Motor

Abstract

The utility model discloses a motor. The motor includes: a pole housing accommodating a stator and a rotor; the annular magnet is fixed to a rotor shaft, and the rotor shaft extends out of the magnetic pole shell; a brush holder, the brush holder adjoining the pole housing, the brush holder comprising a base plate to close the pole housing, the rotor shaft passing through the base plate, the base plate having a housing for the annular magnet; the circuit board is located on the side, opposite to the magnetic pole shell, of the base plate, a magnetic induction sensor is installed on the circuit board, the installed magnetic induction sensor is provided with a magnetic induction face parallel to the circuit board, the annular magnet has a first magnetic field component, and the first magnetic field component is located on the side, opposite to the magnetic pole shell, of the base plate. The magnetic induction sensor is arranged radially outside the annular magnet and can be activated by the first magnetic field component, wherein the first magnetic field component is parallel to the rotor shaft. The utility model provides a cost-effective motor scheme.

Description

Technical Field

[0001] The present application relates to a small motor, and more particularly to a motor for driving vehicle components. Background Art

[0002] Vehicles include many movable components such as seats, sunroofs, window glasses, steering columns, etc. These components are driven by motors. The motor includes a stator-rotor assembly part as a driving source and a transmission part as an output. The motor can be a brushed motor. The brushed motor includes a brush holder for the brushes. In addition to arranging the brushes, the brush holder also has other functions, such as covering the pole housing, carrying electronic components, forming a wiring part, and mounting the pole housing to the transmission housing, etc. The number of rotations of the inner rotor of the motor determines the movement stroke of the movable components of the vehicle. A sensor for recording the number of rotations of the rotor is arranged on the brush holder. The sensor includes multiple types according to the installation method and the induction direction. A brush holder arrangement scheme with reduced cost and effective acquisition of the number of rotations of the rotor by the sensor is desired. Summary of the Utility Model

[0003] One aspect of the present application is to provide a motor with a sensor arranged on a brush holder.

[0004] The motor includes a pole housing that houses a stator and a rotor; an annular magnet fixed to a rotor shaft that extends out of the pole housing; a brush holder adjacent to the pole housing, the brush holder including a substrate to enclose the pole housing, the rotor shaft passing through the substrate, the substrate having a receiving portion for the annular magnet; a circuit board located on a side of the substrate opposite to the pole housing, a magnetic induction sensor being mounted on the circuit board, the mounted magnetic induction sensor having a magnetic induction surface parallel to the circuit board, the annular magnet having a first magnetic field component, the magnetic induction sensor being arranged radially outside the annular magnet and being activatable by the first magnetic field component, wherein the first magnetic field component is parallel to the rotor shaft.

[0005] In an embodiment of the motor, the magnetic induction sensor is mounted on a side of the circuit board facing the substrate.

[0006] In an embodiment of the motor, the magnetic induction sensor is located at a position offset from the axial center of the annular magnet.

[0007] In an embodiment of the motor, the magnetic induction sensor is a Hall sensor, and the Hall sensor is surface-mounted and soldered to the circuit board.

[0008] In one embodiment of the motor, the annular magnet has a cylindrical section and a conical section, and the axial position of the magnetic induction sensor relative to the annular magnet corresponds to the conical section.

[0009] In one embodiment of the motor, the magnetic trigger value of the Hall sensor < 10 mT.

[0010] In one embodiment of the motor, a plurality of positioning members are provided on the brush holder, and the circuit board is supported on the plurality of positioning members, and the interval between the circuit board and the brush holder is adjusted by modifying the axial dimension of the positioning members.

[0011] In one embodiment of the motor, the accommodating portion is configured as a cylinder, the accommodating portion protrudes from the substrate, the accommodating portion has a notch, the circuit board is provided with a protruding portion that cooperates with the notch, and the magnetic induction sensor is disposed on the protruding portion.

[0012] In one embodiment of the motor, the brush holder is integrated with a terminal for fixing a part of components and serving as a signal interface on its radial outer edge.

[0013] In one embodiment of the motor, the motor includes a transmission device, and the magnetic pole housing is mounted together with the transmission device housing of the transmission device via the accommodating portion, and the motor is used to adjust a movable component in a vehicle.

[0014] The magnetic induction sensor is mounted on the circuit board, and its magnetic induction surface is parallel to the circuit board, saving installation space. The present application uses the magnetic field component of the annular magnet as the target magnetic field, and positions the magnetic induction sensor relative to the annular magnet to a position where the magnetic induction sensor can sense the specified magnetic field component of the annular magnet, thereby providing a solution for obtaining the number of rotations of the rotor shaft without modifying the component layout of the brush holder, wherein the direction of the specified magnetic field component is parallel to the rotor shaft, that is, perpendicular to the circuit board.

[0015] The present application positions the magnetic induction sensor by modifying the distance between the circuit board and the brush holder substrate. The present application utilizes the circuit board carrying a variety of electronic components and the support member supporting the circuit board, and modifies the distance between the circuit board and the brush holder substrate by changing the axial dimension of the support member.

[0016] The present application uses a surface-mounted Hall sensor as the magnetic induction sensor. Compared with the traditional motor solution using a pin-type Hall sensor, the surface-mounted Hall sensor can be conveniently mounted on the circuit board and is inexpensive. Therefore, the present application provides a cost-effective alternative solution, and the present application also eliminates the structural members for positioning the pin-type Hall sensor in the traditional brush holder.

[0017] By positioning the axial position of the magnetic induction sensor relative to the toroidal magnet within the range corresponding to the conical section of the toroidal magnet, the magnetic induction sensor can sense a sufficient magnetic field component of the toroidal magnet parallel to the rotor axis direction.

[0018] The radial installation of the circuit board is determined by providing a notch on the accommodating part and a protruding part on the circuit board that mates with the notch. The magnetic induction sensor is arranged on the protruding part, with a suitable radial distance from the toroidal magnet.

[0019] Through the following detailed description with reference to the accompanying drawings, other aspects and features of the present application become apparent. However, it should be understood that the drawings are designed only for the purpose of explanation and not as a limitation of the scope of the present application, as it should refer to the appended claims. It should also be understood that the drawings are only intended to conceptually illustrate the structures and processes described herein, and unless otherwise indicated, the drawings are not necessarily drawn to scale. Description of the Drawings

[0020] Referring to the following detailed description of the specific embodiments in conjunction with the accompanying drawings, the present application will be more fully understood. The same reference numerals in the drawings always refer to the same elements in the views. Among them:

[0021] Figure 1 is a schematic diagram of an embodiment of the motor related to the present application;

[0022] Figure 2 is a simplified view of an embodiment of the internal structure of the motor related to the present application;

[0023] Figure 3 is the magnetic field relationship between the magnetic induction sensor and the toroidal magnet in the motor related to the present application;

[0024] Figure 4 is a schematic diagram of an embodiment of the brush holder in the motor related to the present application as viewed from the perspective of the transmission housing; and

[0025] Figure 5 is a schematic diagram of an embodiment of the brush holder in the motor related to the present application as viewed from the perspective of the pole housing. Detailed Description of the Specific Embodiments

[0026] To help those skilled in the art to accurately understand the subject matter claimed in the present application, the following detailed description of the specific embodiments of the present application is provided in conjunction with the accompanying drawings.

[0027] Figure 1Schematic diagram of an embodiment of the motor related to this application. The motor includes a pole housing 12, a brush holder 14, and a transmission housing 16. The rotor and the stator are arranged within the pole housing 12. The brush holder 14 is adjacent to the pole housing 12 and is used to cover the pole housing 12. The transmission is arranged within the transmission housing 16. The pole housing 12 is mounted to the transmission housing 16 via the brush holder 14.

[0028] Figure 2 An embodiment showing the layout of the interior of the motor, especially the brush holder, in a simplified diagram. The brush holder includes a substrate 18, which represents the brush holder in the figure. The substrate 18 has a central opening 20. The rotor shaft 22 extends out of the pole housing 12 and passes through the substrate 18 via the central opening 20.

[0029] The motor includes an annular magnet 24. The annular magnet 24 is also referred to as a "magnetic ring". The annular magnet 24 is fixed to the rotor shaft 22 and rotates with the rotor shaft 22. A receiving portion 26 for the annular magnet 24 is provided on the substrate 18.

[0030] The motor includes a circuit board 28. The circuit board 28 is arranged on the side of the substrate 18 opposite to the pole housing 12. The circuit board 28 is positioned relative to the substrate 18. A magnetic induction sensor 30 is mounted on the circuit board 28. The magnetic induction sensor 30 is arranged radially outside the annular magnet 24.

[0031] The magnetic induction sensor 30 is a Hall sensor and is mounted to the circuit board 28 in the form of surface mount technology (SMT). By identifying the change in the magnetic field direction during the rotation of the annular magnet 24, the magnetic induction sensor 30 can record the number of rotations of the annular magnet 24, i.e., the rotor shaft 22. After being mounted to the circuit board 28, the magnetic induction sensor 30 has a magnetic induction plane parallel to the circuit board 28. The magnetic field direction perpendicular to the magnetic induction plane is shown in the figure in the z - direction. This z - direction is parallel to the rotor shaft 22.

[0032] Figure 3 Shows the magnetic field relationship between the magnetic induction sensor and the annular magnet. For the sake of clear illustration, only the magnetic induction sensor 30, the circuit board 28 to which it is mounted, and the annular magnet 24 are shown. The pole distribution of the annular magnet 24 is briefly shown in the figure, i.e., the N - pole and the S - pole are at two opposite ends along the radial direction, and the magnetic force lines are shown as dotted lines. Corresponding to the radially magnetized annular magnet shown in the figure, the magnetic force lines present an envelope in the form of a sphere. The magnetic induction sensor 30 is arranged radially outside the annular magnet 24 and is in a position where it interferes with the magnetic force line components in the magnetic field of the annular magnet 24. At this position, the first magnetic field component f1 that activates the magnetic induction sensor 30 is decomposed, which is parallel to the rotor shaft 22 and perpendicular to the magnetic induction plane.

[0033] Under normal circumstances, the magnetic induction sensor 30 is arranged at a position corresponding to the axial center of the annular magnet 24. The magnetic field intensity at this position is the largest. However, in this application, the magnetic induction sensor 30 is not arranged here because the magnetic field with a high magnetic field intensity here is not the target magnetic field that can activate the magnetic induction sensor 30. Instead, the magnetic induction sensor 30 is arranged at a position deviating from its axial center relative to the annular magnet 24.

[0034] To obtain a sufficient first magnetic field component f1, it is obtained by adjusting the axial position of the magnetic induction sensor 30 relative to the annular magnet 24. In one embodiment, the spacing distance between the circuit board 28 and the substrate is adjusted so that the magnetic induction sensor 30 mounted on the circuit board is in a better position. It is possible to move only the circuit board 28 without moving the substrate. In another embodiment, the magnetic induction sensor 30 is arranged on the back side of the circuit board 28, that is, the side 38 facing the substrate, so that the magnetic induction sensor 30 maintains a relatively close axial spacing from the annular magnet 24. In still another embodiment, the annular magnet 24 includes a cylindrical section 34 and a conical section 36 in the axial direction. In the conical section 36, the radius of the annular magnet 24 gradually decreases, so that its circumferential surface forms a cone. The axial position of the magnetic induction sensor 30 relative to the annular magnet 24 corresponds to the conical section 36. The relatively large magnetic field components generated by the annular magnet 24 in the cylindrical section 34 are distributed in the direction perpendicular to the rotor shaft 22, that is, the direction where the second magnetic field component f2 is located, while the inclined magnetic force lines in the magnetic field generated in the conical section 36 will distribute more magnetic field components to the direction where the first magnetic field component f1 is located. This application utilizes the characteristic that the magnet generates a magnetic field in multiple dimensions, and positions the magnetic induction sensor 30 at a position where there are more first magnetic field components f1 in the magnetic field.

[0035] Using a magnetic induction sensor 30 with a higher precision only requires a small amount of the first magnetic field component f1 to be activated. In one embodiment, the magnetic trigger value of the magnetic induction sensor 30

[0036] <10 mT (millitesla). In other embodiments, the magnetic trigger value of the magnetic induction sensor 30 < 4 mT. In still another embodiment, activating the magnetic induction sensor 30 is facilitated by increasing the magnetic field intensity of the annular magnet 24.

[0037] A plurality of positioning members are provided on the brush holder. Return to Figure 2The positioning member 32 is disposed between the substrate 18 and the circuit board 28. The circuit board 28 is supported on these positioning members 32 to be positioned relative to the substrate 18. The positioning member 32 can have various forms. For example, the positioning member 32 is provided as a boss or a pin. The distance between the circuit board 28 and the substrate 18 is adjusted by modifying the axial dimension of the positioning member 32, so as to find a suitable axial position of the magnetic induction sensor 30 relative to the annular magnet 24.

[0038] Figure 4 This is an embodiment of the brush holder 14 as seen from the perspective of the transmission housing in the motor related to this application. The magnetic induction sensor 30 is disposed on the back surface of the circuit board 28 and is thus blocked and not shown in the figure. The accommodating portion 26 is configured as a cylindrical column protruding from the substrate 18. The brush holder 14 is mounted to the transmission housing via the accommodating portion 26. The accommodating portion 26 has a notch 40. Correspondingly, the circuit board 28 is provided with a protruding portion 42 that cooperates with the notch 40. The protruding portion 42 is inserted into the notch 40, so that the circuit board 28 is mounted to the accommodating portion 26 in a predetermined orientation and is positioned radially relative to the accommodating portion 26 via the protruding portion 42. The magnetic induction sensor 30 is disposed on the protruding portion on the back surface of the circuit board 28, as Figure 3 shown. The number of magnetic induction sensors is not limited to one, for example, the protruding portion has two, and each protruding portion has one magnetic induction sensor. In the prior art, when the magnetic induction sensor is a pin type (THT, through hole technology), the magnetic induction sensor is disposed on the side of the substrate facing the pole housing, and the magnetic induction surface is parallel to the rotor axis. Therefore, a support member is required to accommodate the magnetic induction sensor. Compared with the prior art, this application can omit the support member and related wiring, simplifying the structure of the brush holder. Figure 5 This is a simplified embodiment of the brush holder 14 as seen from the perspective of the pole housing in the motor related to this application.

[0039] In addition, other components are also carried on the circuit board 28, such as inductors, Hall sensors for other functions, etc. The brush holder 14 is integrated with a terminal 44 at its radial outer edge, and the brush holder 14 and the terminal 44 are integral. Part of the component 46 is fixed in the terminal 44, and part of its pins are soldered to the circuit board 28. The terminal 44 also serves as a signal interface. This application can be obtained by modifying the existing brush holder structure, that is, by using the circuit board in the existing brush holder structure and adjusting the distance between the circuit board and the substrate to determine the axial position of the magnetic induction sensor.

[0040] In one embodiment, the motor involved in the present application is a DC permanent magnet brushed motor. This motor is a 12V motor and can be used for movable components in a vehicle as a driving component for these components. These components include, but are not limited to, seats, sunroofs, window glasses, steering columns, etc. The magnetic induction sensor involved in the present application senses the change in the magnetic field of the ring magnet during the rotation of the rotor, so as to obtain the number of rotations of the rotor to record the movement stroke of the above components.

[0041] Although specific embodiments of the present application have been shown and described in detail to illustrate the principles of the present application, it should be understood that the present application can be implemented in other ways without departing from such principles.

Claims

1. A motor characterized by include: A pole housing (12) accommodating a stator and a rotor; an annular magnet (24) fixed to a rotor shaft (22) extending out of the pole housing (12); a brush holder (14), the brush holder (14) being adjacent to the pole housing (12), the brush holder (14) comprising a base plate (18) for closing the pole housing (12), the rotor shaft (22) passing through the base plate (18), the base plate (18) having a receiving portion (26) for the annular magnet (24); A circuit board (28), the circuit board (28) being located on a side of the substrate (18) opposite to the pole housing (12), a magnetic induction sensor (30) being mounted on the circuit board (28), the mounted magnetic induction sensor (30) having a magnetic induction surface parallel to the circuit board (28), the annular magnet (24) having a first magnetic field component, the magnetic induction sensor (30) being arranged radially outward relative to the annular magnet (24) and being capable of being activated by the first magnetic field component, wherein the first magnetic field component is parallel to the rotor shaft (22).

2. The motor according to claim 1, characterized in that: The magnetic induction sensor (30) is mounted on a side of the circuit board (28) facing the substrate (18).

3. The motor according to claim 1, characterized in that: The magnetic induction sensor (30) is located relative to the annular magnet (24) at a position deviated from the axial center thereof.

4. The motor according to claim 1, characterized in that: The magnetic induction sensor (30) is a Hall sensor, and the Hall sensor is patch-welded to the circuit board (28).

5. The motor according to claim 1, characterized in that: The annular magnet (24) has a cylindrical section (34) and a conical section (36), and the axial position of the magnetic induction sensor (30) relative to the annular magnet (24) corresponds to the conical section (36).

6. The motor according to claim 4, characterized in that: The magnetic trigger value of the Hall sensor is <10mT.

7. The motor according to claim 1, characterized in that: The brush holder (14) is provided with a plurality of positioning members (32), the circuit board (28) is supported on the plurality of positioning members (32), and the interval between the circuit board (28) and the brush holder (14) is adjusted by modifying the axial dimensions of the positioning members (32).

8. The motor according to claim 1, characterized in that: The accommodating portion (26) is configured as a column, the accommodating portion (26) protrudes from the base plate (18), the accommodating portion (26) has a notch (40), the circuit board (28) is provided with a protruding portion (42) matching the notch (40), and the magnetic induction sensor (30) is arranged on the protruding portion (42).

9. The motor according to claim 1, characterized in that: The brush holder (14) is integrated with a connection terminal (44) on its radial outer edge for fixing a part of components (46) and serving as a signal interface.

10. The motor according to any one of claims 1 to 9, characterized in that: The electric motor comprises a transmission device, the pole housing (12) is mounted together with a transmission device housing (16) of the transmission device via the accommodation portion (26), and the electric motor is used to adjust a movable component in a vehicle.

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