Rotating speed detection module and shaded pole motor comprising same

Abstract

The rotating speed detection module comprises a rear cover, a Hall circuit board and a magnetic ring installed at the tail end of a rotor shaft, the rear cover comprises a shell and a Hall installation portion protruding out of the outer surface of the shell, the magnetic ring is located in the shell, and the Hall installation portion is located in the shell. The Hall mounting part is provided with a mounting groove for inserting the Hall circuit board and a dismounting opening which is arranged opposite to the outer surface of the shell and is communicated with the mounting groove; a clamping groove is formed in the Hall circuit board, and a buckle connected with the clamping groove in a clamped mode is arranged in the installation groove and located on the side face of the Hall installation part where the dismounting opening is located. According to the rotating speed detection module, the Hall circuit board is inserted into the Hall installation part of the rear cover, installation is convenient, the installation stability is improved through cooperation of the buckles, the Hall circuit board can be separated from the buckles through the disassembly openings, and rapid disassembly is achieved.

Description

Technical Field

[0001] This utility model relates to the field of motor technology, and in particular to a speed detection module and a shaded-pole motor containing the same. Background Technology

[0002] As market demands for motor functionality continue to rise, many motors now require speed detection capabilities for system monitoring and control. While some shaded-pole motors currently incorporate speed detection, several issues remain, including complex structural designs, insecure Hall effect circuit board mounting, difficulty in disassembly and assembly, and inconvenient installation. For instance, some motors integrate the Hall effect circuit board into the housing, making disassembly difficult. Another method involves pressing the Hall effect circuit board with bent terminals (e.g., patent number CN202022693244). While this structure brings the Hall sensor and magnetic ring closer and allows for disassembly, it requires bending the terminals, which necessitates tools for smaller motors, further complicating the process. Additionally, the crimped terminals are prone to breakage and have a short lifespan. Utility Model Content

[0003] To address the technical problems of existing motors with speed detection functions, such as unstable Hall effect circuit boards, difficulty in disassembly and assembly, and inconvenient installation, this utility model provides a speed detection module and a shaded-pole motor containing it to solve the above problems.

[0004] This utility model proposes a speed detection module, including a rear cover, a Hall circuit board, and a magnetic ring installed at the end of a rotor shaft. The rear cover includes a housing and a Hall mounting portion protruding from the outer surface of the housing. The magnetic ring is located inside the housing. The Hall mounting portion has a mounting groove for inserting the Hall circuit board and a disassembly port arranged opposite to the outer surface of the housing and communicating with the mounting groove. The Hall circuit board is provided with a slot, and the side of the Hall mounting portion located in the mounting groove and at the disassembly port has a buckle that engages with the slot.

[0005] In an optional embodiment of this utility model, when the Hall circuit board is located in the mounting groove, the surface of the Hall circuit board where the Hall element is located is tangent to the circumferential surface of the concentric circle of the magnetic ring.

[0006] In an optional embodiment of this utility model, the vertical distance d between the Hall element (201) and the magnetic ring (3) satisfies the following relationship:

[0007]

[0008] Where r is the radius of the magnetic ring; B0 is the surface magnetism of the magnetic ring; B min This is the minimum trigger threshold for the Hall element.

[0009] In an optional embodiment of this utility model, the vertical distance d between the Hall element and the magnetic ring is 1.2mm to 1.8mm.

[0010] In an optional embodiment of this utility model, the buckle is positioned close to the opening of the mounting groove, and the distance between the buckle and the opening of the mounting groove is less than the distance between the disassembly port and the opening of the mounting groove.

[0011] In an optional embodiment of this utility model, the cross-section of the buckle along the lateral side of the rear cover is triangular, and the slope of the buckle faces the opening of the mounting groove.

[0012] In an optional embodiment of this utility model, the surface of the housing connected to the Hall mounting portion has a notch communicating with the mounting groove.

[0013] In an optional embodiment of this utility model, when the Hall circuit board is located in the mounting groove, the distance between the Hall circuit board and the surface of the rear cover is greater than the distance between the Hall circuit board and the surface where the disassembly port is located.

[0014] In an optional embodiment of this utility model, the disassembly port is a T-shaped structure, comprising a vertical section and a horizontal section. The horizontal section is parallel to the insertion direction of the Hall circuit board, and the vertical section is located at the end of the horizontal section near the buckle.

[0015] In an optional embodiment of this utility model, the rear cover further includes a connecting lug located on the outer surface of the housing, and the connecting lug is provided with a mounting hole.

[0016] In an optional embodiment of this utility model, the connecting lug is further provided with a weight-reducing hole, which is located inside the mounting hole.

[0017] In an optional embodiment of this utility model, the end of the connecting lug protrudes from the end face of the housing, so that a stepped limiting surface is formed between the connecting lug and the housing to cooperate with the rear bracket of the shaded-pole motor.

[0018] In an optional embodiment of this utility model, the inner bottom surface of the housing is provided with a recessed portion.

[0019] This utility model also proposes a shaded-pole motor, including the speed detection module described above.

[0020] The beneficial effects of this utility model are:

[0021] (1) The speed detection module of this utility model inserts the Hall circuit board into the Hall mounting part of the rear cover, which is easy to install. The installation stability is improved by the cooperation of the buckle, and the Hall circuit board can be disengaged from the buckle through the disassembly port to achieve quick disassembly.

[0022] (2) The present invention connects the interior of the housing with the mounting groove of the Hall mounting part, thereby reducing the distance and obstruction between the magnetic ring and the Hall element and improving the magnetic induction intensity. Attached Figure Description

[0023] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0024] Figure 1 This is an exploded view of a specific embodiment of the shaded-pole motor described in this utility model;

[0025] Figure 2 This is a front view of a specific embodiment of the shaded-pole motor described in this utility model;

[0026] Figure 3 yes Figure 2 Sectional view along axis AA;

[0027] Figure 4 This is a schematic diagram showing the distance between the Hall element and the magnetic ring in the speed detection module of this utility model;

[0028] Figure 5 This is a perspective view of the Hall effect circuit board in this utility model;

[0029] Figure 6 This is a perspective view of the rear cover as seen from the side.

[0030] Figure 7 This is a half-sectional schematic diagram of the rear cover in this utility model;

[0031] Figure 8 This is a perspective view of the present invention as seen from the top of the rear cover;

[0032] Figure 9 This is a schematic diagram of the assembly of the Hall circuit board and the rear cover in this utility model.

[0033] In the diagram, 1. Rear cover, 101. Housing, 1011. Notch, 1012. Recessed part, 102. Hall mounting part, 1021. Mounting groove, 1022. Disassembly port, 1023. Snap fastener, 103. Connecting lug, 1031. Mounting hole, 2. Hall circuit board, 201. Hall element, 202. Slot, 203. Interlocking contact part, 204. Gap, 3. Magnetic ring, 4. Rotor shaft, 5. Sloping surface, 6. Opening, 7. Vertical section, 8. Horizontal section, 9. Weight reduction hole, 10. Step limiting surface, 11. Screw, 12. Nut, 13. Rear bracket, 14. Front bracket, 15. Stator. Detailed Implementation

[0034] The embodiments of this utility model are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this utility model, and should not be construed as limiting this utility model.

[0035] Example 1

[0036] like Figures 1-3 and Figure 7 As shown, a speed detection module includes a rear cover 1, a Hall circuit board 2, and a magnetic ring 3 installed at the end of a rotor shaft 4. The Hall circuit board 2 is a circuit board with a Hall element 201. The rear cover 1 is used to cover the rear end of a shaded-pole motor and is fixedly connected to the rear bracket 13 of the shaded-pole motor by screws 11. The rear cover 1 includes a housing 101 and a Hall mounting part 102 protruding from the outer surface of the housing 101. The magnetic ring 3 is located inside the housing 101. The Hall mounting part 102 has a mounting groove 1021 for inserting the Hall circuit board 2 and a disassembly port 1022 arranged opposite to the outer surface of the housing 101 and communicating with the mounting groove 1021. The Hall circuit board 2 is provided with a slot 202. The side of the Hall mounting part 102 located in the mounting groove 1021 and at the disassembly port 1022 has a buckle 1023 that engages with the slot 202.

[0037] After the motor is installed, as follows Figure 3 , Figure 4 and Figure 9 As shown, the magnetic ring 3 mounted on the rotor shaft 4 on one side of the rear bracket 13 is completely placed inside the rear cover 1. At this time, the Hall circuit board 2 installed on the rear cover 1 is directly opposite the arc surface of the magnetic ring 3. The magnetic ring 3 and the rear cover 1 adopt a separate structure, which can be easily replaced when either part is damaged.

[0038] When installing the Hall circuit board 2, it is inserted into the opening 6 of the mounting slot 1021 and fixed by the engagement of the slot 202 and the buckle 1023. When disassembling the Hall circuit board 2, the Hall circuit board 2 is pressed inward from the disassembly port 1022. Since the buckle 1023 is located on the surface of the disassembly port 1022, the slot 202 of the Hall circuit board 2 can be separated from the buckle 1023 of the Hall mounting part 102, thereby allowing the Hall circuit board 2 to be pulled out. Compared with the prior art, the Hall circuit board 2 and the rear cover 1 in this utility model are installed in a detachable manner, which is convenient and reliable to install and can achieve quick disassembly.

[0039] To ensure that the Hall element 201 can effectively sense the magnetic field lines of the magnetic ring 3, the distance between the Hall element 201 and the magnetic ring 3 needs to be limited. The intensity of the magnetic field lines sensed by the Hall element 201 is related not only to the distance between the Hall element 201 and the magnetic ring 3, but also to the magnetic properties of the magnetic ring 3. If the magnetic properties of the magnetic ring 3 are enhanced, the distance between the Hall element 201 and the magnetic ring 3 can be increased. Under normal circumstances, the perpendicular distance d between the Hall element 201 and the magnetic ring 3 satisfies the following relationship:

[0040]

[0041] Where r is the radius of the magnetic ring (3); B0 is the surface magnetism of the magnetic ring (3); B min The minimum trigger threshold of the Hall element (201) is given.

[0042] For motors commonly used in this field, such as Figure 4 As shown, the vertical distance d between the Hall element 201 and the magnetic ring 3 can be 1.2mm to 1.8mm.

[0043] To improve the sensing effect, the Hall circuit board 2 and the magnetic ring 3 are preferably arranged as follows: when the Hall circuit board 2 is located in the mounting groove 1021, the surface of the Hall circuit board 2 where the Hall element 201 is located is tangent to the circumferential surface of the concentric circle of the magnetic ring 3. The concentric circle of the magnetic ring 3 is a circle formed with the central axis of the magnetic ring 3 as the center point, extending outwards to the Hall circuit board 2 and tangentially contacting it. The spatial position of the magnetic ring 3 within the rear cover 1 is as follows: Figure 3 As shown, the magnetic ring 3 is not in contact with the Hall circuit board 2.

[0044] The structure of rear cover 1 is as follows Figures 6-8 As shown, the housing 101 is a hollow cylindrical structure with one end open, connecting to the rear bracket 13, and the other end having an inner bottom surface. The Hall mounting part 102 is a rectangular block protruding from the surface of the housing 101, and the opening 6 of the mounting groove 1021 faces laterally. When the Hall circuit board 2 is installed into the mounting groove 1021, the Hall element 201 faces the inside of the housing 101, directly opposite the magnetic ring 3. Since the Hall mounting plate body is relatively thin, and the Hall element 201 protrudes from its surface, the opening 6 of the mounting groove 1021 is preferably cross-shaped, which can both provide installation space for the Hall circuit board 2 and provide a stable limiting function. After the Hall circuit board 2 is installed, the distance between the Hall circuit board 2 and the surface of the rear cover 1 is greater than the distance between the Hall circuit board 2 and the surface where the disassembly port 1022 is located, in order to provide a larger space for the Hall element 201 inside the Hall circuit board 2.

[0045] The inner bottom surface of the housing 101 is preferably provided with a recessed portion 1012. The function of the recessed portion 1012 is to avoid the rotor shaft 4, so as to facilitate the rotation of the rotor shaft 4 and prevent the rotor shaft 4 from hitting the inner bottom surface of the housing 101.

[0046] The structure of Hall effect circuit board 2 is as follows: Figure 5 As shown, the Hall effect circuit board 2 is elongated. Its surface features a slot 202, a Hall element 201, and a mating contact 203, designed with a "gold finger" structure. A gap 204 is left between the Hall element signal output terminal 201 and the power ground terminal to avoid interference with the Hall output pulse signal. The mating contact 203 is "windowed" to expose copper foil, allowing the Hall effect circuit board 2 to also function as a terminal. This simplifies the terminal structure of the shaded-pole motor, making it easier to use, significantly reducing design and operating costs, and improving connection performance.

[0047] Example 2

[0048] Based on Embodiment 1, this embodiment designs the front and rear positions of the latch 1023 and the disassembly port 1022 on the side of the Hall mounting part 102. The disassembly port 1022 is set to press the Hall circuit board 2 to disengage it from the latch 1023. If the distance between the disassembly port 1022 and the latch 1023 is too far, the Hall circuit board 2 needs to undergo a large deformation to disengage from the latch 1023. Therefore, this utility model preferably sets the disassembly port 1022 close to the latch 1023.

[0049] The buckle 1023 is designed to secure the Hall circuit board 2. Since there is a certain amount of clearance between the Hall circuit board 2 and the inner cavity of the mounting groove 1021, if the buckle 1023 is placed deep inside the mounting groove 1021, it would be impossible to observe the connection between the Hall circuit board 2 and the buckle 1023, making it difficult to align and position the slot 202 and the buckle 1023. Therefore, in this embodiment, the buckle 1023 is positioned close to the opening 6 of the mounting groove 1021, and the distance between the buckle 1023 and the opening 6 of the mounting groove 1021 is less than the distance between the disassembly port 1022 and the opening 6 of the mounting groove 1021. In other words, the disassembly port 1022 is located behind the buckle 1023.

[0050] Example 3

[0051] This embodiment optimizes the shape of the buckle 1023 based on the above embodiment. The buckle 1023 can be a protrusion of any shape. In order to avoid jamming during the insertion of the Hall circuit board 2, this embodiment preferably makes the cross-section of the buckle 1023 along the lateral direction of the rear cover 1 triangular, and the slope surface 5 of the buckle 1023 faces the opening 6 of the mounting groove 1021. When the Hall circuit board 2 is inserted into the mounting groove 1021, the slope surface 5 at the front end of the buckle 1023 can provide guidance for the Hall circuit board 2, allowing the Hall circuit board 2 to slide naturally through the buckle 1023. Figure 7 In the schematic diagram of a half-section of the housing 101 shown, the buckle 1023 is located in front of the disassembly port 1022, and the ramp surface 5 of the buckle 1023 is directly opposite the opening 6 of the mounting groove 1021.

[0052] Example 4

[0053] Based on the above embodiments, this embodiment improves the shape of the disassembly port 1022. The disassembly port 1022 can be an arbitrary shape hole, as long as it can press the Hall circuit board 2. In order to observe the length of the Hall circuit board 2 extending into the mounting groove 1021 and to observe the removal of the Hall circuit board 2, this embodiment preferably designs the disassembly port 1022 as a T-shaped structure, such as... Figure 6 As shown, the disassembly port 1022 includes a vertical section 7 and a horizontal section 8. The horizontal section 8 is parallel to the insertion direction of the Hall circuit board 2, and the vertical section 7 is located at the end of the horizontal section 8 near the latch 1023. The horizontal section 8 extends approximately to the inner bottom surface of the mounting groove 1021. The Hall circuit board 2 can be observed to be installed in place through the horizontal section 8, and the Hall circuit board 2 can be pressed through the vertical section 7.

[0054] Example 5

[0055] Based on the above embodiments, this embodiment provides a notch 1011 on the surface of the housing 101 where the Hall mounting portion 102 connects, communicating with the mounting groove 1021. From Figure 7 and Figure 8 As can be seen, the mounting groove 1021 is connected to the interior of the housing 101. The notch 1011 is designed to eliminate the obstruction between the magnetic ring 3 and the Hall element 201, so as to improve the magnetic induction effect. At the same time, the notch 1011 can also make way for the Hall element 201, so that the vertical distance between the Hall element 201 and the magnetic ring 3 is closer.

[0056] Example 6

[0057] Based on the above embodiments, such as Figure 6As shown, the rear cover 1 also includes connecting lugs 103 located on the outer surface of the housing 101, and the connecting lugs 103 are provided with mounting holes 1031. The connecting lugs 103 are used to fix the rear bracket 13, and preferably two are arranged symmetrically. The mounting holes 1031 are used to install screws 11. When installing the rear cover 1, it is only necessary to align the mounting holes 1031 with the screws 11 extending from the screw holes of the rear bracket 13 and install them downwards. Finally, the cover is locked onto the screws 11 by nuts 12 to achieve fixation. The structure is simple and the installation is convenient.

[0058] In a further design, the connecting lug 103 is also provided with a weight reduction hole 9, which is located inside the mounting hole 1031. The housing 101, the Hall mounting part 102, and the connecting lug 103 are integrally molded using an injection molding process. The weight reduction hole 9 can reduce the weight of the motor and also save injection molding material.

[0059] To facilitate the installation of the rear cover 1 and the rear bracket 13 and to make it easier to position the mounting hole 1031, it is preferable that the end of the connecting lug 103 protrudes from the end face of the housing 101, so that a stepped limiting surface 10 is formed between the connecting lug 103 and the housing 101 to mate with the rear bracket 13 of the shaded-pole motor. When the stepped limiting surfaces 10 at the two connecting lugs 103 are engaged with the rear bracket 13, the mounting hole 1031 is aligned with the screw hole 11 of the rear bracket 13.

[0060] Example 7

[0061] A shaded-pole motor, such as Figure 1 and Figure 2 As shown, it includes a rotor, a stator 15, a front bracket 14, a rear bracket 13, and the speed detection module mentioned above. The rotor is located inside the stator 15, and the stator 15 is located between the front bracket 14 and the rear bracket 13. The screw 11 passes through the front bracket 14, the stator 15, the rear bracket 13, and the rear cover 1, and is finally fixed by the nut 12.

[0062] In this specification, the illustrative expressions of the terms do not necessarily refer to the same embodiments. Moreover, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments.

[0063] Based on the above-described preferred embodiments of this utility model, and through the foregoing description, those skilled in the art can make various changes and modifications without departing from the technical concept of this utility model. The technical scope of this utility model is not limited to the contents of the specification, but must be determined according to the scope of the claims.

Claims

1. A rotational speed detection module, characterized by: The device includes a rear cover (1), a Hall circuit board (2), and a magnetic ring (3) mounted on the end of a rotor shaft (4). The rear cover (1) includes a housing (101) and a Hall mounting part (102) protruding from the outer surface of the housing (101). The magnetic ring (3) is located inside the housing (101). The Hall mounting part (102) has a mounting groove (1021) for inserting the Hall circuit board (2) and a disassembly port (1022) arranged opposite to the outer surface of the housing (101) and communicating with the mounting groove (1021). The Hall circuit board (2) is provided with a slot (202), and the Hall mounting part (102) located in the mounting groove (1021) and on the side of the disassembly port (1022) has a buckle (1023) that engages with the slot (202).

2. The rotational speed detection module according to claim 1, characterized in that: When the Hall circuit board (2) is located in the mounting groove (1021), the surface of the Hall circuit board (2) where the Hall element (201) is located is tangent to the circumferential surface of the concentric circle of the magnetic ring (3).

3. The rotational speed detection module according to claim 2, characterized in that: The perpendicular distance d between the Hall element (201) and the magnetic ring (3) satisfies the following relationship: wherein r is the radius of the magnetic ring (3); B0is the surface magnetic of the magnetic ring (3); B min is the minimum triggering threshold of the Hall element (201).

4. The rotational speed detection module according to claim 3, characterized in that: The vertical distance d between the Hall element (201) and the magnetic ring (3) is 1.2 mm to 1.8 mm.

5. The rotational speed detection module according to claim 1, characterized in that: The buckle (1023) is positioned close to the opening (6) of the mounting groove (1021), and the distance between the buckle (1023) and the opening (6) of the mounting groove (1021) is less than the distance between the disassembly port (1022) and the opening (6) of the mounting groove (1021).

6. The rotational speed detection module according to claim 1, characterized in that: The buckle (1023) has a triangular cross section along the rear cover (1) and the slope surface (5) of the buckle (1023) faces the opening (6) of the mounting groove (1021).

7. The rotational speed detection module according to claim 1, characterized in that: The surface of the housing (101) connected to the Hall mounting part (102) has a notch (1011) that communicates with the mounting groove (1021).

8. The rotational speed detection module according to claim 1, characterized in that: When the Hall circuit board (2) is located in the mounting groove (1021), the distance between the Hall circuit board (2) and the surface of the rear cover (1) is greater than the distance between the Hall circuit board (2) and the surface where the disassembly port (1022) is located.

9. The rotational speed detection module according to claim 1, characterized in that: The disassembly port (1022) is a T-shaped structure. The disassembly port (1022) includes a vertical section (7) and a horizontal section (8). The horizontal section (8) is parallel to the insertion direction of the Hall circuit board (2), and the vertical section (7) is located at the end of the horizontal section (8) near the buckle (1023).

10. The rotational speed detection module according to claim 1, characterized in that: The rear cover (1) also includes a connecting lug (103) located on the outer surface of the housing (101), and the connecting lug (103) is provided with a mounting hole (1031).

11. The rotational speed detection module according to claim 10, characterized in that: The connecting lug (103) is also provided with a weight reduction hole (9), which is located inside the mounting hole (1031).

12. The rotational speed detection module according to claim 10, characterized in that: The end of the connecting lug (103) protrudes from the end face of the housing (101) so that a stepped limiting surface (10) is formed between the connecting lug (103) and the housing (101) to cooperate with the rear bracket (13) of the shaded pole motor.

13. The rotational speed detection module according to claim 1, characterized in that: The inner bottom surface of the housing (101) is provided with a recessed portion (1012).

14. A cage rotor machine characterized by: Includes the speed detection module as described in any one of claims 1-12.

Images