Magnetoelectric speed sensor and speed detection system

Abstract

The present application provides a magnetoelectric speed sensor and a speed detection system. The magnetoelectric speed sensor includes a housing, a probe and a connector. The housing and the rotating part are relatively fixed, and the length direction of the housing extends along the axial direction of the rotating part. The probe is arranged in the housing. The probe includes a permeable core, an induction coil, a first permanent magnet and a second permanent magnet. The first permanent magnet, the permeable core and the second permanent magnet are arranged in sequence along the length direction of the housing. The first permanent magnet and the second permanent magnet have the same magnetic pole arrangement direction. The induction coil surrounds the outer side of the permeable core to form an induced magnetic field on the side of the housing for measuring the speed of the rotating part, and the induction coil is electrically connected to the connector. The magnetoelectric speed sensor provided by the present application can generate a large magnetic flux change and enhance the electrical signal output by the magnetoelectric speed sensor.

Description

Technical Field

[0001] The present application relates to the technical field of rotation speed sensors, and in particular to a magnetoelectric rotation speed sensor and a rotation speed detection system. Background Art

[0002] The speed measurement of rotating machinery is one of the monitoring parameters to ensure the safe operation of rotating machinery. If the speed parameter monitoring of rotating machinery fails, the speed of the rotating machinery will be out of control, which will cause the unit to stall, overspeed, or even runaway, causing major equipment damage accidents. The conventional speed measurement method is: a speed measuring and transmitting component (such as a gear plate, groove, cam) is installed on the main shaft of the rotating machinery, and a speed sensor (such as a magnetoelectric speed sensor, eddy current displacement sensor, Hall sensor, inductive sensor, proximity switch) is installed in the radial direction of the main shaft of the rotating machinery, and the speed of the main shaft of the rotating machinery is measured by the speed sensor. Among them, the magnetoelectric speed sensor is widely used due to its simple structure and high reliability.

[0003] like Figure 1a and Figure 1b As shown, a conventional magnetoelectric speed sensor includes an induction coil, an iron core, and a permanent magnet. The induction coil is mounted on an iron core (pure iron), one end of the iron core is a permanent magnet, and the other end is a signal sensing surface. The permanent magnet establishes a stable magnetic field in the space where the induction coil and the iron core are located. Usually, the sensor axis is perpendicular to the main shaft, and the signal sensing surface is located at the top of the sensor (i.e., the radial direction of the rotating shaft), facing the speed measuring and transmitting component. The sensor senses the changes in the magnetic field in the induction coil space caused by the rotation of the speed measuring and transmitting component, and converts the magnetic field changes into speed pulse electrical signals using the principle of magnetoelectric induction. The rotating machinery includes a main shaft and a housing. The main shaft extends to the outside of the housing. The main shaft and the housing are mechanically sealed to prevent internal liquid leakage. The speed measuring and transmitting component used to measure the speed is installed on the main shaft outside the housing.

[0004] However, in some scenarios where the magnetoelectric speed sensor needs to be installed in a sleeve parallel to the main shaft, the installation gap (6±1.5mm) between the speed measuring and transmitting component on the main shaft and the surface of the magnetoelectric speed sensor is much larger than the installation gap (1mm) of the conventional magnetoelectric speed sensor. Due to the large installation gap, the magnetic flux inside the induction coil changes little when the magnetoelectric speed sensor measures the speed, resulting in a weak electrical signal output by the magnetoelectric speed sensor. Summary of the invention

[0005] The present application provides a magnetoelectric speed sensor and a speed detection system. The magnetoelectric speed sensor can generate a large magnetic flux change and enhance the electrical signal output by the magnetoelectric speed sensor.

[0006] In the first aspect, the present application provides a magnetoelectric speed sensor, which is used to measure the speed of a rotating part. The magnetoelectric speed sensor includes a shell, a probe and a connector. The shell and the rotating part are relatively fixed, and the length direction of the shell extends along the axial direction of the rotating part. The probe is arranged in the shell, and the probe includes a magnetic core, an induction coil, a first permanent magnet and a second permanent magnet. The first permanent magnet, the magnetic core and the second permanent magnet are arranged in sequence along the length direction of the shell. The first permanent magnet and the second permanent magnet have the same magnetic pole arrangement direction. The induction coil surrounds the outer side of the magnetic core to form an induced magnetic field on the side of the shell for measuring the speed of the rotating part, and the induction coil is electrically connected to the connector.

[0007] Optionally, in the magnetoelectric speed sensor provided by the present application, the first permanent magnet, the permeable core and the second permanent magnet are arranged side by side in the length direction of the shell, and the first permanent magnet and the second permanent magnet are arranged symmetrically with respect to the permeable core.

[0008] Optionally, the magnetoelectric speed sensor provided in the present application, the probe also includes a skeleton body, the induction coil is wound on the skeleton body, the skeleton body has a hollow cavity with openings at both ends, at least part of the magnetic conductive core is located in the hollow cavity, and there is an air gap between the hollow cavity and the magnetic conductive core for uniform magnetic field distribution.

[0009] Optionally, the magnetoelectric speed sensor provided in the present application has one air gap, and the air gap passes through the center of the magnetoelectric speed sensor in the length direction of the shell.

[0010] Optionally, the magnetoelectric speed sensor provided in the present application has a plurality of air gaps, and the air gaps are symmetrically arranged with respect to the center of the magnetoelectric speed sensor in the length direction of the shell.

[0011] Optionally, in the magnetoelectric speed sensor provided by the present application, the first permanent magnet and the second permanent magnet are respectively abutted against the two ends of the skeleton body along the length direction of the shell to close the hollow cavity, and air gaps are formed between the first permanent magnet and the end of the magnetic core, and between the second permanent magnet and the end of the magnetic core.

[0012] Optionally, in the magnetoelectric speed sensor provided by the present application, the magnetic core includes an abutment portion and an insertion portion, the first end of the insertion portion extends into the hollow cavity, and the outer wall of the insertion portion abuts the inner wall of the hollow cavity, the second end of the insertion portion is connected to the first end of the abutment portion, the abutment portion is located on the outside of the frame body, and the first end of the abutment portion abuts the end of the frame body, and the second end of the abutment portion abuts the first permanent magnet or the second permanent magnet.

[0013] Optionally, in the magnetoelectric speed sensor provided in the present application, one or more air gaps are provided in the length direction of the shell.

[0014] Optionally, in the magnetoelectric speed sensor provided in the present application, the skeleton body and the magnetic conductive core are coaxially arranged.

[0015] In a second aspect, the present application provides a rotational speed detection system, comprising a speed measuring and signaling component that can cause a change in a magnetic field and the above-mentioned magnetoelectric rotational speed sensor, the speed measuring and signaling component being arranged on a rotating part to be detected, and the length direction of the speed measuring and signaling component being along the axial direction of the rotating part, the magnetoelectric rotational speed sensor and the speed measuring and signaling component being arranged relative to each other.

[0016] The magnetoelectric speed sensor and speed detection system provided by the present application are such that when the rotating part with the speed measuring and signaling component is away from the sensing surface of the probe of the magnetoelectric speed sensor, the magnetic flux of the sensing surface of the probe is relatively strong, and the magnetic induction intensity inside the induction coil is relatively large. When the rotating part with the speed measuring and signaling component is close to the sensing surface of the probe, the magnetic flux of the sensing surface of the probe decreases, and due to the magnetic conductivity of the speed measuring and signaling component, the magnetic induction intensity inside the induction coil is weakened, and the magnetic flux passing through the induction coil is reduced, thereby generating an induced alternating voltage in the induction coil. That is, the magnetoelectric speed sensor provided by this embodiment can produce a larger magnetic flux change than a conventional magnetoelectric speed sensor under side induction conditions, thereby enhancing the electrical signal output by the magnetoelectric speed sensor. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present application 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 some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0018] Figure 1a and Figure 1b It is a schematic diagram of the structure of a conventional magnetoelectric speed sensor;

[0019] Figure 2 A schematic diagram of the structure of the magnetoelectric speed sensor provided in Example 1 of the present application;

[0020] Figure 3 for Figure 2 A partial enlarged view of the middle A;

[0021] Figure 4 Schematic diagram 1 of the installation of the magnetoelectric speed sensor provided in Example 1 of the present application;

[0022] Figure 5 Installation diagram of the magnetoelectric speed sensor provided in Example 1 of the present application Figure 2 ;

[0023] Figure 6A schematic diagram of the magnetic field distribution of the magnetoelectric speed sensor in the first state provided in the first embodiment of the present application;

[0024] Figure 7 A schematic diagram of the magnetic field distribution of the magnetoelectric speed sensor in the second state provided in the first embodiment of the present application;

[0025] Figure 8 A schematic diagram of the magnetic field distribution of the magnetoelectric speed sensor in the third state provided in the first embodiment of the present application;

[0026] Fig. 9 A schematic diagram of the magnetic field distribution of the magnetoelectric speed sensor in the fourth state provided in the first embodiment of the present application;

[0027] Fig.10 A schematic diagram of the output waveform of the magnetoelectric speed sensor provided in Example 1 of the present application;

[0028] Fig.11 A schematic diagram of the relationship between the magnetoelectric speed sensor and the speed provided in the first embodiment of the present application;

[0029] Fig.12 A schematic diagram of the structure of a magnetoelectric speed sensor provided in Example 2 of the present application;

[0030] Fig.13 for Fig.12 A partial enlarged view of point B in the middle;

[0031] Fig.14 This is a schematic diagram of the installation of the magnetoelectric speed sensor provided in the second embodiment of the present application;

[0032] Fig.15 A schematic diagram of the magnetic field distribution of the magnetoelectric speed sensor in the first state provided in the second embodiment of the present application;

[0033] Fig.16 This is a schematic diagram of the magnetic field distribution of the magnetoelectric speed sensor in the second state provided in Example 2 of the present application.

[0034] Description of reference numerals:

[0035] 100, 400-magnetoelectric speed sensor; 422, 110-induction coil; 120-iron core; 130-permanent magnet;

[0036] 200-spindle;

[0037] 300, 600-speed measuring and transmitting components;

[0038] 410-housing; 420-probe; 421-magnetic core; 4211-butt portion; 4212-plug portion; 423-first permanent magnet; 424-second permanent magnet; 425-frame body; 4251-hollow cavity; 430-connector; 440-speed measuring sleeve; 450-tail sleeve; 460-bracket; 470-first ferrule; 480-metal hose; 490-second ferrule;

[0039] 500-rotating member; 510-installing sleeve;

[0040] 700-Air Gap. DETAILED DESCRIPTION

[0041] In order to make the purpose, technical scheme and advantages of the present application clearer, the technical scheme in the embodiment of the present application will be described in more detail below in conjunction with the drawings in the preferred embodiments of the present application. In the drawings, the same or similar reference numerals throughout represent the same or similar parts or parts with the same or similar functions. The described embodiments are part of the embodiments of the present application, not all of the embodiments. The embodiments described below with reference to the drawings are exemplary and are intended to be used to explain the present application, and should not be construed as limitations on the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present application. The embodiments of the present application are described in detail below in conjunction with the drawings.

[0042] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, or it can be an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0043] In the description of the present application, it should be understood that the terms "upper", "lower", "front", "back", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0044] The terms "first", "second", "third" (if any) in the specification and claims of this application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the numbers used in this way can be interchanged where appropriate, so that the embodiments of the application described herein can be implemented in an order other than those illustrated or described herein, for example.

[0045] In addition, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover non-exclusive inclusions. For example, a process, method, system, product, or apparatus that includes a series of steps or elements is not necessarily limited to those steps or elements explicitly listed, but may include other steps or elements not explicitly listed or inherent to such process, method, product, or apparatus.

[0046] The rotating machine includes a main shaft 200 and a housing. The main shaft 200 extends to the outside of the housing. The main shaft 200 and the housing are mechanically sealed to prevent internal liquid leakage. A speed measuring and transmitting component 300 for measuring the rotation speed is installed on the main shaft 200 outside the housing. Figure 1a and Figure 1b This is a schematic diagram of the structure of a conventional magnetoelectric speed sensor. Figure 1a and Figure 1b As shown, the conventional magnetoelectric speed sensor 100 includes an induction coil 110, an iron core 120, and a permanent magnet 130. The induction coil 110 is mounted on the iron core 120 (also called pure iron), one end of the iron core 120 is opposite to the permanent magnet 130, and the other end of the iron core 120 is a signal sensing surface. The permanent magnet 130 establishes a stable magnetic field in the space where the induction coil 110 and the iron core 120 are located. Usually, the axis of the magnetoelectric speed sensor 100 is perpendicular to the rotation axis, and the signal sensing surface of the iron core 120 is located in the radial direction of the main shaft 200, facing the speed measuring and transmitting component 300. The magnetoelectric speed sensor 100 senses the changes in the magnetic field in the induction coil space caused by the rotation of the speed measuring and transmitting component 300, and converts the magnetic field changes into speed pulse electrical signals using the principle of magnetoelectric induction.

[0047] However, in some application scenarios, rotating machinery is required to have extremely high sealing performance, such as the main coolant shield pump and wet winding pump used in nuclear power plants, which contain high-temperature and high-pressure radioactive materials inside, and require their main shaft to be completely sealed in the pump casing. Therefore, the magnetoelectric speed sensor needs to be installed in a sleeve parallel to the main shaft, and the installation gap (6±1.5mm) between the speed measurement and signal transmission component on the main shaft and the surface of the magnetoelectric speed sensor is much larger than the installation gap (1mm) of the conventional magnetoelectric speed sensor. Due to the large installation gap, the magnetic flux inside the induction coil changes little when the magnetoelectric speed sensor measures the speed, resulting in a weak electrical signal output by the magnetoelectric speed sensor, which is difficult to meet the signal-to-noise ratio requirements of the subsequent speed measurement system.

[0048] In order to solve the above problems, an embodiment of the present application provides a magnetoelectric speed sensor, which can generate a large magnetic flux change and enhance the electrical signal output by the magnetoelectric speed sensor.

[0049] The present application is described in detail below with reference to specific embodiments.

[0050] Embodiment 1

[0051] Figure 2 A schematic diagram of the structure of the magnetoelectric speed sensor provided in Example 1 of the present application; Figure 3 for Figure 2 A partial enlarged view of the middle A; Figure 4 Schematic diagram 1 of the installation of the magnetoelectric speed sensor provided in Example 1 of the present application; Figure 5 Installation diagram of the magnetoelectric speed sensor provided in Example 1 of the present application Figure 2 .like Figures 2 to 5 As shown, an embodiment of the present application provides a magnetoelectric speed sensor, the magnetoelectric speed sensor 400 is used to measure the speed of a rotating part 500, the magnetoelectric speed sensor 400 includes a shell 410, a probe 420 and a connector 430, the shell 410 and the rotating part 500 are relatively fixed, and the length direction of the shell 410 extends along the axial direction of the rotating part 500, the probe 420 is arranged in the shell 410, the probe 420 includes a permeable core 421, an induction coil 422, a first permanent magnet 423 and a second permanent magnet 424, the first permanent magnet 423, the permeable core 421 and the second permanent magnet 424 are arranged in sequence along the length direction of the shell 410, the first permanent magnet 423 and the second permanent magnet 424 have the same magnetic pole arrangement direction, the induction coil 422 is wrapped around the outer side of the permeable core 421 to form an induced magnetic field on the side of the shell 410 for measuring the speed of the rotating part 500, and the induction coil 422 is electrically connected to the connector 430.

[0052] In a specific implementation, a speed measuring and signaling component 600 is installed on the rotating member 500, and the number of the speed measuring and signaling component 600 is at least one, and each speed measuring and signaling component 600 is evenly spaced. The speed measuring and signaling component 600 is installed on the side of the main shaft of the rotating member 500, and the extension direction of the speed measuring and signaling component 600 is parallel to the side of the main shaft of the rotating member 500. The speed measuring and signaling component 600 can be a gear, a groove, a convex key or a stainless steel bar embedded in the side of the rotating member 500.

[0053] The length direction of the housing 410 is extended along the axial direction of the rotating member 500, and the first permanent magnet 423, the permeable core 421, and the second permanent magnet 424 in the housing 410 are sequentially arranged along the length direction of the housing 410, and the magnetic poles of the first permanent magnet 423 and the second permanent magnet 424 are arranged in the same direction. In other words, the side of the magnetoelectric speed sensor 400 is parallel to the axis of the rotating member 500, and the side of the probe 420 is the sensing surface of the probe 420, so as to form an induced magnetic field for measuring the speed of the rotating member 500 on the side of the housing 410.

[0054] When the rotating member 500 with the speed measuring and signaling component 600 is away from the sensing surface of the probe 420 of the magnetoelectric speed sensor 400, the magnetic flux of the sensing surface of the probe 420 is relatively strong, and the magnetic induction intensity inside the induction coil 422 is relatively large. When the rotating member 500 with the speed measuring and signaling component 600 is close to the sensing surface of the probe 420, the magnetic flux of the sensing surface of the probe 420 decreases, and due to the magnetic conductivity of the speed measuring and signaling component 600, the magnetic induction intensity inside the induction coil 422 is weakened, and the magnetic flux passing through the induction coil 422 is reduced, thereby generating an induced alternating voltage in the induction coil 422. In other words, the magnetoelectric speed sensor 400 provided in this embodiment can generate a larger magnetic flux change than the conventional magnetoelectric speed sensor 100 under the side induction condition, thereby enhancing the electrical signal output by the magnetoelectric speed sensor 400.

[0055] For rotating mechanical equipment with high sealing requirements, the installation gap (6±1.5mm) between the speed measuring and signaling component 600 on the rotating part 500 and the surface of the magnetoelectric speed sensor 400 is much larger than the installation gap (1mm) of the conventional magnetoelectric speed sensor. In this embodiment, when the rotating part 500 with the speed measuring and signaling component 600 is away from the sensing surface of the probe 420 of the magnetoelectric speed sensor 400, the magnetic flux of the sensing surface of the probe 420 is relatively strong. Therefore, the magnetoelectric speed sensor 400 provided in this embodiment can be applied to rotating mechanical equipment with high sealing requirements, such as special machinery such as the main cooling shielded pump of the nuclear power plant reactor and the wet winding pump. Special pumps that require high sealing performance, such as shielded pumps and wet winding pumps.

[0056] like Figure 2 and Figure 3 , Figure 4 and Figure 5 As shown, in order to facilitate the installation of the magnetoelectric speed sensor 400, in some embodiments, the axial direction of the probe 420 is parallel to the axial direction of the rotating member 500, and is installed parallel to the mounting sleeve 510 of the rotating member 500. A long strip-shaped speed measuring and signaling component 600 is embedded in the axial direction of the rotating member 500.

[0057] The magnetoelectric speed sensor 400 also includes a speed measuring sleeve 440, a tail sleeve 450, and a bracket 460. The connector 430 is fixed to the shell of the rotating part 500 through the bracket 460. The connector 430 is connected to one end of the speed measuring sleeve 440 through a first clamping sleeve 470. The other end of the speed measuring sleeve 440 is connected to one end of a metal hose 480 through a second clamping sleeve 490. The other end of the metal hose 480 is connected to the housing 410 through the tail sleeve 450. The probe 420 in the housing 410 is flexibly connected to the connector 430 through a soft wire through the tail 450, the metal hose 480, and the speed measuring sleeve 440.

[0058] To facilitate disassembly, the speed measuring sleeve 440 is threadedly connected to the first ferrule 470 and the second ferrule 490 at both ends.

[0059] The magnetic conductive core 421 is in the shape of a cylinder, a cuboid, a cube, etc. The magnetic conductive core 421 is made of DT4 electrical steel pure iron.

[0060] The induction coil 422 uses enameled wire.

[0061] The housing 410 may be made of non-magnetic metal materials such as 304 stainless steel.

[0062] In this embodiment, the first permanent magnet 423 and the second permanent magnet 424 are respectively located at the two ends of the probe 420, and a constant DC magnetic field is generated in the space of the magnetoelectric speed sensor 400; the permeable core 421 is located between the first permanent magnet 423 and the second permanent magnet 424, so that the magnetic field is evenly distributed along the axial direction in the magnetoelectric speed sensor 400; the induction coil 422 is used to sense the change of the magnetic field. The first permanent magnet 423 and the second permanent magnet 424 have the same magnetic pole direction, and the two opposite magnetic poles of the first permanent magnet 423 and the second permanent magnet 424 are of opposite polarity. A constant magnetic field with magnetic lines distributed along the axial direction is established between the first permanent magnet 423 and the second permanent magnet 424, and the magnetic lines of force form a closed magnetic circuit by passing through the permeable core 421 and the induction coil 422. When the speed measuring and transmitting component 600 of the rotating member 500 passes through the probe 420, the distribution of the magnetic field in space is changed, thereby causing the magnetic flux inside the induction coil 422 to change, and generating an induced alternating voltage in the induction coil 422. The voltage amplitude is proportional to the installation gap and the linear speed, and the induced frequency is synchronized with the trigger frequency. The output characteristic of the magnetoelectric speed sensor 400 is as follows:

[0063] F=n×z Formula (I)

[0064] V=K×n / d Formula (II)

[0065] In formula (1) and formula (2): n is the rotation speed of the rotating part;

[0066] z is the number of teeth of the speed measuring and signaling component (or the number of speed measuring and signaling components);

[0067] F is the output signal frequency of the magnetoelectric sensor;

[0068] V is the peak voltage output by the magnetoelectric sensor;

[0069] d is the gap between the magnetoelectric sensor and the rotating part;

[0070] K is a constant related to the magnetoelectric sensor.

[0071] It can be concluded from the above formula (I) and formula (II) that the output frequency F of the magnetoelectric sensor is only related to the rotation speed n of the rotating part and the number z of the speed measuring and transmitting components, and the output voltage V is proportional to the rotation speed n of the rotating part, inversely proportional to the gap d between the magnetoelectric sensor and the rotating part, and proportional to the constant K related to the magnetoelectric sensor. Among them, the constant K is closely related to the magnetic induction intensity and distribution, the structure of the magnetic conductive material, the number of turns, length, and diameter of the induction coil, so the first permanent magnet, the second permanent magnet, the magnetic conductive core, and the induction coil structure design have a great influence on the output signal of the magnetoelectric sensor. In order to increase the output signal of the magnetoelectric sensor, the first permanent magnet and the second permanent magnet should be arranged according to the measurement method, and a suitable magnetic conductive core structure should be designed so that the magnetoelectric sensor generates a larger magnetic flux change rate in the side induction mode, improves the signal-to-noise ratio of the sensor, and enhances the electrical signal output by the magnetoelectric speed sensor.

[0072] Please continue to see Figure 2 and Figure 3 As shown, in this embodiment, the first permanent magnet 423, the permeable core 421, and the second permanent magnet 424 are arranged side by side in the length direction of the housing 410, and the first permanent magnet 423 and the second permanent magnet 424 are arranged symmetrically with respect to the permeable core 421. The first permanent magnet 423 and the second permanent magnet 424 are arranged side by side at both ends of the permeable core 421, and the first permanent magnet 423 and the second permanent magnet 424 are arranged symmetrically with respect to the permeable core 421, so that a constant magnetic field can be established inside the permeable core 421 and the induction coil 422, and the permeable core 421 located between the first permanent magnet 423 and the second permanent magnet 424 can change the magnetic field distribution between the first permanent magnet 423 and the second permanent magnet 424, thereby forming a relatively uniformly distributed magnetic field inside the induction coil 422 (wherein the magnetic lines of force are distributed along the axis of the induction coil 422).

[0073] Figure 6 A schematic diagram of the magnetic field distribution of the magnetoelectric speed sensor in the first state provided in the first embodiment of the present application; Figure 7 This is a schematic diagram of the magnetic field distribution of the magnetoelectric speed sensor in the second state provided in the first embodiment of the present application. Figure 2 and Figure 3 As shown, Figure 6 and Figure 7As shown, in some embodiments, the probe 420 further includes a frame body 425, the induction coil 422 is wound around the frame body 425, and the frame body 425 is coaxially arranged with the magnetic conductive core 421. The frame body 425 has a hollow cavity 4251 with two ends opened, at least part of the magnetic conductive core 421 is located in the hollow cavity 4251, and an air gap 700 for uniform magnetic field distribution is provided between the hollow cavity 4251 and the magnetic conductive core 421.

[0074] Among them, the first permanent magnet 423, the second permanent magnet 424, the induction coil 422, the magnetic core 421 and the frame body 425 are encapsulated in the housing 410- using non-metallic materials such as epoxy resin. The frame body 425 is used to fix the induction coil 422, which is convenient for coil winding and installation. The frame body 425 can be made of high-performance non-metallic materials such as PPS. The frame body 425 is coaxially installed on the surface of the magnetic core 421 through the hollow cavity 4251.

[0075] There are multiple air gaps 700 , and the air gaps are symmetrically arranged relative to the center of the magnetoelectric rotation speed sensor 400 in the length direction of the housing 410 .

[0076] In this embodiment, the number of air gaps 700 is two, and the first permanent magnet 423 and the second permanent magnet 424 are respectively abutted against the two ends of the frame body 425 along the length direction of the shell to close the hollow cavity 4251. A first air gap 700 is formed between the first permanent magnet 423 and the end of the permeable core 421, and a second air gap 700 is also formed between the second permanent magnet 424 and the end of the permeable core 421. The first air gap 700 and the second air gap 700 are symmetrically arranged relative to the center of the magnetoelectric speed sensor 400 in the length direction of the shell 410.

[0077] It is understandable that the number of the permeable cores 421 can be set to two or more, and an air gap 700 can be formed between the permeable cores 421 in the hollow cavity 4251 of the skeleton body 425; or, the permeable cores 421 and permanent magnets are arranged at intervals in the hollow cavity 4251 of the skeleton body 425, and an air gap 700 is formed between the permanent magnet and the permeable cores 421.

[0078] Figure 6 and Figure 7 The magnetoelectric speed sensor 400 has an air gap 700. Figure 6 The magnetic field distribution when the rotating member 500 with the speed measuring and signaling component 600 is away from the sensing surface of the probe 420 of the magnetoelectric speed sensor 400, Figure 7 The magnetic field distribution when the rotating member 500 with the speed measuring and signaling component 600 approaches the sensing surface of the probe 420 is shown in FIG. Figure 6 and Figure 7It can be seen that in the structure of the magnetoelectric speed sensor 400 with the air gap 700, the magnetic field distribution in the area where the induction coil 422 is located is more uniform, and the magnetic flux changes greatly when the speed measuring and signaling component 600 approaches, so the sensor sensitivity is higher.

[0079] Figure 8 A schematic diagram of the magnetic field distribution of the magnetoelectric speed sensor in the third state provided in the first embodiment of the present application; Fig. 9 This is a schematic diagram of the magnetic field distribution of the magnetoelectric speed sensor in the fourth state provided in Example 1 of the present application. Figure 8 and Fig. 9 The magnetoelectric speed sensor 400 is not provided with an air gap 700. Figure 8 The magnetic field distribution when the rotating member 500 with the speed measuring and signaling component 600 is away from the sensing surface of the probe 420 of the magnetoelectric speed sensor 400, Fig.11 The magnetic field distribution when the rotating member 500 with the speed measuring and signaling component 600 approaches the sensing surface of the probe 420 is shown in FIG. Figure 8 and Fig. 9 It can be seen that in the structure of the magnetoelectric speed sensor 400 without the air gap 700, the magnetic field distribution in the area where the induction coil 422 is located is uneven, and the magnetic flux changes slightly when the speed measuring and signaling component 600 approaches, so the sensor sensitivity is not high.

[0080] Fig.10 A schematic diagram of the output waveform of the magnetoelectric speed sensor provided in Example 1 of the present application; Fig.11 This is a schematic diagram of the relationship between the magnetoelectric speed sensor and the speed provided in the first embodiment of the present application. Fig.10 and Fig.11 As shown, Fig.10 is an output waveform diagram of the magnetoelectric speed sensor 400, Fig.11 The peak-to-peak value of the output voltage of the magnetoelectric speed sensor 400 varies with the speed. At the rated speed (1500RPM), the peak-to-peak value of the sensor output signal exceeds 2000mV. It can be seen that the magnetoelectric speed sensor 400 provided in this embodiment can meet the technical requirements of the main coolant pump of the reactor in a pressurized water reactor nuclear power plant.

[0081] Embodiment 2

[0082] Fig.12 A schematic diagram of the structure of a magnetoelectric speed sensor provided in Example 2 of the present application; Fig.13 for Fig.12 A partial enlarged view of point B in the middle; Fig.14 This is a schematic diagram of the installation of the magnetoelectric speed sensor provided in the second embodiment of the present application. Figure 12 to Figure 14As shown, the permeable core 421 is disposed in the hollow cavity 4251 along the length direction of the housing 410 to form an air gap 700. The air gap 700 in the second embodiment is formed differently from that in the first embodiment, and the remaining structures of the second embodiment and the first embodiment are the same. The structures of the second embodiment and the first embodiment that are the same are described in detail in the first embodiment, and will not be described one by one here.

[0083] In this embodiment, the number of air gaps 700 is one, and the air gap 700 passes through the center of the magnetoelectric speed sensor 400 in the length direction of the housing 410. The permeable core 421 includes an abutting portion 4211 and an inserting portion 4212, the first end of the inserting portion 4211 extends into the hollow cavity 4251, and the outer wall of the inserting portion 4212 abuts against the inner wall of the hollow cavity 4251, the second end of the inserting portion 4212 is connected to the first end of the abutting portion 4211, the abutting portion 4211 is located outside the frame body 425, and the first end of the abutting portion 4211 abuts against the end of the frame body 425, and the second end of the abutting portion 4211 abuts against the first permanent magnet 423 or the second permanent magnet 424.

[0084] Fig.15 A schematic diagram of the magnetic field distribution of the magnetoelectric speed sensor in the first state provided in the second embodiment of the present application; Fig.16 This is a schematic diagram of the magnetic field distribution of the magnetoelectric speed sensor in the second state provided in the second embodiment of the present application. Figure 12 to Figure 14 As shown, Fig.15 and Fig.16 As shown, Fig.15 The magnetic field distribution when the rotating member 500 with the speed measuring and signaling component 600 is away from the sensing surface of the probe 420 of the magnetoelectric speed sensor 400, Fig.16 The magnetic field distribution when the rotating member 500 with the speed measuring and signaling component 600 approaches the sensing surface of the probe 420 is shown in FIG. Fig.15 and Fig.16 It can be seen that in the structure of the magnetoelectric speed sensor 400 with the air gap 700, the magnetic field distribution in the area where the induction coil 422 is located is more uniform, and the magnetic flux changes greatly when the speed measuring and signaling component 600 approaches, so the sensor sensitivity is higher.

[0085] Embodiment 3

[0086] See also Figure 2 , Figure 4 , Figure 5 , Fig.12 and Fig.14As shown, an embodiment of the present application further provides a rotational speed detection system, comprising a speed measuring and signaling component 600 that can cause a change in a magnetic field and a magnetoelectric rotational speed sensor 400 provided in any of the above embodiments, the speed measuring and signaling component 600 is arranged on a rotating part 500 to be detected, and the length direction of the speed measuring and signaling component 600 is along the axial direction of the rotating part 500, and the magnetoelectric rotational speed sensor 400 and the speed measuring and signaling component 600 are arranged relative to each other.

[0087] Specifically, the number of the speed measuring and signaling components 600 is at least one, and each speed measuring and signaling component 600 is evenly spaced. The speed measuring and signaling component 600 is installed on the side of the main shaft of the rotating member 500, and the extension direction of the speed measuring and signaling component 600 is parallel to the side of the main shaft of the rotating member 500. Among them, the speed measuring and signaling component 600 can be a gear, a groove, a cam or a stainless steel bar embedded in the side of the rotating member 500. The side of the magnetoelectric speed sensor 400 is parallel to the axis of the rotating member 500, and the side of the probe 420 is the sensing surface of the probe 420, so as to form an induced magnetic field on the side of the housing 410 for measuring the rotation speed of the rotating member 500.

[0088] When the rotating member 500 with the speed measuring and signaling component 600 is away from the sensing surface of the probe 420 of the magnetoelectric speed sensor 400, the magnetic flux of the sensing surface of the probe 420 is relatively strong, and the magnetic induction intensity inside the induction coil 422 is relatively large. When the rotating member 500 with the speed measuring and signaling component 600 is close to the sensing surface of the probe 420, the magnetic flux of the sensing surface of the probe 420 decreases, and due to the magnetic conductivity of the speed measuring and signaling component 600, the magnetic induction intensity inside the induction coil 422 is weakened, and the magnetic flux passing through the induction coil 422 is reduced, thereby generating an induced alternating voltage in the induction coil 422. In other words, the magnetoelectric speed sensor 400 provided in this embodiment can generate a larger magnetic flux change than the conventional magnetoelectric speed sensor 100 under the side sensing condition.

[0089] For rotating mechanical equipment with high sealing requirements, the installation gap (6±1.5mm) between the speed measuring and signaling component 600 on the rotating part 500 and the surface of the magnetoelectric speed sensor 400 is much larger than the installation gap (1mm) of the conventional magnetoelectric speed sensor. In this embodiment, when the rotating part 500 with the speed measuring and signaling component 600 is away from the sensing surface of the probe 420 of the magnetoelectric speed sensor 400, the magnetic flux of the sensing surface of the probe 420 is relatively strong. Therefore, the magnetoelectric speed sensor 400 provided in this embodiment can be applied to rotating mechanical equipment with high sealing requirements, such as special machinery such as the main cooling shielded pump of the nuclear power plant reactor and the wet winding pump. Special pumps that require high sealing performance, such as shielded pumps and wet winding pumps.

[0090] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A magnetoelectric speed sensor, characterized in that: The magnetoelectric speed sensor is used to measure the speed of a rotating part. The magnetoelectric speed sensor includes a housing, a probe and a connector. The housing and the rotating part are relatively fixed, and the length direction of the housing extends along the axial direction of the rotating part. The probe is arranged in the housing. The probe includes a magnetic core, an induction coil, a first permanent magnet and a second permanent magnet. The first permanent magnet, the magnetic core and the second permanent magnet are arranged in sequence along the length direction of the housing. The first permanent magnet and the second permanent magnet have the same magnetic pole arrangement direction. The induction coil surrounds the outer side of the magnetic core to form an induction magnetic field on the side of the housing for measuring the speed of the rotating part, and the induction coil is electrically connected to the connector. The first permanent magnet, the magnetically permeable core and the second permanent magnet are arranged side by side in the length direction of the shell, and the first permanent magnet and the second permanent magnet are arranged symmetrically with respect to the magnetically permeable core; The probe further comprises a frame body, the induction coil is wound on the frame body, the frame body has a hollow cavity with two ends open, at least part of the magnetic conductive core is located in the hollow cavity, and an air gap for uniform magnetic field distribution is provided between the hollow cavity and the magnetic conductive core; The first permanent magnet and the second permanent magnet are respectively abutted against two ends of the frame body along the length direction of the shell to close the hollow cavity, and the air gap is formed between the first permanent magnet and the end of the permeable core, and between the second permanent magnet and the end of the permeable core; It also includes a speed measuring and signaling component that can cause a magnetic field change, the speed measuring and signaling component is arranged on the rotating part to be detected, and the length direction of the speed measuring and signaling component is along the axial direction of the rotating part, and the magnetoelectric speed sensor and the speed measuring and signaling component are arranged opposite to each other; When the rotating part with the speed measuring and signaling component is away from the inductive surface of the probe of the magnetoelectric speed sensor, the magnetic flux of the inductive surface of the probe is strong and the magnetic induction intensity inside the inductive coil is large. When the rotating part with the speed measuring and signaling component is close to the inductive surface of the probe, the magnetic flux of the inductive surface of the probe decreases.

2. The magnetoelectric speed sensor according to claim 1, characterized in that: The number of the air gap is one, and the air gap passes through the center of the magnetoelectric rotation speed sensor in the length direction of the housing.

3. The magnetoelectric speed sensor according to claim 1, characterized in that: The number of the air gaps is multiple, and the air gaps are symmetrically arranged relative to the center of the magnetoelectric rotation speed sensor in the length direction of the housing.

4. The magnetoelectric speed sensor according to claim 1, characterized in that: The magnetic conductive core includes an abutment portion and an insertion portion, the first end of the insertion portion extends into the hollow cavity, and the outer wall of the insertion portion abuts the inner wall of the hollow cavity, the second end of the insertion portion is connected to the first end of the abutment portion, the abutment portion is located outside the frame body, and the first end of the abutment portion abuts the end of the frame body, and the second end of the abutment portion abuts the first permanent magnet or the second permanent magnet.

5. The magnetoelectric speed sensor according to any one of claims 3 to 4, characterized in that: One or more air gaps are arranged in the length direction of the shell.

6. The magnetoelectric speed sensor according to any one of claims 3 to 4, characterized in that: The frame body is coaxially arranged with the magnetic conductive core.

7. A rotation speed detection system, characterized in that: A magnetoelectric rotation speed sensor as described in any one of claims 1 to 6 is used.

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