Patent Description:
Metering pump systems supply fuel to an engine of a vehicle. For example, metering pump systems can supply fuel to a jet turbine engine of an aircraft or to an engine of an automobile. An improved metering pump system is disclosed hereafter. A metering pump is known from <CIT>. This pump does not measure fuel temperature and actuator displacement by a linear variable displacment transducer.

In one example, a metering pump system includes a variable displacement pump having an inlet and an outlet, a flow sensing valve fluidically connected to the outlet of the variable displacement pump, and an actuator mechanically coupled to a displacement mechanism of the variable displacement pump. The metering pump system also includes an electronic engine controller in communication with the flow sensing valve. An electrohydraulic servo valve is electrically connected to the electronic engine controller and is hydraulically connected to the actuator. The electrohydraulic servo valve is configured to hydraulically drive the actuator to move the displacement mechanism to change displacement of the variable displacement pump.

In another example, a metering pump system includes a variable displacement pump, an actuator mechanically coupled to the variable displacement pump, and a drive unit connected to the actuator. The metering pump system also includes an electronic engine controller electronically connected to the drive unit, a linear variable displacement transducer on the actuator and configured to measure a position of the actuator. The linear variable displacement transducer is in communication with the electronic engine controller. The metering pump system also includes a flow sensing valve fluidically connected to an outlet of the variable displacement pump. The flow sensing valve includes a resistance temperature detector configured to measure a temperature of fuel flow in the flow sensing valve. The resistance temperature detector is electrically connected to the electronic engine controller. The flow sensing valve also includes a further linear variable displacement transducer configured to measure a linear displacement of the flow sensing valve. The linear variable displacement transducer is electrically connected to the electronic engine controller.

In another example, a method of pumping in a system includes pumping fuel through the system with a variable displacement pump, wherein the variable displacement pump comprises a displacement mechanism mechanically connected to an actuator. The fuel is directed through a flow sensing valve connected to an outlet of the variable displacement pump. A temperature of the fuel flowing through the flow sensing valve is sensed via a resistance differential transducer. A linear displacement of the flow sensing valve is sensed via a linear variable differential transducer. The method also includes communicating the temperature of the fuel flowing through the flow sensing valve and the linear displacement of the flow sensing valve to an electronic engine controller. An electrical current is delivered to a servo valve by the electronic engine controller. The servo valve moves the actuator to actuate the displacement mechanism of the variable displacement pump and alter displacement of the variable displacement pump.

<FIG> is a schematic diagram of a metering pump system.

While the above-identified figures set forth one or more embodiments of the present disclosure, other embodiments are also contemplated, as noted in the discussion. In all cases, this disclosure presents embodiments by way of representation and not limitation. It should be understood that numerous other modifications and embodiments can be devised by those skilled in the art. The figures may not be drawn to scale, and applications and embodiments of the present disclosure may include features and components not specifically shown in the drawings.

In the present disclosure, a metering pump system includes a variable displacement pump, a flow sensing valve, an actuator, an electronic engine controller, and a servo valve. The flow sensing valve includes a resistance temperature detector and a linear variable differential transducer configured to measure the temperature of fuel flow through the flow sensing valve and a linear displacement of the flow sensing valve. The actuator is connected to a displacement mechanism of the variable differential pump. The actuator includes another linear variable differential transducer configured to sense or measure the linear displacement of the actuator. The electronic engine controller can calculate a flow rate of fuel exiting the variable displacement pump using the sensed temperature of fuel flow through the flow sensing valve and sensed linear displacement of the flow sensing valve. The electronic engine controller can also calculate a predicted flow rate of fuel leaving the variable displacement pump using the linear displacement of the actuator. The electronic engine controller can compare the calculated flow rate through the flow sensing valve and the predicted flow out of the variable displacement pump to determine the wear of the variable displacement pump. Further the metering pump system can use the actuator to adjust the displacement mechanism of the variable displacement pump based on the flow rate through the flow sensing valve to optimize the performance of the system. The metering pump system will be discussed with reference to <FIG>.

<FIG> is a schematic diagram of metering pump system <NUM>. Metering pump system <NUM> includes variable displacement pump <NUM>, flow sensing valve <NUM>, actuator <NUM>, electronic engine controller <NUM>, and drive unit <NUM> with servo valve <NUM>. Variable displacement pump <NUM> includes inlet <NUM>, outlet <NUM>, and displacement mechanism <NUM>. Flow sensing valve <NUM> includes resistance temperature detector <NUM> and linear variable differential transducer <NUM>. Actuator <NUM> is a piston assembly including housing <NUM>, piston cylinder <NUM>, fluid chamber <NUM>, spring chamber <NUM>, piston rod <NUM>, and linear variable differential transducer <NUM>.

Flow sensing valve <NUM> is fluidically connected to outlet <NUM> of variable displacement pump <NUM>. Resistance temperature detector <NUM> is in contact with an interior of flow sensing valve <NUM> and is configured to measure a temperature of fuel flow through flow sensing valve <NUM>. Linear variable differential transducer is also in contact with an interior of flow sensing valve <NUM> and is configured to measure a linear displacement of flow sensing valve <NUM>. In one example, flow sensing valve <NUM> can be the valve disclosed in <CIT>. In another example, flow sensing valve <NUM> can be any other valve used to determine the flow rate of a fluid within a system.

Actuator <NUM> is mechanically coupled to displacement mechanism <NUM> of variable displacement pump <NUM>. Piston cylinder <NUM>, fluid chamber <NUM>, and spring chamber <NUM> are contained inside housing <NUM> of actuator <NUM>. Fluid chamber <NUM> is on a first side of piston cylinder <NUM>. Spring chamber <NUM> is opposite fluid chamber <NUM> relative to piston cylinder <NUM>. Piston rod <NUM> is attached to piston cylinder <NUM> and extends outside of housing <NUM>. Piston rod <NUM> is operably connected to displacement mechanism <NUM> of variable displacement pump <NUM>. Linear variable differential transducer <NUM> of actuator <NUM> is configured to measure a linear displacement of actuator <NUM>. Linear variable differential transducer <NUM> of actuator <NUM> can measure a liner displacement of actuator <NUM> by measuring a linear displacement of piston cylinder <NUM> and/or piston rod <NUM>.

Electronic engine controller <NUM> is in communication with flow sensing valve <NUM>. More specifically, electronic engine controller <NUM> is in communication with resistance temperature detector <NUM> and linear variable differential transducer <NUM> of flow sensing valve <NUM>. Electronic engine controller <NUM> is also in communication with linear variable differential transducer <NUM> of actuator <NUM>. Thus, resistance temperature detector <NUM> and linear variable differential transducer <NUM> of flow sensing valve <NUM>, linear variable differential transducer <NUM> of actuator <NUM>, and electronic engine controller <NUM> form a continuous positive feedback loop.

Drive unit <NUM> includes servo valve <NUM>. Servo valve <NUM> is electrically connected to electronic engine controller <NUM> and hydraulically connected to actuator <NUM>. Servo valve <NUM> is configured to hydraulically drive actuator <NUM> to move displacement mechanism <NUM> to change displacement of variable displacement pump <NUM>. Servo valve <NUM> can be an electrohydraulic servo valve that drives actuator <NUM> by directing fuel from outlet <NUM> of variable displacement pump <NUM> to fluid chamber <NUM> of actuator <NUM>. In other examples, servo valve <NUM> can direct fuel or fluid from inlet <NUM> of variable displacement pump <NUM>, or any other suitable source, to fluid chamber <NUM> of actuator <NUM>. In one example, displacement mechanism <NUM> can be a swashplate. In another example, displacement mechanism <NUM> can be any other mechanism that alters the displacement of variable displacement pumps. In another example, servo valve <NUM> can be an electropneumatic, electromechanical, or any other kind of servo valve.

In operation, variable displacement pump <NUM> generates fuel flow in metering pump system <NUM> and pulls fuel through inlet <NUM>. The fuel flow is pushed out outlet <NUM> of variable displacement pump <NUM> and through flow sensing valve <NUM>. Resistance temperature detector <NUM> senses a temperature of the fuel flowing through flow sensing valve <NUM>. Linear variable differential transducer <NUM> senses a linear displacement of sensing valve <NUM>. Resistance temperature detector <NUM> and linear variable differential transducer <NUM> communicate the sensed temperature of the fuel flowing through flow sensing valve <NUM> and the sensed linear displacement of sensing valve <NUM> to electronic engine controller <NUM>.

Electronic engine controller <NUM> determines an actual flow rate of fuel through flow sensing valve <NUM> using the sensed temperature of the fuel flowing through flow sensing valve <NUM> and sensed linear displacement of flow sensing valve <NUM>. After receiving the sensed temperature of the fuel flowing through flow sensing valve <NUM> and the sensed linear displacement of flow sensing valve <NUM>, electronic engine controller <NUM> calculates the actual flow rate of the fuel flowing through flow sensing valve <NUM>. In response to the calculated flow rate of fuel flowing through flow sensing valve <NUM>, electronic engine controller delivers an electrical current to servo valve <NUM>. In response to the electrical current received by servo valve <NUM>, servo valve <NUM> sends hydraulic fluid to actuator <NUM> or releases hydraulic fluid from actuator <NUM> to adjust the output of variable displacement pump <NUM>. When servo valve <NUM> sends the hydraulic fluid (i.e., fuel) to actuator <NUM>, the hydraulic fluid fills fluid chamber <NUM>, which moves piston cylinder <NUM> and piston rod <NUM>. As discussed above, piston rod <NUM> is operably connected to displacement mechanism (i.e., swashplate) <NUM> of variable displacement pump <NUM>. The movement of piston rod <NUM> actuates displacement mechanism <NUM> of variable displacement pump <NUM>. When piston rod <NUM> actuates displacement mechanism <NUM> the displacement of variable displacement pump <NUM> changes. Therefore, the displacement of variable displacement pump <NUM> is changed in response to the temperature of the fuel flowing through flow sensing valve <NUM> and the linear displacement of flow sensing valve <NUM>.

Electronic engine controller <NUM> determines a predicted flow rate of fuel out of variable displacement pump <NUM> using the linear displacement of actuator <NUM>. Linear variable differential transducer <NUM> of actuator <NUM> senses a linear displacement of actuator <NUM> and communicates the linear displacement of actuator <NUM> to electronic engine controller <NUM>. Metering pump system <NUM> can be pre-calibrated such that electronic engine controller <NUM> can convert a position measurement of actuator <NUM> to a position measurement of displacement mechanism <NUM>. Electronic engine <NUM> can be pre-programed to convert the position measurement of displacement mechanism <NUM> to a predicted flow rate of variable displacement pump <NUM>. Electronic engine controller <NUM> can compare the actual flow rate of the fuel flow through flow sensing valve <NUM> with the predicted flow rate of the fuel out of variable displacement pump <NUM> to analyze the performance of variable displacement pump <NUM>.

For example, if there is a variance between the actual flow rate of the fuel flow through flow sensing valve <NUM> with the predicted flow rate of the fuel out of variable displacement pump <NUM>, variable displacement pump <NUM> can be worn. Additionally, in response to the variance between the actual flow rate of fuel flow through flow sensing valve <NUM> with the predicted flow rate of the fuel out of variable displacement pump <NUM>, electronic engine controller <NUM> can increase the current sent to servo valve <NUM>. Servo valve <NUM> can then increase the hydraulic fluid sent to actuator <NUM>, which will further actuate displacement mechanism <NUM>, which will increase the pumping rate of variable displacement pump <NUM> to compensate for the difference between the predicted flow rate and the actual flow rate.

Metering pump system <NUM> includes one or more processors and computer-readable memory can contain software that is executable to produce an actual flow rate of fuel through flow sensing valve <NUM> using the sensed temperature of the fuel flowing through flow sensing valve <NUM> and sensed linear displacement of flow sensing valve <NUM>. Further, the one or more processors and computer-readable memory can include software that is executable to convert the position measurement of displacement mechanism <NUM> to a predicted flow rate of variable displacement pump <NUM>. Lastly, the one or more processors and computer-readable memory can contain software that compares the actual flow rate of the fuel flow through flow sensing valve <NUM> with the predicted flow rate of the fuel out of variable displacement pump <NUM> to analyze the performance of variable displacement pump <NUM>.

A metering pump system includes a variable displacement pump having an inlet and an outlet, a flow sensing valve fluidically connected to the outlet of the variable displacement pump, and an actuator mechanically coupled to a displacement mechanism of the variable displacement pump. The metering pump system also includes an electronic engine controller in communication with the flow sensing valve. An electrohydraulic servo valve is electrically connected to the electronic engine controller and is hydraulically connected to the actuator. The electrohydraulic servo valve is configured to hydraulically drive the actuator to move the displacement mechanism to change displacement of the variable displacement pump.

The metering pump of the preceding paragraph can optionally include, additionally and/or alternatively, any one or more of the following features, configurations and/or additional components:.

A metering pump system includes a variable displacement pump, an actuator mechanically coupled to the variable displacement pump, and a drive unit connected to the actuator. The metering pump system also includes an electronic engine controller electronically connected to the drive unit, a linear variable displacement transducer on the actuator and configured to measure a position of the actuator. The linear variable displacement transducer is in communication with the electronic engine controller. The metering pump system also includes a flow sensing valve fluidically connected to an outlet of the variable displacement pump. The flow sensing valve includes a resistance temperature detector configured to measure a temperature of fuel flow in the flow sensing valve. The resistance temperature detector is electrically connected to the electronic engine controller. The flow sensing valve also includes a second linear variable displacement transducer configured to measure a linear displacement of the flow sensing valve. The linear variable displacement transducer is electrically connected to the electronic engine controller.

A method of pumping in a system includes pumping fuel through the system with a variable displacement pump, wherein the variable displacement pump comprises a displacement mechanism mechanically connected to an actuator. The fuel is directed through a flow sensing valve connected to an outlet of the variable displacement pump. A temperature of the fuel flowing through the flow sensing valve is sensed via a resistance differential transducer. A linear displacement of the flow sensing valve is sensed via a linear variable differential transducer. The method also includes communicating the temperature of the fuel flowing through the flow sensing valve and the linear displacement of the flow sensing valve to an electronic engine controller. An electrical current is delivered to a servo valve by the electronic engine controller. The servo valve moves the actuator to actuate the displacement mechanism of the variable displacement pump and alter displacement of the variable displacement pump.

The method of the preceding paragraph can optionally include, additionally and/or alternatively, any one or more of the following features, configurations and/or additional components:.

Claim 1:
A metering pump system (<NUM>) comprising:
a variable displacement pump (<NUM>) comprising an inlet (<NUM>) and an outlet (<NUM>);
a flow sensing valve (<NUM>) fluidically connected to the outlet of the variable displacement pump, the flow sensing valve comprising:
a resistance temperature detector (<NUM>) configured to measure a temperature of flow through the flow sensing valve; and
a first linear variable differential transducer configured to measure a linear displacement of the flow sensing valve;
an actuator (<NUM>) mechanically coupled to a displacement mechanism (<NUM>) of the variable displacement pump, the actuator comprising a second linear variable differential transducer configured to measure a linear displacement of the actuator;
an electronic engine controller (<NUM>) in communication with the flow sensing valve, wherein the electronic engine controller is configured to determine an actual flow rate of fuel through the flow sensing valve using the temperature of the fuel through the flow sensing valve and the linear displacement of the flow sensing valve and to determine a predicted flow rate of the fuel out of the variable displacement pump using the linear displacement of the actuator; and
an electrohydraulic servo valve (<NUM>) electrically connected to the electronic engine controller and hydraulically connected to the actuator, wherein the electrohydraulic servo valve is configured to hydraulically drive the actuator to move the displacement mechanism to change displacement of the variable displacement pump.