Jet Pipe Servovalve Assembly With Sliding Torsion Tube Support

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Solution Overview

Problem

Conventional jet pipe servovalves require powerful and large torque motors to operate accurately at high pressures due to the need for a strong torsion tube to withstand bending, which increases the size, weight, and complexity of the system.

Innovation Solution

A servovalve design where the torsion tube is attached to a slider component that allows sliding movement, reducing the need for the torsion tube to bend and enabling the use of a smaller torque motor by allowing the jet pipe to move without bending the torsion tube, with fluid flow through the slider component to the jet pipe and nozzle.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a strong torsion tube is used to withstand bending at high pressures, then the valve can operate accurately at high pressures, but the torque motor becomes larger and heavier

Engineering Contradiction:
Improveaccuracy at high pressureVSAvoidtorque motor size
Core Design Contradiction:
ReliabilityVSWeight of stationary object

Solution Approach 1:

The patent extracts the bending function from the torsion tube by introducing a separate slider component. The torsion tube is no longer required to bend to accommodate jet pipe movement; instead, the slider handles the sliding motion while the torsion tube maintains its structural integrity for withstanding high pressure forces.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent segments the functional requirements by separating the bending motion function (handled by the slider) from the pressure withstanding function (handled by the torsion tube). This segmentation allows each component to be optimized for its specific function, reducing the overall size and weight of the torque motor.

Inventive Principle:
Principle #1Segmentation

2Device complexity

If the torsion tube is fixed to the housing, then the structure is simplified, but the torque motor must be powerful enough to bend the torsion tube which consumes 80% of its power

Engineering Contradiction:
Improvestructural simplicityVSAvoidtorque motor power consumption
Core Design Contradiction:
Device complexityVSUse of energy by moving object

Solution Approach 1:

The patent extracts the bending motion requirement from the torque motor's function by introducing the slider component. The slider is fixed to the housing and provides the sliding interface, allowing the jet pipe to move without requiring the torque motor to bend the torsion tube. This reduces the torque motor's power consumption from 80% to less than 10%.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The slider acts as an intermediary component between the fixed housing and the moving jet pipe. It mediates the motion by providing a sliding interface, allowing the jet pipe to change position without requiring the torque motor to bend the torsion tube, thus reducing power consumption.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Productivity

If a bigger valve orifice area is used to handle larger flows, then the flow rate increases, but the valve size increases

Engineering Contradiction:
Improveflow rateVSAvoidvalve size
Core Design Contradiction:
ProductivityVSVolume of moving object

Solution Approach 1:

The patent uses hydraulic principles by introducing a slider component that moves within a fluid environment. The slider's movement is facilitated by fluid pressure, allowing for efficient transmission of force and motion. This hydraulic approach enables compact design while maintaining high flow rates, as the fluid medium transmits power efficiently without requiring large mechanical components.

Inventive Principle:
Principle #29Pneumatics and hydraulics

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 reduces the power absorbed by the torque motor from 80% to less than 10%, allowing for a more compact, lighter, and more accurate valve system capable of operating at higher pressures similar to flapper valves.

Implementation Method 1

the jet pipe terminating at one end in a nozzle and at the other end being in fluid flow engagement with and fixedly connected to a fluid supply torsion tube... whereby movement of the valve spool is caused by fluid flowing from the nozzle to engage with the valve spool

Methodology Applied
Scientific EffectFluid flow engagement: Fluid Spray

Implementation Method 2

the end of the torsion tube furthest from the jet pipe is fixedly attached to a slider component having a port configured to be in fluid flow engagement with the fluid source; the slider component mounted for sliding movement responsive to movement of the jet pipe

Methodology Applied
Scientific EffectSliding movement: Friction

Data Source

PatentEP3521636B1Servovalve assembly
Publication Date: 2021.08.18 HAMILTON SUNDSTRAND CORP
  • EP3521636B1 patent drawingFigure 1~2
  • EP3521636B1 patent drawingFigure 3A~3C
  • EP3521636B1 patent drawingFigure 4A~4B

AI summary

A servovalve comprising: a fluid transfer valve assembly comprising a supply port and a control port; a moveable valve spool (2) arranged to regulate flow of fluid from the supply port to the control port in response to a control signal; and a drive assembly configured to axially move the valve spool relative to the fluid transfer assembly in response to the control signal to regulate the fluid flow; wherein the drive assembly comprises a steerable jet pipe (7) moveable by an amount determined by the control signal to cause corresponding movement of the valve spool; the jet pipe terminating at one end in a nozzle and at the other end being in fluid flow engagement with and fixedly connected to a fluid supply torsion tube (5) arranged to receive fluid from a fluid source, whereby movement of the valve spool is caused by fluid flowing from the nozzle to engage with the valve spool, and wherein the end of the torsion tube furthest from the jet pipe is fixedly attached to a slider component (16) having a port (25) in fluid flow engagement with the fluid source, in use; the slider component mounted for sliding movement responsive to movement of the jet pipe responsive to the control signal, and the slider component providing a fluid flow channel between the port and the torsion tube and hence to the jet pipe.