JP2013099095A - Motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a motor capable of deriving a relatively small angle of a skew by which a cogging torque theoretically becomes zero to reduce the cogging torque, of preventing reduction in an output torque of the motor caused by the magnitude of the angle of the skew, of preventing reduction in work efficiency for winding a coil, and of preventing reduction in productivity.SOLUTION: A motor has a lamination core 53 formed by stacking core members 100. A skew 70 gradually inclined in a circumferential direction from one end to the other end in an axial direction is formed to the lamination core 53 by means of slot parts 64 formed between tooth parts 62, 62, ... of the core member 100. An angle θs1 of the skew 70 is determined on the basis of an angle θs2 calculated by a numerical expression (1).

Description

  The present invention relates to a motor technology, and more particularly to a technology for reducing cogging torque.

  Conventionally, a plurality of permanent magnets (magnetic poles) are arranged in the circumferential direction to form a ring-shaped field part, and are arranged to face the inside of the field part and coaxially with the field part in the circumferential direction. The technology of a motor comprising a laminated core that is rotatably supported is known. In the motor having such a configuration, since the laminated core and the field part have mutual attractive force, when the laminated core is rotated even when no current is applied, So-called cogging torque is generated.

  When the cogging torque is generated in this way, there are various problems depending on the intended use of the motor. For example, when the motor is used as a motor for driving an EGR valve, there are the following problems.

  That is, when the energization is turned off and the EGR valve is not operated, a force is applied so that the EGR valve is closed to the fully closed side by an urging force such as a spring from the viewpoint of fail-safe. In such a case, if the generated cogging torque is large, it is necessary to apply a larger biasing force that overcomes the cogging torque. However, when the EGR valve is operated with energization turned on, the urging force becomes a resistance force, and thus the output of the motor needs to be further increased. Thus, when the generated cogging torque is large, there is a problem that it is necessary to further increase the output of the motor. Furthermore, since the output torque varies depending on the valve opening of the EGR valve (by the phase of the motor), there is a problem that the control of the EGR valve becomes unstable.

  On the other hand, techniques for reducing the cogging torque are known. For example, in the techniques described in Patent Documents 1 to 3, a skew that is inclined in the circumferential direction is formed in the laminated core from one end to the other end in the axial direction. Accordingly, the cogging torque curves at the respective portions of the laminated core are combined with each other to cancel each other, and the cogging torque as the whole laminated core can be reduced.

JP 2001-16806 A JP 2005-20930 A JP 2010-279156 A

  However, if the skew angle formed in the laminated core becomes too large, the problem is that the output torque of the motor decreases, the work efficiency of winding the windings decreases, and the productivity of the motors decreases. There was a problem.

  The present invention has been made in view of such a situation, and the problem to be solved is a skew angle at which the cogging torque is theoretically 0 “zero”, and the skew is relatively small. The angle is obtained to reduce the cogging torque, prevent the output torque of the motor from being reduced due to the magnitude of the skew angle, and prevent the work efficiency from being reduced by winding the windings. It is providing the motor which can prevent a fall of property.

  The problem to be solved by the present invention is as described above. Next, means for solving the problem will be described.

That is, in claim 1, a plurality of magnetic poles are arranged in the circumferential direction to form a ring-shaped field portion, and a plurality of magnetic poles are arranged opposite to the inside of the field portion and wound with a winding. A laminated core that is formed by stacking a plurality of core members made of a magnetic plate having a tooth portion, and is supported so as to be rotatable in the circumferential direction coaxially with the field portion. The number of core members is an even number, and in the cross-sectional shape perpendicular to the axis of the laminated core, the plurality of teeth portions of the core member are the same shape and are equally arranged in the circumferential direction, and the field portion In the cross-sectional shape orthogonal to the axial center of each of the plurality of magnetic poles, the plurality of magnetic poles have the same shape and are arranged uniformly in the circumferential direction, and the laminated core is formed by the slot portions formed between the teeth portions of the core member. From one axial end to the other Ku skew inclined in the circumferential direction is formed in accordance with the skew angle θs1 is intended to be determined based on the angular θs2 calculated by the following equation (1).
Formula (1) .. angle θs2 = 360 degrees / number of slot portions / number of magnetic poles × (number of core members−1) / (number of core members / 2)

In the present invention, the skew angle θs1 satisfies the following formula (2).
Formula (2) .. Angle θs2− (Angle θs2 × 10%) <Skew angle θs1 <Angle θs2 + (Angle θs2 × 10%)

  According to a third aspect of the present invention, the number of the slot portions is 7 or more and 12 or less.

  In the present invention, the number of the magnetic poles is four.

  According to a fifth aspect of the present invention, the length of the field portion in the axial direction is longer than the length of the laminated core in the axial direction.

  As effects of the present invention, the following effects can be obtained.

  According to the first aspect of the present invention, a skew angle at which the cogging torque in the entire laminated core is theoretically 0 “zero” and the skew angle is relatively small is obtained to reduce the cogging torque and It is possible to prevent a decrease in the output torque of the motor due to the size of the angle, a decrease in work efficiency for winding the winding, and a decrease in productivity.

  In claim 2, the fluctuation due to the cogging torque in the entire laminated core can theoretically be 0 “zero” or close to 0 “zero”, and the reduction rate of the output torque of the motor is within a slight range. be able to.

  According to the third aspect, the reduction rate of the output torque of the motor can be kept within a desired reduction rate, and an increase in production cost can be prevented.

  According to the fourth aspect of the present invention, it is possible to prevent a decrease in the output torque of the motor while preventing an increase in production cost.

  According to the fifth aspect of the present invention, the skew angle at which the fluctuation due to the cogging torque in the entire laminated core is theoretically 0 “zero” can be obtained regardless of the magnetic flux of the field part.

The disassembled perspective view which showed the structure of the motor which concerns on one Embodiment of this invention. Side surface sectional drawing which showed the structure of a part of motor. FIG. 3 is an end view taken along line AA in FIG. 2. The perspective view which showed the structure of the laminated core. The top view which showed the structure of the core member. The graph which showed the cogging torque curve of the core member. The graph which showed the relationship between the cogging torque with respect to the angle of skew, and the output torque of a motor. The table | surface which showed the relationship between the optimal angle of a skew for every number of slot parts, and the output torque of a motor.

First, an overall configuration of a motor 1 according to an embodiment of the present invention will be briefly described with reference to FIGS.
In the following description, the front-rear direction, the left-right direction, and the up-down direction are defined based on the arrow directions shown in the drawings.

  FIG. 1 is an exploded perspective view showing a configuration of a motor 1 according to an embodiment of the present invention. FIG. 2 is a side sectional view showing a configuration of a part of the motor 1. FIG. 3 is an end view taken along line AA in FIG. FIG. 4 is a perspective view showing the configuration of the laminated core 53.

  The motor 1 shown in FIGS. 1 to 3 is a so-called DC brush motor. The motor 1 mainly includes a case 10, a field part 20, a brush holder 30, a bracket 40, and an armature 50.

  A case 10 shown in FIGS. 1 to 3 accommodates each member constituting the motor 1 and has a function as a yoke. The case 10 is formed in a substantially cylindrical shape with its cylindrical direction directed in the vertical direction. An opening 11 is formed at the upper end of the case 10. A support 12 that faces the opening 11 is formed at the lower end of the case 10. A bearing 13 is disposed inside the support portion 12.

The field part 20 shown in FIGS. 1 to 3 is formed in an annular shape by arranging a plurality of magnets 21 in the circumferential direction. The magnet 21 is formed in a substantially curved plate shape with its plate surface facing the inner diameter direction and the outer diameter direction in the case 10. A plurality of magnets 21 having the same shape (4 in the present embodiment) are provided. The magnets 21, 21, and so on are fixed to the inner peripheral surface of the case 10. The magnets 21, 21,... Are evenly arranged in the circumferential direction, and are formed in a substantially cylindrical shape as a whole with the tube center direction directed upward and downward.
The field portion 20 is an embodiment of the “field portion” in the present invention. The magnet 21 that is a permanent magnet is an embodiment of the “magnetic pole” in the present invention.

  A brush holder 30 shown in FIG. 1 is fitted into the opening 11 of the case 10. The brush holder 30 is formed in a substantially short cylindrical shape whose axial direction is directed in the vertical direction. Terminals 31 and 31 that are current input / output terminals are disposed on the upper side surface of the brush holder 30. The terminals 31 and 31 are electrically connected to brushes 34 and 34 disposed on the lower surface of the brush holder 30, respectively. A housing portion 32 that houses the commutator 52 is formed inside the upper center portion of the brush holder 30. An insertion hole 33 is opened in the upper center portion of the housing portion 32.

  The bracket 40 shown in FIG. 1 closes the case 10. A support portion 41 is formed at the upper center portion of the bracket 40. A bearing 42 is disposed inside the support portion 41.

  The armature 50 shown in FIG. 1 mainly includes a rotating shaft 51, a commutator 52, and a laminated core 53.

  The rotating shaft 51 shown in FIG. 1 to FIG. 4 is disposed on the inner side of the case 10 and coaxially with the case 10 and the field part 20 with the axial direction thereof directed in the vertical direction. The lower end side of the rotating shaft 51 is rotatably supported by the bearing 13. Further, the upper end side of the rotating shaft 51 is rotatably supported by the bearing 42 through the insertion hole 33. Thus, the rotating shaft 51 is rotatably supported inside the case 10 via the bearing 13 and the bearing 42. In addition, the lower end side of the rotating shaft 51 is extended outward as an output shaft of the motor 1.

  The commutator 52 shown in FIG. 1 is formed in a substantially cylindrical shape whose axial direction is directed in the vertical direction. The commutator 52 is fixed to the rotating shaft 51 so as not to rotate relative to the rotating shaft 51, and is disposed inside the housing portion 32 of the brush holder 30. The brushes 34 and 34 of the brush holder 30 are brought into contact with the commutator 52. The electricity supplied from the outside of the motor 1 through the terminal 31 is supplied to the commutator 52 through the brush 34.

The laminated core 53 shown in FIGS. 1 to 4 is formed by stacking a plurality of core members 100 made of a magnetic plate material. The laminated core 53 is formed in a substantially cylindrical shape whose axial direction is directed in the vertical direction. The laminated core 53 is fixed to the rotary shaft 51 below the commutator 52 so as not to be relatively rotatable. Thereby, the laminated core 53 is supported so as to be rotatable around the axis (circumferential direction) via the rotation shaft 51 on the same axis as the field magnet portion 20. The laminated core 53 is disposed so as to face the inside of the field portion 20 and is disposed at the same position as the field portion 20 in the vertical direction position. A winding 65 is wound around the laminated core 53 (more specifically, a plurality of teeth 62 described later). In the drawings other than FIG. 1, the winding 65 is not shown for convenience of explanation.
The core member 100 is an embodiment of the “core member” in the present invention. The laminated core 53 is an embodiment of the “laminated core” in the present invention.

  In the above configuration, a current is supplied to the motor 1 from the outside of the motor 1 via the terminal 31. The current supplied to the terminal 31 is supplied to the commutator 52 by the brush 34 and supplied to the winding 65 wound around the laminated core 53. As a result, the armature 50 rotates around the axis of the rotating shaft 51 by the electromagnetic action with the field magnet portion 20. And the torque of the motor 1 generate | occur | produces because the rotating shaft 51 rotates around an axis | shaft.

Next, the configuration of the laminated core 53 will be described in more detail with reference to FIGS.
FIG. 5 is a plan view showing the configuration of the core member 100.

  The laminated core 53 shown in FIGS. 1 to 4 is formed by stacking a plurality of core members 100 made of a magnetic plate material as described above. The number of core members 100 stacked is an even number. The core member 100 is stacked with its plate surface directed in the same direction (vertical direction) as the axial direction of the laminated core 53. A core member 100 shown in FIG. 5 mainly includes a yoke portion 61 and a teeth portion 62.

  The yoke part 61 shown in FIG. 5 is a part located in the center part of the core member 100. The yoke portion 61 is a substantially plate-like member whose plate surface is directed in the vertical direction, and is formed in a substantially annular shape. An insertion hole 63 through which the rotating shaft 51 is inserted is opened at the center of the yoke portion 61.

The teeth part 62 shown in FIG. 5 is a part located in the outer side part of the core member 100 (outside of the yoke part 61). The teeth part 62 is formed in a substantially T shape in plan view. The teeth part 62 is provided with a plurality (10 in this embodiment) of the same shape. The teeth portions 62, 62,... Are evenly disposed in the circumferential direction on the outer peripheral edge portion of the yoke portion 61, and extend from the outer peripheral edge portion in the longitudinal direction toward the outer radial direction. A winding 65 is wound around the teeth portions 62, 62,... (See FIG. 1). In the following description, the gap formed between the teeth portions 62, 62,... Is referred to as “slot portion 64”. The slot portion 64 is provided with a plurality (10 in this embodiment) of the same shape.
The teeth portion 62 is an embodiment of the “tooth portion” in the present invention.

In the present embodiment, the laminated core 53 is formed by stacking 16 core members 100. Then, the core members 100, 100,... Are in a state of rotating gradually (equally) counterclockwise in plan view as they go down one by one from the uppermost core member 100 arranged (shifting the phase). Arranged). With such a configuration, a plurality (10 in this embodiment) of skews 70, 70,... Are formed on the outer peripheral surface of the laminated core 53. The skews 70, 70,... Are formed so as to incline in the circumferential direction so that the upper side is on the left side and the lower side is on the right side, that is, from the upper end to the lower end.
The skew 70 is an embodiment of “skew” in the present invention.

  As shown in FIG. 4, the core member 100 arranged at the uppermost side among the core members 100, 100.. The core members 101 are referred to as “core member 102, core member 103, core member 104... Core member 115, core member 116” as they go downward from the core member 101 one by one. In addition, the rotation angle of the core member 101 and the core member 116 in plan view is referred to as the skew 70 angle. Further, as shown in FIG. 3, the angle of the skew 70 in this embodiment is referred to as “angle θs1”.

The angle θs1 of the skew 70 is determined based on the “angle θs2” calculated by the following formula (1).
(Equation 1)
Angle θs2 = 360 degrees / number of slots / number of magnetic poles × (number of core members−1) / (number of core members / 2)

  Here, in the present embodiment, the number of the slot portions 64 is 10, as described above. The number of magnetic poles (magnets 21 which are permanent magnets) is 4 as described above. The number of core members 100 is 16 as described above. When these numbers are applied to Equation (1), 16.875 degrees is calculated as the angle θs2.

  Here, FIG. 6 is a graph showing a cogging torque curve of the core member 100 (more specifically, the core member 101 and the core member 109). As described above, the cogging torque curve of the core member 100 substantially coincides with the sine curve. Although not shown, the amplitudes of the cogging torque curves of all the core members 100 (core member 101, core member 102, and core member 116) are substantially the same.

  Then, when 16.875 degrees (angle θs2) calculated by the above formula (1) is set as the angle θs1 of the skew 70, as shown in FIG. 6, the cogging torque curve of the core member 101 and the core member 109 The cogging torque curve is in reverse phase. That is, the cogging torque curve of the core member 101 and the cogging torque curve of the core member 109 are combined with each other and cancel each other.

  Similarly, the cogging torque curve of the core member 102 and the cogging torque curve of the core member 110, the cogging torque curve of the core member 103 and the cogging torque curve of the core member 111, and the cogging torque curve of the core member 104 are the same. , And the cogging torque curve of the core member 108 and the cogging torque curve of the core member 116 are combined with each other and cancel each other.

  As described above, according to the equation (1), the cogging torque curves of the core members 101, 102, 116 are mutually combined and cancel each other. The angle (angle θs2) of the skew 70 that becomes “zero” (there is no fluctuation due to the cogging torque) can be calculated.

  FIG. 7 shows the present embodiment (more specifically, the number of slot portions 64 is 10, the number of magnetic poles (magnets 21 that are permanent magnets) is 4, and the number of core members 100 is 16. 6 is a graph showing the relationship between the cogging torque and the output torque of the motor 1 with respect to the skew 70 angle. As described above, in this embodiment, the angle of the skew 70 at which the fluctuation due to the cogging torque in the entire laminated core 53 is theoretically 0 “zero” is not limited to 16.875 degrees (angle θs2). 34 degrees or about 50 degrees).

  However, according to the graph shown in FIG. 7, the output torque of the motor 1 decreases as the angle of the skew 70 increases. Further, when the angle of the skew 70 is increased, the work efficiency of the work of winding the winding 65 around the tooth portion 62 is lowered, and consequently the productivity of the motor 1 is lowered.

  On the other hand, according to Equation (1), the smallest angle (angle θs2) is calculated among the skew 70 angles at which the fluctuation due to the cogging torque in the entire laminated core 53 is theoretically 0 “zero”. Can do. In other words, according to the formula (1), the output torque of the motor 1 does not decrease most among the angles of the skew 70 where the fluctuation due to the cogging torque in the entire laminated core 53 is theoretically 0 “zero” ( The angle (angle θs2) that can maintain the output torque of the motor 1 can be calculated.

  As described above, when the angle θs1 of the skew 70 is determined to be 16.875 degrees based on the 16.875 degrees (angle θs2) calculated by the equation (1), the fluctuation due to the cogging torque in the entire laminated core 53 is theoretically calculated. It can be 0 “zero”. Moreover, the reduction rate of the output torque of the motor 1 can be kept within a slight range. Compared with the case where the fluctuation due to the cogging torque in the entire laminated core 53 is theoretically set to 0 “zero” by the angle of the skew 70 other than 16.875 degrees (angle θs2) (for example, about 34 degrees or about 50 degrees). Thus, the reduction rate of the output torque of the motor 1 can be minimized. Moreover, since the angle of the skew 70 can be prevented from being increased, it is possible to prevent the work efficiency of the work of winding the winding 65 around the teeth portion 62 from being lowered, and hence the productivity of the motor 1 can be prevented from being lowered. .

  As shown in FIG. 7, when the angle θs1 of the skew 70 is an angle approximated to, for example, 16.875 degrees (angle θs2), the fluctuation due to the cogging torque in the entire laminated core 53 is theoretically (0 “zero”). However, the reduction rate of the output torque of the motor 1 can be kept within a slight range.

The fluctuation due to the cogging torque in the entire laminated core 53 can theoretically be 0 “zero” or close to 0 “zero”, and the rate of decrease in the output torque of the motor 1 can be kept within a slight range. The possible angle θs1 of the skew 70 can be determined so as to satisfy the following formula (2).
(Equation 2)
Angle θs2− (angle θs2 × 10%) <skew angle θs1 <angle θs2 + (angle θs2 × 10%)

  Here, in the present embodiment, the angle θs2 is 16.875 degrees as described above. Therefore, when 16.875 degrees is applied to the formula (2) as the angle θs2, an angle larger than 15.1875 degrees and smaller than 18.5625 degrees is calculated as the angle θs1.

  As described above, when the angle θs1 of the skew 70 is set to an angle larger than 15.1875 degrees calculated by the equation (2) and smaller than 18.5625 degrees, as shown in the range of the symbol X in FIG. The reduction rate of the output torque of the motor 1 can be suppressed to 5% or less (within a slight range). That is, by determining the angle θs1 of the skew 70 so as to satisfy Formula (2), the fluctuation due to the cogging torque in the entire laminated core 53 can theoretically be close to 0 “zero” or 0 “zero”. In addition, the reduction rate of the output torque of the motor 1 can be kept within 5% or less (within a slight range).

  In the present embodiment, the number of slot portions 64 is 10, but the number is not limited to this. That is, in the present invention, the number of the slot portions 64 can be 7 or more and 12 or less.

  Here, FIG. 8 is a table showing the relationship between the optimum angle of the skew 70 and the output torque of the motor 1 for each number of the slot portions 64. The “optimum angle of the skew 70” refers to the angle (angle θs2) calculated by the above formula (1).

  As shown in FIG. 8, when the number of the slot portions 64 is 7 or more, the reduction rate of the output torque of the motor 1 can be kept to 10% or less (desired reduction rate). Further, generally, the production cost increases as the number of the slot portions 64 increases. Therefore, by setting the number of the slot parts 64 to 12 or less, for example, compared with the case where the number of the slot parts 64 is 13 or more, an increase in production cost can be prevented.

  As shown in FIG. 8, the difference in the reduction rate of the output torque of the motor 1 between the case where the number of the slot portions 64 is 10 and the case where it is 20 is 3% (within a slight range). That is, for example, when the number of the slot portions 64 is set to 13 or more, the disadvantage that the production cost increases is larger than the advantage that the rate of decrease in the output torque of the motor 1 is improved, and the disadvantage is as a whole. There is a possibility. On the other hand, in the present invention, the number of the slot portions 64 is set to 12 or less, thereby preventing a disadvantage as a whole.

  Thus, by setting the number of the slot portions 64 to 7 or more and 12 or less, it is possible to keep the output torque reduction rate of the motor 1 within a desired reduction rate (10% or less) and to prevent an increase in production cost. can do.

  In the present embodiment, the number of magnets 21 is four. Here, in general, the production cost increases as the number of magnets 21 increases. Therefore, by setting the number of magnets 21 to 4, for example, it is possible to prevent an increase in production cost compared to the case where the number of magnets 21 is set to 6, or 8, for example.

  For example, when the number of magnets 21 is 2, the angle of the skew 70 becomes too large, and as a result, the output torque of the motor 1 may be greatly reduced. That is, in the present embodiment, the number of magnets 21 is set to 4, thereby preventing a decrease in output torque of the motor 1 while preventing an increase in production cost.

  As shown in FIG. 2, in the present embodiment, the field portion 20 has an axial length (vertical direction) longer than the axial length (vertical direction) of the laminated core 53. It is formed.

  More specifically, the vertical center 20a of the field part 20 and the vertical center 53a of the laminated core 53 are formed at the same height. The upper end portion of the field portion 20 is formed above the upper end portion of the laminated core 53. Further, the lower end portion of the field portion 20 is formed below the lower end portion of the laminated core 53. That is, the laminated core 53 is entirely covered with the field portion 20 in the vertical direction (axial direction).

  Thus, since the length of the field portion 20 in the axial direction (vertical direction) is longer than the length of the laminated core 53 in the axial direction (vertical direction), the magnetic flux of the field portion 20 is reduced. Due to the influence, the phases of the cogging torque curves of the core members 100 (for example, the core member 101 and the core member 109, the core member 102 and the core member 110, etc.) that are combined and cancel each other out of phase or amplitude are different. There is no. That is, according to the above formula (1), the angle θs1 (angle θs2) of the skew 70 at which the fluctuation due to the cogging torque in the entire laminated core 53 is theoretically 0 “zero” regardless of the magnetic flux of the field portion 20. Can be calculated.

As described above, the motor 1 according to one embodiment of the present invention is
A plurality of permanent magnets 21 (magnetic poles) arranged in the circumferential direction and formed in an annular shape,
The field portion 20 is formed by stacking 16 core members 100 made of a magnetic plate, having a plurality of teeth portions 62 around which the winding 65 is wound, arranged opposite to the inside of the field portion 20. 20 and a laminated core 53 supported so as to be rotatable on the same axis as 20 in the circumferential direction;
A motor comprising:
The number of the core members 100 is an even number,
In the cross-sectional shape orthogonal to the axis of the laminated core 53 (planar shape of the laminated core 53), the plurality of tooth portions 62 of the core member 100 have the same shape and are equally arranged in the circumferential direction,
In the cross-sectional shape orthogonal to the axial center of the field part 20 (planar shape of the field part 20), the plurality of magnets 21 (magnetic poles) have the same shape and are equally arranged in the circumferential direction,
By the slot portion 64 formed between the teeth portions 62, 62, ... of the core member 100, a skew 70 that is inclined in the circumferential direction from one end to the other end in the axial direction is formed in the laminated core 53,
The angle θs1 of the skew 70 is determined based on the angle θs2 calculated by the following mathematical formula (1).
Formula (1) .. Angle θs2 = 360 degrees / number of slot portions 64 / number of magnets 21 (magnetic poles) × (number of core members 100−1) / (number of core members 100/2)

  As a result, the angle of skew 70 at which the cogging torque in the entire laminated core 53 is theoretically 0 “zero” and the angle of skew 70 having a relatively small angle (angle θs2) is obtained, and the cogging torque is reduced. In addition, a decrease in the output torque of the motor 1 due to the angle of the skew 70 is prevented, and a decrease in work efficiency for winding the winding 65 is prevented, thereby preventing a decrease in productivity. be able to.

In the motor 1 according to the embodiment of the present invention, the angle θs1 of the skew 70 satisfies the following formula (2).
Formula (2) .. Angle θs2− (angle θs2 × 10%) <angle θs1 of skew 70 <angle θs2 + (angle θs2 × 10%)

  As a result, the fluctuation due to the cogging torque in the entire laminated core 53 can theoretically be 0 “zero” or close to 0 “zero”, and the rate of decrease in the output torque can be kept within a slight range.

  In the motor 1 according to the embodiment of the present invention, the number of the slot portions 64 is 7 or more and 12 or less.

  As a result, the reduction rate of the output torque of the motor 1 can be kept within a desired reduction rate, and an increase in production cost can be prevented.

  In the motor 1 according to the embodiment of the present invention, the number of magnets 21 (magnetic poles) is four.

  As a result, it is possible to prevent a decrease in output torque of the motor 1 while preventing an increase in production cost.

  Further, in the motor 1 according to the embodiment of the present invention, the axial length of the field magnet portion 20 is formed to be longer than the axial length of the laminated core 53.

  As a result, the angle θs1 (angle θs2) of the skew 70 at which the fluctuation due to the cogging torque in the entire laminated core 53 is theoretically 0 “zero” can be calculated regardless of the magnetic flux of the field portion 20.

DESCRIPTION OF SYMBOLS 1 Motor 20 Field part 21 Magnet 53 Laminated core 62 Teeth part 64 Slot part 65 Winding 70 Skew 100 Core member

Claims (5)

A plurality of magnetic poles arranged in the circumferential direction and formed in an annular shape, and
A plurality of core members made of a magnetic plate having a plurality of teeth portions around which windings are wound are arranged facing the inside of the field portion, and are coaxial with the field portion. A laminated core supported rotatably in the circumferential direction;
A motor comprising:
The number of the core members is an even number,
In the cross-sectional shape orthogonal to the axis of the laminated core, each of the plurality of teeth portions of the core member has the same shape and is arranged uniformly in the circumferential direction,
In the cross-sectional shape orthogonal to the axis of the field portion, the plurality of magnetic poles are each of the same shape and are equally arranged in the circumferential direction,
By the slot portion formed between the teeth portions of the core member, a skew that is inclined in the circumferential direction is formed in the laminated core from one end to the other end in the axial direction,
The skew angle θs1 is determined based on the angle θs2 calculated by the following mathematical formula (1).
A motor characterized by that.
Formula (1) .. angle θs2 = 360 degrees / number of slot portions / number of magnetic poles × (number of core members−1) / (number of core members / 2) The skew angle θs1 satisfies the following formula (2):
The motor according to claim 1.
Formula (2) .. Angle θs2− (Angle θs2 × 10%) <Skew angle θs1 <Angle θs2 + (Angle θs2 × 10%) The number of the slot portions is 7 or more and 12 or less.
The motor according to any one of claims 1 and 2. The number of the magnetic poles is 4.
The motor according to any one of claims 1 to 3, characterized in that: The axial length of the field portion is formed to be equal to or longer than the axial length of the laminated core.
The motor according to any one of claims 1 to 4, wherein the motor is provided.

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