Axial Cooler Immersion Reduces Drive Apparatus Diameter

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Solution Overview

Problem

Existing slewing drive apparatuses for construction machines face challenges with increased casing diameter due to coolant paths, leading to space constraints, difficulty in tightening bolts, weak cooling efficiency, and higher manufacturing costs.

Innovation Solution

A drive apparatus with a cooler immersed in lubricating oil, providing heat exchange on both sides and reducing the apparatus's diameter, using a simple box structure with a central coolant path and bolt-through holes for easy assembly and reduced manufacturing complexity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If a coolant path is provided in the casing wall to cool lubricating oil, then cooling function is achieved, but the casing diameter increases and occupies more space

Engineering Contradiction:
Improvelubricating oil temperatureVSAvoidcasing diameter
Core Design Contradiction:
TemperatureVSArea of stationary object

Solution Approach 1:

The cooler is positioned inside the casing along the axial direction rather than embedding the coolant path in the radial casing wall. This dimensional change from radial to axial arrangement reduces the casing diameter while maintaining cooling capability through immersion of the cooler in the lubricating oil.

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

2Temperature

If the casing diameter increases to accommodate a coolant path, then cooling function is provided, but tightening tools cannot enter and bolt assembly becomes difficult

Engineering Contradiction:
Improvelubricating oil temperatureVSAvoidbolt tightening accessibility
Core Design Contradiction:
TemperatureVSEase of operation

Solution Approach 1:

By relocating the cooling function from the radial casing wall to an axial cooler component, the casing diameter is reduced to its minimum necessary size, creating sufficient radial clearance for tightening tools to access and operate on mounting bolts without interference.

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

3Temperature

If coolant path is formed within casing wall thickness, then cooling is achieved, but manufacturing complexity increases due to special molding methods

Engineering Contradiction:
Improvelubricating oil temperatureVSAvoidcasing manufacturing
Core Design Contradiction:
TemperatureVSEase of manufacture

Solution Approach 1:

The cooling function is separated from the casing structure by using a distinct cooler component that can be manufactured independently and then assembled into the casing. This segmentation allows the casing to be manufactured using simple, conventional methods without requiring complex core-based molding processes.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The cooler acts as an intermediary component that provides the cooling function without requiring modifications to the casing structure. This mediator approach simplifies casing manufacturing while achieving the same thermal management objective through a separate, easily manufactured part.

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

Enhances cooling efficiency, reduces apparatus size, simplifies assembly, and lowers manufacturing costs while maintaining compactness and ease of operation.

Implementation Method 1

a cooler formed with a coolant path through which liquid or gas for cooling the lubricating oil passes as a cooling medium

Methodology Applied
Scientific EffectHeat exchange: Heat Exchanger

Implementation Method 2

cooling lubricating oil from an outer periphery by flowing a cooling medium such as water and oil in this coolant path

Methodology Applied
Scientific EffectConvection: Convection

Data Source

PatentEP2645543B1Drive apparatus and construction machine provided with same
Publication Date: 2020.01.08 KOBELCO CONSTR MASCH CO LTD
  • EP2645543B1 patent drawingFigure 1
  • EP2645543B1 patent drawingFigure 2~3
  • EP2645543B1 patent drawingFigure 4

AI summary

Provided is a drive apparatus for a construction machine in which a cooling effect of lubricating oil is enhanced and a manufacturing cost is reduced while the size in a diameter direction is small. The drive apparatus for a construction machine includes: a motor (1) having a motor shaft (5); a speed reducer unit (2) having a speed reducer output shaft (6) and a casing (4) and reducing speed of rotation force of the motor (1), and transmitting the force to an upper slewing body; and a cooler (15) formed with a coolant path (16) through which liquid or gas for cooling lubricating oil (O) inside the casing (4) passes as a cooling medium, wherein the motor (1) and the speed reducer unit (2) are provided in a row in an apparatus-axis direction such that the motor shaft (5) and the speed reducer output shaft (6) are arranged along the same line (Ce), and the cooler (15) is provided in a row with the speed reducer unit (2) in the apparatus-axis direction in a state where at least a part of the cooler (15) is immersed in the lubricating oil (O), so as to enable heat exchange with the lubricating oil (O).