JP7142700B2 - Distributed winding radial gap type rotary electric machine and its stator - Google Patents

Description

The present invention relates to a rotating electrical machine, and more particularly to a distributed winding radial gap rotating electrical machine and its stator.

Rotating electric machines used as power sources for industrial machines and for driving automobiles are required to be highly efficient. In order to increase the efficiency of motors, it is necessary to reduce motor loss, and the general design method is to consider ways to reduce coil copper loss and core iron loss, which are the two major factors in motor loss. is.

Once the output characteristics (rotational speed and torque) of the required motor specifications are determined, the mechanical loss is uniquely determined, so designing to reduce iron loss and copper loss is important. Iron loss can be reduced by the soft magnetic material used.

In general motors, electromagnetic steel sheets are used for the iron core portion, and those with different loss levels depending on the thickness, Si content, etc. are used. Soft magnetic materials include high-performance materials such as iron-based amorphous metals, which have higher permeability and lower core loss than electrical steel sheets, Finemet, and nanocrystalline materials that can be expected to have high magnetic flux density. The steel plate has a very thin plate thickness of 0.025 mm and a Vickers hardness of 900, which is more than five times as hard as an electromagnetic steel plate. It has not been possible to apply high-performance materials to motors.

On the other hand, copper loss is mainly determined by the relationship between the resistance value of the coil and the current. Furthermore, recent automobile drive motors and the like are designed to reduce the resistance value to the theoretical limit by increasing the ratio (space factor) of the conductor to the cross-sectional area of the stator slot. However, in a flat wire coil that can increase the space factor in the slot, the winding of the coil end portions at both ends of the slot becomes a complicated structure. There is a problem that the volume (line length) of is increased, and the resistance value is slightly increased.

In Patent Document 1, two hairpin-shaped conductor segments are inserted into a stator coil of a motor, and each is bent at the coil end on the side opposite to the inserted side to form another circumferentially arranged conductor segment. It is a method of forming an annular coil by welding with a bent conductor of a hairpin-shaped coil. Although this method has the effect of increasing the slot space factor, it requires the bending of thick and hard rectangular conductors during manufacturing, which may cause stress to the stator core, damage to the slot insulator, and damage to the joints. There is a problem that it is difficult to ensure the reliability of welded joints because residual stress remains when bending, and there is room for improvement as a manufacturing method. In addition, since a space around the welded portion must be secured for welding, there is also the problem that the coil end portion becomes large on the welding side.

Japanese Patent Laid-Open No. 2002-300003 is cited as a method for trying to improve them. In the structure of Patent Document 2, a segment conductor insertion type stator coil is divided in the axial direction, and the divided end faces are formed in a shape that can be combined into a V shape, and a conductive paste adhesive is applied to the V-shaped combination part. A method of bonding to form a conductor coil is shown. Since this method eliminates the need for welding at the coil end portions, it is expected that the resistance value of the coil can be kept low by optimally designing the shape of the coil end portions. However, since it is necessary to assemble the conductors one by one by applying an adhesive, there are problems in increasing the number of man-hours and ensuring reliability. It is known that when a conductive paste adhesive is not used, it is generally difficult to make face-to-face contact with the V-shaped fitting portion, and line contact occurs somewhere on the V-face. Moreover, considering manufacturing variations, it is difficult to imagine that all the wires are held on the same axial plane, and it is assumed that it is difficult to manage the positions where each wire can be firmly connected (contacted). be.

Patent Literature 3 discloses a configuration in which coils divided in the axial direction are connected by projections and holes or by projections and recesses. This is also characterized by connecting in a state where the connection part is visible in order to ensure connection reliability. After performing connection processing, a portion of the divided stator core is fitted from the circumferential direction to assemble. This also has problems such as confirmation of reliability of insertion of the contact connection portion, an increase in man-hours, and an increase in man-hours for assembling the core.

Similarly to Patent Document 3, Patent Document 4 discloses a construction method for connecting uneven coil end surfaces. After the coil is inserted into the slot, stress is applied to a part of the coil to widen the width of the inserted coil, and the caulking effect satisfies highly reliable connection (ensuring of conductivity). Although the description of the means for widening after inserting into the core is not clear, there is concern about an increase in the number of man-hours for the width widening process if it is done at all connection points.

JP 2011-239651 A JP 2015-23771 A JP 2013-208038 A JP 2016-187245 A

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

A 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 each have a convex shape and a concave shape at the ends connected to each other, and the convex shape and the concave shape have a combination surface that serves as a contact surface in the direction perpendicular to the axial direction; The convex side dimension of the convex shape is formed to be larger than the concave side dimension of the concave shape, and a pre-molded resin mold ring portion is provided at the apex portion of the coil end configured by the plurality of segment conductors, The resin mold ring portion is formed with a plurality of recesses for holding the vertexes of the coil ends, and an annular wall for insulating and isolating the segment conductors provided in the radial direction. An integrated coil group is constructed by covering the apex portions of the coil ends on the coil ends and fixing them with an adhesive .

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

3 is an exploded perspective view of segment conductors 3 and segment conductors 4 according to the present embodiment; FIG. 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 connection, and the right side is after connection. FIG. 3 is an exploded perspective view of a resin-molded portion of the radial gap type rotating electric machine according to the present embodiment; FIG. 2 is a perspective view of a resin bobbin 2 for slot insulation according to the embodiment shown in FIG. 1; FIG. 4 is a partial perspective view showing a state in which the bobbin 2 according to the present embodiment is inserted into the stator core; 8 is a perspective view of insulating paper 7 according to another embodiment. FIG. 4 is a perspective view showing a state in which insulating paper 7 is folded; FIG. 4 is a partial perspective view showing a state in which insulating paper 7 is inserted into stator core 1. FIG. FIG. 3 is a partial perspective view showing an example of arrangement of segment conductors 3 on the stator core 1 according to the present embodiment. It is a top view of the stator core 1 shown by Fig.4 (a). FIG. 5 is a partial perspective view showing a coil end portion in a state where 48 segment conductors 3 shown in FIG. 4A are arranged in the circumferential direction (a state in which all the coils are inserted). Fig. 5 is a perspective view showing only a plurality of segment conductors 3 with the stator core 1 of Fig. 4(c) removed; FIG. 6 is a perspective view showing a state in which the coil group of the segment conductor 3 shown in FIG. It is a bottom view which shows the resin mold ring part 6 comprised separately shown in FIG.5(c). FIG. 3 is an overall perspective view of a separately configured resin mold ring portion 6; 6B is an overall perspective view before connecting the resin mold ring portion 6 shown in FIG. 6B to the coil group. FIG. FIG. 7 is a perspective view showing a state in which the coil group of the segment conductors 3 and 4 integrated by the resin mold ring portion 6 shown in FIGS. 5 and 6 is assembled to the stator core 1. FIG. 4 is a perspective view showing a state in which a coil group of segment conductors 3 and 4 integrated by a resin mold ring portion 6 is assembled to the stator core 1. FIG. It is a perspective view explaining the relationship between the stator and rotor which concern on this embodiment. FIG. 3 is an axial cross-sectional view showing a form in which the motor according to the present embodiment is assembled; FIG. 3 is a perspective view showing a connection form between segment conductors 3 and 4; FIG. 2 is a front view showing a connection form between segment conductors 3 and 4; FIG. 5 is a partial perspective view showing a manufacturing method as a comparative example of a fitting portion of segment conductors 3 and 4; FIG. 4 is a partial perspective view showing a method of manufacturing a fitting portion of segment conductors 3 and 4 according to the present embodiment. 4 is a partial perspective view of the periphery of tip portions of segment conductors 3 and segment conductors 4. FIG. It is a perspective view of bobbin 2 concerning other embodiments. 3 is an overall perspective view of the stator core 1 before tooth portions 5 are inserted into bobbins 2. FIG. 3 is a partial perspective view of teeth 5 fixed to stator core 1. FIG. 4 is a perspective view of a segment conductor 3 and a segment conductor 4 according to another embodiment; FIG. FIG. 10 is a perspective view showing a state of connection of segment conductors 3 and 4 to a bobbin 2 according to another embodiment;

Before describing embodiments of the present invention, the principle of the present invention will be described.

A segment conductor with a structure in which a segment conductor formed by molding a distributed winding radial gap motor stator coil into a hairpin shape (U-shape) is inserted from both sides in the axial direction of the stator and connected to each other. In the connection structure stator, the two ends of the segment conductors have a combined shape such as a convex shape and a concave shape in which the contact surface is in the direction perpendicular to the axial direction, and the dimensional relationship between the unevenness is the dimensional relationship of the interference fit. In other words, it has a shape whose convex side dimension is larger than its concave side dimension, and in a state in which all the coils arranged in the circumferential direction are aligned and held in an inserted state, a part of the tip of the coil end is covered with resin or other material. Integrate with insulators or high thermal conductivity materials.

As a result, the coil can be reliably positioned, and the axial insertion force when inserting the coil into the slot can be transmitted uniformly and reliably in the axial direction. As mentioned above, the fitting and press-fitting tolerances beyond the interference fit of the uneven tip shape require a very large insertion force. However, if there is no integral part of the coil end as described above, the apex of the coil end will be pushed. Buckling of the coil occurs and it is difficult to insert it successfully.

According to the present invention, since the coil can be uniformly stressed and inserted, all fitting portions can be connected by a single insertion process. Insulating resin bobbins, slot liners, etc. are provided in the slots of the stator core to prevent insulation short circuits between the coil and the core, and assist in inserting the coils into the slots parallel to the axial direction. It is also important to adopt the structure together. Furthermore, after the insertion, the molded parts such as resin at the tips of the coil ends arranged at both ends of the coil end are brought into contact with the motor housing and the bearing holding part, thereby continuously applying axial stress to the stator coil, A structure is employed to hold the fitted and press-fitted coil connection portion so that it does not slip out due to vibration or the like during use as a motor. This can improve connection reliability. Furthermore, since this structure can increase the thermal conductivity from the coil end portion to the bearing holding portion and the housing, it can contribute to reducing the temperature rise of the motor during use and reducing copper loss.

Since the connection of the stator coils constructed as described above can be performed by applying a uniform stress to all the coils, it is possible to connect all the fitting portions by a single insertion process. Insulating resin bobbins, slot liners, etc. are provided in the slots of the stator core to prevent insulation short-circuiting between the coil and the core, so insulation performance can be ensured. Furthermore, after the insertion, the molded parts such as resin at the tips of the coil ends arranged at both ends of the coil end are brought into contact with the motor housing and the bearing holding part, thereby continuously applying axial stress to the stator coil, A structure is employed to hold the fitted and press-fitted coil connection portion so that it does not slip out due to vibration or the like during use as a motor. This can improve connection reliability. Furthermore, since this structure can increase the thermal conductivity from the coil end portion to the bearing holding portion and the housing, it can contribute to reducing the temperature rise of the motor during use and reducing copper loss. It is possible to reduce welding and bending processes during manufacturing.

An embodiment of the present invention will be described below with reference to the drawings and the like. The following description shows specific examples of the content of the present invention, and the present invention is not limited to these descriptions, and various modifications by those skilled in the art within the scope of the technical ideas disclosed in the present specification. Changes and modifications are possible. In addition, in all the drawings for explaining the present invention, parts having the same functions are denoted by the same reference numerals, and repeated explanations thereof may be omitted.

FIG. 1 shows a structure in which segment conductors divided in the axial direction are reconnected in the stator core in a stator for a radial gap type rotating electric machine according to one embodiment of the present invention.

FIG. 1(a) is an exploded perspective view of a segment conductor 3 and a segment conductor 4 according to this embodiment.
As shown in FIG. 1(a), the segment conductor 4 is hairpin-shaped or U-shaped with two legs. Further, the distal end of the segment conductor 3 is convex.

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 conductors 3 and 4 are connected within the axial length of the stator core 1 such that wave windings are formed.

FIG. 1(b) is an enlarged perspective view of the vicinity of the connecting portion of the segment conductor 3 and the segment conductor 4 according to this embodiment, the left side being before connection and the right side being after connection.

The connecting portion of 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 shape is such that the plane parallel to the axial direction is larger than the cross-sectional area of the conductor. A contact connection can be made on the surface.

When it becomes difficult to ensure connection at the same point in the axial direction, the structure is such that contact is made in the axial direction, or a V-shaped shape in which the oblique surfaces are in contact. As a result, manufacturing errors and assembly errors can be suppressed 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 an exploded perspective view of a resin-molded portion of the radial gap type rotating electric machine according to the present embodiment.

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

Insulators are provided in the slots in order to ensure insulation between the coils formed by the segment conductors 3 and 4 and the stator core 1 . In this embodiment, a plastic bobbin 2 is placed in the slot.

The segment conductors 3 are inserted in the circumferential direction and aligned, and the portions including the vertexes of the coil ends are molded with the resin mold ring portion 6 to form hairpins between the resin mold ring portion 6 and the segment conductors 3 . Coil groups are integrated.

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

On the other hand, the coil group of the segment conductor 4 on the opposite side in the axial direction is similarly molded at the vertex of the coil end portion with the resin mold ring portion, and the resin mold ring portion 8 and the coil group of the segment conductor 4 are integrated. The coil group integrated by the resin mold ring portion 8 is inserted into the slot portion of the stator core 1, and further pushed into a predetermined position by a pressure device such as a press, whereby the hairpin coil group and the complete connection portion are coupled. is done.

In the conventional stator manufacturing method, when a group of coils is inserted, stress is applied to the coil end apexes of the coils. It was difficult to completely couple the coils together.

After the coil group is inserted into the stator core, even if an attempt is made to correct the axial dimension by applying axial stress to the apex of the coil end portion of each coil in order to adjust the position of the coil group, one coil The legs of the coil are connected to the legs of the two coils in the circumferential direction. Perfect positioning was difficult because the axial positions of the two coils had variations.

On the other hand, in this embodiment, the coil group is integrated, and the positions of the fitting portions are generally aligned in both directions in the axial direction. .

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

As shown in FIG. 2(b), the slot shape of the stator core 1 is a straight slot having a rectangular cross-section at the slot (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 openings are referred to as open slot geometries.

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

A portion of the bobbin 2 protruding from the stator core 1 in the axial direction is provided with a projection in the circumferential direction (in other words, a collar portion), and this projection enables axial positioning.

The bobbin 2 shown in FIG. 2(a) has a structure divided by chambers 2a to 2f so that the segment conductors 3 and 4 are insulated one by one. Thereby, positioning of the segment conductors 3 and 4 and insulation between the segment conductors 3 and 4 can be performed smoothly.

The bobbin 2 made of resin is generally made of a thermoplastic molded body, and is preferably made of PP, PBT, PPS, LCP, or the like, which has high heat resistance. Also, in recent years, there are materials whose strength and thermal conductivity are enhanced by containing glass fibers, silica, etc., and it is desirable to use them.

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

The stator core 1 of this embodiment is divided into a tooth portion 5 and a core back portion. In the case of a split core configured by splitting and assembling the stator core 1, the aforementioned collar portion of the bobbin 2 is overlapped so as to cover the split portion. Thereby, after the bobbin 2 is inserted, the split core can be held so as not to come apart.

At this time, the tooth part 5 is made of iron-based amorphous metal, low-loss magnetic steel sheet, nano-crystalline alloy foil strip with high saturation magnetization, etc., thereby greatly reducing the iron loss of the main magnetic flux. It is possible to

FIG. 3A is a perspective view of insulating paper 7 according to another embodiment. FIG. 3(b) is a perspective view showing a state in which the insulating paper 7 is folded. 3(c) is a partial perspective view showing a state in which the insulating paper 7 is inserted into the stator core 1. FIG.

The insulating paper 7 is very thin, having a thickness of 0.2 mm or less, and is preferably made of Nomex, which is made of a high-strength insulating material such as aramid. The insulating paper 7 is formed several millimeters longer than the axial length of the stator core 1 .

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

By providing a plurality of slot liners and arranging a plurality of slot liners in one slot of the stator core 1, an insulating structure is achieved. As shown in FIG. 3(c), three B-shaped insulating papers 7 are radially arranged in the slots.

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 embodiment shown in FIGS. 3(a) to 3(c), an example in which the stator core 1 is composed of an integral electromagnetic steel sheet is shown, but the above split core structure can also be adopted. is. The merit of adopting the insulating paper slot liner is that the paper is thin with a thickness of 0.2 mm or less, so it is possible to increase the space factor of the conductor. At present, the thickness of the resin bobbin molded body is limited to about 0.3 mm, depending on the length in the axial direction.

FIG. 4(a) is a partial perspective view showing an arrangement example of the segment conductors 3 on the stator core 1 according to this embodiment.

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

As shown in FIG. 4(a), each segment conductor 3 straddles six slots. Since one slot angle is 7.5 degrees, the angle between the legs of the segment conductor 3 is 45 degrees.

FIG. 4(b) is a top view of the stator core 1 shown in FIG. 4(a).

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. The coil end vertex of the segment conductor 3 is bent. The other leg of the segment conductor 3 is located in the second layer on the outer peripheral side in the radial direction. Here, it can be seen that insertion of the next adjacent coil is difficult because the adjacent slot is blocked when one segment conductor 3 is inserted.

FIG. 4(c) is a partial perspective view showing a coil end portion in a state in which 48 segment conductors 3 shown in FIG. 4(a) 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, they have a shape that allows insertion without interference.

FIG. 5(a) is a perspective view showing only a plurality of segment conductors 3 with the stator core 1 of FIG. 4(c) removed. When the segment conductors 3 are inserted into the stator core 1 and aligned, the coil end portions of the segment conductors 3 are neatly aligned, and the coils inserted into the slots are also aligned axially, radially, and circumferentially. I know there is. It can be seen that the insertion into the stator core 1 is facilitated if this state can be maintained. Therefore, it was considered to fix the coil group of the segment conductor 3 while maintaining this state.

FIG. 5(b) is a perspective view showing a state in which a part of the coil group of the segment conductor 3 shown in FIG. be.

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

FIG. 6(a) is a bottom view showing the separately configured resin mold ring portion 6 shown in FIG. 5(c).

The resin mold ring portion 6 is molded in advance. The resin-molded ring portion 6 has a plurality of concave shapes formed on one side of the ring-shaped part so that the apexes of the aligned coil ends are held with high accuracy.

FIG. 6(b) is an overall perspective view of the resin mold ring portion 6 configured separately.

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

Also, the resin molded 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 and fixing the coil group of the segment conductor 3 with the resin mold ring portion 6, the same effect as the structure shown in FIG. 5B can be obtained. Compared to resin molding, it does not require large-scale equipment, and depending on the selection of the adhesive, it may be cured quickly. In addition, since it is possible to manufacture as a part, it is possible to reduce the thickness and select various resin materials. Furthermore, it is also possible to use a high heat conductive material such as ceramic.

FIG. 7(a) is a perspective view showing a state in which the coil group of the segment conductors 3 and 4 integrated by the resin mold ring portion 6 shown in FIGS. 5 and 6 is being assembled to the stator core 1. FIG. . FIG. 7(b) is a perspective view showing a state in which the coil group of the segment conductors 3 and 4 integrated by the resin mold ring portion 6 is assembled to the stator core 1. As shown in FIG.

As shown in FIG. 7(a), a coil group of segment conductors 3 having convex ends is inserted into the stator core 1 from above in the axial direction. A group of coils of a segment conductor 4 having a concave connecting portion at its tip end is inserted from the axially lower side through the bobbin 2 into the slot.

After the coil group of the segment conductor 4 is inserted from the axial lower side of the stator core 1, the coil group of the segment conductor 3, the stator core 1, and the coil group of the segment conductor 4 are axially compressed by pressing in the axial direction. Pressure molding is performed so that it is at a predetermined position in relation to the dimensions.

As described above, the end shapes of the coil groups of the segment conductors 3 and 4 have a dimensional relationship that is greater than that of tight fitting. It is stressed so that it can be firmly bonded.

FIG. 8(a) is a perspective view illustrating the relationship between the stator and the rotor according to this embodiment.

The rotor of the motor according to this embodiment includes permanent magnets 12 , a rotor core 13 that accommodates the permanent magnets 12 and rotates, 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 squirrel cage 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 magnets 12 are arranged inside or on the surface of the rotor core 13 . A rotor is arranged inside the stator, and the rotor surface and the stator inner surface are opposed to each other with a gap therebetween, and magnetic fluxes are exchanged to operate as a motor.

FIG. 8(b) is an axial cross-sectional view showing an assembled form of the motor according to the present embodiment.

A ball bearing 14 is in contact with the output side of the shaft 11 and a ball bearing 15 is in contact with the non-output side of the shaft 11 . While the outer peripheries of the ball bearings 14 and 15 are fixed, the inner peripheral surfaces of the bearings are rotatably held together with the shaft.

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

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

The housing 20 is configured to be axially tightened with bolts 18 and 19 to apply stress in the axial direction. The stator is held and fixed in place in the axial direction of the housing 20 . In this state, the resin molded ring portion 6 integrating the coil group contacts the axial surface of the bearing holding portion on both the output side and the counter-output side, and is held in a state of applying stress 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 slipping out.

This structure also has the effect of cooling heat generated by Joule loss generated in the coil from the coil end portion to the bearing holding portion by heat conduction. Furthermore, a cooling method in which cooling oil (lubricating oil) is usually applied to the coil end portions that are not resin-molded is often adopted. Therefore, the oil cooling effect is not reduced.

In addition, by continuing to hold the segment conductors 3 and 4 firmly in the axial direction, the segment conductors 3 and 4 can be completely fixed. The process of fixing the coils by means of squeezing becomes unnecessary, and the manufacturing process of the motor can be shortened. Since varnish treatment requires a drying oven (usually a continuous oven) to dry the varnish, the investment cost of the drying oven and the amount of heat (electricity costs) during production can be reduced.

FIG. 9(a) is a perspective view showing the form of connection between the segment conductors 3 and 4. FIG. FIG. 9(b) is a front view showing the form of connection between the segment conductors 3 and 4. FIG.

Since the projections of the segment conductors 3 and the recesses of the segment conductors 4 are connected in a partitioned room inside the bobbin 2, it is important to design the width dimension of the slot of the bobbin 2 firmly.

In the case of uneven shapes, even if the dimensions of the protrusions and recesses are greater than the tight fit, if the dimensions of the bobbin slots are loose, the grooves of the recesses open outward, resulting in a state in which proper connection cannot be made. Therefore, it is desirable that the dimension of the bobbin 2 in the width direction should be approximately the same as the rectangular external dimensions of the segment conductors 3 and 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 it is desirable to have a dimensional relationship that does not open outward when fitted.

Also, as shown in FIG. 9B, the legs of the hairpin coils of the segment conductors 3 and 4 have different lengths. As a result, since the connecting points are different in the axial direction, every other groove in the radial direction is connected at different axial positions.

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

The segment conductor 3 and the segment conductor 4 are formed by press-punching the projections and recesses from the rectangular wire at the same time, thereby increasing the material yield and minimizing the number of presses. In this case, the dimensional relationship between the concave portion and the convex portion is the same as indicated by A. Although some dimensional difference is possible due to springback, it is difficult to positively set the dimensions of the grooves and protrusions.

FIG. 10(b) is a partial perspective view showing a method of manufacturing the fitting portion of the segment conductors 3 and 4 according to this embodiment.

The ends of the segment conductor 3 and the segment conductor 4 are press-worked with different dimensions defined at different points, and different dimension relationships such as B for the groove dimension and C for the projection dimension are formed. At this time, it is desirable to set the size of the protrusion to be large, such as B=1.5 (-0.02 mm to 0 mm) and C=1.5 (0 mm to +0.02 mm), to achieve tight fit.

FIG. 10(c) is a partial perspective view of the periphery of the segment conductors 3 and 4. FIG.

Since it is difficult to manage minute dimensions in the processing of the segment conductors 3 and 4, they are punched out in a dimensional relationship with some leeway, and the dimensions are made by conductive plating 21 and 22 of tin, gold, silver, or the like. shows how to insert The conductive platings 21 and 22 are also effective against corrosion of copper, and it is also useful to apply plating to the punched and cut portions other than the enamel-coated portions of the rectangular conductor after cutting.

FIG. 11(a) is a perspective view of a bobbin 2 according to another embodiment. 11(b) is an overall perspective view of the stator core 1 before the teeth 5 of the stator core 1 are inserted into the bobbin 2. FIG. 11(c) is a partial perspective view of the teeth 5 fixed to the stator core 1. FIG.

In a split core structure in which a 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 a bobbin 2. - 特許庁Magnetic flux concentrates on the teeth 5, and iron loss increases due to residual stress caused by caulking or the like.

In that case, it is effective to hold the resin bobbin 2 as shown in FIG. 11(a). Examples of the material forming the tooth portion 5 include an iron-based amorphous foil strip, a nanocrystalline alloy capable of realizing a high magnetic flux density, Finemet, a thin electromagnetic steel sheet containing 6.5% Si, and the like. These iron cores are cut and held by inserting them into the bobbin 2 as shown in FIG. 11(b). The bobbin 2 at this time has a wall for dividing a room into which the segment conductors 3 and 4 are inserted. FIG. 11(c) shows a state in which the tooth portions 5 are assembled to the core-back core.

FIG. 12(a) is a perspective view of a segment conductor 3 and a segment conductor 4 according to another embodiment. FIG. 12(b) is a perspective view showing a connection state of the segment conductor 3 and the segment conductor 4 to the bobbin 2 according to another embodiment.

The grooves (concave portions) and projections (convex portions) are oriented in a direction rotated 90 degrees from the directions shown in FIGS. 1 and 9 . This is because, as shown in FIG. 12(b), when the bobbins 2 shown in FIG. 11 are overlapped side by side, the concave surface of the cross section of the connecting portion is to avoid coming to the joining surfaces of the bobbin walls. .

Since the 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. This is to avoid, even if only a little, what will happen.

In such a case, it is necessary to impregnate the inside of the slot with varnish, or to perform a sealing treatment to prevent lubricating oil (ATF) from entering the inside of the slot. When using a material with excellent magnetic properties for the teeth (including the case where the teeth are made of high-grade steel plate even in the integrated core), the segment conductors 3 are bent by bending the segment conductors 3 and 4. , stress is applied from the segment conductors 4 to the stator tooth portion.

In this case, when stress is applied to the high-grade iron plate, the magnetic properties deteriorate, and the magnetization properties deteriorate, or the iron loss increases significantly. In the combination method of this embodiment, only stress parallel to the axial direction is applied to the segment conductors 3 and 4, so that the tea core can be manufactured without applying any stress. In addition, since unnecessary stress is not applied, it is also a great effect that the insulating performance is not burdened.

DESCRIPTION OF SYMBOLS 1... Stator core 2... Bobbin 3... Segment conductor 4... Segment conductor 5... Teeth part 6... Resin mold ring part 7... Insulating paper 8... Resin mold ring part 11... Shaft 12... Permanent magnet 13 Rotor core 14 Ball bearing 15 Ball bearing 16 Output shaft side bearing holding portion 17 Anti-output shaft side bearing holding portion 18 Bolt 19 Bolt 20 Housing 21 conductive plating, 22 conductive plating

Claims (8)

a plurality of U-shaped segment conductors;
a stator core into which the plurality of segment conductors are inserted in a distributed winding state;
each of the plurality of segment conductors has a convex shape and a concave shape at the ends connected to each other,
The convex shape and the concave shape have a combination surface that is a contact surface in the direction perpendicular to the axial direction,
The convex side dimension of the convex shape is formed larger than the concave side dimension of the concave shape,
A pre-molded resin-molded ring portion is provided at the apex portion of the coil end configured by the plurality of segment conductors,
The resin mold ring portion is formed with a plurality of recesses for holding the vertexes of the coil ends, and an annular wall for insulating and isolating the segment conductors provided in the radial direction ,
A stator for a distributed winding radial gap type electric rotating machine, which constitutes a coil group integrated by covering the resin mold ring portion with the apex portion of the coil end and bonding and fixing the same with an adhesive . A stator for a distributed winding radial gap type electric rotating machine according to claim 1,
A stator of a distributed winding radial gap type rotating electric machine in which the coil group is formed only in one of axial directions with respect to the stator core. A stator for a distributed winding radial gap type electric rotating machine according to claim 1,
The coil group is a stator of a distributed winding radial gap type rotary electric machine in which the coil groups are formed in both axial directions with respect to the stator core. A stator for a distributed winding radial gap type rotating electric machine according to any one of claims 1 to 3 ,
A stator for a distributed winding radial gap type rotary electric machine in which connecting portions between the segment conductors are inserted into slot grooves formed by bobbins provided in the stator core. A stator for a distributed winding radial gap type rotating electric machine according to any one of claims 1 to 3 ,
A stator for a distributed winding radial gap type rotary electric machine in which connecting portions between the segment conductors are inserted into slot grooves while being covered with insulating paper provided on the stator core. A stator for a distributed winding radial gap type rotating electrical machine according to any one of claims 1 to 5 ,
A stator for a distributed winding radial gap type rotating electric machine, wherein the convex shape and the concave shape, which are the connecting portions between the segment conductors, are plated with tin, gold, and silver. A stator for a distributed winding radial gap type rotating electric machine according to any one of claims 1 to 6 ,
The stator core is a stator for a distributed winding radial gap type electric rotating machine, and has teeth portions made of a material containing an amorphous or nanocrystalline alloy and having magnetic properties superior to those of a core back portion. A distributed winding radial gap type rotating electric machine comprising the stator according to any one of claims 1 to 7 ,
A distributed winding radial gap rotating electrical machine in which a resin mold portion arranged at the coil end apex portion of the stator is held in contact with a motor housing portion.

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