JP2018074685A - Brushless motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a brushless motor capable of preventing a trouble caused by the scattering of shavings in a housing by surely capturing shavings produced when a stator is press-fit into the housing.SOLUTION: Ridges 19 are formed at six positions on the outer circumference of a core 6 of a stator 3. A front insulator 7 is fixed in front of the stator 3. On the outer circumference surface of the front insulator 7, a first bulkhead 21 is formed facing an edge surface 19a of each of the ridges 19 in the foreside of the press-fitting direction. Second bulkheads 22 are formed in both sides of each of the first bulkheads 21 in the circumference direction to be brought into contact with the edge surface 19a of the ridge 19. These form a rectangular pocket 20 surrounded by the first bulkhead 21, the second bulkheads 22, and the edge surface 19a of the ridge 19, to capture shavings A, into the pocket 20, produced by sliding of each of the ridges 19 of the stator 3 over the inner circumferential surface of a housing 2 when the stator 3 is press-fit into the housing 2.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a brushless motor. More specifically, the present invention relates to a rotor that is disposed opposite to a stator by fixing a stator having a winding wound around a core in a press-fitted state to a press-fitting member and generating a magnetic field by energizing the winding. The present invention relates to a brushless motor that applies rotational force.

  As is well known, a brushless motor is operated on the principle of applying a rotational force to a rotor provided with a permanent magnet by controlling energization of a winding wound around a stator core and continuously switching a magnetic field. . For example, in an inner rotor type brushless motor in which a stator is fixed in a housing and a rotor is rotatably supported therein, press-fitting may be used as one method for fixing the stator in the housing.

  Since there is a difference in the thermal expansion between the housing and the stator, when the temperature rises during operation of the motor, there is a case where the press-fit is loosened, and such press-fit looseness is also caused by vibration during operation. If the press-fitting is loosened, the desired performance cannot be maintained due to, for example, the co-rotation of the stator in the housing. Therefore, the tolerance between the inner diameter of the housing and the outer diameter of the stator is carefully managed, and sufficient The press-in allowance is secured.

  However, securing the press-fit allowance contributes to the improvement of the reliability of the motor, but it can be a factor causing trouble due to the generation of shavings. It is the outer periphery of the stator core that is in sliding contact with the inner peripheral surface of the housing during press-fitting. For example, the surface of the housing is galvanized for rust prevention and the like, but the stator core is a silicon steel plate with higher hardness Etc. are produced. For this reason, a phenomenon occurs in which the plating layer on the inner peripheral surface of the housing is scraped by the outer peripheral portion of the stator core along with the press-fitting. Of course, even when the housing and the stator core are made of other materials, the phenomenon that any one of them is scraped during press-fitting similarly occurs. And if the cutting scraps which are conductors are scattered in a housing, the insulation in a motor will fall and it will lead to troubles, such as a short circuit of a contact. Even if the surface treatment is a non-conductor such as a resin, the motor may not be able to rotate due to the scraps entering the bearing.

As a technique paying attention to such a problem, for example, in the brushless motor described in Patent Document 1, a measure is taken to capture scraps generated by press-fitting the stator into a recess formed in the housing. Specifically, the housing has a bottomed cylindrical shape that opens to one side along the axial direction of the rotor, and a recess is formed along the outer periphery of the outermost portion.
As shown in FIG. 1 of Patent Document 1, in the press-fitting operation of the stator, the housing is fixed with the opening portion facing upward, and the stator is press-fitted into the housing from above. The shavings generated by the press-fitting are dropped downward and captured by the recess, and in this state, the recess is sealed by the stator that is press-fitted to the lowest part.

Japanese Patent Laid-Open No. 4-127865

  However, with the technique described in Patent Document 1, the scraps cannot be trapped in the recesses as expected due to the positional relationship between the recesses of the housing and the locations where the scraps are generated during press-fitting.

That is, in the technique of Patent Document 1, since shavings due to sliding contact with the outer peripheral portion of the stator are always generated on the inner peripheral surface of the housing, if the concave portion is formed in the uppermost portion in the housing immediately below the shaving, Based on the idea that scum can be captured. However, the shavings continue to be generated from the start of press-fitting of the stator to the completion, and the shavings generated by the sliding contact are powdery.
For this reason, at the beginning of press-fitting, scraps are generated at the uppermost part of the housing, and the powdered scraps are scattered around while falling in the housing. For this reason, only a part of the shavings can be captured in the recess, and most of the shavings are lost and scattered in the housing, causing the above-mentioned troubles during the subsequent operation of the motor.

  The present invention has been made to solve such problems, and the object of the present invention is to reliably capture the scraps generated when the stator is press-fitted into the housing, and to scatter the scraps in the housing. Accordingly, it is an object of the present invention to provide a brushless motor that can prevent a trouble caused by shavings.

  In order to achieve the above object, a brushless motor according to the present invention fixes a press-fitting member in a press-fitted state to any one of the inner and outer circumferences of a stator formed by winding a winding around a core, and the other of the inner and outer circumferences of the stator. A brushless motor in which a rotor having a rotating shaft concentric with the stator and a permanent magnet is disposed, and a magnetic field is generated by energizing the windings of the stator to apply a rotational force to the rotor. A capturing portion that captures scraps generated by sliding contact with each other during press-fitting with the press-fitting member is formed on a surface of the stator facing the press-fitting member (claim 1).

  According to the brushless motor configured as described above, when the stator and the press-fitting member are press-fitted, shavings are generated due to sliding contact with each other, and the portions where the shavings are generated are gradually press-fitted as the stator moves relative to the press-fitting member. Displaces forward. In accordance with the position displacement of the location where the scrap is generated, the catching portion formed on the opposing surface of the stator is also displaced to the press-fitting front side. For this reason, the trapping portion and the occurrence location of the shaving residue are always kept in a predetermined positional relationship from the start to the completion of press-fitting, and the generated shaving residue is reliably trapped in the catching portion.

As another aspect, it is preferable that the capturing portion is formed on the front side of the press-fitting with respect to the press-fitting direction with respect to the press-fitting member on the opposing surface of the stator with respect to the generation site of the shavings due to the sliding contact. Item 2).
According to this aspect, when the stator and the press-fitting member are press-fitted, shavings are generated mainly on the front side of the press-fitting of the stator, and the catching portion formed on the front side of the press-fitting is inevitably a place where the shavings are generated. Therefore, the scrap is reliably captured by the capturing part.

As another aspect, the stator and the press-fitting member are partially slidably contacted at the time of the press-fitting in a circumferential direction orthogonal to the press-fitting front-rear direction, and the capturing portion is at least in the circumferential direction on the opposing surface of the stator. Preferably, it is formed in a region corresponding to the sliding contact portion with the press-fitting member.
According to this aspect, since the capture part is formed in the region corresponding to the sliding contact portion with the press-fitting member in the circumferential direction on the opposing surface of the stator, the scrap is reliably captured by the capture part.

As another aspect, the capture portion is opposed to the generation site of the shaving residue due to the sliding contact on the front side of the press-fitting, and the first partition wall prevents scattering of the shaving residue to the front side of the press-fitting. Preferably, it is formed (claim 4).
According to this aspect, the first partition that opposes on the front side of the press-fitting with the occurrence site of the shavings prevents the scraps from being scattered forward of the press-fitting.

As another aspect, the capturing part is located on both sides of the first partition and the circumferential direction of the first partition, and the second partition that prevents the scraped scrap from scattering in the circumferential direction. (Claim 5).
According to this aspect, the second partition located on both sides in the circumferential direction of the first partition prevents the scraps from being scattered in the circumferential direction.

As another aspect, it is preferable that an insulator for maintaining insulation between the core and the winding is fixed to at least the press-fitting front side of the stator, and the capturing portion is formed in the insulator.
According to this aspect, since the capturing part is formed in the insulator, it is possible to implement by changing the specifications of only the insulator without changing the specifications of other members.

As another aspect, the insulator capturing portion protrudes toward the press-fitting member from the sliding contact portion of the stator with respect to the press-fitting member, and has elasticity with respect to the press-fitting member in the press-fitted state of the stator and the press-fitting member. It is preferable to press-contact (Claim 7).
According to this aspect, since the capturing part is elastically pressed against the press-fitting member in the press-fitted state of the stator and the press-fitting member, a situation in which shavings leak from the capturing part is prevented.

As another aspect, it is preferable that the first partition wall is continuous over the entire circumference of the facing surface of the stator.
According to this aspect, since the first partition is continuous over the entire circumference of the opposing surface of the stator, it is possible to prevent the scrap from being scattered over the first partition and to the front of the press-fitting.

As another aspect, the stator has a plurality of protruding portions formed at intervals in the circumferential direction in sliding contact with the press-fitting member, and the capturing portion includes the first partition and the first partition. And a third partition wall which prevents the scrap from being scattered to the rear of the press-fitting, continuously with the entire circumference of the opposing surface of the stator by cooperating with the protrusions. Preferably, it is a concave groove (claim 9).
According to this aspect, since the third partition wall continues to the entire circumference of the opposed surface of the stator in cooperation with the protrusions on the back side of the first partition wall, the scraps are prevented from being scattered to the back of the press-fitting. Is done. Then, the shaving residue is enclosed in a concave groove formed between the first partition wall and the third partition wall.

  According to the brushless motor of the present invention, it is possible to reliably capture the shavings generated when the stator and the press-fitting member are press-fitted in the catching portion, and prevent the scraps from being scattered in the housing. It is possible to prevent problems caused by it.

It is sectional drawing which shows the assembly | attachment state of the inner rotor type brushless motor of embodiment. It is a disassembled perspective view which similarly shows the relationship between the housing of a brushless motor, and a stator. It is the elements on larger scale of FIG. 2 which shows the pocket periphery formed in the front part insulator of a stator. FIG. 4 is a cross-sectional view taken along the line IV-IV in FIG. 3, similarly showing the periphery of the pocket formed in the front insulator of the stator. FIG. 5 is a cross-sectional view taken along the line VV in FIG. 4, showing the periphery of the pocket formed in the front insulator of the stator. It is a partial expanded sectional view of the pocket periphery which shows the time of the press injection of a stator. It is a partial expanded sectional view of the pocket periphery which shows the press injection of a stator. It is a partial expanded sectional view of the pocket periphery which shows the time of the press injection completion of a stator. It is a perspective view corresponding to FIG. 3 which shows the other example which formed the 1st partition in the perimeter of the outer peripheral surface of a stator. It is a perspective view corresponding to FIG. 3 which shows the other example which formed the 1st and 3rd partition in the perimeter of the outer peripheral surface of the stator. It is a mimetic diagram showing the inner rotor type brushless motor of an embodiment. It is a schematic diagram which shows the outer rotor type brushless motor of another example. It is a schematic diagram which shows the outer rotor type brushless motor of another example.

Hereinafter, an embodiment in which the present invention is embodied in an inner rotor type brushless motor in which a rotor is rotatably supported on the inner peripheral side of a stator will be described.
1 is a cross-sectional view showing the assembled state of the brushless motor of the present embodiment, FIG. 2 is an exploded perspective view showing the relationship between the housing of the brushless motor and the stator, and FIG. 3 is a pocket formed in the front insulator of the stator. 2 is a partially enlarged view of FIG. 2 showing the periphery, FIG. 4 is a sectional view taken along the line IV-IV of FIG. 3 showing the sliding contact state of the stator with respect to the inner peripheral surface of the housing, and FIG. It is the VV sectional view taken on the line of FIG. 4 which shows a state.

  As a whole, the brushless motor 1 (hereinafter sometimes simply referred to as a motor) press-fits a stator 3 into a bottomed cylindrical housing 2 (press-fit member) that opens to one side, and the rotor 4 enters the stator 3. Is configured to be rotatably supported. In the following description, as indicated by arrows in FIG. 2, the direction along the press-fitting of the stator 3 on the outer peripheral surface of the stator 3 (the surface facing the press-fitting member of the present invention) is the press-fitting front-rear direction (press-fitting front and press-fitting rear). ), And a direction orthogonal to the press-fitting front-rear direction is referred to as a circumferential direction. In addition, the inner and outer directions around the rotation axis L of the rotor 4 are referred to as an inner peripheral side and an outer peripheral side.

  The housing 2 is manufactured by drawing a galvanized steel sheet, and a bearing 5 for supporting the rotor 4 is provided at the center of the innermost innermost part.

  The core 6 of the stator 3 is formed by laminating a plurality of ring-shaped silicon steel plates, and as a whole, has a cylindrical shape along the press-fitting front-rear direction. On the inner periphery of the core 6, six teeth 6 a (shown in FIG. 3) extending in the front-rear direction at equal intervals in the circumferential direction are formed so as to protrude, and slots 6 b are provided between the teeth 6 a in the front-rear direction. It is formed to extend.

  A front insulator 7 is fixed to the front of the core 6 and a rear insulator 8 is fixed to the rear of the core 6. Each insulator 7, 8 is made of a synthetic resin material and has a ring-shaped cross section corresponding to the core 6 as a whole, and the front insulator 7 is equally spaced in the circumferential direction so as to correspond to the teeth 6 a of the core 6. In this case, six protrusions 7a are formed, and although not shown, the rear insulator 8 is also formed with six protrusions corresponding to the teeth 6a.

  In particular, as shown in FIG. 1, through the slots 6b on both sides of the teeth 6a, windings are wound around the teeth 6a, and the windings are arranged in the order of U, V, and W phases. Are connected to each other via a crossover (not shown), and a coil 9 for each phase is formed as a whole. The stator 6 is constituted by the core 6, the front and rear insulators 7, 8 and the coil 9, and the insulation between the core 6 and the coil 9 is maintained by the front and rear insulators 7, 8.

  When the stator 3 is press-fitted inside, the opening of the housing 2 is closed by an end bell 10, and a bearing 11 for supporting the rotor 4 is provided at the center of the end bell 10. In the housing 2, the rotor 4 is disposed concentrically on the inner peripheral side of the stator 3. The rotor 4 is configured by inserting and fixing a rotary shaft 13 at the center of a cylindrical iron core 12 and alternately arranging permanent magnets 14 having different polarities on the outer periphery of the iron core 12.

  Both ends of the rotating shaft 13 of the rotor 4 are supported by bearings 5 and 11 of the housing 2 and the end bell 10, so that the rotor 4 can rotate about the rotating axis L. An end portion of the rotary shaft 13 on the front side of press-fitting greatly protrudes from the housing 2, and this end portion is connected to an object to be driven and functions as an output shaft.

In the housing 2, a circuit board 15 is disposed between the stator 3 and the end bell 10. A rotation angle sensor 16 for each phase for detecting the rotation angle of the rotor 4 and a terminal 17 for each phase are provided on the circuit board 15, and each terminal 17 protrudes outside through the end bell 10.
When the motor 1 is used, electric power is supplied to the motor 1 from the power line connected to each terminal 17, and the coils 9 of each phase are energized at a predetermined timing based on the rotation angle of the rotor 4 detected by the rotation angle sensor 16. A rotational force is applied to the rotor 4 by continuously switching the magnetic field of the coil 9.

  On the other hand, on the outer periphery of the core 6 of the stator 3, protrusions 19 (sliding contact portions with the press-fitting member of the present invention and a plurality of protruding portions) are formed at six locations that are equally spaced in the circumferential direction. The press-fitting of the stator 3 into 2 is performed while these ridges 19 are partially slidably contacted with the inner peripheral surface of the housing 2 in the circumferential direction. As described in [Background Art], when the protrusions 19 of the core 6 are slidably contacted with the inner peripheral surface of the housing 2 during press-fitting, the plating layer applied to the inner peripheral surface is scraped to cause a short circuit or the like. Cutting scraps that cause trouble occur. As a countermeasure, the technique of Patent Document 1 has been proposed, but there is a problem in that it is not possible to surely capture the shavings because a concave portion is formed in the outermost portion in the housing.

  In view of such a problem, the present inventor considered the position of the recess for capturing the scrap. As described in [Problems to be Solved by the Invention], the scraping of the scraps is caused by the fact that the portions where the scraps are generated and the recesses are separated from each other. Move with it. For this reason, no matter where the recess is formed in the housing, it is unavoidable that the portion where the scrap is generated is largely separated from the recess at any timing during the press-fitting operation, and the spillage is not necessarily eliminated.

  When the stator 3 is press-fitted, the ridge 19 moves forward while being in sliding contact with the inner peripheral surface of the housing 2 and the sliding contact area with respect to the inner peripheral surface is gradually enlarged. However, the scrap is generated in the entire sliding contact area. Instead, it occurs at the corner of the ridge 19 on the front side of the press-fitting. Then, the location where the shaving residue is generated is displaced with the movement of the stator 3. Therefore, if a recess (pocket 20 in the present embodiment) is provided on the stator 3 side, the shaving from the start of press-fitting of the stator 3 to the completion is cut. The inventors have found that the place where the residue is generated and the recess can always be kept in the close position.

  Based on the above knowledge, in this embodiment, the front insulator 7 located in front of the press-fitting of each protrusion 19 of the stator 3 is provided with a pocket 20 (capturing portion) for capturing the scraps. 20 will be described in detail.

  In particular, as shown in FIGS. 3 to 5, the ridges 19 are formed in pairs (total of 12 ridges) at six locations at equal intervals in the circumferential direction of the outer periphery of the core 6, and each ridge 19 is press-fitted into the core 6. It extends over the entire front-rear direction. The tolerance between the outer diameter of the core 6 including the ridges 19 and the inner diameter of the housing 2 is carefully controlled, thereby ensuring a sufficient press-fitting allowance. Further, the cross-sectional shape of each protrusion 19 is set so as to contact the inner peripheral surface of the housing 2 at an acute angle as shown by a two-dot chain line in FIG. The contact pressure is increased.

  Each protrusion 19 extends to the front end of the core 6, that is, the boundary between the core 6 and the front insulator 7, and the end surface of the core 6 viewed from the front in the press-fitting direction has six locations spaced at equal intervals in the circumferential direction. Each pair of protrusions 19 has a shape protruding to the outer peripheral side. For this reason, when the stator 3 is press-fitted, the end surface 19a of each protrusion 19 forms a corner and scrapes the plating layer on the inner peripheral surface of the housing 2. Then, the first and second partition walls 21 are respectively provided at six locations equidistantly spaced in the circumferential direction of the outer peripheral surface of the front insulator 7 so as to correspond to the press-fitting front side of each pair of protrusions 19. , 22 form a pocket 20.

  Specifically, first partition walls 21 are formed corresponding to the press-fitting front side of each pair of protrusions 19, and these first partition walls 21 are predetermined from the end surface 19 a of the corresponding protrusion 19 to the press-fitting front side. Opposite to the respective end surfaces 19a at spaced positions. On both sides in the circumferential direction of each first partition wall 21, second partition walls 22 are formed so as to be continuous with the first partition wall 21, and these second partition walls 22 are on the press-fit rear side, that is, on the core 6. It extends toward the ridge 19. And each 2nd partition 22 contacts the end surface of the core 6 so that the end surface 19a of a corresponding protrusion 19 may be pinched | interposed, and it bends at right angle | corner at the contact | abutting part, and faces toward the side spaced apart from the protrusion 19. It is extended.

  Surrounded by the first and second partition walls 21 and 22 and the end surface 19 a of the protrusion 19, a pocket 20 recessed in a substantially square shape is formed on the outer peripheral surface of the front insulator 7. As a result, each pocket 20 is formed in a region corresponding to the pair of protrusions 19 in the circumferential direction.

  As shown in FIG. 4, the end faces of the second partition wall 22 and the ridge 19 coincide or slightly overlap in the circumferential direction, and although not shown, they are formed between the pair of ridges 19. The space continues to the press-fitted rear, but is closed by a rear insulator 8 at the rear end of the core 6. For this reason, each pocket 20 is closed by the first and second partition walls 21 and 22 and the end surface 19a of the protrusion 19 in both the front-rear direction and the circumferential direction with the stator 3 being press-fitted into the housing 2. In addition, the inner peripheral side of each pocket 20 is closed by the front insulator 7, and the outer peripheral side is closed by the housing 2.

  As shown by a two-dot chain line in FIG. 5, the outer diameter of the front insulator 7 including the first and second partition walls 21 and 22 is the same as or larger than the outer diameter of the core 6 including the protrusions 19. Is set slightly larger. For this reason, when the outer diameter of the front insulator 7 is slightly larger than the outer diameter of the core 6, as shown by the solid line in FIG. The part insulator 7 is slightly bent in the direction of diameter reduction about the rotation axis L, and the first and second partition walls 21 and 22 are pressed against the inner peripheral surface of the housing 2 with its own elasticity.

  In order to smoothly guide the front insulator 7 into the housing 2 when the stator 3 is press-fitted, the corners of the second partition walls 22 in the press-fitting direction are rounded.

  The brushless motor 1 according to the present embodiment is configured as described above. Next, the assembly work of the motor 1, particularly the press-fitting work of the stator 3 to the housing 2, and the scraping scrap capturing action by the pocket 20 at that time will be described. .

  First, the stator 6 is completed by assembling the core 6, the front and rear insulators 7 and 8, and the coil 9 in a predetermined relationship. Next, after fixing the housing 2 in a posture in which the opening is directed upward, the stator 3 is press-fitted into the housing 2 from above in a posture in which the front insulator 7 is directed downward.

  6 to 7 are partially enlarged cross-sectional views around the pocket showing the press-fitting process of the stator 3. FIG. 6 shows the press-fitting start, FIG. 7 shows the press-fitting, and FIG. 8 shows the press-fitting completion. Since the stator 3 is press-fitted into the housing 2 from above as described above, the diagonally lower left side of each figure corresponds to the actual lower side, and gravity acts downward.

  In the press-fitting process of the stator 3, first, as shown in FIG. 6, the front insulator 7 of the stator 3 starts to be inserted into the housing 2 in correspondence with the opening of the housing 2. Since the corners of the second partition wall 22 are rounded as described above, the front insulator 7 is smoothly guided into the housing 2. With the insertion, the front insulator 7 is deflected by receiving a force in the direction of diameter reduction through the second partition wall 22, and the first and second partition walls 21 and 22 are pressed against the inner peripheral surface of the housing 2 by its elasticity. .

  Then, the core 6 is inserted into the housing 2 following the front insulator 7, and as shown in FIG. 7, each protrusion 19 of the core 6 moves to the flange while slidingly contacting the inner peripheral surface of the housing 2. As a result, the stator 3 is press-fitted into the housing 2. After the core 6, the rear insulator 8 is also inserted into the housing 2, and the press-fitting operation of the stator 3 is completed when the front insulator 7 reaches the outermost portion in the housing 2 as shown in FIG. 8.

  On the other hand, the iron core 12, the rotating shaft 13, and the permanent magnet 14 are assembled in advance in a predetermined relationship to complete the rotor 4, and the rotor 4 is disposed inside the stator 3 after being press-fitted into the housing 2. Subsequently, when the circuit board 15 is disposed in the housing 2 and the end bell 10 is fixed and closed in the opening of the housing 2, a series of assembling operations of the motor 1 is completed.

  Then, as described with reference to FIG. 7, the protrusions 19 of the core 6 are in sliding contact with the inner peripheral surface of the housing 2 during the press-fitting of the stator 3, and as the protrusions 19 move, The plated layer on the inner peripheral surface of the housing 2 is cut by the corners. For this reason, the shaving residue A is always generated at the corner of each protrusion 19 on the front side of press-fitting, and the location where the shaving residue A is generated is gradually displaced to the front side of press-fitting as the protrusions 19 move.

  Here, the end face 19a that forms the corner of each protrusion 19 forms a pocket 20 in cooperation with the first and second partition walls 21 and 22, and the pocket 20 is where the scrap A is generated. It is arranged at a very close position directly under the. Since the pockets 20 are also provided in the stator 3 itself that generates the scraps A by the ridges 19, the pockets 20 are also displaced to the press-fitting front side together with the locations where the scraps A are generated. For this reason, the pocket 20 and the location where the shaving residue A is generated are always kept in a predetermined positional relationship from the start of press-fitting of the stator 3 to the completion (the relationship in which the pocket 20 is located immediately below the occurrence location).

  Therefore, the shavings A generated by being cut by the corners of the protrusions 19 are dropped by gravity immediately after being generated and are successively captured in the pockets 20 immediately below. In other words, since the corners of the protrusions 19 face the pocket 20, it can be understood that the shavings A due to the corners are always generated in the pocket 20 and captured as it is. The generated scrap A is prevented from scattering forward by press-fitting by the first partition 21, from being scattered to both sides in the circumferential direction by the second partition 22, and further press-fitted by the end face 19 a of the protrusion 19. It is prevented from scattering backward. In addition, since the chip residue A is pushed out in the advancing direction of the ridges 19 of the core 6 at the time of press-fitting, the present invention is effective even if the acting direction of gravity at the time of press-fitting is not downward.

  For this reason, of course, in the press-fitting process of the stator 3, even during the operation of the motor 1 after completion of the assembly, the scrap A is always enclosed in the sealed pocket 20 regardless of the attitude of the motor 1. In particular, in this embodiment, by setting the outer diameter of the front insulator 7 including the first and second partition walls 21 and 22 to be slightly larger than the outer diameter of the core 6 including the protrusions 19, The first and second partition walls 21 and 22 of the partial insulator 7 are pressed against the inner peripheral surface of the housing 2 with elasticity. For this reason, it is possible to more reliably prevent the scrap A from leaking out of the pocket 20 from the gap between each partition wall 21, 22 and the inner peripheral surface of the housing 2.

  Furthermore, if an adhesive is applied to each pocket 20 in advance during the press-fitting operation, the adhesive is cured with the scraps A being caught, so that the leakage of the scraps A can be more reliably prevented.

In the above description, it is assumed that the plating layer on the outer peripheral surface of the housing 2 is cut. However, depending on the specifications of the motor 1 and the like, the protrusion 19 on the core 6 side may be cut. However, even in that case, the shaving residue A is reliably captured in the pocket 20 as well.
In the above description, the case where the stator 3 is press-fitted into the housing 2 from above is described, but the same applies to other postures. For example, the stator 3 is fixed and the housing 2 is fitted into the stator 3 from above. Even in the case of being pressed in, the shavings A generated in the pocket 20 continues to be captured inside.

  As described above, according to the brushless motor 1 of the present embodiment, the chip residue A generated in the housing 2 when the stator 3 is press-fitted can be reliably captured in the pocket 20. For this reason, troubles when the scrap A is scattered around in the housing 2, for example, the insulation in the motor 1 is lowered and a contact short circuit occurs, or the bearings 5 and 11 of the rotating shaft 13 of the rotor 4. It is possible to prevent troubles such as occurrence of seizure.

  Further, since the shaving residue A generated in the housing 2 does not cause a trouble as described above, it is not necessary to reduce the press-fitting allowance of the stator 3 to the housing 2 from an ideal value in order to suppress the generation of the scrap residue A. . As a result, by securing a sufficient press-fitting allowance, it is possible to reliably prevent troubles such as rotation of the stator 3 in the housing 2.

Moreover, in this embodiment, since the pocket 20 is provided in the front insulator 7, it can be implemented by changing the specifications of only the front insulator 7 without changing the specifications of other members such as the core, and the front portion thereof. The formation of the pocket 20 for the insulator 7 is also extremely easy.
For example, when the pocket 20 is provided in the core 6 that is a laminated body of silicon steel plates, it is necessary to form the pocket 20 while gradually changing the shape of a large number of silicon steel plates located at the formation positions of the pockets 20 in the direction before and after press-fitting. Yes, the manufacturing process is quite complicated.

On the other hand, in the case where the pocket 20 is provided in the front insulator 7 which is an injection-molded product made of a synthetic resin material, the first and the first insulators on the front insulator 7 can be simply changed by changing the shape of the mold applied to the injection molding. The second partition walls 21 and 22 can be formed, and the pocket 20 is naturally formed by the coupling with the core 6. In particular, the die cutting direction when forming the first and second partition walls 21 and 22 of the present embodiment matches the die cutting direction of the front insulator 7 itself along the axial direction (the press-fitting front-rear direction).
Therefore, it is possible to cope with a slight change in the shape of the mold for forming the first and second partition walls 21 and 22 without changing the basic configuration of the two-part mold. Therefore, the brushless motor 1 of the present embodiment can be implemented at a very low cost by a simple specification change of only the front insulator 7.

  However, the present invention does not limit the formation target of the pocket 20 to the front insulator 7, but it is also possible to form the pocket 20 in the core 6 although it requires some trouble as described above. Further, when the pocket 20 is formed in the core 6, the position of the pocket 20 in the front-rear direction of the press-fitting is not limited to the front side of the press-fitting. For example, the pocket 20 may be formed at an intermediate position of the core 6 in the front-rear direction.

  On the other hand, in the present embodiment, as described above, the pocket 20 recessed in a substantially square shape by the first and second partition walls 21 and 22 is formed on the outer periphery of the front insulator 7. It is not limited to.

  For example, as shown in another example of FIG. 9, the shape of the first partition wall 21 of the embodiment may be changed to function as the capturing unit of the present invention. The first partition wall 31 of this other example is opposed to the end surface 19a of each protrusion 19 at a predetermined interval as in the embodiment, but the outer peripheral surface of the front insulator 7 (in the present invention). It is different in that it is continuous over the entire circumference of the stator).

  When the scraps A cut at the corners of the protrusions 19 fall during the press-fitting of the stator 3, they are blocked by the first partition wall 31 that is directly under the entire circumference and deposited. It is possible to prevent the waste A from falling over the first partition wall 31 in front of press-fitting, that is, into the housing 2 and scattering. Therefore, the first partition wall 31 of this other example does not contain the scrap residue A like the pocket 20 of the embodiment, but prevents the scrap residue A from scattering into the housing 2. The same effect can be obtained.

  Moreover, you may add the 3rd partition 32 to the press injection back side of the 1st partition 31 shown in FIG. As shown in FIG. 10, the third partition wall 32 extends in the circumferential direction at a position that coincides with the end surface 19 a of each protrusion 19 in the longitudinal direction of press-fitting on the outer circumferential surface of the front insulator 7. . The third partition wall 32 is divided at each protrusion 19, but the third partition wall 32 and the end surface 19 a of the protrusion 19 have end surfaces that coincide or slightly overlap in the circumferential direction.

  For this reason, the third partition wall 32 is continuous with the entire circumference of the outer peripheral surface of the front insulator 7 by cooperating with the protrusions 19, and the entire front insulator 7 is interposed between the third partition wall 32 and the first partition wall 31. A concave groove 33 is formed continuously around the circumference, and this concave groove 33 functions as a capturing portion of the present invention. Therefore, since the shavings A shaved at the corners of the ridges 19 are enclosed in the concave grooves 33, the same effects as those of the embodiment can be obtained.

  By the way, in the present embodiment, the inner rotor type brushless motor 1 is embodied. However, the brushless motor of the present invention is not limited to this, and has a configuration in which a press-fitting member is fixed to any one of the inner and outer circumferences of the stator in a press-fitted state. Any brush motor can be used regardless of the type of motor. For this reason, for example, it can be applied to an outer rotor type brushless motor that rotatably supports the rotor on the outer peripheral side of the stator, or it can be applied to a stepping motor, a switched reluctance motor, or an AC motor using a commercial power source, These motors are also included in the brushless motor of the invention.

Hereinafter, another example embodied in the outer rotor type brushless motor will be briefly described.
There are two types of outer rotor type brushless motors with different rotor support structures. As schematically shown in FIG. 12, one motor 41 adopts a configuration in which the rotor 44 is rotatably supported by another member regardless of the stator 42, and the other motor 51 schematically shows as shown in FIG. The rotor 56 is rotatably supported via the stator 52.

  Therefore, while comparing the configuration of these motors 41 and 51 with the inner rotor type brushless motor 1 of the embodiment shown in FIG. 11, the press-fitted state of the press-fitting members 43 and 53 with respect to the respective stators 42 and 52 and the pockets 46 and 58 ( The formation state of the capturing part) will be described.

  First, as described in the embodiment, the inner rotor type brushless motor 1 shown in FIG. 11 has a housing 2 fixed as a press-fitting member on the outer peripheral side of the stator 3 in a press-fitted state, and the rotor 4 is disposed on the inner peripheral side of the stator 3. Has been. Then, as indicated by a two-dot chain line, the stator 3 corresponds to six protrusions 19 (only one is shown) that are in sliding contact with the inner peripheral surface of the housing 2 when the outer periphery of the stator 3 (core 6) is press-fitted. A pocket 20 is formed on the outer periphery of the (front insulator 7).

  On the other hand, in the outer rotor type brushless motor 41 shown in FIG. 12, a fixed shaft 43 is fixed as a press-fitting member on the inner peripheral side of the stator 42 in a press-fitted state, and the rotor 44 is disposed on the outer peripheral side of the stator 42 and is not shown. The bearing member is rotatably supported. In this case, the fixed shaft 43 functions similarly to fix and hold the stator 42 although the relationship between the inner and outer circumferences of the stator 42 is reversed from that of the housing 2 in FIG. When the fixed shaft 43 is press-fitted into the stator 42, a plurality of ridges 45 (only one is shown) formed on the inner periphery of the stator 42 are in sliding contact with the outer peripheral surface of the fixed shaft 43. Cutting residue A is generated at the corner on the front side of the press-fitting.

  Therefore, in this case, the pockets 46 are respectively formed on the front side of the press-fitting from the corners of the protrusions 45 on the inner peripheral surface of the stator 42. Thus, when the stator 42 is fitted onto the fixed shaft 43 and press-fitted from above (the lower part corresponds to the press-fitting front side), each pocket 46 is always positioned directly below the location where the scrap A is generated. Therefore, although not redundantly described, the generated scrap A can be reliably captured in the pocket 46, and the same effect as the embodiment can be achieved.

  On the other hand, in the outer rotor type brushless motor 51 shown in FIG. 13, the stator 52 is fixed and held by a fixing member (not shown), and a bearing holding member 53 is fixed as a press-fitting member on the inner peripheral side of the stator 52 in a press-fitted state. A rotor 56 is rotatably supported on the outer peripheral side of the stator 52 via a rotating shaft 55 by a bearing 54 fitted in the bearing holding member 53. The bearing holding member 53 in this case has a function of guiding the rotation of the rotor 56 in cooperation with the bearing 54 and the rotation shaft 55.

  As in the case shown in FIG. 12, when the bearing holding member 53 is press-fitted into the stator 52, a plurality of protrusions 57 (only one place is shown) formed on the inner periphery of the stator 52. The scrap A comes into sliding contact with the outer peripheral surface and is generated at the corner of the protrusion 57 on the front side of the press-fitting. Accordingly, pockets 58 are respectively formed on the front side of the press-fitting from the corners of the protrusions 57 on the inner peripheral surface of the stator 52. Thus, when the stator 52 is fitted into the bearing holding member 53 and press-fitted from above (the lower part corresponds to the press-fitting front side), the shavings A generated at the corners of the protrusions 57 are located directly below the pockets. In this case, the same effect as the embodiment can be achieved.

  Although the description of the embodiment is finished above, the aspect of the present invention is not limited to the embodiment and other examples. For example, regarding the specifications of the structure and material of each part of the motor 1, 41, 51, the motor 1, You may change suitably according to the use etc. of 41,51.

  Moreover, in the said embodiment, although the protrusion 19 was formed in the outer peripheral surface of the core 6 of the stator 3, and each protrusion 19 was slidably contacted to the inner peripheral surface of the housing 2 at the time of the press fit, it is not restricted to this. For example, the protrusion 19 may be omitted, and the flat core 6 may be press-fitted while being in sliding contact with the inner peripheral surface of the housing 2. Even in this case, for example, by applying the first partition wall 31 described with reference to FIG. 9, it is possible to prevent the scraps A from being scattered in the housing 2.

  In the above embodiment, the inner peripheral surface of the housing 2 is flat. However, even if a concave groove or a ridge that engages with each ridge 19 on the stator 3 side is formed on the inner peripheral surface, the relative rotation is restricted. Good. In this case, the rotation of the stator 3 does not occur even if the press-fit is loosened, but there is a case where a circumferential play occurs between the housing 2 and the stator 3. For this reason, it is important to secure a sufficient press-fitting allowance, and rattling can be prevented by applying the present invention.

1 Inner rotor type brushless motor 2 Housing (press-fit member)
3, 42, 52 Stator 4, 44, 56 Rotor 6 Core 7 Front insulator 14 Permanent magnet 19, 45, 57 Projection (projection)
20,46,58 pocket (capture part)
DESCRIPTION OF SYMBOLS 21 1st partition 22 2nd partition 31 1st partition 32 3rd partition 33 Concave groove 41,51 Outer rotor type brushless motor A Cutting scrap

Claims (9)

A rotor having a press-fitting member fixed in a press-fitted state to one of the inner and outer circumferences of a stator formed by winding a winding around a core, and having a rotating shaft and a permanent magnet concentric with the stator on the other inner and outer circumferences of the stator In a brushless motor that applies a rotational force to the rotor by generating a magnetic field by energizing the windings of the stator,
A brushless motor, wherein a capture portion that captures scraps generated by sliding contact between the stator and the press-fitting member is formed on a surface of the stator facing the press-fitting member. The said capture | acquisition part was formed in the press injection | emission front side rather than the generation | occurrence | production site | part of the said cutting waste by the said sliding contact in the front-back direction with respect to the said press injection member on the opposing surface of the said stator. Brushless motor. The stator and the press-fitting member partially slidably contact at the time of the press-fitting in a circumferential direction orthogonal to the press-fitting front-rear direction
3. The brushless motor according to claim 2, wherein the capturing portion is formed in a region corresponding to at least a sliding contact portion with the press-fitting member in a circumferential direction on the facing surface of the stator. The capturing part is formed of a first partition wall that opposes the front side of the press-fitting to the generation site of the shavings due to the sliding contact, and prevents the scraps from scattering forward of the press-fitting. The brushless motor according to claim 3. The capturing part is formed by the first partition and a second partition that is located on both sides of the first partition in the circumferential direction and prevents the scraps from being scattered in the circumferential direction. The brushless motor according to claim 4. An insulator that keeps insulation between the core and the winding is fixed to at least the press-fitting front side of the stator,
The brushless motor according to claim 2, wherein the capturing part is formed in the insulator. The insulator capturing portion protrudes closer to the press-fitting member than the sliding contact portion of the stator with respect to the press-fitting member, and presses the press-fitting member with elasticity in a press-fitted state between the stator and the press-fitting member. The brushless motor according to claim 6. The brushless motor according to claim 4, wherein the first partition wall is continuous with the entire circumference of the facing surface of the stator. The stator has a plurality of projecting portions formed at intervals in the circumferential direction in sliding contact with the press-fitting member,
The capture part is continuous with the entire circumference of the opposing surface of the stator by cooperating with the protrusions on the first partition and the press-fitting rear side of the first partition. The brushless motor according to claim 8, wherein the brushless motor is a concave groove formed by a third partition wall that prevents scattering to the back of the press-fitting.

Images