Patent Description:
In many turbine engines, effector actuation systems (vanes angle, nozzle area, etc) are usually modulated, but sometimes a two-position system may be advantageous. In modern turbine engines, weight and space are more critical than previous engines because of the increased externals content added to improve engine efficiency. A traditional modulating actuator system usually has two Electro-Hydraulic Servo Valves (EHSVs) and a solenoid driven transfer valve, which tend to be heavy.

The conventional techniques have been considered satisfactory for their intended purpose. However, there is a need for improved actuator systems. This disclosure provides a solution for this need. <CIT>, <CIT> and <CIT> relate to valve arrangements.

A solenoid valve driven actuator system includes a first solenoid valve having at least one pressure input and a pressure outlet downstream from the at least one pressure input. The system includes a second solenoid valve having at least one pressure input and a pressure outlet downstream from the at least one pressure input. The system includes a pressure-switching valve operatively coupled to the first and second solenoid valves. The system includes an actuator valve operatively coupled to the pressure outlet of the second solenoid valve.

The at least one pressure input of the first solenoid valve includes a first pressure input and a second pressure input. The at least one pressure input of the second solenoid valve includes a first pressure input and a second pressure input. The pressure-switching valve is in fluid communication with the first pressure input of the second solenoid valve. The pressure outlet of the first solenoid valve is in fluid communication with the second pressure input of the second solenoid valve.

The pressure-switching valve can include a first side, a second side and a slidable spool therebetween. The first side of the pressure-switching valve can be in fluid communication with a first pressure source through a first side pressure port. The second side of the pressure-switching valve can be in fluid communication with the pressure outlet of the first solenoid valve through a second side pressure port. The pressure-switching valve can include a secondary pressure port between the first and second sides of the pressure-switching valve. The secondary pressure port can be in fluid communication with a first pressure source. The pressure-switching valve can include an additional secondary pressure port between the first and second sides of the pressure-switching valve. The additional secondary pressure port can be in fluid communication with a second pressure source. At least one of the secondary pressure port or the additional secondary pressure port of the pressure-switching valve can be in fluid communication with a first pressure input of the second solenoid valve.

In accordance with another aspect, a method for controlling an actuator valve with a dual redundant solenoid valves includes providing a low pressure from a low pressure source to a first solenoid valve and providing a high pressure from a high pressure source to the first solenoid valve. The high pressure source is at a higher pressure relative to the low pressure source. The method includes providing the low pressure from the low pressure source to a pressure-switching valve. The method includes providing the high pressure from the high pressure source to the pressure-switching valve. The method includes providing a control pressure from the pressure-switching valve to a first inlet of a second solenoid valve and providing a control pressure from the first solenoid valve to a second inlet of the second solenoid valve.

The method includes controlling an actuator valve with an output of the second solenoid valve.

In some embodiments, the method includes controlling the actuator valve with the output of the second solenoid valve when the first solenoid valve is in a failure mode to the high pressure by providing the high pressure from the first solenoid valve to the pressure-switching valve thereby exposing a first inlet of the second solenoid valve to the low pressure source via the pressure-switching valve. The method can include controlling the actuator valve with the output of the second solenoid valve when the first solenoid valve is in a failure mode to the low pressure by providing the low pressure from the first solenoid valve to the pressure-switching valve thereby exposing a first inlet of the second solenoid valve to the high pressure source via the pressure-switching valve.

The method can include controlling the actuator valve with an output of the first solenoid valve when the second solenoid valve is in a failure mode by exposing a first side of the pressure-switching valve to the high pressure source thereby exposing a first inlet of the second solenoid valve to the low pressure source. The method can include controlling the actuator valve with an output of the first solenoid valve when the second solenoid valve is in a failure mode by exposing a first side of the pressure-switching valve to the low pressure source thereby exposing a first inlet of the second solenoid valve to the high pressure source.

These and other features of the systems and methods of the invention will become more readily apparent to those skilled in the art from the following detailed description of the preferred embodiments taken in conjunction with the drawings.

So that those skilled in the art to which the invention appertains will readily understand how to make and use the devices and methods of the invention without undue experimentation, preferred embodiments thereof will be described in detail herein below with reference to certain figures, wherein:.

Reference will now be made to the drawings wherein like reference numerals identify similar structural features or aspects of the invention.

For purposes of explanation and illustration, and not limitation, a schematic view of an exemplary embodiment of the solenoid valve driven actuator system in accordance with the invention is shown in <FIG> and is designated generally by reference character <NUM>. Other embodiments of the solenoid valve driven actuator systems in accordance with the invention, or aspects thereof, are provided in <FIG> as will be described. The systems and methods described herein can be used to provide a two-position actuator valve that is lighter weight and smaller in size than traditional modulating actuator systems.

As shown in <FIG>, a solenoid valve driven actuator system <NUM> is a dual-redundant actuator system having two solenoid valves controlled on the same or different channels. System <NUM> includes a first solenoid valve <NUM> having a first pressure input <NUM> and a second pressure input <NUM> and a pressure outlet <NUM> downstream from pressure inputs <NUM> and <NUM>. The system <NUM> includes a second solenoid valve <NUM> having a first pressure input <NUM>, a second pressure input <NUM>, and a pressure outlet <NUM> downstream from the pressure inputs <NUM> and <NUM>. The system <NUM> includes a pressure-switching valve <NUM> operatively coupled to the first and second solenoid valves <NUM> and <NUM>, respectively. The system <NUM> includes an actuator valve <NUM> operatively coupled to the pressure outlet <NUM> of the second solenoid valve <NUM>. The first solenoid valve <NUM> controls the pressure going to the second solenoid valve <NUM> both directly and through the pressure switching valve <NUM>. With a failure of either solenoid valve, control over actuator valve <NUM> can be maintained through the working solenoid valve.

With continued reference to <FIG>, the pressure-switching valve <NUM> is in fluid communication with the first pressure input <NUM> of the second solenoid valve <NUM> via a pressure outlet <NUM>. The pressure-switching valve <NUM> includes a first side <NUM>, a second side <NUM> and a slidable spool <NUM> therebetween. The pressure outlet <NUM> of the first solenoid valve <NUM> is in fluid communication with the second pressure input <NUM> of the second solenoid valve <NUM>. The first side <NUM> of the pressure-switching valve <NUM> is in fluid communication with a first pressure source <NUM> through a first side pressure port <NUM>. The second side <NUM> of the pressure-switching valve <NUM> is in fluid communication with the pressure outlet <NUM> of the first solenoid valve <NUM> through a second side pressure port <NUM>. The pressure-switching valve <NUM> includes a secondary pressure port <NUM> between the first and second sides <NUM> and <NUM>, respectively, of the pressure-switching valve <NUM>. The secondary pressure port <NUM> is in fluid communication with a first pressure source <NUM>. The pressure-switching valve <NUM> includes an additional secondary pressure port <NUM> between the first and second sides, <NUM> and <NUM>, respectively, of the pressure-switching valve <NUM>. The additional secondary pressure port <NUM> is in fluid communication with a second pressure source <NUM>. As described in more detail below, depending on the output from the first solenoid valve <NUM> at pressure outlet <NUM>, either the secondary pressure port <NUM> or the additional secondary pressure port <NUM> of the pressure-switching valve <NUM> is in fluid communication with the first pressure input <NUM> of the second solenoid valve <NUM> via pressure outlet <NUM>.

With continued reference to <FIG>, system <NUM> is shown where both first and second solenoid valves <NUM> and <NUM>, respectively, are both operational. In this state, either the first solenoid valve <NUM> or the second solenoid valve <NUM> can control the output to actuator valve <NUM>. In accordance with some embodiments, control of first solenoid valve <NUM> is executed through a communication channel <NUM> and control of second solenoid valve <NUM> is executed with separate communication channel <NUM>, e.g., one independent from communication channel <NUM>. Those skilled in the art will readily appreciate that in accordance with some embodiments, first and second solenoid valves <NUM> and <NUM>, respectively, can be controlled via a single communication channel. The channels, whether a single channel or two independent channels, can be operatively coupled to a FADEC (Full Authority Digital Engine Control). In <FIG>, the second solenoid valve <NUM> is shown in control. Second solenoid valve <NUM> can supply an actuator control cavity <NUM> with a high pressure (e.g., from second pressure source <NUM>) or a low pressure (e.g. from a first pressure source <NUM>) via an actuator control line <NUM>. Low-pressure is schematically shown with the larger dashed lines and high-pressure is schematically shown with the smaller dashed line throughout the figures. The pressure in actuator control cavity <NUM> controls whether spring <NUM> is compressed or released by controlling the axial position of an actuator body <NUM>. In this state, it is also contemplated that the first solenoid valve <NUM> may also be used to control actuator valve <NUM> through the pressure-switching valve <NUM>. Those skilled in the art will readily appreciate that in some embodiments, the actuator valve <NUM> may be arranged differently (e.g., spring <NUM> may positioned within the actuator control cavity <NUM>) or may be a two-position valve.

With reference now to <FIG>, the first solenoid valve <NUM> is in a failure condition where the first solenoid valve <NUM> has failed to high-pressure, e.g. the second pressure source <NUM>. In this condition, the second solenoid valve <NUM> can be operated to direct the output at pressure output <NUM> to either high pressure via second pressure source <NUM> and first solenoid valve <NUM> or low pressure via first pressure source <NUM> and pressure switching valve <NUM>. This ability stems from the opposite nature of the first solenoid valve <NUM> and the pressure-switching valve <NUM>. When first solenoid valve <NUM> outputs a high pressure from pressure outlet <NUM>, the spool <NUM> of pressure switching valve <NUM> moves left, opening the secondary pressure port <NUM> and thereby exposing the low pressure from first pressure source <NUM> to the first pressure input <NUM> of the second solenoid valve <NUM> via pressure outlet <NUM>. The second pressure input <NUM> of the second solenoid valve <NUM> is supplied high pressure from second pressure source <NUM> via the failed first solenoid valve <NUM>. As the second solenoid valve <NUM> is still functional, it is controlled to supply actuator control cavity <NUM> with either the high pressure or low pressure via actuator control line <NUM>.

As shown in <FIG>, the second solenoid valve <NUM> is in control when the first solenoid valve <NUM> has failed to low pressure, e.g. the first power source <NUM>. In this condition, the second solenoid valve <NUM> can be operated to direct the output at pressure output <NUM> to either low pressure via first pressure source <NUM> and first solenoid valve <NUM> or high pressure via second pressure source <NUM> and pressure switching valve <NUM>. This ability stems from the opposite nature of the first solenoid valve <NUM> and the pressure-switching valve <NUM>. When first solenoid valve <NUM> outputs a low pressure from pressure outlet <NUM>, the spool <NUM> of pressure switching valve <NUM> moves right (e.g., relative to the position in <FIG>), opening the additional secondary pressure port <NUM> and thereby exposing the high pressure from second pressure source <NUM> to the first pressure input <NUM> of the second solenoid valve <NUM> via pressure outlet <NUM>. The second pressure input <NUM> of the second solenoid valve <NUM> is supplied low pressure from first pressure source <NUM> via the failed first solenoid valve <NUM>. As the second solenoid valve <NUM> is still functional, it is controlled to supply actuator control cavity <NUM> with either the high pressure or low pressure via actuator control line <NUM>.

As shown in <FIG>, the first solenoid valve <NUM> is in control when the second solenoid valve <NUM> has failed such that second solenoid valve only passes fluid to the left input, e.g., first pressure input <NUM>. In this condition, the first solenoid valve <NUM> can be operated to direct the output at pressure output <NUM> to either low pressure via first pressure source <NUM> and pressure switching valve <NUM> or high pressure via second pressure source <NUM> and pressure switching valve <NUM>. This ability stems from the opposite nature of the first solenoid valve <NUM> and the pressure-switching valve <NUM>. In <FIG>, first solenoid valve <NUM> is shown outputting a high pressure from pressure outlet <NUM>. The high pressure output from first solenoid valve <NUM> is received at side pressure port <NUM> and causes the spool <NUM> of pressure switching valve <NUM> moves left away from second side <NUM> of pressure switching valve <NUM>. This translation of the spool <NUM> causes the secondary pressure port <NUM> to open and thereby exposes the low pressure first pressure source <NUM> to the first pressure input <NUM> of the second solenoid valve <NUM> via pressure outlet <NUM>. The second solenoid valve <NUM> then provides the low-pressure to the actuator control line <NUM> via a pressure outlet <NUM>. In <FIG>, first solenoid valve <NUM> is shown outputting a low pressure from pressure outlet <NUM>. The low pressure output from first solenoid valve <NUM> is received at side pressure port <NUM> and causes the spool <NUM> of pressure switching valve <NUM> to move right toward the second side <NUM> of pressure switching valve <NUM>. This translation of the spool <NUM> causes the additional secondary pressure port <NUM> to open and thereby exposes the high pressure second pressure source <NUM> to the first pressure input <NUM> of the second solenoid valve <NUM> via the pressure outlet <NUM>. The second solenoid valve <NUM> then provides the high-pressure to the actuator control line <NUM> via a pressure outlet <NUM>.

As shown in <FIG>, the first solenoid valve <NUM> is in control when the second solenoid valve <NUM> has failed such that second solenoid valve <NUM> only passes fluid to the right input, e.g., second pressure input <NUM>. In this condition, the first solenoid valve <NUM> can be operated to direct the output at pressure output <NUM> to either low pressure via first pressure source <NUM> or high pressure via second pressure source <NUM>. In this condition, the pressure-switching valve <NUM> does not affect any control of the second solenoid valve <NUM>. In <FIG>, first solenoid valve <NUM> is shown outputting a high pressure from pressure outlet <NUM> to the second pressure input <NUM> of the second solenoid valve <NUM>. The second solenoid valve <NUM> then provides the high-pressure to the actuator control line <NUM> via a pressure outlet <NUM>. In <FIG>, first solenoid valve <NUM> is shown outputting a low pressure from pressure outlet <NUM>. The low-pressure output from first solenoid valve <NUM> is received at the second pressure input <NUM> of the second solenoid valve <NUM>. The second solenoid valve <NUM> then provides the low-pressure to the actuator control line <NUM> via a pressure outlet <NUM>.

As solenoid valves <NUM> and <NUM> are smaller and lighter than EHSVs, system <NUM> provides reduced weight and reduced size envelope as compared with traditional EHSVs. Moreover, if the effector system that the actuator body <NUM> controls does not have its own means of tracking performance (e.g., via position sensor, pressure sensor, temperature sensor, etc.) embodiments of system <NUM> can use proximity probes (which have good resolution to determine position in a non-modulated actuator) to determine the left or right position of the actuator body <NUM>. Proximity probes are magnetic sensors that can be installed in the actuator valve <NUM> to determine position of actuator body <NUM> (e.g., is the actuator body in the left or right position). Proximity probes are lighter than a linear variable differential transformer (LVDT), which would typically be used to detect the position of the actuator in an EHSV system. The ability to use these proximity probes results in further potential weight and size reduction as compared with traditional EHSV systems. Additionally, because solenoid valves <NUM> and <NUM> have little to no internal leakage, system <NUM> also provides for improved fuel system efficiency and reliability as compared with EHSVs. The simplified control nature of solenoid valves, e.g., the simple I/O control structure, provides easier control as compared with EHSVs. As such, in situations where a non-modulated effector is appropriate, system <NUM> offers considerable benefits over traditional EHSVs.

A method for controlling an actuator, e.g. actuator valve <NUM>, with dual redundant solenoid valves, e.g. first and second solenoid valves <NUM> and <NUM>, includes providing a low pressure from a low pressure source, e.g. first pressure source <NUM>, to the first solenoid valve and providing a high pressure from a high pressure source, e.g. second pressure source <NUM> to the first solenoid valve. The method includes providing the low pressure from the low-pressure source to a pressure-switching valve, e.g. pressure switching valve <NUM>. The method includes providing the high pressure from the high-pressure source to the pressure-switching valve. In <FIG>, where both the first and second solenoid valves <NUM> and <NUM> are operational, the method includes providing a control pressure from either the first solenoid valve or the second solenoid valve. The method includes controlling an actuator valve, e.g., actuator valve <NUM>, with an output of the second solenoid valve.

When the first solenoid valve is in a failure mode to the high-pressure source, e.g., as shown in <FIG>, the method includes controlling the actuator valve with the output of the second solenoid valve by providing the high pressure from the first solenoid valve to a second pressure input, e.g., the second pressure input <NUM>, of the second solenoid valve and to the pressure-switching valve thereby exposing a first inlet, e.g. a first inlet <NUM>, of the second solenoid valve to the low pressure source via a pressure outlet, e.g. pressure outlet <NUM>, of the pressure-switching valve. As the second solenoid valve is still functional, the method includes controlling the second solenoid valve to supply an actuator control cavity, e.g. actuator control cavity <NUM>, with either the high pressure or low pressure via an actuator control line, e.g., the actuator control line <NUM>.

When the first solenoid valve is in a failure mode to the low pressure source, e.g., as shown in <FIG>, the method includes controlling the actuator valve with the output of the second solenoid valve by providing the low pressure from the first solenoid valve to the second pressure input of.

the second solenoid valve and to the pressure-switching valve thereby exposing a first inlet, e.g. a first inlet <NUM>, of the second solenoid valve to the high pressure source via the pressure outlet of the pressure-switching valve. As the second solenoid valve is still functional, the method includes controlling the second solenoid valve to supply the actuator control cavity with either the high pressure or low pressure via the actuator control line. When the second solenoid valve is in a failure mode to its left side, as shown in <FIG>, the method includes controlling the actuator valve with an output of the first solenoid valve.

As shown in <FIG>, if a high-pressure output at the pressure outlet is desired, the method includes exposing the first side of the pressure-switching valve to the low-pressure source. The low-pressure source provided to the pressure switching valve acts to expose the first inlet of the second solenoid valve to the high-pressure source via the pressure outlet of the pressure-switching valve and provides a high-pressure source to the actuator control line via a pressure outlet, e.g. pressure outlet <NUM>, of the second solenoid valve.

As shown in <FIG>, if a low-pressure output at the pressure outlet is desired, the method includes controlling the actuator valve with an output of the first solenoid valve by exposing the first side of the pressure-switching valve to the high-pressure source. The high-pressure source provided to the pressure-switching valve acts to expose the first inlet of the second solenoid valve to the low-pressure source via the pressure outlet of the pressure-switching valve, thereby providing a low-pressure source to the actuator control line via the pressure outlet of the second solenoid valve.

When the second solenoid valve is in a failure mode to its right side, as shown in <FIG>, the method includes controlling the actuator valve with an output of the first solenoid valve by exposing a second inlet, e.g. a second inlet <NUM>, of the second solenoid valve to either the high pressure source or low pressure source. As shown in <FIG>, if a high-pressure output at the pressure outlet is desired, the method includes controlling the actuator valve with an output of the first solenoid valve by exposing the second inlet of the second solenoid valve to the low pressure source and thereby providing a low pressure source to the actuator control line via a pressure outlet of the second solenoid valve. As shown in <FIG>, if a low pressure output at the pressure outlet of the second solenoid valve is desired, the method includes controlling the actuator valve with an output of the first solenoid valve by exposing a second inlet of the second solenoid valve to the low pressure source and thereby providing a low pressure source to the actuator control line via a pressure outlet of the second solenoid valve.

The methods and systems of the present invention, as described above and shown in the drawings, provide for solenoid valve driven actuator system, with superior properties including reduced weight and size, and increased reliability and efficiency. The systems and methods of the present invention can apply to a variety of actuators, or the like. While the apparatus and methods of the invention have been shown and described with reference to preferred embodiments, those skilled in the art will readily appreciate that changes and/or modifications may be made thereto without departing from the scope of the invention.

Claim 1:
A solenoid valve driven actuator system, the system comprising
a first solenoid valve (<NUM>) having at least one pressure input (<NUM>, <NUM>) and a pressure outlet (<NUM>) downstream from the at least one pressure input;
a second solenoid valve (<NUM>) having at least one pressure input (<NUM>, <NUM>) and a pressure outlet (<NUM>) downstream from the at least one pressure input;
a pressure-switching valve (<NUM>) operatively coupled to the first and second solenoid valves; and
an actuator valve (<NUM>) operatively coupled to the pressure outlet of the second solenoid valve;
wherein the at least one pressure input (<NUM>) of the first solenoid valve (<NUM>) includes a first pressure
input (<NUM>) and a second pressure input (<NUM>);wherein the at least one pressure input (<NUM>) of the second solenoid valve (<NUM>) includes a first pressure input (<NUM>) and a second pressure input (<NUM>);
wherein the pressure-switching valve (<NUM>) is in fluid communication with the first pressure input (<NUM>) of the second solenoid valve (<NUM>); and
characterized in that the pressure outlet (<NUM>) of the first solenoid valve (<NUM>) is in fluid communication with the second pressure input (<NUM>) of the second solenoid valve (<NUM>).