Piezoelectric cantilever beam multi-dimensional vibration energy collecting device

Abstract

The invention discloses a piezoelectric type cantilever beam multi-dimensional vibration energy collecting device. The piezoelectric type cantilever beam multi-dimensional vibration energy collecting device mainly comprises a spherical base, a plurality of sets of piezoelectric devices and wires. The spherical base is fixed in the shell through a fixing base in the shell, and a plurality of sets of self-aligning ball bearings are arranged on the surface of the spherical base. Each piezoelectric device comprises a cantilever beam, a permanent magnet and an annular magnet, the fixed end of the cantilever beam is in interference fit with the inner ring of the self-aligning ball bearing, the permanent magnet is arranged at the free end of the cantilever beam, and the surface of the cantilever beam is coated with a piezoelectric material to convert vibration energy into electric energy. The annular magnet is fixed in the shell and arranged at an interval with the permanent magnet, the magnetic poles are the same, and the projection of the cantilever beam falls into the outer circle of the annular magnet. One end of the wire is connected with the cantilever beam, and the other end is used for leading out generated electric energy.

Description

Technical Field

[0001] The invention relates to the field of vibration energy collection devices, and in particular to a piezoelectric cantilever beam multi-dimensional vibration energy collection device. Background Art

[0002] According to the different energy conversion mechanisms, vibration energy harvesting devices are mainly divided into three categories: electrostatic, piezoelectric and electromagnetic. Piezoelectric vibration energy harvesters use the piezoelectric effect of piezoelectric materials to generate electrical energy. When the piezoelectric material undergoes mechanical strain, an open circuit voltage is generated on the surface of the material due to the separation of charges. Based on this principle, various types of vibration energy harvesters have emerged. However, mechanical vibrations in natural scenes are usually multi-dimensional, so the collection equipment needs to have the ability to capture vibration energy in multiple directions.

[0003] CN117424488A discloses a multi-dimensional wide-band vibration energy collection device, which can collect wide-band vibration signals from multiple directions and convert the mechanical energy generated by the vibration into electrical energy. However, this multi-dimensional wide-band vibration energy collection device has the following shortcomings: 1. The volume is large and cannot meet the market demand for small-volume energy harvesting devices; 2. The installation structure of the fixed ball is unstable and is easily damaged when the vibration amplitude is large; 3. Unable to control the vibration sensitivity of the cantilever beam; 4. It is impossible to limit the vibration amplitude of the cantilever beam and make the cantilever beam quickly return to a stable state; 5. Although it can collect energy in multiple dimensions, the efficiency of collecting energy to convert mechanical energy into electrical energy is low. Summary of the invention

[0004] The purpose of the present invention is to provide a piezoelectric cantilever beam multi-dimensional vibration energy collection device in response to the corresponding deficiencies in the prior art. The device includes a spherical base and multiple groups of piezoelectric devices arranged on the spherical base. The piezoelectric devices convert the mechanical energy of vibration into electrical energy. The vibration amplitude of the cantilever beam is limited by the cooperation of annular magnets and permanent magnets, and the cooperation of outer rings and inner rings of self-aligning ball bearings. Slight vibrations are filtered out by replacing self-aligning ball bearings with different damping, thereby achieving control of the sensitivity of the cantilever beam to vibration.

[0005] The objective of the present invention is achieved by adopting the following scheme: A piezoelectric cantilever beam multi-dimensional vibration energy collection device, comprising a spherical base, multiple groups of piezoelectric devices, and wires. A fixing seat is fixedly connected to one side of the spherical base, and the fixing seat is fixedly connected in a shell. The surface of the spherical base is provided with multiple groups of self-aligning ball bearings for mounting the piezoelectric devices. Each set of piezoelectric devices includes a cantilever beam, a permanent magnet and an annular magnet. The fixed end of the cantilever beam is interference-fitted in the inner ring of the self-aligning ball bearing, and the free end is provided with a permanent magnet. The surface of the cantilever beam is provided with a piezoelectric material that converts vibration energy into electrical energy. The fixed end of the annular magnet is installed on the inner surface of the shell, and the free end is spaced apart from the free end of the permanent magnet and has the same magnetic pole. The projection of the cantilever beam toward the annular magnet falls into the outer circle of the annular magnet. The wires are connected to the piezoelectric materials on the surface of each cantilever beam, and are collected in the spherical base and then led out of the spherical base to conduct the electrical energy generated by the cantilever beam.

[0006] Preferably, the cantilever beam is a torsion cantilever beam in which any two cross sections rotate relative to each other around the axis of the cantilever beam.

[0007] Preferably, the piezoelectric devices are in five groups, which are respectively arranged in opposite directions of the fixing bases along the X-axis, the Y-axis and the Z-axis, so as to collect multi-dimensional vibration energy.

[0008] Preferably, a counterweight is provided at the fixed end of the cantilever beam.

[0009] Preferably, the surface of the spherical base is provided with a plurality of mounting holes, the outer ring of the self-aligning ball bearing is interference fit in the mounting holes, and the inner ring is interference fit on the fixed end of the cantilever beam.

[0010] Preferably, the inner circle of the free end of the outer ring of the self-aligning ball bearing is provided with a notch, and the notch is used to limit the vibration amplitude of the cantilever beam.

[0011] Preferably, the notch on the inner circle of the free end of the outer ring of the self-aligning ball bearing forms an angle of 30 degrees with the axis of the self-aligning ball bearing.

[0012] Preferably, the piezoelectric material on the surface of the cantilever beam is piezoelectric ceramic.

[0013] Preferably, the piezoelectric ceramic is PbZrxTi1-xO3, wherein X=0.48, and the mass ratio of zirconium to titanium is 52:48.

[0014] Preferably, a gap of 6-8 mm is provided between the free end of the annular magnet and the free end of the permanent magnet.

[0015] The beneficial effects of the present invention are as follows: Multiple sets of piezoelectric devices are set up to capture vibration energy from the X-axis, Y-axis and Z-axis directions, solving the problem that most existing vibration energy harvesters can only collect vibration energy in a single dimension.

[0016] By replacing the self-aligning ball bearings with different damping, the cantilever beam will only swing when the vibration force applied to the cantilever beam is greater than the resistance of the self-aligning ball bearing, thereby controlling the vibration sensitivity of the cantilever beam.

[0017] The limiting structure formed by the cooperation of the inner ring and the outer ring of the self-aligning ball bearing limits the swing of the cantilever beam to avoid damage to the device due to excessive amplitude. The rapid recovery of the equilibrium state is achieved through the cooperation of the permanent magnet and the annular magnet.

[0018] The cantilever beam is a torsion cantilever beam, which significantly improves the energy collection efficiency compared with the strip cantilever beam.

[0019] The invention has a compact structure, the spherical base is fixed in the shell through a fixing seat, the structure is stable and the reliability is high. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is a cross-sectional view of the present invention; Figure 2 It is a schematic diagram of the internal structure of the present invention; Figure 3 It is a structural diagram of a self-aligning ball bearing. DETAILED DESCRIPTION

[0021] like Figures 1 to 3 As shown, A piezoelectric cantilever beam multi-dimensional vibration energy collection device, comprising a spherical base 1, multiple groups of piezoelectric devices, and wires, wherein the piezoelectric devices are 5 groups, which are respectively arranged in opposite directions of a fixing base 3 along the X-axis, the Y-axis, and the Z-axis, and are used to collect multi-dimensional vibration energy; The spherical base 1 is installed on a fixing seat 3 provided on the inner side of the housing 2 by bolts. The fixing seat 3 is installed on the inner side of the housing 2 by bolts. The housing 2 in this embodiment is in a cube shape. The fixing seat 3 is installed at the center of one side of the cube-shaped housing 2. A plurality of sets of self-aligning ball bearings 4 are provided on the surface of the spherical base 1. A plurality of mounting holes are provided on the surface of the spherical base 1. The outer ring of the self-aligning ball bearing 4 is interference-fitted in the mounting hole, and the inner ring is interference-fitted on the fixed end of the cantilever beam 5. The inner circle of the free end of the outer ring of the self-aligning ball bearing 4 is provided with a notch, and the notch is used to limit the vibration amplitude of the cantilever beam 5. The notch of the inner circle of the free end of the outer ring of the self-aligning ball bearing 4 forms an angle of 30 degrees with the axis of the self-aligning ball bearing 4; Each group of piezoelectric devices includes a cantilever beam 5, a permanent magnet 6 and an annular magnet 7. The cantilever beam 5 is a torsion cantilever beam 5 in which any two cross sections rotate relative to each other around the axis of the cantilever beam 5. In this embodiment, the two ends of the torsion cantilever beam 5 are twisted 90 degrees, and the cross sections of the two ends are at an angle of 90 degrees. The torsion cantilever beam can increase the conversion efficiency of the cantilever beam 5 in converting the mechanical energy of vibration into electrical energy. The permanent magnet 7 is in a strip shape and extends axially toward the cantilever beam 5. The annular magnet 7 and the permanent magnet 7 are both made of sintered NdFeB material. The fixed end of the cantilever beam 5 is interference fit in the inner ring of the self-aligning ball bearing 4, and a permanent magnet 6 is provided at the free end. The surface of the cantilever beam 5 is provided with a piezoelectric material that converts vibration energy into electrical energy. The fixed end of the annular magnet 7 is installed on the inner surface of the shell 2, and the free end and the free end of the permanent magnet 6 are spaced apart and have the same magnetic pole; when the free end of the annular magnet 7 is the N pole, the free end of the permanent magnet 6 is also the N pole; when the free end of the annular magnet 7 is the S pole, the free end of the permanent magnet 6 is also the S pole; there is a 6-8mm gap between the free end of the annular magnet 7 and the free end of the permanent magnet 6, and the projection of the cantilever beam 5 toward the annular magnet 7 falls into the outer circle of the annular magnet 7, and the self-aligning ball bearing 4 is made of high-carbon chromium bearing steel; The fixed end of the cantilever beam 5 is also provided with a counterweight block 8, the keyway of the counterweight block 8 is matched with the fixed end of the cantilever beam 5, and the counterweight blocks 8 of different weights can be selected to achieve the force balance of the cantilever beam 5; The wire is connected to the piezoelectric material on the surface of each cantilever beam 5, and is collected in the spherical base 1 and then led out of the spherical base 1, so as to be used to lead out the electric energy generated by the cantilever beam. The wire is connected to the circuit board in the shell 2 or outside the shell 2 after being led out from the spherical base 1. The circuit board is provided with one or more of a standard rectifier circuit, a low-pass filter circuit, and a two-stage signal amplification circuit. The piezoelectric material on the surface of the cantilever beam 5 is a piezoelectric ceramic, and the piezoelectric ceramic is specifically PbZr x Ti 1-x O3 material, where X=0.48, and the mass ratio of zirconium to titanium is 52:48.

[0022] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modification made to the present invention by those skilled in the art without departing from the spirit of the present invention shall fall within the protection scope of the present invention.

Claims

1. A piezoelectric cantilever beam multi-dimensional vibration energy collection device, characterized in that: It comprises a spherical base (1), a plurality of piezoelectric devices, and a conductor. A fixing seat (3) is fixedly connected to one side of the spherical base (1). The fixing seat (3) is fixedly connected to the inner side of a housing (2). A plurality of self-aligning ball bearings (4) for mounting the piezoelectric devices are provided on the surface of the spherical base (1). Each set of piezoelectric devices comprises a cantilever beam (5), a permanent magnet (6) and an annular magnet (7); the fixed end of the cantilever beam (5) is interference-fitted in the inner ring of the self-aligning ball bearing (4); the free end is provided with a permanent magnet (6); the surface of the cantilever beam (5) is provided with a piezoelectric material for converting vibration energy into electrical energy; the fixed end of the annular magnet (7) is mounted on the inner surface of the housing (2); the free end is spaced apart from the free end of the permanent magnet (6) and has the same magnetic pole; the projection of the cantilever beam (5) in the direction of the annular magnet (7) falls within the outer circle of the annular magnet (7); The wires are connected to the piezoelectric material on the surface of each cantilever beam (5), are collected in the spherical base (1), and then lead out of the spherical base (1), so as to lead out the electric energy generated by the cantilever beam.

2. The piezoelectric cantilever beam multi-dimensional vibration energy harvesting device according to claim 1, characterized in that: The cantilever beam (5) is a torsion cantilever beam (5) in which any two cross sections undergo relative rotation about the axis of the cantilever beam (5).

3. The piezoelectric cantilever beam multi-dimensional vibration energy harvesting device according to claim 1, characterized in that: The piezoelectric devices are in five groups, which are arranged in opposite directions of the fixing seat (3) along the X-axis, the Y-axis and the Z-axis, respectively, and are used to collect multi-dimensional vibration energy.

4. The piezoelectric cantilever beam multi-dimensional vibration energy harvesting device according to claim 1, characterized in that: A counterweight block (8) is provided at the fixed end of the cantilever beam (5).

5. The piezoelectric cantilever beam multi-dimensional vibration energy harvesting device according to claim 1, characterized in that: The surface of the spherical base (1) is provided with a plurality of mounting holes, the outer ring of the self-aligning ball bearing (4) is interference-fitted in the mounting holes, and the inner ring is interference-fitted on the fixed end of the cantilever beam (5).

6. The piezoelectric cantilever beam multi-dimensional vibration energy collection device according to claim 5, characterized in that: The inner circle of the free end of the outer ring of the self-aligning ball bearing (4) is provided with a notch, and the notch is used to limit the vibration amplitude of the cantilever beam (5).

7. The piezoelectric cantilever beam multi-dimensional vibration energy collection device according to claim 6, characterized in that: The notch on the inner circle of the free end of the outer ring of the self-aligning ball bearing (4) forms an angle of 30 degrees with the axis of the self-aligning ball bearing (4).

8. The piezoelectric cantilever beam multi-dimensional vibration energy harvesting device according to claim 1, characterized in that: The piezoelectric material on the surface of the cantilever beam (5) is piezoelectric ceramics.

9. The piezoelectric cantilever beam multi-dimensional vibration energy harvesting device according to claim 8, characterized in that: The piezoelectric ceramic is PbZr x Ti 1-x O3, where X=0.48 and the mass ratio of zirconium to titanium is 52:

48.

10. The piezoelectric cantilever beam multi-dimensional vibration energy harvesting device according to claim 1, characterized in that: A gap of 6-8 mm is provided between the free end of the annular magnet (7) and the free end of the permanent magnet (6).

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