JPH11155276A - Linear motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce a magnetic gap and an exciting current by forming a circumference groove at nearly even intervals in the direction of an axial core on the outer-periphery surface of a magnetic body, by burying a non-magnetic conductor into the circumference groove, and by covering the non-magnetic conductor and the outer-periphery surface of the magnetic body with the non- magnetic body. SOLUTION: A circumference groove with a fixed width is formed at fixed intervals on an outer-periphery surface of a magnetic body 10 made of iron, and a circumference groove of the magnetic body 10 is buried by a non-magnetic conductor 14 consisting of aluminum die casting and copper. The outer-periphery surface of the magnetic body 10 and the non-magnetic conductor 14 in the same dimension to external diameter is covered with a non-magnetic body 15. Although amount of a magnetic conductor 11 should be secured by the thickness of air gap, the required amount of a non-magnetic conductor 14 is secured for providing the non-magnetic body 15, so that a thickness g3 of the non-magnetic body 15 is fully sufficient even if it is smaller than an air gap.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a linear motor in which a primary core is a runner and a secondary conductor is a stator.

[0002]

2. Description of the Related Art A linear motor has a configuration in which a squirrel-cage motor is developed on a plane, and the structure is shown in FIG.

[0003] The linear motor is largely divided into a primary core 1 and a secondary conductor 2, and has a long secondary structure in which the secondary side is longer than the primary side. The secondary side serves as a stator, and the primary side serves as a traveling element, and an air gap 3 is formed therebetween.

As shown in FIG. 5 (b), the primary side core 1 is formed by arranging, for example, four core groups 5 each having a laminated thin core plate 4 made of a magnetic material at equal intervals along a circle to form a radial shape. It is sandwiched between a pair of ring-shaped flanges 6 and connected with a plurality of through bolts 7 and nuts (not shown). A wheel 12 is rotatably provided in the flange 6. The core plate 4 is formed in a comb shape having teeth 13 by providing a plurality of slits 8 along the length direction. A coil 9 surrounding the secondary conductor 2 is accommodated in the slit 8.

On the other hand, the secondary-side conductor 2 is a round bar-shaped magnetic body 1.
0 is formed by covering the outer peripheral surface with a nonmagnetic conductor 11 having interference. Here, the magnetic body 10 is formed of iron,
The nonmagnetic conductor 11 is formed of aluminum, copper, or the like.

[0006]

However, the magnetic gap Ga at the air gap 3 is defined as follows: the thickness of the nonmagnetic conductor 11 on the secondary side is g ₁ , and the size of the air gap 3 is g ₂ . Ga = g ₁ + g _{2. As} the value of Ga increases, the exciting current increases and the efficiency of the linear motor deteriorates.

Therefore, an object of the present invention is to provide a linear motor that solves the above problem.

[0008]

According to a first aspect of the present invention, there is provided a linear motor comprising: a plurality of comb-shaped core plates formed by forming a plurality of slits to form a core group; A plurality of cores are arranged radially so that the slits are located on the inner side, and they are connected to each other to form a primary core and a coil is housed in the slit. In a linear motor in which a long secondary conductor formed by providing a magnetic core is movably inserted through an air gap into a space surrounded by a core group in the primary core, an axial center is A circumferential groove is formed at substantially equal intervals in the direction, a non-magnetic conductor is buried in the circumferential groove, and an outer peripheral surface of the non-magnetic conductor and the magnetic material is covered with a non-magnetic material. The configuration of the linear motor covers the outer peripheral surface Characterized by using a magnetic material instead of the magnetic body.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail based on an embodiment shown in the drawings. In this embodiment, since a part of the conventional linear motor is improved, the same parts as those of the conventional linear motor are denoted by the same reference numerals, and the description thereof will be omitted. Only different parts will be described.

(A) Embodiment 1 FIG. 1 shows the configuration of a main part of a linear motor according to Embodiment 1 of the present invention. As shown in the drawing, circumferential grooves having a constant width are formed at regular intervals on the outer peripheral surface of the magnetic body 10 made of iron, and the circumferential grooves of the magnetic body 10 are made of a non-magnetic material made of aluminum die-cast or copper. It is filled with a conductor 14. And
The outer peripheral surfaces of the magnetic body 10 and the nonmagnetic conductor 14 having the same outer diameter are covered with the nonmagnetic body 15.

Here, conventionally, as shown as g ₂ in FIG. 5, the amount of the non-magnetic conductor 11 must be ensured by the thickness of g _2. Since the non-magnetic member 15 is provided on the non-magnetic member 15, even if the thickness g ₃ of the non-magnetic member 15 is smaller than g ₂ , it is sufficient.

In such a linear motor, the magnetic gap G
b can be expressed as Gb = g ₃ + g ₄ . The size g ₄ of the air gap because it can be fabricated on the same level as before, can be placed and g ₄ = g _2. Therefore, the magnetic gap can be made smaller than that of the related art by g ₁ -g _3, which is the thickness of the non-magnetic member 15 thinner than the non-magnetic conductor 11.

(B) Embodiment 2 Next, FIG. 2 shows a configuration of a main part of a linear motor according to Embodiment 2 of the present invention. In this embodiment, the non-magnetic conductor 14 and the non-magnetic body 15 in the first embodiment are combined into a non-magnetic conductor 16.

The other configuration and operation are the same as those of the first embodiment, and the description is omitted.

(C) Embodiment 3 Next, FIG. 3 shows a configuration of a main part of an embodiment 3 of the linear motor according to the present invention. In this embodiment, a magnetic body 17 is provided in place of the non-magnetic body 15 in the first embodiment.

In the case of this embodiment, the size of the magnetic gap Gc is different from those of the first and second embodiments, and only the air gap is provided. As described above, this air gap can be manufactured to the same value as the conventional one. . Therefore, the amount corresponding than conventional thickness g ₂ of the nonmagnetic conductor 11 can be reduced magnetic gap.

(D) Fourth Embodiment Finally, FIG. 4 shows the structure of a main part of a linear motor according to a fourth embodiment of the present invention. This embodiment is different from the third embodiment in that the magnetic body 17 is formed integrally with the magnetic body 10 and a part of the magnetic body 10 on the outer peripheral surface side of the nonmagnetic conductor 14 is replaced with a nonmagnetic conductor. 14a.

In such a linear motor, the size of the magnetic gap Gc is only the air gap as in the third embodiment. Therefore, the amount corresponding than conventional thickness g ₂ of the nonmagnetic conductor 11 can be reduced magnetic gap.

As shown in FIG. 4, when a portion of a different material is exposed on the outer peripheral surface of the secondary-side conductor 2, irregularities are generated on the outer peripheral surface because the thermal expansion coefficients are different from each other. 1 is vibrated. As shown in FIG. 4, when the width dimension of the nonmagnetic conductor 14a is set to be smaller on the outer peripheral side than on the center side, the amount of protrusion of the nonmagnetic conductor 14a to the outer peripheral surface of the secondary side conductor 2 due to thermal expansion is reduced. The vibration of the primary side core 1 is reduced.

[0020]

As can be seen from the above description, claim 1
According to the linear motor according to the above, the thickness of the non-magnetic material forming the outer surface of the secondary side conductor 2 can be made smaller than the thickness of the conventional non-magnetic conductor, so that the magnetic gap can be made smaller than before. Accordingly, a linear motor with a small excitation current and high efficiency is obtained.

According to the second aspect of the present invention, since the outer periphery of the non-magnetic conductor is covered with the magnetic material, the magnetic gap is limited to the air gap, and the magnetic gap is reduced by that much. Therefore, a linear motor having a small excitation current and high efficiency can be obtained.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a main part of a linear motor according to a first embodiment of the present invention.

FIG. 2 is a sectional view showing a main part of a second embodiment of the linear motor according to the present invention;

FIG. 3 is a sectional view showing a main part of a third embodiment of the linear motor according to the present invention.

FIG. 4 is a sectional view showing a main part of a fourth embodiment of the linear motor according to the present invention;

5A is a front view showing a conventional linear motor, and FIG. 5A is a partially cutaway front view, and FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Primary core 2 ... Secondary conductor 3 ... Air gap 4 ... Core plate 5 ... Core group 8 ... Slit 9 ... Coil 10, 17 ... Magnetic body 11, 14, 14a, 16 ... Non-magnetic conductor 15 ... Non-magnetic body

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Keiichi Korogi, Inventor 2-1-1-17 Osaki, Shinagawa-ku, Tokyo Inside the Meidensha Corporation (72) Masayuki Kawaguchi 2-1-1-17 Osaki, Shinagawa-ku, Tokyo Stock Company Inside the company Meidensha (72) Inventor Takayuki Mizuno Inside the company Meidensha, 2-1-1-17 Osaki, Shinagawa-ku, Tokyo

Claims (2)

[Claims] 1. A core group is formed by stacking a plurality of comb-shaped core plates having a plurality of slits formed therein, and a plurality of core groups are radially arranged such that the slits are located on the inside and are connected to each other. By forming the primary core by this, the coil is housed in the slit, and a long secondary conductor formed by providing a non-magnetic conductor on the outer periphery of the cylindrical magnetic body is surrounded by the core group in the primary core In a linear motor that is movably inserted through an air gap through an air gap, circumferential grooves are formed in the outer peripheral surface of the magnetic body at substantially equal intervals in the axial direction, and a non-magnetic conductor is embedded in the circumferential grooves. And a non-magnetic conductor and an outer peripheral surface of a magnetic material covered with a non-magnetic material. 2. The linear motor according to claim 1, wherein a magnetic material is used instead of the non-magnetic material covering the outer peripheral surface.