Scavenge Pump Positioning for Saddle Vehicle Oil Recovery

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Solution Overview

Problem

The existing design of scavenge pumps in saddled vehicles results in a larger displacement amplitude during a swing, leading to the generation of bubbles in the oil, as the pump is positioned farther from the link boss than the crankshaft, causing inefficiencies in oil recovery and cooling.

Innovation Solution

The scavenge pump is positioned between the link boss and the crankshaft, with its discharge port oriented towards the inner wall of the crankcase, which includes a water channel for cooling, and shares a drive shaft with the feed pump, reducing component count and improving space efficiency, while a ribbed inner wall enhances oil cooling by increasing contact area.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the scavenge pump is disposed lower than the crank chamber to facilitate oil recovery, then the oil recovery function is improved, but the displacement amplitude during swing increases causing bubble generation

Engineering Contradiction:
Improveoil recoveryVSAvoidbubble generation
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent changes the positional parameter of the scavenge pump from being disposed lower than the crank chamber to being disposed between the link boss and crankshaft. This parameter change reduces the displacement amplitude during swing while maintaining effective oil recovery capability through the optimized discharge port orientation toward the inner wall.

Inventive Principle:
Principle #35Parameter changes

2Ease of manufacture

If the scavenge pump is disposed farther from the link boss to accommodate the crankshaft positioning, then the crankshaft housing is facilitated, but the swing displacement amplitude increases leading to bubble generation

Engineering Contradiction:
Improvecrankshaft housingVSAvoidbubble generation
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent repositions the scavenge pump in a different spatial arrangement - between the link boss and crankshaft rather than lower than the crank chamber. This dimensional repositioning allows the discharge port to face the inner wall effectively while reducing swing displacement, resolving the contradiction between manufacturing ease and reliability.

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

3Ease of manufacture

If the discharge port is oriented away from the inner wall to simplify structure, then manufacturing is easier, but oil cooling efficiency decreases

Engineering Contradiction:
Improvestructure simplicityVSAvoidoil cooling efficiency
Core Design Contradiction:
Ease of manufactureVSTemperature

Solution Approach 1:

The patent applies local quality by orienting the discharge port specifically toward the inner wall to maximize cooling effectiveness in the critical oil discharge region. This localized optimization of the discharge port orientation enhances oil cooling efficiency where it is most needed without complicating the overall structure.

Inventive Principle:
Principle #3Local quality

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

This configuration reduces bubble generation, improves oil cooling efficiency, and optimizes the design by minimizing displacement amplitude, ensuring effective oil recovery and cooling, and enhancing space efficiency by sharing components.

Implementation Method 1

The inner wall includes a water channel for introducing cooling water around a cylinder

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 2

The inner wall includes a water channel for introducing cooling water around a cylinder

Methodology Applied
Scientific EffectConvection: Convection

Implementation Method 3

The inner wall includes at least one rib... the rib is disposed at the inner wall that is continuous from a cam chain chamber for housing a cam chain

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Data Source

PatentEP3889017B1Saddle type vehicle
Publication Date: 2023.07.05 HONDA MOTOR CO LTD
  • EP3889017B1 patent drawingFigure 1
  • EP3889017B1 patent drawingFigure 2
  • EP3889017B1 patent drawingFigure 3

AI summary

A saddled vehicle includes: a scavenge pump (121) fixed to a crankcase (29) and recovering oil in a crank chamber (41); and a link boss (167) formed at the crankcase (29) and holding a shaft element (166) to be rotatable about a swing axis (Sx) parallel to a rotation axis of a rear wheel, the link boss (167) coupling the crankcase (29) to the vehicle body frame. The scavenge pump (121) is disposed between the link boss (167) and the crankshaft (42) as seen in a side view of the vehicle. This provides a saddled vehicle including a scavenge pump that displaces by a smaller amount when a unit-swing type power unit swings.