Electrical generator or motor structure – Dynamoelectric – Linear
Reexamination Certificate
2002-03-07
2003-12-09
Ramirez, Nestor (Department: 2834)
Electrical generator or motor structure
Dynamoelectric
Linear
C310S012060, C310S013000, C310S015000
Reexamination Certificate
active
06661129
ABSTRACT:
FIELD OF THE INVENTION
The invention relates to an industrial linear motor having relatively high output power among linear motors.
BACKGROUND OF THE INVENTION
A voice coil type of linear motor is used for linear actuators, which are used for moving a magnetic head and an optical pickup and the like in information storage devices. Many of these linear motors are of a movable coil type.
One example of the conventional voice coil-type linear motors is shown in FIG.
15
.
A cylinder-shaped outside yoke
101
of which one side end is open configures a fixed side, and a radially magnetized magnet
102
is provided in the inside of the outside yoke
101
, and a cylinder-shaped inside yoke
103
is supported so as to be able to coaxially slide with respect to the outside yoke
101
in the direction of an arrow J. The inside yoke
103
is supported by a guide roller
106
with respect to a guide
105
so that a gap between the magnet
102
and a coil
104
may be held uniform.
When electric current is fed through the coil
104
, the inside yoke
103
moves in the direction of the arrow J with respect to the outside yoke
101
in accordance with Fleming's left hand rule based on the direction of the current flowing through the coil
104
and the direction of a magnetic flux &phgr; of the magnets
102
inter-linking with the current.
However, the above conventional configuration is suitable for use in applications needing small thrust such as information storage devices. However, when used for industrial applications requiring large thrust, may be poor in volume efficiency or problematic in magnetic efficiency.
Concretely, in the conventional configuration, the configuration of the magnetic circuit requires the outside yoke
101
to coaxially cover the whole inside yoke
103
, thus resulting in small thrust per unit volume and heavy weight.
Also, it requires an open side end portion of the outside yoke or a slit provided in the outside yoke to permit free motion of the coil.
DISCLOSURE OF THE INVENTION
The invention has an object to provide a linear motor that, despite a voice coil-type linear motor, permits such relatively high output power, small size and light weight, high thrust, and high efficiency as to be available as an industrial linear motor.
A linear motor according claim
1
of the invention is configured with a plurality of voice coil-type linear motor units arranged in parallel to each other, characterized in that each of the voice coil-type linear motor units comprises an outside yoke having a cylindrical hollow portion, an inside yoke passing through the hollow portion of the outside yoke, a coil wound around the inside yoke along the axial direction thereof, and a magnet mounted to the inside of the hollow portion of the outside yoke and magnetized to a single pole in the surface facing the coil, wherein the ends of the inside yoke are coupled to an adjacent one of the voice coil-type linear motor units by means of auxiliary yokes, the outside yokes of the voice coil-type linear motor units adjacent to each other are configured such that the inner peripheral surfaces of the magnets may be of different magnetic poles, and thus a closed magnetic path is formed by the inside yokes adjacent to each other, the auxiliary yokes, the outside yokes, and the magnets, whereby, by feeding current through the coils of the voice coil-type linear motor units adjacent to each other, the outside yokes and the inside yokes are effected to move relative to each other based on magnetic action of a magnetic field generated by the closed magnetic path and the coils.
A linear motor according to claim
2
of the invention is configured with a plurality of voice coil-type linear motor units arranged in parallel to each other, characterized in that each of the voice coil-type linear motor units comprises an outside yoke, having a cylindrical hollow portion, an inside yoke, passing through the hollow portion of the outside yoke, a coil mounted to the inside of the hollow portion of the outside yoke and wound along the axial direction of the inside yoke, and a magnet mounted to the inside yoke and magnetized to a single pole in the surface facing the coil, wherein the ends of the inside yoke are coupled to another adjacent above-described voice coil-type linear motor unit by mean of auxiliary yokes, the inside yokes of the voice coil-type linear motor units adjacent to each other are configured such that the outer peripheral surfaces of the magnets may be of different magnetic poles, and thus a closed magnetic path is formed by the inside yokes adjacent to each other, the auxiliary yokes, the outside yokes, and the magnets, and thereby, by feeding current through the coils of the voice coil-type linear motor units adjacent to each other, the outside yokes and the inside yokes are effected to move relative to each other based on magnetic action caused to occur between a magnetic field generated by the closed magnetic path and the coils.
A linear motor according to claim
3
of the invention is configured with a plurality of voice coil-type linear motor units arranged in parallel to each other, characterized in that it comprises inside yokes arranged side by side, coils separately wound in a plurality of sections around the inside yokes along the respective axial directions thereof, and outside yokes having cylindrical hollow portions, into which the inside yokes are inserted, and provided with magnets on the insides of the hollow portions correspondingly to the coils separately wound in the plurality of sections, wherein the magnets are magnetized to a single pole in the surfaces facing the coils, and the outside yokes of the voice coil-type linear motor units adjacent to each other are configured such that the inner peripheral surfaces of the magnets may be of different magnetic poles, and thus a closed magnetic path is formed by a plurality of the outside yokes, the inside yokes, and the magnets, and thereby, by feeding current through the coils, the outside yokes coupled and the inside yokes coupled are effected to move relative to each other based on magnetic action caused to occur between a magnetic field generated by the closed magnetic path and a magnetic field generated by the coils.
A linear motor according to claim
4
of the invention is configured with a plurality of voice coil-type linear motor units arranged in parallel to each other, characterized in that it comprises inside yokes arranged side by side, magnets separately provided in a plurality of sections on the inside yokes along the respective axial directions thereof, and outside yokes having cylindrical hollow portions, into which the inside yokes are inserted, and having coils wound on the insides of the hollow portions correspondingly to the magnets separately provided in the plurality of sections, wherein the magnets are magnetized to a single pole in the surfaces facing the coils and are configured such that the magnets of the voice coil-type linear motor units adjacent to each other may be of different magnetic poles, and thus a closed magnetic path is formed by the outside yokes, the inside yoke, and the magnets, and thereby, by feeding current through the coils, the outside yokes coupled and the inside yokes coupled are effected to move relative to each other based on magnetic action caused to occur between a magnetic field generated by the closed magnetic path and a magnetic field generated by the coils.
A linear motor according to claim
5
of the invention is characterized in that it comprises a movable unit comprising an outside yoke having a cylindrical hollow portion and an annular magnet fixed so as to cover nearly all surface of the inner peripheral surface of the hollow portion, and a fixed unit comprising a column-shaped inside yoke and a coil wound around an outer periphery portion thereof, wherein a plurality of pairs of each of the movable unit and the fixed unit are arranged side by side, opposite ends of the plurality of the fixed units are coupled by individual auxiliary yokes, and the outside yokes
Kinashi Yoshikazu
Suehiro Tsugumitsu
Tamura Shinya
Matsushita Electric - Industrial Co., Ltd.
Mohandesi Iraj A.
Parkhurst & Wendel L.L.P.
Ramirez Nestor
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