Power-Split Axle Drive With Adjustable Axle Lead and Braking

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Solution Overview

Problem

Existing power-split axle drives for agricultural vehicles are structurally complex and inefficient, with inadequate speed and torque transmission, and lack effective braking capabilities.

Innovation Solution

A power-split axle drive system for agricultural vehicles featuring a first auxiliary drive element connected to a power-split transmission via a switching element, allowing adjustable torque transmission and efficient braking through a combination of mechanical and electrical components, including a control device for regulating vehicle axles.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If the auxiliary drive elements are designed with high speed and power, then the drive capacity is sufficient, but the speed and torque transmitted to the power-split axle drive become insufficient

Engineering Contradiction:
Improvedrive capacityVSAvoidtransmitted speed
Core Design Contradiction:
PowerVSSpeed

Solution Approach 1:

A torque converter is introduced as an intermediary device between the auxiliary drive elements and the power-split transmission. This torque converter efficiently transmits and transforms torque from the auxiliary drives to the power-split transmission, resolving the contradiction by enabling high-power auxiliary drives to effectively deliver sufficient torque to the transmission system without direct rigid coupling.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Device complexity

If a rigid connection between axles is implemented, then structural simplicity is achieved, but efficient braking is not possible

Engineering Contradiction:
Improvestructural complexityVSAvoidbraking efficiency
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The connection between axles is made dynamic rather than rigid. The torque converter provides a flexible, adjustable connection that can transmit torque during normal operation but allows independent axle behavior during braking. This dynamic connection enables efficient braking while maintaining structural simplicity, as the torque converter naturally accommodates differential axle movements during deceleration.

Inventive Principle:
Principle #15Dynamics

3Power

If the auxiliary drive is permanently connected to the power-split transmission, then continuous torque transmission is achieved, but structural complexity increases

Engineering Contradiction:
Improvetorque transmissionVSAvoidstructural complexity
Core Design Contradiction:
PowerVSDevice complexity

Solution Approach 1:

The auxiliary drives are periodically connected to the power-split transmission through the torque converter rather than permanently connected. The connection is engaged when torque transmission is needed and can be disengaged when not required, providing continuous torque transmission capability while reducing structural complexity by avoiding permanent rigid connections and associated control mechanisms.

Inventive Principle:
Principle #19Periodic action

Data Source

PatentEP4417451B1Power-split axle drive and agricultural vehicle
Publication Date: 2025.12.24 DEERE & CO
  • EP4417451B1 patent drawingFigure 1
  • EP4417451B1 patent drawingFigure 2
  • EP4417451B1 patent drawingFigure 3

AI summary

The invention relates to a power-split axle drive (20) for an agricultural vehicle (10), comprising a first auxiliary drive element (50), a first vehicle axle (26), a second vehicle axle (28), and a main drive element (22) for providing torque that can be transmitted to a main gearbox (24) via a first shaft (W1). The main gearbox (24) is connected to the second vehicle axle (28). The torque of the main drive element (22) drives at least the second vehicle axle (28) via the main gearbox (24). The power-split axle drive (20) includes a power-split gearbox (52), wherein the power-split gearbox (52) is connected to the second vehicle axle (28) and the main gearbox (24) via a first gear set (54) and to the first vehicle axle (26) via a second shaft.The first auxiliary drive element (50) can be connected to the power-split transmission (52) via a first switching element (56). The invention further relates to an agricultural vehicle (10) and a method for operating a power-split axle drive (20).