PCB Variable Reluctance Resolver With Surface-Mounted Inductors
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Solution Overview
Problem
Conventional resolvers face early failure of windings due to hand-soldering stress and manufacturing handling processes, leading to unreliable angular position sensing.
Innovation Solution
A variable reluctance resolver design featuring a stator assembly with a printed circuit board and automated connection of inductors, combined with a rotor having an annular recess that varies in width with angular position, eliminating hand-soldering and enabling reliable electrical connections and reduced flux leakage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If hand-soldering is used to connect windings to lead wires, then electrical connections can be made, but the windings are stressed to the point of near failure leading to early failure
Solution Approach 1:
The patent replaces the manual mechanical hand-soldering process with an automated pick-and-place machine that uses precision mechanical placement and reflow soldering. This substitution eliminates the mechanical stress and human error associated with hand-soldering, achieving reliable electrical connections without compromising winding integrity.
Solution Approach 2:
The patent changes the soldering process parameters from manual control to automated temperature-controlled reflow soldering. The reflow soldering process uses controlled temperature profiles to melt and re-solidify the solder, creating strong electrical connections without the mechanical stress of hand-soldering, thereby improving reliability while preserving winding strength.
2Ease of manufacture
If windings are installed into slots through manufacturing and handling processes, then the resolver can be assembled, but the windings are stressed or damaged resulting in early failure
Solution Approach 1:
Instead of installing windings into slots through complex handling processes, the patent inverts the approach by using surface-mounted inductors that are placed on the stator assembly after the basic structure is formed. This inversion simplifies the manufacturing process and eliminates the stressful handling of delicate windings, achieving both ease of manufacture and high reliability.
Solution Approach 2:
The patent replaces manual winding installation processes with automated surface-mount technology. The pick-and-place machine automatically positions and attaches inductors to the stator, eliminating the need for manual handling and installation of windings into slots, thereby preventing stress and damage while maintaining manufacturing capability.
3Measurement precision
If conventional electromagnetic coils are used in stator and rotor, then angular position can be sensed, but the complexity of hand-soldering and manufacturing processes increases device complexity
Solution Approach 1:
The patent uses a printed circuit board that serves multiple functions: it provides the structural base for the stator assembly, the electrical connection network for the inductors, and the mounting platform for surface-mounted components. This multi-functionality consolidates what would otherwise be separate complex processes into a single integrated manufacturing flow, reducing device complexity while maintaining sensing precision.
Solution Approach 2:
The patent replaces complex manual winding and soldering processes with automated surface-mount technology. The pick-and-place machine and reflow soldering process provide precise, repeatable electrical connections without the complexity of manual operations, thereby maintaining measurement precision while significantly reducing manufacturing process complexity.
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 enhances the reliability and accuracy of angular position sensing by reducing stress on windings, minimizing early failures, and allowing for single-cycle electrical output per mechanical rotation, while being adaptable to different system sizes.
Implementation Method 1
A plurality of inductors (204) are coupled with an annular printed circuit board (206) first surface, wherein the plurality of inductors (204) are in electrical connection with a power source
Implementation Method 2
Angular position sensors are based on the principle of a variable magnetic flux intensity in the air gap between a stator and a rotor
Implementation Method 3
An annular recess (234) is located in the rotor first surface, the annular recess (234) defining a width (w1, w2) variable with an angular position
Data Source
AI summary
A variable reluctance resolver with a stator assembly including a printed circuit board having a first surface and a second surface. A plurality of inductors coupled with the annular printed circuit board first surface, wherein the plurality of inductors are in electrical connection with a power source. The variable reluctance resolver also having a rotor including a body with a first surface and a second surface, an annular recess located in the rotor first surface. The annular recess including a radially inner surface and a radially outer surface, wherein the annular recess defines a width variable with angular position. The plurality of inductors are located at least partially within the annular recess and the rotor is operable to rotate relative to the stator assembly.