U.S. patent application number 09/802854 was filed with the patent office on 2002-04-25 for vacuum variable capacitor device.
This patent application is currently assigned to KABUSHIKI KAISHA MEIDENSHA. Invention is credited to Fukai, Toshimasa, Hayashi, Naoki, Nemoto, Tomofumi.
Application Number | 20020048136 09/802854 |
Document ID | / |
Family ID | 18598078 |
Filed Date | 2002-04-25 |
United States Patent
Application |
20020048136 |
Kind Code |
A1 |
Nemoto, Tomofumi ; et
al. |
April 25, 2002 |
Vacuum variable capacitor device
Abstract
An adjuster nut is rotatably supported to a vacuum container of
a vacuum variable capacitor of a vacuum variable capacitor device.
The adjuster nut has a nut portion, and a shank made of an
insulating material. The shank has a first end integrated with the
nut portion and a second end adapted to be directly coupled with a
rotational shaft of a driving portion of the vacuum variable
capacitor device. Another type of the adjuster nut has a deformable
bellows, a nut portion, and a shank made of an insulating material.
A second end of the nut portion is coupled with a first end of the
bellows. The shank has a first end coupled with a second end of a
bellows, and a second end adapted to be directly coupled with the
rotational shaft of the driving portion of the vacuum variable
capacitor device.
Inventors: |
Nemoto, Tomofumi; (Shizuoka,
JP) ; Fukai, Toshimasa; (Shizuoka, JP) ;
Hayashi, Naoki; (Shizuoki, JP) |
Correspondence
Address: |
Richard L. Schwaab
FOLEY & LARDNER
Washington Harbour
3000 K Street, N.W., Suite 500
Washington
DC
20007-5109
US
|
Assignee: |
KABUSHIKI KAISHA MEIDENSHA
|
Family ID: |
18598078 |
Appl. No.: |
09/802854 |
Filed: |
March 12, 2001 |
Current U.S.
Class: |
361/277 |
Current CPC
Class: |
H01G 5/14 20130101 |
Class at
Publication: |
361/277 |
International
Class: |
H01G 005/00 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 23, 2000 |
JP |
2000-081097 |
Claims
What is claimed is:
1. A vacuum variable capacitor device comprising: a vacuum
container comprising: an insulated cylinder; a first end plate
mounted at a first end of the insulated cylinder; and a second end
plate mounted at a second end of the insulated cylinder opposite to
the first end of the insulated cylinder; a first electrode formed
on an internal surface of the first end plate, and comprising a
first cylindrical electrode plate; a conductor disposed in the
vacuum container in such a manner as to face the first end plate; a
second electrode mounted to the conductor, and comprising a second
cylindrical electrode plate on a first side of the conductor facing
the first end plate; a guide mechanism disposed between the first
end plate and the conductor in the vacuum container, so as to guide
a movement of the conductor; a bellows having a first end mounted
to the conductor and a second end mounted to the second end plate;
a screw shaft having a first end mounted toward a second side of
the conductor opposite to the first side of the conductor, and a
second end adapted to be inserted in an opening defined in the
second end plate, the opening being disposed on a radial inner side
of the second end of the bellows; an adjuster nut rotatably
supported to the second end plate, being screwed down on the screw
shaft, and being insulative; and a driving portion having a
rotational shaft which is directly coupled with the adjuster
nut.
2. The vacuum variable capacitor device as claimed in claim 1, in
which the adjuster nut rotatably supported to the second end plate
comprises: a nut portion screwed down on the screw shaft; and a
shank integrated with the nut portion, made of an insulating
material, and directly coupled with the rotational shaft of the
driving portion.
3. The vacuum variable capacitor device as claimed in claim 1, in
which the adjuster nut rotatably supported to the second end plate
comprises: a nut portion screwed down on the screw shaft; a shank
made of an insulating material, and directly coupled with the
rotational shaft of the driving portion; and a bellows disposed
between the nut portion and the shank for connecting the nut
portion with the shank.
4. The vacuum variable capacitor device as claimed in claim 2, in
which the shank is made of one of a fiber reinforced plastic and a
polycarbonate.
5. The vacuum variable capacitor device as claimed in claim 3, in
which the shank is made of one of a fiber reinforced plastic and a
polycarbonate.
6. The vacuum variable capacitor device as claimed in claim 1, in
which the first cylindrical electrode plate of the first electrode
comprises a plurality of first cylindrical electrode plates having
different diameters and standing concentrically on the internal
surface of the first end plate, the first cylindrical electrode
plates ranging from an innermost first cylindrical electrode plate
to an outermost first cylindrical electrode plate, and in which the
second cylindrical electrode plate of the second electrode
comprises a plurality of second cylindrical electrode plates having
different diameters and standing concentrically on the first side
of the conductor, the second cylindrical electrode plates ranging
from an innermost second cylindrical electrode plate to an
outermost second cylindrical electrode plate.
7. The vacuum variable capacitor device as claimed in claim 6, in
which each of the first cylindrical electrode plates ranging from
the outermost to a second innermost is put and ousted from between
adjacent two of the second cylindrical electrode plates in an
interdigitating manner, and in which each of the second cylindrical
electrode plates ranging from a second outermost to the innermost
is put and ousted from between adjacent two of the first
cylindrical electrode plates in an interdigitating manner.
8. The vacuum variable capacitor device as claimed in claim 1, in
which the bellows is substantially in a form of a cylinder.
9. An adjuster nut rotatably supported to a vacuum container of a
vacuum variable capacitor of a vacuum variable capacitor device,
the adjuster nut comprising: a nut portion; and a shank made of an
insulating material, the shank having a first end integrated with
the nut portion and a second end adapted to be directly coupled
with a rotational shaft of a driving portion of the vacuum variable
capacitor device.
10. The adjuster nut as claimed in claim 9, in which the shank is
made of one of a fiber reinforced plastic and a polycarbonate.
11. The adjuster nut as claimed in claim 10, in which the second
end of the shank is formed with a flange that is coupled with a
flange of the rotational shaft by means of a bolt, and in which the
shank defines an internal opening extending from the first end to
the second end of the shank.
12. The adjuster nut as claimed in claim 11, in which the nut
portion defines an internal threaded opening extending from a first
end to a second end integrated with the first end of the shank, the
internal threaded opening of the nut portion being smaller in
diameter than the internal opening of the shank in such a manner as
to form a stage along a boundary therebetween.
13. The adjuster nut as claimed in claim 12, in which the first end
of the nut portion is fitted with a bearing.
14. An adjuster nut rotatably supported to a vacuum container of a
vacuum variable capacitor of a vacuum variable capacitor device,
the adjuster nut comprising: a deformable bellows having a first
end, and a second end opposite to the first end; a nut portion
having a first end, and a second end coupled with the first end of
the bellows; and a shank made of an insulating material, the shank
having a first end coupled with the second end of the bellows, and
a second end adapted to be directly coupled with a rotational shaft
of a driving portion of the vacuum variable capacitor device.
15. The adjuster nut as claimed in claim 14, in which the shank is
made of one of a fiber reinforced plastic and a polycarbonate.
16. The adjuster nut as claimed in claim 15, in which the second
end of the shank is formed with a flange that is coupled with a
flange of the rotational shaft by means of a bolt, and in which the
shank defines an internal opening extending from the first end to
the second end of the shank.
17. The adjuster nut as claimed in claim 16, in which the nut
portion defines an internal threaded opening extending from the
first end to the second end of the nut portion, the internal
threaded opening of the nut portion being smaller in diameter than
the internal opening of the shank.
18. The adjuster nut as claimed in claim 17, in which the first end
of the nut portion is fitted with a bearing.
Description
BACKGROUND OF THE INVENTION
[0001] The present invention relates to a vacuum variable capacitor
device that is used for various applications such as an oscillator
of a high power transmitter, a high frequency power source of a
semiconductor manufacturing device, a tank circuit of an inductive
heating device.
[0002] FIG. 3 and FIG. 4 show, respectively, a longitudinal cross
section and a partly enlarged section of a vacuum variable
capacitor, according to Japanese Patent Unexamined Publication
(refereed to as "Kokai Koho" in Japanese) No. 11(1999)-273998 which
is an equivalent for Japanese Patent Application No.
10(1998)-0074755.
[0003] There is provided an insulated cylinder 1 made of an
insulating material such as ceramic and the like. As is seen in
FIG. 3, the insulated cylinder 1 has first and second ends, which
are respectively, joined with a first cylinder 2a and a second
cylinder 2b, to thereby form a cylindrical shape. The first and
second ends of the insulated cylinder 1 is made of copper, and is
blocked by means of, respectively, an immovable end plate 3 and a
movable end plate 4, to thereby form a vacuum container 5. Inside
the immovable end plate 3, there are provided a plurality of first
cylindrical electrode plates F that range from F.sub.1 to F.sub.n
having different diameters. The first cylindrical electrode plates
F.sub.1 to F.sub.n stand on the inside of the immovable end plate
3, and are concentrically disposed at regular radial intervals, to
thereby form an immovable electrode 6.
[0004] There is provided a conductor 7 for mounting a movable
electrode 8. The conductor 7 is so disposed in the vacuum container
5 as to oppose the immovable end plate 3. On a first side of the
conductor 7 facing the immovable end plate 3, there are provided a
plurality of second cylindrical electrode plates M that range from
M.sub.1 to M.sub.n having different diameters. The second
cylindrical electrode plates M.sub.1 to M.sub.n stand on the first
side of the conductor 7, and are concentrically disposed at regular
radial intervals, to thereby form the movable electrode 8. Each of
the second cylindrical electrode plates ranging from M.sub.2 to
M.sub.n is put and ousted from between adjacent two of the first
cylindrical electrode plates F.sub.1 to F.sub.n (interdigitation),
while each of the first cylindrical electrode plates ranging from
F.sub.1 to F.sub.n-1 is put and ousted from between adjacent two of
the second cylindrical electrode plates M.sub.1 to M.sub.n
(interdigitation). There is provided a center pin 9 standing at an
internal center of the immovable end plate 3. There is provided a
movable guide 10 which is cylindrical and functions as a guide. The
movable guide 10 also functions as a lead. The movable guide 10 is
so disposed as to penetrate through a center of the conductor 7.
The center pin 9 is inserted into the movable guide 10 in a
slidable manner.
[0005] There is provided a bellows 15 having a first end which is
mounted to the movable guide 10. The bellows 15 is cylindrical and
retractable. Moreover, the bellows 15 is used for maintaining a
vacuum condition and for energizing. The bellows 15 further has a
second end mounted to an internal face of the movable end plate 4.
There is defined an opening 4a in the movable end plate 4. The
opening 4a is disposed on a radial inner side of the second end of
the bellows 15. There is provided a nut receptacle 11 which is
cylindrical, and stands around the entire circumference of the
opening 4a on the internal face of the movable end plate 4. There
is formed a collar 11a at an internal end of the nut receptacle 11.
There is provided a screw shaft 12 having a first end which is
connected to the movable guide 10. The screw shaft 12 also has a
second end projecting into the nut receptacle 11 through the collar
11a. There is provided an adjuster nut 13 having a first end which
is so supported to the collar 11a by way of a bearing 16 as to
rotate arbitrarily. The first end of the adjuster nut 13 defines a
screw shaft opening 13a so that the adjuster nut 13 is screwed down
on the screw shaft 12. The second end of the screw shaft 12 defines
a coaxial screw opening 12a. With the screw opening 12a, the screw
shaft 12 is screwed down on an adjuster screw 14 having a screw
head 14a. Moreover, the adjuster nut 13 has a large opening 13b
adjacent to the screw shaft opening 13a. The large diameter opening
13b is larger in diameter than the screw shaft opening 13a. There
is defined a stage 13c between the screw shaft opening 13a and the
large diameter opening 13b.
[0006] Described below is how to assuredly maintain a maximum
electrostatic capacity of the vacuum variable capacitor having the
constitution as mentioned above, and to facilitate adjustment of
the maximum electrostatic capacity:
[0007] At first, turn the adjuster nut 13 slightly clockwise (for
right handed screw) so as to shift the screw shaft 12 slightly
lower than a position X (not shown) of the maximum electrostatic
capacity (at the position X, a lower end of the center pin 9 abuts
on an upper end of the screw shaft 12), to thereby adjust the
maximum electrostatic capacity to its predetermined value. The
slight adjustment depends on the variation of the electrostatic
capacity of the vacuum variable capacitors. Then, screw the
adjuster screw 14 into the screw opening 12a to such an extent that
the screw head 14a abuts on the stage 13c. Thereafter, fix the
adjuster screw 14 to the screw shaft 12 by means of an adhesive and
the like. Thereby, even if the adjuster nut 13 is likely to make a
counterclockwise turn at the position X of the maximum
electrostatic capacity, the screw head 14a of the adjuster screw 14
abuts on the stage 13c. Consequently, this can prevent the adjuster
nut 13 from making the counterclockwise turn. Therefore, the screw
shaft 12 cannot go up beyond the position X of the maximum
electrostatic capacity. With this, the maximum electrostatic
capacity can be assuredly maintained, and the adjustment of the
maximum electrostatic capacity can be facilitated.
[0008] On the contrary, described below is how to arbitrarily
variably adjust the electrostatic capacity of the vacuum variable
capacitor having the constitution as mentioned above:
[0009] At first, turn the adjuster nut 13 so as to move the movable
electrode 8 upward and downward by way of the screw shaft 12 and
the movable guide 10. With this, a total area of the movable
electrode 8 opposed to the immovable electrode 6 is varied, to
thereby arbitrarily variably adjust the electrostatic capacity.
With the center pin 9 and the movable guide 10 provided for
constituting a guide mechanism, the movable electrode 8 can be
moved stably, and a withstand voltage as well as the electrostatic
capacity can show stabilized characteristics.
[0010] In the above mentioned related art, the movable guide 10 is
integrated with a movable lead. Contrary to this, however, the
movable guide 10 can be separated from the movable lead. Moreover,
the movable guide 10 is to be electrically insulated from the
center pin 9. The first end of the bellows 15 can be mounted to the
conductor 7, instead of the movable guide 10.
[0011] When using the above vacuum variable capacitor for matching
impedance of the semiconductor thin film manufacturing device, an
operator needs to use a constitution shown in FIG. 5 for the
following reason: Since a load changes continuously, it is
necessary to carry out the impedance matching of the vacuum
variable capacitor following the load change. More specifically, as
is seen in FIG. 5, a vacuum variable capacitor 19 is mounted
horizontally on a mounting base 17 by way of a pair of mounting
plates 18, and a driving portion 21 is also mounted horizontally on
the mounting base 17 by way of a mounting plate 20. A rotational
shaft 22 of the driving portion 21 is coupled with the adjuster nut
13 by way of a coupling member 23. Driving the driving portion 21
allows the adjuster nut 13 to turn clockwise and counterclockwise,
to thereby vary the electrostatic capacity of the vacuum variable
capacitor 19.
[0012] FIG. 6 shows a general matching circuit using the vacuum
variable capacitor 19 shown in FIG. 5. In the matching circuit,
there are also provided a high frequency power source 24, a coil
25, and a load 26. It is necessary to insulate the immovable side
from the movable side of the vacuum variable capacitor 19.
Therefore, the vacuum variable capacitor device shown in FIG. 5 has
a constitution in which each of the mounting plate 18 and the
coupling member 23 is made of insulating material. For such
insulation purpose, the coupling member 23 is continuously provided
even when the coupling member 23 is not necessary. This ends up
complicating the constitution of the vacuum variable capacitor
device, and causing a backlash and the like. Thereby, it is
difficult to control the driving portion 21.
SUMMARY OF THE INVENTION
[0013] It is therefore an object of the present invention to
provide a vacuum variable capacitor device that does not require a
coupling member, to thereby simplify a constitution of the vacuum
variable capacitor device.
[0014] It is another object of the present invention to prevent any
backlash from occurring, to thereby facilitate control of a driving
portion of the vacuum variable capacitor device.
[0015] According to a first aspect of the present invention, there
is provided an adjuster nut rotatably supported to a vacuum
container of a vacuum variable capacitor of a vacuum variable
capacitor device. The adjuster nut comprises a nut portion, and a
shank made of an insulating material. The shank has a first end
integrated with the nut portion and a second end adapted to be
directly coupled with a rotational shaft of a driving portion of
the vacuum variable capacitor device.
[0016] According to a second aspect of the present invention, there
is provided an adjuster nut rotatably supported to a vacuum
container of a vacuum variable capacitor of a vacuum variable
capacitor device. The adjuster nut comprises a deformable bellows,
a nut portion, and a shank. The bellows has a first end, and a
second end opposite to the first end. The nut portion has a first
end, and a second end coupled with the first end of the bellows.
The shank which is made of an insulating material has a first end
coupled with the second end of the bellows, and a second end
adapted to be directly coupled with a rotational shaft of a driving
portion of the vacuum variable capacitor device.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] FIG. 1 is a longitudinal cross section of an adjuster nut 29
of a vacuum variable capacitor device, according to a first
preferred embodiment of the present invention;
[0018] FIG. 2 is a longitudinal cross section of an adjuster nut 31
of the vacuum variable capacitor device, according to a second
preferred embodiment of the present invention;
[0019] FIG. 3 is a longitudinal cross section of a vacuum variable
capacitor, according to a prior art;
[0020] FIG. 4 is a partly enlarged view of the vacuum variable
capacitor shown in FIG. 3;
[0021] FIG. 5 is a longitudinal cross section of the vacuum
variable capacitor device, according to the prior art; and
[0022] FIG. 6 is a schematic of a matching circuit using the vacuum
variable capacitor.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0023] There is provided a vacuum variable capacitor device,
according to a first preferred embodiment of the present
invention.
[0024] FIG. 1 (also refer to FIGS. 3, 4 and 5) shows a longitudinal
cross section of an adjuster nut 29 of the vacuum variable
capacitor device. There is provided a nut portion 27 which is
rotatably supported to a collar 11a of a nut receptacle 11 by way
of a bearing 16, and defines a screw shaft opening 27a. With the
screw shaft opening 27a, the nut portion 27 is screwed down on a
screw shaft 12. There is provided a shank 28 having a first end
which is integrated with the nut portion 27. The shank 28 is shaped
into a cylinder, and is made of an insulating material such as an
FRP (fiber reinforced plastic) or a polycarbonate. The shank 28 has
a flange 28a at a second end thereof. A rotational shaft 22 of a
driving portion 21 has a flange 22a at a first end of the
rotational shaft 22. The flange 22a is tightened and directly
connected to the flange 28a by means of a bolt 32. It is the nut
portion 27 and the shank 28 that constitute the adjuster nut 29.
The other parts of the constitution of the vacuum variable
capacitor device according to the first preferred embodiment are
the same as those of the prior art.
[0025] According to the first preferred embodiment, the shank 28 is
made of an insulating material. The rotational shaft 22 is directly
connected to the shank 28. Thereby, there is no need for a coupling
member 23 (see FIG. 5) that is made of an insulating material. The
absence of the coupling member 23 leads to preferable features such
as; a simplified constitution, no backlash attributable to the
coupling member 23, and facilitating control of the driving portion
21. A driving force by the driving portion 21 is directly
transmitted to the adjuster nut 29, to thereby improve efficiency.
Moreover, varying a length of the shank 28 allows an insulation
distance to become arbitrarily variable between the driving portion
21 and the vacuum variable capacitor 19.
[0026] There is provided a vacuum variable capacitor device,
according to a second preferred embodiment of the present
invention.
[0027] FIG. 2 shows a longitudinal cross section of an adjuster nut
31 of the vacuum variable capacitor device. There is provided a
shank 28 connected to the nut portion 27 by way of a bellows 30.
The adjuster nut 31 is constituted of the nut portion 27, the shank
28 and the bellows 30. The other parts of the constitution of the
vacuum variable capacitor device according to the second preferred
embodiment are the same as those of the prior art.
[0028] According to the second preferred embodiment, there is no
need for the coupling member 23 (see FIG. 5) that is made of the
insulating material. The absence of the coupling member 23, like
the first preferred embodiment, leads to preferable features such
as; a simplified constitution, no backlash attributable to the
coupling member 23, and facilitating control of the driving portion
21. In case there should occur an axial deviation to the adjuster
nut 31 relative to the rotational shaft 22, the bellows 30 is
deformed so as to absorb the axial deviation. Thereby, a rotational
torque of the adjuster nut 31 is prevented from increasing, and
wears and deformations to the screw shaft 12 and the nut portion 27
are inhibited.
* * * * *