Hybrid Marine Pod Drive Layout for Compact Dual-Propeller Propulsion

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Solution Overview

Problem

Existing marine pod drives with two propellers face challenges in achieving compact dimensions and high reliability while meeting environmental and efficiency demands, particularly with the integration of electric drive machines.

Innovation Solution

A marine pod drive design with a first propeller at the trailing end and a second propeller at the leading end, driven by a combination of a mechanical drive machine inside the hull and an electric motor within the pod, allowing independent operation and control, and featuring a hybrid or all-electric configuration for enhanced efficiency and reliability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a mechanical drive train with shafts and transmission elements is used to connect the drive machine to the propellers, then the power transmission is reliable, but the device complexity and maintenance requirements increase

Engineering Contradiction:
Improvepower transmission reliabilityVSAvoiddrive train complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent removes the lower bevel gear unit from the drive train, extracting the problematic mechanical transmission element that caused complexity and maintenance issues. The drive machine is repositioned to eliminate the need for this gear unit, simplifying the overall drive train while maintaining reliable power transmission to both propellers.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The drive system is segmented into two independent drive machines - one for each propeller. This segmentation allows each propeller to be driven independently, reducing the complexity of the overall system while maintaining reliable power transmission. Each drive machine can be optimized separately, and failures in one do not necessarily affect the other.

Inventive Principle:
Principle #1Segmentation

2Volume of moving object

If the drive machine is positioned inside the pod to achieve compact dimensions, then the pod outline dimensions are reduced, but the drive machine arrangement becomes more complex

Engineering Contradiction:
Improvepod volumeVSAvoiddrive machine arrangement complexity
Core Design Contradiction:
Volume of moving objectVSDevice complexity

Solution Approach 1:

The drive machine is repositioned from a horizontal arrangement to a vertical arrangement within the pod. This dimensional change allows the drive train components to be stacked vertically rather than arranged horizontally, achieving compact pod dimensions while simplifying the mechanical connection to the propellers and reducing the number of transmission elements required.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Power

If conventional marine pod drives with two propellers are used, then propulsion capability is improved, but the pod dimensions and complexity increase

Engineering Contradiction:
Improvepropulsion powerVSAvoidpod volume
Core Design Contradiction:
PowerVSVolume of moving object

Solution Approach 1:

The patent merges the drive machines and their associated drive trains into a single integrated pod unit. By combining both drive machines and their simplified drive trains within one compact pod, the system achieves high propulsion power while minimizing the overall volume occupied by the propulsion system.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

Instead of arranging the propellers in a conventional configuration, the patent inverts the arrangement by positioning both propellers at the rear of the pod, one above the other. This inverted arrangement, combined with the repositioned drive machine, achieves high propulsion power in a compact volume by eliminating the need for intermediate transmission elements.

Inventive Principle:
Principle #13The other way round (Inversion)

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 design achieves compact dimensions, high hydrodynamic efficiency, and reliability with independent propeller control, enabling eco-friendly operation, reduced maintenance, and energy generation capabilities, while supporting various power modes.

Implementation Method 1

a second electric motor which is arranged inside a housing of the pod

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

the first propeller is arranged at a trailing end of the pod and the second propeller is arranged at a leading end of the pod, so that the first propeller works as a pushing propeller and the second propeller works as a pulling propeller

Methodology Applied
Scientific EffectHydrodynamic lift and thrust:

Data Source

PatentEP4530176B1Marine pod drive
Publication Date: 2026.04.01 ZF FRIEDRICHSHAFEN AG
  • EP4530176B1 patent drawingFigure 1
  • EP4530176B1 patent drawingFigure 2

AI summary

The present invention relates to a marine pod drive (1, 2) with a first propeller (11) and a second propeller (21), which are arranged at a pod (5). The marine pod drive (1, 2) comprising a first drive machine (10, 210), which drives the first propeller (11) and a second drive machine (20), which drives the second propeller (21). The first drive machine (10, 210) is operatively connected to the first propeller (11) via a drive train (3) comprising a vertical shaft (15) and a lower bevel gear unit (16). The second drive machine (20) is an electric motor, which is arranged inside a housing (4) of the pod (5). The first propeller (11) is arranged at a trailing end of the pod (5) and the second propeller (21) is arranged at a leading end of the pod (5). The invention further relates to a ship (100, 200) with such a marine pod drive (1, 2).