CN116317693A - Combined vibration energy harvester of power machine - Google Patents

Abstract

The invention relates to the technical field of energy harvesting devices, and discloses a composite vibration energy harvesting device for power machinery, which includes a casing, a piezoelectric-electromagnetic vibration collection module, and the collection module is installed in the casing; piezoelectric-electromagnetic vibration The collection module includes elastic beams, four piezoelectric ceramics, two magnets and coils; each piezoelectric ceramic is attached to the upper surface of the elastic beam, each magnet is attached to the center of the piezoelectric ceramic, and the axis of the magnet and the elastic beam The surface axes are parallel and the poles of the two magnets attract each other. The asymmetric spiral elastic beam used in the present invention can increase the length of the elastic beam in a limited space, effectively reduce the stress at the fixed end under the same conditions, effectively avoid the problem of stress concentration, and increase the service life of the device; the spiral elasticity The beam can be regarded as a planar spring. In addition to being able to collect the original natural frequency vibration energy, it broadens the working frequency band of the device to recover energy, and improves the application range and energy harvesting efficiency of the device.

Description

A composite vibration energy harvesting device for power machinery

technical field

The invention relates to the technical field of energy harvesting devices, in particular to a composite vibration energy harvesting device for power machinery.

Background technique

All kinds of power machinery will produce severe low-frequency vibration during operation. Normally, these vibrations are often dissipated in the form of mechanical energy, which is a renewable and clean energy with abundant reserves and wide distribution. If the vibration energy can be converted into electrical energy through the energy harvesting device to supply power to the sensing equipment on the surface of the power machine, the wireless and self-powered sensor network can be realized. This will effectively solve many problems such as the difficulty of traditional sensor wiring, the need for additional energy input, the pollution of the battery, and the difficulty of replacing the battery. At the same time, it can turn waste into treasure and realize the recovery and reuse of useless energy.

At present, there are mainly four energy harvesting methods for tiny low-frequency vibrations, namely electrostatic, piezoelectric, electromagnetic and friction. Electrostatic energy harvesting technology has good integration characteristics, but it needs to apply an initial voltage before generating electric energy, which limits its application range, so it is not widely used. For piezoelectric energy harvesting technology, the single piezoelectric cantilever beam is the most typical vibration energy harvesting structure, which has been extensively studied. Although its energy conversion efficiency is high, piezoelectric ceramics are brittle and prone to fatigue, so their service life is short. Electromagnetic energy harvesting technology has been widely used in many energy harvesters. Among them, the cantilever beam structure has been studied more, but there are problems such as large magnet and coil size and low output voltage. The core components of friction energy harvesting technology are two materials with different triboelectric sequences, which have the characteristics of simple structure, low cost, light weight, high power density and high efficiency.

In recent years, composite energy harvesting technology has been proven to be an effective way to achieve efficient vibration energy acquisition. By rationally designing the structure of the device, it is possible to take into account the advantages of multiple power generation methods and improve space utilization. Scholars at home and abroad have contributed many phased achievements in the field of compound vibration energy harvesting, and various new energy harvesting devices are emerging, but they still face many problems: (1) the existing energy harvesting devices using elastic beams fixed at both ends Although the collection device can achieve better output in a specific frequency band, the fixed parts at both ends of the elastic beam will produce excessive stress, which will easily cause device fatigue and damage to the power generation module, and shorten the life of the device; (2) Most energy sources Harvesting devices do not respond well to random and irregular environmental vibrations, which greatly reduces the range of vibration energy collection; how to improve the life of the device and increase the response frequency band of the device on the premise of ensuring high power output of the energy harvesting device has become technical problems that need to be solved urgently.

Contents of the invention

(1) Solved technical problems

The invention provides a composite vibration energy harvesting device for power machinery, the purpose of which is to overcome the problems of stress concentration and short life of the elastic beam vibration energy harvesting device applied to power machinery, and the vibration energy harvesting device is To solve the problem of weak random and irregular vibration response, a composite vibration energy harvesting device for power machinery using friction-piezoelectric-electromagnetic composite power generation technology can effectively solve the problem of elasticity while ensuring high power collection of power machinery vibration energy. Beam stress concentration problems and improve device response to random vibrations.

(2) Technical solution

To achieve the above object, the present invention provides the following technical solutions:

A composite vibration energy harvesting device for power machinery, comprising a casing, a piezoelectric-electromagnetic vibration collection module, the collection module is installed in the casing; the piezoelectric-electromagnetic vibration collection module includes elastic beams, four piezoelectric ceramics, Two magnets and coils; each piezoelectric ceramic is attached to the upper surface of the elastic beam, each magnet is attached to the center of the piezoelectric ceramic, the axis of the magnet is parallel to the axis of the surface of the elastic beam, and the magnetic poles of the two magnets attract each other. The two coils are respectively installed in the coil frame of the upper shell and the lower shell, and the axis of the magnet is coaxial and collinear with the axis of the coil; the frictional vibration collection module is installed at the inner corner of the lower shell, and each energy harvesting device is installed with multiple Frictional vibration collection module, each frictional vibration collection module includes two end caps, a cylinder, two copper sheets and small balls, the copper sheet is embedded inside the end cap, and the two end caps are respectively embedded in the two ends of the cylinder One end, one of the end caps is connected to the lower shell, and the ball is placed in the cylinder. When the shell is excited by external vibration, the piezoelectric-electromagnetic vibration collection module moves inside the shell under the action of gravity and inertia. Since the elastic beam is fixed by the elastic beam installation groove, it can only accept vertical excitation and convert it into elastic The deformation of the beam and the vertical movement of the magnet will cause the piezoelectric ceramic to generate electric energy under pressure, and complete the piezoelectric power generation; the magnetic flux of the coil changes to generate electric energy, and complete the electromagnetic power generation; the external vibration excitation received by the shell will be transmitted to the friction through the lower shell. In the type vibration collection module, the small ball moves up and down under the action of gravity and inertia. Due to the effect of the cylinder, the small ball can only move vertically. The small ball continuously touches the copper sheets on the upper and lower sides, so that the surface charge is continuously transferred. , so as to complete friction power generation. This device combines friction power generation, piezoelectric power generation, and electromagnetic power generation to convert vibration energy in the external environment into electric energy more efficiently.

Preferably, the casing includes an upper casing and a lower casing arranged symmetrically along the vertical direction, and the upper casing and the lower casing are fixedly connected by an adhesive.

Preferably, the outer surface of the upper casing is provided with a wire hole leading to the inner surface to realize the lead-out of the wire, and the inner surface is provided with a wire groove leading to the wire hole; the inside of the upper casing and the lower casing is provided with a coil frame, so that the coil installation and fixing.

Preferably, the inner surface of the lower shell is provided with a wire groove leading to the wire hole;

Preferably, the outer surface of the lower casing is provided with four installation holes, through which the studs pass through the installation holes of the lower casing, and then locked and fixed by screws;

Preferably, the elastic beam is fixedly connected to the elastic beam fixing slot by adhesive.

Preferably, the piezoelectric ceramics, the magnet and the elastic beam are fixedly connected by an adhesive.

Preferably, an adhesive is used to fix the connection between the coil and the coil frame.

Preferably, the end cover is fixedly connected to the lower casing with an adhesive, the cylinder and the end cover are fixedly connected through friction, the copper sheet and the end cover are fixedly connected with an adhesive, and the ball is freely placed on the cylinder. inside the barrel.

(3) Beneficial effects

Compared with the prior art, the present invention provides a composite vibration energy harvesting device for power machinery, which has the following beneficial effects:

1. The asymmetric spiral elastic beam used in the present invention can increase the length of the elastic beam in a limited space, effectively reduce the stress at the fixed end under the same conditions, effectively avoid the problem of stress concentration, and increase the service life of the device; The helical elastic beam can be regarded as a planar spring. In addition to collecting the original natural frequency vibration energy, it broadens the working frequency band of the device to recover energy, and improves the application range and energy capture efficiency of the device.

2. In the present invention, while the elastic beam moves in the shell in response to external vibration energy, the magnet on the elastic beam not only acts as a counterweight to amplify the movement of the elastic beam, but also causes the magnetic flux in the coil to change to generate an induced electromotive force, thereby The electromagnetic power generation is completed to form a composite energy output, which improves the energy harvesting efficiency of the device.

3. The frictional vibration collection module in the present invention utilizes the idle space of the device, which improves the space utilization rate of the device. The introduction of the frictional vibration collection module can effectively make up for the shortcomings of the piezoelectric-electromagnetic vibration collection module, which has insufficient energy collection capabilities outside the working frequency band and poor response to random vibrations, and improves the collection efficiency of the device for vibration energy in the environment.

Description of drawings

Fig. 1 is a structural representation of the present invention;

Fig. 2 is the front view of the present invention;

In the figure: 1. Housing; 2. Piezoelectric-electromagnetic vibration collection module; 3. Friction vibration collection module; 11. Upper housing; 12. Lower housing; 21. Elastic beam; 22. Piezoelectric ceramics; 23. Magnet ; 24, coil; 31, end cap; 32, cylinder; 33, copper sheet; 34, small ball; 111, wire hole; 112, coil frame; 113, wire groove; 121, installation hole; 122, elastic beam is fixed groove.

Detailed ways

The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention.

Please refer to Fig. 1-Fig. 2, the embodiment of the present application discloses a composite vibration energy harvesting device for power machinery, including: a housing 1; a piezoelectric-electromagnetic vibration collection module 2, which is installed in the housing 1 The piezoelectric-electromagnetic vibration collection module 2 includes an elastic beam 21, four piezoelectric ceramics 22, two magnets 23 and a coil 24; each piezoelectric ceramic 22 is attached to the upper surface of the elastic beam 21, and each magnet 23 Attached to the center of the piezoelectric ceramic, the axis of the magnet 23 is parallel to the axis of the surface of the elastic beam 21, the magnetic poles of the two magnets 23 attract each other, and the two coils 24 are respectively installed in the coil frame 112 of the upper shell 11 and the lower shell 12, The axis of the magnet 23 is coaxial and collinear with the axis of the coil 24; the frictional vibration collection module 3 is installed at the inner corner of the lower casing 12, and each energy harvesting device is equipped with a plurality of frictional vibration collection modules 3, each frictional vibration The collection module includes two end caps 31, a cylinder 32, two copper sheets 33 and small balls 34, the copper sheets 33 are embedded inside the end caps 31, and the two end caps 31 are respectively embedded in the two ends of the cylinder 32, wherein An end cap 31 is connected with the lower casing 12 , and the ball 34 is placed in the cylinder 32 . When the housing 1 is excited by external vibration, the piezoelectric-electromagnetic vibration collection module 2 moves in the housing 1 under the action of gravity and inertia. Since the elastic beam 21 is fixed by the elastic beam installation groove 122, it can only accept vertical excitation. , and transformed into the deformation of the elastic beam 21 and the vertical movement of the magnet 23, thereby causing the piezoelectric ceramic 22 to generate electric energy under pressure, and complete piezoelectric power generation; the magnetic flux of the coil 24 changes to generate electric energy, and complete electromagnetic power generation; The external vibration excitation will be transmitted to the frictional vibration collection module 3 through the lower shell 12, so that the small ball 34 moves up and down under the action of gravity and inertia. Due to the effect of the cylinder 32, the small ball 34 can only move vertically. The ball 34 is constantly in contact with the copper sheets 33 on the upper and lower sides, so that the surface charges are continuously transferred, thereby completing triboelectric power generation. This device combines friction power generation, piezoelectric power generation, and electromagnetic power generation to convert vibration energy in the external environment into electric energy more efficiently.

In this embodiment, the casing 1 includes an upper casing 11 and a lower casing 12 arranged symmetrically along the vertical direction, and the upper casing 11 and the lower casing 12 are fixedly connected by an adhesive.

The outer surface of the upper casing 11 is provided with a wire hole 111 leading to the inner surface to realize the lead out of the wire, and the inner surface is provided with a wire groove 113 leading to the wire hole 111; the inside of the upper casing 11 and the lower casing 12 is provided with a coil frame 112, so that Installation and fixing of the coil 24.

The inner surface of the lower shell 12 is provided with a wire groove 113 leading to the wire hole 111;

The outer surface is provided with four installation holes 121, through which the studs pass through the installation holes 121 of the lower casing 12, and then locked and fixed by screws;

The elastic beam installation groove 122 is used for fixing the elastic beam 21 . The vibration energy collection mechanism inside is protected by the shell 1, and the vibration energy from the outside is transmitted.

In this embodiment, the elastic beam 21 and the elastic beam fixing groove 122 are fixedly connected by an adhesive. The piezoelectric ceramic 22 , the magnet 23 and the elastic beam 21 are fixedly connected by an adhesive. The coil 24 is fixedly connected to the coil frame 112 using an adhesive.

In this embodiment, the end cover 31 is fixedly connected to the lower housing 12 by adhesive, the cylinder 32 is fixedly connected to the end cover 31 by friction force, and the copper sheet 33 is fixedly connected to the end cover 31 by adhesive. , the ball 34 is freely placed in the cylinder 32.

Claims (9)

1. A composite vibration energy harvesting device for power machinery, comprising a housing (1), a piezoelectric-electromagnetic vibration collection module (2), characterized in that: the collection module (2) is installed in the housing (1); The piezoelectric-electromagnetic vibration collection module (2) includes elastic beams (21), four piezoelectric ceramics (22), two magnets (23) and coils (24); each piezoelectric ceramic (22) is attached to On the upper surface of the elastic beam (21), each magnet (23) is attached to the central position of the piezoelectric ceramic, the axis of the magnet (23) is parallel to the surface axis of the elastic beam (21), and the magnetic poles of the two magnets (23) attract each other , the two coils (24) are installed in the coil frame (112) of the upper casing (11) and the lower casing (12) respectively, the axis of the magnet (23) and the axis of the coil (24) are coaxial and collinear; The vibration collection module (3) is installed at the inner corner of the lower casing (12), and each energy harvesting device is equipped with a plurality of frictional vibration collection modules (3), and each frictional vibration collection module includes two end covers (31), Cylinder (32), two copper sheets (33) and small ball (34), copper sheet (33) is embedded in end cap (31) inside, and two end caps (31) are embedded in cylinder (32) respectively ), one of the end caps (31) is connected to the lower casing (12), and the ball (34) is placed in the cylinder (32); when the casing (1) is excited by external vibration, piezoelectric-electromagnetic vibration collection The module (2) moves inside the casing (1) under the action of gravity and inertia, and since the elastic beam (21) is fixed by the elastic beam installation groove (122), it can only accept vertical excitation and converts it into an elastic beam ( 21) Deformation and vertical movement of the magnet (23), thereby causing the piezoelectric ceramic (22) to generate electric energy under pressure to complete piezoelectric power generation; the magnetic flux of the coil (24) changes to generate electric energy to complete electromagnetic power generation; the shell (1) The received external vibration excitation will be transmitted to the frictional vibration collection module (3) through the lower shell (12), so that the small ball (34) moves up and down under the action of gravity and inertia, and due to the action of the cylinder (32), The small ball (34) can only move vertically, and the small ball (34) continuously contacts the copper sheets (33) on the upper and lower sides, so that the surface charges are continuously transferred, thereby completing triboelectric power generation. 2. A composite vibration energy harvesting device for a power machine according to claim 1, characterized in that: said casing (1) comprises an upper casing (11) and a lower casing (12) arranged symmetrically along the vertical direction , The upper casing (11) and the lower casing (12) are fixedly connected by an adhesive. 3. The composite vibration energy harvesting device of a power machine according to claim 1, characterized in that: the outer surface of the upper casing (11) is provided with wire holes (111) leading to the inner surface to realize the connection of wires. Leading out, the inner surface is provided with a wire groove (113) leading to the wire hole (111). 4. The composite vibration energy harvesting device of a power machine according to claim 1, characterized in that: coil holders (112) are provided inside the upper casing (11) and the lower casing (12), so as to facilitate Installation and fixing of coil (24). 5. A composite vibration energy harvesting device for power machinery according to claim 1, characterized in that: the outer surface of the lower housing (12) is provided with four mounting holes (121), through which studs pass through The mounting holes (121) of the lower casing (12) are locked and fixed by screws. 6 . The composite vibration energy harvesting device of a power machine according to claim 1 , characterized in that: the elastic beam ( 21 ) is fixedly connected to the elastic beam fixing groove ( 122 ) with an adhesive. 6 . 7. A composite vibration energy harvesting device for power machinery according to claim 1, characterized in that: an adhesive is used between the piezoelectric ceramic (22), the magnet (23) and the elastic beam (21) Fixed connection. 8 . The compound vibration energy harvesting device for power machinery according to claim 1 , characterized in that: the coil ( 24 ) is fixedly connected to the coil frame ( 112 ) with an adhesive. 9. The composite vibration energy harvesting device of a power machine according to claim 1, characterized in that: the end cover (31) is fixedly connected to the lower casing (12), and the cylinder ( 32) is fixedly connected with the end cap (31) by friction, the copper sheet (33) is fixedly connected with the end cap (31) using an adhesive, and the ball (34) is freely placed in the cylinder (32).

Images