Piston-Rack Sector Gear Layout for Lower Track Wear
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing piston arrangements in internal combustion engines face high wear and inefficiencies due to the forces involved in transferring power from the piston to a rotating shaft, particularly in the cam surface and follower mechanism.
Innovation Solution
A piston arrangement featuring a rotatable element with engagement profiles that couple to a track, allowing power transfer while reducing wear through optimized engagement and distribution of forces, with optional features like multiple followers and non-simple harmonic motion profiles to enhance efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If a follower runs on a cam surface to transfer power from the piston, then power transfer is achieved, but high loads cause high wear on the cam surface and follower
Solution Approach 1:
The invention divides the power transfer function into two separate mechanisms: the cam surface-follower interface for motion control and the toothed sector gear-rack interface for power transfer. This segmentation allows each interface to be optimized for its specific function, reducing wear on both the cam surface and follower while maintaining effective power transfer from the piston to the rotating shaft.
2Speed
If the cam surface and follower are used for power transfer, then motion conversion is achieved, but the forces involved subject these components to high loads
Solution Approach 1:
The invention introduces a toothed sector gear as an intermediary mechanism between the piston-driven rack and the rotating shaft. The rack, driven by the piston through the cam surface, engages with the toothed sector gear which then transfers power to the rotating shaft. This intermediary gear reduces the direct load on the cam surface and follower while maintaining effective motion conversion and power transfer.
3Device complexity
If a single follower runs on the track, then the structure is simple, but wear on the track is high due to concentrated forces
Solution Approach 1:
The invention segments the single follower into multiple followers that run on the cam surface simultaneously. This segmentation distributes the loads and forces across multiple contact points, reducing wear on the cam surface and track while maintaining structural simplicity. The multiple followers work in parallel to achieve the same motion conversion function with reduced individual and cumulative wear.
Data Source
AI summary
A piston arrangement includes a piston movable within a cylinder in reciprocating motion along a piston axis, a rack movable with the piston, a sector gear configured to engage and disengage the rack and rotatable around a sector gear axis, a track adapted to rotate relative to the cylinder around a track axis of rotation, the piston being coupled to the track. The sector gear and the track are coupled in rotation. The track may have a shape such that the movement of the piston coupled to the track is substantially non simple harmonic. Also, an internal combustion engine comprising the piston arrangement.