A piezoelectric hydraulic pump

Abstract

The present invention provides a piezoelectric hydraulic pump, which relates to the technical field of hydraulic pumps, and includes a hydraulic circulation system and a driving system that are sealed and separated by an elastic driving spacer. The hydraulic circulation system and the driving system are detachably connected, and the driving system includes a driving housing and a piezoelectric ceramic that is sealed and arranged in the driving housing, and the piezoelectric ceramic is fixedly connected to the elastic driving spacer. The hydraulic circulation system includes a hydraulic housing and a liquid cavity, a liquid inlet hole, a liquid outlet hole and a one-way hydraulic valve arranged in the hydraulic housing. The liquid cavity and the liquid inlet hole are connected through a liquid inlet channel arranged in the one-way hydraulic valve, and the liquid cavity and the liquid outlet hole are connected through a liquid outlet channel arranged in the one-way hydraulic valve. An annular one-way conducting device is arranged on the liquid inlet channel and the liquid outlet channel, and the elastic driving spacer is connected to the liquid cavity. The problem that the hydraulic pump in the prior art is large in size and heavy in weight and cannot be adapted to the application environment requiring light weight and high efficiency such as aerospace is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of hydraulic pumps, and in particular to a piezoelectric hydraulic pump. Background Art

[0002] The hydraulic pump is the power element of the hydraulic system. It is driven by an engine or an electric motor. It sucks oil from the hydraulic oil tank, forms pressurized oil and discharges it to the actuator. The commonly used hydraulic pumps in the prior art are divided into gear pumps, plunger pumps, vane pumps and screw pumps according to their structures. Their structures are relatively complex and heavy, and they are not suitable for fields such as aerospace that require light weight and high efficiency. Summary of the invention

[0003] In view of the above problems in the prior art, the present invention provides a piezoelectric hydraulic pump, which solves the problem that the hydraulic pumps in the prior art are large in size and heavy in weight and cannot be adapted to application environments such as aerospace that require light weight and high efficiency.

[0004] In order to achieve the above-mentioned object of the invention, the technical solution adopted by the present invention is as follows:

[0005] A piezoelectric hydraulic pump is provided, which comprises a hydraulic circulation system and a driving system which are sealed and separated by an elastic driving spacer, the hydraulic circulation system and the driving system are detachably connected, the driving system comprises a driving housing and a piezoelectric ceramic which is sealed in the driving housing, and the piezoelectric ceramic is fixedly connected to the elastic driving spacer.

[0006] The hydraulic circulation system includes a hydraulic housing and a liquid cavity, a liquid inlet hole, a liquid outlet hole and a one-way hydraulic valve arranged in the hydraulic housing. The liquid cavity and the liquid inlet hole are connected through a liquid inlet channel arranged in the one-way hydraulic valve, and the liquid cavity and the liquid outlet hole are connected through a liquid outlet channel arranged in the one-way hydraulic valve. Annular one-way conduction devices are arranged on the liquid inlet channel and the liquid outlet channel, and an elastic driving diaphragm is passed into the liquid cavity.

[0007] The beneficial effects of the present invention are as follows: by changing the amplitude and frequency of the driving signal loaded on the piezoelectric ceramic, the output flow of the hydraulic circulation system can be accurately controlled. Compared with traditional hydraulic pumps, its structure is more compact, its size is small, its weight is light, its output force is large, and it has no electromagnetic interference. This piezoelectric ceramic pump has broad application prospects in aerospace, precision medicine and other fields.

[0008] The drive system and the hydraulic circulation system are sealed and detachably connected. If only parts in one of the systems are damaged during use, only the damaged system can be replaced, which can reduce use and maintenance costs.

[0009] A one-way hydraulic valve is provided in the hydraulic circulation system. An annular one-way conducting device is provided on both the inlet channel and the outlet channel to separate the liquid path and prevent interference. The annular one-way conducting device on the inlet channel can prevent the fluid from entering the inlet channel during the outlet process, thereby ensuring the outlet pressure; the annular one-way conducting device on the outlet channel can prevent the external system pressure connected to the hydraulic pump from affecting the hydraulic pump, and when the pump is not working, it can prevent the system fluid from flowing back to the liquid tank through the pump, thereby improving the reliability and maximum output force of the hydraulic pump. The action surface between the fluid and the annular one-way conducting device is annular, and the force is more uniform, which is conducive to improving the resilience of the annular one-way conducting device and improving the reliability of operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 Schematic diagram of the structure of a piezoelectric hydraulic pump.

[0011] Figure 2 for Figure 1 Cross-sectional view along the AA direction.

[0012] Figure 3 for Figure 2 A three-dimensional diagram of the one-way hydraulic valve.

[0013] Among them, 1. hydraulic circulation system; 11. hydraulic housing; 12. liquid cavity; 13. liquid inlet hole; 14. liquid outlet hole; 15. one-way hydraulic valve; 151. first valve body; 152. second valve body; 153. liquid inlet elastic sheet; 154. liquid outlet elastic sheet; 155. center column; 156. fastening nut; 157. limit flange; 16. liquid inlet channel; 161. confluence column hole; 162. liquid inlet annular groove; 17 , liquid outlet channel; 171, liquid outlet guide hole; 172, liquid outlet dispersion hole; 173, liquid outlet confluence chamber; 174, liquid outlet annular groove; 18, side liquid inlet tube cavity; 19, accumulator; 191, connecting ring; 192, accumulator plug body; 2, drive system; 21, drive housing; 22, piezoelectric ceramics; 23, radiator; 3, elastic drive spacer; 31, flange plate; 32, elastic deformation plate; 4, copper sealing ring. DETAILED DESCRIPTION

[0014] The specific implementation modes of the present invention are described below so that those skilled in the art can understand the present invention. However, it should be clear that the present invention is not limited to the scope of the specific implementation modes. For those of ordinary skill in the art, as long as various changes are within the spirit and scope of the present invention as defined and determined by the attached claims, these changes are obvious, and all inventions and creations utilizing the concept of the present invention are protected.

[0015] like Figure 1 , Figure 2As shown, the piezoelectric hydraulic pump comprises a hydraulic circulation system 1 and a driving system 2 which are sealed and separated by an elastic driving spacer 3. The hydraulic circulation system 1 is detachably connected to the driving system 2. The driving system 2 comprises a driving housing 21 and a piezoelectric ceramic 22 which is sealed and arranged in the driving housing 21. The piezoelectric ceramic 22 is fixedly connected to the elastic driving spacer 3. The hydraulic circulation system 1 comprises a hydraulic housing 11 and a liquid cavity 12, a liquid inlet hole 13, a liquid outlet hole 14 and a one-way hydraulic valve 15 arranged in the hydraulic housing 11. The liquid cavity 12 is connected to the liquid inlet hole 13 through a liquid inlet channel 16 arranged in the one-way hydraulic valve 15. The liquid cavity 12 is connected to the liquid outlet hole 14 through a liquid outlet channel 17 arranged in the one-way hydraulic valve 15. An annular one-way conducting device is arranged on the liquid inlet channel 16 and the liquid outlet channel 17. The elastic driving spacer 3 is connected to the liquid cavity 12.

[0016] like Figure 2 and Figure 3 As shown, the one-way hydraulic valve 15 includes a valve body, and the liquid inlet channel 16 and the liquid outlet channel 17 are both arranged on the valve body. The annular one-way conductive device includes a liquid inlet elastic sheet 153 arranged at the outlet of the liquid inlet channel and a liquid outlet elastic sheet 154 arranged at the outlet of the liquid outlet channel.

[0017] The valve body includes a first valve body 151 and a second valve body 152 which are overlapped. The center column 155 passes through the liquid inlet elastic sheet 153, the first valve body 151, the second valve body 152 and the liquid outlet elastic sheet 154 from bottom to top in sequence and is threadedly connected with the fastening nut 156. A limiting flange 157 is integrally formed at the bottom end of the center column 155. The top surface of the limiting flange 157 abuts against the bottom surface of the liquid inlet elastic sheet 153, and the bottom surface of the fastening nut 156 abuts against the top surface of the liquid outlet elastic sheet 154. The entire one-way hydraulic valve 15 is assembled into a whole through the connection between the center column 155 and the fastening nut 156. The valve body adopts a split structure of the first valve body 151 and the second valve body 152, which is beneficial to reduce the processing difficulty, ensure the processing accuracy and improve the processing quality.

[0018] The liquid inlet channel 16 includes a plurality of confluence column holes 161 distributed along the circumference of the valve body and radially extending into the valve body. The inner end of the confluence column hole 161 is processed with a conical groove extending inward. The conical groove can reduce the resistance of the liquid inlet, form a favorable flow, and is not easy to flow back. The inner end of the confluence column hole 161 is downwardly penetrated by a liquid inlet annular groove 162, which is coaxial with the valve body. The liquid inlet annular groove 162 connects all the confluence column holes 161 with the liquid cavity 12, and the liquid inlet elastic sheet 153 is arranged between the liquid inlet annular groove 162 and the liquid cavity 12. The liquid inlet elastic sheet 153 is a circular elastic steel sheet. The inner hole passing through the center of the circle is used for the center column 155 to pass through. The outer edge just covers the outer diameter of the liquid inlet annular groove 162. After the fluid flows down from the liquid inlet annular groove 162, the outer edge will be deformed downward under the action of pressure to create a gap, allowing the liquid to flow into the liquid cavity 12. However, the fluid in the liquid cavity 12 reversely applies force to the liquid inlet elastic sheet 153, which will only make it fit more tightly to the bottom surface of the valve body and better seal the liquid inlet annular groove 162. Therefore, the fluid cannot flow back from the liquid cavity 12 into the liquid inlet channel 16, thereby realizing the effect of unidirectional flow.

[0019] The liquid outlet channel 17 includes a liquid outlet guide hole 171 connected to the liquid cavity 12 and extending upward along the middle of the valve body. A plurality of liquid outlet dispersion holes 172 extending radially outward are arranged on the upper part of the liquid outlet guide hole 171. The liquid outlet guide hole 171 is also provided with a conical groove at the upper end of the liquid outlet dispersion hole 172 to reduce the liquid outlet resistance, form a favorable flow, and not easy to flow back. Preferably, the liquid outlet guide hole 171 is arranged along the axis of the central column 155, and the plurality of liquid outlet dispersion holes 172 are evenly distributed along the circumference of the central column 155 and extend radially outward from the central column 155. The liquid outlet guide hole 171 and the liquid outlet dispersion hole 172 are arranged on the central column 155 that can be separated from the valve body, which can reduce the processing difficulty and processing cost.

[0020] The liquid dispersing hole 172 leads to the liquid confluence cavity 173, which is a circular groove coaxial with the valve body and located at the top of the first valve body 151. The top of the liquid confluence cavity 173 is connected to the liquid outlet hole 14 through a liquid outlet annular groove 174, which is an annular groove axially penetrating the second valve body 152 and is coaxial with the second valve body 152. The liquid outlet elastic sheet 154 is arranged between the liquid outlet annular groove 174 and the liquid outlet hole 14. The structure, material and principle of achieving unidirectionality of the liquid outlet elastic sheet 154 are the same as those of the liquid inlet elastic sheet 153.

[0021] The valve body and the liquid outlet hole 14 and the valve body and the liquid cavity 12 are sealed by the copper sealing ring 4. The copper sealing ring 4 between the valve body and the liquid outlet hole 14 is installed between the top surface of the second valve body 152 and the hydraulic housing 11, and the copper sealing ring 4 between the valve body and the liquid cavity 12 is installed between the liquid inlet elastic sheet 153 and the hydraulic housing 11. After the one-way hydraulic valve 15 is installed in the upper part of the liquid cavity 12, it is squeezed against the copper sealing ring 4. Since the copper material is relatively soft and easy to deform, the sealing performance of the liquid inlet channel and the liquid outlet channel can be improved after compaction, and the liquid outlet hydraulic pressure of the hydraulic pump can be improved.

[0022] A heat sink 23 is provided at the bottom end of the piezoelectric ceramic 22. The piezoelectric ceramic 22 is a type of electronic ceramic material with piezoelectric properties and has a piezoelectric effect. The elastic drive spacer 3 includes a flange plate 31 fixed to the outer edge of the top of the piezoelectric ceramic 22. The flange plate 31 is evenly distributed with through holes on the circumference, and the through holes are used for connecting screws connecting the hydraulic circulation system 1 and the drive system 2 to pass through. An elastic deformation sheet 32 ​​is welded on the center hole of the flange plate 31. The elastic deformation sheet 32 ​​is a thin steel sheet with a thickness of no more than 1 mm. The bottom surface of the elastic deformation sheet 32 ​​abuts against the top surface of the piezoelectric ceramic 22. An O-ring is installed between the bottom surface of the flange plate 31 and the top surface of the drive housing 21, and an O-ring is installed between the top surface of the heat sink 23 and the bottom surface of the drive housing 21, thereby ensuring that the piezoelectric ceramic 22 is sealed in the drive housing 21 to prevent fluid or other external impurities from entering and damaging the piezoelectric ceramic 22.

[0023] The liquid inlet hole 13 is connected to the liquid inlet channel 16 through the side liquid inlet tube cavity 18, and an accumulator 19 is arranged in the side liquid inlet tube cavity 18. The accumulator 19 includes a connecting ring 191 that is detachably connected to the side wall of the side liquid inlet tube cavity, and a threaded hole that penetrates radially is processed on the side wall of the side liquid inlet tube cavity. The connecting ring 191 is a hollow cylindrical shape with both ends open, and an external thread that is threadedly connected to the threaded hole is processed on the outer wall surface of the connecting ring 191. The connecting ring 191 is filled with an accumulator plug body 192, and the two ends of the accumulator plug body 192 are respectively connected to the side liquid inlet tube cavity 18 and the outside world. The accumulator plug body 192 is elastic and can block the passage of fluid. The material of the accumulator plug body 192 can be a non-absorbent sponge or nitrile rubber. The accumulator 19 has the functions of absorbing shock and vibration, reducing leakage compensation through thermal expansion, and playing the role of vibration reduction, balance and protection of the hydraulic circuit.

[0024] During the liquid discharge process of the hydraulic pump, a high-frequency sinusoidal positive voltage is applied to the piezoelectric ceramic 22. Due to the inverse piezoelectric effect of the piezoelectric ceramic material, the ceramic material is deformed, thereby driving the elastic deformation sheet 32 ​​to deform toward the side of the liquid chamber 12, squeezing the fluid in the liquid chamber 12, and the fluid pressure in the chamber increases. Due to the unidirectional action of the liquid inlet elastic sheet 153, the fluid cannot enter and pass through the liquid inlet elastic sheet 153 into the liquid inlet channel 16, and can only flow out from the liquid outlet channel 17 to the liquid outlet hole 14.

[0025] When the amplitude of the applied high-frequency sinusoidal positive voltage begins to decrease, the deformation of the piezoelectric ceramic 22 begins to recover, and the elastic driving diaphragm 3 retreats, causing the pressure in the liquid chamber 12 to decrease. The fluid flows from the liquid inlet hole 13 to the side liquid inlet tube cavity 18, and then enters the liquid chamber 12 through the liquid inlet channel 16 and the liquid inlet elastic sheet 153, thereby achieving liquid inflow.

Claims

1. A piezoelectric hydraulic pump, characterized in that: It comprises a hydraulic circulation system and a driving system which are sealed and separated by an elastic driving spacer, the hydraulic circulation system is detachably connected to the driving system, the driving system comprises a driving housing and a piezoelectric ceramic which is sealed and arranged in the driving housing, and the piezoelectric ceramic is fixedly connected to the elastic driving spacer; The hydraulic circulation system comprises a hydraulic housing and a liquid cavity, a liquid inlet hole, a liquid outlet hole and a one-way hydraulic valve arranged in the hydraulic housing, wherein the liquid cavity is connected to the liquid inlet hole via a liquid inlet channel arranged in the one-way hydraulic valve, and the liquid cavity is connected to the liquid outlet hole via a liquid outlet channel arranged in the one-way hydraulic valve, and an annular one-way conducting device is arranged on the liquid inlet channel and the liquid outlet channel, and the elastic driving diaphragm is passed into the liquid cavity; The one-way hydraulic valve comprises a valve body, the liquid inlet channel and the liquid outlet channel are both arranged on the valve body, and the annular one-way conducting device comprises a liquid inlet elastic sheet arranged at the outlet of the liquid inlet channel and a liquid outlet elastic sheet arranged at the outlet of the liquid outlet channel; The valve body comprises a first valve body and a second valve body which are overlapped, the center column passes through the liquid inlet elastic sheet, the first valve body, the second valve body and the liquid outlet elastic sheet in sequence from bottom to top and is threadedly connected with the fastening nut, and a limiting flange is fixedly provided at the bottom end of the center column; The liquid inlet channel comprises a plurality of confluence column holes distributed along the circumference of the valve body and radially extending into the valve body, the inner ends of the confluence column holes are penetrated by a liquid inlet annular groove, the liquid inlet annular groove connects all the confluence column holes with the liquid cavity, and the liquid inlet elastic sheet is arranged between the liquid inlet annular groove and the liquid cavity; The liquid outlet passage comprises a liquid outlet guide hole connected with the liquid cavity and extending upwardly along the middle of the valve body, a plurality of liquid outlet dispersion holes extending radially outward are arranged on the upper part of the liquid outlet guide hole, the liquid outlet dispersion holes lead into the liquid outlet confluence cavity, the top end of the liquid outlet confluence cavity is connected with the liquid outlet hole through a liquid outlet annular groove provided therethrough, and the liquid outlet elastic sheet is provided between the liquid outlet annular groove and the liquid outlet hole; A conical groove is arranged at the upper end of the liquid dispersing hole.

2. The piezoelectric hydraulic pump according to claim 1, characterized in that: The liquid inlet hole is communicated with the liquid inlet channel through a side liquid inlet tube cavity, and an accumulator is arranged in the side liquid inlet tube cavity.

3. The piezoelectric hydraulic pump according to claim 2, characterized in that: The accumulator comprises a connecting ring detachably connected to the side wall of the side liquid inlet tube cavity, the connecting ring is filled with an energy storage plug body, and two ends of the energy storage plug body are respectively connected to the side liquid inlet tube cavity and the outside.

4. The piezoelectric hydraulic pump according to claim 1, characterized in that: The valve body and the liquid outlet hole as well as the valve body and the liquid cavity are sealed by copper sealing rings.

5. The piezoelectric hydraulic pump according to claim 1, characterized in that: The elastic driving spacer comprises a flange plate fixed to the outer edge of the top end of the piezoelectric ceramic, the middle part of the flange plate is sealed and fixedly connected with an elastic deformation sheet, and the bottom surface of the elastic deformation sheet abuts against the top surface of the piezoelectric ceramic.

6. The piezoelectric hydraulic pump according to claim 1 or 5, characterized in that: A heat sink is arranged at the bottom end of the piezoelectric ceramic.

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