JPH07122903A - Rotary joint - Google Patents

Abstract

PURPOSE:To enable electrical contact by an object frequency by arranging the disk part of a first external conductor and the disk part of a second external conductor while holding a prescribed clearance for securing electrical capacitive coupling. CONSTITUTION:A disk-like rotary side external conductor 36 composed of conductive metal is fixed to a connector 32 on the side of a converter and a disk-like fixed side external conductor 38 composed of the conductive metal whose edge part is raised so as to surround the outer peripheral side of the rotary side external conductor 36 is fixed to the connector 34 on the side of a tuner. The prescribed clearance 42 for securing the electrical capacitive coupling between the rotary side external conductor 36 and the fixed side external conductor 38 is held between opposing surfaces on the outer peripheral side of the rotary side external conductor 36 and the inner peripheral side of the fixed side external conductor 38 and bearings 40 are assembled. The rotary side external conductor 36 and the fixed side external conductor 38 are constituted as a mechanically independent non-contact type and are mutually in a free relative rotation mode. Thus, the electrical contact and mechanical contact are held.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary joint, and more particularly, for connecting a coaxial cable, a waveguide or the like about an axis in a microwave communication system, a satellite communication system, etc. Regarding the rotary joint used.

[0002]

2. Description of the Related Art Conventionally, in a microwave communication system or a satellite communication system, for example, when a mobile body such as a vehicle or a ship receives satellite communication or satellite broadcast, the mobile body moves even if the mobile body moves. It is necessary to change the azimuth angle of the receiving antenna frequently so that the receiving antenna installed in the station always faces the direction of the broadcasting satellite. For this reason, the coaxial cable that connects the converter attached to the receiving antenna and the tuner installed in a different location may get wrapped around the drive device for changing the azimuth of the receiving antenna. there were.

Therefore, two devices, a converter and a tuner, can be electrically coupled to each other so as to be relatively rotatable in the axial direction of the coaxial cable, and a rotary joint is used as a device for preventing the above-mentioned fear. .

Such a rotary joint is required to have a function of efficiently transmitting an electric signal (radio wave) from the rotating side to the fixed side or from the fixed side to the rotating side while mechanically rotating, and the form of the feeder line is required. There are known two types, a waveguide type and a coaxial type.

There are contact type and non-contact type outer conductors of the coaxial portion of the above-mentioned two types of rotary joints, the waveguide type and the coaxial type, and FIG. 5 shows a conventional rotary joint. 6 is a sectional view showing the structure of FIG. 6, and FIG. 6 is an equivalent circuit diagram of the rotary joint shown in FIG.

In FIG. 5, the rotary joint 1
00 is applicable to, for example, a receiving antenna of a moving body such as a vehicle or a ship, and a connector 102 connected to the converter side of the receiving antenna and a connector 104 connected to the tuner side are It is electrically connected for relative rotation.

That is, the connector 102 on the converter side has a cylindrical first outer conductor (hereinafter referred to as the rotating outer conductor) 106 made of a conductive metal, and the connector 104 on the tuner side is made of a conductive metal. Has a cylindrical second outer conductor (hereinafter, referred to as a fixed side outer conductor) 108,
A metal ball bearing 110 is used as a bearing between the rotating outer conductor 106 and the fixed outer conductor 108.
A fixed gap is formed through the
06 and the fixed-side outer conductor 108 are mechanically independent and configured as a non-contact type, and are rotatable relative to each other.

Further, the coaxial tube portion 11 of the rotating outer conductor 106
2 and a central conductor 116 installed via a support member 114.
And the support member 12 on the coaxial tube portion 118 of the fixed-side outer conductor 108.
A brush 124 is arranged between the central conductor 122 and the central conductor 122, and the brush 124 is pressed against the central conductor 116 by the spring pressure of a spring 126 arranged on the central conductor 126 side. Has been done. Therefore, even if the rotating outer conductor 106 rotates, the electrical and mechanical contact between the central conductor 116 and the central conductor 122 is maintained.

Therefore, as described above, the connector 102 connected to the converter side of the receiving antenna and the connector 104 connected to the tuner side are electrically connected relatively rotatably.

Further, the coaxial tube portion 1 of the rotating outer conductor 106
A choke circuit 128 of a low impedance portion is formed between the fixed-side outer conductor 108 and the coaxial tube portion 118 of the fixed-side outer conductor 108 at a quarter wavelength of the pass frequency.
A choke circuit 130 of a high impedance part is formed on the inner wall of the hollow hole 6 of FIG.

In the above structure, in the rotary joint 100, the converter-side connector 102 and the tuner-side connector 104 are electrically connected, as shown in the equivalent circuit diagram of FIG. The electrical continuity is enhanced by the low impedance choke circuit 128 and the high impedance choke circuit 130.

Therefore, an electric signal can be continuously transmitted from the converter on the rotating side of the receiving antenna to the tuner side on the fixed side, or from the tuner side to the converter side via the rotary joint 100.

[0013]

However, the above-mentioned conventional rotary joint has the structure of a choke circuit, and the size of the choke circuit depends on the frequency. Since the size becomes large, there is a problem that the entire device becomes large, the structure becomes complicated, and the cost becomes high.

Further, in the above-mentioned conventional rotary joint, a metal ball bearing is used as the bearing so that the rotating outer conductor and the fixed outer conductor rotate relative to each other. There is a problem that it is not possible to significantly reduce the mass and weight and reduce the cost.

Further, when contact and non-contact operations are repeated between the balls of the ball bearing and the race due to the rotation of the rotary joint, leakage current is equivalent to a switching action when passing through the ball bearing. However, there is a problem in that the action of causes noise.

The present invention has been made in view of the above-mentioned various problems of the prior art, and its object is to mechanically connect the first outer conductor and the second outer conductor. In addition to being independently rotatable as an independent non-contact type, by making it possible to electrically contact the first outer conductor and the second outer conductor at a target frequency,
By eliminating the need for a choke circuit, it aims to provide a small, lightweight, and inexpensive rotary joint.

Another object of the present invention is to prevent the generation of noise by using a bearing having a simple structure made of an electrical insulator, and is lightweight and inexpensive. The goal is to provide a unique rotary joint.

[0018]

To achieve the above object, a rotary joint according to the present invention comprises a central conductor and an outer conductor which are coaxially arranged, and the outer conductor rotates relative to each other. In a rotary joint composed of a first outer conductor and a second outer conductor which are freely arranged, the first outer conductor and the second outer conductor are concentric with the central conductor. A disk part is provided, and the disk part of the first outer conductor and the disk part of the second outer conductor maintain a predetermined clearance for ensuring electrical capacitive coupling. So that they are arranged in parallel.

As described above, since the mutually parallel disk portions provided on the first outer conductor and the second outer conductor are arranged on the concentric circles of the central conductor with a predetermined clearance, mechanically It can rotate freely 360 degrees without contact.

Moreover, since these discs are arranged on the concentric circles of the central conductor, their electrical capacity does not change regardless of whether the rotating outer conductor or the fixed outer conductor is rotated. Electrical contact is maintained by sexual coupling.

Then, by changing the size of the mutually parallel disk portions provided on the first outer conductor and the second outer conductor and the clearance interval between the disk portions, the mutually parallel disk portions can be changed. The electrical capacity between them can be adjusted, and electrical contact at a desired frequency becomes possible.

Therefore, according to the present invention, there is no need for a choke circuit like a conventional rotary joint,
Even if the first outer conductor and the second outer conductor rotate relative to each other, it can continuously transmit an electric signal of a target frequency, and has low loss and low power even in a high frequency such as a microwave band. It is possible to obtain the transmission characteristics of reflection, which is small and
It is possible to obtain a lightweight and inexpensive rotary joint.

Further, the rotary joint according to the present invention comprises a central conductor and an outer conductor which are coaxially arranged, and the outer conductor is a first outer conductor and a second outer conductor which are arranged so as to be rotatable relative to each other. In a rotary joint formed of the outer conductor of, the first outer conductor and the second outer conductor while maintaining the coaxiality of the center conductor, the first outer conductor, and the second outer conductor. A dry friction bearing (dry bearing) that performs solid lubrication with a polymer material made of an electrically insulating material is disposed in a sliding portion for allowing relative rotation of the. This dry bearing
Although it is made of a polymer material made of an electrically insulating material as described above, for example, a material made of Teflon resin or PPS resin may be used.

When fixing the dry bearing, for example, the dry bearing is fixed to the first outer conductor by adhesion, press-fitting or pinning, and is slid between the dry outer bearing and the second outer conductor. It should be arranged with the smallest possible clearance. At this time, by dividing the second outer conductor into two parts and sandwiching the dry bearing between them, the sliding between the second outer conductor and the dry bearing is ensured, and the dry bearing is held. Good. In this way, the first outer conductor and the second outer conductor can freely rotate 360 degrees by the solid lubrication of the dry bearing.

Since the dry bearing is lighter in weight than the metal ball bearing and has a simple structure, the weight of the entire rotary joint can be reduced and the manufacturing cost can be reduced. . Moreover, since the dry bearing uses an electrically insulating material, the first outer conductor and the second outer conductor are insulated from each other, and the generation of noise can be prevented.

Therefore, according to the present invention, since a metal ball bearing unlike the conventional rotary joint is not used, it is possible to obtain a lightweight and inexpensive rotary joint which is free from noise. You can

[0027]

Embodiments of the rotary joint according to the present invention will now be described in detail with reference to the drawings.

FIG. 1 is a sectional perspective view for explaining the principle of the rotary joint according to the present invention.
On the concentric circles, a first outer conductor (hereinafter, referred to as a rotation side outer conductor) 12 made of a conductive metal and a second outer conductor (hereinafter, fixed side outer) via a support member (not shown). (Referred to as a conductor) 14 is installed, and a disk-shaped flat plate 16 fixed to one end side of the rotation side outer conductor 12 and a disk-shaped flat plate fixed to one end side of the fixed side outer conductor 14. And the flat plate 18 are attached in parallel with each other with a predetermined clearance 20. The flat plate 16 and the flat plate 18 are each configured to have a predetermined area so that a predetermined electric capacity is generated between them.

Therefore, the flat plate 16 and the flat plate 18 are arranged on the concentric circle of the central conductor 10 so as to be freely rotatable mechanically in a non-contact manner by 360 degrees, and the outer conductor 12 on the rotating side or the fixed side. No matter which of the outer side conductors 14 is rotated, the electric capacitance thereof does not change.

By changing the clearance 20 between the flat plates 16 and 18 and the size of the flat plates 16 and 18 to adjust the electric capacity between the flat plates 16 and 18, It becomes possible to electrically capacitively couple an electric signal having a frequency of.

As described above, in the principle of the rotary joint according to the present invention, the flat plate 16 of the rotating outer conductor 12 and the flat plate 18 of the fixed outer conductor 14 are connected to the central conductor 10.
By electric capacitive coupling which is arranged opposite to each other while holding a predetermined clearance 20 on the concentric circle, electric transmission / reception of a target frequency is performed between the rotating outer conductor 12 and the fixed outer conductor 14. The electrical contact can be made mechanically in a non-contact state.

Therefore, even if the rotating outer conductor 12 and the fixed outer conductor 14 forming the rotary joint relatively rotate, a choke circuit is not required.
Since it is possible to send and receive an electric signal of a target frequency, it is possible to obtain a small-sized, lightweight and inexpensive rotary joint.

FIG. 2 is a sectional view of a main part showing a first embodiment of a rotary joint to which the principle according to the present invention is applied. In FIG.
Can be applied to, for example, a receiving antenna of a mobile body such as a vehicle or a ship, and a connector 32 connected to the converter side of the receiving antenna and a connector 34 connected to the tuner side are It is electrically connected for relative rotation.

That is, a disc-shaped rotating outer conductor 36 made of a conductive metal is fixed to the converter-side connector 32, and the tuner-side connector 34 surrounds the outer circumferential side of the rotating-side outer conductor 36. A disk-shaped fixed-side outer conductor 38 made of a conductive metal having an edge raised is fixed to the.

Electrically capacitive coupling between the rotating outer conductor 36 and the fixed outer conductor 38 is provided between the facing surfaces of the rotating outer conductor 36 and the fixed outer conductor 38 on the inner side. The bearing 40 is assembled in such a manner that a predetermined clearance 42 for ensuring the above is maintained, and the rotating-side outer conductor 36 and the fixed-side outer conductor 38 are mechanically independent non-contact types. And are relatively rotatable with respect to each other.

Further, a center conductor 46 installed at the center of the rotating outer conductor 36 via a support member 44 and a center conductor 50 installed at the center of the stationary outer conductor 38 via a support member 48. A brush 52 is arranged in between, and the brush 52 is pressed against the center conductor 50 by the spring pressure of a spring 54 arranged on the side of the center conductor 46. Therefore, the electrical contact and the mechanical contact between the center conductors 46 and 50 are maintained even when the outer rotating conductor 36 rotates.

Therefore, as described above, the connector 32 connected to the converter side of the receiving antenna and the connector 34 connected to the tuner side are electrically connected so as to be relatively rotatable.

The rotating outer conductor 36 and the fixed outer conductor 3
The bearing 40, which is rotatably assembled with the bearing 8, is prevented from falling off by the pressing member 56 screwed to the opening edge of the fixed-side outer conductor 38.

In the above structure, since the predetermined clearance 42 for ensuring the electric capacitive coupling is held between the facing surfaces of the rotating outer conductor 36 and the fixed outer conductor 38, the rotating outer conductor is held. Even if the conductor 36 and the fixed-side outer conductor 38 rotate relative to each other, the clearance 42 between the facing surfaces of the rotated-side outer conductor 36 and the fixed-side outer conductor 38, and the rotating-side outer conductor 36 and the fixed-side outer conductor 38. An electric signal having a predetermined frequency can be transmitted and received based on the electric capacity between the facing surfaces of the rotating outer conductor 36 and the fixed outer conductor 38, which is determined by the size of the facing surface of the.

That is, in this rotary joint 30, regarding the electrical connection between the connector 32 on the converter side and the connector 34 on the tuner side, as shown in the equivalent circuit diagram of FIG. The central conductor 46 and the central conductor 50 on the fixed outer conductor 38 side are in electrical contact and mechanical contact.

On the other hand, due to the clearance 42 between the rotating outer conductor 36 and the fixed outer conductor 38, a capacitor 58 formed between the facing surfaces of the rotating outer conductor 36 and the fixed outer conductor 38 is provided. Since they are electrically connected to each other through rotation, the rotating-side outer conductor 36 and the fixed-side outer conductor 38 are mechanically independent, non-contact type, and relatively rotatable.

Therefore, it is possible to obtain a small-sized, lightweight and inexpensive rotary joint without the need for a choke circuit like the conventional rotary joint.

Next, a second embodiment of the rotary joint according to the present invention will be described in detail with reference to FIG.

FIG. 4 is a sectional view of the essential parts showing a second embodiment of the rotary joint to which the principle of the present invention is applied. In FIG. 4, the rotary joint 60 is shown.
Can be applied to, for example, a receiving antenna of a moving body such as a vehicle or a ship, and a connector 62 connected to the converter side of the receiving antenna and a connector 64 connected to the tuner side are It is electrically connected for relative rotation.

That is, a disc-shaped rotating outer conductor 66 made of a conductive metal having an outer edge portion 66a protruding downward is fixed to the converter-side connector 62, and a lower surface of the tuner-side connector 64 is attached to the tuner-side connector 64. The fixed side outer conductor fixing plate 65 is fixed to the side by screws 67, and is a disk made of a conductive metal formed to have a predetermined thickness so as to dig into the inner peripheral side of the outer edge portion 66a of the rotating side outer conductor 66. The fixed outer conductor 68 is fixed.

Electrically capacitive coupling between the rotating outer conductor 66 and the fixed outer conductor 68 is provided between the opposing surfaces of the inner periphery of the rotating outer conductor 66 and the outer periphery of the fixed outer conductor 68. A dry bearing 72 for solid lubrication, which is made of an electrically insulating polymer material such as Teflon-based resin or PPS-based resin, is attached so as to maintain a predetermined clearance 70 for ensuring the above. And the rotating outer conductor 6
6 and the fixed-side outer conductor 68 are mechanically independent, non-contact type, and relatively rotatable with respect to each other.

In addition, a center conductor 76 installed at the center of the rotating outer conductor 66 via a support member 74 and a center conductor 80 installed at the center of the stationary outer conductor 68 via a support member 78. A brush 82 is arranged in between, and the brush 82 is pressed against the center conductor 80 by the spring pressure of a spring 84 arranged on the side of the center conductor 76. Therefore, the electrical contact and the mechanical contact between the center conductors 76 and 80 are maintained even when the outer rotating conductor 66 rotates.

Therefore, as described above, the connector 62 connected to the converter side of the receiving antenna and the connector 64 connected to the tuner side are electrically connected so as to be relatively rotatable.

The rotating outer conductor 66 and the fixed outer conductor 6
Dry bearing 72, which is rotatably assembled with 8
As described above, for example, Teflon-based resin or PPS
Solid lubrication is performed using an electrically insulating polymer material such as a system resin, and is fixed to the rotating outer conductor 66. As a fixing method for fixing the dry bearing 72 to the outer conductor 66 on the rotation side, an appropriate method such as bonding, press fitting or pinning may be used. Further, the dry bearing 72 is arranged so as to be sandwiched by the fixed outer conductor 68 and the fixed outer conductor fixing plate 65 with a minimum slidable clearance maintained.

In the above structure, since the predetermined clearance 70 for ensuring the electrical capacitive coupling is held between the facing surfaces of the rotating outer conductor 66 and the fixed outer conductor 68, the rotating outer conductor is secured. Even if the conductor 66 and the fixed outer conductor 68 rotate relative to each other, the clearance 70 between the facing surfaces of the rotated outer conductor 66 and the fixed outer conductor 68, and the rotated outer conductor 66 and the fixed outer conductor 68. An electric signal of a predetermined frequency can be transmitted and received based on the electric capacity between the facing surfaces of the rotating-side outer conductor 66 and the fixed-side outer conductor 68, which is determined by the size of the facing surface of the.

That is, in this rotary joint 60, regarding the electrical connection between the converter-side connector 62 and the tuner-side connector 64, as in the first embodiment, the center of the rotary-side outer conductor 66 side is connected. The conductor 76 and the center conductor 80 on the fixed outer conductor 68 side are in electrical contact and mechanical contact.

On the other hand, due to the clearance 70 between the rotating outer conductor 66 and the fixed outer conductor 68, a condenser formed between the facing surfaces of the rotating outer conductor 66 and the fixed outer conductor 68 is used. The rotating-side outer conductor 66 and the fixed-side outer conductor 68 are mechanically independent, non-contact type, and can rotate relatively freely.

Therefore, it is possible to obtain a small-sized, lightweight and inexpensive rotary joint without the need for a choke circuit like the conventional rotary joint.

Further, the rotating outer conductor 66 and the fixed outer conductor 68 are made of a dry material made of an electrically insulating polymer material.
Since the bearings 72 are slidably rotatable relative to each other, the rotating outer conductor 66 and the fixed outer conductor side 68 are insulated from each other and noise is prevented from occurring. Also, dry
Since the bearing 72 is lighter in weight and has a simpler structure than a metal ball bearing, the overall weight of the rotary joint 60 can be reduced, and the bearing 72 can be manufactured at low cost.

[0055]

Since the present invention is constructed as described above, it has the following effects.

A rotary joint comprising a central conductor and an outer conductor arranged coaxially, the outer conductor comprising a first outer conductor and a second outer conductor arranged so as to be rotatable relative to each other, The first outer conductor and the second outer conductor each include a disc portion concentrically arranged with respect to the center conductor, and the disc portion of the first outer conductor and the disc portion of the second outer conductor. Since, since it is arranged in parallel while maintaining a predetermined clearance for ensuring the electrical capacitive coupling, the mutually parallel disk portions provided on the first outer conductor and the second outer conductor, It is mechanically non-contact and can rotate freely 360 degrees.

Moreover, since the disk portion is arranged on the concentric circle of the central conductor, the electric capacity of the rotating side outer conductor or the fixed side outer conductor does not change and the capacitive coupling does not occur. Since the electrical contact is maintained by the, the size of the mutually parallel disc portions provided on the first outer conductor and the second outer conductor and the clearance interval between the disc portions are changed, thereby By adjusting the electric capacity between the parallel disk portions, it is possible to make electrical contact at a target frequency.

Further, a rotary joint comprising a central conductor and an outer conductor arranged coaxially, the outer conductor comprising a first outer conductor and a second outer conductor arranged so as to be rotatable relative to each other. In the sliding part for making the first outer conductor and the second outer conductor rotatable relative to each other while maintaining the coaxiality of the central conductor, the first outer conductor and the second outer conductor, Since a dry friction bearing that performs solid lubrication using a polymer material made of a static insulating material is provided, the first outer conductor and the second outer conductor are insulated, and the first outer conductor and the second outer conductor are insulated. Generation of noise due to relative rotation with respect to is prevented.

Since the dry friction bearing is lighter in weight than the metallic ball bearing and has a simple structure, the overall weight of the rotary joint can be reduced and the manufacturing cost can be reduced.

Therefore, according to the present invention, a choke circuit such as a conventional rotary joint is not required,
Even if the first outer conductor and the second outer conductor rotate relative to each other, it can continuously transmit an electric signal of a target frequency, and has low loss and low power even in a high frequency such as a microwave band. It is possible to obtain the transmission characteristics of reflection, which is small and
It is possible to obtain a lightweight and inexpensive rotary joint.

Further, according to the present invention, the relative rotation between the first outer conductor and the second outer conductor can be achieved without using a metallic ball bearing unlike the conventional rotary joint. It is possible to obtain a lightweight and inexpensive rotary joint that does not generate noise.

[Brief description of drawings]

FIG. 1 is a sectional perspective view illustrating the principle of a rotary joint according to the present invention.

FIG. 2 is a sectional view of an essential part showing a first embodiment of a rotary joint to which the principle of the present invention is applied.

FIG. 3 is an equivalent circuit diagram of the rotary joint shown in FIG.

FIG. 4 is a sectional view of an essential part showing a second embodiment of a rotary joint to which the principle of the present invention is applied.

FIG. 5 is a sectional view showing a conventional rotary joint.

FIG. 6 is an equivalent circuit diagram of the rotary joint shown in FIG.

[Explanation of symbols]

 10 center conductor 12 rotating outer conductor 14 fixed outer conductor 16 flat plate 18 flat plate 20 clearance 30, 60 rotary joint 32, 62 connector 34, 64 connector 36, 66 rotating outer conductor 38, 68 fixed outer conductor 42, 70 Clearance 44,74 Support member 46,76 Central conductor 48,78 Support member 50,80 Central conductor 52,82 Brush 54,84 Spring 65 Fixed side outer conductor fixing plate 67 Screw 72 Dry bearing

Claims (4)

[Claims] 1. A rotary conductor comprising a central conductor and an outer conductor coaxially arranged, the outer conductor comprising a first outer conductor and a second outer conductor arranged so as to be rotatable relative to each other. In the joint, the first outer conductor and the second outer conductor each include a disc portion arranged concentrically with respect to the central conductor, and the disc portion of the first outer conductor, A rotary joint, wherein the second outer conductor and the disc portion are arranged in parallel with each other while maintaining a predetermined clearance for ensuring electric capacitive coupling. 2. A rotary conductor comprising a central conductor and an outer conductor coaxially arranged, the outer conductor comprising a first outer conductor and a second outer conductor arranged so as to be rotatable relative to each other. In the joint, for maintaining the coaxiality of the center conductor, the first outer conductor, and the second outer conductor, the relative rotation of the first outer conductor and the second outer conductor The rotary joint is characterized in that a dry friction bearing for solid-lubricating a polymer material made of an electrically insulating material is provided in the sliding portion. 3. The center conductor, the first outer conductor, and the second outer conductor are held coaxially between the first outer conductor and the second outer conductor, and the first outer conductor and the second outer conductor are coaxial with each other. 2. The rotary joint according to claim 1, further comprising a dry friction bearing for solid-lubricating a polymer material made of an electrically insulating material that allows the first outer conductor and the second outer conductor to rotate relative to each other. 4. The dry friction bearing is fixed to either one of the first outer conductor and the second outer conductor, and the first outer conductor and the second outer conductor. The rotary joint according to claim 2, wherein the rotary joint slides with respect to the other of the above.