Shut-Off Valve Slide Assembly With Torque-Decoupled Closing Force

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Solution Overview

Problem

Existing shut-off valves require high torque for actuation due to friction and torque forces, leading to mechanical damage from corrosion and contamination, and existing solutions do not effectively decouple the closing force from the actuation torque.

Innovation Solution

A slide valve unit with a support nut and limiting element on the drive spindle, featuring two threaded connections, allows the shut-off element to be actuated by torque until reaching a closed position, where the torque is decoupled, and a spring element applies the closing force independently.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a threaded connection is used to actuate the shut-off element, then the valve can be closed with controlled force, but high torque is required leading to mechanical damage from corrosion and contamination

Engineering Contradiction:
Improvevalve closing reliabilityVSAvoidmechanical damage from corrosion and contamination
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The actuation system is segmented into two independent functions: a first threaded connection for actuating the shut-off element, and a second threaded connection with a support nut for applying closing force. This segmentation allows the closing force application to be separated from the actuation torque transmission, reducing the torque burden on the actuation mechanism during valve closure.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The support nut acts as an intermediary mechanism that converts rotational motion into axial closing force through the second threaded connection. By introducing this intermediary, the system can apply substantial closing force independently of the actuation torque, protecting the primary threaded connection from excessive mechanical stress and damage.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Ease of operation

If torque is applied to close the valve, then the shut-off element reaches the closed position, but friction and torque forces continue to act on the valve unit even after closing

Engineering Contradiction:
Improvevalve closing operationVSAvoidfriction and torque forces after closing
Core Design Contradiction:
Ease of operationVSLoss of energy

Solution Approach 1:

The system transitions from a static torque application to a dynamic force application. During actuation, torque is applied to rotate the drive spindle and move the shut-off element. Once closed, the support nut engages with the limiting element, converting any remaining rotational motion into axial closing force through the threaded connection, thereby eliminating continuous torque requirements and reducing frictional losses.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The support nut is pre-positioned on the drive spindle at a distance from the limiting element. During the closing operation, as the drive spindle rotates and the shut-off element reaches its closed position, the support nut automatically engages with the limiting element,预先 preparing the force transmission path. This preliminary positioning ensures that the closing force is applied at the optimal moment, minimizing energy loss from friction and torque after closing.

Inventive Principle:
Principle #10Preliminary action

3Force

If a spring element is used to apply closing force, then the shut-off element is pressed into the closed position, but the spring force must be decoupled from the actuation torque

Engineering Contradiction:
Improveclosing force on shut-off elementVSAvoiddecoupling mechanism complexity
Core Design Contradiction:
ForceVSDevice complexity

Solution Approach 1:

The patent merges the spring element with the support nut assembly, where the spring acts directly on the support nut. This combination eliminates the need for separate decoupling mechanisms, as the threaded connection between the support nut and drive spindle inherently provides the decoupling function. The spring force is transmitted axially through the support nut to the shut-off element, while the threaded connection allows independent rotational actuation without direct torque coupling to the spring.

Inventive Principle:
Principle #5Merging (Combining)

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

Decouples the closing force from the actuation torque, preventing mechanical damage by absorbing torque through the support nut and ensuring the shut-off element remains closed with spring force alone, maintaining operational reliability.

Implementation Method 1

a spring element (7) which, when the slide valve unit (1) is closed, applies the closing force to the shut-off device (4)

Methodology Applied
Scientific EffectSpring force: Spring

Implementation Method 2

The slide unit has two threaded connections arranged on the drive spindle, a threaded connection between the shut-off device and the drive spindle and a threaded connection between the drive spindle and the support nut

Methodology Applied
Scientific EffectThreaded connection: Screw

Data Source

PatentEP4411183B1Slide unit of a shut-off valve
Publication Date: 2026.04.01 GEORG FISCHER ROHRLEITUNGSSYSTEME AG
  • EP4411183B1 patent drawingFigure 1
  • EP4411183B1 patent drawingFigure 2
  • EP4411183B1 patent drawingFigure 3~4

AI summary

The slide assembly (1) of a shut-off valve (2), preferably a gate valve or diaphragm valve, comprises a drive spindle (3) extending vertically to the flow direction for actuating a shut-off element (4), a shut-off element (4) wherein the shut-off element (4) is adjustably arranged on the drive spindle (3) by means of a threaded connection (9), a spring element (7) for applying the required closing force to the shut-off element (4), and an actuating element (8) axially fixed on the drive spindle (3) for pre-tensioning the spring element (7), wherein the slide assembly (1) has a support nut (5) arranged on the drive spindle (3) and a limiting element (6) forming a stop for the support nut (5) to determine the closed position of the shut-off element (4), and wherein the slide assembly (1) has two threaded connections (9, 10) arranged on the drive spindle (3).a threaded connection (9) between shut-off device (4) and drive spindle (3) and a threaded connection (10) between drive spindle (3) and support nut (5).