KR20000011535A - Stator of outer rotor type motor - Google Patents

Abstract

PURPOSE: A stator of an outer rotor type motor is provided to devise the simplify of the manufacturing process as well as to secure the good property of a motor and the rust preventing effect. CONSTITUTION: The outer rotor type motor(1) for driving a fan of a refrigerator comprises: a casing(2); a rear bearing assembly(3) attached on the casing; a stator(4) attached on the rear bearing assembly; a front bearing assembly(5) attached on the stator; a fan integrated rotor(7) having a rotary shaft(6) rotating around the both bearing assemblies(3, 5) and being supported freely. Herein, the stator(4) is molded by a mold layer(33) made up of thermoplastic resin, and the mold layer covers the outer face of a stator cotter(17). Thereby, the rust is prevented.

Description

Stator of outer rotor type motor {STATOR OF OUTER ROTOR TYPE MOTOR}

The present invention relates to a stator of an outer rotor type motor which allows the outer periphery of the stator core and the winding to be molded in the mold layer.

For example, in the outer rotor type motor for fan drive of a refrigerator, resin molding of the winding part of the stator is carried out except for the outer peripheral surface of the stator core so as to withstand the condensation environment (humidity environment). (See, for example, Japanese Patent Application No. 57-139263). In this case, a thermosetting resin such as unsaturated polyester having excellent heat shock property is used for the resin mold, and since this type of thermosetting resin is inferior in fluidity, a mold layer is formed on the outer peripheral surface of the stator core in a thin shape. It was impossible to do. For this reason, the rust inhibitor was apply | coated to the outer peripheral surface of the stator core which is not covered with the mold resin.

By the way, in the above, since it is the structure which apply | coats a rust inhibitor to the outer peripheral surface of a stator core, there exists the absurdity that the process of assembly work increases and manufacturing cost becomes expensive. At this time, if the outer peripheral surface of the stator core is molded integrally with the mold resin, it is considered that the application of the rust inhibitor is not necessary. However, as described above, the mold layer is formed on the outer peripheral surface of the stator core by the thermosetting resin. In any case, the thickness becomes inevitably thicker, and the gap with the rotor becomes larger so that the characteristics (efficiency) of the motor deteriorate.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object thereof is to provide a stator of an outer rotor type motor capable of achieving a sufficient rust preventing effect and securing a good characteristic of the motor and simplifying the manufacturing process.

1 is a perspective view of a stator showing an embodiment of the present invention,

2 is a perspective view showing a state before a mold layer is formed on the stator;

3 is a longitudinal sectional view of a motor;

4 is a perspective view in the downward direction of the stator before the mold layer is formed;

5 is a longitudinal sectional view of the stator before the mold layer is formed;

6 is a cross-sectional plan view of the stator before the mold layer is formed;

7A is a longitudinal side view of an upper portion of an insulator;

7B is a front view of the upper portion of the insulator,

8 is a transverse plan view of the distal end of the tooth,

9 is a diagram showing the relationship between the thickness of the mold layer of the stator core outer periphery and the heat shock property and the motor efficiency;

10A is a plan view of a tip side portion of a conductor of a terminal block;

10B is a side view of a tip side portion of the conductor of the terminal block;

11 is a cross-sectional plan view partially showing a state in which a stator core is accommodated in a mold;

12A is a longitudinal side view of FIG. 7A showing another embodiment of the present invention, and

12B is a front view of FIG. 7B showing another embodiment of the present invention.

* Explanation of symbols for the main parts of the drawings

1: outer rotor type motor 2: casing

3: rear bearing assembly 4: stator

5: all bearing assembly 6: rotating shaft

7: rotor 17: stator core

17a: center hole 17d: tooth

17e: magnetic pole 18: connector

30, 41: insulator 30c, 41a: outer peripheral wall portion

30d: convex portion 30e: stepped portion

31: winding 31a: cross line

32: terminal block 33: mold layer

33c: extension 34: pin

36: conductor 37: mold

37a: recess 37b: gate

P: dividing line

Conventionally, in the case of resin-molding the winding of the stator of a motor, it is common to use a thermosetting resin excellent in heat resistance, heat shock resistance, and the like. In an outer rotor type motor, it is also molded to the outer periphery of the stator core facing the rotor. It was not carried out. In contrast, the present inventor attempts to integrally mold the resin including the outer periphery of the stator core by using a thermoplastic resin, thereby obtaining sufficient heat resistance and heat shock resistance, and at the same time, the outer periphery of the stator core. It was confirmed that a sufficiently thin mold layer could be formed evenly on the part, and that a sufficiently high motor efficiency could be ensured, thus achieving the present invention.

That is, the stator of the outer rotor-type motor of the present invention includes a stator core, a winding wound on the stator core through an insulator, a pin installed on the insulator and connected to an end of the winding, and a proximal end electrically connected to the pin. And a mold layer made of a thermoplastic resin which is integrally molded with a terminal block having a connector portion for external connection at the front end and an outer periphery of the winding and stator core and a base end of the terminal block (claim 1). Invention).

According to this, since the mold layer made of thermoplastic resin is provided to cover the outer periphery of the stator core, even when used in a humidity environment, it is possible to obtain a sufficient rust prevention effect, and does not require work such as applying a rust inhibitor separately. You can do that. At this time, by using the thermoplastic resin, the mold layer of the outer peripheral portion of the stator core can be made sufficiently thin. It has also been confirmed that sufficient heat resistance and heat shock resistance can be obtained. Since the outer periphery of the winding and the stator core and the base end of the terminal block are molded integrally, the handleability as the stator is improved and the adhesion is further improved. It goes without saying that the mold layer can improve the protection of the winding, the insulation and the mechanical strength.

In this case, the insulator and the terminal block can be made of a thermoplastic resin made of the same kind of base material as the mold layer (invention of claim 2). According to this, since the surface of the resin constituting the mold layer, the surface of the insulator and the terminal block is easy to be thermally welded when the mold layer is formed, the adhesiveness of the mold layer and the insulator and the terminal block is improved, and the linear expansion coefficient is also equal. The three layers of the mold layer, the insulator and the terminal block are tightly integrated.

In addition, the mold layer is molded using a mold, but in order to form a thin mold layer on the outer periphery of the stator core, it is necessary to make the resin, which is a material, with good fluidity. Therefore, when the thermoplastic resin which comprises a mold layer is comprised by adding rubber type elastomer to a base material (invention of Claim 3), the high fluidity | liquidity of a material can be obtained. For example, when used for the fan motor of a refrigerator, as a base material, what is excellent in heat shock resistance, such as PBT (polybutadiene terephthalate) and PPS (polyphenylene sulfite), is preferable.

When the mold layer is formed, the position of the gate into which the resin is injected is placed in the middle portion of the teeth adjacent to the slot-opening portion of the stator core (the invention of claim 4), to the end face of the stator core opposite to the gate. At the same time, the resin is easily enclosed, and the resin injection pressure can be prevented from directly acting on the winding and causing damage to the winding.

In this case, the intersection line of the winding is a cross section opposite to the position of the gate of the stator core, and if it is located in the stepped portion formed so that the diameter becomes smaller in the cross section of the stator core in the insulator (the invention of claim 5), The effect of preventing giving is improved.

Alternatively, the gate position of the mold layer may be arranged on the upper surface of the terminal block (invention of claim 6), whereby the resin injection pressure can be effectively prevented from damaging the winding by acting directly on the terminal block.

However, if the thickness of the mold layer formed on the outer periphery of the stator core is too large, the gap between the stator core and the rotor becomes large, and the efficiency of the motor is lowered, and if it is too thin, the heat shock resistance becomes weak. Therefore, according to the research of the present inventors, it is preferable that the thickness at the outer periphery of the stator core of the mold layer is 3 to 9% of the width size of the magnetic pole of the tooth of the stator core (the invention of claim 7). The thickness size which satisfies both motor efficiency and heat shock resistance can be obtained.

In addition, the outer periphery of the stator core of the mold layer can be made into a uniform surface by correcting the defect of the slot opening part in the molding frame (invention of claim 8), whereby the mold layer of the outer periphery of the stator core can be evenly formed. Heat shock resistance can be made favorable.

In addition, the outer periphery of the mold layer may be configured to be slightly smaller in diameter and extend in the axial direction from the cross section of the stator core, and at the same time, the dividing line is located on the outer periphery of the extension (invention 9). Lines do not appear in the mold layer of the outer periphery of the stator core, and adverse effects on heat shock resistance and the like can be prevented.

The above insulator may be integrally provided with an outer circumferential wall portion that rises toward the outer circumferential side of the coil end portion of the winding, and the height of the outer circumferential wall portion may be 3 times or less the thickness (invention of claim 10). ). According to this, the workability of the recommended work of the winding is improved by the outer peripheral wall portion, and the outer peripheral wall portion has a certain thickness relative to the height, thereby preventing the deformation by the resin injection pressure in advance. have.

The convex portion may be provided on the outer circumferential surface of the outer circumferential wall portion formed integrally with the insulator (invention of claim 11), whereby the convex portion abuts on the inner surface of the molding frame during mold molding, so that the outer circumferential wall portion is made of resin. Deformation by the injection pressure can be prevented.

Here, the terminal block can be configured by insert-molding a conductor formed by drilling a metal plate whose plate surface is plated, and the tip of the conductor in the connector portion becomes a connector pin, but the cut surface of the conductor is inferior in rust resistance. Therefore, two bent parts are provided in the conductor, and the plate surface is twisted by 90 degrees at the two bent parts (invention of claim 12). According to this, a connector pin can make a contact surface the plating surface of a conductor, and can prevent the bad influence, such as a poor electricity supply which a cutting surface of a connector pin rusts.

Hereinafter, one embodiment (claims 1,2,3,4,5,7,8,9,11,12) in which the present invention is applied to an outer rotor-type motor used for driving a fan of a refrigerator, FIG. A description will be given with reference to FIG. 11. First, FIG. 3 shows the overall configuration of an outer rotor type motor (fan motor) 1 according to the present embodiment. The motor 1 also consists of a DC blushless motor without a sensor.

The motor 1 is in this case largely divided into a casing 2, a rear bearing assembly 3 attached to the casing 2, a stator 4 according to the present embodiment attached to the rear bearing assembly 3, A fan-integrated rotor (7) having all bearing assemblies (5) attached to the stator (4) and a rotating shaft (6) rotatably supported by both bearing assemblies (3, 5) is provided.

Among them, the casing 2 is made of plastic such as PBT, for example, and has a thin cylindrical shape in which the rear surface (the surface on the right side in Fig. 3) is opened, and at the same time, a circular hole 2a is formed in the center of the front wall portion thereof. have. In addition, a ring-shaped concave groove 2b is formed in a portion near the front outer circumference of the front wall portion, and three hooks, for example, extending in the front (left side in the drawing) to the outer circumference of the casing 2 (2c) (only one illustration) is formed at 120 degree intervals. Further, for example, four stays 8 (only a part of which are shown) extending radially are integrally installed at the outer circumference of the casing 2 at intervals of 90 degrees. The bell mouse which is not shown in figure is integrally installed.

The rear bearing assembly 3 is also configured to have a bearing 10 made of a spherical sintered metal, for example in a bracket 9 made of galvanized steel. The bracket 9 is configured to have a protruding tube portion 9a that is integrally extended to the front side (left side in the drawing) at the main portion of the thin cylindrical shape with the rear face open, and the rotary shaft is provided at the tip of the protruding tube portion 9a. The hole 9b into which 6 is inserted is formed. In the bracket 9, the bearing 10 is pressed by the pressing part 11 and the spring 12, and the felts 13 and 14 containing oil are provided. In addition, the rear opening of the bracket 9 is closed by a cover member 15 made of, for example, a galvanized steel sheet, and a thrust plate that receives the tip of the rotating shaft 6 at the center of the inner surface of the cover member 15. (16) is provided.

The rear bearing assembly 3 is configured to be tightly wound from the rear side in the casing 2, and at this time, the protruding tube portion 9a of the bracket 9 protrudes forward through the circular hole 2a. . In addition, although not shown in detail, a plurality of convex portions are formed on the inner circumferential surface of the circular hole 2a, and the protruding tube portion 9a is configured to press-fit while filling the convex portion. Further, a so-called return scrap is formed at the end edge portion of the main part of the bracket 9 toward the outer circumferential side, and the return scrap is made to encroach the inner circumferential surface of the casing 2.

The stator 4 has a stator core 17 having a center hole 17a penetrating in the axial direction as will be described later in detail, and the inner circumferential surface of the center hole 17a has a three circumferential direction. The convex part 17b (refer FIG. 6) is formed in several places.

In this case, the rear bearing assembly 3 and the stator 4 are wound by pressing the protruding pipe portion 9a of the bracket 9 into the rear half of the center hole 17a of the stator core 17. The casing 2 is fixed to both sides from each other. In this case, the metals are pressed in, and the shaft center adjustment (so-called extraction) is easily and accurately made, and is made to be firmly fixed without being eccentric. In addition, at this time, the connector part 18 provided in the stator 4 extended downward from the figure is located so that it may overlap with the stay 8 of one (downward direction).

In addition, the all bearing assembly 5 has a configuration substantially equivalent to that of the rear bearing assembly 3, and thus a bracket 19 having a protruding tube portion 19a, a bearing 20 made of a spherical sintered metal, It is comprised so that the bearing pressing part 21, the spring 22, the oil-containing felt 23 and 24, and the cover member 25 may be provided. In this case, the lid member 25 forms an opening 25a at the center, and the protruding tube portion 19a is configured to be relatively short in that it is different from the rear bearing assembly 3.

The all bearing assembly 5 presses the protruding pipe portion 19a of the bracket 19 against the first half of the center hole 17a of the stator core 17 in the opposite direction to the rear bearing assembly 3. It is made to be fixed to the stator 4 by winding. Also in this case, by indentation of metals, axial center adjustment is made easy and accurate, and it is comprised so that it may be firmly fixed without being eccentric. At this time, the fixing member 26 positioned between the protruding tube portion 9a and the distal end surface of the protruding tube portion 19a is disposed in the center hole 17a. The fixing member 26 is formed of, for example, a nylon 6 in a ring shape, and serves to fix the rotating shaft 6 to be described later.

In addition, the rotor 7 is a rotor yoke 27 made of a galvanized steel sheet having a cylindrical shape with a rear end face open, for example, 12 poles (6 pairs) attached to an inner circumferential surface of the rotor yoke 27. The rotor magnets 28 and the fan bosses 29 made of, for example, PBT are installed to cover the outer circumference of the rotor yoke 27. Although not shown, four or three fans (blowing blades) are integrally formed on the outer circumference of the fan boss portion 29.

The rotating shaft 6 is made of, for example, SUS, and has a small diameter portion 6a integrally formed at an intermediate portion thereof. The base end (front end) of the rotary shaft 6 is connected to the center of the rotor yoke 27. In addition, the rotor yoke 27 is provided with the fan boss portion 29 integrated with the rotor yoke 27 by insert molding, and a part of the material is connected through the configuration 27a formed in the rotor yoke 27. It is located on the inner surface side of the cross section of and is provided so that the circumference | surroundings of the rotating shaft 6 may be covered.

The rotor 7 configured in this way is inserted into the bearing 20 by inserting the rotary shaft 6 from the opening 25a of the cover member 25 of the whole bearing assembly 5 and inserted into the rear bearing assembly ( It is assembled by press-fitting into the bearing 10 of 3) until the front end contacts the thrust plate 16. As shown in FIG. Thereby, the rotor 7 is rotatably supported by the two bearings 20 and 10, and the rotor magnet 28 is installed so as to oppose the stator 4 with a slight gap.

In this case, since the bearings 20 and 10 are made of spherical metal of automatic self-aligning structure, the accuracy of the shaft center adjustment of the rotor 7 can be improved further by the rotation shaft 6. At this time, the rotating shaft 6 is inserted while pressing the opening of the fixing member 26 to widen it. In the assembled state of the rotor 7, the fixing member 26 is fitted to the small diameter portion 6a of the rotating shaft 6. It becomes a state, and once assembled, it becomes possible to fix the rotating shaft 6 by the fixing member 26.

The structure of the stator 4 which concerns on a present Example is explained in full detail below. FIG. 1 shows the external appearance of the stator 4, and FIGS. 2, 4 and 5 show the state before forming the mold layer of the stator 4. As shown in FIG. 1, 2, and 5 show the stator 4 in FIG. 3 in a state in which the rear side (right side) is upward (an axial direction is up and down). The up-down direction shown in FIG. 1, FIG. 2, and FIG. 5 is demonstrated as the up-down direction of the stator 4. As shown in FIG.

The stator 4 is a mold layer made of the stator core 17, the insulator 30, the three-phase winding 31 connected to the star, the terminal block 32 integrally having the connector portion 18, and a thermoplastic resin. (33) and the like. Among these, the stator core 17 is constructed by laminating steel sheets in the axial direction, and has nine teeth 17d around the outer periphery of the cylindrical yoke portion 17c as shown in FIG. 6 and the like. The inner circumferential portion of the yoke portion 17c serves as the center hole 17a. In addition, the distal end portion of each tooth 17d has a magnetic pole portion 17e extending in the circumferential direction.

In this case, the insulator 30 is composed of a molded article of thermoplastic resin made of PBT (polybutadiene terephthalate) as a base material and containing a small amount (for example, 15%) of glass components. The insulator 30 is provided in a thin shape along the inner surface of each slot of the stator core 17 and is shown in Figs. 2, 4, 5, 7A and 7B. As described above, the cylindrical peripheral portions 30a and 30b which rise in the axial direction from the upper and lower surfaces of the yoke portion 17c of the stator core 17 are integrally formed on the inner circumferential side.

Moreover, this insulator 30 is comprised integrally with the outer peripheral wall part 30c which rises up and down of each tooth 17d (magnetic part 17b) on the outer peripheral side. In addition, in the present embodiment, as shown in Figs. 4, 7A and 7B, convex portions 30d extending in the longitudinal direction are integrally formed on the outer circumferential side surface of each of the outer circumferential wall portions 30c. . As shown in Fig. 7A, the convex portion 30d is provided so as to protrude almost as large as " Pw " in the outer circumferential direction than the outer surface of the stator core 17 (the magnetic pole portion 17e).

And as shown in FIG. 2, the three pins 34 to which each end part of the three-phase winding 31 of the electricity supply side is connected to the cylindrical upper part 30a of the upper surface side of this insulator 30 are relatively close upwards. While being attached to protrude, the pin 35 to which the end of the common side of each winding 31 is connected is also attached to the position slightly deviated therefrom so as to protrude upward.

On the other hand, the cylindrical portion 30b on the lower surface side is provided to have a smaller diameter in the cross section of the stator core 17 as shown in Fig. 4, whereby the stepped portion 30e is formed. In addition, a hook portion 30f (see FIGS. 3 and 5) for fixing the terminal block 32 is provided in a part of the outer circumferential wall portion 30c located near the pin 34 on the upper side of the insulator 30. It is installed. In addition, although not shown in detail, this insulator 30 is provided in the state divided | segmented into two directions in the up-down direction (axial direction), and it is comprised so that it may be fitted so that it may be inserted in the stator core 17 from the up-down direction.

The winding 31 is wound on the outer circumferential surface of the insulator 3 with respect to each tooth 17d of the stator core 17. At this time, the ends of the windings 31 of each phase are configured to be connected to the pins 34 and 35. As shown in FIG. 4, the intersection line 31a of the winding 31 is formed to pass through the stepped portion 30e at the lower surface side (the opposite side to the pins 34 and 35) of the stator core 17. have.

The terminal block 32 protrudes from the main portion on the proximal end side electrically connected to the three pins 34 in the outer circumferential direction (right side in FIG. 5) and at the same time, expands upward to secure a height-type connector. As shown in Figs. 3, 5 and the like, the base 32a made of a thermoplastic resin containing a relatively large amount (for example, 30%) of a glass component, as shown in Figs. ) Is formed by insert molding three conductors 36. The conductor 36 is formed by cutting a plated steel sheet, and forms a plate shape having a certain width at the base end side (main part side), and at the same time, a hole 36a through which the pin 34 is inserted (Fig. 5). Reference). The base 32a is provided to expose the conductor 36 in the hole 36a portion.

The conductor 36 extends toward the connector portion 18 and its tip protrudes into the housing of the connector portion 18 to become the connector pin 36b, but from the base end to the connector pin 36b at the tip portion, two bent portions are bent. The part is bent in the shape of a so-called lightning bolt.

At this time, as shown in Figs. 10A and 10B, when bent at the two bent portions, a twist is applied and it is made to be twisted 90 degrees between the proximal end and the distal end. Thereby, the conductor 36 is comprised so that the plating surface may face an up-down direction at the base end, and it may be laterally-oriented (a cutting surface may face up and down) at the front-end | tip part (connector pin 36b) part. In addition, in FIG. 10A and FIG. 10B, the cut surface is hatched and shown for convenience.

The terminal block 32 configured as described above has its main portion fitted to the insulator 30 on the upper side of the stator core 17, and at this time, the three pins 34 respectively penetrate the holes 36a of the conductor 36. consist of. And the pin 34 and the conductor 36 are electrically connected by the soldering in that part.

The mold layer 33 winds the above-described winding 31 to accommodate the stator core 17 to which the terminal block 32 is attached, in the forming mold 37 (only a part of which is shown in FIG. 11), and the base of the PBT. It is formed based on injecting molten resin as a material. As shown in Figs. 1 and 3, the mold layer 33 is formed around the entire center of the stator core 17 except for the periphery of the center hole 17a and the upper and lower cross-sectional center holes 17a. It is formed to. Accordingly, the mold layer 33 is the main part of the stator core 17 except for the connector 18 of the outer circumferential surface, the winding 31, the insulator 30, the pins 34 and 35, and the terminal block 32. It is provided so that a part may be integrally covered.

At this time, as shown in Fig. 8, the mold layer 33 covers the outer periphery of the stator core 17 (the magnetic pole portion 17e of the tooth 17d) in a thin shape, and this thin portion The thickness Mw is 3 to 9% of the width Tw of the teeth 17d (the magnetic pole portions 17e). Specifically, the thickness Mw of the thin portion is 0.35 mm with respect to the width Tw of the tooth 17d (the magnetic pole part 17e) of 8.89 mm. The protrusion size Pw of the convex portion 30d of the insulator 30 is equal to or slightly smaller than the thickness Mw.

1 and 3, the mold layer 33 has a ring-shaped convex portion 33a corresponding to the concave groove portion 2b of the casing 2 on the upper surface side of the stator core 17. Is integrally formed, and the caught part 33b (only one is shown) which is located in three places of the outer periphery and which the hook 2c which fixes the said hook is caught is formed integrally. On the other hand, the mold layer 33 is formed integrally with an extension portion 33c extending in a cylindrical shape in the axial direction from the lower surface side of the stator core 17 and opening on the lower surface side.

At this time, the outer diameter size of the extension part 33 is configured to be slightly smaller than the outer size of the part of the mold layer 33 which covers the outer periphery of the stator core 17. As shown in FIG. The dividing line P appears on the outer circumferential surface of the portion 33c (part that becomes a step). In addition, as shown in FIG. 3, the inner circumference of the extension 33 is made to fit very tightly to the outer circumference of the bracket 19 of the bearing assembly 5.

The stator 4 configured as described above is coupled to the rear bearing assembly 3 by fitting the casing 2 as described above. In this case, as shown in FIG. 3, the ring-shaped convex portion of the mold layer 33 is illustrated. 33a is fitted to the recessed portion 2b of the casing 2 to prevent positioning and penetration of water. At the same time, the caught portion 33b is configured to be hooked to the hook 2c to fix the casing 2. This secures the inner circumference of the stator core 17 and the bracket 9 of the rear bearing assembly 3 and the three sides of the casing 2, the rear bearing assembly 3 and the stator 4 are firmly fixed. At the same time, the axial adjustment can be made easily and accurately.

On the other hand, the entire bearing assembly 5 is fitted into the inner circumferential portion of the extension portion 33c of the stator 4, so that the inner circumferential portion of the stator core 17 and the bracket 19 of the entire bearing assembly 5 are fitted. In addition to being fixed, the bearing assembly 5 is also firmly fixed, and the center of gravity adjustment is made easy and accurate. At this time, the gap size formed between the outer circumferential surface of the stator core 17 (except the mold layer 33) and the rotor magnet 28 is made to be 0.5 to 1 mm.

By the way, the mold layer 33 is composed of a thermoplastic resin containing a small amount of glass component for improving the strength and adding a rubber-based elastomer using PBT as a base material. By adding a rubber-based elastomer, the fluidity of the molten material can be further improved, whereby it becomes possible to mold the outer periphery of the stator core 17 sufficiently thinly.

In addition, as described above, the mold layer 33, the insulator 30, and the terminal block 32 are made of the same type of base material (PBT), with only the presence or absence of addition of a rubber-based elastomer and the amount of glass components contained therein. It is composed. As a result, the resin forming the mold layer 33 and the surfaces of the insulator 30 and the terminal block 32 at the time of mold molding tend to be thermally welded, and the mold layer 33, the insulator 30 and the terminal block 32 are formed. In addition to excellent adhesion, the coefficient of linear expansion also becomes equal, so that the three of the mold layer 33, the insulator 30, and the terminal block 32 are tightly integrated.

The mold 37 has a cavity corresponding to the outer shape of the mold layer 33, and as shown in FIG. 11, a stator is formed at a portion corresponding to the outer periphery of the stator core 17 in the cavity. The recessed part 37a is formed corresponding to each slot opening part (space | interval between adjacent magnetic pole parts 17e) which appear around the outer periphery of the core 17. As shown in FIG. This recessed part 37a is provided in consideration of what is called drop at the time of resin hardening.

Further, the gate 37b for injecting resin into the cavity is located in the middle of the adjacent teeth 17d of the slot openings on the upper surface side of the stator core 17. 1 shows the gate portion 33d of the mold layer 33. In addition, although not shown, as mentioned above, the shaping | molding die 37 is provided so that the dividing line P may be located in the step part of the extension part 33c of the mold layer 33. As shown in FIG.

In molding the mold layer 33, the stator 17 wound around the winding 31 and attached to the terminal block 32 is accommodated in the mold 37 in the positioning state. At this time, since the convex portion 30d provided on the outer surface of the outer circumferential wall portion 30c of the insulator 30 protrudes to the outer circumference of the stator core 17, the convex portion 30d forms the molding frame 37. It is almost in contact with. From this state, molten resin is injected through the gate 37b, and at the same time, the inside of the cavity of the molding die 37 is vacuumed.

As a result, the resin is injected into the mold 37, the stator core 17 and the like are molded by the resin, and the flowability of the molten resin is sufficiently high, so that the resin can be satisfactorily even in the thin gap portion of the outer periphery of the stator core 17. Is injected. At this time, the position of the gate 37b is the same as described above, so that the resin easily turns to the cross-sectional portion on the lower surface side through the coil side of the winding 31, so that the injection pressure of the resin directly acts on the winding 31. It is also possible to prevent the damage to the winding 31 in advance. In addition, since the intersection line 31a of the winding 31 is located in the stepped portion 30e of the insulator 30 opposite to the gate 37b, it is also possible to prevent damage to the intersection line 31a.

In addition, since the convex portion 30d of the insulator 30 is almost in contact with the inner surface of the forming mold 37 as described above, the outer peripheral wall portion 30c falls outward and deformed due to the resin injection pressure. Is prevented. Thereafter, defects occur on the surface of the mold layer 33 due to shrinkage when the resin is cooled and cured to form the mold layer 33, but the defects are formed in the concave portion 37a formed in the mold 37. By correcting by this, the mold layer 33 of the outer peripheral part of the stator core 17 can be comprised uniformly, and heat shock resistance can be made favorable. In addition, since the dividing line P is set to be on the outer circumferential surface of the delay portion 33c, it can be prevented from adversely affecting heat shock resistance or the like.

By the way, the motor 1 comprised as mentioned above is used as a cooling air supply fan (or the compressor cooling fan of a machine room) to the inside of a refrigerator (freezer compartment, a refrigerator compartment), for example. In this case, normally, it is exposed to cold air of -10 degreeC, for example, and in defrosting operation, it is exposed to high temperature of about 30 degreeC, for example, and can be used in a humid environment, condensation, and freezing environment.

In the stator 4 having the above-described configuration, the terminal block includes almost all of the stator core 17 except the center hole 17a, the insulator 30 having the windings 31, the pins 34 and 35, and the soldering portion. Since the whole of the base end part of (29) is integrally molded by the mold layer 33 which consists of thermoplastic resins, sufficient rust prevention effect can be acquired even when used in a humid environment. In particular, since the outer periphery of the stator core 17 is also covered by the mold layer 33, a sufficient rust prevention effect can be obtained without requiring application of a rust inhibitor separately.

In this case, it is also confirmed that the mold layer 33 in the outer peripheral portion of the stator core 17 can be made sufficiently thin, and that sufficient heat resistance can obtain heat shock resistance. And by covering by the mold layer 33, the handleability from the stator 4 becomes favorable and granulation property improves more. It goes without saying that the mold layer 33 can secure the winding 31, improve insulation, and improve mechanical strength.

By the way, considering the efficiency of the motor 1, since the gap between the rotor core 17 and the rotor magnet 28 is small, the thickness of the mold layer 33 in the outer circumference of the rotor motor 17 is made as thin as possible. It is desirable to. However, by adopting a thermoplastic resin as the material of the mold layer 33, the mold layer 33 can be formed sufficiently thin in practice, and therefore, the thickness Mw of the mold layer 33 at the outer circumference of the rotor core 17. Too small may cause a decrease in heat shock resistance.

Therefore, according to the research of the present inventors, in order to satisfy both the motor efficiency and the heat shock resistance, the thickness Mw at the outer periphery of the stator core 17 of the mold layer 33 is determined by the teeth of the stator core 17. It was confirmed that it is good to set it as 3 to 9% of the width Tw of the magnetic pole part 17e of (17d). FIG. 9 shows experimental results of examining the relationship between heat shock resistance (curve A) and motor efficiency (curve B) with respect to the thickness at the outer periphery of the stator core 17 of the mold layer 33 by the present inventors. Doing.

In this case, the horizontal axis of FIG. 9 represents the ratio (Mw / Tw) of the thickness Mw of the mold layer 33 to the width Tw of the magnetic pole portion 17e of the tooth 17d in%. In the heat shock acceleration test, the number of times until a crack occurs when the cycle of 1 hour hold at -30 degrees and 1 hour hold at 80 degrees is repeated continuously is shown. As can be understood from FIG. 9, the thickness Mw is applied to the outer periphery of the stator core 17 of the mold layer 33, and the width Tw of the magnetic pole portion 17e of the tooth 17d of the stator core 17. When 3 to 9% of) is obtained, a high motor efficiency (40% or more) is obtained, and at the same time, it can withstand about 200 or more times in the heat shock resistance test, and satisfies both the motor efficiency and the heat shock resistance. do.

In addition, the motor 1 is configured such that a connector on the connection side is connected to the connector portion 18 so as to be connected to the inverter driving circuit. Thus, the tip of the conductor 36 made of a plated steel sheet inserted into the terminal block 32 becomes the connector pin 36b of the connector portion 18, but the connector pin 36b is twisted by 90 degrees. In addition, since the contact surface with the connector on the connecting side is not a cut surface but a plated surface, adverse effects such as poor electricity supply caused by rusting of the cut surface of the connector pin 36b can be prevented in advance.

As described above, according to the present embodiment, in the case of resin-molding the stator winding, the stator 4 is made of thermoplastic resin, whereas the thermosetting resin is used and the mold is not molded to the outer periphery of the stator core. The outer peripheral part of the stator core 17 was also integrally molded by the mold layer 33. As a result, even when used in a high humidity environment, condensation and freezing environment, a sufficient rust prevention effect can be obtained, eliminating the need for application of a rust inhibitor which has been necessary in the past, and simplifying the manufacturing process, and furthermore, By setting the thickness of the layer 33 to be appropriate, it is possible to obtain excellent effects such as excellent heat shock resistance and securing a sufficiently high efficiency of the motor 1.

12A and 12B show another embodiment (corresponding to claim 10) of the present invention. In this embodiment, instead of forming the convex portion 30d in the outer circumferential wall portion 30c of the insulator 30 in the above embodiment, the height size a of the outer circumferential wall portion 41a of the insulator 41 is obtained. Is less than three times the thickness (b), that is, the thickness is made relatively large. In this case, height a has 3 mm and thickness b has 1.5 mm concretely. Even with such a configuration, the outer circumferential wall portion 41a has a certain thickness and can be prevented from being deformed by the resin injection pressure.

Although not shown, the terminal block 32 has its gate position instead of being provided at a position corresponding to the middle portion of the resin injection gate 37b of the molding die 37 and the adjacent teeth 17d of the slot opening portion. It may be suitable for the upper surface of the main portion of the main body (corresponding to claim 6), whereby the resin injection pressure directly acts on the terminal block 32 and effectively prevents damage to the winding 30. have.

In addition, the present invention is not limited to the above-described embodiments, and for example, various materials such as PPS (polyphenylene sulfite) may be used as the thermoplastic resin material constituting the mold layer 3. Even if it is a thin part structure, various changes are possible and it can change and implement suitably within the range which does not deviate from the summary, such as not only the fan motor for refrigerator but also various uses as a motor use.

As described above, according to the stator of the outer rotor type motor of the present invention, since the outer periphery of the winding and the stator core and the base end of the terminal block are configured to be integrally molded by a mold layer made of thermoplastic resin, sufficient rust It has an excellent practical effect that the prevention effect can be obtained and the manufacturing process can be simplified while securing good characteristics of the motor.

Claims (12)

A stator core, a winding wound on the stator core through an insulator, a pin installed on the insulator or connected to an end of the winding, a terminal block having a proximal end electrically connected to the pin and having a connector portion for external connection at the distal end, and the A stator of an outer rotor type motor, comprising a mold layer made of a thermoplastic resin which integrally molds an outer circumferential portion of a winding and a stator core and a proximal end of a terminal block. The method of claim 1, The stator of the outer rotor type motor, wherein the insulator and the terminal block are made of a thermoplastic resin composed of the same kind of base material as the mold layer. The method according to claim 1 or 2, The thermoplastic resin constituting the mold layer is a stator of an outer rotor type motor, wherein a rubber elastomer is added to the base material. The method according to claim 1 or 2, A stator of an outer rotor type motor, wherein a position of the gate of the mold layer is disposed at an intermediate portion of the teeth adjacent to the slot-opening portion of the stator core. The method of claim 4, wherein An intersecting line of the winding is a cross section opposite to the position of the gate of the stator core, and is located in a stepped portion formed in the insulator so that the diameter thereof becomes smaller in the cross section of the stator core. The method according to claim 1 or 2, A stator of an outer rotor type motor, wherein the gate position of the mold layer is disposed on the upper surface of the terminal block. The method according to claim 1 or 2, The thickness of the thickness at the outer circumference of the stator core of the mold layer is 3 to 9% of the width of the magnetic pole of the tooth of the stator core. The method according to claim 1 or 2, The stator of the outer rotor type motor, wherein the outer circumferential portion of the stator core of the mold layer becomes a uniform surface by correcting the defect of the slot-opening portion in the mold. The method according to claim 1 or 2, The outer circumferential surface of the mold layer is slightly smaller in diameter from the cross section of the stator core and extends in the axial direction, and a dividing line is located on the outer circumferential surface of the extension portion. The method according to claim 1 or 2, The insulator includes an outer peripheral wall portion that rises toward the outer peripheral side of the coil end portion of the winding, and the height of the outer peripheral wall portion is three times or less the thickness of the stator of the outer rotor type motor. The method according to claim 1 or 2, An insulator includes an outer circumferential wall portion that rises toward the outer circumferential side of the coil end portion of the winding, and a convex portion is provided on the outer circumferential surface of the outer circumferential wall portion. The method according to claim 1 or 2, The terminal block is formed by insert-molding a conductor made of a metal plate having two bent portions, and the conductor is stator of the outer rotor type motor, wherein the plate surface is twisted 90 degrees at the two bent portions.