Compact Encoder Design via Magnet Overlap and Segmentation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional battery-less encoders require significant space due to the arrangement of counter-shaft gears, magnets, and bearings along the motor rotating shaft, making it difficult to reduce the encoder's size.
Innovation Solution
The encoder design includes a base section with a spindle gear, counter-shaft gear, magnet, and annular bearing member, where the magnet is positioned to overlap the bearing member or gear section, allowing for a compact configuration that reduces the overall size by separating the magnetism detection substrate and counter-shaft gear with a wall section.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If counter-shaft gears, magnets, and bearings are disposed side by side along the motor rotating shaft, then the encoder can function properly, but the encoder size increases
Solution Approach 1:
The patent transitions from a linear arrangement (side by side along the shaft) to a two-dimensional arrangement (overlap in plan view). The magnet is positioned to overlap the bearing member or gear section when viewed from the radial direction, effectively utilizing the radial dimension to reduce axial length. This dimensional change allows components to share space rather than occupy sequential positions along the shaft axis.
2Length of stationary object
If the magnet is positioned to overlap the bearing member or gear section in plan view, then the encoder size is reduced, but assembly accuracy may be affected
Solution Approach 1:
The patent introduces a wall section that divides the encoder into distinct regions: a first region containing the magnetism detection substrate and a second region containing the counter-shaft gear. This segmentation physically separates components that would otherwise interfere with each other, ensuring that the magnet's position for size reduction does not compromise the detection accuracy. The wall acts as a spatial separator that maintains functional independence between detection and transmission components.
Solution Approach 2:
The wall section serves as an intermediary element between the magnetism detection substrate and the counter-shaft gear. It provides both physical separation and magnetic shielding, preventing magnetic field interference from the magnet (attached to the counter-shaft gear) from reaching the magnetism detection substrate. This intermediary structure enables the magnet to be positioned closer to the shaft center for compactness while protecting the detection system from magnetic interference.
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 enables the encoder to maintain accurate detection of rotating speed and position while reducing the encoder's size, improving assembly accuracy and design flexibility in applications like robots and motors.
Implementation Method 1
a magnet provided in the counter-shaft gear; and an annular bearing member provided in the base section and configured to support the counter-shaft gear
Implementation Method 2
an annular bearing member provided in the base section and configured to support the counter-shaft gear
Data Source
AI summary
An encoder includes a base section, a spindle gear attached to a turning shaft section, a counter-shaft gear configured to mesh with the spindle gear and including a cylindrical gear section, a magnet provided in the counter-shaft gear, and an annular bearing member provided in the base section and configured to support the counter-shaft gear. When a straight line extending along the shaft section is represented as a first axis and a straight line orthogonal to the first axis is represented as a second axis, the magnet is disposed to overlap the bearing member in a plan view from a direction in which the second axis extends.