Continuous torque appliance transmission shifter
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Solution Overview
Problem
Washing machine transmission systems experience premature failure due to contamination and uneven torque, leading to increased loading and reduced operational reliability.
Innovation Solution
A direct drive gear system replaces the crank linkage, incorporating a clutch with a cam mechanism and pinion gear for consistent torque, allowing for improved mechanical advantage and resistance to contamination, and a self-centering cam for smooth clutch engagement and disengagement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a crank linkage system is used to shift the transmission, then the shifter can be actuated by an electric motor, but the torque becomes irregular over the operating range causing increased loading and premature failure
Solution Approach 1:
The patent removes the crank linkage from the shifter mechanism, extracting the source of irregular torque. The direct drive gear system eliminates the intermediate crank component that caused torque fluctuations, resulting in more reliable transmission operation while maintaining electric motor actuation capability.
Solution Approach 2:
The patent introduces a direct drive gear system as an intermediary between the electric motor and the shifter arm. This gear system provides a more uniform torque transmission path, replacing the problematic crank linkage and improving reliability while preserving the ability to actuate the shifter electronically.
2Productivity
If a toggle arm system is used to provide cam activation force, then the mechanism can shift transmission modes, but the activation force exceeds the minimum torque causing premature failure
Solution Approach 1:
The patent changes the torque parameter profile by replacing the toggle arm system with a direct drive gear system. This modification ensures that the cam activation force remains within the minimum torque capacity throughout the activation range, preventing premature failure while maintaining transmission shifting functionality.
3Reliability
If higher torque motors are used to overcome increased loading, then the shifter can operate reliably, but energy consumption and cost increase
Solution Approach 1:
The patent converts the harmful effect of irregular torque into a benefit by using a direct drive gear system that produces uniform torque. This allows the use of a smaller, more energy-efficient motor while maintaining reliable shifter operation, effectively turning the original reliability problem into an energy savings opportunity.
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 solution provides longer transmission life, reduced energy consumption, and improved mechanical advantage without the need for higher torque motors, while maintaining efficient motor sizing and resistance to contamination.
Implementation Method 1
The cam includes a peripheral gear which may be driven by a corresponding pinion gear attached to the shaft of a second motor so that activation of the second motor moves the cam around the first axis between the first cam state and the second cam state.
Implementation Method 2
The pinion gear and peripheral gear may be sized to provide no less than a 4:1 speed reduction from a rotation of motor shaft to a rotation of the cam ring.
Implementation Method 3
A cam communicates with the first clutch portion and is rotatable about the first axis between a first cam state moving the first clutch portion to the first clutch state and a second cam state moving the first clutch portions of the second clutch state.
Data Source
AI summary
A washing machine transmission actuator employs a rotating cam for separating a clutch. The cam is rotated by a ring gear communicating with a pinion gear on a motor providing improved minimum torque for a given motor power and thus improved energy efficiency.