Background
The optical fiber rotary connector can realize the transmission of optical signals between relative rotating parts and is commonly used in the occasions that one end is rotated and the other end is fixed, thereby ensuring that the transmission of the optical signals is not interrupted due to the rotation. Compared with the traditional electric slip ring, the optical fiber rotary connector has multiple advantages, can adapt to extremely high rotating speed and has an ultra-long service life; the mechanical strength of the product is higher and more stable; the device has no electromagnetic leakage, good confidentiality and electromagnetic interference resistance; the transmission frequency band is wide; the single mode or the multi-mode can be selected, and the volume is small; the device has the advantages of being suitable for narrow and small-space working occasions and the like, and is widely applied to different fields. The optical fiber rotary connector is used as a connecting mechanism for information transmission by using optical fibers in two non-contact devices, and is used for industrial mechanical arms, winches, oil exploitation equipment, a scanning system for ocean detection, a tracking radar and a submarine robot; the underwater acoustic system of the sea bottom of a military warship, the rotating tower of a combat vehicle, the aircraft in the aerospace field, the CT scanning system of medical equipment, wind power generation, a helicopter, an industrial sensor and other high-speed video, digital and analog signal transmission and control aspects are applied.
With the increase of the number of transmission signals, the single-channel optical fiber rotary connector cannot meet the requirements, and the design of the multi-channel optical fiber rotary connector is imperative. At present, various multi-channel optical fiber rotary connectors are available, for example, optical signal rotary connection is realized by using a DOVE prism image rotation principle, but in the method, a complex planet wheel mechanism is needed to ensure that the rotating speed of a prism is half of that of a rotor, large errors are inevitably caused due to the fact that the precision of a gear and the DOVE prism is difficult to ensure, mechanical structures are excessive, the rotating speed of the optical fiber rotary connector with the structure is not high, only hundreds of rotations exist, and the use of the optical fiber rotary connector is severely limited.
Further, there are a multi-channel optical fiber rotary shaft connector designed by using optical fiber direct coupling, utilizing symmetry of a lens structure, fresnel lens, and the like, and a hollow multi-channel optical fiber rotary connector constructed by using directional light guiding property of V-grooved ring wave, cylindrical waveguide, direct beam coupling method, and the like, and they are not used in large scale because of reasons such as difficulty in ensuring precision, complicated structure, or excessive loss, and their internal components are too many and their use rotation speed is strictly limited.
Disclosure of Invention
The embodiment of the application provides a high-speed multi-channel optical fiber rotary connector, and solves the problems that the optical fiber rotary connector in the prior art is complex in structure and low in rotating speed.
The embodiment of the application provides a high-speed multi-channel optical fiber rotary connector, which comprises a fixed end optical fiber collimator, a rotary end first stage, a rotary end second stage and a rotary end third stage which are sequentially arranged along the same central axis from left to right; the fixed end optical fiber collimator, the rotating end first stage and the rotating end second stage are all packaged in a connector shell;
the first stage of the rotating end comprises a rotating end optical fiber collimator, a collimator shaft sleeve and a first-stage rolling bearing; the second stage of the rotating end comprises an intermediate shaft and a second-stage rolling bearing; the third stage of the rotating end comprises a connecting shaft, a 1 xN bidirectional optical switch and an input shaft;
the rotating end optical fiber collimator is coupled with the fixed end optical fiber collimator, the rotating end optical fiber collimator is fixedly connected with the collimator shaft sleeve, the outer diameter of the collimator shaft sleeve is matched with the inner diameter of the primary rolling bearing, and the outer diameter of the primary rolling bearing is matched with the connector shell;
the collimator shaft sleeve is connected with the intermediate shaft through a primary spring pin, the outer diameter of the intermediate shaft is matched with the inner diameter of the secondary rolling bearing, and the outer diameter of the secondary rolling bearing is matched with the connector shell;
the 1 xN bidirectional optical switch is positioned between the connecting shaft and the input shaft, the connecting shaft is connected with the intermediate shaft through a secondary spring pin, and the input shaft is connected with an external rotary input shaft through a coupler.
Preferably, the fixed end optical fiber collimator is fixed on the connector shell through a set screw; the rotary end optical fiber collimator is fixedly connected with the collimator shaft sleeve through a set screw.
Preferably, the tail end of the collimator shaft sleeve is provided with an external thread, and the collimator shaft sleeve is matched with a round nut and a stop washer to axially fix the primary rolling bearing.
Preferably, the 1 × N bidirectional optical switch is a packaged 1 × N bidirectional optical switch, and includes a 1 × N bidirectional optical switch, a driving circuit, and a power supply packaged together; and the port of the packaged 1 XN bidirectional optical switch is provided with an optical fiber flange.
Preferably, a common end of the 1 × N bidirectional optical switch is connected to a tail fiber of the optical fiber collimator at the rotating end, and N channels of the 1 × N bidirectional optical switch are respectively connected to N optical fiber sensors; and inorganic high-temperature glue is filled in a gap between the rotary end optical fiber collimator and the 1 xN bidirectional optical switch.
Preferably, the first-stage rolling bearing is a first-stage angular contact ball bearing, and the second-stage rolling bearing is a second-stage angular contact ball bearing.
Preferably, the first-stage angular contact ball bearing and the second-stage angular contact ball bearing both adopt ceramic ball bearings.
Preferably, the primary spring pin and the secondary spring pin are split spring pins.
Preferably, the collimator shaft sleeve, the intermediate shaft and the connecting shaft are all provided with mounting holes; the primary spring pin is inserted into a mounting hole of the collimator shaft sleeve corresponding to the intermediate shaft, and a damping gasket is arranged between the end faces of the shafts; the secondary spring pin is inserted into the mounting hole of the intermediate shaft corresponding to the connecting shaft, and a damping gasket is arranged between the end faces of the shaft.
Preferably, the damping gasket is made of fluororubber.
One or more technical solutions provided in the embodiments of the present application have at least the following technical effects or advantages:
in this application embodiment, the high-speed multichannel optical fiber rotary connector that provides includes along same axis from left to right order's stiff end optical fiber collimator, rotation end first level, rotation end second level, rotation end third level, and rotation end first level includes rotation end optical fiber collimator, collimator axle sleeve, one-level antifriction bearing, and rotation end second level includes jackshaft, second grade antifriction bearing, and rotation end third level includes connecting axle, two-way optical switch of 1 xn, input shaft. The invention adopts the mode that two rolling bearings are connected in parallel, thereby improving the rotation precision and stability; meanwhile, the high-precision bearing has small radial run-out, the rotating speed generally can reach tens of thousands of revolutions, and the rotating part mainly consists of a shaft and the bearing, so that the structure is simple, and the high rotating speed of thousands of revolutions or even tens of thousands of revolutions can be realized. The external rotation sequentially passes through the third rotary end stage, the second rotary end stage and the first rotary end stage to reach the optical fiber collimator at the rotary end, and axial, angle and radial deviations caused by the external rotary input shaft are offset by flexible connection between each stage of the rotary end, so that stable rotation of the optical fiber collimator at the rotary end can be ensured. The optical signal can be transmitted between the relative rotating platforms through the coupling of the optical fiber collimator, and the switching between different channels can be realized through the 1 XN bidirectional optical switch. The high-speed multi-channel optical fiber rotary connector provided by the invention has the characteristics of simple structure, convenience in installation, small loss, good optical signal quality, small structure, low cost, simplicity in maintenance and the like, can adapt to a high-speed operating environment, and can resist larger axial deviation, angle deviation and radial deviation.
Detailed Description
In order to better understand the technical solution, the technical solution will be described in detail with reference to the drawings and the specific embodiments.
The present embodiment provides a high-speed multi-channel fiber optic rotary connector, as shown in fig. 1, including: the fixed end optical fiber collimator 2, the rotating end first stage, the rotating end second stage and the rotating end third stage are sequentially arranged from left to right along the same central axis. Except for the third rotary end stage, other parts (namely the fixed end optical fiber collimator 2, the first rotary end stage and the second rotary end stage) are all packaged in the connector shell 1.
The fixed end optical fiber collimator 2 is directly fixedly connected with the connector shell 1, and specifically, the fixed end optical fiber collimator 2 is fixed on the connector shell 1 through a set screw 3.
The rotating end first stage, as shown in fig. 1, includes: the optical fiber collimator comprises a rotary end optical fiber collimator 4, a collimator shaft sleeve 6 and a pair of first-stage angular contact ball bearings 5.
The optical fiber collimator at the rotating end 4 is directly coupled with the optical fiber collimator at the fixed end 2, the outside of the optical fiber collimator at the rotating end 4 is protected by the collimator shaft sleeve 6 and is driven to rotate, the outer diameter of the collimator shaft sleeve 6 is matched with the inner diameter of the first-stage angular contact ball bearing 5, and the outer diameter of the first-stage angular contact ball bearing 5 is directly matched with the connector shell 1.
Specifically, the rotating end optical fiber collimator 4 is fixed with the collimator shaft sleeve 6 through the set screw 3, and the first-stage angular contact ball bearing 5 is matched with the connector housing 1 and the collimator shaft sleeve 6 to ensure the rotation of the rotating end optical fiber collimator 4.
As shown in fig. 1, the collimator sleeve 6 has an external thread at its end, and a round nut 8 and a stop washer 7 are engaged to axially fix the first-stage angular contact ball bearing 5.
The second stage of the rotating end, as shown in fig. 1, comprises: an intermediate shaft 11 and a pair of two-stage angular contact ball bearings 12.
The collimator shaft sleeve 6 is connected with the intermediate shaft 11 through uniformly distributed primary spring pins 10, the outer diameter of the intermediate shaft 11 is matched with the inner diameter of the secondary angular contact ball bearing 12, and the outer diameter of the secondary angular contact ball bearing 12 is directly matched with the connector shell 1.
That is, the second-stage angular contact ball bearing 12 is matched with the connector housing 1 and the intermediate shaft 11 to ensure the rotation of the intermediate shaft 11, the power of the intermediate shaft 11 is transmitted to the collimator shaft sleeve 6 through the uniformly distributed first-stage spring pins 10, the schematic diagram of the first-stage spring pins 10 is shown in fig. 5, the connection mode is shown in fig. 4, holes are formed in the collimator shaft sleeve 6 and the intermediate shaft 11, and the connection position is matched with the damping gasket 9.
The end cover 15 is used for axially positioning the outer ring of the secondary angular contact ball bearing 12 and preventing the bearing and internal parts from axially moving; meanwhile, the gasket 14 is positioned on the inner side of the end cover 15 and plays a role of dust prevention and sealing with the end cover 15; the end cover 15 and the gasket 14 are fixed on the connector shell 1 by screws 13 which are evenly distributed in the circumferential direction.
The third stage of the rotating end, as shown in fig. 2, includes: a connecting shaft 17, a 1 XN bidirectional optical switch 18 and an input shaft 19.
The packaged 1 × N bidirectional optical switch 18 is: the 1 XN bidirectional optical switch, the driving circuit and the power supply are packaged, each channel is switched on and maintained for a certain period of time, the channels are automatically switched, and the port parts are provided with optical fiber flanges to facilitate connection with the optical fiber sensors.
The following description will be given taking as an example that the 1 × N bidirectional optical switch 18 is specifically a 1 × 4 bidirectional optical switch.
One end of the third stage of the rotating end is connected with the intermediate shaft 11 through uniformly distributed second-stage spring pins 16, as shown in fig. 4, and the other end of the third stage of the rotating end is connected with an external rotating input shaft through a coupler. The packaged 1 × 4 bidirectional optical switch is located between the connecting shaft 17 and the input shaft 19 to realize the collection of multi-channel optical signals, and a schematic diagram of the packaged 1 × 4 bidirectional optical switch is shown in fig. 3.
The coupling is a structure for connecting an external rotation input shaft with the present invention, and is a connection method between common rotation shafts, which is not a structure claimed in the present invention. The external rotational input shaft may be the rotational axis of any device under test and is not a claimed structure of the present invention.
Referring to fig. 1, the deviation of the external rotating input shaft due to rotation eccentricity, vibration and the like is transmitted to the high-speed multi-channel optical fiber rotating connector provided by the invention through the coupler, and the external force passing through the flexible coupler is reduced by a part, and then passes through the third stage of the rotating end, the second stage of the rotating end and the first stage of the rotating end of the flexible coupler, so that the first stage of the rotating end is not greatly deformed, and the coupling between the fixed end optical fiber collimator 2 and the rotating end optical fiber collimator 4 is not affected, so that the high-speed multi-channel optical fiber rotating connector provided by the invention can stably work under a severe working condition.
In addition, the gap between the rotating end optical fiber collimator 4 and the 1 × 4 bidirectional optical switch is filled with inorganic high-temperature glue to prevent the optical fiber from being broken when the optical fiber rotates at high speed.
Referring to fig. 4 and 5, the spring pins (including the primary spring pin 10 and the secondary spring pin 16) are split spring pins, and are inserted into corresponding holes of the collimator shaft sleeve 6, the intermediate shaft 11 and the connecting shaft 17 under a certain compression amount, so that the spring pins are ensured not to slide, and play roles in transmitting torque and resisting vibration.
In order to ensure that the optical fiber rotary connector is used at high temperature, the first-stage angular contact ball bearing 5 and the second-stage angular contact ball bearing 12 both adopt ceramic ball bearings, can work at the rotating speed of 20000rpm and do not need lubrication.
When the bearing rotates at a high speed, the bearing is bound to generate higher temperature, the ceramic ball bearing does not need to be lubricated and can resist high temperature, and the ceramic ball bearing has the advantages that the common bearing does not have; in addition, compared with the common deep groove ball bearing, the angular contact ball bearing has higher rotating speed than the deep groove ball bearing under the same size, and is more suitable for occasions with high rotating speed and high precision.
In order to ensure that the optical fiber rotary connector is used at high temperature, the vibration damping gaskets 9 are made of high-temperature-resistant rubber, specifically, fluororubber.
The process for realizing multi-channel rotary connection of the high-speed multi-channel optical fiber rotary connector provided by the invention comprises the following steps: when the rightmost four optical fiber sensor optical signals enter the 1 x 4 bidirectional optical switch, the optical switch is set to switch the channels once every 5 seconds, when the first channel is opened, the optical signals of the first optical fiber sensor can be transmitted to the rotating end optical fiber collimator 4, reach the fixed end optical fiber collimator 2 through coupling, and then reach the signal acquisition equipment; after the 1 × 4 bidirectional optical switch switches the channels, the signal transmission of the second channel (similarly, the third channel and the fourth channel are also included, and are not described in detail) and the corresponding second optical fiber sensor (the third optical fiber sensor corresponds to the third channel, and the fourth optical fiber sensor corresponds to the fourth channel) is the same as the signal transmission principle of the first channel and the first optical fiber sensor. When each channel is communicated, the optical fiber rotary connector works equivalently to one single channel, so that the optical fiber rotary connector can work at a high rotating speed.
In summary, the high-speed multi-channel fiber optic rotary connector provided by the invention is a scheme comprising three-level rotary input and multi-channel transmission, wherein the fixed end fiber collimator is directly matched with the connector shell, and the fixed end fiber collimator is a fixed end; the input shaft, the 1 XN bidirectional optical switch, the connecting shaft, the intermediate shaft and the collimator shaft sleeve jointly form a rotating end. The collimator shaft sleeve and the intermediate shaft are respectively matched with the first-stage angular contact ball bearing and the second-stage angular contact bearing, and the bearings are directly matched with the connector shell to realize the rotation of the collimator at the rotating end; the connecting shaft, the 1 XN bidirectional optical switch and the input shaft are mostly arranged outside the shell of the connector, multi-channel signal bidirectional transmission is mainly realized through the 1 XN bidirectional optical switch, bidirectional transmission of optical signals between the rotating end and the fixed end is realized through coupling of the fixed end optical fiber collimator and the rotating end optical fiber collimator, and single-channel and multi-channel bidirectional signal transmission is realized through single-end connection of the rotating end optical fiber collimator and the 1 XN bidirectional optical switch. The high-speed multi-channel optical fiber rotary connector comprises a fixed body and a rotating body, wherein the fixed body comprises a connector shell and a fixed end optical fiber collimator, the rotating body comprises an optical fiber collimator shaft sleeve, an intermediate shaft, a connecting shaft, an input shaft and a packaged optical switch which are sequentially arranged, the inner diameter of the optical fiber collimator shaft sleeve is matched with the rotary end optical fiber collimator, and the outer diameter of the optical fiber collimator shaft sleeve is matched with a bearing, so that the aim of coupling the rotary end collimator with the fixed end collimator is fulfilled; the middle shaft connects the optical fiber collimator shaft sleeve with the connecting shaft, a vibration damping gasket is added at the connecting position of the shaft ends, and the adjacent two shafts transmit torque through uniformly distributed spring pins; the input shaft transmits the rotation of the rotating equipment into the optical fiber rotating connector through the packaged optical switch and the connecting shaft, the optical switch port packages the optical fiber rotating connector into an optical fiber flange, multi-channel signal transmission is realized through time division multiplexing, the structure is simple, the installation is convenient, and the high-speed running environment can be adapted.
The high-speed multi-channel optical fiber rotary connector provided by the embodiment of the invention at least comprises the following technical effects:
(1) the invention adopts the mode that two rolling bearings are connected in parallel, thereby improving the rotation precision and stability; meanwhile, the high-precision bearing has small radial run-out, the rotating speed generally can reach tens of thousands of revolutions, and the rotating part mainly comprises a shaft and the bearing, so the structure is simple, and the realization of the high rotating speed of thousands of revolutions or even tens of thousands of revolutions is easier.
(2) The rotating end of the invention is connected with an external rotating input shaft, external rotation sequentially passes through a third stage of the rotating end, a second stage of the rotating end and a first stage of the rotating end to reach the optical fiber collimator of the rotating end, and axial, angle and radial deviation caused by the external rotating input shaft are offset by flexible connection between each stage of the rotating end, so that stable rotation of the optical fiber collimator of the rotating end is ensured.
(3) The invention combines the single-channel optical fiber rotary connector with the packaged 1 XN bidirectional optical switch, adopts a time division multiplexing method to collect and analyze a plurality of paths of optical signals, has simple structure, can operate at high rotating speed, and has small loss and good optical signal quality. The device has the characteristics of small structure, low cost, simple maintenance and the like, and can resist larger axial deviation, angle deviation and radial deviation.
(4) The optical fiber rotary connector is connected with the optical switch, signals of a plurality of sensors can be transmitted to the optical fiber rotary connector at the rotating end in different time periods through the switching of the optical switch channels, and then are transmitted to the signal acquisition device through the optical collimator at the stationary end. Theoretically, the collection of the N-path optical signals can be realized by adopting a 1 × N bidirectional optical switch.
Finally, it should be noted that the above embodiments are only for illustrating the technical solutions of the present invention and not for limiting, and although the present invention has been described in detail with reference to examples, it should be understood by those skilled in the art that modifications or equivalent substitutions may be made on the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, which should be covered by the claims of the present invention.