An external rotor motor with end winding magnetizing structure

Abstract

The application belongs to the technical field of electric machines, and particularly relates to an outer rotor motor with an end winding magnetic structure, which comprises an inner stator assembly and an outer rotor assembly; the inner stator assembly comprises an inner stator support and an inner stator core; the inner periphery of the inner stator core is fitted to the outer periphery of the inner stator support, and the winding is embedded in the slot of the inner stator core; the outer rotor assembly comprises an annular wall sleeved on the outer periphery of the inner stator core and end walls located on the axial two sides of the annular wall; the end walls on the left and right sides are both provided with concentric inner rings and outer rings, and the inner ring and the outer ring on the same side form a groove with the end wall; the outer periphery of the inner ring on the left and right sides is provided with a first magnetic steel, and the axial two ends of the winding are respectively located in the grooves on the left and right sides and surround the first magnetic steel. The outer rotor motor solves the actual problem that the end winding does not participate in generating motor power and only serves as loss, improves the utilization rate of the winding and reduces the end loss.

Description

Technical Field

[0001] This invention belongs to the field of motor technology, and specifically relates to an external rotor motor with an end winding magnetization structure. Background Technology

[0002] External rotor motors are mainly used in new energy vehicles, such as pure electric vehicles, hybrid vehicles, and range-extended vehicles, for electric drive, power generation, and wheel hub drive motors. Among these, range-extended vehicles and wheel hub drive motors use external rotor structures more frequently. In robots, such as humanoid robots, external rotor motors are mainly used for drive joints such as legs and upper arms to drive the walking and maneuvering movements of multi-degree-of-freedom humanoid robots.

[0003] In motors, because the windings need to form a loop outside the stator slots, the windings will extend a portion on both sides outside the stator slots, with shapes such as rhombuses or semicircles. Whether it is an internal rotor motor or an external rotor motor, this part of the end winding is often not regarded as the effective part for generating electrical power. Instead, it is converted into an LR circuit model composed of winding loss resistance and leakage inductance through electromagnetic calculations. Summary of the Invention

[0004] To address the issue that the end windings of existing external rotor motors do not contribute to motor power generation and only serve as losses, this invention provides an external rotor motor with an end winding magnetization structure. By setting grooves on the inner walls of the external rotor at both ends of the winding axial direction and installing magnets, a magnetic path is formed between the grooved magnets and the end winding loops. This allows the magnetic lines of force of the grooved magnets to link the end winding loops. As the external rotor rotates, an induced electromotive force is generated inside the end winding coils, thereby fully and effectively utilizing the end windings, reducing losses, and increasing electrical power.

[0005] Specifically, the present invention provides the following technical solution:

[0006] An external rotor motor with an end winding magnetizing structure includes an inner stator assembly and an external rotor assembly;

[0007] The inner stator assembly includes an inner stator support and an inner stator core; the inner circumferential surface of the inner stator core is fitted onto the outer circumferential surface of the inner stator support, and a winding is embedded in the slot of the inner stator core;

[0008] The outer rotor assembly includes an annular wall sleeved on the outer periphery of the inner stator core and end walls located on both axial sides of the annular wall; concentric inner and outer rings are provided on the end walls on both the left and right sides, and a groove is formed between the inner and outer rings on the same side and the end wall;

[0009] The outer circumferential surfaces of the inner rings on both the left and right sides are provided with first magnets, and the axial ends of the winding are respectively located in the grooves on the left and right sides and surround the first magnets.

[0010] Preferably, the outer rotor assembly further includes a second magnet attached to the inner wall of the annular wall, the second magnet being located radially outside the inner stator core and surrounding the inner stator core.

[0011] Preferably, the outer rotor assembly consists of a left half of the outer rotor and a right half of the outer rotor; each of the left half of the outer rotor and the right half of the outer rotor includes half of the annular wall and an end wall located on one axial side of the annular wall.

[0012] The outer rotor has a central shaft at the center of the end wall on the right half side; the inner stator bracket is sleeved on the outer periphery of the central shaft and connected to the central shaft through a first bearing;

[0013] The left half of the outer rotor has a hollow end wall structure. The inner stator support has an axially extending extension in the direction close to the left half of the outer rotor. The outer circumferential surface of the extension is connected to the inner circumferential surface of the inner ring through a second bearing.

[0014] Preferably, the ends of the outer rings on both the left and right sides are chamfered.

[0015] Preferably, the thickness of the outer ring on the same side is not greater than the thickness of the inner ring.

[0016] The beneficial effects achieved by this invention are as follows:

[0017] (1) The present invention provides an external rotor motor with an end winding magnetization structure. The inner and outer rings form grooves at the winding ends. By arranging the first magnet, a magnetic path is formed at the winding ends, which fully utilizes the end winding coil portion to generate effective electrical power, thereby improving the winding utilization rate and reducing end losses.

[0018] (2) The present invention provides an external rotor motor with an end winding magnetization structure. The right half and the left half of the external rotor are connected to the inner stator support through the first bearing and the second bearing, respectively. The stability of the external rotor is enhanced by the double support at different axial positions. At the same time, the stator and rotor are integrated into one unit by the double support of the external rotor. As an integrated component, it can be applied to multiple fields such as vehicle subsystems and robot drive joints, improving integration convenience, easy maintenance and compactness.

[0019] (3) The present invention provides an external rotor motor with an end winding magnetization structure, wherein the left half and the right half of the external rotor each include half of the annular wall, so that the second magnet attached to the inner wall of the annular wall is set in a split manner, which facilitates installation and reduces magnet loss.

[0020] (4) The present invention provides an external rotor motor with an end winding magnetization structure. The outer ring of the groove on the left half and right half of the external rotor is chamfered. The thickness of the outer ring is less than that of the inner ring to prevent the magnetic field of the inner diameter of the external rotor from forming a magnetic field loop and forming a large leakage magnetic field. Attached Figure Description

[0021] Figure 1 This is an overall side sectional view of an external rotor motor provided in an embodiment of the present invention.

[0022] Figure 2 This is a schematic diagram of the structure of the right half of the outer rotor in an external rotor motor provided in an embodiment of the present invention.

[0023] Figure 3 This is a schematic diagram of the structure of the left half of the outer rotor in the external rotor motor provided in an embodiment of the present invention.

[0024] Figure 4 This is a schematic diagram of the magnetizing magnetic circuit of an external rotor motor provided in an embodiment of the present invention.

[0025] Figure 5 This is a schematic diagram showing the end chamfers of the right half outer ring and the left half outer ring of the outer rotor in an external rotor motor provided in an embodiment of the present invention.

[0026] The diagram shows: 1. Inner stator support; 2. Inner stator core; 3. Winding; 4. Left half of outer rotor; 5. Right half of outer rotor; 6. Inner ring of the right half of outer rotor; 7. Outer ring of the right half of outer rotor; 8. Groove of the right half of outer rotor; 9. Inner ring of the left half of outer rotor; 10. Outer ring of the left half of outer rotor; 11. Groove of the left half of outer rotor; 12. First magnet; 13. Second magnet; 14. Central shaft; 15. First bearing; 16. Second bearing; 17. Chamfer. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. The following embodiments are used to illustrate the present invention, but are not intended to limit the scope of the present invention. Where specific techniques or conditions are not specified in the embodiments, they shall be performed in accordance with the techniques or conditions described in the literature in the art, or in accordance with the product manual.

[0028] Example 1

[0029] Example 1 provides an external rotor motor with an end winding magnetizing structure, see [link to example]. Figures 1-3 This includes the inner stator assembly and the outer rotor assembly;

[0030] The inner stator assembly includes an inner stator bracket (1) and an inner stator core (2); the inner circumferential surface of the inner stator core (2) is fitted onto the outer circumferential surface of the inner stator bracket (1), and a winding (3) is embedded in the slot of the inner stator core (2); the inner stator bracket (1) is the support center of the inner stator assembly and the outer rotor assembly, and is connected to the external fixed end through circumferential bolts;

[0031] The outer rotor assembly consists of a left half (4) and a right half (5) of the outer rotor; the left half (4) and the right half (5) of the outer rotor each independently include an annular wall sleeved on the outer periphery of the inner stator core (2) and an end wall located on one axial side of the annular wall.

[0032] The right half of the outer rotor (5) has a concentric inner ring (6) and outer ring (7) on its end wall. The inner ring (6) and outer ring (7) on the right half of the outer rotor and the end wall form a groove (8) on the right half of the outer rotor.

[0033] The left half of the outer rotor (4) has a concentric inner ring (9) and outer ring (10) on its end wall. The inner ring (9) and outer ring (10) on the left half of the outer rotor and the end wall form a groove (11) on the left half of the outer rotor.

[0034] The outer circumferential surfaces of the inner ring (6) on the right half of the outer rotor and the inner ring (9) on the left half of the outer rotor are provided with first magnets (12). The two axial ends of the winding (3) are located in the groove (8) on the right half of the outer rotor and the groove (11) on the left half of the outer rotor, respectively, and surround the first magnets (12), thereby forming a magnetic conductive path for the winding ends. Figure 4 This is a schematic diagram of the magnetization circuit of the external rotor motor. Taking the left side as an example, the N pole magnetic field line of the first magnet (12) in the groove (11) on the left side of the external rotor passes through the air in the groove on the left side of the external rotor and enters the end winding. After the magnetic field line exits the end winding, it enters the outer ring (10) of the groove on the left side of the external rotor, then enters the end cover on the left side of the external rotor, and then returns to the S pole of the first magnet (12) in the groove (11) on the left side of the external rotor via the inner ring (9) of the groove on the left side of the external rotor, forming a complete magnetic circuit through the end of the winding.

[0035] The outer rotor assembly also includes a second magnet (13) attached to the inner wall of the annular wall of the left half (4) and the right half (5) of the outer rotor. The second magnet (13) is located radially outside the inner stator core (2) and surrounds the inner stator core (2). The second magnet (13) on the left half (4) and the second magnet (13) on the right half (5) of the outer rotor are set separately, which facilitates installation and reduces magnet loss.

[0036] The right half (5) of the outer rotor has a central shaft (14) at the center of its end wall; the inner stator bracket (1) is sleeved on the outer periphery of the central shaft (14) and connected to the central shaft (14) through the first bearing (15); the outer rotor motor outputs motor driving force to the outside through the central shaft (14) or receives mechanical rotation and works in the power generation state.

[0037] The end wall of the left half (4) of the outer rotor is a hollow structure. The inner stator support (1) has an axially extending extension in the direction close to the left half (4) of the outer rotor. The outer circumferential surface of the extension is connected to the inner circumferential surface of the inner ring (9) of the left half of the outer rotor through the second bearing (16).

[0038] Both the outer ring (7) on the right half of the outer rotor and the outer ring (10) on the left half of the outer rotor are chamfered (17) at their ends. Figure 5 As shown, this is to help reduce magnetic leakage.

[0039] The thickness of the outer ring (7) on the right half of the outer rotor is less than the thickness of the inner ring (6) on the right half of the outer rotor; the thickness of the outer ring (10) on the left half of the outer rotor is less than the thickness of the inner ring (9) on the left half of the outer rotor. In this embodiment, the ratio of the axial thickness of the outer ring on the left / right half of the outer rotor to the axial thickness of the inner ring on the left / right half of the outer rotor is approximately 0.80 to 0.90.

[0040] Although the present invention has been described in detail above with general descriptions, specific embodiments, and experiments, modifications or improvements can be made to it, which will be obvious to those skilled in the art. Therefore, all such modifications or improvements made without departing from the spirit of the present invention fall within the scope of protection claimed by the present invention.

Claims

1. An external rotor motor with an end winding magnetizing structure, characterized in that, Includes the inner stator assembly and the outer rotor assembly; The inner stator assembly includes an inner stator support and an inner stator core; the inner circumferential surface of the inner stator core is fitted onto the outer circumferential surface of the inner stator support, and a winding is embedded in the slot of the inner stator core; The outer rotor assembly includes an annular wall sleeved on the outer periphery of the inner stator core and end walls located on both axial sides of the annular wall; concentric inner and outer rings are provided on the end walls on both the left and right sides, and a groove is formed between the inner and outer rings on the same side and the end wall. The outer circumferential surfaces of the inner rings on both the left and right sides are provided with first magnets, and the axial ends of the winding are respectively located in the grooves on the left and right sides and surround the first magnets. The outer rotor assembly also includes a second magnet attached to the inner wall of the annular wall, the second magnet being located radially outside the inner stator core and surrounding the inner stator core.

2. An external rotor motor with an end winding magnetizing structure according to claim 1, characterized in that, The outer rotor assembly consists of a left half of the outer rotor and a right half of the outer rotor; each of the left half of the outer rotor and the right half of the outer rotor includes half of the annular wall and an end wall located on one axial side of the annular wall. The outer rotor has a central shaft at the center of the end wall on the right half side; the inner stator bracket is sleeved on the outer periphery of the central shaft and connected to the central shaft through a first bearing; The left half of the outer rotor has a hollow end wall structure. The inner stator support has an axially extending extension in the direction close to the left half of the outer rotor. The outer circumferential surface of the extension is connected to the inner circumferential surface of the inner ring through a second bearing.

3. An external rotor motor with an end winding magnetizing structure according to claim 1, characterized in that, The ends of the outer rings on both the left and right sides are chamfered.

4. An external rotor motor with an end winding magnetizing structure according to claim 1, characterized in that, The thickness of the outer ring on the same side is not greater than the thickness of the inner ring.

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