Planetary Hybrid Transmission Clutch Layout for Multi-Mode Torque Control

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Solution Overview

Problem

Existing hybrid power transmission mechanisms lack the ability to easily and reliably switch between a motor/generator functioning as a starter motor, an assist motor, or a generator, limiting their operational flexibility.

Innovation Solution

A hybrid power transmission mechanism incorporating a planetary gear mechanism, first and second clutches, and a controller to switch between states, allowing the motor/generator to function as a starter motor, assist motor, or generator by controlling the clutches and speed changing mechanism, enabling efficient power transmission and torque management.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a hybrid power transmission mechanism uses a motor/generator without switching capability, then the structure is simpler, but the operational flexibility and ability to switch between starter motor, assist motor, and generator modes is lost

Engineering Contradiction:
Improveoperational flexibilityVSAvoidstructure complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent applies dynamics by making the power transmission path configurable through clutches that can engage or disengage based on operational mode. The first clutch connects/disconnects the engine from the motor/generator, while the second clutch connects/disconnects the motor/generator from the driven machine, enabling dynamic reconfiguration of the system architecture to support multiple operational modes

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent implements multi-functionality by designing a single motor/generator unit that can perform multiple roles (starter motor, assist motor, and generator) through the strategic engagement and disengagement of clutches. The planetary gear mechanism also serves multiple functions by enabling different power flow paths depending on clutch states

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Adaptability or versatility

If the motor/generator is designed for high torque to cover all operating modes, then all modes can be supported, but the motor size increases and efficiency decreases

Engineering Contradiction:
Improveoperational flexibilityVSAvoidmotor torque
Core Design Contradiction:
Adaptability or versatilityVSPower

Solution Approach 1:

The patent applies segmentation by dividing the power transmission system into distinct modules connected through clutches: the engine, the motor/generator, and the driven machine. This modular segmentation allows the motor/generator to operate in different modes (starter, assist, generator) by selectively engaging or disengaging specific clutch connections, thereby supporting multiple operational modes without requiring the motor to be oversized for all scenarios simultaneously

Inventive Principle:
Principle #1Segmentation

3Loss of energy

If the motor/generator is downsized to reduce heat generation, then efficiency improves, but the ability to provide sufficient torque for all operating modes is compromised

Engineering Contradiction:
Improveheat generationVSAvoidoperational flexibility
Core Design Contradiction:
Loss of energyVSAdaptability or versatility

Solution Approach 1:

The patent applies dynamics by making the power transmission path configurable through clutches that can engage or disengage based on operational mode. The first clutch connects/disconnects the engine from the motor/generator, while the second clutch connects/disconnects the motor/generator from the driven machine, enabling dynamic reconfiguration of the system architecture to support multiple operational modes

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent implements multi-functionality by designing a single motor/generator unit that can perform multiple roles (starter motor, assist motor, and generator) through the strategic engagement and disengagement of clutches. The planetary gear mechanism also serves multiple functions by enabling different power flow paths depending on clutch states

Inventive Principle:
Principle #6Universality (Multi-functionality)

Data Source

PatentEP4124487B1Hybrid power transmission mechanism
Publication Date: 2024.05.29 KUBOTA CORP
  • EP4124487B1 patent drawingFigure 1
  • EP4124487B1 patent drawingFigure 2
  • EP4124487B1 patent drawingFigure 3

AI summary

A hybrid power transmission mechanism (1) includes an engine (2); a motor/generator (3) having a rotor (31) and a stator (32); a driven machine (4); a planetary gear mechanism (5) having a sun gear (51), an internal gear (52), a planetary gear (53), and a planetary carrier shaft (54); a first clutch (9); and a second clutch (10). The planetary carrier shaft (54) includes a first extension shaft part (54a) and a second extension shaft part (54b) extending from the planetary gear (53) in opposite directions along a rotational axis direction of the planetary gear (53). A first shaft (7) that outputs power of the engine (2) is drivingly connected to the first extension shaft part (54a) of the planetary carrier shaft (54), and a second shaft (8) that inputs power to the driven machine (4) is drivingly connected to the second extension shaft part (54b) of the planetary carrier shaft (54). The internal gear (52) is drivingly connected to the rotor (31). The first clutch (9) is switchable between a connected state of allowing transmission of power between the first shaft (7) and the internal gear (52) and a disconnected state of not allowing transmission of power between the first shaft (7) and the internal gear (52). The second clutch (10) is switchable between an allowing state of allowing rotation of the sun gear (51) and a blocking state of not allowing rotation of the sun gear (51).