Drill Motor Housing Forging Composite Steel Alloy Lining

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Solution Overview

Problem

Existing methods for producing a drilling motor housing with a coiled inner surface face challenges in achieving low manufacturing tolerances and ensuring high operational reliability, particularly with metallic linings, as adhesion and uniform thickness requirements are difficult to meet.

Innovation Solution

The method involves pushing a prefabricated lining pipe into a casing pipe, which are then forged together using a mandrel to form a composite body, allowing for cold or hot deformation to achieve the required shape and metallurgical properties, ensuring dimensional accuracy and bonding between the steel jacket and sliding alloy lining.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If a lining is applied to the pre-profiled inner surface of the casing tube by electroplating, casting, flame forming, plasma spraying, or heat setting, then the lining can be formed on the helical inner surface, but the manufacturing tolerances are comparatively high and uniform thickness is difficult to achieve

Engineering Contradiction:
Improvemanufacturing toleranceVSAvoidlining application complexity
Core Design Contradiction:
Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The lining is prepared in advance as a separate tube with the required thickness and properties before insertion into the casing tube. This preliminary preparation allows precise control of the lining thickness and properties without the limitations of post-profiled application methods.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The lining tube is inserted into the casing tube, creating a nested structure where the pre-formed lining tube serves as the inner layer. This nesting approach allows the lining to be formed with uniform thickness before being constrained by the helical profile during cold forging.

Inventive Principle:
Principle #7Nested doll (Nesting)

2Manufacturing precision

If cold forging is used to form the helical inner surface, then the strength of the composite body is increased and tight manufacturing tolerances are achieved, but the method is not suitable for producing hollow workpieces with a helical inner surface when the lining is applied afterward

Engineering Contradiction:
Improvedimensional accuracyVSAvoidsuitability for helical inner surface
Core Design Contradiction:
Manufacturing precisionVSAdaptability or versatility

Solution Approach 1:

The lining tube is pre-formed with the required thickness and material properties before insertion. This preliminary action enables the subsequent cold forging process to achieve tight tolerances on the helical inner surface without compromising the lining's uniformity or adhesion.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The invention creates a composite structure by cold forging the casing tube and lining tube together. This composite formation process ensures intimate metallurgical bonding while maintaining the helical inner surface geometry and achieving tight manufacturing tolerances throughout.

Inventive Principle:
Principle #40Composite materials

3Reliability

If the lining tube is inserted into the casing tube and forged together over a mandrel, then intimate bond and precise dimensional accuracy are achieved, but the device complexity increases

Engineering Contradiction:
Improveoperational reliabilityVSAvoidmanufacturing process complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The lining tube is inserted into the casing tube to form a nested configuration before forging. This nesting simplifies the overall process by combining two components into one integrated operation, ensuring intimate bonding and precise dimensional accuracy simultaneously.

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The insertion and forging operations are combined into a single integrated process step. The lining tube and casing tube are forged together in one operation over the mandrel, merging the bonding and shaping functions into a unified process that enhances reliability without requiring multiple separate steps.

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 approach ensures low manufacturing tolerances and high operational reliability by achieving an intimate bond and precise dimensional accuracy without the need for post-processing, enhancing the metallurgical properties and adhesion of the composite body.

Implementation Method 1

cold forged over a mandrel which determines the helical inner surface of the housing

Methodology Applied
Scientific EffectCold forming: Cold-forming

Implementation Method 2

hot forging over a mandrel before the composite body is cold forged

Methodology Applied
Scientific EffectHot forming: Hot Isostatic Pressing

Implementation Method 3

cold forging of the outer casing and the inner lining tube to form the finished composite body

Methodology Applied
Scientific EffectCold forging: Cold-forming

Implementation Method 4

hot forging over a mandrel before the composite body is cold forged

Methodology Applied
Scientific EffectHot forging: Hot Isostatic Pressing

Data Source

PatentEP3181259B1Method of manufacturing a housing for a drill motor
Publication Date: 2019.02.13 GFM GMBH
  • EP3181259B1 patent drawingFigure 1~2
  • EP3181259B1 patent drawingFigure 3~4
  • EP3181259B1 patent drawingFigure 5~6

AI summary

A method for manufacturing a housing for a drill motor is described, comprising a tubular steel shell (1) with a helical inner surface (2) and a lining (3) made of a sliding alloy following the helical inner surface (2) for receiving (4) a helical rotor, wherein a shell tube (5) is forged over a mandrel. To create advantageous manufacturing conditions, it is proposed that the lining (3) in the form of a prefabricated lining tube (6) be inserted into the shell tube (5) and that the shell tube (5) and the lining tube (6) be forged together over the mandrel, which defines the helical inner surface (8) of the housing, to form a composite body (7).