Systems and methods to reduce oscillations in magnetic couplings

Patent metadata

Field	Value
Publication number	US-9303454-B2
Application number	US-201414582410-A
Country	US
Kind code	B2
Filing date	Dec 24, 2014
Priority date	Jun 29, 2011
Publication date	Apr 5, 2016
Grant date	Apr 5, 2016

Abstract

A drilling system includes a magnetic coupling and an oscillation absorber. The magnetic coupling has a rotor that rotates about an axis of rotation. The oscillation absorber is in operable communication with the magnetic coupling and includes an outer layer coupled to a separator layer of the magnetic coupling to form an enclosed area. An absorber shaft of the oscillation absorber is at least partially within the enclosed area and is coupled to the rotor. The absorber further includes an outer mover arranged such that rotation of the absorber shaft causes the outer mover to rotate due to interaction of inner absorber shaft magnets and outer mover magnets.

First claim

What is claimed is:

1. A drilling system comprising:
a turbine;
a magnetic coupling coupled to the turbine including:
a rotor having a plurality of inner magnets disposed thereon in circular arrangement in an inner magnet region;
an outer housing surrounding the inner magnet region and separated from the inner magnet region by a separator layer and including outer magnets and arranged such that rotation of the outer housing causes the rotor to rotate about an axis of rotation; and
a first electrically conductive layer disposed on the rotor that creates an eddy current that opposes oscillations in the relative positions between the rotor and the outer housing; and

an alternator coupled to the magnetic coupling that provides electricity at an output;
a load coupled to the output; and
an electrical damping circuit coupled in parallel with the load and configured to cancel oscillations in the electricity at a self excitation frequency of the magnetic coupling.

2. The drilling system of claim 1 , wherein the magnetic coupling further includes:
a second electrically conductive layer disposed on the outer mover between the outer magnets and the first electrically conductive layer.

3. The drilling system of claim 2 , wherein the first and second electrically conductive layers are formed of copper.

4. The drilling system of claim 1 , further comprising:
an alternator coupled to the magnetic coupling.

5. The drilling system of claim 1 , further comprising:
a pump coupled to the magnetic coupling.

6. A drilling system comprising:
a turbine;
a magnetic coupling coupled to the turbine including:
a rotor having a plurality of inner magnets disposed thereon in circular arrangement in an inner magnet region; and
an outer housing surrounding the inner magnet region and separated from the inner magnet region by a separator layer and including outer magnets and arranged such that rotation of the outer housing causes the rotor to rotate about an axis of rotation; and
an alternator coupled to the magnetic coupling that provides electricity at an output;
a load coupled to the output; and
an electrical damping circuit coupled in parallel with the load and configured to cancel oscillations in the electricity at a self excitation frequency of the magnetic coupling.

7. The drilling system of claim 6 , wherein the electrical damping circuit includes:
a resistor;
a capacitor; and
an inductor;
wherein the resistor, the capacitor and the inductor are coupled in series between the output and a ground and receive a rectified alternator signal from the output.

Assignees

• Scholz Eckard
• Brand Helge
• Baker Hughes Inc

Inventors

• Scholz Eckard
• Brand Helge

Classifications

• H02K49/043

  with a radial airgap · CPC title

• F16D3/14

  combined with a friction coupling for damping vibration or absorbing shock · CPC title

• F16F15/03

  using {magnetic or} electromagnetic means (F16F9/53, {F16F15/005} take precedence) · CPC title

• E21B17/04

  between rod {or the like} and bit or between rod and rod {or the like} · CPC title

• E21B7/00 Primary

  Special methods or apparatus for drilling · CPC title