Patent Application
20070143983
1. Field of the Invention
The present invention relates to a method and an apparatus of producing a stator by inserting one sides of a plurality of prepared coils into the slot of a stator core, inserting the other sides of the plurality of prepared coils into another slot, and spirally combining the coils as viewed from the one side of the stator core.
2. Description of the Related Art
As a method of producing a stator having a prepared coil can be a method of directly winding wire on the inner teeth of a stator core and a method of inserting a prepared coil into a slot of a stator core.
However, in these methods, only a coil obtained by concentrically winding wire on each magnetic pole can be formed. Therefore, a motor using such a stator core causes a nonuniform torque by a phenomenon in which the density of a circular magnetomotive force is nonuniform. Since the nonuniform torque causes the vibration and noise of a motor, there are various propositions to solve the problems.
A motor capable of conspicuously reducing the nonuniform torque can be formed using a stator (hereinafter referred to as a “spiral coil stator”) obtained by inserting one sides of the plurality of prepared coils into the slot of a stator core, inserting the other sides of the plurality of coils into another slot, and spirally combining the coils as viewed from the one side of the stator core.
The obtained stators have short coil ends, their heights are relatively equal, have compact shapes, and are not so nonuniform in torque when they are used in a motor, thereby reducing the vibration and noise of the motor.
However, the above-mentioned spiral coil stator has to be generated by inserting each of both sides of a coil into a slot one by one with another coil overlap each other, and it is hard to mechanically perform the process. Therefore, it is necessary to manually insert a prepared coil into the slot of a stator core, thereby resulting in poor operability in production and high production cost.
On the other hand, as a technique relating to a spiral coil stator, the patent document 1 discloses a method of producing a stator of a motor obtained by sequentially inserting in the direction of the circumference of a stator core a coil piece which is formed in a coil shape and has an inner circumference layer insertion side and an outer circumference layer insertion side into the stator core of the motor in which a plurality of slots having an outer circumference layer and an inner circumference layer, including: a plural wire piece inserting step, as a step of inserting a plural wire coil piece obtained by winding plural turns of a bundle of lead lines of plural fine lines into the slot, of sequentially inserting N plural wire coil piece into the outer circumference layer N pieces distant from the inner circumference layer of the slot in the coil piece insertion order; a single wire piece inserting step, as a step of inserting into the slot after the N-th plural wire coil piece the single wire coil piece obtained by winding plural turns of a single wire line, of inserting the single wire coil piece into the outer circumference layer N pieces distant from the inner circumference layer of the slot; and an interruption inserting step of interruption-inserting the outer circumference layer insertion side of the single wire coil piece after temporarily taking out the inner circumference layer insertion side of the plural wire coil piece from the slot when the outer circumference layer insertion side of the last N single wire coil pieces below the previously inserted inner circumference layer insertion side of the plural wire coil piece.
The patent document 2 discloses a brushless DC motor having a stator coil provided in a slot of a stator by dividing the number of coil lead lines to be prepared at one stage into a plurality of stages.
The patent document 3 discloses a method for producing a multiplayer armature coil for continuously winding a plurality of adjacent inphase coils such that they can be stored in every second slot using 2-layer winding and multiplayer armature coils having the number of slots less than 1 for each phase per pole. After a part of plural layers of continuously wound homopolar coils are stored in the respective slots, at least a part of the coils of other adjacent poles are stored in the slots, and the remaining adjacent continuously wound part or all of coils stored in the slots.
However, in the patent documents 1, 2, and 3 above, the above listed patent documents 1, 2, and 3 do not disclose a method of mechanically performing the operation of inserting a prepared coil into a slot of a stator core, but require manually inserting a coil, and cannot produce a coil at a lower cost on a commercial basis.
[Patent Document 1] Japanese Published Patent Application No. H10-42528
[Patent Document 2] Japanese Published Patent Application No. H10-28346
[Patent Document 3] Japanese Published Patent Application No. S56-41736
The present invention aims at providing a method and an apparatus for producing a stator at a low cost on a commercial basis as a spiral coil stator by designing the operation of mechanically and efficiently inserting a prepared coil in a spiral coil stator into a slot of a stator core.
To attain the above-mentioned objective, the method for producing a stator formed by inserting one side of each of a plurality of prepared coils into each slot, and then inserting the other side of each of the plurality of prepared coils into another slot according to the present invention uses a jig having on its outer circumference a holding groove group formed by a plurality of slit-shaped holding grooves with pitches of integral multiple pitches of a slot of a stator core;
projects one side of each of the plurality of prepared coils outside the jig, and arranges each coil along the circumference of the jig with the other side of each of the plurality of prepared coils inserted into the holding groove group;
mounts on the end surface of the jig an auxiliary member having a plurality of blade portions provided corresponding to one or more inner teeth of the stator core, and holds one side of each of the plurality of prepared coils in the corresponding space between the blade portions;
inserts the jig into the inner circumference of the stator core from the auxiliary member side, guides one side of each of the plurality of prepared coils by the auxiliary member, and pushes the one side of each of the plurality of prepared coils into a corresponding slot of the stator core by the edge portion of the jig; and
thus rotates the jig arranged at the inner circumference of the stator core, arranges the jig such that the holding groove can match a corresponding slot of the stator core, pushes the other side of each of the plurality of prepared coils toward the outer circumference by the push out device, and inserts the other side of each of the plurality of prepared coils into the corresponding slot of the stator core.
In the above-mentioned producing method, a plurality of coils can be inserted into a slot with each side overlapping another side in a spiral form, and a spiral stator core can be mechanically and efficiently produced.
In the above-mentioned producing method, it is desired that overlapped coils are inserted by repeating two or more times the operation of inserting one side of each of the plurality of prepared coils and the other side of each of the plurality of prepared coils into the slots by the jig. According to this aspect of the present invention, a sufficient number of coils can be inserted into the slots by repeatedly performing the operation two or more times although the restrictions on the inner diameter of a stator core, etc. do not allow a sufficient width or length of the holding groove of a jig, and a sufficient number of coils cannot be inserted into the slots in one inserting operation. In addition, since spirally overlapping coils can be inserted as a plurality of layers, coil ends can be more equally shortened.
Furthermore, it is desired that a push out jig obtained by arranging a tabular pusher which narrows toward its tip on the holding groove is used as the push out device, the tip of the pusher of the push out jig is inserted into each of the corresponding holding grooves, the other side of the coil inserted into the holding groove is pushed out toward the outer circumference, and inserted into the corresponding slot of the stator core. According to this aspect of the present invention, the sides of a plurality of coils held in the holding grooves of the jig can be simultaneously inserted into the corresponding slots by inserting and pushing the tip of the pusher of the push out jig into each of the corresponding holding grooves.
It is also desired that a device for generating repulsion by an eddy-current by passing an electric current through a coil is used as the push out device, and the coil is pushed out by the repulsion toward the outer circumference from the holding groove of the jig, thereby inserting the coil into the corresponding slot of the stator core. According to this aspect of the present invention, the side of a coil can be inserted into a corresponding slot by a simple operation of passing a current through the coil.
Furthermore, it is desired that a device for generating a Lorentz force by passing a current through a coil by generating a magnetic field traversing the holding groove of the jig is used as the push out device, and the coil is pushed out toward the outer circumference from the holding groove of the jig by the Lorentz force, and inserted into the corresponding slot of the stator core. According to this aspect of the present invention, the side of a coil can be inserted into a corresponding slot by a simple operation of passing a current through the coil.
It is also desired to pass a direct current or an alternating current of a low frequency of 20 Hz or lower through the coil inserted into the slot of the stator core, and press the coil toward the stator core. According to the aspect of the present invention, the inserted coil can be correctly held in the slot.
Furthermore, it is also desired to rotate a jig while pushing one side of each of the plurality of prepared coils toward the stator core and the other side of each of the plurality of prepared coils toward the jig with a direct current or an alternating current at a low frequency of 20 Hz or lower flowing through the coil when the jig is rotated the slot of the stator core with one side of each of the plurality of prepared coils inserted into the corresponding slot of the stator core and the other side of each of the plurality of prepared coils inserted into the holding groove of the jig and held therein. According to the aspect of the present invention, since the jig can be rotated with one side of each of the plurality of prepared coils pressed toward the stator core, and the other side of each of the plurality of prepared coils toward the jig, the insulating coating wire can be protected against damage between the jig and the stator core.
Additionally, it is also desired to press using a pair of rotation auxiliary jigs each coil end projecting from the stator core and both end surfaces of the jig toward the jig in the axis direction when the jig is rotated for the slot of the stator core with one side of each of the plurality of prepared coils inserted into the corresponding slot of the stator core and the other side of each of the plurality of prepared coils inserted into the holding groove of the jig and held therein. According to the aspect of the present invention, the by pressing the coil end toward the jig in the axis direction by the rotation auxiliary jigs, the loop of the coil is enlarged, thereby reducing the force applied to the jig by the enlargement of the coil against the rigidity of the coil when the jig rotates, and preventing the deformation of the jig.
Furthermore, it is desired to insert one by one the side of each coil into each slot in one operation by inserting one side of each of the plurality of prepared coils into every second slot of a stator core and then inserting the other side of each of the plurality of prepared coils into the remaining slot. According to the aspect of the present invention, since the half number of holding grooves as the slots of the stator core can be formed in the jig, the width and the length of the holding groove can be sufficiently set, and the total sectional area of the coil wire that can be held on the holding groove, that is, the total sectional area of the coil wire that can be inserted into the slots of the stator core in one operation, can be increased relatively largely.
Furthermore, when the total sectional area of the coil inserted into the slots of the stator core is Scu, the inner radius of the stator core is Rin, the number of slot is Slot, and the width of the holding groove is d, it is desired that the present invention is applied to the stator core satisfying the equation of Scu>Rin·d−Slot·d2/4π.
According to the aspect of the present invention, the coil wire held in the holding groove of the jig can be easily and correctly inserted into the slot of the stator core.
On the other hand, the apparatus for producing a stator formed by inserting one side of each of the plurality of prepared coils into a slot of a stator core, and then inserting the other side of each of the plurality of prepared coils into another slot according to the present invention includes:
a jig having on its outer circumference a holding groove group that can be inserted into the inner circumference of the stator core, and formed by a plurality of slit-shaped holding grooves with pitches of integral multiple pitches of the slot of the stator core;
an auxiliary member having a plurality of blade portions provided corresponding to one or more inner teeth of the stator core; and
a push out device for inserting the coil inserted into the holding groove group of the jig into the corresponding slot.
According to the above-mentioned producing apparatus, one side of each of the plurality of coils is projected outside the jig, and the other side of each of the plurality of prepared coils is inserted into the holding groove group, each coil is arranged along the circumference of the jig, an auxiliary member having a plurality of blade portions provided corresponding to one or more inner teeth of the stator core is mounted on the end surface of the jig, one side of each of the plurality of prepared coils is held in the space between the corresponding blade portions, and the jig is inserted from the auxiliary member side into the inner circumference of the stator core, and guiding one side of each of the plurality of prepared coils by the auxiliary member, and pushing the side into the corresponding slot of the stator core by the edge portion of the jig. Thus, by rotating the jig arranged on the circumference of the stator core, positioning the jig such that the holding groove can match the corresponding slot of the stator core, pushing the other side of each of the plurality of prepared coils by the push out device toward the outer circumference, inserting the side into a corresponding slot of the stator core, thereby capable of inserting each one side of a plurality of coils into the slot in such a way that spiral overlapping can be performed, and mechanically and efficiently producing a spiral stator.
According to the present invention, a plurality of coils can be inserted into the slot with each side overlapping another side in a spiral form, and a spiral stator can be mechanically and efficiently produced.
The mode for embodying the present invention is explained below by referring to the attached drawings
In
The producing apparatus has a substantially cylindrical jig 20 inserted inside the inner circumference of the stator core 10. The jig 20 has a central axis portion 21, a hole 22 provided at the center of the top surface of the axis portion 21, and a plurality of holding grooves 23 radially formed from the outer circumference of the axis portion 21 from the outer circumference of the axis portion 21 toward the outer circumference of the cylindrical jig.
The holding groove 23 is formed with pitches of integral multiple pitches of the slot 12 of the stator core 10. In this mode for embodying the present invention, the holding groove 23 is formed with double the pitch of the slot 12 of the stator core 10, and the holding grooves 23 a half in number of the slots 12 are formed. In this mode for embodying the present invention, the holding groove 23 is radially formed from the outer circumference of the axis portion 21 of the jig 20 along the radius of the jig, but the holding groove 23 can be, for example, spirally curved, etc., or tilted relative to the radial array. In this case, the number of coil sides stored in the holding grooves can be increased.
The coil C is arranged along the circumference of the jig 20 with one side Ca projected outside the jig 20, and the other side Cb inserted into the holding groove 23 of the jig 20. Especially, as shown in
On one end surface of the jig 20, an auxiliary member 70 is arranged. The auxiliary member 70 is cylindrical on the whole, and has a base portion 71 and a plurality of tabular blade portions 72 arranged from the base portion 71 along the circumference at predetermined intervals extending in the axis direction. Between the blade portions 72, a slit-shaped space 73 is formed. The auxiliary member 70 is provided such that the separate end portion of the blade portion 72 touches one end surface of the jig 20. At this time, one side Ca of the coil C held by the jig 20 in the aspect described above is inserted into each corresponding space 73 of the blade portion 72, and one side Ca is set in the state of projecting toward the outer circumference.
The circumference of the blade portion 72 of the auxiliary member 70 touches the inner circumference of the inner tooth 11 of the stator core 10, and the space 73 is positioned corresponding to the slot 12 of the stator core 10 in the rotation and positioning processes, thereby inserting the auxiliary member 70 into the stator core 10.
In
A circular body 33 is attached to the outer circumference of the axis 31 such that it can be slid vertically. The circular body 33 has inner teeth to be engaged with the guide groove 32 of the axis 31 at the inner circumference of the circular body 33. At the lower surface of the circular body 33, a plurality of tabular pushers 34 are attached, and each pusher 34 is engaged with the corresponding guide groove 32 of the axis 31, and radially attached to the axis 31. The pusher 34 has a taper portion 34a tapering toward the lower portion of the axis 31. The guide groove 32 of the axis 31 and the pusher 34 are, in this mode for embodying the present invention, formed by the number and at the pitch such that they can be inserted every second slot 12 of the stator core 10.
As described above, the other side Cb of the coil C is inserted into the holding groove 23, and a plurality of coils C are arranged along the circumference of the jig 20. In this state, the coil C is interposed between the spaces 73 of the blade portion 72 of the auxiliary member 70, and the auxiliary member 70 is mounted on the end surface of the jig 20. The coil C is held with one side Ca projected toward outside the jig 20 and the auxiliary member 70.
In this state, the jig 20 is inserted from the auxiliary member 70 side into the inner circumference of the stator core 10. At this time, as shown in
Thus, when the jig 20 is inserted from the auxiliary member 70 side into the inner circumference of the stator core 10, the edge portion 27 of the jig 20 pushes the one side Ca of the coil C into the slot 12 of the stator core 10 using the space 73 between the blade portions 72 as a guide as shown in
Next, as shown in
The circular body 33 is slid down on the axis 31, and the pusher 34 is inserted into the holding groove 23 from the lower end. Then, the other side Cb of the coil C inserted into the holding groove 23 is pushed by the taper portion 34a of the pusher 34 toward the outer circumference and inserted into the slot 12 of the stator core 10.
Thus, the one side Ca of the coil C is inserted into the slot 12, and the other side Cb of the coil C is inserted into the fifth slot 12 ahead from the one side Ca of the coil C. Since the inserting operation is performed simultaneously on a plurality of coils C, the coils C are inserted such that the coil ends look spiral from the end surface of the stator core 10 as shown in
After the one side Ca of the coil C held by the jig 20 is inserted, the jig 20 is rotated and positioned, and the other side Cb is inserted. Therefore, the coil C is appropriately expanded in the direction of the circumference and inserted. Furthermore, unlike the method of inserting the coil from one end of a normal stator core to the other end, the coil C is inserted from the inner circumference toward the inner tooth 11 of the stator core 10. Therefore, the coil C is appropriately expanded in the direction of the circumference and inserted. As a result, the coil end can be reduced.
Since the stator core is arranged in the direction of the circumference with each coil C partially overlapping each other, the nonuniform cogging torque can be considerably reduced in a motor, thereby conspicuously decreasing the vibration and noise. Furthermore since the coil end can be compact and can evenly project, a compact stator core 10 and a compact motor using the stator core 10 can be realized.
Thus, in the formed stator core, as shown in
In this method, although a sufficient amount of coils C cannot be inserted and held in inserting one slot 12 into the holding groove 23 of the jig 20, a sufficient amount of coils C can be inserted as shown in
In this mode for embodying the present invention, the power supply 40 is connected to both end portions of the coil C with the jig 20 formed by a nonmagnetic substance such as, for example, aluminum inserted into the inner circumference of the stator core 10, one side Ca of the coil C inserted into the corresponding slot 12 of the stator core 10, and the other side Cb inserted into the corresponding holding groove 23 of the jig 20, thereby passing an electric current through the coil C. In this case, the jig 20 is rotated and positioned such that the holding groove 23 of the jig 20 holding the other side Cb of the coil C can match the fifth slot 12 ahead for the slot 12 into which the side Ca is inserted. In this state, if a sudden transient current is passed through the coil C, the repulsion by the eddy-current works and causes the effect of the force to push out the coil C toward the outer circumference. As a result, the other side Cb of the coil C can be inserted into the corresponding slot 12. Thus, since the coil can be pushed out toward the outer circumference only by passing the current, the structure of the producing apparatus can be simplified, and the coil can be quickly inserted.
In this mode for embodying the present invention, a permanent magnet M is embedded in the radial partition positioned between the holding grooves 23 of the jig 20, and the permanent magnet M forms a circular magnetic field G across the holding groove 23. In this state, when the current passes through the coil C from a power supply 40, a Lorentz force works, a push out force to push out the other side Cb of the coil C held by the holding groove 23 is generated toward the outer circumference. As a result, the other side Cb can be inserted into a corresponding slot 12.
This mode is basically the same as the mode shown in
In this mode, a drawing device 50 is used as a push out device for the coil C. The drawing device 50 is provided on both end surfaces of the stator core 10, and has an arm 51 provided as possibly traveling forward and backward near the both end surfaces along the radius, and a hook 52 attached at the tip of the arm 51. Then, the arm 51 is moved toward the inner circumference of the stator core 10, the hook 52 is hung on other side Cb of the coil C, and then the arm 51 is returned toward the outer circumference, thereby drawing the other side Cb of the coil C toward the outer circumference. By a pair of drawing devices 50 arranged near both end surfaces of the stator core 10 pulling the other side Cb of the coil C toward the outer circumference with the side hung on the hook 52, the other side Cb can be pushed into the corresponding slot 12 from the holding groove 23.
In
In this mode for embodying the present invention, an air pressure device 60 is used as a push out device. The air pressure device 60 has an air pressure machine 61 for supplying compressed air, a tube for supplying the air, and a nozzle 63 attached at the tip portion of the tube 62. The nozzle 63 is cylindrical, and a number of spouts 64 are formed on the circumference surface. The jig 20 is provided with a central hole 25. The nozzle 63 is inserted into the hole 25. In the holding groove 23 of the jig 20, a slit-shaped aperture led to the hole 25 is formed at the end portion in the side end portion of the inner circumference. Therefore, by arranging the nozzle 63 in the hole 25 of the jig 20 and supplying compressed air to the nozzle 63 through the tube 62 by the air pressure machine 61, the compressed air is blown from the spouts 64 of the nozzle 63, the compressed air is supplied from the aperture at the inner circumference of the holding groove 23 of the jig 20, and the other side Cb of the coil C held in the holding groove 23 is pushed into the predetermined slot 12. The air pressure device 60 can also be used with each of the above-mentioned push out devices.
In this mode for embodying the present inventions the number of the holding grooves 23 of the jig 20 is the same as the number of the slot 12 of the stator core 10. That is, the holding grooves 23 are provided with the pitch of the slot 12. The other Cb is inserted into the holding groove 23 of the jig 20 and held therein, and each coil C is arranged along the circumference of the jig 20 with one side Ca exposed outside, and the auxiliary member 70 is provided in this state, and one side Ca of the coil C is exposed outside through the space 73 of the blade portion 72 of the auxiliary member 70. Then, the jig 20 is rotated and positioned such that the blade portion 72 of the auxiliary member 70 can touch the inner circumference of each inner tooth 11 of the stator core 10, and the jig 20 is inserted into the inner circumference of the stator core 10 from the auxiliary member 70 side, thereby pressing one side Ca of the coil C projected outside the edge portion 27 of the jig 20, and inserting the one side Ca of the coil C into the corresponding slot 12 of the stator core 10 through the space 73 of the blade portion 72.
Next, as shown in
In the thus obtained stator core 10, the coil having one side Ca of the coil C positioned on the outer circumference side and the other side Cb positioned on the inner circumference side has coil ends spirally overlapping on the end surface of the stator core 10.
That is, when the line of the coil C is arranged in a line on the holding groove 23 of the jig 20, and inserted into the slot 12 of the stator core 10 from the holding groove 23, and by assuming that the total sectional area of the coils inserted into the slots 12 is Scu, the inner radius of the stator core 10 is Rin, the number of slots is Slot, and the width of the holding groove is d, the following equations 1 and 2 hold.
(when only one coil is inserted into each slot: for example, in the case of the mode for embodying the present invention shown in
Scu>(Rin−Rdd)×d={Rin−(d×Slot/(4π))}×d=Rin×d−Slot×d2/4π [equation 1]
(in the case where two coils are inserted into each slot: for example, in the case of the mode for embodying the present invention shown in
Scu>(Rin−Rdd)×d×2={Rin−(d×Slot/(2π))}×d×2=2×Rin×d−Slot×d2/π [equation 2]
Therefore, for the stator core to which the above-mentioned equations can be applied, a line of coils C is arranged for the holding groove 23 of the jig 20, and can be inserted into the slot 12 of the stator core 10 from the holding groove 23, thereby appropriately realizing the producing method according to the present invention.
In the mode for embodying the present invention, when the one side Ca of the coil C is inserted into the slot 12 of the stator core 10, the jig 20 is rotated by predetermined degrees, and the holding groove 23 holding the other side Cb is positioned in a predetermined slot 12, the coil ends projecting from the both end surfaces of the stator core 10 and the jig 20 are pressed by a pair of rotation support jigs 80 in the axis direction toward the jig 20.
That is, as shown in
In
As a result, when the jig 20 is rotated against the stator core 10 and the loop of the coil C is expanded, the pressure board 83 of the rotation support jig 80 presses the coil ends, thereby expanding the coil C in the width direction, expanding the coil against the rigidity of the coil C, reducing the force exerted on the jig 20, and preventing the partition portions of the holding grooves 23 of the jig 20 from being deformed.
In each of the above-mentioned embodiments, the coil C can be held in the slot 12 using the electromagnetic suction. For example, by continuously passing an electric current through the coil C after inserting the one side Ca (C1a, C2a), the one side Ca (C1a, C2a) can be pressed to the stator core 10 as a magnetic substance. In the case of the push out device using the Lorentz force, the electric current is passed in the direction in which the other side Cb (C1b, C2b) does not projected from the holding groove 23 or the current through the electromagnet is stopped and remove the magnetic field G when the electromagnet Em is used. Thus, the one side Ca (C1a, C2a) can be more correctly held in the slot 12.
By similarly passing the current continuously through the coil C after inserting the other side Cb (C1b, C2b), the one side Ca (C1a, C2a) and the other side Cb (C1b, C2b) can be correctly held in the slot 12.
By continuously passing the current through the coil C when the jig 20 is rotated and positioned after inserting the one side Ca (C1a, C2a), the electromagnetic suction prevents the one side Ca (C1a, C2a) from projecting from the slot 12 by the force generated by the rotation of the jig 20, and from being pressed between the stator care 10 and jig 20. In the case of the push out device using the Lorentz force, the electric current is passed in the direction in which it does not project from the holding groove 23, thereby correctly holding the other side Cb (C1b, C2b) on the holding groove 23, preventing the other side Cb (C1b, C2b) from projecting from the holding groove 23 by the force of the rotation of the jig 20, and then preventing it from being pressed between the stator core 10 and the jig 20.
The current passed to generate the electromagnetic suction can be a current whose repulsion by the eddy-current in the coil C can be ignored. For example, it can be a direct current or an alternating current of 20 Hz or less.
In the above-mentioned mode for embodying the present invention, the other side Cb (C1b, C2b) is inserted from the slot into which the one side Ca (C1a, C2a) is inserted into the fifth slot 12 ahead, but the position of the slot is not limited to the fifth.
In
| Number | Date | Country | Kind |
|---|---|---|---|
| 2005-362939 | Dec 2005 | JP | national |
