Double Fan Design for Compact Electric Grinder Cooling
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Electric hand-held grinders with pot-shaped bearing housings face challenges in achieving a low overall height due to increased space requirements for motor cooling and dust extraction, leading to difficulties in using the tools in complex machining situations.
Innovation Solution
A double fan design with fan blades on both axial sides of a parting surface separates the bearing housing into two fan chambers, with one set of blades for dust extraction and the other for motor cooling, and at least one opening for discharging cooling air in the bearing housing, allowing direct attachment without air gaps, reducing overall height.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If a cup-shaped bearing housing is used with separate cooling air discharge at the boundary between motor housing and bearing housing, then motor cooling is achieved, but machine height increases
Solution Approach 1:
The patent combines the dust extraction fan and motor cooling functions into a single integrated fan unit located within the cup-shaped bearing housing. The fan simultaneously performs both dust extraction and motor cooling, eliminating the need for separate cooling air discharge paths and reducing machine height.
Solution Approach 2:
The patent utilizes the radial space within the cup-shaped bearing housing to accommodate the dual-function fan, rather than extending the machine height axially. The fan is positioned to draw air from the motor housing through the bearing housing, utilizing the existing three-dimensional space efficiently.
2Adaptability or versatility
If a double fan design with separate fan chambers is implemented, then both dust extraction and motor cooling are achieved in one housing, but manufacturing complexity increases
Solution Approach 1:
The bearing housing is segmented into two functional chambers by a partition wall: a first fan chamber for dust extraction and a second fan chamber for motor cooling. This segmentation allows each chamber to be optimized for its specific function while maintaining a unified cup-shaped structure that is manufacturable.
Solution Approach 2:
The cup-shaped bearing housing serves multiple functions: it houses the dual-function fan, provides structural support, enables both dust extraction and motor cooling, and eliminates the need for separate cooling housings. This multi-functionality reduces overall device complexity despite the internal partitioning.
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
The double fan design significantly reduces the overall height of the electric hand grinder, enabling efficient motor cooling and dust extraction or separation with reduced space requirements, facilitating use in challenging machining situations.
Implementation Method 1
a fan (24) is provided in the bearing housing (14), which has an axial airflow direction in operation, in order to cool the motor (18) and/or to separate or extract dust
Data Source
Figure 1
Figure 2
AI summary
The machine has a pot shaped bearing housing (14) connected with a machine housing (12). A fan (24) is mounted in the machine housing for dust extraction or separation. The fan is designed as a double fan and includes fan blades (26) on both sides of a separation surface, where a set of fan blades serves for dust extraction, while another set of fan blades serves for motor cooling. The separation surface divides the bearing housing into two fan chambers (32, 34), and an opening (40) is provided in the bearing housing for exhausting of cooling air.