JP2006129650A - Motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a motor that has high concentricity with a rotor and a stator even when split cores are used and that does not reduce the holding strength of a bearing even when a cylindrical portion for holding the bearing is formed on a bearing holder. <P>SOLUTION: The motor 1 comprises a motor casing 2 made of a press-formed material of an iron-system metal, a stator 3 provided with a plurality of split cores 31 fixed annularly to the motor casing 2, a rotor 4 provided with a rotating shaft 41, and first and second bearings 5, 6 that support the rotating shaft 41 rotatably at the sides of first and second open ends 21, 22 of the motor casing 2. Fitting projections 91, 96 are formed at one side and fitting holes 92, 97 into which the fitting projections 91, 96 are fitted are formed on the other side between a first holder side flange portion 76 and a first casing side flange portion 26, and between a second holder side flange portion 87 and a second casing side flange portion 27. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a motor fixed to an inner peripheral surface of a motor case.

  Among various motors, a three-phase inner rotor type DC brushless motor includes a motor case 2 ′ having a first open end 21 ′ and a second open end 22 ′ at both ends, and an inner periphery of the motor case 2 ′. A stator 3 'having a plurality of split cores 31' fixed in an annular shape with respect to the surface, and a rotor 4 'having a rotating shaft 41' extending in the axial direction inside the stator 3 '. The rotating shaft 41 'can be rotated by a first bearing 5' and a second bearing 6 'disposed on the first open end 21' side and the second open end 22 'side of the motor case 2'. It is supported by.

Here, the first bearing 5 'and the second bearing 6' are each a first bearing holder 7 'attached to the motor case 2' so as to cover the first open end 21 'of the motor case 2'. And the second bearing holder 8 '. Further, the first bearing holder 7 'and the second bearing holder 8' are fitted and fixed to the motor case 2 'by fitting portions 11', 12 ', 13' and 14 '. By fixing, the motor case 2 ′ is positioned with the first bearing holder 7 ′ and the second bearing holder 8 ′, thereby adjusting the coaxiality between the rotor 4 ′ and the stator 3 ′ ( For example, see Patent Document 1).
JP 2003-111335 A

  Since such a motor uses the split core 31 ', there is an advantage that the line area ratio of the winding is high, whereas the split core 31' alone cannot be fixed in the motor case 2 '. is there. Therefore, the split core 31 'needs to be fixed to the inner peripheral surface of the motor case 2' by a method such as an adhesive, a fixing pin, a resin mold, or shrink fit, so that the coaxiality between the rotor 4 'and the stator 3' is increased. Is greatly affected by the machining accuracy of the inner peripheral surface of the motor case 2 'and the accuracy when the first bearing holder 7' and the second bearing holder 8 'are fixed to the motor case 2'.

  However, conventionally, since the motor case 2 'is generally manufactured by extruding an aluminum material or the like, the processing accuracy of the inner peripheral surface of the motor case 2' is low. When the next processing is performed, the cost increases.

  Further, when the first bearing holder 7 'and the second bearing holder 8' are fitted and fixed in the motor case 2 'made of an aluminum material, if this fitting portion is tightened, a string is generated, and the string is generated. If it falls into the motor case 2 ', there is a problem that insulation failure occurs.

  Further, in order to hold the bearings 5 'and 6' in the bearing holders 7 'and 8', the bearing holders 7 'and 8' need to be drawn to form cylindrical portions 75 'and 85'. When drawing is performed, this portion becomes thin, and the holding strength of the bearings 5 'and 6' decreases.

  Such a problem can be generally solved by manufacturing the motor case 2 'with a ferrous metal press product. However, in the case of a ferrous metal press product, the first bearing holder 7' and the second bearing holder are used. Since the accuracy when the 8 'is fitted and fixed to the motor case 2' is low, there is a problem that the coaxiality between the rotor 4 'and the stator 3' decreases.

  In view of the above problems, an object of the present invention is to provide a motor having a high degree of coaxiality between a rotor and a stator even when a split core is used.

  Another object of the present invention is to provide a motor in which the holding strength of the bearing does not decrease even when the cylindrical portion for holding the bearing is formed in the bearing holder.

  In order to solve the above problems, in the present invention, at least one of the motor case having an open end, a plurality of split cores fixed in an annular shape with respect to the inner peripheral surface of the motor case, and the plurality of the cores A stator including a coil wound around each of the split cores, a rotating shaft extending in an axial direction inside the stator, a rotor including a magnet fixed to an outer peripheral surface of the rotating shaft, and the motor case In the motor having a bearing that rotatably supports the rotating shaft on the open end side of the motor, the motor case is an iron-based metal press-molded product, and the bearing covers the open end of the motor case. Is held by a bearing holder attached to the open end side of the motor case, and the bearing holder and the motor case are at least partially overlapped with each other in the axial direction. And a case-side flange portion, on one side of the holder-side flange portion and the case-side flange portion, an engaging protrusion is formed that protrudes toward the other side. An engagement hole into which the engagement protrusion is fitted is formed.

  In the present invention, since a ferrous metal press-formed product is used as the motor case, the dimensional accuracy of the inner peripheral surface is high. Therefore, even if the split core is fixed to the inner peripheral surface without performing secondary processing on the inner peripheral surface of the motor case, a high degree of coaxiality can be secured between the motor case and the stator, thus reducing processing costs. it can. Further, since the bearing holder and the motor case are positioned by the engagement protrusion and the engagement hole in the holder side flange portion and the case side flange portion at least partially overlapping in the axial direction, the bearing holder and the motor case Can be positioned easily. Further, since the positioning is performed by the engagement protrusion and the engagement hole, the accuracy is high, so that the coaxiality between the motor case and the bearing is high, and a high coaxiality can be ensured between the rotor and the stator. Moreover, since the motor case is an iron-based metal press-molded product, the engagement protrusion or the engagement hole can be easily formed. Furthermore, if the motor case is made of iron-based metal, there is an advantage that the motor case can be used for forming the magnetic path, which is suitable for miniaturization of the motor.

  The present invention can also be applied when both ends of the motor case are open ends. That is, in another embodiment of the present invention, a motor case having a first open end and a second open end at both ends, and a plurality of split cores fixed in an annular shape with respect to the inner peripheral surface of the motor case , And a stator including a coil wound around each of the plurality of divided cores, a rotating shaft extending in the axial direction inside the stator, and a rotor including a magnet fixed to the outer peripheral surface of the rotating shaft And a motor having a first bearing and a second bearing that rotatably support the rotary shaft on the first open end side and the second open end side of the motor case, It is a ferrous metal press-molded product, and the first bearing of the first bearing and the second bearing is a first of the motor case so as to cover a first open end of the motor case. 1st attached to the open end A first holder-side flange portion and a first case-side flange portion that are held by a bearing holder and at least partially overlap each other in the axial direction on the first open end side of the first bearing holder and the motor case. A first engaging projection projecting toward the other side is formed on one side of the first holder side flange portion and one side of the first case side flange portion. Has a first engagement hole into which the first engagement protrusion is fitted.

  Here, also in the second bearing, like the first bearing, the second bearing attached to the second open end side of the motor case so as to cover the second open end of the motor case. The second open end side of the second bearing holder and the motor case, which is held by the holder, includes a second holder side flange portion and a second case side flange portion that overlap at least partially in the axial direction. A second engagement protrusion protruding toward the other side is formed on one side of the second holder side flange portion and the second case side flange portion, and on the other side. It is preferable to employ a configuration in which a second engagement hole into which the second engagement protrusion is fitted is formed.

  In the present invention, the bearing holder is preferably an iron-based metal molded product. If comprised in this way, even when the cylindrical part for hold | maintaining a bearing is formed in a bearing holder, the holding strength of a bearing does not fall.

  In the present invention, when one of the first bearing holder and the second bearing holder is made of an aluminum-based metal, the engagement hole is formed in the holder side flange portion of the one bearing holder. Preferably, the engagement protrusion is formed on the case-side flange portion that overlaps with the one bearing holder among the first case-side flange portion and the second case-side flange portion. That is, when the bearing holder is made of an aluminum-based metal, the engagement protrusion cannot be formed at the time of cutting, but can be formed relatively easily by drilling. On the other hand, if it is a press-processed product, it is easy to form protrusions. Therefore, it is preferable to form the engaging protrusion on the case side flange portion made of a press-processed product.

  In the present invention, the engagement hole is preferably a half-cut engagement hole that is recessed to a midway position in the thickness direction. In other words, if the engagement hole is formed as a through hole, a burr or the like may drop off and cause insulation failure inside the motor case. However, if the engagement hole is a half-cut hole, the burr will drop into the motor case. Therefore, it is possible to prevent an insulation failure caused by a drop of burrs or the like.

  In the motor to which the present invention is applied, since the iron-based metal press-formed product is used as the motor case, the dimensional accuracy of the inner peripheral surface is high. Therefore, even if the split core is fixed to the inner peripheral surface without performing secondary processing on the inner peripheral surface of the motor case, a high degree of coaxiality can be secured between the motor case and the stator, thus reducing processing costs. it can. Further, since the bearing holder and the motor case are positioned by the engagement protrusion and the engagement hole in the holder side flange portion and the case side flange portion at least partially overlapping in the axial direction, the bearing holder and the motor case Can be positioned easily. Further, since the positioning is performed by the engagement protrusion and the engagement hole, the accuracy is high, so that the coaxiality between the motor case and the bearing is high, and a high coaxiality can be ensured between the rotor and the stator. Moreover, since the motor case is an iron-based metal press-molded product, the engagement protrusion or the engagement hole can be easily formed. Furthermore, if the motor case is made of an iron-based metal, there is an advantage that the motor case can be used for forming a magnetic path.

  A motor to which the present invention is applied will be described with reference to the drawings.

(overall structure)
FIG. 1 is a sectional view of a motor to which the present invention is applied. In FIG. 1, the motor 1 of this embodiment is a three-phase inner rotor 4-type DC brushless motor 1, and includes a motor case 2 having a first open end 21 and a second open end 22 at both ends, and an annular shape. And a rotor 4 having a rotating shaft 41 extending in the axial direction inside the stator 3 and a magnet 42 fixed to the outer peripheral surface of the rotating shaft 41. The rotating shaft 41 is rotatably supported by the first bearing 5 and the second bearing 6 on the first open end 21 side and the second open end 22 side of the motor case 2.

  Here, the stator 3 includes a plurality of divided cores 31 and a coil 32 wound around each of the divided cores 31, and the plurality of divided cores 31 and the coil 32 are insulated and separated by an insulator 33. ing. When such a split core 31 is used, there is an advantage that the line area ratio of the winding is high, but the split core 31 alone cannot be fixed in the motor case 2. Accordingly, the split core 31 is fixed in an annular shape with respect to the inner peripheral surface of the motor case 2 by a method such as an adhesive, a fixing pin, a resin mold, and shrink fitting.

  Here, each of the first bearing 5 and the second bearing 6 includes a first bearing holder 7 and a first bearing holder 7 attached to the open end side of the motor case 2 so as to cover the first open end 21 of the motor case 2. The two bearing holders 8 are respectively held. That is, the first bearing holder 7 and the second bearing holder 8 are formed with small-diameter cylindrical portions 75 and 85 at the center portions thereof, and the first bearing 5 and the second bearing holder 8 are formed in the cylindrical portions 75 and 85. Two bearings 6 are fixed.

  Further, the first bearing holder 7 and the second bearing holder 8 are fitted and fixed to the motor case 2 by the fitting portions 11 and 12, and the first opening of the motor case 2 is performed by such fitting and fixing. The end 21 and the second open end 22 are in a state of being blocked by the first bearing holder 7 and the second bearing holder 8.

  A cup-shaped cover 29 is further attached to the second open end 22 side of the motor case 2 by a bolt or the like outside the second bearing holder 8, and an encoder (see FIG. (Not shown) or the like is formed.

(Configuration of motor case 2 and bearing holder)
In this embodiment, the motor case 2, the first bearing holder 7 and the second bearing holder 8 are each configured as shown below,
Motor case 2: Press-formed product of ferrous metal First bearing holder 7: Press-formed product of ferrous metal Second bearing holder 8: Press-formed product of ferrous metal It consists of press-formed products of steel plate members such as cold rolled steel plate (SPCC) and galvanized steel plate (SECEF).

  In the motor 1 configured as described above, a first case-side flange portion 26 projecting radially outward is formed on the first open end 21 side of the motor case 2, while the first bearing holder 7 first holder side flange portion 76 partially overlaps the first case side flange portion 26 in the axial direction.

  The first case-side flange portion 26 has first engagement protrusions 91 formed at a plurality of locations in the circumferential direction at the time of press formation, while the first holder-side flange portion 76 has a circumferential direction. A first engagement hole 92 into which the first engagement protrusion 91 is fitted is formed at a plurality of locations during press formation. Here, the first engagement hole 92 is a half punched hole that is recessed to a middle position in the thickness direction.

  On the second open end 22 side of the motor case 2, a second case side flange portion 27 projecting radially inward is formed, while the second holder side flange portion 87 of the second bearing holder 8 is formed. Are partially overlapped with the second case side flange portion 27 in the axial direction.

  The second holder-side flange portion 87 has second engagement projections 96 formed at a plurality of locations in the circumferential direction at the time of press formation, while the second case-side flange portion 27 has a circumferential direction. A second engagement hole 97 into which the second engagement protrusion 96 is fitted is formed at a plurality of locations when the press is formed. Here, the second engagement hole 97 is a half punched hole that is recessed to a middle position in the thickness direction.

(Assembly method)
In the assembly process of the motor 1 having such a configuration, first, the coil 32 is wound around each of the split cores 31, and then the plurality of split cores 31 are fixed along the inner peripheral surface of the motor case 2. The stator 3 is configured.

  Next, after the first bearing holder 7 holding the first bearing 5 is fitted and fixed to the first open end 21 side of the motor case 2, it is fixed with a bolt or the like as necessary. At that time, the first engagement protrusion 91 of the first case side flange portion 26 is fitted into the first engagement hole 92 of the first holder side flange portion 76, and the first bearing holder 7 is attached to the motor case 2. It positions to the 1st open end 21 side.

  Next, the tip end side of the rotating shaft 41 of the rotor 4 is inserted from the second open end 22 side of the motor case 2, and the rotating shaft 41 is inserted into the first bearing 5.

  Next, the second bearing holder 8 holding the second bearing 6 is attached to the second open end 22 side of the motor case 2. At that time, the base end side of the rotating shaft 41 of the rotor 4 is inserted into the second bearing 6. Further, the second engagement protrusion 96 of the second holder side flange portion 87 is fitted into the second engagement hole 97 of the second case side flange portion 27, and the second bearing holder 8 is attached to the motor case 2. Position on the second open end 22 side. In this way, the motor 1 is assembled.

(Main effects of this form)
As described above, in the motor 1 according to the present embodiment, the iron case metal press-molded product is used as the motor case 2, and therefore the dimensional accuracy of the inner peripheral surface is high. Accordingly, even if the inner peripheral surface of the motor case 2 is not subjected to secondary processing and the split core 31 is provided on the inner peripheral surface, a high degree of coaxiality can be ensured between the motor case 2 and the stator 3. Cost can be reduced.

  Further, the bearing holders 7 and 8 and the motor case 2 are formed such that the engagement protrusions 91 and 96 and the engagement holes 92 and the holder-side flange portions 76 and 87 and the case-side flange portions 26 and 27 at least partially overlap in the axial direction Therefore, the bearing holders 7 and 8 and the motor case 2 can be easily positioned.

  Further, since the positioning is performed by the engagement protrusions 91 and 96 and the engagement holes 92 and 97, the positioning accuracy is high, so the coaxiality between the motor case 2 and the bearings 5 and 6 is high, and the rotor 4 and the stator 3 A high degree of coaxiality can be secured.

  Moreover, since the motor case 2, the first bearing holder 7, and the second bearing holder 8 are all iron-based metal press-molded products, the engagement protrusions or the engagement holes can be easily formed. .

  Furthermore, if the motor case 2 is made of iron-based metal, there is an advantage that the motor case 2 can be used for forming a magnetic path.

  Furthermore, since the bearing holder is an iron-based metal molded product, even when the cylindrical portions 75 and 85 for holding the bearing are formed on the bearing holder, the holding strength of the bearing does not decrease.

(First modification)
In the above embodiment, each member has the following configuration. Motor case 2: Iron-based metal press-formed product First open end 21 side First case-side flange portion 26: first engaging protrusion 91
First bearing holder 7: Press-formed product of ferrous metal First holder side flange portion 76: First engagement hole 92
2nd open end 22 side 2nd case side flange part 27: 2nd engagement hole 97
Second bearing holder 8: Press-formed product of ferrous metal Second holder side flange portion 87: Second engaging protrusion 96
Motor case 2: Press-formed product of ferrous metal First open end 21 side First case side flange 26: First engagement hole 92 (or first engagement protrusion) 91)
1st bearing holder 7: Press-formed product of ferrous metal 1st holder side flange part 76: 1st engagement protrusion 91 (or 1st engagement hole 92)
Second open end 22 side Second case side flange portion 27: second engagement hole 97 (or second engagement protrusion 96)
Second bearing holder 8: Press-formed product of ferrous metal Second holder side flange portion 87: Second engagement protrusion 96 (or second engagement hole 97)
Can be adopted. That is, since it is easy to form both the engagement protrusion and the engagement hole in the case of an iron-based metal press-molded product, for example, the first engagement protrusion 91 and the second engagement protrusion 96 are provided. The first holder-side flange portion 76 and the second holder-side flange portion 87 are respectively formed, and the first engagement hole 92 and the second engagement hole 97 are formed in the first case-side flange portion 26 and the second case-side flange portion 26, respectively. Each of the case side flange portions 27 may be formed. In addition, the first engagement protrusion 91 and the second engagement protrusion 96 are formed in the first case side flange portion 26 and the second case side flange portion 27, respectively, and the first engagement hole 92 and the second engagement protrusion 92 are formed. The engagement holes 97 may be formed in the first holder side flange portion 76 and the second holder side flange portion 87, respectively.

(Second modification)
Moreover, in the said form, although both the 1st bearing holder 7 and the 2nd bearing holder 8 were formed with the press-molded product of the iron-type metal, this example and the 3rd and 4th modification shown below are shown. As shown in FIG. 1, one or both of the first bearing holder 7 and the second bearing holder 8 may be formed of a cut product of an aluminum-based metal. However, forming the engaging protrusions by cutting significantly reduces the processing efficiency, so the following configuration Motor case 2: Press-formed product of ferrous metal First open end 21 side First case side flange 26: first engaging protrusion 91
First bearing holder 7: Aluminum-based metal cut product First holder-side flange portion 76: First engagement hole 92
2nd open end 22 side 2nd case side flange part 27: 2nd engagement protrusion 96
Second bearing holder 8: Aluminum-based metal cut product Second holder side flange portion 87: Second engagement hole 97
As described above, it is preferable to form an engagement hole on the side of the aluminum metal cut product. Thus, if the engagement hole is formed in the bearing holder made of a machined product of an aluminum-based metal, it can be formed efficiently.

(Third Modification)
Further, the following configuration Motor case 2: Press-formed product of iron-based metal First open end 21 side First case side flange portion 26: First engagement protrusion 91
First bearing holder 7: Aluminum-based metal cut product First holder-side flange portion 76: First engagement hole 92
Second open end 22 side Second case side flange portion 27: second engagement protrusion 96 (or second engagement hole 97)
Second bearing holder 8: Press-formed product of ferrous metal Second holder side flange portion 87: Second engagement hole 97 (or second engagement protrusion 96)
May be adopted.

(Fourth modification)
Further, the following configuration Motor case 2: Iron-based metal press-formed product First open end 21 side First case side flange portion 26: First engagement protrusion 91 (or second engagement hole 97)
1st bearing holder 7: Press-formed product of ferrous metal 1st holder side flange part 76: 1st engagement hole 92 (or 2nd engagement protrusion 96)
2nd open end 22 side 2nd case side flange part 27: 2nd engagement protrusion 96
Second bearing holder 8: Aluminum-based metal cut product Second holder side flange portion 87: Second engagement hole 97
May be adopted.

(Other variations)
In the above embodiment, both ends of the motor case 2 are open ends, but at one end of the motor case 2 the bearing is directly held by the motor case 2 and only the other end is an open end. The present invention may be applied to the motor 1. Further, when one or both of the first bearing holder 7 and the second bearing holder 8 are made of an aluminum-based metal, a die-cast product may be used. Moreover, you may use the press work goods made from an aluminum-type metal for one or both of the 1st bearing holder 7 and the 2nd bearing holder 8. FIG.

  Moreover, in the said form, the member and open end which are arrange | positioned at the left side toward drawing were set to 1st, and the member and open end which were arrange | positioned at the right side toward drawing were set to the bearing holder 2nd, On the contrary, There may be.

It is sectional drawing of the motor to which this invention is applied. It is sectional drawing of the conventional motor.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Motor 2 Motor case 3 Stator 4 Rotor 5 1st bearing 6 2nd bearing 21 1st open end 22 2nd open end 26 1st case side flange part 27 2nd case side flange part 31 Split core 41 Rotating shaft 76 First holder side flange portion 87 Second holder side flange portion 91 First engagement protrusion 92 First engagement hole 96 Second engagement protrusion 97 Second engagement hole

Claims (7)

A motor case with at least one open end;
A plurality of split cores fixed in an annular shape with respect to the inner peripheral surface of the motor case, and a stator including a coil wound around each of the plurality of split cores;
A rotor including a rotating shaft extending in the axial direction inside the stator, and a magnet fixed to an outer peripheral surface of the rotating shaft;
A motor having a bearing rotatably supporting the rotating shaft on the open end side of the motor case;
The motor case is an iron-based metal press-molded product,
The bearing is held by a bearing holder attached to the open end side of the motor case so as to cover the open end of the motor case,
The bearing holder and the motor case include a holder-side flange portion and a case-side flange portion at least partially overlapping in the axial direction,
An engagement projection that protrudes toward the other side is formed on one side of the holder side flange portion and the case side flange portion, and an engagement hole into which the engagement projection fits is formed on the other side. A motor characterized by being formed. A motor case having a first open end and a second open end at both ends;
A plurality of split cores fixed in an annular shape with respect to the inner peripheral surface of the motor case, and a stator including a coil wound around each of the plurality of split cores;
A rotor including a rotating shaft extending in the axial direction inside the stator, and a magnet fixed to an outer peripheral surface of the rotating shaft;
A motor having a first bearing and a second bearing for rotatably supporting the rotary shaft on the first open end side and the second open end side of the motor case;
The motor case is an iron-based metal press-molded product,
Of the first bearing and the second bearing, the first bearing is attached to the first open end side of the motor case so as to cover the first open end of the motor case. Held in the bearing holder,
The first open end side of the first bearing holder and the motor case includes a first holder side flange portion and a first case side flange portion at least partially overlapping in the axial direction,
A first engagement protrusion that protrudes toward the other side is formed on one side of the first holder side flange portion and one side of the first case side flange portion, and the other side includes the first engagement protrusion. A motor having a first engagement hole into which a first engagement protrusion is fitted. In Claim 1, the 2nd bearing is held by the 2nd bearing holder attached to the 2nd open end side of the motor case so that the 2nd open end of the motor case may be covered,
The second open end side of the second bearing holder and the motor case includes a second holder side flange portion and a second case side flange portion at least partially overlapping in the axial direction,
A second engagement projection that protrudes toward the other side is formed on one side of the second holder side flange portion and the second case side flange portion, and the other side includes the second engagement projection. A motor having a second engagement hole into which a second engagement protrusion is fitted.   4. The motor according to claim 1, wherein the bearing holder is an iron-based metal press-molded product. 4. The bearing holder according to claim 3, wherein one of the first bearing holder and the second bearing holder is made of an aluminum-based metal, and the engagement hole is formed in the holder-side flange portion of the one bearing holder. And
The motor characterized in that the engagement projection is formed on a case side flange portion that overlaps with the one bearing holder among the first case side flange portion and the second case side flange portion.   4. The bearing holder according to claim 1, wherein the bearing holder is made of an aluminum-based metal, the engagement protrusion is formed on the case-side flange portion, and the engagement hole is formed on the holder-side flange portion. A motor characterized by having   7. The motor according to claim 1, wherein the engagement hole is a half-cut engagement hole that is recessed to a midway position in the thickness direction.

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