Long life space dual channel fiber optic rotary joint

Abstract

The application relates to a double-channel optical fiber connecting device, in particular to a long-service-life space double-channel optical fiber rotary connector, which solves the problems of poor environmental adaptability, complex assembly and high precision requirements in machining and assembly of the existing optical fiber rotary connector. The long-service-life space double-channel optical fiber rotary connector comprises a stator sleeve, a rotor sleeve, a first optical assembly and a second optical assembly; the first optical assembly comprises a first self-focusing lens, a beam expanding assembly, a cone lens group which are sequentially arranged in the stator sleeve along an optical path, and a beam reducing assembly and a second self-focusing lens which are sequentially arranged in the rotor sleeve along the optical path; the second optical assembly comprises a third self-focusing lens and a fourth self-focusing lens which are sequentially arranged along the optical path; coaxial double channels are formed through the first optical assembly and the second optical assembly, signal transmission in the rotating process is realized, and mechanical transmission mechanisms such as gears and magnets do not need to be arranged.

Description

TECHNICAL FIELD

[0001] The present application relates to a dual-channel optical fiber connection device, in particular to a long-life space dual-channel optical fiber rotary connector. BACKGROUND

[0002] The optical fiber rotary connector is an important optical device for signal transmission, which uses optical fiber as a transmission medium to realize signal transmission between a rotating platform and another static platform. The optical fiber rotary connector has been widely used in many fields in today's rapid development of signal transmission. At present, with the rapid development of aerospace industry, the optical fiber rotary connector applied in the field of aerospace needs to have the characteristics of high reliability and long life.

[0003] The commonly used optical fiber rotary connector currently includes a Dove prism structure, a mirror structure and a lens structure. Among them, the optical fiber rotary connector with the Dove prism structure adopts the light transmission principle of the Dove prism, and realizes 2:1 speed reduction through a gear transmission mechanism, which offsets the 1:2 rotation ratio of the Dove prism object image, so as to realize the multi-channel signal transmission between the stator end and the rotor end. Since it has a mechanical structure, its adaptability in space environment is poor, and its reliability is low. Moreover, the environmental adaptability of the Dove prism is poor, and dew will appear on the surface of the Dove prism under humid and hot conditions, resulting in abnormal transmission of optical signals. The optical fiber rotary connector with the mirror structure uses a mirror to realize the turning of the light beam, and after multiple reflections, the light beam enters the receiving end to complete the signal transmission. In this structure, a magnet or a gear can be selected as the support of the mirror. Due to the mirror structure, the transmission path of the multi-channel light beam transmission is relatively complex, the assembly is difficult, and part of the light beam will be blocked, which increases the insertion loss of the optical fiber rotary connector. At the same time, the magnet and gear structure will reduce the reliability of the optical fiber rotary connector and the environmental adaptability. The optical fiber rotary connector with the lens structure uses a Fresnel lens or a spherical lens structure to construct a passive symmetric optical structure dual-channel optical fiber rotary connector. Part of the optical device at the transmitting end is placed off-axis, and the light beam is transmitted to the receiving end through the Fresnel lens or the spherical lens. However, the coupling light beam capacity of the receiving end in this structure is poor, and the precision requirements for processing and assembly are high. Moreover, this structure is mainly used for one-way signal transmission, and it is difficult to complete bidirectional transmission. SUMMARY

[0004] The purpose of the present application is to solve the problems of poor environmental adaptability, complex assembly and high precision requirements for processing and assembly of the optical fiber rotary connector in the prior art, and to provide a long-life space dual-channel optical fiber rotary connector.

[0005] To achieve the above-mentioned purpose, the technical solution provided by the present application is as follows:

[0006] The application discloses a long-life space double-channel optical fiber rotary connector which comprises coaxially rotatingly connected stator sleeve and rotor sleeve, and is characterized in that: the long-life space double-channel optical fiber rotary connector further comprises a first optical assembly and a second optical assembly; the first optical assembly comprises a first self-focusing lens, a beam expanding assembly, a cone lens group which are sequentially arranged in the stator sleeve along an optical path, and a beam shrinking assembly and a second self-focusing lens which are sequentially arranged in the rotor sleeve along the optical path; the first self-focusing lens is arranged at one end of the stator sleeve away from the rotor sleeve, an input end is connected with a first input optical fiber; the beam shrinking assembly is arranged at one end of the rotor sleeve close to the stator sleeve, an incident end corresponds to an emitting end of the cone lens group; and an output end of the second self-focusing lens is connected with a first output optical fiber; the second optical assembly comprises a third self-focusing lens and a fourth self-focusing lens which are sequentially arranged along the optical path; the third self-focusing lens is arranged at the other end of the stator sleeve, an input end is connected with a second input optical fiber; and the fourth self-focusing lens is arranged at one end of the rotor sleeve, an output end is connected with a second output optical fiber.

[0007] Further, two optical windows are arranged at the other end of the stator sleeve and one end of the rotor sleeve respectively, and a mounting through hole is formed on the optical window along a central axis;

[0008] The third self-focusing lens is arranged in the mounting through hole of the optical window corresponding to the stator sleeve, and the fourth self-focusing lens is arranged in the mounting through hole of the optical window corresponding to the rotor sleeve.

[0009] Further, a stator end cover is arranged at one end of the stator sleeve, a first through hole is arranged on the stator end cover along the central axis, and the first self-focusing lens is arranged in the first through hole;

[0010] A rotor end cover is arranged at the other end of the rotor sleeve, a second through hole is formed on the rotor end cover along the central axis, and the second self-focusing lens is arranged in the second through hole.

[0011] Further, the cone lens group comprises a first cone lens and a second cone lens which are sequentially arranged along the optical path, and the cone surface of the first cone lens and the cone surface of the second cone lens are oppositely arranged.

[0012] Further, the beam expanding assembly comprises a first concave lens, a first meniscus lens and a second meniscus lens which are sequentially arranged along the optical path, and the convex surfaces of the first meniscus lens and the second meniscus lens are directed to the other end of the stator sleeve.

[0013] Further, the beam shrinking assembly comprises a third meniscus lens, a fourth meniscus lens and a second concave lens which are sequentially arranged along the optical path.

[0014] The convex surfaces of the third meniscus lens and the fourth meniscus lens are directed to one end of the rotor sleeve.

[0015] Further, the stator sleeve and the rotor sleeve are connected through a ceramic ball bearing, and a bearing retainer of the ceramic ball bearing is made of polyimide material.

[0016] Further, the beam expanding assembly is configured as a Keplerian beam expanding system or a Cassegrain system.

[0017] Advantages of the present application:

[0018] 1. The long-life space double-channel optical fiber rotary connector of the present application is provided with coaxial first and second optical assemblies to form a coaxial double channel, and the stator sleeve and the rotor sleeve are connected in rotation to realize signal transmission during rotation, without the need to set up mechanical transmission mechanisms such as gears and magnets, so that the assembly difficulty is greatly reduced, and the risk of the optical fiber rotary connector being unable to work due to the failure of the mechanical transmission mechanism is reduced, and the connector has the characteristics of high reliability and strong environmental adaptability in space environment.

[0019] 2. The long-life space double-channel optical fiber rotary connector of the present application is passive, has strong anti-electromagnetic interference energy, and can be used in special or extreme environments, and can also be applied to the fields of radar or medical treatment.

[0020] 3. The two signal transmission channels in the long-life space double-channel optical fiber rotary connector of the present application can realize bidirectional transmission. The first self-focusing lens is combined with the first concave lens and the beam expanding assembly to realize magnification expansion of the expanded collimated light beam, and then the light beam is modulated into a hollow light beam through the second cone lens group. By selecting cone lenses with different cone angles and / or changing the distance between the two cone lenses, collimated hollow light beams with different central apertures can be obtained.

[0021] 4. In the long-life space double-channel optical fiber rotary connector of the present application, the laser beam of the external channel will not be blocked by the middle channel, which reduces the insertion loss of the external channel and improves the overall performance of the optical fiber rotary connector.

[0022] 5. In the long-life space double-channel optical fiber rotary connector of the present application, high-precision self-lubricating ceramic ball bearings are used to ensure the stability and reliability of optical signal transmission, and have a long service life. The ceramic ball bearings are lubricated with materials that have little ion radiation effect and low condensable volatile matter, which ensures that the long-life space double-channel optical fiber rotary connector has a radiation-resistant and low-pollution working environment, and has good space adaptability. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 is a structural schematic diagram of an embodiment of the present application.

[0024] Explanation of reference signs:

[0025] 1 - stator end cover, 2 - bolt, 3 - rotor end cover, 4 - bearing pressure ring, 5 - bearing seat, 6 - stator sleeve, 7 - mirror frame, 8 - pressure ring, 9 - gasket, 10 - ceramic ball bearing, 11 - optical window, 12 - first meniscus lens, 13 - second meniscus lens, 14 - first conical lens, 15 - second conical lens, 16 - second input optical fiber, 17 - third self-focusing lens, 18 - first output optical fiber, 19 - fourth self-focusing lens, 20 - second output optical fiber, 21 - third meniscus lens, 22 - fourth meniscus lens, 23 - second concave lens, 24 - second self-focusing lens, 25 - first self-focusing lens, 26 - first input optical fiber, 27 - rotor sleeve, 28 - self-focusing lens mounting bracket, 29 - first concave lens. DETAILED DESCRIPTION

[0026] The long-life space double-channel optical fiber rotary connector comprises a stator sleeve 6, a rotor sleeve 27, a first optical assembly, and a second optical assembly; the stator sleeve 6 and the rotor sleeve 27 are coaxially connected through a ceramic ball bearing 10, and the ceramic ball bearing 10 mainly comprises a bearing pressure ring 4, a bearing retainer, a bearing seat 5, and a ceramic ball, and is a key component for guaranteeing signal transmission and service life.

[0027] The first optical assembly is used for transmitting a first optical signal and comprises, in sequence along an optical path, a first self-focusing lens 25, a first concave lens 29, a first meniscus lens 12, a second meniscus lens 13, a conical lens set in the stator sleeve 6, and a third meniscus lens 21, a fourth meniscus lens 22, a second concave lens 23, and a second self-focusing lens 24 in the rotor sleeve 27. Each optical lens in the first optical assembly is connected to the stator sleeve 6 or the rotor sleeve 27 through a mirror frame 7, and a pressure ring 8 and a gasket 9 are arranged to improve the stability of the optical lens.

[0028] The first optical signal is input to the first self-focusing lens 25 arranged at the end of the stator sleeve 6 away from the rotor sleeve 27 after expansion and collimation, and then passes through the expansion assembly composed of the first concave lens 29, the first meniscus lens 12, and the second meniscus lens 13 to realize large-magnification expansion and collimation of the first optical signal. The convex surfaces of the first meniscus lens 12 and the second meniscus lens 13 face the other end of the stator sleeve 6. The first optical signal after expansion and collimation is shaped into a collimated hollow light beam by the taper lens group composed of the first taper lens 14 and the second taper lens 15 arranged opposite to each other as the external channel. The present application has a second optical assembly arranged along the central axis to form a central channel. Therefore, the conversion of the first optical signal into a collimated hollow light beam can avoid being blocked by the central channel. The collimated hollow light beam is shrunk and collimated by the shrinking assembly composed of the third meniscus lens 21, the fourth meniscus lens 22, and the second concave lens 23, and is incident parallelly into the second self-focusing lens 24 to be coupled into the first output optical fiber 18 to realize high-efficiency transmission of the signal. The convex surfaces of the third meniscus lens 21 and the fourth meniscus lens 22 face the end of the rotor sleeve 27 close to the stator sleeve 6.

[0029] The first optical signal corresponding to the laser beam is output as a collimated light beam after expansion by the first self-focusing lens 25 to realize one-stage expansion. The above expansion assembly is a Galilean expansion system composed of the first concave lens 29, the first meniscus lens 12, and the second meniscus lens 13 to realize two-stage expansion of the first optical signal. In other embodiments of the present application, the expansion assembly can also use a Keplerian expansion system or a Cassegrain system. The present application uses the first self-focusing lens 25 and the Galilean expansion system to form a two-stage expansion system to realize multiple compensation expansion of the laser beam in the external channel, and then uses the taper lens group to expand the local hollow light beam range.

[0030] Two optical windows 11 are arranged at the other end of the stator sleeve 6 and the end of the rotor sleeve 27, respectively, and mounting through holes are formed in the two optical windows 11 along the central axis. The second optical assembly is used for transmitting the second optical signal and includes the third self-focusing lens 17 and the fourth self-focusing lens 19. The third self-focusing lens 17 is arranged in the mounting through hole of the optical window 11 corresponding to the stator sleeve 6, and the fourth self-focusing lens 19 is arranged in the mounting through hole of the optical window 11 corresponding to the rotor sleeve 27. The second optical signal is incident to the third self-focusing lens 17 through the second input optical fiber 16 and then output by the second output optical fiber 20 through the fourth self-focusing lens 19.

[0031] In order to improve installation flexibility, one end of the stator sleeve 6 is provided with a stator end cover 1, and the both are fixed by bolts 2; the stator end cover 1 is provided with a first through hole along the central axis, and the first self-focusing lens 25 is arranged in the first through hole; the other end of the rotor sleeve 27 is provided with a rotor end cover 3, the rotor end cover 3 is provided with a second through hole along the central axis, and the second self-focusing lens 24 is arranged in the second through hole; the first self-focusing lens 25 and the second self-focusing lens 24 are connected with the stator end cover 1 and the rotor end cover 3 respectively through the self-focusing lens mounting bracket 28.

[0032] In the application, the ceramic ball bearing 10 is lubricated by low-quality-loss and low-volatile non-metallic material, the non-metallic material has less volatile matters, effectively reducing the pollution to the optical system, and the bearing retainer is made of polyimide material, greatly improving the service life from the aspects of material and structure; meanwhile, the optical lens and the optical window 11 in the application are made of radiation-resistant optical glass, effectively avoiding the influence of space particle radiation.

Claims

1. A long-life space dual-channel optical fiber rotary connector, comprising a stator sleeve (6) and a rotor sleeve (27) coaxially connected, characterized in that: a first optical assembly and a second optical assembly are further included; the first optical assembly comprises a first self-focusing lens (25), a beam expanding assembly, a tapered lens group arranged in the stator sleeve (6) in sequence along an optical path, and a beam shrinking assembly and a second self-focusing lens (24) arranged in the rotor sleeve (27) in sequence along the optical path, the first self-focusing lens (25) is arranged at one end of the stator sleeve (6) away from the rotor sleeve (27), an input end is connected to a first input optical fiber (26), the beam shrinking assembly is arranged at one end of the rotor sleeve (27) close to the stator sleeve (6), an incident end corresponds to an exit end of the tapered lens group, and an output end of the second self-focusing lens (24) is connected to a first output optical fiber (18); the tapered lens group comprises a first tapered lens (14) and a second tapered lens (15) arranged in sequence along the optical path, and a tapered surface of the first tapered lens (14) and a tapered surface of the second tapered lens (15) are oppositely arranged; the second optical assembly comprises a third self-focusing lens (17) and a fourth self-focusing lens (19) arranged in sequence along the optical path, the third self-focusing lens (17) is arranged at the other end of the stator sleeve (6), an input end is connected to a second input optical fiber (16), and the fourth self-focusing lens (19) is arranged at one end of the rotor sleeve (27), and an output end is connected to a second output optical fiber (20). 2.The long-life space dual-channel optical fiber rotary connector according to claim 1, characterized in that: two optical windows (11) are further included and arranged at the other end of the stator sleeve (6) and one end of the rotor sleeve (27) respectively, and a mounting through hole is formed on the optical window (11) along a central axis; the third self-focusing lens (17) is arranged in the mounting through hole of the optical window (11) corresponding to the stator sleeve (6), and the fourth self-focusing lens (19) is arranged in the mounting through hole of the optical window (11) corresponding to the rotor sleeve (27). 3.The long-life space dual-channel optical fiber rotary connector according to claim 2, characterized in that: a stator end cover (1) is arranged at one end of the stator sleeve (6), the stator end cover (1) is provided with a first through hole along the central axis, and the first self-focusing lens (25) is arranged in the first through hole; a rotor end cover (3) is arranged at the other end of the rotor sleeve (27), the rotor end cover (3) is provided with a second through hole along the central axis, and the second self-focusing lens (24) is arranged in the second through hole. 4.The long-life space dual-channel optical fiber rotary connector according to claim 3, characterized in that: the beam expanding assembly comprises a first concave lens (29), a first meniscus lens (12) and a second meniscus lens (13) arranged in sequence along the optical path, and convex surfaces of the first meniscus lens (12) and the second meniscus lens (13) face the other end of the stator sleeve (6). 5.The long-life space dual-channel optical fiber rotary connector according to claim 4, characterized in that: ​ ​ ​ ​ ​ ​ ​ The beam narrowing assembly comprises a third meniscus lens (21), a fourth meniscus lens (22) and a second concave lens (23) arranged in sequence along the light path. The convex surfaces of the third meniscus lens (21) and the fourth meniscus lens (22) face one end of the rotor sleeve (27).

6. The long-life space dual-channel optical fiber rotary joint according to claim 5, characterized in that: The stator sleeve (6) and the rotor sleeve (27) are connected through a ceramic ball bearing (10), and the bearing retainer of the ceramic ball bearing (10) is made of polyimide material.

7. The long-life space dual-channel optical fiber rotary joint according to claim 1, characterized in that: The beam expanding assembly is arranged as a Keplerian beam expanding system or a Cassegrain system.

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