Washing Machine Drum Pulley Indexing for Reliable Position Locking
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing washing and drying machines lack reliable drum locking mechanisms that can handle multiple locking positions and recognize the angular position of the pulley, leading to unreliable operation and potential issues with inertia and centrifugal force.
Innovation Solution
A device comprising a pulley with a ramp and an indexing finger that uses the main motor's power to position and lock the rotary drum, overcoming inertia and mechanical forces, and includes an elastic means for precise positioning and a method with two electrical cut-off means for automatic door opening.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a movable element is used to cooperate with a recess in the pulley for positioning, then the drum can be stopped at a determined position, but the blocking is unreliable due to inertia and centrifugal force pulling the element out
Solution Approach 1:
The indexing finger is given a curved profile that matches the arcuate shape of the recess in the pulley. This curved geometry allows the finger to ride smoothly along the recess during drum rotation and automatically engage with the notch at the desired stopping position, utilizing the natural rotational motion rather than fighting against inertia and centrifugal forces.
Solution Approach 2:
The invention converts the harmful effects of inertia and centrifugal force into beneficial engagement. The indexing finger is designed to be pushed outward by centrifugal force during rotation, which ensures firm engagement with the recess and notch. The elastic means is compressed during normal operation and automatically engages the locking position when the drum reaches the desired position, transforming the destabilizing forces into a reliable locking mechanism.
2Measurement precision
If additional power components and recognition systems are added for reliable positioning, then positioning accuracy improves, but device complexity and cost increase
Solution Approach 1:
The indexing mechanism is entirely passive and self-actuating. The indexing finger automatically engages with the recess and notch through the drum's own rotational motion and centrifugal force, without requiring any additional motors, sensors, or control systems. The elastic means provides automatic engagement and disengagement based on the drum's position, making the system self-regulating and eliminating the need for external power components for positioning.
Solution Approach 2:
The indexing finger serves multiple functions: it acts as a position sensor, a locking mechanism, and a control element all in one component. The same recess in the pulley serves both as a guide for the indexing finger during rotation and as a locking notch at the stopping position. This multi-functionality eliminates the need for separate recognition systems and power components.
3Adaptability or versatility
If a single indexing finger is used for positioning, then the device remains simple, but multiple locking positions cannot be achieved
Solution Approach 1:
The indexing mechanism is segmented into multiple independent indexing fingers, each capable of engaging with its own corresponding recess and notch on the pulley. This segmentation allows the drum to be positioned and locked at multiple discrete positions without requiring a complex multi-component system. Each finger-recess-notch combination operates independently, providing versatile positioning capability while maintaining mechanical simplicity.
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 rapid, reliable, and precise positioning and locking of the rotary drum for loading and unloading laundry, ensuring secure operation without additional power or recognition systems, and is adaptable to standard tubs and pulleys.
Implementation Method 1
an indexing finger (19) cooperating with at least one notch (20) provided on the periphery (24) of said pulley (16) to position the rotary drum (7), said indexing finger (19) comprising at least two operating positions, a first position corresponding to the rest state in which the indexing finger (19) is outside said at least one notch (20), and a second position corresponding to stopping of the rotary drum (7) in which the indexing finger (19) is introduced into said at least one notch (20)
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A device for positioning and locking a rotary drum of a washing and/or clothes-drying machine comprises a washing tub (6) surrounding said rotary drum (7), said rotary drum (7) being connected to a rotation drive shaft, said rotation drive shaft extending through a flange of the washing tub (6) and being rotated by a pulley (16) attached to one end of said shaft, said pulley (16) extending outside the washing tank (6), a motor (17) and a belt (18) driving said pulley (16) in rotation, an indexing finger cooperating with at least one notch formed on the periphery of said drive pulley (16) of the washing tank (6) to position the rotary drum (7), the indexing finger comprising at least two operating positions, a first position corresponding to the state of rest in which the indexing finger is outside said at least one notch, and a second position corresponding to the stopping of the rotary drum (7) in which the indexing pin is introduced into said at least one notch. The device (12) comprises a tractor finger (14) linked to the indexing finger, the pulley (16) comprises at least one ramp, the tractor finger (14) is equipped with an interface cooperating with said ramp and the interface of the tractor finger slides along the ramp of the pulley (16) to drive the indexing finger between said at least two operating positions. Use in particular in a top-loading washing and/or drying machine.