Oil Separator Inertia Collision Pre-Separation

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing oil separators are inefficient in removing relatively large oil particles from blow-by gas, leading to potential failure or inadequate separation, especially when used as pre-separators for larger particles.

Innovation Solution

An oil separator design featuring a blow-by gas passage with a separation wall that changes the flow direction, including a first surface forming an obtuse angle with the upstream passage and a second surface extending perpendicularly, along with a narrowed passage and a stepped surface, effectively traps large oil particles using inertia, and a drain for returning separated oil to the crankcase.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a sheet spring is used to close the opening of the flow passage in an inertia collision type oil separator, then small oil particles can be trapped effectively, but large oil particles may adhere to the sheet spring causing failure

Engineering Contradiction:
Improveoil particle separation efficiencyVSAvoidseparation reliability
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The invention divides the oil separator into two distinct sections: a pre-separator for large oil particles and a main separator for small oil particles. This segmentation allows each section to be optimized for its specific function, preventing large particles from interfering with the delicate sheet spring mechanism while maintaining effective separation of small particles.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The pre-separator performs preliminary separation of large oil particles before the blow-by gas enters the main separator. This preliminary action removes potentially harmful large particles that could adhere to the sheet spring, ensuring reliable operation of the main separation mechanism.

Inventive Principle:
Principle #10Preliminary action

2Reliability

If a labyrinth type oil separator is used, then large oil particles can be separated, but the separation efficiency for large particles is insufficient when used as a pre-separator

Engineering Contradiction:
Improveoperational reliabilityVSAvoidlarge particle removal efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The pre-separator employs a specific local configuration with a narrowed passage and strategically positioned separation wall to create high-velocity flow conditions optimal for large particle separation. This localized optimization enhances large particle removal efficiency specifically where needed, rather than relying on the general labyrinth structure alone.

Inventive Principle:
Principle #3Local quality

3Measurement precision

If the blow-by gas is accelerated through a narrow gap to collide with a wall, then small oil particles can be trapped, but the structure is complex and prone to failure with large particles

Engineering Contradiction:
Improvesmall particle separation capabilityVSAvoidseparator structure complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The invention segments the separation function into two distinct devices: a simple pre-separator for large particles and a more complex main separator for small particles. This segmentation allows the complex accelerated flow mechanism to be isolated to only where it is needed, reducing overall system vulnerability and simplifying the pre-separation stage.

Inventive Principle:
Principle #1Segmentation

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 enhances the separation efficiency of large oil particles, minimizes pressure loss, and prevents oil re-entrainment in the blow-by gas, allowing for effective pre-separation before further processing by a post-separator.

Implementation Method 1

the oil particles contained in the blow-by gas adhere to the collision plate owing to the inertia of the oil particles

Methodology Applied
Scientific EffectInertia: Inertia

Implementation Method 2

a separation wall for changing a flow direction of the blow-by gas that has passed through the upstream passage

Methodology Applied
Scientific EffectFlow direction change:

Implementation Method 3

The blow-by gas is accelerated as the blow-by gas flows through this gap

Methodology Applied
Scientific EffectFlow acceleration:

Implementation Method 4

a drain for returning separated oil to the crankcase

Methodology Applied
Scientific EffectGravity: Gravitation

Data Source

PatentEP3205851B1Oil separator
Publication Date: 2020.12.02 NIFCO INC
  • EP3205851B1 patent drawingFigure 1
  • EP3205851B1 patent drawingFigure 2
  • EP3205851B1 patent drawingFigure 3

AI summary

Provided is an oil separator having a high efficiency in removing oil particles of relatively large sizes. A blow-by gas passage of the oil separator (2) includes an upstream passage (18) and a downstream passage (20) extending at an angle to the upstream passage. A separation wall (36) provided in the downstream passage includes a first surface (40, 78) forming an obtuse angle relative to the upstream passage, and a second surface (42) adjoining the first surface on a downstream side thereof and defining a planar surface extending substantially perpendicularly to the upstream passage. The blow-by gas is accelerated in the upstream passage, and the flow direction of the blow-by gas is changed by the first surface without substantially changing the flow speed and without disturbing the flow before the blow-by gas flows along the second surface. At this time, the oil particles in the blow-by gas collide with and are trapped by the second surface owing to the inertia of the oil particles.