improvement of a mechanical vibration damping structural system, wherein the displacements or deflections caused by the variable direction loads applied to this system or only part thereof exhibit elastic instability, which is determined during system preparation by applying the elastic structure corresponding to the required loads.

BACKGROUND OF THE INVENTION The present invention relates to the field of vibration isolation structural systems, where the transmission of vibrations from the substrate to the substrate is isolated and reduced, in particular compact, versatile vibration isolation hangers with low .

2. State of the art

We experience unwanted vibrations in many technological processes as well as in the environment. There are many known technical solutions for reducing and reducing the transmission of vibrations from one machine part to another. They are collectively referred to as vibration dampers or suspension mechanisms such as various shock absorbers, cushions, various mechanical springs, pneumatic and hydraulic devices, and various combinations thereof. Many of the known special vibration isolation systems are characterized by the fact that by reducing the low system vibration resonances they do not sufficiently ensure this at higher vibration frequencies.

Such a disadvantage of the mechanical vibration isolation system is described in International Patent Application PCT / US / 90/04608, published as WO91 / 02921, Schwingungsisoliations system. The mechanical vibration isolation system provided therein is adapted to damping vibrations where small instability prevails in the axial direction, which is generally the load direction of the object placement platform, i.e.. y. vertical direction. This is true for any other transverse direction, which is generally a horizontal direction. The described vibration isolation system uses a combination of insulators (dampers) in which axially arranged insulators (dampers) are interconnected so that they are ready to suppress omnidirectional vibrations. Each damper shall be so arranged and arranged that it will dampen displacements caused by either the axial or transverse components of the oscillation in any direction. By acting together, they (dampers) provide damping in all directions. In this description, axial dampers are called vertical, transverse bars are horizontal, and the concept itself is innovative. This can be accepted because, after reviewing the previous analogs, such quality vibration isolation systems could not be detected, and subsequent inventions confirm the efficiency of the use of the concept and its practical significance.

At the same time, it should be noted that their theoretical basis was first published by Professor P.M. Alabuzhev in 1967. What in practice, e.g. Professor P.M. Alabazev called the vibration isolation system described in International Application WO94 / 13999 a "quasi-zero rigidity" for the use of resilient systems for the vibration isolation of dynamic objects. This is based on the later works of Russian scholars, e.g. A. N. Zotov Bn6poH3OJunOpi> i c KBa3HHyjieBož HcecTKOCTbio (He (In) Tera3OBoe ^ ejio 2005. http://www.ogbus.ru). The concept of quasi-rigid stiffness is based on the fact that in a tightened elastic system, the displacement force returning to its original position is sinusoidal and, for a small segment, linear, while the size of the segment itself depends on the angles of tensioning and returning elastic elements. By choosing the appropriate mass, this vibration-free mass, which is static, can be supported by springs with a quasi-zero stiffness.

The circular vibration isolation suspension system described in International Application WO94 / 13999 includes a plurality of mixed (co-operative) vibration isolators for spring-loaded support and isolation of an object on a work platform. Each mixed insulator consists of a vertical displacement insulator, which is dynamically linked to a horizontal displacement insulator, while the vertical motion damper has a support spring which is concentric to the bushing and through it is connected to the base platform. One end of the support spring unit serves for the positive axial stiffness and load removal of the machine by the work platform, and there is provided a suspension insulator that removes the work platform load and provides a negative axial stiffness. The support spring assembly, when operated with said suspension insulator, generally results in a low vertical stiffness of the system.

The negative stiffening mechanism mounted inside the bushing works in contrast to the positive stiffening mechanism. The horizontal displacement damper consists of three flexible rods which are connected to the vertical displacement insulator.

The closest technical solution to the present invention is described in U.S. Pat. No. 5,833,204. The vibration-inducing vertical and horizontal components of an object placed on a work platform are damped by a system of mixed (co-acting) vibration isolators.

The vertical displacement damper consists of a positive rigid mechanism in the form of a support spring located in the center of the device, one end of which is connected to the support surface of the center rod, and the other end acts on a lever system of intricately spaced which deform each other during displacement and have the ability not only to counteract the axial force of the spring, but also to reduce the radial oscillation of the object, which binds the outer body of the device to the work platform and rigidly moved horizontally. Radial object deflections (tilts?) Are thus blocked by a force displacement corresponding to the deflection of the levers, which reduces both the vertical and the horizontal components of the force. The main disadvantage of the described system is that in order to balance the resulting forces, each of the leverage forces must have a large shoulder and the angle of inclination of the vertically inclined rods is small. In addition, adjusting the deformation of the levers required for performance is difficult and time-consuming. In conclusion, the sequences conclude that the radial deviations of the object are reduced in proportion to the magnitude of the longitudinal deviation. Since the object of the present invention is the reduction of radial misalignments, it is determined that an accurate mass centering of the object is required. This is a major disadvantage of the present invention.

3. The essence and novelty of the invention

The invention is based on the fact that, in a tensioned elastic system, the force returning to its original position from the displacement is sinusoidal. As is known, sin0 ° = 0. In the present mechanical vibration isolation system, clamped by vertical and horizontal springs, the clamping force is maintained by means of a system of vertical and horizontal levers, and the forces returning to their initial position consist of close to 0 ° vertical and horizontal inclination deflections. This provides a quasi-zero system rigidity in a very small range of displacements. Of course, this range of displacements also applies to the mass of the object, which is to be calculated separately for the different masses by the support springs acting on the object's pallet. The vertical rigid levers for balancing the forces are four and spaced equally from the center axis of the rod. This allows you to place an object on that pallet at a distance from the center rather than just aligning the center of mass with the axis of the center rod. A special pallet suspension reduces the horizontal tilt of the pallet.

4. Description of the drawings

The invention is illustrated by the drawings in FIGS. 1 and FIG. 2.

FIG. 1 shows: 1 - Object Tray; 2 - tilt vibration isolator; 3 - upper support plate; 4 - mounting lock; 5 - tilt shock absorber; 6 - mounting lock; 7 - center rod; 8- upper plate of the damping unit; 9 - Rigid suspension rod; 10 - Nut; 11 - central part of the clamping screw; 12 - horizontal damping system housing; 15 - movable shock absorber housing for clamping screw; 16 threaded screw end; 17 - plate spring mounting plate; 18 movable dampers block flat springs; 19 - Base plate; 20 - lower support stand; 21 - mounting plate for flat springs; 22 - earthworm with support spring mechanism housing; 23 - worm wheel of the spring spring mechanism; 24 - Screw-mounting sleeve with threaded column; 25 - Supporting threaded sleeve; 26 - Central Supporting Spring; 27 - lower damping block plate; 28 - adjustable support leg; 29 horizontal damping unit spring; 30 - clamping screw; 31 - Horizontal spring adjustment nut; 32 - Washer; 33 - horizontal bars of the damping unit; 38 - fixed body of shock absorbers; 39 - Upper Support Stand; 40 - axis; a - Hole for transporting pallet mounting.

FIG. Figure 2 shows: 34 - Horizontal rod mounting nut; 35 - washer; 36 - intermediate; 37 - Hydraulic dampers axle with grooves filled with silicone fluid.

5. Construction and principle of operation

FIG. The construction of the vibration isolation system shown in Figure 1 is based on a base plate 19 on which the support stands, upper 39 and lower 20, are provided with adjustable feet 28. Such support systems can have three or four, depending on the capacity of the particular device. In the center of the base plate 19 is located a mechanism for adjusting the central bearing spring 26, consisting of a wormhole mounting bushing 24 with a threaded column which rotates freely in the hole of the base plate 19. Attached to the bushing 24 is a worm wheel 23 of a central retaining spring mechanism and a central threaded bushing 25 having anti-rotation protection against one another.

A worm wheel 23 is connected to an earthworm 22 mounted in a housing rigidly connected to a base brick 19. The bushing 25 rests on a support spring 26. The spring 26 rests on a damping unit consisting of parts 8, 12 (two pieces) and 13. On the upper plate of the damping unit The four rigid suspension rods 9 are attached by means of 8 nuts 10, to which the lower end plate 10 of the damping unit 27 is fixed by means of the lower end nuts 10. The center rod 7 is rigidly attached to the plate 27 and extends freely through the bore 24 of the bushing. The diameter of the hole ensures a possible tilt of the rod. An upper support plate 3 is rigidly mounted on the upper end of the central rod, which engages with the object tray 1 through the tilt vibration insulator 2 and the two to four tilt dampers 5 attached to the object tray 1 and plate 3 by mounting brackets 4 and 6 respectively. Also, the housing 38 and 14 of the damping unit are mounted. The housing 38 is fixed and rigidly secured to the base plate 19, and the housing 14 is secured to the plate 19 through flat springs 18 secured on one side to the housing 14 and on the other. a housing 21 rigidly connected to a base plate 19. The springs 18 are secured by plates 17. The housing 38 and the movable housing 14 are tightly interconnected by a clamping screw 30, which is fixed by a nut 15 at its threaded end 16 to a movable housing 14. spring 29, through washer 32 secured by a nut 31.

The clamping screw 30 consists of three parts, of which the peripheral parts of the screw 30 are connected by a central part 11. The peripheral parts of the screw 30 pass freely through the part 12 and the central rod 17 is carefully led through the hole of the central screw part 30. the holes a required to secure the pallet to the stands 39 in case of transportation. The fixed housing 38 and the movable housing 14 have horizontal holes for hydraulic dampers having a series of grooves filled with silicone fluid (Fig. 2).

The axles 37 of the hydraulic dampers, with the possibility of free rotation in their holes at the ends, are sealed by the spacers 36 and locked by the washers 35. The damping axle end nuts 34 are rigidly secured to the horizontal damping block rods 33. All of these rods are 8.

The vibration-proof quasi-rigid system works as follows. As the worm wheel 23 is rotated, the bushing 25 extends over the threaded column of the bushing 24 and at the same time compresses the support spring 26 which, together with the load on the object tray 1, is pressed into the optimum damping position. The system is adjusted to the specific load resulting from the weight of the object pallet for a given range of loads, each of which has its own pair of springs 26 and 29 to be calculated. When the pallet 1 is applied, the spring 26 of the damping unit is compressed by an unobstructed size, so that the spring 26 is displaced to an optimum height for rotation. rods 33 close to horizontal position. The tension of the spring 29 is then adjusted, which, through the clamping screw 30, elongates the movable body 14 to the stationary body 38. At a given tensile magnitude of the spring 29, conditions result in the system's quasi-static rigidity range. Horizontal vibration damping is achieved by four rigid bars 9 which support the object tray 1 through the plate 27, the bar 7, the plate 3, and the tilt vibration isolator 2 and the tilt dampers 5, which allow the object to be positioned on the rectangle with respect to the axis, while the system remains operational.

Claims (6)

Definition of the Invention 1. A mechanical quasi-rigid vibration isolation system, consisting of an upper object tray resting on a set of dampers of elastic and horizontal oscillations associated with a resilient structure, centered on a lower base plate centered on a support spring adjusting device adjustable so that this spring provides the vertical stiffness and position required by the load mass of the center rod mounted in the center of the jib, providing the other end with a quasi-linear stiffness in the opposite direction to the first lever in close interaction with the horizontal lever assembly. when the earthworm is mounted rigidly on the base plate and the worm is concentrated concentrically on a support sleeve which freely passes the central strut through its inner hole in particular, they are rotationally protected, resting on one end on the base plate and on the other end on the support spring, while the bearing surface of the center rod is the lower surface of the upper part of the horizontal damping unit connected to the rod. rigidly connected to the underside of the center rod and to the upper, four rigid rods equally spaced from the center and freely passing through the baseplate, which are weighted by the small horizontal sliding capability made possible by the customized design of the damping unit. 2. A mechanical quasi-zero rigid vibration isolation system according to claim 1, characterized in that the upper part of the horizontal damping unit is connected to the base plate through housings, one of which is rigidly fixed to the base plate and the other opposite to the first plate is rigidly attached to said plate. only its lower part, which is only the fixing body of the flat springs connecting it to the upper part, whereas the upper part of the body therefore has low flexibility, which in turn necessitates a small vertical displacement of the upper part of the damping unit. for the rods of the damping unit to have a pair of end portions of their porous ends mounted on one side to the upper parts of said damping bodies and on the other to the upper part of the damping unit, at least one horizontal hydraulic damping and the center clamping screw passes freely through the center of the housing, which through the center plate hole joining its ends freely engages the center rod of the system and is clamped by means of an adjustable spring. 3. A mechanical quasi-rigid vibration isolation system according to claims 1 and 2, characterized in that it has three or four rigidly connected baseplate supports for supporting the weight of the object pallet and a pallet tilt damping suspension closely connected to the upper bearing surface of the center rod. 4. A mechanical quasi-rigid vibration isolation system according to claims 1 and 2, characterized in that the hydraulic dampers are mounted in horizontal holes in the fixed housing of the dampers block associated with the baseplate and having a series of grooves filled with viscous fluid; , in addition, their ends are sealed with gaskets and rigidly fixed in the vicinity of horizontal bars, spaced equally from the axis of the damping unit. 5. A mechanical quasi-rigid vibration isolation system according to claims 1, 2, 3 and 4, characterized in that different support springs are selected for different masses of the object. 6. A mechanical quasi-rigid vibration isolation system according to claims 1, 2 and 3, characterized in that the object substrate is suspended on a limited rigidity bar through the central rod, lower damping block plate and elastic rest of the system structure.