CN206668842U - A kind of dish type non-linear low frequency vibration isolator based on positive and negative Stiffness principle - Google Patents

Abstract

The utility model discloses a kind of dish type non-linear low frequency vibration isolator based on positive and negative Stiffness principle, it is made up of power input portion, extension spring system, stage clip system and shell, extension spring system realizes positive rigidity, stage clip system realizes negative stiffness, and the two, which is combined, makes static system power displacement curve that quasi- zero stiffness characteristic be presented.The utility model has continued the excellent anti-vibration performance of nonlinear isolation device, simultaneously by adjusting helicitic texture, and the number of increase and decrease extension spring group, the applicable vibration isolation mass range of vibration isolator can be greatly improved, overcomes the shortcomings that common nonlinear isolation device vibration isolation mass range is small.

Description

A Disc-shaped Nonlinear Low-Frequency Vibration Isolator Based on the Principle of Parallel Connection of Positive and Negative Stiffness

technical field

The utility model belongs to the field of low-frequency vibration isolation, and in particular relates to a disc-shaped nonlinear low-frequency vibration isolator based on the principle of parallel connection of positive and negative stiffnesses with a relatively large adjustment range of vibration isolation quality.

Background technique

Low-frequency vibration in engineering affects the stability and precision of equipment, reduces the strength of parts and even causes fatigue damage, causing unnecessary losses, and also brings noise pollution. Low-frequency vibration in some fields can also endanger the physical and mental health of workers . To address this limitation, effective low-frequency vibration isolation design is a research focus in various engineering fields.

According to the traditional passive vibration isolation theory, the linear vibration isolation system has a better isolation effect on medium and high frequency vibrations, but due to the contradiction between its deformation and stiffness, the performance of isolating low frequency vibrations is poor. Therefore, the linear vibration isolation system is difficult to meet various low-frequency vibration isolation requirements in the engineering field. If active or semi-active vibration isolation is used, although good low-frequency vibration isolation performance can be achieved, it will involve control technology, increase the complexity of the system, and it is difficult to avoid excessive structure, high energy consumption and high cost.

The nonlinear vibration isolation system based on the principle of parallel connection of positive and negative stiffness can overcome the shortcomings of the linear vibration isolation system, and has good low-frequency vibration isolation performance, so it has attracted the attention of researchers in various fields. However, to ensure good vibration isolation performance of this system, it is necessary to require that the actual load cannot have a large deviation from its equilibrium load. By designing the adjustment device, the mass application range of the vibration isolation system can be increased, but the mass adjustment range of the existing system is still insufficient, that is, it cannot be adjusted in a large range.

Contents of the invention

In view of the above defects or improvement needs of the prior art, the utility model provides a low-frequency vibration isolator based on the principle of parallel connection of positive and negative stiffness. It uses multiple groups of springs to form a nonlinear system. One spring in each group provides positive stiffness, and the other spring provides negative stiffness. Due to the special mechanical structure design, the vibration isolator converts the vibration transmitted from the outside into the rotation of the main shaft. Its advantage is that the number of spring groups and pretightening force can be flexibly adjusted according to the load, which expands the range of vibration isolation quality, has strong adaptability, and has better low-frequency vibration isolation effect.

The utility model includes a power input part, a tension spring system, a compression spring system and a casing. The guide rod is the connector between the utility model and the vibration-isolated object, and the two are connected through the flange at the end of the guide rod. The guide rod sleeve is in interference fit with the guide rod, and is in clearance fit with the housing sleeve, so that the guide rod can move linearly under the restriction of the housing sleeve. The casing sleeve is fixed on the outer wall of the casing box by bolts.

The middle part of the guide rod, the guide rod sleeve and the housing sleeve has through radial holes, and the positioning bolts can pass through the guide rod, the guide rod sleeve and the housing sleeve under the condition of no load. The position of the guide rod is fixed relative to the housing.

The guide rod and the vertical connecting rod are hinged through a pin shaft, and there is a cotter pin on the pin shaft to limit the axial position of the pin shaft. All the hinge joints of the utility model adopt this method, so it will not be described in detail below. The vertical connecting rod and the horizontal connecting rod are hinged through pin shafts, and the end of the horizontal connecting rod is an inner spline sleeve. The horizontal connecting rod is nested in the middle of the spline shaft through the inner spline sleeve.

The extension spring system is composed of extension spring spline sleeves, several extension springs and an extension spring adjustment mechanism. The extension spring spline sleeve is nested at one end of the spline shaft, several extension springs are radially hinged around the extension spring spline sleeve, and the other end of the extension spring is hinged with an extension spring adjustment mechanism.

The tension spring adjusting mechanism is composed of tension spring adjusting bolts and tension spring adjusting nuts. The tension spring adjusting bolts pass through the light hole of the shell box, and the ends of the tension spring adjusting bolts are screwed with tension spring adjusting nuts. Adjusting the tension spring adjusting nuts is The pre-tightening force of the corresponding extension spring can be adjusted.

The compression spring system is composed of a compression spring spline sleeve, several compression spring connections, several compression springs and a compression spring adjustment mechanism. The compression spring spline sleeve is nested on the other end of the spline shaft, and the compression spring Several compression springs are hinged around the spline sleeve, and several compression springs are nested at the connection end of the compression spring, and the other ends of the compression springs are nested on the boss at the connection end of the compression spring. stretching and rotation without causing instability of the compression spring during the deformation process. The compression spring is connected with the compression spring adjusting mechanism and is hinged.

The compression spring adjustment mechanism is composed of a compression spring adjustment and a compression spring adjustment bolt, and one end of the compression spring adjustment part has a blind hole for positioning the compression spring adjustment bolt. The pressure spring adjusting bolt is screwed on the threaded hole of the shell box, and the pressure spring preload can be adjusted by adjusting the pressure spring adjusting bolt.

The casing includes a casing box, a limit block, a casing cover, a bearing and a bearing cover. Wherein, the limit block is fixed on the inner wall of the housing box by bolts, and plays the role of limiting the position of the pressure spring adjusting part and providing the sliding direction. The housing cover is bolted to the ribs of the housing box. The bearing is embedded in the through hole in the center of the housing cover. The bearing cover is fixed on the housing cover, and the ring-shaped structure protruding from its side is embedded in the central through hole of the housing cover, and the end is abutted on the outer ring of the bearing to limit the axial position of the bearing.

The beneficial effects of the utility model:

Multiple groups of springs are used to form a nonlinear system. One spring in each group provides positive stiffness, and the other spring provides negative stiffness. Due to the special mechanical structure design, the vibration isolator converts the vibration transmitted from the outside into the rotation of the main shaft. Its advantage is that the number of spring groups and pretightening force can be flexibly adjusted according to the load, which expands the range of vibration isolation quality, has strong adaptability, and has better low-frequency vibration isolation effect.

Description of drawings

Fig. 1 is a three-dimensional schematic view of the power input part of the utility model.

Fig. 2 is a three-dimensional schematic view of the tension spring system of the present invention.

Fig. 3 is a schematic perspective view of the compression spring system of the present invention.

Fig. 4 is a perspective view of the utility model.

Fig. 5 is a graph showing the nonlinear force-displacement characteristic of the utility model.

Fig. 6 is a schematic diagram of adjusting the pre-tightening force of the extension spring of the present invention.

Fig. 7 is a schematic diagram of adjusting the pretightening force of the compression spring of the present invention.

In the figure: 1—power input part, 2—tension spring system, 3—pressure spring system, 4—shell, 11—guide rod, 12—shell sleeve, 13—guide rod sleeve, 14—locating bolt, 15—pin Shaft, 16—vertical link, 17—horizontal link, 18—spline shaft, 21—extension spring adjustment mechanism, 211—extension spring adjustment bolt, 212—extension spring adjustment nut, 22—extension spring, 23—extension spring Spline sleeve, 31—pressure spring adjustment mechanism, 311—pressure spring adjustment member, 312—pressure spring adjustment bolt, 32—pressure spring, 33—pressure spring connection, 34—pressure spring spline sleeve, 41—shell box, 42 —limiting block, 43—housing cover, 44—bearing, 45—bearing cover.

detailed description

As shown in Figure 4, the utility model comprises power input part 1, extension spring system 2, stage clip system 3 and shell 4, and during work, the shell part of this device is connected with vibration input source, and the guide bar of power input part 1 11. The end flange is fixedly connected with the vibration-isolated object.

As shown in Figure 1, the power input part 1 is composed of a guide rod 11, a casing sleeve 12, a guide rod sleeve 13, a positioning bolt 14, a pin shaft 15, a vertical connecting rod 16, a horizontal connecting rod 17 and a spline shaft 18. Composition, wherein, the guide rod 11 is a connecting piece with the vibration-isolated object, the guide rod 11 and the vibration-isolated object are connected through the flange at the end of the guide rod 11, the guide rod sleeve 13 is set on the guide rod 11, and the outer shell sleeve The sleeve 12 is set on the guide rod sleeve 13, the guide rod sleeve 13 is interference fit with the guide rod 11, and the guide rod sleeve 13 and the shell sleeve 12 are clearance fit, so that the guide rod 11 can be made under the restriction of the shell sleeve 12. Linear movement, the casing sleeve 12 is fixed on the outer wall of the casing box 41 by bolts.

The middle part of the guide rod 11, the guide rod sleeve 13 and the housing sleeve 12 has a through radial hole. In the case of no load, the positioning bolt 14 can pass through the guide rod 11, the guide rod sleeve 13 and the housing sleeve. 12 , to fix the position of the guide rod 11 relative to the casing sleeve 12 .

Described guide rod 11 and vertical connecting rod 16 are hinged by pin shaft 15, cotter pin is arranged on pin shaft 15 and is used for limiting the axial position of pin shaft 15, vertical connecting rod 16 and horizontal connecting rod 17 are hinged by pin shaft 15, horizontal The end of the connecting rod 17 is an inner spline sleeve, and the transverse connecting rod 17 is nested in the middle of the spline shaft 18 through the inner spline sleeve.

When the vibration source has no vibration, that is, when the utility model is in a static state, the radial hole on the guide rod 11 and the radial hole on the casing sleeve 12 can be overlapped by the vibration-isolated object due to its own weight. The positioning bolts 14 are used to fix the vibration-isolated object on the guide rod 11, and the guide rod 11 and the vibration-isolated object can freely vibrate in the shell sleeve 12. When the vibration source vibrates, the vibration-isolated object vibrates relative to the vibration source. This vibration form is transmitted to the spline shaft 18 through the mutually hinged guide rod 11, vertical connecting rod 16 and horizontal connecting rod 17, and the motion form is also The linear vibration of the guide rod 11 is converted into the reciprocating swing of the spline shaft 18 .

As shown in Figure 2, the extension spring system 2 is composed of extension spring spline sleeve 23, several extension springs 22 and extension spring adjustment mechanism 21. Extension spring spline sleeve 23 is nested on one end of spline shaft 18, and extension spring spline A plurality of extension springs 22 are radially hinged around the cover 23, and the other end of each extension spring 22 is hinged with an extension spring adjustment mechanism 21.

As shown in Figure 6, the extension spring adjustment mechanism 21 is composed of an extension spring adjustment bolt 211 and an extension spring adjustment nut 212. The extension spring adjustment bolt 211 passes through the housing box 41, and the extension spring adjustment bolt 211 ends are screwed with an extension spring. Adjust the nut 212 , adjust the tension spring adjustment nut 212 to adjust the pretightening force of the corresponding tension spring 22 .

The spline shaft 18 drives the extension spring spline sleeve 23 to swing back and forth, so that several extension springs 22 undergo telescopic deformation and negligible small rotation. Therefore, the stiffness curve formed by the force acting on the guide rod 11 to balance the action of the extension spring 22 and the displacement of the guide rod 11 has a positive stiffness characteristic.

As shown in Figure 3, the described compression spring system 3 is made up of compression spring spline cover 34, several compression spring connectors 33, several compression springs 32 and compression spring adjustment mechanism 31, and compression spring spline cover 34 is nested At the other end of the spline shaft 18, several stage clip connectors 33 are hinged around the stage clip spline sleeve 34, and several stage clips 32 are nested in the ends of the stage clip connector 33, and the other ends of each stage clip 32 are nested in the pressure spring. On the boss at the end of the spring connector 33, this arrangement can realize the free expansion and contraction and rotation of the compression spring 32, and at the same time, the compression spring 32 will not be unstable during the deformation process. The compression spring connector 33 is hinged to the compression spring adjustment mechanism 31 .

As shown in Figure 7, described stage clip adjusting mechanism 31 is made of stage clip adjusting part 311 and stage clip adjusting bolt 312, and stage clip adjusting part 311 has blind hole at one end, for stage stage adjusting bolt 312 positioning. The stage clip adjusting bolt 312 is screwed on the threaded hole of the shell box 41, and the stage stage adjusting bolt 312 can be adjusted to adjust the stage stage 32 pretightening force.

As shown in Fig. 4 and Fig. 7, described casing 4 comprises casing box 41, stop block 42, casing cover 43, bearing 44 and bearing cover 45, and stop block 42 is fixed on the inner wall of casing box 41 by bolt, To limit the position of the compression spring regulator 311 and provide the sliding direction, the housing cover 43 is fixed on the rib plate of the housing box 41 by bolts, the bearing 44 is embedded in the through hole in the center of the housing cover 43, and the bearing cover 45 is fixed on the On the casing cover 43 , the annular structure protruding from the side of the bearing cover 45 is embedded in the central through hole of the casing cover 43 , and the end of the bearing cover 45 abuts on the outer ring of the bearing 44 to limit the axial position of the bearing 44 .

The spline shaft 18 drives the compression spring spline sleeve 34 to swing back and forth, so that several compression springs 32 undergo telescopic deformation and reciprocating rotation. When the guide rod 11 moved downward through the equilibrium position, the stage clip 32 changed from the vertical state to the oblique state, and the elastic force of the stage clip 32 decreased, but the moment radius of the elastic force to the spline shaft 18 increased, finally making the elastic force Torque first decreases and then increases, and a similar situation occurs when the guide rod 11 moves upwards through the equilibrium position. Finally, the stiffness curve formed by the force acting on the guide rod 11 to balance the action of the compression spring 32 and the displacement of the guide rod 11 shows a negative stiffness characteristic.

The combination of the positive and negative stiffnesses of the extension spring system 2 and the compression spring system 3 makes the overall force-displacement curve of the utility model present the quasi-zero stiffness non-linear characteristic shown in FIG. 5 . When the working state of the vibration isolator is in the working area, the utility model has a large bearing capacity, and when the guide rod 11 vibrates in the working area, it can maintain a relatively stable external force. When the working state of the vibration isolator is in the non-working area, the large stiffness characteristic of the force-displacement curve can play a role in limiting the vibration.

In the present utility model, as shown in Fig. 6 and Fig. 7, adjusting the tension spring adjusting nut 212 and the tension spring adjusting bolt 312 at the ends of the tension spring system 2 and the compression spring system 3 can increase the tension of the tension spring 22 and the compression spring 32 respectively. Tightening force, so that the vibration-isolated objects of different masses can be in a static equilibrium position. In addition, when any two tension springs 22 and compression springs 32 are used as a group of springs, the nonlinear characteristics shown in Figure 5 can be realized, so increasing or decreasing the same number of tension and compression spring groups can greatly improve the vibration isolation quality range of the present utility model . Furthermore, the friction between the guide rod sleeve 13 and the casing sleeve 12 in the utility model can provide partial damping for the utility model to dissipate vibration energy, and a damper can be added in the specific implementation process to improve the vibration isolation of the utility model Effect.

Claims (1)

1. A disc-shaped nonlinear low-frequency vibration isolator based on the principle of positive and negative stiffness parallel connections, characterized in that: it includes a power input part (1), an extension spring system (2), a compression spring system (3) and a casing (4) , the housing (4) is fixedly connected to the vibration input source, and the end of the guide rod (11) of the power input part (1) is fixedly connected to the vibration-isolated object; The power input part (1) consists of a guide rod (11), a housing sleeve (12), a guide rod sleeve (13), a positioning bolt (14), a pin shaft (15), a vertical connecting rod (16), a horizontal A connecting rod (17) and a spline shaft (18), wherein the guide rod (11) is a connecting piece with the vibration-isolated object, and the guide rod (11) and the vibration-isolated object pass through the end of the guide rod (11) The flange is connected, the guide rod sleeve (13) is sleeved on the guide rod (11), the shell sleeve (12) is sleeved on the guide rod sleeve (13), and the guide rod sleeve (13) interferes with the guide rod (11) Cooperate, the guide rod sleeve (13) and the shell sleeve (12) are clearance fit, so that the guide rod (11) can do linear motion under the restriction of the shell sleeve (12), and the shell sleeve (12) is fixed by bolts On the outer wall of the casing box (41); the middle part of the guide rod (11), the guide rod sleeve (13) and the casing sleeve (12) has a through radial hole. In the case of no load, the positioning bolt (14) can pass guide rod (11), guide rod cover (13) and casing sleeve (12), the position of guide rod (11) is fixed relative to casing sleeve (12); Described guide rod ( 11) It is hinged with the vertical connecting rod (16) through the pin shaft (15). There is a cotter pin on the pin shaft (15) to limit the axial position of the pin shaft (15). The vertical connecting rod (16) and the horizontal connecting rod (17) ) is hinged by a pin shaft (15), the end of the transverse connecting rod (17) is an inner spline sleeve, and the transverse connecting rod (17) is nested in the middle of the spline shaft (18) through the inner spline sleeve; The extension spring system (2) is composed of an extension spring spline sleeve (23), several extension springs (22) and an extension spring adjustment mechanism (21), and the extension spring spline sleeve (23) is nested on the spline shaft (18) one end, several extension springs (22) are radially hinged around the extension spring spline sleeve (23), and the other end of each extension spring (22) is hinged with an extension spring adjustment mechanism (21); said extension spring adjustment mechanism (21) consists of a tension spring adjusting bolt (211) and a tension spring adjusting nut (212). The tension spring adjusting bolt (211) passes through the shell box (41), and the end of the tension spring adjusting bolt (211) is screwed with a tension spring adjustment Nut (212), adjust the extension spring adjusting nut (212) to adjust the preload of the corresponding extension spring (22); Described compression spring system (3) is made up of compression spring spline cover (34), several compression spring connectors (33), several compression springs (32) and compression spring adjustment mechanism (31), compression spring spline The sleeve (34) is nested on the other end of the spline shaft (18), several compression spring connectors (33) are hinged around the compression spring spline sleeve (34), and several compression spring connectors (33) are nested at the end Compression spring (32), the other end of each compression spring (32) is nested on the boss at the end of the compression spring connector (33); the compression spring connector (33) is hinged with the compression spring adjustment mechanism (31); The compression spring adjustment mechanism (31) is composed of a compression spring adjustment part (311) and a compression spring adjustment bolt (312). There is a blind hole at one end of the compression spring adjustment part (311) for the positioning of the compression spring adjustment bolt (312); The bolt (312) is screwed on the threaded hole of the shell box (41), and the pre-tightening force of the stage spring (32) can be adjusted by adjusting the stage clip adjusting bolt (312); Described shell (4) comprises shell box (41), limit block (42), shell cover (43), bearing (44) and bearing cover (45), and limit block (42) is fixed on shell box by bolt. On the inner wall of (41), it plays the role of limiting the position of the compression spring adjustment piece (311) and providing the sliding direction. The casing cover (43) is fixed on the rib plate of the casing box (41) by bolts, and the bearing (44) is inlaid In the through hole in the center of the housing cover (43), the bearing cover (45) is fixed on the housing cover (43), and the ring structure protruding from the side of the bearing cover (45) is embedded in the central through hole of the housing cover (43). (45) end abuts on the bearing (44) outer ring, to limit the axial position of bearing (44).