Oil-Free Vehicle Air Compressor with Balanced Dual Compression

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Solution Overview

Problem

Vehicle-mounted single-cylinder piston type air compressors face issues with unbalanced stress and increased vibration due to rising exhaust pressure, leading to short service life and large occupied space.

Innovation Solution

A vehicle-mounted electric oil-free air compressor integrating a double-acting piston with primary and secondary compression functions, where the piston's primary and secondary compression forces act alternately to balance stress, and a high-efficiency flywheel shaft is used to stabilize operation and reduce vibration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of stationary object

If a single-cylinder piston type air compressor is used to reduce occupied space, then the device size is reduced, but the stress balance deteriorates and vibration increases

Engineering Contradiction:
Improveoccupied spaceVSAvoidstress balance
Core Design Contradiction:
Area of stationary objectVSStability of the object's composition

Solution Approach 1:

The single-cylinder piston compressor is segmented into two independent compression chambers (first and second chambers) within the same cylinder, each with its own piston. This segmentation allows the pistons to operate in opposite phases, balancing the stress on the crankshaft while maintaining a compact single-cylinder structure.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces a dual-chamber configuration within the single cylinder, utilizing the radial dimension to create two compression spaces. The pistons are positioned at different angular positions (180 degrees apart), transforming the stress application from a single-point load to a distributed balanced load on the crankshaft.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Stress or pressure

If exhaust pressure is increased to meet new national standards, then the compression capability is improved, but the stress imbalance worsens and vibration increases

Engineering Contradiction:
Improveexhaust pressureVSAvoidstress balance
Core Design Contradiction:
Stress or pressureVSStability of the object's composition

Solution Approach 1:

The two pistons operate in periodic alternating fashion, with one piston in compression stroke while the other is in intake or exhaust stroke. This periodic action ensures that the compression forces are distributed evenly over time, preventing stress concentration and reducing vibration even at high exhaust pressures.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The second piston acts as a counterweight to the first piston, with its compression forces opposing and balancing the forces of the first piston. This counterbalancing effect reduces the net stress on the crankshaft and connecting rods, allowing higher exhaust pressures to be achieved without excessive vibration.

Inventive Principle:
Principle #8Anti-weight (Counterweight)

3Use of energy by moving object

If a direct-current synchronous permanent magnet motor with spline connection is used, then the driving efficiency is improved, but the device complexity increases

Engineering Contradiction:
Improvedriving efficiencyVSAvoiddevice complexity
Core Design Contradiction:
Use of energy by moving objectVSDevice complexity

Solution Approach 1:

The spline connection acts as an intermediary mechanism between the motor shaft and the pistons, providing both power transmission and mechanical coupling. This intermediary structure enables efficient direct-drive operation while maintaining manageable device complexity through a well-established mechanical connection type.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 solution achieves balanced piston stress and reduced vibration, resulting in a stable and efficient operation with extended service life and compact design.

Implementation Method 1

a flywheel shaft driven by an elastic body to rotate

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Data Source

PatentEP3869039B1Vehicle-mounted electric oil-free air compressor
Publication Date: 2022.05.25 RUILI GROUP RUIAN AUTO PARTS CO LTD
  • EP3869039B1 patent drawingFigure 1
  • EP3869039B1 patent drawingFigure 2~3
  • EP3869039B1 patent drawingFigure 4~5

AI summary

The present invention relates to a vehicle-mounted electric oil-free air compressor, including a motor (1), a box body (3), a piston (21), and a flywheel shaft (30), wherein the motor (1) is fixed on the box body (3), a cylinder cover (10) is provided at the top of the box body (3), a main shaft of the motor (1) is provided with a coupling driving end (32), the flywheel shaft (30) is driven by an elastic body (31) to rotate, wherein the piston (21) is provided with a primary intake valve piece (8) and a primary exhaust valve piece (7), the box body (3) is provided with a secondary cavity (14), a secondary exhaust valve piece (15) is provided at a vent hole on one side of the cavity, and the primary exhaust valve piece (7) is also a secondary intake valve piece of the compressor. Thus, the exhaust pressure is increased. When the piston reciprocates, the stress is balanced and the vibration is small, and with the assistance of a high-efficiency flywheel, the operation of the air compressor is stable.