Hydrostatic Camshaft Phaser Variable Displacement Pump
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Solution Overview
Problem
Existing variable camshaft timing (VCT) systems in internal combustion engines require a separate oil pump to pressurize fluid for camshaft phaser actuation, which adds complexity and energy consumption.
Innovation Solution
A hydrostatic camshaft phaser system utilizing a variable displacement pump to adjust camshaft timing by altering fluid displacement between advancing and retarding chambers, eliminating the need for a separate oil pump by using engine oil and fluid pathways integrated with the camshaft and bearing surfaces.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a separate oil pump is used to pressurize fluid for camshaft phaser actuation, then reliable fluid supply is ensured, but device complexity and energy consumption increase
Solution Approach 1:
The patent combines the oil pump function with the camshaft phaser assembly by integrating a variable displacement pump directly into the phaser housing. The pump uses the rotational motion of the camshaft itself to drive fluid pressurization, eliminating the need for a separate oil pump while ensuring reliable fluid supply for phaser actuation
Solution Approach 2:
The camshaft phaser system serves itself by using the camshaft's own rotational energy to drive the integrated variable displacement pump. The pump automatically pressurizes fluid based on camshaft rotation, requiring no external power source or separate pumping mechanism, thereby reducing system complexity and energy consumption
2Stress or pressure
If a separate oil pump is used to pressurize fluid for camshaft phaser actuation, then adequate fluid pressure is achieved, but energy consumption increases
Solution Approach 1:
The patent employs a variable displacement pump that dynamically adjusts fluid displacement based on the instantaneous needs of the camshaft phaser actuation. The pump's displacement varies with camshaft rotational position and load requirements, optimizing energy efficiency by delivering only the necessary fluid pressure and flow at each moment rather than continuous high-pressure output
Solution Approach 2:
The integrated pump operates in periodic cycles synchronized with camshaft rotation, pressurizing fluid only during specific portions of the camshaft cycle when actuation is needed. This periodic operation reduces overall energy consumption compared to a separate pump that would need to maintain continuous pressure
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 allows for efficient adjustment of camshaft timing without a separate oil pump, reducing complexity and energy consumption while maintaining precise control over engine performance.
Implementation Method 1
hydraulically-actuated camshaft phaser with a rotor having a vane extending radially outwardly from a hub; a stator housing that receives the rotor and includes an advancing chamber and a retarding chamber defined at least partially by the vane
Implementation Method 2
a variable displacement pump, in fluid communication with the hydraulically-actuated camshaft phaser... the first chamber receives fluid from a first non-continuous groove extending along a camshaft surface or a bearing surface
Implementation Method 3
the first chamber receives fluid from a first non-continuous groove extending along a camshaft surface or a bearing surface and the second chamber receives fluid from a second non-continuous groove extending along the camshaft surface or the bearing surface during a first portion of camshaft rotation
Data Source
AI summary
A hydrostatic camshaft phaser system includes a hydraulically-actuated camshaft phaser with a rotor; and a stator housing that receives the rotor and includes an advancing chamber and a retarding chamber defined at least partially by the vane; and a variable displacement pump, in fluid communication with the hydraulically-actuated camshaft phaser, comprising a first chamber in fluid communication with the advancing chamber and a second chamber in fluid communication with the retarding chamber; the first chamber receives fluid from a first non-continuous groove extending along a camshaft surface or a bearing surface and the second chamber receives fluid from a second non-continuous groove extending along the camshaft surface or the bearing surface during a first portion of camshaft rotation, and the first chamber receives fluid from the second non-continuous groove and the second chamber receives fluid from the first non-continuous groove during a second portion of camshaft rotation.