Concentric Camshaft Phaser Integration with Compression Brake
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for integrating a camshaft phaser onto a concentric camshaft are costly and complex, and midrange applications require a compression release brake in conjunction with variable valve timing, which poses additional challenges.
Innovation Solution
A splined interface between the phaser and concentric camshaft, an actuator-driven rod, a clearance hole in the lobe pin, and oil supply through the camshaft inner tube, along with a bolt-on front bearing, enable efficient integration and operation of the camshaft phaser and compression release brake.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional methods are used to integrate camshaft phaser onto concentric camshaft, then reliability is improved, but device complexity and manufacturing cost increase
Solution Approach 1:
The patent combines the camshaft phaser assembly with the concentric camshaft by integrating the phaser housing onto the camshaft body, creating a unified component structure. This merging eliminates separate mounting brackets and fasteners, reducing device complexity while maintaining the reliability of phaser-camshaft connection through direct structural integration.
Solution Approach 2:
The concentric camshaft design incorporates multiple functions within a single structure: the outer camshaft provides variable valve timing through the phaser mechanism, while the inner camshaft provides compression release brake functionality. This multi-functionality reduces the need for separate components and simplifies the overall integration structure.
2Reliability
If traditional camshaft phaser mounting methods are used, then operational reliability is improved, but manufacturing cost increases
Solution Approach 1:
By integrating the phaser housing directly onto the camshaft body as a unified structure, the patent eliminates the need for separate mounting brackets, fasteners, and assembly steps. This reduces manufacturing cost through fewer parts and simplified assembly processes while maintaining mounting reliability through direct structural integration.
Solution Approach 2:
The camshaft assembly is segmented into modular components (outer camshaft, inner camshaft, phaser mechanism) that can be manufactured separately and then assembled. This segmentation allows for optimized manufacturing of each component while reducing overall production cost through standardized interfaces and simplified assembly procedures.
3Object-generated harmful factors
If fixed valve events are used to meet emissions requirements, then engine simplicity is maintained, but emissions optimization becomes increasingly challenging
Solution Approach 1:
The patent implements variable valve timing through a dynamic phaser mechanism that allows the camshaft to rotate relative to the crankshaft, changing valve timing events based on engine operating conditions. This dynamic adjustability enables optimized emissions control across different engine loads and speeds while maintaining the mechanical simplicity of a camshaft-based system.
Solution Approach 2:
The system changes the timing parameter of valve events by allowing rotation of the camshaft relative to the crankshaft through the phaser mechanism. This parameter change enables optimization of emissions by adjusting valve timing to match different operating conditions without changing the fundamental engine architecture.
4Adaptability or versatility
If variable valve timing is implemented without compression release brake, then valve timing flexibility is improved, but midrange application requirements are not met
Solution Approach 1:
The concentric camshaft design provides multi-functionality by incorporating both variable valve timing (through the outer camshaft phaser) and compression release brake (through the inner camshaft) within a single integrated system. This approach meets midrange application requirements without requiring separate, complex systems for each function.
Solution Approach 2:
The patent uses a nested structure where the inner camshaft (providing compression release brake) is positioned within the outer camshaft (providing variable valve timing). This nesting arrangement allows both functions to coexist in a compact configuration, reducing overall system complexity while meeting all functional requirements.
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 provides a cost-effective and efficient integration of the camshaft phaser and compression release brake, optimizing engine performance by allowing variable valve timing and reducing complexity, while maintaining reliability and reducing emissions.
Implementation Method 1
A splined interface between the phaser and concentric camshaft
Implementation Method 2
an actuator at rear of camshaft actuated by an actuation rod
Implementation Method 3
adding a clearance hole to the lobe pin for clearance to the actuation rod
Implementation Method 4
supplying oil to camshaft bearings via the concentric camshaft inner tube
Data Source
AI summary
Valve trains employing a splined interface between phaser(s) and a concentric camshaft, actuator at rear of camshaft actuated by an actuation rod, adding a clearance hole to the lobe pin for clearance to the actuation rod, supplying oil to camshaft bearings via the concentric camshaft inner tube, and bolt on front camshaft bearing. The valve trains may further employ a third rocker lever that is usable for a selectable valve event (e.g. compression release brake) while also implementing variable valve timing and a concentric camshaft.