Motor assembly and reciprocating rotary motor having the same

Abstract

This invention relates to a motor assembly and a reciprocating rotary motor having the motor assembly. The motor assembly includes a first stator core, a second stator core, and a magnet located between the first and second stator cores. Both the first and second stator cores are non-circular stator cores, and the number of stator teeth on the stator cores is equal to the number of motor phases * 2n + 2, where n = 1, 2, 3... Compared with the prior art, this invention has advantages such as reducing motor inertia, further reducing the torque requirement for reciprocating operation, and improving response time.

Description

Technical Field

[0001] This invention relates to an electric motor, and more particularly to an electric motor assembly and a reciprocating rotary electric motor having the electric motor assembly. Background Technology

[0002] In some reciprocating rotational motions, the motion process is achieved by a reciprocating rotary motor. A reciprocating rotary motor is a type of motor that can drive a load to swing (oscillate) back and forth within a limited angular range (usually less than 360 degrees, commonly a few degrees to more than 100 degrees). It is significantly different from common continuous rotary motors (such as ordinary DC motors, AC induction motors, and servo motors).

[0003] Reciprocating rotary motors are widely used in applications requiring limited angles, rapid and precise oscillation, such as laser scanning: laser printers, barcode scanners, and galvanometers in laser projectors.

[0004] Therefore, the core of a reciprocating rotary motor lies in its ability to directly and efficiently realize the rapid and precise oscillation of the load within a limited angle. Its requirements for acceleration and deceleration are extremely strict. If a traditional continuous rotary motor is used, the rotor inertia of this type of motor is large, which makes it impossible for the motor to obtain extremely high acceleration and deceleration speeds, and thus cannot meet the application requirements of rapid reciprocating scanning of the system.

[0005] A search revealed that Chinese Patent Publication No. CN117318381A discloses a lidar motor. This existing patent allows the rotor assembly and the rotating mirror assembly to be connected as one unit, which not only improves assembly efficiency but also reduces the connection gap between the rotor housing and the rotating mirror mounting bracket, making it less prone to axial and radial movement and improving the accuracy of the lidar motor. However, this existing patent still uses a traditional motor structure, which has a large load and motor inertia, limiting the control accuracy of the motor and making it difficult to achieve extremely high acceleration and deceleration speeds, thus preventing the lidar from achieving rapid reciprocating scanning. Summary of the Invention

[0006] The purpose of this invention is to overcome the defects of the prior art by providing a motor assembly and a reciprocating rotary motor having the motor assembly, thereby reducing the motor inertia, further reducing the torque requirement for reciprocating operation of the motor, and improving the response time.

[0007] The objective of this invention can be achieved through the following technical solutions:

[0008] According to one aspect of the present invention, a motor assembly is provided, including a first stator core, a second stator core, and a magnet located between the first stator core and the second stator core, wherein both the first stator core and the second stator core are non-circular stator cores, and the number of stator teeth on the stator core is equal to the number of motor phases * 2n + 2, where n = 1, 2, 3...

[0009] As a preferred technical solution, the first stator core has at least three stator teeth, and stator windings are provided on the non-end stator teeth. The second stator core has the same stator teeth and corresponding windings as the first stator core.

[0010] As a preferred technical solution, the stator teeth of the first stator core and the stator teeth of the second stator core are aligned one-to-one.

[0011] As a preferred technical solution, the stator teeth of the first stator core and the stator teeth of the second stator core are misaligned by a tooth angle θ1 in the circumferential direction.

[0012] As a preferred technical solution, the specific range of the tooth misalignment angle θ1 is as follows: 0≤θ1≤(360° / P), where P is the rotor pole number of the corresponding circular motor.

[0013] As a preferred technical solution, the stator teeth of the first stator core and the stator teeth of the second stator core both have a helical tooth angle θ2.

[0014] As a preferred technical solution, the specific range of the helical tooth angle θ2 is as follows: 0<θ2≤(360° / S), where S is the number of stator slots of the corresponding circular motor.

[0015] As a preferred technical solution, the stator teeth of the first stator core and the stator teeth of the second stator core are arranged in opposite directions.

[0016] As a preferred technical solution, the magnet has a non-circular structure.

[0017] According to another aspect of the invention, a reciprocating rotary motor having a motor assembly is provided, the motor including any of the motor assemblies described above.

[0018] Compared with the prior art, the present invention has the following advantages:

[0019] 1) This invention uses a non-circular stator, which facilitates the subsequent installation of the load closer to the shaft, thereby reducing the motor inertia, further reducing the torque requirement for reciprocating operation, and improving the response time. This enables the motor to oscillate back and forth, meeting the application requirements of rapid reciprocating scanning for lidar.

[0020] 2) The present invention adopts a split stator, which makes it easier to design and manufacture non-circular stators to adapt to application scenarios with special space constraints, thereby greatly simplifying the winding process and realizing highly automated manufacturing.

[0021] 3) The stator teeth of the stator core of this invention adopt a staggered tooth design. This staggered tooth design introduces a phase difference to the cogging torque components generated by different areas of the cogging by physically staggering the arrangement of the stator tooth slots. When these torque pulsations of different phases are superimposed, they cancel each other out, thereby significantly reducing the peak value of the total cogging torque, thereby reducing the cogging torque of the motor, reducing the torque pulsation of the motor, making the motor run more smoothly, and improving the running accuracy of the motor.

[0022] 4) The stator teeth of the stator core of this invention adopt a staggered tooth + helical tooth design. This design not only disrupts the synchronicity of circumferential magnetic permeability changes, causing a circumferential phase difference in the cogging torque components generated in each segment, but also disrupts the synchronicity of axial magnetic permeability changes, causing an axial phase difference in the torque components generated at the same circumferential position in different axial sections. The combination of the two disrupts the synchronicity of magnetic permeability changes in both circumferential and axial dimensions, achieving torque pulsation cancellation in three-dimensional space, thereby further reducing the cogging torque of the motor and further reducing the torque pulsation of the motor.

[0023] 5) The stator teeth of the stator core of the present invention are arranged with staggered teeth + helical teeth + helical teeth in opposite directions. That is, on the basis of the previous one, the helical teeth are arranged in opposite directions. The reverse helical teeth can specifically eliminate the difficult-to-suppress high-order cogging harmonics, further greatly reducing the cogging torque of the motor and further greatly reducing the torque pulsation of the motor, thereby making the motor run more smoothly and improving the running accuracy of the motor. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the main structure of Embodiment 1 of the present invention;

[0025] Figure 2 This is a three-dimensional structural diagram of Embodiment 1 of the present invention;

[0026] Figure 3(a) is a schematic diagram of the front view structure of Embodiment 2 of the present invention;

[0027] Figure 3(b) is a three-dimensional structural schematic diagram of Embodiment 2 of the present invention;

[0028] Figure 3(c) is a schematic diagram of the stator tooth projection structure of Embodiment 2 of the present invention;

[0029] Figure 4(a) is a schematic diagram of the front view structure of Embodiment 3 of the present invention;

[0030] Figure 4(b) is a three-dimensional structural schematic diagram of Embodiment 3 of the present invention;

[0031] Figure 4(c) is a schematic diagram of the stator tooth projection structure of Embodiment 3 of the present invention;

[0032] Figure 5(a) is a schematic diagram of the front view structure of Embodiment 4 of the present invention;

[0033] Figure 5(b) is a three-dimensional structural schematic diagram of Embodiment 4 of the present invention;

[0034] Figure 5(c) is a schematic diagram of the stator tooth projection structure of Embodiment 4 of the present invention;

[0035] Where 1 is the first stator core, 2 is the magnet, and 3 is the second stator core.

[0036] 1-1, 1-2, 1-3, 1-4, 1-5, 1-6, 1-7, and 1-8 are the first to eighth stator teeth, 1-A is the stator tooth of the first stator core, 3-A is the stator tooth of the second stator core, θ1 is the misalignment angle between the upper and lower stator teeth, and θ2 is the helical angle between the upper and lower stator teeth themselves. Detailed Implementation

[0037] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0038] Example 1

[0039] like Figure 1 As shown, the motor assembly of the present invention includes a first stator core 1, a second stator core 3, and a magnet 2 located between the first stator core 1 and the second stator core 3. Both the first stator core 1 and the second stator core 3 are non-circular stator cores, and the number of stator teeth on their stator cores is greater than the number of motor phases. The present invention uses a non-circular split stator, which facilitates the subsequent installation of the load in a position close to the shaft, reduces the motor inertia, lowers the torque requirement for reciprocating operation, and improves the response time, meeting the application requirements of rapid reciprocating scanning of lidar.

[0040] like Figure 2As shown, the first stator core 1 has at least three stator teeth, and more preferably, it has eight stator teeth. The first stator tooth 1-1, the second stator tooth 1-2, the third stator tooth 1-3, the fourth stator tooth 1-4, the fifth stator tooth 1-5, and the sixth stator tooth 1-6 are provided with annular windings (not shown in the figure). The seventh stator tooth 1-7 and the eighth stator tooth 1-8 are auxiliary stator teeth, which are not provided with windings. That is, these two stator teeth are only for balancing the magnetic circuit and the cogging torque, and no windings are provided. The second stator core 3 is provided with the same stator teeth and corresponding windings. The first stator core 1 and the second stator core 3 are aligned one-to-one.

[0041] Reciprocating rotary motors with this design offer a range of unique advantages in specific applications (such as rapid reciprocating scanning with LiDAR), making them an irreplaceable alternative to continuous rotary motors.

[0042] This invention employs a split stator assembly design, which facilitates the design and manufacture of non-circular stators to adapt to applications with special space constraints. Furthermore, the split stator allows for individual winding before assembly into a complete stator, eliminating the challenges of complex wire threading and winding within narrow stator slots inherent in traditional integral stators. The more open winding space also facilitates achieving higher slot fill factor (the proportion of copper wire area within the slot), thereby improving motor efficiency and power density. Therefore, the split stator assembly of this invention significantly simplifies the winding process and enables highly automated manufacturing, making it highly competitive in applications requiring high efficiency, low cost, mass production (especially for applications like LiDAR), and those demanding special shapes, efficient heat dissipation, or ease of maintenance.

[0043] Example 2

[0044] like Figures 3(a) to 3(c) As shown, the present invention includes a first stator core 1, a second stator core 3, and a magnet 2 located between the first stator core 1 and the second stator core 3. The first stator core 1 and the second stator core 3 are both non-circular stator cores, and the number of stator teeth on their stator cores is greater than the number of phases of the motor.

[0045] Figure 3(c) shows a projected view of the teeth of the upper and lower stators of the motor, including stator teeth 1-A of the first stator core and stator teeth 3-A of the second stator core. The center lines connecting the corresponding positions of the stator teeth of the first and second stator cores are shown. The included angle θ1 of the center lines represents the misalignment angle between the stator teeth 1-A of the first stator core 1 and the stator teeth 3-A of the second stator core 3 in the circumferential direction. The specific range of the misalignment angle θ1 is as follows: 0 ≤ θ1 ≤ (360° / P), where P is the rotor pole number of the corresponding circular motor, i.e., the rotor pole number of the non-circular motor converted into the corresponding circular motor.

[0046] In this embodiment, the stator teeth of the stator core adopt a staggered tooth design. The core principle is to disrupt the synchronicity of magnetic permeability changes, thereby weakening the superposition effect of periodic torque pulsations generated at each slot position. In the traditional non-staggered tooth design, all stator teeth and slots are strictly aligned in the circumferential direction. When the rotor rotates, the air gap magnetic permeability changes at all slot positions are synchronous. That is to say, when the relative position of a tooth with the permanent magnet causes the cogging torque it generates to reach a positive peak value, all other teeth also reach their respective peak values ​​(or valley values, depending on the pole-slot fit) almost simultaneously. This synchronicity causes the individual cogging torque pulsations generated by all teeth to be directly superimposed, forming a total cogging torque pulsation with a large amplitude.

[0047] The staggered tooth design in this embodiment introduces a phase difference to the cogging torque components generated by different areas of the cogging by physically offsetting the arrangement of the stator tooth slots. These torque pulsations of different phases cancel each other out when superimposed, thereby significantly reducing the total peak value of the cogging torque, reducing the cogging torque of the motor, reducing the torque pulsation of the motor, making the motor run more smoothly, and improving the operating accuracy of the motor.

[0048] Example 3

[0049] like Figures 4(a) to 4(c) As shown, the present invention includes a first stator core 1, a second stator core 3, and a magnet 2 located between the first stator core 1 and the second stator core 3. The first stator core 1 and the second stator core 3 are both non-circular stator cores, and the number of stator teeth on their stator cores is greater than the number of phases of the motor.

[0050] Figure 4(c) shows a projected view of the teeth of the upper and lower stators of the motor, including stator teeth 1-A of the first stator core and stator teeth 3-A of the second stator core. The center lines connecting the corresponding positions of the stator teeth in the first and second stator cores are defined. The included angle θ1 of these center lines represents the misalignment angle between the stator teeth 1-A of the first stator core 1 and the stator teeth 3-A of the second stator core 3 in the circumferential direction. The specific range of the misalignment angle θ1 is: 0 ≤ θ1 ≤ (360° / P), where P is the number of rotor poles of the motor.

[0051] As shown in Figure 4(c), both the stator teeth of the first stator core 1 and the stator teeth of the second stator core 3 have a helical tooth angle θ2, where the helical tooth angle θ2 is the angle between the center points of the upper and lower edges connecting the same stator tooth and the center of the circle. Preferably, the specific range of the helical tooth angle θ2 is as follows: 0 < θ2 ≤ (360° / S), where S is the number of stator slots of the corresponding circular motor, that is, the number of stator slots of the non-circular motor converted into the corresponding circular motor.

[0052] In this embodiment, the stator teeth of the stator core adopt a staggered tooth + helical tooth design. This design not only disrupts the synchronicity of circumferential magnetic permeability changes, causing a circumferential phase difference in the cogging torque components generated in each segment, but also disrupts the synchronicity of axial magnetic permeability changes, causing an axial phase difference in the torque components generated at the same circumferential position in different axial sections. The combination of these two approaches disrupts the synchronicity of magnetic permeability changes in both circumferential and axial dimensions, thereby achieving torque pulsation cancellation in three-dimensional space. This further reduces the cogging torque of the motor and further reduces the torque pulsation of the motor.

[0053] Example 4

[0054] like Figures 5(a) to 5(c) As shown, the present invention includes a first stator core 1, a second stator core 3, and a magnet 2 located between the first stator core 1 and the second stator core 3. The first stator core 1 and the second stator core 3 are both non-circular stator cores, and the number of stator teeth on their stator cores is greater than the number of phases of the motor.

[0055] Figure 5(c) shows a projected view of the teeth of the upper and lower stators of the motor, including stator teeth 1-A of the first stator core and stator teeth 3-A of the second stator core. The center lines connecting the corresponding positions of the stator teeth of the first and second stator cores are shown. The included angle θ1 of the center lines represents the misalignment angle between stator teeth 1-A of the first stator core 1 and stator teeth 3-A of the second stator core 3 in the circumferential direction. The specific range of the misalignment angle θ1 is as follows: 0 ≤ θ1 ≤ (360° / P), where P is the number of rotor poles of the motor.

[0056] As shown in Figure 5(c), both the stator teeth of the first stator core 1 and the stator teeth of the second stator core 3 have a helical tooth angle θ2, where the helical tooth angle θ2 is the angle between the two lines from the center points of the upper and lower edges connecting the same stator tooth to the center of the circle. Preferably, the specific range of the helical tooth angle θ2 is as follows: 0 < θ2 ≤ (360° / S), where S is the number of slots in the stator assembly.

[0057] As shown in Figure 5(c), the stator teeth of the first stator core 1 and the stator teeth of the second stator core 3 are arranged in opposite directions, one clockwise and the other counterclockwise.

[0058] In this embodiment, the stator teeth of the stator core are arranged with staggered teeth, helical teeth, and helical teeth in opposite directions. That is, based on embodiment 3, the helical teeth are arranged in opposite directions. This reverse design can specifically eliminate the difficult-to-suppress high-order cogging harmonics, further greatly reducing the cogging torque of the motor and further greatly reducing the torque pulsation of the motor, thereby making the motor run more smoothly and improving the running accuracy of the motor.

[0059] Example 5

[0060] The present invention provides a reciprocating rotary motor having a motor assembly, including the motor assembly described in any of embodiments 1-4.

[0061] The reciprocating rotary motor with this design offers a series of unique advantages in specific applications (such as rapid reciprocating scanning with LiDAR), making it an irreplaceable choice over continuous rotary motors. Furthermore, due to the limited angle of motion, the power and signal lines of this reciprocating rotary motor can be directly connected to the motor body, eliminating the need for complex rotating conductive slip rings or hydraulic rotary joints to transmit power and signals. This significantly simplifies system design, reduces size and cost, and improves reliability (avoiding issues such as slip ring wear and poor contact). Simultaneously, the limited angular motion completely avoids the cable tangling problems that can occur with continuous rotary motors, simplifying wiring design.

[0062] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in the present invention, and these modifications or substitutions should all be covered within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. An electric machine assembly comprising a first stator core (1), a second stator core (3) and a magnetic steel (2) located between the first stator core (1) and the second stator core (3), characterized in that, The first stator core (1) and the second stator core (3) are both non-circular stator cores, and the number of stator teeth on their stator cores is equal to the number of motor phases * 2n + 2, where n = 1, 2, 3...

2. An electric machine assembly as in claim 1, wherein, The first stator core (1) has at least three stator teeth, and stator windings are provided on the non-end stator teeth. The second stator core (3) has the same stator teeth and corresponding windings as the first stator core (1).

3. An electric machine assembly as in claim 2, wherein, The stator teeth of the first stator core (1) and the stator teeth of the second stator core (3) are aligned one-to-one.

4. An electric machine assembly as recited in claim 2 wherein, The stator teeth of the first stator core (1) and the stator teeth of the second stator core (3) are misaligned by a tooth angle θ1 in the circumferential direction.

5. An electric machine assembly as recited in claim 4 wherein, The specific range of the tooth misalignment angle θ1 is as follows: 0≤θ1≤(360° / P), where P is the rotor pole number of the corresponding circular motor.

6. An electric machine assembly as recited in claim 2 wherein, The stator teeth of the first stator core (1) and the stator teeth of the second stator core (3) both have a helical tooth angle θ2.

7. An electric machine assembly as in claim 6, wherein, The specific range of the helical tooth angle θ2 is as follows: 0<θ2≤(360° / S), where S is the number of stator slots of the corresponding circular motor.

8. An electric machine assembly as recited in claim 2 wherein, The stator teeth of the first stator core (1) and the stator teeth of the second stator core (3) are arranged in opposite directions.

9. An electric machine assembly as recited in claim 1, wherein, The magnet (2) has a non-circular structure.

10. A reciprocating rotary electric machine having an electric machine assembly, characterized by, The motor includes the motor assembly described in any one of claims 1-9.

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