JP5327701B2 - Linear motor - Google Patents

Description

  The present invention mainly relates to the configuration of a linear motor used in a feed mechanism of a machine tool, a positioning device of a semiconductor manufacturing apparatus, or the like.

2. Description of the Related Art Conventionally, a permanent magnet synchronous linear motor used for a machine tool feed mechanism, a semiconductor manufacturing apparatus positioning device, and the like includes a field magnetic pole in which permanent magnets are arranged at an equal pitch on a field iron core, an armature core, and the core. The armature is provided with an armature coil that is concentratedly wound around the teeth, and either the field magnetic pole or the armature can be used as a stator and the other as a mover.
The linear motor is required to generate little heat, and as a motor with low heat generation, there are many magnetic fluxes collected by the teeth wound around the coil, and the relationship between the number of magnetic poles by the permanent magnet and the number of teeth of the armature core is Conventionally, 8n: 9n (n: natural number) or 5n: 6n (n: natural number) is used.
A linear motor is called a moving coil type linear motor with a field pole as a stator and an armature as a mover, and a field magnet as a mover and armature as a moving magnet type linear motor. However, here, the former moving coil type linear motor will be mainly described.
FIG. 7 is a sectional side view of a moving coil linear motor showing the first prior art.
In FIG. 7, 1 is a field magnetic pole, 2 is a field iron core, 3 is a permanent magnet, 4 is an armature, 41 is an armature core, 5 is a tooth, and 6 is an armature winding.
The field magnetic pole 1 on the stator side is formed by arranging a plurality of permanent magnets 3 on the field core 2 at equal pitches so that the polarities are alternately different. Further, the armature 4 on the movable element side is disposed opposite to the magnetic pole surface of the permanent magnet 3 through a magnetic gap. The armature 4 includes an armature core 41 formed by punching an electromagnetic steel sheet in a comb shape and forming a plurality of teeth 5 at the tip, and an armature winding 6 formed by winding a coil around the plurality of teeth 5 by concentrated winding. Consists of In this example, the relationship between the number of magnetic poles by the permanent magnet and the number of teeth of the armature core is a linear motor of 8n: 9n (n: natural number), and n = 1 is shown.
FIG. 8 is a side sectional view of a moving coil linear motor showing the second prior art. 8 is the same as the components described in FIG. 7, and thus the same reference numerals are given and description thereof is omitted.
Unlike the second prior art, this example shows a case where the relationship between the number of magnetic poles by the permanent magnet and the number of teeth of the armature core is a linear motor of 4n: 3n (n: natural number) and n = 2. It has become.
Further, in order to reduce the cogging thrust and to enhance the insulation of the motor, a motor in which every other tooth is concentratedly wound has been invented. (For example, see Patent Document 1)
Patent No. 4055773

However, the linear motor generally has a long armature core tooth depth, and the relationship between the number of magnetic poles of the permanent magnet and the number of teeth of the armature core is 8n: 9n (n: natural number) or 5n: 6n (n : In a linear motor (natural number), the teeth pitch is short relative to the magnetic pole pitch, so there is a lot of magnetic flux collected by the coil wound around the coil, but the coil pitch is short relative to the magnetic pole pitch. There was a problem that the magnetic flux increased and it was easily affected by thrust saturation.
In addition, in the case of a linear motor having a 4n: 3n (n: natural number) relationship between the number of magnetic poles of permanent magnets and the number of teeth of an armature core, the coil pitch is long with respect to the magnetic pole pitch. However, since the teeth pitch is longer than the magnetic pole pitch, there is a problem that the magnetic flux collected by the teeth wound around the coil is small.
Further, in the linear motor described in Patent Document 1, the relationship between the number of magnetic poles by the permanent magnet and the number of teeth of the armature core is the same as that of the linear motor such as 4n: 3n (n: natural number), and the cogging thrust is reduced. However, there is a problem that the harmonic component of the induced voltage is large and the control characteristics are deteriorated.
The present invention has been made in view of such problems, and is less susceptible to thrust saturation, has a large amount of magnetic flux collected by the teeth wound around the coil, and reduces harmonic components of the induced voltage. An object of the present invention is to provide a linear motor that can handle the above.

In order to solve the above problem, the invention described in claim 1 is directed to a field magnetic pole in which a plurality of permanent magnets having different polarities are alternately arranged on a field core at an equal pitch, and the field magnetic pole and the magnetic gap are arranged. Between the field magnetic pole and the armature, the armature including an armature core and an armature winding formed by winding the coil in a concentrated winding around a tooth of the core. In a linear motor that is relatively driven with one of them as a stator and the other as a mover, the armature core teeth include a first tooth that winds the coil, and a first tooth that does not wind the coil. The relationship between the number of magnetic poles by the permanent magnet and the number of teeth of the armature core is 4n: 6n-1 (n: natural number), and the tooth pitch of the armature core Is 2τ / 3 with respect to the magnetic pole pitch τ And the coil pitch wound around the armature core is 4τ / 3 with respect to the magnetic pole pitch τ, and the second tooth has a rectangular shape, and the first tooth is In addition, it is characterized in that a projecting portion that realizes a divergent shape is provided at the tip portion and has a substantially rectangular shape that is longer than the second teeth .
According to a second aspect of the present invention, in the linear motor according to the first aspect, a length Ltd2 in a direction orthogonal to the magnet array of the second tooth that does not wind the coil is a length that the coil is wound. It is characterized by being shorter than the length Ltc2 in the direction orthogonal to the magnet row of one tooth.
The invention according to claim 3, in the linear motor according to claim 2, the length Ltd2 of the second teeth without winding the coil, the length of the first tooth winding the said coil Ltc2 The ratio Ltd2 / Ltc2 is set to 0.5 ≦ (Ltd2 / Ltc2) <1.
According to a fourth aspect of the present invention, in the linear motor according to any one of the first to third aspects, auxiliary teeth having a shape different from the shape of the first teeth are provided at both ends of the armature core. It is characterized by providing.

According to the first aspect of the present invention, it is possible to obtain a configuration of a linear motor that is less susceptible to thrust saturation and has a large amount of magnetic flux collected by the teeth wound around the coil.
In addition , a linear motor configuration can be obtained in which the magnetic flux collected by the teeth wound with the coil is large.
According to the second and third aspects of the invention, in addition to the above-described effect, the harmonic component of the induced voltage of the coil can be reduced and the control characteristics can be improved .
According to the invention described in 請 Motomeko 4, in addition to the effects described above, to obtain a reduced linear motor arrangement of cogging thrust.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a sectional side view of a moving coil type linear motor showing a first embodiment of the present invention. It should be noted that constituent elements of the present invention that are the same as those in the prior art are assigned the same reference numerals, and descriptions thereof are omitted, and only different points will be described.
In FIG. 1, 51, 52, 53, 54, 55, and 56 are teeth formed by winding coils, 71, 72, 73, 74, and 75 are teeth that do not wind coils, 61, 62, 63, 64, and 65. , 66 are armature windings.
The present invention is different from the prior art as follows.
That is, the coils 51 are wound around the teeth 51, 52, 53, 54, 55, 56 of the armature core 41 by concentrated winding to form the armature windings 61, 62, 63, 64, 65, 66, and the coils Between the wound teeth 51, 52, 53, 54, 55, and 56, teeth 71, 72, 73, 74, and 75 that do not wind coils are arranged, respectively, and the teeth that wind the coils and the coils are wound. This is the point that teeth that do not rotate are placed alternately.
In the linear motor, the relationship between the number of magnetic poles by the permanent magnet 3 and the number of teeth of the armature core 41 is 4n: 6n−1 (n: natural number), and the tooth pitch of the armature core 41 is the magnetic pole pitch τ. On the other hand, the coil pitch of the armature windings 61, 62, 63, 64, 65, 66 wound around the teeth 51, 52, 53, 54, 55, 56 of the armature core 41 is 2τ / 3. to the magnetic pole pitch tau, there as 4.tau / 3, the direction of the length L _td1 parallel coil and winding no teeth magnet array has a length in a direction parallel to the magnet rows of teeth for winding the coil L _tc1 It has a shorter configuration.
Here, the armature windings are wound in the normal winding every other tooth from the left end tooth 51 of FIG. 1 and arranged so that the phase order is the U phase, the V phase, and the W phase. FIG. 1 shows the case where n = 2.
By the way, in the above description, the armature winding is wound in the normal winding every other tooth from the left end tooth in FIG. 1, and the phase sequence is arranged to be the U phase, the V phase, and the W phase. However, the winding may be wound in the reverse direction so that the phase sequence is the U phase, the V phase, and the W phase.
Moreover, although the example arrange | positioned so that it may become a U phase, a V phase, and a W phase also about the phase order was described, the V phase, the W phase, the U phase or the W phase, the U phase, the V phase, or the W phase, the V phase , U phase, V phase, U phase, W phase, or U phase, W phase, V phase.

FIG. 2 is a diagram showing the relationship between the mover position and the interlinkage magnetic flux in the first embodiment, and shows the magnetic flux waveform collected by the teeth.
In order to confirm the effects of the first embodiment, for example, the dimensions of the armature core _{L td1 = 6.9 [mm],} L tc1 = 1.0 [mm], L td2 = L tc2 = 34.5 [ mm] was simulated. From FIG. 2, comparing the case where the armature core is not wound (first embodiment) and the case where the armature core is not wound (prior art), the former armature core is not wound. In the case, the effect of increasing the magnetic flux collected by the teeth wound around the coil was confirmed. Moreover, since the coil pitch was longer than the magnetic pole pitch, the effect of being less susceptible to thrust saturation was also confirmed.
Therefore, according to the first embodiment, the prior art has wound the coils around all the teeth, but the teeth 51, 52, 53, 54, 55, 56 that wind the coils as shown in FIG. The teeth 61, 62, 63, 64, 65 that do not wind the coil are alternately arranged, and the teeth that wind the coil are disposed between the six teeth that constitute the conventional armature. It is possible to provide a linear motor that is less susceptible to saturation and has the effect of increasing the amount of magnetic flux collected by the teeth wound around the coil.

FIG. 3 is a sectional side view of a moving coil type linear motor showing a second embodiment of the present invention. Since the second embodiment is the same as the components described in the first embodiment, description thereof is omitted.
In the linear motor (FIG. 1) of the first embodiment, the teeth 71, 72, 73, 74, 75 that do not wind the coil are arranged between the teeth 51, 52, 53, 54, 55, 56 wound with the coil. in the configuration, the teeth of the length L _tc2 and winding without teeth the coil length L _td2 winding the coil but showed equal example, a linear motor of the second embodiment, the 3 The length L _{td2 of the} teeth around which the coil is not wound is shorter than the length L _{tc2 of the} teeth _around which the coil is wound.

FIG. 4 is a diagram showing the relationship between the mover position and the interlinkage magnetic flux in the second embodiment, and shows the magnetic flux waveform collected by the teeth.
In order to confirm the effects of the second embodiment, for example, the dimensions of the armature core _{L td1 = 6.9 [mm],} L tc1 = 1.0 [mm], L tc2 = 34.5 in [mm] In some cases, the simulation was performed by changing L _td2 = 34.5 [mm], 32.0 [mm], and 29.5 [mm].
If the length L _{td2 of the} teeth not wound with the coil is made shorter than the length L _{tc2 of the} teeth wound with the coil, the interlinkage magnetic flux waveform of the coil approaches a sine wave as shown in FIG. The effect of improving the control characteristics to reduce the harmonic component of the voltage was confirmed.
Therefore, according to the second embodiment, the length L _{td2 of the} tooth that does not _wind the coil is made shorter than the length L _{tc2 of the} tooth that _winds the coil. It is possible to provide a linear motor capable of reducing the harmonic component of the induced voltage.

FIG. 5 is a sectional side view of a moving coil type linear motor showing a third embodiment of the present invention.
In the linear motors of the first and second embodiments (FIGS. 1 and 3), the shape of the teeth 51, 52, 53, 54, 55, and 56 wound with the coil, and the teeth 71 not wound with the coil, 72, 73, 74, and 75 have the same rectangular shape, but the linear motor of the third embodiment has, for example, a sharp tip shape of the teeth around which the coil is wound as shown in FIG. The tip shape is different from that of the teeth that do not wind the coil.

  Therefore, in the third embodiment, since the tip shape of the tooth around which the coil is wound is different from the tip shape of the tooth around which the coil is not wound, the area of the tooth tip is increased compared to the root of the tooth. There is an effect that the magnetic flux collected by the teeth wound with the coil is further increased than in the first and second embodiments.

FIG. 6 is a side sectional view of a moving coil type linear motor showing a fourth embodiment of the present invention.
The fourth embodiment is different from the third embodiment in that auxiliary teeth 81 and 82 having shapes different from the shapes of the teeth 51 and 56 around which the coils are wound are disposed at both ends of the armature core 41. .

  Since the auxiliary teeth are arranged in the fourth embodiment, there is an effect that the cogging thrust is reduced in addition to the effects obtained in the first to third embodiments.

1 is a side sectional view of a moving coil type linear motor showing a first embodiment of the present invention; It is a figure which shows the relationship between the needle | mover position and linkage flux in 1st Example, Comprising: The thing showing the magnetic flux waveform which teeth collect, The sectional side view of the moving coil type | mold linear motor which shows 2nd Example of this invention, It is a figure which shows the relationship between the needle | mover position and linkage flux in 2nd Example, Comprising: The thing showing the magnetic flux waveform which teeth collect, Side sectional view of a moving coil type linear motor showing a third embodiment of the present invention, The sectional side view of the moving coil type | mold linear motor which shows 4th Example of this invention, Side sectional view of a moving coil linear motor showing the first prior art, Side sectional view of a moving coil linear motor showing the second prior art

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Field magnetic pole 2 Field iron core 3 Permanent magnet 4 Armature 41 Armature core 5, 51, 52, 53, 54, 55, 56 Teeth which winds a coil,
6, 61, 62, 63, 64, 65, 66 armature winding,
71, 72, 73, 74, 75 Teeth that do not wind coils,
81, 82 Auxiliary teeth

Claims (4)

Field magnetic poles in which a plurality of permanent magnets having different polarities alternately arranged on a field iron core at an equal pitch,
The armature having an armature core and an armature winding formed by winding a coil around the armature core and a concentrated winding around the field magnetic pole and a magnetic gap. In a linear motor that is configured to travel relatively using either a field magnetic pole or the armature as a stator and the other as a mover,
The teeth of the armature core are composed of a first tooth that winds the coil and a second tooth that does not wind the coil.
The relationship between the number of magnetic poles by the permanent magnet and the number of teeth of the armature core is 4n: 6n-1 (n: natural number)
And the tooth pitch of the armature core is 2τ / 3 with respect to the magnetic pole pitch τ, and the coil pitch wound around the armature core is 4τ / 3 with respect to the magnetic pole pitch τ,
The second tooth has a rectangular shape,
The linear motor according to claim 1, wherein the first tooth has a substantially rectangular shape that is provided with a projecting portion that realizes a divergent shape at a tip portion and is longer than the second tooth . The length Ltd2 in the direction orthogonal to the magnet array of the second teeth that does not wind the coil is shorter than the length Ltc2 in the direction orthogonal to the magnet array of the first tooth that winds the coil The linear motor according to claim 1. The length Ltd2 of the second tooth that does not wind the coil, and the length Ltc2 of the first tooth that winds the coil
The linear motor according to claim 2 , wherein the ratio Ltd2 / Ltc2 is set to 0.5 ≦ (Ltd2 / Ltc2) <1.   The linear motor according to any one of claims 1 to 3, wherein auxiliary teeth having a shape different from the shape of the first teeth are provided at both ends of the armature core.

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