Tyre Pressure Rotary Feedthrough With Floating Rotor Coupling

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Solution Overview

Problem

Rotary unions with a radial arrangement of stator and rotor assemblies are prone to leaks and damage due to axle shaft deformation, leading to functional impairments or failure, as they cannot compensate for axial deformation eccentricities.

Innovation Solution

A rotary feedthrough design with a rotor assembly comprising a rotor part at a radial distance from the axle shaft, connected via a torque-locking driver with axial play, and centered by a bearing relative to the stator assembly, decoupling rotational motion from axial deformations through a radially floating coupling.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If a radial arrangement of stator and rotor assemblies is used, then the installation space in the axial direction is reduced, but the system becomes sensitive to axial deformation eccentricities causing seal damage and leaks

Engineering Contradiction:
Improveinstallation spaceVSAvoidseal integrity
Core Design Contradiction:
Volume of moving objectVSReliability

Solution Approach 1:

The rotor assembly is made dynamically adjustable through an axial adjustment mechanism that allows the rotor to be positioned at different axial locations relative to the stator. This dynamic positioning capability enables the system to compensate for axial deformation eccentricities by adjusting the rotor's axial position to maintain proper seal contact, thereby resolving the contradiction between compact radial arrangement and seal integrity under deformation conditions.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The invention changes the axial position parameter of the rotor assembly relative to the stator assembly. By providing an adjustment mechanism that modifies this parameter, the system can adapt to varying axial deformation conditions while maintaining reliable seal operation, thus resolving the contradiction between space efficiency and reliability.

Inventive Principle:
Principle #35Parameter changes

2Power

If the rotor assembly is directly connected to the axle shaft, then torque transmission is efficient, but axial deformation of the axle shaft causes radial displacement and functional impairment

Engineering Contradiction:
Improvetorque transmissionVSAvoidfunctional stability
Core Design Contradiction:
PowerVSReliability

Solution Approach 1:

The connection between the rotor assembly and axle shaft is segmented into two independent functions: torque transmission and axial positioning. The torque transmission function is maintained through direct mechanical coupling, while the axial positioning function is provided by the adjustment mechanism. This segmentation allows each function to be optimized independently, resolving the contradiction between efficient torque transmission and functional stability under deformation.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The adjustment mechanism acts as an intermediary between the rotor assembly and the deforming axle shaft. It provides a decoupling effect that allows the rotor to maintain its operational position relative to the stator while accommodating axial deformations of the axle shaft, thus protecting the system from functional impairment while maintaining torque transmission.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Reliability

If seals are placed between rotor and stator assemblies for gas transfer, then gas sealing is achieved, but axial deformation leads to seal damage and leaks

Engineering Contradiction:
Improvegas sealingVSAvoiddeformation damage
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The seal system is made dynamically adjustable through the axial adjustment mechanism. As the axle shaft deforms axially, the mechanism allows the rotor to shift its axial position accordingly, maintaining optimal seal contact pressure and preventing seal damage or leakage. This dynamic adaptation resolves the contradiction between achieving reliable gas sealing and preventing deformation-induced seal failure.

Inventive Principle:
Principle #15Dynamics

4Adaptability or versatility

If movement clearance is provided for rotor assembly adjustment, then deformation compensation is possible, but functional impairments may occur due to excessive play

Engineering Contradiction:
Improvedeformation compensationVSAvoidoperational precision
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The adjustment mechanism provides partial movement clearance - enough to compensate for expected axial deformation eccentricities but limited to prevent excessive play that would cause functional impairment. The clearance is precisely controlled to match the anticipated deformation range, resolving the contradiction between adaptability and operational precision.

Inventive Principle:
Principle #16Partial or excessive action

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 effectively isolates the rotor assembly from axial deformation eccentricities, preventing seal damage and leaks by decoupling rotational motion, ensuring reliable operation even under high axle loads.

Implementation Method 1

centered by a bearing arranged between the stator assembly and the rotor part at an axial distance to the driver

Methodology Applied
Scientific EffectRadially floating coupling:

Implementation Method 2

a driver which can be connected to the axle shaft in a torque-locking manner and which is engaged in a radially floating manner to transmit a rotary motion from the axle shaft to the rotor part

Methodology Applied
Scientific EffectTorque transmission: Torque

Data Source

PatentEP4714685A1Rotary feedthrough forming part of a tyre pressure control system of a vehicle and vehicle equipped therewith
Publication Date: 2026.03.25 PTG REIFENDRUCKREGELSYSTEME GMBH
  • EP4714685A1 patent drawingFigure 1~2
  • EP4714685A1 patent drawingFigure 3
  • EP4714685A1 patent drawingFigure 4~6

AI summary

The invention relates to a rotary feedthrough 4 as part of a tire pressure control system of a vehicle, comprising a rotor assembly 6 which can be connected to a wheel-carrying axle shaft 2 of the vehicle in a torque-locking manner and a stator assembly 5 which is arranged in a fixed position relative to the rotational movement of the rotor assembly 6, wherein at least one sealed or sealable annular transmission channel is located between the rotor assembly 6 and the stator assembly 5, through which a pathway is provided for the transfer of a gas from the stator assembly 5 to the rotor assembly 6 and/or vice versa for the purposes of tire pressure control.A special feature is that the rotor assembly 6 comprises a rotor part 7 arranged at a radial distance from the outer surface of the axle shaft 2, with the rotor-side path(s) required for the rotational transmission of a gas, and a driver 8 which can be connected to the axle shaft 2 in a torque-locking manner and which engages with the rotor part 7 in a radially floating manner to transmit a rotational movement from the axle shaft 2 to the rotor part 7, and that the rotor part 7 is centered relative to the stator assembly 5 by means of a bearing 16 arranged between the stator assembly 5 and the rotor part 7 at an axial distance from the driver 8.