Patent application number | Description | Published |
20080303280 | ENGINE START SYSTEM WITH QUADRATURE AC EXCITATION - A starter-generator system may be used to supply sufficient starting torque to start an aircraft main engine. The main starter-generator stator winding may be connected to a constant frequency (CF) power source to create a rotating field in the main starter-generator air gap. This rotating field, in turn, may induce current on the main rotor winding, which may be a closed circuit formed by main rotor field winding and exciter armature winding. The interaction between the main rotor current and the air gap flux may give rise to the starting torque to start the main engine. Adjusting the voltage supplied to the exciter stator field winding can modify the induced voltage and current on the rotor circuit to control the rotor current and starting torque. The starter-generator system may also be used to start an aircraft main engine by directly connecting the main stator winding to a power source without powering the exciter stator. | 12-11-2008 |
20080303490 | GENERATOR WITH QUADRATURE AC EXCITATION - A generator system is configured to supply two phase excitation current from an exciter rotor to a main generator rotor. When driven by a variable speed prime mover, the generator system provides relatively constant frequency AC power by independently controlling the main rotor flux rotational speed. The generator system includes an exciter stator that induces current in the exciter rotor windings at a desired frequency and phasing. The exciter rotor windings are electrically connected to the main rotor windings to provide two-phase excitation current to the main rotor windings. Excitation is supplied to the exciter stator from an exciter controller, which controls the frequency and phasing of the exciter excitation, based on the rotational speed of the generator, to maintain a constant output frequency. The exciter frequency control function of the exciter controller may be eliminated when the generator system is driven by a constant speed prime mover or when a narrow band variable frequency output is required. | 12-11-2008 |
20090045784 | A NOVEL AIRCRAFT ENGINE STARTER/GENERATOR - A rotor resistor and switch combination may cause a starter/generator device to function as an asynchronous device when in a start mode. Thus, starting torque may result. A starter/generator device may include an exciter rotor winding, a main rotor winding, and a resistor and switch combination positioned between the exciter rotor winding and the main rotor winding to control a flow of current in the main rotor winding during a start mode of the starter/generator device. A method of optimizing starting torque of a starter/generator device without a start controller unit during a start mode may include providing a main rotor winding of the starter/generator device, and providing a control to control a flow of current in the main rotor winding during the start mode. | 02-19-2009 |
20090091201 | AXIAL IMPACT LINER - An axial impact liner comprises a bearing liner having a shear member and a pocket. A spring and a supply of oil may be included within the pocket. In the event of an axial load, such as from a bearing or main rotor failure, the axial impact liner can shear in the axial direction and absorb the energy of the axial load by forcing the shear member into the oil filled pocket and against the spring. The pocket comprises a volume capable of accommodating the full axial distance that the rotor could move. | 04-09-2009 |
20090137324 | AXIAL IMPACT SHAFT SYSTEM - A stub shaft of a main rotor shaft of a generator has its flange or shoulder removed from its outer portion so in the event of a bending failure of the stub shaft the resulting axial load of the stub shaft is not transmitted to the main rotor shaft. Instead of a retention plug adjacent the distal end of the inside portion of the stub shaft, a knock out plug is lightly press-fit into the main rotor shaft. In the event of a failure, the outside portion of the stub shaft enters the main rotor shaft without applying an axial load onto the main rotor shaft, moves axially and displaces the knock-out plug without exiting the main rotor shaft. | 05-28-2009 |
20090224599 | PARALLELED HVDC BUS ELECTRICAL POWER SYSTEM ARCHITECTURE - A power generation and distribution system utilizes two or more AC generators each of which may be driven by a separate prime mover such as a turbine. The generators may be driven at different rotational speeds. AC power from the generators may be rectified and applied to a common DC bus. Electrical loads may be applied to the common bus and may establish an electrical power requirement. Allocation of electrical power requirement may be made among the generators based on power available from the turbines. | 09-10-2009 |
20090326737 | SMART HYBRID ELECTRIC AND BLEED ARCHITECTURE - An aircraft architecture may be designed to create an optimal balance between electric power and bleed power in order to match or improve current more electric architecture (MEA) performance while simplifying power extraction from the engines as well as simplifying the electrical system. Conventional aircraft architectures may use electric only ECS and cabin pressurization systems (so-called “no bleed” systems). Alternatively, older conventional aircraft may use strictly engine bleed air to provide power for ECS and cabin pressurization systems. The present invention, on the other hand, provides an architecture which may optimize the use of both engine bleed air and MEA designs to provide a system that may be simpler and potentially more reliable and available as compared to conventional aircraft architectures. | 12-31-2009 |
20110068753 | GENERATOR WITH QUADRATURE AC EXCITATION - A generator system is configured to supply two phase excitation current from an exciter rotor to a main generator rotor. When driven by a variable speed prime mover, the generator system provides relatively constant frequency AC power by independently controlling the main rotor flux rotational speed. The generator system includes an exciter stator that induces current in the exciter rotor windings at a desired frequency and phasing. The exciter rotor windings are electrically connected to the main rotor windings to provide two-phase excitation current to the main rotor windings. Excitation is supplied to the exciter stator from an exciter controller, which controls the frequency and phasing of the exciter excitation, based on the rotational speed of the generator, to maintain a constant output frequency. The exciter frequency control function of the exciter controller may be eliminated when the generator system is driven by a constant speed prime mover or when a narrow band variable frequency output is required. | 03-24-2011 |