Vertical Engine Lubrication via Crankshaft Passageways

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Solution Overview

Problem

Conventional vertical engines face challenges in efficiently directing lubricating oil to tappet chambers without increasing pumping power loss, managing oil consumption, and maintaining stable lubrication due to complex factors like pressure variations and component layouts.

Innovation Solution

The design includes a system of lubricating oil passageways that force-feed lubricating oil from an oil pump through the crankshaft and direct it to the cylinder head, ensuring reliable lubrication without increasing pump capacity, and uses overhead valves with recesses for direct lubrication, minimizing noise and oil consumption.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If lubricating oil is force-fed by use of the pump, then lubricating oil can be supplied to multiple components, but the capacity of the oil pump has to be increased which leads to increase in pumping power loss

Engineering Contradiction:

Improvelubrication reliabilityVSAvoidpumping power loss

Core Design Contradiction:

ReliabilityVSLoss of energy

Solution Approach 1:

The lubrication system is segmented into multiple independent passageways: a main passageway for primary lubrication points and branch passageways for secondary points. This allows the oil pump to maintain its original capacity while distributing lubricating oil to multiple components through the segmented network, avoiding the need to increase pump capacity and thus reducing pumping power loss.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different passageways are designed with different characteristics to suit local lubrication needs. The main passageway handles high-flow requirements while branch passageways handle localized lubrication points, allowing each section to be optimized independently without requiring a universally oversized pump.

Inventive Principle:

Principle #3Local quality

2Reliability

If gas flows within the crankcase by the breather are used to direct oil mist, then lubrication can be achieved, but it is difficult to meet both directing necessary oil amount and minimizing oil in discharged gas from the breather

Engineering Contradiction:

Improvelubrication reliabilityVSAvoidoil consumption

Core Design Contradiction:

ReliabilityVSLoss of substance

Solution Approach 1:

The lubrication function is extracted from the gas flow system and implemented through dedicated lubricating oil passageways. This separates the lubrication delivery mechanism from the breather gas flow, allowing precise control of oil delivery to lubrication points without oil being carried away in the discharged gas, thus minimizing oil consumption while ensuring reliable lubrication.

Inventive Principle:

Principle #2Taking out (Extraction)

3Reliability

If phase difference in inner pressure variation is produced between the crankcase and the tappet chamber, then oil mist can be directed, but the amount of lubricating oil fluctuates due to unstable inner pressure variation

Engineering Contradiction:

Improvelubrication deliveryVSAvoidoil amount stability

Core Design Contradiction:

ReliabilityVSStability of the object's composition

Solution Approach 1:

The pressure-differential-based oil mist delivery system is replaced with a direct mechanical lubrication system using dedicated passageways. Lubricating oil is delivered directly to the tappet chamber through controlled passageways independent of crankcase pressure variations, eliminating the instability caused by fluctuating pressure differences while ensuring consistent lubrication delivery.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

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 solution reliably directs lubricating oil to the tappet chamber without increasing pumping power loss and maintains efficient lubrication, reducing noise and oil consumption, while being less influenced by engine operating conditions.

Implementation Method 1

a first lubricating oil passageway for supplying lubricating oil, sent out from the oil pump, to a lower bearing of the crankshaft; a second lubricating oil passageway extending through the interior of the crankshaft from the lower bearing to an upper bearing of the crankshaft

Methodology Applied

Scientific EffectPressure gradient: Pressure Gradient

Implementation Method 2

a third lubricating oil passageway provided in the cylinder barrel adjacent to the upper surface of the cylinder barrel and extending from the crankcase to immediately below stem end portions of the air intake valve and the exhaust valve so that lubricating oil leaked from the second lubricating oil passageway flows therethrough

Methodology Applied

Scientific EffectGravity: Gravitation

Data Source

PatentUS8813715B2Vertical engine

Publication Date: 2014.08.26 HONDA MOTOR CO LTD

AI summary

A vertical engine includes: an oil pump provided adjacent to the lower surface of a cylinder barrel and connected to a lower end portion of a cam gear shaft to be driven by the gear shaft; a first lubricating oil passageway for supplying lubricating oil from the oil pump to a lower bearing of a crankshaft; a second lubricating oil passageway extending through the crankshaft from the lower bearing to an upper bearing of the crankshaft; a third lubricating oil passageway provided adjacent to the upper surface of the barrel and extending from the crankcase to immediately below stem end portions of intake and exhaust valves so that lubricating oil leaked from the second lubricating oil passageway flows therethrough; and a fourth lubricating oil passageway for returning lubricating oil, dripped down from the third lubricating oil passageway to the stem end portions, to the pump.