RU2611691C1 - Active antivibration platform based on magnetorheological elastomers - Google Patents

Abstract

FIELD: mechanical engineering.

SUBSTANCE: active vibration isolating platform contains at least three active dampers, which comprise a solenoid, core, the membrane made of a magnetorheological elastomer. The core is placed inside the solenoid and is associated with the base. The membrane is fixed on the perimeter of the housing. The movable rigid center is located in the central part of the membrane and is mounted with clearance relative to the core. At least three active suspension assemblies are disposed in parallel active dampers between fixed and movable plates. Active suspension junctions contain massive correctors, hinges "shaft-hub" or elastic joints in the form of a flat spring, pendulums carrying the coil springs with adjustable preliminary tension, flat springs and conical poles for hanging object.

EFFECT: adjustment and stabilization of the position and acceleration of the object, increasing the load capacity to enable automatic object positioning mode with high precision movements with the minimal time transient increase in the number of degrees of mobility.

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Description

Technical field

The invention relates to precision engineering, and in particular, to an active vibration-isolating system, which can be used in technological and research equipment: in scanning probe and optical microscopes, in ion, electronic, X-ray and optical lithography installations, in coordinate measuring machines, in laser systems, equipment for machining, etc.

State of the art

Known controlled support containing a solenoid with a core inside, located between the base and the supporting part. A solenoid covers an elastic element of magnetorheological (MP) material. The elastic element is in contact with the surfaces of the base and the supporting part. An additional elastic element of MP material is installed in conjunction with the supporting part and is in contact with the surface of the core. In this case, the base, the supporting part and the core of the solenoid are made of magnetic material. An increase in the load capacity and speed of the steered support is achieved (RF Patent No. 2404380, IPC F16F 9/53 (2006.01), F16F 15/03 (2006.01), 09/30/2009). An electric current of a certain magnitude is supplied to the solenoid, as a result of which a closed magnetic field arises in the magnetic circuit, consisting of a core, a support part, a main elastic element, a support part and an additional elastic element. In this case, mainly an axial magnetic field is formed in the main elastic element. The magnetic particles of the elastic element enclosed in the elastic matrix are oriented along the lines of the magnetic field, are displaced in the direction of greatest induction, changing the geometric dimensions of the elastic element, its elastic modulus and viscosity, as a result of which the supporting part moves along the vertical axis. By adjusting the magnitude of the electric current, which provides an automatic system, there is an effective damping of oscillations from external disturbances.

A disadvantage of the known device is the small range of displacements in the active mode of the primary and secondary elastic elements of MP material. This is due to the fact that the magnetic force from the side of the solenoid must overcome the large elastic forces arising from the deformation of the main and additional elastic elements, which are proportional to their elastic modulus and large cross-sectional area.

Known magnetic damper (RF Patent 2244178, IPC F16F 6/00, effective date: 02/28/2003 Magnetic damper) containing a base, suspensions containing vibration dampers, as well as magnets mounted in a closed line, and a conductive vibration damper installed with the ability to interact with streams formed by magnets. This damper is two-stage. Suspension of the protected object, located on a moving base, is carried out on racks due to elastic vibration dampers with tensile elements, they represent the first stage of its vibration isolation. Vibration isolation is also carried out due to the magnetic coupling of pairs of magnets fixed to the base with brackets and conductive plates fixed to the movable base.

The disadvantage of this magnetic damper is its ability to damp vibrations only in passive and semi-active modes. The specified device is not able to serve as a source of movement.

A spring-pendulum vibration protection system with a mass corrector is also known, comprising a horizontal pendulum, a supporting spring hanging a pendulum and a mass corrector made in the form of a load on the lever, the axis of which passes through the swing axis of the pendulum. Effective damping of high-frequency oscillations is achieved (Vibroprotective systems with quasi-zero stiffness) / P.M. Alabuzhev, A.A. Gritchin, L.I. Kim and others; Edited by K.M. Ragulskis. - L .: Engineering, Leningrad. Department, 1986.- 96 p.). The tension of the carrier spring is adjusted so as to hang the mass of the pendulum. Effective damping of high-frequency oscillations is achieved by providing a low intrinsic resonant frequency, which is controlled by a mass corrector by moving the load along the lever.

A disadvantage of the known device is the impossibility of damping oscillations at low frequencies close to the natural resonant frequency.

Known closest to the claimed device is an active support containing a housing in the cavity of which a solenoid is located. Inside the solenoid, a core is mated to the base. A membrane of elastic MP material is fixed around the perimeter on the body. The inner surface of the membrane is located with a gap relative to the core. The body, base and core are made of magnetic material. Achieving increased load capacity and speed of the support, as well as the ability to move the object in a given direction with an increased range of values (RF Patent No. 2404381, IPC F16F 9/53 (2006.01), F16F 15/03 (2006.01), 09/30/2009). An electric current is supplied to the solenoid, under the influence of which a closed magnetic field arises in the magnetic circuit. A radial magnetic field with induction is formed in the membrane, the value of which has a maximum near the core. Under the influence of this magnetic induction, the membrane moves axially within the gap. By regulating the magnitude of the electric current, there is an effective damping of oscillations from external disturbing influences.

A disadvantage of the known device is the insufficient loading capacity of the membrane of an elastic magnetorheological material due to the presence of an axial clearance within which the membrane moves.

Disclosure of invention

The technical result provided by the present invention is to solve the problem of active vibration isolation and damping, adjusting and stabilizing the position and accelerating the object, increasing the load capacity with the possibility of automatic positioning of the object with increased accuracy of movements with a minimum transition time, with an active vibration-isolating platform based on MP elastomers processes, increasing the number of degrees of mobility (two angular movements are added to the axial displacement tions, which is especially important for multi-axis vibration isolation).

The achievement of the technical result is ensured by the fact that the active vibration-isolating platform includes active dampers containing a solenoid, a core located inside the solenoid and paired with a base, an MP elastomer membrane fixed along the perimeter on the body, and a movable rigid center located in the central part of the membrane, installed with a clearance relative to the core. In this case, between the movable and the fixed plates of the platform, three or more active dampers are installed in parallel, evenly spaced around the perimeter of the platform, in order to increase its carrying capacity and ensure the stability of the object. Moreover, parallel to the active dampers between the movable and fixed plates can be located three or more nodes of the elastic suspension, containing mass correctors, hinges "shaft-sleeve", pendulums bearing coil springs with the ability to adjust their pre-tension, flat springs and conical supports for hanging an object .

Moreover, instead of the “shaft-sleeve” hinge, an elastic hinge in the form of a flat spring can be installed in the elastic suspension assembly.

An active vibration-isolating platform contains at least three active dampers and three nodes of elastic suspension, one for each damper, with a mass corrector, evenly spaced around the perimeter of the platform. The active damper contains an electromagnetic system and a membrane of MP elastomer with a rigid center, forming a working air gap in the electromagnetic system. The damper works as follows: when a control current is supplied to the electromagnetic coil in the electromagnetic system, a closed magnetic field arises. A radial magnetic field with induction is formed in the membrane, the value of which has a maximum near the rigid center. Under the influence of this magnetic induction, a rigid-center membrane moves axially within the air gap.

In a preferred embodiment, all active dampers comprise a membrane with a rigid center of magnetic material.

The elastic suspension units allow you to adjust the platform for active vibration isolation to the desired mass of the object using an adjustable carrier spring and the required resonant frequency using a mass corrector. The elastic suspension assembly of the vibration-isolating platform is a horizontal pendulum with an adjustable bearing spring and a mass corrector. The mass of the pendulum is the equivalent of 1 / n of the mass of the vibration-insulated object, where n is the number of suspensions.

In the best embodiment, the nodes of the elastic suspension of the platform contain instead of hinges "shaft-sleeve" elastic hinges in the form of thin-walled plates.

List of drawings

The possibility of carrying out the invention is illustrated by examples of specific performance of the active vibration-isolating platform.

In FIG. 1 shows a diagram of an active anti-vibration platform based on MP elastomer.

In FIG. 2 shows a diagram of an active damper.

In FIG. 3 shows a diagram of an elastic suspension assembly with a mass corrector.

In FIG. 4 shows a diagram of an elastic suspension assembly in the form of an elastic hinge.

The implementation of the invention

The active vibration-isolating platform based on the MP elastomer (Fig. 1) contains a movable plate (1), a fixed plate (2) with four active dampers based on the MP elastomer (4) located between them and four nodes of the elastic suspension based on a system with quasi-zero stiffness ( 3).

The active damper (Fig. 2) contains a membrane of MP elastomer (5), an electromagnetic coil (6), a magnetic casing (7), a core (8), a casing (9), a magnetic flange (10), a movable rigid center ( eleven).

The membrane of the MP elastomer (5) at the periphery is fixed using a casing (9) at the end of the casing-magnetic circuit (7), which in turn is fixed on the flange-magnetic circuit (10). The core (8), on which the solenoid (6) is placed, is also fixed on the magnetic flange (10). A movable rigid center (11) is fixed in the central part of the membrane of MP elastomer (5).

Each elastic suspension assembly (Fig. 3) contains a mass corrector (12), a shaft-sleeve hinge (13), a pendulum (14), an arch support (15) of a bearing coil spring (16), a pendulum travel limiter (17), a flat spring (18), a conical support (19) and a coil spring adjustment system (20).

The hinge of the elastic suspension assembly can be made in the form of an elastic hinge (Fig. 4), which can be played by a flat spring (21)

An object whose position must be stabilized, providing vibration isolation from external disturbing influences, is mounted on a movable plate (1), and a fixed plate (2) is mounted on the base.

An electric current of a certain value, depending on the characteristics of the coil, is supplied to the electromagnetic coil (6) of each damper (4), as a result of which in the magnetic circuit, into which the core (8) enters, the magnetic flange (10), the magnetic casing (7), the membrane from the MP elastomer (5), the moving rigid center (11), a closed magnetic field arises. At the same time, the membrane (5) with a movable rigid center (11) is attracted to the core (8), while changing the stiffness due to the magnetic field acting on the MP elastomer (5).

The elastic suspension unit (3) is designed to increase the load capacity and adjust the low resonant frequency of the active vibration-isolating platform based on the MP elastomer. The movable platform (1) with the object is located on conical supports (19), which, using flat springs (18) transmit the force from the mass of the object to the pendulum (14), which makes oscillating movements in the shaft-sleeve joint (13), which is fixed on a fixed plate (2), in addition, the pendulum (14) is suspended in an arch support (15) on a bearing coil spring (16) (see view B). By adjusting the tension of the carrier spring (16) using the adjustment system (20), it is possible to adjust the elastic suspension unit to vibration isolation of an object of a certain mass. Due to the selection of the weight and distance of the mass corrector (12) to the hinge (13), the elastic suspension unit is tuned to the required resonant frequency.

The elastic suspension unit can be made in various designs. The elastic suspension assembly (Fig. 4) contains the same elements: a mass corrector, a pendulum, an arched support for a coil spring, a flat spring, a conical support and a system for adjusting a coil spring. This suspension unit contains, instead of the usual “shaft-sleeve” hinge, an elastic hinge made structurally in the form of a flat spring (21). This eliminates the backlash and sliding friction forces, which increases the accuracy and smoothness of movement of the suspension unit. In addition, the design may not have a limiter for the movement of the pendulum.

The adjustment system of the bearing coil spring (20) can be made constructively in the form of a threaded rod fixed from rotation in the arch support (15) using two flats made on it (section B-B). On the rod, on one side, a supporting coil spring (16) is fixed, and on the other hand there are two nuts designed to adjust the pre-tension of the supporting coil spring (16).

Claims (1)

An active vibration-isolating platform, including active dampers containing a solenoid, a core located inside the solenoid and paired with a base, a magnetorheological (MP) elastomer membrane fixed along the perimeter on the housing, and a movable rigid center located in the central part of the MP elastomer membrane installed with a gap relative to the core, characterized in that between the movable and fixed plates of the platform are parallel installed from three or more active dampers, evenly spaced along platform diameter; parallel to the active dampers between the movable and fixed plates are three or more nodes of the elastic suspension, containing mass correctors, shaft-sleeve hinges or elastic hinges in the form of a flat spring, pendulums bearing coil springs with the possibility of adjusting their pre-tension, flat springs and conical supports for hanging the object.

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