CN203670596U - Simply-supported-beam type dynamic vibration absorber adjustable in frequency - Google Patents

Abstract

The utility model aims to provide a simply-supported-beam type dynamic vibration absorber adjustable in frequency. The simply-supported-beam type dynamic vibration absorber adjustable in frequency comprises a base, a stepping motor, two sliders, a transmission lead screw and a metal beam, wherein a dovetail groove is formed in the base, the lower end of each slider is of a dovetail-shaped structure, the upper end of each slider is a supporting arm with a hole, a through hole with threads is formed in the middle of each slider, the lower ends of the two sliders are installed in the dovetail groove, a centralized mass block is installed in the middle of the metal beam, the two ends of the metal beam penetrate through the holes of the supporting arms at the upper ends of the two sliders respectively, reverse threads are symmetrically arranged on the outer wall of the transmission lead screw, the transmission lead screw penetrates through the through holes in the middles of the two sliders and is matched with the threads of the through holes, and the first end of the transmission lead screw is connected with the stepping motor. The simply-supported-beam type dynamic vibration absorber adjustable in frequency overcomes the defect that a traditional spiral spring vibration absorber can be influenced by mounting pre-tightening force easily. Compared with a cantilever-type vibration absorber, the degree of the requirement for extending space outwards is reduced. Compared with an electromagnetic or electrodynamic adjustable vibration absorber, electromagnetic leakage is little.

Description

A simply supported beam dynamic vibration absorber with adjustable frequency

technical field

The utility model relates to a vibration absorber.

Background technique

For a long time, how to control and reduce the vibration of structures has been a research hotspot. Vibration absorption technology is a relatively mature and effective method among many vibration control methods, which is embodied in the dynamic vibration absorber manufactured by using the vibration absorption principle.

Dynamic vibration absorbers can generally be divided into three categories: passive, semi-active, and fully active. The structural parameters of the passive dynamic shock absorber, that is, the stiffness and mass are not adjustable. It has a good vibration-absorbing effect on single-frequency vibration, but it has the disadvantage of a single controllable frequency. The fully active dynamic vibration absorber adjusts the vibration state of the vibration absorber through the vibration state feedback of the main vibration system, so that the dynamic force of the dynamic vibration absorber subsystem on the main vibration system is opposite to the vibration acceleration of the main vibration system, thereby reducing the main vibration. It is a broadband periodic vibration or random vibration response. According to adjustable parameters, semi-active vibration absorbers are divided into: adjustable quality and adjustable stiffness.

The utility model patent with the application number 201020244612.2 describes a dynamic vibration absorber that changes the natural frequency by changing the mass. This vibration absorber has a simple structure, but it cannot provide a continuously changing natural frequency by adjusting the number of masses. In practical applications Not convenient.

Contents of the invention

The purpose of the utility model is to provide a simply supported beam dynamic vibration absorber with adjustable frequency that can be adjusted for vibration responses at different frequencies to reduce the vibration noise of a certain frequency of the equipment.

The purpose of this utility model is achieved in that:

The utility model is a simply supported beam type dynamic vibration absorber with adjustable frequency. There is a dovetail groove on the seat, the lower end of the slider is a dovetail structure, the upper end of the slider is a support arm with a hole, and the middle part of the slider is a threaded through hole. The slider has two , the lower ends of the two sliders are installed in the dovetail groove and can move along the dovetail groove. There is a centralized mass block in the middle of the metal beam. The two ends of the metal beam pass through the holes of the support arms at the upper end of the two sliders. Reverse threads are arranged symmetrically on the outer wall of the bar. The transmission lead screw passes through the through holes in the middle of the two slide blocks and matches the threads of the two through holes. The first end of the drive lead screw is connected to the stepping motor.

The utility model can also include:

1. It also includes a limiter. The limiter includes a support rod, a nut, and a base. The lower end of the support rod is provided with a thread. The support rod is installed in the nut through the thread. The nut is connected to the base through a connecting rod, and the base is installed on the base. One surface of the concentrated mass block is provided with a limit slot or/and a limit hole in the middle, and the support rod is located in the limit slot or passes through the limit slot so as to limit the lateral movement of the concentrated mass block.

2. There are two support rods, and the two support rods and nuts together form a U-shaped fork structure.

3. A support plate is installed on the end opposite to the stepping motor on the base, a self-aligning bearing is installed in the middle of the support plate, and the second end of the transmission screw fits in the adapter sleeve of the self-aligning bearing.

4. An inverted T-slot is set on the base, and the base is installed in the inverted T-slot.

The utility model has the advantages that: the utility model overcomes the traditional helical spring vibration absorber which is easily affected by the installation pretightening force. Compared to cantilevered shock absorbers, the need for outward extension space is reduced. Electromagnetic leakage is less compared to electromagnetic and electrically tuned vibration absorbers.

Description of drawings

Fig. 1 is the structural representation of the utility model;

Fig. 2 is the cooperation schematic diagram of guide rail, slide block, leading screw of the present utility model;

Fig. 3 is a layout diagram of the mounting and assembling holes of the base of the present invention.

Detailed ways

The utility model is described in more detail below in conjunction with accompanying drawing example:

Referring to Figures 1-3, the base 4 is a basic base for installing and fixing other components. The vibration-absorbing body is a metal beam 1 structure with simple support at both ends and adjustable working length. The material of the metal beam 1 structure is spring steel. In the length direction of the base 4, there is a dovetail groove in the center, which is used as a guide rail for installing the slider 2, and restricts the movement of the slider 2 in other directions so that it can only move along one degree of freedom. One side of the dovetail groove There are inverted T-shaped grooves in the same direction in processing, which are used to install the limiter 9. Base 4 is fixedly installed with a support plate 8 with bolt at the other end of placing motor, has hole on the support plate, cooperates with self-aligning bearing 7. Each of the four corners of the base 4 is provided with a through hole 11, which can be conveniently installed on the device. One end has 4 threaded holes 10, to install and fix the stepper motor 6. The other end has threaded hole 12 in the groove, cooperates with the threaded hole of support plate 8 to be used for fixing support plate.

The transmission lead screw 3 is a lead screw processed with symmetrical arrangement and reverse threads, one end of which fits in the adapter sleeve of the self-aligning bearing 7, and the other end is aligned with the stepper under the condition that the axis centers of the two shafts are in line with each other. Motor 6 is fixed.

There are two sliders 2, the bottom of which is a dovetail structure that matches the guide rail, and the middle part is also processed with internal threads that match the drive screw 3. When installing, the two sliders need to be installed on the drive screw in reverse 3 sides. A support arm 5 is also fixedly installed on the top of the slider, and it is necessary to ensure that the square opening of the support arm 5 is parallel to the base during installation.

The two ends of the metal beam 1 are respectively inserted into the supporting arms 5, and the position of the concentrated mass in the middle is adjusted so that it has the same distance from the supporting arms 5 at both ends. The limiter 9 is a U-shaped fork with a square base, and the U-shaped structure can stretch into the groove processed on the concentrated mass, so that the concentrated mass is only moved vertically. There are threads on the support rod of the U-shaped fork, and it is fixed on the base 4 by working together with the nut and the square base.

The design principle of this patent is that when the natural frequency of the vibration absorber is consistent with the target vibration frequency, the vibration absorber can greatly absorb or reduce the vibration amplitude of the target. For the simple beam structure in the vibration absorber, after determining the three parameters of its cross-sectional shape, material, and boundary conditions, the first-order natural frequency itself is only the length of the beam between the constraints at its two ends (called the working length ) is inversely proportional to the quadratic, so only by adjusting the length between the constraints at both ends of the beam structure, the natural frequency of the dynamic vibration absorber can be changed so that it is consistent with the target frequency to achieve the purpose of absorbing vibration.

The utility model mainly includes a base with a dovetail groove, a slide block with a support arm structure, a stepping motor, a transmission device, a metal beam with a concentrated mass, and a limit device, which are six major mechanisms. When the stepper motor starts to work, the transmission device connected to it can simultaneously drive the two sliders to move towards each other at the same speed and distance, and the working length of the beam structure in the support arm at both ends of the slider is changed, and the natural frequency Change.

Claims (6)

1. the adjustable dynamic vibration absorber of freely-supported beam type frequency, it is characterized in that: comprise pedestal, stepper motor, slide block, turn-screw, beams of metal, stepper motor is arranged on one end of pedestal, on pedestal, have dovetail groove, the underpart of slide block is swallowtail-shaped structure, the upper end portion of slide block is with porose support arm, the middle part of slide block is screwed through hole, described slide block has two, the underpart of two slide blocks is arranged in dovetail groove and can moves along dovetail groove, beams of metal middle part is with lumped mass piece, the hole of two upper end of slide block portion support arms is passed respectively at the two ends of beams of metal, on turn-screw outer wall, be symmetrical arranged reverse thread, turn-screw passes the through hole at two slide blocks middle parts and matches with the screw thread of two through holes, the first end of turn-screw connects stepper motor.

2. the adjustable dynamic vibration absorber of a kind of freely-supported beam type frequency according to claim 1, it is characterized in that: also comprise snubber, snubber comprises strut, nut, base, strut lower end is provided with screw thread, strut is arranged in nut by screw thread, nut is connected by connecting rod with base, floor installation is on pedestal, on a face of lumped mass piece, restraining groove is set or/and middle part arranges spacing hole, thereby strut is arranged in restraining groove or through the transverse shifting of restraining groove restriction set mass block.

3. the adjustable dynamic vibration absorber of a kind of freely-supported beam type frequency according to claim 2, is characterized in that: described strut has two, two struts form U-shaped fork structure together with nut.

4. according to the arbitrary described adjustable dynamic vibration absorber of a kind of freely-supported beam type frequency of claim 1-3, it is characterized in that: dunnage is installed in the one end that is positioned at stepper motor subtend on pedestal, selfaligning bearing is installed at dunnage middle part, and the second end of turn-screw is linked in the adapter sleeve of selfaligning bearing.

5. according to the adjustable dynamic vibration absorber of a kind of freely-supported beam type frequency described in claim 2 or 3, it is characterized in that: inverted T shape groove is set on pedestal, and floor installation is in inverted T shape groove.

6. the adjustable dynamic vibration absorber of a kind of freely-supported beam type frequency according to claim 4, is characterized in that: inverted T shape groove is set on pedestal, and floor installation is in inverted T shape groove.

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