Balancing Machine Air Hose Attachment to Non-Rotating Spindle

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Solution Overview

Problem

Existing unbalance measuring machines for vehicle tires face challenges in accurately determining tire imbalance due to external forces introduced by the rotary joint and air hose, requiring complex zero point shift corrections, which are time-consuming and limit machine availability.

Innovation Solution

The air hose and electrical lines are attached to the non-rotating part of the spindle, away from the rotary joint, effectively eliminating the first harmonic of forces caused by the rotary joint, allowing for error-free imbalance measurement without the need for zero point shift corrections.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the air hose and electrical lines are connected to the rotary joint, then the vehicle tire can be filled with air during rotation and air pressure can be maintained, but additional forces are introduced into the force transducers that distort the imbalance measurement

Engineering Contradiction:
Improvemeasurement speedVSAvoidimbalance measurement accuracy
Core Design Contradiction:
ProductivityVSMeasurement precision

Solution Approach 1:

The system separates the air supply function from the rotary joint by providing a second air supply line that connects directly to the hollow axle (non-rotating part), independent of the rotary joint. This segmentation allows the rotary joint to be used only for electrical connections while the air supply is provided through a separate path, eliminating the distortion forces caused by connecting the air hose to the rotary joint.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The hollow axle serves as an intermediary structure that provides both mechanical support and a pathway for the air supply. By routing the air hose through the hollow axle rather than through the rotary joint, the system uses the hollow axle as a mediator to deliver air to the rotating shaft and vehicle tire without introducing distortion forces into the measurement system.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Measurement precision

If zero point shift corrections are performed for each tire type, then measurement accuracy can be maintained, but machine availability is significantly reduced due to the time-consuming correction process

Engineering Contradiction:
Improveimbalance measurement accuracyVSAvoidmachine availability
Core Design Contradiction:
Measurement precisionVSProductivity

Solution Approach 1:

The system performs preliminary balancing of the rotary joint during manufacturing or initial setup, ensuring that the rotary joint itself is balanced. This preliminary action eliminates the need for repeated zero point shift corrections for different tire types, as the rotary joint no longer introduces systematic distortion forces that would require correction for each measurement.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system achieves self-correction by eliminating the source of distortion forces. By separating the air supply from the rotary joint and properly balancing the rotary joint, the measurement system automatically provides accurate readings without requiring external correction procedures for different tire types, making the measurement process self-sufficient.

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

This solution enables accurate and efficient imbalance measurement for all tire types without the need for complex corrections, ensuring the unbalance measuring machine is available for unrestricted use, as the external forces do not influence the measured values.

Implementation Method 1

The cause of the imbalance in a rotating vehicle tire is known to be due to an unequal mass distribution of the vehicle tire, i. H. the mass of the vehicle tire is not distributed rotationally symmetrically. As a result, the axis of rotation does not coincide with the stable main axis of inertia of the vehicle tire

Methodology Applied
Scientific EffectInertia: Inertia

Implementation Method 2

The supply of air to the vehicle tire is also maintained while the imbalance is being measured, so that it is possible to control the air pressure inside the vehicle tire and keep it constant

Methodology Applied
Scientific EffectPressure gradient: Pressure Gradient

Data Source

PatentEP2837923B1Balancing machine
Publication Date: 2018.06.20 SEICHTER GMBH
  • EP2837923B1 patent drawingFigure 1

AI summary

An unbalance measuring machine for determining the imbalance of vehicles, comprising a hollow shaft that can be rotated by a drive and rotates relative to a fixed hollow axle. A tubular air supply for inflating the vehicle tire is centrally located inside the hollow shaft and rotates with the shaft, which in turn rotates the tire to determine the imbalance. A swivel coupling is located at the end of the air supply facing away from the tire, to which an air hose is connected and attached. Force transducers are provided between the hollow axle and the machine bed of the unbalance measuring machine to measure the forces occurring between the hollow axle and the machine bed during operation. In this type of unbalance measuring machine, the air hose leading to the swivel coupling is attached not only to the swivel coupling but also to the hollow axle at a distance from the swivel coupling.An alternative design involves dispensing with the use of a rotary coupling and inflating the vehicle tire via the air hose and the non-rotating air supply while the shaft is stationary. The air hose is then disconnected from the air supply, but the supplied air remains in the vehicle tire.