Screw Spindle Pump Motor Cooling Without Rotative Seals

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Solution Overview

Problem

Existing screw pumps lack an efficient cooling mechanism for the drive engine and rely on rotative sealing elements that are prone to wear and tear.

Innovation Solution

The screw pump design incorporates an axial fluid outlet that allows a portion of the pressurized fluid to flow through a sealless hole along the drive shaft into the drive engine for cooling, eliminating the need for rotative sealing elements.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If a radial outlet connection is used for fluid discharge, then the pump structure is simple, but the drive motor cannot be cooled effectively

Engineering Contradiction:
Improvedrive motor temperatureVSAvoidspindle housing structure
Core Design Contradiction:
TemperatureVSDevice complexity

Solution Approach 1:

The axial outlet connection serves dual functions: it discharges pumped fluid and simultaneously channels cooling fluid to the drive motor. This multi-functionality resolves the contradiction by integrating cooling capability into the existing outlet structure without adding separate cooling pathways.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The outlet connection is divided into two separate inlets: one for pumped fluid discharge and one for cooling fluid supply. This segmentation allows independent optimization of each function while maintaining a compact overall structure.

Inventive Principle:
Principle #1Segmentation

2Reliability

If rotative sealing elements are used at the drive shaft, then the sealing function is achieved, but wear and reliability issues occur

Engineering Contradiction:
Improvesealing system reliabilityVSAvoidsealing structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The sealing function is extracted from the rotating drive shaft and transferred to a stationary seal at the housing. This eliminates rotative sealing elements that are prone to wear, achieving the sealing function through a static interface between the drive shaft and housing.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The mechanical rotative sealing system is replaced with a stationary sealing arrangement. The seal is fixed in the housing and interfaces with the rotating drive shaft without being attached to it, substituting a wear-prone mechanical sealing system with a more reliable stationary sealing mechanism.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Temperature

If the drive motor is cooled by diverting pumped fluid, then cooling is achieved, but sealing elements subject to rotational stress are required

Engineering Contradiction:
Improvedrive motor temperatureVSAvoidsealing element durability
Core Design Contradiction:
TemperatureVSReliability

Solution Approach 1:

The sealing function is extracted from the rotating components and placed in a stationary housing seal. This allows cooling fluid to be diverted through the drive motor without requiring rotative sealing elements, as the seal remains stationary and is not subject to rotational stress.

Inventive Principle:
Principle #2Taking out (Extraction)

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 provides active cooling for the drive engine, enhancing efficiency and engine power, while eliminating the risk of wear associated with rotative sealing elements.

Implementation Method 1

a part of the fluid flowing from the fluid outlet of the spindle housing flows through the sealless bore along the drive shaft into the drive motor, cools it

Methodology Applied
Scientific EffectHeat transfer: Conduction (thermal)

Data Source

PatentEP4198261B1Screw spindle pump
Publication Date: 2025.04.09 LEISTRITZ PUMPEN
  • EP4198261B1 patent drawingFigure 1
  • EP4198261B1 patent drawingFigure 2
  • EP4198261B1 patent drawingFigure 3

AI summary

A screw spindle pump comprising a spindle housing (2) in which a drive spindle (3) and at least one meshing running spindle (4) are received in spindle bores, and an outer housing (5) enclosing the spindle housing (2), on which an axial inlet port (6) and a radial outlet port (9) are provided, wherein the spindle housing (2) has an axial fluid outlet for the fluid conveyed through the spindle housing (2) via the drive and running spindles (3, 4), and a drive motor (11) comprising a drive shaft (12) which runs through a bore (23) in a housing wall (15) axially closing the interior of the outer housing (5) and is coupled to the drive spindle (12), wherein a portion of the fluid flowing from the fluid outlet of the spindle housing (2) flows through the sealless bore (23) along the drive shaft (12) into the drive motor (11), cooling it. and flows back into the outer casing (5).