Rotary Joint Contactless Annular Electrical Connection
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Solution Overview
Problem
Traditional rotary electrical connections face reliability and wear issues due to electrical contact, and existing contactless solutions often require rotational symmetry and central axis alignment for phase and amplitude consistency.
Innovation Solution
A contactless annular electrical connection using annular waveguide structures with transverse electromagnetic (TEM) waves propagating across an axial gap between rotating parts, allowing for relative rotation without electrical conduction and maintaining phase and amplitude consistency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional slip rings with electrical contact connections are used, then power and electrical signals can be transmitted from stationary to rotating structures, but reliability and wear issues occur due to continuous physical contact
Solution Approach 1:
The patent replaces the mechanical electrical contact system (brushes pressing against rotating conductors) with an electromagnetic field-based energy transfer system. The stationary part generates electromagnetic fields that couple with corresponding fields in the rotating part, enabling power and signal transmission without physical contact, thereby eliminating wear and improving reliability
Solution Approach 2:
The patent introduces electromagnetic fields as an intermediary medium to transfer energy and signals between the stationary and rotating parts. The electromagnetic fields act as a mediator that couples the two parts without requiring direct physical contact, solving the wear and reliability problems of traditional contact-based systems
2Duration of action of moving object
If contactless rotary joints with capacitive or inductive coupling are used, then wear is eliminated, but rotational symmetry and central axis alignment are required to maintain constant phase and amplitude transmission
Solution Approach 1:
The patent employs asymmetric electromagnetic field distribution patterns that are specifically designed to maintain constant phase and amplitude relationships during rotation. By carefully configuring the geometry and positioning of the electromagnetic coupling elements, the system achieves rotationally invariant field interactions without requiring the rotating part to maintain precise symmetry or central alignment
Solution Approach 2:
The patent transitions from traditional planar or axial electromagnetic coupling to a three-dimensional field configuration. By utilizing volumetric electromagnetic field distributions and spatially distributed coupling elements, the system achieves rotational invariance through geometric arrangement in multiple dimensions rather than relying on two-dimensional rotational symmetry
3Stability of the object's composition
If traditional rotary joints with rotational symmetry are used, then phase and amplitude transmission remain constant during rotation, but the input and output ports must be placed at the center axis of rotation
Solution Approach 1:
The patent moves the input and output ports from the central axis (one-dimensional constraint) to the periphery of the electromagnetic coupling region (two-dimensional or three-dimensional freedom). This spatial reconfiguration allows ports to be positioned at various locations around the rotation axis while maintaining stable phase and amplitude transmission through the engineered electromagnetic field distributions
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Enables reliable, wear-free, and phase-consistent signal transmission across a full 360-degree rotation, with the central core region available for other uses like optical signal transmission, and supports multiplexing of multiple signals.
Implementation Method 1
first feed is operatively coupled to the first annular waveguide structure to produce a transverse electromagnetic 'TEM' wave that propagates from the annular gap of the first annular waveguide structure, across the axial gap, to the annular gap of the second annular waveguide structure
Data Source
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AI summary
A rotary joint includes a contactless electrical connection that has an annular shape, not extending into a central region surrounded and defined by the annular contactless electrical connection. The annular shape of the electrical connection portions allows other uses for the central region, such as for passing an optical signal through the rotary joint. Feeds are coupled to annular waveguide structures in both halves of the rotary joint, for input and output of signals. The feeds may provide connections to the annular waveguide structures at regularly-spaced circumferential intervals around the waveguide structures, such as at about every half-wavelength of the incoming (and outgoing) signals. The annular waveguide structures propagate signals in an axial direction, parallel to the axis of rotation of the rotary joint. The signals propagate contactlessly (non-electrically-conductively) across a gap in the axial direction between the two annular waveguides.