# US 2021/0079934 A1 · Servovalve for regulating the flow or pressure of a fluid

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- Number: US 2021/0079934 A1
- Document ID: US20210079934A1
- Status: Published application
- Kind: A1
- Application number: 17/044,323
- Filed: 2019-03-21
- Published: 2021-03-18
- Earliest claimed: 2018-03-30
- Assignees: Fluid Actuation & Control Toulouse
- Applicants: Fluid Actuation & Control Toulouse
- Inventors: Guylain OZZELLO
- Web page: https://patentgrep.com/patent/US20210079934A1

## CPC

- F15B 13/044: operated by electrically-controlled means, e.g. solenoids, torque-motors
- F16K 31/08: using a permanent magnet
- F15B 13/0406: {for rotary valves}
- F15B: SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- F16K: VALVES; TAPS; COCKS; ACTUATING-FLOATS; DEVICES FOR VENTING OR AERATING {(devices for emptying and evacuating the excess liquid in valves or conduits F16L55/07)}

## Abstract

The invention relates to a servovalve for regulating the flow or pressure of a fluid, comprising: a control stage comprising at least one permanent magnet, at least one coil and an armature (13) configured to be able to be driven in rotation around an axial direction; a power stage comprising a filler plate (23) and a drum (22) mounted rotatably in said filler plate (23); a slender mechanical transmission shaft (31) extending along said axial direction and having a first end (31a) connected to said armature (13) and an opposite end (31b) connected to said drum (22); characterized in that said control stage further comprises a slender torsionally flexible tube (32) extending along the axial direction (8) around said slender transmission shaft (31) and having a first end (32a) secured with said armature (13), shrunk onto said first end (31a) of said transmission shaft (31), and an opposite end (32b) clamped by a tube support (33) extending as far as said filler plate (23), so as to form a flexible mobile assembly that limits the frictional forces between said drum (22) and said filler plate (23) of the servovalve.

## Claims

### Claim 1

A servovalve for regulating the flow or pressure of a fluid, comprising:
a control stage comprising at least one permanent magnet, at least one coil and an armature configured to be able to be driven in rotation about a direction, called the axial direction, if at least one coil is supplied with an electric current, said angular displacement of said armature being proportional to said supply current,
a power stage comprising a filler plate and a drum mounted rotatably in said filler plate and each comprising fluid circulation channels arranged so as to be able to be placed in fluid communication according to the position of the drum with respect to the filler plate to deliver a fluid to connection ports at a flow rate or pressure depending in particular on the rotation of said drum relative to the filler plate,
a slender mechanical transmission shaft extending along said axial direction and having a first end connected to said armature and an opposite end connected to said drum so as to be able to mechanically transmit a control torque delivered by said armature to said drum along a torque transmission axis,
wherein said control stage further comprises a slender torsionally flexible tube extending along the axial direction around said slender transmission shaft and having a first end secured with said armature, shrunk onto said first end of said transmission shaft, and an opposite end clamped by a tube support extending as far as said filler plate, so as to form a flexible mobile assembly that limits the frictional forces between said drum and said filler plate of the servovalve.

### Claim 2 (depends on 1)

The servovalve according to claim 1, wherein said end of said slender mechanical transmission shaft secured to said drum is connected to said drum by means of a torque transmission plate secured to said drum, extending perpendicularly to said axial direction and having rigidity in said torque transmission axis and flexibility in the other directions.

### Claim 3 (depends on 2)

The regulating servovalve according to claim 2, characterized in that said drum and said torque transmission plate are formed in one piece.

### Claim 4 (depends on 2)

The regulating servovalve according to claim 2, wherein said torque transmission plate is rigid in the axial direction and flexible in all other directions.

### Claim 5 (depends on 1)

The regulating servovalve according to claim 1, wherein said tube support is made of carbide.

### Claim 6 (depends on 1)

The regulating servovalve according to claim 1, wherein said torsionally flexible tube has a length and a diameter whose ratio is greater than or equal to 8.