Rotationally Secured Cylindrical Joint for Thermal Expansion Tolerance
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Solution Overview
Problem
Existing rotation-proof connections face challenges in assembly due to misalignment of complementary structures and are prone to material overload and insufficient force transmission under varying temperature conditions, especially when components have different expansion coefficients.
Innovation Solution
The solution involves a device with a cylindrical outer surface and inner surface forming a rotationally fixed connection, where the outer surface has holding teeth and the inner surface features longitudinal and transverse projections that are harder than the teeth, allowing for deformation and preventing relative movement between components, while accommodating thermal expansion without material damage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If complementary structures (ribs and recesses) are not in proper relative position, then assembly is difficult, but adding guiding structures increases device complexity
Solution Approach 1:
The oblique guiding structures are pre-formed on the ribs and recesses before assembly, automatically guiding the components into proper alignment as they approach each other during assembly. This preliminary alignment feature eliminates the need for manual positioning while maintaining structural simplicity.
2Reliability
If outer diameter expands due to thermal expansion, then material overload occurs, but preventing expansion reduces adaptability to temperature conditions
Solution Approach 1:
The patent utilizes the thermal expansion parameter change by designing the inner component with sufficient radial clearance to accommodate the outer component's expansion. The softer inner material deforms radially outward to accommodate the expanding outer component, transforming the thermal expansion from a harmful effect into a manageable parameter change that maintains connection integrity across temperature ranges.
3Reliability
If inner diameter of recess expands due to thermal expansion, then play increases and force transmission becomes insufficient, but preventing expansion causes material damage
Solution Approach 1:
The patent accepts the parameter change of inner diameter expansion due to thermal effects and designs the connection to accommodate this change. The radial clearance and softer material properties allow the inner component to expand without causing material damage, while the positive connection through deformed material beads maintains sufficient force transmission capability.
4Strength
If harder material is used for projections, then deformation capability decreases, but softer material deforms too easily under thermal load
Solution Approach 1:
The patent applies different material properties to different components: the outer component uses harder material for the projections to maintain structural strength, while the inner component uses softer material that can deform locally at the interface. This local quality differentiation allows the harder outer projections to provide structural integrity while the softer inner material accommodates thermal deformation through localized yielding.
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 ensures secure, rotation-proof and axial movement prevention between components, reducing the risk of material overload and ensuring reliable force transmission across a wide temperature range by allowing for radial deformation and maintaining a secure connection.
Implementation Method 1
the longitudinal projections can deform the adjacent material of the toothing, so that material beads of the material of the toothing form adjacent to the longitudinal projections, thereby preventing a relative movement between the two components
Implementation Method 2
Particularly with connection partners with different expansion coefficients, the problem arises that, under unfavorable temperature conditions, the outer diameter of the pin expands so much that the part provided with the recess is destroyed
Data Source
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AI summary
The invention relates to a device comprising a first component (11) and a second component (12). The first component (11) comprises a cylindrical outer surface (13), and the second component (12) comprises a cylindrical inner surface (17) which is arranged on the outer surface (13) coaxially with a longitudinal central axis (m). First connection surfaces of the first component interact with second connection surfaces of the second component in order to prevent a relative rotational movement of the components (11, 12). The invention is characterized in that one of the connection surfaces forms a retaining toothing (22), and the other connection surface forms mutually spaced longitudinal protrusions (18) which are distributed over the circumference and the tooth flanks of which extend parallel to the longitudinal central axis (m).