Vane-Type Phaser With Segmented Cavity And Fixed Clearance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing vane-type phasers in engines face challenges in maintaining consistent clearance between the vane and cavity during relative axial movement, leading to potential leakage and increased manufacturing complexity, and require high hydraulic pressure to control camshaft phase.
Innovation Solution
A camshaft assembly with a tubular first shaft and a second shaft, where the phaser features a disc with arcuate cavities and closure plates, a movable vane dividing the cavities into working chambers, and a locking pin for hydraulic pressure control, ensuring fixed clearance and reduced component manufacturing tolerances.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the vane is received in an arcuate cavity with axial movement between drive and driven members, then the phaser can achieve relative rotation to change camshaft phase, but the clearance between the vane and cavity varies leading to leakage
Solution Approach 1:
The phaser is divided into two separate axial positions: the drive member and the driven member. The vane is secured to the drive member at a first axial position while the cavity is formed in the driven member at a second axial position. This segmentation allows the clearance between the vane and cavity to be precisely controlled and kept constant, eliminating leakage while maintaining the ability to achieve relative rotation for camshaft phase adjustment.
2Reliability
If the vane is secured between closure plates with precise axial positioning, then leakage is eliminated and sealing is improved, but manufacturing precision requirements increase
Solution Approach 1:
The vane is pre-secured to the drive member at a predetermined first axial position using a securing mechanism (such as adhesive, mechanical interference, or fasteners). This preliminary positioning ensures that when the phaser is assembled and operated, the clearance between the vane and the cavity in the driven member remains constant. The closure plates are positioned at a second axial position to seal the cavity, and the pre-established axial offset between the vane and cavity eliminates the need for high precision during final assembly.
3Force
If high hydraulic pressure is used to control camshaft phase, then the phaser can overcome friction and inertial forces, but energy consumption increases and system complexity increases
Solution Approach 1:
The phaser utilizes the dynamic motion of the vanes within the cavity to convert hydraulic pressure into rotational motion. As hydraulic pressure is applied, the vanes move dynamically within the constant clearance cavity, efficiently transmitting force to rotate the drive member relative to the driven member. This dynamic operation reduces energy losses compared to static high-pressure systems, as the controlled clearance minimizes leakage and maximizes hydraulic force transmission efficiency.
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 solution eliminates leakage, simplifies assembly, reduces manufacturing complexity, and allows for precise control of camshaft phase with consistent hydraulic pressure, enhancing the operational efficiency and cost-effectiveness of the phaser system.
Implementation Method 1
When pressure medium is pumped into one chamber and discharged from the other, the members are rotated relative to one another to change the phase of the camshaft relative to the crankshaft
Implementation Method 2
seals fitted to the radially inner and outer sides of the vanes can readily ensure an adequate seal between the vanes and the cavity walls
Data Source
AI summary
A vane-type phaser connected to drive an assembled camshaft includes a drive member and a driven member each connected to a respective one of the inner and outer shafts of the camshaft. A first of the members includes a disc with at least one arcuate cavity that is open at both axial ends. The second member includes two closure plates sealing off the axial ends of each cavity of the first member and at least one vane formed separately from the closure plates which is movably received in a respective cavity to divide the cavity into two variable volume working chambers. Each vane is secured at both its axial ends to the two closure plates.