Brushless DC Motor Cooling Airflow Arrangement
Solution Overview
Problem
Existing impact tools face challenges in effectively dissipating heat generated by the brushless DC motor, current providing device, and controller, which affects their performance and longevity.
Innovation Solution
The impact tool design includes a brushless DC motor, a current providing device, and a controller arranged adjacently to each other, with a cooling fan to dissipate heat effectively, and the current providing device and controller are positioned upstream of the motor in the cooling air flow to maximize heat dissipation, utilizing a radiation member with a heat radiating surface aligned with the cooling air flow.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If the brushless DC motor, current providing device and controller are arranged adjacently to each other, then the heat dissipation efficiency is improved, but the device complexity increases
Solution Approach 1:
The brushless DC motor, current providing device, and controller are merged into a single housing structure, arranged adjacently to share the cooling air flow path. This integration allows all heat-generating components to be cooled by the same cooling system, improving heat dissipation efficiency while reducing the number of separate cooling systems needed.
Solution Approach 2:
The housing serves multiple functions: it contains the brushless DC motor, current providing device, and controller, while also acting as a thermal management system. The housing incorporates cooling air inlets and outlets that provide unified cooling for all components, making the housing a multi-functional element that combines structural support with thermal management.
2Temperature
If the current providing device and controller are arranged upstream of the motor in the cooling air flow, then the heat dissipation efficiency is improved, but the wiring length increases
Solution Approach 1:
The current providing device and controller are positioned in the upstream region of the cooling air flow, where the cooling air is freshest and has the highest heat absorption capacity. This local optimization ensures that the components generating the most heat (current providing device and controller) receive the most effective cooling, improving overall heat dissipation efficiency despite the increased wiring length.
3Device complexity
If the cooling fan is attached to the rotational shaft of the brushless DC motor, then the device complexity is reduced, but the heat dissipation efficiency may be compromised
Solution Approach 1:
The cooling fan is combined with the brushless DC motor by attaching it to the motor's rotational shaft. This integration eliminates the need for a separate cooling fan motor and drive mechanism, reducing device complexity. The cooling fan utilizes the existing rotational motion of the motor shaft, converting it into cooling air flow that passes through the housing and cools all components.
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 enhances heat dissipation, prolongs the tool's lifespan, and allows for a more compact design by effectively cooling the components that generate significant heat, particularly the current providing device and controller.
Implementation Method 1
a cooling fan which generates a cooling air flow
Implementation Method 2
the brushless DC motor, the current providing device and the controller are arranged adjacently to each other and cooled by a cooling air generated by the cooling fan
Data Source
Figure 1
Figure 2
Figure 3
AI summary
An impact comprising: a motor (20) defined as a brushless DC motor; a battery (130); a cooling fan (90); a driving current providing device (70) which provides current from the battery (130) to the motor (20); and a controller (60) which controls the driving current providing device (70). The motor (20), the controller (60) and the driving current providing device (70) are arranged adjacently to each other and are cooled by the cooling air generated by the cooling fan (90).