JPH0440168Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a multi-core optical rotary joint that uses a trapezoidal prism to transmit light between optical fibers on a rotating side and a stationary side.

[Prior Art] FIG. 2 shows a schematic diagram of a conventional multi-core optical rotary joint.

A rod lens 3 and a trapezoidal prism (Dove prism) 4 are arranged on the rotation center axis of the rotation side, and the rotation side is
A reduction gear mechanism (not shown) is provided between the rotating side and the trapezoidal prism 4 so that the trapezoidal prism 4 rotates 180 degrees in the same direction when rotated 360 degrees.
The rotation of the trapezoidal prism 4 maintains the connection between the corresponding rotating optical fiber 1 and the stationary optical fiber 2.

[Problems to be solved by the invention] In this way, in the past, since the optical prism (trapezoidal prism 4) is placed on the rotation center axis on the rotating side, power lines, cooling pipes, etc. It cannot be passed over the rotation center axis. Therefore, for example, when connecting a power line for power supply to the rotating side, it was necessary to use a slip ring or the like. For this reason, it is necessary to install a slip ring in a combined optical/electrical rotary joint that sends light and electricity together, and the rotary joint is large and
It becomes complicated and expensive.

The purpose of the present invention is to eliminate the drawbacks of the prior art mentioned above and to provide a new multi-core optical rotary joint that can easily supply not only optical signals but also electric power to the rotating side (or stationary side). .

[Means for Solving the Problems] The present invention consists of a cylindrical rotating gear that rotates due to rotational input from the rotating side and has teeth formed on its outer circumferential surface, and A gear mechanism for trapezoidal prisms arranged in plurality, each having a trapezoidal prism, and rotationally driven by a rotating gear; A rotary side gear mechanism has a plurality of rod lenses to which optical fibers on the rotating side are coupled and is rotationally driven by a rotating gear, and a rotary side gear mechanism that is fixed on the stationary side in correspondence with each trapezoidal prism and faces the trapezoidal prism and is rotated by a rotating gear. A rod lens coupled with an optical fiber is provided to optically oppose the rod lens via a trapezoidal prism, and an optical fiber is coupled to each rod lens on the stationary side. The rotation ratio of the trapezoidal prism gear mechanism to the number of rotations of the trapezoidal prism is set to 1/2.

[Operation] Since the rotating gear serving as the center of rotation has a hollow cylindrical shape, a power line, a cooling pipe, etc. can be passed through the hollow portion at the center of the rotating gear.

The trapezoidal prism rotates at 1/2 the rotation speed of the rod lens on the rotating side, and transmits the rotating image on the rotating side to the stationary side as a static image, so even if the rotating side rotates, the optical fiber on the rotating side and the light on the stationary side are connected. The connection relationship between the fibers and the opposing optical fibers is maintained.

[Example] An example of the present invention will be described below with reference to FIG.

In FIG. 1, 5 is a fixed body installed on the stationary side. The fixed body 5 includes a cylindrical portion 6 and a flange portion 7. A cylindrical rotary gear 8 is rotatably supported on the outer periphery of the cylindrical portion 6. Further, rod lenses 3 are provided on the flange portion 7 at appropriate intervals along its circumferential direction. The rod lens 3 is disposed toward the axial direction of the cylindrical portion 6.
In the illustrated example, two rod lenses 3 are provided at two locations on the flange portion 7. A stationary optical fiber 2 is connected to each rod lens 3 by an optical connector (not shown).

Teeth are formed on the outer peripheral surface of the rotating gear 8.
A trapezoidal prism built-in gear 9 is meshed with the toothed portion B on the flange portion 7 side as a gear mechanism for the trapezoidal prism. Two trapezoidal prism built-in gears 9 are provided on the outer periphery of the rotating gear 8, and a trapezoidal prism 4 is provided on the central axis of each trapezoidal prism built-in gear 9. Also, the tooth portion A on the rotating side of the rotating gear 8
A rotation side gear 10 is meshed with each trapezoidal prism 4 as a rotation side gear mechanism.
Each rotating gear 10 is provided with a rod lens 3. The rod lens 3 is placed at a position facing one side of the trapezoidal prism 4 and optically opposed to the rod lens 3 of the stationary side optical fiber 2 via the trapezoidal prism 4. A rotating side optical fiber 1 is connected to the rod lens 3 of the rotating side gear 10 by an optical connector (not shown).

The rotation on the rotating side is caused by the rotating gear 8 due to the rotating part 11.
is input. As the rotating gear 8 rotates, the rotating gear 10 and the trapezoidal prism built-in gear 9 rotate in the same direction. The tooth part A of the rotating gear 8 has twice the number of teeth as the tooth part B, and when the rotating gear 8 makes one rotation (360 degrees),
The rotation side gear 10 rotates once (360 degrees), while the trapezoidal prism built-in gear 9 (trapezoid prism 4) rotates 1/2 rotation (180 degrees). (Alternatively, when the rotating gear 8 rotates 360 degrees, the rotating gear 10
The trapezoidal prism built-in gear 9 may rotate 360 degrees (one rotation). ) Since the rotating gear 8 (cylindrical part 6) has a cylindrical shape and a hollow structure at the center, power lines, cooling pipes, etc. can be passed from the stationary side to the rotating side through the hollow part 12. Alternatively, a small slip ring may be provided in the hollow portion 12 to provide an optical/electrical composite type multi-core optical rotary joint that also supplies power from the stationary side to the rotating side.

Since the tooth portion A of the rotating gear 8 and the rotating side gear 10 meshing therewith are bevel gears, the axial movement of the gear 9 with a built-in trapezoidal prism is controlled by the fixed body 5.
This can be controlled by the flange portion 7 and the rotating gear 10.

[Effect of the idea] This invention has the following effects.

(1) The rotating gear, which is the center of rotation of the rotary joint, has a hollow cylindrical shape, and a trapezoidal prism is provided on its outer periphery, so the lead wire for power supply to the motor and transmitting/receiving device is connected to the hollow part of the center of the rotating gear. Alternatively, a cooling hose or the like can be easily passed through it, and not only optical signals but also electric power can be easily supplied to the rotating side or the stationary side. Furthermore, since there is no need to use a slip ring or the like for power supply, a small and lightweight rotary joint can be manufactured at low cost.

(2) Since multiple trapezoidal prisms are installed around the outer circumference of the rotating gear, it is possible to use multiple optical fibers.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view showing an embodiment of a multi-core optical rotary joint according to the present invention, and FIG. 2 is a schematic configuration diagram showing a conventional multi-core optical rotary joint. In the figure, 1 is a rotating side optical fiber, 2 is a stationary side optical fiber, 3 is a rod lens, 4 is a trapezoidal prism,
5 is a fixed body, 6 is a cylindrical part, 7 is a flange part, 8 is a rotating gear, 9 is a gear with a built-in trapezoidal prism, 10 is a rotating side gear, 11 is a rotating part, and 12 is a hollow part.

Claims (1)

[Scope of utility model registration request] In a multi-core optical rotary joint that connects an optical fiber on a rotating side and an optical fiber on a stationary side, a cylindrical rotating gear that rotates in response to rotational input from the rotating side and has teeth formed on its outer peripheral surface; A plurality of gear mechanisms for trapezoidal prisms are disposed on the outer periphery of the stationary side of the rotating gear, each having a trapezoidal prism, and are rotationally driven by the rotating gear; It has a plurality of rod lenses arranged facing the trapezoidal prisms and coupled with optical fibers on the rotating side, and a rotating side gear mechanism that is rotationally driven by a rotating gear, and fixed on the stationary side in correspondence with each trapezoidal prism. A rod lens that faces the trapezoidal prism and is connected to an optical fiber on the rotating side is provided optically opposite to the rod lens through the trapezoidal prism, and an optical fiber is connected to each rod lens on the stationary side. A multi-core optical rotary joint characterized in that the rotation ratio between the rotation speed of the rod lens of the side gear mechanism and the rotation speed of the trapezoidal prism of the trapezoidal prism gear mechanism is set to 1/2.