Patent Publication Number: US-2023160401-A1

Title: Actuator with integrated cooling

Description:
BACKGROUND 
     The present disclosure relates to actuators and, more particularly, to an actuator with integrated cooling. 
     In aircraft and other applications, actuators can be used to cause other components to move in a given manner. For example, in an aircraft, an actuator can be connected to a controllable surface to cause that controllable surface to pivot upwardly or downwardly based on current conditions. In other cases, an actuator in a gas turbine engine of an aircraft can be used to control openings and closings of doors or valves. 
     Developing actuators for use in gas turbine engines, in particular, presents several unique challenges. Among these is the challenge of designing the actuators to be able to survive a fire in an operation or a certification test. Normally, when an actuator is operating and moving, fuel or another fluid circulates in and out of the actuator body to aid in actuator cooling and/or seal cooling. When the actuator is not moving, however, fuel does not circulate in and out of the actuator body to aide in actuator cooling and it becomes necessary to provide the actuator with heavy thermal blanketing. This heavy thermal blanketing is typically added to the exterior of the actuator to survive fire or other high-temperature conditions. 
     The heavy thermal blanketing adds significant weight and envelope to the actuator and can be prone to damage during engine servicing. 
     BRIEF DESCRIPTION 
     According to an aspect of the disclosure, an actuator is provided. The actuator includes a first body defining an interior, a second body disposed about the first body and defining space between an exterior of the first body and an interior of the second body, a plunger including a head sealably disposed in the interior and a rod connected to the head and sealably extended through the first and second bodies and first and second fluid systems. The first fluid system is insulated from the space. A first fluid is moved relative to the interior for causing the plunger to extend or retract by way of the first fluid system. A second fluid is moved through the space by way of the second fluid system. 
     In accordance with additional or alternative embodiments, the first fluid includes fuel and the second fluid includes coolant. 
     In accordance with additional or alternative embodiments, the second fluid includes one or more of air, engine oil and a liquid- or air-based media. 
     In accordance with additional or alternative embodiments, an envelope of the actuator is substantially delimited by an exterior shape and size of the second body. 
     In accordance with additional or alternative embodiments, the first and second bodies include first and second snouts, respectively, and the actuator further includes first seals engageable between the head and the first body, second seals engageable between the rod and the first snout and third seals engageable between the rod and the second snout. 
     In accordance with additional or alternative embodiments, the first fluid system includes a first port and a second port which extend from an exterior of the second body, through the space and into the interior and the second fluid system includes an inlet and an outlet which extend from an exterior of the second body and into the space. 
     In accordance with additional or alternative embodiments, stoppers are disposed to constrain the first body relative to the second body. 
     According to an aspect of the disclosure, a heat exchanger including the actuator is provided where the first fluid is at a first temperature and the second fluid is at a second temperature which is different from the first temperature. 
     In accordance with additional or alternative embodiments, the first fluid includes fuel and the second fluid includes coolant. 
     In accordance with additional or alternative embodiments, the second fluid includes one or more of air, engine oil and a liquid- or air-based media. 
     In accordance with additional or alternative embodiments, the coolant is temporarily hotter than the fuel. 
     In accordance with additional or alternative embodiments, the first fluid includes fuel and the second fluid includes air which is hotter than the fuel. 
     According to an aspect of the disclosure, a method of assembling an actuator is provided. The method includes arranging a partial first body within a partial second body, coupling a first fluid system, which is insulated from a space between the partial first body and the partial second body that is unenclosed, with an interior of the partial first body that is unenclosed, coupling a second fluid system with the space, inserting a head of a plunger with a rod connected thereto into the interior of the partial first body, sliding a first snout over the rod and into the partial first body to enclose the interior and sliding a second snout over the rod and into the partial second body to enclose the space. 
     In accordance with additional or alternative embodiments, the method further includes additively manufacturing at least the partial first body and the partial second body. 
     In accordance with additional or alternative embodiments, the method further includes arranging first seals between the head and the partial first body, arranging second seals between the first snout and the rod and arranging third seals between the second snout and the rod. 
     In accordance with additional or alternative embodiments, the method further includes constraining the partial first body relative to the partial second body. 
     According to an aspect of the disclosure, a method of assembling an actuator is provided. The method includes arranging a partial first body with a first snout within a partial second body with a second snout, coupling a first fluid system, which is insulated from a space between the partial first body and the partial second body that is unenclosed, with an interior of the partial first body that is unenclosed, coupling a second fluid system with the space, inserting a head of a plunger with a rod connected thereto into the interior of the partial first body such that the rod extends through the first snout and the second snout, attaching a first end cap to the first partial body to enclose the interior and attaching a second end cap to the second partial body to enclose the space. 
     In accordance with additional or alternative embodiments, the method further includes additively manufacturing at least the partial first body and the partial second body. 
     In accordance with additional or alternative embodiments, the method further includes arranging first seals between the head and the partial first body, arranging second seals between the first snout and the rod and arranging third seals between the second snout and the rod. 
     In accordance with additional or alternative embodiments, the method further includes constraining the partial first body relative to the partial second body. 
     Additional features and advantages are realized through the techniques of the present disclosure. Other embodiments and aspects of the disclosure are described in detail herein and are considered a part of the claimed technical concept. For a better understanding of the disclosure with the advantages and the features, refer to the description and to the drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       For a more complete understanding of this disclosure, reference is now made to the following brief description, taken in connection with the accompanying drawings and detailed description, wherein like reference numerals represent like parts: 
         FIG.  1    is a schematic side view of an actuator in accordance with embodiments; 
         FIG.  2    is a flow diagram illustrating a method of assembling an actuator in accordance with embodiments; 
         FIG.  3    is a graphical depiction of the method of  FIG.  2    in accordance with embodiments; 
         FIG.  4    is a flow diagram illustrating a method of assembling an actuator in accordance with embodiments; and 
         FIG.  5    is a graphical depiction of the method of  FIG.  4    in accordance with embodiments. 
     
    
    
     DETAILED DESCRIPTION 
     As will be described below, an actuator is provided with an integrated cooling system. The actuator can be produced through additive manufacturing techniques, for example, and includes a series of cooling passages that surround the hydraulic body of the actuator. A fluid or gas, such as air (e.g., engine bleed/bypass air, or ram air from outside the aircraft), can flow through the cooling passages. This creates a thermal barrier to protect the fuel seals of the actuator from fire or extreme heat of a fire. 
     With reference to  FIG.  1   , an actuator  101  is provided and includes a first body  110 , a second body  120 , a plunger  130 , a first fluid system  140  and a second fluid system  150 . The first body  110  is formed to define an interior  111  and is arranged within the second body  120 . The second body  120  is thus disposed about the first body  110  and defines a space  121  between an exterior of the first body  110  and an interior of the second body  120 . Stoppers  170  can be disposed in the space  121  to constrain or prevent movement of the first body  110  relative to the second body  120 . The plunger  130  includes a head  131  and a rod  132  connected to the head  131 . The head  131  is sealably disposed in the interior  111 . The rod  132  extends from the head  131  and sealably extends through the first body  110  (i.e., through a portion of the first body  110  that can be provided as a first snout  112  and as shown in  FIGS.  3  and  5    and as described below) and through the second body  120  (i.e., through a portion of the second body  120  that can be provided as a second snout  122  and as shown in  FIGS.  3  and  5    and as described below). The first fluid system  140  is insulated from the space  121  and is configured to move a first fluid relative to the interior  111  to thereby cause the plunger  130  to extend or retract. The second fluid system  150  is configured to move a second fluid through the space  121  and includes an inlet  151  (i.e., a cooling flow inlet) and an outlet  152  (i.e., a cooling flow outlet). 
     First seals  161  can be provided between the head  131  and an interior surface of the first body  110 . Second seals  162  can be provided between an exterior surface of the rod  132  and the first snout  112 . Third seals  163  can be provided between the exterior surface of the rod  132  and the second snout  122 . The first fluid system  140  includes a first port  141  and a second port  142 . The first port  141  extends from an exterior of the second body  120 , through the space  121  and into the interior  111  at a first side (i.e., an extend side) of the head  131  and the first seals  161 . The second port  142  extends from the exterior of the second body  120 , through the space  121  and into the interior  111  at a second side (i.e., a retract side) of the head  131  and the first seals  161 . 
     When the first fluid in the first port  141  and at the first side of the head  131  and the first seals  161  has a greater pressure than the first fluid in the second port  142  and at the second side of the head  131  and the first seals  161 , the plunger  130  is extended through the first snout  112  and the second snout  122  as long as there is no loading applied to the rod to resist the extension. Conversely, when the first fluid in the second port  142  and at the second side of the head  131  and the first seals  161  has a greater pressure than the first fluid in the first port  141  and at the first side of the head  131  and the first seals  161 , the plunger  130  could be retracted unless the retract area exposed to the pressure of the second port  142  is less than the extend area exposed to the pressure of the first port  141  (area is smaller by the area of the plunger rod  132 ). Notably, force=pressure*area, so force balance (no motion) is achieved when the pressure at the second port  142  is higher than the pressure at the first port  141 . 
     In accordance with embodiments, the first fluid can include or be provided as fuel and the second fluid can include or be provided as coolant. In some cases, the second fluid can include or be provided as one or more of air, engine oil and a liquid- or air-based media. 
     In any case, since the second fluid can be provided as coolant, the actuator  101  has an available cooling system and does not need to be surrounded or embedded in heavy thermal blanketing. As such, the actuator  101  can be deployed or installed in a system without heavy thermal blanketing such that an envelope  102  of the actuator  101  is substantially delimited by an exterior shape and size of the second body  120 . 
     In accordance with additional or further embodiments, the actuator  101  can be provided as or a part of a heat exchanger  103 . In these or other cases, the first fluid can be provided to the actuator  101  acting as the heat exchanger  103  at a first temperature T 1  and the second fluid can be provided to the actuator  101  acting as the heat exchanger  103  at a second temperature T 2 , which is different from the first temperature. In an exemplary case, as above, the first fluid can include or be provided as fuel and the second fluid can include or be provided as coolant such as one or more of air, engine oil and a liquid- or air-based media. In some instances, the actuator  101  acting as the heat exchanger  103  can be operated in a reverse thermal exchange mode in which the coolant, which would normally be colder than the fuel, is at least temporarily hotter than the fuel (i.e., when exterior air is hotter than the fuel during ground conditions). 
     With reference to  FIGS.  2  and  3   , a method of assembling an actuator, such as the actuator  101  of  FIG.  1    described above, is provided. The method includes arranging a partial first body  310  within a partial second body  320  (block  201 ), coupling a first fluid system  330 , which is insulated from a space  321  between the partial first body  310  and the partial second body  320  that is at least initially unenclosed, with an interior  311  of the partial first body  310  that is also at least initially unenclosed (block  202 ) and coupling a second fluid system  340  with the space  321  (block  203 ). In accordance with embodiments, the partial first body  310  can include sidewalls, a closed end at one end of the sidewalls and an open end at the other end of the sidewalls. Similarly, the partial second body  320  can include sidewalls, a closed end at one end of the sidewalls that corresponds to the closed end of the partial first body  310  and an open end at the other end of the sidewalls that corresponds to the open end of the partial first body  310 . The method further includes inserting ahead  351  of a plunger  350  with a rod  352  connected thereto into the interior  311  of the partial first body  310  (block  204 ) such that the rod  352  extends away from the head  351  and out of the interior  311  and the space  321 . In addition, the method includes sliding a first snout  361  over the rod  352  and into the partial first body  310  at the open end to enclose the interior  311  (block  205 ) and sliding a second snout  362  over the rod  352  and into the partial second body  320  at the open end to enclose the space  321  (block  206 ). 
     In accordance with embodiments, the method can also include additively manufacturing at least the partial first body  310  and the partial second body  320  prior to the arranging of block  201  (block  207 ). This additive manufacturing can be achieved by any additive manufacturing or three-dimensional (3D) printing processes. Also, the method can include arranging first seals  371  between the head  351  and the partial first body  310 , arranging second seals  372  between the first snout  361  and the rod  352  and arranging third seals  373  between the second snout  362  and the rod  352  (block  208 ) and constraining movement of the partial first body  310  relative to the partial second body  320  (block  209 ) using stoppers  380 . 
     With reference to  FIGS.  4  and  5   , a method of assembling an actuator, such as the actuator  101  of  FIG.  1    described above, is provided. The method includes arranging a partial first body  510  with a first snout  511  within a partial second body  520  with a second snout  521  (block  401 ), coupling a first fluid system  530 , which is insulated from a space  522  between the partial first body  510  and the partial second body  520  that is at least initially unenclosed, with an interior  512  of the partial first body  510  that is also at least initially unenclosed (block  402 ) and coupling a second fluid system  540  with the space  522  (block  403 ). In accordance with embodiments, the partial first body  510  can include sidewalls, a closed end at one end of the sidewalls, which is closed by the first snout  511 , and an open end at the other end of the sidewalls. Similarly, the partial second body  520  can include sidewalls, a closed end at one end of the sidewalls, which is closed by the second snout  521  and which corresponds to the closed end of the partial first body  310 , and an open end at the other end of the sidewalls that corresponds to the open end of the partial first body  310 . The method further includes inserting a head  551  of a plunger  550  with a rod  552  connected thereto into the interior  512  of the partial first body  510  such that the rod  552  extends away from the head  551  and out of the interior  511  through the first snout  511  and out of the space  521  through the second snout  521  (block  404 ). In addition, the method includes attaching a first end cap  561  to the partial first body  510  at the open end thereof to enclose the interior  512  (block  405 ) and attaching a second end cap  562  to the partial second body  520  at the open end thereof to enclose the space  522  (block  406 ). 
     In accordance with embodiments, the method can also include additively manufacturing at least the partial first body  510  and the partial second body  520  prior to the arranging of block  401  (block  407 ). This additive manufacturing can be achieved by any additive manufacturing or three-dimensional (3D) printing processes. Also, the method can include arranging first seals  571  between the head  551  and the partial first body  510 , arranging second seals  572  between the first snout  511  and the rod  552  and arranging third seals  573  between the second snout  521  and the rod  552  (block  408 ) and constraining movement of the partial first body  510  relative to the partial second body  520  (block  409 ) using stoppers  580 . 
     Technical effects and benefits of the present disclosure are the provision of an actuator with integrated cooling passages. This eliminates heavy thermal blanketing and thus offers significant weight and envelope reduction for the actuator as well as reducing the tendency of actuator features being damaged during servicing. The integrated cooling passages could also allow actuators to operate in hotter ambient temperature environments that current technology allows. In addition, the actuator with integrated cooling passages could be used in reverse operations for normal operating conditions, where air is hotter than fuel, in which case the actuator could act as a fuel/air heat exchanger to cool air. 
     The corresponding structures, materials, acts, and equivalents of all means or step plus function elements in the claims below are intended to include any structure, material, or act for performing the function in combination with other claimed elements as specifically claimed. The description of the present disclosure has been presented for purposes of illustration and description, but is not intended to be exhaustive or limited to the technical concepts in the form disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the disclosure. The embodiments were chosen and described in order to best explain the principles of the disclosure and the practical application, and to enable others of ordinary skill in the art to understand the disclosure for various embodiments with various modifications as are suited to the particular use contemplated. 
     While the preferred embodiments to the disclosure have been described, it will be understood that those skilled in the art, both now and in the future, may make various improvements and enhancements which fall within the scope of the claims which follow. These claims should be construed to maintain the proper protection for the disclosure first described.