Motor with self-locking function

Abstract

The invention belongs to the technical field of rotating motors, and discloses a motor with a self-locking function, and the motor comprises a housing which is internally provided with a polygonal cavity, and the polygonal cavity is provided with at least two groups of corner parts which are oppositely arranged; the stator magnets are arranged in the polygonal cavity in pairs, the stator magnets are installed at the corner parts in a one-to-one correspondence mode, the sides, facing the center, of the stator magnets are provided with arc-shaped faces, the arc-shaped faces are provided with grooves penetrating through the stator magnets in the height direction, and the stator magnets are divided into a plurality of stator magnetic poles through the grooves; the grooves in each stator magnet are formed in the same position; the plurality of arc-shaped surfaces are encircled to form a mounting area, the rotor is rotatably arranged in the mounting area, and the motor shaft is fixed in the center of the rotor and penetrates out of the shell. The motor with the self-locking function is high in self-locking stability, low in abrasion and adaptive to a compact structure.

Description

Technical Field

[0001] The present invention relates to the technical field of rotating electrical machines, and particularly to an electrical machine with a self-locking function. Background Art

[0002] Currently, as a core driving element, electrical machines have been widely used in precision equipment such as bionic manipulators and parking brakes. In scenarios such as parking braking and human-machine interaction, the electrical machine needs to have a reliable self-locking function to prevent reverse displacement. Existing technologies mostly adopt a screw-nut transmission structure to achieve mechanical self-locking. However, such a structure is prone to thread wear and clearance accumulation due to long-term axial load, which not only reduces the service life, but also its volume and weight are difficult to meet the requirements of miniaturized equipment.

[0003] To solve this problem, some solutions attempt to achieve non-contact locking through magnetic coupling between the stator and the rotor. However, limited by the uniformity of the magnetic field distribution and the rotor moment of inertia, the actual locking force fluctuates greatly, and it is prone to unlocking under high-frequency start-stop or impact loads, resulting in insufficient stability.

[0004] Therefore, there is an urgent need for an electrical machine with a self-locking function to solve the above technical problems. Summary of the Invention

[0005] The purpose of the present invention is to provide an electrical machine with a self-locking function, which has high self-locking stability, low wear, and is suitable for a compact structure.

[0006] To achieve this purpose, the present invention adopts the following technical solutions:

[0007] Provide an electrical machine with a self-locking function, including:

[0008] A housing, which is provided with a polygonal cavity inside, and the polygonal cavity is provided with at least two groups of oppositely arranged corner portions;

[0009] A plurality of stator magnets, which are arranged in pairs in the polygonal cavity, the stator magnets are respectively installed on the corner portions one by one, an arc surface is provided on the side of the stator magnet facing the center, and a groove is provided on the arc surface that penetrates the stator magnet in the height direction, the groove divides the stator magnet into several stator magnetic poles, and the opening positions of the grooves on each stator magnet are the same;

[0010] A rotor and a motor shaft, a plurality of the arc surfaces enclose an installation area, the rotor is rotatably arranged in the installation area, and the motor shaft is fixed to the center of the rotor and passes through the housing.

[0011] As a preferred solution, the housing includes a plurality of first side walls and a plurality of second side walls. The width of the first side wall is greater than the width of the second side wall. The plurality of first side walls and the plurality of second side walls are alternately arranged and enclose to form the polygonal cavity. The corner portion is an area surrounded by the second side wall and parts of the first side walls on both sides thereof.

[0012] As a preferred solution, the stator magnet further includes a first side surface, two second side surfaces, and two transition surfaces. The two second side surfaces are symmetrically arranged on both sides of the two first side surfaces. One side of each of the two transition surfaces is connected to one of the two second side surfaces, and the other side is connected to the arc surface respectively.

[0013] The first side surface abuts against the second side wall, and the two second side surfaces respectively abut against the two first side walls in a one-to-one correspondence.

[0014] As a preferred solution, adjacent stator magnets are arranged at intervals to form a gap portion, and the first side wall is exposed from the gap portion.

[0015] The housing is made of metal.

[0016] As a preferred solution, the cross-section of the housing is an octagonal structure. The housing includes four first side walls and four second side walls. The four first side walls are arranged in pairs opposite to each other, and the four second side walls are arranged in pairs opposite to each other.

[0017] The number of both the corner portions and the stator magnets is four.

[0018] As a preferred solution, each stator magnet is provided with a groove. The groove is located at the center of the arc surface, and the groove divides the stator magnet into two stator magnetic poles with the same width.

[0019] As a preferred solution, each stator magnet is provided with at least two grooves. The at least two grooves are spaced on the arc surface to divide the stator magnet into at least three stator magnetic poles with the same width.

[0020] As a preferred solution, the ratio of the width of the groove to the width of the arc surface ranges from 1:3 to 1:10.

[0021] As a preferred solution, the rotor includes a plurality of tooth portions arranged in pairs, and the number of the tooth portions is at least six.

[0022] As a preferred solution, a plurality of limiting protrusions are provided at the end of the polygonal cavity. The plurality of limiting protrusions are arranged in one-to-one correspondence with the plurality of stator magnets, and the stator magnets abut against the limiting protrusions in the height direction.

[0023] Advantages of the present invention:

[0024] The motor with a self-locking function provided by the present invention includes a housing, stator magnets, a rotor and a motor shaft. Multiple corner portions are provided in a polygonal cavity, and the corner portions are arranged in pairs opposite to each other. The stator magnets are respectively installed at the corner portions, and the arc surfaces of the stator magnets enclose an installation area for accommodating the rotor, optimizing the magnetic field distribution. Further, grooves are provided on the arc surfaces of the stator magnets, and the grooves divide the stator magnets into several stator magnetic poles, causing the magnetic reluctance of the air-gap magnetic field to be disconnected, forming a discontinuous magnetic field, increasing the logarithm of the magnetic reluctance, increasing the magnetic flux density of the rotor, and the positions of the grooves on each stator magnet are the same, so as to form a symmetrical layout of the stator magnetic poles, improving the symmetry of the air-gap magnetic field, making the cogging torque of the motor larger, enhancing the mechanical performance and self-locking performance of the motor. Compared with the motor structure provided with a lead screw-nut transmission structure, the wear is lower and the volume is also smaller, so that it can be adapted to a compact structure. Description of the drawings

[0025] Figure 1 is a schematic structural diagram of the motor with a self-locking function provided by the present invention;

[0026] Figure 2 is a top view of the motor with a self-locking function provided by the present invention;

[0027] Figure 3 is a schematic structural diagram of the housing provided by the present invention;

[0028] Figure 4 is a schematic structural diagram of the stator magnet provided by the present invention;

[0029] Figure 5 is a simulation diagram of the magnetic flux density of the stator magnet under different grooving conditions;

[0030] Figure 6 is a simulation diagram of the cogging torque of the motor when the stator magnet grooves are symmetrically arranged;

[0031] Figure 7 is a simulation diagram of the cogging torque of the motor when the stator magnet grooves are not provided;

[0032] Figure 8 is a simulation diagram of the cogging torque of the motor when the stator magnet grooves are asymmetrically arranged.

[0033] In the figure:

[0034] 1. Housing; 11. First side wall; 12. Second side wall; 13. Limit projection;

[0035] 2. Stator magnet; 21. Arc surface; 22. First side; 23. Second side; 24. Transition surface; 10. Groove;

[0036] 3. Rotor;

[0037] 4. Motor shaft;

[0038] 100. Polygonal cavity; 101. Corner part. Detailed implementation manner

[0039] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It can be understood that the specific embodiments described herein are only used to explain the present invention, rather than limiting the present invention. Additionally, it should be noted that for the convenience of description, only the parts related to the present invention rather than all the structures are shown in the drawings.

[0040] In the description of the present invention, unless otherwise clearly defined and limited, the terms "connected", "connected to", and "fixed" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection or an electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, and it can be the internal communication of two components or the interaction relationship between two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0041] In the present invention, unless otherwise clearly defined and limited, the first feature being "above" or "below" the second feature may include the direct contact between the first and second features, or may include the situation where the first and second features are not in direct contact but in contact through other features between them. Moreover, the first feature being "above", "above the top of", and "on the top of" the second feature includes the first feature being directly above and obliquely above the second feature, or merely indicating that the first feature has a higher horizontal height than the second feature. The first feature being "below", "below the bottom of", and "under the bottom of" the second feature includes the first feature being directly below and obliquely below the second feature, or merely indicating that the first feature has a lower horizontal height than the second feature.

[0042] In the description of this embodiment, the terms such as "above", "below", "right", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of description and simplifying the operation, 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, and thus cannot be understood as a limitation to the present invention. In addition, the terms "first" and "second" are only used for distinction in description and have no special meaning.

[0043] This embodiment provides a motor with a self-locking function, which can be applied to bionic mechanical fingers to lock and maintain the bending angle of the finger joints without continuous power output; it can also be applied to a parking brake to maintain the braking state during parking without continuous power output.

[0044] Exemplarily, as Figures 1-4 shown, the motor includes a housing 1, a stator magnet 2, a rotor 3, and a motor shaft 4. Among them, the housing 1 is a polygonal structure, and a polygonal cavity 100 is provided therein. The polygonal cavity 100 is provided with a plurality of corner portions 101. The number of corner portions 101 is an even number and they are arranged in pairs opposite to each other. A plurality of stator magnets 2 are provided. The plurality of stator magnets 2 are arranged in pairs in the polygonal cavity 100. The stator magnets 2 are respectively installed on the corner portions 101 one by one. An arc surface 21 is provided on the side of the stator magnet 2 facing the center. The plurality of arc surfaces 21 enclose an installation area. The rotor 3 is rotatably arranged in the installation area. The rotor 3 includes a plurality of tooth portions, and tooth grooves are formed between adjacent tooth portions. The motor shaft 4 is fixed to the center of the rotor 3 and passes through the housing 1.

[0045] Furthermore, as Figure 1 and Figure 2 shown, a groove 10 penetrating the stator magnet 2 in the height direction is provided on the arc surface 21. The groove 10 divides the stator magnet 2 into several stator magnetic poles, and the opening positions of the grooves 10 on each stator magnet 2 are the same.

[0046] Specifically, in the motor with a self-locking function provided in this embodiment, the stator part adopts a split structure and has a plurality of stator magnets 2 arranged in pairs. The stator magnets 2 are respectively installed on the corner portions 101 one by one. The arc surfaces 21 of the respective stator magnets 2 enclose an installation area for accommodating the rotor 3, optimizing the magnetic field distribution. In addition to being spaced apart from each other between the stator magnets 2, further, a groove 10 is provided on the arc surface 21 of the stator magnet 2. The groove 10 divides the stator magnet 2 into several stator magnetic poles, causing the magnetic reluctance of the air-gap magnetic field to be disconnected, forming a discontinuous magnetic field, increasing the logarithm of the magnetic reluctance, increasing the magnetic flux density of the rotor 3, and the opening positions of the grooves 10 on each stator magnet 2 are the same, so as to form a symmetric stator magnetic pole layout, improving the symmetry of the air-gap magnetic field, making the cogging torque of the motor larger, enhancing the mechanical performance and self-locking performance of the motor. Compared with the motor structure provided with a lead screw-nut transmission structure, the wear is lower and the volume is also smaller, so that it can be adapted to a compact structure.

[0047] Exemplarily, the housing 1 includes a plurality of first side walls 11 and a plurality of second side walls 12. The width of the first side walls 11 is greater than the width of the second side walls 12. The plurality of first side walls 11 and the plurality of second side walls 12 are alternately arranged and enclose to form a polygonal cavity 100. The corner portion 101 is an area surrounded by the second side wall 12 and parts of the first side walls 11 on both sides thereof. The outer side walls of the stator magnets 2 abut against the first side walls 11 and the second side walls 12, and the installation structure is compact.

[0048] Specifically, as Figures 1-4As shown, the stator magnet 2 further includes a first side surface 22, two second side surfaces 23, and two transition surfaces 24. The two second side surfaces 23 are symmetrically arranged on both sides of the two first side surfaces 22. One side of each of the two transition surfaces 24 is connected to one of the two second side surfaces 23 respectively, and the other side is connected to the arc surface 21 respectively. The first side surface 22 abuts against the second side wall 12, and the two second side surfaces 23 abut against the two first side walls 11 in a one-to-one correspondence.

[0049] In this embodiment, the cross-section of the housing 1 is an octagonal structure. The housing 1 includes four first side walls 11 and four second side walls 12. The four first side walls 11 are arranged in pairs opposite to each other, and the four second side walls 12 are arranged in pairs opposite to each other; the number of the corner portions 101 and the stator magnets 2 is four. The included angle between the first side wall 11 and the adjacent second side wall 12 is 135°, so as to form an octagonal structure with equal interior angles. In some embodiments, the cross-section of the housing 1 can also be set as a dodecagonal structure, a hexadecagonal structure, etc.

[0050] Exemplarily, the ratio of the width of the first side wall 11 to the width of the second side wall 12 ranges from 2:1 to 5:1, preferably 3:1.

[0051] Exemplarily, as Figure 1 and Figure 2 shown, the adjacent two stator magnets 2 are arranged at intervals to form a gap portion. The first side wall 11 is exposed from the gap portion. The material of the housing 1 is metal, and specifically, copper alloy or stainless steel can be used, etc. Figure 5 As shown by A in

[0052] Exemplarily, a plurality of limiting bumps 13 are provided at the end of the polygonal cavity 100. The plurality of limiting bumps 13 are arranged in one-to-one correspondence with the plurality of stator magnets 2. The stator magnet 2 abuts against the limiting bump 13 in the height direction, and the height position of the stator magnet 2 is defined by the limiting bump 13. Specifically, the limiting bump 13 is formed by the inward concavity of the housing 1.

[0053] In this embodiment, as Figure 1 、 Figure 2 and Figure 4As shown, each stator magnet 2 is provided with a groove 10, the groove 10 is located at the center of the arc surface 21, and the groove 10 divides the stator magnet 2 into two stator magnetic poles with the same width. The distribution of the stator magnetic poles is not only symmetrical left and right, front and back, but also a centrosymmetric structure, making the distribution of the air-gap magnetic field more symmetrical. In this embodiment, the magnetic resistance in the air gap is disconnected and discontinuous. At this time, one stator magnetic pole becomes two stator magnetic poles, and the number of magnetic resistance pairs in the air gap also doubles. The magnetic field density in the tooth part is larger, and the magnetic resistance between the stator magnetic pole and the tooth part air gap also becomes larger, and thus the cogging torque that can be generated also increases.

[0054] Figure 5 Fig. is the simulation of the magnetic flux density of the stator magnet 2 under different grooving conditions. Among them, A shows the magnetic flux density of the stator magnet 2 when a symmetrical groove 10 is set, B shows the magnetic flux density of the stator magnet 2 when no groove 10 is set, and C shows the magnetic flux density of the stator magnet 2 when an asymmetrical groove 10 is set. By observing the magnetic flux on the rotor 3, it can be found that the magnetic flux lines in A are more concentrated, significantly higher than the cases of no grooving and setting an asymmetrical groove 10. Please further refer to Figures 6-8 , when the motor is provided with four symmetrical grooves 10 (each stator magnet 2 is provided with a groove 10 at the same position), the cogging torque of the motor is 4 mNm, while the cogging torque of the motor without the groove 10 on the stator magnet 2 is 2 mNm. When the motor is provided with four asymmetrical grooves 10 (each stator magnet 2 is provided with a groove 10 at different positions), the cogging torque of the motor is less than 2 mNm; it can be seen that the cogging torque performance of the symmetrical grooving scheme in this embodiment is twice that of the non-grooved one, and the cogging torque performance of the asymmetrical grooving scheme is even worse than the non-grooved scheme.

[0055] In some embodiments, each stator magnet 2 is provided with at least two grooves 10, and the at least two grooves 10 are spaced on the arc surface 21 to divide the stator magnet 2 into at least three stator magnetic poles with the same width, which can also increase the magnetic resistance of the air-gap magnetic field and increase the cogging torque.

[0056] Exemplarily, the ratio of the width of the groove 10 to the width of the arc surface 21 ranges from 1:3 to 1:10. Preferably, the ratio of the width of the groove 10 to the width of the arc surface 21 is 1:6.

[0057] Exemplarily, as Figure 1 and Figure 2 shown, multiple tooth parts on the rotor 3 are arranged in pairs, and the number of tooth parts is at least six. In this embodiment, the rotor 3 is provided with six tooth parts.

[0058] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, rather than limitations on the implementation manners of the present invention. For those of ordinary skill in the art, various obvious changes, re-adjustments and substitutions can be made without departing from the protection scope of the present invention. It is not necessary and impossible to enumerate all the implementation manners here. Any modifications, equivalent substitutions and improvements made within the spirit and principle of the present invention shall be included within the protection scope of the claims of the present invention.

Claims

1. A motor with a self-locking function, characterized in that, Comprising: A housing (1) with a polygonal cavity (100) provided therein, and at least two sets of oppositely arranged corner portions (101) are provided in the polygonal cavity (100); A plurality of stator magnets (2), arranged in pairs in the polygonal cavity (100), the stator magnets (2) are respectively mounted on the corner portions (101) in a one-to-one correspondence, an arc surface (21) is provided on the side of the stator magnet (2) facing the center, and a groove (10) penetrating the stator magnet (2) in the height direction is provided in the arc surface (21), and the groove (10) divides the stator magnet (2) into several stator magnetic poles, and the opening positions of the grooves (10) on each stator magnet (2) are the same; A rotor (3) and a motor shaft (4), a plurality of the arc surfaces (21) enclose an installation area, the rotor (3) is rotatably arranged in the installation area, and the motor shaft (4) is fixed to the center of the rotor (3) and penetrates the housing (1).

2. The motor with a self-locking function according to claim 1, wherein, The housing (1) includes a plurality of first side walls (11) and a plurality of second side walls (12), the width of the first side walls (11) is greater than the width of the second side walls (12), the plurality of first side walls (11) and the plurality of second side walls (12) are alternately arranged and enclose to form the polygonal cavity (100), and the corner portion (101) is an area surrounded by the second side wall (12) and parts of the first side walls (11) on both sides thereof.

3. The motor with a self-locking function according to claim 2, wherein, The stator magnet (2) further includes a first side surface (22), two second side surfaces (23) and two transition surfaces (24), the two second side surfaces (23) are symmetrically arranged on both sides of the two first side surfaces (22), one side of each of the two transition surfaces (24) is respectively connected to the two second side surfaces (23), and the other side is respectively connected to the arc surface (21); The first side surface (22) abuts against the second side wall (12), and the two second side surfaces (23) respectively abut against the two first side walls (11) in a one-to-one correspondence.

4. The motor with a self-locking function according to claim 2, wherein, Adjacent two of the stator magnets (2) are arranged at intervals to form a gap portion, and the first side wall (11) is exposed from the gap portion; The housing (1) is made of metal.

5. The motor with a self-locking function according to claim 2, characterized in that, The cross section of the housing (1) is an octagonal structure, the housing (1) includes four of the first side walls (11) and four of the second side walls (12), the four first side walls (11) are arranged in pairs opposite to each other, and the four second side walls (12) are arranged in pairs opposite to each other; The number of both the corner portions (101) and the stator magnets (2) is four.

6. The motor with a self-locking function according to any one of claims 1-5, characterized in that, One groove (10) is provided on each stator magnet (2), the groove (10) is located at the center of the arc surface (21), and the groove (10) divides the stator magnet (2) into two stator magnetic poles with the same width.

7. The motor with a self-locking function according to any one of claims 1-5, characterized in that, At least two grooves (10) are provided on each stator magnet (2), and the at least two grooves (10) are spaced on the arc surface (21) to divide the stator magnet (2) into at least three stator magnetic poles with the same width.

8. The motor with a self-locking function according to any one of claims 1-5, characterized in that, The ratio of the width of the groove (10) to the width of the arc surface (21) ranges from 1:3 to 1:

10.

9. The motor with a self-locking function according to any one of claims 1-5, characterized in that, The rotor (3) includes a plurality of tooth portions arranged in pairs, and the number of the tooth portions is at least six.

10. The motor with a self-locking function according to any one of claims 1-5, characterized in that, A plurality of limiting bumps (13) are provided at the end of the polygonal cavity (100), and the plurality of limiting bumps (13) are arranged in one-to-one correspondence with the plurality of stator magnets (2), and the stator magnets (2) are abutted against the limiting bumps (13) in the height direction.

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