Cryogenic Piston Pump Hydraulic Balancing

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing fuel delivery devices for cryogenic fuels, such as natural gas, face challenges in compensating for oscillating mass forces without using rotating components and shaft bearings, which are typically required to counteract these forces.

Innovation Solution

A piston pump design that hydraulically couples the pump piston to a balancing mass, allowing the movement of the pump piston to balance oscillating inertial forces without rotating components, using a hydraulic volume with separate partial volumes and a balancing mass that moves oppositely to the pump piston, and is prestressed mechanically or pneumatically to ensure reliable resetting.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If rotating components are used to compensate oscillating mass forces, then force balance is improved, but device complexity increases due to shaft bearings and rotating parts

Engineering Contradiction:
Improveforce balanceVSAvoiddevice complexity
Core Design Contradiction:
Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The patent replaces the traditional rotating mechanical balance system with a hydraulic coupling system. The pump piston is hydraulically connected to a balancing mass through a hydraulic medium, allowing force transmission without mechanical contact. This substitution eliminates shaft bearings and rotating components while achieving force balance through hydraulic pressure transmission.

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

Solution Approach 2:

The patent employs a hydraulic volume containing a hydraulic medium to couple the pump piston to the balancing mass. The hydraulic pressure generated by pump piston movement is transmitted to move the balancing mass in opposition, creating force balance. This hydraulic approach replaces complex mechanical rotating balance mechanisms.

Inventive Principle:
Principle #29Pneumatics and hydraulics

2Stability of the object's composition

If a balancing mass is added to compensate oscillating forces, then force balance is improved, but device complexity increases due to additional components

Engineering Contradiction:
Improveforce balanceVSAvoiddevice complexity
Core Design Contradiction:
Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The patent merges the balancing function with the existing pump structure by integrating the balancing mass into the pump housing. The balancing mass is positioned within the same housing that contains the pump piston, and both elements share the hydraulic coupling system. This integration reduces the number of separate components compared to traditional external balance mechanisms.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The hydraulic volume serves multiple functions: it transmits hydraulic pressure from the pump piston, provides a coupling mechanism for the balancing mass, and enables force balance compensation. This multi-functionality reduces the need for separate balancing components and simplifies the overall device structure.

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

3Stability of the object's composition

If the balancing mass moves in opposition to the pump piston, then force balance is improved, but sealing requirements increase to prevent leakage

Engineering Contradiction:
Improveforce balanceVSAvoidsealing reliability
Core Design Contradiction:
Stability of the object's compositionVSReliability

Solution Approach 1:

The hydraulic medium acts as an intermediary between the pump piston and the balancing mass, transmitting force through fluid pressure rather than direct mechanical contact. This intermediary approach allows for smoother force transmission and reduces the severity of sealing requirements compared to direct mechanical coupling, as hydraulic seals can accommodate minor movements and pressure variations.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 solution effectively compensates for oscillating mass forces, enabling a compact and efficient fuel delivery system without the need for rotating components, achieving nearly complete balance of inertial forces and minimizing leakage through sealing mechanisms.

Implementation Method 1

The pump piston (2) is hydraulically coupled to the balancing mass (7) via a hydraulic volume (6), so that the movement of the pump piston (2) leads to a movement of the balancing mass (7)

Methodology Applied
Scientific EffectHydraulic pressure transmission: Hydraulic Press

Implementation Method 2

The balancing mass (7) is permanently subjected to gas pressure on its side facing away from the hydraulic volume (6)

Methodology Applied
Scientific EffectGas pressure: Pressure Increase

Implementation Method 3

The pump piston (2) delimits a compression chamber (not shown) in which fuel can be compressed

Methodology Applied
Scientific EffectMechanical compression: Compression

Data Source

PatentEP3724502B1Fuel delivery device for cryogenic fuels
Publication Date: 2021.09.29 ROBERT BOSCH GMBH
  • EP3724502B1 patent drawingFigure 1
  • EP3724502B1 patent drawingFigure 2
  • EP3724502B1 patent drawingFigure 3

AI summary

The invention relates to a fuel delivery device for cryogenic fuels, comprising a piston pump (1) for delivering the cryogenic fuel at a high pressure, said piston pump (1) having a pump piston (2) that can be moved back and forth and delimits a compression chamber at one end and a pressure chamber (5), which is formed in a hollow cylinder (4) and to which a hydraulic pressure medium can be supplied, at the other end. According to the invention, the pump piston (2) separates the pressure chamber (5) from a hydraulic volume (6) with a first sub-volume (6.1) which is formed within the hollow cylinder (4) and at least one additional sub-volume (6.2) which is formed outside of the hollow cylinder (4) and is delimited by a compensating mass (7) that can be moved back and forth.