JP6917787B2 - Rotating machine - Google Patents

Description

The present invention relates to a rotary electric machine.

In recent years, motors used for electric power steering and the like are required to have a high output density. The strength of the magnetic field that can be generated by the coil is determined by the number of turns of the coil and the magnitude of the current flowing through the coil.The strength of the magnetic field has a strong effect on the output of the motor. Copper wires are being thickened. However, while it is possible to increase the current by adopting a thick wire, there is a problem in the manufacturing process of the motor that the thick wire makes it difficult to process the electric wire. Generally, the thicker the wire, the more difficult it is to bend the wire, and in the centralized winding coil, it affects the adhesion between the bobbin and the wire when the wire is wound around the bobbin. The bobbin of the centralized winding coil has a large aspect ratio, and the adhesion between the long side, which is substantially parallel to the rotation axis of the rotor, and the electric wire has a great influence on the output density of the motor. The low adhesion occurs because when an electric wire is wound around a bobbin having a substantially rectangular shape, the electric wire swells without being cut along the contour of the bobbin, and this phenomenon is referred to as winding swelling here. Suppressing this winding swelling is an unavoidable issue in order to achieve both thickening of the centralized winding coil and improvement of output density.
Patent Document 1 discloses a configuration in which the radius of curvature R2 on the winding end side of the coil is made larger than the radius of curvature R1 on the winding start side of the coil in the two curved portions constituting the bobbin end.

Japanese Unexamined Patent Publication No. 2006-06778

It is required to reduce the winding swelling of the coil.

The rotary electric machine according to the first aspect of the present invention is a rotary electric machine having a stator having a plurality of centralized winding coils formed by winding a coil around a bobbin covering an iron core. The end portion is provided with an end portion arranged in the longitudinal direction of the straight portion, and the end portion includes two curved portions and a bending defining portion which are in contact with the straight portion and have a radius of curvature larger than half the width of the bobbin. At least a part of the bending regulation portion exists at a position separated from the straight portion in the longitudinal direction by more than half the width of the bobbin, and the surface roughness of the end portion is coarser than the surface roughness of the straight portion. ..

According to the present invention, the winding swelling of the coil can be reduced.

Diagram showing the appearance of the stator The figure which shows the iron core 2 around which the coil 4 is wound. The figure which shows the iron core 2 before the coil 4 is wound Cross section of bobbin 3 The figure which shows the detail of the end part 32 The figure which shows the process of winding a coil 4 around a bobbin 3. 7 (a) is a plan view of the bobbin 3, and FIG. 7 (b) is a bottom view of the bobbin 3. The figure which shows the problem which may occur when the winding bulge of a coil is not suppressed. The figure which shows the shape of the end part 32 in the modification 3 The figure which shows the shape of the end part 32 in the modification 5 The figure which shows the shape of the end 32A in the 2nd Embodiment The figure which shows the shape of the end part 32A in the modification of the 2nd Embodiment The figure which shows the shape of the end part 32B in 3rd Embodiment The figure which shows the shape of the bobbin 3 in 4th Embodiment The figure which shows bobbin 3 and its manufacturing process in 5th Embodiment The figure which shows the bobbin 3 in the modification of the 5th Embodiment The figure which shows the bobbin 3 in the 6th Embodiment The figure which shows how the bobbin 3 is assembled to the winding machine 90, and the coil 4 is wound around the bobbin 3.

-First Embodiment-
Hereinafter, the first embodiment of the electric motor, which is a rotary electric machine according to the present invention, will be described with reference to FIGS. 1 to 8.

(Overview of stator)
FIG. 1 is a diagram showing the appearance of the stator. The electric motor 100 includes a stator 1 and a rotor (not shown). The stator 1 includes a plurality of iron cores 2, and a coil 4 is intensively wound around each iron core 2. In other words, the electric motor 100 adopts centralized winding as a form of winding. When the coil 4 is energized, a magnetic field is generated and a rotor (not shown) rotates.

FIG. 2 is a diagram showing an iron core 2 in a state after the coil 4 is wound, and FIG. 3 is a diagram showing an iron core 2 in a state before the coil 4 is wound. Hereinafter, the direction of the arrow H shown in FIG. 2 is referred to as a height direction or a longitudinal direction, the direction of the arrow D is referred to as a depth direction, and the direction of the arrow W is referred to as a width direction. Here, a one-way arrow is used to clarify that H, D, and W merely represent the direction and not the dimension.

The iron core 2 is made of an iron-based metal. The iron core 2 is manufactured by, for example, casting or machining. Further, the iron core 2 can be manufactured by stacking a plurality of thin steel plates punched in the cross-sectional shape of the iron core, or by compacting powdered metal. The iron core 2 is covered with a bobbin 3 formed of an insulating material such as resin for electrical insulation with the coil 4. As shown in FIG. 3, the bobbin 3 is inserted from both ends in the longitudinal direction of the iron core 2, and the coil 4 is wound after the bobbin 3 is inserted. The main material of the coil 4 is copper, aluminum, or the like.

To wind the coil 4 around the iron core 2, for example, a combination of the iron core 2 and the bobbin 3 is fixed to the winding machine, and one end of the electric wire is fixed to the bobbin 3 or a jig around it. A method can be adopted in which the iron core 2 and the bobbin 3 are rotated and the coil 4 is wound around the bobbin 3. Further, the coil 4 may be wound by turning the nozzle, which is the feeding port of the electric wire, around the bobbin 3 while feeding the electric wire. In the following, the electric wire before being wound around the iron core 2 is also referred to as a coil 4.

(Cross section of bobbin 3)
FIG. 4 is a cross-sectional view of the bobbin 3. In FIG. 4, since the coil 4 is cut in the plane around which the coil 4 is wound, the top and bottom of FIG. 4 are in the height direction, and the left and right of FIG. 4 are in the width direction. When the bobbin 3 is conveniently divided according to its shape, the bobbin 3 is divided into an end portion 32, a straight portion portion 31, and an end portion 32 from the top in the longitudinal direction. As shown in FIG. 4, the width of the bobbin 3 is hereinafter referred to as the bobbin width BW.

The outer shape of the straight line portion 31 is composed of a straight line, and has a cavity in which the iron core 2 is inserted. However, since the straight portion 31 is formed by a combination of the two members as shown in FIG. 3, a cut may be present in the middle in the longitudinal direction as shown in FIG. Although there are two end portions 32 in FIG. 4, since the shapes are the same, only the upper end portion 32 will be described here. The end portion 32 includes a first curved portion 12, a second curved portion 13, and a third curved portion 14. The first curved portion 12 and the third curved portion 14 are arcs having the same radius of curvature larger than the BW. The second curved portion 13 is an arc having a radius of curvature smaller than that of the first curved portion 12 and the third curved portion 14.

(Details of end 32)
FIG. 5 is a diagram showing details of the end portion 32. However, in FIG. 5, in order to clarify the respective configurations, the joint portion between the straight portion 31 and the end portion 32, the joint portion between the first curved portion 12 and the second curved portion 13, and the second curved portion 13 and the third The joints of the curved portions 14 are displayed at intervals. Further, in FIG. 5, the broken line indicates the boundary between the straight portion 31 and the end portion 32.

When both ends of the first curved portion 12 are referred to as contact ends 12A and apex ends 12B, the contact ends 12A come into contact with the straight line portion 31, and the apex ends 12B come into contact with the second curved portion 13. When both ends of the third curved portion 14 are referred to as contact ends 14A and apex ends 14B, the contact ends 14A come into contact with the straight line portion 31, and the apex ends 14B come into contact with the second curved portion 13. Since the first curved portion 12, the second curved portion 13, and the third curved portion 14 have the above-mentioned geometric features, the longitudinal length from the boundary between the straight portion 31 and the end portion 32 to the top of the second curved portion 13. The distance L in the direction exceeds half of the bobbin width BW.

(Coil 4 winding process)
FIG. 6 is a diagram showing a process of winding the coil 4 around the bobbin 3. In FIG. 6, the broken line represents the coil 4. In FIG. 6, a gap is formed between the bobbin 3 and the coil 4 for convenience of illustration, but in reality, the bobbin 3 and the coil 4 are substantially in close contact with each other. First, the coil 4 is arranged along the straight line portion 31 as shown in FIG. 6A. Next, as shown in FIG. 6B, the coil 4 is lightly bent at the boundary between the straight portion 31 and the first curved portion 12, and is arranged along the first curved portion 12. Then, the coil 4 is largely bent at the second curved portion 13 as shown in FIG. 6 (c). As described above, since the second curved portion 13 is a portion that causes a large bending, the second curved portion 13 is also referred to as a “bending regulation portion” below. Finally, as shown in FIG. 6D, the coil 4 is lightly bent at the boundary between the third curved portion 14 and the straight portion 31. In the following, winding the coil 4 in the direction shown in FIG. 6 is referred to as "winding the coil 4 around the bobbin 3 clockwise".

(Difference between top and bottom of bobbin)
When the coil 4 is wound around the bobbin 3, the coil 4 moves in the depth direction by about the thickness of the coil 4 each time it goes around the bobbin 3. In order to increase the density of the coil, this movement is concentrated at the end of the bobbin 3 as shown in FIG. This movement may be performed at either the upper end portion or the lower end portion of the bobbin 3, but the description will be continued here assuming that the movement is performed at the upper end portion.

FIG. 7A is a plan view of the bobbin 3, and FIG. 7B is a bottom view of the bobbin 3. However, in FIG. 7, only one layer of the coil 4 is shown. At the upper end of the bobbin 3, as shown in FIG. 7A, the coil 4 diagonally crosses the end of the bobbin 3. On the other hand, at the lower end of the bobbin 3, as shown in FIG. 7B, the coil 4 crosses the end of the bobbin 3 in parallel. In each of FIGS. 7 (a) and 7 (b), the cut surface for cutting the bobbin 3 along the coil 4 is referred to as a cut surface 6A and a cut surface 6B. The cross section obtained by cutting on the cut surface 6B is the cut surface shown in FIG. 4, and strictly speaking, when cut on the cut surface 6A, the width of the cut surface is slightly larger than that of BW. However, since all of the first curved portion 12, the second curved portion 13, and the third curved portion 14 increase at the same ratio as the BW, the relationship between the radius of curvature and the width is maintained. That is, the winding bulge is reduced at both the upper end and the lower end of the bobbin 3 as described below.

(Reduction of winding bulge)
Since the bobbin 3 has the following three characteristic configurations, the winding swelling is remarkably reduced.
The first characteristic configuration is a third curved portion 14 having a large radius of curvature, which is arranged at a position where the coil 4 is wound from the end portion of the bobbin 3 toward the long side. Since the radius of curvature of the third curved portion 14 is large and the coil 4 is smoothly connected to the straight portion 31, the coil 4 to be wound starts to be wound around the straight portion 31 with a small winding bulge. If the radius of curvature of the third curved portion 14 is small, the coil 4 that has not been sufficiently bent will be largely released from the bobbin 3 and will start to be wound around the long side portion of the bobbin 3, resulting in a large winding bulge. It causes.

The second characteristic configuration is the first curved portion 12 having a large radius of curvature, which is arranged from the straight portion 31 to the end of the bobbin, that is, the portion where the coil 4 is wound toward the second curved portion 13. be. The radius of curvature of the first curved portion 12 is large, and the coil 4 to be wound is directed toward the tip portion of the bobbin 3 without being affected by strong bending because it is smoothly connected to the straight portion 31 of the bobbin 3. The coil 4 is wound with a gentle bending, and the size of the winding bulge of the coil 4 wound around the straight portion 31 that has already passed is not increased. If the radius of curvature of the first curved portion 12 is small, the coil 4 bent along the first curved portion 12 is affected by the abrupt bending process on both the front and rear sides of the bending base point, and has already been affected. The coil 4 wound around the long side that has passed through receives a force that moves in the direction of being released from the bobbin 3, which causes a large winding bulge.

The third characteristic configuration is the second curved portion 13, which is a bending regulating portion, which is arranged at the tip end portion of the bobbin 3 and serves as a bending base point of the coil 4. Since the bending regulation portion is provided near the tip portion of the bobbin 3, the coil 4 is strongly bent near the end portion of the bobbin 3. Therefore, it is not necessary to sharply bend the coil 4 near the boundary between the straight portion 31 and the end portion 32, and it is possible to prevent an increase in winding swelling due to unbent or the like.

(Rolling bulge)
FIG. 8 is a diagram showing problems that may occur when the winding swelling of the coil 94 is not suppressed. The bobbin 93 shown in FIG. 8 has a shape different from that of the bobbin 3 described above. In FIG. 8, the coil 94 is wound around the bobbin 93 by only one layer for simplification. Further, in FIG. 8, similarly to FIG. 6, the coil 94 is wound clockwise around the bobbin 93. As shown in FIG. 8, the distance between the coil 94 and the iron core 92 due to the winding bulge differs before and after winding. Specifically, the bulge 99 of the coil 94 after reaching the end portion is larger than the bulge 98 of the coil 94 before reaching the end portion, and the distance between the coil 94 and the iron core 92 is further increased. Then, the distance between the adjacent coils 94 is shortened due to this winding bulge. Therefore, when the winding bulge is large, it is necessary to take measures such as separating the iron cores 92 from each other. Further, in order to minimize the influence of the winding bulge, it is not enough to take measures against the maximum winding bulge portion, that is, the bulging portion of reference numeral 99 in FIG. 8, and the winding bulge should be reduced over the entire long side of the bobbin 93. is necessary.

According to the first embodiment described above, the following effects can be obtained.
(1) The electric motor 100 includes a stator 1 having a plurality of centralized winding coils formed by winding a coil 4 around a bobbin 3 covering an iron core 2. The bobbin 3 includes a straight portion 31 and an end portion 32 arranged in the longitudinal direction of the straight portion 31. The end portion 32 includes two curved portions, that is, a first curved portion 12 and a third curved portion 14, which are in contact with the straight portion 31 and have a radius of curvature larger than half of the bobbin width BW. The end portion 32 further includes a bending defining portion, for example, a second curved portion 13, which exists at a distance of more than half of the bobbin width BW in the longitudinal direction from the straight portion portion 31. Therefore, the winding swelling of the coil 4 can be reduced.

(2) The second curved portion 13 has an arc shape having a radius of curvature smaller than that of the first curved portion 12 and the third curved portion 14.

(3) The first curved portion 12 and the third curved portion 14 have the same radius of curvature. In other words, the end 32 is symmetrical. Therefore, not only when the coil 4 is wound around the bobbin 3 in a clockwise direction as shown in FIG. 6, but also when the coil 4 is wound around the bobbin 3 in a counterclockwise direction, the winding swelling can be similarly suppressed. In a centralized winding motor, the coil 4 is wound around the bobbin 3 clockwise and counterclockwise by the salient pole in the direction in which the salient pole of the stator is viewed from the rotating shaft side of the rotor. There are many examples in which Therefore, the shape of the bobbin 3 in the present embodiment, which can reduce the winding swelling in any winding direction, is useful. Further, since the bobbin 3 is symmetrical, molding is easy.

(4) The bobbin 3 includes two end portions 32 and one straight line portion 31, and the straight line portion 31 is sandwiched between the two end portions 32. That is, in the present embodiment, the bobbin 3 is provided with end portions 32 having the same shape at the upper end and the lower end. Therefore, the winding swelling of the coil 4 can be reduced over the entire circumference. Further, since the parts of the two end portions 32 can be shared, the manufacturing and management costs can be reduced.

(Modification example 1)
The radius of curvature of the first curved portion 12 and the third curved portion 14 may be different. It is sufficient that each of the radius of curvature of the first curved portion 12 and the radius of curvature of the third curved portion 14 is larger than half of the bobbin width BW.

(Modification 2)
The radius of curvature of the third curved portion 14 may be smaller than the radius of curvature of the first curved portion 12 and the third curved portion 14, as well as less than half of the bobbin width BW.

(Modification example 3)
The end portion 32 may be configured to include a straight line or a curved line in addition to the first curved portion 12, the second curved portion 13, and the third curved portion 14.

FIG. 9 is a diagram showing the shape of the end portion 32 in the modified example 3. As shown in FIG. 9, the end portion 32 in this modification has a recess 16 in addition to the first curved portion 12, the second curved portion 13, and the third curved portion 14. The recess 16 exists between the first curved portion 12 and the second curved portion 13, and between the second curved portion 13 and the third curved portion 14, and is recessed toward the inside of the bobbin 3. The recess 16 can reduce the amount of material used for the bobbin 3. Further, the presence of the recess 16 forms a gap through which air flows between the coil 4 and the bobbin 3, so that the heat dissipation of the bobbin 3 and the coil 4 is improved. For the following reasons, even in the form of the bobbin 3 in this modification, the same winding swelling reduction effect as in the first embodiment described above can be obtained.

Considering the winding of the coil 4 around the bobbin 3 shown in FIG. 9, it is not mechanically realistic that the coil 4 is wound so as to enter the recess 16 of the bobbin 3. In other words, the recess 16 provided in the bobbin 3 is not a substantial winding surface of the coil 4. In this case, the actual winding surface of the coil 4 exists at the position of the thread when a thin and soft thread is wound around the winding surface of the bobbin 3 and an appropriate tension is applied, and the circumference of the bobbin 3 is the shortest. It is a surface drawn by a curve connected by. Therefore, the bobbin 3 in the modified example 3 can also obtain the same winding swelling reducing effect as that of the first embodiment described above.

(Modification example 4)
The bobbin 3 may include at least one end 32. For example, the bobbin 3 may have a bobbin having an upper portion having the shape of the end portion 32 described above and a lower portion having a shape different from that of the end portion 32.

(Modification 5)
The angle of the arc forming the second curved portion 13 may be 180 degrees or more.
FIG. 10 is a diagram showing the shape of the end portion 32 in the modified example 5. As shown in FIG. 10, the angle of the arc constituting the second curved portion 13 may be 180 degrees or more.

-Second embodiment-
A second embodiment of the electric motor, which is a rotary electric machine according to the present invention, will be described with reference to FIG. In the following description, the same components as those in the first embodiment are designated by the same reference numerals, and the differences will be mainly described. The points not particularly described are the same as those in the first embodiment. In the present embodiment, the shape of the end portion 32 is different from that of the first embodiment.

FIG. 11 is a diagram showing the shape of the end portion 32A in the second embodiment. The end portion 32A is composed of a first curved portion 12, a connecting portion 15, and a third curved portion 14. The point where the radius of curvature of the first curved portion 12 is larger than half of the bobbin width BW is the same as that of the first embodiment, but the height of the arc, that is, the apex from the boundary between the straight portion 31 and the end portion 32A. The longitudinal distance M to the end 12B exceeds half of the bobbin width BW. The same applies to the third curved portion 14, the radius of curvature of the third curved portion 14 is larger than half of the bobbin width BW, and the longitudinal distance M from the boundary between the straight portion 31 and the end portion 32A to the apex end 14B is More than half of the bobbin width BW. The connecting portion 15 is a straight line connecting the apex end 12B of the first curved portion 12 and the apex end 14B of the third curved portion 14.

In the present embodiment, the apex end 12B of the first curved portion 12 and the apex end 14B of the third curved portion 14 serve as bending defining portions.

According to the second embodiment described above, the following effects can be obtained.
(1) Each of the first curved portion 12 and the third curved portion 14 has a contact end 12A and a contact end 14A which are ends in contact with the straight portion 31, and an apex end 12B and an end portion which are not in contact with the straight portion 31. It is provided with a vertex end 14B. The apex end 12B and the apex end 14B are separated from the straight line portion 31 in the longitudinal direction by more than half of the bobbin width BW. The bending defining portions in the present embodiment are the apex end 12B and the apex end 14B.

(Modified example of the second embodiment)
The connecting portion 15 does not have to be a straight line. For example, as in the first embodiment, it may be an arc that is convex upwards or an arc that is convex downwards.
FIG. 12 is a diagram showing the shape of the end portion 32A in the modified example of the second embodiment. The connecting portion 15 has a downwardly convex arc shape. Also in this modification, the radius of curvature of the first curved portion 12 is larger than half of the bobbin width BW as in the second embodiment, and the length from the boundary between the straight portion 31 and the end portion 32A to the apex end 12B. The distance M in the direction exceeds half of the bobbin width BW. Further, the radius of curvature of the third curved portion 14 is larger than half of the bobbin width BW, and the distance M in the longitudinal direction from the boundary between the straight portion 31 and the end portion 32A to the apex end 14B exceeds half of the bobbin width BW. In the present embodiment, the apex end 12B of the first curved portion 12 and the apex end 14B of the third curved portion 14 serve as bending defining portions, so that even if the connecting portion 15 is a downwardly convex arc, the first The winding bulge of the coil 4 can be reduced as in the embodiment of 1.

-Third embodiment-
A third embodiment of the electric motor, which is a rotary electric machine according to the present invention, will be described with reference to FIG. In the following description, the same components as those in the first embodiment are designated by the same reference numerals, and the differences will be mainly described. The points not particularly described are the same as those in the first embodiment. In the present embodiment, the shape of the end portion 32 is mainly different from that of the first and second embodiments.

FIG. 13 is a diagram showing the shape of the end portion 32B in the third embodiment. However, in FIG. 13, in order to clarify the respective configurations, the joint portion between the straight portion 31 and the end portion 32B and the joint portion between the first curved portion 12 and the third curved portion 14 are displayed at intervals. .. The end portion 32B is composed of a first curved portion 12 and a third curved portion 14. The point where the radius of curvature of the first curved portion 12 is larger than half of the bobbin width BW is the same as that of the first embodiment, but the height of the arc, that is, the apex from the boundary between the straight portion 31 and the end portion 32A. The longitudinal distance N to the end 12B exceeds half of the bobbin width BW. The same applies to the third curved portion 14, the radius of curvature of the third curved portion 14 is larger than half of the bobbin width BW, and the longitudinal distance N from the boundary between the straight portion 31 and the end portion 32A to the apex end 14B is More than half of the bobbin width BW.

In the present embodiment, the apex end 12B of the first curved portion 12 and the apex end 14B of the third curved portion 14 are joined, and this joint point serves as a bending defining portion. In other words, the intersection of the first curved portion 12 and the third curved portion 14 is the bending defining portion in the present embodiment. Although this joint point exists at the center of the end portion 32B in the width direction in FIG. 13, it may exist at a position deviated from the center in the width direction.

According to the third embodiment described above, the following effects can be obtained.
(1) The bending defining portion is an intersection of the apex end 12B and the apex end 14B. Therefore, the configuration of the end portion 32B can be simplified.

-Fourth Embodiment-
A fourth embodiment of the electric motor, which is a rotary electric machine according to the present invention, will be described with reference to FIG. In the following description, the same components as those in the first embodiment are designated by the same reference numerals, and the differences will be mainly described. The points not particularly described are the same as those in the first embodiment. In the present embodiment, the shape of the contact portion between the iron core 2 and the bobbin 3 is mainly different from that in the first embodiment.

(Constitution)
FIG. 14 is a diagram showing the shape of the bobbin 3 in the fourth embodiment. The bobbin 3 has a protrusion 20 or a recess 21 on a surface facing the end of the iron core 2. The iron core 2 combined with the bobbin 3 has a recess or protrusion corresponding to the protrusion 20 or recess 21 of the bobbin 3 and having a fitting relationship with the protrusion 20 or recess 21 of the bobbin 3. The protrusion 20 of the bobbin 3 and the recess of the iron core 2 or the recess 21 of the bobbin 3 and the protrusion of the iron core 2 are fitted together. Since the bobbin 3 has a long end to the tip 32, the bobbin 3 is likely to receive a force from the coil 4 when winding the coil 4, but the relative positional relationship between the iron core 2 and the bobbin 3 due to the fitting of the protrusion and the recess. Can be kept constant. In FIG. 14, the bobbin 3 has a recess 21 at the upper portion and a protrusion 20 at the lower portion in the longitudinal direction, but each may be a recess 21 or any may be a protrusion 20.

(Manufacturing method of iron core 2)
The iron core 2 can be manufactured by various methods, but when a plurality of thin steel plates are stacked and manufactured, the manufacturing can be simplified as follows. When a thin steel plate is punched into the cross-sectional shape of the iron core 2, dowels are formed at the same location on each steel plate. This dowel is formed by striking a metal with a sharp tip on one side of a steel plate. Therefore, by using this dowel as the recess or protrusion of the iron core 2 described above, the step of forming the recess or protrusion in the iron core 2 can be omitted.

According to the fourth embodiment described above, the following effects can be obtained.
(1) The iron core 2 and the bobbin 3 are fitted by a combination of protrusions and recesses. Since the bobbin 3 has a long end to the tip 32, the bobbin 3 is likely to receive a force from the coil 4 when winding the coil 4, but the relative positional relationship between the iron core 2 and the bobbin 3 due to the fitting of the protrusion and the recess. Can be kept constant.

-Fifth Embodiment-
A fifth embodiment of the electric motor, which is a rotary electric machine according to the present invention, will be described with reference to FIG. In the following description, the same components as those in the first embodiment are designated by the same reference numerals, and the differences will be mainly described. The points not particularly described are the same as those in the first embodiment. The present embodiment is different from the first embodiment mainly in that the surface roughness of the end portion of the bobbin is roughened.

FIG. 15 is a diagram showing a bobbin 3 and a manufacturing process thereof according to the fifth embodiment. The outer shape of the bobbin 3 is the same as that of the first embodiment, but is different from the first embodiment in that the surface roughness is defined. That is, the surface roughness of the end portion 32 is coarser than the surface roughness of the straight portion 31, and the friction coefficient is large. Therefore, slippage at the end 32 of the coil 4 is prevented. When the region for roughening the surface roughness is referred to as the surface roughness-imparting surface 17, the surface roughness-imparting surface 17 may be the entire area of the end portion 32 or a part of the end portion 32.

The bobbin 3 is formed by pouring an insulating material into the upper mold 35 and the lower mold 36. A roughness generating portion 34 corresponding to the surface roughness imparting surface 17 is formed on the inner peripheral portion of the upper mold 35, and the surface roughness imparting surface 17 is realized only by molding without requiring additional processing. be able to.

According to the fifth embodiment described above, the following effects can be obtained.
(1) The surface roughness of the end portion 32 is coarser than the surface roughness of the straight portion 31. When the friction coefficient between the bobbin 3 and the coil 4 is small and slippage is likely to occur, the winding bulge may be large, but in the present embodiment, the surface roughness of the end portion 32 is roughened. Therefore, the slip of the coil 4 from the bobbin 3 can be prevented, and the effect of preventing the winding swelling, which is the effect obtained by the shape of the end portion 32, can be more reliably achieved.

(Modified example of the fifth embodiment)
Protrusions may be provided instead of processing the surface roughness.
FIG. 16 is a diagram showing a bobbin 3 in a modified example of the fifth embodiment. The outer shape of the bobbin 3 is the same as that of the first embodiment, but a protrusion is provided on the surface of the end portion 32. This protrusion is provided on the surface in contact with the coil 4 to prevent the coil 4 from slipping. The length of the protrusion is not particularly limited, but it is desirable that the protrusion is shorter than the diameter of the coil 4.

According to this modification, the following effects can be obtained.
(1) The end portion 32 has a protrusion shorter than the diameter of the coil 4 on the surface in contact with the coil 4. Therefore, the slip of the coil 4 from the bobbin 3 can be prevented, and the effect of preventing the winding swelling, which is the effect obtained by the shape of the end portion 32, can be more reliably achieved.

-Sixth Embodiment-
A sixth embodiment of the electric motor, which is a rotary electric machine according to the present invention, will be described with reference to FIGS. 17 to 18. In the following description, the same components as those in the first embodiment are designated by the same reference numerals, and the differences will be mainly described. The points not particularly described are the same as those in the fifth embodiment. The present embodiment is different from the first embodiment mainly in that a through hole is provided at the end portion.

FIG. 17 is a diagram showing a bobbin 3 in the sixth embodiment. The outer shape of the bobbin 3, that is, the shape of the surface where the bobbin 3 and the coil 4 are in contact with each other is the same as that of the first embodiment. The bobbin 3 is provided with holes 19 penetrating in the depth direction at both ends. In other words, the hole 19 penetrates the plane around which the coil 4 is wound, that is, the plane including the height direction and the width direction shown in FIG. This hole 19 is used when winding the coil 4 around the bobbin 3 as described below. The iron core 2 is inserted inside the straight portion 31, and the width of the resin near the boundary between the straight portion 31 and the end portion 32 is thin. Therefore, it is not realistic to provide the hole 19 in the straight line portion 31, and the hole 19 is provided in the end portion 32. However, the hole 19 may exist across the straight portion 31 and the end portion 32.

FIG. 18 is a diagram showing a state in which the bobbin 3 is assembled to the winding machine 90 and the coil 4 is wound around the bobbin 3. The winding machine 90 includes a winding machine base 38 and a pin 37. When winding the coil 4 around the bobbin 3, the bobbin 3 is placed on the winding machine base 38, and the pin 37 is inserted into the hole 19 of the bobbin 3. Then, the winding machine base 38 rotates around the rotation center 33, and the coil 4 is wound around the bobbin 3. Therefore, the force that the bobbin 3 receives from the coil 4 at the time of winding is transmitted to the winding machine base 38 by turning the hole 19 and the pin 37. That is, it is possible to prevent the bobbin 3 from being destroyed by avoiding the generation of high stress inside the bobbin 3, and to regulate the relative positional relationship between the bobbin 3 and the iron core 2.

According to the sixth embodiment described above, the following effects can be obtained.
(1) The end portion 32 has a hole 19 penetrating a plane around which the coil is wound. Therefore, it is possible to prevent the bobbin 3 from being destroyed by avoiding the generation of high stress inside the bobbin 3, and to regulate the relative positional relationship between the bobbin 3 and the iron core 2.

(Modified example of the sixth embodiment)
A recess may be provided instead of the hole 19. In the sixth embodiment, the hole 19 has a role of fixing the bobbin 3 to the winding machine base 38 in combination with the pin 37 when the winding machine base 38 rotates. Therefore, the bobbin 3 may be combined with the pin 37 instead of the hole 19 which is a through hole, and may be provided with a recess which can be fixed to the winding machine base 38. This recess is perpendicular to the plane around which the coil 4 is wound, that is, the plane including the height and width directions shown in FIG. For example, the recess formed by closing one outlet of the hole 19 is the recess in this modification.

In each of the above-described embodiments and modifications, the split core type in which each salient pole portion of the stator 1 is divided is shown as an example, but an iron core other than the split core type such as an integral core may be used. .. Further, although the method of molding the bobbin 3 in advance and inserting it from both ends of the iron core has been given as an example, the bobbin 3 may be molded so as to be molded, or may be integrally formed without being divided. As the material of the bobbin 3, resin is given as an example, but the material may be used as long as it can provide the necessary electrical insulation between the iron core 2 and the coil 4. Further, the structure of the bobbin 3 is mainly described for the portion to be the winding surface of the coil 4, but the bank for preventing the displacement of the coil 4 and the structure for regulating the winding position are described around the winding surface. An object may be provided, and even in such a case, the essence of the present invention remains unchanged.

In each of the above-described embodiments and modifications, the change in shape when the winding surface of the coil 4 around the end portion 32 is advanced in the radial direction of the stator 1 is not mentioned. However, the winding surface of the coil 4 around the end portion 32 may be changed according to the radial direction of the stator 1 according to the desired shape. For example, the position of the tip of the bobbin 3 may be different in order to change the position of the tip of the coil 4 for each winding of the coil 4, and the winding start and end of the coil 4 and other places where the winding bulge is particularly remarkable. The bobbin 3 end shape of the present invention may be applied only to this.

It is desirable that the detailed shape of the end portion 32 pays attention to the minimum bending radius of the coil 4 and the tension applied to the coil 4 at the time of winding. Considering that the insulating coating of the coil 4 is prevented from being broken, it is desirable that the minimum bending radius of the coil 4 is at least half the wire diameter of the coil 4. In other words, it is desirable that the radius of curvature of the second curved portion 13 and the shape of the connecting portion 15 be determined in consideration of the wire diameter of the coil 4 to be used. Further, it is desirable that the tension is wound in consideration of the tension that the coil 4 can be wound without stretching is about 100 MPa and the tension that keeps the elongation at 5% is about 180 MPa. Since the winding swelling can be reduced by adopting the shape of the bobbin 3 of each of the above-described embodiments and modifications, it is not necessary to adopt a method of reducing the winding swelling by increasing the winding tension. It is also possible to reduce the damage and elongation of the coil 4 by reducing the winding tension and winding the coil.

Each of the above-described embodiments and modifications may be combined. For example, a bobbin having all the features shown in the fourth embodiment, the fifth embodiment, and the sixth embodiment is also included in the scope of the present invention. Although various embodiments and modifications have been described above, the present invention is not limited to these contents. Other aspects conceivable within the scope of the technical idea of the present invention are also included within the scope of the present invention.

1 ... Stator 2 ... Iron core 3 ... Bobbin 4 ... Coil 12 ... First curved part 12A, 14A ... Connection end 12B, 14B ... Apex end 13 ... Second curved part 14 ... Third curved part 19 ... Hole 20 ... Protrusion 21 ... Recess 31 ... Straight line 32, 32B ... End 100 ... Electric motor

Claims (8)

A rotary electric machine having a stator having a plurality of centralized winding coils formed by winding a coil around a bobbin covering an iron core.
The bobbin includes a straight portion and an end portion arranged in the longitudinal direction of the straight portion.
The end portion comprises two curved portions and a bending defining portion that are in contact with the straight portion and have a radius of curvature larger than half the width of the bobbin.
At least a part of the bending regulation portion exists at a position separated from the straight portion in the longitudinal direction by more than half the width of the bobbin.
The surface roughness of the end portion is coarser than the surface roughness of the straight portion, that is, a rotary electric machine. In the rotary electric machine according to claim 1,
The bending regulation portion is a rotary electric machine which is an intersection of the two bending portions. In the rotary electric machine according to claim 1,
The bending regulation portion is a rotary electric machine having an arc shape having a radius of curvature smaller than half the width of the bobbin. In the rotary electric machine according to claim 1,
Each of the two curved portions includes a contact end which is an end portion which is in contact with the straight portion and an apex end which is an end portion which is not in contact with the straight portion.
The apex ends of the two curved portions are separated from the straight portion in the longitudinal direction by more than half the width of the bobbin.
The bending regulation portion is a rotary electric machine which is the apex end. In the rotary electric machine according to claim 1,
A rotary electric machine in which the iron core and the bobbin are joined by a combination of protrusions and dents. In the rotary electric machine according to claim 1,
The end portion is a rotary electric machine having a hole penetrating a plane around which the coil is wound or a recess perpendicular to the plane. In the rotary electric machine according to claim 1,
The two curved parts are rotary electric machines having the same radius of curvature. In the rotary electric machine according to claim 1,
The bobbin is a rotary electric machine having two ends and one straight portion, the straight portion being sandwiched between the two ends.

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