Belt-Operated Starter-Generator Drive Segmentation

Solution Overview

Problem

The existing belt-driven starter-generator drives for internal combustion engines require complex tensioner connections and high belt pretension for starting, which compromises efficiency and CO2 balance, and necessitates special precautions for switching between start-up and generator operations.

Innovation Solution

A secondary drive plane with a toothed belt connection between a generator pulley and a crankshaft pulley, allowing for releasable coupling via a magnetic or centrifugal clutch, enabling high torque transmission without the need for complex tensioners and optimizing belt pretension.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If a frictional V-ribbed belt is used to connect the pulleys for quiet operation, then noise is reduced, but high belt pretension is required for high torques during starting process

Engineering Contradiction:

ImprovenoiseVSAvoidbelt pretension

Core Design Contradiction:

Object-affected harmful factorsVSForce

Solution Approach 1:

The drive system is segmented into two separate belt drives: a first V-ribbed belt drive for generator operation and a second toothed belt drive for starting operation. This segmentation allows each belt type to be optimized for its specific function without compromise.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The system dynamically switches between the two belt drives based on operational mode. The coupling means engages the second toothed belt drive during starting and disengages it during generator operation, allowing optimal belt characteristics for each phase.

Inventive Principle:

Principle #15Dynamics

2Force

If high belt pretension is applied for starting process, then high torque transmission is achieved, but CO2 balance deteriorates and complex tensioner connections are required

Engineering Contradiction:

Improvetorque transmissionVSAvoidtensioner connections

Core Design Contradiction:

ForceVSDevice complexity

Solution Approach 1:

The drive system is segmented into two separate belt drives: a first V-ribbed belt drive for generator operation and a second toothed belt drive for starting operation. This segmentation allows each belt type to be optimized for its specific function without compromise.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The high pretension requirement is extracted from the V-ribbed belt drive and assigned to the toothed belt drive. The toothed belt's positive engagement mechanism inherently provides high torque transmission without requiring complex tensioner connections.

Inventive Principle:

Principle #2Taking out (Extraction)

3Device complexity

If a single belt drive is used for both starting and generating, then device simplicity is maintained, but overall efficiency deteriorates due to compromise design

Engineering Contradiction:

Improvedrive structureVSAvoidoverall efficiency

Core Design Contradiction:

Device complexityVSProductivity

Solution Approach 1:

The drive system is segmented into two separate belt drives: a first V-ribbed belt drive for generator operation and a second toothed belt drive for starting operation. This segmentation allows each belt type to be optimized for its specific function without compromise.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The coupling means provides multi-functionality by enabling the system to operate in two distinct modes: generator mode using the V-ribbed belt and starting mode using the toothed belt. This universal interface allows optimal performance across different operational requirements.

Inventive Principle:

Principle #6Universality (Multi-functionality)

4Adaptability or versatility

If the belt span is changed when switching between start-up and generator operation, then functional flexibility is achieved, but special precautions are needed to ensure necessary belt pretension

Engineering Contradiction:

Improveoperational flexibilityVSAvoidbelt pretension maintenance

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The drive system is segmented into two separate belt drives: a first V-ribbed belt drive for generator operation and a second toothed belt drive for starting operation. This segmentation allows each belt type to be optimized for its specific function without compromise.

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

This solution eliminates the need for costly tensioner connections and allows for reduced belt pretension, enhancing efficiency and smoothness during generator operation while maintaining high torque capability for starting, thus improving the CO2 balance.

Implementation Method 1

the coupling means is a magnetic coupling or a centrifugal clutch

Methodology Applied

Scientific EffectMagnetic coupling: Magnetism

Implementation Method 2

the coupling means is a magnetic coupling or a centrifugal clutch

Methodology Applied

Scientific EffectCentrifugal force: Centrifugal Force

Implementation Method 3

The positive fit of the toothed belt between the crankshaft pulley and generator pulley enables a very high transmission torque

Methodology Applied

Scientific EffectFriction: Friction

Data Source

PatentEP2241747B1Belt-operated starter-generator drive

Publication Date: 2018.08.15 CONTITECH ANTRIEBSSYSTEME GMBH

Figure 1~2

AI summary

The belt-driven starter generator pinion has a pinion (2) provided in a pinion plane of a crankshaft disk (4) that is connected with a crankshaft. A generator disk (5) is provided which is connected with a generator. An ancillary unit disk (6,7,8) is provided, which is connected with an ancillary unit. The all disks are connected with each other by a belt (9).