【Technical Field】
The present inventive concept relates to a magnetic
bearing device and a hot-dip galvanizing apparatus including
the magnetic bearing device.
【Background Art】
10 In a hot-dip galvanizing process, a steel sheet may be
immersed in a galvanizing bath, filled with molten zinc via a
snout, and may proceed in a vertical direction in a state of
contact with a pot roll in the galvanizing bath, thereby being
supported by the pot roll.
15 The pot roll may be a sink roll or a stabilizing roll.
Such a sink roll may function to change a moving direction of
the steel sheet, and such a stabilizing roll may function to
correct a shape of the steel sheet.
In addition, mechanical contact is inevitable in a roll
20 shaft bearing of a pot roll known in the art, which is rotated,
for example, by rotating an axis of the bearing or by using ball
bearings.
When such a bearing is used in the galvanizing process,
the bearing may be gradually abraded while the pot roll rotates
25 in the hot-dip galvanizing bath, and vibrations and noise may
3
occur due to unstable rotation.
In addition, such contact-type bearings not only
drastically shorten the lifespan thereof, but may also cause
surface defects on a plated steel sheet, such as non-uniformity
5 in plating thickness deviations, due to vibrations of the pot
roll.
Recently, non-contact type bearing devices such as
magnetic bearing devices have been developed, in order to
prevent problems of the contact type bearing devices as
10 described above.
Meanwhile, it is necessary to prevent a magnetic bearing
device from colliding with a roll axis by maintaining a constant
distance between the magnetic bearing device and the roll axis,
for example.
15 However, when magnetic force, generated to maintain a
constant distance between the magnetic bearing device and the
roll axis, is not precisely controlled, it may be difficult to
prevent the magnetic bearing device from colliding with the roll
axis.
20 That is, when the magnetic bearing device is not precisely
controlled, the lifespan of the magnetic bearing device may be
shortened due to collisions with the roll axis.
Further, the pot roll may be vibrated when collisions
between the magnetic bearing device and the roll axis occur,
25 since the magnetic bearing device may not be precisely
4
controlled.
In addition, surface defects, such as non-uniformity in
plating thickness deviations, may occur in a plated steel sheet
due to vibrations of the pot roll, similarly to those occurring
5 in contact type bearing devices as described above.
Accordingly, it is necessary to study a magnetic bearing
device enabling such problems to be solved, and a hot-dip
galvanizing apparatus including the magnetic bearing device.
10 【Disclosure】
【Technical Problem】
An aspect of the present inventive concept may provide
a magnetic bearing device in which a support of a roll shaft
is precisely controlled in a non-contact manner, and a hot-dip
15 galvanizing apparatus including the magnetic bearing device.
【Technical Solution】
According to an aspect of the present inventive concept,
a magnetic bearing device may include a support unit disposed
adjacent to a roll shaft and generating a magnetic field toward
20 the roll shaft, and a magnetic force receiving unit coupled to
the roll shaft and only including a magnetic material in a
portion facing the support unit, wherein the magnetic material
is magnetized by the magnetic force.
In addition, the magnetic force receiving unit of the
25 magnetic bearing device may include a magnetic member formed
5
of the magnetic material and disposed on the portion facing the
support unit in the roll shaft, and a nonmagnetic member formed
of a nonmagnetic material and disposed on a portion other than
the portion on which the magnetic member is disposed on the roll
5 shaft.
In addition, the magnetic force receiving unit of the
magnetic bearing device may further include an axial sheath
member fitted onto the roll shaft and with which the magnetic
member and the nonmagnetic member are combined.
10 In addition, the magnetic member of the magnetic bearing
device may have a cylindrical shape, and have the same width
as the portion facing the support unit in the roll shaft.
In addition, the magnetic member of the magnetic bearing
device may have a disc shape, and the number of the magnetic
15 member may correspond to a width of the portion facing the
support unit in the roll shaft.
In addition, the roll shaft of the magnetic bearing device
may be formed of a nonmagnetic material.
In addition, the support unit of the magnetic bearing
20 device may include a magnetic support disposed adjacent to the
roll shaft and supporting the roll shaft in at least one of an
axial direction or a radial direction of the roll shaft, and
a sensor electrically connected to the magnetic support to
measure and control an intensity of vibrations of the magnetic
25 support.
6
In addition, the magnetic support of the magnetic bearing
device may further include a radial magnetic member disposed
in a radial direction of the roll shaft and supporting the roll
shaft in the radial direction of the roll shaft when the roll
5 shaft rotates, and an axial magnetic member disposed to face
a stepped portion, formed in the roll shaft or the axial sheath
member of the magnetic force receiving unit fitted on the roll
shaft, in an axial direction of the roll shaft and supporting
the roll shaft in the axial direction of the roll shaft when
10 the roll shaft rotates.
In addition, the support unit of the magnetic bearing
device may further include a housing part with which the
magnetic support and the sensor are combined, and a radial touch
disc having a disc shape and combined with the housing part or
15 an inner side of the radial magnetic member, wherein an internal
diameter of the radial touch disc is smaller than an internal
diameter of the radial magnetic member.
In addition, the support unit of the magnetic bearing
device may further include an axial touch disc combined with
20 the housing part to be disposed between the axial magnetic
member and the stepped portion of the roll shaft.
In addition, the magnetic force receiving unit of the
magnetic bearing device may include the magnetic material only
on a portion facing the magnetic support and the sensor in the
25 roll shaft.
7
According to another aspect of the present inventive
concept, a hot-dip galvanizing apparatus may include a
galvanizing bath configured to accommodate molten zinc, a pot
roll disposed on a transportation path of a steel sheet moving
5 into the galvanizing bath, and the magnetic bearing device
described above and disposed on a roll shaft of the pot roll.
【Advantageous Effects】
As set forth above, a magnetic bearing device and a hot-dip
10 galvanizing apparatus including the magnetic bearing device
according to an exemplary embodiment in the present disclosure
can support a roll shaft in a non-contact manner.
In particular, when the roll shaft is supported by
magnetic force, the magnetic force can be controlled to only
15 affect a portion to be supported in the roll shaft. Accordingly,
the support of the roll shaft by the magnetic force can be
precisely controlled in the magnetic bearing device and the
hot-dip galvanizing apparatus including the magnetic bearing
device according to the exemplary embodiment in the present
20 disclosure.
Since collisions between the roll shaft 2 and the magnetic
bearing device 1 are prevented, problems such as non-uniformity
in plating thickness deviations caused by vibrations of the pot
roll may be solved and quality of the steel sheet may be improved.
25
8
【Description of Drawings】
FIG. 1 is a perspective view illustrating a hot-dip
galvanizing apparatus according to an exemplary embodiment in
the present disclosure;
5 FIG. 2 is a cross-sectional view illustrating a magnetic
bearing device according to an exemplary embodiment in the
present disclosure;
FIG. 3 is a side view illustrating a magnetic force
receiving unit in a magnetic bearing device according to an
10 exemplary embodiment in the present disclosure;
FIG. 4 is an exploded perspective view of a magnetic force
receiving unit in a magnetic bearing device according to an
exemplary embodiment in the present disclosure;
FIG. 5 is an exploded perspective view illustrating a
15 magnetic force receiving unit in a magnetic bearing device
according to an exemplary embodiment in the present disclosure;
FIG. 6 is a cross-sectional view illustrating a radial
touch disc in a magnetic bearing device according to another
exemplary embodiment in the present disclosure;
20 FIG. 7 is a front view and a perspective view illustrating
a radial magnetic member of a magnetic support part in a magnetic
bearing device according to an exemplary embodiment in the
present disclosure;
FIG. 8 is a perspective view illustrating an axial
25 magnetic member of a magnetic support part in a magnetic bearing
9
device according to an exemplary embodiment in the present
disclosure; and
FIG. 9 is a perspective view illustrating a sensor unit
in a magnetic bearing device according to an exemplary
5 embodiment in the present disclosure.
【Modes for Carrying out the Invention】
Hereinafter, exemplary embodiments of the present
inventive concept will be described with reference to the
10 accompanying drawings. The present inventive concept may,
however, be exemplified in many different forms and should not
be construed as being limited to the specific embodiments set
forth herein. Those skilled in the art could easily suggest
various embodiments, modifications, and equivalents falling
15 within the scope of the present invention by adding, modifying,
and deleting components.
The same reference numbers will be used throughout this
specification to refer to the same or like components.
A magnetic bearing device 1 and a hot-dip galvanizing
20 apparatus including the magnetic bearing device 1 according to
an exemplary embodiment in the present disclosure may support
a roll shaft 2, and more specifically, may support the roll shaft
2 in a non-contact manner.
In particular, the magnetic bearing device 1 and the
25 hot-dip galvanizing apparatus including the magnetic bearing
10
device 1 according to the exemplary embodiment in the present
disclosure may support the roll shaft 2 with magnetic force.
According to the exemplary embodiment in the present disclosure,
the magnetic force may affect only a portion to be supported
5 in the roll shaft 2, and thereby the support of the roll shaft
2 may be precisely controlled by the magnetic force.
Accordingly, since collisions between the roll shaft 2
and the magnetic bearing device 1 are prevented, problems such
as non-uniformity in plating thickness deviations caused by
10 vibrations of the pot roll may be solved and quality of the steel
sheet may be improved.
FIG. 1 is a perspective view illustrating a hot-dip
galvanizing apparatus according to an exemplary embodiment in
the present disclosure. Referring to FIG. 1, the hot-dip
15 galvanizing apparatus according to the exemplary embodiment in
the present disclosure may include a galvanizing bath 4 in which
molten zinc is accommodated, a pot roll 3 disposed on a
transportation path of the steel sheet moving into the
galvanizing bath 4, and a magnetic bearing device 1, to be
20 described later, disposed on the roll shaft 2 of the pot roll
3.
In this manner, the galvanizing bath 4 and the pot roll
3 may be provided to galvanize the steel sheet.
Here, the pot roll 3 may include a sink roll configured
25 to change a moving direction of the steel sheet, and a
11
stabilizing roll configured to correct a shape of the steel
sheet.
In particular, since the hot-dip galvanizing apparatus
according to the exemplary embodiment in the present disclosure
5 includes the magnetic bearing device 1, the roll shaft 2 of the
pot roll 3 may be precisely supported.
FIG. 2 is a cross-sectional view illustrating a magnetic
bearing device 1 according to an exemplary embodiment in the
present disclosure, and FIG. 3 is a side view illustrating a
10 magnetic force receiving unit 200 of the magnetic bearing device
1 according to an exemplary embodiment in the present
disclosure.
Referring to FIGS. 2 and 3, the magnetic bearing device
1 according to the exemplary embodiment in the present
15 disclosure may include a support unit 100 disposed adjacent to
the roll shaft 2 and generating a magnetic field toward the roll
shaft 2, and a magnetic force receiving unit 200 coupled to the
roll shaft 2. The magnetic force receiving unit 200 may include
a magnetic material in only a portion facing the support unit
20 100, thereby being magnetized with magnetic force of the
magnetic field generated in the support unit 100.
That is, since an effect of the magnetic force of the
magnetic field generated in the support unit 100 is concentrated
on the portion of the magnetic force receiving unit 200 disposed
25 on the roll shaft 2, the support of the roll shaft 2 may be
12
precisely controlled.
The support unit 100 may function to support the roll shaft
2 in a non-contact manner using the magnetic force. That is,
the support unit 100 may generate the magnetic field, and
5 support the roll shaft 2 by interaction with the roll shaft 2.
In this regard, the support unit 100 may include a magnetic
support 110 supporting the roll shaft 2 in at least one of an
axial direction or a radial direction by the magnetic force,
and a sensor unit 120 for sensing vibrations. This will be
10 described later in detail with reference to FIGS. 7 to 9.
In addition, the support unit 100 may include a housing
130 with which the magnetic support 110 and the sensor unit 120
are combined, and a radial touch disc 140 and an axial touch
disc 150 which serve to prevent collisions of the magnetic
15 support 110 with the roll shaft 2. This will be described later
in detail with reference to FIGS. 5 and 6.
Here, when the roll shaft 2 is formed of a magnetic
material, the roll shaft 2 may be directly affected by the
magnetic field generated in the support unit 100 to be polarized
20 and supported by an attractive force or a repulsive force.
In particular, even when the roll shaft 2 is not formed
of a magnetic material, the roll shaft 2 may be supported by
the interaction between the support unit 100 and the magnetic
force receiving unit 200 since the magnetic force receiving unit
25 200 to be described later, is coupled to the roll shaft 2.
13
That is, the roll shaft 2 of the magnetic bearing device
1 according to the exemplary embodiment in the present
disclosure may be formed of a nonmagnetic material.
In this manner, since the roll shaft 2 is not affected
5 by the magnetic field generated in the support unit 100 when
the roll shaft 2 is formed of the nonmagnetic material, only
the portion formed of the magnetic material in the magnetic
force receiving unit 200, to be described later, may be affected
by the magnetic field generated in the support unit 100.
10 Accordingly, the support unit 100 may support the roll shaft
2 in more precisely controlled manner.
That is, when the roll shaft 2 is formed of the magnetic
material, an induced current formed by the magnetic force
transmitted from a portion facing the support unit 100 in the
15 roll shaft 2 or the magnetic field generated in the support unit
100 may affect the other portion of the roll shaft 2, resulting
in a control error occurrence.
In addition, when the roll shaft 2 is formed of a
nonmagnetic material, a heat generation problem caused by the
20 induced current formed by the magnetic force may be solved.
The magnetic force receiving unit 200 may function to
precisely control the support unit 100 to support the roll shaft
2, by concentrating the magnetic field generated in the support
unit 10.
25 In this regard, the magnetic force receiving unit 200 may
14
include the magnetic material at only a portion facing the
support unit 100 in the roll shaft 2. In such a manner, the
magnetic force may be concentrated on the portion formed of the
magnetic material in the magnetic force receiving unit 200 due
5 to the interaction with the magnetic field generated in the
support unit 100.
In particular, the portion formed of the magnetic material
in the magnetic force receiving unit 200 may be preferably
disposed on a portion, facing the magnetic support 110 and
10 sensor unit 120 of the support unit 100, in the roll shaft 2.
The magnetic support 110 and sensor unit 120 of the support unit
100 will be described later.
That is, the magnetic force receiving unit 200 of the
magnetic bearing device 1 according to the exemplary embodiment
15 in the present disclosure may include a magnetic member 210
formed of the magnetic material, disposed only in the portion
facing the magnetic support 110 and sensor unit 120, on the roll
shaft 2.
This is because the support unit 100 generates the
20 magnetic force in a portion in which the magnetic support 110
and the sensor unit 120 face the roll shaft 2.
More specifically, the magnetic force receiving unit 200
may include the magnetic member 210 and a nonmagnetic member
220.
25 That is, the magnetic force receiving unit 200 of the
15
magnetic bearing device 1 according to the exemplary embodiment
in the present disclosure may further include the magnetic
member 210 formed of a magnetic material and disposed on the
portion facing the support unit 100 in the roll shaft 2, and
5 the nonmagnetic member 220 formed of a nonmagnetic material and
disposed on a portion other than the portion on which the
magnetic member is disposed, in the roll shaft.
Here, the magnetic material may include, for example, iron,
cobalt, nickel, or a ferritic/martensitic stainless steel. In
10 addition, the nonmagnetic material may include, for example,
a non-metallic material such as a ceramic, or a metal, such as
an austenite-based stainless steel.
In addition, the magnetic member 210 and the nonmagnetic
member 220 may have a cylindrical shape or a disc shape so as
15 to be coupled to the roll shaft 2. This will be described later
in detail with reference to FIG. 4.
Further, the magnetic force receiving unit 200 may further
include an axial sheathing member 230 by which the magnetic
member 210 and the nonmagnetic member 220 may be easily coupled
20 to the roll shaft 2.
That is, the magnetic force receiving unit 200 of the
magnetic bearing device 1 according to the exemplary embodiment
in the present disclosure may further include the axial
sheathing member 230 fitted to the roll shaft 2 and with which
25 the magnetic member 210 and the nonmagnetic member 220 are
16
combined.
The axial sheathing member 230 may be provided since it
may be difficult to couple the magnetic member 210 or the
nonmagnetic member 220 to the roll shaft 2 when the roll shaft
5 2 does not have a rod shape having a constant diameter but a
shape having diameters varying along its length.
That is, since only the inner side of the axial sheathing
member 230 is formed to have a shape corresponding to the roll
shaft 2, it is not necessary to form the magnetic member 210
10 and nonmagnetic member 220 having different sizes.
Here, when the roll shaft 2 is formed of a nonmagnetic
material, the axial sheathing member 230 may also be formed of
a nonmagnetic material. Accordingly, the magnetic force may
be effectively concentrated by the magnetic force receiving
15 unit 200.
FIG. 4 is an exploded perspective view illustrating a
magnetic force receiving unit 200 of a magnetic bearing device
1 according to an exemplary embodiment in the present disclosure.
Referring to FIG. 4, the magnetic member 210 of the magnetic
20 bearing device 1 according to the exemplary embodiment in the
present disclosure may have a cylindrical shape. A width of
the magnetic member 210 may be the same as a width of the portion
facing the support unit 100 in the roll shaft 2.
In addition, the magnetic member 210 of the magnetic
25 bearing device 1 according to the exemplary embodiment in the
17
present disclosure may have a disc shape, and the number of the
magnetic member 210 may correspond to the width of the portion
facing the support unit 100 in the roll shaft 2.
That is, the magnetic member 210 and the nonmagnetic
5 member 220 may have the cylindrical shape or the disc shape to
be coupled to the roll shaft 2.
Here, when the magnetic member 210 and the nonmagnetic
member 220 have the cylindrical shape, the magnetic member 210
and the nonmagnetic member 220 may be easily coupled to the roll
10 shaft 2. That is, the coupling may only be completed by
inserting the cylindrical magnetic member 210 having the same
width as the portion facing the support unit 100 into the roll
shaft 2, and the cylindrical nonmagnetic member 220 having the
same width as a portion that does not face the support unit 100
15 in the roll shaft 2.
Meanwhile, when the magnetic member 210 and nonmagnetic
member 220 have a disc shape, it is advantageous that the
magnetic member 210 and the nonmagnetic member 220 do not need
to be manufactured every time that the magnetic member 210 and
20 nonmagnetic member 220 are provided to the support unit 100 or
roll shaft 2 having various shapes. That is, the magnetic
member 210 may be stacked by a width equal to the width of the
portion facing the support unit 100 in the roll shaft 2, to be
coupled to the roll shaft 2, and the nonmagnetic member 220 may
25 be stacked by a width equal to the width of the portion that
18
does not face the support unit 100 in the roll shaft 2, to be
coupled to the roll shaft 2.
FIG. 5 is an exploded perspective view illustrating a
magnetic force receiving unit 200 in a magnetic bearing device
5 1 according to an exemplary embodiment in the present disclosure,
and FIG. 6 is a cross-sectional view illustrating a radial touch
disc 140 in a magnetic bearing device 1 according to another
exemplary embodiment in the present disclosure.
Referring to FIGS. 5 and 6, the support unit 100 of the
10 magnetic bearing device 1 according to the exemplary embodiment
in the present disclosure may further include a housing 130 with
which the magnetic support 110 and the sensor unit 120 are
combined, and a radial touch disc 140 coupled to the housing
130 or an inner side of a radial magnetic member 111of the
15 magnetic support 110. An interior diameter D2 of the radial
touch disc 140 may be smaller than an interior diameter D1 of
the radial magnetic member 111.
In addition, the support unit 100 of the magnetic bearing
device 1 according to the exemplary embodiment in the present
20 disclosure may further include an axial touch disc 150 disposed
between an axial magnetic member 112 of the magnetic support
110 and a stepped portion s of the roll shaft 2 and combined
with the housing 130.
That is, the support unit 100 may include the radial touch
25 disc 140 and the axial touch disc 150 to prevent the magnetic
19
support 110 from colliding with the roll shaft 2.
The magnetic support 110 and the sensor unit 120 may be
combined to the housing 130. In this regard, the housing 130
may include a housing body 131 as a base member.
5 That is, the housing body 131 may be combined with the
magnetic support 110, the sensor unit 120, or the like. In this
regard, the housing body 131 may have a cylindrical shape so
that the magnetic support 110, the sensor unit 120, or the like
are combined therewith. The housing body 131 may include a
10 stepped portion corresponding to a difference in diameters of
the magnetic support 110, the sensor unit 120, and the like.
Further, the housing 130 may include a cable tube
configured to electrically connect the magnetic support 110,
the sensor unit 120, and the like to an external controller.
15 That is, the cable tube may function to protect a control cable
or communication cable connected to coils of the magnetic
support 110 and the sensor unit 120 from a high temperature
environment and the like.
In addition, the housing 130 may further include a housing
20 cover 133 to prevent the magnetic support 110 and the sensor
unit 120 from moving out from the housing body 131 after the
magnetic support 110 and the sensor unit 120 are combined with
an inner side of the housing body 131. The housing cover 133
may be combined with an end of the housing body 131 having the
25 cylindrical shape.
20
In addition, a gasket g may be combined with the housing
130 to block inflow of an external material such as a hot-dip
galvanizing material while combining the magnetic support 110
and the sensor unit 120 with the housing body 131.
5 The radial touch disc 140 may function to prevent the
radial magnetic member 111 of the magnetic support 110, which
will described later, from colliding with the roll shaft 2.
That is, the radial touch disc 140 may come into contact
with the roll shaft 2 before the radial magnetic member 111 comes
10 into contact with the roll shaft 2, when no current is applied
to the radial magnetic member 111 and thereby the magnetic field
is not generated. Accordingly, the radial touch disc 140 may
prevent the radial magnetic member 111 from colliding with the
roll shaft 2.
15 In this regard, the interior diameter D2 of the radial
touch disc 140 may be smaller than the interior diameter D1 of
the radial magnetic member 111.
In addition, the radial touch disc 140 may be combined
with an inner side of the radial magnetic member 111, as
20 illustrated in FIG. 5.
According to another exemplary embodiment in the present
disclosure, an outer side of the radial touch disc 140 may be
combined with the housing 130, as illustrated in FIG. 6. The
radial touch disc 140 may be disposed adjacently to the radial
25 magnetic member 111.
21
The axial touch disc 150 may function to prevent the axial
magnetic member 112 of the magnetic support 110, to be described
later, from colliding with the roll shaft 2.
That is, when no current is applied to the axial magnetic
5 member 112 and thereby, the magnetic field is not formed, the
axial touch disc 150 may come into contact with the roll shaft
2 before the axial magnetic member 112 comes into contact with
the roll shaft 2. Accordingly, collision between the axial
magnetic member 112 and the roll shaft 2 may be prevented.
10 In this regard, the axial touch disc 150 may be combined
with the housing 130 and disposed between the axial magnetic
member 112 and the stepped portion s of the roll shaft 2.
FIG. 7 is a front view and a perspective view illustrating
a radial magnetic member 111 of a magnetic support 110 in a
15 magnetic bearing device 1 according to an exemplary embodiment
in the present disclosure, FIG. 8 is a perspective view
illustrating an axial magnetic member 112 of a magnetic support
110 in a magnetic bearing device 1 according to an exemplary
embodiment in the present disclosure, and FIG. 9 is a
20 perspective view illustrating a sensor unit 120 in a magnetic
bearing device 1 according to an exemplary embodiment in the
present disclosure.
Referring to FIGS. 7 to 9, the support unit 100 of the
magnetic bearing device 1 according to the exemplary embodiment
25 in the present disclosure may include the magnetic support 110
22
disposed adjacent to the roll shaft 2 and supporting the roll
shaft 2 in at least one of an axial direction and a radial
direction of the roll shaft 2, and the sensor unit 120
electrically connected to the magnetic support 110 and
5 measuring and controlling the intensity of the vibration
generated in the magnetic support 110.
That is, the support unit 100 may include the magnetic
support 110 and the sensor unit 120 to support the roll shaft
2 by the magnetic force in a non-contact manner.
10 The magnetic support 110 may form the magnetic field to
support the roll shaft 2.
Here, when the roll shaft 2 is formed of a magnetic
material, the roll shaft 2 may be directly affected by the
magnetic field generated in the magnetic support 110 and thereby
15 polarized. Accordingly, the roll shaft 2 may be supported by
an attractive force or a repulsive force.
In particular, even when the roll shaft 2 is not formed
of a magnetic material, the roll shaft 2 may be supported by
an interaction between the magnetic support 110 and the magnetic
20 force receiving unit 200 since the magnetic force receiving unit
200 is combined with the roll shaft 2.
In this regard, the magnetic support 110 may include the
radial magnetic member 111 supporting the roll shaft 2 in a
radial direction of the roll shaft 2, and the axial magnetic
25 member 112 supporting the roll shaft 2 in an axial direction
23
of the roll shaft 2.
That is, the magnetic support 110 in the magnetic bearing
device 1 according to the exemplary embodiment in the present
disclosure may include the radial magnetic member 111 formed
5 in a radial direction of the roll shaft 2 and supporting the
roll shaft 2 in the radial direction of the roll shaft 2 when
the roll shaft 2 rotates, and the axial magnetic member 112
disposed to face the roll shaft 2 or the stepped portion s formed
on the axial sheathing member 230 of the magnetic force
10 receiving unit 200 fitted on the roll shaft 2 in the axial
direction and supporting the roll shaft 2 in the axial direction
of the roll shaft 2 when the roll shaft 2 rotates.
The radial magnetic member 111 may include a radial
magnetic member body 111a, a radial core 111b, and a radial coil
15 111c to support the roll shaft 2 in the radial direction of the
roll shaft 2.
The radial magnetic member body 111a may be configured
to surround the roll shaft 2 in a circumferential direction of
the roll shaft 2, and combined with the housing 130. In addition,
20 the radial core 111b may be formed at an inner side of the radial
magnetic member body 111a.
The radial core 111b may be formed at regular intervals
on the inner side of the radial magnetic member body 111a, and
the intervals may be adjusted, as needed. In addition, the
25 radial coil 111c may be wound on the radial core 111b. Here,
24
the magnetic polarity of the radial core 111b may be alternately
arranged in an N-S-N-S.
The radial coil 111c may serve to generate the magnetic
field by applying current. The radial coil 111c may be formed
5 of ceramic-coated wires for high temperature so as to maintain
performance of the magnetic force in a hot-dip galvanizing bath
4 at the high temperature of about 460 ºC.
In addition, the radial coil 111c may be connected to the
outside through the cable tube or the like, so as to be protected
10 from an external environment such as heat damage.
Here, the magnetic force of the radial magnetic member
111 may be proportional to the number of the radial core 111b,
the number of windings of the radial coil 111c, and the applied
current.
15 The axial magnetic member 112 may include an axial
magnetic member body 112a, an axial core and an axial coil 112b
to support the roll shaft 2 in the axial direction of the roll
shaft 2.
The axial magnetic member body 112a may be formed to face
20 the roll shaft 2 or the stepped portion s of the axial sheathing
member 230. However, the axial touch disc 150 and the like may
be disposed between the axial magnetic member body 112a and the
stepped portion s.
In addition, the axial magnetic member body 112a may be
25 combined with the housing 130, and wound with the axial coil
25
112b.
The axial coil 112b may wind along grooves formed on the
axial magnetic member body 112a in a circumferential direction.
The axial coil 112b may function to form the magnetic field
5 by applying current. The axial coil 112b may be formed of
ceramic-coated wires for high temperature so as to maintain
performance of the magnetic force in the hot-dip galvanizing
bath 4 at the high temperature of about 460 ºC.
Here, the magnetic force of the axial magnetic member 112
10 may be proportional to the number of windings of the axial coil
112b and the applied current.
The sensor unit 120 may function to adjust the amount of
current applied to the magnetic support 110 by sensing
vibrations generated in the radial direction or the axial
15 direction of the roll shaft 2. In this regard, the sensor unit
120 may include a sensor 121, a sensor cover 122, and a controller
123.
The sensor 121 may function to sense the vibrations
generated in the radial direction or the axial direction of the
20 roll shaft 2. In this regard, the sensor 121 may include a
sensor body 121a configured to surround the roll shaft 2 in the
circumferential direction, a sensor core 121b formed on an inner
side of the sensor body 121a, and a sensor coil 121c winding
the sensor core 121b.
25 The sensor cover 122 may function to protect the sensor
26
121 from an external environment such as a high temperature.
In this regard, the sensor cover 122 may surround the sensor
121.
The controller 123 may function to adjust the amount of
5 the current applied to the magnetic support 110 by collecting
vibration data from the sensor 121. The controller 123 may be
integrated with the sensor body 121a, or externally formed and
electrically connected to the sensor 121. In addition, the
controller 123 may be electrically connected to the magnetic
10 support 110 so as to control the magnetic support 110.

We claim
【Claim 1】
A magnetic bearing device, comprising:
5 a support unit disposed adjacent to a roll shaft and
generating a magnetic field toward the roll shaft; and
a magnetic force receiving unit coupled to the roll shaft
and only including a magnetic material in a portion facing the
support unit, wherein the magnetic material is magnetized by
10 the magnetic force.
【Claim 2】
The magnetic bearing device of claim 1, wherein the
magnetic force receiving unit comprises:
15 a magnetic member formed of the magnetic material and
disposed on the portion facing the support unit in the roll shaft;
and
a nonmagnetic member formed of a nonmagnetic material and
disposed on a portion other than the portion on which the
20 magnetic member is disposed, in the roll shaft.
【Claim 3】
The magnetic bearing device of claim 2, wherein the
magnetic force receiving unit further comprises an axial sheath
25 member fitted onto the roll shaft and with which the magnetic
28
member and the nonmagnetic member are combined.
【Claim 4】
The magnetic bearing device of claim 2, wherein the
5 magnetic member has a cylindrical shape, and has the same width
as the portion facing the support unit in the roll shaft.
【Claim 5】
The magnetic bearing device of claim 2, wherein the
10 magnetic member has a disc shape, and the number of the magnetic
member corresponds to a width of the portion facing the support
unit in the roll shaft.
【Claim 6】
15 The magnetic bearing device of claim 1, wherein the roll
shaft is formed of a nonmagnetic material.
【Claim 7】
The magnetic bearing device of claim 1, wherein the
20 support unit comprises:
a magnetic support disposed adjacent to the roll shaft
and supporting the roll shaft in at least one of an axial
direction or a radial direction of the roll shaft; and
a sensor electrically connected to the magnetic support
25 to measure and control an intensity of vibrations of the
29
magnetic support.
【Claim 8】
The magnetic bearing device of claim 7, wherein the
5 magnetic support comprises:
a radial magnetic member disposed in a radial direction
of the roll shaft and supporting the roll shaft in the radial
direction of the roll shaft when the roll shaft rotates; and
an axial magnetic member disposed to face a stepped
10 portion, formed in the roll shaft or in an axial sheath member
of the magnetic force receiving unit fitted on the roll shaft,
in an axial direction of the roll shaft and supporting the roll
shaft in the axial direction of the roll shaft when the roll
shaft rotates.
15
【Claim 9】
The magnetic bearing device of claim 8, wherein the
support unit further comprises:
a housing part with which the magnetic support and the
20 sensor are combined; and
a radial touch disc having a disc shape and combined with
the housing part or an inner side of the radial magnetic member,
wherein an internal diameter of the radial touch disc is smaller
than an internal diameter of the radial magnetic member.
25
30
【Claim 10】
The magnetic bearing device of claim 9, wherein the
support unit further comprises:
an axial touch disc combined with the housing part to be
5 disposed between the axial magnetic member and the stepped
portion of the roll shaft.
【Claim 11】
The magnetic bearing device of claim 7, wherein the
10 magnetic force receiving unit includes the magnetic material
only on a portion facing the magnetic support and the sensor
in the roll shaft.
【Claim 12】
15 A hot-dip galvanizing apparatus, comprising:
a galvanizing bath configured to accommodate molten zinc;
a pot roll disposed on a transportation path of a steel
sheet moving into the galvanizing bath; and
a magnetic bearing device as claimed in any one of claims
20 1 to 11, wherein the magnetic bearing device is disposed on a
roll shaft of the pot roll.