Valve Timing Adjustment Device with Planetary Bearing
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Solution Overview
Problem
Existing valve timing adjustment devices for internal combustion engines suffer from abnormal noise due to collisions between the driving rotor and the driven rotor, which are not adequately addressed by current designs.
Innovation Solution
The device incorporates a planetary rotor with a single sequence type planetary bearing and an elastic component to generate a restoring force, causing the driving rotor to incline and maintain contact with the driven rotor on both sides, thereby reducing noise through a thrust-bearing mechanism.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the driving rotor is supported by the driven rotor as a thrust bearing, then the driving rotor can rotate smoothly, but abnormal noise is generated due to collision between the driving rotor and driven rotor when the driving rotor moves axially
Solution Approach 1:
The patent introduces a planetary rotor as an intermediary component between the driving rotor and driven rotor. The planetary rotor includes a planetary bearing with rolling elements that mediate the axial movement and support forces, preventing direct collision between the driving and driven rotors while maintaining smooth rotation
Solution Approach 2:
The patent changes the support mechanism parameters by transitioning from direct thrust bearing contact to a planetary bearing system with rolling elements. This parameter change allows the system to maintain rotational smoothness while eliminating the collision-induced noise through the rolling contact mechanism
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 configuration effectively restricts the driving rotor's movement and collision with the driven rotor, significantly reducing abnormal noise and enhancing silence by maintaining contact and applying pressure through the inclination.
Implementation Method 1
an elastic component interposed between the planetary rotor and the planetary carrier to generate a restoring force biasing the planetary rotor to the eccentric side such that the driving rotor is inclined to the driven rotor
Implementation Method 2
a single sequence type planetary bearing having an outer ring held by the planetary gear, an inner ring supported by the planetary carrier in the radial direction and receiving the restoring force from the elastic component, and a plurality of spherical rolling elements interposed between the outer ring and the inner ring
Data Source
AI summary
A planetary rotor includes: a planetary gear engaged with a driving rotor and a driven rotor on an eccentric side; and a single sequence type planetary bearing having an outer ring held by the planetary gear, an inner ring supported by a planetary carrier in the radial direction and receiving a restoring force from an elastic component, and a plurality of spherical rolling elements interposed between the outer ring and the inner ring. The outer ring is arranged to form a rolling contact part in contact with the spherical rolling element on the eccentric side, with a contact angle to a specific side in the axial direction. A thrust-bearing part where the driving rotor is supported by the driven rotor on the specific side and on the eccentric side is located closer to a rotation center line of the driven rotor than the rolling contact part is.