Grinding Tool Eccentric Shaft Clutch Speed Control
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Solution Overview
Problem
Existing grinding tools with eccentric rotation mechanisms face issues of rotational speed instability and energy loss, leading to surface marks and safety hazards due to inefficient braking and complex mechanisms.
Innovation Solution
A grinding tool with a clutch system comprising sliding clutch members, one made of plastic and the other of metal, connected along a conical sliding surface to control the rotational speed of the grinding disc, preventing excessive speed increase when unloaded and maintaining speed during grinding, ensuring consistent and safe operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the grinding disc is freely rotatable when unloaded, then the rotational speed increases to match the drive shaft speed, but this causes impulsive grinding and surface marks when pressed against the workpiece
Solution Approach 1:
The patent introduces a friction engagement mechanism as an intermediary between the drive shaft and grinding disc. This friction-based coupling acts as a speed control mediator that prevents the grinding disc from reaching full drive shaft speed when unloaded, thereby avoiding impulsive grinding and surface marks while maintaining reliable operation during actual grinding
2Force
If the grinding disc is strongly pressed against the workpiece, then grinding force is sufficient, but the braking force stops the rotation and reduces grinding performance
Solution Approach 1:
The patent employs a dynamic friction engagement mechanism that automatically adjusts its braking characteristics based on operating conditions. During normal grinding operations, the friction coupling maintains appropriate rotational speed without excessive braking, thereby preserving grinding performance while still preventing speed runaway when unloaded
3Speed
If friction braking is used to control rotational speed, then speed increase is prevented, but energy loss increases due to braking before energy transmission to workpiece
Solution Approach 1:
The friction engagement mechanism serves dual functions: it acts as both a speed control device and a driving force transmission mechanism. The same friction interface that limits speed when unloaded also transmits driving force during grinding operations, eliminating the need for separate braking and driving systems and thereby reducing overall energy loss
4Speed
If the direction of rotation changes instantaneously during grinding, then braking control is achieved, but large shock occurs affecting workpiece surface and operator safety
Solution Approach 1:
The friction engagement mechanism provides gradual speed control and damping before potential shock conditions arise. By continuously managing the rotational speed through friction coupling, the system cushions against sudden direction changes and shock impulses, protecting both the workpiece surface and operator safety
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 provides stable rotational speed control, preventing surface marks and ensuring efficient grinding with complex rotational motion, reducing energy loss and operational safety by maintaining consistent rotation direction.
Implementation Method 1
a clutch including a grinding-disc-side clutch member and a rotary-disc-side clutch member that are connected to each other along a sliding surface that is capable of sliding and capable of transmitting a driving force
Data Source
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AI summary
[Problem] To provide a grinding tool with the eccentric rotation shaft of the grinding disc rotatably installed at a position that is shifted from the center line of the drive shaft of the drive motor, wherein: the rotation rate of the grinding disc is limited to a stable range of rotation rates, preventing extreme elevation in the rotation rate even when not grinding and no load is applied and preventing extreme reduction in the rotation rate even when load is applied during grinding; the workpiece is ground efficiently; and the tool does not generate marks or patterns on the ground surface. [Solution] This grinding tool with the eccentric rotation shaft of the grinding disc with attached grinding material installed via a bearing at a position that is shifted from the central drive shaft line of a rotating disc fixed on a drive shaft that is connected to a motor, is characterized in comprising a clutch in which a grinding disc-side clutch component member installed on the grinding disc or on the eccentric rotation shaft that is fixed to the grinding disc and a rotating disc-side clutch component member installed on the rotating disc are linked via a sliding surface capable of sliding and of transmitting the drive force.