Spatial off-axis dual-channel optical fiber rotary connector

Abstract

The invention relates to an optical fiber rotary connector, in particular to a spatial off-axis dual-channel optical fiber rotary connector, and aims to overcome the defects that in the prior art, the requirements for machining, assembling and adjusting precision and assembling consistency of an optical fiber rotary connector are high, loss is large, or transmission stability and efficiency are prone to being affected. The invention discloses a spatial off-axis dual-channel optical fiber rotary connector, which comprises a rotor sleeve, and a first collimating lens, a second collimating lens and a plano-convex lens which are arranged in the rotor sleeve, the first lens, the second lens, the plate glass, the first meniscus lens, the second meniscus lens and the second self-focusing lens are arranged in the stator shell, and the first self-focusing lens, the first lens and the second lens are respectively provided with a concave surface part along the central axis. The first shaping lens is used for shaping and transmitting the laser beam transmitted by the first collimating lens to the first self-focusing lens; the first meniscus lens and the second meniscus lens are used for transmitting the second laser beam input by the second collimating lens.

Description

Technical Field

[0001] The invention relates to an optical fiber rotary connector, in particular to a spatial off-axis dual-channel optical fiber rotary connector. Background Art

[0002] Fiber optic rotary connector, also known as fiber optic slip ring, is an optical communication device that realizes stable transmission of optical fiber signals in a rotating state. It effectively solves the problem of signal transmission between rotating parts and stationary parts, and has the advantages of large channel capacity, strong anti-electromagnetic interference ability, no contact loss and fast transmission rate. Through precise design, the optical fiber inside can maintain good alignment and coupling state during relative rotation, ensuring that the optical signal can be transmitted with low loss and high reliability. Therefore, fiber optic rotary connector has a wide range of application scenarios in many fields. In radar systems, it is used for signal transmission between rotating platforms and stationary platforms to ensure the stable transmission of radar data during rotation scanning; in the field of industrial automation, it can realize the accurate transmission of control signals and feedback signals during robot joint movement to ensure the precise operation of robots; in the field of aerospace, between the rotating parts of aerospace motion mechanisms, it can complete high-speed and large-capacity data interaction in complex space environments and motion states, and at the same time, in scenarios such as rotating scanning devices in medical equipment and rotating communication equipment on sailing ships, it meets the signal transmission requirements of high bandwidth, low loss and anti-interference.

[0003] Most existing rotary connectors are coaxial, and the signal transmission channel coincides with the center axis. When the center axis is occupied, the signal cannot be transmitted. In this case, an off-axis fiber optic rotary connector is required. Compared with coaxial fiber optic rotary connectors, off-axis fiber optic rotary connectors can solve the problem of being unable to transmit optical signals when the center axis is occupied by other media or devices.

[0004] The Chinese patent with publication number CN108710177A discloses a novel off-axis optical fiber rotary connector system, which includes a signal input unit, a rotary connection unit and a signal output unit. The signal input unit transmits the optical signal to the rotary connection unit with the help of a multi-circular input channel and an optical fiber collimator. In the rotary connection unit, the annular grating deflects the light into the annular matrix, and its conical reflection film ensures the signal reflection transmission, the shading tube shades the light, and the fixed rubber ring stabilizes the component. The signal is emitted from the exit window after multiple reflections. The signal output unit couples the optical signal through the lens system corresponding to the receiving end channel, outputs it through the optical fiber collimator, and can also collect data. The system is based on wavelength division multiplexing, solves the problem of central axis occupancy, has a simple structure, is easy to process, has good stability and high coupling efficiency, has broad prospects in the field of spatial optical interconnection and optical fiber communication, and provides a reliable solution for optical communication signal transmission. This method can realize the directional transmission of off-axis light beams in a state of relative rotational motion, but it uses the reflection of the light beam in the annular matrix to realize the transmission of the light beam, which requires high processing and assembly accuracy of the structural parts, and has large losses during the transmission process. At the same time, under some extreme environmental conditions, the annular grating and annular substrate used may not be able to maintain long-term stable operation, reducing the reliability of the system.

[0005] The Chinese patent with publication number CN115166909A discloses an off-axis optical fiber rotary connector based on a double collimating lens and a TEC optical fiber. It uses four double collimating lens systems evenly distributed at 360 degrees as rotors, combined with the stator of the double collimating lens system, and realizes multi-signal transmission through relative motion processes such as separation, tangency, and intersection. In this method, there are internal threaded holes at both ends of the hollow rotating shaft disk, and the graduated studs are adapted to assemble rotating hollow shafts with different shaft diameters. This method realizes signal transmission under different shaft diameter conditions, and adopts a combination of TEC optical fiber and a double collimating lens system to increase the alignment time and beam transmission efficiency, effectively avoiding the problem of the center axis being occupied. However, its transmission power is unstable, and the consistency requirements for the assembly of the optical-mechanical structure are high. When the optical fiber jumper used is a single-mode optical fiber, the beam transmission efficiency will be greatly reduced, which is not conducive to the transmission of optical signals.

[0006] The Chinese patent with publication number CN110361814A proposes a multi-channel off-axis optical fiber rotary connector using a hollow annular cone, which uses the conical surface reflection of the hollow annular cone to couple the beam signal at the rotor end to the transmission optical fiber at the stator end. This method can transmit multiple signals at the same time and has the characteristics of high coupling efficiency, simple structure, good stability, and no signal crosstalk. However, the transmission efficiency of this method is greatly affected by the processing and adjustment accuracy of the hollow annular cone. At the same time, the rotation rate of the rotor has a great influence on the stability of signal transmission.

[0007] The Chinese patent with publication number CN103149642A proposes an off-axis optical fiber rotary connector based on a right-angle prism. This method uses a right-angle prism to achieve collimated light beam steering, while changing the number of flanges at the optical input and output, thereby affecting the rotational fluctuation of the insertion loss. It uses passive components, is easy to install, greatly reduces the sensitivity of angle and axial deviation, reduces system insertion loss, and can achieve bidirectional transmission, but the transmission fluctuation is large. Summary of the invention

[0008] The purpose of the present invention is to solve the shortcomings of the prior art optical fiber rotary connector, such as high processing and adjustment accuracy and assembly consistency requirements, large loss, or easily affected transmission stability and efficiency, and to provide a spatial off-axis dual-channel optical fiber rotary connector.

[0009] To achieve the above objectives, the technical solutions provided by the present invention are as follows:

[0010] A spatial off-axis dual-channel optical fiber rotary connector comprises a rotor end and a stator end, wherein the rotor end comprises a rotor sleeve and a first collimating lens, a second collimating lens and a plano-convex lens arranged in the rotor sleeve, and the stator end comprises a stator housing and a first lens, a second lens, a flat glass, a first meniscus lens, a second meniscus lens, a second self-focusing lens and a first self-focusing lens arranged on the flat glass in sequence in the stator housing; the rotor sleeve and one end of the stator housing are coaxially connected for rotation; the input ends of the first collimating lens and the second collimating lens are respectively connected to a first input optical fiber and a second input optical fiber, and are respectively used for collimating a first laser beam input by the first input optical fiber and a second laser beam input by the second input optical fiber, and the output ends of the first collimating lens and the second collimating lens correspond to the edge position of the convex surface of the plano-convex lens and the position close to the central axis, respectively. The first lens is arranged at one end of the stator housing, and the end faces of both ends of the first lens are respectively arranged as first plane parts near the edge positions, and the positions near the central axis are respectively arranged as first concave parts; the end face of one end of the second lens close to the first lens is a plane, and the other end face is arranged as a second plane part corresponding to the first plane part, and the second concave part is arranged corresponding to the first concave part; the collimated first laser beam is shaped by the plano-convex lens, the first plane part, the second plane part and the flat glass and transmitted to the first meniscus lens, and the collimated second laser beam is shaped by the plano-convex lens, the first concave part and the second concave part and transmitted to the first self-focusing lens; the concave surfaces of the first meniscus lens and the second meniscus lens face the second self-focusing lens, and are used to transmit the first laser beam to the second self-focusing lens; the output ends of the second self-focusing lens and the first self-focusing lens are respectively connected to the first output optical fiber and the second output optical fiber.

[0011] Furthermore, the rotor sleeve is embedded in one end of the stator housing; a rotor end cover is embedded in one end of the rotor sleeve, and two through holes are provided on the rotor end cover, which are respectively used to set a first collimating lens and a second collimating lens; the other end of the rotor sleeve is an open end, which is set toward the first lens.

[0012] Furthermore, a stator end cover is provided at the other end of the stator housing, the stator end cover is fixedly connected to the stator housing by screws, and a through hole is provided on the stator end cover for arranging the first output optical fiber;

[0013] The side wall of the stator housing is provided with a through hole for arranging the second output optical fiber.

[0014] Furthermore, the flat glass has a through hole along the central axis, and the first self-focusing lens is arranged in the through hole of the flat glass.

[0015] Furthermore, the first collimating lens and the second collimating lens are both configured as self-focusing lenses.

[0016] Furthermore, the first input optical fiber and the second input optical fiber are configured as multimode optical fibers or thermal expansion core optical fibers or large core diameter optical fibers;

[0017] The first output optical fiber and the second output optical fiber are both configured as multimode optical fibers.

[0018] Furthermore, the outer wall of the rotor sleeve and the inner wall of the stator housing are rotatably connected via a bearing;

[0019] The plano-convex lens, the first lens, the second lens, the flat glass, the first meniscus lens and the second meniscus lens are respectively fixedly connected to the rotor sleeve or the stator housing through a pressing ring.

[0020] Beneficial effects of the present invention:

[0021] 1. The present invention considers the off-axis dual-channel laser beam transmission in a rotating state by using an all-optical link from a system level. The rotor end has a simple structure, which is convenient for connecting the rotating part of the motion mechanism. The off-axis dual-channel is set to realize signal transmission between relative rotating mechanisms, solving the problem of multi-channel signal transmission when the central channel cannot be transmitted. The present invention utilizes the planar portion of the first lens and the planar portion of the second lens, as well as the concave portion of the first lens and the concave portion of the second lens, to respectively realize the modulation of the transmission beams of different channels, improve the coupling efficiency of the beams of different channels, and reduce the transmission loss.

[0022] 2. The dual-channel beam transmission in the present invention does not have the phenomenon of shielding, effectively reducing the loss in the transmission process, reducing the occurrence of signal attenuation and distortion, and helping to improve the efficiency of beam transmission. At the same time, the external channel and the internal channel share different parts of the same lens, making the overall structure compact.

[0023] 3. The receiving end of the present invention adopts a self-focusing lens and a multi-mode optical fiber to improve the beam coupling efficiency. At the same time, it is convenient to adopt broadband beam transmission in wavelength division multiplexing technology to improve the transmission bandwidth and transmission capacity.

[0024] 4. The present invention adopts an all-optical link design, has good anti-electromagnetic interference capability, simplifies the structural setting of the rotor end, makes it more environmentally adaptable, and is suitable for complex space environments.

[0025] 5. The present invention adopts a transmission form without mechanical transmission structure, with simple structure setting, no friction and wear physical process such as mechanical contact, and has the advantages of high reliability, long life and simple maintenance, especially in the application field with strict requirements on weight, stability and environmental adaptability. At the same time, it can realize high-speed, large-capacity, high-bandwidth and stable transmission of multi-channel signals in the off-axis state, and improve the adaptability and service life of the system under spatial conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 is a schematic structural diagram of an embodiment of the present invention;

[0027] Description of reference numerals:

[0028] 1-rotor sleeve, 2-stator housing, 3-bearing, 4-spacer, 5-plano-convex lens, 6-first lens, 7-first input optical fiber, 8-second lens, 9-flat glass, 10-first meniscus lens, 11-second meniscus lens, 12-screw, 13-statator end cover, 14-pressing ring, 15-first self-focusing lens, 16-multimode optical fiber, 17-second self-focusing lens, 18-rotor end cover, 19-first collimating lens, 20-second collimating lens, 21-second input optical fiber. DETAILED DESCRIPTION

[0029] The present invention provides a spatial off-axis dual-channel optical fiber rotary connector structure as shown in FIG. Figure 1 As shown, it includes a rotor sleeve 1 arranged at the rotor end and a stator housing 2 at the stator end, the rotor sleeve 1 is coaxially embedded at one end of the stator housing 2, and also includes a first collimating lens 19, a second collimating lens 20 and a plano-convex lens 5 arranged in the rotor sleeve 1, and a first lens 6, a second lens 8, a flat glass 9, a first meniscus lens 10, a second meniscus lens 11, a second self-focusing lens 17 arranged in sequence in the stator housing 2, and a first self-focusing lens 15 arranged at the other end of the second lens 8 near the stator housing 2. The plano-convex lens 5, the first lens 6, the second lens 8, the flat glass 9, the first meniscus lens 10, and the second meniscus lens 11 are fixedly connected to the rotor sleeve 1 or the stator housing 2 respectively through a pressing ring 14.

[0030] An annular mounting groove is provided on the outer wall of the rotor sleeve 1, and bearings 3 are provided at both ends of the mounting groove, which are used to connect with the inner wall of the stator housing 2 through the bearings 3 to achieve rotational connection. Spacers 4 are provided between the bearings 3 at both ends of the mounting groove, and the relative positions of the bearings 3 are limited by the spacers 4. A rotor end cover 18 is embedded at one end of the rotor sleeve 1, and two through holes are provided on the rotor end cover 18, which are respectively used to set a first collimating lens 19 and a second collimating lens 20. The other end of the rotor sleeve 1 faces the first lens 6 and is set as an open end.

[0031] The input ends of the first collimating lens 19 and the second collimating lens 20 are connected to the first input optical fiber 7 and the second input optical fiber 21, respectively, and are used to collimate the first laser beam input by the first input optical fiber 7 and the second laser beam input by the second input optical fiber 21, respectively. The output ends of the first collimating lens 19 and the second collimating lens 20 correspond to the edge position of the convex surface of the plano-convex lens 5 and the position close to the central axis, respectively. In this embodiment, the first collimating lens 19 and the second collimating lens 20 are both configured as self-focusing lenses. In other embodiments of the present invention, they can also be configured as other collimating components or collimating lenses. The first input optical fiber 7 and the second input optical fiber 21 can be configured as multimode optical fibers or thermal expansion core TEC optical fibers or large core diameter optical fibers.

[0032] The first lens 6 is arranged at one end of the stator housing 2. The end faces of both ends of the first lens 6 are arranged as the first plane portion near the edge, and the position near the center axis is arranged as the first concave portion. The end face of the second lens 8 near one end of the first lens 6 is a plane, and the other end face is arranged as the second plane portion corresponding to the first plane portion, and the second concave portion is arranged as the first concave portion. The concave surfaces of the first meniscus lens 10 and the second meniscus lens 11 face the second self-focusing lens 17, which are used to transmit the first laser beam to the second self-focusing lens 17; the output ends of the second self-focusing lens 17 and the first self-focusing lens 15 are respectively connected to the first output optical fiber and the second output optical fiber, both of which are used to shrink and couple the laser beams. The first output optical fiber and the second output optical fiber are both arranged as multimode optical fibers 16.

[0033] A stator end cover 13 is provided at the other end of the stator housing 2. The stator end cover 13 is fixedly connected to the stator housing 2 by screws 12. A through hole is provided on the stator end cover 13, and the first output optical fiber passes through the through hole to connect to an external device; a through hole is provided on the side wall of the stator housing 2, and the second output optical fiber passes through the through hole to connect to an external device.

[0034] In order to make the overall structure more compact, a through hole is opened along the central axis of the flat glass 9 , and the first self-focusing lens 15 is arranged in the through hole of the flat glass 9 .

[0035] The dual-channel laser beam transmission path of the present invention is specifically as follows: the first laser beam of the dual-channel laser beam is incident from the first input optical fiber 7 to the first collimating lens 19, then expanded and collimated, and then shaped and transmitted through the plano-convex lens 5, the first plane portion of the first lens 6, the second plane portion of the second lens 8, the flat glass 9, the first meniscus lens 10, and the second meniscus lens 11, and then transmitted to the second self-focusing lens 17, coupled to the multimode optical fiber 16 for output. The other laser beam is incident from the second input optical fiber 21 to the second collimating lens 20, then expanded and collimated, and then shaped and transmitted through the plano-convex lens 5, the first concave portion of the first lens 6, and the second concave portion of the second lens 8, and then transmitted to the first self-focusing lens 15, coupled to the multimode optical fiber 16 for output. The spatial off-axis dual-channel optical fiber rotary connector can be realized by matching the lens structures of the above types, wherein the parameters such as the radius of curvature, thickness, spacing, and material of each lens are set according to the laser signal requirements or the structural size requirements.

Claims

1. A spatial off-axis dual-channel optical fiber rotary connector, comprising a rotor end and a stator end, characterized in that: The rotor end comprises a rotor sleeve (1), and a first collimating lens (19), a second collimating lens (20), and a plano-convex lens (5) arranged in the rotor sleeve (1); the stator end comprises a stator housing (2), and a first lens (6), a second lens (8), a flat glass (9), a first meniscus lens (10), a second meniscus lens (11), a second self-focusing lens (17), and a first self-focusing lens (15) arranged on the flat glass (9) in sequence in the stator housing (2); The rotor sleeve (1) and one end of the stator housing (2) are coaxially rotatably connected; The input ends of the first collimating lens (19) and the second collimating lens (20) are respectively connected to the first input optical fiber (7) and the second input optical fiber (21), and are respectively used to collimate the first laser beam input by the first input optical fiber (7) and the second laser beam input by the second input optical fiber (21); the output end of the first collimating lens (19) and the output end of the second collimating lens (20) correspond to the edge position of the convex surface of the plano-convex lens (5) and the position close to the central axis; The first lens (6) is arranged at one end of the stator housing (2); the end surfaces of both ends of the first lens (6) are respectively arranged as first plane portions near the edge positions, and the positions near the central axis are respectively arranged as first concave portions; the end surface of one end of the second lens (8) near the first lens (6) is a plane, and the other end surface is arranged as a second plane portion corresponding to the first plane portion, and the second concave portion is arranged corresponding to the first concave portion; the collimated first laser beam is shaped by the plano-convex lens (5), the first plane portion, the second plane portion and the flat glass (9) and transmitted to the first meniscus lens (10); the collimated second laser beam is shaped by the plano-convex lens (5), the first concave portion and the second concave portion and transmitted to the first self-focusing lens (15); The concave surfaces of the first meniscus lens (10) and the second meniscus lens (11) face the second self-focusing lens (17) and are used to transmit the first laser beam to the second self-focusing lens (17); the output ends of the second self-focusing lens (17) and the first self-focusing lens (15) are connected to the first output optical fiber and the second output optical fiber respectively.

2. According to claim 1, a spatial off-axis dual-channel optical fiber rotary connector, characterized in that: The rotor sleeve (1) is embedded in one end of the stator housing (2); a rotor end cover (18) is embedded in one end of the rotor sleeve (1), and two through holes are provided on the rotor end cover (18), which are respectively used to set a first collimating lens (19) and a second collimating lens (20); the other end of the rotor sleeve (1) is an open end, which is arranged toward the first lens (6).

3. According to claim 2, a spatial off-axis dual-channel optical fiber rotary connector, characterized in that: A stator end cover (13) is arranged at the other end of the stator housing (2), the stator end cover (13) is fixedly connected to the stator housing (2) by means of screws (12), and a through hole is provided on the stator end cover (13) for arranging a first output optical fiber; The side wall of the stator housing (2) is provided with a through hole for arranging a second output optical fiber.

4. A spatial off-axis dual-channel optical fiber rotary connector according to any one of claims 1 to 3, characterized in that: The flat glass (9) has a through hole along the central axis, and the first self-focusing lens (15) is arranged in the through hole of the flat glass (9).

5. The spatial off-axis dual-channel optical fiber rotary connector according to claim 4, characterized in that: The first collimating lens (19) and the second collimating lens (20) are both configured as self-focusing lenses.

6. The spatial off-axis dual-channel optical fiber rotary connector according to claim 5, characterized in that: The first input optical fiber (7) and the second input optical fiber (21) are configured as multimode optical fibers, thermal expansion core optical fibers, or large core diameter optical fibers; The first output optical fiber and the second output optical fiber are both configured as multimode optical fibers (16).

7. The spatial off-axis dual-channel optical fiber rotary connector according to claim 6, characterized in that: The outer wall of the rotor sleeve (1) and the inner wall of the stator housing (2) are rotatably connected via a bearing (3); The plano-convex lens (5), the first lens (6), the second lens (8), the flat glass (9), the first meniscus lens (10), and the second meniscus lens (11) are respectively fixedly connected to the rotor sleeve (1) or the stator housing (2) via a pressing ring (14).

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