RU2515822C2 - Damping device for extension and torsion vibrations - Google Patents

Abstract

FIELD: machine building.

SUBSTANCE: device comprises a casing with a cylindrical hole, a stop member set on the casing, a stem with a thrust collar placed in the casing cavity and damping elements of two types. The damping elements are located in the casing cavity between the thrust collar and the stop member. The damping elements of the first type comprise disk springs. The damping elements of the second type comprise disks and gaskets set between them; at that the disks and gaskets are made from materials with different ability to absorb mechanical energy in the course of deformation and destruction under shock load.

EFFECT: improved damping characteristics in the wide range of frequencies and amplitudes.

10 cl, 1 dwg, 1 tbl

Description

The invention relates to the field of engineering, and in particular to devices for damping the movement of machine links, cushioning and shock loads.

Known damper (RU 2274783), which includes a piston with a rod, a spring and a viscous fluid filled hydraulic cylinder enclosed in a cylindrical cartridge, and is additionally equipped with two sets of blade mechanism consisting of a carrier, an impeller and a guide. Each of the mechanisms is installed in different hydraulic, upper and lower chambers, respectively. The piston is kept from rotation relative to the cylindrical cartridge by means of a key connection, the key of which is fixed to the piston. Drove motionlessly fixed on the piston coaxially to it from both its opposite ends. Each impeller is connected to the carrier by means of spiral slots, and to the guide by means of a cylindrical movable connection and an axial limiter with the possibility of its rotation around its own axis during reciprocating movement of the piston.

The design of the damper is complex, while in case of exceeding the load and cutting the key, the damper loses its functionality.

Known poppet shock absorber of the drill string (SU 1273494), comprising a housing, inside which is mounted with the possibility of telescopic movement of the shaft, forming a cavity with the housing for placing the cup spring cups formed by flat and conical rings, while additional one above the cup spring springs are installed on top of each other flat and conical rings arranged to fit the inner surface of each subsequent ring to the outer surface of the previous one.

A design feature is the need to adjust the stiffness of the shock absorber by appropriate selection of cup spring packages and rearrangement of additional rings. With regard to the scope of the shock absorber - drilling and the need to take into account the influence of field conditions - the design features of the shock absorber complicate its operation.

Known damper of longitudinal and torsional vibrations (RU 2184834), which is the prototype of the claimed technical solution and includes a housing, shaft and a system of elastic elements connecting the shaft to the housing, in the lower part of which are mounted radial and axial bearings, and the system of elastic elements is made in the form of concentrically arranged pipes of various diameters and stiffness, interconnected sequentially and tightly, and with the housing and shaft - tightly, inside the shaft is a throttling device.

Different types of elastic elements are selective to force vibrations acting on them. So, for example, Belleville springs and combinations of them are preferable to use when damping low-frequency vibrations, while in practice in different machines both low-frequency and high-frequency vibrations are observed. For example, in the drive system of a sucker-rod pumping unit, vibrations with a frequency of 20 ... 2000 Hz are observed.

In the prototype, the task of damping vibrations in a wide range of frequencies is not disclosed. A system of concentrically arranged pipes of various diameters and stiffness, connected together in series, has the ability to damp low-frequency vibrations, the possibility of its use for damping high-frequency vibrations is unlikely.

The technical result of the invention is to increase the damping capabilities of the device in a wide range of frequencies and amplitudes.

The technical result is achieved by the fact that in a device for damping longitudinal and torsional vibrations, comprising a body with a cylindrical hole, an emphasis mounted on the body, a rod with a stop shoulder located in the cavity of the body, and at least two types of damping elements placed in the cavity of the housing between the thrust shoulder and the stop, one of which contains Belleville springs, the second type of damping elements contains disks and gaskets installed between them, and the disks and gaskets are made of materials, giving varying ability of the material to absorb mechanical energy during deformation and fracture under impact load, while further:

- disks and gaskets are made of materials having different toughness;

- disks and gaskets are made of materials having different hardness;

- holes are made in the disks and gaskets, the diameter of which corresponds to the diameter of the rod;

- the emphasis is made in the form of a sleeve with a hole for the rod mounted on the housing;

- discs and gaskets are installed between the end surface of the thrust collar and Belleville springs;

- discs and gaskets are installed between the end surface of the sleeve and the disk springs;

- discs and gaskets are made of metal;

- Belleville springs are formed into packets, and the packets are formed into groups, each of which has a spring stiffness different from the spring stiffness of another group;

the cavity of the device is filled with a liquid with lubricating and anticorrosive properties, and a rod sealing device is made in the sleeve of the cylindrical body.

Disks and gaskets made of materials having different toughness and hardness are a system for damping high-frequency vibrations.

Impact strength characterizes the ability of a material to absorb mechanical energy in the process of deformation and fracture under the influence of impact load.

Disks and gaskets installed between them, made of materials having different toughness and (or) hardness, are a model of a Bingham (non-Newtonian) fluid with the ability to damp like high-frequency longitudinal vibrations, as well as torsional vibrations due to friction between the contacting end surfaces of the disks and gaskets.

Installing disks and gaskets between the end surface of the thrust collar and disk springs or between the end surface of the sleeve and disk springs, making holes in the disks and gaskets whose diameter corresponds to the diameter of the rod, and also making disks and gaskets made of metal are the preferred methods for constructing the device.

The formation of Belleville springs into packages that are formed into groups, each of which has a spring stiffness different from the stiffness of the springs of the other group, are methods of increasing the bearing capacity of the device.

Filling the device cavity with a liquid with lubricating and anti-corrosion properties is a method of: a) preventing corrosion of the damper elements; b) reduce the effect of contact corrosion at the ends of the Belleville springs.

The execution in the sleeve of the cylindrical body of the sealing device on the rod is necessary to prevent leakage of lubricating and anti-corrosion fluid from the cavity of the device.

Figure 1 shows a structural diagram of the device.

The device consists of a cylindrical body 1 with a threaded section 2, into which a sleeve 3 is screwed, which serves as a stop. Inside the cavity of the device formed by the housing 1 and the sleeve 3, a rod 4 with a stop collar 5 is placed, and Belleville springs 6 are formed into spring packages between the sleeve 3 and the stop collar 5. Spring packs are formed into groups of springs 7 and 8, consisting of springs of different stiffness.

Between the thrust shoulder 5 and the Belleville springs 6 are installed disks 9, between which gaskets 10 are installed.

The disks 9 and gaskets 10 can be installed both between the stop collar 5 and the Belleville springs 6, and between the sleeve 3 and the Belleville springs 6.

Threaded elements 11 and 12 are made on the housing 1 and on the rod 4, designed to connect the device with the links of machines and plants.

The table shows some materials from which it is possible to manufacture disks 9 and gaskets 9.

Disc material Gasket material Steel 45 Steel 08, steel 10, automatic steel, bronze, copper, aluminum Steel Ftoroplast

These materials have different toughness and hardness. A sealing device 13 is made in the sleeve 3. The cavity of the device is filled with oil 14.

The device operates as follows.

Under the influence of a tensile load, the rod 4 extends from the housing 1, while the disk springs 6 are deformed until the end surfaces stop at the beginning of the springs (spring packs) of lower stiffness, and then more springs. The energy of low-frequency oscillatory processes in the system is partially absorbed by compression of the springs 6.

Oil 14 through technological or special gaps between the disk springs 6 and the housing 1, between the disks 9 and the gaskets 10 and the housing 1, between the thrust shoulder 5 and the housing 1 is pumped into the cavity of the housing between the thrust shoulder 7 and the sleeve 3, while partially damping the resulting oscillatory processes.

The power load also acts on the disks 9 and gaskets 10. The latter, having less rigidity and, accordingly, higher viscosity, dampen high-frequency harmonics of oscillatory processes.

Similar processes of vibration damping occur in the device and during the reverse stroke, the oil 14 from the cavity of the device between the stop shoulder 5 and the sleeve 3 is pumped through the corresponding gaps described above, back to the cavity between the stop shoulder 5 and the bottom of the housing.

Oil passes from the damper cavities through the gap between the stem 4 and the sleeve 3 are prevented by the seal 13.

Torsional vibrations are damped due to friction on the end surfaces of the disks 9 and gaskets 10 that are tightly in contact with each other.

Structurally, the proposed technical solution is industrially feasible.

Claims (10)

1. Device for damping longitudinal and torsional vibrations, comprising a housing with a cylindrical hole, an abutment mounted on the housing, a rod with a thrust shoulder located in the cavity of the housing, and at least two types of damping elements placed in the cavity of the housing between the thrust shoulder and emphasis, one of which contains Belleville springs, characterized in that the second type of damping elements contains disks and gaskets installed between them, made of materials having different ability of the material to absorb amb mechanical energy during deformation and fracture under impact loads. 2. The device according to claim 1, characterized in that the disks and gaskets are made of materials having different toughness. 3. The device according to claim 1, characterized in that the disks and gaskets are made of materials having different hardness. 4. The device according to claim 1, characterized in that the holes and disks are made holes, the diameter of which corresponds to the diameter of the rod. 5. The device according to claim 1, characterized in that the emphasis is made in the form of a sleeve with a hole for the rod mounted on the housing. 6. The device according to claim 1, characterized in that the disks and gaskets are installed between the end surface of the thrust collar and disk springs. 7. The device according to p. 5, characterized in that the disks and gaskets are installed between the end surface of the sleeve and the disk springs. 8. The device according to claim 1, characterized in that the disks and gaskets are made of metal. 9. The device according to claim 1, characterized in that the disk springs are formed into packages, and the packages are formed into groups, each of which has a spring stiffness different from that of the springs of the other group. 10. The device according to claim 1, characterized in that the cavity of the device is filled with a liquid having lubricating and anticorrosive properties, and a sealing device on the rod is made in the sleeve of the cylindrical body.