VCR Phasing Mechanism Using Planetary Actuation and Torsion Spring
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Solution Overview
Problem
Conventional rotational phasing systems require significant axial force and increased packaging size to achieve desired relative rotation between components, leading to higher costs and complexity.
Innovation Solution
The use of a planetary actuator with a two-way clutching mechanism, coupled with a torsion spring, allows for selective relative rotation between a crank shaft and an eccentric shaft using rotary displacement, reducing the axial height and force required, and enabling efficient phasing in a variable compression ratio system.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If conventional rotational phasing systems are used to achieve desired relative rotation between components, then the phasing function is achieved, but significant axial force and increased packaging size are required
Solution Approach 1:
The patent replaces conventional mechanical phasing systems with a planetary actuator mechanism that uses rotary displacement instead of axial force. The planetary actuator converts rotational input from the crank shaft into controlled rotational phasing of the eccentric shaft, eliminating the need for large axial forces and reducing the overall axial height of the system.
Solution Approach 2:
The patent changes the operating parameters from axial force application to rotary displacement input. By using the planetary actuator's gear ratio mechanism, a small rotary displacement at the input can produce the desired rotational phasing at the output, effectively changing the force/displacement parameters to achieve the same phasing function with reduced axial dimensions.
2Ease of operation
If conventional rotational phasing systems are used to achieve desired relative rotation between components, then the phasing function is achieved, but significant axial force and increased packaging size are required
Solution Approach 1:
The planetary actuator serves multiple functions: it provides the phasing mechanism, acts as a force multiplier through its gear ratio, and integrates the locking/unlocking functionality through the two-way clutch mechanism. This multi-functionality reduces the need for separate components, thereby reducing overall system complexity despite the advanced mechanism used.
Solution Approach 2:
The two-way clutch mechanism automatically locks and unlocks based on the direction of torque flow, eliminating the need for external control systems or additional actuators. The system self-regulates its locking state based on operational conditions, reducing control complexity while maintaining precise phasing control.
3Ease of operation
If conventional rotational phasing systems are used to achieve desired relative rotation between components, then the phasing function is achieved, but higher costs are incurred
Solution Approach 1:
The patent segments the phasing system into distinct functional modules: the planetary actuator for motion conversion, the two-way clutch for automatic locking/unlocking, and the torsion spring for torque offset. This modular segmentation allows for standardized manufacturing of each component and simplifies assembly, thereby reducing overall system cost despite the advanced functionality.
4Force
If a torsion spring is used to offset torque load, then torque balance is improved, but additional component is added
Solution Approach 1:
The torsion spring is integrated into the planetary actuator assembly, sharing the same mounting structure and rotational path. Rather than being a separate external component, the torsion spring is merged with the existing actuator housing and gear train, providing torque offset functionality without requiring additional mounting space or complex external linkages.
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 solution reduces the axial height and cost of the phasing system while allowing for precise control of relative rotation, enhancing the efficiency and compactness of rotary systems like internal combustion engines.
Implementation Method 1
a torsion spring coupled between the gear hub and the cradle rotor. The torsion spring is configured to apply a torque load in a first direction between the gear hub and the cradle rotor to offset a torque load applied in a second direction by either one of the eccentric shaft or the crank shaft
Data Source
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AI summary
A phasing system is provided. A phase angle between the gear hub and the cradle rotor can be driven by a planetary actuator. In some non-limiting examples, an input shaft rotationally coupled between a rotary actuator for rotation therewith. Rotation of the input shaft can unlock relative rotation between the cradle rotor and the gear hub. In some non-limiting examples, the phasing system can include a gear hub and a cradle rotor, and a torsion spring arrange therebetween. The torsion spring can be configured to apply an internal torque load between the gear hub and the cradle rotor to offset an external torque load applied to the gear hub or the cradle rotor.