Variable Geometry Turbine Sleeve Actuation for Reliable Vane Control
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Solution Overview
Problem
Existing variable nozzle turbines (VNT) face reliability issues due to binding of the actuation mechanism under high-temperature conditions and suffer from low efficiency at both high and low engine operating conditions due to mismatched nozzle vane angles, leading to inefficient turbine operation across the entire operating range.
Innovation Solution
A variable geometry turbine device with a gear rotating sleeve, rack actuator, and elastic nozzle mechanism that adjusts turbine flow capacity by selectively opening radial channels and utilizing pressure differences and elastic forces to guide airflow efficiently under different engine conditions, reducing the need for a complex 'four-bar linkage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a complex four-bar linkage actuation mechanism is used to achieve nozzle vane angle adjustability, then the turbine can match different flow characteristics under different engine operating conditions, but the reliability of the actuation mechanism deteriorates due to binding under high-temperature conditions
Solution Approach 1:
The patent extracts and eliminates the complex four-bar linkage actuation mechanism from the system. Instead of using a mechanical linkage with multiple moving parts that can bind under high-temperature conditions, the invention uses a simpler direct actuation method where the nozzle vane angles are adjusted through a more reliable mechanism that avoids the binding issues of the traditional four-bar linkage while maintaining the ability to match different flow characteristics under varying engine operating conditions.
Solution Approach 2:
The patent replaces the traditional mechanical four-bar linkage actuation system with an alternative actuation approach that uses a rack actuator with gear rotating sleeve. This substitution eliminates the binding problem inherent in the four-bar linkage mechanism while preserving the functionality of adjusting nozzle vane angles to match different engine operating conditions, thereby improving reliability without sacrificing adaptability.
2Adaptability or versatility
If the nozzle vane angle is adjusted significantly to match high or low engine operating conditions, then the turbine flow capacity can be adapted, but the turbine efficiency deteriorates due to mismatched vane angles causing large attack angles
Solution Approach 1:
The patent implements a dynamic adjustment mechanism that allows the nozzle vane angles to be optimized for different engine operating conditions. The rack actuator with gear rotating sleeve enables continuous adjustment of the nozzle vane angles, allowing the system to adapt dynamically to varying flow requirements while maintaining optimal efficiency by avoiding excessive angle deviations that would create large attack angles and energy losses.
Solution Approach 2:
The patent changes the operational parameters of the nozzle vane angles through the rack actuator mechanism. By adjusting the vane angles within an optimal range rather than extreme deviations, the system achieves different turbine flow capacities for high, medium, and low operating conditions while maintaining high efficiency. This parameter optimization prevents the large attack angles that would otherwise occur with significant angle adjustments.
3Device complexity
If a single turbocharger is used to cover the entire engine operating range, then the system complexity is reduced, but the turbocharger cannot operate efficiently across the entire operating range
Solution Approach 1:
The patent applies dynamics by making the turbocharger system adjustable through the rack actuator and gear rotating sleeve mechanism. This allows a single turbocharger to dynamically adapt its flow capacity to match different engine operating conditions, effectively covering the entire operating range from low to high conditions. The dynamic adjustment capability enables one turbocharger to perform the work that would traditionally require multiple fixed turbochargers, maintaining high efficiency across the full range while avoiding 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
The device achieves high reliability and efficient turbine operation across the entire operating range by adjusting turbine flow capacity, solving efficiency issues caused by small or large nozzle opening angles in traditional VNTs, and optimizing airflow guidance.
Implementation Method 1
an elastic nozzle mechanism configured to move reciprocally along an axial direction of the exhaust port under a cooperative action of a pressure difference and an elastic force
Implementation Method 2
an elastic nozzle mechanism configured to move reciprocally along an axial direction of the exhaust port under a cooperative action of a pressure difference and an elastic force
Implementation Method 3
a rack actuator configured to drive the gear rotating sleeve to rotate circumferentially
Implementation Method 4
a turbine disposed inside the turbine casing
Data Source
AI summary
A variable geometry turbine device includes: a turbine casing provided with an inlet duct, and defining an exhaust port and a bypass chamber therein; a gear rotating sleeve disposed inside the bypass chamber; a rack actuator; combined nozzle guide vanes including: a fixed nozzle and an elastic nozzle mechanism; and a turbine. A first annular chamber and a second annular chamber are defined between the exhaust port and the bypass chamber. A first radial channel and a second radial channel are defined under the bypass chamber, and are connected to the first annular chamber and the second annular chamber respectively. A side of the gear rotating sleeve defines a first notch and a second notch configured to be selectively connected to the first radial channel and the second radial channel respectively; and opening and closing of the first radial channel and the second radial channel have a time difference.