An electrical conversion unit and a valve positioner having the same

Abstract

The present invention relates to the technical field of valve positioners, and discloses an electrical conversion unit and a valve positioner having the same. The electrical conversion unit 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 first permanent magnet, and a second permanent magnet. The nozzle baffle component fixed to the upper end of the main shaft moves within the movable space of the upper end cover to control the nozzle opening. The rotor is sleeved on the main shaft, and three rotor bosses are unevenly distributed radially on the outer tube wall of the sleeve. The stator 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, with a coil wound between the two lower stator bosses. Permanent magnets 1 and 2 are respectively connected between the upper stator boss and the corresponding two lower stator bosses. The three unevenly distributed stator bosses are staggered and correspond to the three rotor bosses. The present invention provides an electrical conversion unit with an annular air gap and no 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 environments of modern industry, precise process control is a key factor in ensuring product quality and improving production efficiency. As a crucial component of industrial control systems, the performance of control valves directly impacts the stability and efficiency of the entire production process. Intelligent valve positioners play a vital role in China's industrial automation sector. As a key component in industrial process control systems, they precisely control valve position and serve as the "brain" of control valve regulation, directly ensuring improved control accuracy and efficiency in production processes.

[0003] In 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 principle of electromagnetics, 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 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 high linear conversion between electrical signals and pneumatic outputs.

[0004] Currently, the electrical conversion units used in most intelligent valve positioners incorporate a key component, a flexible hinge. This mechanical connection effectively transmits electromagnetic force to the movable component. Furthermore, when power is removed and the electromagnetic force is eliminated, the flexible hinge returns the movable component to its initial position, which is crucial for maintaining system stability and repeatability. But this also causes some problems: the first is the wear and fatigue problem: 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 repeatedly bent. 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 requires 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 movement, 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 in need of research. Summary of the Invention

[0006] In view of the series of shortcomings brought about by the flexible hinges in the above-mentioned prior art, such as wear, inconvenience in maintenance and replacement, complex manufacturing and high cost, and low stability, and 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 solutions:

[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 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 an intermediate sleeve, Three rotor bosses are unevenly distributed radially 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 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 end faces of the upper stator boss and the left and right outer end faces of the corresponding two lower stator bosses; the three unevenly distributed stator bosses are staggered and correspond to the three rotor bosses, and together with the coil, the permanent magnet 1 and the permanent magnet 2, form three magnetic circuits.

[0009] Preferably, the nozzle baffle component includes a nozzle baffle, a nozzle block, and a nozzle baffle fixing pin. A pin hole 1 is provided in the middle of the nozzle baffle, and a pin hole 2 perpendicular to the axial direction of the main shaft is provided at the upper end of the main shaft. The nozzle baffle fixing pin passes through the pin hole 1 and the pin hole 2 to laterally rivet the nozzle baffle 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.

[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 on 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 the 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 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 de-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; after power is turned on, the magnetic torque generated to control the magnetic field can return the rotor that deviates from the center position 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 a traditional electrical conversion unit, which is beneficial to achieving the working stability of the electrical conversion unit, reducing wear and tear, and extending the service life, while reducing manufacturing costs.

[0021] 2. The upper stator, lower stator and rotor of the present invention constitute three magnetic circuits and three working air gaps. 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, can more effectively utilize the magnetic flux, and is more conducive to increasing 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 following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are merely embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying any creative work.

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

[0025] Figure 2 This is a schematic structural diagram of the present invention without the upper end cover installed;

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

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

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

[0029] Figure 6 It 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 structural schematic diagram of the lower end cover in the present invention;

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

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

[0034] Figure 11 It is a schematic structural diagram of the rotor in the present invention;

[0035] Figure 12 1. It is a structural diagram 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-main shaft, 4-nozzle, 5-rotor, 6-coil, 7-permanent magnet 1, 8-permanent magnet 2, 9-activity space, 10-sleeve, 11-rotor boss, 12-upper stator, 13-lower stator, 14-upper stator boss, 15-lower stator boss, 16-crossbeam, 17-slot 1, 18-slot 2, 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] The following describes embodiments of the present invention in detail, 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 are not to be construed as limiting the present invention.

[0040] In the description of the present invention, it should be understood that the terms "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating directions or positional relationships, are based on the directions or positional relationships shown in the accompanying 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 direction, be constructed and operated in a specific direction, and therefore should not be understood as limiting the present invention.

[0041] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature identified as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, "plurality" means two or more, unless otherwise specifically defined.

[0042] Example:

[0043] like Figures 1-12 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 serving as the 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 that cooperates 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. 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 provided in the middle of the nozzle baffle 19, and a pin hole 2 is provided 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 hole 1 and the pin hole 2, and the nozzle baffle 19 is riveted horizontally 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 block 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. 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 mounted 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 outside of the upper stator 12, and two lower stator bosses 15 are provided on the outside of the lower stator 13. A crossbeam 16, around which the coil 6 is wound, is connected between the two lower stator bosses 15. This means that the present invention does not require a custom coil bobbin; the coil 6 can be directly wound around the reserved space on the lower stator 13. The coil 6 is used to provide a controlled magnetic field excitation for the electrical conversion unit, disrupting the balance of the original magnetic field and causing the rotor 5 to deflect, thereby enabling the electrical conversion unit to operate.

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

[0051] To be more specific, a slot 17 is provided on each of the left and right end faces of the upper stator boss 14, and a slot 2 18 is provided on the left and right outer end faces 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 slot 2 18.

[0052] The three unevenly 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 and the lower end cover 2 are connected by several screws, which 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-slot cylindrical head screws 25 are respectively passed through the corresponding upper and lower end cover threaded holes 26 and stator boss threaded holes 27 to realize the connection between the upper stator 12, the lower stator 13 and 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 on 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 polarities of the permanent magnet 1 7 and the permanent magnet 2 8 must be consistent during installation 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 consists of two parts: the original magnetic field generated by permanent magnets 1 7 and 2 8, and the controlled magnetic field generated by energizing control coil 6. The controlled magnetic field disrupts the balance of the original magnetic field, enabling the electrical conversion unit to operate normally.

[0059] The upper stator 12, lower stator 13 and 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 by C in Figure 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 by A in Figure 13, and air gap 2 is as indicated by B in Figure 13).

[0060] When the control coil 6 is not energized, two magnetic circuits are formed under the original magnetic field generated by permanent magnet 1 7 and permanent magnet 2 8, so that the rotor 5 maintains its 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 permanent magnet 1 7 and 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, encircling magnetic circuit, which helps to more evenly distribute the magnetic lines of force. In a magnetic circuit, magnetic lines of force naturally flow along the path of least magnetic resistance. Due to the continuity of the annular air gap, the magnetic lines of force can flow more smoothly, reducing the phenomenon of magnetic line concentration 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 voltage drops in each section of the magnetic circuit. The design of the annular air gap helps to more rationally distribute the magnetomotive force, thereby improving the distribution of magnetic lines of force.

[0064] 2) Increase output torque;

[0065] The annular air gap design maximizes the relative size of the air gap within a confined space, enabling more efficient use of magnetic flux and increasing output torque. Within the entire magnetic circuit, the air gap is a crucial factor influencing the magnitude of the electromagnetic force and torque. The size of the air gap directly influences the distribution of magnetic flux and the output torque of the electrical conversion unit. Due to its geometric properties, the annular air gap provides a larger air gap area within the same volume, allowing more magnetic flux to pass through and, in turn, increasing output torque.

[0066] 3) Reduce vibration;

[0067] Each annular air gap in the electrical conversion unit of the present invention, due to its symmetry and uniform magnetic field distribution, can reduce vibration during operation. Generally, in magnetic circuit structures, vibration is caused by uneven magnetic field distribution. This uneven magnetic field leads to force imbalance, which in turn causes vibration. The annular air gap reduces this imbalance by providing a uniform distribution of magnetic field lines, thereby reducing vibration. Furthermore, the annular air gap design reduces force imbalances caused by changes in magnetic flux, further reducing vibration.

[0068] The working principle of the electrical conversion unit of the present invention is shown in Figure 13 and is divided into two parts: Figure 13(a) shows the initial state when no power is applied. At this 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. 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 along the radial direction, the bosses of the lower stator 13 and 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 Figure 13(a), forming a total of two magnetic circuits. At this time, the magnetic flux passing through air gap 1 and air gap 2 is the same. This balanced state of magnetic flux allows the rotor 5 to maintain its initial stable state.

[0069] After power is applied, the control of the specific rotor deflection angle relies primarily on electromagnetic principles. When current is passed through coil 6 in the direction shown in Figure 13(b), its north and south poles can be determined by the right-hand screw rule, simultaneously forming the control magnetic field of the device of the present invention, which is the third magnetic circuit. At this time, in air gap 1, the control magnetic field generated by coil 6 aligns with the magnetic flux direction of the original magnetic field generated by the permanent magnet, indicating that the magnetic flux through air gap 1 will increase. Simultaneously, in air gap 2, the control magnetic field generated by coil 6 aligns with the magnetic flux direction of the original magnetic field generated by the permanent magnet, indicating that the magnetic flux through air gap 2 will decrease. These two factors work together to cause rotor 5 to rotate clockwise, thereby driving the nozzle baffle assembly to move, causing the nozzle stopper 20 within the nozzle baffle assembly to approach the nozzle 4, thereby changing the nozzle opening.

[0070] Similarly, when power is removed, the control magnetic field generated by coil 6 disappears, leaving only two magnetic circuits in the device of the present invention, formed by the original magnetic field generated by the permanent magnets. At this point, the magnetic flux in air gap 1 decreases, while the magnetic flux in air gap 2 increases, causing 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 energizing coil 6 and the original magnetic field generated by permanent magnets 1 7 and 2 8. This changes the distribution of magnetic flux, thereby generating a torque. This interaction-generated torque causes the rotor 5 to deflect. Specifically, the magnitude of the torque (i.e., the specific deflection angle) is controlled by controlling the current input to coil 6. The magnitude of the current in coil 6 directly affects the strength of the control magnetic field. 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 require changing the direction of the current. By precisely controlling the magnitude of the current, the deflection angle of the rotor 5 can be precisely controlled. Specifically, to stop the rotor 5 at a specific angle, the current in coil 6 is controlled. When the torque generated by the control magnetic field balances the torque generated by the original magnetic field, the magnetic flux distribution in air gaps 1 and 2 is balanced again, allowing the rotor 5 to reach a new equilibrium position and stop.

[0072] It should be noted that although the rotor 5 will be 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 are designed to be mounted offset from the three stator bosses, rather than aligned perfectly. This allows the magnetic field to control the magnetic flux in air gaps 1 and 2 upon power-up, causing the rotor 5, which has deviated from its neutral position, to return to its neutral position. If the device itself experiences vibration or displacement, the rotor 5 will deviate from its initial position. However, due to the initial magnetic field, the magnetic flux in air gaps 1 and 2 remains the same, achieving a state of magnetic flux balance, ensuring that the rotor 5 returns to its designed initial position.

[0074] Based on the above principles, the present invention will completely replace the flexible hinge, which is beneficial to achieving the stability of the operation of the electrical conversion unit, reducing wear and extending the service life, and 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] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. Reference can be made to the common and similar parts between the various embodiments. For the devices disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple, and the relevant parts can be referred to the method description.

[0078] The above description of the disclosed embodiments is intended to enable one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be readily 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 is not limited to the embodiments shown herein but is intended to conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An electrical conversion unit, characterized in that: The cam is provided with a plurality of cams, each of which is connected to the upper and lower ends of the cam as a base; the cam is provided with a plurality of cams, each of which is connected to the upper end of the cam as a base; the cam is provided with a plurality of cams, each of which is connected to the upper end of the cam as a base; the cam is provided with a plurality of cams, each of which is connected to the upper end of the cam as a base; the cam is provided with a plurality of cams, each of which is connected to the upper end of the cam as a base; the plurality of cams, each of which is connected to the upper end of the cam as a base; the plurality of cams, each of which is connected to the upper end of the cam as a base; the plurality of cams, each of which is connected to the upper end of the cam as a base Three rotor bosses are unevenly distributed radially 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 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 end faces of the upper stator boss and the left and right outer end faces of the corresponding two lower stator bosses; the three unevenly distributed stator bosses are staggered and correspond to the three rotor bosses, and together with the coil, the permanent magnet 1 and the permanent magnet 2, 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 provided in the middle of the nozzle baffle, and a pin hole 2 is provided at the upper end of the main shaft, which 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: A vent hole for supplying air to the nozzle is vertically opened on the upper portion of the upper end cover, and an annular groove is opened at the vent hole, and a sealing ring is adapted to be installed in the annular groove.

4. The electrical conversion unit according to claim 1, characterized in that: A main shaft mounting groove is provided on the upper portion 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. A lower end cover bearing baffle is also installed below the lower end cover rolling bearing.

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

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

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 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 polarity of the permanent magnet 1 and the permanent magnet 2 must be consistent during installation; when the coil is controlled to be de-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 conversion unit according to any one of claims 1 to 9.

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