Dual-Motor Power Tool System for Battery and AC Operation
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Solution Overview
Problem
Power tools face limitations in portability and runtime when relying on a single power source, with corded tools being non-portable and cordless tools having limited performance and runtime, and existing dual-voltage solutions do not efficiently switch between battery and AC power sources.
Innovation Solution
A power tool design featuring a dual-motor configuration with a DC motor and an AC motor, where the motors are coaxially arranged and connected via a coupling member such as a clutch or one-way bearing, allowing seamless switching between battery-powered and AC-powered operation, optimizing torque and battery life.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If a power tool uses a single battery power source, then portability is improved, but runtime and performance are limited
Solution Approach 1:
The power tool is designed with dual motor capability - a DC motor for battery operation and an AC motor for mains power operation. The tool can function in multiple modes (battery-only, AC-only, or combined), making it universally adaptable to different power sources and usage scenarios, thereby extending runtime without sacrificing portability.
Solution Approach 2:
The power system is segmented into two independent motor units - a DC motor unit for portable battery operation and an AC motor unit for stationary mains operation. This segmentation allows each motor to be optimized for its specific power source while enabling the tool to switch between modes based on runtime needs and portability requirements.
2Length of moving object
If a power tool uses a single battery power source, then portability is improved, but performance is reduced
Solution Approach 1:
The tool incorporates both DC and AC motors, allowing it to perform high-power tasks when connected to AC power while maintaining portable battery operation for lighter tasks. This multi-functionality ensures optimal performance across different operating conditions without compromising portability.
Solution Approach 2:
The system dynamically switches between DC motor and AC motor operation based on power availability and task requirements. The controller adjusts motor operation modes in real-time, enabling the tool to deliver high performance when AC power is available while maintaining portable operation when battery power is used.
3Force
If a power tool uses dual motors in series configuration, then torque is improved, but the tool cannot operate on battery power alone
Solution Approach 1:
The motor configuration is made dynamic through a switching mechanism that can connect the motors in series for high-torque AC operation or isolate the DC motor for independent battery operation. This dynamic reconfiguration allows the system to adapt between high-performance mode and portable operation mode as needed.
Solution Approach 2:
A switching mechanism or clutch system acts as an intermediary between the DC and AC motors, enabling flexible connection and disconnection arrangements. This intermediary component allows the motors to be connected in series for enhanced torque when AC power is available, while permitting the DC motor to operate independently on battery power when needed.
4Adaptability or versatility
If a power tool uses dual motors in parallel configuration, then battery operation is enabled, but torque is reduced
Solution Approach 1:
The system dynamically switches between parallel motor configuration for battery operation and series motor configuration for AC operation. The switching mechanism adjusts the motor connection topology in real-time based on the power source being used, optimizing torque output for each operating mode while maintaining battery operation capability.
5Adaptability or versatility
If a power tool switches between battery and AC power, then versatility is improved, but device complexity increases
Solution Approach 1:
A switching mechanism or clutch system acts as an intermediary between the DC and AC motors, enabling flexible connection and disconnection arrangements. This intermediary component allows the motors to be connected in series for enhanced torque when AC power is available, while permitting the DC motor to operate independently on battery power when needed.
Data Source
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AI summary
A power tool includes a housing and an output shaft supported by the housing for rotation about an axis. The power tool further includes a first motor disposed in the housing and a second motor disposed in the housing and coupled to the first motor. The first motor drives the output shaft and does not drive the second motor when in a first power mode, and the second motor drives the first motor and the output shaft when in a second power mode.