Rotary Pump Rotor Sheet Metal Insert Design

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Solution Overview

Problem

Existing rotor pumps are complex to manufacture and repair due to the use of inserts, which can lead to dimensional inaccuracies and uneven cooling, resulting in excessive wear or poor efficiency.

Innovation Solution

A rotor pump design where a sheet metal part is inserted into the rotor after production, allowing for easy assembly and repair, with the sheet metal part being fastened using bent edges or beads to prevent displacement and facilitate lubrication, enabling the use of different material pairings and uniform cooling.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If inserts are cast or overmoulded in the rotor, then the rotor can be manufactured as a single piece, but the inserts will change their specified position leading to dimensional inaccuracies and excessive wear

Engineering Contradiction:
Improvemanufacturing processVSAvoiddimensional accuracy of wing receptacle
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The rotor is divided into a plastic rotor body and separate metal inserts. The inserts are produced separately with high precision, then mechanically fitted into the rotor. This segmentation allows each component to be manufactured independently with optimal processes, avoiding the positioning errors that occur when inserts are integrated during molding.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The metal inserts are pre-manufactured with their precise dimensions and positions determined before assembly. The rotor is then manufactured without the inserts, and the inserts are subsequently fitted into predetermined receptacles. This preliminary preparation ensures dimensional accuracy is established before final assembly, preventing the positioning deviations that occur during integrated manufacturing.

Inventive Principle:
Principle #10Preliminary action

2Ease of manufacture

If inserts are integrated during injection molding or die casting, then the rotor can be produced as a single component, but the inserts will cool unevenly due to different temperature coefficients and heat storage capacity

Engineering Contradiction:
Improvesingle piece productionVSAvoiduniform cooling
Core Design Contradiction:
Ease of manufactureVSTemperature

Solution Approach 1:

The rotor is segmented into a plastic body and separate metal inserts that are assembled after production. This allows the plastic rotor to cool uniformly during its molding process without the thermal interference of metal inserts, eliminating the uneven cooling and deformation problems associated with integrated metal-plastic components.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The metal inserts are extracted from the integrated manufacturing process and produced separately. The rotor is manufactured as a plastic component alone, allowing uniform cooling and contraction during molding. The metal inserts are then added as separate elements, avoiding the thermal compatibility issues that arise when metal and plastic are molded together.

Inventive Principle:
Principle #2Taking out (Extraction)

3Productivity

If inserts are cast or overmoulded in the rotor, then the rotor can be manufactured efficiently, but the rotor cannot be repaired if the inserts become damaged or worn out

Engineering Contradiction:
Improvemanufacturing efficiencyVSAvoidrepairability of rotor
Core Design Contradiction:
ProductivityVSEase of repair

Solution Approach 1:

The rotor is segmented into a removable plastic body and separate metal inserts. The inserts are held in place by retention features such as recesses in the rotor body and corresponding protrusions on the inserts, or by friction fit. This modular design allows the inserts to be easily removed and replaced when worn, enabling repair without replacing the entire rotor assembly.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The metal inserts are designed as replaceable components that can be removed when worn or damaged. The rotor body retains the inserts through mechanical features, allowing the inserts to be discarded and replaced with new ones, while the rotor body itself is recovered and reused. This approach enables cost-effective repair by replacing only the worn inserts rather than the entire rotor.

Inventive Principle:
Principle #34Discarding and recovering

4Temperature

If sheet metal part is inserted after rotor production, then the rotor can be manufactured with uniform cooling and constant wall thickness, but the assembly process becomes more complex

Engineering Contradiction:
Improveuniform coolingVSAvoidassembly process
Core Design Contradiction:
TemperatureVSDevice complexity

Solution Approach 1:

The rotor is manufactured as a complete plastic component with uniform wall thickness and cooling channels designed into the mold. The metal inserts are pre-prepared with their final dimensions and features. During assembly, the inserts are simply placed into predetermined receptacles in the rotor, requiring minimal additional operations beyond basic insertion and retention feature engagement.

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

This design simplifies production and repair, ensures uniform cooling, and allows for the use of incompatible materials, improving efficiency and extending the rotor's lifespan by enabling easy replacement of worn parts.

Implementation Method 1

the outwardly pointing edges of the sheet metal part are bent around the edges of the slot openings

Methodology Applied
Scientific EffectElastic deformation: Plasticity

Implementation Method 2

the groove can be used to convey lubricant so that the sliding surface between the sheet metal part and the wing is permanently full of lubricant

Methodology Applied
Scientific EffectFriction reduction: Lubrication

Implementation Method 3

the rotor and/or the vane can consist of plastic, whereby material pairings can also be selected that cannot be paired per se

Methodology Applied
Scientific EffectMaterial compatibility:

Data Source

PatentEP1952027B1Rotary pump
Publication Date: 2011.03.09 JOMA POLYTEC GMBH
  • EP1952027B1 patent drawingFigure 1
  • EP1952027B1 patent drawingFigure 2
  • EP1952027B1 patent drawingFigure 3

AI summary

The invention relates to a rotary pump which comprises a pump housing (12) with a pump chamber, a rotor (18), mounted to rotate in the pump chamber and having a slot (44) extending at an angle to the axis of rotation, a vane (20), mounted in the slot of the rotor to be displaceable therein, said vane subdividing the pump chamber into two compartments and resting against the inner circumferential wall of the pump chamber. The vane carries out a relative movement with respect to rotor and the rotor a relative movement with respect to the inner circumferential wall. The slot of the rotor has a respective insert (46) on both sides facing the vane, said insert being a sheet metal part and enclosing the slot edges with its ends facing the slot openings.