BLDC Transmission Actuator Layout for Compact Gear Shifting

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Solution Overview

Problem

Existing gearbox actuators for vehicles face challenges in accurately determining the position of gearbox components, are overly complex and large, lack standardization, and utilize inefficient DC motors that increase production costs and negatively impact the gearbox in non-operation modes.

Innovation Solution

A mechanical transmission actuator utilizing a brushless direct current (BLDC) motor with a compact design, featuring a motor body separate from the gear assemblies, and employing a reduced number of gear stages to achieve the required torque and speed, thereby reducing overall size and production costs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If DC electric motors are used to actuate the gearbox, then the actuator can change transmission modes, but the torque produced is small relative to size requiring more reduction stages

Engineering Contradiction:
ImprovetorqueVSAvoidactuator size
Core Design Contradiction:
PowerVSVolume of moving object

Solution Approach 1:

The patent changes the motor type from DC to BLDC, fundamentally altering the torque-density parameter. BLDC motors produce significantly higher torque per unit volume compared to DC motors, allowing the actuator to achieve required torque with fewer reduction stages and smaller overall size.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent extracts and eliminates unnecessary reduction stages from the gear train. By using a BLDC motor with inherently higher torque output, the design removes intermediate gear reductions that were required with DC motors, simplifying the overall transmission system.

Inventive Principle:
Principle #2Taking out (Extraction)

2Power

If the number of reduction stages is increased to provide required torque, then torque capability improves, but the overall size of the actuator increases

Engineering Contradiction:
ImprovetorqueVSAvoidactuator length
Core Design Contradiction:
PowerVSLength of stationary object

Solution Approach 1:

Changing from DC to BLDC motor alters the torque-generation parameter, achieving higher torque output without proportionally increasing motor size. This parameter change allows meeting torque requirements with a more compact overall actuator configuration.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent segments the transmission system by removing unnecessary intermediate reduction stages. The BLDC motor's high torque capability allows direct coupling with fewer gear stages, reducing the axial length occupied by the reduction train.

Inventive Principle:
Principle #1Segmentation

3Ease of manufacture

If DC motors with brushes are used, then the motor can be driven simply, but the brushes wear out reducing motor lifespan

Engineering Contradiction:
Improvemotor simplicityVSAvoidmotor lifespan
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent replaces the mechanical brush-contact system with an electronic commutation system. BLDC motors use electronic controllers to switch current in the stator windings, eliminating physical brushes and commutators. This substitution maintains ease of manufacture through standardized components while dramatically improving reliability by removing wear-prone mechanical contacts.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

4Power

If more reduction stages are added to the gear assembly, then torque is increased, but the number of parts and complexity increases

Engineering Contradiction:
ImprovetorqueVSAvoidnumber of parts
Core Design Contradiction:
PowerVSDevice complexity

Solution Approach 1:

The BLDC motor's superior torque-density parameter allows achieving required output torque with fewer reduction stages. This reduces the number of gear assemblies, shafts, and bearings needed, simplifying the overall device while maintaining torque capability.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent segments out unnecessary intermediate reduction stages from the power transmission path. By starting with a higher-torque motor, the design eliminates redundant mechanical components, reducing part count and assembly complexity.

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

The proposed solution enables accurate position detection, reduces the actuator's size and complexity, achieves standardization across different vehicle designs, and improves efficiency by using a BLDC motor that maintains lower torque in non-operation modes, thus minimizing negative impacts on the gearbox.

Implementation Method 1

a motor body configured to produce a generated torque using electric current applied thereto

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentEP4509740A1A mechanical transmission actuator for a vehicle and related methods
Publication Date: 2025.02.19 FICO TRIAD
  • EP4509740A1 patent drawingFigure 1~3
  • EP4509740A1 patent drawingFigure 2
  • EP4509740A1 patent drawingFigure 4~5

AI summary

The present mechanical transmission actuator for a vehicle comprises a BLDC motor body, a motor shaft, a first gear assembly, and a selector gear assembly. The BLDC motor body is configured to produce a generated torque using electric current applied thereto. The motor shaft moved by the generated torque, wherein the motor shaft defines a motor axis of rotation. The first gear assembly is connected to the motor shaft, wherein the first gear assembly defines a first axis of rotation. The selector gear assembly is connected to the first gear assembly, wherein the selector gear assembly defines a selector axis of rotation. In use, the motor axis of rotation is arranged substantially perpendicular to the first axis of rotation and the selector axis of rotation. It may further comprise an electronics carrier arranged on a plane XY, wherein the first axis of rotation, the second axis of rotation and the selector axis of rotation may be arranged substantially perpendicular to the plane XY and wherein the motor axis of rotation is arranged substantially parallel to the plane XY. The electronics carrier comprises a first sensor, wherein the selector gear assembly further comprises a magnet connected to the first sensor such that, in use, an airgap is provided between the magnet and the first sensor.