Electric tool and motor

Abstract

The utility model discloses an electric tool and a motor. The electric tool includes: a functional member; the motor drives the functional part to work; the power supply device at least supplies power to the motor; the motor comprises a stator assembly, and the stator assembly comprises a stator core and a multi-phase winding. The stator iron core is provided with a plurality of teeth on which wires can be wound, each multi-phase winding comprises a plurality of coils, and each coil is composed of a plurality of wires which are wound on the same tooth in parallel; the at least two coils belonging to the in-phase winding are wound on the adjacent teeth, and the coil turns of the at least two coils belonging to the in-phase winding are different; the number of turns of the coil is the number of turns of a plurality of wires wound on the same tooth in parallel.

Description

Technical Field

[0001] The present application relates to the technical field of electric tools, and in particular to an electric tool and a motor. Background Art

[0002] Most of the cutting, fastening, impact and other tools widely used in various scenes such as construction and gardening are currently driven by electric energy supply. The electric tools are equipped with a motor controlled by a controller. The motor has a fixed stator assembly and a rotor assembly that rotates during operation. The stator assembly includes a stator winding. The energized stator winding can provide a magnetic field to drive the rotor assembly to rotate, and then drive the output shaft and tool functional parts to operate. The winding method of the stator winding varies in difficulty and may cause changes in motor performance.

[0003] This section provides background information related to the present application which is not necessarily prior art. Utility Model Content

[0004] One object of the present application is to solve or at least alleviate part or all of the above problems. To this end, one object of the present application is to provide an electric tool and a motor.

[0005] In order to achieve the above objectives, this application adopts the following technical solutions:

[0006] An electric tool comprises: a functional part; a motor, driving the functional part to perform operation; a power supply device, at least supplying power to the motor; the motor comprises a stator assembly, the stator assembly comprises a stator core and a multi-phase winding; the stator core has a plurality of teeth for winding wires, each of the multi-phase windings comprises a plurality of coils, each coil is composed of a plurality of wires wound in parallel on the same tooth; at least two coils belonging to the same phase winding are wound on adjacent teeth, and the number of coil turns of the at least two coils belonging to the same phase winding is different; the number of coil turns is the number of turns of the plurality of wires wound in parallel on the same tooth.

[0007] In some embodiments, the number of coil turns of each coil belonging to the same-phase winding is n1 or n2, where n1 and n2 are positive integers.

[0008] In some embodiments, the number of coil turns of each coil belonging to the same-phase winding is alternately n1 or n2 along the circumferential direction of the stator core, where n1 and n2 are positive integers.

[0009] In some embodiments, when the sum of the number of coil turns of two coils wound around adjacent teeth is an even number 2*n, n1 is equal to n-1, and n2 is equal to n+1, where n is a positive integer greater than or equal to 2.

[0010] In some embodiments, when the sum of the number of coil turns of two coils wound around adjacent teeth is an odd number 2*n+1, n1 is equal to n, and n2 is equal to n+1, where n is a positive integer.

[0011] In some embodiments, each phase winding includes one or more pairs of coils wound around adjacent teeth, and other coils belonging to non-same-phase windings exist between the two pairs of coils belonging to the same-phase winding and wound around adjacent teeth.

[0012] In some embodiments, wire slots are formed between adjacent teeth, and a pair of two coils belonging to the same-phase winding and wound on adjacent teeth respectively enter the wire slots formed by the current tooth and the adjacent teeth that are not in phase, and exit from the wire slots formed by the current tooth and the adjacent teeth that are in phase; and / or, a pair of two coils belonging to the same-phase winding and wound on adjacent teeth respectively enter the wire slots formed by the current tooth and the adjacent teeth that are in phase, and exit from the wire slots formed by the current tooth and the adjacent teeth that are not in phase.

[0013] In some embodiments, the sum of the number of coil turns of the plurality of coils constituting each phase winding is equal.

[0014] In some embodiments, the multi-phase winding is a three-phase winding and is connected in a delta configuration.

[0015] In some embodiments, the number of parallel branches of the three-phase winding is 1.

[0016] In some embodiments, the stator core has 12 teeth, and the 12 teeth are defined as T1 to T12 along the circumference of the stator core; the four coils wound on T1, T2, T8, and T7 are connected in series in sequence to form a first phase winding, wherein the number of turns of the coils wound on T1 and T7 is n1, and the number of turns of the coils wound on T2 and T8 is n2; the four coils wound on T9, T10, T4, and T3 are connected in series in sequence to form a second phase winding, wherein the number of turns of the coils wound on T3 and T9 is n1, and the number of turns of the coils wound on T4 and T10 is n2; the four coils wound on T5, T6, T12, and T11 are connected in series in sequence to form a third phase winding, wherein the number of turns of the coils wound on T5 and T11 is n1, and the number of turns of the coils wound on T6 and T12 is n2; wherein n1 and n2 are positive integers.

[0017] A motor comprises a stator assembly, wherein the stator assembly comprises a stator core and a three-phase winding; the stator core comprises a plurality of teeth for winding wires; the multi-phase windings each comprise a plurality of coils, each coil being composed of a plurality of wires wound in parallel on the same tooth; at least two coils belonging to the same-phase winding are wound on adjacent teeth, and the number of coil turns of the at least two coils belonging to the same-phase winding is different; the number of coil turns is the number of turns of the plurality of wires wound in parallel on the same tooth.

[0018] In some embodiments, the motor is a brushless motor.

[0019] The benefit of the present application lies in that the coils belonging to the same-phase winding in the stator winding of the electric tool motor are at least partially adjacent, and at least partially have different numbers of turns, thereby simplifying the process difficulty when winding the stator winding, reducing the rework rate, and making it possible to adapt to the needs of different application scenarios by adjusting the number of coil turns while taking into account the motor performance requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is a three-dimensional diagram of an electric tool as one embodiment of the present application;

[0021] Figure 2 is a three-dimensional diagram of a motor in an electric tool as one embodiment of the present application;

[0022] Figure 3 yes Figure 2 An exploded view of the motor shown;

[0023] Figure 4 yes Figure 3 a plan view of a stator assembly in the illustrated motor;

[0024] Figure 5 yes Figure 4 A schematic diagram of a stator winding in a stator assembly being wound on a stator core;

[0025] Figure 6a It is a comparative diagram of motor speed under different winding methods;

[0026] Figure 6b It is a comparative diagram of motor power under different winding methods;

[0027] Figure 6c This is a schematic diagram comparing the motor efficiency under different winding methods.

[0028] Caption:

[0029] 100. Power tool; 10. Casing; 20. Functional parts; 30. Motor; 31. Rotor assembly; 32. Stator assembly; 321. Stator core; 322. Stator winding / multi-phase winding; 3211. Tooth; 3221. Coil. DETAILED DESCRIPTION

[0030] Before any embodiments of the application are explained in detail, it is to be understood that the application is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the above drawings.

[0031] In this application, the terms "comprises", "includes", "has" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device that includes a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of more restrictions, an element defined by the sentence "comprises a ..." does not exclude the presence of other identical elements in the process, method, article or device that includes the element.

[0032] In this application, the term "and / or" is a description of the association relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this application generally indicates that the related objects before and after are in an "and / or" relationship.

[0033] In the present application, the terms "connect", "combine", "couple", and "install" may refer to direct connection, combination, coupling, or installation, or indirect connection, combination, coupling, or installation. For example, direct connection refers to two parts or components being connected together without the need for an intermediate piece, and indirect connection refers to two parts or components being connected to at least one intermediate piece respectively, and the two parts or components being connected via the intermediate piece. In addition, "connect" and "couple" are not limited to physical or mechanical connections or couplings, and may include electrical connections or couplings.

[0034] In the present application, it will be understood by those of ordinary skill in the art that relative terms (e.g., "about," "approximately," "substantially," etc.) used in conjunction with quantities or conditions include the values ​​and have the meaning indicated by the context. For example, the relative terms include at least the degree of error associated with the measurement of a specific value, the tolerances caused by manufacturing, assembly, and use associated with a specific value, and the like. Such terms should also be considered to disclose a range defined by the absolute values ​​of the two endpoints. Relative terms may refer to plus or minus a certain percentage (e.g., 1%, 5%, 10% or more) of the indicated value. Numerical values ​​that do not use relative terms should also be disclosed as specific values ​​with tolerances. In addition, "substantially" may refer to plus or minus a certain degree (e.g., 1 degree, 5 degrees, 10 degrees or more) on the basis of the indicated angle when expressing a relative angular position relationship (e.g., substantially parallel, substantially perpendicular).

[0035] In this application, it will be understood by those skilled in the art that the function performed by a component can be performed by one component, multiple components, one part, or multiple parts. Similarly, the function performed by a part can also be performed by one part, one component, or a combination of multiple parts.

[0036] In the present application, the terms "upper", "lower", "left", "right", "front", "back" and other directional words are described based on the orientation and positional relationship shown in the accompanying drawings, and should not be understood as limiting the embodiments of the present application. In addition, in the context, it is also necessary to understand that when it is mentioned that an element is connected to another element "upper" or "lower", it can not only be directly connected to another element "upper" or "lower", but also indirectly connected to another element "upper" or "lower" through an intermediate element. It should also be understood that directional words such as upper side, lower side, left side, right side, front side, back side, etc. not only represent the positive orientation, but can also be understood as the lateral orientation. For example, the bottom can include directly below, lower left, lower right, lower front, and lower back, etc.

[0037] The technical solution proposed in this application is described in detail below with reference to the accompanying drawings and specific embodiments.

[0038] Figure 1 An electric tool 100 is shown as one embodiment in the present application. Figure 1 The power tool 100 shown is a reciprocating saw. The power tool 100 in other embodiments may also be other types of handheld power tools such as electric circular saws, jigsaws, electric drills, impact wrenches, or bench tools such as miter saws and table saws, or outdoor power equipment such as lawn mowers and snow blowers. It is understandable that the power tool 100 using the technical solution of the present application is not limited to reciprocating saws, nor is it limited to the tool categories described above.

[0039] refer to Figure 1 The electric tool 100 includes a housing 10, a functional part 20 and a motor 30. The housing 10 constitutes the main body of the electric tool 100, which connects or supports other components and forms a storage space, which can accommodate or partially accommodate other components. The functional part 20 is a component of the electric tool 100 that actually performs operations such as cutting, tightening, grinding, and impacting. Taking a reciprocating saw as an example, its functional part 20 is a saw blade. The reciprocating saw may include a transmission assembly that converts the power of the prime mover into reciprocating motion of the saw blade, and the saw blade reciprocates to cut the target workpiece. The functional parts 20 of other electric tools 100 may also be circular saw blades, chains, drill bits, etc. The motor 30 is the prime mover in the electric tool 100, which can be accommodated in the storage space of the housing 10. When the motor shaft of the motor 30 rotates, it can directly or indirectly drive the functional part 20 to operate through the transmission assembly.

[0040] In addition to the housing 10, the functional parts 20 and the motor 30, the power tool 100 may also include a power supply device. The power supply device can at least provide electrical energy to the motor 30, and can also provide power to other related circuits. Specifically, a drive circuit is connected between the power supply device and the motor 30, and the electrical energy provided by the power supply device can be transmitted from the drive circuit to the motor 30 through a DC bus. In some embodiments, the power supply device of the power tool 100 can be a battery pack, which is detachably connected to the power tool 100. In other embodiments, the power tool 100 can also be powered by mains electricity, an AC power supply in combination with a power adapter or a transformer, rectifier, or voltage stabilizing circuit.

[0041] Figure 2 , 3 An electric machine 30 is shown as one embodiment in the present application. Figure 2 , 3 The motor 30 shown is a three-phase brushless outer rotor motor 30. It is understandable that the motor 30 to which the technical solution of the present application is applied is not limited to this type.

[0042] refer to Figure 2 , 3 The motor 30 includes a rotor assembly 31 and a stator assembly 32. The rotor assembly 31 includes a component that rotates when the motor 30 is working, and the stator assembly 32 includes a component that is fixed in position when the motor 30 is working. The stator and rotor assemblies 32, 31 are nested with each other. The stator assembly 32 includes a stator core 321 and a stator winding 322 wound on the stator core 321. The stator winding 322 is generally a multi-phase winding 322. When the motor 30 is working, the stator winding 322 wound on the stator core 321 is energized in a changing manner and generates a changing magnetic field. The electromagnetic induction between the stator and rotor assemblies 32, 31 can drive the rotor assembly 31 to rotate to generate an electromagnetic torque, and then drive the rotation of the motor shaft or related components to drive the load and convert electrical energy into mechanical energy. In some embodiments, the motor 30 also includes components such as a fan and a bracket.

[0043] In some embodiments, the motor 30 is a brushless motor that is electronically commutated and does not include brushes.

[0044] In some embodiments, the motor 30 is an outer rotor motor, and the stator assembly 32 is nested in the rotor assembly 31. In other embodiments, the motor 30 is an inner rotor motor, and the rotor assembly 31 is nested in the stator assembly 32.

[0045] In some embodiments, the motor 30 is a three-phase motor, and its stator winding 322 includes three-phase windings A, B, and C. In other embodiments, the motor 30 is a non-three-phase motor such as a five-phase motor.

[0046] As mentioned above, in the electronic components of the motor 30, the stator core 321 and the multi-phase winding 322 wound thereon work together to generate magnetic flux. Figure 4 , 5 , the stator core 321 has a plurality of teeth 3211 for winding the wire. In some embodiments, the stator core 321 has a plurality of teeth 3211 for winding the wire circumferentially. When the motor 30 is an outer rotor motor, the teeth 3211 on the stator core 321 may extend radially outward from the center, and when the motor 30 is an inner rotor motor, the teeth 3211 on the stator core 321 may extend radially inward from the outer circumference. In some embodiments, the teeth 3211 on the stator core 321 may be evenly distributed, and the spacing between adjacent teeth in the circumferential direction may be equal. In other embodiments, the teeth 3211 on the stator core 321 may also be unevenly distributed. It can be understood that the above description takes the outer contour of the stator core 321 as an example of a circle, but the outer contour of the stator core 321 may also be a circular shape such as an ellipse, or a rectangular shape.

[0047] A wire slot is formed between two adjacent teeth, and the wire wound on the tooth 3211 will pass through one wire slot on both sides of the tooth and pass through the other wire slot. The wire will be wound around the tooth 3211 for several turns to form a coil 3221 wound around the tooth, and the number of turns of the wire wound around the tooth is called the number of turns of the coil 3221 on the tooth. In some embodiments, the coil 3221 wound around the tooth 3211 is formed by winding multiple wires in parallel, and the number of turns of the coil is the number of turns of the multiple wires wound in parallel on the same tooth 3211. The number of wires wound in parallel is different from the above number of turns of the coil. For example, 6 wires are wound around the tooth 3211 for three turns in parallel, and the number of turns of the coil 3221 on the tooth is 3.

[0048] Each phase winding in the stator winding 322 can be composed of coils 3221 wound on different teeth 3211 in series or in parallel. The winding method of each phase winding is related to the number of parallel branches of the multi-phase winding 322 and affects the number of wire ends of the stator winding 322. When the number of parallel branches is 1, taking a three-phase motor as an example, the stator winding 322 has 6 wire ends, which are the head wire ends and the tail wire ends of the three phases A, B, and C respectively. One phase winding can be composed of multiple coils 3221 wound on different teeth 3211 in series. When the number of parallel branches is 2, taking a three-phase motor as an example, the stator winding 322 has 12 wire ends, which are two head wire ends and two tail wire ends of the three phases A, B, and C respectively. One phase winding can be composed of multiple coils 3221 wound on different teeth 3211 in series and in parallel. In some embodiments, the motor 30 is a three-phase motor, and its stator winding 322 is connected in a triangle shape, and the three phases are connected end to end, that is, the A phase head end is connected to the C phase tail end, the C phase head end is connected to the B phase tail end, and the B phase head end is connected to the A phase tail end. The motor 30 can use the A, B, and C three-phase head end wire ends to access the drive signal from the drive circuit. In other embodiments, the motor 30 is a three-phase motor, and its stator winding 322 is connected in a star shape.

[0049] In the present application, at least two coils 3221 belonging to the same-phase winding are wound on adjacent teeth, and the number of coil turns of at least two coils 3221 belonging to the same-phase winding is different. Specifically, assuming that a phase winding of the motor 30 is composed of a plurality of coils 3221 wound on different teeth 3211 connected in series, then in this embodiment, at least two coils 3221 under the same-phase winding are continuously and sequentially wound on a pair of adjacent teeth, and the number of turns of at least two coils 3221 is different. It should be noted here that two adjacent coils may not be two coils with different numbers of turns, and two coils with different numbers of turns may not be adjacent.

[0050] The output performance of the motor 30 is affected by the stator winding 322. When the winding method of the stator winding 322 is the same, if j wires with a wire diameter of rb are wound on the teeth and nb turns are wound, if i*(ra*ra)*na is equal to j*(rb*rb)*nb, it can be regarded as equivalent to i wires with a wire diameter of ra being wound on the teeth and na turns, where i, j, na, and nb are positive integers. By setting the coil 3221 under the same-phase winding to different numbers of coil turns, it is beneficial to flexibly select the number of wires wound in parallel and the wire diameter, so as to adapt to the specific needs of different application scenarios, and to take into account the considerations of size design, process difficulty, etc. while ensuring performance.

[0051] In some embodiments, the number of coil turns of each coil 3221 belonging to the same-phase winding in the motor 30 is n1 or n2, wherein n1 and n2 are positive integers, and n1 is not equal to n2, that is, the coil 3221 belonging to the same-phase winding has two possible numbers of coil turns. In some cases, the two numbers of coil turns of each phase winding in the motor 30 are the same, and the stator winding 322 as a whole has two possible numbers of coil turns; in other cases, the two numbers of coil turns of each phase winding in the motor 30 are different. Taking a three-phase motor as an example, the number of coil turns of the coil 3221 under the A-phase winding may be n1 or n2, and the number of coil turns of the coil 3221 under the B-phase winding may be n1' or n2'. In other embodiments, in the stator winding 322 of the motor 30, the number of coil turns of each coil 3221 belonging to the same-phase winding can be other positive integers not equal to n1 or n2 in addition to n1 and n2, that is, the coil 3221 belonging to the same-phase winding has more than two possible numbers of coil turns.

[0052] In some embodiments, the number of coil turns of each coil 3221 belonging to the same-phase winding in the motor 30 is alternately n1 or n2 along the circumference of the stator core 321, that is, it is arranged with n1 and n2 as a period along the circumference. Here, it is described that the number of coil turns of each coil 3221 under the same-phase winding is alternately n1 and n2, but the coils 3221 with alternating turns are not necessarily wound on adjacent teeth. For example, it is assumed that a one-phase winding of the motor 30 is composed of four coils 3221 connected in series and wound on teeth T1, T2, T8, and T7 in sequence, and their number of coil turns is n1, n2, n1, and n2 in sequence, and the teeth T2 and T7 with different numbers of coil turns are not adjacent. In other embodiments, in the stator winding 322 of the motor 30, the number of coil turns of each coil 3221 belonging to the same-phase winding can also be set to n1 or n2 along the circumference of the stator core 321 based on other rules. For example, it can be arranged with a period of n1, n2, n2, and n1 along the circumferential direction, or with a period of n1, n2, and n2 along the circumferential direction, or with a period of n2, n1, and n1 along the circumferential direction. Other conceivable arrangement methods will not be described in detail.

[0053] In some embodiments, following the foregoing, the number of turns of each coil 3221 belonging to the same-phase winding in the motor 30 is alternately n1 or n2 along the circumference of the stator core 321, and there is at least one pair of coils wound on adjacent teeth and having different numbers of turns under the same-phase winding. If the sum of the number of turns of the two coils is an even number 2n, then n1 is equal to n-1, and n2 is equal to n+1, where n is a positive integer greater than or equal to 2. If the sum of the number of turns of the two coils is an odd number 2n+1, then n1 is equal to n, and n2 is equal to n+1, where n is a positive integer. For example, assume that a single-phase winding of the motor 30 includes two coils wound on teeth T1 and T2, the sum of the number of turns of the coil 3221 on T1 and T2 is 7, the number of turns of the coil 3221 on T1 is 3, and the number of turns of the coil 3221 on T2 is 4; the sum of the number of turns of the coil 3221 on T1 and T2 is 8, the number of turns of the coil 3221 on T1 is 3, and the number of turns of the coil 3221 on T2 is 5.

[0054] In some embodiments, the same-phase winding in the motor 30 is composed of one or more pairs of coils 3221 wound on adjacent teeth, and the number of coil turns of each coil 3221 belonging to the same-phase winding is alternately n1 or n2 along the circumference of the stator core 321, so the same-phase winding can be regarded as composed of multiple pairs of coils 3221 wound on adjacent teeth and with different numbers of coil turns. If the sum of the number of coil turns of each pair of coils 3221 wound on adjacent teeth is an even number 2n, then the number of turns of one coil is n-1, and the number of turns of the other coil is n+1. If the number of turns of each pair of coils 3221 wound on adjacent teeth is 2n+1, then the number of turns of one coil is n, and the number of turns of the other coil is n+1. For example, assuming that a single-phase winding of the motor 30 includes four coils wound around teeth T1, T2, T7, and T8, the number of turns of the coil 3221 on T1, T2, T7, and T8 can be 3, 4, 3, and 4 respectively, or the number of turns of the coil 3221 on T1, T2, T7, and T8 can be 3, 5, 3, and 5 respectively.

[0055] It should be noted that the magnitude relationship between the above n1 and n2 is not specifically limited. When the wire is wound on the starting tooth 3211, the number of coil turns can be the smaller one of n1 and n2, that is, starting from the starting tooth 3211, the number of coil turns on each tooth along the circumference of the stator core 321 is "less" and "more" alternately. For example, T1 is the starting tooth, the number of coil turns on the odd-numbered teeth is n-1 or n, and the number of coil turns on the even-numbered teeth is n+1. Alternatively, the number of coil turns of the coil 3221 on the starting tooth 3211 can also be the larger one of n1 and n2, that is, starting from the starting tooth 3211, the number of coil turns on each tooth along the circumference of the stator core 321 is "more" and "less" alternately. For example, T1 is the starting tooth, the number of coil turns on the odd-numbered teeth is n+1, and the number of coil turns on the even-numbered teeth is n-1 or n.

[0056] In some embodiments, following the foregoing, the same-phase winding in the motor 30 is composed of one or more pairs of coils 3221 wound on adjacent teeth, and the number of coil turns of each coil 3221 belonging to the same-phase winding is alternately n1 or n2 along the circumference of the stator core 321, then the stator winding 322 can be regarded as composed of multiple pairs of coils 3221 wound on adjacent teeth and with different numbers of coil turns. For example, the A-phase winding is composed of several pairs of coils 3221 wound on adjacent teeth, the B-phase winding is composed of several pairs of coils 3221 wound on adjacent teeth that are different from the A-phase winding, and the C-phase winding is composed of several pairs of coils 3221 wound on adjacent teeth that are different from the A-phase winding and the B-phase winding. In some embodiments, there are other coils 3221 belonging to non-same-phase windings between the two pairs of coils 3221 wound on adjacent teeth belonging to the same-phase winding. For example, there are coils 3221 under the B-phase winding and / or the C-phase winding between the two pairs of coils 3221 wound on adjacent teeth of the A-phase winding.

[0057] In some embodiments, the sum of the number of coil turns of the plurality of coils 3221 constituting each phase winding in the motor 30 is equal. Specifically, taking a three-phase motor as an example, the sum of the number of coil turns of each coil 3221 constituting the A phase winding, the sum of the number of coil turns of each coil 3221 constituting the B phase winding, and the sum of the number of coil turns of each coil 3221 constituting the C phase winding are equal. In some embodiments, the winding methods of each phase winding in the motor 30 may be equivalent to each other.

[0058] In addition, in addition to adjusting the number of turns of each coil under the same-phase winding to adapt to the scene changes, designing the winding order of the wire / coil 3221 on each tooth 3211 can also further optimize the relevant processes of the stator winding 322 of the motor 30 to achieve technical effects such as reducing the rework rate and scrap rate. In some embodiments, a pair of two coils wound on adjacent teeth belonging to the same-phase winding can be respectively inserted from the wire slot formed by the current tooth and the adjacent teeth that are not in phase, and can be passed out from the wire slot formed by the current tooth and the adjacent teeth in the same phase. In other embodiments, a pair of two coils wound on adjacent teeth belonging to the same-phase winding can be respectively inserted from the wire slot formed by the current tooth and the adjacent teeth in the same phase, and can be passed out from the wire slot formed by the current tooth and the adjacent teeth that are not in phase.

[0059] For example, it is assumed that the stator core 321 in the motor 30 has 12 teeth 3211, and the 12 teeth are defined as T1 to T12 along the circumferential direction, and the A-phase winding is composed of coils 3221 wound in series on teeth T1, T2, T8, and T7 in sequence. A wire slot S12 is formed between T12 and T1, a wire slot S1 is formed between T1 and T2, and a wire slot S2 is formed between T2 and T3. For the two coils wound on adjacent teeth T1 and T2, the coil 3221 on T1 passes through the wire slot S12 between it and the non-same-phase adjacent tooth T12, and passes through the wire slot S1 between it and the same-phase adjacent tooth T2; the coil 3221 on T2 passes through the wire slot S2 between it and the non-same-phase adjacent tooth T3, and passes through the wire slot S1 between it and the same-phase adjacent tooth T1.

[0060] A wire slot S6 is formed between T6 and T7, a wire slot S7 is formed between T7 and T8, and a wire slot S8 is formed between T8 and T9. For the two coils wound on adjacent teeth T7 and T8, the coil 3221 on T7 enters from the wire slot S7 between it and the adjacent tooth T8 in the same phase, and exits from the wire slot S6 between it and the adjacent tooth T6 that is not in the same phase; the coil 3221 on T8 enters from the wire slot S7 between it and the adjacent tooth T7 in the same phase, and exits from the wire slot S8 between it and the adjacent tooth T9 that is not in the same phase.

[0061] In order to make the technical solution of this application clearer, Figures 2 to 5The three-phase outer rotor motor 30 shown in FIG. 3 is further described in detail. The stator assembly 32 of the motor 30 is nested in the rotor assembly 31, and its stator core 321 has 12 teeth 3211 defined as T1 to T12 along its circumferential direction, and the teeth 3211 extend radially outward. The number of parallel branches of the stator winding 322 of the motor 30 is 1, which is connected in a triangle. Each phase winding is composed of two pairs of coils 3221 wound on adjacent teeth, wherein the A-phase winding is composed of four coils 3221 wound on T1, T2, T8, and T7 in series, the B-phase winding is composed of four coils 3221 wound on T9, T10, T4, and T3 in series, and the C-phase winding is composed of four coils 3221 wound on T5, T6, T12, and T11 in series. The number of coil turns of the coils 3221 on teeth T1 to T12 is alternately 3 or 4. Each phase winding includes two pairs of coils 3221 wound on adjacent teeth. Between the two pairs of coils 3221 wound on adjacent teeth under the A phase winding, there is a pair of coils 3221 wound on adjacent teeth under the B phase winding and a pair of coils 3221 wound on adjacent teeth under the C phase winding. The winding methods of the three-phase windings are equivalent to each other. The two pairs of coils 3221 wound on adjacent teeth under the same phase winding are mirror images in the coil interlacing method. Taking the A phase winding as an example, the coil 3221 on T1 enters from the wire slot S12, winds 3 turns, and then passes out from S1. The coil 3221 on T2 enters from the wire slot S2, winds 4 turns, and then passes out from S1; the coil 3221 on T7 enters from the wire slot S7, winds 3 turns, and then passes out from S6. The coil 3221 on T8 enters from the wire slot S7, winds 4 turns, and then passes out from S8. See Table 1 below for details.

[0062]

[0063]

[0064] Table 1

[0065] The above winding method is recorded as Scheme 1, the winding method in which the number of coil turns on each tooth is changed to 2 or 5 alternately while other designs remain unchanged is recorded as Scheme 2, and another winding method in which the number of parallel branches is 2, the number of parallel-wound wires and the wire diameter are reduced, and the number of coil turns on each tooth is 7 is recorded as Scheme 3. Figures 6a to 6c As shown in Table 2 below, it can be found from the data of relevant experiments that when coils with different turns are used under the same-phase winding, the speed fluctuation, output power, output efficiency and other performances of the motor 30 are optimized or equal to those when coils with equal turns are used. When coils with different turns are used to form the stator winding 322, a smaller difference in the number of turns of the coils under the same-phase winding is more beneficial to the performance optimization of the motor 30.

[0066]

[0067] Table 2

[0068] Another three-phase inner rotor motor 30 is introduced below. The rotor assembly 31 of the motor 30 is nested in the stator assembly 32. The stator core 321 has six teeth 3211 defined as T1 to T6 along its circumferential direction. The teeth 3211 extend radially inward. The number of parallel branches of the stator winding 322 of the motor 30 is 1. Each phase winding is composed of a pair of coils 3221 wound around adjacent teeth, as shown in Table 3 below.

[0069]

[0070] Table 3

[0071] Next, another five-phase motor 30 is introduced. Its stator core 321 has 10 teeth 3211 defined as T1 to T10 along its circumferential direction. The number of parallel branches of the stator winding 322 of the motor 30 is 1.

[0072] Table 4.

[0073]

[0074]

[0075] Table 4

[0076] The above shows and describes the basic principles, main features and advantages of the present application. Those skilled in the art should understand that the above embodiments do not limit the present application in any form, and any technical solution obtained by equivalent replacement or equivalent transformation falls within the protection scope of the present application.

Claims

1. An electric tool comprising: Functional parts; A motor, driving the functional parts to operate; A power supply device, at least for supplying power to the motor; The motor comprises a stator assembly, wherein the stator assembly comprises a stator core and a multi-phase winding; the stator core has a plurality of teeth for winding wires, and each of the multi-phase windings comprises a plurality of coils, and each of the coils is composed of a plurality of wires wound in parallel on the same tooth; It is characterized in that at least two coils belonging to the same phase winding are wound on adjacent teeth, and the number of coil turns of at least two coils belonging to the same phase winding is different; the number of coil turns is the number of turns of the multiple wires wound on the same tooth.

2. The electric tool according to claim 1, characterized in that: The number of turns of each coil belonging to the same-phase winding is n1 or n2, wherein n1 and n2 are positive integers.

3. The electric tool according to claim 2, characterized in that: The number of coil turns of each of the coils belonging to the same-phase winding is alternately n1 or n2 along the circumferential direction of the stator core, wherein n1 and n2 are positive integers.

4. The electric tool according to claim 3, characterized in that: When the sum of the number of coil turns of the two coils wound around adjacent teeth is an even number 2*n, n1 is equal to n-1, and n2 is equal to n+1, where n is a positive integer greater than or equal to 2.

5. The electric tool according to claim 3, characterized in that: When the sum of the number of coil turns of the two coils wound around adjacent teeth is an odd number 2*n+1, n1 is equal to n, and n2 is equal to n+1, wherein n is a positive integer.

6. The electric tool according to claim 2, characterized in that: Each phase winding includes one or more pairs of coils wound around adjacent teeth, and between the two pairs of coils belonging to the same-phase winding and wound around adjacent teeth, there exists another coil belonging to a non-same-phase winding.

7. The electric tool according to claim 6, characterized in that: A wire slot is formed between adjacent teeth, and a pair of two coils belonging to the same-phase winding and wound on adjacent teeth respectively enter the wire slot formed by the current tooth and the adjacent teeth that are not in phase, and exit from the wire slot formed by the current tooth and the adjacent teeth that are in phase; and / or, a pair of two coils belonging to the same-phase winding and wound on adjacent teeth respectively enter the wire slot formed by the current tooth and the adjacent teeth that are in phase, and exit from the wire slot formed by the current tooth and the adjacent teeth that are not in phase.

8. The electric tool according to claim 1, characterized in that: The sum of the number of turns of the plurality of coils constituting each phase winding is equal.

9. The electric tool according to claim 1, characterized in that: The multi-phase winding is a three-phase winding and is connected in a triangle.

10. The electric tool according to claim 1, characterized in that: The number of parallel branches of the multi-phase winding is 1.

11. The electric tool according to claim 9, characterized in that: The stator core has 12 teeth, and the 12 teeth are defined as T1 to T12 along the circumference of the stator core; the four coils wound on T1, T2, T8, and T7 are connected in series in sequence to form a first phase winding, wherein the number of turns of the coils wound on T1 and T7 is n1, and the number of turns of the coils wound on T2 and T8 is n2; the four coils wound on T9, T10, T4, and T3 are connected in series in sequence to form a second phase winding, wherein the number of turns of the coils wound on T3 and T9 is n1, and the number of turns of the coils wound on T4 and T10 is n2; the four coils wound on T5, T6, T12, and T11 are connected in series in sequence to form a third phase winding, wherein the number of turns of the coils wound on T5 and T11 is n1, and the number of turns of the coils wound on T6 and T12 is n2; wherein n1 and n2 are positive integers.

12. A motor comprising a stator assembly, wherein the stator assembly comprises a stator core and a multi-phase winding; The stator core has a plurality of teeth for winding the conductors; The multi-phase windings each include a plurality of coils, each of the coils being composed of a plurality of wires wound in parallel on the same tooth; It is characterized in that At least two coils belonging to the same-phase winding are wound on adjacent teeth, and the number of coil turns of at least two coils belonging to the same-phase winding is different; the number of coil turns is the number of turns of the multiple wires wound on the same tooth.

13. The motor according to claim 12, characterized in that The motor is a brushless motor.

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