Balancing Shaft Partial Bearing Surface Weight Reduction

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Solution Overview

Problem

Existing balancer shafts for single or multi-cylinder engines are heavy, leading to increased fuel consumption and reduced performance, necessitating a reduction in weight while maintaining balance compensation.

Innovation Solution

The balancer shaft design features a bearing point with a partially circumferential running surface, allowing for weight reduction by cutting free areas and reducing adjacent imbalance weight sections, along with a race segment that completes the running surface, enabling use in both conventional and new engine housings, and providing a long service life and smooth operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional balancer shafts with full circumferential bearing surfaces are used, then reliable support and lubrication are ensured, but the weight and moving masses increase significantly

Engineering Contradiction:
Improvebearing support reliabilityVSAvoidbalancer shaft weight
Core Design Contradiction:
ReliabilityVSWeight of moving object

Solution Approach 1:

The bearing point is segmented into two parts: a partial running surface formed directly on the balancer shaft body and a separate race segment that completes the circumferential support. This segmentation allows the running surface to be reduced (saving weight) while the race segment provides the necessary complete bearing support, resolving the contradiction between reliability and weight.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The race segment is extracted as a separate component that can be optimally designed and positioned. By taking out the complete circumferential support function and implementing it through a separate race segment, the main balancer shaft body can be lighter while still achieving full bearing support when the race segment is in place.

Inventive Principle:
Principle #2Taking out (Extraction)

2Weight of moving object

If the running surface is reduced to save weight, then bearing friction and lubrication performance deteriorate

Engineering Contradiction:
Improvebalancer shaft weightVSAvoidbearing friction
Core Design Contradiction:
Weight of moving objectVSObject-affected harmful factors

Solution Approach 1:

The race segment acts as an intermediary between the partial running surface on the balancer shaft and the complete bearing support required. It mediates by providing the additional bearing surface area needed for proper lubrication and friction reduction, while allowing the main shaft to remain lightweight.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 design achieves a significant weight reduction of 20-40% compared to conventional balancer shafts, ensuring universal use, easy assembly, and maintaining balance compensation, while also reducing bearing friction and enhancing lubrication.

Implementation Method 1

a bearing point with a running surface that extends partially over a circumference of the bearing point, in each case viewed in cross-section in the longitudinal direction of the balancer shaft, comprises a depression which, together with the running surface, forms a cross-sectional area in which the axis of rotation lies outside of the cross-sectional area

Methodology Applied
Scientific EffectWeight reduction through material removal:

Implementation Method 2

a race segment that completes or spans the partial running surface through the support surface of the race segment

Methodology Applied
Scientific EffectBearing support:

Data Source

PatentEP2156070B1Balancing shaft
Publication Date: 2014.07.16 HERZOG INTERTEC GMBH
  • EP2156070B1 patent drawingFigure 1~3
  • EP2156070B1 patent drawingFigure 4~6b
  • EP2156070B1 patent drawingFigure 7~8

AI summary

The invention relates to a balancing shaft for a single- or multi cylinder motor having at least one unbalanced weight section (21, 22; 23, 24) and at least one bearing point (16, 17), wherein the at least one unbalanced weight section (21, 22; 23, 24) is allocated to the bearing point (16, 17) and the bearing point (16, 17) has a radial contact surface (18) that extends only partially over a circumference of the bearing point (16, 17) and a centrifugal force resulting from the rotation of the balancing shaft (11) lies inside a region of the bearing point (16, 17) formed by the contact surface (18) extending partially over the circumference of the bearing point (16, 17), wherein a contact ring segment (51) is allocated to the partially formed contact surface (18) that is adjacent to the partially formed contact surface (18) of the bearing point (16, 17) and, along with the partially formed contact surface (18), forms a completely closed contact surface (20) of the bearing point (16, 17) and comprises at least one lateral edge (54) limiting the width of the contact ring segment (51), said lateral edge spanning the partially formed contact surface (18) and being provided in a self-supporting fashion.