Dynamic Cam Lobe Coupling for Variable Valve Actuation
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Solution Overview
Problem
Existing variable valve actuation systems require additional hardware to control unneeded motion, such as spring returns, and lack a simple method for dynamic engagement or disengagement of cam lobes on the camshaft, which complicates the operation of intake and exhaust valves.
Innovation Solution
A cam-driven internal combustion engine system with a rotating camshaft and selectively disengageable cam lobes, utilizing a coupler and controller to dynamically engage or disengage rotational force, allowing for activation or deactivation of valves on a cycle-by-cycle basis without additional hardware, using a mechanism like an internal keyway and slidable disk for precise alignment and engagement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If additional hardware (spring return) is used to maintain follower contact with cam lobe, then reliability of valve actuation is improved, but device complexity increases
Solution Approach 1:
The patent removes the spring return component from the system by implementing a different mechanism where the follower can be dynamically engaged or disengaged from the cam lobe through a coupler system, eliminating the need for additional hardware to maintain contact
2Reliability
If cam lobe is continuously engaged with follower, then valve actuation reliability is maintained, but ability to deactivate valve dynamically is lost
Solution Approach 1:
The patent implements a dynamic system where the cam lobe can be selectively engaged or disengaged from the follower through a coupler mechanism controlled by a controller, allowing the valve to be activated or deactivated on a cycle-by-cycle basis based on engine operating conditions
3Adaptability or versatility
If multiple piece rocker arm with locking components is used, then selective cam lobe operation is achieved, but device complexity increases
Solution Approach 1:
The patent extracts the complexity from the rocker arm structure and places it in the cam lobe coupling system, using a coupler to selectively engage or disengage the cam lobe from the follower, simplifying the overall valve train while maintaining selective operation capability
Data Source
AI summary
Disclosed is a method and system for intermittently operating poppet valves in an internal combustion engine when desired by the selective locking or unlocking of one or more cam lobes with the camshaft. One or more cam lobes, with a small radial clearance, ride on a camshaft such that an engagement mechanism may be activated as desired to lock the cam lobe to the camshaft, thereby activating the respective poppet valve. The cam lobe is prevented from moving axially to ensure correct alignment with a follower. A suitable holding device may be used to ensure the non-activated cam lobes are restrained at a suitable orientation relative to the cam follower.