JP6573649B2 - Motor manufacturing method and motor - Google Patents

Description

  The present invention relates to a motor manufacturing method and a motor.

  In motor design, it is important how many magnetic fluxes are linked to the stator windings to generate a large torque. In particular, in a compact motor, it is important how efficiently a magnetic flux (hereinafter referred to as an interlinkage magnetic flux) interlinked with a coil of a winding can be passed.

  For this reason, various proposals have been made regarding the configuration of the motor. For example, Patent Document 1 and Patent Document 2 propose a shape for efficiently flowing a magnetic flux. For example, Patent Document 3 proposes a current control method for efficiently flowing a magnetic flux.

JP 2003-153476 A JP 2003-79084 A JP 2005-20876 A

  Generally, leakage occurs in the flow of magnetic flux in the motor. That is, there is a leakage magnetic flux. For this reason, it is preferable to design in order to generate more interlinkage magnetic fluxes, focusing on reducing the leakage magnetic flux in the motor design stage. However, in the above-mentioned documents, a quantitative approach regarding leakage magnetic flux is not made.

  A method for manufacturing a motor according to an embodiment is a method for manufacturing a motor including a stator having a plurality of teeth around which windings are wound and a rotor having a magnet, and is formed by the adjacent teeth. A magnetic circuit model including a magnetic flux flowing in a slot as a circuit element, calculating a magnetic flux in the magnetic circuit model, and determining a teeth angle of the motor based on the calculated magnetic flux. is there.

  The motor according to an embodiment includes a stator having a plurality of teeth around which a winding is wound, and a rotor having a magnet, and the teeth are provided at a predetermined tooth angle. The ratio of the slot magnetic flux to the maximum value of the tooth magnetic flux is 5% or more and 20% or less, and the tooth magnetic flux is calculated in a magnetic circuit model including the magnetic flux flowing in the slot formed by the adjacent teeth as a circuit element. The slot magnetic flux is a magnetic flux calculated in the magnetic circuit model.

  The motor according to an embodiment includes a stator having a plurality of teeth around which a winding is wound, and a rotor having a magnet, and the teeth are provided at a predetermined tooth angle. The predetermined tooth angle is a tooth angle at which the tooth magnetic flux calculated using the tooth angle as a variable in a magnetic circuit model including a magnetic flux flowing in a slot formed by the adjacent teeth as a circuit element is maximized.

  According to the embodiment, it is possible to provide a motor manufacturing method and a motor that can improve the amount of interlinkage magnetic flux while suppressing the amount of leakage magnetic flux.

It is a schematic diagram which shows an example of a structure of the motor which should determine a teeth angle. It is a flowchart which shows the flow of the manufacturing method of a motor. It is a schematic diagram which shows an example of the magnetic circuit model produced by step 100 shown in FIG. It is a graph which shows the change with respect to the teeth angle of the teeth magnetic flux and slot magnetic flux computed from the magnetic circuit model of the motor. It is a schematic diagram which shows the magnetic circuit model produced with respect to the motor of 4 poles and 6 slots. It is a schematic diagram which shows the magnetic flux of each closed circuit of a magnetic circuit model. It is a figure which shows an example of a magnetoresistive matrix. It is an enlarged view of the VIII part shown in FIG. 5, and shows teeth magnetic flux, slot magnetic flux, and air gap magnetic flux.

  Embodiments of the present invention will be described below with reference to the drawings. In the drawings, the same elements are denoted by the same reference numerals, and redundant description is omitted as necessary.

  In the motor manufacturing method described in the present embodiment, a magnetic circuit model considering leakage flux is constructed at the motor design stage, and the leakage flux is small and linked based on the magnetic flux calculated from the magnetic circuit model. The teeth angle that increases the magnetic flux is determined. FIG. 1 is a schematic diagram showing an example of the configuration of the motor 1 whose teeth angle should be determined. The motor 1 is, for example, a radial type motor driven by a three-phase alternating current. However, the motor manufacturing method according to the present embodiment may be used for motors having other configurations. The motor 1 is a motor used for an injection molding machine, for example, and requires a high torque.

The motor 1 includes a rotor 10 having a diameter D _r (that is, a radius D _r / 2) and a stator 11 having a diameter D _s (that is, a radius D _s / 2). The thickness of the motor 1 is L _stk . That is, the length of the motor 1 in the depth direction of FIG. 1 is L _stk . Between the rotor 10 and the stator 11, there is an air gap 17 of length _{L g.} The rotor 10 is provided with a magnet. Specifically, N-pole permanent magnets 13 _N and S-pole permanent magnets 13 _S are alternately arranged on the outer periphery of the rotor yoke 12 of the rotor 10. Hereinafter, the permanent magnet 13 _N and the permanent magnet 13 _S are collectively referred to as a magnet 13. The thickness of the magnet 13 (the length in the radial direction) is L _pm . The rotor shaft diameter is D _rs (that is, the length from the rotation center to the rotor yoke 12 is D _rs / 2).

The stator 11 disposed outside the rotor 10 has a plurality of teeth 14. More specifically, the teeth 14 are formed so as to protrude inwardly (that is, the rotor 10 side) from the stator yoke 15 that constitutes the outer periphery of the stator 11. Here, the thickness (the length in the radial direction) of the stator yoke 15 is L _sy . The length of the teeth 14 (the length of the portion projecting toward the stator yoke 15 on the rotor 10) is L _t. The teeth 14 are provided at equal intervals in the circumferential direction of the stator 11. A winding (not shown) is wound around the tooth 14. In addition, although the winding method of the winding to the teeth 14 is concentrated winding, for example, distributed winding may be sufficient. Further, a slot 16 is formed by adjacent teeth 14. A predetermined number of slots 16 are formed in the motor 1. Here, the predetermined number and N _s. That is, the total number of slots 16 of the motor 1 is _{N s.} Therefore, the total number of teeth 14 of the motor 1 is also _{N s.}

Further, the tooth angle of the motor 1 and theta _t, the slot angle of the motor 1 and theta _s. Here, the teeth angle is a central angle corresponding to the circumferential width of one tooth 14. The slot angle is a central angle corresponding to the width of one slot 16 in the circumferential direction. The circumferential widths of the teeth 14 and the slots 16 are based on, for example, the position of the inner circumference of the stator yoke 15 as shown in FIG. 1, but the teeth angle is determined by using the circumferential width at a more inner position. And a slot angle may be defined. Further, the teeth angle can be said to be an angle range occupied by the teeth 14 of the stator 11 when viewed from the rotation center of the rotor 10. Similarly, the slot angle can be said to be an angle range occupied by the slot 16 of the stator 11 when viewed from the rotation center of the rotor 10.

Here, the total number N _s of the slots 16, the tooth angle θ _t , and the slot angle θ _s satisfy the following formula (1) from their definitions. Here, N _s is a predetermined value, and θ _t and θ _s are parameters whose values are determined by the manufacturing method in the present embodiment.

In the motor manufacturing method according to the present embodiment, the leakage magnetic flux can be suppressed in the motor 1 in which the dimensions of the dimensions that determine the configuration of the motor do not depend on the teeth angle θ _t and the slot angle θ _s are determined in advance. An appropriate teeth angle θ _t is determined. As a result, high torque is realized in the motor 1 in which the dimensions of the portions that do not depend on the teeth angle θ _t and the slot angle θ _s are predetermined.

FIG. 2 is a flowchart showing the flow of the motor manufacturing method according to the present embodiment. In this manufacturing method, first, in step 100 (S100), a magnetic circuit model including the magnetic flux flowing in the slot 16 as a circuit element is created. FIG. 3 is a schematic diagram showing an example of a magnetic circuit model created in step 100 shown in FIG. As described above, a magnetic circuit model including the magnetic flux flowing in the slot 16 as a circuit element in step 100 is created. That is, as shown in FIG. 3, in order to consider the magnetic flux traversing the slot 16 in the circumferential direction in the magnetic circuit model, the path of the magnetic flux traversing the slot 16 in the circumferential direction is set in the magnetic circuit model. Then, the magnetic resistance R _{slot in the} path is set in the magnetic circuit model. That is, the magnetic resistance R _slot is the magnetic resistance of the slot 16, and more specifically, is the magnetic resistance with respect to the magnetic flux flowing through the slot 16 in the circumferential direction. Thereby, the magnetic circuit model becomes a model in consideration of the leakage magnetic flux leaking into the slot 16.

In the magnetic circuit model shown in FIG. 3, in addition to the magnetic resistance R _slot , magnetic resistances R _t , R _sy , R _g , R _pm , R _ry and magnetomotive forces λ _ni , λ _pm are set. Here, the magnetic resistance _Rt is the magnetic resistance of the tooth 14, and more specifically, the magnetic resistance with respect to the magnetic flux flowing in the radial direction through the tooth 14. The magnetic resistance R _sy is the magnetic resistance of the stator yoke 15, and more specifically, is the magnetic resistance against the magnetic flux flowing in the circumferential direction in the portion corresponding to one slot 16 of the stator yoke 15. The magnetic resistance _Rg is the magnetic resistance of the air gap 17, and more specifically, is the magnetic resistance with respect to the magnetic flux that flows through the air gap 17 in the radial direction. The magnetic resistance R _pm is the magnetic resistance of the magnet 13, and more specifically, is the magnetic resistance against the magnetic flux that flows through the magnet 13 in the radial direction. The magnetic resistance R _ry is the magnetic resistance of the rotor yoke 12, and more specifically, is the magnetic resistance against the magnetic flux flowing in the circumferential direction through the portion corresponding to one slot 16 of the rotor yoke 12. Further, the magnetomotive force λ _ni is a magnetomotive force generated when a current flows through the winding, and can be calculated from the number n of windings and the current i. The magnetomotive force λ _pm is a magnetomotive force generated by the magnet 13 (permanent magnet 13 _N or permanent magnet 13 _S ), and is determined by the magnetic force of the magnet 13.

In the magnetic circuit model shown in FIG. 3, a closed circuit including a magnetomotive force λ _ni and magnetoresistances R _sy , R _t , and R _slot , a magnetomotive force λ _pm , magnetic resistances R _pm , R _g , R _slot , R _a closed circuit constituted by _ry is formed. In FIG. 3, the magnetic circuit model is shown only for two slots, but the above-described two closed circuits can be set for all slots.

Here, the magnetoresistance can be generally calculated by the following equation (2). In equation (2), R is the magnetic resistance, l is the magnetic path length, S is the magnetic path cross-sectional area, and μ is the magnetic permeability. The magnetic permeability varies depending on the medium. For example, in the case of air, μ = μ ₀ = 4π × 10 ⁻⁷ , and in the case of iron, μ = μ ₀ × 10 ³ = 4π × 10 ^−4. In this case, μ = μ ₀ × 1.05 = 4.2π × 10 ⁻⁷ .

As can be seen from Equation (2), the magnetic resistance is determined according to the dimensions of each part of the motor 1. Therefore, magnetic resistance set in the magnetic circuit model generated in step 100 is a function of the tooth angle theta _t. That is, in step 100, creates a magnetic circuit model which is defined using a magnetoresistive expressed as a function of the tooth angle theta _t.

Returning to FIG. 2, the continuation of the flowchart will be described. After step 100, in step 101 (S101), the magnetic flux in the magnetic circuit model is calculated. As described above, since the magnetic resistance in the magnetic circuit model created in step 100 is a function of the tooth angle θ _t , the calculated magnetic flux can also be expressed as a function of the tooth angle θ _t . In step 101, specifically, the tooth magnetic flux and the slot magnetic flux in the magnetic circuit model are calculated. The teeth magnetic flux refers to the magnetic flux flowing through the teeth 14 in the magnetic circuit model. The slot magnetic flux refers to a magnetic flux flowing through the slot 16 in the magnetic circuit model. That is, the slot magnetic flux is a leakage magnetic flux. In step 101, only one of the tooth magnetic flux and the slot magnetic flux may be calculated.

After step 101, in step 102 (S102), based on the flux calculated in step 101, to determine the tooth angle theta _t of the motor 1. That is, to determine the specific values of the tooth angle theta _t. In step 102, for example, the tooth angle of the motor 1 is determined based on the slot magnetic flux and the tooth magnetic flux calculated in step 101. For example, the teeth angle of the motor 1 is determined based on the magnitude of the slot magnetic flux with the maximum value of the tooth magnetic flux as a reference. Specifically, for example, the tooth angle at which the ratio of the slot magnetic flux to the maximum value of the tooth magnetic flux is within a predetermined range is determined as the tooth angle of the motor 1. Here, the maximum value of the tooth flux is the maximum value of the tooth flux expressed as a function of the tooth angle theta _t. Further, the size of the slot flux referred to here is the size of the slot flux expressed as a function of the tooth angle theta _t. That may be determined the value of the tooth angle theta _t based on the evaluation value E of the following formula (3). In Expression (3), φ _{t_max} is the maximum value of the teeth magnetic flux, and φ _s is the slot magnetic flux.

FIG. 4 is a graph showing changes of the teeth magnetic flux φ _t and the slot magnetic flux φ _s (that is, leakage magnetic flux) calculated from the magnetic circuit model of the motor 1 with respect to the tooth angle θ _t . More specifically, the graph of FIG. 4 is a graph showing the teeth magnetic flux φ _t and the slot magnetic flux φ _s when the tooth angle θ _t is changed within a range satisfying the relationship of the expression (1). In FIG. 4, the broken line graph represents the teeth magnetic flux φ _t and the solid line graph represents the slot magnetic flux φ _s . In step 102, for example, any value in the range of θ _t1 to θ _t2 is determined as the value of the teeth angle θ _t . Here, θ _t1 and θ _t2 indicate the lower limit and the upper limit of the range of the tooth angle such that the evaluation value E falls within a predetermined range from the first value to the second value.

  Here, the first value is, for example, 5%, and the second value is 20%. In other words, by setting the teeth angle within which the evaluation value E falls within the range of 5% to 20% as the teeth angle of the motor 1, compared to the case where other teeth angles are employed, the leakage flux is suppressed and the teeth are The flowing magnetic flux can be increased. That is, by adopting such a teeth angle, it is possible to realize a highly efficient motor 1 that can generate a high torque.

  In other words, in the motor 1 provided with teeth at a predetermined tooth angle, the evaluation value E calculated based on the magnetic circuit model including the magnetic flux flowing in the slot 16 as a circuit element is 5% or more and 20% or less. In this case, it can be said that the design for realizing the high-efficiency motor 1 capable of generating a high torque is performed.

Note that the value of the teeth angle θ _t may be determined by other methods without being limited to the above determination method. For example, in step 102, the tooth angle at which the teeth magnetic flux is maximized may be determined as the tooth angle of the motor 1. In this case, in step 101, the slot magnetic flux does not have to be calculated.

  In other words, in the motor 1 in which the teeth are provided at a predetermined tooth angle, the predetermined tooth angle is a tooth magnetic flux calculated using the tooth angle as a variable in a magnetic circuit model including the magnetic flux flowing in the slot 16 as a circuit element. In the case of the maximum teeth angle, it can be said that the design for realizing the highly efficient motor 1 capable of generating high torque is being performed.

Next, a method for manufacturing the motor according to the present embodiment will be described using a specific example. Here, as an example, a 4-pole 6-slot motor 1 will be described as an example. That is, the motor 1 including four magnets 13 (two permanent magnets _13N and two permanent magnets _13S ) and six slots 16 will be described as an example.

  FIG. 5 is a schematic diagram showing a magnetic circuit model created for the motor 1 having 4 poles and 6 slots. In the case of the 4-pole 6-slot motor 1, for example, two closed circuits can be considered for each slot 16 as shown in FIG. 5, and a magnetic circuit model composed of a total of 12 closed circuits can be created.

Here, the magnetic resistance R _pm is expressed by the following equation (4) from the above equation (2). In Equation (4), the permeability of the magnet 13 is expressed in μ _mag .

Further, the magnetic resistance _Rg is expressed by the following equation (5) from the above equation (2). In the equation (5), the magnetic permeability of the air gap 17 is represented by _air permeability μ _air .

Further, the magnetic resistance R _ry is expressed by the following equation (6) from the above equation (2). In Equation (6), the magnetic permeability of the rotor yoke 12 is expressed by the magnetic permeability μ _iron of _iron .

Further, the magnetic resistance R _slot is expressed by the following equation (7) from the above equation (2). In equation (7), the magnetic permeability of the slot 16 is expressed by _air permeability μ _air .

Further, the magnetic resistance R _t is expressed by the following equation (8) from the above equation (2). In Formula (8), the magnetic permeability of the teeth 14 is expressed by the magnetic permeability μ _iron of _iron .

Further, the magnetic resistance R _sy is expressed by the following formula (9) from the above formula (2). In the equation (9), the magnetic permeability of the stator yoke 15 is expressed by the magnetic permeability μ _iron of _iron .

As indicated above, each of the magnetic resistance in the magnetic circuit model can be expressed as a function of the tooth angle theta _t. In the above formulas, it reluctance R _ry, R _sy is theta _t in the expression is not specified, from equation (1), which is a function of the tooth angle theta _t also these magnetoresistive I understand.

  In step 101 described above, a closed circuit equation represented by the following equation (10) is solved based on the created magnetic circuit model.

Here, J is a magnetic flux row vector represented by the following equation (11). Incidentally, J ₁₂ from each element J _1, as shown in FIG. 6 shows the magnetic flux of the closed circuit of the magnetic circuit model.

A in equation (10) is a magnetoresistive matrix, specifically as shown in FIG. In Equation (10), λ is a magnetomotive force row vector expressed by Equation (12) below. Each element λ ₁ to λ ₁₂ is a magnetomotive force in each closed circuit corresponding to each magnetic flux J ₁ to J ₁₂ shown in FIG. As described above, since the magnetomotive forces λ _ni and λ _pm are known values, the elements λ ₁ to λ ₁₂ are known.

  Note that J, A, and λ described above are examples in which the motor 1 is a 4-pole 6-slot motor as shown in FIG. 5. It goes without saying that the elements change.

In step 101, the closed circuit equation represented by the equation (10) is solved to calculate the teeth magnetic flux φ _t and the slot magnetic flux φ _s . FIG. 8 is an enlarged view of a portion VIII shown in FIG. 5 and illustrates the teeth magnetic flux φ _t , the slot magnetic flux φ _s , and the air gap magnetic flux φ _g . Air gap flux phi _g, in a magnetic circuit model, a magnetic flux flowing through the air gap 17. These magnetic fluxes satisfy the following formula (13).

In step 102, for example, an evaluation value E is calculated based on the teeth magnetic flux φ _t and the slot magnetic flux φ _s obtained by solving the closed circuit equation, and an appropriate tooth angle value is determined. Thereby, the amount of flux linkage can be improved while suppressing the amount of leakage flux of the motor 1.

  Note that the present invention is not limited to the above-described embodiment, and can be changed as appropriate without departing from the spirit of the present invention.

1 Motor 10 Rotor 11 Stator 12 Rotor Yoke 13 Magnet 14 Teeth 15 Stator Yoke 16 Slot 17 Air Gap

Claims (7)

A method of manufacturing a motor having a stator having a plurality of teeth around which a winding is wound, and a rotor having a magnet,
Create a magnetic circuit model that includes the magnetic flux flowing in the slot formed by the adjacent teeth as a circuit element,
Calculate the magnetic flux in the magnetic circuit model,
Based on the calculated magnetic flux, determine the teeth angle of the motor ,
The teeth angle is an angle defined by the circumferential width of the base portion of the teeth,
The method of manufacturing a motor, wherein the magnetic circuit model is defined using a magnetic resistance expressed as a function of the teeth angle . Calculate slot magnetic flux and teeth magnetic flux in the magnetic circuit model,
The motor manufacturing method according to claim 1, wherein a tooth angle of the motor is determined based on the calculated slot magnetic flux and the tooth magnetic flux. The motor manufacturing method according to claim 2, wherein a tooth angle of the motor is determined based on a magnitude of the slot magnetic flux with respect to a maximum value of the teeth magnetic flux. The method of manufacturing a motor according to claim 3, wherein a tooth angle at which a ratio of the slot magnetic flux to a maximum value of the tooth magnetic flux is within a predetermined range is determined as a tooth angle of the motor. Calculate the tooth magnetic flux in the magnetic circuit model,
The method of manufacturing a motor according to claim 1, wherein a tooth angle at which the calculated tooth magnetic flux is maximized is determined as a tooth angle of the motor. A stator having a plurality of teeth around which windings are wound;
A rotor having a magnet, and
The teeth are provided at a predetermined teeth angle,
The predetermined tooth angle, with respect to the maximum value of the tooth flux, a tooth angle ratio of the slot magnetic flux becomes 5% or more and 20% or less,
The teeth magnetic flux is a magnetic flux calculated by using a tooth angle as a variable in a magnetic circuit model including a magnetic flux flowing in a slot formed by the adjacent teeth as a circuit element,
Said slot flux, Ri flux der calculated the tooth angle as a variable in the magnetic circuit model,
The teeth angle is an angle defined by the circumferential width of the base portion of the teeth,
The magnetic circuit model is a motor defined using a magnetic resistance expressed as a function of the teeth angle . A stator having a plurality of teeth around which windings are wound;
A rotor having a magnet, and
The teeth are provided at a predetermined teeth angle,
The predetermined tooth angle, Ri tooth angle der the tooth flux is maximum calculated teeth angle as a variable in the magnetic circuit model including a magnetic flux flowing in is formed by the teeth adjacent slots as an element of the circuit,
The teeth angle is an angle defined by the circumferential width of the base portion of the teeth,
The magnetic circuit model is a motor defined using a magnetic resistance expressed as a function of the teeth angle .

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