Drivetrain Test Stand Coupling With Tire-Like Torsional Damping
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Solution Overview
Problem
Existing powertrain test benches are unsuitable or incapable of reliably testing electrically driven powertrains before installation, as the behavior measured on the bench does not correspond to its behavior when installed in a vehicle due to the rigid and inelastic rotational behavior of electric drive motors, which is not adequately compensated by the test bench.
Innovation Solution
A coupling module for a powertrain test bench that includes a wheel rim and wheel hub with a base and side wall, featuring an annular damping element in frictional contact with the wheel hub's inner surface, replicating the torsional vibration damping properties of a vehicle tire, allowing for a more realistic simulation of the drivetrain's elasticity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a rigid coupling is used to connect driveshaft to drive shaft on test bench, then structural simplicity is improved, but drivetrain elasticity is worsened
Solution Approach 1:
A damping element is introduced as an intermediary component between the wheel rim and wheel hub. This damping element has a frictional contact surface that contacts the wheel hub, creating a controlled friction connection that provides the necessary elasticity and vibration damping while maintaining structural simplicity.
Solution Approach 2:
The frictional contact surface on the damping element allows for adjustable friction parameters. By modifying the friction coefficient through surface treatment or material selection, the drivetrain elasticity can be tuned to match real vehicle conditions without complicating the overall coupling structure.
2Power
If electric drive motor with rigid rotational behavior is used, then power density is improved, but measurement accuracy is worsened
Solution Approach 1:
The damping element with frictional contact acts as a mediator between the rigid electric drive motor and the drivetrain components. This friction connection introduces compliance that allows the test bench to accurately measure drivetrain behavior including vibrations and elastic deformations, while still utilizing the high power density of electric motors.
3Device complexity
If short drive path is used to locate drive motor directly on axle, then device complexity is improved, but drivetrain elasticity is worsened
Solution Approach 1:
The damping element with frictional contact surface serves as a compensatory intermediary that restores drivetrain elasticity despite the short drive path. This allows direct motor-to-axle mounting for structural simplicity while the damping element provides the necessary elastic behavior for accurate testing.
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 coupling module ensures a drivetrain elasticity that mimics the actual installed state in a vehicle, enabling a considerably more realistic test of the drivetrain by utilizing the elasticity of rubber vehicle tires, thus bridging the discrepancy between bench and in-vehicle behavior.
Implementation Method 1
an annular damping element (25) arranged on the wheel rim (23), which is in frictional contact with an inner surface (24''') of the side wall (24'') of the wheel hub (24)
Data Source
Figure 1~3
Figure 4~5
AI summary
The invention relates to a coupling module (20) for a drive train test stand for connecting an articulated shaft (22) to a driveshaft (21) The coupling module (20) comprises a wheel rim (23) and a wheel cap (24) with a base surface (24') and a lateral wall (24'''), wherein the wheel rim (23) can be rotationally fixed to the driveshaft (21), and the wheel cap (24) can be rotationally fixed to the articulated shaft (22). The coupling module (20) according to the invention is characterized in that a vehicle wheel (25) is arranged on the wheel rim (23), the tread (25') of said wheel being in frictional contact with the inner face (24''') of the lateral wall (24'') of the wheel cap (24). The invention additionally relates to a corresponding output module for a drive train test stand and to a corresponding drive train test stand for testing a vehicle drive train.