Valve Timing Control Apparatus Tilt Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing valve timing control apparatuses experience frictional wearing and noise due to tilting of the second rotator relative to the first rotator, caused by vibrations from the internal combustion engine, which affects the accuracy and reliability of valve timing adjustment.
Innovation Solution
The valve timing control apparatus includes a first rotator, a second rotator, and a planetary gear, where the second rotator has a small diameter portion and a large diameter portion with stopper portions that project radially outward, allowing for reduced tilt and minimized contact with the first rotator, thereby reducing frictional wearing and noise.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the second rotator is supported with clearance between axial end parts, then the second rotator can rotate smoothly, but the rotational axis tilts due to vibrations causing frictional wearing and noise
Solution Approach 1:
The invention introduces a radial dimension constraint through stopper portions that project radially outward, complementing the existing axial clearance support. This creates a three-dimensional constraint system (axial + radial) that prevents rotational axis tilting while maintaining rotational smoothness through the clearance design.
Solution Approach 2:
The stopper portions act as intermediary elements between the second rotator and the first rotator, providing radial support and preventing excessive tilting. These stopper portions engage with the first rotator only when necessary to limit tilt, allowing normal rotation to proceed smoothly through the clearance.
2Reliability
If stopper portions are made large to prevent tilting, then rotational stability improves, but the device size increases
Solution Approach 1:
Instead of making the entire second rotator larger, the invention applies local reinforcement only where needed - the stopper portions radially projecting from specific circumferential locations. This provides targeted tilt prevention without increasing the overall volume of the rotating components.
Solution Approach 2:
The stopper portions provide just enough radial support to prevent excessive tilting, rather than completely eliminating all movement. The clearance allows normal operational variations while the stopper portions engage only when tilt exceeds acceptable limits, providing partial action that maintains stability without over-constraining the system.
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 design minimizes the generation of frictional wearing and noise by limiting the tilt of the second rotator's rotational axis, ensuring precise and reliable valve timing adjustment without increasing the size of the stopper portions, thus enhancing the durability and performance of the apparatus.
Implementation Method 1
The planetary gear is meshed with a first gear portion and a second gear portion and is adapted to make a planetary motion and thereby to change the relative phase between the crankshaft and the camshaft
Implementation Method 2
the stopper portion is adapted to contact the first rotator in a rotational direction to limit a change in a relative phase between the crankshaft and the camshaft
Data Source
AI summary
A driven-side rotator is rotatable synchronously with a camshaft and is supported between a gear member and a sprocket member of the driving-side rotator in an axial direction. A stopper portion of the driven-side rotator is adapted to contact the driving-side rotator in a rotational direction to limit a change in a relative phase between the crankshaft and the camshaft. The stopper portion radially outwardly projects from a small diameter portion provided at one end part of the driven-side rotator. A large diameter portion is provided at the other end part of the driven-side rotator and has a radial size that is measured from a rotational axis to a radially outer peripheral surface of the large diameter portion and is equal to or larger than that of the stopper portion.