Wobble Drive Phase Alignment for Vibration Reduction
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Solution Overview
Problem
Hand-held power tools like rotary hammers experience oscillations and vibrations due to inertial forces, leading to increased wear and noise, which existing balancing measures fail to fully mitigate.
Innovation Solution
A wobble drive mechanism with adjustable wobble fingers whose axes enclose an angle between 10° and 170° or 190° to 350°, allowing for optimal phase alignment between the piston and balancing unit motions, reducing oscillations through a second wobble finger that converts rotary motion into translatory or rotary motion of a balancing unit.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If a wobble drive with wobble fingers is used to convert rotary motion into oscillating translatory motion, then the driving function is achieved, but oscillations and vibrations occur due to inertial forces
Solution Approach 1:
The patent introduces a balancing mass mounted on the wobble plate that rotates with it. This balancing mass is positioned to counteract the inertial forces generated by the wobble fingers during operation, thereby reducing the oscillations and vibrations that would otherwise be produced by the conversion of rotary motion to oscillating translatory motion
2Object-generated harmful factors
If mass balancing measures are taken to eliminate oscillation phenomena, then vibrations are reduced, but device complexity increases
Solution Approach 1:
The balancing mass is integrated directly into the wobble plate structure, merging the balancing function with the existing rotating component. This eliminates the need for separate balancing mechanisms and reduces overall device complexity while still achieving vibration reduction
Solution Approach 2:
The wobble plate itself serves dual purposes: it converts rotary motion to oscillating motion through the wobble fingers, and it provides balancing functionality through the integrated balancing mass. The structure serves itself by incorporating the balancing function within the existing moving component
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 significantly reduces oscillations and vibrations, enhancing the smooth operation and longevity of hand-held power tools by allowing for precise adjustment and optimal force balancing.
Implementation Method 1
a wobble bearing situated on the drive shaft and having a wobble plate mounted on the wobble bearing... converts a rotary motion of a drive element into an oscillating, translatory motion of a driven element
Implementation Method 2
at least one wobble finger to set at least one other element into a linear translatory motion
Implementation Method 3
a second wobble finger is provided for this purpose on the wobble plate and converts the rotary motion of the drive shaft into a translatory motion of a balancing mass
Data Source
AI summary
The invention relates to a wobble drive of a hand-held machine tool, particularly a drilling or chipping hammer, having a drive shaft, a wobble bearing disposed on the drive shaft, and a wobble plate supported on the wobble bearing. At least two wobble fingers having wobble finger axes being provided on the wobble plate. The invention provides that the axes of the wobble fingers form an angle different from 180°.