Motor rotating speed detection assembly and switched reluctance motor using same

Abstract

The utility model discloses a motor rotating speed detection assembly and a switched reluctance motor using the same, and the motor rotating speed detection assembly comprises a magnetic ring which sleeves a part, extending out of the outer side of a motor stator, of a motor rotating shaft; the magnetic isolation body is used for being fixed to the end, facing the magnetic ring, of a framework of the motor stator; the axial ring body is located on the circumferential outer side of the magnetic ring and approximately extends in the axial direction of the motor rotating shaft, and the radial ring body is connected with the axial ring body and approximately extends in the radial direction of the motor rotating shaft. The Hall sensing device at least comprises a Hall element which is arranged on one side, facing the magnetic ring, of the axial ring body; the sensing surface of the Hall element faces the magnetic ring; the radial ring body is suitable for forming an axial barrier between the Hall element and the motor stator.

Description

TECHNICAL FIELD

[0001] The utility model relates to motor technical field especially, relates to a kind of motor rotating speed detection assembly and switch reluctance motor using it. BACKGROUND

[0002] In order to obtain the rotating speed of motor, sensor for detecting rotating shaft can be used for detection, such as Hall, electromagnetic, photoelectric and magnetic sensitive type. Among them, the advantages of electromagnetic type are simple structure, low cost and high reliability and stability, but its disadvantage is sensitive to vibration, and the anti-interference ability is weak. The advantages of photoelectric type include good anti-interference, compact structure, strong measuring ability, non-contact measurement, etc., and its disadvantage is that the optical fiber has requirements for the use environment, and is easily disturbed by the optical fiber. The advantages of magnetic sensitive type include large output amplitude, wide operating temperature range, good vibration resistance, etc., and its disadvantage is relatively narrow measuring range and relatively high cost. Hall has the ability to adapt to harsh working environment, strong anti-interference ability, long service life, high reliability, etc., but it is also easily disturbed by magnetic field, has poor interchangeability, and the signal changes with temperature, etc.

[0003] For Hall detection method, a magnetic ring is generally installed on the rotating shaft of the motor, and a Hall element corresponding to the magnetic ring is provided. When the motor is working, the magnetic ring rotates, so that the Hall element can output an induction signal under the magnetic field change of the magnetic ring. The control board of the motor obtains the rotating speed of the motor according to the induction signal. However, for brush motor, the coil of the motor also generates a magnetic field when the motor is working. The leakage magnetic field of the magnetic field will interfere with the Hall element, which will cause the induction signal output by the Hall element to be distorted or lost, and further cause inaccurate speed measurement, which is not conducive to the working stability of the motor.

[0004] Based on the above situation, the publication number CN217769777U discloses a motor for food processor and food processor, which adopts a speed measurement structure including a magnetic ring, a Hall module and a magnetic shield. The magnetic shield is arranged outside the Hall element to reduce the magnetic signal interference of the magnetic field generated by the winding coil of the motor on the Hall element. The magnetic shield is provided with a through slot, so that the Hall element can effectively sense the magnetic field change of the magnetic ring during rotation, and the Hall element can output accurate induction signal according to the magnetic field change of the magnetic ring, so that the control board of the food processor can accurately obtain the rotating speed of the rotating shaft according to the induction signal. More specifically, the Hall module includes a substrate, and the Hall element and the magnetic shield are arranged on the substrate. The magnetic shield is preferably fixed on the substrate by adhesive.

[0005] For the above-mentioned motor in the prior art, firstly, the substrate needs to be configured and the layout and assembly of the substrate relative to other components of the motor need to be considered; secondly, the bonding method of the magnetic isolation sleeve and the substrate has the problems of being not environmentally friendly and being not firm due to insufficient amount of adhesive or being difficult to clean due to excessive amount of adhesive.

[0006] Therefore, the structure of the motor speed detection device needs to be further optimized by simplifying the assembly method. Utility model content

[0007] The first object of the utility model is to provide a motor speed detection assembly to solve the technical problem of optimizing the overall structure for easy assembly.

[0008] The second object of the utility model is to provide a switched reluctance motor to solve the technical problem of optimizing the overall structure of the speed detection assembly for easy assembly.

[0009] The motor speed detection assembly of the utility model is implemented as follows:

[0010] A motor speed detection assembly comprises:

[0011] A magnetic ring is sleeved on the part of the motor rotating shaft that extends outside the motor stator;

[0012] A magnetic isolation body is used to be fixed on the end of the frame of the motor stator that faces the magnetic ring; the magnetic isolation body comprises an axial ring body that extends along the axial direction of the motor rotating shaft and is located on the circumferential outer side of the magnetic ring, and a radial ring body that extends along the radial direction of the motor rotating shaft and is connected with the axial ring body;

[0013] A Hall sensing device comprises at least a Hall element that is arranged on the side of the axial ring body that faces the magnetic ring; the sensing surface of the Hall element faces the magnetic ring; and the radial ring body is adapted to form an axial barrier between the Hall element and the motor stator.

[0014] In the optional implementation of the utility model, the axial length of the axial ring body is not less than the axial length of the magnetic ring.

[0015] In the optional implementation of the utility model, the axial ring body comprises a first annular body, a transition part connected with one end of the first annular body that faces the radial ring body, and a second annular body connected with one end of the transition part that faces the radial ring body; wherein

[0016] One end of the second annular body that is away from the transition part is connected with the radial ring body;

[0017] The diameter of the inner hole of the second annular body is smaller than the diameter of the inner hole of the first annular body.

[0018] In the optional implementation of the utility model, the first annular body and the second annular body are parallel to the axial direction of the motor rotating shaft; and

[0019] The radial annular body is perpendicular to the axial direction of the motor rotating shaft;

[0020] The radial annular body is located in the axial interval formed between the axial end of the magnetic ring and the axial end of the motor stator.

[0021] In the optional implementation of the utility model, the radial annular body has an inner hole with a diameter greater than the outer diameter of the magnetic ring.

[0022] In the optional implementation of the utility model, the transition part is perpendicular to the first annular body and the second annular body, respectively.

[0023] In the optional implementation of the utility model, the outer side wall of the second annular body is adapted to be attached to the hole wall of the inner circular hole formed by the framework of the motor stator; and

[0024] The transition part is adapted to be carried on the axial end surface of the magnetic ring of the framework of the motor stator.

[0025] In the optional implementation of the utility model, the end portion of the framework of the motor stator corresponding to the edge of the inner circular hole is formed with a rounded corner.

[0026] In the optional implementation of the utility model, the outer corner formed by the radial annular body and the second annular body is formed with a chamfer.

[0027] In the optional implementation of the utility model, the Hall sensing device further comprises an outer shell body for fixing the Hall element;

[0028] The outer shell body is adapted to be fixed on the motor end cover.

[0029] The switch reluctance motor of the utility model is realized as follows:

[0030] A switch reluctance motor, comprising: the motor rotating speed detection assembly.

[0031] By adopting the above technical solution, this utility model has the following beneficial effects: The motor speed detection component and the switched reluctance motor using it of this utility model, through the setting of a magnetic shield, surround the magnetic ring and Hall element inside the magnetic shield. For the Hall element, the magnetic shield forms an axial barrier between the Hall element and the motor stator, which can prevent the magnetic field generated by the motor stator coil during operation from interfering with the Hall element due to leakage magnetic field. This avoids the distortion or loss of the induction signal output by the Hall element, thereby improving the accuracy of the motor speed detection result. As for the fixing process of the magnetic shield itself, it can be directly assembled onto the frame of the motor stator, and is minimally affected by improper operation during manual assembly, thus making the assembly process convenient and efficient. Attached Figure Description

[0032] Figure 1 This is an exploded structural diagram of the motor speed detection component of this utility model applied to a specific motor.

[0033] Figure 2 This is a partial cross-sectional view of the motor speed detection component of this utility model applied to a specific motor.

[0034] Figure 3 This is a schematic diagram of the skeleton of the motor speed detection component of this utility model applied in a specific motor.

[0035] Figure 4 This is a schematic diagram of the structure of the magnetic shielding element in a specific motor, which is an application of the motor speed detection component of this utility model.

[0036] Figure 5 This is a schematic diagram of the cooperation structure between the magnetic shield and the Hall sensor in the motor speed detection component of this utility model;

[0037] Figure 6 This is a schematic diagram of the cooperation structure between the magnetic shield and the frame of the motor speed detection component of this utility model;

[0038] Figure 7 This is a schematic diagram of the cooperation structure between the magnetic shielding body, Hall sensor, and magnetic ring of the motor speed detection component of this utility model.

[0039] In the figure: 1. Motor shaft; 2. Motor end cover; 3. Frame; 4. Stator core; 5. Magnetic ring; 61. Hall element; 62. Housing; 7. Axial ring; 71. First ring; 72. Second ring; 73. Transition part; 8. Radial ring; 1. Rounded corner; 2. Chamfer. Detailed Implementation

[0040] To make the contents of this utility model easier to understand, the present utility model will be further described in detail below with reference to specific embodiments and accompanying drawings.

[0041] Embodiment 1:

[0042] Please refer to Figures 1 to 7 As shown in the drawings, the embodiment provides a motor rotating speed detection assembly, which comprises a magnetic ring 5, a magnetic shield and a Hall sensing device used in cooperation.

[0043] Specifically, the magnetic ring 5 is sleeved on the part of the motor rotating shaft 1 extending outside the motor stator, so that the magnetic ring 5 can move synchronously with the rotation of the motor rotating shaft 1. The magnetic ring 5 is made of magnetic material and has a uniformly distributed magnetic field on the surface, which presents an N / S alternating magnetic field polarity to the outside.

[0044] The magnetic shield is fixed on the end of the frame 3 of the motor stator facing the magnetic ring 5. The magnetic shield 5 is formed by stamping a metal with good magnetic conductivity and has high magnetic permeability, which can better guide the magnetic field. In the case of an excessively strong external magnetic field, the wall thickness of the magnetic shield can be increased, or the metal with excellent magnetic conductivity can be replaced and the metal can be magnetized to increase the magnetic shielding effect of the magnetic shield.

[0045] The magnetic shield comprises an axial ring body 7 extending along the axial direction of the motor rotating shaft 1 and located on the circumferential outer side of the magnetic ring 5, and a radial ring body 8 connected to the axial ring body 7 and extending along the radial direction of the motor rotating shaft 1; and the Hall sensing device at least comprises a Hall element 61 arranged on the side of the axial ring body 7 facing the magnetic ring 5; and the sensing surface of the Hall element 61 faces the magnetic ring 5. The Hall sensing device further comprises an outer shell 62 for fixing the Hall element 61; here the outer shell 62 does not form an obstruction lower than the sensing surface of the Hall element 61, and the outer shell 62 is suitable for being fixed on the motor end cover 2, so that the Hall element 61 is fixed during the operation of the motor.

[0046] Based on the above, it needs to be further explained that the axial length of the axial ring body 7 in the embodiment is not less than the axial length of the magnetic ring 5. Under this design, on the one hand, the assembly requirement of the magnetic shield and the frame 3 can be met, and on the other hand, the axial and radial protection of the Hall element 61 can be formed.

[0047] Next, an example of a case that is convenient to process and can meet the use requirements will be described in conjunction with the drawings. The axial ring body 7 comprises a first annular body 71, a transition part 73 connected to one end of the first annular body 71 facing the radial ring body 8, and a second annular body 72 connected to one end of the transition part 73 facing the radial ring body 8; wherein one end of the second annular body 72 away from the transition part 73 is connected to the radial ring body 8; the diameter of the inner hole of the second annular body is smaller than the diameter of the inner hole of the first annular body 71.

[0048] On the basis of the above structure, it is to be noted that for the first annular body 71 and the second annular body 72 of the present embodiment, the first annular body 71 and the second annular body 72 can both be parallel to the axial direction of the motor rotating shaft 1, which is easy to process and is more easily assembled to the frame 3 of the motor stator. Of course, in theory, the first annular body 71 and the second annular body 72 here can be slightly inclined relative to the axial direction of the motor rotating shaft 1 to meet the use requirements. Or one of the first annular body 71 and the second annular body 72 is parallel to the axial direction of the motor rotating shaft 1 and the other is not parallel, which also meets the use requirements. Therefore, for the specific parallelism of the first annular body 71 and the second annular body 72 relative to the axial direction of the motor rotating shaft 1, the present embodiment does not make absolute limitation, and based on this, it is also to be noted that for the transition part 73, in one optional implementation, the transition part 73 is perpendicular to the first annular body 71 and the second annular body 72 respectively; in another optional implementation, the transition part 73 is in a non-perpendicular distribution state relative to the first annular body 71 and the second annular body 72.

[0049] On the basis of the above structure, the outer side wall of the second annular body 72 is adapted to fit the hole wall of the inner circular hole formed by the frame 3 of the motor stator; and the transition part 73 is adapted to be carried on the axial end face of the frame 3 of the motor stator towards the magnetic ring 5. Specifically, when the magnetic shield is assembled to the frame 3, the transition part 73 is overlapped with the frame 3 after winding, and there is a gap between the second annular body 72 in the initial state and the hole wall of the inner circular hole formed by the frame 3, which will produce radial deformation after the stator is dipped and dried, and the outer wall surface of the second annular body 72 abuts, thereby firmly fixing the magnetic shield on the frame 3.

[0050] Based on this, in order to improve the smoothness and efficiency of the assembly process of the magnetic shield and the frame 3, the end of the frame 3 of the motor stator towards the magnetic ring 5 corresponds to the edge of the inner circular hole and forms a rounded corner K1. Correspondingly, the outer corner formed by the radial ring body 8 and the second annular body 72 forms a chamfer K2.

[0051] Based on the above situation, in combination with the drawings, the present embodiment is described with the case that the first annular body 71 and the second annular body 72 are both parallel to the axial direction of the motor rotating shaft 1, based on which, the radial ring body 8 is perpendicular to the axial direction of the motor rotating shaft 1; and the radial ring body 8 is located in the axial interval formed between the axial side end of the magnetic ring 5 and the motor stator facing each other, and the radial ring body 8 also forms the axial barrier between the Hall element 61 and the motor stator, so for the radial dimension of the radial ring body 8, since it needs to meet the magnetic shielding effect between the motor stator and the Hall element 61, the radial dimension of the radial ring body 8 cannot be less than the dimension of the Hall element 61 along the axial direction perpendicular to the motor rotating shaft 1.

[0052] In addition, regarding the axial length of the first annular body 71 and the second annular body 72, it is necessary to further explain that:

[0053] The first annular body 71 is mainly used for forming a magnetic shielding protection for the circumferential direction outer side end of the Hall element 61, and thus the axial length of the first annular body 71 cannot be less than the dimension of the Hall element 61 along the axial direction of the motor rotating shaft 1 in the use state. The second annular body 72 needs to meet the hole wall fitting of the inner hole of the motor stator frame 3, and thus in order to form a reliable and firm fitting between the magnetic shielding body and the frame 3, the axial length of the second annular body 72 cannot be too small, and of course cannot be too large to prevent it from causing interference to the normal use of the stator core 4 of the motor stator.

[0054] In addition, it is also necessary to be explained that the diameter of the inner hole of the radial annular body 8 is greater than the outer diameter of the magnetic ring 5, which is convenient for assembly and aggregation of other non-magnetic rings 5 magnetic fields on the bottom side of the magnetic ring 5. The diameter of the inner hole of the ring body can be adjusted according to the mounting mode and the outer diameter of the magnetic ring 5, and other foreign matters can be blocked from approaching the magnetic ring 5.

[0055] In summary, for the motor rotating speed detection assembly of the embodiment, when the motor is working, the magnetic ring 5 rotates synchronously with the motor rotating shaft 1, so that the Hall element 61 can output accurate induction signals according to the magnetic field changes of the magnetic ring 5, so that the control board of the motor can accurately obtain the rotating speed of the motor rotating shaft 1 according to the induction signals. By arranging the magnetic shielding body, the magnetic ring 5 and the Hall element 61 are arranged inside the magnetic shielding body. For the Hall element 61, the magnetic shielding body forms an axial shielding between the Hall element 61 and the motor stator, which can avoid the problem that the magnetic field generated by the stator coil of the motor during work will cause interference to the Hall element 61 due to magnetic leakage, thereby avoiding the deformation or loss of the induction signals output by the Hall element 61, and further improving the accuracy of the motor rotating speed detection result. That is, when there is an external magnetic field near the Hall element 61 during use, the magnetic field will preferentially gather in the magnetic shielding body, and a magnetic field environment with less magnetic field can be created inside the magnetic shielding body to ensure the induction effect between the Hall element and the magnetic ring 5.

[0056] Embodiment 2:

[0057] On the basis of the motor rotating speed detection assembly of embodiment 1, the embodiment provides a switched reluctance motor, which comprises the motor rotating speed detection assembly of embodiment 1.

[0058] The above specific embodiments further illustrate the purpose, technical scheme and advantages of the utility model, and it should be understood that the above is only a specific embodiment of the utility model and is not used to limit the utility model. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the utility model should be included in the protection scope of the utility model.

[0059] In the description of the utility model, it needs to be understood that the terms indicating the orientation or position relationship are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the utility model and simplifying the description, and cannot be understood as the limitation of the utility model.

[0060] In the utility model, unless otherwise explicitly specified and limited, the terms such as '' installation '' '' connection '' '' fixed '' and the like should be understood broadly, for example, can be fixed connection, or can be detachable connection, or can be integrated, can be mechanical connection, or can be electrical connection, can be directly connected, or indirectly connected through intermediate medium, can be the communication inside two elements or the interaction relationship of two elements. For ordinary skilled in the art, the specific meaning of the above terms in the utility model can be understood according to the specific circumstances.

[0061] In the description of the utility model, it needs to be explained that the orientation or position relationship indicated by the terms '' center '' '' upper '' '' lower '' '' left '' '' right '' '' vertical '' '' horizontal '' '' inner '' '' outer '' and the like is based on the orientation or position relationship shown in the drawings, or is the orientation or position relationship when the utility model product is usually placed, and is only for the convenience of describing the utility model and simplifying the description, and cannot be understood as the limitation of the utility model. In addition, the terms '' first '' '' second '' '' third '' and the like are only used for distinguishing description, and cannot be understood as indicating or implying relative importance.

[0062] In addition, the terms '' horizontal '' '' vertical '' '' overhang '' and the like do not mean that the component must be absolutely horizontal or overhanging, but can be slightly inclined. For example, '' horizontal '' only means that its direction is more horizontal relative to '' vertical '', and does not mean that the structure must be completely horizontal, but can be slightly inclined.

[0063] In the utility model, unless otherwise explicitly specified and limited, the first feature above or below the second feature can include that the first and second features are in direct contact, or can include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, the first feature above, above and above the second feature includes that the first feature is directly above and obliquely above the second feature, or only means that the horizontal height of the first feature is higher than that of the second feature. The first feature below, below and below the second feature includes that the first feature is directly below and obliquely below the second feature, or only means that the horizontal height of the first feature is less than that of the second feature.

Claims

1. A motor speed detection component, characterized in that, The motor speed detection assembly comprises: a magnetic ring, which is sleeved on the part of the motor rotating shaft extending outside the motor stator; a magnetic isolation body, which is used to be fixed on the end of the frame of the motor stator facing the magnetic ring; the magnetic isolation body comprises an axial ring body extending along the axial direction of the motor rotating shaft and located on the circumferential outer side of the magnetic ring, and a radial ring body extending along the radial direction of the motor rotating shaft and connected with the axial ring body; a Hall sensing device, which comprises at least a Hall element arranged on the side of the axial ring body facing the magnetic ring; the sensing surface of the Hall element faces the magnetic ring; the radial ring body is adapted to form an axial isolation between the Hall element and the motor stator.

2. The motor rotation speed detection assembly according to claim 1, characterized by The axial length of the axial ring body is not less than the axial length of the magnetic ring.

3. The motor rotation speed detection assembly according to claim 1 or 2, characterized by The axial ring body comprises a first ring body, a transition part connected with one end of the first ring body facing the radial ring body, and a second ring body connected with one end of the transition part facing the radial ring body; wherein one end of the second ring body away from the transition part is connected with the radial ring body; the diameter of the inner hole of the second ring body is smaller than the diameter of the inner hole of the first ring body.

4. The motor rotational speed detection assembly according to claim 3, characterized by The first ring body and the second ring body are parallel to the axial direction of the motor rotating shaft; and the radial ring body is perpendicular to the axial direction of the motor rotating shaft; the radial ring body is located in the axial interval formed between the axial side end of the magnetic ring and the motor stator.

5. The motor rotational speed detection assembly according to claim 4, characterized by The diameter of the inner hole of the radial ring body is greater than the outer diameter of the magnetic ring.

6. The motor rotational speed detection assembly according to claim 4, characterized by The transition part is perpendicular to the first ring body and the second ring body, respectively.

7. The motor rotational speed detection assembly according to claim 6, characterized by The outer side wall of the second ring body is adapted to fit the hole wall of the inner circular hole formed by the frame of the motor stator; and the transition part is adapted to be carried on the axial end surface of the frame of the motor stator facing the magnetic ring.

8. The motor rotational speed detection assembly according to claim 7, characterized by The end of the frame of the motor stator facing the magnetic ring corresponds to the edge of the inner circular hole and forms a rounded corner.

9. The motor rotational speed detection assembly according to claim 4, characterized by The outer corner formed by the radial ring body and the second ring body forms a chamfered corner.

10. The motor rotational speed detection assembly according to claim 1, characterized by, The Hall sensing device further comprises an outer housing for fixing the Hall element; the outer housing is adapted to be fixed on the motor end cover.

11. A switched reluctance motor characterised in that, The motor speed detection assembly comprises: the motor speed detection assembly according to any one of claims 1 to 10.

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