Electrical generator or motor structure – Dynamoelectric – Linear
Reexamination Certificate
2001-02-12
2003-04-15
Ramirez, Nestor (Department: 2834)
Electrical generator or motor structure
Dynamoelectric
Linear
C074S4710XY
Reexamination Certificate
active
06548917
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates a planar motor, and more particularly to a planar motor having a stator and a mover in which permanent magnets are arranged to reduce a leakage magnetic flux, thereby increasing a magnetic flux density and generating a strong thrust.
2. Description of the Background Art
A planar motor is constructed such that a mover is moved on a plane while separated a predetermined height above or distance apart from a surface of a stator. The planar motion of the mover may be adopted to drive a head unit for mounting components on a printed circuit board in the X-Y direction in a component mounting device. In this case, in order to generate a driving force to move the head unit in the X-Y direction, the planar motor needs to have a strong thrust.
FIG. 1
is a perspective view of a planar motor in accordance with a conventional art, and
FIGS. 2A and 2B
are plan views of a permanent magnet part arranged on a plane surface of the stator of FIG.
1
.
As shown in
FIG. 1
, the planar motor includes a stator
10
and a mover
20
. The stator
10
includes a permanent magnet part
12
having a plurality of S-pole permanent magnets
12
a
and a plurality of N-pole permanent magnets
12
b
arranged in a grid form on the plane surface of the stator frame
11
. The mover
20
includes an armature coil part
21
at the bottom surface of an armature frame
22
.
In order for the armature coil part
21
to receive an electric signal, there is provided a cable
22
a
at one side of the mover
20
. When the electric signal is applied to the cable
22
a
, a thrust is generated between the armature coil part
21
of the mover
20
and the permanent magnet part
12
of the stator
10
.
In order to move the mover
20
in the X-Y direction on the plane of the stator by virtue of the thrust generated between the permanent magnet part
12
and the armature coil part
21
, the mover
20
needs to be lifted up a predetermined height from the plane surface of the stator
10
.
In order to lift up the mover
20
from the plane surface of the stator at a predetermined height, a nozzle (not shown) is installed at the mover
20
.
When air is jetted through the nozzle, the mover
20
is lifted up a predetermined height from the surface of the stator
10
by virtue of the air-jetting force, and in this state, the mover
20
moves freely on the plane of the stator
10
.
In order to move the mover
20
in the X-Y direction on the plane of the stator
10
, as shown in
FIG. 2A
, the permanent magnet part
12
corresponding to the armature coil part
21
installed at the mover
20
includes a plurality of S-pole permanent magnets
12
a
and a plurality of N-pole permanent magnets
12
b
formed in a grid form on the plane of the stator frame
11
.
In detail, the permanent magnet part
12
is formed in a manner that, centering around the S-pole permanent magnet
12
a
, a respective corner of each of a plurality of the N-pole permanent magnets
12
b
contacts respectively each corner of the S-pole permanent magnet
12
a
, or conversely, centering around the N-pole permanent magnet
12
b
, a respective corner of each of a plurality of the S-pole permanent magnets
12
a
contacts respectively each corner of the N-pole permanent magnet
12
b
, whereby a grid is formed.
The permanent magnet part
12
, having the plurality of S-pole permanent magnets
12
a
and the plurality of N-pole permanent magnets
12
b
arranged such that each corner of each permanent magnet contacts a corner of another permanent magnet, includes quadrangular space
12
c
formed between the S-pole permanent magnets
12
a
and the N-pole permanent magnets
12
b
, as shown in FIG.
2
A. Because of this space
12
c
, the packing density of the permanent magnets is low on the whole permanent magnet part
12
, causing a problem that the thrust of the planar motor becomes weak.
Thus, in order to improve the low packing density of the permanent magnet part
12
, as shown in
FIG. 2A
, the S-pole permanent magnets
12
a
and the N-pole permanent magnets
12
b
of the permanent magnet part
12
are arranged to be inclined at a predetermined angle such that each of a plurality of the N-pole permanent magnets
12
b
contacts a side of the four sides of a plurality of the S-pole permanent magnets
12
a
or each of a plurality of the S-pole permanent magnets
12
a
contacts a side of the four sides of a plurality of the N-pole permanent magnets
12
b
, as shown in FIG.
2
B.
As the S-pole permanent magnets
12
a
and the N-pole permanent magnets
12
b
are arranged to contact with each other as shown in
FIG. 2B
, the packing density of the permanent magnet part of
FIG. 2B
is enhanced compared to the permanent magnet part of FIG.
2
A.
In this case, however, since the S-pole permanent magnets
12
a
and the N-pole permanent magnets
12
b
are so closely arranged and polarized, the number of magnetic flux interlinkage lines interlinked with current flowing along the armature coil part
21
is reduced, so that leakage current is generated.
In addition, since the length of magnetization formed by the S-pole permanent magnets
12
a
and the N-pole permanent magnets
12
b
is shortened, the strength of the permanent magnets is reduced, resulting in that the overall thrust of the planar motor is weakened.
SUMMARY OF THE INVENTION
Therefore, an object of the present invention is to provide a planar motor which is capable of reduce a leakage magnetic flux by increasing packing density of S-pole permanent magnets and N-pole permanent magnets arranged on a plane of a stator frame as well as increasing the number of magnetic flux interlinkage lines interlinked with current flowing along an armature coil part installed at a mover frame and capable of increasing the intensity of magnet by increasing the length of magnetization.
Another object of the present invention is to provide a planar motor which is capable of reducing a leakage magnetic flux by increasing the number of magnetic flux interlinkage lines and capable of generating stronger thrust by increasing the length of magnetization and the intensity of magnet.
To achieve these and other advantages and in accordance with the purpose of the present invention, as embodied and broadly described herein, there is provided a planar motor including: a mover having an armature coil part installed at the bottom of an armature frame for receiving an electric signal, and a stator with a first permanent magnet part installed having S-pole permanent magnets and N-pole permanent magnets arranged in a manner that one corner of each of the N-pole permanent magnets contacts one of each of the four corners of a respective one of the S-pole permanent magnets on the plane surface of a stator frame installed facing the armature coil part of the mover, and inserted permanent magnets arranged at spaces formed as the corners of the S-pole permanent magnets contact the corners of N-pole permanent magnets.
REFERENCES:
patent: 6005309 (1999-12-01), Chitayat
patent: 6069418 (2000-05-01), Tanaka
patent: 6188147 (2001-02-01), Hazelton et al.
patent: 6257512 (2001-07-01), Schoeck et al.
patent: 402309536 (1990-12-01), None
Chun Jang Sung
Hwang Ji Hyun
Jung Hyun Kyo
Kim Do Hyun
Fleshner & Kim LLP
Jones Judson H.
Mirae Corporation
Ramirez Nestor
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