Coaxial Transmission Actuator Reducer for Compact Gear Control

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Solution Overview

Problem

Conventional automotive transmission control apparatuses require larger mounting spaces due to eccentric driving mechanisms, leading to increased size and complexity, while lacking flexibility in mounting and efficiency.

Innovation Solution

The apparatus features a coaxial design with a reduction unit housed within a driving unit, where the inner gear member is eccentrically coupled to the main shaft, allowing for high power transmission with reduced size and improved deceleration effects, utilizing a cycloidal tooth profile for enhanced durability and efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If eccentric driving is used to improve reducer efficiency, then power transmission efficiency is improved, but the apparatus size and mounting space requirements increase

Engineering Contradiction:
Improvepower transmission efficiencyVSAvoidmounting space
Core Design Contradiction:
Loss of energyVSVolume of stationary object

Solution Approach 1:

The reduction unit is nested within the driving unit, with the inner gear member positioned inside the outer gear member. This nested configuration allows the eccentric driving mechanism to achieve high power transmission efficiency while minimizing the overall apparatus size and mounting space requirements.

Inventive Principle:
Principle #7Nested doll (Nesting)

2Loss of energy

If module spacing is increased for eccentric driving, then reducer efficiency is improved, but device complexity and assembly difficulty increase

Engineering Contradiction:
Improvereducer efficiencyVSAvoidassembly complexity
Core Design Contradiction:
Loss of energyVSDevice complexity

Solution Approach 1:

The driving unit and reduction unit are merged into a single integrated apparatus, with the inner gear member and outer gear member coupled together through eccentric engagement. This merging eliminates the need for separate mounting spaces and simplifies the assembly process while maintaining high reducer efficiency.

Inventive Principle:
Principle #5Merging (Combining)

3Volume of stationary object

If coaxial design is implemented to reduce size, then apparatus compactness is improved, but manufacturing precision requirements increase

Engineering Contradiction:
Improveapparatus sizeVSAvoidcoaxial alignment precision
Core Design Contradiction:
Volume of stationary objectVSManufacturing precision

Solution Approach 1:

The inner gear member is designed with an asymmetric eccentric structure relative to the outer gear member, creating intentional offset between their centers. This asymmetric design enables compact coaxial arrangement while the eccentric geometry itself compensates for alignment tolerances, reducing the stringency of manufacturing precision requirements.

Inventive Principle:
Principle #4Asymmetry

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 transmission control apparatus, enhances precision in rotational force transmission, and achieves higher output torque, while simplifying the coupling structure and reducing weight.

Implementation Method 1

an inner gear member (310) eccentrically coupled to the main shaft (200) and including a first gear portion (311) and a second gear portion (312)

Methodology Applied
Scientific EffectEccentric mechanism: Eccentric

Implementation Method 2

a first receiving gear portion (321) of an outer gear member (320) engaged with the first gear portion (311); and a second receiving gear portion (511) of an output unit (500) engaged with the second gear portion (312)

Methodology Applied
Scientific EffectGear engagement: Gear

Data Source

PatentEP3674580B1Automotive transmission control apparatus
Publication Date: 2022.03.16 SL CORP
  • EP3674580B1 patent drawingFigure 1
  • EP3674580B1 patent drawingFigure 2
  • EP3674580B1 patent drawingFigure 3(a)~3(b)

AI summary

Provided is an automotive transmission control apparatus. The automotive transmission control apparatus includes: a housing; a main shaft provided in the housing; a driving unit coupled to the main shaft and configured to be driven based on a signal for controlling a gear position of a transmission; a reduction unit housed within the driving unit; and an output unit to receive a rotational force of the reduction unit and output the rotational force with a reduced rotational speed. The reduction unit includes: an inner gear member coupled to the main shaft and including a first gear portion and a second gear portion; and an outer gear member fixed to the housing and including a first receiving gear portion engaged with the first gear portion. Further, the output unit includes a second receiving gear portion engaged with the second gear portion.