Power Tool Gear Reducer With Direction-Dependent Torque and Speed
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Power tools that perform different actions based on motor rotation direction require varying rotation speeds and torque outputs, which existing designs struggle to achieve efficiently without complex control mechanisms.
Innovation Solution
A power tool incorporating a gear speed reducer with a planetary gear mechanism and a reduction-ratio change mechanism, utilizing a one-way clutch and lock mechanism to adjust the number of effective planetary gear stages based on motor rotation direction, allowing for distinct speed and torque outputs in normal and reverse directions without controlling motor speed.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If the motor rotates in normal direction for low-speed high-torque action, then torque output is improved, but rotation speed deteriorates
Solution Approach 1:
The gear speed reducer dynamically changes its reduction ratio based on motor rotation direction. In normal rotation direction, it provides a first reduction ratio for low-speed high-torque output. In reverse rotation direction, it provides a second reduction ratio for high-speed low-torque output. This dynamic adaptation resolves the contradiction by allowing the system to have both high torque and high speed capabilities through a single mechanism.
Solution Approach 2:
The reduction ratio parameter of the gear speed reducer is changed based on rotation direction. The mechanism includes a reduction-ratio change mechanism that switches between at least two different reduction ratios depending on whether the motor rotates in normal or reverse direction, enabling the system to optimize both torque and speed performance for different operational requirements.
2Speed
If the motor rotates in reverse direction for high-speed low-torque action, then rotation speed is improved, but torque output deteriorates
Solution Approach 1:
The gear speed reducer dynamically changes its reduction ratio based on motor rotation direction. In reverse rotation direction, it provides a second reduction ratio (smaller than the first) for high-speed low-torque output, enabling rapid return movements or positioning operations where speed is prioritized over torque.
Solution Approach 2:
The reduction ratio parameter is switched to a second value when the motor rotates in reverse direction. This parameter change allows the output shaft to rotate at higher speed with proportionally reduced torque, matching the operational requirements for reverse actions.
3Ease of operation
If separate control mechanisms are added to control motor rotation speed for different actions, then speed and torque control is improved, but device complexity deteriorates
Solution Approach 1:
The gear speed reducer with reduction-ratio change mechanism automatically adapts to different operational requirements based on motor rotation direction without requiring external control signals. The mechanism self-regulates the reduction ratio according to the rotation direction, eliminating the need for complex control systems while maintaining ease of operation.
Solution Approach 2:
The gear speed reducer serves multiple functions by providing different reduction ratios for different rotation directions. A single mechanism handles both low-speed high-torque and high-speed low-torque requirements, making the control system unnecessary and simplifying the overall device structure.
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
Enables the power tool to perform actions requiring low-speed high-torque or high-speed low-torque outputs simply by changing motor rotation direction, enhancing efficiency and reducing mechanical complexity.
Implementation Method 1
The gear speed reducer includes three stages of planetary gear mechanisms
Implementation Method 2
a one-way clutch mounted onto the shaft of the first-stage carrier, the one-way clutch being configured to permit rotation of the sun gear of the second stage relative to the carrier of the first stage
Implementation Method 3
a lock mechanism configured to non-rotatably lock the carrier of the first stage
Data Source
AI summary
A power tool includes a motor and a gear speed reducer. The motor has a motor shaft that is rotatable in a normal direction and in a reverse direction. The gear speed reducer is operably coupled to the motor shaft. The gear speed reducer is configured such that a reduction ratio of the gear speed reducer is changed in response to a change of a rotation direction of the motor shaft.