Valve Electrohydraulic Actuation With Decoupled Fail-Safe Preloading

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional electrohydraulic systems for rotary valves require significant energy for adjustment and do not allow independent operation of valve movement from the return mechanism, necessitating continuous actuation of the preloading device.

Innovation Solution

A decoupled hydraulic system where the preloading device is independent of the hydraulic piston, allowing separate steps for valve actuation and preloading, with a pretensioning device using an elastic element to secure a predetermined position during failures.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the preloading device is coupled to the hydraulic piston for simultaneous valve adjustment and return, then the valve can be adjusted and returned, but significantly more energy is required and the valve movement cannot be operated independently of the return mechanism

Engineering Contradiction:
ImproveIndependent operation of valve actuation and preloadingVSAvoidEnergy consumption for valve adjustment
Core Design Contradiction:
Ease of operationVSUse of energy by moving object

Solution Approach 1:

The system is divided into two independent hydraulic circuits: one for valve actuation (hydraulic piston) and one for preloading (pretensioning device). This segmentation allows independent operation of valve movement and preloading, eliminating the need for continuous preloading actuation and reducing energy consumption.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

A check valve is introduced as an intermediary component between the hydraulic piston and the pretensioning device. This check valve allows the hydraulic piston to be decoupled from the preloading device, enabling independent operation while maintaining the necessary mechanical connections.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If the preloading device is continuously actuated to maintain readiness, then the system is prepared for emergency closure, but energy is wasted through continuous actuation

Engineering Contradiction:
ImproveReadiness for emergency closureVSAvoidEnergy wasted through continuous preloading actuation
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The pretensioning device is preloaded in advance through a separate hydraulic circuit, so that when an emergency occurs, the elastic element is already tensioned and ready to immediately rotate the output shaft to the predetermined position without requiring continuous actuation.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The elastic element in the pretensioning device stores energy autonomously once preloaded, maintaining system readiness without requiring continuous external actuation. The stored energy in the elastic element automatically activates when needed, eliminating wasted energy from continuous operation.

Inventive Principle:
Principle #25Self-service

3Volume of moving object

If a compact cylinder design is used where the piston engages the drive shaft, then the system is more compact, but the hydraulic connection and decoupling mechanism becomes more complex

Engineering Contradiction:
ImproveSystem compactnessVSAvoidHydraulic connection and decoupling mechanism
Core Design Contradiction:
Volume of moving objectVSDevice complexity

Solution Approach 1:

The cylinder housing serves dual functions: it acts as both the hydraulic pressure chamber and the mechanical guide for the piston rod that engages the drive shaft. This merging of functions reduces the number of separate components and achieves compactness without excessive complexity.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The check valve is designed to perform multiple functions: it allows hydraulic pressure transmission during normal operation, enables decoupling during emergency closure, and maintains system integrity. This multi-functionality reduces the need for additional specialized components.

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

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 system achieves energy-efficient and compact operation of rotary valves, enabling independent valve actuation and secure positioning without continuous preloading, suitable for both open and closed states.

Implementation Method 1

a hydraulic piston (20) configured to be actuated by a pressure medium and arranged to rotate the output shaft (10)

Methodology Applied
Scientific EffectHydraulic pressure: Pressure Increase

Implementation Method 2

a pretensioning device (30) configured to store energy by pretensioning an elastic element (31) and to transfer the same to the output shaft (10) in the event of a fault

Methodology Applied
Scientific EffectElastic energy storage: Elasticity

Implementation Method 3

a check valve (53, 54) arranged between one of the cylinder housings (22, 23) and the hydraulic cylinder (37), which is configured to decouple the preloading device from the hydraulic piston (20)

Methodology Applied
Scientific EffectCheck valve flow control: Valve

Data Source

PatentEP4051911B1Electrohydraulic system for a valve
Publication Date: 2025.10.01 ROBERT BOSCH GMBH
  • EP4051911B1 patent drawingFigure 1
  • EP4051911B1 patent drawingFigure 2
  • EP4051911B1 patent drawingFigure 3

AI summary

The present invention relates to an electrohydraulic system (100) for a valve, which system is configured to rotatingly drive a valve, the system (100) comprising the following: an output shaft (10), which can be directly connected to the valve in order to rotatably drive the valve and extends along a first axis (Ax1); a hydraulic piston (20), which is configured to be actuated by means of a pressure medium and is arranged to rotate the output shaft (10), the hydraulic piston (20) extending along a second axis (Ax2), which is perpendicular to the first axis; a preload device (30), which is configured to store energy by means of the preloading of an elastic element (31) and to transmit said energy to the output shaft in the event of a fault such that a predefined position of the output shaft (10) can be ensured, the preload device (30) being preloaded by means of at least one hydraulic cylinder (37), the elastic element (31) extending along a third axis (Ax3), the hydraulic piston (20) being guided into a first cylinder housing (22) and into a second cylinder housing (23), at least one of the cylinder housings (22, 23) being connected to the hydraulic cylinder (37), a check valve (53, 54) being arranged between the one of the cylinder housings (22, 23) and the hydraulic cylinder (37), which check valve is configured to decouple the preload device (30) from the hydraulic piston, the blocking direction going from the hydraulic cylinder (37) to the one cylinder housing (22, 23).