Neutral Split Gear Engine Startup Energy Reduction

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Solution Overview

Problem

Motor vehicles equipped with split gear transmissions face challenges in starting up quickly and efficiently, especially in cold temperatures, due to high energy demands and increased load on the engine from viscous lubricants, which can lead to unnecessary battery energy usage and prolonged start-up times.

Innovation Solution

A method that involves engaging a neutral split gear in the gearbox during engine shutdown and startup, based on lubricant temperature and viscosity conditions, to prevent power transmission to lay shafts, reducing energy demands and load on the engine.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If the engine is started up with the split gear in neutral position, then the energy consumption and load on the engine are reduced, but the gear box must be controlled to engage neutral gear during shutdown and startup

Engineering Contradiction:
Improveenergy consumption during startupVSAvoidgear box control complexity
Core Design Contradiction:
Use of energy by moving objectVSDevice complexity

Solution Approach 1:

The control unit engages the neutral split gear position before the engine startup process begins. By preemptively positioning the gear box in neutral during shutdown, the system prevents power transmission to lay shafts during cranking, thereby reducing energy consumption and startup load without requiring complex real-time control during startup itself.

Inventive Principle:
Principle #10Preliminary action

2Speed

If the lay shaft rotates in viscous lubricant during cold start, then the engine can start up, but the energy demand and load on the engine increase significantly

Engineering Contradiction:
Improveengine startup speedVSAvoidenergy demand during startup
Core Design Contradiction:
SpeedVSUse of energy by moving object

Solution Approach 1:

The invention extracts or removes the lay shaft from the power transmission path by engaging the neutral split gear position. This separation prevents the lay shaft from rotating during engine startup, eliminating the energy demand associated with rotating components embedded in viscous lubricant during cold starts, while still allowing the engine to crank and start normally.

Inventive Principle:
Principle #2Taking out (Extraction)

3Use of energy by moving object

If the clutch is disengaged during startup to reduce load, then the energy consumption decreases, but the startup time is prolonged

Engineering Contradiction:
Improvebattery energy usageVSAvoidstartup time
Core Design Contradiction:
Use of energy by moving objectVSLoss of time

Solution Approach 1:

The neutral split gear position acts as an intermediary mechanism between the clutch and the lay shaft. Instead of relying solely on clutch disengagement to reduce load, this intermediate gear position directly prevents power transmission to the lay shaft, achieving energy reduction without the time penalty associated with clutch operation, thereby optimizing both energy consumption and startup time.

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentEP2331849B1Method and computer programme product for improving performance of a motor vehicle
Publication Date: 2013.07.31 SCANIA CV AB
  • EP2331849B1 patent drawingFigure 1~2
  • EP2331849B1 patent drawingFigure 3
  • EP2331849B1 patent drawingFigure 4a

AI summary

The present invention relates to a method for improving performance of a motor vehicle (100) comprising an engine(230) and a gear box (240) with an input shaft (236), a main shaft (237) and at least one lay shaft (320), where in operational power is arranged to be transmitted to the input shaft (236) of the gear box, where in operational power in a first split gear (SL) is arranged to be transmitted from the input shaft (236) to the lay shaft (320). The operational power in a second split gear (SH) is arranged to be transmitted to lay shaft (320) via the main shaft (237), where in the operational power in a third neutral split gear (SN) is not transmitted to the lay shaft (320) or the main shaft (237). The method comprises the step of, when starting up the engine, when applicable, affecting the gear box (240) in a way such that said third neutral split gear (SN) is engaged, so that no operational power is transmitted to said lay shaft (320) and main shaft (237).