Multi-Planetary Single Motor Drive Unit for Hybrid Powertrains

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Solution Overview

Problem

Hybrid powertrains for vehicles require additional components like motor/generators, brakes, and clutches, increasing vehicle cost and packaging space, while offering limited fuel economy improvements through different operating modes.

Innovation Solution

The implementation of a multi-planetary, single motor drive unit that can function as a compact electric drive axle or power-split drive axle arrangement, utilizing planetary gearing and a single electric machine, allowing for various operating modes including all-wheel drive configurations, and modular design for economies of scale in production.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If hybrid powertrains use multiple motor/generators, brakes and clutches to achieve different operating modes, then fuel economy is improved, but vehicle cost and packaging space increase

Engineering Contradiction:

Improvefuel economyVSAvoidnumber of components

Core Design Contradiction:

Use of energy by moving objectVSDevice complexity

Solution Approach 1:

The patent combines multiple functions (motor, generator, differential, final drive) into a single integrated electric machine assembly with planetary gear sets. This merging eliminates the need for separate motor/generators, brakes, and clutches while maintaining the ability to operate in multiple modes (electric-only, hybrid, regenerative braking), thereby reducing component count and complexity while preserving fuel economy benefits

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The single electric machine is designed to perform multiple functions: it can operate as a motor in electric-only mode, as a generator in regenerative braking mode, and can be selectively connected or disconnected through the planetary gear mechanisms. This multi-functionality replaces what would traditionally require separate dedicated components for each function, reducing overall system complexity while maintaining all necessary operating modes

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Adaptability or versatility

If hybrid powertrains include multiple motor/generators, brakes and clutches, then different operating modes are achieved, but packaging space requirements increase

Engineering Contradiction:

Improveoperating modesVSAvoidpackaging space

Core Design Contradiction:

Adaptability or versatilityVSVolume of moving object

Solution Approach 1:

The patent employs nested planetary gear sets where smaller planetary gear mechanisms are contained within larger differential assemblies, which are in turn integrated into the final drive housing. This nested arrangement allows multiple gear reduction stages and functional components to occupy overlapping spatial volumes, significantly reducing the overall packaging space required compared to linear arrangements of separate components

Inventive Principle:

Principle #7Nested doll (Nesting)

Solution Approach 2:

The patent transitions from a traditional linear arrangement of separate powertrain components to a three-dimensional integrated assembly where the electric machine, planetary gear sets, and differential are concentrically arranged around a common rotational axis. This dimensional reorganization allows components to share space radially and axially, reducing the longitudinal and lateral packaging footprint while maintaining all necessary operating modes

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

3Power

If traditional gearing arrangements are used, then power transmission is achieved, but compactness is reduced

Engineering Contradiction:

Improvepower transmissionVSAvoidcompactness

Core Design Contradiction:

PowerVSVolume of moving object

Solution Approach 1:

The patent utilizes planetary gear mechanisms where multiple pinion gears are arranged radially around a central sun gear, with all components rotating around a common axis. This radial, spherical arrangement allows power transmission through compact circular paths, achieving high torque multiplication and efficient power transfer in a much smaller volume compared to linear gear trains or belt-drive systems

Inventive Principle:

Principle #14Spheroidality (Curvature)

Data Source

PatentUS9950607B2Powertrain with multi-planetary, single motor drive unit

Publication Date: 2018.04.24 GM GLOBAL TECHNOLOGY OPERATIONS LLC

AI summary

A powertrain includes an output member, and first and second simple planetary gear sets. The planetary gear sets each have a first, a second, and a third member including a sun gear, carrier, and ring gear member. The drive unit includes a single electric machine operable as a motor and having a rotor connected to rotate in unison with and drive the sun gear member of the first planetary gear set. An interconnecting member connects the second member of the first planetary gear set to rotate in unison with the first member of the second planetary gear set. The third member of the first planetary gear set or the second member of the second planetary gear set is continuously grounded to the stationary member or operatively connected to be driven by an engine. The third member of the second planetary gear set is continuously operatively connected to the output member.