RU2235234C2 - Mechanical damper and its spring - Google Patents

Abstract

FIELD: mechanical engineering.

SUBSTANCE: damper has two axially aligned female (3) and male (4) ring members. Springs (7) are interposed between them. Female (3) and male (4) members are made of flanges provided with the same number of the radial holes (5) and (6) arranged over periphery. The number of springs should be even but no less than four. The springs are made of pins. The spring-pins (7) are secured in the female member and movably fitted in the male member made of as a link pair. Spring (7) is made of a beam of variable cross-section the ends of which have members for restricting the number of degrees of freedom between which there is a deforming part.

EFFECT: decreased vibration loading.

12 cl, 3 dwg

Description

The present invention relates to the field of mechanics to the section damping vibrations in systems, and more particularly relates to damping devices containing springs mounted between two parts coaxially or coaxially located.

This invention is applicable to liquid-propellant rocket engines (LRE), for example, for fastening electric drives to the throttles of the fuel supply systems of the engines controlled by them.

State of the art

For a mechanical damper, a number of vibration isolating devices are currently known in the art, in which a damping element is installed between the vibration transmitter and the vibration receiver, as in the vibration isolating support according to the RF patent No. 2029157 according to MKI 6 F 16 F 11/00 with a priority of 08/02/91. This device is selected as an analogue of the invention.

Known torsion vibration absorber from US patent No. 2775105 according to NCI 464-101 with a priority of 02/10/1954. This absorber contains coaxial flanges. For fastening, the flanges contain an equal number of holes equally spaced around the circumference along which the flanges are fastened with rivets. In the design, a damping element is installed between the vibration transmitting and vibration receiving parts. This device is also taken in the form of an analogue of the invention. The disadvantage of the analogue is the problematic prevention of the transmission of high-frequency vibrations from the vibration transmitter to the vibration receiver as applied to flange joints.

From French patent No. 2787851 according to MKI 6 F 16 F 15/121, a damper device with a priority of 12.24.98 is known, which, in particular, can be used in turbopump engines of a rocket engine. This damper device, as claimed, contains two coaxially arranged, one inside the other, annular, covering and covered parts. In the gap between these parts, commensurate with their thickness, a damping element (spring) is placed. These parts are equipped with fasteners, respectively, to the vibration transmitter and vibration receiver of the machine. These signs coincide with those of the claimed invention. In the device according to the patent of France, the female and male parts are made quite rigid and have an annular shape. Between them there is a part made in the form of a metal strip of a certain width with the first and second free ends. The strip is mounted around the aforementioned inner cylindrical shell having a wavy shape substantially inscribed in a convex polygon. This device is taken as a prototype of the invention “Mechanical damper”. Its disadvantage is that it is difficult for them to prevent the transmission of multidirectional high-frequency vibrations from the vibration transmitter to the vibration receiver in flange connections.

For springs of a mechanical damper, springs used in damper devices are known in the art. So, in the same French patent No. 2787851 according to MKI 6 F 16 F 15/121, a spring made of elastic metal is known. The disadvantage of this spring is that it cannot effectively absorb large loads and damp high-frequency mechanical vibrations. This device is taken as an analogue of the claimed invention "Spring".

From the Federal Republic of Germany patent No. 3148903 for class B 64 C 27/51 with priority dated 12/10/1981, an elastic damping device for turbine blades is known. The spring in it has the shape of a beam of variable cross-section at the ends, made of elastic material. Although this spring is mainly under the influence of axial loads, there are also transverse loads in it. This spring is taken as a prototype of the claimed invention "Spring". The disadvantage of the prototype is that it does not provide effective damping of transverse vibrations, including high-frequency vibrations, which is especially important in cars similar to powerful rocket engines.

SUMMARY OF THE INVENTION

The basis of the present invention, “Mechanical damper” installed on the machine, is the task of reducing the amplitude and vibration overload of the vibrations of the vibration receiver of the machine compared to the vibrations of its vibration transmitter as applied to the electric drive mounted on a controlled hydraulic throttle rocket engine. Vibrations arising on such an engine are transmitted to the throttle body, where their maximum value is limited by the operating conditions of the electric motor on the machine.

The essence of the invention lies in the fact that the mechanical damper installed on the machine contains two annular female and male parts coaxially located inside the other, with a gap commensurate with the thickness of the parts between them, in which the spring is placed, while these female and male parts are provided with fastening elements respectively to the vibration transmitter and vibration receiver of the machine.

A distinctive feature of this invention lies in the fact that the female and male parts are made in the form of flanges with the same number of radial holes equally spaced around the circumference, the springs have an even number, but not less than four, and they are made in the form of pins radially directed in these parts and longitudinally placed in their radial openings, while the spring pins are fixed in the female part and slidably mounted in the male part (in the form of a rocker pair), providing elastic fixation of one of these their details are relatively different.

It should be noted that it is also possible to fasten the springs in the male part and move the landing in the female part.

In a particular case, in the covering part, arcuate windows are equally spaced around the circumference, separated from each other by radial pylons.

In another particular case, the mechanical damper is characterized in that on the flange parts made in the form of flanges, holes are provided longitudinally with respect to the axis along the circumference of the hole for attaching one part to the vibration transmitter and the other to the vibration receiver of the machine, and the fastening elements to the vibration transmitter and vibration receiver are made in the form of bolts with nuts and longitudinally with respect to the axis of the directed equally spaced holes in the female and male parts so that the bolts are inserted into these holes Stia, moreover arranged circumferentially adjacent its threaded bolt ends directed in opposite directions and between vibroperedatchikom and female member and also between the male part and vibropriemnikom gaps formed therein to accommodate the bolt heads.

In another particular case, the springs are fastened in the female part using a threaded connection.

In the following particular case, the end of the spring movably set in the male part is made in the form of a truncated body of revolution on both sides. For technological reasons, it is most advisable to choose a ball as a body of revolution.

In many special cases, it is advisable that the spring between the attachment point and the end made in the form of a truncated ball should have the shape of a truncated cone with a taper of 1: 6.5 and fillets at their edges.

In energy-intensive constructions, it is often advisable to carry out the spring pins from beryllium bronze.

The main materials of the remaining parts are steel. Perhaps the use of aluminum alloys.

In another particular case, in the female and male parts, 12 radial holes equally spaced around the circumference are made, in which 12 springs are installed, and 12 are made longitudinally with respect to the axis of the holes directed equally circumferentially, in which 12 bolts are installed, which are fastening elements to the vibration transmitter and vibration receiver, and the threads of adjacent circumferential bolts are directed in opposite directions.

The technical result of the present invention is to reduce vibration overloads and vibration amplitudes of a vibration receiver on a machine and increase the reliability of a technical object using the example of a rocket engine. It should also be noted an increase in the safety margin of some parts of the vibration receiver of the machine, which is an additional technical result of the implementation of the invention.

Another invention, it is intended for use in a “Mechanical damper”, is a “Mechanical damper spring”.

The challenge facing the invention of the “Spring of a mechanical damper” is to create a spring that would provide an effective opportunity to compensate for vibrations in two mutually perpendicular directions, and thanks to their installation in the damper design in two corresponding mutually perpendicular positions, it is possible to compensate for high-frequency vibrations in all three directions of space . Known springs effectively perceive vibrations in basically one direction, as this essentially takes place in the damping device according to the FRG patent No. 3148903. For the perception of fluctuations in a larger number of directions, springs of a complicated design are required.

The proposed spring is characterized by unexpected simplicity of design and efficiency in operating conditions at high frequency vibrations.

The essence of the invention of “Spring mechanical damper” is that it is made in the form of a beam (beam) of variable cross-section, containing in two places, mainly at its ends, elements of limitation of its degrees of freedom, between which an elastically deformable section is made. The spring is made in the form of a pin made of elastic metal, as elements of a limiter of degrees of freedom at one of its ends it contains elements of termination of a spring, and at the other end of it as elements of a limiter of degrees of freedom a slider of a rocker pair is made, while a truncated section is made as an elastically deformable section a cone with an acute angle at the apex or close to it in configuration, which is an element of revolution.

In a particular case, thread and a threaded end face coaxially to a truncated cone are made as elements of a spring seal in the region of one end of the spring.

In another particular case, in the spring, the slider of the rocker pair is made in the form of a ball truncated on both sides, coaxial with the thread and a truncated cone.

In the following particular case, the elastically deformable section is made in the form of a truncated cone with a taper of 1: 6.5.

In addition, in the particular case of a threaded end, the spring is equipped with a hexagon.

As for the material of the spring, it is possible to use elastic steels, nickel alloys, and in especially critical cases it is advisable to perform the spring from BrB2 beryllium bronze.

The technical result of the proposed invention “Spring mechanical damper” is that it allowed us to develop a simple and small-sized design of a mechanical damper for attachment points in high-power rocket engines, where vibration overloads reach about 400 g, and the vibration frequency reaches 2000 Hz, and for different directions of these vibrations in space.

Due to the fact that the spring is a stepped beam in the form of a body of revolution, it is equally strong in all directions in a plane normal to its axis. This allows you to make its design technological in manufacture and relatively cheap.

List of drawings

Figure 1 presents a section aa (see figure 2) of a mechanical damper.

Figure 2 presents a view In (see figure 1) on a mechanical damper.

Figure 3 presents the spring of the mechanical damper.

Examples of the invention

Let's consider two examples - “Mechanical damper” and “Spring of mechanical damper”.

The mechanical damper is shown in figures 1 and 2, where 1 is the vibration transmitter, and 2 is the vibration receiver of the machine. For the case of our examples, by machine we mean a liquid rocket engine (LRE). We consider a liquid fuel throttle as a vibration transmitter, and an electric drive of this throttle as a vibration receiver.

Actually the damper device consists of coaxially located covering 3 and covered 4 parts. The female part 3 has 12 threaded radial holes 5, equally spaced around the circumference, and the male part 4 has 12 radial holes equally spaced around the circumference 6. A pin spring (pin) 7 is inserted on each thread pair and secured 7. Thus, the device contains 12 pins 7. The spring (pin) 7 contains a thread 8 (see FIG. 3), through which it is screwed into the corresponding threaded hole 5 of the female part 3 on an adhesive providing thread lock. The spring (pin) 7 has a hexagon 9 at one end and a flange 10 that provides the required accuracy for installing the spring (pin) 7. At its other end, the spring (pin) is made in the form of a truncated ball 11 on two sides, which is connected to the thread by a truncated cone 12 with a taper of 1: 6.5, at their ends containing fillets 13 and 14.

Springs (pins) 7 are made of beryllium bronze, and the remaining parts are made of structural steel.

The female part 3 is attached to the vibration receiver 2, i.e. with electric drive, using bolts 15, nuts 16 and 17 and washers 18. The male part 4 is fastened to the vibration transmitter 1, i.e. with a fuel throttle, using bolts 19, nuts 16, 17 and washers 18. It should be noted that, as can be seen from the drawing of figure 1, the threaded ends of the bolts 15 and 19 are directed in opposite directions. This is done to reduce the size and weight of the device.

The male part 4 has a seat 20 in the vibration transmitter 1, and the female flange 3 has a seat 21 in the vibration receiver 2. There is a gap 22 between the heads of the bolts 15 and the vibration transmitter 1, and a gap 23 is made between the heads of the bolts 19 and the vibration receiver 2. These gaps can be , in principle, provided and by performing the appropriate recesses in the specified details. In addition, the female part 3 has equally spaced circular arched windows 24 and 25, separated from each other by radial pylons 26.

Mechanical damper works as follows. This damper is installed on the rocket engine between the hydraulic throttle 1 (vibration transmitter) and its electric drive 2 (vibration receiver). As a result of the operation of the machine, a large spectrum of vibrations arises, including high-frequency ones, for example, up to about 2 kHz with vibration overloads up to about 400 g. These vibrations occur directly on the vibration transmitter 1. In the absence of a damping device or its insufficiency, the vibrations would be transmitted without significant reduction to the vibration receiver 2, which would lead to unacceptable frequency vibrations and vibration overloads of the electric drive and its abnormal operation or failure.

The damper, as shown in figures 1 and 2, perceives and partially dampens to the permissible limits of vibration of the vibration transmitter. The damping of oscillations is as follows. From the vibration transmitter 1, the vibrations are transmitted to the male flange 4. The vibrational energy is absorbed in the pins (springs) 7, including at the point of friction of the pins (springs) 7 about the place of their landing by a truncated ball 11 in the hole 6 (i.e. in the rocker pair) and in places of bending vibrations of the pins (springs) 7 in places of a truncated cone 12 (see figure 3). It should be noted that the male part 4 and the female part 3 are fastened together using pins (springs) 7, so they can elastically move relative to each other in all directions, compensating for the effect of vibrations of the vibration transmitter 1 on the vibrations of the vibration receiver 2, ensuring normal operation of the electric drive on a hydraulic throttle (not shown in the drawings). The presence on the covering part 3 of arched windows 24 and 25 and radial pylons 26 also contributes to the damping of vibrations.

The spring (pin) 7 shown in FIG. 3 has the following design features. One end of the spring (pin) has a spherical shape in the form of a ball 11 truncated on both sides by end surfaces 27 and 28. The spring has a pin shape. The base of the pin is a truncated cone 12 with a taper of 1: 6.5. The other end of the spring is made in the form of a fastening thread 8. The truncated cone 12 at its edges passes into the end surface 28 of the truncated ball and the end surface 29 of the thread 8, which are paired with the conical surface of the truncated cone 12 with fillets 13 and 14.

Spring (pin) 7 operates as follows (see figure 3). The truncated ball 11, which is the slider of the rocker pair, can elastically oscillate and move relative to the thread 8 and the flange 10. Elements 8 and 10, as well as 11 are limiters of the degree of freedom of the spring (pin) 7. The thread 8 with the flange 10 provides a fixed mounting of this end on details to which is attached. The other end of the spring (pin) 7 with the ball 11, truncated on both sides, has the ability to elastically move in any direction perpendicular to the axis of the part, perceiving the corresponding vibrations. In addition, the spring (pin) 7 can move in the axial direction along the seating surface of the mating part, providing friction to the end of the spring (pin) 7 with a truncated ball 11 and damping (reducing) vibration vibrations by them. The presence of fillets 13 and 14 prevents the destruction of the part along the truncated cone 12.

Industrial applicability

The inventions are ready for industrial use. They can be widely used in rocketry under conditions of high-frequency loads and high vibration overloads. They can be used in other similar machines that have high-frequency overloads.

Claims (12)

1. A mechanical damper mounted on a machine and comprising two annular female and male parts coaxially located inside the other, with a gap commensurate with the thickness of the parts between them, in which the spring is located, wherein the female and male parts are provided with fastening elements respectively to the vibration transmitter and vibration receiver machines, characterized in that the female and male parts are made in the form of flanges with the same number of radially there are an even number of holes, springs, but not less than four, and they are made in the form of pins radially directed in these parts and longitudinally placed in their radial holes, while the spring pins are fixed in the female part and movably mounted in the male part in the form of a rocker pairs, providing elastic fixation of one of these parts relative to the other. 2. The mechanical damper according to claim 1, characterized in that on the annular parts made in the form of flanges, holes are arranged longitudinally with respect to the axis along the circumference for mounting one part to the vibration transmitter and the other to the vibration receiver of the machine, and the fastening elements to the vibration transmitter and vibration receiver are made in the form of bolts with nuts and longitudinally relative to the axis of the directed equally spaced holes in the female and male parts so that the bolts are inserted into these holes, poison circumferentially spaced bolts with their threaded ends in opposite directions, and between vibroperedatchikom and female member and also between the male part and vibropriemnikom gaps formed therein to accommodate the bolt heads. 3. The mechanical damper according to claim 1 or 2, characterized in that in the enclosing part there are made arcuate windows equally spaced around the circumference, separated from each other by radial pylons. 4. The mechanical damper according to claim 1 or 2, characterized in that the fastening of the springs in the enclosing part is carried out using a threaded connection. 5. The mechanical damper according to claim 1 or 4, characterized in that the end of the spring movably set in the male part is made in the form of a truncated body of revolution on both sides. 6. The mechanical damper according to claim 1, or 2, or 3, characterized in that in the female and male parts there are twelve radial holes equally spaced around the circumference, in which twelve springs are installed, and also made twelve longitudinally relative to the axis of the equally spaced the circumference of the holes in which twelve bolts are installed, which are fasteners to the vibration transmitter and vibration receiver, and the threads of the neighboring circumferential bolts are directed in opposite directions. 7. The spring of the mechanical damper, made in the form of a beam of variable cross section, containing in two places, mainly at its ends, elements of limitation of its degrees of freedom, between which an elastically deformable section is made, characterized in that the spring is made in the form of a pin of elastic metal, as elements of the limiter of degrees of freedom at one of its ends are elements of termination, and at the other end of it as an element of a limiter of degrees of freedom, a slider of the rocker pair is made, while the elastically deformable section made in the form of a truncated cone with an acute angle at the apex or an element close to it in configuration, which is a body of revolution. 8. The spring according to claim 7, characterized in that the elements of the spring seal in the region of one end of the spring are made in the form of a thread and a threaded end coaxially with a truncated cone. 9. Spring according to claim 7 or 8, characterized in that the slide of the rocker pair is made in the form of a ball truncated on both sides, coaxial with thread and a truncated cone. 10. Spring according to claim 7 or 8, characterized in that the elastically deformable section is made in the form of a truncated cone with a taper of 1: 6.5. 11. Spring according to claim 7 or 8, characterized in that at the end with a thread, the spring is equipped with a hexagon. 12. The spring according to claim 7, characterized in that it is made of beryllium bronze BrB2.

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