Axial Piston Blank Extrusion for Precision and Lower Machining Cost

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Solution Overview

Problem

Current manufacturing methods for axial piston machines are costly and inefficient, with high machining requirements and low surface quality, affecting the component strength and accuracy of piston blanks.

Innovation Solution

A manufacturing method involving impact extrusion to produce a piston blank with a shank section, ball head section, and sealing section, followed by machining to create a through hole and spherical cap geometry, which reduces subsequent machining costs and improves surface quality and component accuracy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If conventional machining methods are used to produce piston blanks, then manufacturing precision can be achieved, but manufacturing costs increase and productivity decreases

Engineering Contradiction:
Improvepiston blank precisionVSAvoidmanufacturing efficiency
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

The method performs preliminary shaping through extrusion to create a near-net-shape piston blank before final machining. This preliminary action removes the bulk of material and establishes the basic geometry, so that subsequent machining only requires minimal finishing operations to achieve final precision, thereby improving both productivity and reducing costs.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The invention changes the manufacturing parameter from direct machining of finished parts to extrusion forming followed by minimal machining. This parameter change in the manufacturing process allows the piston blank to be formed with close tolerances through the extrusion process itself, reducing the need for extensive post-machining operations.

Inventive Principle:
Principle #35Parameter changes

2Manufacturing precision

If conventional machining methods are used to produce piston blanks, then manufacturing precision can be achieved, but manufacturing costs increase

Engineering Contradiction:
Improvepiston blank precisionVSAvoidmanufacturing cost
Core Design Contradiction:
Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The extrusion process performs preliminary shaping to create a near-net-shape piston blank with close tolerances before final machining. This preliminary action eliminates the need for multiple machining passes and reduces material waste, significantly lowering manufacturing costs while maintaining high precision requirements.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The method incorporates feedback control in the extrusion process to maintain dimensional accuracy and surface quality. By monitoring and adjusting extrusion parameters in real-time, the process achieves consistent near-net-shape accuracy, reducing the need for expensive post-machining operations and tooling.

Inventive Principle:
Principle #23Feedback

3Strength

If conventional machining methods are used, then piston blanks can be produced, but surface quality is insufficient affecting component strength

Engineering Contradiction:
Improvecomponent strengthVSAvoidsurface quality
Core Design Contradiction:
StrengthVSManufacturing precision

Solution Approach 1:

The extrusion process creates a refined grain structure and smooth surface finish during the forming operation itself, before machining. This preliminary action produces a near-net-shape blank with improved surface quality and enhanced mechanical properties due to the directional grain flow, reducing the need for extensive surface finishing operations.

Inventive Principle:
Principle #10Preliminary action

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 method significantly reduces manufacturing costs and improves the surface quality and strength of piston blanks, enabling cost-effective production of axial piston machines with enhanced operational performance.

Implementation Method 1

an intermediate blank is produced by extrusion in particular a blank, preferably a solid body, is formed using an impact extrusion tool

Methodology Applied
Scientific EffectImpact Force: Impact Force

Implementation Method 2

an intermediate blank is produced by extrusion

Methodology Applied
Scientific EffectExtrusion: Extrusion

Data Source

PatentEP3676495B1Production method, piston blank, piston and axial piston machine having said piston
Publication Date: 2021.06.02 SCHAEFFLER TECHNOLOGIES AG & CO KG
  • EP3676495B1 patent drawingFigure 1
  • EP3676495B1 patent drawingFigure 2
  • EP3676495B1 patent drawingFigure 3

AI summary

Axial piston machines are known that work as a pump and/or motor, wherein the axial piston machines have at least one axial piston. In relation to this, a production method is proposed comprising the method steps: producing an intermediate blank (7) of a piston (2), in particular an axial piston, for an axial piston machine (1) by means of extrusion, wherein the intermediate blank (7) has a shaft section (7b), a ball head section (7a) and a sealing section (7c), wherein the shaft section (7b) connects the ball head section (7a) to the sealing section (7c); and producing a piston blank (14) from the intermediate blank (7), wherein a through opening (15) is introduced into the intermediate blank (7) by means of machining, wherein the through opening (15) extends within the piston blank (7) in the longitudinal direction.