Compact Vehicle Drive Train with Integrated Power Transfer

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Solution Overview

Problem

Modern motor vehicles require more compact drive trains to accommodate increasing technology and equipment, necessitating a reduction in size and weight, particularly in all-wheel drive configurations where packaging space for components is limited.

Innovation Solution

A compact power transfer unit is achieved by integrating a power transfer ring gear with the differential carrier, eliminating the need for separate drive components and reducing the number of components through which power is transmitted, thereby minimizing space and strain on bearings.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a separate external power transfer unit is added to convert a two-wheel drive vehicle to four-wheel drive, then all-wheel drive capability is achieved, but the vehicle size and weight increase

Engineering Contradiction:
Improveall-wheel drive capabilityVSAvoidvehicle weight
Core Design Contradiction:
Adaptability or versatilityVSWeight of moving object

Solution Approach 1:

The patent combines the power transfer unit with the existing transmission case, integrating the pinion gear and power transfer ring gear into the transmission housing. This merging eliminates the need for a separate external power transfer unit, reducing vehicle weight while maintaining all-wheel drive capability. The differential carrier is also integrated into the transmission case, further consolidating components.

Inventive Principle:
Principle #5Merging (Combining)

2Adaptability or versatility

If a separate external power transfer unit is added to convert a two-wheel drive vehicle to four-wheel drive, then all-wheel drive capability is achieved, but the packaging space increases

Engineering Contradiction:
Improveall-wheel drive capabilityVSAvoidpackaging space
Core Design Contradiction:
Adaptability or versatilityVSVolume of moving object

Solution Approach 1:

The power transfer unit is merged with the transmission case, with the pinion gear and power transfer ring gear housed within the existing transmission housing. This integration eliminates the need for separate external mounting space, reducing the overall packaging volume required for all-wheel drive components.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent nests the power transfer ring gear on the differential carrier, which itself is mounted in the transmission case. The pinion gear is rotatably mounted within the transmission case and meshes with the power transfer ring gear. This nested arrangement of gears within the existing transmission housing minimizes the space required for the power transfer unit.

Inventive Principle:
Principle #7Nested doll (Nesting)

3Power

If multiple separate drive components are used between the differential carrier and power transfer ring gear, then power transmission is achieved, but the device complexity and space requirements increase

Engineering Contradiction:
Improvepower transmissionVSAvoidnumber of components
Core Design Contradiction:
PowerVSDevice complexity

Solution Approach 1:

The patent extracts and eliminates intermediate drive components from the power transmission path. Instead of using multiple separate gears or mechanisms between the differential carrier and power transfer ring gear, the design directly meshes the pinion gear with the power transfer ring gear, simplifying the component structure while maintaining effective power transmission.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The differential carrier and power transfer ring gear are integrated as a single assembly, with the power transfer ring gear mounted on or integrally formed with the differential carrier. This merging reduces the number of separate components and simplifies the power transmission path from the differential to the drive wheels.

Inventive Principle:
Principle #5Merging (Combining)

4Power

If multiple separate drive components are used in the power transmission path, then power transmission is achieved, but parasitic losses and bearing strain increase

Engineering Contradiction:
Improvepower transmissionVSAvoidparasitic losses
Core Design Contradiction:
PowerVSLoss of energy

Solution Approach 1:

The patent removes intermediate drive components from the power transmission path, eliminating the parasitic losses associated with additional gears and bearings. The direct meshing of the pinion gear with the power transfer ring gear, which is integrated on the differential carrier, minimizes energy loss and reduces strain on bearing components.

Inventive Principle:
Principle #2Taking out (Extraction)

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 the overall size of the drive train, minimizes parasitic losses, and optimizes torque distribution, enhancing efficiency and mechanical integrity while allowing for the conversion of two-wheel drive vehicles to four-wheel drive without significant alterations.

Implementation Method 1

The pinion gear meshes directly with the power transfer ring gear. The power transfer unit pinion gear is configured to rotate when driven by the power transfer ring gear.

Methodology Applied
Scientific EffectGear meshing: Gear

Data Source

PatentEP3181392B1Compact vehicle drive train
Publication Date: 2021.04.14 COUNTYTRAC
  • EP3181392B1 patent drawingFigure 1
  • EP3181392B1 patent drawingFigure 2
  • EP3181392B1 patent drawingFigure 3

AI summary

A vehicle drive train comprising a transmission 11 having a differential 3 mounted in a transmission case 7, the differential 3 having a differential carrier 3a and a power transfer ring gear 2, the power transfer ring gear 2 being mounted on or integrally formed with the differential carrier 3a, the vehicle drive train further comprising a power transfer unit 8 having a pinion gear 4 which is rotatably mounted in the transmission case 7 and meshes directly with the power transfer ring gear 2. The present invention provides a more compact vehicle drive train assembly including a configuration that minimises the space occupied by the existing components and in particular provides a power transfer unit 8 which allows for a more compact arrangement.