Hydraulic Lash Adjuster Air Bubble Separation via Piston Recess
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Hydraulic lash adjusters with incompressible fluids face performance issues due to air bubbles, leading to valve lift loss and potential engine failure, as they fail to maintain consistent contact with valve train components.
Innovation Solution
A hydraulic lash adjuster design featuring a longitudinally extending pushrod with a piston having an internal reservoir and a fluid pathway with multiple turns and a circumferential recess, which guides hydraulic fluid flow to separate and expel air bubbles, ensuring consistent operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If air bubbles are introduced into the hydraulic fluid, then the lash adjuster can compress, but this causes valve lift loss and potential engine failure
Solution Approach 1:
The patent implements a preliminary air removal action by designing a fluid pathway with multiple turns and a circumferential recess that creates a trap for air bubbles before they can enter the high-pressure region. This preliminary action prevents air bubbles from causing compression and maintaining reliable contact between the lash adjuster and valve train components throughout operation.
2Reliability
If a simple fluid pathway is used, then the device complexity is reduced, but air bubbles cannot be effectively separated and expelled
Solution Approach 1:
The patent applies dimensionality change by introducing a circumferential recess that creates a three-dimensional air trap within the fluid pathway. This recess forms a pocket that captures air bubbles, utilizing the vertical dimension to separate air from the hydraulic fluid flow path, thereby enhancing air removal effectiveness without adding complex external components.
3Object-affected harmful factors
If the fluid pathway has multiple turns, then air bubbles are separated and expelled, but the device complexity increases
Solution Approach 1:
The patent merges the air separation function with the existing fluid pathway structure by integrating multiple turns and a circumferential recess into the piston's internal geometry. This combining approach allows the fluid pathway to simultaneously perform its primary function of hydraulic fluid delivery and the secondary function of air bubble separation and expulsion, reducing the need for additional separate components.
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
The design effectively removes air bubbles from the hydraulic fluid, maintaining consistent contact with valve train components and enhancing engine performance by preventing valve lift loss and potential failures.
Implementation Method 1
A hydraulic lash adjuster located between valve train components may eliminate lash by utilizing a high pressure volume located under a piston. This high pressure volume includes an incompressible fluid, such as oil, that enters via a valve.
Implementation Method 2
A hydraulic lash adjuster design featuring a longitudinally extending pushrod with a piston having an internal reservoir and a fluid pathway with multiple turns and a circumferential recess, which guides hydraulic fluid flow to separate and expel air bubbles
Data Source
AI summary
A hydraulic lash adjuster includes a longitudinally extending pushrod having a proximal end and a distal end, and a cavity located at the distal end and a piston received in the cavity. The piston includes an internal reservoir and a fluid pathway to the internal reservoir. The fluid pathway includes a longitudinal passage and a radial passage.