A series-parallel adjustable laminated hydraulic piezoelectric energy harvesting device

Abstract

The present invention relates to a piezoelectric energy harvesting device, specifically a laminated hydraulic piezoelectric energy harvesting device with adjustable series and parallel connections, which includes a housing, a flow guiding orifice plate, an insulating base, an insulating film, piezoelectric sheets, insulating compression rings, buffer blocks, end caps, and watertight connectors. In the present invention, N piezoelectric sheets (N is a positive integer greater than or equal to 2) are stacked, and the positive and negative electrodes of each piezoelectric sheet are led out by wires and connected to the watertight connectors to achieve adjustable series and parallel connections and sealing of the device; lubricating oil is injected into the device to reduce frictional losses and improve power generation efficiency; insulating glue is injected into the device to protect the piezoelectric sheets, reduce the influence caused by high-pressure hydraulics, reduce the occurrence of electric leakage, enable the device to work in a more complex environment, and reduce maintenance costs; a flow guiding orifice plate for guiding the flow is installed in the cavity of the device, so that the fluid pressure can act more fully on the piezoelectric sheets and improve power generation efficiency.

Description

Technical Field

[0001] The present invention relates to a hydraulic piezoelectric energy harvesting device, and more particularly to a laminated hydraulic piezoelectric energy harvesting device with adjustable series-parallel connection. Background Art

[0002] With the rapid development of China's industry, hydraulic systems are widely used in many fields. When the system operates, the pressure pulsations generated in the pipeline will cause adverse effects such as equipment vibration and noise pollution, and the fluid-induced vibration energy will also be wasted because it cannot be utilized. In recent years, the country's requirements for energy conservation and environmental protection have been continuously increasing, and the fluid-induced vibration piezoelectric energy harvesting technology is also being widely studied. Currently, the hot spot in the research on energy harvesting technology at home and abroad is the piezoelectric energy harvesting technology using piezoelectric materials. This technology utilizes the fluid-structure interaction effect. When the piezoelectric material deforms during the flow-blocking process, electrical energy will be generated. This technology has many advantages, including simple structure, no electromagnetic interference, no pollution, no heat generation, and easy integration.

[0003] However, at the present stage, there are still some deficiencies in the piezoelectric energy harvesting device. The power of a single piezoelectric wafer is relatively low, making it difficult to meet the requirements of low-power-consuming components; after the piezoelectric energy harvesting device is installed, its voltage and current cannot be adjusted, resulting in the device being able to cooperate with only specific components, with low versatility and flexibility; there are still many problems with sealing and insulation in high-pressure hydraulic systems, and the piezoelectric wafers are subjected to relatively large pulsating pressures, increasing the possibility of damage to the piezoelectric wafers and increasing the maintenance cost. In order to improve this situation, it is urgent to develop a piezoelectric energy harvesting device with greater power, higher efficiency, better versatility, and higher flexibility to improve the collection efficiency of fluid-induced vibration energy in the pipeline. Summary of the Invention

[0004] In view of the fluid-induced vibration generated by the flow of the fluid medium in the hydraulic system, the present invention designs a laminated hydraulic piezoelectric energy harvesting device with adjustable series-parallel connection. To solve the problem of the relatively low power of a single piezoelectric wafer, the present invention stacks multiple piezoelectric wafers. To improve the versatility and flexibility of the device, the present invention adopts a method of adjustable series-parallel connection of piezoelectric wafers, leading out the positive and negative electrodes of each piezoelectric wafer with wires, facilitating the transmission of electrical energy to external low-power-consuming components, and performing series-parallel combinations of any number of piezoelectric wafers; to solve the problems of sealing and insulation of the device in a high-pressure hydraulic system, the present invention injects insulating glue into the device to protect the piezoelectric wafers, reduce the probability of their damage, reduce the occurrence of leakage, and reduce the maintenance cost of the device; uses a watertight joint to connect with the wire and seal the insulating glue; injects lubricating oil into the device to reduce frictional losses, improve the power generation efficiency, and reduce the occurrence of leakage; the present invention installs a flow guiding orifice plate for guiding the flow in the cavity of the device, enabling the fluid pressure to act more fully on the piezoelectric wafers and improving the power generation efficiency.

[0005] A series-parallel adjustable laminated hydraulic piezoelectric energy harvesting device, comprising a housing, a flow guiding orifice plate, an insulating base, an insulating film, piezoelectric sheets, insulating compression rings, plugs, end caps, watertight connectors, wires, sealing rings, buffer blocks, insulating glue, and lubricating oil; there is a housing cavity in the middle of the housing, and the outer diameters are different, showing a stepped shape. One end of the small-diameter part of the housing is provided with an external thread for connecting a pipeline system, and the other end is provided with an internal thread for connecting the flow guiding orifice plate. A threaded hole is provided in the middle of the large-diameter part of the housing for injecting lubricating oil and connecting the plug, and an internal thread is provided on the end face of the large-diameter part of the housing for connecting the end cap; the outer diameter of the end cap is different, showing a stepped shape and provided with a threaded hole for connecting the watertight connector, and the outer side of the large-diameter part is provided with a thread for connecting the housing; the insulating base is closely attached to the end face on the side where the inner diameter of the housing cavity changes, and both sides are sealed by sealing rings; the insulating film, piezoelectric sheets, insulating compression rings, and buffer blocks form a piezoelectric energy harvesting assembly; one side of the piezoelectric energy harvesting assembly with the insulating film is positioned by the end face of the insulating base, and the other side is positioned by the end face of the large-diameter part of the end cap; there are N groups of piezoelectric sheets, insulating compression rings, and buffer blocks in the piezoelectric energy harvesting assembly, where N is a positive integer greater than or equal to 2. An insulating film with the same diameter as the piezoelectric sheet is installed between the piezoelectric sheet close to the insulating base and the insulating base. The side of the buffer block close to the end cap is sealed with the adjacent end cap surface by a sealing ring. The positive and negative electrodes of the piezoelectric sheet are connected to the watertight connector through the holes provided in the insulating compression ring, piezoelectric sheet, buffer block, and end cap; in a combination of a piezoelectric sheet, an insulating compression ring, and a buffer block, the outside of the buffer block is closely attached to the inside of the insulating compression ring, and the end faces of the buffer block and the insulating compression ring are respectively closely attached to different faces of the adjacent two piezoelectric sheets.

[0006] Furthermore, the flow guiding orifice plate is provided with a straight hole and four symmetrically distributed inclined holes that diverge outward along the flow direction for guiding the flow, so that the fluid pressure acts more evenly on the piezoelectric sheets, thereby making the deformation of the piezoelectric sheets more sufficient, increasing the power generation efficiency, and is provided with an internal hexagonal groove for tightening the flow guiding orifice plate.

[0007] Furthermore, in the piezoelectric energy harvesting assembly, the positive and negative electrodes of the piezoelectric sheet are connected to the watertight connector through the holes provided in the insulating compression ring, piezoelectric sheet, buffer block, and end cap, for realizing the adjustment and conversion of different combinations of series and parallel connections of N piezoelectric sheets (N is a positive integer greater than or equal to 2), improving the versatility and flexibility of the device; the insulating glue is injected into the device through the holes provided in the insulating compression ring, piezoelectric sheet, end cap, and buffer block, and at the same time, the watertight connector is used for sealing, for protecting the piezoelectric sheet and reducing the influence caused by excessive fluid pressure, so that the device can work more stably in a more complex environment.

[0008] Furthermore, the lubricating oil is injected into the injection device through the holes provided in the housing and the insulating pressure ring for lubricating the insulating pressure ring, reducing the friction during its movement, thereby reducing energy loss and increasing the power generation efficiency. The insulating base and the insulating pressure ring are provided with sealing ring fixing grooves for fixing the sealing ring, which can prevent the leakage of high-pressure liquid and insulating glue, and at the same time can cooperate with the plug to prevent the leakage of lubricating oil; sealant is applied at the connection between the insulating pressure ring and the insulating base and at the connection between two adjacent insulating pressure rings to prevent the leakage of lubricating oil.

[0009] Furthermore, the elastic modulus of the material used for the insulating pressure ring is greater than that of the buffer block, and the elastic modulus of the buffer block is greater than that of the insulating glue. Using elastic materials can better protect the piezoelectric sheet, and at the same time, the difference in the elastic modulus of the materials ensures that the piezoelectric sheet can deform normally. When the fluid pressure is too high, the buffer block will play a buffering role; when the piezoelectric sheet deforms and restores, the buffer block can play a good promoting role.

[0010] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0011] (1) The present invention uses N piezoelectric sheets (N is a positive integer greater than or equal to 2) for stacked assembly and leads out the positive and negative electrodes thereof with wires to connect to the watertight joint, enabling series-parallel adjustment of any combination of N piezoelectric sheets (N is a positive integer greater than or equal to 2), improving the versatility and flexibility of the device, and at the same time enabling good sealing of the device.

[0012] (2) The present invention uses a flow guiding orifice plate to apply the fluid pressure more evenly on the piezoelectric sheet, enabling it to deform more fully and improving the power generation efficiency of the device.

[0013] (3) The present invention injects lubricating oil into the cavity between the housing and the insulating pressure ring, effectively reducing the friction between the housing and the insulating pressure ring, reducing energy loss, and improving the power generation efficiency of the device.

[0014] (4) The present invention injects insulating glue into the cavity between the piezoelectric sheet, the buffer block, and the insulating pressure ring, which can better protect the piezoelectric sheet, reduce the occurrence of electric leakage, reduce the influence of the high-pressure hydraulic environment, reduce the maintenance cost of the device, and enable it to be applied to more complex occasions. Description of the Drawings

[0015] Figure 1 is the overall structural schematic diagram of the device when installing three piezoelectric sheets;

[0016] Figure 2 is the structural schematic diagram of the housing;

[0017] Figure 3 is the structural schematic diagram of the flow guiding orifice plate;

[0018] Figure 4 It is a schematic structural diagram of an insulating base;

[0019] Figure 5 It is a schematic structural diagram of insulating pressure rings a, b, and c;

[0020] Figure 6 It is a schematic structural diagram of piezoelectric wafers a and b with holes;

[0021] Figure 7 It is a schematic structural diagram of an end cap;

[0022] Figure 8 It is a schematic structural diagram of buffer block c;

[0023] The labels in the above figures are: 1. Housing; 2. Flow guiding orifice plate; 3. Insulating base; 4. Insulating film; 5. Piezoelectric wafer; 6. Insulating pressure ring a; 7. Insulating pressure ring b; 8. Plug; 9. Piezoelectric wafer a with hole; 10. Piezoelectric wafer b with hole; 11. Insulating pressure ring c; 12. End cap; 13. Watertight joint; 14. Wire; 15. Seal ring d; 16. Seal ring c; 17. Buffer block c; 18. Insulating glue; 19. Lubricating oil; 20. Buffer block b; 21. Seal ring b; 22. Buffer block a; 23. Seal ring a; 1.1. External thread; 1.2. Internal thread; 1.3, 6.2, 7.2 holes; 1.4. Internal thread; 2.1. Straight hole; 2.2. Oblique hole; 2.3. External thread; 2.4. Internal hexagonal groove; 3.1, 3.2, 11.2, 11.3. Seal ring fixing grooves; 6.1, 7.1, 9.1, 10.1, 11.1, 12.2, 17.1. Drainage lead holes; 12.1 External thread; 12.3. Threaded hole. Specific embodiments

[0024] In order to make the objectives, technical solutions, and advantages of the present invention clearer and more understandable, the present invention will be further described in detail below in conjunction with the attached drawings of a piezoelectric energy harvesting device with three piezoelectric wafers installed.

[0025] Figure 1An embodiment of the present invention includes a housing (1), a flow guiding orifice plate (2), an insulating base (3), an insulating film (4), a piezoelectric sheet (5), an insulating pressing ring a (6), an insulating pressing ring b (7), a plug (8), a perforated piezoelectric sheet a (9), a perforated piezoelectric sheet b (10), an insulating pressing ring c (11), an end cover (12), a watertight joint (13), a wire (14), a sealing ring d (15), a sealing ring c (16), a buffer block c (17), an insulating adhesive (18), a lubricating oil (19), a buffer block b (20), a sealing ring b (21), a buffer block a (22), and a sealing ring a (23); The middle of the housing (1) is a housing cavity, and the outer diameter is different in size, showing a stepped shape. One end of the small-diameter part of the housing (1) is provided with an external thread for connecting to the pipeline system, and the other end is provided with an internal thread for connecting to the flow guiding orifice plate (2). The middle part of the large-diameter part of the housing (1) is provided with a threaded hole for injecting the lubricating oil (19) and connecting to the plug (8). The end face of the large-diameter part of the housing (1) is provided with an internal thread for connecting to the end cover (12); The outer diameter of the end cover (12) is different in size, showing a stepped shape and provided with a threaded hole for connecting to the watertight joint (13), and the outer side of the large-diameter part is provided with a thread for connecting to the housing (1); The insulating base (3) is closely attached to the end face on one side of the inner diameter change in the housing cavity, and its two sides are sealed by the sealing ring a (23) and the sealing ring b (21); The insulating film (4), the piezoelectric sheet (5), the perforated piezoelectric sheet a (9), the perforated piezoelectric sheet b (10), the insulating pressing ring a (6), the insulating pressing ring b (7), the insulating pressing ring c (11), the buffer block a (22), the buffer block b (20), and the buffer block c (17) form a piezoelectric energy harvesting assembly; One side of the piezoelectric energy harvesting assembly with the insulating film (4) is positioned by the end face of the insulating base (3), and the other side is positioned by the end face of the large-diameter part of the end cover (12); An insulating film (4) with the same diameter as the piezoelectric sheet (5) is installed between the piezoelectric sheet (5) and the insulating base (3). The side of the buffer block (17) is sealed by the sealing ring (16), and the side close to the end cover is sealed by the sealing ring (15). The positive and negative electrodes of the piezoelectric sheet (5), the perforated piezoelectric sheet a (9), and the perforated piezoelectric sheet b (10) are connected to the watertight joint (13) through the holes provided in the insulating pressing ring a (6), the insulating pressing ring b (7), the insulating pressing ring c (11), the perforated piezoelectric sheet a (9), the perforated piezoelectric sheet b (10), the buffer block c (17), and the end cover (12) by the wire (14).

[0026] In the described housing (1), there is an external thread (1.1) for connecting to a pipeline system, an internal thread (1.2) for connecting to a flow guiding orifice plate (2), a hole (1.3) for injecting lubricating oil (19) and connecting a plug (8), and an internal thread (1.4) for connecting to an end cap (12); the flow guiding orifice plate (2) is provided with a straight hole (2.1) and four symmetrically distributed inclined holes (2.2) that diverge outward along the flow direction for guiding the flow, so that the fluid pressure acts more evenly on the piezoelectric sheet (5), the perforated piezoelectric sheet a (9), and the perforated piezoelectric sheet b (10), thereby enabling them to deform more fully. There is an internal hexagonal groove (2.3) for tightening the flow guiding orifice plate (2).

[0027] The described insulating base (3) is provided with a sealing ring fixing groove (3.1) and a sealing ring fixing groove (3.2) for fixing sealing ring a (23) and sealing ring b (21); the insulating pressing ring c (11) is provided with a sealing ring fixing groove (11.2) and a sealing ring fixing groove (11.3) for fixing sealing ring c (16) and sealing ring d (15) to prevent the leakage of insulating glue (18) and cooperate with the plug (8) to prevent the leakage of lubricating oil (19); at the joints of the insulating pressing ring a (6) and the insulating base (3), the insulating pressing ring a (6) and the insulating pressing ring b (7), and the insulating pressing ring b (7) and the insulating pressing ring c (11), sealing glue is applied to prevent the leakage of lubricating oil.

[0028] In the described insulating pressing ring a (6), insulating pressing ring b (7), perforated piezoelectric sheet a (9), perforated piezoelectric sheet b (10), insulating pressing ring c (11), end cap (12), and buffer block c (17), there are holes (6.1), (7.1), (9.1), (10.1), (11.1), (12.2), and (17.1) for leading out wires (14) and pouring insulating glue (18) to protect the piezoelectric sheet (5), perforated piezoelectric sheet a (9), and perforated piezoelectric sheet b (10), reduce the influence caused by excessive fluid pressure, reduce the occurrence of electric leakage, and enable them to work more stably in a more complex environment; the end cap (12) is provided with a threaded hole (12.3) for connecting a watertight joint (13) to prevent the leakage of insulating glue (18) and achieve series-parallel adjustment; the insulating pressing ring a (6) and the insulating pressing ring b (7) are provided with holes (6.2) and (7.2) for injecting lubricating oil (19) to lubricate the insulating pressing ring a (6), insulating pressing ring b (7), and insulating pressing ring c (11), reduce the friction when they deform and move, and thus reduce energy loss to increase the power generation efficiency.

[0029] The elastic modulus of the materials used for the insulating pressure ring a (6), insulating pressure ring b (7), and insulating pressure ring c (11) is greater than that of the materials used for the buffer block a (22), buffer block b (20), and buffer block c (17); the elastic modulus of the materials used for the buffer block a (22), buffer block b (20), and buffer block c (17) is greater than that of the insulating glue (18).

[0030] The working principle of this embodiment of the series-parallel adjustable laminated hydraulic piezoelectric energy harvesting device is as follows: After the fluid enters the device, through the diversion of the diversion orifice plate (2), the pressure pulsation generated by the fluid will act more uniformly on the piezoelectric sheet (5). At this time, the piezoelectric sheet (5) deforms, and at the same time, the pressure is transmitted to the buffer block a (22), buffer block b (20), buffer block c (17) and the perforated piezoelectric sheet a (9), perforated piezoelectric sheet b (10) laminated together with it, causing them to deform together; when there is no pressure, the buffer block a (22), buffer block b (20), and buffer block c (17) will assist the piezoelectric sheet (5), perforated piezoelectric sheet a (9), and perforated piezoelectric sheet b (10) to return to the initial state. During the continuous deformation process of the piezoelectric sheet (5), perforated piezoelectric sheet a (9), and perforated piezoelectric sheet b (10), electrical energy will be generated. At this time, the positive and negative electrodes of the piezoelectric sheet (5), perforated piezoelectric sheet a (9), and perforated piezoelectric sheet b (10) are connected to the watertight joint (13) through the wire (14), so as to achieve the adjustable series-parallel connection, and finally transmit the electrical energy to the external low-power consumption components to realize power supply or power storage for them.

[0031] The above description is only the preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A series-parallel adjustable laminated hydraulic piezoelectric energy harvesting device, characterized in that: It includes a housing, a flow guiding orifice plate, an insulating base, an insulating film, a piezoelectric sheet, an insulating compression ring, a plug, an end cover, a watertight joint, a wire, a sealing ring, a buffer block, insulating glue, and lubricating oil; the middle of the housing is a housing cavity, and the outer diameters are different and in a stepped shape. One end of the small-diameter part of the housing is provided with an external thread for connecting to the pipeline system, and the other end is provided with an internal thread for connecting to the flow guiding orifice plate. The middle part of the large-diameter part of the housing is provided with a threaded hole for injecting lubricating oil and connecting to the plug. The end face of the large-diameter part of the housing is provided with an internal thread for connecting to the end cover; the outer diameter of the end cover is different, and the outer side of the large-diameter part is provided with a thread for connecting to the housing. The end cover is in a stepped shape and is provided with a threaded hole for pouring insulating glue, leading out wires, and connecting to the watertight joint to prevent the leakage of insulating glue; the insulating base is closely attached to the end face on the side where the inner diameter of the housing cavity changes, and both sides are sealed by sealing rings; the insulating film, piezoelectric sheet, insulating compression ring, and buffer block form a piezoelectric energy harvesting assembly. The side with the insulating film of the piezoelectric energy harvesting assembly is positioned by the end face of the insulating base, and the other side is positioned by the end face of the large-diameter part of the end cover; there are N groups of piezoelectric sheets, insulating compression rings, and buffer blocks in the piezoelectric energy harvesting assembly, where N is a positive integer greater than or equal to 2. The buffer block, insulating compression ring, and piezoelectric sheet not close to the insulating film near the end cover are provided with holes for leading out wires and pouring insulating glue to protect the piezoelectric sheet. An insulating film with the same diameter as the piezoelectric sheet is installed between the piezoelectric sheet near the insulating base and the insulating base. The side of the buffer block close to the end cover is sealed with the adjacent end cover surface by a sealing ring. The positive and negative electrodes of the piezoelectric sheet are connected to the watertight joint through the holes provided in the insulating compression ring, piezoelectric sheet, buffer block, and end cover, and the watertight joint is connected to the positive and negative electrodes of the piezoelectric sheet through wires to achieve adjustable series and parallel connections; in a combination of a piezoelectric sheet, insulating compression ring, and buffer block, the outside of the buffer block is closely attached to the inside of the insulating compression ring, and the end faces of the buffer block and the insulating compression ring are respectively closely attached to different faces of the adjacent two piezoelectric sheets.

2. The stacked hydraulic piezoelectric energy harvesting device with adjustable series-parallel connection according to claim 1, characterized in that: The flow guiding orifice plate is provided with a straight hole and four symmetrically distributed inclined holes that diverge outward along the flow direction for guiding the flow, and is provided with an internal hexagonal groove for tightening the flow guiding orifice plate.

3. The stacked hydraulic piezoelectric energy harvesting device with adjustable series-parallel connection according to claim 1, characterized in that: The insulating compression ring is provided with holes for injecting lubricating oil to lubricate the insulating compression ring; sealant is applied at the connection between the insulating compression ring and the insulating base and at the connection between two adjacent insulating compression rings to prevent the leakage of lubricating oil.

4. A series-parallel adjustable laminated hydraulic piezoelectric energy harvesting device according to claim 1, characterized in that: The elastic modulus of the material used for the insulating compression ring is greater than the elastic modulus of the buffer block, and the elastic modulus of the material used for the buffer block is greater than the elastic modulus of the insulating glue.

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