Patent Application
20180045118
This invention generally relates to a pressure regulating valve, and more particularly, to a sleeve of a pressure regulating valve for use in a fuel line of an aircraft engine.
Gas turbine engines are typically used to power an aircraft. A fuel system provides fuel to various portion of the gas turbine engine. The fuel system includes various valves such as a pressure regulating valve, a high pressure relief valve, and a filter bypass valve that cooperate with each other to supply fuel to the gas turbine engine in a controller and accurate manner.
During operation of the fuel system, the pressure regulating valve commonly experiences a rotational force due to the fluid flow there through. In conventional assemblies, an anti-rotation device is positioned between the spool and the sleeve of the pressure regulating valve to minimize the effects of the rotational force, or not included if fluid housing does not cause flow rotation. The flow through the valve, and any rotational forces resulting from the flow, are dependent on the valves position within the fluid housing. As a result, the pressure regulating valves arranged within the fluid housing are not interchangeable with other systems because the anti-rotation device (or lack thereof) of each is dependent on the housing arrangement.
According to one embodiment, a sleeve for a pressure regulating valve includes a sleeve body surrounding a central axis and defined by an overall length extending from a first end to a second end. The sleeve body has a central sleeve bore extending from the first end to the second end. The sleeve body includes a first set of windows circumferentially spaced about the central axis and a second set of windows axially spaced from the first set of windows and circumferentially spaced about the central axis. Each window of the first set of windows is defined by a plurality of small holes.
According to another embodiment, a sleeve for a pressure regulating valve includes a sleeve body surrounding a central axis and defined by an overall length extending from a first end to a second end. The sleeve body has a central sleeve bore extending from the first end to the second end. The sleeve body includes a first set of windows circumferentially spaced about the central axis and a second set of windows axially spaced from the first set of windows and circumferentially spaced about the central axis. Each window of the first set of windows radially aligns a fluid flow there through.
According to another embodiment, a pressure regulating valve includes a valve housing defining an internal bore and having a valve inlet to receive a fluid at a first pressure and a fluid outlet to return fluid to a pump. A sleeve surrounds a central axis and is defined by an overall sleeve length extending from a first sleeve end to a second sleeve end. The sleeve body has a central sleeve bore. The sleeve includes a set of windows circumferentially spaced about the central axis adjacent the valve inlet. Each window of the set of windows is defined by a plurality of small holes. A piston is received within the central sleeve bore. A spring assembly biases the piston within the sleeve to a valve closed position. When the pressure at the valve inlet is greater than a spring biasing load, the piston moves to a valve open position to provide fluid to the valve outlet.
The subject matter, which is regarded as the invention, is particularly pointed out and distinctly claimed in the claims at the conclusion of the specification. The foregoing and other features, and advantages of the invention are apparent from the following detailed description taken in conjunction with the accompanying drawings in which:
An example of a pressure regulating valve 38, such as used in the fuel supply system 20 is illustrated in more detail in
The valve housing 50 extends from an open first end 64 to an enclosed second end 66. The sleeve 52 is inserted through the open first end 64 and is held fixed within the valve housing 50 by inwardly, or radially, extending seat portions 68. The seat portions 68 cooperate with the sleeve 52 to define the chambers. The sleeve 52 is positioned substantially within the first 58 and second 60 chambers. The enclosed second end 66 of the valve housing 50 includes a recess 70 that receives a first end 72 of the sleeve 52 in a press-fit. A seal 74 is provided between an outer surface of the sleeve 52 and an inner surface of the recess 70.
An outer surface of the second end 76 of the sleeve 52 is sealed against one seat portion 68 with a seal 78. An outer surface of a center portion 80 of the sleeve 52 is sealed against another seat portion 68 with a seal 82. The sleeve 52 comprises a cylindrical body that is open at each sleeve end 72, 76 to define a central sleeve bore 84.
The sleeve 52 includes a first set of windows 86 that are positioned within the first chamber 58 and a second set of windows 88 that are positioned within the second chamber 60. The first set of windows 86 is in fluid communication with the pressure inlet 54 and the second set of windows 88 is in fluid communication with the pressure outlet 56.
The spool or piston 42 slides within the sleeve bore 84. The piston 42 extends from a first end 90 to a second end 92. An outer surface of the first end 90 abuts against an inner surface of sleeve 52 and also slides along the inner surface of the sleeve 52 at the first sleeve end 72. An outer surface of the second end 92 slides along an inner surface of the sleeve 52 and also abuts the sleeve 52 at the second sleeve end 76. The piston 42 includes a piston chamber 94 at the first end 90 that is at a fluid pressure P1 corresponding to the fluid pressure at the pressure inlet 54. The piston 42 includes a spring chamber 96 at the second end 92 that receives one end of the spring 44.
The piston 42 includes a plurality of recessed areas 98, referred to as “buckets,” which are formed about an outer circumference of the piston 42. Enclosed bottom surfaces of the recessed areas 98 are radially inward of a piston outer surface 100 that contacts the sleeve 52. The recessed areas 98 at least partially overlap the center portion 80 of the sleeve 52 when the piston 42 is fit within the sleeve 52. When the pressure regulating valve 38 is in the closed position (
The closure 40 is positioned within the third chamber 62 of the valve housing 50 and includes a flange portion 102 that is seated against an end face of the valve housing 50 to close off the open end of the valve housing 50. The closure 40 defines an internal cavity 104 that receives the spacer 46, adjusting screw 48, and spring 44.
An annulus 106 is formed between an outer surface of the closure 40 and an inner surface of the valve housing 50. A separate pressure inlet 108 supplies pressure to the annulus 106 at a second pressure P2. The closure 40 includes a plurality of ports 110 that are formed about an outer circumference of a first end 112 of the closure 40. The ports 110 fluidly connect the annulus 106 with the internal cavity 104 of the closure 40.
The spacer 46 includes an elongated body portion 118 with a spring seat flange 120 at one end. The elongated body portion 118 is received within the spring 44 such that one end of the spring 44 abuts against the spring seat flange 120. An optional washer 122 (
The adjusting screw 48 includes an end 126 that is inserted into the opening 124 of the spacer 46. The adjusting screw 48 includes a flange 128 that is seated against the spring seat flange 120 when the end 126 is received within the opening 124. The adjusting screw 48 has an elongated body 130 that extends from the flange 128 to a threaded end 132 that receives a nut 134. A washer 152 is utilized with the nut 134 to prevent axial movement during operation.
The closure 40 includes end face portion 114 with a center bore 116. The elongated body 130 of the adjusting screw 48 extends through the bore 116 into an outer cavity 138 formed within a closure extension portion 154 that extends outwardly from the end face portion 114. The nut 134 is tightened against the end face portion 114 within the outer cavity 138 to adjust the spring force of the spring 44. A plug 140 is inserted into the closure extension portion 154 to seal the outer cavity 138.
The spring force and the fluid pressure from the separate pressure inlet 108 cooperate to bias the piston 42 to the closed position. When the pressure at the pressure inlet 200 overcomes the combination of the spring force and pressure from pressure inlet 108, the piston moves the valve 38 to the open position to fluidly connect the pressure inlet 54 to the outlet 56. It should be understood that the pressure regulating valve illustrated and described herein is intended as an example only, and pressure regulating valves having other configurations are within the scope of the disclosure.
Referring now to
The plurality of small through holes 200 that define a window 86 may be substantially uniform, or alternatively, may vary in size and/or shape. Although the small holes 200 are illustrated as being circular in shape, holes having another shape, such as oval or square for example, are contemplated herein. In the illustrated, non-limiting embodiment, the plurality of small holes 200 that define each window 86 are arranged in rows and/or columns with adjacent rows or columns being staggered or offset from one another. In addition, the pluralities of small holes 200 that define each of the first set of windows spaced about the periphery of the sleeve 52 may be substantially uniform or may have different configurations. In the illustrated, non-limiting embodiment, the small holes 200 that define each first window 86 are separated from one another by a distance. However, embodiments where the small holes 200 extend continuously about the entire periphery of the sleeve 52 to evenly redistribute the flow are also considered within the scope of the disclosure.
The small holes 200 restrict the amount and direction of fluid flow there through. In an embodiment, the small holes 200 have a length to diameter ratio between about 1 and 2. By replacing the large opening with a plurality of small holes 200, each of the first set of windows 86 is intended to straighten or radially align the fluid flow as it passes to the pressure inlet 54. As a result, the rotational forces acting on the pressure regulating valve 38 are reduced, and the need for an anti-rotation component is eliminated. Consequently, a pressure regulator valve 38 having first windows 86 defined by a plurality of small openings 200 may be used interchangeably between systems with different fluid housings.
While the invention has been described in detail in connection with only a limited number of embodiments, it should be readily understood that the invention is not limited to such disclosed embodiments. Rather, the invention can be modified to incorporate any number of variations, alterations, substitutions or equivalent arrangements not heretofore described, but which are commensurate with the spirit and scope of the invention. Additionally, while various embodiments of the invention have been described, it is to be understood that aspects of the invention may include only some of the described embodiments. Accordingly, the invention is not to be seen as limited by the foregoing description, but is only limited by the scope of the appended claims.
