Automatic Rim Centering via Friction Torque and Speed Feedback

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Solution Overview

Problem

Automatic centering of wheels onto rim mounting devices in vehicle wheel service machines is often not accurately achieved, leading to manual adjustments and potential damage or wear, especially with modern aluminum wheel rims.

Innovation Solution

The implementation of a system that detects slipping between the wheel and the rim mounting plate using rotational speed detectors and a high-friction lining to improve torque transmission and eliminate the need for a drive pin, allowing for automatic centering and simplified operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If a drive pin is used to transmit torque between the rim mounting plate and the wheel, then torque transmission is improved, but the complexity of the rim mounting device increases and the risk of damage or wear to the wheel rim increases

Engineering Contradiction:
Improvetorque transmissionVSAvoidrim mounting device complexity
Core Design Contradiction:
PowerVSDevice complexity

Solution Approach 1:

The patent removes the drive pin component from the rim mounting device. Instead of using a mechanical drive pin to transmit torque, the system relies on friction between the rim mounting plate and the wheel rim, combined with a high-friction lining, to achieve torque transmission during automatic centering operations.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces the mechanical drive pin system with a friction-based torque transmission system. The high-friction lining creates sufficient friction force to transmit torque from the rim mounting plate to the wheel rim, eliminating the need for mechanical engagement components like drive pins.

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

2Manufacturing precision

If manual adjustment of the wheel or rim is required for centering, then centering precision is improved, but the productivity of the service machine decreases

Engineering Contradiction:
Improvecentering precisionVSAvoidservice operation speed
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

The patent implements an automatic centering system where the rim mounting device automatically centers the wheel rim onto the mounting plate through controlled rotation and friction-based torque transmission. The system self-adjusts without requiring manual intervention, maintaining centering precision while eliminating the time loss associated with manual adjustments.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent uses detectors to monitor the rotational speed of both the rim mounting plate and the wheel rim, and a control unit compares these speeds to detect slipping. Based on this feedback, the system automatically adjusts the rotational speed to maintain optimal friction-based torque transmission, ensuring accurate automatic centering without manual intervention.

Inventive Principle:
Principle #23Feedback

3Ease of operation

If the rotational speed of the rim mounting plate is not controlled, then the ease of operation is improved, but slipping between the wheel and rim mounting plate occurs causing wear or damage

Engineering Contradiction:
Improveoperation simplicityVSAvoidrisk of damage or wear
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent implements a feedback control system using detectors to monitor the rotational speeds of the rim mounting plate and the wheel rim. The control unit compares these speeds and detects slipping conditions. When slipping is detected, the system automatically adjusts the rotational speed of the rim mounting plate to eliminate slipping, preventing wear or damage while maintaining ease of operation.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent makes the rotational speed of the rim mounting plate dynamically adjustable rather than fixed. The control unit continuously monitors the operational conditions and automatically adjusts the rotational speed to optimize friction-based torque transmission and prevent slipping, enhancing reliability without complicating operation.

Inventive Principle:
Principle #15Dynamics

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 enhances the automatic centering of wheels, reduces the risk of damage or wear, and improves torque transmission, thereby accelerating service operations while minimizing the complexity and cost of the machine.

Implementation Method 1

a high-friction lining is provided on a rim support surface of the rim mounting device for increasing friction between the rim mounting device and the wheel

Methodology Applied
Scientific EffectFriction: Friction

Implementation Method 2

a first detector is provided for detecting a rotational speed of the rim mounting device

Methodology Applied
Scientific EffectRotational speed detection:

Implementation Method 3

a second detector is provided for detecting a rotational speed of the wheel mounted to the rim mounting device

Methodology Applied
Scientific EffectRotational speed detection:

Implementation Method 4

a controller is provided for receiving a first output signal of the first detector and a second output signal of the second detector, and for controlling a driving circuit of the motor based on a comparison result of the first and second output signals so that a slipping between the wheel and the rim mounting plate is eliminated

Methodology Applied
Scientific EffectFeedback control: Feedback

Data Source

PatentEP2540529B1Automatic rim centering system for a tyre changing machine
Publication Date: 2015.08.12 SNAP ON EQUIP SRL
  • EP2540529B1 patent drawingFigure 1
  • EP2540529B1 patent drawingFigure 2
  • EP2540529B1 patent drawingFigure 3

AI summary

The invention concerns vehicle wheel service machines, in particular automatic tyre changers, having a wheel or rim mounting device (2) which is mounted rotatably about an axis (11) and to which a wheel (1) is to be fixed. The vehicle wheel service machine comprises first and second detectors (6, 7) and a controller to detect the rotational speeds of the rim mounting device (2) and the wheel (1) respectively. Furthermore, a method for controlling the rotational speed of the rim mounting device (2) is provided. If the detected rotational speeds are different, slipping is determined and eliminated by approximating the rotational speed of the rim mounting device (2) to that of the wheel (1). A rim mounting device (2) can comprise a rim mounting plate having a rim support surface with a high-friction lining adapted to increase friction between the rim mounting plate and the wheel (1).