Rotary Interface Disc With Radial Rollers for Silent Haptics

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Solution Overview

Problem

Rotary interface elements for vehicle interiors face issues with increased friction and noise as diameter increases, leading to deformation and potential damage, and existing solutions like ball bearings are costly and noisy, while haptic feedback vibrations further reduce perceived quality.

Innovation Solution

The implementation of radial rollers with noise-reducing rings made of elastic material, supported by a bent ring for haptic feedback, provides a cost-effective and silent rotation mechanism that maintains rotor disc rigidity without precise machining or gluing, using injection-molded plastic and overmolded rubber components.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of moving object

If the diameter of the rotary interface element is increased, then the interface element can provide better user interaction and control, but the friction caused by the contact bearing increases

Engineering Contradiction:
Improvediameter of rotary interface elementVSAvoidfriction
Core Design Contradiction:
Area of moving objectVSForce

Solution Approach 1:

The patent replaces the traditional contact bearing (mechanical sliding friction system) with a magnetic field-based detection system. The rotor contains magnets that interact with a Hall effect sensor or reed switch array in the stator, eliminating the need for physical contact between moving parts. This substitution of mechanical friction with magnetic field interaction allows large diameter rotors to operate with minimal friction and wear.

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

2Area of moving object

If the diameter of the rotary interface element is increased, then the interface element provides better control, but vibrations and noise increase

Engineering Contradiction:
Improvediameter of rotary interface elementVSAvoidvibrations and noise
Core Design Contradiction:
Area of moving objectVSObject-generated harmful factors

Solution Approach 1:

By replacing the mechanical contact bearing with a magnetic field-based sensing system, the patent eliminates the primary source of vibrations and noise associated with friction and mechanical contact. The magnetic interaction between rotor magnets and stator sensors occurs without physical contact, significantly reducing mechanical vibrations and acoustic noise even in large diameter implementations.

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

3Device complexity

If only a central bearing is implemented with reduced diameter, then the interface element structure is simplified, but the rotor disc bends inwards and the rotor shaft deforms under torque

Engineering Contradiction:
Improvebearing structureVSAvoidrotor disc rigidity
Core Design Contradiction:
Device complexityVSStrength

Solution Approach 1:

The patent eliminates the need for a substantial central bearing structure by using magnetic field interaction for both support and detection functions. The rotor can be designed as a lightweight disc with magnets embedded in it, supported magnetically or with minimal mechanical contact, which prevents bending and deformation under torque while maintaining structural simplicity.

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

4Strength

If ball bearings are used to support the rotor disc, then the rotor disc rigidity is maintained, but the cost increases and noise is generated

Engineering Contradiction:
Improverotor disc rigidityVSAvoidcost
Core Design Contradiction:
StrengthVSEase of manufacture

Solution Approach 1:

The patent replaces expensive precision ball bearings with a magnetic field-based support and detection system. The rotor contains embedded magnets that interact with sensors in the stator, providing both structural support and rotational position detection without the need for precision-machined metal bearings. This substitution significantly reduces manufacturing costs while eliminating ball bearing noise.

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

5Force

If grease or lubricant is used to reduce friction, then the friction is reduced temporarily, but regular refilling is required

Engineering Contradiction:
ImprovefrictionVSAvoidlubricant service life
Core Design Contradiction:
ForceVSDuration of action of moving object

Solution Approach 1:

The patent eliminates the need for lubricants by replacing the mechanical sliding contact bearing with a magnetic field-based interaction system. The rotor magnets interact with stator sensors through magnetic fields without physical contact, eliminating friction entirely and removing the requirement for lubricant application and periodic refilling maintenance.

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

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 reduces friction and noise, maintains rotor disc rigidity, and enhances perceived quality by providing a silent and cost-effective rotary interface element that supports the rotor disc and generates effective haptic feedback without deformation or the need for precise metal parts.

Implementation Method 1

The rotary interface element comprises radial rollers, three non-limiting example being provided, which are regularly placed around the rotor shaft, under the rotor disc

Methodology Applied
Scientific EffectRolling friction: Friction

Implementation Method 2

The radial rollers may comprise each a noise reducing ring, which is in contact with the rotor disc. The noise reducing ring may be made of elastic material, in particular rubber.

Methodology Applied
Scientific EffectVibration absorption: Damping

Implementation Method 3

the bottom arches carrying two haptic fingers that engage in the haptic asperities

Methodology Applied
Scientific EffectMechanical feedback: Mechanical Force

Data Source

PatentEP3627286B1Rotary interface element
Publication Date: 2022.01.19 DAV
  • EP3627286B1 patent drawingFigure 1~2
  • EP3627286B1 patent drawingFigure 3~4
  • EP3627286B1 patent drawingFigure 5

AI summary

The invention relates to a rotary interface element (100), comprising: • a rotor (1), the rotation of which causes a control signal, the rotor (1) comprising: • a rotor disc (11) comprising a disc-shaped contact surface (S) on which a user (U) can press one or more fingers, flush with a surrounding surface in which the rotary interface element (100) is implemented, • a rotor shaft (13), bound in rotation with the rotor disc (11), • a stator (3), stationary with respect to the rotor (1), the stator (3) comprising : • a disc shaped recess (30) for the rotor disc (11), • a bearing (31) for the rotor shaft, characterized in that it further comprises radial rollers (5), disposed radially with respect to the rotor disc (11) in housings (35, 37) made in the stator (3), under the rotor disc (11), resting against the side of the rotor disc (11) opposite the contact surface (S), having a cylindrical central body (51) against which the rotor disc (11) is resting.