RU2603208C2 - Pump with piezoelectric drive - Google Patents

Abstract

FIELD: pumps.

SUBSTANCE: invention relates to devices for pumping fluids and can be used in industry, on transport and in everyday life in pumping liquids, other incompressible and compressible fluids, as well as in oil production from wells. Pump includes a housing, as well as arranged therein and connected in series, rear spacer piezoelectric unit, piezoelectric motion unit configured to move relative to housing in direction of change of its length, front spacer piezoelectric unit. Displacer of pumped medium is connected to front end of piezoelectric motion unit, or with a place located between front and rear ends of piezoelectric motion unit, or with rear end of piezoelectric motion unit, or with rear spacer piezoelectric unit.

EFFECT: longer service life of piezoelectric pump.

19 cl, 10 dwg

Description

The invention relates to a device for pumping fluids, and can be used in industry, transport and at home when pumping liquids, other incompressible and compressible fluids, as well as in oil production from wells.

The closest analogue of the claimed technical solution is a piezoelectric pump for pumping fluids, described in patent RU 2452872, published 10.06.2012, IPC ⁸ F04B 9/00. The pump contains a displacer of the pumped medium, a housing located in the housing and connected in series to the rear pressure piezoelectric block, a piezoelectric movement block, which is movable relative to the body, and a front pressure piezoelectric block. Spacer piezoelectric blocks and a piezoelectric motion block are made using a material capable of changing its length when an electric potential is applied to them, for example, from a piezoceramic material.

The electrical impulses arriving at the spacer piezoelectric blocks cause their alternate fixation inside the housing. The piezoelectric motion block under the influence of an electric impulse arriving at it periodically moves another one not fixed inside the spacer piezoelectric block by one step. The displacer is connected to the front spacer piezoelectric block through a leaf spring. This leads to a stepwise movement of the displacer relative to the housing in one direction.

The leaf spring, which provides smoothing of vibrational vibrations transmitted to the displacer, due to its small size, has high mechanical stresses in the material. This, together with the cyclical nature of the load, leads to a low resource of its operation, and as a result to a low resource of operation of the pump as a whole.

Thus, the task to which this technical solution is directed is to create a reliable piezoelectric pump.

The technical result achieved by the implementation of the invention is to increase the life of the piezoelectric pump.

To solve the problem with achieving a technical result in a known pump with a piezoelectric drive (piezoelectric pump) containing a displacer of the pumped medium, a housing located in the housing and connected in series to a rear spacer piezoelectric block, a piezoelectric motion block configured to move relative to the housing in the direction of change its length, as well as the front pressure piezoelectric block, according to the claimed invention, the displacer pump the medium to be connected to the front end of the piezoelectric motion block, or to a location located between the front and rear ends of the piezoelectric motion block, or to the rear end of the piezoelectric motion block, or to the rear spacer piezoelectric block.

Due to the new form of communication between the displacer of the pumped medium, as well as the rear spacer piezoelectric block, the piezoelectric motion block and the front spacer piezoelectric block, it is possible to reduce the mechanical stresses in the material of the connecting elements and create a reliable pump with a piezoelectric drive (piezoelectric pump).

These advantages of the invention, as well as its features are illustrated by the best options for implementation with reference to the drawings.

Figure 1 depicts a pump with a piezoelectric drive (piezoelectric pump), in which the displacer of the pumped medium is connected to the front end of the piezoelectric movement unit;

Figure 2 is a sectional view of a piezoelectric pump in the region of a rear spacer piezoelectric block (wires not shown). The displacer of the pumped medium is connected to the front end of the piezoelectric movement unit;

Figure 3 is a sectional view of a piezoelectric pump in the region of a piezoelectric motion block (wires not shown). The displacer of the pumped medium is connected to the front end of the piezoelectric movement unit;

Figure 4 is a tear on the block of motion to demonstrate the compression rod;

Figure 5 is a sectional view of a piezoelectric pump in the region of the front spacer piezoelectric block (wires not shown). The displacer of the pumped medium is connected to the front end of the piezoelectric movement unit;

6 is a piezoelectric pump, in which the displacer of the pumped medium is connected to a place located between the front and rear ends of the piezoelectric motion block;

7 is a section of a piezoelectric pump at the junction of the displacer with the piezoelectric motion block (wires not shown). The displacer of the pumped medium is connected to a place located between the front and rear ends of the piezoelectric motion block;

Fig. 8 is a sectional view of a piezoelectric pump between a junction of a displacer with a piezoelectric motion block and a front spacer piezoelectric block (wires not shown). The displacer of the pumped medium is connected to a place located between the front and rear ends of the piezoelectric motion block;

Fig.9 is a piezoelectric pump in which a displacer of the pumped medium is connected to the rear end of the piezoelectric movement unit (wires not shown);

Figure 10 - piezoelectric pump, in which the displacer of the pumped medium is connected to the rear spacer piezoelectric block (wires not shown).

The pump with a piezoelectric drive (piezoelectric pump) 1 (Figs. 1, 6, 9 and 10) comprises a tubular body 2 located in it and connected in series to a rear spacer piezoelectric block 3, a piezoelectric motion block 4, a front spacer piezoelectric block 5. Rear the piezoelectric block 3 consists of a bracket 6 and piezoelectric packs 7 and 8. The bracket 6 is a U-shaped part consisting of two longitudinal plates and a transverse plate connecting them. Piezo packets 7 and 8 are located between the longitudinal plates of the bracket 6. Directions for changing the lengths of the piezo packets 7 and 8 are perpendicular to the longitudinal plates of the bracket 6.

The front spacer piezoelectric block 5 consists of a bracket 9 and piezoelectric packs 10 and 11. The bracket 9 is a U-shaped part consisting of two longitudinal plates and a transverse plate connecting them. Piezo blocks 10 and 11 are located between the longitudinal plates of the bracket 9. The direction of change in the length of the piezo packets 7 and 8 is perpendicular to the longitudinal plates of the bracket 9. Depending on the required pressure, the required number of piezo packets in the spacer piezoelectric blocks 3 and 5 of the pump 1 are used.

The spacer piezoelectric blocks 3 and 5 and the piezoelectric motion block 4 are made using a material capable of changing its length when an electric potential is applied to them, for example, from a piezoceramic material. As the piezoceramic material, for example, lead zirconate, lead titanate, barium titanate, calcium titanate, or a combination thereof, for example, in the form of solid solutions can be used.

Spacer piezoelectric blocks and a piezoelectric block of motion can be made of layers and / or plates of piezoelectric material, between which are layers of conductive material, for example, metal. Layers of conductive material are designed to connect electrical wires. The plates of the piezoelectric material of the rear and front spacer piezoelectric blocks 3 and 5 are parallel to the direction of change of the length of the piezoelectric motion unit 4. The plates of the piezoelectric material of the rear spacer piezoelectric block 3 are parallel to the longitudinal plates of the bracket 6. And the plates of the piezoelectric material of the front spacer piezoelectric block 5 are parallel staple longitudinal plates 9. Piezoelectric material piezoelectric plates 4-parameter motion block arranged perpendicular to the direction of movement changes the length of the piezoelectric unit 4.

A displacer of the pumped medium is located at the front of the pump 12. A cover 13 is located at the back of the pump. The back cover 13 can be made deformable, for example, in the form of a sealed bellows. When pumping liquids with a pump 1 under conditions of high or variable ambient pressure, the housing 2 can be completely or partially filled with a liquid, for example, polyethylsiloxane liquid. When the ambient pressure and / or temperature changes, the liquid filling the internal sealed cavity of the housing 2, in which the piezoelectric blocks 3, 4, and 5 move, can be forced into the deformable back cover 13 and come back from it. Due to the incompressibility of the liquid, the back cover 13 due to the displacement of the displacer 12 simultaneously expands and contracts with it.

To ensure cyclic operation of the pump 1, an inlet valve 14 and an exhaust valve 15. The valves are located in the front of the housing 2 in front of the displacer 12. As a displacer of the pumped medium 12, a plunger 16 can be used, which is located in the plunger body 17. The plunger body 17 is connected to the housing 2. In the place located between the front and rear ends of the piezoelectric block of motion 4, can be located plate 18 (6 and 7). Hydroprotection 19 (figures 1, 6, 9 and 10) isolates the medium pumped by the plunger pair from the area of the housing 2, in which the piezoelectric blocks 3, 4 and 5 move. Hydroprotection 19 can be made in the form of a part of thin elastic material having a peripheral edge and hole. For example, hydroprotection can be made in the form of an elastic membrane or diaphragm. The peripheral edge of the part made of thin elastic material is hermetically fixed around the inner cavity of the housing 2 in the area between the front spacer piezoelectric block 5 and the displacer of the pumped medium 12. In the hole of the part made of thin elastic material there is a displacer of the pumped medium 12, the edge of this hole is hermetically fixed to the displacer of the pumped medium 12, thus sealing in front the inner part of the cavity of the housing 2 in which the piezoelectric blocks 3, 4 and 5 are located.

Hydroprotection 19 may be made in the form of a bellows tube. In this case, one hole of the bellows tube, which can be considered a peripheral edge, is hermetically fixed around the internal cavity of the housing 2 in the region between the front spacer piezoelectric block 5 and the displacer 12 (plunger 16). The other hole of the bellows tube is hermetically fixed on the displacer of the pumped medium 12 (plunger 16), thus sealing in front the inner part of the cavity of the housing 2, in which the piezoelectric blocks 3, 4 and 5 are located. The holes 29 made in the housing 2 connect the hydroprotection surface 19 facing the displacer of the pumped medium 12, with the environment.

Hydroprotection can also be made in the form of an oil seal mounted on the housing 2 and covering the plunger 16, not allowing the pumped fluid, as well as the fluid surrounding the pump 1 (if any), to penetrate into the pump housing 2.

The displacer of the pumped medium 12 (plunger 16) is connected with at least one pusher 20 to the front end of the piezoelectric motion block 4, or to a place located between the front and rear ends of the piezoelectric motion block 4, or to the rear end of the piezoelectric motion block 4, or with the rear spacer piezoelectric block 5. Pushers 20 are located between the piezoelectric blocks and the inner surface of the cheek 25. Pushers 20 reduce the vibrational vibrations transmitted to the plunger 16 that are generated during the forward movement of the front piezoelectric spacer block 5. The pushers 20 are made of a material that provides due to its elasticity and damping properties, acceptable vibration damping oscillation of the displacer 12 coming to it from piezoelectric units. However, the cross section of the pushers 20 provide their resistance to compressive loads, an acceptable level of mechanical stresses in their material, as well as their strength under cyclic loads.

The electric wire 21 is connected to the piezoelectric packs 7 and 8 of the rear spacer piezoelectric block 3. The electric wire 22 is connected to the piezoelectric block of motion 4. The electric wire 23 is connected to the piezoelectric packets 10 and 11 of the front spacer piezoelectric block 5. The electric wires 21, 22 and 23 are connected to the electric the connector 27. The electrical connector 27 may be located in the cover 13, providing the connection of an electric power cable from the outside of the pump.

The power cable, connected to the pump from the outside, can be made four-core with three power cores and one common core. Also, the power cable can be made three-core with three shielded cores, each core in this case will have its own screen. Also, the cable may have additional conductors for feedback sensors and telemetry devices.

The tubular body 2 can consist of several parts interconnected to form an inner tubular cavity. For example, the housing 2 may consist of two friction plates 24 and two cheeks 25 (FIGS. 2, 3) fastened with bolts 26. The piezo packs 7, 8, 10, 11 of the rear 3 and front 5 spacer piezoelectric blocks abut against their friction plates 24 respectively, through the longitudinal plates of the brackets 6 (for the rear unit 3) or 9 (for the front unit 5). The size of the cheeks 25 between the faces contacting with the friction plates 24 is made with very high accuracy. In Fig.2, the piezoelectric packet 10 of the rear spacer piezoelectric block 9 fell into the section.

The transverse plate of the U-shaped bracket 6 of the rear spacer piezoelectric block 3 is facing forward. The transverse plate of the U-shaped bracket 9 of the front spacer piezoelectric block 5 is turned back. The piezoelectric motion block 4 is connected at its rear end to the transverse plate of the U-shaped bracket 6 of the rear spacer piezoelectric block 3. The piezoelectric motion block 4 is connected with its front end to the transverse plate of the U-shaped bracket 9 of the front spacer of the piezoelectric block 5. The connection is made by an elastic element or elements .

The piezoelectric motion block 4 may contain a compression rod 28 (FIGS. 3, 4) inside the hole, extending from the rear end of block 4 to its front end. The connection of the piezoelectric movement unit 4 with the U-shaped brackets 6 and 9 can be made by a compression rod 28. The compression rod 28 in this case connects the transverse plates of the U-shaped brackets 6 and 9, for example, by means of threaded connections.

Also, the piezoelectric motion block may comprise elastic compression plates outside itself, which are a continuation of the longitudinal plates of the U-shaped brackets and extending from the rear end of the piezoelectric motion block 4 to the front. The connection of the piezoelectric motion block 4 with the U-shaped brackets in this case is made by elastic compression plates, which are a continuation of the longitudinal plates of the U-shaped brackets 6 and 9.

At the pump shown in figures 1, 2, 3 and 5, the plunger 16 using the pushers 20 is connected to the front end of the piezoelectric movement unit 4. At this point, the bracket 9 is connected to the compression rod 28 and to the pushers 20.

At the pump shown in Fig.6, 7 and 8, the plunger 16 using the pushers 20 is connected to a place located between the front and rear ends of the piezoelectric block of motion 4. At this point there is a plate 18, it can be mounted on a compression rod 28. Also, the plate 18 may have a sliding connection with the compression rod 28. Pushers 20 are connected to the plate 18.

In the pump of FIG. 9, the plunger 16 is connected by means of pushers 20 to the rear end of the piezoelectric movement unit 4. At this point, the bracket 6 is connected to the compression rod 28 and to the pushers 20. The material of the compression rod 28 in this design of the pump 1 has a strong preliminary tensile strain. This deformation is ensured during assembly.

At the pump shown in Fig. 10, the plunger 16 is connected to the rear spacer piezoelectric block 3 by means of pushers 20. The bracket 6 in this design may have the form of a closed frame, its part farthest from the plunger 16 is connected to the pushers 20. The material of the compression rod 28 has a strong preliminary tensile strain. This deformation is ensured during assembly.

The device operates as follows.

In the first injection phase, the backward piezoelectric block 3 (FIGS. 1, 2, 3 and 5) of the piezoelectric pump 1 is in the open state, i.e. the U-shaped bracket 6 presses the housing 2 from the inside in the transverse direction. This is due to the supply of electric potential to its piezoelectric packets 7 and 8 from the electrical connector 24 through the wire 21. The front piezoelectric block 5 in this phase is in a free state, between the U-shaped bracket 9 and the walls of the housing 2 there is minimal or no spacing force. At the same time, there is no clearance. The presence of a gap indicates improper adjustment, malfunction, work with a temperature beyond the limit or wear of the pump 1. The gap leads to additional vibration, deterioration of pressure and rapid failure of the device.

In the second injection phase, the electric potential flows through wire 22 to the piezoelectric motion block 4, and this block increases its length. At the same time, the front spacer unit 5 connected to it moves a small distance, overcoming the force of the compression rod 28.

In the third injection phase, the electric potential through the wire 23 is supplied to the front pressure piezoelectric block 5, namely, to its piezoelectric packets 10 and 11, and the bracket 9 starts to press on the housing 2 from the inside. In other words, block 5 goes into the open state. At the same time, the electric potential through the wire 21 ceases to flow to the rear pressure piezoelectric block 3, and it goes into a free state, that is, it ceases to press on the housing 2 from the inside, or exerts the lowest possible pressure. However, the gap in this case between the housing and the bracket 9 is also absent.

In the fourth injection phase, the electric potential ceases to flow through the wire 22 to the piezoelectric motion block 4. Block 4 goes into a free state, that is, reduces its length. In this case, a short distance piezoelectric block 3 moves forward a short distance under the action of force from the compression rod 28. At the end of the fourth phase, the electric potential through the wire 23 ceases to flow to the front pressure piezoelectric block 5, and it goes into a free state - it ceases to exert pressure from the inside 2.

This phase rotation provides a stepwise movement of the piezoelectric blocks 3, 4 and 5 forward. Since the plunger 16 is connected with the moving piezo blocks by means of pushers 20, the pumped medium moves forward with it, filling the space between the plunger 16 and the plunger body 17. The inlet valve 14 is closed and the exhaust valve 15 is open. Through it, the pumped medium leaves the piezoelectric pump 1 under pressure.

The phase sequence during injection is repeated many times until the displacer of the pumped medium 12 (plunger 16) reaches its extreme forward position. This moment is determined by the curve of the electric current in the wire 22. Also, this moment can be monitored by the feedback sensor of the position of the piezoelectric blocks or displacer.

After the displacer reaches the pumped medium 12 (plunger 16) of its extreme forward position, suction begins. In the first suction phase, the back-end piezoelectric block 3 of the piezoelectric pump 1 is in a free state, that is, the U-shaped bracket 6 does not press on the housing 2 from the inside, or presses with the lowest possible force. This is due to the lack of electric potential on the wire 21 and the piezoelectric packs 7. The front spacer piezoelectric block 5 in this phase is in the open state, between the bracket 9 and the walls of the housing 2 the maximum force.

In the second phase of the suction, the electric potential flows through the wire 22 to the piezoelectric motion block 4, and the block increases its length. In this case, the rear spacer block 3 moves back a small distance, counteracting the force of the compression rod 28.

In the third phase of the suction, the electric potential disappears on the wire 23, on the front spacer piezoelectric block 5, namely on its piezoelectric packets 10 and 11, and the bracket 9 ceases to press on the housing 2 from the inside. In other words, block 5 goes into a free state. At the same time, the electric potential through the wire 21 enters the rear pressure piezoelectric block 3, and it goes into the open state, that is, it begins to put pressure on the housing 2 from the inside.

In the fourth phase of the suction, the electric potential ceases to flow through the wire 22 to the piezoelectric motion block 4. The block under the action of the compression rod 28 goes into a free state, that is, reduces its length. At the same time, the front piezoelectric block 5 moves back a small distance.

Such a phase sequence during suction is repeated many times until the displacer of the pumped medium 12 (plunger 16) reaches the extreme rear position. The moment of reaching the extreme rear position is determined by the increase in current in the wire 22. Also, this moment can be monitored by the feedback sensor of the extreme rear position of the piezoelectric blocks (not shown in the figures).

Since the plunger 16 is connected to the piezoblocks moving backwards using the pushers 20, the pumped medium is sucked in with it, filling the space between the plunger 16 and the plunger body 17. The inlet valve 14 is open and the exhaust valve 15 is closed.

Pushers 20 due to their elasticity and damping properties reduce the vibrational vibrations transmitted to the plunger 16 that are generated when the piezoelectric blocks 3, 4 and 5 are moving. This reduces the possibility of cavitation of the pumped medium, as well as the longitudinal vibration of the pump 1.

The most successfully declared pump with a piezoelectric drive (piezoelectric pump) is industrially applicable in transport and in industry when pumping liquids with a high pressure and a relatively low flow rate, where the use of other types of pumps is difficult in terms of weight and size and efficiency indicators.

Claims (19)

1. A pump with a piezoelectric drive, containing a displacer of the pumped medium, a housing located in the housing and connected in series to the rear spacer piezoelectric block, a piezoelectric motion block configured to move relative to the housing in the direction of changing its length, a front spacer piezoelectric block, characterized in that the displacer of the pumped medium is connected to the front end of the piezoelectric motion block, or to a place located between the front and rear to ntsami piezoelectric motion block or the rear end of a piezoelectric motion block or reverse piezoelectric spacer block. 2. The pump according to claim 1, characterized in that each expansion piezoelectric block consists of a U-shaped bracket and at least one piezoelectric packet; U-shaped bracket consists of two longitudinal plates and a transverse plate connecting them; a piezo pack is located between the longitudinal plates of the U-shaped bracket; the direction of the change in the length of the piezoelectric packet is perpendicular to the longitudinal plates. 3. The pump according to claim 1, characterized in that the spacer piezoelectric blocks and / or piezoelectric motion block is made using piezoelectric material. 4. The pump according to claim 3, characterized in that the piezoceramic material is lead zirconate, lead titanate, barium titanate, calcium titanate in any ratio. 5. The pump according to claim 1, characterized in that the housing is partially filled with liquid. 6. The pump according to claim 1, characterized in that in addition to the rear of the housing there is a deformable rear cover. 7. The pump according to claim 6, characterized in that the deformable back cover is made in the form of a sealed bellows. 8. The pump according to claim 6 or 7, characterized in that the housing is completely filled with liquid. 9. The pump according to claim 1, characterized in that a plunger is used as a displacer for the pumped medium. 10. The pump according to claim 1, characterized in that it is additionally introduced hydroprotection in the form of a part of thin elastic material having a peripheral edge and a hole; the peripheral edge of the part made of thin elastic material is hermetically fixed around the internal cavity of the housing in the region between the front spacer piezoelectric block and the displacer of the pumped medium; a displacer of the pumped medium is located in the hole of the part made of thin elastic material, the edge of this hole is hermetically fixed to the displacer of the pumped medium, sealing the front of the internal cavity of the housing, which contains the front pressure piezoelectric block, the piezoelectric motion block, the rear pressure piezoelectric block. 11. The pump of claim 10, characterized in that the hydroprotection is made in the form of a bellows tube, or an elastic membrane, or a diaphragm. 12. The pump according to claim 9, characterized in that the hydraulic protection is additionally introduced in the form of an oil seal, hermetically fixed in the housing in the area between the front spacer piezoelectric block and the plunger, the back of the plunger is made to slide in the stuffing box. 13. The pump according to claim 1, characterized in that the connection of the displacer of the pumped medium with the front end of the piezoelectric motion block, or with a place located between the front and rear ends of the piezoelectric motion block, or with the rear end of the piezoelectric motion block, or with the rear spacer piezoelectric the block is made using at least one pusher; the pusher is located between the piezoelectric blocks and the inner surface of the housing. 14. The pump according to claim 1, characterized in that the housing consists of several parts interconnected to form an internal cavity of a tubular shape. 15. The pump according to claim 1, characterized in that the housing consists of two friction plates and two cheeks bolted together with the formation of an internal cavity of a tubular shape of rectangular cross section; rear and front spacer piezoelectric blocks abut against friction plates from the inside. 16. The pump according to claim 2, characterized in that the transverse plate of the U-shaped bracket of the rear spacer piezoelectric block is facing forward; the transverse plate of the U-shaped bracket of the front spacer piezoelectric block facing back; the piezoelectric block of movement with its rear end is connected to the transverse plate of the U-shaped bracket of the rear spacer piezoelectric block, and its front end is connected to the transverse plate of the U-shaped bracket of the front spacer of the piezoelectric block. 17. The pump according to clause 16, characterized in that the piezoelectric block of movement contains inside itself in the hole a compression rod extending from the rear end of the block to the front; the connection of the piezoelectric motion block with U-shaped brackets is made by a compression rod. 18. The pump according to 17, characterized in that the connection of the compression rod with U-shaped brackets is threaded. 19. The pump according to clause 16, wherein the piezoelectric block of movement contains elastic compressing plates outside themselves, which are a continuation of the longitudinal plates of U-shaped brackets and passing from the rear end of the piezoelectric block of motion to the front; the connection of the piezoelectric motion block with U-shaped brackets is made by elastic compression plates, which are a continuation of the longitudinal plates of U-shaped brackets.

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