Electromechanical Friction Shock Absorber for Unbalanced Drum Loads
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Solution Overview
Problem
Existing shock absorbers in washing machines fail to effectively manage unbalanced loads and vibrations due to fixed damping forces, leading to inefficiencies and increased energy consumption, and are not adaptable to dynamic changes in laundry load and drum movement.
Innovation Solution
An electromechanical friction shock absorber system with two brake shoes, a step motor, and a coupling connection system that uses a stroke sensor to adjust damping force based on laundry load and drum movement, preventing tensioning and optimizing power usage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a fixed damping force is used in shock absorbers, then the structure is simple and manufacturing cost is low, but the shock absorber cannot adapt to unbalanced loads and vibrations of different magnitudes
Solution Approach 1:
The shock absorber employs a step motor to dynamically adjust the damping force according to the actual vibration conditions. The system transitions from a static fixed damping structure to a dynamic adjustable system, enabling adaptation to different unbalanced loads while maintaining reasonable structural complexity through modular design.
Solution Approach 2:
A vibration sensor is integrated into the system to detect drum vibration levels and provide feedback to the control unit. The control unit processes this information and adjusts the step motor accordingly, creating a closed-loop feedback system that enables the shock absorber to adapt to changing load conditions automatically.
2Speed
If a gear system is used to adjust damping force, then the damping can be varied, but the speed cannot reach the speed of the dynamic system and tensioning occurs
Solution Approach 1:
The invention removes the gear system entirely from the design. Instead of using mechanical gears to adjust damping force, the system directly drives the brake shoe through a step motor, eliminating the speed limitation and tensioning problems associated with gear systems while maintaining the ability to vary damping force.
Solution Approach 2:
The traditional mechanical gear transmission system is replaced with a direct electromagnetic drive system using a step motor. This substitution eliminates mechanical complexity, achieves higher response speeds matching the dynamic system, and prevents tensioning forces from developing in the transmission components.
3Use of energy by moving object
If magnetic effect is used to produce damping force, then the force can be controlled, but continuous electricity supply is required increasing energy consumption
Solution Approach 1:
The step motor operates in a periodic, intermittent manner rather than continuously. It activates only when vibration detection indicates the need for damping adjustment, thereby significantly reducing electricity consumption compared to continuous magnetic field generation while maintaining effective damping force control when needed.
Solution Approach 2:
The system uses the vibration sensor and control unit to automatically determine when damping adjustment is needed, eliminating the need for continuous external control. The shock absorber serves itself by detecting its own operational conditions and making appropriate adjustments only when necessary, reducing energy consumption.
4Force
If friction element is pressed perpendicular to pressing axis, then friction force can be produced, but the coil force cannot overcome the spring force
Solution Approach 1:
Instead of pressing the friction element perpendicular to the pressing axis as in conventional designs, the invention applies the friction force parallel to the pressing axis. The step motor directly pushes the brake shoe against the friction element along the axis of pressing, inverting the traditional approach and enabling the coil force to effectively overcome the spring force and produce the required friction damping.
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 system provides real-time control of washing machine drum dynamics, reducing vibrations and energy consumption by adjusting damping force according to the laundry load and drum speed, while maintaining low production costs.
Implementation Method 1
a brake screw for clamping and unclamping the brake shoes around the said support axes, which brake screw is connected to the shock absorber body via a bracket and rotated via a step motor
Implementation Method 2
two brake shoes which contact the friction element only from the outside thereof; two friction elements whose two sides are completely open in the shock absorber work axis
Data Source
AI summary
An electromechanical friction shock absorber is used in washing machines wherein the washing drum rotates on the horizontal axis and comprises at least one cylindrical shock absorber piston, at least one shock absorber body that surrounds the shock absorber piston, moving telescopically along the same work axis with the piston, and a bearing piston from its end part. At least one brake shoe is seated in the clearances provided on the shock absorber body via sliding surfaces. At least one friction element is located on the inner part of the brake shoe and the outer part of the shock absorber and includes surfaces along the work axis that do not contact the brake shoe. At least one lock ring bears the shock absorber piston on the shock absorber body and prevents the friction element from getting displaced out of the body, with the inventive electromechanical friction shock absorber.