Reciprocating Blade Apparatus Reduces Vibration via Eccentric Cam Guidance
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Solution Overview
Problem
Existing reciprocating blade apparatuses in handheld working machines experience vibrations and noise due to the arc motion of the crank arm, which disrupts the smooth reciprocation of the blades.
Innovation Solution
The joint members of the power train are guided to move along an axis parallel to the reciprocating blades' direction and through the rotation axis of the eccentric cams, allowing for smooth blade reciprocation and reducing vibrations and noise.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the crank arm is used to transmit power to the reciprocating blades, then the blades can be reciprocated, but vibrations and noise occur due to arc motion of the crank arm
Solution Approach 1:
The patent extracts the harmful arc motion component from the power transmission mechanism by replacing the crank arm with a slider-crank mechanism. The slider component separates the reciprocating motion function from the rotating motion, eliminating the arc motion that causes vibrations and noise while maintaining effective blade reciprocation.
Solution Approach 2:
The slider acts as an intermediary element between the rotating drive shaft and the reciprocating blades. It converts the rotational motion into linear reciprocating motion through a guided sliding action, serving as a mediator that eliminates the direct arc motion connection and its associated harmful vibrations and noise.
2Adaptability or versatility
If the top end of the crank arm moves in a direction intersecting the moving direction of the reciprocating blades, then the connecting part can accommodate the motion, but the blades cannot reciprocate smoothly
Solution Approach 1:
The patent introduces dynamic guidance through the slider mechanism, which allows the connecting part to adapt to the rotating motion dynamically while maintaining smooth linear reciprocation of the blades. The slider's guided motion provides the necessary adaptability without compromising reciprocation smoothness.
3Power
If the crank arm structure is used for power transmission, then the mechanism can convert rotational motion to reciprocating motion, but vibrations are applied to the blades
Solution Approach 1:
The patent substitutes the traditional crank arm mechanical system with a slider-crank mechanism. This mechanical substitution replaces the arc-based motion transmission with a guided linear sliding motion, maintaining power transmission effectiveness while eliminating the vibrations generated by the crank arm's rotating geometry.
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 solution enables the blades to reciprocate smoothly, significantly reducing vibrations and noise in the brush cutter, thereby improving operational efficiency and user comfort.
Implementation Method 1
a reciprocating member (30A, 30B) having a joint (30t) engaged with the blade member (2) and fitted with an eccentric cam (31), and a guide member (32A) engaged with the reciprocating member (30A, 30B)
Implementation Method 2
the guide member (32A) is spaced from a center (Op) of the rotation axis (31X) by a predetermined distance and guides the reciprocating member (30A, 30B) to be able to move along an axis line (Gp) which is parallel to the moving direction of the blade member (2) and runs through the center (Op) of the rotation axis (31X) of the eccentric cam (31)
Data Source
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AI summary
A reciprocating blade apparatus (1) includes a pair of reciprocating blades (2A, 2B) stacked on one another in a thickness direction, and a transmission case (3) including a power train configured to reciprocate the pair of reciprocating blades (2A, 2B). The power train includes a pair of eccentric cams (31), and a pair of reciprocating members (30A, 30B) including fitting holes (30m) in which the eccentric cams (31) are fitted, respectively. The pair of reciprocating members (30A, 30B) is guided to be able to move along an axis line (Gp) which is parallel to a moving direction of the pair of reciprocating blades (2A, 2B) and runs through a rotation axis (31X) of the eccentric cams (31).