Electrical conversion unit and valve positioner with same

Abstract

The invention relates to the technical field of valve positioners, and discloses an electrical conversion unit and a valve positioner with the electrical conversion unit, the electrical conversion unit comprises an upper end cover, a lower end cover, a nozzle baffle part, a main shaft, a nozzle, a rotor, a stator, a coil, a permanent magnet I and a permanent magnet II; a nozzle baffle part fixed at the upper end of the main shaft moves in the moving space of the upper end cover to control the opening degree of the nozzle; the rotor is sleeved on the main shaft, and three rotor bosses are non-uniformly distributed on the outer pipe wall of the sleeve along the radial direction; the stator comprises an upper stator and a lower stator, an upper stator boss is arranged on the outer side of the upper stator, two lower stator bosses are arranged on the outer side of the lower stator, and a coil is wound between the two lower stator bosses; a permanent magnet I and a permanent magnet II are respectively connected between the upper stator boss and the two corresponding lower stator bosses; and the three stator bosses which are non-uniformly distributed correspond to the three rotor bosses in a staggered manner. The invention provides an electrical conversion unit with an annular air gap and without a flexible hinge.

Description

Technical Field

[0001] The present invention relates to the technical field of valve positioners, and more particularly to an electrical conversion unit and a valve positioner having the same. Background Art

[0002] In the complex production environment of modern industry, precise process control is the key factor to ensure product quality and improve production efficiency. As an important part of industrial control system, the performance of control valve will directly affect the stability and efficiency of the entire production process. Valve intelligent positioner occupies an important position in the field of national industrial automation. It is a key component in industrial process control system, used to accurately control the position of valve, and is the "brain" of control valve regulation. It is a direct guarantee for improving the control accuracy and efficiency of production process.

[0003] In the existing intelligent positioners, the electrical conversion unit mostly adopts the nozzle baffle type. The function of the electrical conversion unit is to convert the electrical signal into a pneumatic signal. It is the core component of the positioner, and its performance directly determines the control accuracy of the positioner. Working on the electromagnetic principle, the electrical conversion unit generates a polarized magnetic field through a permanent magnet or an excitation coil, and the electrical control signal generates a control magnetic field through the control coil. The interaction between the two magnetic fields generates a force or torque that is proportional to the control signal and can reflect the polarity of the control signal, thereby causing its moving part to produce a linear displacement or angular displacement mechanical movement. This process involves fluid-solid-magnetic multi-field coupling, and the working principle is complex. Reasonable design of the magnetic circuit and key component parameters is necessary to achieve a high linear conversion between electrical signals and pneumatic outputs.

[0004] At present, the structure of most electrical conversion units for valve intelligent positioners involves a key part, the flexible hinge. As a mechanical connection, the flexible hinge can effectively transmit electromagnetic force to the movable part. Moreover, when the power is cut off and the electromagnetic force is removed, the movable part will return to its initial position under the action of the flexible hinge, which is very important for maintaining the stability and repeatability of the system. But this also causes some problems: the first is the problem of wear and fatigue: the flexible hinge will experience wear and fatigue during repeated rotation and bending, especially in applications where the valve positioner electrical conversion unit needs to be bent repeatedly, long-term use will lead to its performance degradation and shortened life; the second is the maintenance and replacement problem: over time, the flexible hinge needs regular maintenance and replacement, and generally the flexible hinge is riveted in the electrical conversion unit, which is not easy to completely disassemble and reinstall, which increases operating costs and maintenance workload; the third is the manufacturing complexity and cost problem: the electrical conversion unit has very strict requirements on the physical properties of the flexible hinge, and requires precise material selection and manufacturing processes to ensure its performance, which also increases the manufacturing cost of the electrical conversion unit; the fourth is the problem of low stability: during the action, the flexible hinge may vibrate, thereby affecting the stability of the electrical conversion unit.

[0005] Therefore, how to design an electrical conversion unit for valves that can replace flexible hinges, has low manufacturing cost, long service life and high control accuracy is currently needed to be studied. Summary of the invention

[0006] In view of a series of shortcomings of the flexible hinges in the above-mentioned prior art, such as wear, inconvenient maintenance and replacement, complex manufacturing and high cost, and low stability, as well as to overcome the problem of low linearity of traditional electrical conversion units, the present invention provides an electrical conversion unit with an annular air gap and no flexible hinge, and a valve positioner having the same.

[0007] To achieve the above object, the present invention adopts the following technical solution:

[0008] An electrical conversion unit comprises an upper end cover, a lower end cover, a nozzle baffle component, a main shaft, a nozzle, a rotor, a stator, a coil, a permanent magnet 1 and a permanent magnet 2; the upper end cover is connected up and down with the lower end cover as a base; an activity space is opened on the upper end cover, the nozzle baffle component is installed on the upper end of the main shaft, and the upper end of the main shaft together with the nozzle baffle component is adapted to extend into the activity space, and the lower end of the main shaft is rotatably installed on the lower end cover; the nozzle matched with the nozzle baffle component is installed on the upper end cover in a direction perpendicular to the main shaft, and the nozzle baffle component moves in the activity space to control the nozzle opening; the rotor is sleeved on the main shaft between the upper and lower end covers through a middle sleeve, Three rotor bosses are unevenly distributed in the radial direction on the outer tube wall of the sleeve, and the deflection of the rotor drives the main shaft to rotate; the stator connected to the upper end cover and the lower end cover includes an upper stator and a lower stator, an upper stator boss is provided on the outer side of the upper stator, and two lower stator bosses are provided on the outer side of the lower stator, and a crossbeam wound around the coil is connected between the two lower stator bosses; the permanent magnet 1 and the permanent magnet 2 are respectively connected between the left and right side end surfaces of the upper stator boss and the left and right outer side end surfaces of the corresponding two lower stator bosses; the three unevenly distributed stator bosses are staggered and correspond to the three rotor bosses, and then combined with the coil, the permanent magnet 1 and the permanent magnet 2 to form three magnetic circuits.

[0009] Preferably, the nozzle baffle component includes a nozzle baffle, a nozzle stopper, and a nozzle baffle fixing pin. A pin hole 1 is provided in the middle of the nozzle baffle, and a pin hole 2 is provided at the upper end of the main shaft and is perpendicular to the axial direction thereof. The nozzle baffle fixing pin passes through the pin hole 1 and the pin hole 2, and the nozzle baffle is laterally riveted to the main shaft. The nozzle baffle can swing left and right with the nozzle baffle fixing pin as the center; the nozzle stopper corresponding to the nozzle is installed on one side of the nozzle baffle.

[0010] Preferably, a vent hole for supplying air to the nozzle is vertically opened on the upper portion of the upper end cover, an annular groove is opened at the vent hole, and a sealing ring is adapted to be installed in the annular groove.

[0011] Preferably, a main shaft mounting groove is opened in the upper part of the lower end cover, and the lower end of the main shaft is mounted in the main shaft mounting groove through a lower end cover rolling bearing, and a lower end cover bearing baffle is also installed below the lower end cover rolling bearing.

[0012] Preferably, the upper end cover is connected to the lower end cover by a plurality of screws, and the plurality of screws respectively pass through the corresponding stator bosses in the middle, so that the stator is connected to the upper end cover and the lower end cover.

[0013] Preferably, the upper end cover and the lower end cover are each provided with four end cover threaded holes, each lower stator boss is provided with a stator boss threaded hole, and the upper stator boss is provided with two stator boss threaded holes; the four screws respectively pass through the upper and lower corresponding end cover threaded holes and stator boss threaded holes to connect the upper stator, the lower stator, the upper end cover, and the lower end cover.

[0014] Preferably, a slot 1 is provided on each of the left and right end faces of the upper stator boss, and a slot 2 is provided on the left and right outer end faces of the two lower stator bosses respectively, and the permanent magnet 1 and the permanent magnet 2 are respectively inserted between the corresponding slot 1 and the slot 2.

[0015] Preferably, the upper stator, the lower stator and the rotor are made of soft magnetic materials with strong magnetic conductivity, the upper end cover and the lower end cover are made of non-magnetic conductive materials, and the permanent magnet 1 and the permanent magnet 2 are made of hard magnetic materials.

[0016] Preferably, the polarity of the permanent magnet 1 and the permanent magnet 2 must be consistent during installation; when the coil is controlled to be not energized, two magnetic circuits are formed under the original magnetic field generated by the permanent magnet 1 and the permanent magnet 2, so that the rotor maintains an initial stable state; when the coil is controlled to be energized, three magnetic circuits are formed under the interaction of the original magnetic field generated by the permanent magnet 1 and the permanent magnet 2 and the controlled magnetic field generated by the coil, generating an output torque on the rotor, causing the rotor to deflect and drive the main shaft to rotate together.

[0017] The present invention further provides a valve positioner having the electrical conversion unit.

[0018] Compared with the prior art, the electrical conversion unit of the present invention has the following beneficial effects:

[0019] 1. The present invention replaces the traditional flexible hinge with a magnetic circuit structure: the electrical conversion unit device of the present invention is designed with a three-petal non-uniformly distributed rotor boss structure, and there is a certain offset during installation, that is, there are certain technical requirements for setting the initial position of the rotor installation: the three bosses of the rotor and the three bosses of the stator are not installed completely correspondingly, and there is a certain misalignment between them; the magnetic torque that controls the magnetic field after power is turned on can make the rotor that deviates from the center position return to the center position, which is the same as the effect of a mechanical balance spring.

[0020] The present invention can replace the flexible hinge component that must exist in the traditional electrical conversion unit, which is conducive to achieving the working stability of the electrical conversion unit and reducing wear and tear to extend the service life, while reducing the manufacturing cost.

[0021] 2. The upper stator, lower stator and rotor of the present invention constitute three magnetic circuits and three working air gaps, wherein the upper stator and rotor constitute one working air gap (air gap 3), and the lower stator and rotor constitute two working air gaps (air gap 1 and air gap 2).

[0022] The present invention adopts an annular air gap: compared with the traditional planar rectangular air gap, the advantages of the annular air gap are: 1) improving the distribution of magnetic lines of force: the annular air gap can provide a continuous, surrounding magnetic circuit, which helps to distribute the magnetic lines of force more evenly and reduce the concentration and local saturation of magnetic lines of force; 2) improving the output torque: the design of the annular air gap maximizes the relative size of the air gap within a limited space, which can more effectively utilize the magnetic flux and help increase the output torque; 3) reducing vibration: due to its symmetry and uniform magnetic field distribution, the annular air gap can reduce the vibration of the electrical conversion unit during operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0024] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0025] Figure 2 It is a schematic diagram of the structure of the present invention without installing the upper end cover;

[0026] Figure 3 It is the explosion structure schematic diagram of the present invention:

[0027] Figure 4 It is a schematic diagram of the structure of the upper end cover in the present invention;

[0028] Figure 5 It is a schematic diagram of the installation of the upper end cover and the nozzle in the present invention;

[0029] Figure 6 is a front view of the upper end cover of the present invention;

[0030] Figure 7 yes Figure 6 Cross-section view in the AA direction;

[0031] Figure 8 It is a schematic diagram of the structure of the lower end cover in the present invention;

[0032] Fig. 9 It is a structural schematic diagram of the upper stator in the present invention;

[0033] Fig.10 It is a structural schematic diagram of the lower stator in the present invention;

[0034] Fig.11 It is a schematic diagram of the structure of the rotor in the present invention;

[0035] Fig.12 is a schematic diagram of the structure of the nozzle baffle component;

[0036] FIG13( a ) is a diagram showing the working principle of the present invention when the coil is not energized;

[0037] FIG13( b ) is a diagram showing the working principle of the present invention after the coil is energized;

[0038] In the figure: 1-upper end cover, 2-lower end cover, 3-spindle, 4-nozzle, 5-rotor, 6-coil, 7-permanent magnet one, 8-permanent magnet two, 9-activity space, 10-sleeve, 11-rotor boss, 12-upper stator, 13-lower stator, 14-upper stator boss, 15-lower stator boss, 16-cross beam, 17-slot one, 18-slot two, 19-nozzle baffle, 20-nozzle stopper, 21-nozzle baffle fixing pin, 22-vent, 23-lower end cover rolling bearing, 24-lower end cover bearing baffle, 25-cross recessed cylindrical head screw, 26-end cover threaded hole, 27-stator boss threaded hole, 28-shaft collar sleeve. DETAILED DESCRIPTION

[0039] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.

[0040] In the description of the present invention, it is necessary to understand that the terms "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0041] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0042] Example:

[0043] like Figure 1-Figure 12 As shown, an electrical conversion unit of the present invention includes an upper end cover 1, a lower end cover 2, a nozzle baffle component, a main shaft 3, a nozzle 4, a rotor 5, a stator, a coil 6, a permanent magnet 1 7, and a permanent magnet 2 8.

[0044] Specifically, the upper end cover 1 is connected to the lower end cover 2 as a base up and down; an activity space 9 is opened on the upper end cover 1, and the activity space 9 is specifically a long strip hole with a circular middle. The nozzle baffle component is installed on the upper end of the main shaft 3, and the upper end of the main shaft together with the nozzle baffle component is adapted to extend into the activity space 9, and the lower end of the main shaft 3 is rotatably installed on the lower end cover 2; the nozzle 4 matched with the nozzle baffle component is installed on the upper end cover 1 in a direction perpendicular to the main shaft, and the nozzle baffle component moves in the activity space 9 to control the opening of the nozzle 4, and a threaded hole for installing the nozzle 4 is opened on the front of the upper end cover 1.

[0045] To be more specific, the nozzle baffle component includes a nozzle baffle 19, a nozzle stopper 20, and a nozzle baffle fixing pin 21. A pin hole 1 is opened in the middle of the nozzle baffle 19, and a pin hole 2 is opened at the upper end of the main shaft 3 and is perpendicular to its axial direction. The nozzle baffle fixing pin 21 passes through the pin holes 1 and 2, and the nozzle baffle 19 is laterally riveted to the main shaft 3. The nozzle baffle 19 can swing left and right with the nozzle baffle fixing pin 21 as the center; a nozzle stopper 20 corresponding to the nozzle 4 is installed on one side of the nozzle baffle 19, and the nozzle stopper 20 and the nozzle baffle 19 are interference fit.

[0046] The nozzle baffle 19 in the electrical conversion unit of the present invention can change its position by adjustment to ensure that the nozzle stopper 20 matches the nozzle opening.

[0047] At the same time, a vent hole 22 for supplying air to the nozzle 4 is vertically opened on the upper part of the upper end cover 1, and an annular groove is opened at the vent hole 22, and a sealing ring is adapted to be installed in the annular groove.

[0048] The rotor 5 is sleeved on the main shaft 3 between the upper and lower end covers through the middle sleeve 10. Three rotor bosses 11 are unevenly distributed radially on the outer tube wall of the sleeve 10. The main shaft 3 and the sleeve 10 are interference fit, so that the deflection of the rotor 5 drives the main shaft 3 to rotate.

[0049] The stator connected to the upper end cover 1 and the lower end cover 2 includes an upper stator 12 and a lower stator 13. An upper stator boss 14 is provided on the outer side of the upper stator 12, and two lower stator bosses 15 are provided on the outer side of the lower stator 13. A crossbeam 16 for winding the coil 6 is connected between the two lower stator bosses 15, that is, the present invention does not require a customized coil skeleton, and the coil 6 can be directly wound on the reserved position on the lower stator 13. The coil 6 is used to provide a controlled magnetic field excitation for the electrical conversion unit device to break the balance of the original magnetic field, so that the rotor 5 is deflected, and the electrical conversion unit device works.

[0050] The left and right side end surfaces of the upper stator boss 14 and the left and right outer side end surfaces of the corresponding two lower stator bosses 15 are respectively connected to the permanent magnet 1 7 and the permanent magnet 2 8 .

[0051] More specifically, a slot 17 is provided on each of the left and right end surfaces of the upper stator boss 14, and a slot 2 18 is correspondingly provided on the left and right outer end surfaces of the two lower stator bosses 15. The permanent magnet 1 7 and the permanent magnet 2 8 are respectively inserted between the corresponding slot 1 17 and the slot 2 18.

[0052] The three non-uniformly distributed stator bosses correspond to the three rotor bosses 11 in a staggered manner, and together with the coil 6, the permanent magnet 1 7 and the permanent magnet 2 8 form three magnetic circuits.

[0053] In a specific embodiment of the present invention, the upper end cover 1 is connected to the lower end cover 2 by several screws, and the screws are preferably cross-recessed cylindrical head screws 25. Several cross-recessed cylindrical head screws 25 pass through the corresponding stator bosses in the middle to connect the stator to the upper end cover 1 and the lower end cover 2.

[0054] More specifically, four end cover threaded holes 26 are correspondingly provided on the upper end cover 1 and the lower end cover 2, each lower stator boss 15 is provided with a stator boss threaded hole 27 for positioning the lower stator 13, and the upper stator boss 14 is provided with two stator boss threaded holes 27 for positioning the upper stator 12; four cross-recessed cylindrical head screws 25 pass through the corresponding upper and lower end cover threaded holes 26 and stator boss threaded holes 27, respectively, to connect the upper stator 12, the lower stator 13 with the upper end cover 1, and the lower end cover 2.

[0055] In a specific embodiment of the present invention, a main shaft mounting groove is opened in the upper part of the lower end cover 2, and the lower end of the main shaft 3 is installed in the main shaft mounting groove through the lower end cover rolling bearing 23. A shaft ring sleeve 28 is also provided between the main shaft 3 and the lower end cover rolling bearing 23, and a lower end cover bearing baffle 24 is also installed below the lower end cover rolling bearing 23.

[0056] In a specific embodiment of the present invention, the upper stator 12, the lower stator 13 and the rotor 5 are made of soft magnetic materials with strong magnetic conductivity (such as 1J85), the upper end cover 1 and the lower end cover 2 are made of non-magnetic materials, and the permanent magnet 1 7 and the permanent magnet 2 8 are made of hard magnetic materials (such as neodymium iron boron).

[0057] In a specific embodiment of the present invention, the permanent magnet 1 7 and the permanent magnet 2 8 must have consistent polarities when installed to provide an original magnetic field balance for the electrical conversion unit device.

[0058] The magnetic field in the electrical conversion unit of the present invention is composed of two parts, one part is the original magnetic field generated by the permanent magnet 1 7 and the permanent magnet 2 8, and the other part is the control magnetic field generated after the control coil 6 is energized. The control magnetic field breaks the balance of the original magnetic field to achieve the normal operation of the electrical conversion unit device.

[0059] The upper stator 12, the lower stator 13 and the rotor 5 of the electrical conversion unit of the present invention also constitute three working air gaps in total, wherein the upper stator 12 and the rotor 5 constitute one working air gap (air gap 3, as indicated at C in FIG. 13 ), and the lower stator 13 and the rotor 5 constitute two working air gaps (air gap 1 and air gap 2, wherein air gap 1 is as indicated at A in FIG. 13 , and air gap 2 is as indicated at B in FIG. 13 ).

[0060] When the control coil 6 is not energized, two magnetic circuits are formed under the original magnetic field generated by the permanent magnet 1 7 and the permanent magnet 2 8, so that the rotor 5 maintains an initial stable state; when the control coil 6 is energized, three magnetic circuits are formed under the interaction of the original magnetic field generated by the permanent magnet 1 7 and the permanent magnet 2 8 and the control magnetic field generated by the coil 6, which generates an output torque on the rotor 5, causing the rotor 5 to deflect and drive the main shaft 3 to rotate together.

[0061] The electrical conversion unit of the present invention adopts an annular air gap. Compared with the traditional planar rectangular air gap, the annular air gap has the following advantages:

[0062] 1) Improve the distribution of magnetic lines of force;

[0063] The annular air gap provides a continuous, surrounding magnetic circuit, which helps to distribute the magnetic lines of force more evenly. In the magnetic circuit, the magnetic lines of force will naturally flow along the path with the least magnetic resistance. Due to the continuity of the annular air gap, the magnetic lines of force can flow more smoothly, reducing the concentration of magnetic lines of force and local saturation. This uniform distribution helps to reduce energy loss and improve the efficiency of the magnetic circuit. In Kirchhoff's second law of magnetic circuits, the total magnetomotive force of any closed magnetic circuit is equal to the algebraic sum of the magnetic pressure drops of each section of the magnetic circuit. The design of the annular air gap helps to distribute the magnetomotive force more reasonably, thereby improving the distribution of magnetic lines of force.

[0064] 2) Increase output torque;

[0065] The design of the annular air gap maximizes the relative size of the air gap within a limited space, which can more effectively utilize the magnetic flux and increase the output torque. In the entire magnetic circuit, the air gap is an important factor affecting the size of the electromagnetic force and electromagnetic torque. The size of the air gap will directly affect the distribution of the magnetic flux and the output torque of the electrical conversion unit. Due to its geometric characteristics, the annular air gap can provide a larger air gap area within the same volume, thereby allowing more magnetic flux to pass through, thereby increasing the output torque.

[0066] 3) Reduce vibration;

[0067] Each annular air gap of the electrical conversion unit of the present invention can reduce the vibration of the electrical conversion unit during operation due to its symmetry and uniform distribution of magnetic field. Generally, in a magnetic circuit structure, the generation of vibration is related to the uneven distribution of the magnetic field. The uneven magnetic field will cause an imbalance of force, thereby generating vibration. The annular air gap reduces this imbalance by providing a uniform distribution of magnetic field lines, thereby reducing vibration. In addition, the design of the annular air gap also reduces the force imbalance caused by the change of magnetic flux, further reducing vibration.

[0068] The working principle of the electrical conversion unit of the present invention is shown in FIG13 , which is divided into two parts: FIG13 (a) is the initial state when no power is applied, at which time the electrical conversion unit device of the present invention only has the original magnetic field generated by permanent magnet 1 7 and permanent magnet 2 8, and this magnetic field provides a stable magnetic field environment for the rotor 5. It should be noted here that since the three rotor bosses 11 are not evenly distributed in the radial direction, the lower stator 13 and the bosses of the rotor 5 are misaligned, so the air gap 1 is smaller than the air gap 2 in the initial state. At the same time, under the original magnetic field, the magnetic path of the electrical conversion unit device of the present invention is shown in FIG13 (a), forming two magnetic circuits in total. At this time, the magnetic flux passing through air gap 1 and air gap 2 is the same, and this balanced state of magnetic flux allows the rotor 5 to maintain an initial stable state.

[0069] After power is turned on, the control of the specific deflection angle of the rotor mainly depends on the electromagnetic principle. When the current in the direction shown in Figure 13 (b) is passed through the coil 6, its N and S poles can be obtained by the right-hand screw rule, and the control magnetic field of the device of the present invention will be formed at the same time, that is, the third magnetic circuit. At this time, in the air gap 1, the control magnetic field generated by the coil 6 is consistent with the magnetic flux direction of the original magnetic field generated by the permanent magnet, that is, the magnetic flux passing through the air gap 1 will increase; at the same time, in the air gap 2, the control magnetic field generated by the coil 6 is opposite to the magnetic flux direction of the original magnetic field generated by the permanent magnet, that is, the magnetic flux passing through the air gap 2 will decrease. The two work together to make the rotor 5 rotate clockwise, thereby driving the nozzle baffle component to move, so that the nozzle stopper 20 in the nozzle baffle component is close to the nozzle 4, thereby changing the opening of the nozzle.

[0070] Similarly, when the power is turned off, the control magnetic field generated by the coil 6 will disappear, and only two magnetic circuits formed by the original magnetic field generated by the permanent magnet will remain in the device of the present invention. At this time, the magnetic flux in the air gap 1 will be relatively reduced, while the magnetic flux in the air gap 2 will be relatively increased, causing the rotor 5 to return to its initial state.

[0071] In the electrical conversion unit of the present invention, the deflection of the rotor 5 is caused by the interaction between the control magnetic field generated by the coil 6 after being energized and the original magnetic field generated by the permanent magnet 1 7 and the permanent magnet 2 8, resulting in a change in the distribution of the magnetic flux, thereby generating a torque. The torque generated by this interaction causes the rotor 5 to deflect. Specifically, the magnitude of the control torque (i.e., the control of the specific deflection angle) is achieved by controlling the magnitude of the current input to the coil 6. The magnitude of the current in the coil 6 directly affects the strength of the control magnetic field. At the same time, the direction of the current also determines the direction of the torque, thereby changing the rotation direction of the rotor 5. Of course, the present invention does not need to change the direction of the current. By accurately controlling the magnitude of the current, the deflection angle of the rotor 5 can be accurately controlled. That is, if the rotor 5 is to be stopped at a specific angle, by controlling the magnitude of the current in the coil 6, when the torque generated by the control magnetic field is balanced with the torque generated by the original magnetic field, the magnetic flux distribution in the air gap 1 and the air gap 2 is balanced again, so that the rotor 5 can reach a new equilibrium position and stop.

[0072] It should be noted that although the rotor 5 is affected by its own inertia during the stopping process, since the torque generated by the control magnetic field is balanced with the torque generated by the original magnetic field, the rotor 5 will eventually reach a stable equilibrium state, and the process time is very short.

[0073] In the electrical conversion unit of the present invention, the three rotor bosses 11 and the three stator bosses are designed not to be installed completely correspondingly, but to have a certain misalignment, so that after power is turned on, the magnetic flux in the air gap 1 and the air gap 2 is changed due to the effect of controlling the magnetic field, so that the rotor 5 that has deviated from the middle position returns to the middle position. If the device body shakes or shifts, the initial position of the rotor 5 will deviate, but due to the existence of the initial magnetic field, the magnetic flux in the air gap 1 and the air gap 2 is the same, that is, a state of magnetic flux balance will be reached, so that the rotor 5 will definitely return to the designed initial position again.

[0074] Based on the above principles, the present invention will completely replace the flexible hinge, which is beneficial to achieving the working stability of the electrical conversion unit and reducing wear and tear to extend the service life, while reducing manufacturing costs.

[0075] Meanwhile, the rotation limit position of the rotor in the electrical conversion unit of the present invention is determined by two factors: 1) the lower stator forming the air gap 1 and the boss corresponding to the rotor are completely aligned; 2) the maximum current that the coil can withstand.

[0076] The present invention further provides a valve positioner having the electrical conversion unit.

[0077] In this specification, each embodiment is described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be referred to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part.

[0078] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An electrical conversion unit, characterized in that: It includes an upper end cover, a lower end cover, a nozzle baffle component, a main shaft, a nozzle, a rotor, a stator, a coil, a permanent magnet 1 and a permanent magnet 2; the upper end cover is connected to the lower end cover as a base up and down; an activity space is opened on the upper end cover, the nozzle baffle component is installed on the upper end of the main shaft, and the upper end of the main shaft together with the nozzle baffle component is adapted to extend into the activity space, and the lower end of the main shaft is rotatably installed on the lower end cover; the nozzle matched with the nozzle baffle component is installed on the upper end cover in a direction perpendicular to the main shaft, and the nozzle baffle component moves in the activity space to control the nozzle opening; the rotor is sleeved on the main shaft between the upper and lower end covers through a middle sleeve, and the sleeve Three rotor bosses are unevenly distributed in the radial direction on the outer tube wall, and the deflection of the rotor drives the main shaft to rotate; the stator connected to the upper end cover and the lower end cover includes an upper stator and a lower stator, an upper stator boss is provided on the outer side of the upper stator, and two lower stator bosses are provided on the outer side of the lower stator, and a crossbeam wound around the coil is connected between the two lower stator bosses; the permanent magnet 1 and the permanent magnet 2 are respectively connected between the left and right side end surfaces of the upper stator boss and the left and right outer side end surfaces of the corresponding two lower stator bosses; the three unevenly distributed stator bosses are staggered and correspond to the three rotor bosses, and then combined with the coil, the permanent magnet 1 and the permanent magnet 2 to form three magnetic circuits.

2. An electrical conversion unit according to claim 1, characterized in that: The nozzle baffle component includes a nozzle baffle, a nozzle block, and a nozzle baffle fixing pin. A pin hole 1 is opened in the middle of the nozzle baffle, and a pin hole 2 is opened at the upper end of the main shaft and is perpendicular to its axial direction. The nozzle baffle fixing pin passes through the pin hole 1 and the pin hole 2, and the nozzle baffle is laterally riveted to the main shaft. The nozzle baffle can swing left and right with the nozzle baffle fixing pin as the center; the nozzle block corresponding to the nozzle is installed on one side of the nozzle baffle.

3. An electrical conversion unit according to claim 1 or 2, characterized in that: The upper portion of the upper end cover is also vertically provided with an air vent hole for supplying air to the nozzle, and an annular groove is provided at the air vent hole, and a sealing ring is adapted to be installed in the annular groove.

4. An electrical conversion unit according to claim 1, characterized in that: A main shaft installation groove is provided on the upper part of the lower end cover, and the lower end of the main shaft is installed in the main shaft installation groove through a lower end cover rolling bearing. A lower end cover bearing baffle is also installed below the lower end cover rolling bearing.

5. An electrical conversion unit according to claim 1, characterized in that: The upper end cover is connected to the lower end cover by a plurality of screws, and the plurality of screws respectively pass through the corresponding stator bosses in the middle, so that the stator is connected to the upper end cover and the lower end cover.

6. An electrical conversion unit according to claim 5, characterized in that: The upper end cover and the lower end cover are each provided with four end cover threaded holes, each lower stator boss is provided with a stator boss threaded hole, and the upper stator boss is provided with two stator boss threaded holes; the four screws pass through the upper and lower corresponding end cover threaded holes and stator boss threaded holes respectively, so as to connect the upper stator, the lower stator, the upper end cover and the lower end cover.

7. An electrical conversion unit according to claim 1, characterized in that: The left and right end surfaces of the upper stator boss are each provided with a slot 1, and the left and right outer end surfaces of the two lower stator bosses are correspondingly provided with a slot 2, and the permanent magnet 1 and the permanent magnet 2 are respectively inserted between the corresponding slot 1 and the slot 2.

8. The electrical conversion unit according to claim 1, characterized in that: The upper stator, the lower stator and the rotor are made of soft magnetic materials with strong magnetic conductivity, the upper end cover and the lower end cover are made of non-magnetic conductive materials, and the permanent magnet 1 and the permanent magnet 2 are made of hard magnetic materials.

9. The electrical conversion unit according to claim 1, characterized in that: The polarities of the permanent magnet 1 and the permanent magnet 2 must be consistent during installation; when the coil is controlled to be not energized, two magnetic circuits are formed under the original magnetic field generated by the permanent magnet 1 and the permanent magnet 2, so that the rotor maintains an initial stable state; when the coil is controlled to be energized, three magnetic circuits are formed under the interaction of the original magnetic field generated by the permanent magnet 1 and the permanent magnet 2 and the controlled magnetic field generated by the coil, generating an output torque on the rotor, causing the rotor to deflect and drive the main shaft to rotate together.

10. A valve positioner, characterized in that: The invention comprises the electrical appliance conversion unit as described in any one of claims 1 to 9.

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