Distributed Transmission Mounting for Portable Power Tool Accuracy
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing portable power tools, such as rotary hammers, face challenges in maintaining high running accuracy and reducing vibration due to tolerance summation in transmission element mounting, leading to play and decreased performance.
Innovation Solution
The transmission elements are mounted in a distributed manner between the inner and machine housings, with axial and radial support provided by the inner and machine housings respectively, allowing for uncoupling of the inner housing from the machine housing's bearing function, thereby reducing tolerance-related play and enhancing running accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If transmission elements are mounted in the inner housing by bearing elements, then the transmission elements are supported axially and radially, but tolerance summation occurs leading to play and reduced running accuracy
Solution Approach 1:
The patent divides the bearing function into two separate segments: the inner housing provides axial support while the machine housing provides radial support. This segmentation prevents tolerance summation between axial and radial bearing elements, thereby reducing play and improving running accuracy of transmission elements.
Solution Approach 2:
The patent introduces an intermediate flange as a mediator component that connects the inner housing to the machine housing. This flange serves as an intermediary structure that enables the distributed mounting arrangement, allowing axial and radial support functions to be separated while maintaining structural integrity.
2Strength
If the inner housing is made thicker to provide radial support, then radial bearing capacity is improved, but material usage and costs increase
Solution Approach 1:
The patent extracts the radial support function from the inner housing and assigns it to the machine housing. This extraction allows the inner housing to be made thinner since it only needs to provide axial support, thereby reducing material usage and costs while maintaining adequate radial bearing capacity through the machine housing.
Data Source
AI summary
A hand-power tool, in particular a drill and/or chiseling hammer, includes a transmission, a machine housing, and an inner housing arranged within the machine housing. The inner housing is provided for at least partially receiving at least one transmission element of the transmission. The at least one transmission element is supported jointly by the inner housing and by the machine housing.