Coaxial Two-Part Valve for Low-Loss Working-Gas Transfer

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Solution Overview

Problem

Existing external heat source engines face challenges in achieving efficient gas transfers with minimal pressure and thermal losses, and existing valve distributions are inefficient in managing the flow of working gas between chambers, leading to reduced performance and increased energy consumption.

Innovation Solution

A slide valve with two coaxial parts - a working gas guide part and a distribution part - that synchronizes with the piston's movement to facilitate gas flow between the working chamber and exchangers, ensuring large passage sections and minimizing pressure and thermal losses.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of moving object

If a single-piece slide valve is used, then the passage section for working gas is larger, but heat exchanges between hot and cold flows increase significantly

Engineering Contradiction:
Improvepassage sectionVSAvoidheat exchanges
Core Design Contradiction:
Area of moving objectVSLoss of energy

Solution Approach 1:

The slide valve is divided into two separate coaxial parts: a stationary guide part and a movable distribution part. This segmentation allows the hot and cold flows to be physically separated into different internal passages, preventing harmful heat exchanges while maintaining large passage sections for efficient gas transfer.

Inventive Principle:
Principle #1Segmentation

2Device complexity

If a single-piece slide valve is used, then the structure is simpler, but discontinuities create double valve effects that hinder gas circulation

Engineering Contradiction:
Improvevalve structureVSAvoidgas circulation efficiency
Core Design Contradiction:
Device complexityVSProductivity

Solution Approach 1:

The movable distribution part is nested within the stationary guide part, forming a coaxial arrangement. This nested structure eliminates discontinuities and double valve effects by providing continuous, smooth passage sections for gas flow, thereby improving circulation efficiency while maintaining structural compactness.

Inventive Principle:
Principle #7Nested doll (Nesting)

3Manufacturing precision

If cam-controlled valve distribution is used, then valve timing is precise, but the passage section is insufficient and pressure losses increase

Engineering Contradiction:
Improvevalve timingVSAvoidpassage section
Core Design Contradiction:
Manufacturing precisionVSArea of moving object

Solution Approach 1:

The distribution part is designed to rotate dynamically during the engine cycle, with windows that selectively align with ports in the cylinder head. This dynamic rotation enables precise valve timing control while simultaneously providing large, continuous passage sections through the internal passages, reducing pressure losses.

Inventive Principle:
Principle #15Dynamics

4Productivity

If the valve passage section is increased to minimize pressure losses, then gas transfer efficiency improves, but heat exchanges between hot and cold flows increase

Engineering Contradiction:
Improvegas transfer efficiencyVSAvoidheat exchanges
Core Design Contradiction:
ProductivityVSLoss of energy

Solution Approach 1:

The valve incorporates separate internal passages for hot and cold flows within the segmented structure. This allows large passage sections to be provided for each flow independently, minimizing pressure losses and improving transfer efficiency, while the physical separation prevents harmful heat exchanges between the hot and cold gas streams.

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP4077891B1Coaxial two-part valve, and external hot-source engine comprising same
Publication Date: 2025.09.17 HEVATECH
  • EP4077891B1 patent drawingFigure 1a~2c
  • EP4077891B1 patent drawingFigure 3~4
  • EP4077891B1 patent drawingFigure 5~6

AI summary

The present invention relates to a gate valve (10) for a motor (1) with an external heat source comprising a cylinder (2), a piston (3), a cylinder head (4), a working chamber (5) for a working gas, a valve train comprising the gate valve bringing the working chamber selectively into communication with different resources. The gate valve (10) comprises two coaxial portions: - a portion (11) for guiding the working gas, comprising internal passages opening radially through at least one outlet that communicates selectively with the working chamber (5) via at least one opening (41) provided in the cylinder head (4), and - a portion (16) for distributing the working gas, which is movable and arranged on the periphery of the guide portion (11), comprising at least one window (17) that brings the working chamber (5) selectively into communication with at least one of the internal passages, such that the working gas flows selectively between the working chamber (5) and the different resources. The present invention also relates to a motor with an external heat source comprising the gate valve.