Inductive Rotary Joint Coaxial Line Design
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional electrical connections between power inverters and inductive rotary joints in computer tomographs experience significant energy losses and heating due to the transmission of high power over long cable lengths, leading to inefficiency and the need for additional cooling.
Innovation Solution
The use of coaxial lines with interconnected outer conductors and inner conductors supplied with voltages that sum to zero, or inner conductors with equally high opposite polarities, to minimize losses by compensating capacitive and magnetic field-related losses, and employing a line arrangement with a grounded outer conductor for further reduction in losses.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If conventional cables are used to transmit high power from inverter to inductive rotary joint, then power transmission is achieved, but significant energy losses and cable heating occur
Solution Approach 1:
The patent changes the voltage parameters by supplying inner conductors with voltages that sum to zero (balanced voltages), and modifies the cable structure by interconnecting outer conductors along their length. This transforms the conventional single-cable configuration into a differential pair configuration, reducing capacitive leakage currents and energy losses during power transmission.
Solution Approach 2:
The patent introduces an intermediary balanced voltage system between the inverter and the inductive rotary joint. By using two coaxial cables with interconnected outer conductors and opposite-polarity inner conductors, the system creates a differential signal path that acts as an intermediary to reduce electromagnetic interference and energy losses in the power transmission path.
2Device complexity
If conventional single-coaxial-line configuration is used, then simple connection is achieved, but high power losses occur due to capacitive currents
Solution Approach 1:
The patent segments the power transmission path into two separate coaxial lines instead of using a single cable. Each line has its own inner and outer conductors, allowing independent voltage assignment. The outer conductors are interconnected along their length, creating a balanced differential configuration that reduces capacitive currents and energy losses while maintaining manageable system complexity.
3Power
If high power of 100 kW is transmitted through long cables, then power delivery to gantry is achieved, but cable heating requires additional cooling
Solution Approach 1:
The patent changes the electrical parameters by using balanced voltages on inner conductors that sum to zero, which reduces the electromagnetic field strength and associated heating effects. The interconnection of outer conductors along their length provides a low-impedance return path that reduces current density and resistive heating, enabling high power transmission without excessive cable temperature rise.
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
This configuration significantly reduces energy losses and eliminates the need for additional cooling, enhancing the efficiency and design of computer tomographs by minimizing heat generation and power loss during high-power transmission.
Implementation Method 1
the secondary winding on the rotatable part of the gantry, which is magnetically coupled to the primary winding
Implementation Method 2
each of the inner conductors is supplied by the inverter with voltages, with a sum of the voltages supplied to the inner conductors being substantially equal to zero
Data Source
AI summary
An inductive rotary joint for computer tomographs includes an inverter and an inductive rotary coupler. A primary winding of the inductive rotary coupler is fed by the inverter via a line, with energy transmitted by the inductive rotary coupler being supplied to a load through a secondary winding. The line includes at least two coaxial lines, each coaxial line having an outer conductor or shield with the two outer conductors or shields being interconnected along a major part of their length, and an inner conductor, with the inner conductors being supplied by the inverter with voltages, the sum of which is substantially equal to zero.