Integrated Rotating Subsystems
A Complex Rotating Subsystem
As radar and other antenna systems become more complex and data transfer requirements increase, Diamond Antenna customers are requesting several components in one rotational package to create a complete integrated rotating subsystem. Requests for various rotational devices packaged together can include any or all of the following: RF rotary joint, slip ring, APG (encoder) package, fiber optic rotary joints, and fluid & media rotary unions.
Diamond Antenna has over 2000 RF rotary joint designs available for selecting the right design of waveguide and coaxial RF microwave transmission channels. A modular approach is typically selected and when possible a capacitive-coupled, non-contacting approach along with high quality seals and bearings are chosen to ensure RF performance meets or exceeds the intended life of the product. Packaging multiple RF channels is a Diamond Antenna core competency in addition to complete subsystem integration.
Diamond Antenna has hundreds of designs with integrated slip rings. Many include the Roltran Roll-Ring® which is an innovative next-generation slip ring that uses a rolling, instead of sliding, electrical contact for transfer of data and power signals. The rolling contact at the electrical interface provides extended operating life without field maintenance and allows customers to avoid unscheduled interruptions and downtime for maintenance (no cleaning or brush block replacement required) before the entire rotary joint assembly is removed for scheduled factory service.
Diamond Roltran Roll-Ring® Cross Section
Closeup of Diamond Roltran Roll-Ring®
The APG (typically an encoder or resolver) is used to synchronize return data with azimuth position. The typical Diamond APG drive system includes a large diameter shaft mount to transfer rotation from the main bearings to a precision gear located concentric to the axis of rotation. The main gear then transfers position to one or two smaller gears, precisely located relative to the main gear. All gears are rated AGMA 14 or better in order to ensure accuracy. Solid stainless-steel rods transfer the motion to the encoder shafts.
A Fiber Optic Rotary Joint (FORJ) is the optical equivalent of the electrical slip ring. The FORJ allows uninterrupted transmission of an optical signal while rotating along the fiber axis and provides data rate transfer to 10 Gbit/s. Single and multi-mode transmission is available in one or multiple fiber optic channels.
A Fluid/Media Rotary Union (FRU) allows the transfer of air, gas or liquid through the rotational interface. Liquid transfer is often required for the cooling of components at the antenna. One or more channels can be integrated within the rotating subsystem.
