Turbocharger Variable Nozzle Calibration
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Solution Overview
Problem
Existing turbocharger systems with variable nozzles exhibit significant deviations in characteristics between individual products, particularly at the minimum flow position, due to manufacturing variations, which affect their performance and efficiency.
Innovation Solution
A method for calibrating turbochargers by adjusting the variable nozzle's flow position based on predetermined speed or outlet pressure, ensuring consistency across products, involving steps like driving the turbocharger with a fluid supply, monitoring speed or pressure, and fixing the nozzle position at a steady-state condition to set a calibration flow position.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If individual turbocharger products are manufactured without calibration, then manufacturing complexity is reduced, but deviations in characteristics between individual products increase
Solution Approach 1:
The patent changes the parameter being controlled from physical dimensions (nozzle geometry, bearing clearances) to operational parameters (actuator position, stop positions). By adjusting where the actuator stops rather than changing physical dimensions, the system achieves consistency across individual products while maintaining simple manufacturing processes.
Solution Approach 2:
The calibration process is performed as a preliminary action before the turbocharger is delivered to the customer. During this preliminary calibration, the actuator is driven through its full range of motion and stop positions are adjusted to account for individual manufacturing variations, ensuring consistent performance without requiring precision manufacturing.
2Measurement precision
If the minimum flow position is precisely manufactured, then calibration accuracy is improved, but manufacturing complexity and cost increase
Solution Approach 1:
The patent replaces mechanical precision (precise minimum flow position manufacturing) with a control system approach. Instead of relying on precision-machined mechanical components, the system uses an actuator with adjustable stop positions to achieve the same calibration accuracy, substituting mechanical precision with electronic/control system adjustment.
Solution Approach 2:
The system transitions from a static, fixed minimum flow position determined by manufacturing to a dynamic, adjustable stop position that can be calibrated for each individual unit. This allows the system to adapt to individual variations rather than requiring all units to be manufactured to the same precise specification.
3Device complexity
If stop positions are fixed during manufacturing, then device complexity is reduced, but deviations between individual products increase
Solution Approach 1:
The stop positions are adjusted during a preliminary calibration action performed on each individual turbocharger before delivery. This preliminary adjustment accounts for manufacturing variations in each unit, ensuring consistent performance across all products while keeping the overall system relatively simple.
Solution Approach 2:
The calibration process uses feedback from monitoring the turbocharger's actual performance characteristics to adjust the stop positions. By measuring the actual behavior of each individual unit and adjusting accordingly, the system compensates for manufacturing variations and achieves consistent performance across all products.
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 method reduces deviations between turbocharger products by standardizing the calibration flow position, enhancing accuracy and repeatability, and improving the thermal efficiency of combustion engines by compensating for manufacturing-induced variations.
Implementation Method 1
a turbine and a compressor connected to each other by a shaft, the turbine having an inlet and an outlet and the compressor having an inlet and an outlet
Implementation Method 2
the compressor having an inlet and an outlet
Data Source
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AI summary
A calibration flow position of a variable nozzle (6) of a turbocharger is set by a method for calibrating the turbocharger, which comprises a turbine (2) and a compressor (1). In this method, the turbocharger is driven by a predetermined fluid supply. Further, the flow position of the variable nozzle (6) is changed while the rotational speed (N) of the turbocharger or an outlet pressure (P2C) of the compressor (1) is monitored. The calibration flow position is fixed based on the monitored quantities.