PTC Heating Assembly With Profile Parts for Tolerance Compensation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing electric heating devices face issues with manufacturing tolerances and dimensional fluctuations of PTC elements, leading to inefficient heat extraction and potential damage due to stress peaks caused by wedge elements.
Innovation Solution
The solution involves using a positioning frame with profile parts connected to the PTC element and receiving pocket, featuring tongue and groove joints to compensate for manufacturing tolerances and ensure uniform heat extraction, with optional adhesive for secure assembly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If a wedge element is used to clamp the PTC element and contact sheets, then good heat transfer is achieved, but stress peaks occur which can cause the PTC element or ceramic insulating layer to break
Solution Approach 1:
The receiving pocket is designed with a downwardly tapering cross-sectional shape that creates a gradual compression zone. This geometric configuration cushions the PTC element and insulating layers against excessive stress by distributing the clamping force progressively, preventing sudden stress peaks that would cause breakage while maintaining adequate heat transfer pressure.
Solution Approach 2:
The receiving pocket's cross-sectional shape is changed from cylindrical to downwardly tapering. This parameter change in geometry transforms the stress distribution pattern, converting concentrated stress peaks into distributed gradual compression, thereby protecting fragile components while maintaining thermal contact.
2Manufacturing precision
If the wedge element is made thicker to ensure adequate coverage, then manufacturing tolerances are compensated, but the free space in the receiving pocket becomes insufficient leading to poor heat extraction
Solution Approach 1:
The receiving pocket is designed with a downwardly tapering cross-sectional shape, transitioning from a uniform thickness approach to a dimensional gradient. This allows the pocket to accommodate thicker wedge elements for tolerance compensation at the insertion end, while maintaining adequate free space at the lower end for heat extraction, effectively solving the contradiction through spatial dimensioning.
3Temperature
If the receiving pocket shape is made precise to match the PTC element, then optimal heat transfer is achieved, but manufacturing tolerances cause deviations from the specified shape
Solution Approach 1:
The downwardly tapering design of the receiving pocket creates a built-in tolerance compensation mechanism. The gradual taper provides a cushioning zone that absorbs shape deviations caused by manufacturing tolerances, ensuring that even if the pocket shape deviates from specifications, adequate heat transfer is maintained through the progressive compression pattern.
4Temperature
If the PTC element is pressed firmly against the receiving pocket surface, then heat extraction is improved, but dimensional fluctuations in the PTC element lead to stress peaks and potential breakage
Solution Approach 1:
The receiving pocket's cross-sectional shape is changed to downwardly tapering, which transforms the pressure distribution parameter. Instead of uniform or concentrated pressure, the taper creates progressive compression that maintains firm contact for heat extraction while distributing stress to prevent breakage of dimensionally fluctuating PTC elements.
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
This design effectively compensates for manufacturing tolerances, maintaining efficient heat dissipation and preventing damage to PTC elements, while allowing for economic manufacturing.
Implementation Method 1
at least one profile part (26) which is connected in a heat-conducting manner to the PTC element (4) on opposite main side surfaces of the PTC element, wherein outer main side surfaces of the profile parts (26) opposite the PTC element are connected in a heat-conducting manner to an inner surface (136) of the receiving pocket (102)
Data Source
AI summary
An electric heating device includes a housing which forms a receiving pocket in which at least one PTC heating assembly with at least one PTC element received in a positioning frame and strip conductors electrically conductively connected to the PTC element for energizing the PTC element with different polarity is received. In order to compensate for manufacturing tolerances without significantly impairing the heat dissipation from the PTC element, at least one profile part is connected opposite main side surfaces of the PTC element in a heat-conducting manner. Outer main side surfaces of the profile parts opposite the PTC element are connected to an inner surface of the receiving pocket in a heat-conducting manner in each case. The profile parts are connected to the positioning frame.