Stepper Motor Magnet Pin Insertion With Rotary Cartridge Feed
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing methods for inserting magnet pins into rotor or stator slots in stepper motors face challenges such as high cycle times, magnet pin fracture, and positioning errors due to tolerance stack-up, leading to inefficiencies and increased downtime.
Innovation Solution
A magnetic pin insertion system using a rotary drive and precision machined cartridge with guide chutes and adjustable tongues, allowing radial insertion of magnet pins into slots, facilitated by gravity or a pre-loaded spring, and ensuring precise alignment and separation of pins during rotation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If traditional linear motion push rod method is used to insert magnet pins, then insertion can be achieved, but cycle time is excessive (several seconds per pin) and productivity is low
Solution Approach 1:
The system divides the insertion process into multiple parallel operations by providing multiple cartridges (e.g., 4 cartridges) that can simultaneously insert magnet pins into different slots of the workpiece. This segmentation of the insertion function across multiple independent units enables parallel processing, dramatically reducing the total cycle time compared to sequential single-pin insertion.
Solution Approach 2:
The rotary drive mechanism enables continuous rotation of the workpiece through the insertion zone, allowing magnet pins to be inserted continuously as slots pass by, rather than requiring repeated positioning and indexing operations. The gravity feed system maintains continuous supply of magnet pins to the insertion point, eliminating idle time between insertions.
2Manufacturing precision
If precision location and control in X and Y directions is implemented using rotary and elevation axes, then positioning accuracy can be achieved, but device complexity increases
Solution Approach 1:
The system replaces complex two-dimensional positioning (X and Y axes with rotary and elevation mechanisms) with a simpler one-dimensional rotational approach. The workpiece rotates on a single axis while cartridges remain stationary in the radial direction, eliminating the need for complex rotary positioning tables and elevation adjustment mechanisms while maintaining precise slot alignment through rotational indexing.
Solution Approach 2:
The workpiece itself provides the positioning reference through its rotational symmetry and fixed slot geometry. As the workpiece rotates, slots automatically present themselves at the correct angular positions relative to the stationary cartridges, eliminating the need for external positioning fixtures and complex coordinate control systems.
3Productivity
If sliding action insertion method is used, then magnet pins can be inserted, but magnet pin fracture occurs due to positioning errors and twisting
Solution Approach 1:
The cartridge design provides precise radial positioning of magnet pins at the exact height where slots are located on the rotating workpiece. This eliminates positioning errors in the radial direction that cause twisting and fracture. The gravity feed mechanism ensures pins are delivered smoothly without impact or misalignment, maintaining consistent positioning potential throughout the insertion process.
Solution Approach 2:
The system replaces the mechanical push rod sliding action with a gravity-driven feed mechanism. Magnet pins are delivered vertically downward into slots under gravity, eliminating the lateral sliding motion that causes twisting. The insertion force is applied purely in the axial direction through gravity, preventing rotational stress and fracture on the magnet pins.
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 system achieves a 1700% improvement in cycle time and nearly 100% reduction in magnet pin fracture, enabling efficient and accurate insertion of all pins in the correct orientation without twisting or breaking, thus enhancing motor assembly efficiency.
Implementation Method 1
allows mainly gravity, or alternatively a preloaded push spring, to feed magnetic pins into the slots
Implementation Method 2
allows mainly gravity, or alternatively a preloaded push spring, to feed magnetic pins into the slots
Data Source
AI summary
A magnetic pin insertion system comprises a rotary drive of a workpiece (rotor or stator) that a set of axially oriented slots around a circumferential surface that are receptive of magnetic pins. A cartridge holds an axially oriented stack of magnetic pins in guide chutes for each axial section of the workpiece. A pre-loaded feed mechanism (a weight or push spring) pushes the pins into successive slots of the workpiece as the rotary drive rotates the workpiece. Each cartridge chute terminates in an adjustable tongue, with a specified gap from the workpiece, that provides a resistive surface for shearing each pin away from other pins in the stack as they are pushed into their successive slots.