RU2654890C1 - Method of protected object dynamic oscillations damping and device for its implementation - Google Patents

Abstract

FIELD: machine building.

SUBSTANCE: group of inventions refers to machine building. Parallel to the elastic elements the helical non-self-braking mechanisms containing screws with flywheel nuts are additionally introduced into the system. Connecting helical non-self-braking mechanisms to the disks via gear wheels. Adjusting the brake pads clamping to the discs using the control unit and system of the sensors. Adjusting the system parameters to provide the effect of simultaneous oscillations dynamic damping along the motion two coordinates. Device contains two non-self-braking helical mechanisms. Pressing force to the discs is controlled by means of rheostats using a unit for measuring and processing of the signals received from the sensors system. Moment of inertia regulating mechanism is a combination of the helical non-self-braking mechanism flywheel nuts and a gear train.

EFFECT: enabling ensuring the protected object oscillations damping by two coordinates.

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Description

The invention relates to mechanical engineering, in particular to methods and devices for vibration protection and vibration isolation, as well as to suspension models of various vehicles.

Industrial equipment and apparatus are operated in conditions of intense dynamic loading, which creates accompanying vibrational loads on the main components and assemblies of these machines. To reduce or neutralize the effect of vibrations on the operation of the equipment as a whole and its components, in particular, additional elements are introduced into the structure of the mechanism necessary for damping object vibrations or for implementing dynamic damping modes at some stage of its operation. Questions of the theory of the physical phenomenon in the dynamics of mechanical oscillatory systems are considered in detail in the works of domestic and foreign scientists, including in [1-3].

The tasks of vibration protection and vibration isolation are also in demand in the design of suspension systems for cars and other vehicles for various purposes. This allows you to reduce the impact of vibration effects on the nodes and parts of the designed means of transportation and transportation of various goods, as well as to increase comfort.

Despite all the elaboration of this section of the dynamics of machines and equipment, damping of vibrations can be attributed to the number of urgent scientific and technical problems of modern engineering and mechanical engineering, including unresolved issues of accounting for interactions between elements in systems with two or more degrees of freedom.

A number of constructive solutions and theoretical developments are known for creating dynamic vibration dampers, but the question of simultaneous damping of oscillations by several degrees of freedom remains poorly understood.

Technical level

Patent search revealed several inventions devoted to the dynamic damping of vibrations in systems with several degrees of freedom, which have in their structure additional elements, mechanisms and devices for converting motion.

A known method of vibration protection of mobile technological machines [Ustinov Yu.F., Muravyov V.A., Zhulay V.A. and others. The method of vibration protection of mobile technological machines. Patent No. 2310781 C2, IPC F16F 15/02, B60G 17/02, priority November 20, 2007], which consists in connecting the object to be protected from vibration with an excitation source through vibration isolators. Vibration isolators contain interconnected elastic elements of different stiffnesses, between which a rigid connection is established, consisting of bolts, nuts, washers, axles, jumpers and plates. To operate the machine in transport or operating mode, the connection diagram of the elastic elements and the overall reduced stiffness of the vibration isolator are changed by eliminating or restoring the rigid bonds between the elastic elements. EFFECT: reduction of vibration of the cabin (body) of the mobile technological machine during its operation both in the working stationary position (operating mode) and during its movement, i.e. when working in the transport mode.

The disadvantages of this invention is the lack of accounting for movement along the second coordinate of the movement, as well as the simultaneous dynamic damping of oscillations in two coordinates.

Also known is the design of the vibration isolator [Kochetov OS, Stareeva M.O., Stareeva M.M. Cable vibration isolator. Patent No. 2509930 C2, IPC F16F 7/14, F16F 13/00, priority 03/20/2014], containing an elastic element made of segments of a steel cable made in an arcuate shape, which are arranged in a row left and right along the length of the upper and lower base plates, in which, by means of planks, the ends of the segments of the steel cable are fixed, and the vertices of the arcs of the segments of the steel cable are facing the vertical axis of the vibration isolator. The vibration-insulated object is mounted by means of threaded holes, the axes of which are parallel to each other and lie in a vertical plane passing through the vertical axis of the vibration isolator. Along the length of the upper and lower base plates and in the strips, longitudinal grooves are made for pressing in the ends of the cable, or along the length of the upper and lower base plates and in the strips are made threaded holes for securing the ends of the cable with screws 9. The length of the upper and lower base plates along the entire the lengths of the slats are fixed in a row to the left and right of the vertical axis of the vibration isolator hydraulic dampers, which can be installed along the entire length of the slats, and with a certain (constant) or variable pitch, depending on the characteristics of the vibration insulated object.

Each of the hydraulic dampers contains a rod rigidly fixed in the bottom of a cylindrical sleeve coaxial with it with the formation of a sealed annular cavity between the outer surface of the rod and the inner surface of the cylindrical sleeve, the bottom of which is fixed in the sleeve, rigidly connected with the base of the protected object. A spring is located in the annular cavity, which rests with the lower end in the bottom, and the upper - in the piston, made in the form of a disk, and located with a throttling clearance relative to the rod.

In the upper part of the stem there is a cover movable relative to the stem, consisting of an annular flange with a seal relative to the stem and rigidly connected to the sleeve flange, coaxial with the stem and covering the outer surface of the cylindrical sleeve through the seal. Coaxial to the rod is a spring, the upper end of which is supported by the cover, and the lower end by the piston. The support element of the vibration-insulated object is fixed on the lid.

During vibrations of a vibroinsulated object, the arcuate segments of the cable absorb both vertical and horizontal loads, thereby weakening the dynamic effect on the vibroisolated object, i.e. spatial vibration protection and shock protection are provided. Due to friction between the steel cores of the cable, the vibrational energy is dissipated and the transmission of forces to the foundation is reduced.

The vibrations of the vibration-insulated object are transmitted to the rod, while the spring perceives vertical loads, thereby weakening the dynamic effect. It is possible to significantly increase the damping in the system at resonant operating modes due to energy dissipation as the medium passes through the throttling holes in the piston. It is possible to significantly increase the damping in the system at resonant operating modes due to energy dissipation as the medium passes through the throttling gap in the piston.

The invention has several disadvantages, in particular, the lack of control of the dynamic state of the system during operation of the vibration isolator. Accounting for the dynamic damping of oscillations in two coordinates is also not considered.

A device is known [Teploukhov V.V., Dmitriev B.C., Yangulov B.C. Lidar stabilization device in the horizon plane. Patent No. 2335673 C2, IPC F16F 15/08, G12B 5/00, F16F 11/00, priority 10/10/2008], containing lidar, which includes two telescopes: a transmitter and a receiver. The optical elements of the telescopes are mounted on a common housing, which is a frame structure. The body includes (upper and lower) rings, interconnected by jibs.

The lidar is mounted on the upper ring of the housing. The upper ring is fixed through elastic-viscous shock absorbers located along the perimeter of the housing, consisting of parallel-mounted elastic elements 6 and liquid linear dampers, to the brackets. The brackets, in turn, are fixed on the base of the car.

An elastic element and a damper are attached to the upper ring. The elastic element can be made in the form of a cylindrical helical compression spring or a multicore helical compression spring, which has a more gentle characteristic with small dimensions, or can be a spring like an automobile. The other end of the elastic element is attached to the bracket.

In the process of transportation, to avoid damage to the elements of the movable part due to a collision with the body, there are two transport arresters that rigidly fix in space the movable part of the mechanical system (lower ring with brackets).

The damper represents a typical construction of a damping device of a linear type and consists of a cylindrical body mounted on the upper ring; piston mounted on the bracket. The piston can linearly move in the damper body, while the piston is connected to the bracket through an isolation device that allows the piston to make small angular movements in the damper body. The internal cavity of the damper body is filled with a very viscous (e.g. polysiloxane) fluid.

Thus, the lidar is installed through visco-elastic shock absorbers (spring, damper) on the brackets, which in turn are attached to the car. The pendulum movable system has a center of mass (m) below the plane of location of the viscoelastic shock absorbers.

In the operating mode of the lidar, it is subject to vibrational mechanical loads from a working car engine, which serves as a generator of power for systems (navigation, gas analysis, information, television, weather systems) functionally connected with the lidar.

Due to the presence of the pendulum of the mechanical system (lidar - case) at any time, the vertical position of this mechanical system is ensured along the vertical position, and the suspension of the frame of elastic elements and dampers allows damping from external mechanical influences, for example, from the engine idling in the operating mode of the lidar.

Despite the claimed technical result of the effect of damping oscillations, the invention has disadvantages associated with the dynamic damping of oscillations in two degrees of freedom. The system also lacks elements that control the dynamic state.

For the prototype adopted the method [Hoverdovsky V.N., Chang Myung Lee. The method of vibration isolation of a helicopter pilot and suspension of the seat to implement the method. Patent No. 2597042 C1, IPC B64D 11/06, B60N 2/50, priority 09/10/2016], which consists in introducing an additional elastic element with adjustable stiffness parallel to the action of the first elastic element in the suspension. The total rigidity of both elastic elements is minimized over a given interval of amplitudes of relative displacements of the system, determined by the conditions of its safe operation. An additional control signal is generated and activated to control the parameters of the elastic element at a frequency lower than the fundamental frequency of the natural oscillations of the system. The seat suspension comprises a steering mechanism, an elastic element and a device for controlling the parameters of the elastic element. The suspension is equipped with an additional elastic element with adjustable alternating stiffness, installed parallel to the action of the first elastic element. The control device contains two channels, one of which has the ability to activate at a frequency less than the main frequency of the vibrational movement of the system. Achieved is the expansion of the frequency range of vibration isolation with given restrictions on the amplitudes of the relative displacements

The seat suspension for implementing the method comprises a guide mechanism including a base, two pairs of levers arranged in parallel planes symmetrically to the longitudinal axis of the suspension and forming a kinematic chain of movable joints with bearings and an output structural element, the element being provided with a platform for attaching the seat with the possibility of its movement and fixing by means of a mechanism during the adjustment process, as well as an elastic element made, for example, in the form of a rodless stump matic spring. In addition, the suspension is equipped with an additional elastic element made, for example, in the form of two removable modules compactly placed in parallel planes on the outer surfaces of the base, each module containing springs, a central sleeve and a housing, as well as a spring pre-setting device, and the springs made in the form of interchangeable sets of plates made of spring steel, one ends of which are placed in grooves made with a certain angular pitch on the central sleeve mounted in the bearing the support on the base, and the other ends in grooves made with the same angular step on the housing with the possibility of supercritical elastic deformation during assembly and adjustment, the bushings being provided, for example, with slots for power closure with levers, and the housings are rigidly connected to the base. In addition, the suspension is equipped with a device for controlling the parameters of the elastic element, comprising a unit 14 for air selection from the pneumatic network of the helicopter, an air preparation unit and at least two control channels, one of which (conditionally, control channel No. 1) contains an air distributor with an electromagnetic actuator and the other (conditionally, control channel No. 2) is an air distributor with an electromagnetic actuator, while the device is equipped with a sensor of angular movements of the levers relative to the main Bani, air pressure sensor at the inlet of a spring and a controller consisting of a programmable microprocessor, provided with a power supply and operating according to a predetermined set of algorithms.

The disadvantage of this invention is: the lack of a dynamic damping system, including two degrees of freedom.

The aim of the invention is to provide simultaneous damping of vibrations of the protection object in two coordinates.

The method of dynamic vibration damping, which consists in using a vibration protection system to damp rotational and translational vibrational movements that occur during base vibrations transmitted to the protection object through springs, differs in that screw non-self-locking mechanisms equipped with flywheel nuts and gears are introduced parallel to the elastic elements in the system wheels connected through rods with disks and connected to flywheel nuts fixed in ball-bearing bearings on the object of protection, regulate increment disks by using the braking device associated with the control unit, communication is carried out between the partial formation systems by the control unit and the sensor system is adapted and ratio parameters of the system creates the effect of simultaneous dynamic damping vibrations in two coordinates.

The device of dynamic vibration damping, which is a vibration-protective system, is distinguished by the introduction of two non-self-locking screw mechanisms parallel to the springs, the connection of their flywheel nuts with gears connected by rods to the disks, and the disks are equipped with brake linings controlled through rheostats using a signal measuring and processing unit, received from the sensor system, which allows you to adjust the parameters of the vibration protection system to implement joint modes of dynamic damping of vibrations simultaneously in two degrees of freedom.

The device for controlling the moment of inertia, connecting the flywheel nuts of non-self-locking screw mechanisms introduced parallel to the springs, differs in that it is a gear transmission consisting of gears connected through rods to discs equipped with brake linings, which allows you to adjust the moment of inertia of the object of protection and connectivity movements between non-self-locking screw mechanisms.

The method and device are illustrated by the calculation scheme in FIG. one.

In FIG. 1 are marked: base 1, object of protection 14, based on two symmetrically located blocks, each of which consists of an elastic element 6, 7 and a non-self-locking screw mechanism containing a screw 4, 5 and a flywheel nut 8, 9, mounted in a ball bearing on object of protection, gears 10, 11 connected by rods 12, 13 with disks 15, 16 through holes in the object of protection 14.

Both units have braking devices 17, 18, through rheostats 19, 20 connected to the control and information processing unit 21, to which a system of sensors installed on the basis of 2, 3 and on the protection object 22, 23 is connected.

The invention works as follows (Fig. 1). The movements of the base 1, measured by sensors 2, 3 through elastic elements 6, 7 with stiffnesses k ₁ and k ₂ and parallel non-self-locking screw mechanisms 4, 5 are transmitted to the protection object 14, which has sensors 22, 23.

The control unit 21 processes the information on the amplitude and frequency of oscillations collected by the sensors 2, 3 and 22, 23, after which, depending on their readings, with the help of rheostats 19, 20 it changes the force of pressing the brake pads 17, 18 on the disks 15, 16, connected through rods with gears 10, 11, thereby by means of gearing with flywheel nuts 8, 9, the moment of inertia in the non-self-locking screw mechanisms is regulated.

The use of gears allows you to control the consistency of the movements of partial systems with coordinates y ₁ and y _2, respectively, and implement a mode of simultaneous dynamic damping of oscillations in two coordinates, which is not considered in the prototype.

Literature

1. Nashif A., Jones D., Henderson J. Damping of vibrations. M .: Mir, 1988 .-- 448 p.

2. Karamyshkin V.V. Dynamic damping. L .: Engineering, 1988 .-- 108 p.

3. Eliseev S.V., Khomenko A.P. Dynamic damping: the concept of feedback and structural methods of mathematical modeling. Novosibirsk, 2014.357 s.

Claims (3)

1. The method of dynamic vibration damping, which consists in using a vibration protection system to damp rotational and translational vibrational movements that occur during base vibrations transmitted to the object of protection through elastic elements, characterized in that non-self-locking screw mechanisms containing screws are additionally introduced parallel to the elastic elements in the system with flywheel nuts and connected to the discs via gears, regulate the pressing of the brake linings to the discs using the control unit and sensor systems, adjust system parameters to provide the effect of simultaneous dynamic damping of oscillations along two movement coordinates. 2. A device for dynamic damping of vibrations, which is a vibration-protective device, characterized in that two non-self-locking screw mechanisms are additionally introduced parallel to the elastic elements, containing screws with flywheel nuts and connected via gears to discs, the rotation of which is regulated by brake linings, and the force their pressing on the discs is controlled through rheostats using the unit for measuring and processing signals received from the sensor system, which allows you to adjust the parameters vibration protection system for implementing joint modes of dynamic damping of oscillations simultaneously along two movement coordinates. 3. The device for the dynamic damping of vibrations according to claim 2, characterized in that the inertia torque control mechanism is a combination of flywheel nuts of a non-self-locking screw mechanism and a gear transmission consisting of gears connected through rods to disks, which makes it possible to regulate the connectedness of movements between non-self-locking screw mechanisms.

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