Cooktop Knob Assembly With Jointed Shaft Alignment
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing cooking appliance knobs face issues with misalignment due to assembly tolerance, leading to degraded appearance quality and operation failures, and lack a stable support structure for the knob and display device, which can result in inaccurate rotation measurement and increased safety risks.
Innovation Solution
A knob assembly with a joint that absorbs positional errors between the knob and valve shaft, featuring a knob ring that can rotate independently and is fixed to the front panel, incorporating a Hall sensor and magnet for precise rotation measurement, and a display device integrated into the knob ring for improved user convenience and safety.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a knob is directly connected to a valve shaft without a joint, then the structure is simple, but assembly tolerance causes misalignment and operation failure
Solution Approach 1:
A joint is introduced as an intermediary component between the knob and valve shaft. The joint includes a joint body with a first shaft coupling portion connected to the valve shaft and a second shaft coupling portion connected to the knob shaft, serving as a mediator that absorbs assembly tolerance and prevents misalignment while maintaining structural integrity.
Solution Approach 2:
The knob assembly is segmented into distinct components: the knob, knob shaft, joint, and valve shaft. This segmentation allows each component to be manufactured independently with standard tolerances, and the joint absorbs the cumulative tolerance, preventing misalignment issues that would occur with a direct rigid connection.
2Ease of operation
If a knob ring is added for independent rotation and display device integration, then user convenience and information display are improved, but device complexity increases
Solution Approach 1:
The knob ring serves multiple functions: it can rotate independently to control timer settings, provides a mounting structure for the display device showing firepower and timer information, and maintains aesthetic appearance. This multi-functionality consolidates several features into a single component, improving user convenience without proportionally increasing complexity.
Solution Approach 2:
The display device is merged with the knob ring structure, where the knob ring body serves as the housing or mounting structure for the display. This integration eliminates the need for separate housings and reduces the number of components, making the added functionality more efficient.
3Measurement precision
If Hall sensor and magnet are integrated for precise rotation measurement, then measurement precision is improved, but device complexity and manufacturing cost increase
Solution Approach 1:
The Hall sensor and magnet combination replaces mechanical rotation measurement mechanisms (such as mechanical encoders or limit switches) with a non-contact magnetic field-based sensing system. This provides precise rotation measurement without mechanical wear or complex mechanical structures.
Solution Approach 2:
The system uses changes in magnetic field parameters (strength, direction) detected by the Hall sensor as the magnet rotates, converting mechanical rotation into electrical signal variations. This parameter transformation enables precise digital measurement of rotation position and angle.
4Reliability
If the knob structure is designed to restrict rotation when not pushed, then safety is improved, but ease of operation decreases
Solution Approach 1:
The knob structure transitions from a static locked state to a dynamic unlocked state when force is applied. The push-rotation mechanism includes movable components that shift position when the knob is pushed, temporarily disabling the rotation restriction and allowing controlled rotation for timer adjustment, then automatically returning to the locked state.
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 stabilizes the knob operation, reduces the risk of misalignment and operation failures, enhances appearance quality, and provides accurate rotation measurement and control, while also improving user convenience and safety by integrating a display device for firepower and timer settings.
Implementation Method 1
incorporating a Hall sensor and magnet for precise rotation measurement
Data Source
AI summary
A knob assembly includes a front panel, a knob located at a front side of the front panel and configured to rotate based on operation by a user, a knob shaft that is coupled to the knob and that extends through the front panel, a supporting pipe that receives the knob shaft and that supports the knob shaft, the supporting pipe being configured to maintain a position relative to the front panel, a valve configured to control supply of gas to the appliance, a valve shaft connected to the valve and configured to control the valve to adjust a flow rate of gas based on rotation of the valve shaft, and a joint that couples the knob shaft to the valve shaft and that is configured to transfer at least one of a rotational motion or a linear motion of the knob shaft to the valve shaft.