Rotary Connector Research Articles

Optoelectronic rotary connector for data transmission

Many technical solutions require the transmission of data between rotating parts. The article presents a data transmission solution based on an optoelectronic rotary connector. The optoelectronic connector is characterised by high speed of data transmission and long life of the mechanical components, with the choice of synchronous and asynchronous data transmission modes. Keywords: optoelectronic rotary connector, optical data transmission, detection of optical radiation

Principles of compensation of optical rays' rotation and multi-channel optical rotary connectors.

This paper deals with some theoretical issues concerning the methods of compensation of optical beams' rotation as well as the ways to design multi-channel optical rotary connectors (ORCs) operating on the compensation principle. A theoretical foundation is given for a general method of compensation of optical beams' rotation that is based on stage-by-stage transformation of beam rotation angular velocity by using a set of optical transducers mounted sequentially along the light rays. The compensation process is described in general form by some mathematical equations. One of its solutions opens the possibility to make ORCs (based on the compensation principle of operation) without any geared mechanisms. They are much smaller than their analogues and provide high reliability and long-term operation at high rotation velocities. An example of the technical realization of an ORC based on two fiber-optic transducers of the original design is adduced. The construction of an ORC including a pioneering fiber-optic compensator (FOC) of high quality that can invert the beam rotation direction is described in detail. This FOC is made as a hollow fiber cylinder. The technological issues of manufacturing this compensator are briefly considered. Besides, the ORC construction with a compensator based on a triangular prism and two light guide bundles to transfer the images is described and analyzed theoretically. These bundles are optically coupled by one butt via the above prism, while their other butts are mounted along the rotation axis. An ORC facility with this compensator can be successfully used to transfer analog signals since it has potentially low rotational oscillations of optical signal amplitude at a level of several percent.

Analysis of multichannel optical rotary connectors based on the compensation operating principle with mirror and prismatic optical compensators (Part 1)

Analysis of multichannel optical rotary connectors based on the compensation operating principle with mirror and prismatic optical compensators (Part 1)

A magnetic rotary optical fiber connector for optogenetic experiments in freely moving animals

Performing optogenetic experiments in a behaving animal presents a unique technical challenge. In order to provide an optical path between a fixed light source and a chronically implanted fiber in a freely moving animal, a typical experimental setup includes a detachable connection between the light source and the head of the animal, as well as a rotary joint to relieve torsional stress during movement. We have combined the functionality of the head mounted connector and the rotary joint into a single integrated device that is inexpensive, simple to build, and easy to use. A typical rotary connector has a transmission efficiency of 80% with a rotational variability of 4%, but can be configured to have a rotational variability of 2% at the expense of a reduced transmission efficiency. Depending on configuration, rotational torque ranges from 14 to 180μNm, making the rotary connector suitable for use with small animals such as mice. Benchmark tests demonstrate that our connectors perform similarly to commercially available solutions in terms of transmission efficiency, rotational variability, and torque but at a fraction of the cost. Unlike currently available solutions, our unique design requires a single optical junction which significantly reduces overall light loss. In addition, magnets allow the connectors and caps to "snap into place" for quick yet reliable connection and disconnection. Our rotary connector system offers superior performance, reduced cost, and is easily incorporated into existing optogenetic setups.

Behaviour analysis of undersized fish escaping through square meshes and separating grids in simulated trawling experiment

Understanding the fish escape behaviour through bycatch reduction devices is the cornerstone of their application as technical conservation measures. To evaluate square meshes and sorting grids as successful size-selective bycatch reduction devices in finfish trawls, we conducted a simulated trawling experiment to assess the effects of illumination, towing speed and mesh or grid orientation on the escape behaviour of undersized fish through square meshes and rigid grids. Juvenile masu salmon ( Oncorhynchus masou) with average body length 13 cm were used as the experimental fish. A speed-controllable motor was used to tow the framed net in a circular water tank. An infrared CCD (charge-coupled devices) camera fixed to the towed net by means of a rotary connector was used to observe fish behaviour. In contrast to the active escape seen under lighted conditions, there was no active voluntary escape under dark conditions. As a result, no fish escaped through parallel and backward-sloping meshes, and only 13% of fish escaped through the forward-sloping meshes when the towing speed was increased. On the other hand, the encounter probability and passive escape through the longer openings in the backward-sloping grid increased under the dark condition, resulting in the highest escape ratio. This increased from 67 to 87% on increasing the towing speed from 1 to 1.5 knots, and shortened the swimming time before escaping from 5 to 1.5 min (the highest escape ratio and the shortest swimming time before escaping under the dark condition). Frame-by-frame analysis of some escape events demonstrated easy, passive fish escape through the grids with no change in the normal swimming direction. The results support the backward-sloping grid as an efficient bycatch-reduction device, especially in demersal trawling when placed well ahead of the codend, working in the dark at high towing speeds.

Pressure Loss Characteristics in Rotating Coolant Passages of Gas Turbine.

Pressue loss characteristics of flow in rotating coolant passages of gas turbine intermediate shaft were studied experimentally. The effects of rotational Reynolds number and coolant flow rate on the pressure loss characteristics of flow in the coolant passages were investigated by using a rotatinal test facility with disks having diameter of 0.5m and maximum rotational speed of 4800 rpm. A multi-points pressure measurement system with a rotary connector was employed to measure both the wall static pressure along the passages and the total pressure in the intermediate shaft. The results led to an understanding that the strength of the swirl flow controls the total pressure distribution in the central portion of the shaft. On the other hand, there occurreed a large pressure loss at both the junction and in the region of branching of coolant passages.

Chronically Instrumented Conscious Dog Model in Cardiovascular Toxicology Studies

A chronically instrumented dog model has been developed to conduct preclinical studies of the cardiovascular pharmacology and toxicology of pharmaceuticals. Eight conscious, unrestrained dogs can be simultaneously studied while cardiovascular signals are acquired through the use of flexible tethers, sealed mercury rotary connectors, and digital data acquisition and analysis systems. Test articles can be administered by either oral or intravenous routes. Intravenous infusions are performed via indwelling cannulae and remote controlled infusion pumps. The principle of operation is explained for implantable micromanometers, and sonomicrometers as well as electromagnetic, transit time, and Doppler blood flowmeters. Historical references are provided for the development of several of these devices. Techniques are described to perform aseptic thoracotomy surgery and to implant devices to measure cardiac left ventricular and aortic blood pressure, left ventricular wall thickness or segment length, and blood flow...

Application of fiber optics for deep-sea exploration systems

Optical fibers, optical transmission systems, and optical Accessories to apply fiber optics to deep-sea exploration systems are described. The discussion of fibers cover the construction of the fiber and cable and the useful life of optical fibers. Considerations in designing a system (number of fibers and multiplexing method) are discussed. Accessories such as optical feedthroughs, optical connectors, and optical rotary connectors are examined. A composite fiber-optic/coaxial cable system successfully operated for one year is described. >

Optical rotary connector

As optical fiber usage widens, a new kind of optical fiber connector becomes necessary. This connector would be connecting two optical fiber bundles with different speeds around an axis without interruption. It is difficult to make such a connector, especially one with a hollow axis used for mechanical power transmissions. Using an optical fiber bundle for an image inversion and a differential gear system, we have developed an optical rotary connector with a hollow axis that can be used for a multichannel connection.

Continuous measurement of optical fibre transmission loss characteristics during drawing process

An online measurement method using an optical rotary connector is proposed for continuously monitoring optical fibre loss characteristics during manufacture. This method provides a complete transmission loss spectrum and OTDR measurements of optical fibres during the drawing process. The results coincide with corresponding offline cutback measurements to better than ±0.2 dB/km.