Motor Stator and Motor
Motor stator in which a plurality of first guide grooves (321) and second guide grooves (322) that govern the winding position of conductors are formed on the upper end portion and lower end portion of insulators (32) which cover each of the stator teeth (31). The inclination of the first guide grooves is equal to the pitch of the first guide grooves, and the inclination of the second guide grooves is configured to be 0. The second-guide-groove start and end points are positioned on a straight line extending in the (−Z) direction from the first-guide-groove end point (3212) and from the adjoining first-guide-groove start point (3211) on the (−Y) side.
Latest Nidec Corporation Patents:
1. Technical Field
The present invention relates to electrically powered motors, and in particular, to stators.
2. Description of the Related Art
Electrically powered motors to date have been furnished with a stator, and with magnetic-field producing magnets, which are the drive part that rotates a motor's rotor section relative to its stator section. Stators include an annular core, insulators as nonconducting components that cover teeth sections of the core, and coils formed by wrapping conductors onto the insulators. In midsized motors such as are used for “electric power steering systems” (as termed in, for example, U.S. Pat. App. Pub. No. 2002/0175574, but also referred to as “steer-by-wire systems”), conductors of relatively large diameter are wrapped around insulators and employed as the coils.
In such motors, owing to the fact that motor efficiency increases with conductor diameter, technology for improving the slot-fill factor of the coils by wrapping on the conductors in regular rows without gaps is paramount. In the present specification, the term “space factor” (as termed in, for example, paragraph [0006] of both U.S. Pat. App. Pub. No. 2004/0263015 and Pat. App. Pub. No. 2005/0029894, but also referred to as “slot-fill factor,” or “slot-fill ratio”) is intended to mean the ratio of the area occupied by the conductors with respect to the cross-sectional area in the interval (slot) between adjoining stator teeth.
In stator implementations employing large-diameter conductors that do not bend readily, when the conductors are wound onto the teeth, it can happen that a conductor, as wrapped onto a tooth from one flank to the other flank, does not bend fully around a terminus of the tooth, and is instead left riding up off the tooth, not lying in full contact along the flanks. For example, in stator implementations in which the insulators are formed with tooth-flank guide grooves, it can happen that the conductors fail to be guided by the guide grooves, which is prohibitive not only of attaining evenly-rowed wrapping but also of smooth conductor windings, and limits improvement in the slot-fill factor of the coils.
BRIEF SUMMARY OF THE INVENTIONThe present invention makes it possible to build coils smoothly onto an electric motor stator. The present invention also makes it possible to reduce the thickness of coils on stator insulator surfaces, and to prevent the conductors from separating from the insulators.
In one example of the present invention, an electric motor stator comprises multiple teeth radially arrayed and centered on a specified center axis, insulators respectively covering said multiple teeth, and multiple coils constructed by winding multiple layers of conductors on said multiple teeth starting from said insulators. In an top end section which covers an top end and forms one end in a direction along the respective center axes of said multiple teeth, said insulator is provided with multiple upper guide grooves which are arrayed in parallel to one another at a pitch approximately equal to the diameter of said conductor, and which restrict the winding position of said conductor.
In another example of the present invention, the motor stator is provided with multiple teeth radially arrayed and centered on a specified center axis, insulators respectively covering said multiple teeth, and multiple coils constructed by winding multiple layers of conductors starting from said insulators. At the top end section which covers the top end which forms one end in a direction along the respective center axes of said multiple teeth, said insulators are provided with a protruding wall which extends in the conductor laminar direction on said center axis side of said teeth, or on the opposite side of said center axis, and which is convex toward said teeth. Said protruding wall is constructed along the winding direction of said top end portion of the coil first layer conductor, and contacts said first layer to restrict the winding position of said conductor.
In yet another example of the present invention, the motor stator comprises multiple teeth radially arrayed and centered on a specified center axis; multiple teeth inside end sections disposed at the respective end sections on said center axis side of said multiple teeth, while opening on both sides of the teeth in a circumferential direction with respect to the center of said center axis; insulators respectively covering said multiple teeth; and multiple coils constructed by winding multiple layers of conductors starting at said insulators. Said insulators comprise inside end guide grooves which restrict the winding position of said conductors at the inside end sections which cover the surfaces on the side opposite to that of the respective said center axes of said multiple teeth inside end sections.
The present invention permits the smooth construction of coils. In particular, it enables the smooth construction of coils by preventing conductor mis-winding at the top end of the multiple teeth.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
Below preferred embodiments of the present invention will be explained with reference to figures. In the descriptions that follow, references to the positional relationships of each of the parts, or to upper, lower, right and left directions, etc. will in all cases be for the purpose of indicating positional relationships or direction in the diagrams, and will not indicate positional relationships or directions with respect to the actual machine when assembled.
First EmbodimentOverall Motor Structure
A cylindrical rotor yoke 22 is attached to the shaft 21 inside the housing 11, and a multipole magnetized field magnet 23 is affixed to the outer perimeter surface of the rotor yoke 22. The stator 3 is disposed so that the center axis J1 of the annular stator 3 coincides with the center axis of the shaft 21.
The stator 3 comprises a plurality of teeth 31, arranged in a radial fashion with center axis J1 as the center (that is, extending from the inner circumferential surface of the housing 11 toward the shaft 21 (and the field magnet 23)); a plurality of insulators 32 respectively covering the plurality of teeth 31; and a plurality of coils 35, constructed by winding a conductor in multiple layers along insulators 32 on each of the plurality of teeth 31. In other words, the plurality of insulators 32 are provided respectively between the plurality of teeth 31 and the plurality of coils 35. Each of the teeth 31 is elongate in the axial direction (that is, the Z direction), and the coils 35 are formed by winding a conductor in the axially along the outer periphery of the insulator 32. Additional details of the stator 3 will be discussed later.
On the cover plate 12 side of the stator 3, a base plate attachment part 51 is affixed to the inner circumferential surface of the housing 11, and a circuit board 52 is attached to the base plate attachment part 51 so as to be positioned in between the cover plate 12, and the field magnet 23 and stator 3. The stator 3 and the circuit board 52 are electrically connected through a cross-over wire attached to the base plate attachment part 51.
In the motor, the shaft 21 and ball bearings 131, 132 perform the role of a bearing mechanism to rotatably support the rotor yoke 22 relative to the housing 11, centered on the center axis J1. The drive current supplied to the stator 3 through the circuit board 52 is controlled so that rotational power is generated between the stator 3 and the field magnet 23 centered on the center axis J1, and the shaft 21 rotates together with the rotor yoke 22.
A drive circuit for controlling the drive current supplied to the stator 3 and a Hall sensor 521 is attached to the circuit board 52 at the axial bottom side of the field magnet 23. The direction of rotation and rotational position of the field magnet 23 are detected by the Hall sensor 521 to control drive current to the stator 3. In other words, the motor 1 is what is known as a brushless motor.
Stator Structure
As shown in
Each of the insulators 32, as shown in
Each of the insulators 32 is in turn, as shown in
When forming a coil 35 (cf.
As shown in
As shown in
In each of the insulators 32, in the inner edge portions that cover the surface on the radially outward side of the tooth inner edge portions 311, inner-edge-portion guide grooves 325 are furnished on both sides of the tooth 31, and on the upper- and lower-end tooth inner edge portions 311, to govern the conductor wind-on position of the coils 35.
As shown in
The first partitions 323 cover the upper-end surface of the teeth 31, both flanks of the parts of the teeth 31 above the center in the axial orientation, the rim surfaces on the upper end of the outside section 30, areas on the radially inward surface of the outside section 30 in the section thereof above the center, the end surfaces on the upper side of the teeth inner edge portions 311, and areas on the radially outward surface of the teeth inner edge portions 311 in the section thereof above the center.
The second partition 324 is for the most part of the same form as the first partition 323, except that its shape is the reverse of the first partition 323, and it is provided with the second guide grooves 322. More specifically, it covers the lower section of the teeth 31, the underside rim surfaces of the outside section 30 and the teeth inner edge portion 311, the radially inward surface of the outside section 30, and areas on the radially outward surface of the teeth inner edge portion 311 in the lower section thereof. The insulators 32 formed by the first partitions 323 and the second partitions 324 are sandwiched between the teeth inner edge portions 311 and the outside section 30.
Of the two flanks on a tooth 31, along the outer side of the flank on which the conductor is wound heading from the second partition 324 end of the tooth toward the first partition 323 end, the first partition 323 taper surface 3231a is provided on the inner side surface of the first partition 323 (that is, the side facing the flank of the tooth 31), and the second partition 324 taper surface 3241a is provided on the outer side surface of the second partition 324 (that is, the side opposite that which faces the flank of the tooth 31). Likewise, along the outer side of the tooth 31 flank on which the conductor is wound heading from the first partition 323 end of the tooth toward the second partition 324 end, the first partition 323 taper surface 3231a is provided on the outer side surface of the first partition 323, and the second partition 324 taper surface 3241a is provided on the inner side surface of the second partition 324.
The inclination direction and angle of the taper surfaces 3231a and 3231b as seen from the first guide groove 321 side are made to be the same as the respective inclination direction and angle of the taper surfaces 3241a and 3241b as seen from the second guide groove 322 side. This contributes to designing for shared use of parts (for example, making in common part of the molding forms and part of the design data) required for the manufacture of the first partition 323 and second partition 324.
As shown in
The circled reference numerals “1s” through “8s,” and “0” and “1e” through “7e” in
When a coil 35 is formed around the periphery of an insulator 32, the conductor is first led from position 0 in
Next, the conductor passes sequentially from the
The coil 35 first layer 351 between positions 1s and 1e in
When formation of the coil 35 first layer 351 is complete, the conductor that forms the coil 35 second layer 352 is guided sequentially along the insulator 32 (+X) side, (−Z) side, and (−X) side to position 1s. Thereafter, the conductor that forms the second layer 352 is wound in a direction crossing the first layer 351 conductor at the upper end portion of the insulator 32, so that the first layer 351 conductor and the second layer 352 conductor cross at a crossing position 350. In other words, at the upper end portion of the insulator 32, the first layer 351 conductor and the second layer 352 conductor have differing inclinations. In the present embodiment, the first layer 351 conductor has a “positive inclination,” whereas the second layer 352 has a “negative inclination.”
As shown in
The second layer 352 conductor, by being guided to lay in contact on two first layer 351 conductors adjoining each other on the (+X) flank, the lower end portion, and the (−X) flank of the insulator 32, is wound onto the insulator 32 in parallel with the first layer 351, and positioned at position 2s. That is, along the insulator 32 (+X) side and (−X) flanks, the second layer 352 conductor is accommodated in the hollow formed by two adjoining conductors from among the first layer 351 conductors which are densely wound with virtually no gaps. Thus by being guided in this hollow, the conductor is wound onto the first layer 351 in such a way that it is arrayed parallel to the first layer 351 and parallel to the center axis J1. Similarly, at the lower end portion of the insulator 32, the second layer 352 conductor is wound onto the first layer 351 such that it is arrayed parallel to the first layer 351 conductor and parallel to the imaginary plane 300 (cf.
Thereafter, by winding the conductor in the same way onto the coil 35 first layer 351, the second layer 352 is formed by the eight rows of conductors arrayed in parallel to the first layer 351 conductor on each face of the teeth 31 (a section (for example, the conductor on the radially innermost row) of the eight conductor rows may cross the 351 conductor). In the coil 35 second layer 352 as well, the eight conductor rows are densely wound with virtually no gaps so that adjacent conductors contact one another.
Between the
With respect to the insulator 32, the angle and surface area formed by the first inner protruding wall 3213 first contact part 3215 (cf.
Thereafter, the conductor is similarly wound until the coil reaches a specified number of layers, and a stator 3 is formed by disposing the coils 35 around each of the teeth 31 and the coils 35.
As explained above, plurality of first guide grooves 321 and plurality of second guide grooves 322 to guide the coils 35 are formed in the upper and lower end portions of the insulators 32; the first guide groove 321 is disposed at an inclination of just one pitch with respect to the imaginary plane 300 (cf.
The coil 35 second layer 352 conductor thus crosses the first layer 351 conductor at a crossing position 350 along the upper end of the tooth 31. Furthermore, by laying in contact on two conductors that, among the first layer 351 conductors densely wound with virtually no gaps onto the flanks of the teeth 31, adjoin each other, the second layer 352 conductors are arrayed parallel to the first layer 351 conductor. Similarly, the third and fourth layer conductors cross the layers they contact below along the upper end of the teeth 31 (that is, the second and third layers), and are arrayed in parallel to the second and third layer conductors on the flanks of the teeth 31.
As a result, crossing of conductors (for example, crossing of the first layer 351 conductor and the second layer 352 conductor) on both faces of the teeth 31 (that is, both faces of the insulator 32) during winding of the conductor from the second layer 352 forward can be prevented, and the thickness of the coil 35 on both faces of the teeth 31 (the height in the X direction from the insulator 32 face in
The coil 35 second layer 352 conductor is also arrayed parallel to the first layer 351 conductor at the bottom end of the teeth 31 (as is true for the third and fourth layers). Crossing of conductors at the bottom end of the teeth 31 can thus be prevented during winding of conductors from the second layer 352 forward, and the coil 35 thickness in the Z direction at the bottom end of the teeth 31 can also be reduced. As a result, a further size reduction of the stator 3 is achieved, leading to a size reduction of the motor 1.
On the stator 3, guiding of the coil 35 by the first guide groove 321 and the second guide groove 322 results in its disposition at an inclination with respect to the imaginary plane 300 at the top end of the teeth 31, making it parallel to the center axis J1 at each face of the teeth 31. It is thus possible to achieve tighter winding of the coil 35 conductor with respect to the teeth 31 compared to the case when the conductor is inclined with respect to the center axis J1 on both faces of the teeth 31.
The coil 35 first layer 351 conductor is moved to the (−Y) side by one pitch width of the first guide groove 321 and second guide groove 322 (that is, a distance approximately equal to the conductor diameter) with each revolution around the perimeter of the insulator 32. As a result, the coil 35 first layer 351 can be constructed smoothly and at a high slot-fill factor with virtually no provision of spacing between adjacent conductors. By forming the second layer 352 and forward by further winding of conductors on the first layer 351 which has been thus aligned at a high slot-fill factor, the coil 35 can be smoothly constructed and conductor mis-winding avoided. A high coil 35 slot-fill factor can thus be achieved without adding complexity to the stator 3 manufacturing process.
On the stator 3 insulator 32, the first layer 351 winding is restricted by the first guide groove 321 and the second guide groove 322, therefore winding errors caused by the second layer 352 conductor becoming lodged between first layer 351 conductors, etc. can be reliably prevented, and the coil 35 can be smoothly constructed. That is, aligned winding can be achieved. Also, winding of the conductor row on the radially innermost side among the second layer 352 is restricted by the inner edge portion guide groove 325. At the radially inner end section of the teeth 31, therefore, second layer 352 conductor mis-winding caused by mis-winding of the radially innermost conductor row of the second layer 352 toward the radial inside direction can be prevented, and the coil 35 can be smoothly constructed.
At the insulator 32, the winding position at the center axis J1 side and the outside section 30 side of the plurality of layers of conductors which cross at the first guide groove 321 is guided by the first inner protruding wall 3213 and first outer protruding wall 3214, which are mutually convex facing the plurality of first guide grooves 321. Therefore the coil 35 can be smoothly constructed even at the end section of the plurality of first guide grooves 321 center axis J1 side and the outside section 30 side. The first inner protruding wall 3213 and the first outer protruding wall 3214 restrict the position and direction of winding of the first layer 351 and second layer 352 conductors by use of the first layer contact parts 3215 and 3216 and the second layer contact parts 3217 and 3218, thus achieving an aligned winding of the first layer 351 and the second layer 352, so that aligned winding of the coil 35 can be more easily realized.
On the insulator 32, the taper surfaces 3231a and 3231b are disposed on the second partition 324 side of the first partition 323, the taper surfaces 3241a and 3241b are disposed on the first partition 323 side of the second partition 324, and the taper surfaces 3231a, 3231b overlap with the taper surfaces 3241a, 3241b when winding onto the first partition 323 and second partition 324 teeth 31, thus enabling the prevention of gap formation between the first partition 323 and the second partition 324, while simplifying the assembly of the first partition 323 and the second partition 324.
Furthermore, on the insulator 32, of the two flanks on a tooth 31, along the flank on which the conductor is wound from the second partition 324 section to the first partition 323 section, the taper surfaces 3231a and 3241a are provided on the inner side surface of the first partition 323 and the outer side surface of the second partition 324. In turn, along the flank on which the conductor is wound heading from the first partition 323 section to the second partition 324 section the taper surfaces 3231a and 3241a are provided on the outer side surface of the first partition 323 and the inner side surface of the second partition 324. In other words, for the first partition 323 and the second partition 324, at the first guide groove 321 and second guide groove 322 the taper surfaces 3231a, 3231b are formed on the outside of the face on the start point 3211 and 3221-flanks, and the taper surfaces 3231a, 3231b are formed on the inside of the face on the end point 3212 and 3222-flanks. Therefore on the face at the side on which the conductor is wound from the top toward the bottom (that is, the face on the side of the first guide groove 321 end point 3212), the first partition 323 is positioned on the outside of the second partition 324 in the area of the joint between the first partition 323 and the second partition 324. On the face at the side on which the conductor is wound from the bottom toward the top (that is, the face on the side of the second guide groove 322 end point 3222), the second partition 324 is positioned on the outside of the first partition 323 in the area of the joint between the first partition 323 and the second partition 324. As a result, catching of the conductor (and the winding machine 9 nozzle) on the joint between the first partition 323 and the second partition 324 during winding of the conductor on the teeth 31 can be prevented, and the coil 35 can be smoothly constructed.
Second Embodiment
In a motor according to a second embodiment, as with the motor 1 according to the first embodiment, insulators 32a are provided with a first partition 323 and a second partition 324 respectively attached on the (+Z) side and the (−Z) side of the teeth 31 (cf.
As shown in
Also, similar to the insulator 32 shown in
In the motor stator according to the second embodiment, the shape of the insulator 32a in the region of the first guide groove 321 and the second guide groove 322 can be made the same by making the inclination of the first guide groove 321 and the second guide groove 322 equal. As a result, the same parts can be used to manufacture the insulator 32a first partition 323 and the second partition 324.
In the stator according to the second embodiment, because the coil 35 conductor is guided by the first guide groove 321 and the second guide groove 322, the conductor during winding of the second layer 352 conductor crosses the first layer 351 conductor at the upper and lower ends of the teeth 31 and is wound onto the teeth 31. Along the flanks of the teeth 31, the first layer 351 conductor and the second layer 352 conductor are aligned so as to be parallel to one another. By this means, as with the first embodiment, crossing of conductors on the two faces of the teeth 31 is prevented when winding the second layer 352 and subsequent conductor layers, and the thickness of the coil 35 on both faces of the teeth 31 can be reduced. By making the coil 35 conductor parallel to the center axis J1 on each face of the teeth 31, the conductor can be wound more densely with respect to the teeth 31.
Again, as with the first embodiment, by moving the coil 35 first layer 351 conductor by one pitch only to the (−Y) side for each revolution around the periphery of the insulator 32a, there are virtually no gaps created between adjoining conductors, and the coil 35 can be smoothly constructed with a high slot-fill factor. Because the conductor winding is restricted by the first guide groove 321 and the second guide groove 322 in the insulator 32a, conductor mis-winding can be reliably prevented and the coil 35 smoothly constructed.
Third Embodiment
As shown in
As shown in
As explained above, in the motor insulator 32 according to the third embodiment, the bending of parts from the crown section of the first guide groove 321 and the second guide groove 322 up to the winding end point is kept gradual, without changing the width of the first guide groove 321 and the second guide groove 322 in the X direction. This makes it possible to stop the conductor from separating from the insulator 32 in the region around the first guide groove 321 end point 3212 and in the region of the second guide groove 322 end point 3222 and, by preventing mis-winding of the conductor, to smoothly construct the coil 35. The thickness of the coil 35 on both faces of the insulator 32 can also be reduced. This structure which makes it possible to keep separation of the conductor from the insulator 32 under control is particularly suited to a stator in which the axial length of the teeth 31 is longer than the width thereof, and in which the radius of curvature at the top and lower end portions of the insulator 32 is relatively small.
It will be appreciated that it is acceptable for the end section at which the radius of curvature varies to be only one of the end sections from the first guide groove 321 side and the second guide groove 322 side. “Radius of curvature” at the start point and the end point sides refers to an approximate radius of curvature. For example, it can be interpreted as an average radius of curvature, and can also be interpreted as a minimum radius of curvature on the start point and end point sides.
While several preferred embodiments of the present invention have been explained, the present invention is not limited to the foregoing embodiments, and may be variously modified.
For example, for the stator 3 insulator, the first guide groove 321 can be set to be parallel to the imaginary plane 300, and the second guide groove 322 can be disposed so as to be inclined by just one pitch with respect to the imaginary plane 300, so that the coil 35 is formed such that conductors cross only at the bottom end of the teeth 31.
In the stator 3, a high slot-fill factor coil 35 can be constructed by winding the coil 35 conductor in such a way that it is parallel to the center axis J1 on each face of the teeth 31 and moves by just one pitch unit for each revolution around the insulator. Thus from the standpoint of building the coil 35 at a high slot-fill factor, the total respective inclinations of, for example, the first guide groove 321 and the second guide groove 322 do not have to be equal to the pitch. For example, the respective inclinations of the first guide groove 321 and the second guide groove 322 could be set at a 0.7× and 0.3× the pitch.
From the standpoint of improving the coil 35 slot-fill factor, it is preferable that the inclination of the first guide groove 321 and the second guide groove 322 be greater than 0, and that it be less than the pitch of the first guide groove 321 and the second guide groove 322. In other words, it is preferable to make the difference in distance from the center axis J1 to the first guide groove 321 start point 3211 and end point 3212, and the difference in distance from the center axis J1 to the second guide groove 322 start point 3221 and end point 3222 be less than the pitch of the first guide groove 321 and the second guide groove 322.
For the stator 3, speaking only from the standpoint of reducing the coil 35 thickness at both faces of the teeth 31, it is sufficient for the various coil 35 layers to be mutually aligned in parallel and to be wound along approximately the center axis J1; they may be slightly inclined with respect to the center axis J1. Therefore when the coil 35 is formed so that the conductors cross only at the top end (and/or the bottom end) of the teeth 31, then for example the first guide groove 321 and the second guide groove 322 may be disposed in parallel to the imaginary plane 300. In that case, the coil 35 conductor is disposed so as to be slightly inclined with respect to the center axis J1 at both sides or at one side of the teeth 31. For a conductor inclination at both faces of the teeth 31, that inclination is equal to one pitch unit of the first guide groove 321 and second guide groove 322.
A reduction in the coil 35 thickness can be achieved on both faces of the teeth 31 even in cases where, for example, one or two rows of a conductor among the eight conductor rows of the coil 35 second layer 352 cross the first layer 351 conductor on the various faces of the teeth 31. Thus, by virtue of the majority of conductor rows in each layer being mutually aligned in parallel with the conductors in adjacent layers on each face of the teeth 31, the thickness of the coil 35 can be reduced on both faces of the teeth 31, even in cases in which some conductors cross on the face of teeth 31 with the conductors of an adjacent layer.
A guide groove which joins the first guide groove 321 start point 3211 and the second guide groove 322 end point 3222, and a guide groove which joins the first guide groove 321 end point 3212 and the second guide groove 322 start point 3221 may be constructed on a face of the insulator. The conductor which forms the coil 35 first layer 351 may also be wound from the center axis J1 side to the outside section 30 side with respect to the insulator.
In cases where it is possible to prevent mis-winding of the conductor and smoothly construct the coil 35 by slackening the conductor winding to some degree with respect to the teeth 31 so as to cause the conductors to cross only at the top end (and/or bottom end) of the teeth 31, the insulator first guide groove 321 and/or second guide groove 322 may be omitted. In cases where mis-winding of the conductor row on the radially innermost side of the second layer 352 is reliably prevented by contact, etc. with the first inner protruding wall 3213, the insulator 32 inner edge portion guide groove 325 may be omitted.
Insulators attached to plurality of (nine in the present preferred embodiment) teeth 31 may be comprised of nine first partitions 323 connected or integrally formed in an annular shape, and nine second partitions 324 connected or integrally formed in an annular shape. The insulator is not limited to being formed by attachment of a resin-molded first partition 323 and second partition 324 to the teeth 31 and could, for example, be formed by molding a thermoplastic resin for the teeth 31. In such cases, the plurality of teeth 31 could be said to be covered by a single insulator. With such an insulator, plurality of first guide grooves 321 are formed on the upper end portions which cover the respective top ends of the plurality of teeth 31 (that is, the respective upper end portions of the plurality of parts which cover the respective plurality of teeth 31), and plurality of second guide grooves 322 are formed at the bottom ends which cover the respective bottom ends of the plurality of teeth 31.
The stator 3 may be a segmented type in which laminar components including the individual teeth 31 are appropriately situated—for example, in which in between adjoining teeth 31 the outside section 30 is discontinuous.
Motors provided with the stator 3 are not limited to inner rotor types; they may also be of the outer rotor type.
Claims
1. An electric motor stator comprising:
- a plurality of teeth disposed in a radial form centered about a predetermined center axis;
- insulators respectively covering said plurality of teeth, along an upper end portion of said insulators that covers an upper end-one end in an orientation paralleling the center axis—of each of said plurality of teeth, said insulators being provided with a plurality of upper guide grooves rowed parallel to each other at a pitch approximately equal to the diameter of the conductors, for governing the wind-on position of the conductors; and
- a plurality of coils provided on each of said plurality of teeth by winding conductors onto said insulators through to multiple layers.
2. A motor stator as set forth in claim 1, wherein in each of said plurality of coils:
- on flanks, parallel to the center axis, of said teeth, first layer conductors and second layer conductors wound on said first layer conductors are arranged parallel to one another; and
- in the upper end of said teeth, said first layer conductors and said second layer conductors cross each other.
3. A motor stator as set forth in claim 2, wherein:
- along each flank of said teeth, said first layer conductor and said second layer conductors are parallel to the center axis; and
- in said upper end, said first layer conductors and said second layer conductors are angled with respect to a plane parallel to the center axis and perpendicular to said teeth.
4. A motor stator set forth in claim 2, wherein the plurality of upper guide grooves is formed at an incline with respect to a plane parallel to a center axis and perpendicular to said teeth.
5. A motor stator set forth in claim 4, wherein in the conductors as wound, the difference in radial distance from the center axis to the beginning and to the end of a one of the upper guide grooves is said pitch or less.
6. A motor stator set forth in claim 4, wherein the angle of inclination of each of the plurality of upper guide grooves with respect to a plane parallel to the center axis and perpendicular to said teeth is from 5° to 20°.
7. A stator motor set forth in claim 1, wherein:
- said insulators, in lower end portions thereof covering the lower ends of each of said plurality of teeth, are further provided with a plurality of guide grooves, arranged in parallel at said pitch, for governing the wind-on position of the conductors; and
- in the conductors as wound, the end of a one of the upper guide grooves and the beginning of a one of the lower guide grooves are formed on a straight line parallel to the center axis, and the end of a one of the lower guide grooves and the beginning of another of the upper guide grooves adjoining said one of the upper guide grooves are formed on a straight line parallel to the center axis.
8. A motor stator as set forth in claim 7, wherein the difference in radial distance from the center axis to the respective beginnings and ends of the plurality of upper guide grooves is said pitch or less.
9. A motor stator as set forth in claim 8, wherein:
- the difference in radial distance from the center axis to the respective beginnings and ends of the plurality of upper guide grooves is equal to said pitch; and
- the radial distances from the center axis to the respective beginnings and ends of the plurality of lower guide grooves are equal.
10. A motor stator as set forth in claim 8, wherein:
- the difference in radial distance from the center axis to the respective beginnings and ends of the plurality of upper guide grooves and the plurality of lower guide grooves is equal to one-half said pitch; and
- said insulators further comprise first partitions covering, along an orientation paralleling the center axis, said plurality of teeth from the center to the end with the plurality of upper guide grooves; and a second partition covering said plurality of teeth from the said center to the end with the plurality of lower guide grooves.
11. A motor stator as set forth in claim 8, wherein the angle of inclination of each of the plurality of upper guide grooves with respect to a plane parallel to the center axis and perpendicular to said teeth is from 5° to 20°.
12. An electric motor comprising:
- a first assembly having a stator as set forth in claim 1;
- a second assembly disposed opposing said stator, and having a field magnet for generating between said second assembly and said stator rotational force centered on the center axis; and
- a bearing mechanism for supporting said second assembly to enable it to rotate relative to said first assembly, centered on the center axis.
13. An electric motor stator comprising:
- a plurality of teeth disposed in a radial form centered about a predetermined center axis;
- insulators respectively covering said plurality of teeth; and
- a plurality of coils provided on each of said plurality of teeth by winding conductors onto said insulators through to multiple layers; wherein along an upper end portion of said insulators that covers an upper end—one end in an orientation paralleling the center axis—of each of said plurality of teeth, said insulators are provided, on the center-axis side of the tooth, or on the side thereof opposite the center axis, with a first protruding wall extending in the orientation in which the conductors are layered, and bulging radially; and said first protruding wall is disposed paralleling the orientation in which conductors in a first layer of a coil in the upper end portion of said insulators are wound, and is furnished with a feature for coming into contact with said first layer to govern the wind-on position of the conductors in said first layer.
14. A motor stator as set forth in claim 13, wherein said first protruding wall is disposed paralleling the orientation in which conductors in a second layer of said coil are wound, and is furnished with a feature for coming into contact with said second layer to govern the wind-on position of the conductors in said second layer.
15. A motor stator as set forth in claim 13, wherein:
- said insulators in the upper end portion thereof are further provided with a second protruding wall opposite said first protruding wall across the tooth, extending in the orientation in which the conductors are layered and bulging radially; and
- said second protruding wall is disposed paralleling the orientation in which the conductors in said first layer of a coil in the upper end portion of said insulators are wound, is furnished with a feature for coming into contact with said first layer to govern the wind-on position of the conductors in said first layer.
16. A motor stator as set forth in claim 15, wherein said second protruding wall is disposed paralleling the orientation in which conductors in a second layer of said coil in the upper end portion of said insulators are wound, and is further furnished with a feature for coming into contact with said second layer to govern the wind-on position of the conductors in said second layer.
17. A motor stator as set forth in claim 13, wherein in each of said plurality of coils:
- on flanks, parallel to the center axis, of said teeth, first layer conductors and second layer conductors on said first layer conductors are arranged parallel to one another; and
- in the upper end of said teeth, said first layer conductors and said second layer conductors cross each other.
18. A motor stator as set forth in claim 17, wherein:
- along each flank of said teeth, said first layer conductors and said second layer conductors are parallel to the center axis; and
- in said upper end, said first layer conductors and said second layer conductors are angled with respect to a plane parallel to the center axis and perpendicular to said teeth.
19. A motor stator as set forth in claim 13, further comprising:
- a plurality of tooth inner edge portions provided at the leading end of the center-axis side of each of said plurality of teeth, and, centered on the center axis, flaring along the perimeter to both sides of the teeth; wherein
- in each of the inner edge portions of said insulators that cover the surface of the inner edge portions of the plurality of teeth on the side opposite the center-axis side, said insulators are provided with inner-edge-portion guide grooves for governing the wind-on position of the conductors.
20. A motor stator as set forth in claim 13, wherein in insulator edge portions where upper end surfaces, being upper ends of each of said insulators, and flanks of said insulators, covering each flank of said plurality of teeth, are connected to each other, a plurality of edge grooves for governing the wind-on position of the first layer conductors in said coil is provided.
21. A motor stator as set forth in claim 20 wherein said insulators along an upper end portion thereof are further provided with a plurality of upper guide grooves rowed parallel to each other at a pitch approximately equal to the diameter of the conductors, for governing the wind-on position of the conductors.
22. A motor stator as set forth in claim 21, wherein:
- said insulators, in lower end portions thereof covering the lower ends of each of said plurality of teeth, are further provided with a plurality of guide grooves, arranged in parallel at said pitch, for governing the wind-on position of the conductors; and
- in the conductors as wound, the end of a one of the upper guide grooves and the beginning of a one of the lower guide grooves are positioned on a straight line parallel to the center axis, and the end of a one of the lower guide grooves and the beginning of another of the upper guide grooves adjoining said one of the upper guide grooves are formed on a straight line parallel to the center axis.
23. A motor stator as set forth in claim 13, wherein in upper end portions, being upper ends of each of said insulators, a plurality of upper guide grooves rowed parallel to each other at a pitch approximately equal to the diameter of the conductors is furnished for governing the wind-on position of the conductors.
24. An electric motor comprising:
- a first assembly having a stator as set forth in claim 13;
- a second assembly disposed opposing said stator, and having a field magnet for generating between said second assembly and said stator rotational force centered on the center axis; and
- a bearing mechanism for supporting said second assembly to enable it to rotate relative to said first assembly, centered on the center axis.
25. An electric motor stator comprising:
- a plurality of teeth disposed in a radial form centered about a predetermined center axis;
- a plurality of tooth inner edge portions provided at the leading end of the center-axis side of each of said plurality of teeth, and, centered on the center axis, flaring along the perimeter to both sides of the teeth
- insulators respectively covering said plurality of teeth; and
- a plurality of coils provided on each of said plurality of teeth by winding conductors onto said insulators through to multiple layers; wherein
- in each of the inner edge portions of said insulators that cover the surface of the inner edge portions of the plurality of teeth on the side opposite the center-axis side, said insulators are provided with inner-edge-portion guide grooves for governing the wind-on position of the conductors.
26. A motor stator as set forth in claim 25, wherein in each of said plurality of coils:
- on flanks, parallel to the center axis, of said teeth, first layer conductors and second layer conductors wound on said first layer conductors are arranged parallel to one another; and
- in the upper end of said teeth, said first layer conductors and said second layer conductors cross each other.
27. A motor stator as set forth in claim 26, wherein:
- along each flank of said teeth, said first layer conductors and said second layer conductors are parallel to the center axis; and
- in said upper end, said first layer conductors and said second layer conductors are angled with respect to a plane parallel to the center axis and perpendicular to said teeth.
28. A motor stator as set forth in claim 25, wherein inner-edge-portion guide grooves engage the first windings among the conductors in said second layer and in subsequent layers.
29. A motor stator as set forth in claim 28, wherein the conductors in said first layer are wound on said insulator from the side opposite the center axis toward the center axis, and the conductors the subsequent second layer are wound on said insulator from the center axis toward the side opposite the center axis.
30. An electric motor comprising:
- a first assembly having a stator as set forth in claim 25;
- a second assembly disposed opposing said stator, and having a field magnet for generating between said second assembly and said stator rotational force centered on the center axis; and
- a bearing mechanism for supporting said second assembly to enable it to rotate relative to said first assembly, centered on the center axis.
Type: Application
Filed: Jul 27, 2005
Publication Date: Feb 2, 2006
Applicant: Nidec Corporation (Kyoto)
Inventor: Motofumi Otsuji (Kyoto)
Application Number: 11/161,248
International Classification: H02K 1/00 (20060101);