JP2005253293A - Motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a motor in which a stator core can be fixed easily in a housing and to particularly provide an inner rotor motor. <P>SOLUTION: The motor includes a cylindrical housing 2 having protruding stripes 21 of a crest-like section, a stator core 32 in which a plurality of core pieces 31 having a core back 31a and teeth 31b are coupled through a coupling part, and each coupling part is bent to be annularly formed. The opposed surfaces of the core pieces 31 of both the ends of the stator core 32 are brought into contact with the protruding stripes 21, and disposed in the housing 2. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention belongs to a motor, particularly an inner rotor motor.

  2. Description of the Related Art Conventionally, a stator core in an inner rotor motor is known in which a plurality of core pieces C1a are formed from a core precursor C1 connected through thin connection portions C1b as shown in a plan view in FIG. . This core precursor is obtained by punching a plate made of a magnetic material and laminating a plurality of sheets as shown in a perspective view in FIG. Each core piece C1a is composed of a core back Y and a tooth T, and a not-shown resin insulator is attached from both thickness directions, and then a not-shown conducting wire is wound around the tooth T. And each connection part is bent so that the circumferential direction end surface of the core back | bag Y of both ends may be match | combined, and it is deform | transformed cyclically | annularly, and it becomes stator core S1.

  The stator core S1 is fixed in a cylindrical housing H1 as shown in a radial sectional view in FIG. As a fixing means in this case, press-fitting and an adhesive are known.

  Further, as shown in a plan view in FIG. 11, another motor has a protrusion C2b for each portion connecting a plurality of core pieces C2a, and is wound and laminated to form a stator core S2. FIG. As shown in the cross-sectional view, there is also a method in which the projections C2b are press-fitted into the same number of recesses H2a provided in the housing H2 as the projections C2b, respectively, and the stator core S2 is fixed to the housing.

JP 2001-008388 A JP 2002-095193 A

  However, in the case of press-fitting, if the press-fitting margin is too small, the surface pressure applied to the inner peripheral surface of the housing and the outer peripheral surface of the stator core is reduced, and the concentricity between the two is deteriorated, so that vibration and noise during rotation increase. . Conversely, if the press-fit margin is too large, when inserting the stator core into the housing, galling will occur at the entrance of the housing, which may cause rattling during rotation, and the magnetic field will be circumferential in the circumferential direction due to the uneven pitch of the slots after press-fit. It becomes non-uniform and the characteristics deteriorate.

  Further, in the case of using an adhesive, it is necessary to temporarily fix the stator core in the housing by some means until the adhesive is dry, and it is also necessary to take fire prevention measures because the adhesive is flammable.

  Furthermore, in fixing with the stator core protrusion and the housing recess, the housing must have recesses as many as the number of core pieces, and the press-fit margin cannot be adjusted. .

  Therefore, an object of the present invention is to provide a motor capable of easily and reliably fixing a stator core in a housing.

  In order to solve the problem, a motor according to the present invention includes a housing having a cylindrical portion having at least one axial end opened, and a plurality of core pieces connected in a row through connecting portions, and bent at each connecting portion. A stator core disposed in the housing in an annular shape so that an outer peripheral surface of each core piece is in contact with an inner peripheral surface of the cylindrical portion, a winding wound around the core piece, and the housing And a rotor having a cylindrical rotor magnet so as to face the stator core, and a long protrusion in the axial direction protrudes radially inward in the housing. And the ridges are positioned between the core pieces at both ends of the stator core.

  According to the motor of the present invention, since the outer peripheral length of the stator core is smaller than the inner peripheral length of the housing, the annularly formed stator core can be loosely fitted into the housing. Therefore, no galling occurs. And the convex part of a housing can be inserted and fixed to a mark, and a work process can be simplified. Furthermore, the protrusion provided in the housing also has a means for preventing the stator core from rotating away from the housing.

  A cut surface is formed on the outer peripheral side edge portion of the opposite end portions of the two core pieces at both end positions of the stator core so as to face the protruding line. Furthermore, if the surface projecting radially inward of the ridge and the cut surface are in a parallel positional relationship, the shapes of the fixed end surfaces match and the fixed end surfaces come into contact with each other during rotation. The end portion is not displaced from the ridge, and the ridge and the core back end can be reliably fixed without being damaged.

  Further, if the axial end of the ridge located on the opening side of the cylindrical portion is formed in a tapered shape toward the opening side of the cylindrical portion, the operation of inserting the stator core into the housing is easy. Can be.

  Furthermore, if the ridge is formed by indenting a part of the cylindrical portion inwardly, it can be easily recessed without reducing accuracy without using a complicated method of forming the housing. The shape can be changed by adjusting the pressing force to be recessed.

  According to the motor configured as described above, the stator core can be easily fixed without forcibly press-fitting the housing into the housing or using an adhesive, and the stator core can be prevented from coming off and rotating from the housing. Therefore, the productivity of the motor is improved.

Embodiment 1
A motor according to a first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is an axial sectional view showing a motor according to the embodiment, and FIG. 2 is an AA sectional view in FIG. However, in FIG. 2, the rotating shaft and its peripheral parts are omitted.

  The motor 1 includes a housing 2 having a cylindrical portion with a front end (upper end in the drawing) opened small and a rear end (lower end in the drawing) opened widely, a stator 3 fixed to the inner peripheral surface of the housing 2, A cylindrical yoke 4, a rotating shaft 5, a circuit board 6, and a plate 8 are provided.

  The stator 3 includes a stator core 32 in which a plurality of core pieces 31 are continuous in the circumferential direction, a coil 33 wound around the stator core 32, and insulators 34 and 35 that sandwich the stator core 32 from both sides in the axial direction. Each core piece 31 includes a core back 31a extending in the circumferential direction and teeth 31b protruding radially inward from the center of the core back 31a. The teeth 31b have a T-shape in plan view, and a coil 33 is wound around the T-shaped vertical bar portion.

  The yoke 4 is disposed concentrically with the housing 2 and has a small front end and a large rear end. A cap 7 having a shaft hole at the center is attached to the opening at the rear end. A magnet 9 is fixed to the outer peripheral surface of the yoke 4 so as to face the stator core 32. The yoke 4 is fixed to the rotary shaft 5 by press-fitting the rotary shaft 5 into the opening at the front end and the shaft hole of the cap 7.

  The circuit board 6 is fixed to the rear of the yoke 4 on the inner peripheral surface of the housing 2, and a lead 61 for connecting the coil 33 and an external circuit is attached to the circuit board 6, and a hall element 62 is mounted on the upper surface.

  The rotating shaft 5 passes through the housing 2, the yoke 4, the cap 7, the circuit board 6 and the plate 8 in the axial direction. A front bearing 51 is mounted between the front end opening of the housing 2 and the rotating shaft 5, and a plate 8 having a shaft hole at the center is fixed to the rear end opening, and the shaft hole and the rotating shaft are fixed. By mounting the rear bearing 52 between the rotary shaft 5 and the rotary shaft 5, the rotary shaft 5 is rotatably supported. The rotary shaft 5 is fitted with a resin washer 53 at a position between the front end surface of the yoke 4 and the front bearing 51, and a metal washer 54 and a resin washer 55 at a position between the circuit board 6 and the rear bearing 52, respectively. ing. The metal washer 54 prevents the rotating shaft 5 from coming off.

  Next, a method for manufacturing the stator core 32 and a method for assembling the motor 1 will be described. By punching out the electromagnetic steel sheet with a metal mold, a core precursor 32 ′ in which a plurality of core pieces 31 are connected via a thin connecting portion 31 c as shown in a plan view in FIG. 3 is formed. Each core piece 31 includes a core back 31a formed between the connecting portions 31c and a T-shaped tooth 31b extending vertically from the center of the core back 31a, and a groove ( Alternatively, a positioning portion 31d that forms a mountain (or groove) in bottom view is formed simultaneously with the punching. Each core piece 31 has a line-symmetric shape with the teeth 31b as the center except for the core pieces 31 at both ends. Both end surfaces 32a and 32b of the core precursor 32 'have cut surfaces at the edge portions that become the outer peripheral side when deformed in an annular shape in plan view.

  A plurality of core precursors 32 ′ are stacked in the thickness direction so that the positioning portions 31 d coincide with each other, and then sandwiched between resin-made insulators 34 and 35 from both sides in the axial direction. Then, a coil 33 made of a conductive wire is wound around the teeth 31b. The stator 3 including the stator core 32 and the coil 33 is obtained by bending this at each connecting portion 31 c and deforming it into an annular shape.

  Further, as shown in FIGS. 4 and 5 as an axial cross-sectional view and an enlarged perspective view, the housing 2 is pressed from the outer peripheral surface of the housing 2 toward the radially inner side when the housing is manufactured. A convex strip 21 having a V-shaped cross section that is recessed inward and has a peak at the central axis of the cylindrical portion is provided, and a recess 22 is also provided for positioning when the stator 3 is inserted into the housing 2. It is formed indented inward by pressing one end in the axial direction from the surface. The recess 22 does not need to be located in the same axial direction as the ridge 21 as shown in the drawing, and may be formed in any radial direction of the housing 22.

Then, the front bearing 51 is press-fitted into the housing 2, and the rear bearing 52 is press-fitted into the plate 8. Then, the stator 3 is inserted from the rear of the housing 2, and one axial end of the stator core 32 is brought into contact with the recess 22. When the stator 3 is inserted into the housing 2, both end faces 32 a and 32 b are engaged with the ridges 21, so that the attitude of the stator core 32 with respect to the housing 22 is not interfered by components on the circuit board 6 such as the Hall element 62. It can be determined easily, and rotation of the stator core 32 after insertion is also prevented. At this time, as shown in FIG. 6 as an enlarged view of a portion B in FIG. 2, the ridges 21 of the housing 2 are in contact with both end faces 32a and 32b of the stator 3, and the taper of the ridges 21 is formed in a plan view. The angle θ ₃₂ formed by the portion in contact with the angle θ ₂₁ and the ridge 21 is approximately (θ ₂₁ + 2θ ₃₂ ) = 360 °. Therefore, the surfaces of the ridges 21 that are in contact with both end surfaces 32 a and 32 b and the surfaces of the both end surfaces 32 a and 32 b that are in contact with the ridges 21 are parallel to each other, and the core back 31 a can be more easily fixed to the housing 2. Yes.

  In addition, after inserting the stator 3, the recess 2 and the cut-and-raised portion 23 are provided in the axial direction of the stator 3 by pressing the raised portion 23 in the vicinity of the axial end of the housing 2 on the side where the stator 3 is inserted. The upper and lower ends are fixed to the housing 2. Further, the resin washer 53, the yoke 4 to which the magnet 9 is attached, and the cap are press-fitted into the rotating shaft 5. Then, the rotary shaft 5 is accommodated together with the yoke 4 and the like in the housing 2 to which the stator 3 is fixed, and the tip of the rotary shaft 5 is passed through the front bearing 51. Subsequently, after the circuit board 6 on which the Hall element 62 and the like are mounted is fixed in the housing 2, a metal washer 54 and a resin washer 55 are press-fitted into the rear part of the rotating shaft 5. Then, the housing 1 is sealed by the plate 8 with the rear bearing 52 attached thereto, whereby the motor 1 is obtained.

Embodiment 2
FIG. 7 is an axial sectional view showing a part of the motor of the second embodiment. In the second embodiment, the protrusion 2 is formed in the axial direction in the same manner as the first embodiment, and in addition, the tapered portion 24 is provided at the opening side end where the stator 3 of the protrusion 21 is inserted. Is provided. As a result, the stator 3 can be easily inserted. The insertion of the stator 3 is fixed to the housing 2 by inserting the ridges 21 of the housing 2 as marks as in the first embodiment.

  As mentioned above, although embodiment of the motor according to this invention was described, this invention is not limited to this embodiment, A various deformation | transformation thru | or correction | amendment are possible without deviating from the scope of this invention.

  For example, in the said embodiment, although the front-end | tip location of the protruding item | line 21 of the housing 2 is provided in the outer-diameter direction rather than the height of planar view of the both end surfaces 32a and 32b of the stator 3, the protruding item | line 21 is higher than height. May also have its tip in the inner diameter direction. That is, as shown in FIG. 6, the end faces 32a and 32b of the stator 3 are adjacent to each other, but they may be fixed via the ridges 21 without being adjacent to each other.

  Further, the ridges 21, the recesses 22, and the cut-and-raised portions 23 provided in the housing 2 do not need to be provided in the same axial direction of the housing 2 as illustrated, and may be provided in any of the radial directions of the housing.

1 is an axial sectional view showing a motor according to Embodiment 1. FIG. It is an axial sectional view showing a housing used for the motor. It is an expansion perspective view which shows the principal part of the said housing. It is AA sectional drawing of FIG. It is the B section enlarged view of FIG. It is a top view which shows the precursor of the stator core used for the said motor. FIG. 6 is an axial cross-sectional view showing a main part of a motor according to a second embodiment. It is a top view which shows the precursor of the stator core in the conventional motor. It is a perspective view which shows the state which laminated | stacked the said precursor. It is radial direction sectional drawing which shows the place which fixed the stator core in the conventional motor to the housing. It is a top view which shows the precursor of the stator core in another conventional motor. It is radial direction sectional drawing which shows the place which fixed the stator core in another conventional motor to the housing.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Motor 2 Housing 21 Convex strip 22 Indentation 23 Cut and raised part 24 Tapered part 3 Stator 31 Core piece 32 Stator core 32a, 32b Both end surface 33 Coil 34, 35 Insulator 4 Yoke 5 Rotating shaft 6 Circuit board 7 Cap 8 Plate 9 Magnet

Claims (5)

A housing having a cylindrical portion open at least in one axial direction;
A plurality of core pieces are connected in a row via a connecting portion, and the outer peripheral surface of each core piece is formed in an annular shape so as to contact the inner peripheral surface of the cylindrical portion by being bent at each connecting portion. An arranged stator core;
A winding wound around the core piece;
A rotor having a rotating shaft rotatably supported by the housing and having a cylindrical rotor magnet so as to face the stator core;
The motor is characterized in that an axially long ridge is formed on the housing so as to protrude radially inward, and the ridge is located between both core pieces at both ends of the stator core. .   2. The motor according to claim 1, wherein a cut surface that faces the convex strip is formed on an outer peripheral side edge portion of an end portion of the core pieces at both ends of the stator core facing each other.   The motor according to claim 2, wherein a surface projecting radially inward of the ridge and the cut surface are in a parallel positional relationship.   4. The axial end portion of each of the ridges located on the opening side of the cylindrical portion is formed in a tapered shape toward the opening side of the cylindrical portion. 5. The motor according to Crab.   The motor according to claim 1, wherein the ridge is formed by indenting a part of the cylindrical portion inward.

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