JP5487020B2 - Rotating electric machine - Google Patents

Description

  The present invention relates to a rotating electrical machine such as a stepping motor including a stator formed by winding a plurality of main poles that are winding poles, and a rotor that is rotatably disposed inside the stator.

  2. Description of the Related Art Conventionally, stepping motors have been widely used in driving parts including information equipment fields such as printers, facsimiles, and copying machines, and industrial equipment fields such as FA equipment. In recent years, the total demand for stepping motors has been increasing year by year, and their applications have been widespread. Accordingly, there has been an increasing demand for compact motor design and cost reduction that can contribute to the equipment side. Small, inexpensive, high-speed, high-torque, and low-vibration rotations are required for rotating electrical machines such as stepping motors.

  As this type of stepping motor, for example, in the case of a hybrid type using a magnetic body and a permanent magnet for the rotor, ones having a configuration shown in Japanese Patent Laid-Open No. 3-212149, Japanese Utility Model Laid-Open No. 55-24020, etc. are frequently used. ing. In other words, a stator is formed by winding a plurality of main poles that protrude radially inward from an annular magnetic body frame, and a shaft is formed between the pair of magnetic bodies via an air gap. A hybrid rotor formed by sandwiching a permanent magnet magnetized in the direction is opposed to each other.

  In the stepping motor described above, a step angle of 1.8 ° is often used. However, in order to maintain and control the step angle with high accuracy, a step angle between the stator and the rotor is used. It is required to manage the air gap of 0.05 mm, for example. For this reason, a metal end cap or bracket such as aluminum is fixed to the motor case that supports the stator, a ball bearing is held on this, and the rotor shaft of the rotor is rotatably supported by the ball bearing. It has become. However, such a stepping motor has a problem that not only the motor case is enlarged, but also the cost is increased as a result of using a large amount of metal material.

On the other hand, there is a conventional one in which the outer peripheral surface of the core of the stator is used as a part of the motor case and the motor cover is attached only on both sides in the axial direction of the stator. It is shown in Japanese Patent Publication No. 8-28959.

JP-A-3-212149 Japanese Utility Model Publication No. 55-24020 Japanese Patent Publication No. 6-95817 Japanese Patent Publication No. 8-28959

  In Patent Document 3 and Patent Document 4 described above, since the cover can be arranged on both sides in the axial direction of the stator to form a motor case, the structure is simplified, and the ones in Reference Document 1 and Reference Document 2 are used. Compared to cost reduction, the cover mounting structure is exclusively screwed and welded, and the mounting structure is still complicated, requiring time and cost. ing.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to obtain an inexpensive rotating electrical machine such as a stepping motor that can easily and reliably fix a motor cover to a stator core.

  In order to achieve the above object, in the rotating electrical machine of the present invention, a stator core comprising a substantially annular core back portion and a plurality of main poles protruding inwardly from the core back portion, A stator including a winding wound around the main pole of the stator core, a rotor rotatably provided through an air gap inside the stator, and at least one of axially opposite sides of the stator The motor cover is formed by press-molding a metal plate, and the motor cover is formed with an annular outer frame portion whose end edge contacts the end surface of the stator core from the outside in the axial direction. A plurality of fixed pieces extending in the direction from the axially outer side to the axially inner side are formed integrally with the outer frame portion, and the through holes are formed through the respective fixed pieces, thereby leading the tip of the outer holes. Forming a caulking action part on the part, at least on the stator core A state in which the edge of the annular outer frame abuts against the end surface of the stator core by forming a recess at a position corresponding to the caulking action part and deforming the caulking action part so that a part of the caulking action part enters the recess. The motor cover is fixed to the stator core.

The edge on the caulking action portion side of the hole in the fixing piece of the motor cover described above and the edge on the motor cover side of the recess in the stator core are brought close to each other, and a part of the caulking action portion enters the recess. In this case, it is preferable to generate a force directed inward in the axial direction on the fixed piece.
In particular, the hole of the fixed piece is arranged so that at least the edge on the side of the fixed piece extending direction is substantially V-shaped, and the edge of the recess is arranged so as to intersect with both side edges of the V-shaped edge of the hole. It is desirable that the position corresponding to the vertex of the V shape in the caulking action portion is deformed.

Also, the width dimension in the direction perpendicular to the axial direction of the recess should be set larger than the width dimension of the punch hole and smaller than the width dimension of the fixed piece, and the end face of the stator core opposite to the motor cover May be formed continuously.

Furthermore, the substantially annular core back part of the stator core is shaped to have a substantially regular quadrilateral shape, and the annular outer frame part of the motor cover is formed in a substantially regular quadrilateral shape in accordance with this, and the fixed piece is formed in the outer frame part. It is better to place them at the four corners of the regular quadrilateral. In this case, each of the fixed pieces may have a shape integrally including side pieces that are substantially parallel to the two pieces on both sides of the corner where the fixed piece is disposed.

  A fixed piece is integrally formed on the outer frame portion of the motor cover, and a caulking action portion is formed therethrough, and a caulking action portion is deformed, and the caulking action portion is deformed to enter the concave portion of the stator core. The motor cover can be fixed to the stator core in a state where the edge of the portion is in contact with the end surface of the stator core, and the motor cover can be easily fixed. In particular, if the edge on the caulking action portion side of the hole in the fixing piece of the motor cover and the edge on the motor cover side of the recess in the stator core are brought close to each other at an angle, one of the caulking action portions When the portion enters the recess, a pulling force is generated on the fixing piece toward the inner side in the axial direction, and the outer cover can be brought into close contact with the stator core to fix the motor cover.

  In addition, if at least the edge of the fixing piece extending direction side is substantially V-shaped in the hole of the fixing piece, and the position corresponding to the vertex of the V-shape in the caulking action portion is deformed, Not only can the caulking position be aimed easily, but the width dimension at the caulking action portion becomes small, so that deformation becomes easier, the workability for caulking is remarkably improved, and the edge of the recess is V of the punched hole. Since both the side edges of the character-shaped edge cross each other, it is possible to generate a tensile force toward the inner side in the axial direction with respect to the fixed piece at both the crossed parts, and the fixing strength of the motor cover can be increased.

It is a cutting front view showing the rotary electric machine by one embodiment of the present invention. It is a top view of the rotary electric machine of FIG. It is a top view which shows the positional relationship of the stator and rotor of FIG. The bush of FIG. 1 is shown, (a) is a front view, (b) is a cutting | disconnection front view. FIG. 3 is a partial front view of the rotating electrical machine of FIG. 1 as viewed from the X arrow of FIG. 2. It is an enlarged view of FIG. 5, (a) is a front view, (b) is a cut side view. It is a perspective view which shows the rotary electric machine by other embodiment of this invention. FIG. 8 is a partially exploded perspective view of the stator core and the motor cover of FIG. 7.

  An embodiment of a rotating electrical machine according to the present invention will be described below with reference to the drawings.

  1 and 2 show the overall configuration of a two-phase hybrid (HB) type stepping motor which is an example of the present invention. FIG. 1 is a cut front view, FIG. 2 is a plan view, and FIG. FIG. 2 is a view showing a configuration of a main part of a motor and a combination of a stator having a main pole number of 8 and an HB type rotor as viewed from the axial direction, and illustration of windings is omitted; The neck, which is the winding pole of the main pole, is each wound, and the windings wound around every other four main poles are connected to form one phase, and the remaining four main poles This is an HB type rotating electrical machine in which another one-phase portion is formed to form a two-phase winding as a whole. The stator is an example of adopting an 8-main pole structure excellent in high speed without generating unbalanced electromagnetic force.

  The stator 10 has an annular core back portion 12a having a substantially regular quadrilateral outer shape, and eight main poles 12b that are radially inwardly protruded from the core back portion 12a and arranged at equal intervals in the circumferential direction. The stator core 12 is composed of two-phase windings 14 (shown in FIG. 1) wound around the main poles 12b, and upper and lower insulating members interposed between the main poles 12b and the windings 14. 16 and 18, and three inductor teeth 12c project from the tip of each main pole 12b which is a wound pole. In each main pole 12b, the three inductor teeth 12c are arranged at equal intervals and at symmetrical positions with respect to the center line of the main pole 12b.

The stator core 12 is configured by laminating a plurality of silicon steel plates. As shown in FIG. 3, four main poles 12b arranged on two lines perpendicular to each other on the vertical axis (X axis) and the horizontal axis (Y axis), that is, four main poles arranged every 90 °. The pole 12b constitutes one phase (A phase, C phase), and the remaining four mechanical angles are separated from each other by 90 °, and the main pole is disposed at a mechanical angle of 45 degrees from the main phase. 12b forms two phases (B phase, D phase). In each phase, the four main poles 12b every 90 ° are excited and driven so as to have different polarities alternately when the winding 14 is energized.

  As shown in FIG. 1, insulating members 16 and 18 are incorporated into the stator core 12 so as to sandwich and cover the neck portions of the main poles 12 b, that is, the winding portions, from both sides in the axial direction. It is wound around each main pole 12b via these insulating members 16,18.

  On the other hand, as shown in FIG. 1, the rotor 20 arranged inside the stator core 12 includes two rotor magnetic poles 24A and 24B fixed to the rotor shaft 22 side by side in the axial direction, and this rotation. A disk-shaped permanent magnet 26 sandwiched between the child magnetic poles 24A and 24B and magnetized in the axial direction. Each of the rotor magnetic poles 24A and 24B is configured by laminating silicon steel plates and the like, and a plurality (22 in this embodiment) of magnetic teeth 25 are provided at equal intervals on the outer periphery thereof. . The pair of rotor magnetic poles 24A and 24B are arranged with a tooth pitch shifted by ½, and the rotor element 28 is constituted by the two rotor magnetic poles 24A and 24B and the permanent magnet 26 sandwiched therebetween. Has been. A knurled portion 22a is formed at a position of the rotor shaft 22 corresponding to the rotor magnetic poles 24A and 24B, and the rotor shaft 22 is press-fitted and fixed to the pair of rotor magnetic poles 24A and 24B sandwiching the permanent magnet 26. In the processed portion 22a, the rotor magnetic poles 24A and 24B are prevented from rotating and are firmly fixed. The permanent magnet 26 is composed of, for example, a ferrite magnet. Of course, other magnet materials, rare earth magnets such as neodymium can also be used.

Since the number of teeth of the magnetic teeth 25 of the rotor magnetic poles 24A and 24B is 22, the rotor magnetic tooth pitch is 360 ° / 22 = 16.36 °, and the step angle is a two-phase machine. The value is equally divided and is 4.09 °. That is, this motor is of the HB type, and as is clear from the above, if one rotor magnetic pole 24A shown in FIG. The magnetic teeth 25 of the other rotor magnetic pole 24 </ b> B magnetized to the N pole are separated from each other in the axial direction by the thickness of the permanent magnet 26. Accordingly, the pitch between the N pole and the S pole of the magnetic teeth 25 as the rotor element 28 is 8.18 °, and the value obtained by dividing this value by the number of phases is the step angle, so this embodiment is a two-phase machine. The step angle is 4.09 ° as described above.

In FIG. 1, an upper cover 30 and a lower cover 32 are disposed on both sides in the axial direction of the stator 10 (referred to as upper and lower sides for convenience), and the motor cover is mounted together with the outer peripheral surface of the stator core 12 of the stator 10. It is composed. The outer shapes of the covers 30 and 32 are each formed in a substantially regular quadrilateral shape like the stator core 12. The lower cover 32 includes a bottom plate portion 32a constituting a bottom surface, a quadrilateral outer frame portion 32b, and an inner frame portion 32c formed concentrically with the rotor shaft 22, and is integrally formed with a resin such as PPS or PBT. Has been. The lower cover 32 is fixed to the stator 10 in a state where the end surface of the outer frame portion 32 b is in contact with the lower surface of the stator core 12. As this fixing method, for example, a part of the lower insulating member 18 and a part of the lower cover 32 are closely opposed to each other over a plurality of locations on almost the entire circumference, and an ultrasonic wave is applied between the two so-called supersonic waves. It is fixed by sonic welding. The lower cover 32 covers the insulating member 18 and the winding 14 that are led out from the lower surface of the stator core 12.

  A terminal portion for connection to the outside is provided on one side of the lower cover 32 described above. That is, as shown in FIGS. 1 and 2, a part of the outer frame portion 32b of the lower cover 32 is cut out, and a receiving portion 32d extending laterally is formed on the bottom plate portion 32a at this position. A circuit board 36 is attached to the lower insulating member 18 by using a pin (kage pin) planted on the insulating member 18, and the end of the winding wire 14 is tangled and soldered to the pin. Thus, the circuit board 36 is electrically connected. A part of the circuit board 36 is led out from the outer surface of the stator core 12 and supported by the receiving portion 32d, and a connector 38 is mounted on the circuit board 36 at this position. Therefore, by supplying an external power source and signals using this connector 38, the winding 14 can be energized and controlled.

The upper cover 30 is formed by press-molding a thin metal plate, and includes a top plate portion 30a and a quadrilateral outer frame portion 30b. The center portion of the top plate portion 30a includes a lower cover 32. An opening 30c having an inner diameter substantially equal to the inner diameter of the inner frame portion 32c is formed. The upper cover 30 is fixed to the stator 10 by a caulking technique, which will be described later, with the lower end surface of the outer frame portion 30b in contact with the upper surface of the stator core 12. On the top surface of the top plate portion 30a, a mounting plate 34 having substantially the same outer shape as that formed by stamping a metal plate with a press is fixed by, for example, spot welding. The mounting plate 34 also has an opening 34a at the center thereof that matches the opening 30c of the top plate 30a.

  As is apparent from FIG. 3, axial through holes 12 d are formed at the four corners of the stator core 12 at rotationally symmetric positions every 90 °. The upper and lower upper and lower covers 30 and 32 of the stator core 12 are provided with insertion holes corresponding to the through holes 12d, and the mounting plate 34 is formed with screw holes 34b corresponding to the insertion holes. ing. When the motor is mounted, the bolts passed through the through holes 12d and the insertion holes are screwed into the screw holes 34b of the mounting plate 34.

  Bearing bushes 40A and 40B are attached to inner peripheral portions on both axial sides of the stator core 12, and metal bearings 42A and 42B for rotatably supporting the rotor shaft 22 are held on the bushings. The bearing bushes 40A and 40B are of the same shape and are formed of a resin such as PPS, and have a structure as shown in FIG. That is, a stepped fitting portion 40b having an outer diameter substantially equal to the inner diameter of the inductor teeth 12c in each main pole 12b of the stator core 11 is formed at the lower portion of the annularly formed main body portion 40a. A cover support surface 40c is formed on the end surface of the outer peripheral portion of 40a, an inlay portion 40d protruding outward in the axial direction is provided inside the cover support surface 40c, and a bearing holding surface is provided on the inner periphery of the main body portion 40a. 40e is formed, and the cover part 40f extended inwardly is provided in the spigot part 40d side of this bearing holding cylinder surface 40e. The outer peripheral surface of the fitting portion 40b, the outer peripheral surface of the spigot portion 40d, and the bearing holding surface 40e are formed concentrically.

  Metal bearings 42A and 42B are fixed to the bearing holding surfaces 40e of the both bearing bushes 40A and 40B by press fitting inside. Both bearing bushes 40A and 40B are attached to the stator core 12 from both sides in the axial direction with the stepped fitting portions 40b facing each other. That is, the fitting portions 40b of the bearing bushes 40A and 40B are fitted to the inner diameters of the inductor teeth 12c in the main poles 12b of the stator core 12, and the respective stepped surfaces are used as the end faces of the stator core 12. The bearing bushes 40A and 40B are attached by abutting, and the alignment of the bearing bushes 40A and 40B with respect to the stator core 12 is performed by the fitting surface (outer peripheral surface) of the stepped fitting portion 40b, and the axial position is the stepped fitting portion. It will be regulated by the stepped surface of 40b. The metal bearings 42A and 42B are oil-impregnated sleeves obtained by impregnating a sintered porous metal with a lubricant, for example.

  The lower bearing bush 40 </ b> B is simultaneously fixed by fixing the lower cover 32 to the stator core 12. That is, when the bearing bush 40B is attached by fitting its fitting portion 40b inside each main pole 12b of the stator core 12, the main body portion 40a is fitted to the inner peripheral surface of the lower insulating member 18. The lower case 32 is disposed below the stator 10 in this state. At this time, when the upper end surface of the outer frame portion 32b of the lower case 32 comes into contact with the lower surface of the stator core 12, the upper end surface of the inner frame portion 32c of the lower case 32 comes into contact with the mounting support surface 40c of the bearing bush 40B. . Then, by fixing the lower cover 32 to the insulating member 18 by ultrasonic welding, a state in which the bearing bush 40 </ b> B partially fitted and held in the stator core 12 is sandwiched between the stator core 12 and the lower cover 32. And is securely fixed. The inlay portion 40 d of the lower bearing bush 40 </ b> B is loosely fitted into the inner frame portion 32 c of the lower cover 32, and the tip thereof is accommodated in the inner frame portion 32 c without being led out from the lower cover 32.

  The upper bearing bush 40 </ b> A is attached to the stator core 12 after the rotor 20 is incorporated into the stator 10, and is fixed simultaneously by fixing the upper cover 30 to the stator 10. That is, the rotor 20 is inserted into the inner side of the stator core 12 of the stator 10 to which the lower bearing bush 40B and the lower cover 32 are fixed, and the lower portion of the rotor shaft 22 of the rotor 20 is connected to the bearing bush 40B. The rotor magnetic poles 24 </ b> A and 24 </ b> B of the rotor 20 are made to face the inner surfaces of the main poles 12 b of the stator core 12 by being inserted inside the held metal bearing 42 </ b> B. Thereafter, the bearing bush 40A holding the metal bearing 42A is inserted into the metal bearing 42A from the upper end of the rotor shaft 22 with the fitting portion 40b facing downward, and the fitting portion 40b is inserted into the stator. The core 12 is fitted inside the main pole 12b. After the fitting portion 40 b of the bearing bush 40 </ b> A is fitted to the stator core 12, the upper cover 30 is fixed to the stator core 12.

  When the upper cover 30 is fixed to the stator core 12, the lower end surface of the outer frame portion 30b of the upper cover 30 is brought into contact with the upper surface of the stator core 12, and at the same time, the upper cover is attached to the mounting support surface 40c of the bearing bush 40A. Since the 30 top plate portions 30a come into contact with each other, the bearing bush 40A is sandwiched between the stator core 12 and the upper cover 30 and is securely fixed. At this time, the spigot portion 40d of the bearing bush 40A is loosely inserted into the opening 30c of the top plate portion 30a of the upper cover 30 and the opening 34a of the mounting plate 34, as shown in FIG. Projects from the top surface. Therefore, by using the lead-out portion of the inlay portion 40d, the rotor shaft 22 can be accurately matched with the input portions of various devices when the motor is attached to various devices.

  Next, the fixing of the upper cover 30 to the stator 10 will be described. As described above, the regular quadrilateral upper cover 30 has the top plate portion 30a and the outer frame portion 30b, but the outer frame portion 30b corresponding to the four corners of the regular quadrilateral has a fixed piece 30d as shown in FIG. Are provided integrally and extended downward. Here, as shown in FIG. 3, the stator core 12 has a shape in which each corner of the regular quadrilateral is chamfered, and each fixed piece 30d is arranged corresponding to this portion. As clearly shown in FIG. 6A, a hole 30e is provided near the lower portion of the fixed piece 30d, and a portion below the hole 30e of the fixed piece 30d is a caulking action portion 30f. Two tapered surfaces 30e1 and 30e2 are formed on the inner lower edge of the punch hole 30e so as to have a V-shaped configuration with the lowest center position. At the position of the stator core 12 corresponding to the lower portion of the fixed piece 30d, a concave portion 12e opening in a rectangular shape is provided on the outer surface. Here, the upper edge of the recess 12e is partially crossed with the tapered surfaces 30e1 and 30e2 of the hole 30e of the fixing piece 30d when the lower end surface of the outer frame portion 30 of the upper cover 30 is in contact with the upper surface of the stator core 12. It is set to such a height.

  When the upper cover 30 is fixed to the stator 10, as described above, the upper bearing bush 40A is attached to the stator core 12, and then the upper cover 30 is placed on the stator core 12 with the outer frame portion 30b. Are arranged in contact with the upper end surface of the stator core 12, and then the central portions of the action portions 30f of the respective fixing pieces 30d located at the four corners of the upper cover 30 are directed from the outside to the inside. The upper cover 30 is caulked and fixed by stamping, that is, a part of the action portion 30f is deformed and inserted into each of the recesses 12e.

  At this time, part of the action portion 30f of the fixed piece 30d enters the concave portion 12e of the stator core 12 to prevent the upper cover 30 from being detached and prevented from falling off. In the case of the structure of the present embodiment, the upper cover is particularly preferable. 30 strong fixations are realized. That is, as can be seen from FIGS. 6A and 6B, the tapered surfaces 30e1 and 30e2 of the lower edge of the punch hole 30e in the fixed piece 30d, that is, the upper edge tapered surface of the action portion 30f is the concave portion 12e of the stator core 12. When the action portion 30f is deformed into the recess 12e, a downward pulling force is generated in the fixed piece 30d as the upper edge tapered surface of the action portion 30f enters the recess 12e. As a result, the upper cover 30 can be pressed against the stator core 12, and the pressing forces act at the four corners of the upper cover 30, and the entire upper cover 30 can be firmly fixed to the stator core 12.

In the above-described caulking operation, the caulking action portion corresponding to the V-shaped apex of the lower edge of the punching hole 30e may be used for the purpose, and this position is the place where the caulking action portion 30f is most easily deformed in terms of strength. Therefore, the caulking work is easy, and deformation due to caulking can be obtained symmetrically. In other words, in general, the caulking operation tends to be relatively difficult to manage the applied force, the deformed shape, and the deformation amount. However, with the above-described shape, the caulking operation is easy and a reproducible deformation amount is obtained. It is possible.

  In the stepping motor having the above-described configuration, the step angle that can be rotated by the pulse signal is set to 4.09 °, and the rotation angle is set larger than that of the general 1.8 °. Therefore, it can be rotated at this speed. That is, it can be said that the embodiment is a stepping motor capable of increasing the speed. Since the output of the motor is proportional to the product of the rotation speed and the torque, the output increases as a result of this increase in speed, resulting in increased efficiency.

  On the other hand, unlike the conventional stepping motor, metal bearings 42A and 42B are used as bearings for the rotor 20 in the stepping motor described above. Since these types of metal bearings 42A and 42B are so-called sliding bearings, the air gap between the stator and the rotor is set to be slightly larger than the air gap in the case of a ball bearing. In this case, the air gap between the stator and the rotor affects the efficiency of the motor, and the efficiency tends to decrease as the air gap increases. However, in the above embodiment, since the speed is increased and the efficiency is increased by setting the step angle, even if the metal bearings 42A and 42B are used as the bearings, the efficiency decreases. As a result of improving the efficiency only to compensate, a stepping motor that exhibits an efficiency equal to or higher than the conventional case can be obtained.

  Here, the stator core 12 is configured by laminating a predetermined number of silicon steel plates, and adopts a method of laminating the silicon steel plates that are press-punched into a predetermined shape one after another by 90 °. As a result, it is possible to obtain the effect of suppressing variation in the permeance vector. That is, since the stator core 12 shown in FIG. 3 has a 90 ° point symmetrical structure, the permeance vector due to a slight difference in the size of the punching die or a difference in the thickness of the silicon steel plate can be obtained by rotating and overlapping the 90 °. This variation can be canceled.

  Next, Embodiment 2 of the present invention will be described with reference to FIGS. In these drawings, the same reference numerals as those described above indicate the same or corresponding ones.

  7 and 8, an upper cover 30 ′ formed by press-molding a thin metal plate includes a top plate portion 30a ′ and a substantially regular quadrilateral outer frame portion 30b ′. An opening 30c ′ having an inner diameter substantially equal to the inner diameter of the inner frame portion of the lower cover 32 is formed at the center of 30a ′. On the top surface of the top plate portion 30a ', a mounting plate (not shown) having substantially the same outer shape and formed by stamping a metal plate with a press is fixed by, for example, spot welding.

Fixing pieces 30d 'which are integral with the outer frame portion 30b' and extend downward are provided at the positions of the four corners of the regular quadrilateral in the outer frame portion 30b 'of the upper cover 30'. Each fixed piece 30d ′ corresponds to the chamfered position of the corner of the regular quadrilateral of the stator core 12, but in this embodiment, it is continuous with both sides of the chamfered portion of the stator core 12. Side pieces 30d1 and 30d2 parallel to the two sides of the stator core 12 are integrally provided. The both side pieces 30d1 and 30d2 function as a detent for the upper cover 30d 'with respect to the stator core 12, and also serve as reinforcement against deformation during caulking. A punch hole 30e 'is provided near the lower center of each fixed piece 30d', and a portion below the punch hole 30e 'of the fixed piece 30d' is a caulking action portion 30f '. As in the case of the first embodiment, the inner lower edge of the punch hole 30e 'has a V-shaped configuration with the lowest center position, and two tapered surfaces are formed.

At the position of the stator core 12 corresponding to the lower portion of the fixed piece 30d, a concave portion 12e 'opening on the outer surface is provided. Here, the upper edge of the recess 12e ′ is flush with the tapered surface of the hole 30e ′ of the fixing piece 30d ′ in a state where the lower end surface of the outer frame portion 30b ′ of the upper cover 30 ′ is in contact with the upper surface of the stator core 12. It is set to a height that crosses. In the case of this embodiment, the recess 12e 'is continuously formed from the position of the upper edge to the lower end position of the stator core 12. Further, on the peripheral surface of the stator core 12, stepped grooves 12f are formed in the axial direction from the four corners of the regular quadrilateral to the side pieces on both sides thereof, and each fixed piece 30d ′ of the upper cover 30 ′ is provided with this stepped portion. It fits in the upper part of the groove 12f, and is arranged so that the four side surfaces of the stator core 12 and the side pieces 30d1 and 30d2 of the fixed piece 30d ′ are flush with each other.

  Also in this embodiment, as in the case of the first embodiment, the center portion of the caulking action portion 30f ′ is caulked and deformed to enter the recess 12e ′, whereby the upper cover 30 ′ is caulked and fixed to the stator core 12. In addition, the upper cover 30 ′ is provided with side pieces 30 d 1 and 30 d 2 which are integrally orthogonal to each other and are in contact with two mutually orthogonal pieces of the stator core 12. Therefore, the upper cover 30 ′ can be reliably prevented from rotating with respect to the stator core 12, and the upper cover 30 ′ can be firmly fixed to the stator core 12. In particular, when the stepped groove 12f into which the fixed piece 30d 'is fitted is formed in the stator core 12 as in the second embodiment, the effect of preventing the rotation becomes more remarkable.

  The rotating electrical machine according to the present invention is capable of high-speed rotation, achieves high efficiency, and can reduce the cost by adopting a metal bearing. As a stepping motor, it can be used for copying machines and printers that are OA devices. On the other hand, it is possible to provide an inexpensive, high-speed, high-torque, low-vibration rotating electrical machine, which is expected to make a significant industrial contribution. In addition, application to medical equipment, FA equipment, robots, amusement machines, and housing equipment is also highly expected.

10: Stator 12: Stator core 12b: Main poles 12e, 12e ': Recess 14: Winding wire 20: Rotor 30: Upper cover 30b, 30b': Outer frame portions 30d, 30d ': Fixing pieces 30e, 30e' : Holes 30f, 30f ': Caulking action portions 30d1, 30d2: Side pieces

Claims (7)

A stator including a substantially annular core back portion, a stator core composed of a plurality of main poles protruding inwardly from the core back portion, and a winding wound around the main pole of the stator core With the child,
A rotor provided rotatably inside the stator via an air gap;
In a rotating electrical machine comprising: a motor cover that covers at least one of both sides in the axial direction of the stator;
The motor cover is formed by press-molding a metal plate, and the motor cover is formed with an annular outer frame portion whose end edge is in contact with the end surface of the stator core from the outside in the axial direction. Are integrally formed with a plurality of fixed pieces extending from the outside in the axial direction toward the inside in the axial direction. A caulking action portion is formed, and a recess is formed at least in a position corresponding to the caulking action portion in the stator core, and the caulking action portion is deformed so that a part thereof enters the recess. The rotating electrical machine, wherein the motor cover is fixed to the stator core in a state where an end edge of the annular outer frame portion is in contact with an end surface of the stator core. The edge on the caulking action part side of the punching hole of the fixing piece and the edge on the motor cover side of the concave part of the stator core are close to each other, and a part of the caulking action part is 2. The rotating electrical machine according to claim 1, wherein a tensile force is generated on the fixed piece toward the inside in the axial direction when entering the recess. The edge of the fixing piece has a substantially V-shaped edge at least in the extending direction of the fixing piece, and the edge of the concave portion intersects the taper portions on both side edges of the V-shaped edge of the opening hole. The rotating electrical machine according to claim 1 or 2, wherein a position corresponding to a vertex of the V-shape is deformed in the caulking action portion. The width dimension of the direction orthogonal to the axial direction of the said recessed part is set larger than the width dimension of the said punching hole, and smaller than the width dimension of the said fixing piece, The Claim 1 characterized by the above-mentioned. Rotating electric machine. The substantially annular core back portion of the stator core is formed in a shape having a substantially regular quadrilateral shape, and the annular outer frame portion of the motor cover is also formed in a substantially regular quadrilateral shape in accordance with this, and the fixed piece Are respectively disposed at four corners of a regular quadrilateral in the outer frame portion. 6. The rotating electrical machine according to claim 5, wherein each of the fixed pieces integrally includes a side piece that is substantially parallel to two pieces on both sides of the corner where the fixed piece is disposed.   The rotating electrical machine according to any one of claims 1 to 6, wherein the concave portion is continuously formed up to an end surface of the stator core opposite to the motor cover.

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