A stacked smart material driven resonant hydraulic pump and method of operation thereof

Abstract

This invention discloses a resonant hydraulic pump driven by stacked smart materials and its working method, relating to the field of smart hydraulic pumps. By significantly altering the pump chamber volume through hydraulic pendulum resonance, the pump's suction and discharge capabilities are enhanced, increasing its output flow rate. The technical solution of this invention includes a stacked smart material electro-mechanical converter, a pump chamber, a hydraulic pendulum, a cover plate, and an adjusting screw connected in sequence. The stacked smart material electro-mechanical converter includes a base, a housing, stacked smart materials, an output rod, and a pre-tightening end cap. The pump chamber includes a plunger, a diaphragm, a suction valve, and a discharge valve. The hydraulic pendulum includes a hydraulic pendulum with a spring fitted at its lower part, and a large disc spring housed in an annular groove. The cover plate is fixedly connected to the top opening of the chamber, and the adjusting screw passes through the cover plate, with the two connected by threads. This increases the output flow rate of the hydraulic pump, improving its efficiency.

Description

Technical Field

[0001] This invention relates to the field of intelligent hydraulic pumps, and more particularly to a resonant hydraulic pump driven by stacked intelligent materials. Background Technology

[0002] Due to the fast response, wide bandwidth, and high power density of smart materials, smart material-driven hydraulic pumps offer advantages such as high output accuracy, a wide operating bandwidth, and light weight. Therefore, smart material-driven hydraulic pumps have broad development prospects in aerospace, engineering machinery, and biomedicine. Smart material-driven hydraulic pumps primarily utilize stacked smart materials such as magnetostrictive materials and piezoelectric ceramics. By performing high-frequency periodic elongation and contraction movements of the stacked smart materials, the volume within the pump chamber is changed, causing pressure variations and achieving the purpose of oil suction and discharge. However, because the deformation of the stacked smart materials is very small, with the maximum output displacement typically at the micrometer level, the volume change within the pump chamber is limited, resulting in weak oil suction and discharge capacity, which restricts the increase in hydraulic pump output flow. Currently, the output flow of smart material-driven hydraulic pumps still falls far short of practical applications. To improve the output flow rate of hydraulic pumps driven by stacked smart materials, the usual approach is to increase the output displacement of the stacked smart materials and increase the quantity of stacked smart materials. However, this approach has limitations in terms of the improvement rate and the input power increases exponentially. There is a lack of exploration into structural innovations for hydraulic pumps driven by stacked smart materials. Summary of the Invention

[0003] To address the above problems, this invention proposes a resonant hydraulic pump driven by stacked smart materials and its working method. By using hydraulic pendulum resonance to significantly change the pump chamber volume, the pump's suction and discharge capacity is enhanced, thereby increasing the pump's output flow rate.

[0004] The technical solution of the present invention is as follows: it includes a stacked smart material electro-mechanical converter I, a pump chamber II, a hydraulic swing body III, a cover plate IV, and an adjusting screw V connected in sequence;

[0005] The stacked smart material electro-mechanical converter I includes a base 1, a housing 2 mounted on the base 1, a stacked smart material 19 housed in the housing 2, an output rod 18 mounted on the upper end of the stacked smart material 19, and a pre-tightening end cap 17 mounted on the upper end of the output rod 18. The lower part of the output rod 18 is provided with a protruding ring, and a disc spring 3 is provided between the pre-tightening end cap 17 and the protruding ring. The pre-tightening end cap 17 and the housing 2 are threadedly connected.

[0006] The pump chamber II is provided with a pump chamber, and oil suction holes and oil discharge holes are opened on the left and right sides of the pump chamber. An input hole is opened at the bottom of the pump chamber and an output hole is opened at the top.

[0007] The pump chamber II includes a plunger 4 slidably connected in the input port, a diaphragm 13 fixedly connected in the output port, an oil suction valve 6 fixedly connected to the oil suction port via an oil suction plate 7, and an oil discharge valve 15 fixedly connected to the oil suction port via an oil discharge plate 14. The plunger 4 is fixedly connected to the top of the output rod 18. The plunger 4 can be replaced by a diaphragm.

[0008] The hydraulic swing body III has a cavity that connects with the output hole;

[0009] The hydraulic pendulum III includes a hydraulic pendulum 12 slidably connected in the cavity. The hydraulic pendulum 12 is a stepped shaft shape with a larger top and a smaller bottom. An annular groove is provided on the top surface of the hydraulic pendulum 12. A spring 9 is fitted on the lower part of the hydraulic pendulum 12. The spring 9 abuts against the bottom of the cavity and the stepped surface of the hydraulic pendulum 12. A large disc spring 11 is accommodated in the annular groove.

[0010] The cover plate IV is fixedly connected to the top opening of the cavity. The adjusting screw V passes through the cover plate IV and the two are threaded together. The bottom of the adjusting screw V is annular and presses against the large disc spring 11.

[0011] In use, the spring 9 is compressed under the action of the hydraulic pendulum 12 and the hydraulic pendulum body III, generating an upward force on the hydraulic pendulum 12. The large disc spring 11 is compressed under the action of the hydraulic pendulum 12 and the adjusting screw V, generating a downward force on the hydraulic pendulum 12. The hydraulic pendulum 12 swings up and down under the combined action of the spring 9 and the large disc spring 11.

[0012] Furthermore, the stacked smart material is a piezoelectric material or a magnetostrictive material. This allows it to perform high-frequency periodic elongation and shortening movements after being energized, and the motion is transmitted to the plunger 4 via the output rod 18.

[0013] Furthermore, the oil suction valve plate 6 has an elastic plate in the middle, and the oil suction pressure plate 8 has an oil passage hole in the middle with a cross-sectional area larger than that of the elastic plate. The area of ​​the inner opening of the oil inlet hole is smaller than that of the elastic plate.

[0014] The oil discharge valve plate 15 has a second elastic plate in its middle, and the oil discharge pressure plate 14 has a second oil passage hole in its middle with a cross-sectional area smaller than that of the second elastic plate. The area of ​​the inner opening of the oil discharge hole is larger than that of the second elastic plate. The pump chamber II has two pipe interfaces on its left and right sides, which are respectively connected to the oil discharge hole and the oil suction hole. Thus, when the oil pressure in the pump chamber is too low, the first elastic plate can be forced to deform inward to facilitate oil intake; when the oil pressure in the pump chamber is too high, the second elastic plate can be forced to deform outward to facilitate oil discharge.

[0015] Furthermore, the diaphragm is made of beryllium bronze, PDMS film, Kapton flexible film, or PET plastic film.

[0016] Furthermore, the hydraulic pendulum 12 remains in contact with the diaphragm 13. The position of the hydraulic pendulum 12 is adjusted by adjusting screw V until it contacts the diaphragm 13, so that pressure changes within the pump chamber II are transmitted to the hydraulic pendulum 12 through the diaphragm, causing it to move.

[0017] This invention also discloses a method for operating a resonant hydraulic pump driven by stacked smart materials, the specific steps of which are as follows:

[0018] S1. Calculate the resonant frequency of the mechanical system composed of the hydraulic pendulum, spring and disc spring, and set the frequency of the driving signal that drives the stacked smart material to the calculated resonant frequency.

[0019] S2. The stacked smart materials undergo periodic elongation and shortening movements at a resonant frequency, which are transmitted to the plunger via the output rod. The plunger then moves at a high frequency within the pump chamber, causing the pressure within the pump chamber to change at a resonant frequency.

[0020] S3. The pressure change in the pump chamber is transmitted to the hydraulic pendulum through the diaphragm. The hydraulic pendulum is subjected to the force of the diaphragm and moves in the vertical direction.

[0021] Because the frequency of pressure change in the pump chamber is equal to the resonant frequency of the mechanical system composed of the hydraulic pendulum, spring and disc spring, the hydraulic pendulum resonates, which makes the displacement of the hydraulic pendulum larger than that of the stacked smart material.

[0022] When the hydraulic pendulum resonates, the change in the volume of the pump cavity will no longer depend on the displacement of the stacked smart materials, but on the resonant displacement of the hydraulic pendulum. This increases the change in the volume of the pump cavity, enhances the suction and discharge capacity, and thus increases the flow rate.

[0023] The advantages of this invention are: it increases the output flow rate of the hydraulic pump and improves the efficiency of the hydraulic pump without increasing the quantity of stacked smart materials or increasing the output displacement of the stacked smart materials; it explores a new structure for the hydraulic pump, drives the stacked smart materials with a resonant frequency, and makes the hydraulic pendulum resonate to increase the flow rate of the hydraulic pump, making full use of the wide bandwidth of the smart materials and improving their energy utilization rate; the resonant hydraulic pump driven by the stacked smart materials has a simple structure and is easy to implement. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the resonant hydraulic pump structure driven by stacked smart materials in this invention;

[0025] Figure 2 This is a front sectional view of the resonant hydraulic pump driven by stacked smart materials in this invention.

[0026] Figure 3 This is a schematic diagram of the oil suction valve plate and its pressure plate provided in an embodiment of the present invention;

[0027] Figure 4 This is a schematic diagram of the oil drain valve plate and its pressure plate provided in an embodiment of the present invention;

[0028] Figure 5 This is a schematic diagram of a membrane provided in an embodiment of the present invention.

[0029] Figure 6 A schematic diagram of a hydraulic pendulum provided for an embodiment of the present invention.

[0030] In the diagram, Ⅰ is the stacked smart material electro-mechanical converter, Ⅱ is the pump chamber, Ⅲ is the hydraulic swing body, Ⅳ is the cover plate, and Ⅴ is the adjusting screw;

[0031] 1 is the base, 2 is the outer shell, 3 is the disc spring, 4 is the plunger, 5 is the fixing screw, 6 is the oil suction valve plate, 7 is the oil suction pressure plate, 8 is the first sealing ring, 9 is the spring, 10 is the second sealing ring, 11 is the large disc spring, 12 is the hydraulic swing arm, 13 is the diaphragm, 14 is the oil discharge pressure plate, 15 is the oil discharge valve plate, 16 is the third sealing ring, 17 is the pre-tightening end cap, 18 is the output rod, and 19 is the stacked intelligent material. Detailed Implementation

[0032] To clearly illustrate the technical features of this patent, the following detailed description is provided through specific embodiments and in conjunction with the accompanying drawings.

[0033] The present invention provides a resonant hydraulic pump driven by stacked smart materials and its working method. The pump chamber volume is significantly changed by hydraulic pendulum resonance, thereby enhancing the pump's oil suction and discharge capacity and increasing the pump's output flow rate.

[0034] To achieve the above objectives, the embodiments of the present invention adopt the following technical solutions:

[0035] like Figure 1 As shown, it includes: stacked smart material electro-mechanical converter I, pump chamber II, hydraulic swing body III, cover plate IV, and adjusting screw V.

[0036] The stacked smart material electro-mechanical converter I is installed below the pump chamber II, the hydraulic swing body III is installed above the pump chamber II, and the cover plate IV is installed on the hydraulic swing body III and is screwed into the adjusting screw V.

[0037] The stacked smart material electromechanical converter I, such as Figure 2As shown, it includes a base 1, a housing 2 connected to the base 1 by screws, a stacked smart material 19 placed flat on the base 1, an output rod 18 installed on the upper end of the stacked smart material 19, a disc spring 3 installed on the upper end of the output rod 18, and a pre-tightening end cap 17 installed on the disc spring 3. The pre-tightening end cap is threadedly engaged with the housing 2.

[0038] In the above, the disc spring 3 is compressed by rotating the pre-tightening end cap downward, thereby applying pre-pressure to the stacked smart material 19 through the output rod 18.

[0039] The pump chamber II includes a plunger 4 mounted on the upper end of the output rod 18 by fixing screws 5, and an oil suction valve plate 6 and an oil suction pressure plate 7 (e.g., mounted on the left side of the pump chamber by screws) connected to the plunger 4. Figure 3 As shown), the oil drain valve plate 15 and the oil drain pressure plate 14 (as shown) are connected to the right side of the pump chamber by screws. Figure 4 As shown), the diaphragm 13 (as shown) is installed at the upper end of the pump cavity. Figure 5 As shown, a pump chamber is formed in the gap between the diaphragm 13 and the plunger 4, and a sealing ring 16 is installed between the pump chamber body II and the plunger 4, and a sealing ring 8 is installed between the pump chamber body II and the hydraulic swing body III.

[0040] As described above, sealing ring 8 and sealing ring 16 prevent oil leakage from the pump chamber. There are two pipe interfaces on the left and right sides of the pump chamber II, respectively, which are combined with the oil discharge valve plate 15 and oil discharge pressure plate 14, and the oil suction valve plate 6 and oil suction pressure plate 7 to form the oil discharge port and oil suction port. The oil discharge valve plate 15 and oil suction valve plate 6 provide unidirectional oil flow distribution. When the pressure inside the pump chamber II increases, the oil discharge valve plate 15 opens; when the pressure inside the pump chamber II decreases, the oil suction valve plate 6 opens.

[0041] The hydraulic pendulum III includes a hydraulic pendulum 12 (such as...). Figure 6 As shown), its position is adjusted by adjusting screw V until it contacts diaphragm 13. Spring 9 is compressed under the action of hydraulic pendulum 12 and the inner wall of hydraulic pendulum body III, generating an upward force on hydraulic pendulum 12. Large disc spring 11 is compressed under the action of adjusting screw V and hydraulic pendulum 12, generating a downward force on hydraulic pendulum 12. Sealing ring II 10 is between hydraulic pendulum body III and cover plate IV to prevent oil leakage.

[0042] This invention also discloses a method for operating a resonant hydraulic pump driven by stacked smart materials, the specific steps of which are as follows:

[0043] S1. Calculate the resonant frequency f of the mechanical system composed of the hydraulic pendulum, spring, and large disc spring. The calculation formula is:

[0044]

[0045] k 弹 and k 碟These are the stiffnesses of the spring and the disc spring, respectively, in m. 摆 It is the mass of the hydraulic pendulum.

[0046] The frequency of the driving signal that drives the stacked smart materials is set to the calculated resonant frequency f.

[0047] S2. The stacked smart materials undergo periodic elongation and shortening movements at a resonant frequency, which are transmitted to the plunger via the output rod. The plunger then moves at a high frequency within the pump chamber, causing the pressure within the pump chamber to change at the resonant frequency f.

[0048] S3. The pressure change in the pump cavity is transmitted to the hydraulic pendulum through the diaphragm. The hydraulic pendulum is subjected to the force of the diaphragm and moves in the vertical direction at the frequency of the pressure change in the pump cavity, that is, at the resonant frequency f of the hydraulic pendulum. Therefore, the hydraulic pendulum resonates, which makes the displacement of the hydraulic pendulum larger than that of the stacked smart materials.

[0049] When the hydraulic pendulum resonates, the change in the volume of the pump cavity will no longer depend on the displacement of the stacked smart materials, but on the resonant displacement of the hydraulic pendulum. This increases the change in the volume of the pump cavity, enhances the suction and discharge capacity, and thus increases the flow rate.

[0050] The advantages of this invention are: it increases the output flow rate of the hydraulic pump and improves the efficiency of the hydraulic pump without increasing the quantity of stacked smart materials or increasing the output displacement of the stacked smart materials; it explores a new structure for the hydraulic pump, drives the stacked smart materials with a resonant frequency, and makes the hydraulic pendulum resonate to increase the flow rate of the hydraulic pump, making full use of the wide bandwidth of the smart materials and improving their energy utilization rate; the resonant hydraulic pump driven by the stacked smart materials has a simple structure and is easy to implement.

[0051] There are many specific ways to implement this invention. The above description is only a preferred embodiment of this invention. It should be noted that for those skilled in the art, several improvements can be made without departing from the principle of this invention, and these improvements should also be considered within the scope of protection of this invention.

Claims

1. A resonant hydraulic pump driven by stacked smart materials, characterized in that, It includes a stacked smart material electro-mechanical converter (Ⅰ), a pump chamber (Ⅱ), a hydraulic swing body (Ⅲ), a cover plate (Ⅳ), and an adjusting screw (Ⅴ) connected in sequence. The stacked smart material electro-mechanical converter (Ⅰ) includes a base (1), a housing (2) installed on the base (1), a stacked smart material (19) housed in the housing (2), an output rod (18) installed on the upper end of the stacked smart material (19), and a pre-tightening end cap (17) installed on the upper end of the output rod (18). The lower part of the output rod (18) is provided with a convex ring, and a disc spring (3) is provided between the pre-tightening end cap (17) and the convex ring. The pre-tightening end cap (17) and the housing (2) are threaded together. The pump chamber (II) is provided with a pump chamber, and oil suction holes and oil discharge holes are opened on the left and right sides of the pump chamber. An input hole is opened at the bottom of the pump chamber and an output hole is opened at the top. The pump chamber (II) includes a plunger (4) slidably connected in the input hole, a diaphragm (13) fixedly connected in the output hole, an oil suction valve (6) fixedly connected to the oil suction hole via an oil suction pressure plate (7), and an oil discharge valve (15) fixedly connected to the oil suction hole via an oil discharge pressure plate (14). The plunger (4) is fixedly connected to the top of the output rod (18). The hydraulic swing body (Ⅲ) has a cavity that connects with the output hole; The hydraulic pendulum (Ⅲ) includes a hydraulic pendulum (12) slidably connected in the cavity. The hydraulic pendulum (12) is a stepped shaft with a larger top and a smaller bottom. An annular groove is provided on the top surface of the hydraulic pendulum (12). A spring (9) is fitted on the lower part of the hydraulic pendulum (12). The spring (9) rests between the bottom of the cavity and the stepped surface of the hydraulic pendulum (12). A large disc spring (11) is accommodated in the annular groove. The cover plate (Ⅳ) is fixedly connected to the top opening of the cavity. The adjusting screw (Ⅴ) passes through the cover plate (Ⅳ) and the two are threaded together. The bottom of the adjusting screw (Ⅴ) is annular and presses on the large disc spring (11).

2. The resonant hydraulic pump driven by stacked smart materials according to claim 1, characterized in that, The stacked smart material is a piezoelectric material or a magnetostrictive material.

3. The resonant hydraulic pump driven by stacked smart materials according to claim 1, characterized in that, The oil suction valve plate (6) is provided with an elastic plate in the middle, and the oil suction pressure plate (7) is provided with an oil passage hole with a cross-sectional area larger than that of the elastic plate in the middle. The oil drain valve plate (15) has an elastic plate 2 in the middle, and the oil drain pressure plate (14) has an oil passage hole 2 with a cross-sectional area smaller than that of the elastic plate 2 in the middle, and the area of ​​the inner opening of the oil drain hole is larger than that of the elastic plate 2.

4. The resonant hydraulic pump driven by stacked smart materials according to claim 1, characterized in that, The diaphragm is made of beryllium bronze, PDMS film, Kapton flexible film, or PET plastic film.

5. A resonant hydraulic pump driven by stacked smart materials according to claim 1, characterized in that, The hydraulic pendulum (12) remains in contact with the diaphragm (13).

6. A method for operating a resonant hydraulic pump driven by stacked smart materials as described in claim 1, characterized in that, The specific steps are as follows: S1. Calculate the resonant frequency of the mechanical system composed of the hydraulic pendulum, spring and disc spring, and set the frequency of the driving signal that drives the stacked smart material to the calculated resonant frequency. S2. The stacked smart materials undergo periodic elongation and shortening movements at a resonant frequency, which are transmitted to the plunger via the output rod. The plunger then moves at a high frequency within the pump chamber, causing the pressure within the pump chamber to change at a resonant frequency. S3. Pressure changes within the pump chamber are transmitted to the hydraulic pendulum via the diaphragm. The hydraulic pendulum is subjected to the force of the diaphragm and moves in the vertical direction.

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