Integrated Brush Holder for Power Tool Commutator Positioning
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Solution Overview
Problem
Existing brush holders in power tools, such as grinders, accumulate tolerances and rattle, leading to inaccurate positioning of the brush with respect to the commutator, which affects the tool's performance.
Innovation Solution
A brush holder design that includes a single brush-holding metal plate with integrated screw holes or pin holes, and a spiral spring to ensure accurate positioning and contact with the commutator, reducing tolerance accumulation and rattling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If separate brush housing and base are used, then ease of manufacture is improved, but manufacturing precision deteriorates due to tolerance accumulation between parts
Solution Approach 1:
The patent merges the brush housing and base into a single integrated brush holder component. This eliminates the interface between separate parts, preventing tolerance accumulation and ensuring accurate brush positioning relative to the commutator while maintaining manufacturability through single-piece construction
2Device complexity
If separate brush housing and base are used, then device complexity is reduced, but reliability deteriorates due to rattling and positional inaccuracy
Solution Approach 1:
The integrated brush holder design eliminates the interface between separate components, preventing rattling and maintaining consistent brush-to-commutator positioning. This improves reliability while the simple monolithic structure actually reduces device complexity compared to multiple assembled parts
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 design improves the positional accuracy of the brush with respect to the commutator, enhancing the tool's performance and reliability by minimizing tolerance accumulation and rattling.
Implementation Method 1
an elastic member configured to urge the brush toward the commutator
Data Source
AI summary
A power tool includes a brush holder with a brush positioned more accurately with respect to a commutator. A grinder as a power tool includes a housing, a stator fixed to the housing, a rotor rotatable relative to the stator and including a commutator and a coil, a brush that comes in contact with the commutator, a brush-holding metal plate having a screw hole and holding the brush, and a screw extending through the screw hole and directly fastened to the housing.