JP2000333437A - Linear motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To ensure good insulation between armature coils and facilitate assembling work and reduce ripples in the driving force. SOLUTION: A linear motor comprises a secondary-side part holder, installed with a secondary-side part constituted of a plurality of field magnetic poles and an armature part holder installed with an armature part 4, which is disposed facing the secondary-side part via a space and has a plurality of concentratedly wound armature coils 6. The secondary-side part and the armature part 4 are disposed facing each other, in parallel in the advancing direction. The field magnetic poles of the secondary-side part are disposed in the advancing direction of the movable part at a pitch Pm, so that two adjacent poles are of different polarities. The armature coils 6 are also disposed in the advancing direction of the movable part at a pitch Pc. The pole pitch Pm and the coil pitch Pc are such that the relationship Pc=5/3×Pm is satisfied.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a linear motor for constant-speed feed and high-speed positioning, which requires a small thrust ripple and a small yaw and pitch of a mover.

[0002]

2. Description of the Related Art Conventional linear motors have a configuration in which concentrated winding armature coils are arranged without being overlapped. However, since these coils do not generate a cogging force, they are used for applications requiring a small speed ripple. Are suitable. Further, since the coil has a simple structure in which concentrated coils are arranged without being overlapped, insulation is easy, and application to a voltage of 200 V or the like is possible. FIGS. 9 to 11 show a conventional linear motor.
Shown in 9 is a front cross-sectional view of the linear motor viewed from the moving direction of the mover, FIG. 10 is a plan cross-sectional view along the line AA in FIG. 9, and FIG. 11 is a side view showing an armature portion. 9 to 11, the linear motor 1 includes a movable section 2 and a fixed section 3. The movable part 2 is composed of a so-called coreless type armature part 4 and an armature part support 5 to which the armature part 4 is attached. The armature unit 4 is configured by arranging a plurality of, for example, six, concentratedly wound armature coils 6 in a line in the traveling direction and molding them with a resin 7. The armature coil 6 has a three-phase, three-coil, four-pole basic configuration, and the coil pitch Pc of the armature coil 6 is 4/3 × Pm. The six armature coils 6 are arranged in the order of U, W, and V phases from the left on the paper. As shown in FIG. 11, the concentrated winding armature coil 6 has a shape in which two coil sides 6 that mainly generate thrust and are opposed to the secondary sides 8a and 8b are parallel to each other. And these six armature coils 6
Are arranged in a line in the traveling direction. In addition, the fixing part 3
Secondary side portion 8 as a so-called field pole made of a permanent magnet
a, 8b, and secondary side supports 9a, 9b as so-called back yokes to which the secondary sides 8a, 8b are attached. The permanent magnets constituting the secondary side portions 8a and 8b are arranged at every Pm pitch so as to have a different polarity from the adjacent permanent magnets, and are arranged side by side so that the opposing permanent magnets have the different polarity. ing. The secondary side portions 8a and 8b and the armature portion 4 are arranged facing each other in parallel to the traveling direction, and two secondary side support members 9 are provided.
a and 9b are connected and supported by a support member 10.

[0003]

However, the prior art has the following problems. (1) Since armature coils of different phases are adjacent to each other, when used at a high voltage such as 200 V, insulation failure may occur. (2) In order to increase the insulation, it is necessary to insert an insulator between the armature coils, which requires time and labor for assembling and increases the manufacturing cost. (3) Thrust ripples occur due to the use of concentrated winding armature coils. The present invention has been made to solve such a problem, and an object of the present invention is to provide a linear motor having good insulation between armature coils, easy to assemble, and having very small thrust ripple. is there.

[0004]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a secondary side support having a secondary side composed of a plurality of field poles attached thereto, and an air gap formed in the secondary side. And an armature portion support body to which an armature portion having a plurality of concentratedly wound armature coils is attached, and the secondary side portion and the armature portion face each other in the traveling direction. In a linear motor arranged in parallel to
The field poles of the secondary side are arranged in the traveling direction of the movable section so as to be different from the adjacent poles at every Pm pitch, and the plurality of armature coils are arranged at every Pc pitch in the traveling direction of the movable section. And the coil pitch Pc is set to Pc
= 5/3 × Pm.

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. The basic structure of the linear motor according to the present invention is substantially the same as the structure of the linear motor according to the prior art except for the armature portion, and the same or corresponding members as those in FIGS. Is omitted. [First Embodiment] FIG. 1 is a side view of an armature portion showing an arrangement of armature coils according to a first embodiment of the present invention. As shown in FIG. 1, the armature unit 4 is configured by molding a concentrated winding armature coil 6 arranged in a line in the traveling direction with a resin 7. The armature coil 6 is composed of six coils in three phases. When the pitch of the field poles on the secondary side is Pm, the coil pitch Pc of the concentrated winding armature coil 6
Are set as Pc = 5/3 × Pm, and are arranged side by side in the traveling direction of the movable portion for each pitch. The arrangement of these six armature coils 6 is, from the left in the drawing, a forward winding U-phase coil, a reverse winding V-phase coil, a forward winding W-phase coil, a reverse winding U-phase coil, The V-phase coil is wound in the forward direction, and the W-phase coil is wound in the reverse direction. When the coil pitch Pc is represented by an electrical angle, 5/3 × 180 = 300 degrees. FIG. 2 shows the relationship between the winding coefficient with respect to the coil width Wc / magnet pitch Pm and the loss when a predetermined thrust is generated for one armature coil 6.
Shown in In FIG. 2, A1 and A2 indicate that the ratio of the air core width (the width of the space at the center of the coil) to the coil width Wc is 0.
6 using the armature coil 6, B1 and B2 using the armature coil 6 having the ratio of the air core width to the coil width Wc of 0.4, and C1 and C2 using the armature coil 6 for the coil width Wc. An example using an armature coil 6 having a width ratio of 0.2 is shown. In the present invention, the coil pitch Pc is set to 5
Since it is set to / 3 × Pm, it is necessary to consider Wc / Pm at 5/3 or less. The winding coefficient is maximum when Wc / Pm is around 4/3. Since the number of turns can be increased by increasing the coil width Wc, the loss can be minimized where Wc / Pm is greater than 4/3.
However, as Wc / Pm approaches 5/3, the distance between the coils becomes narrower, and insulation between the armature coils 6 becomes a problem. In the present invention, the coil width Wc can be determined by the size of the field pole pitch Pm and the required insulation interval. For example, when the field pole pitch Pm is 18 mm and Wc / Pm that can reduce the loss is 4/3, the coil pitch Pc = 5/3 × 18 mm = 30 mm Coil width Wc = 4/3 × 18 mm = 24 mm Coil interval Wg = Pc-Wc = 30 mm-24 mm = 6 mm. That is, the distance between the armature coils 6 is as large as 6 mm. In the case of the prior art, there was a problem that the insulation could not be ensured at the time of high voltage specification because the coil interval was very narrow, but in the case of the present invention, the gap between the armature coils 6 was as large as 6 mm. So
Even if no insulator is inserted therein, insulation can be reliably ensured.

[Second Embodiment] Next, a second embodiment will be described. FIG. 3 is a front sectional view of the linear motor viewed from the traveling direction of the movable unit, and FIG. 4 is a diagram illustrating a coil arrangement of the armature unit. The fixing part 3 of the second embodiment has the same structure as that of the first embodiment. The difference from the first embodiment is the structure of the armature section 4. The armature unit 4 is composed of two coil layers in which the concentrated winding armature coils 6 are arranged in a line in the traveling direction, a nonmagnetic insulator 11 is inserted between the coil layers, and the whole is molded with a resin 7. Make up. The first coil layer 6a on the left side of the drawing and the second coil layer 6b on the right side of the drawing each have a concentrated winding armature coil 6 when the pitch of the field poles is Pm.
The coil pitch Pc is set to Pc = 5/3 × Pm, and is arranged in the traveling direction of the movable portion for each pitch. Further, the first coil layer and the second coil layer are
They are displaced in the traveling direction of the movable part with a displacement S of 5/6 × Pm. This can be expressed as an electrical angle of 5/6 × 180.
= 150 degrees. Therefore, the first coil layer 6a of the armature portion 4 is arranged in the order of a U-phase coil wound in the forward direction, a V-phase coil wound in the reverse direction, and a W-phase coil wound in the forward direction from the left on the paper, and The layers are arranged in the order of a U-phase coil wound in the reverse direction, a V-phase coil wound in the forward direction, and a W-phase coil wound in the reverse direction. The one configured in this manner is the first type.
There is an effect similar to that of the embodiment. Further, when the armature portion 4 is viewed from the side surface (when viewed from the secondary side portion), a portion where coils of different phases overlap each other appears. That is, in the armature section 4,
Since the phase zones are distributed in the thickness direction of the air gap between the armature portion 4 and the secondary side portions 8a and 8b, thrust ripples generated due to variations in the magnetization of the field poles such as permanent magnets and displacements are reduced. be able to.

[Third Embodiment] Next, a third embodiment will be described with reference to FIG.
It will be described based on. The third embodiment is different from the second embodiment in that the method of arranging the armature coil 6 of the armature portion 4 is changed. The coil arrangement of the first coil layer and the second coil layer is the same, but the first coil layer and the second coil layer are displaced by 2/3 × Pm (electrical angle 120 degrees). I have. The first coil layer includes a U-phase coil wound in a forward direction, a V-phase coil wound in a reverse direction, and
Arranged in the order of the forward winding W-phase coil, the second coil layer is
V-phase coil wound in the forward direction from the left, W-phase coil wound in the reverse direction,
The coils are arranged in the order of the U-phase coils wound in the forward direction. In the third embodiment, the same effect as in the second embodiment can be obtained. However, in the third embodiment, the displacement between the first coil layer 6a and the second coil layer 6b is reduced by 120 electrical degrees. Since the length of the armature portion 4 is reduced, there is an advantage that the length of the armature portion 4 can be reduced.

[Fourth Embodiment] Next, a fourth embodiment will be described with reference to FIG. The fourth embodiment is similar to the second and third embodiments.
In this embodiment, the method of arranging the coils of the armature section 4 is changed. Each coil arrangement of the first coil layer 6a and the second coil layer 6b is the same, but the first coil layer 6a and the second coil layer 6b are formed by １ ／ × Pm (electrical angle 60 °).
(Degree). First coil layer 6a
Are arranged in the order of a U-phase coil wound in the forward direction from the left, a V-phase coil wound in the reverse direction, and a W-phase coil wound in the forward direction. The second coil layer 6b is formed of a W-phase coil wound in the reverse direction from the left. The direction-winding U-phase coil and the reverse-winding V-phase coil are arranged in this order. The fourth embodiment can also obtain the same effects as those of the above-described second and third embodiments, but the fourth embodiment has the same effects as the first and second coil layers 6a and 6b. Since the displacement is reduced to 60 degrees in electrical angle, there is an advantage that the length of the armature portion 4 can be further reduced.

Fifth Embodiment Next, a fifth embodiment will be described with reference to FIGS. The fifth embodiment differs from the first to fourth embodiments in that the coil width and coil pitch of the armature portion 4 are changed. First, the coil width Wc of all the coils is set to Wc = 4/3 × Pm. Such a large coil width Wc can generate a large thrust. For applications that do not have high withstand voltage specifications, as shown in FIG.
c is configured as Pc = 4/3 × Pm, and as shown in FIG.
The coil pitch Pc is configured as Pc = 5/3 × Pm. The coil pitch Pc is set to 4/3 × Pm rather than 5/3 × Pm, so that the length of the armature portion can be reduced. Therefore, the coil pitch Pc is changed according to the application. . Thereby, a linear motor can be manufactured at low cost.

Sixth Embodiment In the second to fifth embodiments, the insulator 11 is inserted between the first coil layer 6a and the second coil layer 6b. The insulator 11 may be constituted by a printed circuit board in which the connection between the first coil layer 6a and the second coil layer 6b is patterned. In this case, the connection processing between the armature coils 6 can be simplified.

The present invention is not limited to the configuration of each of the above embodiments, but may be configured as follows. (a) Either the armature portion or the secondary side portion may be a stator or a mover. (b) Not only a permanent magnet linear motor but also an electromagnet linear motor may be used, and any linear motor having an armature such as an induction linear motor or a reluctance linear motor may be used. Good. (c) The armature portion may be of a type having a core instead of a coreless type.

[0012]

As described above, the present invention has the following effects. (1) Since the armature coils wound in a concentrated manner are arranged at a predetermined interval, even in a high voltage specification of 200 V,
Sufficient insulation can be provided. (2) There is no need to insert an insulator between the armature coils, the assembly is simple, and the manufacturing cost can be reduced. (3) Since the armature coils are displaced on both the left and right sides of the armature part, the phase bands can be distributed, and the thrust ripple due to the variation in the magnetization of the field poles such as permanent magnets and the displacement is reduced. be able to.

[Brief description of the drawings]

FIG. 1 is a coil layout diagram showing a first embodiment of the present invention.

FIG. 2 shows the coil width Wc / in one armature coil.
It is a graph which shows the relationship between a winding pitch and loss with respect to magnet pitch Pm.

FIG. 3 is a front sectional view of a linear motor according to a second embodiment of the present invention.

FIG. 4 is a coil layout diagram showing a second embodiment of the present invention.

FIG. 5 is a coil layout diagram showing a third embodiment of the present invention.

FIG. 6 is a coil layout diagram showing a fourth embodiment of the present invention.

FIG. 7 is a coil layout diagram showing a fifth embodiment of the present invention.

FIG. 8 is a coil layout diagram showing a fifth embodiment of the present invention.

FIG. 9 is a front sectional view showing a linear motor according to the related art.

FIG. 10 is a plan sectional view taken along the line AA in FIG. 8;

FIG. 11 is a coil layout diagram according to the related art.

[Explanation of symbols]

 1 linear motor, 2 movable part, 3 fixed part, 4 armature part, 5 armature part support, 6 armature coil, 7 resin, 8a, 8b secondary part, 9a, 9b secondary part support, 10 support member, 11 insulator

Continuation of the front page F term (reference) 5H604 AA08 BB11 CC01 CC02 CC04 CC20 PB02 PE06 QB04 5H641 BB06 BB18 BB19 GG02 GG03 GG05 GG07 GG11 GG12 HH02 HH03

Claims (6)

[Claims] A secondary side support having a secondary side comprising a plurality of field poles mounted thereon, and a plurality of concentratedly wound armature coils opposed to the secondary side via a gap. A linear motor having an armature support having an armature mounted thereon, wherein the secondary side and the armature are arranged facing each other and parallel to the traveling direction. The field poles of the section are arranged in the traveling direction of the movable section so as to be different from the adjacent poles at every Pm pitch, and the plurality of armature coils are arranged side by side in the traveling direction of the movable section at every Pc pitch. A linear motor, wherein the coil pitch Pc is Pc = 5/3 × Pm. 2. The linear motor according to claim 1, wherein said armature coil of said armature portion is constituted by two layers of a first coil layer and a second coil layer. 3. The linear motor according to claim 2, wherein, when n is an integer, the first coil layer and the second coil layer are displaced by n / 6 × Pm. 4. The linear motor according to claim 1, wherein a width Wc of the armature coil is set to Wc = 4/3 × Pm. 5. The linear motor according to claim 2, wherein an insulator made of a non-magnetic material is inserted between the first coil layer and the second coil layer. 6. The linear motor according to claim 5, wherein the insulator is constituted by a printed circuit board in which connection between a first coil layer and a second coil layer is patterned.