JP6187314B2 - Electric motor - Google Patents

Description

  The present invention relates to an electric motor including an insulating cover that partitions a bracket and a terminal and insulates each of the bracket and the terminal.

  As a conventional electric motor, an inner rotor type electric motor is known in which a rotor is rotatably disposed inside a stator. The electric motor is used as, for example, a brushless DC motor for rotationally driving a blower fan mounted on an air conditioner.

  As a conventional brushless DC motor, the stator has a bottomed cylindrical outline formed by resin molding except for the inner peripheral surface of the stator core around which the stator winding is wound via an insulator. A plurality of terminals connected to the stator winding are erected in the axial direction at intervals in the circumferential direction of the end surface on the axial end surface of the outer shell. A circuit board on which an electric circuit for controlling energization to the stator winding is formed is placed on a part of the axial end surface of the outer shell. In addition, some of the plurality of terminals protrude from the surface of the circuit board and are electrically connected to the circuit board. On the outer peripheral surface of the outer shell, a bottomed cylindrical bracket is press-fitted so as to cover the axial end surface of the outer shell and the circuit board.

  An insulating cover that divides the bracket and the plurality of terminals and insulates each other is disposed between the bracket and the plurality of terminals. The insulating cover has an upper surface wall that covers the upper side of the plurality of terminals, and an outer periphery that extends downward from the bracket-side end of the upper surface wall and contacts the axial end surface of the outer shell and covers the side of the plurality of terminals on the bracket side It is formed in an L-shaped cross section including a wall and a pair of side walls integrally formed at both ends of the top wall and the outer peripheral wall and extending downward from the top wall (see, for example, Patent Document 1). For example, the insulating cover of Patent Document 1 includes a terminal that is electrically connected to the circuit board and protrudes from the surface of the circuit board, and a terminal that is not electrically connected to the circuit board and protrudes from the outer axial end surface. Covering. The insulating cover includes a plurality of insulating pieces extending downward from the lower end portion of the outer peripheral wall, and a storage portion for storing the plurality of insulating pieces is provided on the outer peripheral surface of the outer shell at positions corresponding to the plurality of terminals. ing. Each side wall is formed to have the same length so as not to hit the surface of the circuit board, and is not electrically connected to the circuit board, and around the terminals protruding from the outer axial end face, the circuit board Therefore, a gap is formed between the side wall of the insulating cover and the axial end surface of the outer shell.

  The conventional brushless DC motor configured as described above is applied to the upper surface wall of the insulating cover from the outside due to the influence of the gap formed between the side wall of the insulating cover and the axial end surface of the outer shell when the electric motor is assembled. When a pressing force is applied toward the axial end surface of the outer shell, the inner peripheral side of the upper surface wall of the insulating cover is deformed so as to sink into the axial end surface side of the outer shell. Due to the deformation of the insulating cover, the outer peripheral wall of the insulating cover protrudes outward from the outer peripheral surface of the outer shell, and the insulating piece provided at the lower end of the outer peripheral wall is located outside the outer peripheral surface storage portion of the outer shell. It may be in a protruding state. If the bracket is pressed into the outer peripheral surface of the outer shell in this state, the outer peripheral wall or locking piece of the insulating cover may be sandwiched between the bracket and the outer peripheral surface of the outer shell and destroyed, leading to poor insulation between the bracket and the terminal. there were.

JP 2013-201809 A

  In view of the above problems, an object of the present invention is to provide an electric motor that can prevent deformation of an insulating cover during assembly of the electric motor.

In order to solve the above problems, an electric motor according to the present invention includes a bottomed cylindrical stator having an outer shape formed by molding, a circuit board placed on an axial end surface of the outer shape , an axial end surface, and a circuit. A bottomed cylindrical bracket press-fitted to the outer peripheral surface of the outer shell so as to cover the substrate , a plurality of terminals erected on the axial end surface in the circumferential direction of the axial end surface, and the bracket; An insulating cover for partitioning a plurality of terminals and insulating each of the terminals, the insulating cover including an upper surface wall covering the upper side of the terminal and a shaft extending downward from an end of the upper surface wall on the bracket side. An outer peripheral wall that contacts the end face in the direction and covers the side of the terminal on the bracket side, and a side wall that is integrally formed at one end of the upper surface wall and the outer peripheral wall, extends downward from the upper surface wall, and contacts the axial end face It is formed in an L-shaped cross-section having a side wall , Among the plurality of terminals, it is formed so as to cover the side of the circumferential direction of not electrically connected to the circuit board terminal, the outer peripheral wall and side walls, the distance between the top and upper wall of the inner surface of the terminal is given It has the height used as the space | interval of.

Further, in the electric motor of the present invention, the insulating cover includes an extension portion that extends from the end portion on the opposite side of the side wall bracket to the upper surface wall in the circumferential direction so as to extend in the circumferential direction and contacts the end surface in the axial direction. It is provided with.

Furthermore, the electric motor of the present invention covers a cylindrical stator with a bottom formed by molding, a circuit board placed on the axial end surface of the outer casing, and the axial end face and the circuit board. A cylindrical bracket with a bottom that is press-fitted into the outer peripheral surface of the outer shell, a plurality of terminals erected on the axial end surface at intervals in the circumferential direction of the axial end surface, and the bracket and the plurality of terminals are partitioned And an insulating cover for insulating each of the insulating cover, and the insulating cover extends downward from the bracket-side end of the upper surface wall and covers the upper end of the terminal. An outer peripheral wall that contacts and covers the side of the terminal on the bracket side, and is formed in an L-shaped cross section. The axial end surface extends upward from the axial end surface to at least the inner surface on one end side of the upper surface wall. abuts with the abutment portion, the abutment portion includes a plurality Among the terminals, as well as contact with the inner surface of the upper wall of the not electrically connected to the circuit board terminal side, the interval between the top and upper wall of the inner surface of the pin and having a height which is a predetermined distance .

According to the electric motor of the present invention, the insulating cover extends downward from the bracket-side end portion of the upper surface wall, covering the upper side of the terminal, contacts the end surface in the axial direction, and extends to the side of the terminal on the bracket side. The outer peripheral wall is formed to have an L-shaped cross section including an outer peripheral wall that covers and a side wall that is integrally formed at one end of the upper surface wall and the outer peripheral wall and extends downward from the upper surface wall and contacts the end surface in the axial direction . Of the plurality of terminals, formed so as to cover the sides in the circumferential direction of the terminals that are not electrically connected to the circuit board. The outer peripheral wall and the side wall have a predetermined distance between the upper end of the terminal and the inner surface of the upper surface wall. By having a height to be spaced, when the motor is assembled, a force is applied from the outside to the upper end wall of the insulating cover toward the axial end surface of the outer shell around the terminals that are not electrically connected to the circuit board. The side wall is in contact with the axial end surface of the outer shell. Since it is, it is possible to prevent the insulating cover is deformed.

Further, according to the electric motor of the present invention, the insulating cover integrally extends from the end opposite to the bracket of the side wall to the upper surface wall in the circumferential direction so as to contact the end face in the axial direction. By providing the extension portion , the side wall is formed in an L-shaped cross section, so that the strength of the side wall can be improved.

Further, according to the electric motor of the present invention, the insulating cover includes an upper surface wall that covers the upper side of the terminal, and extends downward from the bracket-side end of the upper surface wall so as to contact the end surface in the axial direction. And an outer peripheral wall that covers the outer wall, and is formed in an L-shaped cross section, and has an abutting portion that extends upward from the axial end surface and abuts against at least one inner surface of the upper surface wall. The abutting portion abuts the inner surface of the upper surface wall on the terminal side that is not electrically connected to the circuit board among the plurality of terminals, and has a height at which the distance between the upper end of the terminal and the inner surface of the upper surface wall is a predetermined distance. When the motor is assembled, even if a force is applied from the outside to the upper surface wall of the insulating cover toward the axial end surface of the outer shell around the terminals that are not electrically connected to the circuit board , the contact portion Is in contact with the inner surface of one end of the top wall Runode, it is possible to prevent the insulating cover is deformed.

It is explanatory drawing which shows the electric motor by this invention, (a) is a top view, (b) is AA sectional drawing of (a). 1 is a partially exploded perspective view showing an electric motor according to the present invention. It is an external view which shows the B arrow of the insulating cover in FIG. It is a disassembled perspective view which shows the stator and insulation cover of the electric motor by this invention. It is explanatory drawing which shows the state which attached the insulating cover which shows the electric motor by this invention, (a) is a partial exploded perspective view, (b) is the elements on larger scale, which expanded the C section shown to (a), (c). FIG. 2 is a partial enlarged cross-sectional view in which a portion D shown in FIG. It is explanatory drawing which shows 2nd Embodiment of the state which attached the insulating cover which shows the electric motor by this invention, (a) is a partial exploded perspective view, (b) is the elements on larger scale which expanded E part shown to (a). A perspective view and (c) are partial expanded sectional views which expanded D section shown in Drawing 1 (b).

  Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. 1 to 5 are diagrams illustrating the electric motor according to the present embodiment. The electric motor M in this embodiment is an inner rotor type electric motor, and is used, for example, as a brushless DC motor for rotationally driving a blower fan mounted on an air conditioner.

  As shown in FIGS. 1 and 2, the electric motor M includes a bottomed cylindrical stator 1 and a rotor 2 having a rotor output shaft 21 at the center of the stator 1 and rotatably disposed. The stator 1 is molded with resin except for the inner peripheral surface 121 of the stator core 12 to form a bottomed cylindrical outer shell 11.

  The stator 1 is provided with a bottomed cylindrical first bracket 31 that is integrally embedded in the center of the lower end surface 111 in the axial direction of the outer shell 11. The first bracket 31 is made of, for example, a galvanized steel plate, and houses one bearing 22 that supports the rotor output shaft 21 of the rotor 2. Further, the circuit board 4 is mounted on the stator 1 on the upper end surface 112 in the axial direction on the opening 11 a side of the outer shell 11, and covers the circuit board 4 and the upper end surface 112 in the axial direction on the outer peripheral surface 113 of the outer shell 11. A fixed bottomed cylindrical second bracket 32 is provided. Similarly to the first bracket 31, the second bracket 32 is made of, for example, a galvanized steel plate, and has a bottomed cylindrical bearing housing portion 321 protruding in the axial direction for housing the other bearing 23 at the center. ing.

  Further, the stator 1 includes a stator core 12 made of a laminate of electromagnetic steel plates, an insulator 13 for insulatingly covering the stator core 12, and a stator winding 14 wound around a tooth portion (not shown) of the stator core 12 via the insulator 13. And. The rotor 2 is attached to a rotor output shaft 21 that is rotatably supported by bearings 22 and 23, a disk-shaped rotor core 24 that is coaxially attached to the rotor output shaft 21, and an outer peripheral side of the rotor core 24. A plurality of plate-like rotor magnets 25 are provided. The stator 1 and the rotor 2 configured as described above have the inner peripheral surface 121 (the tip surface of the tooth portion) of the stator core 12 opposed to the outer peripheral surface 251 of the rotor magnet 25 with a predetermined interval (so-called air gap). Has been placed.

  As shown in FIGS. 2 and 4, a press-fitting step surface 114 for press-fitting the second bracket 32 is provided on the outer peripheral surface 113 of the outer shell 11 on the upper end surface 112 side in the axial direction. The press-fitting step surface 114 is formed one step lower in the radial direction of the stator 1 so that the outer peripheral surface 322 of the second bracket 32 and the outer peripheral surface 113 of the outer shell 11 are flush with each other when the second bracket 32 is press-fitted. Yes. Further, the press-fitting step surface 114 has an outer diameter slightly larger than the inner diameter of the second bracket 32, so that the second bracket 32 can be press-fitted into the press-fitting step surface 114.

  On the upper end surface 112 in the axial direction of the outer shell 11, five terminals 151 to 155 erected at intervals in the circumferential direction of the upper end surface 112 in the axial direction are provided. The four terminals 151 to 154 are connected to the stator winding 14 embedded in the outer shell 11, and the terminals 151 to 153 are soldered to the circuit board 4 and electrically connected to the U of the stator winding 14. Phase, V phase, and W phase terminals, and the terminal 154 is an N phase terminal that is not electrically connected to the circuit board 4. The remaining one terminal 155 is a terminal that fixes the circuit board 4 to the upper end surface 112 in the axial direction.

  Further, on the upper end surface 112 in the axial direction of the outer shell 11, three bosses 161 to 163 for placing the circuit board 4 in a positioned state are provided. Further, the two bosses 161 and 162 also function as bosses for positioning the insulating cover 5 attached to the upper end surface 112 in the axial direction.

  As shown in FIGS. 2 to 5, the insulating cover 5 is a cover made of a resin such as PBT (polybutylene terephthalate) that partitions the second bracket 32 and the four terminals 151 to 154 and insulates them. The insulating cover 5 includes an upper surface wall 51 that covers the upper side of the four terminals 151 to 154, an outer peripheral wall 52 that extends downward from the end 511 on the second bracket 32 side of the upper surface wall 51, and the upper surface wall 51 and the outer peripheral wall 52. A side wall 53 is formed integrally with one end (terminal 154 side) and extends downward from the top wall 51. The insulating cover 5 includes a side wall 54 that is integrally formed with the other end (on the terminal 151 side) of the upper surface wall 51 and the outer peripheral wall 52 and extends downward from the upper surface wall 51. The insulating cover 5 has an annular fan shape and is formed in an L-shaped cross section, and an upper surface wall 51, an outer peripheral wall 52, a side wall 53, and a side wall 54 are integrally formed.

  The top wall 51 is provided with two fitting holes 512 and 513 formed so as to face the two bosses 161 and 162. The insulating cover 5 is positioned by press-fitting two fitting holes 512 and 513 into the two bosses 161 and 162. The outer peripheral wall 52 has a lower end portion 521 that abuts the upper end surface 112 in the axial direction and covers the sides of the four terminals 151 to 154 on the second bracket 32 side (the outer peripheral surface 322 side of the second bracket 32). Yes. The side wall 53 has a lower end portion 533 abutting against the upper end surface 112 in the axial direction and covers the side of the terminal 154 in the circumferential direction. The side wall 54 is formed in a length that does not hit the surface 41 of the circuit board 4 and covers the side of the terminal 151 in the circumferential direction. Further, as shown in FIG. 3, the side wall 53 is integrally formed on the insulating cover 5 in the circumferential direction from the end 531 opposite to the second bracket 32 of the side wall 53 toward the upper surface wall 51. The extended portion 532 is provided. The lower end portion of the extended portion 532 also comes into contact with the upper end surface 112 in the axial direction. Furthermore, as shown in FIG. 5, the outer peripheral wall 52 and the side wall 53 have a height H at which the distance between the upper ends of the four terminals 151 to 154 and the inner surface 514 of the upper surface wall 51 is a predetermined distance T. Yes. The formation of the side wall 53 having the height H ensures the above-described predetermined interval T even if there is a manufacturing variation in the insulating cover 5, so that the side wall 53 is lifted from the upper end surface 112 in the axial direction. do not become.

  Furthermore, the insulating cover 5 includes four insulating pieces 522 extending downward from the lower end 521 of the outer peripheral wall 52. The four insulating pieces 522 are formed at positions corresponding to the four terminals 151 to 154 at intervals in the circumferential direction of the outer peripheral wall 52. The four insulating pieces 522 are pieces formed to protrude slightly outward in the radial direction from the outer peripheral wall 52 with the same curvature as the outer peripheral wall 52.

  On the other hand, on the press-fitting step surface 114 of the outer shell 11, as shown in FIG. 4, on the upper end surface 112 side of the press-fitting step surface 114, four storage portions 115 in which four insulating pieces 522 are stored have four terminals 151-1. It is provided at a position corresponding to 154. The four storage portions 115 are formed of grooves that match the shapes of the four insulating pieces 522 and are formed one step lower in the radial direction from the press-fitting step surface 114. The four storage portions 115 are formed such that the radial depth is greater than the thickness of the insulating piece 522, and the outer peripheral surface of the insulating piece 522 is disposed on the inner side of the press-fitting step surface 114. By forming the four insulating pieces 522, an insulating distance between the four terminals 151 to 154 and the second bracket 32 can be secured.

  When assembling the electric motor M configured as described above, the circuit board 4 is aligned so as to be fitted into the three bosses 161 to 163, and the four terminals 151 to 153 and 155 are projected from the circuit board 4. . As a result, the circuit board 4 is mounted on the upper end surface 112 of the outer shell 11, and the four terminals 151 to 153 and 155 are soldered. Next, the fitting holes 512 and 513 of the upper surface wall 51 of the insulating cover 5 are press-fitted into the two bosses 161 and 162, and the four insulating pieces 522 are stored in the four storage portions 115. As a result, the insulating cover 5 is attached to the upper end surface 112 side of the outer shell 11.

  At this time, the upper surface of the four terminals 151 to 154 is covered by the upper surface wall 51. Further, the side of the four terminals 151 to 154 on the second bracket 32 side is covered by the outer peripheral wall 52, and the lower end portion 521 of the outer peripheral wall 52 is in contact with the upper end surface 112 in the axial direction of the outer shell 11. Further, the side wall 53 covers the side of the terminal 154 in the circumferential direction, and the lower end 533 of the side wall 53 is in contact with the upper end surface 112 of the outer shell 11 in the axial direction. Further, the periphery of the terminal 154 is a place where the circuit board 4 does not exist, and a gap having a height H is formed between the inner surface 514 of the upper surface wall 51 and the upper end surface 112 in the axial direction of the outer shell 11.

  As a result, the upper end surface 112 in the axial direction of the outer shell 11 is externally connected to the upper surface wall 51 of the insulating cover 5 around the terminal 154 where a gap is formed between the upper surface wall 51 and the upper end surface 112 in the axial direction of the outer shell 11. Even when a pressing force is applied, the lower end portion 533 of the side wall 53 is in contact with the upper end surface 112 in the axial direction of the outer shell 11, so that the inner peripheral side of the upper surface wall 51 of the insulating cover 5 is the outer shell. 11 can be prevented from being deformed so as to sink into the axial upper end surface 112 side. Therefore, as in the prior art, the outer peripheral wall 52 of the insulating cover 5 protrudes outwardly from the press-fitting stepped surface 114 of the outer shell 11, and the insulating piece 522 provided at the lower end 521 of the outer peripheral wall 52 has the outer shell 11. The press-fitting stepped surface 114 does not fall out of the storage portion 115. For this reason, when the second bracket 32 is press-fitted into the press-fitting step surface 114 of the outer shell 11, the outer peripheral wall 52 and the insulating piece 522 of the insulating cover 5 are sandwiched between the second bracket 32 and the press-fitting step surface 114 of the outer shell 11 and destroyed. Insulation failure between the second bracket 32 and the terminal 154 can be prevented.

  Further, since the side wall 53 of the insulating cover 5 has an extension 532 formed by extending the side wall 53 and is formed in an L-shaped cross section, the strength of the side wall 53 can be improved. Therefore, even if a pressing force is applied to the upper surface wall 51 of the insulating cover 5 from the outside toward the upper end surface 112 in the axial direction of the outer shell 11, the side wall 53 of the insulating cover 5 is not destroyed.

  In the electric motor M according to the first embodiment described above, the insulating cover 5 is integrally formed at one end (on the terminal 154 side) of the upper surface wall 51 and the outer peripheral wall 52, and extends downward from the upper surface wall 51 to form the outer shell 11. Although the side wall 53 which contacts the upper end surface 112 in the axial direction is provided, the present invention is not limited to this. For example, in the electric motor M according to the second embodiment, instead of forming the side wall 53 on the insulating cover 5, as shown in FIG. 6, the electric motor M is integrally formed on the upper end surface 112 in the axial direction of the outer shell 11. A contact portion 6 such as a side wall or a boss that extends upward from the upper end surface 112 in the axial direction and abuts at least the inner surface 514 on one end side (terminal 154 side) of the upper surface wall 51 is provided. Even if it does in this way, a deformation | transformation of the insulating cover 5 can be prevented at the time of the assembly of the electric motor M similarly to the above-mentioned 1st Embodiment. In another embodiment, instead of forming the side wall 53 on the insulating cover 5, a boss is provided between the terminal 153 and the terminal 154 on the upper end surface 112 in the axial direction of the outer shell 11, and this boss is opposed to the boss. As described above, even if the fitting hole is provided in the upper surface wall 51 of the insulating cover 5, the deformation of the insulating cover 5 can be prevented at the time of assembling the electric motor M as in the above-described embodiment.

DESCRIPTION OF SYMBOLS 1 Stator 11 Outer 11a Opening 111 Lower end surface 112 Upper end surface 113 Outer peripheral surface 114 Press-fitting level difference surface 115 Storage part 12 Stator core 121 Inner peripheral surface 13 Insulator 14 Stator winding 151-155 Terminal 161-163 Boss 2 Rotor 21 Rotor output shaft 22 Bearing DESCRIPTION OF SYMBOLS 23 Bearing 24 Rotor core 25 Rotor magnet 251 Outer peripheral surface 31 1st bracket 32 2nd bracket 321 Bearing storage part 322 Outer peripheral surface 4 Circuit board 41 Surface 5 Insulation cover 51 Upper surface wall 511 End part 512,513 Fitting hole 514 Inner surface 52 Outer peripheral wall 521 Lower end portion 522 Insulating piece 53 Side wall 531 End portion 532 Extension portion 533 Lower end portion 54 Side wall 6 Abutting portion H Height T Interval M Electric motor

Claims (3)

A bottomed cylindrical stator having an outer shape formed by molding, a circuit board placed on an axial end surface of the outer shape, and an outer peripheral surface of the outer shell so as to cover the axial end surface and the circuit board A bottomed cylindrical bracket press-fitted into a plurality of terminals, a plurality of terminals erected on the axial end face in the circumferential direction of the end face in the axial direction, and the bracket and the plurality of terminals are partitioned And an electric motor provided with an insulating cover for insulating each of them,
The insulating cover extends downward from the bracket-side end of the upper surface wall and covers the upper side of the terminal, and contacts the end surface in the axial direction and covers the side of the terminal on the bracket side. Formed in an L-shaped cross section including an outer peripheral wall, a side wall that is integrally formed at one end of the upper surface wall and the outer peripheral wall, extends downward from the upper surface wall, and contacts the end surface in the axial direction;
The side wall is formed so as to cover a circumferential side of a terminal that is not electrically connected to the circuit board among the plurality of terminals.
The electric motor according to claim 1, wherein the outer peripheral wall and the side wall have a height at which a distance between an upper end of the terminal and an inner surface of the upper surface wall is a predetermined distance. The insulating cover includes an extension portion that integrally extends from the end portion of the side wall opposite to the bracket to the upper surface wall in the circumferential direction and contacts the end surface in the axial direction. the electric motor according to claim 1, characterized in that the. A bottomed cylindrical stator having an outer shape formed by molding, a circuit board placed on an axial end surface of the outer shape, and an outer peripheral surface of the outer shell so as to cover the axial end surface and the circuit board A bottomed cylindrical bracket press-fitted into a plurality of terminals, a plurality of terminals erected on the axial end face in the circumferential direction of the end face in the axial direction, and the bracket and the plurality of terminals are partitioned And an electric motor provided with an insulating cover for insulating each of them,
The insulating cover extends downward from the bracket-side end of the upper surface wall and covers the upper side of the terminal, and contacts the end surface in the axial direction and covers the side of the terminal on the bracket side. An outer peripheral wall and a L-shaped cross section,
The axial end surface includes a contact portion that extends upward from the axial end surface and contacts at least an inner surface on one end side of the upper surface wall,
The abutting portion abuts against an inner surface of the upper surface wall on a terminal side that is not electrically connected to the circuit board among the plurality of terminals, and a distance between an upper end of the terminal and an inner surface of the upper surface wall is predetermined. An electric motor characterized by having a height that becomes an interval of.

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