Miniature passive wireless sensor applied to high-speed motor rotor temperature measurement

Abstract

The utility model relates to the technical field of sensors, in particular to a miniature passive wireless sensor applied to temperature measurement of a high-speed motor rotor, which comprises a temperature sensing unit, a flexible connecting unit and a transmitting unit, and is characterized in that the temperature sensing unit comprises a surface acoustic wave resonator chip, a matching element and a temperature sensing end welding point; the transmitting unit comprises a spiral antenna unit, a fixed base and a transmitting end welding point. A first shielding layer, a second shielding layer and a third shielding layer are arranged, the first shielding layer and the second shielding layer which are good in conductivity are used for manufacturing a shielding cover and the like to surround an emission unit, a high-frequency magnetic field generates induction current on the surface of a metal shielding body, and a reverse magnetic field generated by the current can counteract part of an external magnetic field; and the first shielding layer is made of a permalloy plate, has high magnetic conductivity and can guide magnetic field lines to pass through the shielding layer, so that the magnetic field intensity of the space where the internal emission unit is located is greatly reduced.

Description

TECHNICAL FIELD

[0001] The utility model relates to sensor technical field especially relates to the micro passive wireless sensor for high -speed motor rotor temperature measurement is applied. BACKGROUND

[0002] With the large -scale popularization and penetration of new energy vehicles, currently has become the strong engine of the development of the automobile industry. At present, the driving motor type applied to the new energy vehicle mainly is alternating -current asynchronous motor and permanent magnet synchronous motor, and the permanent magnet synchronous motor application presents the trend of increasing year by year. As the power source of new energy vehicles, permanent magnet synchronous motor has energy density, operation reliable, speed performance and other characteristics, compared to other types of motor. Can provide greater power output under the same quality, size, is the ideal motor type for new energy vehicles, and the key to the development of motor to high efficiency, high stability and high reliability is to adopt reliable temperature on -line monitoring means and efficient heat dissipation system to inhibit motor temperature rise.

[0003] For the related technology in the above, the defect of the existing wireless sensor is that in the wireless transmission process, it is easy to be disturbed by surrounding electromagnetic environment, metal object and other factors, leading to signal attenuation, distortion or loss, reducing the accuracy and reliability of temperature measurement data, such as the strong electromagnetic field generated when high-speed motor runs, which will interfere with the signal transmission of the sensor, therefore, the utility model provides the micro passive wireless sensor for high-speed motor rotor temperature measurement. UTILITY MODEL CONTENT

[0004] The purpose of the present application is to provide a micro passive wireless sensor for high-speed motor rotor temperature measurement, to solve the problem of signal attenuation, distortion or loss caused by the interference of surrounding electromagnetic environment, metal object and other factors in the wireless transmission process, reducing the accuracy and reliability of temperature measurement data, such as the strong electromagnetic field generated when high-speed motor runs, which will interfere with the signal transmission of the sensor.

[0005] To achieve the above purpose, the present application provides the following technical scheme: the micro passive wireless sensor for high-speed motor rotor temperature measurement, including temperature sensing unit, flexible connection unit, transmitting unit, characterized in that: the temperature sensing unit includes a surface acoustic wave resonator chip, a matching element, a temperature sensing end welding point, the transmitting unit includes a spiral antenna unit, a fixed base, a transmitting end welding point, the temperature sensing unit and the transmitting unit are welded and connected through the flexible connection unit, thereby forming a micro passive wireless sensor whole, the diameter of the spiral antenna unit of the sensor transmitting unit is slightly smaller than that of the fixed base, the outer side of the transmitting unit is provided with a shielding assembly.

[0006] Preferably, the shielding assembly comprises a first shielding layer arranged outside the fixed base, an outer side of the first shielding layer is arranged with a second shielding layer, an outer side of the second shielding layer is arranged with a third shielding layer, and outer sides of the first shielding layer, the second shielding layer and the third shielding layer are all arranged with slots matched with the flexible connecting unit.

[0007] Preferably, the first shielding layer is made of a permalloy plate, the second shielding layer is made of a copper plate, and the third shielding layer is made of an aluminum plate.

[0008] Preferably, the inner wall side of the first shielding layer is fixedly connected with a pair of elastic plates, the outer side of the fixed base is arranged with a pair of grooves matched with the elastic plates, the side of the elastic plate is fixedly connected with a limiting block, and the outer side of the fixed base is arranged with a clamping groove matched with the limiting block.

[0009] Preferably, the helical antenna unit and the fixed base are connected into a sensor transmitting unit by rivet gluing.

[0010] Preferably, the sensor transmitting unit and the exposed flexible connecting unit are fixed by epoxy resin or other potting glue.

[0011] In summary, the technical effects and advantages of the utility model are as follows:

[0012] 1. In the utility model, the first shielding layer, the second shielding layer and the third shielding layer are arranged, the first shielding layer and the second shielding layer with good conductivity are used to make shielding covers, etc., so as to surround the transmitting unit, an induced current is generated on the surface of the metal shielding body under the high-frequency magnetic field, and a reverse magnetic field generated by the current can offset part of the external magnetic field, thereby reducing the interference of the strong electromagnetic field on the sensor, the first shielding layer is made of a permalloy plate, has high magnetic permeability, can guide the magnetic field lines through the shielding layer, greatly reduces the magnetic field intensity of the space where the internal transmitting unit is located, effectively isolates the coupling interference of the low-frequency magnetic field and the fixed magnetic field, and through the cooperation of the temperature sensing unit, the flexible connecting unit and the transmitting unit, the miniaturization and flexible design of the sensor are realized, the sensor can be adapted to the narrow space inside the high-speed motor rotor, the problem that the rotor temperature is difficult to obtain in the motor design process is solved, the sensor can be applied in the motor design stage, and can be applied on a large motor or similar high-speed rotating equipment.

[0013] 2. In the utility model, the diameter of the helical antenna unit of the sensor transmitting unit is slightly smaller than that of the fixed base, so that the sensor transmitting unit is more firm when being fixed by glue potting. DRAWINGS

[0014] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings described below only illustrate some of the embodiments of the present application, and all other embodiments obtained by those of ordinary skill in the art without creative effort based on these drawings also belong to the scope of protection of the present application.

[0015] Figure 1 It is a first perspective view of the axial side structure of the present application.

[0016] Figure 2 It is a second perspective view of the axial side structure of the present application.

[0017] Figure 3 It is a structure diagram of the groove and the clamping groove in the present application.

[0018] Figure 4 It is a structure diagram of the spiral antenna unit in the present application.

[0019] Figure 5 It is an enlarged structure diagram of A in the present application. Figure 2

[0020] In the figure: 1, temperature sensing unit; 2, flexible connecting unit; 3, transmitting unit; 4, surface acoustic wave resonator chip; 5, matching element; 6, temperature sensing end welding point; 7, spiral antenna unit; 8, fixed base; 9, transmitting end welding point; 10, elastic plate; 11, limiting block; 12, groove; 13, clamping groove; 14, first shielding layer; 15, second shielding layer; 16, third shielding layer; 17, slot. DETAILED DESCRIPTION

[0021] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort belong to the scope of protection of the present application.

[0022] In the description of the present application, it should be noted that, unless otherwise explicitly specified and limited, the terms "mounting", "provided with", "sleeved / connected", "connected" and the like should be understood broadly, for example, "connected" can be fixedly connected, or detachably connected, or integrally connected; can be mechanically connected, or electrically connected; can be directly connected, or indirectly connected through an intermediate medium; can be the internal connection of two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to the specific circumstances. ​

[0023] Embodiment one: reference Figures 1-5 The micro passive wireless sensor applied to high-speed motor rotor temperature measurement shown in the application, including temperature sensing unit 1, flexible connection unit 2, transmitting unit 3, temperature sensing unit 1 installation hole is set in the position of motor rotor core to be installed, sensor transmitting unit 3 installation hole is set in the position of rotor balance disc, temperature sensing unit 1 includes surface acoustic wave resonator chip 4, matching element 5, temperature sensing end welding point 6, surface acoustic wave resonator chip 4, matching element 5 are partially welded to sensor temperature sensing unit 1 by using hot air gun, transmitting unit 3 includes spiral antenna unit 7, fixed base 8, transmitting end welding point 9, temperature sensing unit 1 and transmitting unit 3 are welded and connected through flexible connection unit 2, temperature sensing unit 1 is provided with temperature sensing end welding point 6 at one end, which can be connected with flexible connection unit 2 through the point, surface acoustic wave resonator chip 4 on sensor temperature sensing unit 1 adopts resonant working principle, adopts piezoelectric ceramic material as chip base, uses semiconductor photoetching process to form interdigital electrode and reflection grid structure on the surface of piezoelectric base at any time, surface acoustic wave resonator chip 4 contains an interdigital transducer, which is both an input transducer and an output transducer. The reflection grid is located on both sides of the interdigital transducer, and the reflection grids on both sides form an acoustic resonance cavity. The interdigital transducer converts sound and electricity. Its working principle is: the external excitation signal is loaded on the input interdigital transducer, the interdigital transducer converts the electrical signal into a surface acoustic wave, the surface acoustic wave propagates along the surface of the piezoelectric crystal to both sides, is reflected and superimposed by the reflection grids on both sides, and is output through the interdigital transducer. Spiral antenna unit 7 and fixed base 8 are combined into one by riveting and gluing; the length of the spiral wire is adjusted to adjust the center frequency within a reasonable range, realizing the function of antenna; the nominal center frequency of sensor transmitting unit 3 is 460MHz±10MHz, the standing wave ratio SWR is less than 3.0dbi, and the transmitting end welding point 9 is connected with one end of the flexible connection unit 2 by welding, thereby forming a micro passive wireless sensor as a whole. The diameter of the spiral antenna unit 7 of the sensor transmitting unit 3 is slightly smaller than that of the fixed base 8, so that the sensor transmitting unit 3 is more firm when it is fixed by glue pouring, the transmitting end welding point 9 of the sensor transmitting unit 3 is divided into two welding points of grounding foot and signal foot, the grounding foot is electrically connected by the bottom of the sensor transmitting unit 3 and the installation position; the signal foot is electrically connected with the center point of the spiral antenna unit 7 through the internal wire of the sensor transmitting unit 3, the flexible connection unit 2 selects coaxial radio frequency cable, the length of the cable can be adjusted and customized according to requirements, the cable specification can select RF1.13 or other parameter similar specification cable, the outer side of transmitting unit 3 is provided with shielding assembly.

[0024] Embodiment two: reference Figures 1-5, based on the same idea as the above embodiment one, the embodiment also proposes that the shielding assembly comprises a first shielding layer 14 arranged outside the fixed base 8, the outside of the first shielding layer 14 is provided with a second shielding layer 15, the outside of the second shielding layer 15 is provided with a third shielding layer 16, the outside of the first shielding layer 14, the second shielding layer 15 and the third shielding layer 16 are provided with a slot hole 17 matched with the flexible connecting unit 2, the first shielding layer 14 and the second shielding layer 15 with good conductivity are used to make a shielding cover, etc., to surround the transmitting unit, the induced current generated on the surface of the metal shielding body can offset part of the external magnetic field, thereby reducing the interference of the strong electromagnetic field on the sensor; the first shielding layer 14 is made of permalloy plate, has high magnetic permeability, can guide the magnetic field lines through the shielding layer, greatly reduces the magnetic field strength of the space where the internal transmitting unit 3 is located, effectively isolates the low-frequency magnetic field and fixed magnetic field coupling interference, the second shielding layer 15 is made of copper plate, and the third shielding layer 16 is made of aluminum plate; the inner wall side of the first shielding layer 14 is fixedly connected with a pair of elastic plates 10, a pair of recesses 12 matched with the elastic plates 10 are arranged on the outside of the fixed base 8, the side of the elastic plate 10 is fixedly connected with a limiting block 11, and the outside of the fixed base 8 is provided with a clamping groove 13 matched with the limiting block 11; the fixed base 8 extrudes the elastic plate 10 until the fixed base 8 abuts against the inner wall bottom of the first shielding layer 14, the elastic plate 10 restores the elasticity to drive the limiting block 11 to be clamped with the clamping groove 13 to limit the fixed base 8; the helical antenna unit 7 and the fixed base 8 are connected into the sensor transmitting unit 3 in a rivet plus glue bonding mode; the sensor transmitting unit 3 and the exposed flexible connecting unit 2 are filled and fixed by using epoxy resin or other filling glue, and a flexible connecting unit 2 wiring channel is left between the motor rotor core and the rotor balance disc.

[0025] Finally, it should be noted that: the above only for the preferred embodiments of the present application, and not for limiting the present application, although the present application has been described in detail with reference to the foregoing embodiments, for those skilled in the art, it still can modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part of the technical features, any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application, shall be included in the protection scope of the present application.

Claims

1. A micro passive wireless sensor applied to temperature measurement of high-speed motor rotor, comprising a temperature sensing unit (1), a flexible connection unit (2) and a transmitting unit (3), characterized in that: The temperature sensing unit (1) comprises a surface acoustic wave resonator chip (4), a matching element (5), and a temperature sensing end soldering point (6), the transmitting unit (3) comprises a spiral antenna unit (7), a fixed base (8), and a transmitting end soldering point (9), the temperature sensing unit (1) and the transmitting unit (3) are welded and connected through the flexible connecting unit (2), so as to form a micro passive wireless sensor as a whole, the diameter of the spiral antenna unit (7) of the sensor transmitting unit (3) is slightly smaller than that of the fixed base (8), and the transmitting unit (3) is provided with a shielding assembly on the outer side.

2. The micro passive wireless sensor for temperature measurement of high speed motor rotor according to claim 1, characterized in that: The shielding assembly comprises a first shielding layer (14) arranged on the outer side of the fixed base (8), a second shielding layer (15) arranged on the outer side of the first shielding layer (14), and a third shielding layer (16) arranged on the outer side of the second shielding layer (15), and the outer sides of the first shielding layer (14), the second shielding layer (15) and the third shielding layer (16) are all provided with slot holes (17) matched with the flexible connecting unit (2).

3. The micro passive wireless sensor for temperature measurement of high speed motor rotor according to claim 2, characterized in that: The first shielding layer (14) is made of a permalloy plate, the second shielding layer (15) is made of a copper plate, and the third shielding layer (16) is made of an aluminum plate.

4. The micro passive wireless sensor for temperature measurement of high speed motor rotor according to claim 2, characterized in that: The inner wall side of the first shielding layer (14) is fixedly connected with a pair of elastic plates (10), the outer side of the fixed base (8) is provided with a pair of grooves (12) matched with the elastic plates (10), the side surface of the elastic plate (10) is fixedly connected with a limiting block (11), and the outer side of the fixed base (8) is provided with a clamping groove (13) matched with the limiting block (11).

5. The micro passive wireless sensor for temperature measurement of high speed motor rotor according to claim 4, characterized in that: The spiral antenna unit (7) and the fixed base (8) are connected into the sensor transmitting unit (3) through rivet and glue adhesion.

6. The micro passive wireless sensor for temperature measurement of high speed motor rotor according to claim 1, characterized in that: The sensor transmitting unit (3) and the exposed flexible connecting unit (2) are fixed by epoxy resin or other potting glue.

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