Motor rotating speed detection device and power system

Abstract

The utility model relates to a motor rotating speed detection device and a power system, which are used for detecting the rotating speed of a motor, the detection device comprises a turntable and a Hall sensor, the turntable comprises at least two gear discs along the axial direction, the number of teeth of each layer of gear disc is different or the gear discs are arranged in a staggered manner along the circumferential direction, and the gear discs are made of magnetic materials. The gear disc synchronously rotates along with the motor rotor; the Hall sensors are used for detecting the rotating speed of the gear discs, and the corresponding Hall sensor is arranged beside each gear disc. According to the scheme, the gear discs are provided with the corresponding Hall sensors, the number of teeth of each layer of gear disc is different, or the gear discs are arranged in the circumferential direction in a staggered mode, so that in the two Hall sensors, results obtained by measurement of each Hall sensor are different, and parameters measured by the at least two Hall sensors can be analyzed and processed, so that the measurement accuracy of the gear discs is improved. Therefore, the maximum rotating speed which can be distinguished by the motor rotating speed detection device is increased, and the rotating speed measurement range of the Hall sensor is enlarged.

Description

Technical Field

[0001] The utility model relates to the technical field of motor speed measurement, in particular to a motor speed detection device and a power system. Background Art

[0002] Since high-order new energy vehicles will be equipped with four electric drives, and dual electric drives or four electric drives will be used respectively at the front and rear of the vehicle. At this time, the large magnetic field of the motor stator will interfere with the general vehicle-mounted resolver speedometer due to the distance, so that the motor will be forced to increase its size to avoid magnetic field interference, but this leads to the problem that the vehicle width needs to be increased (the left and right wheelbases in the vehicle width direction are increased), resulting in the need to increase the vehicle body chassis and strengthen the design. The SEP400 electric drive system is an existing system that directly integrates a dual motor and a gearbox to avoid magnetic field interference, but it increases the size of the electric drive housing. In the prior art, in order to solve the problem of increased vehicle width, a Hall sensor is used to measure the motor speed, but the motor speed needs to be limited to below 13,500 rpm. If the speed exceeds this value, the measured speed will be distorted. Summary of the Utility Model

[0003] Based on this, a motor speed detection device and a power system are provided to improve the problems in the prior art that the vehicle body width increases when using a vehicle-mounted resolver speedometer for motor speed measurement or high speeds cannot be measured when using a Hall sensor.

[0004] On the one hand, the utility model provides a motor speed detection device for detecting the speed of a motor. The detection device includes:

[0005] A turntable, which axially includes at least two gear discs. The number of teeth of each layer of gear discs is different or they are circumferentially offset. The gear discs are made of magnetic material and rotate synchronously with the motor rotor.

[0006] A Hall sensor for detecting the speed of the gear discs. A corresponding Hall sensor is provided beside each gear disc.

[0007] Based on the above technical solution, the utility model can be further improved as follows.

[0008] In one implementation, there are two gear discs on the turntable, and there is a certain distance between adjacent gear discs axially.

[0009] In one implementation, the number of teeth of adjacent gear discs on the same turntable is different, and the tooth profile of each gear disc is evenly arranged along the circumferential direction.

[0010] In one implementation, the number of teeth of the gear discs on the same turntable is the same, and adjacent gear discs are axially rotated and offset and do not coincide.

[0011] In one implementation, the turntable further includes:

[0012] A connecting portion, the connecting portion is a hollow annular structure and is coaxially arranged with the gear disk, and at least two gear disks are axially connected to the connecting portion.

[0013] In one implementation, each gear disk is provided with two corresponding Hall sensors, and the Hall sensors are arranged along the radial direction of the corresponding gear disk.

[0014] In one implementation, the detection device further includes:

[0015] A fixing plate, the fixing plate is perpendicular to the axis of the turntable, the fixing plate is arranged between two gear disks and is parallel to the gear disks, and Hall sensors are installed on the fixing plate.

[0016] In one implementation, the turntable includes two gear disks, two Hall sensors are corresponding to each gear disk, and the four Hall sensors are respectively installed on two opposite sides of the same fixing plate.

[0017] On the other hand, the present utility model further provides a power system, including a motor speed detection device, and the power system further includes:

[0018] A motor housing,

[0019] A motor end cover, the Hall sensor is fixed on the motor housing or the motor end cover;

[0020] A motor rotor, and a turntable is fixed on the motor rotor.

[0021] In one implementation, the turntable includes:

[0022] A connecting portion, the connecting portion is a hollow annular structure and is coaxially arranged with the gear disk, and at least two gear disks are axially connected to the connecting portion;

[0023] The connecting portion is sleeved and fixed on the rotating shaft of the motor rotor, and the turntable rotates synchronously with the motor rotor.

[0024] The beneficial effects of the present utility model are as follows: A gear disk that rotates synchronously with the motor rotor is provided, and the rotation speed of the gear disk is detected by a Hall sensor. Since the rotation speed of the gear disk is equal to that of the motor rotor, the corresponding motor rotation speed can be detected through the Hall sensor. Since the turntable of this application is provided with at least two gear disks, and each gear disk is provided with a corresponding Hall sensor. Since at least two Hall sensors are respectively close to and act on different gear disks, and the number of teeth of each layer of gear disks is different or they are circumferentially staggered, the results measured by each of the two Hall sensors are different. That is, by analyzing and processing the parameters measured by at least two Hall sensors, the maximum rotation speed that the motor rotation speed detection device can distinguish is increased, thereby increasing the measurement range of the Hall sensor for the rotation speed. In summary, adopting the solution of this application avoids the problem of the increased body width caused by using a vehicle-mounted resolver in the prior art, and also avoids the problem that high rotation speeds cannot be measured when using a Hall sensor. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 is a schematic structural diagram of a motor rotation speed detection device in an embodiment;

[0026] Figure 2 is Figure 1 a side view of;

[0027] Figure 3 is Figure 1 a front view of;

[0028] Figure 4 is a schematic structural diagram of a motor rotation speed detection device in another embodiment;

[0029] Figure 5 is Figure 4 a side view of;

[0030] Figure 6 is Figure 4 a front view of;

[0031] Figure 7 is a schematic structural diagram of a motor rotation speed detection device in another embodiment;

[0032] Figure 8 is Figure 7 a side view of;

[0033] Figure 9 is Figure 7 a front view of.

[0034] In the drawings, the components represented by the reference numerals are as follows:

[0035] 10, turntable; 11, gear disk; 12, connecting part;

[0036] 20. Hall sensor Detailed implementation manners

[0037] In order to make the objectives, technical solutions and advantages of the present application clearer, the present application will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0038] In the existing motor speed detection device, a vehicle-mounted resolver is used to measure the motor speed. However, in order to avoid magnetic field interference, the vehicle width will be increased. If a single Hall sensor 20 is used to measure the speed, the motor speed needs to be limited to below 13,500 rpm. If the speed exceeds this value, the measured speed will be distorted.

[0039] A motor speed detection device, see Figure 1 、 Figure 4 and Figure 7 , which is used to detect the speed of the motor. The detection device includes a turntable 10 and a Hall sensor 20. The turntable 10 axially includes at least two gear disks 11. The number of teeth of each layer of gear disk 11 is different or they are circumferentially offset. The gear disk 11 is made of a magnetic material and rotates synchronously with the motor rotor. The Hall sensor 20 is used to detect the speed of the gear disk 11, and a corresponding Hall sensor 20 is provided beside each gear disk 11.

[0040] Adopting this solution, a gear disk 11 that rotates synchronously with the motor rotor is provided, and the Hall sensor 20 is used to detect the speed of the gear disk 11. Since the speed of the gear disk 11 is equal to that of the motor rotor, the corresponding motor speed can be detected through the Hall sensor 20. Since the turntable 10 of the present application is provided with at least two gear disks 11, and each gear disk 11 is provided with a corresponding Hall sensor 20. Since at least two Hall sensors 20 are respectively close to and act on different gear disks 11, and the number of teeth of each layer of gear disk 11 is different or they are circumferentially offset, the results measured by each of the two Hall sensors 20 are different. That is, by analyzing and processing the parameters measured by at least two Hall sensors 20, the maximum speed that the motor speed detection device can distinguish can be increased, thereby increasing the measurement range of the Hall sensor 20 for the speed. In summary, adopting the solution of the present application avoids the problem of increased vehicle body width caused by using a vehicle-mounted resolver in the prior art, and also avoids the problem that high speeds cannot be measured when using the Hall sensor 20.

[0041] In this application, multiple Hall sensors 20 are used simultaneously, and multiple gear disks 11 are provided on the turntable 10, and each gear disk 11 has a corresponding Hall sensor 20 for position detection; optionally, for the Hall sensor 20 measuring the current gear disk 11, the center line of the Hall sensor 20 can be set along the direction in which the gear disk 11 extends radially.

[0042] Specifically, the position of the Hall sensor 20 is fixed and does not rotate with the motor. Therefore, when the motor rotor drives the turntable 10 to rotate, since the Hall sensor 20 remains stationary, at least two Hall sensors 20 measure the influence of the rotation of the gear disk 11 on the magnetic field. That is to say, the Hall sensor 20 can measure and obtain the rotational speed of the motor rotor.

[0043] The working principle of the Hall sensor 20 is as follows: The principle of the Hall sensor 20 for measuring the rotational speed of a gear is mainly based on the Hall effect; when the object to be measured, such as a gear or a rack, rotates, its metal part will pass in front of the Hall sensor 20, causing a change in the magnetic field; this change will lead to a change in the magnetic flux density, thereby affecting the magnetic field distribution on the Hall element; when the magnetic flux passes through the Hall element, an electromotive force difference, that is, the Hall electromotive force, will be generated on both sides of the element; this electromotive force difference is related to the intensity of the magnetic field and the structure of the element, so it can be used to measure the change in the magnetic field. Specifically, when the Hall sensor 20 measures the rotational speed, when the gear or the rack rotates, its metal part will pass in front of the Hall sensor 20, causing a change in the magnetic field; this change leads to a change in the magnetic flux density, thereby affecting the magnetic field intensity passing through the Hall element; the Hall element will generate a Hall electromotive force when the magnetic field changes, and this electromotive force is proportional to the intensity of the magnetic field; the generated Hall electromotive force is then converted into an alternating electric signal, which is processed and amplified by the built-in circuit, and finally a rectangular pulse signal is output; these signals can be further processed to determine the rotational speed and position information.

[0044] In use, the Hall gear sensor is widely used in the fields of the automotive industry, mechanical manufacturing, robotics, etc. due to its high precision and reliability, especially in measuring rotational speed and position confirmation, etc.

[0045] In some embodiments, refer to Figure 1 、 Figure 4 and Figure 7 , there are two gear disks 11 on the turntable 10, and there is a certain distance between adjacent gear disks 11 along the axial direction. In this way, by setting two gear disks 11, multiple corresponding Hall sensors 20 can be set to measure the rotational speeds of different gear disks 11, and then the different data obtained by the two Hall sensors 20 are comprehensively processed to obtain the specific value of the motor rotational speed, thereby accurately judging the rotational speed of the motor.

[0046] In some embodiments, refer toFigures 1 to 3 , which shows the structure of the turntable having two gear discs 11, and the two gear discs 11 have 64 teeth and 32 teeth respectively. Refer to Figures 4 to 6 , which shows the structure of the turntable having two gear discs 11, and the two gear discs 11 have 64 teeth and 48 teeth respectively; the number of teeth of adjacent gear discs 11 on the same turntable 10 is different, and the tooth profile of each gear disc 11 is evenly arranged along the circumferential direction. In this way, during measurement, on the same turntable 10, the number of teeth of different gear discs 11 can be made different, so that the magnetic field effects on the Hall sensors 20 corresponding to different gear discs 11 are different. Therefore, different data can be measured at the Hall sensors 20 corresponding to different gear discs 11, and through comprehensive analysis and processing of two groups of different data, the upper limit of the rotational speed detection can be increased, so as to facilitate the measurement of higher rotational speeds of the engine.

[0047] In some embodiments, refer to Figures 7 to 9 , which shows the structure of the turntable having two gear discs 11, and the two gear discs 11 have 64 teeth and 64 teeth respectively. The number of teeth of the gear discs 11 on the same turntable 10 is the same, and the adjacent gear discs 11 are rotated and staggered axially and do not coincide. In this way, by staggering the two gear discs 11, the magnetic field effects on the Hall sensors 20 corresponding to different gear discs 11 are different. When two Hall sensors 20 are provided and each gear disc 11 corresponds to one Hall sensor 20, the measurement results obtained by each Hall sensor 20 are inconsistent. By analyzing the measurement parameters obtained by the Hall sensors 20, the target rotational speed to be measured can be obtained, and comprehensive processing is performed to increase the highest rotational speed that can be measured by the rotational speed detection device of the present application.

[0048] In some embodiments, refer to Figure 1 , Figure 2 and Figure 3 , the turntable 10 further includes a connecting portion 12. The connecting portion 12 has a hollow annular structure and is coaxially arranged with the gear disc 11. The connecting portion 12 is axially connected to at least two gear discs 11. In this way, by providing the connecting portion 12, different gear discs 11 are connected together, and at the same time, due to the hollow structure of the connecting portion 12, it is convenient to fix the connecting portion 12 to the motor rotating shaft, so that the turntable 10 can rotate synchronously with the motor.

[0049] In some embodiments, refer to Figure 2 , each gear disc 11 is provided with two corresponding Hall sensors 20, and the Hall sensors 20 are arranged radially along the corresponding gear disc 11. In this way, each gear disc 11 is provided with a plurality of Hall sensors 20, which can avoid the situation where the rotational speed of the motor cannot be measured when a single Hall sensor 20 is damaged or fails. Therefore, this setting improves the stability of the measurement of the motor rotational speed.

[0050] In some embodiments, the detection device further includes a fixing plate which is perpendicular to the axis of the turntable 10. The fixing plate is arranged between the two gear disks 11 and parallel to the gear disks 11, and a Hall sensor 20 is mounted on the fixing plate. In this way, the fixing plate is provided to mount the Hall sensor 20, thereby fixing the position of the Hall sensor 20 so that the Hall sensor 20 can remain stationary at the same position to stably measure the gear disk 11.

[0051] In some embodiments, the turntable 10 includes two gear disks 11, and there are two Hall sensors 20 corresponding to each gear disk 11. The four Hall sensors 20 are respectively mounted on two opposite sides of the same fixing plate. In this way, by fixing all the Hall sensors 20 on the same fixing plate, the effects of sharing a circuit board and saving space are achieved, and the integration degree of the internal structure of the motor is also improved.

[0052] In an embodiment, when using a shared circuit board, the fixing plate can be installed in the middle of the two gear disks 11. The fixing plate can be set as a thin plate, such as a rectangular plate or a flat plate with an arc-shaped clearance groove opened on the side facing the gear disk 11. The Hall sensors 20 are arranged and connected on two opposite sides of the fixing plate to electrically connect the Hall sensors 20; when setting four Hall sensors 20, the four Hall sensors 20 can be symmetrically arranged along both sides of the fixing plate. See Figure 2 , the fixing plate can be a thin plate arranged in the vertical direction, the thickness direction of the fixing plate is parallel to the axis of the turntable 10, the fixing plate is arranged in the middle of the two gear disks 11, the fixing plate is arranged in the middle of the four Hall sensors 20, and both of its two side surfaces are respectively connected to the two Hall sensors 20.

[0053] In an embodiment, if there are higher requirements for the rotation speed detection of the motor, it can be achieved by increasing the number of gear disks 11 along the axis of the turntable 10, such as increasing the gear disk 11 to three.

[0054] A power system includes a motor rotation speed detection device. The power system further includes a motor housing, a motor end cover, and a motor rotor. The Hall sensor 20 is fixed on the motor housing or the motor end cover; a turntable 10 is fixed on the motor rotor.

[0055] By adopting the above solution, by fixing the turntable 10 on the motor rotor, the turntable 10 will rotate synchronously with the motor rotor. By fixing the Hall sensor 20 on the motor housing or the motor end cover, the position of the Hall sensor 20 is fixed and is affected by the rotation of the motor rotor, so as to facilitate the Hall sensor 20 to measure the rotation speed of the motor rotor.

[0056] In the embodiments, the Hall sensor 20 can be directly fixed on the motor housing or the motor end cover, or the Hall sensor 20 can be first fixed on the fixing plate and then fixed on the motor housing or the motor end cover through the fixing plate.

[0057] In some embodiments, the turntable 10 includes a connecting portion 12. The connecting portion 12 has a hollow annular structure and is coaxially arranged with the gear disk 11. The connecting portion 12 is axially connected with at least two gear disks 11; the connecting portion 12 is sleeved and fixed on the rotating shaft of the motor rotor, so that the turntable 10 rotates synchronously with the motor rotor. In this way, by providing the connecting portion 12, the turntable 10 can be sleeved on the motor rotor, so that the turntable 10 rotates synchronously with the motor rotor.

[0058] Specifically, the connecting portion 12 is a hollow structure. A plurality of square grooves can be further provided around the hollow hole of the connecting portion 12. The square grooves are connected to the central circular hole of the connecting portion 12. The square grooves extend radially outward along the outer wall of the circular hole and form a square groove structure. The square grooves axially penetrate through the connecting portion 12 along the axial direction of the connecting portion 12; the square grooves are uniformly arranged along the circumferential direction of the circular hole, and the square grooves can be provided with four; during specific connection, the turntable 10 and the motor rotor can be clamped through the square grooves and the corresponding structures on the motor rotor, so that the turntable 10 and the motor rotor do not rotate relatively after being fixed, so as to ensure the stability after the turntable 10 and the motor rotor are connected.

[0059] In the embodiments, when two layers of gear disks 11 are provided, the number of teeth of the gear disks 11 can be set as follows:

[0060] When the number of teeth of one gear disk 11 is 64 and the number of teeth of the other gear disk 11 is 48, see Figures 4 to 6 , since the number of teeth of the two gear disks 11 is different, the two gear disks 11 must not coincide, so that the data measured by the Hall sensors 20 respectively corresponding to the two gear disks 11 outside the two gear disks 11 are different, thus facilitating the integration of data to improve the measurement upper limit of the rotational speed of the present application;

[0061] When the number of teeth of one gear disk 11 is 64 and the number of teeth of the other gear disk 11 is 32, see Figures 1 to 3 , the two gear disks 11 are arranged in a circumferentially staggered manner. Since the number of teeth of the two gear disks 11 is different, the two gear disks 11 must not coincide, so that the data measured by the Hall sensors 20 respectively corresponding to the two gear disks 11 outside the two gear disks 11 are different, thus facilitating the integration of data to improve the measurement upper limit of the rotational speed of the present application; in order to increase the staggering range of the two gear disks 11, the tooth top of a 32-tooth gear disk 11 can correspond to the tooth bottom of the 64-tooth gear disk 11;

[0062] When the number of teeth of one gear disk 11 is 64 and the number of teeth of the other gear disk 11 is 64, see Figures 7 to 9, the two gear disks 11 are arranged with a circumferential offset. For example, the tooth tip of one gear disk 11 can correspond to the tooth root of the other gear disk 11, so that the data measured by the Hall sensors 20 respectively corresponding to the two gear disks 11 outside the two gear disks 11 are different, which is convenient for data integration to improve the measurement upper limit of the rotational speed of this application.

[0063] In the embodiment, the material of the gear disk 11 is an iron magnetic material, such as magnetic materials like carbon steel, etc.; the Hall sensor 20 of this application is a dynamic self-calibrating peak detection differential Hall effect gear sensor, and the model adopted by the Hall sensor 20 can be ATS616LSG.

[0064] In the embodiment, when multiple different Hall sensors 20 are set, for the Hall sensors 20 detecting the same gear disk 11, their angles can be 5° or 10°, as long as different tooth disk positions can be read.

[0065] In the embodiment, since the two gear disks 11 are connected by the connecting portion 12, certain requirements are imposed on the thicknesses of both the connecting portion 12 and the gear disk 11, and they need to be able to withstand a rotational speed of 30,000 revolutions; for the thickness of the gear disk 11, it is also necessary to ensure that the Hall sensors 20 measuring the upper and lower layer gear disks 11 do not misread the tooth profiles of the other gear disk 11.

[0066] It should be noted that the drawings provided in this embodiment only illustrate the basic concept of the present utility model in a schematic manner. Therefore, only the components related to the present utility model are shown in the drawings, rather than being drawn according to the number, shape, and size of the components in actual implementation. The type, quantity, and ratio of each component in actual implementation can be arbitrarily changed, and the component layout type may also be more complex.

[0067] The structures, ratios, sizes, etc. shown in the drawings of this specification are only used to cooperate with the content disclosed in the specification for those familiar with this technology to understand and read, and are not used to limit the limiting conditions under which the present utility model can be implemented. Therefore, they do not have technical essence. Any modification of the structure, change of the proportional relationship, or adjustment of the size, without affecting the effects that the present utility model can produce and the purposes that can be achieved, should still fall within the scope that can be covered by the technical content disclosed by the present utility model.

[0068] In the description of the present utility model, it should be understood that the orientation or positional relationship indicated by the terms "width", "thickness", "upper", "lower", "left", "right", "vertical", "horizontal", "axial", "radial", "circumferential", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the present utility model.

[0069] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one of such features. In the description of the present utility model, the meaning of "a plurality" is at least two, such as two, three, etc., unless otherwise specifically defined.

[0070] In the present utility model, unless otherwise clearly specified and limited, the terms "mounted", "connected", "connected to", "fixed", etc. shall be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the internal communication of two elements or the interaction relationship between two elements, unless otherwise clearly limited. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.

[0071] In the description of this specification, the description with reference to terms such as "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present utility model. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0072] The above-described embodiments only represent several implementation manners of the present application. The description is relatively specific and detailed, but it should not be construed as a limitation to the scope of the utility model patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present application, several modifications and improvements can still be made, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application shall be subject to the appended claims.

Claims

1. A motor speed detection device, used to detect the speed of a motor, characterized in that: The detection device includes: A rotating disk (10), the rotating disk (10) comprising at least two gear disks (11) along the axial direction, the number of teeth of each layer of gear disks (11) being different or being circumferentially staggered, the gear disks (11) being made of magnetic material, and the gear disks (11) rotating synchronously with the motor rotor; A Hall sensor (20), the Hall sensor (20) being used to detect the rotation speed of the gear plate (11), and a corresponding Hall sensor (20) is arranged next to each gear plate (11).

2. The motor speed detection device according to claim 1, characterized in that: The rotating disk (10) is provided with two gear disks (11), and adjacent gear disks (11) are spaced a certain distance apart in the axial direction.

3. The motor speed detection device according to claim 1 or 2, characterized in that: The numbers of teeth on adjacent gear plates (11) on the same rotating disk (10) are different, and the tooth shape of each gear plate (11) is evenly distributed along the circumferential direction.

4. The motor speed detection device according to claim 1 or 2, characterized in that: The gear plates (11) on the same rotating disk (10) have the same number of teeth, and adjacent gear plates (11) are staggered in axial rotation and do not overlap.

5. The motor speed detection device according to claim 1, characterized in that: The turntable (10) further comprises: A connecting portion (12), the connecting portion (12) being in a hollow annular structure and being coaxially arranged with the gear plate (11), the connecting portion (12) being axially connected to at least two of the gear plates (11).

6. The motor speed detection device according to claim 1, characterized in that: Each gear plate (11) is provided with two corresponding Hall sensors (20), and the Hall sensors (20) are arranged along the radial direction of the corresponding gear plate (11).

7. The motor speed detection device according to claim 1, characterized in that: The detection device also includes: A fixing plate, wherein the fixing plate is perpendicular to the axial direction of the rotating disk (10), the fixing plate is arranged between the two gear disks (11) and is parallel to the gear disks (11), and the Hall sensor (20) is mounted on the fixing plate.

8. The motor speed detection device according to claim 7, characterized in that: The rotating disk (10) comprises two gear disks (11), each of the gear disks (11) is provided with two corresponding Hall sensors (20), and the four Hall sensors (20) are respectively installed on two opposite sides of the same fixed plate.

9. A power system, characterized in that: The motor speed detection device according to any one of claims 1 to 8, wherein the power system further comprises: Motor housing, A motor end cover, the Hall sensor (20) being fixed on the motor housing or the motor end cover; A motor rotor, on which the rotating disk (10) is fixed.

10. The power system according to claim 9, characterized in that: The turntable (10) comprises: A connecting portion (12), the connecting portion (12) being in a hollow annular structure and being coaxially arranged with the gear plate (11), the connecting portion (12) being axially connected to at least two of the gear plates (11); The connecting portion (12) is sleeved and fixed on the rotating shaft of the motor rotor, and enables the rotating disk (10) to rotate synchronously with the motor rotor.

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