Compound Planetary Transmission for Wide-Range Power Tool Torque
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Solution Overview
Problem
Existing power tools lack a transmission arrangement that can produce a wide range of output speeds and torques, limiting their versatility for tasks such as drilling large diameter holes, installing drywall screws, and high-speed drilling operations, often requiring consumers to purchase separate tools for standard and heavy-duty applications.
Innovation Solution
A multi-speed compound planetary transmission system with a gearset portion that includes an input sun gear, compound planet gears, and ring gears, allowing for selective operation in different gear reduction ratios to provide a wide range of speed and torque outputs, optimized for use with modern high-capacity batteries.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a single-speed or dual-speed transmission is used, then the device complexity is reduced, but the adaptability is insufficient to perform diverse operations across a wide range of speeds and torques
Solution Approach 1:
The patent employs a compound planetary gear system where multiple planet gears with different pitch diameters are nested on the same planet carrier, allowing one transmission mechanism to provide multiple gear reduction ratios. This nested configuration enables diverse speed and torque outputs without requiring separate transmission systems for different operations.
Solution Approach 2:
The transmission system dynamically shifts between different gear reduction ratios by selectively engaging various planet gears with the ring gear through a hub assembly. This dynamic switching capability allows the transmission to adapt its characteristics based on operational requirements, providing both high-speed and high-torque modes from a single mechanism.
2Force
If the transmission is configured for high torque operations, then the torque output is improved, but the high speed performance is impaired
Solution Approach 1:
The transmission system dynamically shifts between different gear reduction ratios by selectively engaging various planet gears with the ring gear through a hub assembly. This dynamic switching capability allows the transmission to adapt its characteristics based on operational requirements, providing both high-speed and high-torque modes from a single mechanism.
Solution Approach 2:
The system changes its operational parameters by selecting different planet gears with different pitch diameters to mesh with the ring gear. This parameter change allows the same transmission mechanism to provide different gear reduction ratios, enabling it to deliver either high speed or high torque depending on which planet gear is engaged.
3Adaptability or versatility
If multiple separate tools are purchased for standard and heavy-duty applications, then the adaptability is improved, but the loss of substance increases due to purchasing and maintaining multiple tools
Solution Approach 1:
The patent creates a universal power tool with a multi-ratio planetary transmission that can perform both standard and heavy-duty operations. By providing a wide range of output speeds and torques through a single transmission system, the tool becomes multi-functional, eliminating the need for consumers to purchase separate tools for different applications.
Solution Approach 2:
The patent employs a compound planetary gear system where multiple planet gears with different pitch diameters are nested on the same planet carrier, allowing one transmission mechanism to provide multiple gear reduction ratios. This nested configuration enables diverse speed and torque outputs without requiring separate transmission systems for different operations.
4Adaptability or versatility
If a wide range of gear reduction ratios is provided, then the adaptability is improved, but the device complexity increases
Solution Approach 1:
The patent employs a compound planetary gear system where multiple planet gears with different pitch diameters are nested on the same planet carrier, allowing one transmission mechanism to provide multiple gear reduction ratios. This nested configuration enables diverse speed and torque outputs without requiring separate transmission systems for different operations.
Solution Approach 2:
The patent combines multiple planet gears with different pitch diameters into a single planetary stage that shares common components (sun gear, ring gear, planet carrier). This merging of multiple gear functions into a single integrated mechanism provides a wide range of gear reduction ratios while minimizing the overall complexity compared to using separate gear trains.
Data Source
AI summary
A tool having a housing assembly, which defines a handle, a motor assembly, a trigger assembly, a spindle and a transmission assembly. The motor assembly is received in the housing assembly and has an output shaft. The trigger assembly is coupled to the housing assembly and is configured for use in actuating the motor assembly. The transmission assembly transmits rotary power between the output shaft of the motor assembly and the spindle. The transmission assembly includes a planetary stage with an input sun gear, an output planet carrier and a compound planet gear having a first planet gear and a second planet gear coupled together for common rotation on the output planet carrier. The planetary stage is selectively operable in a first gear reduction and a second, relatively lower gear reduction in which the compound planet gear cooperates to produce at least one intermediate gear reduction within the planetary stage.