Patent Description:
Gas turbine engines are used to power aircraft, watercraft, power generators, and the like. Gas turbine engines typically include a compressor, a combustor, and a turbine. The compressor compresses air drawn into the engine and delivers high pressure air to the combustor. In the combustor, fuel is mixed with the high pressure air and is ignited. Products of the combustion reaction in the combustor are directed into the turbine where work is extracted to drive the compressor and, sometimes, an output shaft. Left-over products of the combustion are exhausted out of the turbine and may provide thrust in some applications.

Gas turbine engines may be powered by a fuel source that is combusted during operation of the gas turbine engine. The fuel source may be stored in a tank and pumped from the tank to the combustor of the gas turbine engine. Gas turbine engines may use lubricant in areas with rotating components to cool the components and reduce friction produced during the operation of the gas turbine engine. The lubricant may collect in one or more sumps and can be recirculated back to the areas of the gas turbine engine using oil pumps. Fuel and oil pumping systems that are electrically driven remains an area of interest in the field of gas turbine engines. Publication <CIT> discloses a fuel supplying system with a circuit for delivering fuel from a fuel tank to an outlet. The system further includes first and second supply circuits connected to the outlet. <CIT> describes an oil and fuel control system comprising an electric motor; a dual channel motor drive unit coupled to the electric motor and an oil delivery system comprising an oil pump and oil accessories and a fuel delivery system comprising a fuel pump and fuel accessories, both coupled to a single rotor of the electric motor.

The present invention relates to an apparatus as laid out in claim <NUM> and related method in claim <NUM>.

These and other features of the present disclosure will become more apparent from the following description of the illustrative embodiments.

For the purposes of promoting an understanding of the principles of the disclosure, reference will now be made to a number of illustrative embodiments illustrated in the drawings and specific language will be used to describe the same.

<FIG> and <FIG> illustrate a pumping system <NUM>-A and a pumping system <NUM>-B, respectively, for use with a gas turbine engine. The pumping system <NUM>-A is configured for redundant powered operation and includes a motor generator <NUM> and a fuel system <NUM>. The motor generator <NUM> includes a plurality of power sources <NUM>, <NUM>, <NUM>.

Alternating current (AC) power output by each of the plurality of power sources <NUM>, <NUM>, <NUM> of the generator or electric machine <NUM> is converted to direct current (DC) power, e.g., rectified, by a corresponding one of a first inverter-rectifier <NUM>, a second inverter-rectifier <NUM>, and a third inverter-rectifier <NUM>. Output of the first inverter-rectifier <NUM> may be electrically connected to a first power source DC bus <NUM>. Output of the second inverter-rectifier <NUM> may be electrically connected to a second power source DC bus <NUM>. Output of the third inverter-rectifier <NUM> may be electrically connected to a third power source DC bus <NUM>. Additionally, the DC buses <NUM>, <NUM> and <NUM> can also be powered by an alternate source of DC power for example a battery on the aircraft.

Additionally or alternatively, the first inverter-rectifier <NUM>, the second inverter-rectifier <NUM>, and the third inverter-rectifier <NUM> may invert input DC power transferred, e.g., from a battery or another energy storage device, via a corresponding one of the first power source DC bus <NUM>, the second power source DC bus <NUM>, and the third power source DC bus <NUM> to AC power for use by the electric machine <NUM> via a respective one of the plurality of power sources <NUM>, <NUM>, <NUM> when the electric machine <NUM> is operating as a motor and providing drive torque to the engine for example during starting of the gas turbine engine.

The fuel system <NUM> includes a first fuel pump motor <NUM>, a second fuel pump motor <NUM>, a first fuel pump <NUM>, a second fuel pump <NUM>, a first fuel pump shaft <NUM>, and a second fuel pump shaft <NUM>. The first fuel pump motor <NUM> is mechanically connected to drive the first fuel pump <NUM> via the first fuel pump shaft <NUM>. The second fuel pump motor <NUM> is mechanically connected to drive the second fuel pump <NUM> via the second fuel pump shaft <NUM>. Each of the first fuel pump motor <NUM> and the second fuel pump motor <NUM> are electrically connected to and powered by the plurality of power sources <NUM>, <NUM> of the generator <NUM>.

Each of the first fuel pump motor <NUM> and the second fuel pump motor <NUM> may be a surface or an internal permanent magnet motor configured to operate according to and synchronously with the input drive frequency.

In one example, the first fuel pump motor <NUM> is driven by a first variable drive controller <NUM> and the second fuel pump motor <NUM> is driven by a second variable drive controller <NUM>. The first variable drive controller <NUM> is powered by the first power source DC bus <NUM> and the second variable drive controller <NUM> is powered by the second power source DC bus <NUM>.

Each of the first fuel pump <NUM> and the second fuel pump <NUM> is a positive displacement pump configured such that fuel flow within the fuel system <NUM> is proportional to the speed of the first fuel pump <NUM> and the second fuel pump <NUM>, respectively. Examples of the first fuel pump <NUM> and the second fuel pump <NUM> include, but are not limited to, a gear pump, a generated rotor pump (or gerotor pump), and a vane pump.

A pumping system <NUM>-B for use with a gas turbine engine is shown in <FIG>. The pumping system <NUM>-B is configured for redundant powered operation and includes a motor generator <NUM> and an oil system <NUM>. The motor generator <NUM> includes a plurality of power sources <NUM>, <NUM>, <NUM>.

The oil system <NUM> is configured for redundant powered operation and includes a first oil pump motor <NUM>, a second oil pump motor <NUM>, an oil pump <NUM>, and an oil pump shaft <NUM>. The first oil pump motor <NUM> and the second oil pump motor <NUM> are mechanically connected in series with the oil pump <NUM> via the oil pump shaft <NUM>. Each of the first oil pump motor <NUM> and the second oil pump motor <NUM> is electrically connected to and powered by the plurality of power sources <NUM>, <NUM>, <NUM>. The first oil pump motor <NUM> is driven by a third variable drive controller <NUM> that is powered by the first power source <NUM>. The second oil pump motor <NUM> is driven by a fourth variable drive controller <NUM> that is powered by the second power source <NUM>.

The oil pump <NUM> is configured to be driven by both or a single one of the first oil pump motor <NUM> and the second oil pump motor <NUM>. The oil pump <NUM> is a positive displacement pump configured such that oil flow within the oil system is proportional to the speed of the oil pump <NUM>. Examples of the oil pump <NUM> include, but are not limited to, a gear pump, a generated rotor or gerotor pump, and a vane pump.

The first power source <NUM> of the motor generator <NUM> may comprise a first power source configured to supply power to the first fuel pump motor <NUM> and the first oil pump motor <NUM>. The first power source <NUM> may supply power to one or more other components of an aircraft, such as, but not limited to, an engine (not shown). The second power source <NUM> of the motor generator <NUM> may comprise a second power source and may be electrically connected to supply power to the second fuel pump motor <NUM> and the second oil pump motor <NUM>. The third power source <NUM> may provide power to multiple electrical buses. For example, the third power source <NUM> may be electrically connected via connection <NUM> to power one or more aircraft systems, subsystems, and/or components. Other implementations, such as implementations including different power sources and/or a different number of power sources are also contemplated.

In one example, the first inverter-rectifier <NUM> converts AC power generated by the generator <NUM> to DC power for use by the first variable drive controller <NUM>, the third variable drive controller <NUM>, the first fuel pump motor <NUM>, the first oil pump motor <NUM>, and other components powered by the first power source <NUM>. As another example, the second inverter-rectifier <NUM> converts AC power generated by the generator <NUM> to DC power for use by the second variable drive controller <NUM>, the fourth variable drive controller <NUM>, the second fuel pump motor <NUM>, the second oil pump motor <NUM>, and other components powered by the second power source <NUM>.

In one embodiment of the system a controller <NUM> monitors and controls operation of the fuel system <NUM> and the oil system <NUM>, such as by monitoring and controlling operation of one or more other controllers, control modules, or other components that perform logic and/or processing operations to control operation of subcomponents of the fuel system <NUM> and the oil system <NUM>. As described in reference to at least <FIG>, the controller <NUM> is communicatively connected to the first variable drive controller <NUM> and the second variable drive controller <NUM> that are, in turn, connected to the first fuel pump motor <NUM>, the second fuel pump motor <NUM>, the first fuel pump <NUM>, and the second fuel pump <NUM> to monitor and control operation of the first fuel pump motor <NUM>, the second fuel pump motor <NUM>, the first fuel pump <NUM>, and the second fuel pump <NUM>. The controller <NUM> is communicatively connected to the third variable drive controller <NUM> and the fourth variable drive controller <NUM> that are, in turn, connected to the first oil pump motor <NUM>, the second oil pump motor <NUM>, and the oil pump <NUM> to monitor and control operation of the first oil pump motor <NUM>, the second oil pump motor <NUM>, and the oil pump <NUM>. The controller <NUM> needs to be partitioned to provide two separate and isolated controls for each of the two fuel pumps and each of the two oil pumps using different power sources to provide redundancy to the fuel and oil pump functions.

A high-power switch or contact breaker, such as a contactor <NUM>, is electrically connected between the second power source <NUM> and both the second fuel pump motor <NUM> and the second oil pump motor <NUM>. The controller <NUM> operates to open and close the contactor <NUM> based on one or more operating conditions of the system <NUM>. In an example, the controller <NUM> sends a signal or issues a command to open the contactor <NUM> to electrically disconnect the second fuel pump motor <NUM> and the second oil pump motor <NUM> from the second power source <NUM>. One purpose to disconnect the second power source <NUM> with the contactor is when there is a short circuit in pump motors <NUM> or <NUM> or the respective drive controllers <NUM> and <NUM> to avoid the second power source being shorted which would otherwise result in failure of that power source. In some instances, one or more of the first variable drive controller <NUM>, the second variable drive controller <NUM>, the third variable drive controller <NUM>, and the fourth variable drive controller <NUM> may be embodied as being a part of controller <NUM>, where each variable drive controller is independent and isolated from the other variable drive controllers.

<FIG> illustrate a pumping system <NUM>-A and a pumping system <NUM>-B, respectively, for use with a gas turbine engine. The pumping system <NUM>-A includes the fuel system <NUM> configured for redundant powered operation and the pumping system <NUM>-B includes the oil system <NUM> configured for redundant powered operation.

As shown in <FIG>, the first fuel pump <NUM> is connected to and configured to be driven by the first pump motor <NUM> and the second fuel pump <NUM> is connected to be driven by the second fuel pump motor <NUM>. The variable drive controllers <NUM> and <NUM> control the fuel flow by controlling the speed of the first fuel pump <NUM> and the second fuel pump <NUM>. In an example, the first variable drive controller <NUM> and the second variable drive controller <NUM> supply electric power to a corresponding one of the first fuel pump motor <NUM> and the second fuel pump motor <NUM> to drive one of the first fuel pump <NUM> and the second fuel pump <NUM> to achieve the required pump speed. The first fuel pump <NUM> is fluidly connected to a fuel supply line <NUM> and the second fuel pump <NUM> is fluidly connected to a fuel supply line <NUM>.

Check valves <NUM> and <NUM> may be used on the output fuel pumps <NUM> and <NUM> to prevent backflow through an inoperative pump.

The first variable drive controller <NUM> and the second variable drive controller <NUM> control the first fuel pump motor <NUM> and the second fuel pump motor <NUM> to cause one of the first fuel pump <NUM> and the second fuel pump <NUM> to achieve the required combined operating speed corresponding to the fuel flow to the engine. The first variable drive controller <NUM> may be commanded or programmed to control electric power supplied to the first fuel pump motor <NUM> when one of the second fuel pump <NUM> becomes inoperable. The second variable drive controller <NUM> may be commanded or programmed to control electric power supplied to the second fuel pump motor <NUM> when the first fuel pump <NUM> becomes inoperable.

In normal, none failure operation, the total fuel flow is equal to the sum of the two fuel pump flows. For identically sized pumps this is proportional to the sum of the two pump speeds and the proportion of the fuel flow for the two pumps is based on the speed ratio of the two identical pumps. Since the pressure across the two pumps is equal the power ratio and torque ratio of the two identical pumps is based on the speed ratio of the two pumps. So the power ratio for the two pump motors is equal to the pump speed ratio and also pump flow ratios. So the variable drive controllers can set the motor power ratio by controlling the motor speed ratio.

In one example, the first variable drive controller <NUM> and the second variable drive controller <NUM> are programmed to vary the electric power supplied to the first fuel pump motor <NUM> and the second fuel pump motor <NUM> to divide the power demand of the fuel pump <NUM> between the first fuel pump motor <NUM> and the second fuel pump motor <NUM>. The power distribution may split <NUM> percent power in any amount between the two pump motors <NUM>, <NUM>. For example, the power may be distributed <NUM>/<NUM>, <NUM>/<NUM>, <NUM>/<NUM>, <NUM>/<NUM>, <NUM>/<NUM>, <NUM>/<NUM>, <NUM>/<NUM>, <NUM>/<NUM> between the two pump motors <NUM>, <NUM>. The first variable drive controller <NUM> and the second variable drive controller <NUM> may control the power split by controlling the proportion of torque output by each of the first fuel pump motor <NUM> and the second fuel pump motor <NUM>. For example, to achieve a predefined desired speed of the fuel pump <NUM>, the first variable drive controller <NUM> and the second variable drive controller <NUM> may operate the first fuel pump motor <NUM> and the second fuel pump motor <NUM> to produce output speed values that are equal for a <NUM>/<NUM> power split or may operate the first fuel pump motor <NUM> at twice the speed of the second fuel pump motor <NUM> for a <NUM>/<NUM> power split.

The first fuel pump motor <NUM> and the second fuel pump motor <NUM> are both configured to operate in a speed control mode where the sum of the speeds of the two motors is proportional to the fuel flow assuming identical fuel pumps.

In the speed control mode, each of the first variable drive controller <NUM> and the second variable drive controller <NUM> controls frequency input to the first fuel pump motor <NUM> and the second fuel pump motor <NUM> to achieve the required speed of the first fuel pump motor <NUM> and the second fuel pump motor <NUM>.

In response to one of the first fuel pump motor <NUM> and the second fuel pump motor <NUM> becoming inoperable, the variable drive controllers <NUM> and <NUM> increase the speed of the other one of the first fuel pump motor <NUM> and the second fuel pump motor <NUM> in operation. For example, in response to the first fuel pump motor <NUM> becoming inoperable, the variable drive controllers <NUM> and <NUM> are programmed to increase the speed of the second fuel pump motor <NUM> in operation. As another example, the variable drive controllers <NUM> and <NUM> are programmed to, in response to the second fuel pump motor <NUM> becoming inoperable, increase the speed of the first fuel pump motor <NUM> in operation.

Since the total fuel flow is the sum of the fuel flow from both fuel pumps <NUM>, <NUM>, each fuel pump <NUM>, <NUM> provides up to one-half of the total fuel flow at all times. The resulting fuel flow, in response to a given variable controller drive or motor becoming inoperative, is no lower than the lowest fuel flow from either of the two pumps at the time of failure. So engine flameout due to failure of a fuel pump, fuel motor or controller drive can be prevented if each pump is providing at least the minimum fuel flow to prevent engine flameout at all times, which is typically below <NUM>% of the instantaneous fuel flow at all operating conditions.

The variable speed controller can respond very rapidly to increase motor speed and hence pump flow after failure of the other drive, motor or pump. This will allow the fuel flow to recovery rapidly after failure of one of the other fuel pump system and therefore limit the loss of engine thrust.

Further the rate of any speed increase of the motors can be limited to avoid fuel flow increases that could stall the gas turbine compressor based on pre-programmed fuel flow rate limits. This will ensure that in any fuel transient following a pump motor failure will not surge the gas turbine.

With reference to <FIG>, each of the first oil pump motor <NUM> and the second oil pump motor <NUM> is electrically connected such that the oil pump <NUM> is configured to be driven by both or a single one of the first oil pump motor <NUM> and the second oil pump motor <NUM>. To meet a predefined oil flow demand that may correspond to a predefined speed of the oil pump <NUM>, one or both of the third variable drive controller <NUM> and the fourth variable drive controller <NUM> supply a predefined amount of electric power to a corresponding one of the first oil pump motor <NUM> and the second oil pump motor <NUM> to drive the oil pump <NUM> to achieve the required pump speed.

The oil pump <NUM> illustratively includes a plurality of pumping elements as suggested in <FIG>. The oil pump <NUM> includes a first pumping element <NUM> fluidly connected to a first oil scavenge line <NUM> and a second pumping element <NUM> fluidly connected to a second oil scavenge line <NUM>. The oil pump <NUM> further includes a third pumping element <NUM> fluidly connected to a lubrication supply line <NUM> of the gas turbine engine.

The third variable drive controller <NUM> and the fourth variable drive controller <NUM> may be commanded or programmed to vary electric power supplied to the first oil pump motor <NUM> and to the second oil pump motor <NUM> based on a power demand of the oil pump <NUM> to maintain a predefined target pump speed. In one example, the third variable drive controller <NUM> and the fourth variable drive controller <NUM> may be programmed to control the electric power supplied to the first oil pump motor <NUM> and the second oil pump motor <NUM> and divide and optimize the power demand of the oil pump <NUM> between the first oil pump motor <NUM> and the second oil pump motor <NUM>. The power distribution may split <NUM> percent power in any amount between the two pump motors <NUM>, <NUM>. For example, the power may be distributed <NUM>/<NUM>, <NUM>/<NUM>, <NUM>/<NUM>, <NUM>/<NUM>, <NUM>/<NUM>, <NUM>/<NUM>, <NUM>/<NUM>, <NUM>/<NUM> between the two pump motors <NUM>, <NUM>. The split of power for each of the pump motors can be controlled by controlling the ratio of torques output by the pump motors, for example, equal output torque values providing a <NUM>/<NUM> power split.

In some instances, each of the first oil pump motor <NUM> and the second oil pump motor <NUM> is configured to operate in a speed control mode with a speed scheduled torque or droop limit to control the ratio of power to each motor at the operating speed. In another example, the controller <NUM> is programmed to operate one of the first oil pump motor <NUM> and the second oil pump motor <NUM> in the speed control mode and another one of the first oil pump motor <NUM> and the second oil pump motor <NUM> in the torque control mode.

In response to one of the first oil pump motor <NUM> and the second oil pump motor <NUM> becoming inoperable, the variable speed drive controllers <NUM> and <NUM> increase supply of electric power to the other one of the first oil pump motor <NUM> and the second oil pump motor <NUM> in operation. For example, in response to the first oil pump motor <NUM> becoming inoperable, the variable speed drives <NUM> and <NUM> are programmed to increase supply of electric power to the second oil pump motor <NUM> in operation. As another example, the variable speed drives <NUM> and <NUM> are programmed to, in response to the second oil pump motor <NUM> becoming inoperable, increase supply of electric power to the first oil pump motor <NUM> in operation.

The variable speed drives <NUM> and <NUM> are configured to increase the supply of electric power to the other operable pump motor <NUM>, <NUM> up to <NUM> percent power of that pump motor <NUM>, <NUM> so that the operable pump motor <NUM>, <NUM> is supplying <NUM> percent of the power to operate the pump <NUM>. The variable speed drives <NUM> and <NUM> may detect that one of the pump motors <NUM>, <NUM> is inoperable based on one or more of a voltage and/or amperage demand of the pump motors <NUM>, <NUM>, a rotational speed or torque reading of the pump motors <NUM>, <NUM>, or any other suitable measurement that indicates one or both pump motors <NUM>, <NUM> have degraded or are fully inoperable.

The oil system <NUM> is configured for redundant powered operation using overrunning clutches <NUM>, <NUM>. Each of the first oil pump motor <NUM> and the second oil pump motor <NUM> of the oil system <NUM> is mechanically coupled to the oil pump <NUM> via the overrunning clutches <NUM>, <NUM>, respectively. A first overrunning clutch <NUM> is coupled with the first oil pump motor <NUM> and a second overrunning clutch <NUM> is coupled with the second oil pump motor <NUM>. The first overrunning clutch <NUM> is configured to decouple the first oil pump motor <NUM> from the oil pump shaft <NUM> in response to the first oil pump motor <NUM> becoming inoperable. The second overrunning clutch <NUM> is configured to decouple the second oil pump motor <NUM> from the oil pump shaft <NUM> in response to the second oil pump motor <NUM> becoming inoperable. Implementing an overrunning clutch coupling prevents, or minimizes effects of, a back-drive and/or braking effect of the first oil pump motor <NUM> when the first oil pump motor <NUM> becomes inoperable and a back-drive and/or braking effect of the second oil pump motor <NUM> when the second oil pump motor <NUM> becomes inoperable. Put another way, the first oil pump motor <NUM> and the second oil pump motor <NUM> that becomes inoperable does not add drag to the first oil pump motor <NUM> and the second oil pump motor <NUM> still in operation, which, in turn, enables implementation of oil pump motors <NUM>, <NUM> having smaller size and/or smaller input power needs than may be necessary to support redundant oil pump motors <NUM>, <NUM> not coupled using the overrunning clutch.

<FIG> and <FIG> illustrate a bidirectional pumping system <NUM> and a bidirectional pumping system <NUM>, respectively, for use with a gas turbine engine and configured for redundant powered operation.

The bidirectional fuel and oil system <NUM> includes a fuel pump motor <NUM>, a first fuel pump <NUM>, an oil pump motor <NUM>, an oil pump <NUM>, a bidirectional pump motor <NUM>, a second fuel pump <NUM>, overrunning clutches <NUM>, <NUM>, and pump shafts <NUM>, <NUM>. Each of the bidirectional pump motor <NUM>, the fuel pump motor <NUM>, and the oil pump motor <NUM> are electrically connected to a plurality of power sources <NUM>, <NUM>, <NUM> such that the bidirectional pump motor <NUM> is configured to drive the second fuel pump <NUM> in normal operation and also in response to at least one of the fuel pump motor <NUM> and the first fuel pump <NUM> becoming inoperable, and the bidirectional pump motor <NUM> is configured to drive the oil pump <NUM> in response to the oil pump motor <NUM> becoming inoperable. Check valves <NUM> and <NUM> are placed on the output of the fuel pumps <NUM> and <NUM> to prevent reverse flow through the check valves in the event one pump is inoperative.

As shown in <FIG> and <FIG>, the first fuel pump <NUM> is mechanically connected to be driven by the fuel pump motor <NUM> via a first pump shaft <NUM> and the second fuel pump <NUM> is mechanically connected to be driven by the bidirectional pump motor <NUM> via a second pump shaft <NUM>. As shown in <FIG>, the fuel pump <NUM> is fluidly connected to a first fuel supply line <NUM> and the second fuel pump <NUM> is fluidly connected to a second fuel supply line <NUM>.

Variable drive controllers <NUM>, <NUM>, and <NUM> control the fuel/oil flow by controlling the speed of the fuel pump motor <NUM>, the oil pump motor <NUM>, and the bidirectional pump motor <NUM>, respectively. In an example, the variable drive controllers <NUM>, <NUM>, and <NUM> supply electric power to a corresponding one of the fuel pump motor <NUM>, the oil pump motor <NUM>, and the bidirectional pump motor <NUM> to drive a corresponding one of the first fuel pump <NUM>, the oil pump <NUM>, and the second fuel pump <NUM> to achieve the required pump speed and hence desired engine fuel and oil flow.

In normal operation the bidirectional drive controller <NUM> is controlling the speed and hence fuel flow of the second fuel pump <NUM> through the first overrunning clutch <NUM>, the second overrunning clutch <NUM> being disengaged due to the rotational direction of the bidirectional pump motor <NUM>. The fuel variable drive controller <NUM> may be commanded or programmed to increase the speed of the fuel pump motor <NUM> to provide all the fuel flow when at least one of the bidirectional pump motor <NUM> and the second fuel pump <NUM> becomes inoperable. The bidirectional variable drive controller <NUM> may be commanded or programmed to increase the speed of the bidirectional pump motor <NUM> to provide all the fuel flow when at least one of the fuel pump motor <NUM> and the first fuel pump <NUM> becomes inoperable In both cases fuel flow will only be temporarily reduced for the pump system that fails and that loss of fuel flow will rapidly be recovered as the remaining pump system accelerates to the speed required for the total fuel flow.

In one example, the fuel variable drive controller <NUM> and the bidirectional variable drive controller <NUM> are programmed to vary the electric power supplied to the fuel pump motor <NUM> and to the bidirectional pump motor <NUM>, respectively. The fuel variable drive controller <NUM> and the bidirectional variable drive controller <NUM> may divide the power demand of the fuel pump <NUM> and fuel pump <NUM> between the fuel pump motor <NUM> and to the bidirectional pump motor <NUM>. The power distribution may split <NUM> percent power in any amount between the two pump motors <NUM> and <NUM>. For example, the power may be distributed <NUM>/<NUM>, <NUM>/<NUM>, <NUM>/<NUM>, <NUM>/<NUM>, <NUM>/<NUM>, <NUM>/<NUM>, <NUM>/<NUM>, <NUM>/<NUM> between the two pump motors <NUM> and <NUM>.

The fuel pump motor <NUM>, the oil pump motor <NUM> and the bidirectional pump motor <NUM> may be configured to operate in a speed control mode.

In response to the oil pump motor <NUM> becoming inoperable, the variable drive controller <NUM> slows down the bidirectional pump motor <NUM> driving the second fuel pump <NUM> through the first overrunning clutch <NUM> while the fuel pump motor <NUM> is increased at the same rate to maintain the total fuel flow. The bidirectional motor then reverses speed direction and ceases to drive the second fuel pump motor through the first overrunning clutch <NUM>. In the reverse speed direction the bidirectional pump motor will drive the oil pump <NUM> through the second overrunning clutch <NUM> to the correct speed to deliver the engine oil flow.

To optimize the speeds of the bidirectional pump motors and fuel and oil pumps, first and second gearboxes <NUM>, <NUM> may be mechanically coupled between the bidirectional pump motor <NUM> and the second fuel pump <NUM> and/or between the bidirectional pump motor <NUM> and the oil pump <NUM>, respectively.

<FIG> illustrates an example process <NUM> for providing redundant power in a system with a gas turbine engine. In an example, one or more operations of the process <NUM> may be performed by the controller <NUM> that includes multiple independent and isolated variable drive controllers or by one or more other individual controllers in accordance with the present disclosure. As described in reference to at least <FIG>, <FIG>, <FIG>, <FIG>, and <FIG>, the controller <NUM> communicates with one or more variable drive controllers, such as, the first variable drive controller <NUM>, the second variable drive controller <NUM>, the third variable drive controller <NUM>, and the fourth variable drive controller <NUM>, that drive the pump with one of the first pump motor and the second pump motor, in response to the other of the first pump motor and the second pump motor becoming inoperable, to continuously drive the pump without interruption.

The process <NUM> begins at block <NUM>, where the controller <NUM>, e.g., via one or more variable drive controllers, supplies electric power to the first pump motor <NUM>, <NUM> from the first power source <NUM> of the plurality of power sources <NUM>, <NUM>, <NUM>. The controller <NUM>, at block <NUM>, supplies electric power, e.g., via one or more variable drive controllers, to the second pump motor <NUM>, <NUM> from the second power source <NUM> of the plurality of power sources <NUM>, <NUM>, <NUM>. At block <NUM>, the controller <NUM>, e.g., via one or more variable drive controllers, drives the pump <NUM>, <NUM> with the first pump motor <NUM>, <NUM> and the second pump motor <NUM>, <NUM> via a pump shaft <NUM>, <NUM>.

The controller <NUM>, at block <NUM>, determines whether the first pump motor <NUM>, <NUM> is inoperable. In response to the first pump motor <NUM>, <NUM> being inoperable, the controller <NUM> drives, e.g., via one or more variable drive controllers, the pump <NUM>, <NUM> with the second pump motor <NUM>, <NUM>, at block <NUM>. In response to the first pump motor <NUM>, <NUM> being operable, i.e., not inoperable, the controller <NUM> continues to block <NUM>, wherein the controller <NUM> determines whether the second pump motor <NUM>, <NUM> is inoperable.

In response to the second pump motor <NUM>, <NUM> being operable, i.e., not inoperable, the controller <NUM> returns to block <NUM> where the controller <NUM> drives, e.g., via one or more variable drive controllers, the pump <NUM>, <NUM> with the first pump motor <NUM>, <NUM> and the second pump motor <NUM>, <NUM>. In response to the second pump motor <NUM>, <NUM> being inoperable, the controller <NUM>, at block <NUM>, drives, e.g., via one or more variable drive controllers, the pump <NUM>, <NUM> with the first pump motor <NUM>, <NUM>. The process <NUM> may then end for example in response to the gas turbine engine being shut down.

An example arrangement of redundant electrical drives includes two fuel pump motors or motor power supplies each powering one of two fuel pumps. For example, the arrangement may include a first fuel pump motor coupled to a first power source that is driven by a first power source, such as, but not limited to, a high power electrical starter generator. As another example, the arrangement may include a second fuel pump motor coupled to a second power source that is driven by a second power source, such as, but not limited to, a different generator or battery power source.

In one example, to avoid, or to minimize, fuel flow interruption, the first and second power sources coupled to the first and second redundant fuel pump motors may be active. The first and second fuel pump motor may be configured to operate in a speed control mode. Operating the fuel pump motors in speed control mode may support achieving an optimum power split between the fuel pump motors, such that a portion of power demand supplied by each of the first fuel pump motor and the second fuel pump motor may be adjusted according to respective power availability, capacity, and other parameters of the first fuel pump motor and the second fuel pump motor.

Such load sharing between the two fuel pump motors being powered by different power sources may increase efficiency of the aircraft propulsion system, as a whole, and/or one or more subsystems of the of the aircraft propulsion system by optimizing which power source is used at any given instance depending on the available power from each power source and the efficiency of the power sources at that operating condition.

Load sharing for the fuel motors can also optimize the power from each pump to minimizing the effects of, component over-temperature or health to avoid damage to any one component of the redundant system,.

An example arrangement of redundant electrical drives includes two oil pump motors or motor power sources on common oil pump shaft. For example, the arrangement may include a first oil pump motor coupled to a first power source that is driven by a first power source, such as, but not limited to, a high power electrical starter generator. As another example, the arrangement may include a second oil pump motor coupled to a second power source that is driven by a second power source, such as, but not limited to, an aircraft power source, a low power generator, and so on.

In one example, to avoid, or to minimize, oil flow interruption the first and second power sources coupled to the first and second redundant oil pump motors may be active. The first oil pump motor may be configured to operate in a speed control mode and the second oil pump motor may be configured to operate in a torque control mode. Operating the first oil pump motor in the speed control mode and the second oil pump motor in the torque control mode may support achieving an optimum power split between the oil pump motors, such that a portion of power demand supplied by each of the first oil pump motor and the second oil pump motor may be adjusted according to respective power availability, capacity, and other parameters of the first oil pump motor and the second oil pump motor.

Such load sharing between the two oil pump motors being coupled to different power sources that are, in turn, electrically connected to different power sources may increase efficiency of the aircraft propulsion system, as a whole, and/or one or more subsystems of the of the aircraft propulsion system by optimizing which aircraft power source is used at any given instance dependent on the available power for each power source or depending on the efficiency of the power sources at that condition.

Load sharing between the two oil pump motors may be used minimize the effects of, component over-temperature or component health to avoid damage of any one component of the redundant system. As just some examples, load sharing may be implemented using torque droop control, e.g., decreasing output frequency of a drive in response to output torque of that drive being greater than a predefined output torque threshold, or using speed and torque control.

An example redundant electrical drives arrangement includes a fuel system having two separately (electrically) driven pumping components. Each pumping components may be configured to provide a predefined minimum fuel flow during operation. Each one of the two pumping components may be configured to provide up to a predefined maximum fuel flow in response to the other fuel pump stopping operation, where the predefined maximum fuel flow corresponds to a maximum fuel flow demand of the system.

The redundant electrical drive arrangement of the present disclosure providing uninterrupted, or nearly uninterrupted, system operation by avoiding flameout and other conditions in response to sudden single drive failure and so on. The disclosed redundant electrical drive system is configured to prevent mechanical or electrical consumption by the failed component of the system, e.g., added drag, that may limit effectiveness of the motor still in operation.

Power or torque of each of the first pump motor and the second pump motor may be optimized to maximize efficiency without exceeding capability of each of the first pump motor and the second pump motor or the respective variable drive controllers. For example, each of the first pump motor and the second pump motor may be configured to operate such that a corresponding amount (or a portion, or a proportion) of power delivered by the first pump motor and the second pump motor is based on the temperature or health of the motors and the respective variable drive controllers. During a starting operation, one or both of the first pump motor and the second pump motor may generate a portion or all power used to initiate operation of the gas turbine.

The redundant electrical drive system of the present disclosure supports controlling the power demand for each of the power sources of the first oil pump motor and the second oil pump motor by controlling torque of the respective one of the first oil pump motor and the second oil pump motor. For example, power necessary to operate the oil pump is a product of an angular velocity of the shaft and a combination of a first torque of the first oil pump motor and a second torque of the second oil pump motor. In other words, values of the first torque and the second torque may be adjusted relative to one another to a total torque value necessary to operate the oil pump.

In some instances, the amount of power used to overcome drag generated by a pump motor that has become inoperable may constitute a large portion of pumping power used to maintain seamless system operation. Likewise, a size of the corresponding power source to each of the first and second pump motors may need to be able to accommodate additional power used to overcome the power drag when the pump motor supported by the other power source becomes inoperable. Thus, frequently, one or both pump motors, as well as, power sources providing energy to these pump motors in a redundant system may need to be configured to support such an additional power usage, thereby adding significant weight, cost and volume to the motors, drives and generator or battery power source. Also, if bearings fail in one motor or motor seizes due to an over-temperature condition, then failed motor torque could prevent pumping by remaining motor.

In the redundant system of the present disclosure, the first and second oil pump motors driving an oil pump may be connected with one another through an overrunning clutch. Implementing the overrunning clutch coupling may assist in preventing, or minimizing effects of, a back-drive and/or braking effect of the first oil pump motor and the second oil pump motor when the first oil pump motor and the second oil pump motor, respectively, become inoperable. Put another way, the first oil pump motor and the second oil pump motor that becomes inoperable does not add drag to the first oil pump motor and the second oil pump motor still in operation, which, in turn, enables implementation of oil pump motors, drives and generator or battery power sources having smaller size and/or smaller input power capabilities than may otherwise be necessary to support redundant oil pump motors not coupled using the overrunning clutch.

One embodiment of the pumping system of the present invention includes using induction motors as the oil pump motors where the exact volumetric oil flow is not critical to the operation of the engine. Induction motors have the advantage of inherent load sharing where two motors are driving the same pump due to the slip speed to torque relationship for an induction motor.

An example implementation of the pumping system of the present disclosures includes a motor generator having a plurality of power sources and a fuel system configured for redundant powered operation. The fuel system includes a first fuel pump motor, a second fuel pump motor, a fuel pump, and a fuel pump shaft. The first fuel pump motor and the second fuel pump motor are mechanically connected in series with the fuel pump via the fuel pump shaft, and each of the first fuel pump motor and the second fuel pump motor being electrically connected to the plurality of power sources such that the fuel pump is configured to be driven by both or a single one of the first fuel pump motor and the second fuel pump motor. The pumping system includes an oil system configured for redundant powered operation. The oil system including a first oil pump motor, a second oil pump motor, an oil pump, and an oil pump shaft. The first oil pump motor and the second oil pump motor are mechanically connected in series with the oil pump via the oil pump shaft, and each of the first oil pump motor and the second oil pump motor being electrically connected to the plurality of power sources such that the oil pump is configured to be driven by both or a single one of the first oil pump motor and the second oil pump motor.

One other embodiment of the pumping system of the present disclosure includes a controller programmed to control at least one of speed and torque of the first fuel pump motor and second fuel pump motor to drive the fuel pump at a predefined speed, wherein the predefined speed of the fuel pump is based on fuel flow requested by the engine.

Another embodiment of the pumping system of the present disclosure includes a controller programmed to control electric power supplied to the first fuel pump motor and the second fuel pump motor to optimize the power demand from the engine or aircraft power sources and provide a total power and torque output to cause the fuel pump to operate at the predefined speed.

Still another embodiment of the pumping system of the present disclosure includes the controller being programmed to increase electric power to the first fuel pump motor in response to the second fuel pump motor becoming inoperable.

Yet another embodiment of the pumping system of the present disclosure includes the controller being programmed to drive one of the first fuel pump motor and the second fuel pump motor based on a torque limit.

Another embodiment of the pumping system of the present disclosure includes a power split for each of the first fuel pump motor and the second fuel pump motor being optimized based on a maximum operating temperature of the first fuel pump motor, second fuel pump motor and the dedicated controllers.

Still another embodiment of the pumping system of the present disclosure includes a controller programmed to control speed or torque of the first oil pump motor and the second oil pump motor based on the oil flow requested by the engine.

Another embodiment of the pumping system of the present disclosure includes the controller being programmed to control the power or torque supplied to the first oil pump motor and the second oil pump motor according to the power available from the engine and aircraft power sources for the two motors.

Yet another embodiment of the pumping system of the present disclosure includes the controller being configured to increase electric power to the first oil pump motor in response to the second oil pump motor becoming inoperable.

Still another embodiment of the pumping system of the present disclosure includes the controller being programmed to drive one of the first oil pump motor and the second oil pump motor based on a torque limit.

As another example, the pumping system of the present disclosure includes an overrunning clutch coupled with the first pump motor and the second pump motor. The overrunning clutch is configured to permit the first pump motor to drive the pump without driving the second pump motor, in response to the second pump motor becoming inoperable.

In an example, a pumping system of the present disclosure includes a motor generator having a plurality of power sources, a first pump motor, a second pump motor, a pump, and a pump shaft. The first pump motor is electrically connected to the plurality of power sources, the second pump motor is electrically connected to the plurality of power sources, and the first pump motor and the second pump motor being coupled to the pump via the pump shaft to provide single or redundant supply of power to operate the pump.

As yet another example, the pumping system of the present disclosure provides redundant supply of power by providing uninterrupted operation of the pump in response to one of the first pump motor and the second pump motor stopping operation.

Another embodiment of the pumping system of the present disclosure is such that one of the first pump motor and the second pump motor operates in a speed control mode.

Still another embodiment of the pumping system of the present disclosure is such that one of the first pump motor and the second pump motor operates in a torque control mode.

One embodiment of the pumping system of the present disclosure is such that the first pump motor is a first fuel pump motor, the second pump motor is a second fuel pump motor, the pump is a fuel pump, and the pump shaft is a fuel pump shaft.

Another embodiment of the pumping system of the present disclosure is such that the first pump motor is a first oil pump motor, the second pump motor is a second oil pump motor, the pump is an oil pump, and the pump shaft is an oil pump shaft.

Still another embodiment of the pumping system of the present disclosure is such that each of the first pump motor and the second pump motor is electrically powered by a different one of the plurality of power sources.

Yet another embodiment of the pumping system of the present disclosure is such that the plurality of power sources include one of an engine generator winding and an aircraft power bus.

Claim 1:
A pumping system (<NUM>-A, <NUM>-B, <NUM>-A, <NUM>-B, <NUM>, <NUM>) for use with a gas turbine engine, the pumping system (<NUM>-A, <NUM>-B, <NUM>-A, <NUM>-B, <NUM>, <NUM>) comprising:
a plurality of power sources (<NUM>, <NUM>, <NUM>);
a fuel system (<NUM>) configured for redundant operation, the fuel system (<NUM>) including a fuel pump motor (<NUM>, <NUM>, <NUM>, <NUM>), a first fuel pump (<NUM>, <NUM>), and a second fuel pump (<NUM>, <NUM>), the fuel pump motor (<NUM>, <NUM>, <NUM>, <NUM>) being mechanically connected with the first fuel pump (<NUM>, <NUM>) to drive the first fuel pump (<NUM>, <NUM>), and the fuel pump motor (<NUM>, <NUM>, <NUM>, <NUM>) being electrically connected to at least one power source of the plurality of power sources (<NUM>, <NUM>, <NUM>);
an oil system (<NUM>) configured for redundant operation, the oil system (<NUM>) including an oil pump motor (<NUM>, <NUM>, <NUM>), and an oil pump (<NUM>, <NUM>), the oil pump motor (<NUM>, <NUM>, <NUM>) is mechanically connected with the oil pump (<NUM>, <NUM>) to drive the oil pump (<NUM>, <NUM>), characterized by the oil pump motor (<NUM>, <NUM>, <NUM>) being electrically connected to at least one power source of the plurality of power sources (<NUM>, <NUM>, <NUM>); and
a bidirectional pump motor (<NUM>) electrically connected to at least one power source of the plurality of power sources (<NUM>, <NUM>, <NUM>), and the bidirectional pump motor (<NUM>) is mechanically connected with the second fuel pump (<NUM>, <NUM>) and the oil pump (<NUM>, <NUM>) such that the bidirectional pump motor (<NUM>) is configured to drive either the second fuel pump (<NUM>, <NUM>) or the oil pump (<NUM>, <NUM>).