Motorcycle Pivot Bearing with Intersecting Axes

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Solution Overview

Problem

Existing front wheel suspension systems for motorcycles, such as the 'Duolever' design, face challenges with ball joints requiring high space, weight, and installation effort due to the need for multiple standard roller bearings to achieve necessary degrees of freedom for suspension and steerability, leading to breakaway torques and increased complexity.

Innovation Solution

A compact pivot bearing system with two intersecting pivot axes, utilizing tapered roller bearings in an O-arrangement, which allows for radial and axial load absorption and reduces breakaway torque, featuring a bearing housing with a rotatable journal and a clamping bush, eliminating the need for additional fastening components like nuts or screws.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If multiple standard roller bearings are combined to provide required degrees of freedom for suspension and steering, then the necessary pivot movements are achieved, but the installation space requirement increases significantly

Engineering Contradiction:
Improvedegrees of freedomVSAvoidinstallation space
Core Design Contradiction:
Adaptability or versatilityVSVolume of stationary object

Solution Approach 1:

The patent combines multiple roller bearings (first and second roller bearings with perpendicular pivot axes) into a single integrated pivot bearing unit. The bearing inner ring serves as a common element for both roller bearings, allowing them to share space and structural support. This merging reduces the overall installation space while maintaining the required degrees of freedom for both suspension and steering movements.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The second roller bearing is nested within the structural framework created by the first roller bearing and bearing inner ring. The bearing outer ring of the second roller bearing is supported on the bearing inner ring or its extension, creating a nested configuration where one bearing system is contained within or integrated with the other, thereby optimizing space utilization.

Inventive Principle:
Principle #7Nested doll (Nesting)

2Adaptability or versatility

If multiple standard roller bearings are combined to achieve necessary degrees of freedom, then pivot movements are enabled, but the weight increases

Engineering Contradiction:
Improvedegrees of freedomVSAvoidbearing assembly weight
Core Design Contradiction:
Adaptability or versatilityVSWeight of moving object

Solution Approach 1:

By merging multiple roller bearings into a single integrated unit with shared components (bearing inner ring, common support structures), the total weight of the bearing assembly is reduced compared to using separate, independent bearings. The shared structural elements eliminate redundant material and reduce overall mass.

Inventive Principle:
Principle #5Merging (Combining)

3Adaptability or versatility

If multiple standard roller bearings are combined to provide required degrees of freedom, then suspension and steering functionality is achieved, but the assembly effort increases

Engineering Contradiction:
Improvedegrees of freedomVSAvoidassembly effort
Core Design Contradiction:
Adaptability or versatilityVSEase of manufacture

Solution Approach 1:

The integrated design of the pivot bearing with merged components reduces the number of separate parts that need to be assembled. The bearing inner ring serves multiple functions and supports multiple roller bearings simultaneously, reducing assembly steps and effort compared to installing separate bearing assemblies.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The bearing inner ring serves as a universal component that provides support for both the first and second roller bearings, as well as serving as a structural connection element. This multi-functionality reduces the total number of components and simplifies the assembly process.

Inventive Principle:
Principle #6Universality (Multi-functionality)

4Volume of stationary object

If ball joints are used in the front suspension, then the suspension system is compact, but breakaway torque increases due to static to sliding friction transition

Engineering Contradiction:
Improvesuspension spaceVSAvoidbreakaway torque
Core Design Contradiction:
Volume of stationary objectVSForce

Solution Approach 1:

The patent replaces ball joint mechanics with roller bearing mechanics. Instead of spherical contact surfaces that transition from static to sliding friction, the design uses roller elements that maintain rolling friction throughout the movement range. This substitution eliminates the breakaway torque phenomenon while maintaining compact dimensions.

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

The pivot bearing system provides a lightweight, easy-to-install, and space-efficient solution for motorcycle front wheel suspension, enhancing steerability and reducing frictional forces, thus improving handling and logistical aspects.

Implementation Method 1

Particularly noteworthy are the practically non-existent breakaway torque (significantly reduced static and sliding friction)

Methodology Applied
Scientific EffectRolling friction: Friction

Implementation Method 2

the first bearing part and/or the second bearing part comprises at least one rolling bearing, in particular a tapered roller bearing

Methodology Applied
Scientific EffectTapered roller bearing mechanism: Roller

Data Source

PatentEP3024717B1Swivel bearing
Publication Date: 2020.09.02 BAYERISCHE MOTOREN WERKE AG
  • EP3024717B1 patent drawingFigure 1
  • EP3024717B1 patent drawingFigure 2~4
  • EP3024717B1 patent drawingFigure 5~6

AI summary

The invention concerns a pivot bearing (34), in particular for a front wheel suspension system of a motorbike, comprising a first bearing part (36) which enables a component to pivot about a first pivot axis (M1). The pivot bearing (34) comprises a second bearing part (38) which enables a component to pivot about a second pivot axis (M2), the two pivot axes (M1, M2) intersecting. The two bearing parts (36, 38) are connected to each other and form a structural unit.