Reduction Gear Mounting for Heat Dissipation in Road Milling Machines

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing self-propelled road milling machines face challenges with heat dissipation and mechanical wear in their reduction gear systems, particularly when adapting to different milling tube lengths, which limits milling depth and rigidity.

Innovation Solution

The reduction gear is non-rotatably fastened to the machine frame between the drive device and the drive-side roller housing wall, allowing for better heat dissipation and increased rigidity, with active cooling and a smaller diameter to minimize wear and enhance milling depth.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If the reduction gear is arranged inside the roller base body or surrounded by protective tubes, then the structure is compact and protected, but heat dissipation is impaired and thermal load increases

Engineering Contradiction:
Improveheat dissipationVSAvoidprotective structure
Core Design Contradiction:
TemperatureVSDevice complexity

Solution Approach 1:

The reduction gear is extracted from the roller base body and mounted externally on the machine frame. This separation removes the heat-generating component from the thermally constrained environment inside the roller base, allowing for significantly improved heat dissipation without requiring complex protective tubing while reducing thermal load on the gear system

Inventive Principle:
Principle #2Taking out (Extraction)

2Temperature

If the reduction gear is arranged on the side opposite the drive side, then space is utilized, but heat build-up increases due to additional drive shaft and poor dissipation conditions

Engineering Contradiction:
Improveheat build-upVSAvoiddrive shaft length
Core Design Contradiction:
TemperatureVSLength of moving object

Solution Approach 1:

The reduction gear housing serves as an intermediary structure that is rigidly mounted to the machine frame rather than being integrated into the roller base. This intermediary mounting approach allows the reduction gear to be positioned optimally for heat dissipation while maintaining a direct, short drive connection from the drive device, eliminating the need for long drive shafts and reducing heat build-up

Inventive Principle:
Principle #24Intermediary (Mediator)

3Length of moving object

If the reduction gear diameter is minimized, then the milling depth can be increased, but the bending moments on connecting elements increase due to small lever arm

Engineering Contradiction:
Improvemilling depthVSAvoidbending moments
Core Design Contradiction:
Length of moving objectVSForce

Solution Approach 1:

The reduction gear is mounted in a separate dimension outside the roller base body, attached rigidly to the machine frame. This spatial repositioning allows the gear to have a smaller diameter (enabling greater milling depth) while the rigid frame mounting provides sufficient structural support to handle bending moments, decoupling the gear size constraint from the structural support constraint

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

4Stability of the object's composition

If the reduction gear is rigidly fastened to the machine frame, then rigidity and heat dissipation are improved, but the structure becomes more complex

Engineering Contradiction:
ImproverigidityVSAvoidmounting structure
Core Design Contradiction:
Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The reduction gear housing is rigidly merged with the machine frame through direct fastening, combining the structural support function and the heat dissipation function into a single integrated arrangement. This merging provides high rigidity for stable operation and excellent heat dissipation to the ambient air, while actually simplifying the overall structure by eliminating separate protective tubes and complex mounting mechanisms

Inventive Principle:
Principle #5Merging (Combining)

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 configuration improves heat dissipation and mechanical rigidity, reducing wear and enabling deeper milling while simplifying maintenance and reducing the need for protective gear, thus expanding the machine's application range.

Implementation Method 1

The arrangement of the reduction gear on the drive side of the roller housing wall enables better heat dissipation

Methodology Applied
Scientific EffectHeat dissipation: Convection

Implementation Method 2

The arrangement of the reduction gear on the drive side of the roller housing wall enables better heat dissipation

Methodology Applied
Scientific EffectThermal radiation: Thermal Radiation

Implementation Method 3

with active cooling

Methodology Applied
Scientific EffectForced convection: Forced Convection

Data Source

PatentEP2336426B2Self-propelled street milling machine
Publication Date: 2018.02.07 WIRTGEN GMBH
  • EP2336426B2 patent drawingFigure 1
  • EP2336426B2 patent drawingFigure 2
  • EP2336426B2 patent drawingFigure 3

AI summary

The machine (1) has a machine frame (2), and a rotary grinder (4) arranged at the frame. A drive device (6) drives the grinder, and a reduction gear i.e. planetary gear, is arranged between the drive device and the roller. The roller is arranged between roller housing walls of a roller housing (11), and a quick changing system has a roller base body and a milling tube element. A housing of the gear is fastened to the frame in a torque-proof manner in an inner side of the frame between the drive device and one of the roller housing walls.