Patent Application
20170037879
The present disclosure relates to a cryogenic pump, and more particularly to a hydraulic actuator associated with the cryogenic pump.
A machine, such as a large mining truck or a locomotive, includes a dual fuel engine that uses more than one fuel to power various components of the machine. The dual fuel engine operates on a mixture of a gaseous fuel, such as natural gas, and a petroleum distillate fuel, such as diesel. The gaseous fuel is introduced into a cylinder of the engine at high pressure while combustion is still in progress by the petroleum distillate fuel.
A cryogenic pump is associated with the dual fuel engine for drawing and pressurizing the natural gas stored in a cryogenic storage tank. The cryogenic pump includes plungers to pressurize the natural gas. The plungers are driven by hydraulic actuators via a number of push rods. Sometimes, during actuation, hydraulic fluid that is used to actuate the hydraulic actuators may leak along the push rods into other components of the cryogenic pump. Leakage of the hydraulic fluid may cause the hydraulic fluid to mix with the natural gas. This may affect an overall working of the dual fuel engine.
U.S. Pat. No. 5,371,828 describes an improved vaporization system. The improved vaporization system includes an automated valve. The improved vaporization system also includes a positive displacement pumping system. The positive displacement pumping system includes a pair of pumps. The pair of pumps operate in opposition to one another to provide continuous and constant volumetric flow to an improved vaporizer. The improved vaporizer includes a stack of heated disks to flash vaporize the liquid. The valves are improved by providing one-way flow.
In one aspect of the present disclosure, a hydraulic actuator for a cryogenic pump is provided. The hydraulic actuator includes a piston. The hydraulic actuator also includes a base housing. The hydraulic actuator further includes a push rod assembly. The push rod assembly includes a tube guide. The push rod assembly also includes a push rod. The push rod is operatively coupled to the piston. The push rod is adapted to reciprocate within the tube guide. The hydraulic actuator also includes a sealing assembly having a hollow cylindrical configuration. The sealing assembly includes a first static seal portion at one end of the sealing assembly. The first static seal portion being connected to the base housing. The sealing assembly also includes a second static seal portion at another end of the sealing assembly. The second static seal portion is connected to the push rod. The sealing assembly further includes an expandable annular bellow extending between the first and second static seal portions. The sealing assembly is adapted to prevent flow of a first fluid in a first direction.
Other features and aspects of this disclosure will be apparent from the following description and the accompanying drawings.
Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or the like parts. Also, corresponding or similar reference numbers will be used throughout the drawings to refer to the same or corresponding parts.
Referring to
The engine referred to herein may embody a reciprocating dual fuel engine. The dual fuel engine may operate on a mixture of the gaseous fuel, such as the natural gas, and a petroleum distillate fuel, such as diesel. The dual fuel engine may embody a compression or spark ignition engine. Alternatively, the engine may embody any engine that uses pressurized gaseous natural gas, without limiting the scope of the disclosure.
Further, the engine is mounted on the machine that may be a stationary machine or a mobile machine associated with an industry such as, mining, construction, farming, transportation, or any other industry known in the art. The machine may be an earth moving machine, such as a wheel loader, an off-highway truck, a motor grader, or any other suitable earth moving machine. The machine may also be an on-highway truck, a passenger vehicle, etc.
Those skilled in the art will appreciate that the cryogenic pump 10 of the present disclosure is not limited to applications involving the pumping of the natural gas, or, more particularly, engine fuel delivery systems. Instead, the cryogenic pump 10 of the present disclosure may be used in any application involving the pumping of a cryogenic liquid.
The cryogenic pump 10 includes a warm end assembly 12 and a cold end assembly 14. The cold end assembly 14 is disposed opposite to the warm end assembly 12. The warm end assembly 12 forms an upper portion of the cryogenic pump 10. The warm end assembly 12 includes components that are intended to drive the cryogenic pump 10. The components of the warm end assembly 12 may be made from materials rated for cryogenic service. The warm end assembly 12 and its components will now be described in greater detail with reference to
The top housing 20 includes a fluid inlet 30. The fluid inlet 30 is fluidly coupled to a fluid supply (not shown). Further, the top housing 20 includes a number of spool valve assemblies 32. The spool valve assemblies 32 pressurizes a first fluid entering through the fluid inlet 30. The spool valve assemblies 32 introduce the pressurized first fluid into a piston cavity (not shown) of the piston housing 22. A lower end of the top housing 20 is coupled to an upper end the piston housing 22. Further, a lower end of the piston housing 22 is coupled to an upper end of the base housing 26. The piston housing 22 and the base housing 26 define the fluid reservoir 24. The fluid reservoir 24 houses the first fluid. In the illustrated example, the first fluid is a hydraulic fluid. The top housing 20, the piston housing 22, and the base housing 26 are coupled to one another via a number of first fastening members 36. The first fastening members 36 may include any one of a screw, bolt, rivet, pin, etc.
Further, the cold end assembly 14 forms a lower portion of the cryogenic pump 10. The cold end assembly 14 includes components that are intended to come in contact with the second fluid. The components of the cold end assembly 14 may be constructed from materials rated for cryogenic service. The cold end assembly 14 and its components will be now described in greater detail with reference to
The cold end assembly 14 includes a number of heads 40 (shown in
Referring to
The cryogenic pump 10 includes an intermediate structure 16. The intermediate structure 16 extends between the warm end assembly 12 and the cold end assembly 14. The intermediate structure 16 includes components that are intended to actuate the components in the cold end assembly 14. The intermediate structure 16 and its components will be described in greater detail with reference to
Referring to
The cryogenic pump 10 includes a number of hydraulic actuators 56. In one example, the cryogenic pump 10 includes six hydraulic actuators 56. Alternatively, the cryogenic pump 10 may include any number of hydraulic actuators 56, without limiting the scope of the disclosure. One of the hydraulic actuators 56 will now be explained in detail below. However, it should be noted that the description is equally applicable to other hydraulic actuators 56, without limiting the scope of the disclosure.
Referring to
As shown in
Referring now to
Referring now to
As shown in
The sealing assembly 66 includes an expandable annular bellow 72. The bellow 72 is disposed between the first static seal portion 68 and the second static seal portion 70. The bellow 72 acts as a biasing member during a reciprocating motion of the hydraulic actuator 56. More particularly, the bellow 72 provides a biasing force to the first push rod 62 during the reciprocating motion of the hydraulic actuator 56. Components of the sealing assembly 66 may be manufactured from variety of materials including, but not limited to, stainless steel, polytetrafluoroethylene (PTFE), etc. In an example, where the sealing assembly 66 is made of PTFE, the sealing assembly 66 may include an additional spring (not shown) disposed between the first static seal portion 68 and the second static seal portion 70 to provide a required amount of the biasing force. It should be noted that the sealing assembly 66 is associated with each of the hydraulic actuators 56 of the cryogenic pump 10.
Referring now to
Further, the sealing assembly 76 includes an expandable annular bellow 82. The bellow 82 is disposed between the first static seal portion 78 and the second static seal portion 80. The bellow 82 acts as a biasing member during the reciprocating motion the plunger 74. More particularly, the bellow 82 provides a biasing force to the plunger 74 during the reciprocating motion of the hydraulic actuator 56. Components of the sealing assembly 76 are manufactured from variety of materials including, but not limited to, stainless steel, polytetrafluoroethylene (PTFE), etc. In an example, where the sealing assembly 76 is made of PTFE, the sealing assembly 76 may include an additional spring (not shown) disposed between the first static seal portion 78 and the second static seal portion 80 to provide a required amount of the biasing force. It should be noted that the sealing assembly 76 is associated with each of the hydraulic actuators 56 of the cryogenic pump 10. Further, in some examples, the hydraulic actuators 56 may omit the sealing assembly 76, and only include the sealing assembly 66, without limiting the scope of the present disclosure.
The present disclosure relates to the hydraulic actuator 56 of the cryogenic pump 10 that may be associated with various fluid pumping systems used in industries, such as mining, construction, farming, etc. Moreover, the cryogenic pump 10 may be used in any application requiring the pumping of cryogenic fluids. For example, the cryogenic pump 10 of the present disclosure has particular applicability to the pumping of the natural gas, such as LNG, at high pressures in fuel delivery systems for engines associated with machines, such as, locomotives and large mining trucks.
Referring to
Referring to
The disclosed sealing assemblies 66, 76 prevent leakage and mixing of the first fluid and the second fluid in the cryogenic pump 10. Further, the sealing assemblies 66, 76 prevent foreign matter from reaching the components of the hydraulic actuators 56. The sealing assemblies 66, 76 eliminate usage of dynamic and sliding sealing components that are prone to wear and tear during operation. Thus, the disclosed sealing assemblies 66, 76 provide a lower cost and high performance sealing assembly for the cryogenic pump 10.
While aspects of the present disclosure have been particularly shown and described with reference to the embodiments above, it will be understood by those skilled in the art that various additional embodiments may be contemplated by the modification of the disclosed machines, systems and methods without departing from the spirit and scope of what is disclosed. Such embodiments should be understood to fall within the scope of the present disclosure as determined based upon the claims and any equivalents thereof.
