Hand-Held Power Tool Cooling Fan Axial Overlap Design
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing handheld power tools face challenges in achieving a compact design while ensuring effective cooling and efficient energy conversion for rotary percussion mechanisms.
Innovation Solution
The design incorporates a fan wheel that overlaps partially with the rotary percussion mechanism and gear unit in the axial direction, along with a housingless electric motor, to facilitate a compact form factor and enhanced cooling, utilizing a planetary gear system and integrated percussion mechanism cover for efficient energy transmission and cooling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If the fan wheel is arranged between the drive unit and the rotary impact mechanism, then cooling effectiveness is improved, but the overall length of the tool increases
Solution Approach 1:
The fan wheel is nested within the axial space of the rotary impact mechanism, with the fan wheel's diameter being smaller than the rotary impact mechanism's diameter. This allows the cooling function to be integrated within the existing structural envelope rather than adding linear length to the tool.
Solution Approach 2:
Instead of arranging the fan wheel in series along the axial direction (which would increase length), the invention positions it in a radial/planar arrangement where it overlaps axially with the rotary impact mechanism. This dimensional reorganization allows cooling airflow generation without proportionally increasing the tool's overall length.
2Temperature
If separate cooling and impact mechanisms are provided, then cooling effectiveness is improved, but device complexity increases
Solution Approach 1:
The fan wheel is integrated with the drive shaft, which is already a core component of the rotary impact mechanism. This merging eliminates the need for a completely separate cooling mechanism while still providing effective cooling through the fan wheel's rotation driven by the same motor that powers the impact mechanism.
Solution Approach 2:
The drive shaft serves dual functions: transmitting rotational power to the rotary impact mechanism and simultaneously driving the fan wheel for cooling purposes. This multi-functionality reduces the number of separate components needed while maintaining effective cooling performance.
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 results in a compact handheld power tool with improved cooling and energy efficiency, achieving a short overall length and effective thermal management.
Implementation Method 1
a unit that includes at least one component designed to generate a cooling airflow, especially by creating a negative pressure through which air is drawn in for cooling
Implementation Method 2
a housingless electric motor, which is designed to convert electrical energy into rotational energy
Implementation Method 3
The rotary impact mechanism comprises at least one gear unit, wherein the fan wheel and the gear unit overlap at least partially in the axial direction
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The invention relates to a hand-held power tool device having: a drive unit (12a; 12b; 12c) that has a drive shaft (14a; 14b; 14c); at least one rotary impact mechanism (16a; 16b; 16c); and at least one cooling air unit (36a; 36b; 36c) which has at least one fan wheel (38a; 38b; 38c) situated between the drive unit (12a; 12b; 12c) and the rotary impact mechanism (16a; 16b; 16c). According to the invention, the fan wheel (38a; 38b; 38c) and the rotary impact mechanism (16a; 16b; 16c) at least partially overlap in an axial direction (40a; 40b; 40c).