CN108825718A - A kind of grounding type nonlinear energy trap inhibiting vibration of rotor system - Google Patents

Abstract

The invention discloses a grounded nonlinear energy well for suppressing the vibration of a rotor system, which comprises a nonlinear energy well body and a fixing frame. The nonlinear energy well body includes a fixed ring, a connecting component, a vibrator-absorbing mass block, a weak stiffness spring and a bearing component. The bearing assembly cooperates with the shaft, which includes a shaft sleeve, bearing and bearing sleeve; the weak stiffness spring cooperates with the bearing assembly and the vibrator-absorbing mass block, and the connecting assembly cooperates with the fixed ring and the vibrator-absorbing mass block, which includes a segmented linear stiffness rod, absorbing vibration There are gap holes with different diameters on the same circumference of the sub-mass blocks, which are matched with the segmented linear stiffness rods to form a segmented linear stiffness and fit nonlinear cubic stiffness; the fixed frame is fixed on the frame, reflecting the present invention grounding. The invention can effectively suppress the broadband vibration of the rotor system, and belongs to the field of vibration and noise control. The overall structure is simple and compact, the additional mass is small, the reliability is high, the use is convenient, and no external energy supply is required.

Description

A Grounded Nonlinear Energy Sink for Suppressing Rotor System Vibration

technical field

The invention relates to the technical field of vibration and noise control, in particular to a grounded nonlinear energy well for suppressing the vibration of a rotor system, which is used for vibration suppression of the rotor system, a core component of a rotating machine.

Background technique

Vibration is a typical hazard to the safe operation of rotating machinery. For multi-span rotors, the operating speed is usually above the first-order critical speed. It must pass through the first-order critical speed during the start and stop phases. At this time, strong resonance will occur, which seriously affects the performance of the unit. Stable operation. With the continuous efforts of the "2025 Plan" of the national equipment manufacturing industry, higher and higher requirements are put forward for the efficient, reliable and long-term stable operation of rotating machinery. Therefore, the efficient control of the vibration of its rotor system is particularly important and is an urgent problem to be solved.

Installing dynamic vibration absorbers is a common method for vibration control of rotor systems. By adding a vibration absorber, the vibration of the rotating machine can be transmitted to the tiny mass of the vibration absorber, and the low-frequency vibration can be maintained. Dynamic shock absorbers can be divided into two types: passive and active (or semi-active).

At present, passive vibration absorbers are widely used in the field of vibration suppression of rotating machinery. Its structure is simple and does not require an energy source. Sensitive, and because the structure is too complex, resulting in low applicability.

As mentioned earlier, both passive vibration absorbers and active (or semi-active) vibration absorbers have corresponding disadvantages in practical applications. A new vibration suppression device must be developed to meet the requirements of modern rotating machinery with simple structure and wide frequency bandwidth for vibration absorption and suppression. The nonlinear energy well can meet the above requirements.

Contents of the invention

The grounded nonlinear energy well of the present invention is a lightweight device coupled with the rotor system through a key nonlinear fitting element. Lightweight refers to the mass of the tiny vibrator and the nonlinear cubic stiffness fitted inside the nonlinear energy well. It has an extremely efficient vibration energy absorption capacity, and has a good suppression performance on the broadband vibration of the rotor system.

The object of the present invention is to propose a grounded nonlinear energy well for suppressing the vibration of the rotor system. Grounding means that the body of the nonlinear energy well is fixed on the frame. The key is the utilization of the non-linear cubic stiffness method for fit fitting of piecewise linear stiffness rods and clearance holes, and the application of weak stiffness springs between the bearing sleeve (rotor system) and the vibrator-absorbing mass.

In order to solve the above technical problems, the implementation structure scheme that the present invention adopts is:

A grounded nonlinear energy well for suppressing vibration of a rotor system, said nonlinear energy well comprising two parts: a nonlinear energy well body and a fixing frame;

The nonlinear energy well body includes a bearing assembly that cooperates with the rotor system, and a connecting assembly that cooperates with the fixed ring and the vibration-absorbing mass block;

The rotor system includes a disk and a shaft; the bearing assembly includes a bearing, a bearing sleeve and a shaft sleeve, the shaft sleeve is sleeved on the shaft, the bearing sleeve is mounted on the shaft sleeve, and a bearing sleeve is arranged on the outer side of the bearing, and the bearing sleeve is connected to the shaft through a weak stiffness spring. The vibration-absorbing mass block is connected; the function of the sleeve is to prevent the axial movement of the nonlinear energy well body;

The connecting assembly includes 4 connecting rods and 4 segmented linear stiffness rods, the connecting rods are fixedly connected to the vibrator-absorbing mass block and the fixing ring through nuts, and one end of the segmented linear stiffness rods is fixedly connected to the fixing ring through nuts, The other end forms a gap fit connection with the gap hole of the vibrator-absorbing mass block;

The same circumference of the vibrator-absorbing mass block is provided with a connection hole and a gap hole; the connection hole is 4 circular holes with equal diameters and cross distribution; the gap hole is 4 circular holes with different diameters and cross distribution, respectively connected to the connection components A connecting rod is arranged in the connecting hole; a segmented linear stiffness rod is arranged in the clearance hole.

The fixing frame is fixed on the frame, and the other end is fixedly connected to the nonlinear energy well body, so as to prevent the nonlinear energy well body from rotating with the shaft, and the two ends of the shaft are connected with the shaft end supporting base.

On the same circumference, the fixing ring is provided with a through hole that is mated with the connecting component.

There are four mutually perpendicular positioning holes on the inner wall of the vibrator-absorbing mass block, and four mutually perpendicular positioning holes are provided on the bearing sleeve, and four weak stiffness springs are positioned between the vibrator-absorbing mass block and the bearing sleeve.

The weak stiffness spring plays the role of connecting the rotor system and the main body of the nonlinear energy well, and allows the circumferential disturbance of the main body of the nonlinear energy well.

The bearing assembly contains bearings inside, so that when the nonlinear energy well body absorbs the vibration of the rotor system, it does not rotate with the shaft;

The bearing assembly contains a shaft sleeve, and the function of the shaft sleeve is to prevent the vibration absorber body from moving axially with the shaft.

When the nonlinear energy well of the present invention is working, the rotor system vibrates and transmits the vibration force to the vibrator-absorbing mass block through the bearing assembly and the weak stiffness spring, driving the connecting rod to vibrate, and the vibrator-absorbing mass block is further connected to the four segmented linear stiffness rods. Contact and collision, and then the vibrator-absorbing mass block dynamically absorbs the vibration force energy of the rotor system.

The mass of the vibrator-absorbing mass block can be replaced.

Four connection holes and four clearance holes on the same circumference of the vibrator-absorbing mass block are arranged in a crossing manner.

The beneficial effects of the present invention are:

1. The bearing and fixing ring in the whole device avoid the circumferential rotation of the nonlinear energy well body, and the shaft sleeve avoids the axial movement of the nonlinear energy well body, which defines the working state of the device.

2. The holes on the vibrator-absorbing mass block in the whole device are matched with the connecting components, and the diameter of these holes and the mass of the vibrator-absorbing mass block can be adjusted by replacing different vibrator-absorbing mass blocks, so that the vibrator-absorbing mass block and the segment The gap fit of the linear stiffness rod can be adjusted, and then the nonlinear cubic stiffness fitted by the nonlinear energy well body can be adjusted, and different body parts of the nonlinear energy well of the present invention can be designed, which can absorb the rotor system under different working conditions. vibration.

3. The 4 connecting rods in the whole device have the same diameter and are installed in parallel. The diameters of the 4 piecewise linear rigidity rods are different and are installed in parallel. Cubic law change) piecewise linear stiffness rod, so that the gap between the piecewise linear stiffness rod and the absorber mass block can be adjusted, and then the nonlinear cubic stiffness fitted by the nonlinear energy well body can be adjusted. Different body parts of the nonlinear energy well of the present invention are designed to absorb the vibration of the rotor system under different working conditions.

5. The whole device utilizes the mechanism of the nonlinear energy well to form the nonlinear energy well of the present invention, which is wider than the vibration suppression frequency band of the linear vibration absorber.

Description of drawings

Fig. 1 is a structural schematic diagram of a grounded nonlinear energy well for suppressing rotor system vibration applied to a specific rotor system according to the present invention;

Fig. 2 is a structural schematic diagram of the nonlinear energy well body of a grounded nonlinear energy well that suppresses the vibration of the rotor system according to the present invention

Fig. 3 is a schematic diagram of a stationary ring of a grounded nonlinear energy well that suppresses vibration of a rotor system according to the present invention;

4 is a schematic diagram of a grounded nonlinear energy well with a set of diameter connection components for suppressing rotor system vibration according to the present invention;

Fig. 5 is a schematic diagram of a vibrator-absorbing mass block with a set of diameter clearance holes of a grounded nonlinear energy well of the present invention that suppresses the vibration of the rotor system;

Fig. 6 is a structural schematic diagram of a grounded nonlinear energy well for suppressing vibration of a rotor system according to the present invention, with the bearing assembly removed from the sleeve;

Fig. 7 is a schematic diagram of a fixed frame of a grounded nonlinear energy well for suppressing vibration of a rotor system according to the present invention;

Fig. 8 is a mechanism fitting curve diagram of piecewise linear stiffness and nonlinear cubic stiffness of a grounded nonlinear energy well for suppressing rotor system vibration of the present invention;

Fig. 9 is a graph of the amplitude-frequency characteristics when the rotor system does not add a grounded nonlinear energy well for suppressing the vibration of the rotor system according to the present invention.

Fig. 10(a) is the amplitude-frequency characteristic curve of the rotor system and the nonlinear energy well of the present invention when the clearance hole between the gap hole of the vibrator-absorbing mass block of the nonlinear energy well of the present invention and the piecewise linear stiffness rod is 0.25 mm. ;

Fig. 10(b) is a curve diagram of the amplitude-frequency characteristics of the rotor system and the nonlinear energy well of the present invention when the gap between the clearance hole of the vibrator-absorbing mass block of the nonlinear energy well of the present invention and the piecewise linear stiffness rod is 0.5 mm. ;

Fig. 10(c) is a graph of the amplitude-frequency characteristics of the rotor system and the nonlinear energy well of the present invention when the clearance hole between the gap hole of the vibrator-absorbing mass block of the nonlinear energy well of the present invention and the piecewise linear stiffness rod is 0.75 mm. .

Detailed ways

In the following, the nonlinear energy well of the present invention will be further described in detail in combination with the accompanying drawings 1-9, 10(a), 10(b), and 10(c) and examples.

A grounded nonlinear energy sink for suppressing vibration of a rotor system is applied to a specific node of a specific rotor system, including a nonlinear energy sink body, a fixed frame 2 , a frame 14 and a shaft end support 15 . It includes a bearing assembly, a connecting assembly, a vibrator-absorbing mass block 5 and a fixing ring 12. Refer to FIG. 7 for the fixing frame 2 . The piecewise linear stiffness of the nonlinear energy well for vibration suppression of this rotor system fits the action mechanism of the nonlinear cubic stiffness and the action mechanism of the nonlinear energy well mechanism, see FIG. 8 . The vibration suppression effect diagram of the rotor system under the condition that the nonlinear energy well of the present invention has three clearance fits, see Fig. 9 and Fig. 10 comprehensively.

The bearing assembly cooperates with the vibrator-absorbing mass block 5 through the weak stiffness spring 9, the connection assembly connects the fixed ring 12 and the vibrator-absorbing mass block 5, and the fixed frame 2 is fixed on the frame 14 through fastening bolts 3 to realize grounding, which illustrates nonlinear The energy well body does not rotate together with the rotor during operation. .

The length of the connecting rod 4 and the segmented linear stiffness rod 6 between the fixed ring 12 and the vibrator-absorbing mass block 5 can be changed within a certain range by turning the nut 1 . The stiffness of the shock absorber body can be further adjusted.

The diameters of the four connecting rods 4 are the same, and the diameters of the four segmented linear rigidity rods 6 are not equal, and are in the shape of stepped shafts.

The main body of the nonlinear energy well is shown in Figure 2. The connecting component between the vibrator-absorbing mass 5 and the fixed ring 12 is an important part to realize the fitting nonlinear stiffness. are held together by nut 1. The segmented linear stiffness rod 6 and the fixing ring 12 are fixed together by the nut 1, and form a clearance fit with the gap hole of the vibrator mass 5, and the segmental linear stiffness rod 6 with high stiffness corresponds to the gap with a large diameter on the vibrator mass 5 hole.

The fixing frame 2 plays the role of fixing the nonlinear energy well body to prevent it from rotating with the shaft 13, and cooperates with the frame 14 to reflect grounding.

The length of the connecting rod 4 and the segmented linear stiffness rod 6 between the vibration-absorbing mass block 5 and the fixed ring 12 can be changed within a certain range by turning the nut 1, which can effectively adjust the stiffness of the vibration absorber body;

The diameter of the gap hole and the mass of the vibrator mass 5 can be adjusted by replacing different vibrator-absorbing mass blocks 5, so that the gap fit formed by fitting and forming nonlinear stiffness can be adjusted, and then the stiffness of the nonlinear energy well body can also be controlled;

The 4 connecting rods 4 in the connecting assembly have the same diameter and are installed in parallel, and the 4 piecewise linear stiffness rods 6 have different diameters and are installed in parallel and crossed. The piecewise linear stiffness rod 6 with the change of cubic law forms different gap fits with the vibrator-absorbing mass 5, so that the fitted nonlinear cubic stiffness can be changed, and then the stiffness of the nonlinear energy well body can also be controlled.

When the nonlinear energy well of the present invention is working, the rotor system vibrates and transmits the vibration force to the vibrator-absorbing mass block 5 through the bearing assembly and the weak stiffness spring 9, driving the connecting rod 4 to vibrate, and further absorbing the vibrator-mass block 5 and 4 subsections The linear stiffness rods 6 contact and collide with each other, and then the vibrator-absorbing mass block 5 dynamically absorbs the vibration force energy of the rotor system.

During the working process of the nonlinear energy well body, this gap fit forms a piecewise linear stiffness, fitting the nonlinear cubic stiffness.

The diameter of the connecting rod 4, the diameter of the piecewise linear rigidity rod 6, the diameter of the clearance hole on the vibrator mass 5 and the quality of the vibrator mass 5, these parameters can have various changes through proper calculation, and then Different body parts of the nonlinear energy well of the present invention can be designed to meet the vibration of the rotor system under different working conditions.

As shown in Figure 5, a plurality of circular holes are distributed on the vibrator-absorbing mass block 5, among which 4 connecting holes are evenly distributed and have equal diameters, and are used to connect with 4 connecting rods 4, and there are 4 other uniform diameters on the same circumference. The distributed clearance holes correspond to the segmented linear rigidity rods 6 respectively, and the larger the diameter, the greater the stiffness of the correspondingly fitted segmental linear rigidity rods 6 . Four mutually perpendicular positioning holes are opened on the inner wall of the vibrator-absorbing mass block 5 , and together with the four mutually perpendicular positioning holes on the bearing sleeve 8 , four weak stiffness springs 9 are positioned.

Combined with Figure 8, the mechanism of piecewise linear stiffness fitting nonlinear cubic stiffness is illustrated: for a spring with cubic nonlinearity, the relationship between its reaction force and stiffness is y=kx ³ , and the fitting effect is very good as can be seen from the figure, indicating that The effectiveness of piecewise linear stiffness fitting to nonlinear cubic stiffness also illustrates the rationality of this design from the side.

The goal of this embodiment is to suppress the vibration of the rotor system, which is the core component of the rotating machine. Referring to Figures 9 and 10, it can be seen that as the nonlinear energy well of the present invention is installed on the rotor system, the vibration of the rotor system decreases significantly. decreases, the vibration suppression rate increases. And it has a vibration suppression effect on frequency bands of different widths, and can be adaptively changed with different matching gaps. It shows the broadband vibration suppression characteristic of the nonlinear energy well of the present invention, and the effect is remarkable. It can reduce the failure of the overall rotating mechanical equipment during operation, and make up for the deficiency of the current vibration suppression technology.

A grounding nonlinear energy well for suppressing the vibration of the rotor system in the present invention suppresses the vibration of the rotor system as follows:

When the nonlinear energy well of the present invention is working, the rotor system vibrates and transmits the vibration force to the vibrator-absorbing mass block 5 through the bearing assembly and the weak stiffness spring 9, driving the connecting rod 4 to vibrate, and further absorbing the vibrator-mass block 5 and 4 subsections The linear stiffness rods 6 contact and collide with each other, and then the vibrator-absorbing mass block 5 dynamically absorbs the vibration force energy of the rotor system.

The specific process is as follows:

When the rotor system rotates and the vibration is too small, the vibration force is transmitted from the bearing assembly to the vibrator-absorbing mass block 5, which drives the connecting rod 4 to vibrate. The vibration amplitude of the connecting rod 4 is smaller than that of the segmented linear stiffness rod 6 and the absorbing vibrator mass 5, the relative clearance of the gap hole, at this time, the segmented linear stiffness rod 6 is not in contact with the vibrator-absorbing mass block 5, and only the connecting rod 4 is matched with the vibrator-absorbing mass block 5. At this time, the body of this kind of nonlinear energy well is equivalent to a linear dynamic vibration absorber, and the vibration suppression effect is not very obvious;

When the vibration is too large, the less rigid rods in the segmental linear stiffness rods 6 contact and collide with the small-diameter clearance holes of the vibrator mass block 5, and the second, third, and fourth segmental linear stiffness rods The rod 6 contacts and collides with the vibrator-absorbing mass block 5, and then the vibrator-absorbing mass block 5 dynamically absorbs the vibration force energy of the rotor system.

To sum up, the above explanation is only a preferred embodiment of the rotor system dynamic vibration absorber using the nonlinear energy sink mechanism of the present invention, and is not intended to limit the protection scope of the present invention. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present invention shall be included within the protection scope of the patent rights of the present invention.

Claims (8)

1. A grounded non-linear energy well for suppressing the vibration of the rotor system, characterized in that, the non-linear energy well comprises two parts, a non-linear energy well body and a fixed mount; The nonlinear energy well body includes a bearing assembly matched with the rotor system, and a connection assembly matched with the fixed ring (12) and the vibration-absorbing mass block (5); The rotor system includes a disc (7) and a shaft (13); the bearing assembly includes a bearing (10), a bearing sleeve (8) and a shaft sleeve (11), and the shaft sleeve (11) is sleeved on the shaft (13) , the bearing (10) is sleeved on the shaft sleeve (11), and the outer side of the bearing (10) is provided with a bearing sleeve (8), and the bearing sleeve (8) is connected with the vibrator-absorbing mass block (5) through a weak stiffness spring (9); the The effect of the shaft sleeve (11) is to prevent the axial movement of the nonlinear energy well body; The connecting assembly includes 4 connecting rods (4) and 4 segmented linear stiffness rods (6), and the connecting rods (4) are fixedly connected to the vibrator-absorbing mass block (5) and the fixing ring (12) through nuts , one end of the segmented linear stiffness rod (6) is fixedly connected to the fixed ring (12) through a nut, and the other end forms a gap fit connection with the gap hole of the vibrator-absorbing mass block (5); The same circumference of the vibration-absorbing mass block (5) is provided with connecting holes and gap holes; the connecting holes are 4 circular holes with equal diameters and intersecting distribution; the gap holes are 4 circular holes with unequal diameters and intersecting distribution, respectively A connecting rod (4) is placed in the connecting hole in the connecting component; a segmented linear rigidity rod (6) is placed in the gap hole. The fixed frame (2) is fixed on the frame (14), and the other end is fixedly connected to the nonlinear energy well body to prevent the nonlinear energy well body from rotating with the shaft (13). The support seat (15) is matched and connected. 2. A grounded non-linear energy sink for suppressing rotor system vibration according to claim 1, characterized in that the fixing ring (12) is provided with a through hole on the same circumference to cooperate with the connecting component. 3. A kind of grounding type nonlinear energy well for suppressing rotor system vibration as claimed in claim 1, is characterized in that, have 4 mutually perpendicular positioning holes on the inner wall of the vibrator-absorbing mass block (5), the bearing sleeve ( 8) is provided with 4 positioning holes perpendicular to each other, and 4 weak stiffness springs (9) are positioned between the vibrator-absorbing mass (5) and the bearing sleeve (8). 4. A grounded nonlinear energy well for suppressing vibration of the rotor system as claimed in claim 1, characterized in that the weak stiffness spring (9) plays the role of connecting the rotor system and the main body of the nonlinear energy well , allowing the disturbance in the circumferential direction of the nonlinear energy well body. 5. A grounded nonlinear energy well for suppressing rotor system vibration as claimed in claim 1, characterized in that the bearing assembly contains a bearing (10) inside to realize that the nonlinear energy well body does not follow the vibration of the rotor system when absorbing the vibration of the rotor system. The shaft (13) rotates together; The bearing assembly contains an axle sleeve (11), and the effect of the axle sleeve (11) is to prevent the vibration absorber body from axially moving along with the axle (13). 6. A grounded nonlinear energy well for suppressing rotor system vibration as claimed in claim 1, characterized in that, When the nonlinear energy well of the present invention works, the rotor system vibrates and transmits the vibration force to the vibrator-absorbing mass block (5) through the bearing assembly and the weak stiffness spring (9), driving the connecting rod (4) to vibrate, further absorbing the vibrator-mass block (5) Contacting and colliding with four segmented linear stiffness rods (6), and then absorbing the vibrator mass block (5) to dynamically absorb the vibration force energy of the rotor system. 7. A grounded nonlinear energy well for suppressing vibration of a rotor system according to claim 1, characterized in that the mass of the vibrator-absorbing mass (5) can be replaced. 8. A grounded nonlinear energy well for suppressing rotor system vibration as claimed in claim 1, characterized in that the 4 connection holes and 4 clearance holes of the vibrator-absorbing mass block (5) on the same circumference are intersecting arrangement.