Three-dimensional dynamic vibration absorber based on parallel mechanism

Abstract

The present application relates to the technical field of mechanical vibration and damping and noise reduction, and particularly relates to a three-dimensional dynamic vibration absorber based on a parallel mechanism, which comprises a fixed frame, a vibration-absorbing mass, and three identical branch kinematic chains; the fixed frame comprises a lower bottom plate, an upper top plate, and a guide rod; the guide rod is installed between the lower bottom plate and the upper top plate; the branch kinematic chain is sleeved on the guide rod; the vibration-absorbing mass is installed between the lower bottom plate and the upper top plate; and the branch kinematic chain is connected with the vibration-absorbing mass through a spherical hinge. The present application can effectively suppress multi-dimensional line spectrum vibration of a dynamic mechanical device and overcome the problems of large size and large additional mass of existing multi-dimensional dynamic vibration absorbers.

Description

Technical Field

[0001] This invention relates to the field of mechanical vibration and vibration reduction technology, and in particular to a three-dimensional dynamic vibration absorber based on a parallel mechanism. Background Technology

[0002] Vibration control of power machinery has become a crucial factor affecting the safety and reliability of ship propulsion systems. Currently, vibration control for power machinery primarily focuses on the vibration transmission path, employing techniques such as double-layer vibration isolation and floating raft vibration isolation. These measures effectively reduce vibration energy transmission and provide excellent broadband vibration reduction in the mid-to-high frequency range, but their effectiveness in reducing low-frequency characteristic spectrum vibrations is limited. Dynamic vibration absorbers, which suppress the vibration of the main system through their own vibration, offer advantages such as low environmental dependence, simple installation, and targeted control of characteristic spectrum vibrations, providing an important technical solution for addressing the low-frequency characteristic spectrum vibration problem in power machinery.

[0003] Considering that the linear vibrations of power machinery are mostly multidimensional vibrations, and that horizontal vibrations are not negligible in addition to vertical vibrations, multidimensional dynamic vibration absorbers are needed to control them. However, most existing dynamic vibration absorbers are unidirectional, and even the few multidimensional dynamic vibration absorbers are essentially composed of multiple unidirectional absorbers. While they have advantages such as simple design and convenient installation, they also have disadvantages such as large space dimensions and heavy accessories. Summary of the Invention

[0004] The technical problem solved by this invention is to provide a three-dimensional dynamic vibration absorber based on a parallel mechanism, which can effectively suppress the multidimensional line spectrum vibration of power machinery and overcome the problems of large size and large added mass of existing multidimensional dynamic vibration absorbers.

[0005] The technical solution adopted in this invention is as follows:

[0006] A three-dimensional dynamic vibration absorber based on a parallel mechanism includes a fixed frame, a vibration-absorbing mass block, and three identical branch kinematic chains. The fixed frame includes a lower base plate, an upper top plate, and a guide rod. The guide rod is installed between the lower base plate and the upper top plate. The branch kinematic chains are sleeved on the guide rod. The vibration-absorbing mass block is installed between the lower base plate and the upper top plate. The branch kinematic chains and the vibration-absorbing mass block are connected by a ball joint.

[0007] The bottom plate is a hollow hexagonal structure with alternating long and short sides, and a boss is fixedly installed on the short side.

[0008] The upper top plate and the lower bottom plate have corresponding structures. One end of the guide rod is fixedly installed inside the boss, and the other end is connected to the upper top plate.

[0009] The upper and lower ends of the branch kinematic chain are respectively equipped with spring groups.

[0010] The saddle is mounted on the guide rod via a linear bearing.

[0011] The branch kinematic chain includes a slide saddle and a connecting rod; one end of the connecting rod is connected to the slide saddle via a three-degree-of-freedom upper ball joint, and the other end is connected to the vibration-absorbing mass block via a three-degree-of-freedom lower ball joint.

[0012] The spring assembly includes an upper spring and a lower spring; one end of the upper spring is fixedly connected to the upper end of the slide saddle, and the other end is fixedly connected to the top plate; one end of the lower spring is fixedly connected to the lower end of the slide saddle, and the other end is fixedly connected to the boss at the bottom end of the base plate.

[0013] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0014] (1) The present invention provides a three-dimensional dynamic vibration absorber based on a parallel mechanism. The vibration-absorbing mass block has three translational degrees of freedom, so the vibration absorber can simultaneously suppress the line spectrum vibration of the vibration source device in three directions.

[0015] (2) The three-dimensional dynamic vibration absorber based on the parallel mechanism provided by the present invention contains only one vibration-absorbing mass block compared with the multi-dimensional dynamic vibration absorber composed of multiple one-dimensional dynamic vibration absorbers. Therefore, the vibration absorber is smaller in size and has less added mass to the main system.

[0016] (3) The three-dimensional dynamic vibration absorber based on parallel mechanism provided by the present invention has the advantages of compact mechanical structure and high modularity. It can be installed on vibration source equipment very conveniently and can be applied to the line spectrum vibration control of pump equipment in nuclear power plants. It has a wide range of application prospects. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the overall structure of a three-dimensional dynamic vibration absorber based on a parallel mechanism provided by the present invention;

[0018] Figure 2 This is a schematic diagram of the fixing frame structure of the present invention;

[0019] Figure 3 This is a schematic diagram of the branched kinematic chain structure of the present invention. Figure 1 ;

[0020] Figure 4 This is a schematic diagram of the branched kinematic chain structure of the present invention. Figure 2 ;

[0021] Figure 5 This is a schematic diagram of the present invention installed in a vibration source device;

[0022] Figure 6 This is a diagram showing the vibration absorption effect of the present invention after it is installed in a vibration source device;

[0023] In the diagram: 1: Fixed frame, 2: Vibration-absorbing mass block, 3: Branch kinematic chain, 11: Lower base plate, 12: Upper top plate, 13: Guide rod, 31: Saddle, 32: Spring assembly, 33: Connecting rod, 34: Linear bearing, 35: Upper ball joint, 36: Lower ball joint, 111: Boss, 321: Upper spring, 322: Lower spring. Detailed Implementation

[0024] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0025] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0026] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0027] like Figure 1 and Figure 2 As shown, the present invention provides a three-dimensional dynamic vibration absorber based on a parallel mechanism, comprising a fixed frame 1, a vibration-absorbing mass block 2, and three identical branch kinematic chains 3; the fixed frame 1 includes a lower base plate 11, an upper top plate 12, and a guide rod 13; the lower base plate 11 is a hollow hexagonal structure with alternating long and short sides, and a boss 111 is fixedly installed on the short side; the upper top plate 12 corresponds structurally to the lower base plate 11; one end of the guide rod 13 is fixedly installed inside the boss 111, and the other end is connected to the upper top plate 12; the branch kinematic chains 3 are sleeved on the guide rod 13, and spring groups 32 are respectively provided at the upper and lower ends of the branch kinematic chains 3; the vibration-absorbing mass block 2 is provided inside the lower base plate 11;

[0028] like Figure 3 and Figure 4 As shown, the branch kinematic chain 3 includes a slide saddle 31, a spring assembly 32, and two identical connecting rods 33; the slide saddle 31 is sleeved on the guide rod 13 via a linear bearing 34, and the spring assembly 32 is installed at the upper and lower ends of the slide saddle 31; one end of the connecting rod 33 is connected to the slide saddle 31 via a three-degree-of-freedom upper ball joint 35, and the other end is connected to the vibration-absorbing mass block 2 via a three-degree-of-freedom lower ball joint 36.

[0029] The spring assembly 32 consists of an upper spring 321 and a lower spring 322, which have identical structures and stiffness. One end of the upper spring 321 is fixedly connected to the upper end of the slide saddle 31, and the other end is fixedly connected to the top plate 12. One end of the lower spring 322 is fixedly connected to the lower end of the slide saddle 31, and the other end is fixedly connected to the boss 111 at the bottom of the base plate 11, so that the slide saddle 31 can only perform a single degree of freedom elastic movement along the axis of the guide rod 13. The two connecting rods 33 in the branch kinematic chain 3 have the same structure and length, and are arranged in parallel to ensure that the vibration-absorbing mass has three translational degrees of freedom.

[0030] Both the spring assembly 32 and the vibration-absorbing mass block 2 can be replaced, thereby adjusting the vibration absorption frequency to meet the vibration reduction performance requirements of different vibration source devices.

[0031] like Figure 5 As shown, the dynamic vibration absorber of the present invention is installed on a vibration isolation device for a vibration source device. The four dynamic vibration absorbers are evenly distributed at the feet of the vibration source device, and the feet of the vibration source device are supported by the vibration isolators. Figure 6 The diagram shows the average vibration reduction effect at the connection points between the vibration source equipment's feet and the four vibration isolators before and after installing the dynamic vibration absorber of the present invention. Near the characteristic frequency of the vibration source equipment operating at its rated speed, the vibration reduction effect in the X and Y directions within a 2Hz bandwidth is no less than 10dB, and the vibration reduction effect in the Z direction within a 2Hz bandwidth is no less than 5dB.

[0032] The dynamic vibration absorber proposed in this invention can absorb vibrations from three directions of the vibration source equipment, and has the advantages of high modularity, compact structure, and better vibration absorption effect.

[0033] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0034] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A three-dimensional dynamic vibration absorber based on a parallel mechanism, characterized in that, It includes a fixed frame (1), a vibration-absorbing mass block (2), and three identical branch kinematic chains (3); the fixed frame (1) includes a lower base plate (11), an upper top plate (12), and a guide rod (13); the guide rod (13) is installed between the lower base plate (11) and the upper top plate (12), the branch kinematic chains (3) are sleeved on the guide rod (13), the vibration-absorbing mass block (2) is installed between the lower base plate (11) and the upper top plate (12), and the branch kinematic chains (3) and the vibration-absorbing mass block (2) are connected by a ball joint; The upper and lower ends of the branch kinematic chain (3) are respectively provided with spring groups (32); The branch kinematic chain (3) includes a saddle (31) and a connecting rod (33); one end of the connecting rod (33) is connected to the saddle (31) through a three-degree-of-freedom upper ball joint (35), and the other end is connected to the vibration-absorbing mass block (2) through a three-degree-of-freedom lower ball joint (36); The slide saddle (31) is mounted on the guide rod (13) via a linear bearing (34); The spring assembly (32) includes an upper spring (321) and a lower spring (322); one end of the upper spring (321) is fixedly connected to the upper end of the slide saddle (31), and the other end is fixedly connected to the upper top plate (12); one end of the lower spring (322) is fixedly connected to the lower end of the slide saddle (31), and the other end is fixedly connected to the boss (111) at the bottom end of the lower bottom plate (11).

2. The three-dimensional dynamic vibration absorber based on a parallel mechanism according to claim 1, characterized in that, The bottom plate (11) is a hollow hexagonal structure with alternating long and short sides, and a boss (111) is fixedly installed on the short side.

3. The three-dimensional dynamic vibration absorber based on a parallel mechanism according to claim 2, characterized in that, The upper top plate (12) and the lower bottom plate (11) are structurally corresponding. One end of the guide rod (13) is fixedly installed inside the boss (111), and the other end is connected to the upper top plate (12).

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