Compact Gear-Shifting Device for Handheld Power Tools
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Solution Overview
Problem
Conventional hand-held power tools with gear-shifting devices require a large amount of space due to their complex structure, making them bulky and difficult to implement efficiently.
Innovation Solution
A compact gear-shifting device with a switching element that axially displaces to change gears, utilizing a loading element that rotates in the circumferential direction of the gearbox housing, allowing for simple and reliable gear changes with a minimal space requirement, featuring a guide element and guide groove for precise displacement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If a conventional gear-shifting device is used, then gear shifting function is achieved, but the device requires a large amount of space and has complex structure
Solution Approach 1:
The patent merges the shifting element and urging element into a integrated gear-shifting device that operates within the existing gear housing space. The shifting element combines axial movement for gear engagement while the urging element provides rotational forcing action, creating a compact unified mechanism that eliminates the need for separate complex shifting mechanisms.
Solution Approach 2:
Instead of using a traditional mechanism where gears are shifted by radial or axial movement of entire gear assemblies, this invention inverts the approach by using an axially movable shifting element that engages gear teeth directly, combined with a rotatably mounted urging element that provides the forcing action. This inverted mechanism achieves gear shifting in a compact configuration.
2Volume of moving object
If a compact gear-shifting device is used, then space requirement is reduced, but gear shifting reliability may be compromised
Solution Approach 1:
The urging element is pre-loaded to provide continuous forcing action on the shifting element throughout the gear-shifting process. This pre-loaded urging mechanism ensures that the shifting element maintains reliable engagement with gear teeth during axial movement, preventing missed shifts or incomplete engagement even in the compact configuration.
Solution Approach 2:
The shifting element acts as an intermediary component that translates the rotational motion of the urging element into axial movement for gear engagement. This intermediary mechanism ensures reliable gear shifting by providing a controlled, progressive engagement process that maintains force application throughout the shifting sequence.
Data Source
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AI summary
The invention relates to a handheld power tool comprising a housing, in which housing a drive motor (120) and a transmission (130) for driving an output shaft (210) are arranged, which transmission can be driven by the drive motor (120), wherein the transmission (130) is arranged in a transmission housing (132), and wherein a gear-shifting device (135) is provided for shifting the gears of the transmission (130), which gear-shifting device (135) has a shifting element (240) for shifting gears, which shifting element is in particular mounted so as to be movable substantially axially to the transmission housing (132), and which gear-shifting device has an impingement element (230) which is in particular mounted so as to be rotatable in the circumferential direction of the transmission housing (132), the gears being shifted by rotating the impingement element (230) in the circumferential direction of the transmission housing (132).