Backpack Blower Electric Motor Impeller Weight Reduction
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Solution Overview
Problem
Backpack leaf blowers face a trade-off between maximizing blowing capacity and minimizing weight and bulkiness due to the use of internal combustion engines, which are heavy.
Innovation Solution
A backpack blower design featuring a housing with a mixed flow fan assembly and an impeller driven by a motor, where the impeller has dual airflow paths and a coupler with ribs to connect the drive shaft, allowing for efficient air flow generation and distribution while reducing the device's size and weight.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If an internal combustion engine is used to provide maximum blowing capacity, then the blowing capacity is improved, but the weight and bulkiness of the device increase
Solution Approach 1:
The patent replaces the internal combustion engine with an electric motor to generate the required air flow. This substitution eliminates the heavy combustion engine while maintaining the blower's capacity through the use of an electric motor driven impeller system, directly resolving the contradiction between blowing capacity and weight.
Solution Approach 2:
The patent changes the power source parameter from thermal (internal combustion engine) to electrical (motor), which fundamentally alters the weight-to-power ratio. This parameter change enables the system to achieve high blowing capacity without the weight penalty of combustion engines.
2Productivity
If an internal combustion engine is used to provide maximum blowing capacity, then the blowing capacity is improved, but the bulkiness of the device increases
Solution Approach 1:
The replacement of the internal combustion engine with an electric motor system reduces the overall device volume. Electric motors are generally more compact than combustion engines for equivalent power output, and the elimination of associated components (exhaust system, fuel storage, etc.) further reduces bulkiness while maintaining blowing capacity.
3Ease of operation
If the device size and weight are reduced, then user comfort is improved, but the blowing capacity may be compromised
Solution Approach 1:
The patent changes the power delivery parameters by using an electric motor that can provide high torque at low speeds, enabling compact impeller design. This parameter change allows the system to maintain high blowing capacity in a reduced-size package, improving user comfort without sacrificing 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
The design enhances airflow efficiency and reduces the blower's size and weight, improving user comfort and performance by positioning the center of mass closer to the user, thus reducing strain and increasing blowing capacity.
Implementation Method 1
an impeller supported in the chamber and driven by the motor to generate an air flow... the fans being operable to draw air in opposing directions and to direct air radially outwardly
Data Source
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AI summary
A blower comprising: a housing at least partially defining a chamber having a chamber inlet and a chamber outlet, the chamber having a non-circular cross-section proximate the chamber outlet; a tube assembly in fluid communication with the chamber, the tube assembly having a tube inlet coupled to the chamber outlet and a tube outlet, the tube assembly having a non-circular cross-section proximate the tube inlet; and an impeller operable to generate an air flow within the chamber and through the tube assembly.