Exhaust Flap Coupling With Spring Isolation for Drive Heat Reduction
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Solution Overview
Problem
Electric exhaust gas flap devices face thermal load issues due to heat transfer from the exhaust flow, leading to mechanical stress and unreliable operation, with existing solutions failing to adequately address these challenges while maintaining manufacturability and reliability.
Innovation Solution
The coupling device is equipped with a transmission element that is axially adjustable and supported by a prestressing spring, reducing thermal expansion effects and heat transfer through a design that minimizes direct heat conduction and radiation, using materials with low thermal conductivity and a geometric configuration that enhances thermal insulation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the exhaust flap is directly connected to the electric drive through a rigid coupling device, then the positioning accuracy and response speed are improved, but the thermal load and mechanical stress on the electric drive increase significantly
Solution Approach 1:
The coupling device is divided into multiple segments: a first coupling element connected to the electric drive, a second coupling element connected to the exhaust flap, and a transmission element connecting the first and second coupling elements. This segmentation allows the thermal expansion of the exhaust flap assembly to be isolated from the electric drive, reducing thermal load while maintaining positioning accuracy through the coordinated movement of the segmented components.
Solution Approach 2:
The transmission element acts as an intermediary between the electric drive and the exhaust flap. It includes a preload spring that compensates for thermal expansion and mechanical stress, allowing the system to maintain precise flap positioning while protecting the electric drive from excessive thermal and mechanical loads generated during exhaust system operation.
2Reliability
If a rigid coupling device is used to ensure reliable torque transmission, then the reliability of torque transmission is improved, but the thermal expansion compensation capability deteriorates
Solution Approach 1:
The coupling device incorporates dynamic elements including a preload spring and axially movable first and second coupling elements. These dynamic components allow the coupling device to adapt to thermal expansion and contraction of the exhaust flap assembly while maintaining reliable torque transmission. The preload spring provides continuous contact force to ensure positive torque transmission, while the axial movability of the coupling elements allows for thermal expansion compensation.
3Ease of manufacture
If fewer components are used in the coupling device, then the manufacturing cost is reduced, but the reliability and precision of flap positioning may deteriorate
Solution Approach 1:
The coupling device merges multiple functions into an integrated assembly: the first coupling element, second coupling element, transmission element with preload spring, and retention element work together as a coordinated unit. This merging approach ensures reliable flap positioning through the synergistic interaction of components while maintaining manufacturing efficiency. The preload spring and retention element are integrated into the coupling device structure, eliminating the need for separate adjustment mechanisms and reducing overall system complexity.
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 configuration effectively reduces thermal load on the electric drive, ensures reliable positioning of the exhaust gas flap, and allows for cost-effective production by using fewer components, thereby enhancing the operational reliability and efficiency of the electric exhaust gas flap device.
Implementation Method 1
the prestressing spring (18) which is configured to axially drive or preload the transmission element (16) against the output shaft (9) and to compensate for thermal stress
Implementation Method 2
The preload spring is axially supported on the connecting element and/or the drive shaft as well as on the transmission element
Implementation Method 3
reducing thermal expansion effects and heat transfer through a design that minimizes direct heat conduction and radiation
Implementation Method 4
reducing thermal expansion effects and heat transfer through a design that minimizes direct heat conduction and radiation
Data Source
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AI summary
The present invention relates to an electric exhaust flap device (1) for controlling a flowable cross-section (5) of an exhaust pipe (6) of an exhaust system (8) of an internal combustion engine, comprising an electric drive (2) having an output shaft (9) which can be driven by the electric drive (2) to rotate about a rotary axis (10), an exhaust flap (3) having a drive shaft (12) aligned coaxially to the rotary axis (10) and which can be rotated about the rotary axis (10) to control the cross-section (5) to be controlled, and a coupling device (4) for transmitting torques between the output shaft (9) and the drive shaft (12).A reduced thermal load on the electric drive (2) can be achieved if the coupling device (4) has a connecting element (17) that is rotationally fixed to the drive shaft (12), a transmission element (16) that is rotationally fixed and axially adjustable to the output shaft (9) and that is rotationally fixed and axially adjustable to the connecting element (17), and a preload spring (18) that is axially supported on the connecting element (17) and/or on the drive shaft (12) and on the transmission element (16) and that axially drives the transmission element (16) against the output shaft (9).