The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 14, 1996
Filed:
May. 04, 1994
Daniel Lerner, Missouri City, TX (US);
Peter Masak, Missouri City, TX (US);
Schlumberger Technology Corporation, Sugar Land, TX (US);
Abstract
An integrated modulator and turbine-generator includes a turbine impeller which is directly coupled by a drive shaft to a modulator rotor downstream from the impeller. The modulator rotor is further coupled by a drive shaft and a gear train to a three phase alternator downstream of the modulator rotor. The modulator stator blades are arranged downstream of and adjacent to the modulator rotor and the alternator is provided with a Hall effect tachometer. The turbine impeller directly drives the modulator rotor and the alternator generates power. The speed of rotation of the modulator rotor is adjusted by reference to the speed of rotation of the alternator as indicated by the tachometer and to a reference frequency. A control circuit including an electromagnetic braking circuit coupled to the tachometer and the stator windings of the alternator stabilizes the alternator speed and thus the rotor speed and modulates the rotor to obtain the desired frequency of the mudborne pressure wave by selectively shorting the stator windings of the alternator. During periods when braking is not applied, the alternator generates power for control and sensor electronics.