Rotary Piston Pump Direct Drive Torque Synchronization

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Solution Overview

Problem

Hydropower plants with rotary piston engines face inefficiencies due to torque differences between meshing rotary pistons, leading to increased wear and bearing load, which reduces the efficiency of the direct hydraulic drive method.

Innovation Solution

The rotary pistons are designed with helically arranged blades covering an angular range close to a full revolution, allowing for direct mechanical coupling to generators and eliminating the need for synchronization gears, reducing torque differences and wear, and utilizing plain bearings lubricated by the fluid medium for reduced maintenance and compact design.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If meshing rotary pistons are used for direct drive, then synchronization of rotary motion is achieved, but torque differences cause wear on rotary pistons and increased bearing load

Engineering Contradiction:
Improvesynchronization of rotary motionVSAvoidwear on rotary pistons and bearing load
Core Design Contradiction:
Stability of the object's compositionVSReliability

Solution Approach 1:

The system is divided into two independent drive chains, each with its own hydraulic motor and generator. This segmentation eliminates the meshing contact between rotary pistons while maintaining synchronized operation through independent control, thereby reducing wear and bearing load on individual components.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The mechanical meshing connection between rotary pistons is replaced with independent hydraulic motors that can be mechanically coupled to generators. This substitution eliminates the harmful mechanical contact and torque transmission issues while maintaining the synchronization function through independent hydraulic control.

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

2Reliability

If synchronization gear is used to eliminate torque differences, then wear is reduced, but device complexity increases

Engineering Contradiction:
Improvereduced wearVSAvoiddevice complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The synchronization function is extracted from the mechanical meshing system and implemented through independent hydraulic motor control. This removes the need for additional synchronization gears or mechanical intervention devices, reducing overall system complexity while maintaining reliability through independent drive chains.

Inventive Principle:
Principle #2Taking out (Extraction)

3Loss of energy

If direct hydraulic drive is used, then efficiency is improved, but torque fluctuations cause pulsation and bearing load

Engineering Contradiction:
ImproveefficiencyVSAvoidpulsation and bearing load
Core Design Contradiction:
Loss of energyVSObject-generated harmful factors

Solution Approach 1:

The single direct drive system is segmented into two independent direct drive chains. Each chain operates with its own hydraulic motor and generator, allowing independent optimization of torque delivery. This segmentation smooths out pulsations and bearing loads that would occur in a single direct drive system while maintaining high efficiency.

Inventive Principle:
Principle #1Segmentation

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 enhances efficiency by minimizing torque fluctuations, reducing wear and bearing loads, and enabling oil-free operation, resulting in a more economically efficient and compact hydropower plant with reduced pulsation and increased pump pressure handling capacity.

Implementation Method 1

a fluid flow from the inlet to the outlet opening sets the first and second rotary pistons in rotation about the first and second axes, respectively

Methodology Applied
Scientific EffectHydraulic motor: Hydraulic Press

Implementation Method 2

the blades of the rotary pistons run helically along the circumferential surface of the rotary piston, sweeping an angular range that is close to a fraction of a full revolution

Methodology Applied
Scientific EffectHelical geometry: Helix

Implementation Method 3

the meshing movement of the two rotary lobes with each other, which enables direct drive of each individual rotary lobe

Methodology Applied
Scientific EffectMeshing: Gear

Implementation Method 4

utilizing plain bearings lubricated by the fluid medium for reduced maintenance and compact design

Methodology Applied
Scientific EffectLubrication: Lubrication

Data Source

PatentEP2914812B1Rotary piston pump having direct drive
Publication Date: 2024.10.23 HUGO VOGELSANG MASCHINENBAU GMBH
  • EP2914812B1 patent drawingFigure 1
  • EP2914812B1 patent drawingFigure 2
  • EP2914812B1 patent drawingFigure 3

AI summary

The invention relates to a rotary piston pump, comprising a pump housing having a pump chamber, an inlet opening, an outlet opening, a first, multi-vane rotary piston, which is arranged in the pump chamber and is rotatably supported about a first axis, a second, multi-vane rotary piston arranged in the pump chamber, which is rotatably supported about a second axis that is spaced from the first axis and which meshes with the first rotary piston, wherein the first and second rotary pistons produce a fluid flow from the inlet opening to the outlet opening by rotating about the first and second axes, respectively, and a drive device, which is mechanically coupled to the rotary pistons in order to drive the rotary pistons. According to the invention, the drive device comprises a first electric drive motor, which is mechanically coupled to the first rotary piston in order to drive the first rotary piston, and a second electric drive motor, which is mechanically coupled to the second rotary piston in order to drive the second rotary piston.