JPWO2020017133A1 - Distributed winding radial gap type rotary electric machine and its stator - Google Patents

Abstract

An object of the present invention is to connect segment conductors with high reliability.
The distributed winding radial gap type rotary electric machine and its stator according to the present invention are a stator in which a plurality of U-shaped segment conductors 3 and 4 and a plurality of segment conductors 3 and 4 are inserted in a distributed winding state. It has a core 1. The plurality of segment conductors 3 and 4 each have a convex shape and a concave shape formed at the tip portions connected to each other, and the convex shape and the concave shape have a combined surface in which the axial vertical direction is a contact surface. There is. The convex side dimension of the convex shape is formed larger than the concave side dimension of the concave shape, and a coil group in which a coil end composed of a plurality of segment conductors 3 and 4 is integrated by a resin molding ring portion 6 is formed. Configure.

Description

The present invention relates to a rotary electric machine, and more particularly to a distributed winding radial gap type rotary electric machine and a stator thereof.

High efficiency is required for power sources for industrial machines and rotary electric machines used for driving automobiles. In order to improve the efficiency of the motor, it is necessary to reduce the loss of the motor, and a design method that considers a design to reduce coil copper loss and iron core iron loss, which are the two major causes of motor loss, is common. Is.

Once the output characteristics (rotation speed and torque) of the motor requirement specifications are determined, the mechanical loss is uniquely determined, so a design that reduces iron loss and copper loss is important. Iron loss can be reduced depending on the soft magnetic material used.

In a general motor, an electromagnetic steel sheet is used for the iron core portion, and a motor having a different loss level depending on its thickness and Si content is used. Soft magnetic materials include high-performance materials such as iron-based amorphous metals, which have higher magnetic permeability and lower iron loss than electromagnetic steel sheets, finemets, and nanocrystal materials that can be expected to have high magnetic flux density. In the system, the plate thickness is as thin as 0.025 mm, and the hardness is 900, which is more than 5 times as hard as the electromagnetic steel plate, and there are many problems in manufacturing the motor at low cost. High-performance materials cannot be applied to motors.

On the other hand, copper loss is mainly determined by the relationship between the resistance value of the coil and the current, and measures are taken such as reducing the coil resistance value by cooling and reducing the current value by suppressing the decrease in the residual magnetic flux density of the magnet. Further, in recent years, automobile drive motors and the like are designed to increase the ratio of the conductor to the cross-sectional area of the stator slot (space factor) and reduce the resistance value to the limit of the theoretical limit. However, a flat wire coil that can increase the space factor in the slot has a complicated structure in which the coil end portions at both ends of the slot are routed, and by connecting these conductors by a method such as welding, the coil end portion There is a problem that the volume (line length) of the coil becomes large and the resistance value becomes slightly large.

In Patent Document 1, a two-legged hairpin-shaped conductor segment is inserted into a stator coil of a motor, and each is bent and molded at a coil end portion on the opposite side to the inserted side, and another is arranged in the circumferential direction. This is a method of forming an annular coil by welding with a bent-formed conductor of a hairpin-shaped coil. While this method has the effect of increasing the slot space factor, it requires bending and molding a thick and hard flat conductor during manufacturing, resulting in stress on the stator core, damage to the slot insulator, and connection. However, since residual stress remains when bending, there is a problem that it is difficult to secure the reliability of welded joints, and there is room for improvement as a manufacturing method. Further, since it is necessary to take a space around the welded portion in order to perform welding, there is a problem that the coil end portion becomes large on the welded side.

Patent Document 2 is an example of a method for attempting to improve them. In the structure of Patent Document 2, the stator coil of the segment conductor insertion method is divided in the axial direction, the divided end faces are formed into a shape that can be combined as a V shape, and a conductive paste adhesive is held at the V-shaped combination portion. A method of joining to form a conductor coil is shown. In this method, welding at the coil end portion is eliminated, so that the effect of suppressing the resistance value of the coil to be low can be expected by optimally designing the shape of the coil end portion. However, since it is necessary to assemble the conductors one by one by applying an adhesive, there are problems in increasing man-hours and ensuring reliability. When the conductive paste adhesive is not used, it is generally difficult for the V-shaped fitting portion to come into contact with the surface, and it is known that the V-shaped fitting portion makes line contact somewhere on the V surface. Moreover, considering the manufacturing variation, it is unlikely that all the wires are held on the same axial plane, and it is assumed that it is difficult to manage each wire at a position where it can be firmly connected (contacted). To.

Patent Document 3 discloses a configuration in which a coil divided in the axial direction is connected by a protrusion and a hole, or a convex shape and a concave shape. This is also characterized by connecting with the connection part visible in order to ensure connection reliability. After performing the connection process, a part of the divided stator core is fitted from the circumferential direction and assembled. This also has problems such as confirmation of reliability of insertion of the contact connection part, increase in man-hours, and increase in core assembly man-hours.

Patent Document 4 discloses a method of connecting uneven coil end faces as in Patent Document 3. After inserting it into the slot, stress is applied to a part of the coil to widen the inserted coil, and the caulking effect satisfies a highly reliable connection (ensuring conductivity). Although the description of the means for widening after inserting into the core is not clear, there is a concern that the man-hours for the widening process will increase if all the connection points are used.

Japanese Unexamined Patent Publication No. 2011-239651 JP-A-2015-23771 Japanese Unexamined Patent Publication No. 2013-208038 Japanese Unexamined Patent Publication No. 2016-187245

An object of the present invention is to connect segment conductors with high reliability.

The distributed winding radial gap type rotary electric machine and its stator according to the present invention include a plurality of U-shaped segment conductors and a stator core into which the plurality of segment conductors are inserted in a distributed winding state. The plurality of segment conductors have a convex shape and a concave shape formed at the tip portions connected to each other, and the convex shape and the concave shape have a combined surface in which the axial vertical direction is a contact surface. The convex side dimension of the convex shape is formed larger than the concave side dimension of the concave shape, and the coil end composed of the plurality of segment conductors is integrated with a resin or other insulating material or a high thermal conductive member. Make up a group.

According to the present invention, segment conductors can be connected to each other with high reliability.

It is an exploded perspective view of the segment conductor 3 and the segment conductor 4 which concerns on this embodiment. It is an enlarged perspective view of the vicinity of the connection portion of the segment conductor 3 and the segment conductor 4 according to the present embodiment, the left side is before the connection, and the right side is after the connection. It is a developed perspective view of the resin mold part of the radial gap type rotary electric machine which concerns on this embodiment. It is a perspective view of the resin bobbin 2 for slot insulation which concerns on embodiment shown in FIG. It is a partial perspective view which shows the state which the bobbin 2 which concerns on this embodiment is inserted into a stator core. It is a perspective view of the insulating paper 7 which concerns on another embodiment. It is a perspective view which shows the state which the insulating paper 7 was bent. It is a partial perspective view which shows the state which the insulating paper 7 is inserted into the stator core 1. It is a partial perspective view which shows the arrangement example to the stator core 1 of the segment conductor 3 which concerns on this embodiment. It is a top view of the stator core 1 shown in FIG. 4 (a). It is a partial perspective view which shows the coil end part in the state which 48 segment conductors 3 shown in FIG. 4A are arranged in the circumferential direction (the state where all the coils are inserted). It is a perspective view which shows only a plurality of segment conductors 3 by removing the stator core 1 of FIG. 4C. FIG. 5 is a perspective view showing a state in which a part of the coil group of the segment conductor 3 shown in FIG. 5A near the apex of the coil end is solidified by the resin molding ring portion 6. It is a bottom view which shows the resin molding ring part 6 which was configured separately as shown in FIG. 5C. It is the whole perspective view of the resin molding ring part 6 which was configured separately. It is an overall perspective view before connecting the resin molding ring part 6 shown in FIG. 6B to a coil group. FIG. 5 is a perspective view showing a state in which the coil group of the segment conductors 3 and 4 integrated with the resin molding ring portion 6 shown in FIGS. 5 and 6 is assembled to the stator core 1. The perspective view which shows the state which the coil group of the segment conductor 3 and 4 integrated by the resin molding ring part 6 was assembled to the stator core 1 is shown. It is a perspective view explaining the relationship between a stator and a rotor which concerns on this embodiment. It is sectional drawing in the axial direction which shows the mode in which the motor which concerns on this embodiment is assembled. It is a perspective view which shows the connection form of a segment conductor 3 and a segment conductor 4. It is a front view which shows the connection form of a segment conductor 3 and a segment conductor 4. It is a partial perspective view which shows the manufacturing method as a comparative example of the fitting part of the segment conductor 3 and the segment conductor 4. It is a partial perspective view which shows the manufacturing method of the fitting part of the segment conductor 3 and the segment conductor 4 which concerns on this embodiment. It is a partial perspective view around the tip portions of the segment conductor 3 and the segment conductor 4. It is a perspective view of the bobbin 2 which concerns on another embodiment. It is the whole perspective view before the tooth part 5 of a stator core 1 is inserted into a bobbin 2. FIG. 5 is a partial perspective view in which the teeth portion 5 is fixed to the stator core 1. It is a perspective view of the segment conductor 3 and the segment conductor 4 which concerns on another embodiment. It is a perspective view which shows the connection state of the segment conductor 3 and the segment conductor 4 to the bobbin 2 which concerns on another embodiment.

Before explaining the embodiment of the present invention, the principle of the present invention will be described.

A segment conductor in which a distributed winding radial gap type motor stator coil is formed into a hairpin shape (U shape), and a segment conductor having a structure in which coils inserted from both axial directions in a part of the stator axial direction are connected to each other. In the connection structure stator, the two tips of the segment conductor have a combination shape such as a convex shape and a concave shape in which the contact surface is in the vertical direction in the axial direction, and the dimensional relationship of the unevenness is the dimensional relationship of the tight fit. That is, a part of the tip of the coil end is made of resin or other material, with the convex side dimension having a shape larger than the concave side dimension and all the coils arranged in the circumferential direction being aligned and held in a state of being inserted. It is integrated with an insulator or a high heat conductive member.

As a result, the positioning of the coil can be reliably performed, and the axial insertion force when the coil is inserted into the slot portion can be uniformly and reliably transmitted in the axial direction. Since a very large insertion force is required for fitting and press-fitting tolerances that are larger than the above-mentioned tight fitting of the tip shape of the unevenness, it is necessary to firmly apply stress parallel to the fitting part in the axial direction at the time of press-fitting. However, if there is no integrated part of the coil end mentioned above, the apex of the coil end is pushed, but due to the inclination of the coil and the apex of a plurality of coils separately hitting the pushing jig, It is difficult to insert the coil well due to buckling of the coil.

According to the present invention, the coil can be inserted by uniformly applying stress, so that all the fitting portions can be connected by only one insertion step. Further, in the slot portion of the stator core, an insulating resin bobbin, a slot liner, etc. for preventing an insulation short circuit between the coil and the core are provided to support the insertion of the coil in parallel with the slot portion in the axial direction. It is also important to adopt the structure together. Furthermore, after insertion, by arranging the molded parts such as resin at the tip of the coil ends arranged at the coil ends at both ends in contact with the motor housing and the bearing holding part, the stator coil is continuously subjected to axial stress. A structure is adopted in which the fitted and press-fitted coil connection is held so that it does not come out due to vibration when used as a motor. This can improve the connection reliability. Further, since this structure is a structure capable of increasing the thermal conductivity from the coil end portion to the bearing holding portion and the housing, it can contribute to the reduction of the temperature rise of the motor during use and the reduction of copper loss.

Since the stator coils configured as described above can be inserted by applying stress so as to be uniform in all the coils, all the fitting portions can be connected by only one insertion step. Further, since the slot portion of the stator core is provided with an insulating resin bobbin, a slot liner, etc. for preventing an insulation short circuit between the coil and the core, insulation performance can be ensured. Furthermore, after insertion, by arranging the molded parts such as resin at the tip of the coil ends arranged at the coil ends at both ends in contact with the motor housing and the bearing holding part, the stator coil is continuously subjected to axial stress. A structure is adopted in which the fitted and press-fitted coil connection is held so that it does not come out due to vibration when used as a motor. This can improve the connection reliability. Further, since this structure is a structure capable of increasing the thermal conductivity from the coil end portion to the bearing holding portion and the housing, it can contribute to the reduction of the temperature rise of the motor during use and the reduction of copper loss. It is possible to reduce the welding and bending processes during manufacturing.

Hereinafter, embodiments of the present invention will be described with reference to the drawings and the like. The following description shows specific examples of the contents of the present invention, and the present invention is not limited to these descriptions, and various works by those skilled in the art will be made within the scope of the technical ideas disclosed in the present specification. It can be changed and modified. Further, in all the drawings for explaining the present invention, those having the same function may be designated by the same reference numerals, and the repeated description thereof may be omitted.

FIG. 1 shows a structure in which a stator of a radial gap type rotary electric machine according to an embodiment of the present invention, in which a segment conductor is divided in the axial direction, is reconnected in the stator core.

FIG. 1A is an exploded perspective view of the segment conductor 3 and the segment conductor 4 according to the present embodiment.
As shown in FIG. 1 (a), the segment conductor 4 has a hairpin shape or a U shape having two legs. The tip of the segment conductor 3 has a convex shape.

A hairpin-shaped or U-shaped segment conductor 4 is provided on the opposite side of the segment conductor 3 in the axial direction. The tip of the segment conductor 4 has a concave shape. The segment conductor 3 and the segment conductor 4 are connected in the axial length of the stator core 1 so that a wave winding is formed.

FIG. 1B is an enlarged perspective view of the vicinity of the connection portion between the segment conductor 3 and the segment conductor 4 according to the present embodiment, the left side is before the connection and the right side is after the connection.

The connecting portion between the segment conductor 3 and the segment conductor 4 is formed so that the convex shape and the concave shape are substantially the same shape and mesh with each other, and the surface parallel to the axial direction is made larger than the conductor cross-sectional area and is parallel to the axial direction. Contact connection can be made on the surface.

When it becomes difficult to secure a connection at the same position in the axial direction, the structure is such that the contact is in the axial direction or the diagonal surface is in a V shape. As a result, it is possible to suppress manufacturing errors and assembly errors even when the axial lengths of a large number of coils in the circumferential direction and the radial direction are different.

FIG. 1 (c) is a developed perspective view of a resin mold portion of the radial gap type rotary electric machine according to the present embodiment.

The number of slots of the stator core 1 according to the present embodiment is 48 slots in the circumferential direction. The slot portion of the stator core 1 is arranged with an angular pitch of 7.5 degrees in the circumferential direction.

An insulator is provided in the slot portion in order to secure insulation between the coil composed of the segment conductors 3 and 4 and the stator core 1. In the present embodiment, the plastic bobbin 2 is arranged in the slot portion.

The segment conductors 3 are aligned while being inserted in the circumferential direction, and the portion including the apex of the coil end is molded by the resin molding ring portion 6, and the hairpins of the resin molding ring portion 6 and the segment conductor 3 are formed. The coil group is integrated.

By fixing a part of the coil end of the hairpin coil group, the coil group can be handled stably without using a large-scale jig. The hairpin coil group integrated by the resin molding ring portion 6 is inserted into the slot portion of the stator core 1.

On the other hand, in the coil group formed by the segment conductor 4 on the opposite side in the axial direction, the apex portion of the coil end portion is similarly molded by the resin molding ring portion, and the resin molding ring portion 8 and the coil group of the segment conductor 4 are integrated. The coil group integrated by the resin molding ring portion 8 is inserted into the slot portion of the stator core 1, and further pushed to a predetermined position by a pressurizing device such as a press to completely bond the hairpin coil group and the connecting portion. Is done.

In the conventional method of manufacturing a stator, when a coil group is inserted, stress is applied to the apex of the coil end of the coil, so that the coil is tilted and the insertion amount and insertion force of many coils are different. It was difficult to completely connect the coils.

Also, after inserting the coil group into the stator core, even if an axial stress is applied to the apex of the coil end of each coil to correct the axial dimension in order to adjust the position of the coil group, one coil The legs are connected to the legs of the two coils in the circumferential direction. Due to the variation in the axial positions of the two coils, perfect positioning was difficult.

On the other hand, in the present embodiment, the coil group is integrated, and the positions of the fitting portions are almost the same in both directions in the axial direction, so that the coupling can be performed firmly and stably by applying pressure to the whole. ..

FIG. 2A is a perspective view of the resin bobbin 2 for slot insulation according to the embodiment shown in FIG. FIG. 2B is a partial perspective view showing a state in which the bobbin 2 according to the present embodiment is inserted into the stator core 1.

As shown in FIG. 2B, the slot shape of the stator core 1 is a straight slot in which the shape of the slot (groove) portion has a rectangular cross section in the groove portion into which the segment conductors 3 and 4 are inserted. The opening is formed on the gap side, in other words, on the side facing the rotor. Such an opening is referred to as an open slot shape.

In the bobbin 2 shown in FIG. 2A, the portion of the stator core 1 that enters the slot portion has a parallel surface shape that can be inserted into the straight slot.

Further, in the bobbin 2, a protrusion in the circumferential direction (in other words, a collar portion) is provided at a portion protruding in the axial direction from the stator core 1, and the structure is such that positioning can be performed in the axial direction by this protrusion.

Further, in the bobbin 2 shown in FIG. 2A, the segment conductors 3 and 4 are separated by the rooms 2a to 2f so as to be insulated one by one. As a result, the positioning of the segment conductors 3 and 4 and the insulation between the segment conductors 3 and the segment conductors 4 can be smoothly performed.

The resin bobbin 2 is usually made of a thermoplastic molded body, and is preferably made of PP, PBT, PPS, LCP, etc., which have high heat resistance. Further, in recent years, there are materials whose strength and thermal conductivity have been increased by containing glass fiber, silica, etc., and it is desirable to use them.

It is desirable that the bobbin 2 is manufactured within a tolerance range that can be assembled with respect to the width direction dimension of the slot, and is installed so that there is no play in the circumferential direction, the radial direction, or the axial direction.

The stator core 1 of the present embodiment is divided into a teeth portion 5 and other core back portions. In the case of a divided core in which the stator core 1 is divided and assembled, the above-mentioned flange portion of the bobbin 2 is overlapped so as to cover the divided portion. As a result, after the bobbin 2 is inserted, the split core can be held so as not to come apart.

At this time, the iron loss of the main magnetic flux is significantly reduced by adopting a tooth portion 5 composed of an iron-based amorphous metal, a low-loss electromagnetic steel plate, a nanocrystal alloy foil band having high saturation magnetization, or the like. It is possible to do.

FIG. 3A is a perspective view of the insulating paper 7 according to another embodiment. FIG. 3B is a perspective view showing a state in which the insulating paper 7 is bent. FIG. 3C is a partial perspective view showing a state in which the insulating paper 7 is inserted into the stator core 1.

The insulating paper 7 has a very thin thickness of 0.2 mm or less, and it is desirable that the insulating paper 7 has high strength such as aramid and is composed of an insulator such as Nomex. Further, the insulating paper 7 is formed to be several mm longer than the axial length of the stator core 1.

As shown in FIG. 3A, the insulating paper 7 is valley-folded at intervals. Then, as shown in FIG. 3A, the insulating paper 7 is a slot liner having a B-shaped cross section.

An insulating structure is formed by providing a plurality of the slot liners and arranging a plurality of the slot liners in one slot of the stator core 1. As shown in FIG. 3C, three B-shaped insulating papers 7 are arranged in the slots in the radial direction.

Since this slot liner can be inserted from the axial direction of the slot, the shape of the slot may be a semi-closed slot (slot shape in which the slot opening is half closed) as shown in the figure.

In the embodiment shown in FIGS. 3A to 3C, an example in which the stator core 1 is composed of an integral piece of an electromagnetic steel plate is shown, but it can also be adopted in the case of the split core structure shown above. Is. The merit of adopting the insulating paper slot liner is that the space factor of the conductor can be increased because the paper is as thin as 0.2 mm or less. At present, the thickness of the resin bobbin molded product is limited to about 0.3 mm, although it depends on the axial length and the like.

FIG. 4A is a partial perspective view showing an example of arrangement of the segment conductor 3 according to the present embodiment on the stator core 1.

In this embodiment, the stator core 1 is provided with 48 slots. When the number of rotor magnetic poles of the stator core 1 is eight poles, the straddle of the distributed winding coil composed of the segment conductor 3 has an angle of 45 degrees.

As shown in FIG. 4A, each segment conductor 3 jumps over and straddles 6 slots. Since the angle of one slot is 7.5 degrees, the angle between the legs of the segment conductors 3 is 45 degrees.

FIG. 4B is a top view of the stator core 1 shown in FIG. 4A.

One leg of the segment conductor 3 is arranged in the slot insertion hole of the first layer on the outer peripheral side in the radial direction. It is bent at the apex of the coil end of the segment conductor 3. The other leg of the segment conductor 3 is in the second layer on the outer peripheral side in the radial direction. Here, it can be seen that it is difficult to insert the next adjacent coil because the adjacent slot is closed when one segment conductor 3 is inserted.

FIG. 4C is a partial perspective view showing a coil end portion in a state in which 48 segment conductors 3 shown in FIG. 4A are arranged in the circumferential direction (a state in which all the coils are inserted). When the segment conductors 3 are aligned and lined up, the shape is such that they can be inserted without interference.

FIG. 5A is a perspective view showing only the plurality of segment conductors 3 with the stator core 1 of FIG. 4C removed. When the segment conductors 3 are aligned while being inserted into the stator core 1, the coil ends of the segment conductors 3 are neatly aligned, and the coils inserted into the slots are also aligned in the axial, radial, and circumferential directions. You can see that there is. It can be seen that if this state can be maintained, the insertion into the stator core 1 becomes easy. Therefore, it was considered to fix the coil group of the segment conductor 3 while maintaining this state.

FIG. 5B is a perspective view showing a state in which a part of the coil group of the segment conductor 3 shown in FIG. 5A near the apex of the coil end is solidified by the resin molding ring portion 6. is there.

As a result, the coil group of the segment conductor 3 maintains its posture, and the coil group can be treated as one. This integrated coil group is assembled as shown in FIG. 1 (c).

FIG. 6A is a bottom view showing the resin molding ring portion 6 configured as a separate body shown in FIG. 5C.

The resin molding ring portion 6 is molded in advance. The resin molded ring portion 6 is formed with a plurality of recessed shapes on one surface of the ring-shaped component so that the coil end apex portion of the aligned coil end group is accurately held.

FIG. 6B is an overall perspective view of the resin molding ring portion 6 configured as a separate body.

The segment conductors 3 provided in three layers in the radial direction are each insulated and isolated by the annular wall of the resin molding ring portion 6.

Further, the resin molding ring portion 6 has the same shape that can firmly hold the shape of the apex portion of the coil end of the segment conductor 3.

By covering the coil group of the segment conductor 3 with the resin molding ring portion 6 and adhesively fixing the resin molding ring portion 6, the same effect as the structure shown in FIG. 5B can be obtained. Compared to resin molds, large-scale equipment is not required, and depending on the selection of adhesive, it may be cured faster. In addition, since it can be manufactured as a part, it has the advantage of reducing the wall thickness and selecting various resin materials. Further, it can be configured with a high thermal conductive member such as ceramic.

FIG. 7A shows a perspective view showing a state in which the coil group of the segment conductors 3 and 4 integrated with the resin molding ring portion 6 shown in FIGS. 5 and 6 is being assembled to the stator core 1. .. FIG. 7B is a perspective view showing a state in which the coil groups of the segment conductors 3 and 4 integrated by the resin molding ring portion 6 are assembled to the stator core 1.

As shown in FIG. 7A, a coil group of the segment conductor 3 having a convex tip is inserted into the stator core 1 from the upper part in the axial direction. Further, a coil group of the segment conductor 4 having a concave connecting portion at the tip portion from the lower side in the axial direction is inserted into the slot via the bobbin 2.

After the coil group of the segment conductor 4 is inserted from the lower side of the stator core 1 in the axial direction, the coil group of the segment conductor 3, the stator core 1, and the coil group of the segment conductor 4 are axially pressed by the axial pressurization by the press. It is pressure-molded so that it will be in a predetermined position due to the dimensional relationship of.

As described above, the tip shapes of the coil groups of the segment conductors 3 and 4 are more dimensional than the tight fit, but they are made uniform by applying pressure parallel to the axial direction to the resin molding ring portion 6. Since stress is applied, it can be firmly bonded.

FIG. 8A is a perspective view illustrating the relationship between the stator and the rotor according to the present embodiment.

The rotor of the motor according to the present embodiment includes a permanent magnet 12, a rotor core 13 that houses and rotates the permanent magnet 12, and a shaft 11 that supports the rotor core 13. In this embodiment, an example in the case of a permanent magnet synchronous motor is shown, but the rotor may be a cage-shaped conductor rotor of an induction motor or a magnetic salient pole rotor of a reluctance motor.

In the case of a permanent magnet synchronous motor, the permanent magnet 12 is arranged inside or on the surface of the rotor core 13. A rotor is arranged inside the stator, and the surface of the rotor and the inner surface of the stator face each other through a gap, and magnetic flux is exchanged to operate as a motor.

FIG. 8B is an axial sectional view showing an assembled form of the motor according to the present embodiment.

A ball bearing 14 is brought into contact with the shaft 11 on the output side of the shaft 11, and a ball bearing 15 is brought into contact with the shaft 11 on the opposite output side. With the outer circumferences of the ball bearings 14 and 15 fixed, the inner peripheral surface of the bearing is rotatably held integrally with the shaft.

The outer circumference of the ball bearing 14 is held by the output side bearing holding portion 16. The outer circumference of the ball bearing 15 is held by the bearing holding portion 17 on the non-output side.

The output-side bearing holding portion 16 and the counter-output-side bearing holding portion 17 are configured by the housing 20 in a state of maintaining coaxiality.

The housing 20 is held by tightening bolts 18 and 19 in the axial direction and applying stress in the axial direction. The stator is held and fixed at a predetermined position in the axial direction of the housing 20. In this state, the resin molding ring portion 6 in which the coil group is integrated is in contact with the axial surface of the bearing holding portion on both the output side and the non-output side, and is held in a state where stress is applied in the axial direction.

As a result, even when the rotor vibrates as a motor due to torque pulsation or load fluctuation and vibration or stress is applied to the stator, the housing 20 prevents the stator coil group from coming off.

In addition, this structure also has the effect of cooling the heat generated by the Joule loss generated in the coil from the coil end portion to the bearing holding portion by heat conduction. Further, a cooling method in which cooling oil (lubricating oil) is usually applied to the coil end portion that is not resin-molded is often adopted, and the coil end is directly applied to the coil ends of the segment conductors 3 and 4 that are not surrounded by resin. Therefore, the oil cooling effect is not reduced.

Further, by keeping the segment conductors 3 and 4 firmly held in the axial direction, the segment conductors 3 and 4 can be completely fixed. Therefore, the varnish treatment (resin) that has been required for fixing the segment conductors 3 and 4 until now. The process of fixing the coil by means of the above is not required, and the manufacturing process of the motor can be shortened. Since the varnish treatment requires a drying furnace (usually a continuous furnace) for drying the varnish, it also leads to reduction of investment cost of the drying furnace and cost such as heat quantity (electricity cost) at the time of manufacturing.

FIG. 9A is a perspective view showing a connection form between the segment conductor 3 and the segment conductor 4. FIG. 9B is a front view showing a connection form between the segment conductor 3 and the segment conductor 4.

Since the connection between the convex portion of the segment conductor 3 and the concave portion of the segment conductor 4 is performed in a room divided in the bobbin 2, it is important to firmly design the widthwise dimension of the slot of the bobbin 2.

In the case of a concave-convex shape, even if the convex and concave dimensions are made larger than the tight fit, if the bobbin slot size is loose, the concave groove will open outward, and it will not be possible to connect properly. Therefore, it is desirable that the dimensions of the bobbin 2 in the width direction are substantially the same as the flat outer dimensions of the segment conductor 3 and the segment conductor 4.

The clearance tolerance for assembly should be at least about 20 microns in the case of the outer diameter dimension of about 2 mm to 3 mm in this embodiment, and the dimensional relationship should be such that it does not open outward at the time of fitting.

Further, as shown in FIG. 9B, the legs of the hairpin coils of the segment conductor 3 and the segment conductor 4 have different lengths. As a result, the points to be connected differ in the axial direction, so that every other groove in the radial direction is connected at a different axial position.

FIG. 10A is a partial perspective view showing a manufacturing method as a comparative example of the fitting portion of the segment conductor 3 and the segment conductor 4.

By simultaneously pressing and punching the convex portion and the concave portion of the segment conductor 3 and the segment conductor 4 from the state of a flat wire, the yield of the material can be increased and the number of presses can be minimized. At this time, the dimensional relationship between the concave portion and the convex portion becomes the same as shown by A. Although there is a slight difference in dimensions due to springback, it is difficult to positively set the dimensions of the grooves and protrusions.

FIG. 10B is a partial perspective view showing a method of manufacturing a fitting portion between the segment conductor 3 and the segment conductor 4 according to the present embodiment.

The tips of the segment conductor 3 and the segment conductor 4 are press-processed by defining the dimensions at different points, and the groove dimensions are set to B and the protrusion dimensions are set to different dimensional relationships such as C. At this time, it is desirable to set a large size of the convex portion such as B = 1.5 (−0.02 mm to 0 mm) and C = 1.5 (0 mm to +0.02 mm) to fit the convex portion.

FIG. 10C is a partial perspective view of the segment conductor 3 and the periphery of the tip of the segment conductor 4.

Since it is difficult to control minute dimensions in the processing of the segment conductor 3 and the segment conductor 4, punch them out to a sufficient dimensional relationship, and make the dimensions with conductive plating 21 and 22 such as tin, gold, and silver. Shows how to insert. The conductive platings 21 and 22 are also effective as a countermeasure against corrosion of copper, and a method of plating a punched cut portion other than a portion of a flat conductor having an enamel coating after cutting is also useful.

FIG. 11A is a perspective view of the bobbin 2 according to another embodiment. FIG. 11B is an overall perspective view of the stator core 1 before the teeth portion 5 is inserted into the bobbin 2. FIG. 11C is a partial perspective view in which the tooth portion 5 is fixed to the stator core 1.

In the split core having a structure in which the stator core 1 is divided into a tooth portion 5 and a core back portion, the material of the tooth portion 5 is held by the bobbin 2. Since the magnetic flux is concentrated in the tooth portion 5, iron loss increases due to residual stress such as caulking. Therefore, it is desired to hold the tooth portion 5 in a state where it is just cut.

In that case, it is effective to hold the bobbin 2 made of resin as shown in FIG. 11A. Examples of the material constituting the tooth portion 5 include an iron-based amorphous foil band, a nanocrystal alloy capable of achieving a high magnetic flux density, Finemet, and a thin electromagnetic steel sheet containing 6.5% Si. Holding is performed by inserting the cut pieces of these iron cores into the bobbin 2 as shown in FIG. 11 (b). The bobbin 2 at this time has a wall for separating the room into which the segment conductor 3 and the segment conductor 4 are inserted. FIG. 11C shows a state in which the teeth portion 5 is assembled into a core back core.

FIG. 12A is a perspective view of the segment conductor 3 and the segment conductor 4 according to another embodiment. FIG. 12B is a perspective view showing a state in which the segment conductor 3 and the segment conductor 4 are connected to the bobbin 2 according to another embodiment.

The shape is such that the groove (recessed portion) and the protrusion (convex portion) are oriented in the direction shown in FIGS. 1 and 9 and the direction rotated by 90 degrees. This is to prevent the concave surface of the cross section of the connection portion from coming to the mating surface of the bobbin walls when the bobbins 2 shown in FIG. 11 overlap each other as shown in FIG. 12 (b). ..

Since coils of the same phase are arranged in the same slot, the potential difference is small and there is no problem even if the charged part is exposed, but if the surface is large, it will come into contact due to the inclusion of impurities and the parallel coil. This is to avoid becoming a problem as much as possible.

In such a case, it is also necessary to perform a varnish impregnation treatment in the slot and a sealing treatment for preventing the intrusion of lubricating oil (ATF) into the slot. When a material with excellent magnetic properties is used for the teeth portion (including the case where the teeth portion is a high-grade steel plate even in an integrated core), the segment conductor 3 is subjected to a process of bending the segment conductor 3 and the segment conductor 4. And the segment conductor 4 applies stress to the stator teeth portion.

In this case, when stress is applied to the high-grade iron plate, the magnetic characteristics deteriorate, the magnetization characteristics deteriorate, and the iron loss increases significantly. In the combined method of the present embodiment, since the segment conductor 3 and the segment conductor 4 are subjected to stress parallel to the axial direction, the tee score can be manufactured without applying any stress. In addition, since no extra stress is applied, it is also a great effect that the insulation performance is not burdened.

1 ... stator core, 2 ... bobbin, 3 ... segment conductor, 4 ... segment conductor, 5 ... teeth part, 6 ... resin molding ring part, 7 ... insulating paper, 8 ... resin molding ring part, 11 ... shaft, 12 ... Permanent magnet, 13 ... rotor core, 14 ... ball bearing, 15 ... ball bearing, 16 ... output shaft side bearing holding part, 17 ... anti-output shaft side bearing holding part, 18 ... bolt, 19 ... bolt, 20 ... housing, 21 ... Conductive plating, 22 ... Conductive plating

Claims (9)

Multiple U-shaped segment conductors and
A stator core, in which the plurality of segment conductors are inserted in a distributed winding state, is provided.
The plurality of segment conductors have a convex shape and a concave shape formed at the tip portions connected to each other.
The convex shape and the concave shape have a combination surface in which the axial direction is the contact surface.
The convex side dimension of the convex shape is formed larger than the concave side dimension of the concave shape.
A stator of a distributed winding radial gap type rotary electric machine in which a coil end composed of the plurality of segment conductors constitutes a coil group in which a resin or other insulating material or a high thermal conductive member is integrated. The stator of the distributed winding radial gap type rotary electric machine according to claim 1.
The coil group is a stator of a distributed winding radial gap type rotary electric machine formed in only one of the axial directions with the stator core as a boundary. The stator of the distributed winding radial gap type rotary electric machine according to claim 1.
The coil group is a stator of a distributed winding radial gap type rotary electric machine formed in both axial directions with the stator core as a boundary. A stator of any of the distributed winding radial gap type rotary electric machines according to claims 1 to 3.
In the coil group, a stator of a distributed winding radial gap type rotary electric machine in which a resin molded product and the coil end are connected by an adhesive. A stator of any of the distributed winding radial gap type rotary electric machines according to claims 1 to 4.
The connecting portion between the segment conductors is a stator of a distributed winding radial gap type rotary electric machine to be inserted, which is arranged in a slot groove formed by a bobbin provided in the stator core. A stator of any of the distributed winding radial gap type rotary electric machines according to claims 1 to 4.
The connecting portion between the segment conductors is a stator of a distributed winding radial gap type rotary electric machine that is inserted into a slot groove while being covered with insulating paper provided on the stator core. A stator of any of the distributed winding radial gap type rotary electric machines according to claims 1 to 6.
The convex shape and the concave shape, which are the connecting portions between the segment conductors, are stators of a distributed winding radial gap type rotary electric machine which is plated containing tin, gold, and silver. A stator of any of the distributed winding radial gap type rotary electric machines according to claims 1 to 7.
The stator core is a stator of a distributed winding radial gap type rotary electric machine having a teeth portion made of a material containing an amorphous or nanocrystal alloy and having better magnetic properties than a core back portion. A distributed winding radial gap type rotary electric machine provided with any of the stators according to claims 1 to 8.
A distributed winding radial gap type rotary electric machine that holds a resin mold portion arranged at the apex of the coil end of the stator in contact with the motor housing portion.

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