Vehicle Drivetrain Test Stand With Direct Hub-Coupled Load Motor

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Solution Overview

Problem

Existing vehicle test stands require a large setup area and complex, expensive mechanical support structures, especially when testing a powertrain already installed in a vehicle.

Innovation Solution

A compact test bench for a motor vehicle powertrain using electric load motors with a motor shaft connected directly to the vehicle hub, integrated load sensors, and a shutdown module, allowing for rotational fixation and direct torque transmission without intermediate shafts, supported by a chassis to maintain realistic vehicle characteristics.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of stationary object

If traditional mechanical support structures and intermediate shafts are used to connect the load motor to the vehicle hub, then the structural stability and torque transmission are ensured, but the test stand requires a large setup area and complex mechanical frames

Engineering Contradiction:
Improvetest spaceVSAvoidmechanical support structure
Core Design Contradiction:
Area of stationary objectVSDevice complexity

Solution Approach 1:

The invention extracts and eliminates the intermediate shaft and complex mechanical support structures from the system. The load motor is connected directly to the vehicle hub, removing unnecessary mechanical components while maintaining functional integrity. This extraction principle directly reduces the test space requirement and simplifies the mechanical support structure.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The vehicle hub serves multiple functions: it acts as both the mounting point for the wheel and the direct connection point for the load motor. This multi-functionality eliminates the need for separate intermediate shafts and support structures, reducing both the test space and mechanical complexity while maintaining structural stability for torque transmission.

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

2Ease of manufacture

If intermediate shafts and complex mechanical linkages are used to connect the load motor to the hub, then torque transmission is achieved, but the test stand becomes more expensive and requires bulkier frames

Engineering Contradiction:
Improvemanufacturing costVSAvoidtorque transmission
Core Design Contradiction:
Ease of manufactureVSPower

Solution Approach 1:

The intermediate shaft and complex mechanical linkages are extracted from the system. The direct connection between the load motor and hub simplifies the manufacturing process, reduces component count, and lowers overall system cost while maintaining adequate torque transmission capability through the direct drive connection.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The invention replaces the mechanical intermediate shaft system with a direct electrical-mechanical connection. The load motor directly drives the hub without mechanical intermediaries, simplifying the mechanical system while maintaining torque transmission. This substitution reduces manufacturing complexity and cost.

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

3Ease of operation

If the vehicle is completely supported by the frame structure during testing, then alignment between the motor vehicle and load machines is improved, but the chassis-specific characteristics are affected

Engineering Contradiction:
ImprovealignmentVSAvoidchassis characteristics
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

Instead of completely supporting the vehicle on the frame structure, the invention uses the vehicle's own chassis as the support structure. The load motor connects directly to the hub, providing partial support only where needed for the test. This partial action approach maintains chassis-specific characteristics while achieving sufficient alignment for testing.

Inventive Principle:
Principle #16Partial or excessive action

Solution Approach 2:

The vehicle's chassis serves its own support function during testing rather than relying on an external frame structure. The chassis naturally provides the required support and alignment, maintaining its original characteristics. This self-service approach eliminates the need for bulky external frames while preserving vehicle-specific behaviors.

Inventive Principle:
Principle #25Self-service

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 solution reduces the required test space, eliminates the need for bulky frames, and allows for realistic testing of powertrain performance without affecting chassis-specific characteristics, enabling efficient and cost-effective single-test runs for the entire powertrain.

Implementation Method 1

at least one load sensor, wherein the motor shaft can be drivenly connected to the hub via the load sensor

Methodology Applied
Scientific EffectForce sensing: Force

Data Source

PatentEP4320418B1Test stand for a drive train of a motor vehicle
Publication Date: 2025.11.26 ZF FRIEDRICHSHAFEN AG
  • EP4320418B1 patent drawingFigure 1~2
  • EP4320418B1 patent drawingFigure 3~4
  • EP4320418B1 patent drawingFigure 5~6

AI summary

The invention relates to a test stand (100) for a drive train of a motor vehicle (20), comprising at least one load motor (110) having a motor housing (111) and a motor shaft (112), at least one load sensor (120) and at least one parking module (130), the motor shaft (112) being designed to be drivingly connected to a hub (21) of the motor vehicle (20), and the load sensor (120) being designed to detect a load transmitted by the motor shaft (112) to the hub (21). The drive train test stand (1) according to the invention is characterised in that an axial side (115) of the motor housing (11) facing the hub (21) and the at least one parking module (130) are designed to be connected to one another for conjoint rotation, in that the motor shaft (112) is designed as a hollow shaft (112), in that a shaft (113) guided through the hollow shaft (112) is designed to be indirectly or directly connected to the hub (21) for conjoint rotation, in that the load sensor (120) is provided on an axial side (116) of the motor housing (111) facing away from the hub (21), and in that the hollow shaft (112) can be drivingly connected to the shaft (113) via the load sensor (120).