Electric motor and method for manufacturing electric motor

Abstract

The present disclosure relates to an electric motor, comprising a stator assembly and a rotor assembly. The stator assembly comprises a stator core assembly, wherein the stator core assembly comprises: a stator core body comprising stator teeth and slots, which are alternately arranged in a circumferential direction; a winding, which comprises a plurality of wires extending through the slots and wound around the stator teeth; and a stator-core outer ring, which is configured to be separate from the stator core body and is provided with a hollow portion, the hollow portion being configured to receive the stator core body. The rotor assembly comprises a rotor shaft, which is configured to be rotatable relative to the stator assembly. The present disclosure further relates to a surgical device comprising the electric motor. The present disclosure further relates to a method for manufacturing the electric motor.

Description

Electric motor and method for manufacturing an electric motor Technical Field

[0001] The present disclosure relates to the field of electric machines, and more particularly to an electric machine, and also to a method for manufacturing such an electric machine. Background Art

[0002] Motors, such as surgical motors, particularly those used in orthopedic surgery, require high power density, low vibration, and low noise due to their specialized operating environments and requirements. Furthermore, these motors must be small in diameter and lightweight for easy handheld use. High power density implies high rotational speeds, which typically increase vibration and noise. Furthermore, stator windings for slender motors with small diameters often present difficulties.

[0003] How to balance the motor's high power density, low vibration, low noise, small diameter, and light weight is an urgent problem to be solved in order to improve the performance of motors, such as surgical motors, and enhance their market competitiveness. The present disclosure aims to solve this problem. Summary of the Invention

[0004] To this end, according to one aspect of the present disclosure, a motor is provided, comprising:

[0005] A stator assembly, the stator assembly comprising a stator core assembly, and the stator core assembly comprising:

[0006] a stator core body comprising stator teeth and slots alternately arranged in a circumferential direction;

[0007] a winding comprising a plurality of wires extending through the slots and wound around the stator teeth;

[0008] a stator core outer ring configured separately from the stator core main body and having a hollow portion configured to receive the stator core main body; and

[0009] The rotor assembly includes a rotor shaft configured to be rotatable relative to the stator assembly.

[0010] According to various embodiments, the motor proposed in the present disclosure may include one or more of the following further improvements.

[0011] In some embodiments, the slots include slot openings that open on a radially outer periphery of the stator core body.

[0012] In some embodiments, the width of the slot opening in the circumferential direction is 1-1.3 mm.

[0013] In some embodiments, the stator teeth include first yoke portions located on a radially outer periphery of the stator core body, and each of the slot openings is disposed between two adjacent first yoke portions.

[0014] In some embodiments, the stator core outer ring includes a second yoke and a third yoke alternately arranged in the circumferential direction, wherein the second yoke is configured to cooperate with the corresponding first yoke of the stator core body, and the third yoke is configured to cooperate with the corresponding slot of the stator core body.

[0015] In some embodiments, the radial thickness of the third yoke is greater than the radial thickness of the second yoke.

[0016] In some embodiments, an interference fit is formed between the second yoke and the corresponding first yoke; and / or an interference fit is formed between the third yoke and the corresponding notch.

[0017] In some embodiments, an interference fit is formed between the second yoke and the corresponding first yoke with a single-sided interference amount of 0.005mm-0.015mm; and / or an interference fit is formed between the third yoke and the corresponding notch with a single-sided interference amount of 0.005mm-0.015mm.

[0018] In some embodiments, the stator core body is provided with a central hole, the central hole is configured to cooperate with the rotor shaft, and the stator core body is further provided with a continuous inner circumferential wall for defining the central hole.

[0019] In some embodiments, the minimum thickness of the inner peripheral wall is 0.02 mm-0.29 mm.

[0020] In some embodiments, a potting material is provided on the inner peripheral wall of the central hole of the stator core body.

[0021] In some embodiments, nine slots are provided in the stator core body.

[0022] In some embodiments, a magnetic shoe with four poles is provided on the rotor shaft of the rotor assembly.

[0023] In some embodiments, the number of the wires received by each slot ranges from 144 to 252, and the slot fill rate of each slot is 40% to 50%.

[0024] In some embodiments, the winding includes two axial protruding ends opposite to each other, and the axial height of the axial protruding ends does not exceed 2.5 mm.

[0025] In some embodiments, the stator core assembly is formed by stacking silicon steel sheets, and the silicon steel sheets are self-bonding silicon steel sheets.

[0026] In some embodiments, the thickness of the self-adhesive silicon steel sheet is 0.1 mm.

[0027] In some embodiments, the stator assembly includes a housing.

[0028] In some embodiments, a transition fit is formed between the outer ring of the stator core and the housing.

[0029] In some embodiments, the motor further includes a potting material portion disposed between the housing and the stator core outer ring and / or between the stator core body and the stator core outer ring and / or a potting material portion wrapping the winding at two axial protruding ends of the winding.

[0030] In some embodiments, the motor further includes a first end cover disposed at a first axial end of the housing, and the motor further includes a potting material portion disposed between the housing and the first end cover.

[0031] In some embodiments, the electric machine further comprises a sensor assembly configured to sense an angular position of the rotor shaft, the sensor assembly being positioned at an end of the rotor shaft proximate the second axial end of the housing.

[0032] In some embodiments, the motor further comprises an electrical connector configured to electrically connect the winding with an external fitting and / or to electrically connect the sensor assembly with an external fitting, and the electrical connector is provided separately from the sensor assembly.

[0033] In some embodiments, the electrical connector is disposed on a side of the sensor assembly opposite to the side facing the stator core assembly.

[0034] In some embodiments, the motor further includes a second end cover disposed at a second axial end of the housing opposite to the first axial end.

[0035] In some embodiments, the electrical connector is disposed within an end cap cavity of the second end cap.

[0036] In some embodiments, the sensor assembly is axially positioned between an axially inner end of the second end cap and the stator core assembly.

[0037] In some embodiments, the axial length of the stator core assembly is 62%-70% of the axial length of the housing.

[0038] In some embodiments, the axial length of the housing is 14-20 mm greater than the length of the stator core assembly.

[0039] In some embodiments, the motor further includes a potting material portion disposed between the second end cover and the electrical connector and / or between the second end cover and the sensor assembly and / or between the sensor assembly and the housing and / or between the sensor assembly and the stator core assembly.

[0040] In some embodiments, the motor includes a first bearing arranged in the first end cover and a second bearing arranged in the second end cover, the first bearing and the second bearing are configured to support the rotor shaft, wherein the outer diameter of the first bearing, the inner diameter of the center hole, and the outer diameter of the second bearing decrease in sequence.

[0041] In some embodiments, the axial inner end of the second end cover is inserted into the second axial end of the housing, and the motor further includes a bushing arranged around a portion near the axial inner end of the second end cover and the second axial end of the housing, and the bushing is welded to the second end cover at a butt weld portion, wherein the bushing is provided with a first chamfered portion and the second end cover is provided with a second chamfered portion at the butt weld portion, so that the first chamfered portion and the second chamfered portion form an annular groove at the butt weld portion to accommodate the weld.

[0042] In some embodiments, a first O-ring seal is provided between the bushing and the portion of the second end cover, and / or a second O-ring seal is provided between the bushing and the second axial end of the housing.

[0043] According to another aspect of the present disclosure, a surgical device is provided, comprising the motor according to any one of the aforementioned embodiments.

[0044] According to another aspect of the present disclosure, a method for manufacturing a motor is provided, comprising:

[0045] Step S1: stacking silicon steel sheets to form a stator core assembly of a stator assembly, and forming the stator core assembly includes:

[0046] Sub-step S1.1: forming a stator core body of the stator core assembly so that the stator core body includes stator teeth and slots alternating in a circumferential direction;

[0047] Sub-step S1.2: extending a wire through the slot and winding the wire around the stator teeth to form a winding;

[0048] Sub-step S1.3: forming a stator core outer ring of the stator core assembly separately from the stator core main body, so that the stator core outer ring is formed with a hollow portion;

[0049] Sub-step S1.4: inserting the stator core body into the hollow portion of the stator core outer ring to form the stator core assembly; and

[0050] Step S2: providing a rotor assembly, and arranging a rotor shaft of the rotor assembly to be rotatable relative to the stator assembly.

[0051] According to various embodiments, the method for manufacturing an electric machine proposed in the present disclosure may include one or more of the following further developments.

[0052] In some embodiments, in the sub-step S1.1, the slots of the stator core body are formed with slot openings opening on the radial outer periphery of the stator core body.

[0053] In some embodiments, in the sub-step S1.1, the stator teeth are formed to include first yokes located on the radial outer periphery of the stator core body, and each of the slot openings is disposed between two adjacent first yokes.

[0054] In some embodiments, in the sub-step S1.3, the stator core outer ring is formed to include a second yoke portion and a third yoke portion alternately arranged in the circumferential direction, wherein the radial thickness of the third yoke portion is greater than the radial thickness of the second yoke portion.

[0055] In some embodiments, in the sub-step S1.4, the second yoke is aligned with the corresponding first yoke of the stator core body to form an interference fit, and the third yoke is aligned with the corresponding notch of the stator core body to form an interference fit.

[0056] In some embodiments, the sub-step S1.1 includes forming the stator core body with 9 slots evenly distributed along the circumferential direction.

[0057] In some embodiments, the rotor shaft of the rotor assembly provided in the sub-step S1.4 is provided with a magnetic tile having four poles.

[0058] In some embodiments, the sub-step S1.2 includes receiving the number of wires in each slot in a range of 144-252, so that the slot fill rate of each slot is 40%-50%.

[0059] In some embodiments, in the sub-step S1.2, the winding is formed to include two axial protruding ends opposite to each other, and the axial height of the axial protruding ends does not exceed 2.5 mm.

[0060] In some embodiments, the step S1 further includes a sub-step S1.5 after the sub-step S1.4: providing a housing for forming the motor, and installing the stator core outer ring into the housing in a transition fit manner to form an intermediate stage stator assembly.

[0061] In some embodiments, the step S1 further includes a sub-step S1.4a after the sub-step S1.4 and before the sub-step S1.5: wrapping outer insulation paper on the outer periphery of the stator core outer ring.

[0062] In some embodiments, the step S1 also includes a sub-step S1.6 after the sub-step S1.5: potting the formed intermediate stage stator assembly, including potting the potting material between the shell and the stator core outer ring and / or between the stator core outer ring and the stator core body and / or potting into two axial protrusions surrounding the winding.

[0063] In some embodiments, the sub-step S1.1 also includes forming a center hole in the stator core body; the sub-step S1.6 also includes forming a potting material layer on the inner circumferential wall of the center hole; the step S1 also includes a sub-step S1.7 after the sub-step S1.6: processing the inner circumferential wall of the center hole formed with the potting material layer into a continuous inner circumferential wall with a minimum thickness of 0.02mm-0.29mm.

[0064] In some embodiments, the step S1.7 includes first turning the inner peripheral wall formed with the potting material layer and then honing the inner peripheral wall.

[0065] In some embodiments, at the end of sub-step S1.7, potting material remains on the inner peripheral wall of the central hole.

[0066] In some embodiments, step S1 also includes sub-step S1.51 after sub-step S1.5 and before sub-step S1.6: providing a first end cover and installing the first end cover at the first axial end of the shell, wherein sub-step S1.6 also includes potting material between the first end cover and the shell and between the first end cover and the stator core assembly.

[0067] In some embodiments, after the sub-step S1.6, the method further comprises a sub-step S1.7: disposing a sensor assembly for sensing the angular position of the rotor shaft at an end of the rotor shaft close to the second axial end of the housing.

[0068] In some embodiments, after the sub-step S1.7, the method further includes a sub-step S1.8: providing an electrical connector separately from the sensor assembly, and electrically connecting the winding to an external fitting and / or electrically connecting the sensor assembly to an external fitting through the electrical connector.

[0069] In some embodiments, the sub-step S1.8 further comprises arranging the electrical connector on a side of the sensor assembly opposite to the side facing the stator core assembly.

[0070] In some embodiments, the sub-step S1.8 further includes: providing a second end cap with an end cap cavity, installing the electrical connector in the end cap cavity, and installing the second end cap to the second axial end of the housing.

[0071] In some embodiments, the sensor assembly is axially located between the second end cap and the stator core assembly.

[0072] In some embodiments, after sub-step S1.8, the method further includes sub-step S1.9: potting via the second end cover to pot the potting material between the second end cover and the electrical connector and / or between the second end cover and the sensor assembly and / or between the sensor assembly and the housing and / or between the sensor assembly and the stator core assembly.

[0073] In some embodiments, after sub-step S1.8, step S2 further includes sub-step S2.1: providing a first bearing for installation in the first end cover and a second bearing for installation in the second end cover, and installing the first bearing and the second bearing on the rotor shaft to form a rotor shaft subassembly, wherein the outer diameter of the first bearing, the inner diameter of the center hole and the outer diameter of the second bearing decrease successively.

[0074] In some embodiments, step S2 also includes a sub-step S2.2 after sub-step S2.1: inserting the rotor shaft sub-assembly through the first end cover, the center hole of the stator core assembly, and at least a portion of the end cover cavity of the second end cover in sequence to install the rotor shaft sub-assembly in place.

[0075] In some embodiments, the step S1 further includes a sub-step S1.15 between the sub-step S1.1 and the sub-step S1.2: placing insulating paper in the notch.

[0076] In some embodiments, the sub-step S1.15 also includes: providing insulating paper, and marking the insulating paper according to the structure of the stator teeth and slots of the stator core body, folding the insulating paper at each mark to fold the insulating paper into a shape including circumferentially alternating slot corresponding portions and stator tooth corresponding portions, and arranging the folded insulating paper on the outer periphery of the stator core body so that the slot corresponding portions of the insulating paper are laid in the corresponding slots, and the stator tooth corresponding portions wrap the outer periphery of the corresponding stator teeth.

[0077] In some embodiments, the sub-step S1.15 further includes marking an axial disconnection position in each stator tooth corresponding portion;

[0078] The step S1 further includes a sub-step S1.25 between the sub-step S1.2 and the sub-step S1.3: disconnecting the insulating paper at each of the axial disconnection positions and shaping the disconnected insulating paper to wrap at least a portion of the slot opening of the corresponding slot.

[0079] In some embodiments, the sub-step S1.15 further includes making the two axial ends of the insulating paper higher than the corresponding axial ends of the stator core assembly by an axial height of 0.75-1 mm.

[0080] The insulating paper is rectangular in its unfolded state.

[0081] In some embodiments, the step S1 includes forming the stator core assembly using self-bonding silicon steel sheets.

[0082] In some embodiments, the thickness of the self-adhesive silicon steel sheet used is 0.1 mm.

[0083] In some embodiments, the sub-step S1.1 includes setting the width of the slot opening in the circumferential direction to 1-1.3 mm.

[0084] In some embodiments, the sub-step S1.8 includes inserting the axial inner end of the second end cover into the second axial end of the shell, and the method also includes a step S4 after the sub-step S1.8: setting a bushing around a portion near the axial inner end of the second end cover and the second axial end of the shell.

[0085] In some embodiments, the method further comprises a sub-step S4.1 after the step S4: welding the bushing and the second end cover to each other at a butt weld portion.

[0086] In some embodiments, the sub-step S1.8 includes setting a second chamfered portion on the second end cover at the butt weld portion, the step S4 includes setting a first chamfered portion on the bushing at the butt weld portion, and making the first chamfered portion and the second chamfered portion form an annular groove at the butt weld portion; the sub-step S4.1 includes welding at the annular groove.

[0087] In some embodiments, the method includes step S3 between sub-step S1.8 and step S4: setting a first O-ring at the portion of the second end cover, and / or setting a second O-ring at the second axial end of the housing; wherein, step S4 includes installing the bushing circumferentially around the first O-ring and / or the second O-ring. BRIEF DESCRIPTION OF THE DRAWINGS

[0088] In order to more clearly illustrate the technical solutions of the embodiments of the present disclosure, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present disclosure and should not be considered as limiting the scope. A person of ordinary skill in the art can also derive other relevant drawings based on these drawings without inventive effort. In the drawings:

[0089] FIG1 is an exploded perspective view of a motor according to an exemplary embodiment;

[0090] FIG2 is an axial cross-sectional view of a motor according to an exemplary embodiment;

[0091] 3 is a perspective schematic diagram of a stator core body of a stator core assembly according to an exemplary embodiment;

[0092] 4 is a perspective schematic diagram of a stator core outer ring of a stator core assembly according to an exemplary embodiment;

[0093] 5 is an axial end view of a stator core assembly formed by the stator core body shown in FIG3 and the stator core outer ring shown in FIG4;

[0094] 6 is a cross-sectional view of an assembled stator core body in a direction perpendicular to the axial direction according to an exemplary embodiment, wherein a central hole of the stator core body is not processed into a final state;

[0095] 7 is a cross-sectional view of an assembled stator core body according to an exemplary embodiment, in a direction perpendicular to the axial direction, wherein a central hole of the stator core body is processed into a final state;

[0096] FIG8 schematically illustrates in plan view a stack of silicon steel sheets used to form a stator core assembly according to an exemplary embodiment;

[0097] FIG9 shows a perspective schematic diagram of a sensor assembly for a motor according to an exemplary embodiment from a first perspective;

[0098] FIG10 shows a perspective schematic diagram of a sensor assembly for a motor according to an exemplary embodiment from a second viewing angle different from the first viewing angle;

[0099] FIG11 shows a perspective schematic diagram of an electrical connector for a motor according to an exemplary embodiment;

[0100] FIG12 illustrates an axial cross-sectional view of a rotor shaft subassembly according to an exemplary embodiment;

[0101] FIG13 illustrates a cross-sectional view perpendicular to the axial direction of a rotor shaft according to an exemplary embodiment, showing magnetic shoes mounted on the rotor shaft;

[0102] FIG14 shows a schematic plan view of insulating paper for a winding of a motor according to an exemplary embodiment;

[0103] FIG15 shows a perspective view of folded insulation paper for windings of a motor according to an exemplary embodiment;

[0104] FIG16 shows a perspective view of a stator core body according to an exemplary embodiment after being equipped with the folded insulation paper shown in FIG15 ;

[0105] FIG17 shows an axial end view of the stator core body shown in FIG16;

[0106] FIG18 shows an axial cross-sectional view of the stator core body shown in FIG16 ;

[0107] FIG19 shows a cross-sectional view perpendicular to the axial direction of the stator core body shown in FIG16 ;

[0108] FIG20 shows a cross-sectional view perpendicular to the axial direction of the stator core body in a final state, in which the insulation paper is shaped to wrap around the slot opening;

[0109] FIG21 is a partial enlarged schematic diagram of portion A in FIG2 ;

[0110] FIG. 22 is a cross-sectional view of a bushing for a motor according to an exemplary embodiment.

[0111] Reference Signs List 1 Electric motor 10 Stator core assembly 100 Stator core body 110 Stator teeth 111 First yoke 111a, 111b Circumferential end of first yoke 120 Notch 1201 First notch 1211 First notch opening 1202 Second notch 1212 Second notch opening 121 Notch opening 130 Winding 131, 132 Axial protruding end of winding 140 Silicon steel sheet 150 Center hole 151 Inner circumferential wall of center hole 200 Stator core outer ring 220 Second yoke 230 Third yoke 250 Hollow portion 300 Insulation paper 301, 302 Circumferential end of insulation paper 301 a, 302a reserved portion 310 stator tooth corresponding portion 311 first disconnected portion 312 second disconnected portion 313 axial disconnected position 320 notch corresponding portion 400 rotor assembly 410 magnetic tile 420 rotor bushing 450 rotor shaft 451 first end portion of the rotor shaft 452 second end portion of the rotor shaft 453 first bearing 4531 first shoulder 454 second bearing 4541 second shoulder 500 housing 510 first axial end 520 second axial end 530 21 ; h ; the value by which each axial end of the insulating paper protrudes above the corresponding axial end of the stator core assembly; t ; the minimum thickness of the inner circumferential wall of the central hole of the stator core body in the final processed state; T ; the minimum thickness of the inner circumferential wall of the central hole of the stator core body covered with the potting material layer and before processing. DETAILED DESCRIPTION

[0112] Below, with reference to the accompanying drawings, a stator core assembly, a motor including the stator core assembly, and a method for manufacturing the motor according to embodiments of the present disclosure are described in detail. To further clarify the objectives, technical solutions, and advantages of the present utility model, the technical solutions of the embodiments of the present disclosure will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present disclosure, but not all of them.

[0113] Therefore, the following detailed description of the embodiments of the present disclosure provided in conjunction with the accompanying drawings is not intended to limit the scope of the present disclosure as claimed, but merely represents selected embodiments of the present disclosure. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present disclosure without creative effort are within the scope of protection of the present disclosure.

[0114] Unless the context otherwise defines, the singular includes the plural. Throughout the specification, the terms "including", "having", etc. are used herein to specify the presence of the features, numbers, steps, operations, elements, parts or their combination, but do not exclude the presence or addition of one or more other features, numbers, steps, operations, elements, parts or their combination.

[0115] In addition, even though terms including ordinal numbers such as "first," "second," etc. may be used to describe various components, these components are not limited by these terms, and these terms are only used to distinguish one element from other elements. For example, a first component may be referred to as a second component, and similarly, a second component may be referred to as a first component without departing from the scope of the present disclosure.

[0116] In the description of the present invention, it should be understood that the terms "up", "down", "left", "right", "inside", "outside", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, or are the orientations or positional relationships in which the disclosed product is conventionally placed when in use, or are the orientations or positional relationships conventionally understood by those skilled in the art. These are merely for the convenience of describing the present disclosure and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present disclosure.

[0117] As shown in Figures 3-7, according to one aspect of the present disclosure, the present disclosure proposes a stator core assembly 10 for forming a motor 1. According to another aspect of the present disclosure, the present disclosure proposes a stator assembly, which includes the above-mentioned stator core assembly 10. As shown in Figures 1-2, according to another aspect of the present disclosure, the present disclosure proposes a motor 1, which includes the above-mentioned stator assembly or stator core assembly 10. In an application example, the motor 1 is a motor for surgery, more specifically a motor for orthopedic surgery. According to another aspect of the present disclosure, the present disclosure proposes a method for manufacturing a motor 1. The present disclosure also relates to a surgical device including such a motor 1.

[0118] stator core assembly

[0119] As shown in Figures 1-7, according to some embodiments of the stator core assembly 10 proposed in the present disclosure, the stator core assembly 10 may include a stator core body 100 and windings 130. The stator core body 100 includes stator teeth 110 and slots 120 arranged alternately in the circumferential direction. As shown in Figures 3 and 5-7, in a specific embodiment, the stator core body 100 may include nine stator teeth 110 and nine slots 120, and the stator teeth 110 and slots 120 are, for example, evenly arranged in the circumferential direction. The windings 130 (schematically shown in cross-section in Figures 2 and 6-7) are formed by a plurality of conductive wires extending through the slots 120 and wound around the stator teeth 110. According to a specific embodiment, the stator core assembly 10 includes nine windings 130, that is, the number of windings is the same as the number of slots 120.

[0120] According to some embodiments, the slots 120 of the stator core body 100 are provided with slot openings that open on the radial circumference of the stator core body 100. In one variation (not shown), the slot openings of the slots 120 of the stator core body 100 are provided on the radial inner circumference of the stator core body 100. In another variation, as shown in Figures 3 and 4-7, the slot openings 121 of the slots 120 of the stator core body 100 are provided on the radial outer circumference of the stator core body 100.

[0121] In some embodiments, as shown in Figures 14-20, the stator core assembly 10 may further include insulating paper 300 configured to electrically isolate the winding 130 from other components. More specifically, the insulating paper 300 may be laid in each slot 120 and configured to cover the slot opening 121. In a specific embodiment, as shown in Figure 18, the insulating paper 300 may be configured such that each axial end thereof protrudes above the corresponding axial ends 11, 12 of the stator core assembly 10, for example, with the value h of the protrusion being within a range of 0.75 mm to 1 mm. This range ensures insulation of the axial protruding ends 131, 132 of the winding 130, for example, insulation from the stator core body 100, the stator core outer ring 200 described below, and the housing 500 of the motor 1. If the higher value is set too low, the insulation of the axial protruding ends 131 and 132 of the winding 130 is unreliable, which may cause conductivity between the wire and the stator core assembly 10 or the housing 500 of the motor 1; conversely, if the higher value is set too high, the axial protruding ends 131 and 132 of the winding 130 will protrude axially outward higher, resulting in an increase in ineffective windings, increased resistance, and increased heating of the windings, which is not conducive to the operating performance of the stator assembly, and this will cause the axial dimension of the stator core assembly 10 to be lengthened, thereby lengthening the length of the motor 1 including it, increasing the material cost while increasing the weight of the motor, thereby increasing the operating difficulty for the motor user.

[0122] In some embodiments, as shown in Figures 14-17 , the insulating paper 300 can be provided as a monolithic sheet, that is, a single sheet of insulating paper 300 can be folded into a shape capable of covering at least two notches 120 of the stator core body 100 and the stator teeth 110 between the at least two notches 120. Specifically, a single sheet of insulating paper 300, which is, for example, rectangular in its unfolded state (as shown in Figure 14 ), can be folded into a shape corresponding to the at least two notches 120 and the stator teeth 110 between the at least two notches 120, so that the folded insulating paper 300 can be placed over the at least two notches 120 and the stator teeth 110 between the at least two notches 120 via the notch openings 121. Consequently, the number of insulating paper sheets 300 required is less than the number of notches 120 in the stator core body 100. More specifically, the wires of the winding 130 extend through the slots 120 covered with insulating paper 300 and are wound around the stator teeth 110 covered with insulating paper 300. In a specific embodiment, a single piece of insulating paper 300 can have a folded side that is complementary to the at least two slots 120 and the stator teeth 110 between the at least two slots 120, so that the insulating paper 300 can be laid on the stator teeth 110 between the at least two slots 120 in a complementary manner. More specifically, as shown in Figures 3 and 5-7, each stator tooth 110 includes a yoke portion located on the radial periphery of the stator core body 100, which is referred to herein as a "first yoke portion 111", and each slot opening 121 is provided between two adjacent first yoke portions 111. More specifically, the first yoke 111 may include two circumferential ends 111a and 111b circumferentially opposite each other. One circumferential end 111a of the first yoke 111 of a stator tooth 110 forms a radially outer portion that defines one of the two notches 120 adjacent to the stator tooth 110, while the other circumferential end 111b forms a radially outer portion that defines the other of the two notches 120 adjacent to the stator tooth 110. As shown in Figures 16-17 and 19-20, a single insulating paper 300 is provided to cover the inner wall of each of the at least two notches 120 and the first yoke 111 of the stator tooth 110 between the at least two notches 120. The portion of the insulating paper 300 positioned within the notches 120 is referred to as a notch-corresponding portion 320. The portion of the insulating paper 300 covering the first yoke 111 of each stator tooth 110 is referred to as a stator-tooth-corresponding portion 310.More specifically, as shown in Figures 16-17 and 19, the insulating paper 300 can also be configured so that its two circumferential ends 301, 302 can respectively extend circumferentially out of the circumferential outermost slots 120 of the at least two slots 120 by a certain length to form reserved portions 301a, 302a, and the reserved portions 301a, 302a are used to cover the slot openings 121 of the slots 120 corresponding to the reserved portions 301a, 302a after winding the winding 130.

[0123] In a more specific embodiment, as schematically shown in FIG16 , the insulating paper 300 may be provided with an axial disconnection position 313 at the stator tooth corresponding portion 310 of the first yoke portion 111 covering each stator tooth 110. The stator tooth corresponding portion 310 of the insulating paper 300 may be disconnected axially at each axial disconnection position 313. The corresponding portion of the disconnected stator tooth corresponding portion 310 may be shaped to cover at least a portion of the slot opening 121 of the corresponding slot 120. For example, after being disconnected along the axial disconnection position 313, the stator tooth corresponding portion 310 may be divided into a first disconnected portion 311 and a second disconnected portion 312. The first disconnected portion 311 and the second disconnected portion 312 may then be circumferentially bent in opposite directions to cover at least a portion of the slot opening 121 of the corresponding slot 120. Thus, the first disconnected portion 311 of one of the two adjacent stator tooth corresponding portions 310 of the insulating paper 300 can cover the slot opening 121 of a corresponding slot 120 together with the second disconnected portion 312 of the other stator tooth corresponding portion 310 to ensure electrical insulation of the winding 130 from external components at the slot opening 121.

[0124] Therefore, according to the present disclosure, an integral insulating paper 300 is used to cover at least two slots 120 and the corresponding stator teeth 110. After the wire winding is completed, the stator tooth corresponding portion 310 of the insulating paper 300 is cut, for example, so that the corresponding first disconnected portion 311 and the second disconnected portion 312 wrap the slot opening 121 of the corresponding slot 120. On the one hand, the arrangement of the insulating paper 300 is greatly simplified without affecting the wire winding, and at the same time, the problem in the prior art that a single insulating paper applied to a single slot cannot completely cover the wire is solved.

[0125] In the embodiments shown in Figures 15-17 and 19-20, a single insulating paper 300 is provided to cover all stator teeth 110 and all slots 120 of the stator core body 100. In other words, only a single insulating paper 300 is required, and this single insulating paper 300 is folded into a shape capable of covering all stator teeth 110 and all slots 120. More specifically, in this embodiment, as shown in Figures 17 and 19, the single insulating paper 300 is folded so that its circumferential ends 301 and 302 have reserved portions 301a and 302a that extend outside the corresponding slots 120 after assembly. For example, a single insulating paper 300 is folded to have a first reserved portion 301a located at its first circumferential end 301 and a second reserved portion 302a located at its second circumferential end 302. The first reserved portion 301a will extend out of the corresponding first notch marked as 1201 in the stator core body 100 when the insulating paper 300 is assembled into the stator core body 100 to cover the first notch opening 1211 of the first notch 1201. The first reserved portion 302a will extend out of the second notch 1202 in the stator core body 100 adjacent to the first notch 1201 when the insulating paper 300 is assembled into the stator core body 100 to cover the second notch opening 1212 of the second notch 1202.

[0126] As shown in Figures 3-7 and 15, 17, and 19, in an embodiment in which the slot openings 121 of the slots 120 of the stator core body 100 are located on the radially outer periphery of the stator core body 100, the stator core assembly 10 may further include a stator core outer ring 200. The stator core outer ring 200 may be provided with a hollow portion 250 (Figure 4) configured to receive the stator core body 100. In other words, the stator core assembly 10 is a split type, employing the stator core body 100 and the stator core outer ring 200, which are separated from each other and then assembled together. More specifically, the stator core body 100 is inserted into the hollow portion 250 of the stator core outer ring 200 to complete the assembly of the stator core assembly 10. Providing the stator core assembly 10 as a split structure is advantageous because it allows for the formation of slot openings 121 on the radially outer periphery of the stator core body 100, thereby facilitating the winding of the winding 130 conductors and even enabling fully automated winding of multiple strands of conductors. Furthermore, this ensures that the slot openings 121 of the slots 120 of the stator core body 100 are relatively wide in the circumferential direction, further facilitating the winding of the winding 130 conductors. This also effectively increases the winding slot fill rate in the slots 120 while reducing the height of the axial protrusions 131 and 132 of the winding 130 that protrude axially outside the stator core assembly 10. In one specific embodiment, the circumferential width of the slot openings 121 is set to 1–1.3 mm. It should be noted that if the width is set too wide, the wire used to form the winding 130 in the slot 120 may tend to slip from the stator tooth 110 to the outside of the slot 120; if the width is set too narrow, it will be inconvenient to wind the wire when forming the winding 130. Therefore, the above width range can significantly reduce the manufacturing process cost and effectively improve the reliability of the motor operation, especially when used for winding multiple strands of wire in low-voltage, high-speed brushless DC motors. In a specific embodiment, the number of wires in each slot 120 can be in the range of 144-252, and the slot fill rate of each slot 120 can reach 40-50%, which can effectively reduce the reduction in the effective cross-sectional area of ​​the winding caused by the skin effect of current at high frequencies. In a specific embodiment, the height of the axial protruding ends 131 and 132 of the winding 130 that protrude axially outside the stator core assembly 10 is less than 2.5 mm. On the one hand, this can ensure the effective length ratio of the winding 130 and reduce copper loss. On the other hand, it can reduce the axial length of the motor assembly it is used to form and save space. This is particularly beneficial when the motor is used in medical devices.

[0127] In some embodiments, as shown in Figures 3-7 , in an embodiment where the slot openings 121 of the slots 120 of the stator core body 100 are disposed on the radially outer periphery of the stator core body 100, the stator teeth 110 may include first yoke portions 111 located on the radially outer periphery of the stator core body 100, with each slot opening 121 disposed between two adjacent first yoke portions 111. In a more specific embodiment, as shown in Figures 4-5 , the stator core outer ring 200 may include a second yoke portion 220, more specifically disposed on a circumferential wall of the stator core outer ring 200. The second yoke portion 220 may be configured to mate with a corresponding first yoke portion 111 of the stator core body 100. More specifically, the second yoke portion 220 may form a transition fit with the corresponding first yoke portion 111. Alternatively, the second yoke 220 can form an interference fit with the corresponding first yoke 111. For example, the single-sided interference fit of the interference fit can be set to 0.005mm-0.015mm. The interference fit enables the stator core assembly 10 to form a complete magnetic circuit without additional magnetic leakage. In a more specific embodiment, as shown in Figures 4-5, the stator core outer ring 200 can also include a third yoke 230, which is more specifically arranged on the peripheral wall of the stator core outer ring 200. The third yoke 230 can be arranged to cooperate with the corresponding notch 120 of the stator core body 100, more specifically, with the notch opening 121 of the corresponding notch 120. More specifically, a transition fit can be formed between the third yoke 230 and the corresponding notch 120. Alternatively, the third yoke 230 and the corresponding slot 120 can form an interference fit. For example, the single-sided interference fit can be set to 0.005mm–0.015mm. That is, in this embodiment, the stator core outer ring 200 includes second and third yokes 220, 230, arranged alternately in the circumferential direction. More specifically, as shown in Figures 4-5, the radial thickness of the third yoke 230 is greater than the radial thickness of the second yoke 220. The engagement between the third yoke 230 and the corresponding slot 120 not only serves as circumferential positioning, but also improves the fit between the stator core body 100 and the stator core outer ring 200. It also effectively prevents relative rotation between the two in the tangential direction, allowing each stator tooth 110 to be uniformly stressed in the radial direction. As a result, the stator core assembly 10 forms a closed-slot structure, effectively reducing the cogging torque of the stator core assembly 10. This allows the stator core assembly 10 to operate more stably when assembled in the motor 1 , greatly reducing the operating noise and vibration of the motor 1 .

[0128] In some embodiments, as shown in Figures 3, 5, and 7, the stator core body 100 is further provided with a central hole 150 and a continuous inner circumferential wall 151 defining the central hole 150. The central hole 150 can be used, for example, to receive the rotor shaft 450 of the rotor assembly 400, described in detail below. In a specific embodiment, the minimum thickness t of the inner circumferential wall 151 is 0.02 mm–0.29 mm. It should be noted that the "minimum thickness" herein refers to the thickness t of the inner circumferential wall 151 at the location corresponding to the slot 120, more specifically, the thickness t at the location corresponding to the radially innermost portion of the slot 120, as shown in Figure 7. This minimum thickness t can minimize magnetic flux leakage from the stator core body 100, ensuring reduced iron loss, thereby improving efficiency and reducing temperature rise. In a more specific embodiment, the inner circumferential wall 151 of the central hole 150 of the stator core body 100 can be provided with a potting material, such as epoxy resin. The thermal conductivity of the potting compound is, for example, 1.5 W / mK. The presence of the potting compound is beneficial for insulation, noise reduction, and heat dissipation because the potting compound is insulating and can absorb some noise and vibration, and its thermal conductivity is much higher than that of air.

[0129] In some embodiments, as schematically shown in Figure 8, the stator core assembly 10 is formed by stacking silicon steel sheets 140. In a specific embodiment, the silicon steel sheets 140 used to form the stator core assembly 10 are self-adhesive silicon steel sheets. The use of self-adhesive silicon steel sheets can overcome the following technical problems: on the one hand, because ultra-thin silicon steel sheets are easily deformed in the traditional stacking riveting process, on the other hand, the presence of rivet points will produce magnetic leakage. If a single-piece stacking and then welding fixing method is adopted, the insulation between the silicon steel sheets will be destroyed, resulting in an increase in the induced current of the stator core, thereby causing the core to heat up and increase losses. More specifically, the thickness of the self-adhesive silicon steel sheet is approximately 0.1 mm. The stator core assembly uses 0.1 mm self-adhesive silicon steel sheets, which can effectively reduce the eddy current between the silicon steel sheets, thereby reducing iron loss and improving operating efficiency.

[0130] The present disclosure also relates to a stator assembly, which may include the stator core assembly 10 according to any one of the above embodiments.

[0131] motor

[0132] As shown in FIG. 1-2 , the present disclosure further relates to an electric motor 1 , which may include the above-mentioned stator assembly or the stator core assembly 10 according to any one of the above-mentioned embodiments, and thus has improvements and advantages related to the above-mentioned stator core assembly 10 .

[0133] In some embodiments, as shown in Figures 1-2, the motor 1 further includes a rotor assembly 400. More specifically, the rotor assembly 400 may include a rotor shaft 450 that is rotatable relative to the stator assembly. In a specific embodiment, the rotor shaft 450 is inserted into the central hole 150 of the stator core body 100.

[0134] In some embodiments, as shown in Figures 2 and 12-13, the rotor assembly 400 may include a magnetic tile 410 disposed on the rotor shaft 450. According to a specific embodiment, the magnetic tile 410 is laid around the rotor shaft 450. More specifically, as shown in Figure 13, the magnetic tile 410 is a magnetic tile 410 with four poles, for example, N pole-S pole-N pole-S pole arranged in the circumferential direction. More specifically, the rotor shaft 450 of the motor 1 is provided with a magnetic tile 410 with the above-mentioned four poles, and the stator core body 100 is provided with nine slots 120, thereby forming a four-pole and nine-slot slot-pole matching structure, which allows the cogging torque to be reduced and the noise and vibration to be reduced while keeping the overall size of the motor 1 relatively small. In one embodiment, as shown in Figures 2 and 12-13, the rotor assembly 400 may also include a rotor sleeve 420 located around the rotor shaft 450 and the optional magnetic tile 410.

[0135] As shown in FIG2 , according to some embodiments, the motor 1 further includes a housing 500 . In a specific embodiment, the outer periphery of the stator core outer ring 200 of the stator core assembly 10 mates with the inner wall of the housing 500 , for example, forming a transition fit. More specifically, before the stator core assembly 10 is assembled in the housing 500 , a layer of outer insulating paper may be wrapped around the outer periphery of the stator core outer ring 200 . The thickness of the outer insulating paper may be, for example, 0.1 mm, which allows further radial space savings in the motor 1 while ensuring insulation of the stator core assembly 10 relative to the housing 500 . More specifically, the motor 1 may further include a potting compound portion disposed between the housing 500 and the stator core outer ring 200 . Optionally, the motor 1 may further include a potting compound portion disposed between the stator core main body 100 and the stator core outer ring 200 , particularly when a transition fit is formed between the stator core main body 100 and the stator core outer ring 200 . The potting material portion is formed of, for example, potting glue, which may be more specifically epoxy resin. The provision of the potting material portion is conducive to forming a structurally stable motor 1 and is conducive to heat dissipation, vibration reduction, and noise reduction.

[0136] As shown in FIG2 , in some embodiments, the housing 500 may include a first axial end 510 and a second axial end 520 disposed opposite to each other in the axial direction. The motor 1 may further include a first end cap 600 disposed at the first axial end 510 of the housing 500. The first end cap 600 may cover the first axial end 510 of the housing 500. In one embodiment, at least a portion of the outer periphery of the first end cap 600 may mate with the inner wall of the housing 500. For example, a transition fit or interference fit may be formed, or glue may be used to achieve relative fixation between the outer periphery of the first end cap 600 and the inner wall of the housing 500. More specifically, as shown in Figures 2 and 12 , the rotor shaft 450 may include a first end 451 and a second end 452 axially opposite to each other. The first end 451 of the rotor shaft 450 may correspond to the first axial end 510 of the housing 500, and the second end 452 of the rotor shaft 450 may correspond to the second axial end 520 of the housing 500. That is, the orientation of the rotor shaft 450 from its first end 451 to its second end 452 is consistent with the orientation of the housing 500 from the first axial end 510 to the second axial end 520. As shown in Figures 2 and 12 , the motor 1 may further include a first bearing 453 for supporting the rotor shaft 450 near the first end 451 of the rotor shaft 450. More specifically, the first bearing 453 may be mounted in the first end cap 600. In a specific embodiment, the rotor shaft 450 may be provided with a first shoulder 4531 for axially defining the position of the first bearing 453. In a specific embodiment, as shown in FIGS. 2 and 12 , the first end portion 451 of the rotor shaft 450 may extend axially from the first axial end 510 of the housing 500 for coupling with a component that can be driven by the rotor shaft 450 .

[0137] In some embodiments, with the first end cap 600 in place at the first axial end 510 of the housing 500, potting material is applied through the first end cap 600 toward the interior of the housing 500, thereby forming the aforementioned potting material portion. More specifically, the motor 1 may further include a potting material portion 530 disposed within the housing 500 between the first end cap 600 and the stator core assembly 10. More specifically, the motor 1 may further include a potting material portion 540 that encapsulates the windings 130 at their two axial protruding ends 131 and 132. This allows the stator core assembly 10 and windings 130 to be completely encapsulated within the potting material. This provides excellent insulation and thermal conductivity for the axial protruding ends 131 and 132 of the windings 130, effectively preventing contaminants from entering the interior of the stator assembly, and protecting the wires from damage by external intruders. This is particularly important when the motor 1 is used in a surgical device, as it can prevent disinfectant or tissue fluid from entering the interior of the stator assembly. The potting material portion may be composed, for example, of epoxy resin. Potting with the first end cap 600 mounted on the housing 500 also allows for sealing between the first end cap 600 and the housing 200. More specifically, the motor 1 further includes a potting compound portion disposed between the housing 500 and the first end cap 600.

[0138] According to one embodiment, before machining the center hole 150 of the stator core body 100, a potting material layer of a certain thickness can be formed on the inner peripheral wall 151 of the center hole 150. In this case, the minimum thickness T of the inner peripheral wall 151 of the center hole 150 can be, for example, 0.5 mm to 4 mm (as shown in FIG6 ). The inner peripheral wall of the center hole 150 covered with the potting material layer is then machined to achieve a desired minimum thickness t of the inner peripheral wall 151 of the center hole 150 (as shown in FIG7 ), such as the aforementioned 0.02 mm to 0.29 mm. This process of first applying potting material to the center hole 150 and then machining the inner peripheral wall 151 of the center hole 150 to the desired minimum thickness t can enhance the structural strength of the stator core body 100, effectively preventing cracking of the inner peripheral wall 151 of the center hole 150 during machining, and ensuring that the stator structure is not damaged. In addition, such a processing process of the inner circumferential wall 151 of the center hole can not only meet the final requirement of the minimum thickness t of the inner circumferential wall 151 of the center hole 150, but also improve the dimensional accuracy of the center hole 150 and its concentricity with the housing 500, reduce the motor tooth slot torque fluctuation caused by the eccentricity of the stator core body 100, and thus reduce the noise and vibration of the motor 1.

[0139] In one embodiment, the inner circumferential wall 151 of the center hole 150 of the stator core body 100, where the potting material layer is applied, is machined by first turning and then honing. This is because conventional inner hole turning cannot achieve a precision of less than 0.01 mm for the center hole 150. Furthermore, due to the slender shape of the stator core body 100, clamping is difficult, and the center hole 150 may have a certain degree of taper after machining. Reduced precision or center hole taper can lead to performance deviations in the motor 1. Directly honing the center hole results in excessive grinding, significant wear and tear on the honing rod, and a very long and time-consuming process. By machining the center hole 150 first and reserving a margin on one side (for example, 0.03mm-0.04mm), the concentricity of the center hole 150 and the housing 500 is ensured to be within 0.02mm, and then the center hole is honed to the final size. This not only meets the final size requirement of the center hole of the stator core assembly 10 and controls the accuracy of the inner diameter of the center hole to within 0.01mm, but also improves the concentricity of the center hole 150 and the housing 500 to within 0.01mm, thereby reducing the motor cogging torque fluctuation caused by the eccentricity of the stator core assembly 10, thereby reducing the noise and vibration of the motor.

[0140] As shown in FIG2 , in some embodiments, the motor 1 further includes a second end cap 700 disposed at the second axial end 520 of the housing 500. More specifically, the second end cap 700 is configured to cover the second axial end 520 of the housing 500. In a specific embodiment, as shown in FIG2 , the second end cap 700 includes an outer peripheral portion 710 that mates with the inner wall of the housing 500. More specifically, as shown in FIG2 and FIG12 , the motor 1 further includes a second bearing 454 that supports the rotor shaft 450 at its second end 452. In a specific embodiment, as shown in FIG2 , the second bearing 454 may be disposed in the second end cap 700. In a specific embodiment, as shown in FIG2 and FIG12 , the rotor shaft 450 further includes a second shoulder 4541 for defining the axial position of the second bearing 454.

[0141] As shown in Figures 2 and 12, in some embodiments, the outer diameter of the first bearing 453, the inner diameter of the central bore 150 of the stator core body 100, and the outer diameter of the second bearing 454 are sequentially reduced. Thus, the first bearing 453 and the second bearing 454 can be first installed in position on the rotor shaft 450 to form a rotor shaft subassembly, and then the entire rotor shaft subassembly can be inserted through the central bore 150 of the stator core body 100 via the first axial end 510 of the housing 500 to axially position the entire rotor shaft subassembly in the housing 500. More specifically, this allows the rotor shaft subassembly to be sequentially inserted through the first end cap 600, the central bore 150 of the stator core assembly 10, and at least a portion of the end cap cavity of the second end cap 700 to install the rotor shaft subassembly in position.

[0142] This simplifies installation, and once assembled, ensures better concentricity of the rotor shaft 450. More specifically, the potting compound is applied without installing the rotor shaft subassembly. More specifically, the first bearing 453 and the second bearing 454 can form an interference fit with the rotor shaft 450.

[0143] As shown in Figures 1-2 and 9-10, in some embodiments, the motor 1 further includes a sensor assembly 800 configured to sense the angular position of the rotor shaft 450. In one embodiment, the sensor assembly 800 is positioned at the second end 452 of the rotor shaft 450, thereby allowing the sensor assembly 800 to accurately sense the rotor shaft 450. The sensor assembly 800 is more specifically disposed within the housing 500 of the motor 1. In one embodiment, as shown in Figure 2, the sensor assembly 800 is axially disposed between the axially inner end of the second end cap 700, i.e., the end facing the stator core assembly 10, and the stator core assembly 10.

[0144] In some embodiments, as shown in Figures 9-10 , the sensor assembly 800 may include a circuit board (referred to as a second circuit board 810 ) and one or more sensors 820 electrically connected to the second circuit board 810 . Three sensors 820 are shown. In one specific embodiment, the sensors 820 are Hall sensors. More specifically, the one or more sensors 820 are configured to sense the magnetic tiles 410 of the rotor shaft 450 , thereby sensing the angular position of the rotor shaft 450 . In one specific embodiment, as shown in Figures 1-2 and 9-10 , the sensors 820 of the sensor assembly 800 are disposed on the side of the second circuit board 810 facing the stator core assembly 10 . More specifically, the one or more sensors 820 are disposed so as to axially overlap the magnetic tiles 410 of the rotor shaft 450 , thereby enabling the sensors 820 to more accurately sense the magnetic tiles 410 . This arrangement allows the sensors 820 to directly sense the position of the magnetic tiles 410 without increasing the length of the rotor shaft 450 where the magnetic tiles 410 are disposed, thereby avoiding cumulative sensing errors caused by the magnetic tiles. Furthermore, such an arrangement allows for a reduction in the overall axial dimension of the rotor shaft 450, thereby reducing the overall axial dimension of the motor 1. As shown in Figures 1-2 and 9-10, in some embodiments, the second circuit board 810 of the sensor assembly 800 is an annular circuit board including a central hole 850, through which the second end 452 of the rotor shaft 450 can be inserted. This allows the sensor assembly 800 to be positioned close to the magnetic shoe 410 while not interfering with the placement of the second bearing 454 for supporting the rotor shaft 450.

[0145] In some embodiments, as shown in Figures 1-2 and 11, the motor 1 further includes an electrical connector 900 for electrically connecting the windings 130 and / or the sensor assembly 800 to an external component, such as an external controller. In one embodiment, as shown in Figure 2, the electrical connector 900 and the sensor assembly 800 are provided separately from each other, more specifically, as two distinct components. This separate arrangement allows the sensor assembly 800 to be flexibly positioned closer to the magnetic tiles 410 of the rotor shaft 450 to ensure sensing accuracy. It also allows the electrical connector 900 to be flexibly arranged within other available spaces within the motor 1, facilitating connection between the electrical connector 900 and the external component while creating a compact motor 1, thereby achieving a simpler structure. In one specific embodiment, the electrical connector 900 is provided on the side of the sensor assembly 800 opposite the side facing the stator core assembly 10. More specifically, the electrical connector 900 can be provided within the end cap cavity of the second end cap 700. More specifically, the electrical connector 900 is located axially outward of the rotor shaft 450. As described above, the electrical connector 900 is used to connect to an external mating component, so it is placed within the end cap cavity of the second end cap 700 to facilitate connection with the external mating component. In this case, it is particularly advantageous to separate the electrical connector 900 from the sensor assembly 800. If the sensor assembly 800 and the electrical connector 900 are integrally formed, the magnetic shoe 410 of the rotor shaft 450 must also be able to reach the end cap cavity of the second end cap 700 in order for the sensor assembly 800 to sense the position of the rotor shaft 450. Therefore, the rotor shaft 450 must be extended to the end cap cavity of the second end cap 700. This increases the axial length of the rotor shaft 450 and, therefore, the axial length of the motor 1. Furthermore, it results in a more complex internal structure of the end cap cavity of the second end cap 700, resulting in greater runout and wobble errors. Therefore, separating the sensor assembly 800 and the electrical connector 900 allows the internal structure of the end cap cavity of the second end cap 700 to be simplified while shortening the axial dimension of the motor.

[0146] In one embodiment, the axial length of the stator core assembly 10 is set to 62%–70% of the axial length of the housing 500. More specifically, the axial length of the housing 500 is set to be 14–20 mm greater than the length of the stator core assembly 10. This is advantageous because space must be reserved within the housing 500 of the motor 1 for the axial protruding ends of the windings 130, the placement of the sensor assembly 800, and safe insulation distances. When these conditions are met, a shorter motor housing 500 results in a shorter rotor, resulting in improved concentricity, and a shorter and lighter overall motor.

[0147] As shown in FIG11 , in some embodiments, the electrical connector 900 may include a circuit board, referred to as a first circuit board 910 . The first circuit board 910 may include a first axial side and a second axial side, opposite to each other. The first axial side is provided with at least one first contact pin 940 for electrically connecting to the winding 130 and / or at least one second contact pin 920 for electrically connecting to the sensor assembly 800 . More specifically, as shown in FIG10 , the sensor assembly 800 may further include at least one connection portion 830, such as a solder pad, provided on the second circuit board 810 for electrically connecting to the at least one second contact pin 920 . More specifically, the second axial side of the first circuit board 910 of the electrical connector 900 is provided with a plurality of third contact pins 930 for electrically connecting to an external mating component.

[0148] As shown in Figures 1-2, in some embodiments, the motor 10 may further include a potting material portion 550 disposed between the second end cap 700 and the electrical connector 900 and / or between the second end cap 700 and the sensor assembly 800 and / or between the sensor assembly 800 and the housing 500 and / or between the sensor assembly 800 and the stator core assembly 10. The potting material portion is formed of a potting compound, such as an epoxy resin. In one embodiment, the potting compound fully fills the entire motor 1, absorbs noise generated during operation of the motor 1, and does not shrink after curing. This effectively protects the motor 1 from damage during preoperative sterilization and during surgery when the motor 1 is used in a surgical operation.

[0149] In a specific embodiment, potting compound is applied from the outside of the second end cap 700 toward the interior of the motor 1 before the rotor shaft subassembly is installed in the housing 500 and after the second end cap 700 is installed. During the potting compound application, the electrical connector 900 and sensor assembly 800 can be positioned. In this case, space can be left within the end cap cavity of the second end cap 700 for the second end portion 452 of the rotor shaft 450 and the second bearing 454. Furthermore, during this potting compound application, thermally expanded polytetrafluoroethylene (PTFE) can be used as a tool to support the machined center hole 150 of the stator core body 100. After the potting compound is applied, the PTFE solidifies and then contracts on cooling, facilitating removal. As shown above, the electrical connector 900 can be positioned within the end cap cavity of the second end cap 700, and the sensor assembly 800 can be positioned within the housing 500, near the axially inner end of the second end cap 700. The potting compound can be applied to securely mount the electrical connector 900 and sensor assembly 800. On the other hand, since the sensor 820 of the sensor assembly 800, such as the Hall sensor, is relatively sensitive and easily damaged, and is one of the key components affecting the normal operation of the motor, placing it inside the shell and encapsulating it with potting material around it can increase its reliability.

[0150] As shown in Figures 1-2 and 21-22, in some embodiments, the axially inner end of the second end cap 700 is inserted into the second axial end 520 of the housing 500. The motor 1 may further include a bushing 560 disposed around a portion 720 near the axially inner end of the second end cap 700 and the second axial end 520 of the housing 500. The bushing 560 may be welded to the second end cap 700 at a butt weld, for example. In one embodiment, as shown in Figure 21, the bushing 560 is provided with a first chamfered portion 561 and the second end cap 700 is provided with a second chamfered portion 721 at the butt weld, such that the first chamfered portion 561 and the second chamfered portion 721 form an outwardly open annular groove at the butt weld to accommodate the weld. As a result, welding is performed along the bottom of the annular groove, and the weld does not protrude from the outer surface of the motor 1. More specifically, the bushing 560 may form an interference fit with the outer circumference of the housing 500.

[0151] 2 , in some embodiments, a first O-ring 570 may be provided between the bushing 560 and the portion 720 of the second end cap 700, and / or a second O-ring 580 may be provided between the bushing 560 and the second axial end 520 of the housing 500. To this end, as shown in FIG22 , a first peripheral groove 567 and / or a second peripheral groove 568 may be provided in the bushing 560 for accommodating the first O-ring 570 and / or the second O-ring 580, respectively.

[0152] The present disclosure also relates to a surgical device, which includes the motor 1 according to any one of the above embodiments, and thus includes various improvements and advantages associated with the motor 1 .

[0153] Method of manufacturing a motor

[0154] The present disclosure also relates to a method for manufacturing the motor 1 according to the various embodiments described above. The method for manufacturing the motor 1 accordingly has the improvements and advantages described above with respect to the motor. According to one embodiment, as shown in Figures 1-8, the method for manufacturing the motor 1 may include the following steps:

[0155] Step S1: stacking silicon steel sheets 140 to form a stator core assembly 10 of a stator assembly, and forming the stator core assembly 10 includes:

[0156] Sub-step S1.1: forming the stator core body 100 of the stator core assembly 10 so that the stator core body 100 includes stator teeth 110 and slots 120 alternating in a circumferential direction;

[0157] Sub-step S1.2: extending the wire through the slot 120 and winding it around the stator teeth 110 to form the winding 130;

[0158] Sub-step S1.3: forming the stator core outer ring 200 of the stator core assembly 10 separately from the stator core main body 100 , so that the stator core outer ring 200 is formed with a hollow portion 250 ;

[0159] Sub-step S1.4: inserting the stator core body 100 into the hollow portion 250 of the stator core outer ring 200 to form the stator core assembly 10; and

[0160] Step S2: providing a rotor assembly 400 and disposing the rotor shaft 450 of the rotor assembly 400 to be rotatable relative to the stator assembly.

[0161] According to one embodiment, as shown in Figure 8, step S1 includes using self-adhesive silicon steel sheets to form the stator core assembly 10. More specifically, the thickness of the self-adhesive silicon steel sheets used to form the stator core assembly 10 is 0.1 mm.

[0162] According to one embodiment, as shown in Figures 3 and 5-7, in sub-step S1.1, the slot 120 of the stator core body 100 is formed with a slot opening 121 that opens on the radial outer periphery of the stator core body 100. More specifically, sub-step S1.1 includes setting the width of the slot opening 121 in the circumferential direction to be within a range of 1-1.3 mm.

[0163] According to one embodiment, as shown in FIG. 3 and FIG. 5 - 7 , sub-step S1.1 includes forming the stator core body 100 with nine slots 1120 evenly distributed along the circumferential direction.

[0164] According to one embodiment, sub-step S1.2 includes receiving the number of wires in each slot 120 in a range of 144-252, so that the slot fill rate of each slot 120 is 40%-50%.

[0165] According to one embodiment, in sub-step S1.2, the winding 130 is formed to include two axial protruding ends 131, 132 (schematically shown in FIG2) opposite to each other, and the axial height of the axial protruding ends 131, 132 does not exceed 2.5 mm.

[0166] According to some embodiments, as shown in Figures 3-7, in sub-step S1.1, the stator teeth 110 are formed to include yoke portions located on the radial outer periphery of the stator core body 110, referred to herein as first yoke portions 111, and each slot opening 121 is disposed between two adjacent first yoke portions 111. More specifically, each first yoke portion 111 includes two circumferential ends 111a and 111b that are opposite to each other in the circumferential direction, and each circumferential end portion 111a and 111b of the first yoke portion 111 constitutes a radial outer peripheral portion that participates in defining the corresponding slot 120.

[0167] According to some embodiments, as shown in Figures 4-7, in sub-step S1.3, the stator core outer ring 200 is formed to include second yokes 220 and third yokes 230 alternately arranged in the circumferential direction. More specifically, the radial thickness of the third yoke 230 can be set to be greater than the radial thickness of the second yoke 220.

[0168] According to some embodiments, as shown in Figures 5-7, in sub-step S1.4, the second yoke 220 of the stator core outer ring 200 is aligned with the corresponding first yoke 111 of the stator core body 100 to form a transition fit or interference fit. For example, the second yoke 220 and the corresponding first yoke 111 have an interference fit of 0.005mm-0.015mm on one side. Alternatively or additionally, in sub-step S1.4, the third yoke 230 of the stator core outer ring 200 is aligned with the corresponding notch 120 of the stator core body 100 to form a transition fit or interference fit. For example, the third yoke 230 and the corresponding notch 120 have an interference fit of 0.005mm-0.015mm on one side.

[0169] According to one embodiment, step S1 further includes, after sub-step S1.4, sub-step S1.5: providing a housing 500 for forming motor 1 and installing stator core outer ring 200 into housing 500 using a transition fit to form an intermediate-stage stator assembly. Optionally, step S1 further includes, after sub-step S1.4 and before sub-step S1.5, sub-step S1.4a: wrapping the outer periphery of stator core outer ring 200 with outer insulation paper, i.e., installing stator core assembly 10 into housing 500 after the outer insulation paper is wrapped.

[0170] According to one embodiment, as shown in Figure 2, step S1 also includes a sub-step S1.6 after sub-step S1.5: potting the formed intermediate stage stator assembly, including potting the potting material between the shell 500 and the stator core outer ring 200 and / or between the stator core outer ring 200 and the stator core body 100 through the axially opposite first axial end 510 or the second axial end 520 of the shell 500 and / or potting into two axial protruding ends 131, 132 surrounding the winding assembly 130.

[0171] According to one embodiment, as shown in FIG2 , step S1 further includes, after sub-step S1.5 and before sub-step S1.6, sub-step S1.51: providing a first end cap 600 and installing the first end cap 600 at the first axial end 510 of the housing 500. More specifically, sub-step S1.6 also includes applying potting material between the first end cap 600 and the housing 500, and between the first end cap 600 and the stator core assembly 10. Optionally, in sub-step S1.6, the potting material is applied from outside the first end cap 600 while the first end cap 600 is in place on the housing 500.

[0172] According to one embodiment, as shown in Figures 3 and 5-7, sub-step S1.1 further includes forming a center hole 150 in the stator core body 100. According to a more specific embodiment, as shown in Figure 6, sub-step S1.6 further includes forming a potting material layer on the inner peripheral wall 151 of the center hole 150, that is, applying the potting material to the inner peripheral wall 151 of the center hole 150 so that the minimum thickness T of the inner peripheral wall 151 is relatively thick. For example, in this case, the minimum thickness T of the inner peripheral wall 151 of the center hole 150 can be, for example, 0.5mm-4mm. More specifically, step S1 further includes a sub-step S1.7 after sub-step S1.6: processing the inner peripheral wall 151 of the center hole 150 formed with the potting material layer into a continuous inner peripheral wall 151 with a minimum thickness t of 0.02mm-0.29mm (as shown in Figure 7). More specifically, step S1.7 includes first turning the inner peripheral wall 151 with the potting material layer and then honing the inner peripheral wall 151. More specifically, at the end of sub-step S1.7, potting material still remains on the inner peripheral wall 151 of the central hole 150.

[0173] According to one embodiment, as shown in FIG. 14 to FIG. 20 , step S1 further includes a sub-step S1.15 between sub-step S1.1 and sub-step S1.2: placing insulating paper 300 in the slot 120 of the stator core body 100 .

[0174] According to one embodiment, as shown in Figures 14-17 and 19, sub-step S1.15 further includes: providing insulating paper 300, marking the insulating paper 300 according to the configuration of the stator teeth 110 and the slots 120 of the stator core body 100, folding the insulating paper 300 at each mark to form the insulating paper 300 to include circumferentially alternating slot-corresponding portions 320 and stator-tooth-corresponding portions 310, and placing the folded insulating paper 300 on the outer periphery of the stator core body 100 such that the slot-corresponding portions 320 of the insulating paper 300 are laid in the corresponding slots 120 and the stator-tooth-corresponding portions 310 are wrapped around the outer periphery of the corresponding stator teeth 110. More specifically, as shown in Figure 14, the provided insulating paper 300 is rectangular in its unfolded state. In a more specific embodiment, as shown in Figures 16 and 20, sub-step S1.15 also includes marking an axial disconnection position 313 in each stator tooth corresponding portion 310 of the insulating paper 300; step S1 also includes a sub-step S1.25 between sub-steps S1.2 and S1.3: disconnecting the insulating paper 300 at each axial disconnection position 313 and shaping the disconnected insulating paper 300 into a slot opening 121 that wraps around the corresponding slot 120.

[0175] According to one embodiment, as shown in FIG. 18 , sub-step S1.15 further includes making the two axial ends of the insulation paper 300 higher than the corresponding axial ends of the stator core assembly 10 by an axial height value h, where the value of h is 0.75-1 mm.

[0176] According to one embodiment, as shown in Figures 1 and 12-13, the rotor shaft 450 of the rotor assembly 400 provided in sub-step S1.4 is provided with a magnetic tile 410 having four poles. More specifically, the motor 1 is formed into a slot-pole matching structure with four poles and nine slots.

[0177] According to some embodiments, as shown in Figures 2 and 9-10, after sub-step S1.6, the method for manufacturing the electric motor 1 further includes a sub-step S1.7 of positioning a sensor assembly 800 for sensing the angular position of the rotor shaft 450 at the end 452 of the rotor shaft 450 adjacent to the second axial end 520 of the housing 500. More specifically, the sensor assembly 800 is disposed in the housing 500 of the electric motor 1.

[0178] According to some embodiments, as shown in Figures 2 and 11 , after sub-step S1.7, the method for manufacturing electric motor 1 further includes sub-step S1.8: providing an electrical connector 900 separately from sensor assembly 800, electrically connecting winding 130 to an external mating component and / or electrically connecting sensor assembly 800 to an external mating component via electrical connector 900. More specifically, sub-step S1.8 also includes providing electrical connector 900 on a side of sensor assembly 800 opposite the side facing stator core assembly 10. More specifically, as shown in Figure 2 , sub-step S1.8 also includes providing a second end cap 700 having an end cap cavity, installing electrical connector 900 in the end cap cavity, and mounting second end cap 700 to second axial end 520 of housing 500. More specifically, sensor assembly 800 is axially positioned between second end cap 700 and stator core assembly 10.

[0179] According to some embodiments, as shown in FIG. 2 , after sub-step S1.8, the method for manufacturing electric motor 1 further includes sub-step S1.9: potting through the second end cap 700 to apply potting material between the second end cap 700 and the electrical connector 900, and / or between the second end cap 700 and the sensor assembly 800, and / or between the sensor assembly 800 and the housing 500, and / or between the sensor assembly 800 and the stator core assembly 10. During this potting process, thermally expanded polytetrafluoroethylene (PTFE) can be used as a tool to support the machined center hole 150 of the stator core body 100. After the potting material is applied, the PTFE solidifies and then contracts on cooling, facilitating removal. Optionally, this potting process leaves space within the end cap cavity of the second end cap 700 for the bearing 454 supporting the rotor shaft 450.

[0180] According to some embodiments, as shown in Figures 2 and 12, after sub-step S1.8, step S2 further includes sub-step S2.1: providing a first bearing 453 for installation in the first end cap 600 and a second bearing 454 for installation in the second end cap 700, and installing the first bearing 451 and the second bearing 454 on the rotor shaft 450 to form a rotor shaft subassembly, wherein the outer diameter of the first bearing 453, the inner diameter of the central hole 150 of the stator core body 100, and the outer diameter of the second bearing 454 decrease in sequence. More specifically, step S2 further includes sub-step S2.2 after sub-step S2.1: sequentially inserting the rotor shaft subassembly through the first end cap 600, the central hole 150 of the stator core assembly 10, and at least a portion of the end cap cavity of the second end cap 700 to install the rotor shaft subassembly in place.

[0181] According to some embodiments, as shown in Figures 1 and 2, sub-step S1.8 includes inserting the axially inner end of the second end cap 700 into the second axial end 520 of the housing 500. The method for manufacturing the motor 1 further includes, after sub-step S1.8, step S4: disposing a bushing 560 around a portion 720 near the axially inner end of the second end cap 700 and the second axial end 520 of the housing 500. More specifically, the method for manufacturing the motor 1 further includes, after step S4, sub-step S4.1: welding the bushing 560 to the second end cap 700 at a butt weld. More specifically, as shown in Figure 21, sub-step S1.8 includes setting a second chamfered portion 721 at the butt welding portion on the second end cover 700, and step S4 includes setting a first chamfered portion 561 at the butt welding portion on the bushing 560, and forming an annular groove at the butt welding portion with the first chamfered portion 561 and the second chamfered portion 721; sub-step S4.1 includes welding at the annular groove, more specifically applying solder to the bottom of the annular groove so that the formed weld does not protrude from the outer surface of the motor 1.

[0182] According to some embodiments, as shown in Figures 2 and 22, the method for manufacturing the motor 1 includes a step S3 between sub-steps S1.8 and S4: disposing a first O-ring 570 at the portion 720 of the second end cap 700 and / or disposing a second O-ring 580 at the second axial end 520 of the housing 500; wherein step S4 includes installing the bushing 560 circumferentially around the first O-ring 570 and / or the second O-ring 580. More specifically, the bushing 560 may be provided with respective circumferential grooves 567 and 568 for accommodating the first O-ring 570 and / or the second O-ring 580.

[0183] The exemplary implementation schemes of the stator core assembly, the motor, and the method for manufacturing the motor proposed in the present invention are described in detail above with reference to the preferred embodiments. However, it will be understood by those skilled in the art that, without departing from the concept of the present invention, various modifications and variations can be made to the above-mentioned specific embodiments, and various technical features and structures proposed in the present invention can be combined in various ways without exceeding the scope of protection of the present invention.

[0184] The scope of the present disclosure is not limited by the above-described embodiments but by the appended claims and their equivalents.

Claims

1. A motor, comprising: A stator assembly, the stator assembly comprising a housing and a stator core assembly assembled within the housing, and the stator core assembly comprising: A stator core body, including stator teeth and notches alternately arranged in the circumferential direction; A winding, the winding comprising a plurality of wires extending through the notches and wound around the stator teeth; A stator core outer ring, constructed separately from the stator core body and having a hollow portion, the hollow portion being configured to receive the stator core body; and A rotor assembly, including a rotor shaft configured to be rotatable relative to the stator assembly; Wherein, the notches include notch openings opening on the radially outer periphery of the stator core body, the stator teeth include a first yoke portion located on the radially outer periphery of the stator core body, and each of the notch openings is disposed between two adjacent ones of the first yoke portions; Wherein, the stator core outer ring includes second yoke portions and third yoke portions alternately arranged in the circumferential direction, wherein the second yoke portions are configured to cooperate with corresponding first yoke portions of the stator core body, and the third yoke portions are configured to cooperate with corresponding notches of the stator core body; Wherein, the stator core body is provided with a central hole and a continuous inner peripheral wall for defining the central hole, and the rotor shaft is inserted into the central hole; Wherein, there are 9 notches provided in the stator core body, and magnetic tiles with 4 poles are provided on the rotor shaft.

2. The motor according to claim 1, wherein: The width of the notch opening in the circumferential direction is 1 - 1.3 mm; and / or The number of wires received by each of the notches ranges between 144 - 252, and the slot fill factor of each notch is 40% - 50%; and / or The minimum thickness of the inner peripheral wall is 0.02 mm - 0.29 mm.

3. The motor according to claim 1 or 2, wherein, The radial thickness of the third yoke portion is greater than the radial thickness of the second yoke portion; and / or An interference fit is formed between the second yoke portion and the corresponding first yoke portion; and / or An interference fit is formed between the third yoke portion and the corresponding notch.

4. The motor according to claim 3, wherein: An interference fit is formed between the second yoke portion and the corresponding first yoke portion with a unilateral interference amount of 0.005 mm - 0.015 mm; and / or An interference fit is formed between the third yoke portion and the corresponding notch with a unilateral interference amount of 0.005 mm - 0.015 mm.

5. The electric machine according to claim 1 or 2, wherein, The winding includes two axially protruding ends opposite to each other, and the axial height of the axially protruding ends does not exceed 2.5 mm.

6. The motor according to claim 1 or 2, wherein, The stator core assembly is formed by stacking silicon steel sheets, the silicon steel sheets are self - adhesive silicon steel sheets, and the thickness of the self - adhesive silicon steel sheets is 0.1 mm.

7. The electric machine according to claim 1 or 2, wherein, The motor further includes a potting material portion provided between the housing and the stator core outer ring and / or between the stator core body and the stator core outer ring and / or a potting material portion wrapping the winding at two axially protruding ends of the winding.

8. The electric machine according to claim 7, wherein, The motor further includes: A first end cover disposed at the first axial end of the housing, and the motor further includes a potting material portion disposed between the housing and the first end cover; A second end cover, the second end cover being disposed at the second axial end of the housing opposite to the first axial end.

9. The electric machine according to claim 8, wherein, The motor further includes: A sensor assembly configured to sense the angular position of the rotor shaft, the sensor assembly being positioned at an end of the rotor shaft near the second axial end of the housing; and An electrical connector configured to electrically connect the winding to an external mating member and / or electrically connect the sensor assembly to an external mating member, the electrical connector being disposed separately from the sensor assembly; Wherein, the electrical connector is disposed on the other side of the sensor assembly opposite to the side facing the stator core assembly; Wherein, the sensor assembly is axially disposed between the axial inner end of the second end cover and the stator core assembly.

10. The motor according to claim 9, wherein, The electrical connector is disposed in the end cover cavity of the second end cover.

11. The motor according to claim 9, wherein: The axial length of the stator core assembly is 62% - 70% of the axial length of the housing; and / or The axial length of the housing is 14 - 20 mm greater than the length of the stator core assembly.

12. The motor according to claim 9, wherein, The motor further includes a potting material portion disposed between the second end cover and the electrical connector and / or between the second end cover and the sensor assembly and / or between the sensor assembly and the housing and / or between the sensor assembly and the stator core assembly.

13. The motor according to claim 9, wherein, The motor includes a first bearing disposed in the first end cover and a second bearing disposed in the second end cover, the first bearing and the second bearing being configured to support the rotor shaft, wherein the outer diameter of the first bearing, the inner diameter of the central hole, and the outer diameter of the second bearing decrease in sequence.

14. The electric machine according to claim 1 or 2, wherein, The axial inner end of the second end cover is inserted into the second axial end of the housing, and the motor further includes a bushing disposed around a part near the axial inner end of the second end cover and the second axial end of the housing, the bushing being welded to the second end cover at the butt welding portion, wherein at the butt welding portion, the bushing is provided with a first chamfer portion and the second end cover is provided with a second chamfer portion, so that the first chamfer portion and the second chamfer portion form an annular groove at the butt welding portion to accommodate the weld seam; Wherein: A first O-ring is disposed between the bushing and the portion of the second end cover, and / or A second O-ring is disposed between the bushing and the second axial end of the housing.

15. The motor according to claim 1 or 2, wherein, The stator core assembly includes an integral insulating paper, the insulating paper having a shape folded to correspond to at least two of the slots and the stator teeth between the at least two slots, so as to be able to cover the at least two slots and the stator teeth between the at least two slots via the slot openings.

16. A surgical device, comprising the motor according to any one of the preceding claims.

17. A method of manufacturing a motor, comprising: Step S1: Stack silicon steel sheets to form a stator core assembly of a stator assembly, and forming the stator core assembly includes: Sub-step S1.1: Form a stator core body of the stator core assembly such that the stator core body includes stator teeth and notches alternating in the circumferential direction, wherein notches of the stator core body are formed with notch openings opening on a radially outer periphery of the stator core body, the stator teeth are formed to include first yoke portions located on the radially outer periphery of the stator core body, and each of the notch openings is disposed between two adjacent first yoke portions; wherein the stator core body is formed with 9 notches uniformly distributed in the circumferential direction; Sub-step S1.2: Extend a wire through the notch and wind it around the stator teeth to form a winding; Sub-step S1.3: Separately form a stator core outer ring of the stator core assembly from the stator core body such that the stator core outer ring is formed with a hollow portion, wherein the stator core outer ring is formed to include second yoke portions and third yoke portions alternately arranged in the circumferential direction; Sub-step S1.4: Insert the stator core body into the hollow portion of the stator core outer ring to form the stator core assembly, wherein the second yoke portions are arranged to cooperate with corresponding first yoke portions of the stator core body, and the third yoke portions are arranged to cooperate with corresponding notches of the stator core body; Sub-step S1.5: Provide a housing for forming the motor, and fit the stator core outer ring into the housing to form an intermediate-stage stator assembly; and Step S2: Provide a rotor assembly, and arrange a rotor shaft of the rotor assembly to be rotatable relative to the stator assembly, wherein magnetic tiles with 4 poles are arranged on the rotor shaft.

18. The method of manufacturing an electric machine according to claim 17, wherein, The step S1 further includes a sub-step S1.15 between the sub-step S1.1 and the sub-step S1.2: Provide an integral insulating paper, mark the insulating paper according to the configuration of the stator teeth and notches of the stator core body, fold the insulating paper at each marked position to fold the insulating paper into a shape including circumferentially alternating notch corresponding portions and stator tooth corresponding portions, and dispose the folded insulating paper on the outer periphery of the stator core body such that the notch corresponding portions of the insulating paper are laid in corresponding notches, and the stator tooth corresponding portions wrap the outer peripheries of corresponding stator teeth.

19. A method of manufacturing an electric machine according to claim 17 or 18, wherein, The step S1 further includes: Sub-step S1.6 after the sub-step S1.5: Pot the formed intermediate-stage stator assembly, including potting potting material between the housing and the stator core outer ring and / or between the stator core outer ring and the stator core body and / or potting to surround two axial ends of the winding; Sub-step S1.51 after the sub-step S1.5 and before the sub-step S1.6: Provide a first end cap and mount the first end cap at the first axial end of the housing, wherein the sub-step S1.6 further includes potting potting compound between the first end cap and the housing and between the first end cap and the stator core assembly.

20. The method of manufacturing an electric machine according to claim 19, wherein: After the sub-step S1.6, the method further includes a sub-step S1.7: Dispose a sensor assembly for sensing the angular position of the rotor shaft at an end of the rotor shaft near the second axial end of the housing; After the sub-step S1.7, the method further includes a sub-step S1.8: Dispose an electrical connector separately from the sensor assembly, and electrically connect the winding to an external mating part and / or electrically connect the sensor assembly to an external mating part through the electrical connector; After the sub-step S1.8, the method further includes a sub-step S1.9: Perform potting via the second end cap to pot the potting compound between the second end cap and the electrical connector and / or between the second end cap and the sensor assembly and / or between the sensor assembly and the housing and / or between the sensor assembly and the stator core assembly.

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