Friction Ring for Random Orbital Sander Braking
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Solution Overview
Problem
Conventional random orbital sanding tools face issues with the sanding pad continuing to rotate after the power motor stops, requiring an effective braking mechanism that is durable and does not compromise sanding efficiency or quality, as existing solutions like elastic rubber rings wear out quickly and affect motor load and speed.
Innovation Solution
A friction ring is integrated into the tool holder, contacting the eccentric block to apply a friction force that quickly stops the sanding pad's rotation, featuring a base part, sleeve part, and friction part designed for constant contact and easy replacement, with a simple structure and low cost.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of time
If an elastic rubber ring is used as a brake mechanism, then the sanding pad can be stopped quickly after motor shutdown, but the rubber ring wears out quickly and increases motor load
Solution Approach 1:
The friction ring is designed as a simple, inexpensive, replaceable component that can be easily replaced when worn. This allows the use of a simple friction-based braking mechanism without the reliability concerns of permanent brake systems, as the ring can be quickly swapped out when wear occurs.
Solution Approach 2:
The friction ring is extracted as a separate, independent component from the motor and sanding pad assembly. It is disposed on the tool holder and contacts the eccentric block, separating the braking function from the main sanding mechanism, allowing independent replacement and maintenance.
2Loss of time
If a brake mechanism is added to stop the sanding pad, then the stop time is reduced, but the structure becomes more complex
Solution Approach 1:
The friction ring utilizes the rotational motion of the eccentric block itself to create the braking effect. The ring is disposed on the tool holder and contacts the rotating eccentric block, using the block's own motion to generate friction without requiring additional moving parts or complex actuation mechanisms.
Solution Approach 2:
The friction ring is designed as a thin, flexible component that can be easily mounted on the tool holder and maintains contact with the eccentric block through its own elasticity and the pressure from the sanding pad assembly, avoiding the need for rigid brake components.
3Reliability
If the friction ring constantly contacts the eccentric block, then braking effectiveness is maintained, but friction wear occurs
Solution Approach 1:
The friction ring is designed as a simple, inexpensive, replaceable component that can be easily replaced when worn. This allows the use of a simple friction-based braking mechanism without the reliability concerns of permanent brake systems, as the ring can be quickly swapped out when wear occurs.
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 friction ring effectively and quickly stops the sanding pad's rotation, is easy to replace, and maintains sanding efficiency by minimizing wear and power loss, ensuring reliable braking without compromising motor speed or tool performance.
Implementation Method 1
the friction ring stops a rotation of the tool holder and the sanding pad by a friction force exerting on the surface of the eccentric block
Data Source
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AI summary
A random orbital sanding tool (30) includes a power motor (31), a driving spindle (32) connected to the power motor (31), an eccentric block (33) connected to the driving spindle (32), a tool holder (34) disposed on the eccentric block (33), and a sanding pad (35) connected to the tool holder (34) and indirectly driven by the power motor (31). The random orbital sanding tool (30) includes a friction ring (37) disposed on the tool holder (34), the friction ring (37) contacts a surface of the eccentric block (33) facing the sanding pad (35), the friction ring (37) stops rotation of the tool holder (34) and the sanding pad (35) by a friction force exerting on the surface of the eccentric block (33) when the power motor (31) stops operation, the friction ring (37) includes a base part (371) protruding into a gap between the tool holder (34) and the eccentric block (33), a sleeve part (372) diverged and extended from the base part (371).