Moving-Coil Brushless Motor With Inductive Power Transfer
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Industrial moving coil actuators face limitations in rotation due to cabled connections, which can lead to cable wear and failure, and conventional solutions like brush commutators introduce friction and reliability issues.
Innovation Solution
A brushless motor with a synchronous moving-coil rotary actuator integrated with a wireless power transfer system, utilizing a cylindrical transformer for inductive coupling across a small air gap between primary and secondary coils, eliminating the need for moving cables and brushes/slip rings.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If a moving cable connection is used to supply power to the moving coil actuator, then efficient energy transfer is achieved, but the actuator rotation is limited and cable wear occurs leading to failure
Solution Approach 1:
The patent extracts the cable connection from the system by implementing a wireless power transfer mechanism. The moving coil actuator is powered through electromagnetic induction from a stationary coil, eliminating the physical cable that causes wear and rotation limitations while maintaining efficient energy transfer.
Solution Approach 2:
The mechanical cable connection is replaced with an electromagnetic field-based power transfer system. The stationary coil generates a time-varying magnetic field that induces current in the moving coil, substituting the mechanical power transmission with an electromagnetic one that allows full rotation without wear.
2Ease of operation
If a brush commutator is used to enable rotation, then the actuator can rotate freely, but friction and reliability issues are introduced
Solution Approach 1:
The brush commutator's mechanical contact-based rotation is replaced with a wireless electromagnetic power transfer system. The moving coil acts as a secondary winding in a transformer, receiving power inductively from the stationary primary coil, thereby eliminating brushes and commutators entirely while maintaining rotation freedom without friction.
Solution Approach 2:
The patent introduces an electromagnetic field as an intermediary to transfer power across the air gap between the stationary coil and moving coil. This intermediary enables power transmission without direct mechanical contact, allowing free rotation while avoiding the friction and reliability problems of brush commutators.
3Ease of operation
If slip rings are used for commutation, then rotation is enabled, but friction and reliability issues occur
Solution Approach 1:
The slip rings' mechanical sliding contact system is replaced with wireless electromagnetic induction. The moving coil serves as the secondary winding that receives power through magnetic coupling from the stationary primary coil, eliminating the need for slip rings and their associated friction and reliability problems.
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
The solution enables efficient power transfer without mechanical connections, reducing inertia, minimizing friction, and enhancing reliability by decoupling the actuator from the wireless power transfer system, thus overcoming the limitations of traditional cabled and commutated systems.
Implementation Method 1
The wireless power transfer system employs a cylindrical transformer in order to transfer, through inductive coupling, power across a small air gap between primary and secondary transformer coils.
Implementation Method 2
The actuator includes a stator comprised of inner and outer cylindrical arrays of permanent magnets between which is positioned a cylindrical rotor coil assembly
Implementation Method 3
The permanent magnets of the stator are preferably arranged in a quasi-Halbach configuration in which circumferentially magnetized permanent magnets are added in between radially magnetized permanent magnets.
Data Source
AI summary
A moving coil brushless motor including an actuator having a stator and a rotor. The stator includes a cylindrical array of permanent magnets. The rotor includes a coil assembly having a plurality of coils interposed between a stator back plate and the permanent magnet array. The coil assembly rotates relative to the array of permanent magnets. A center shaft is disposed to rotate about a longitudinal axis. A cylindrical transformer is disposed within an interior space circumscribed by the stator back plate and includes a primary side and a secondary side. The primary side includes a primary coil and the secondary side includes a secondary coil magnetically coupled to the primary coil. Primary electronics are in communication with secondary electronics attached to the center shaft. The secondary electronics are configured to receive power from the secondary coil and to provide current to the actuator.