Patent Application
20250198397
The present disclosure relates to a fuel pump, a remanufactured yoke for the fuel pump, and a method of remanufacturing a yoke for the fuel pump.
Internal combustion engines are equipped with a hydraulically-actuated fuel injection system (HEUI fuel system) that employs a fuel pump for providing actuating fluid at elevated pressures to injectors of the engines. The fuel pump includes a number of pistons, a housing, and a yoke. The pistons and the yoke are received within the housing. The yoke is pivotally disposed in the housing and is movable through a range of angular positions for controlling the stroke length of the pistons, thereby controlling a fluid output of the fuel pump.
The yoke may be subjected to wear and tear during operation of the fuel pump. The yoke is limited in lifetime due to premature wear and tear from operation. The yoke includes a layer of nitride which, if penetrated, renders the yoke unusable. As the yoke may be expensive, replacement of the entire yoke may increase servicing and replacement costs of the engine, which may not be desirable.
U.S. Pat. No. 5,704,272 describes an improved axial-piston energy converting device which is provided by utilizing a thin ceramic wear plate insert, having a typical thickness of only about 0.005 to 0.040 inches, as a cam surface secured by atmospheric pressure to an underlying support surface of a steel cam plate support structure. Attachment of the wear plate to the cam plate supporting surface is accomplished by polishing both a supporting surface of the cam plate, and a mating surface of the wear plate to a very smooth finish, and wiping a thin film of a fluid such as oil onto one of the polished surfaces prior to placing the wear plate onto the supporting surface. The highly polished surfaces, together with the light film of oil, result in a joint that is essentially air-tight. Atmospheric pressure acting on the cam surface of the wear plate serves to hold the wear plate tightly in place on the support surface in the same manner that a pair of Johansson blocks are held together if their highly polished surfaces mate.
In an aspect of the present disclosure, a remanufactured yoke for a fuel pump is provided. The remanufactured yoke includes a body having a base and a sidewall extending orthogonally from the base. The base and the sidewall together define a receiving space. The sidewall defines an inner surface facing the receiving space and an outer surface opposite the inner surface. The remanufactured yoke also includes a wear plate removably disposed within the receiving space defined by the base and the sidewall. The wear plate is in contact with the base of the body. The remanufactured yoke further includes a coupling member coupled with the body and the wear plate to prevent a rotational movement of the wear plate relative to the body.
In another aspect of the present disclosure, a fuel pump is provided. The fuel pump includes a pump housing. The fuel pump also includes a remanufactured yoke removably coupled to the pump housing and pivotable about a yoke axis. The remanufactured yoke includes a body having a base and a sidewall extending orthogonally from the base. The base and the sidewall together define a receiving space. The sidewall defines an inner surface facing the receiving space and an outer surface opposite the inner surface. The remanufactured yoke also includes a wear plate removably disposed within the receiving space defined by the base and the sidewall. The wear plate is in contact with the base of the body. The remanufactured yoke further includes a coupling member coupled with the body and the wear plate to prevent a rotational movement of the wear plate relative to the body.
In yet another aspect of the present disclosure, a method of remanufacturing a yoke for a fuel pump is provided. The method includes providing the yoke including a body. The body has a base and a sidewall extending orthogonally from the base. The base and the sidewall together define a receiving space. The method also includes removing a predetermined layer of material from the base of the body. The method further includes providing a wear plate having a thickness corresponding to a thickness of the predetermined layer of material removed from the base. The method includes disposing the wear plate within the receiving space defined by the base and the sidewall, such that the wear plate contacts the base of the body. The method also includes receiving a coupling member within the wear plate and the base. The method further includes preventing a rotational movement of the wear plate relative to the body based on receipt of the coupling member within the wear plate and the base.
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 like parts.
The engine system 100 includes one or more engine cylinders 102. Each engine cylinder 102 defines a cylinder bore 104 therethrough, a piston 106 slidably disposed within the cylinder bore 104, and a cylinder head 108 disposed on top of the engine cylinder 102. The piston 106 is operably coupled to a crankshaft 110 (shown in part) through a connecting rod 112. Although only one engine cylinder 102 is shown in
The engine system 100 includes a fuel injector 116 in fluid communication with the cylinder bore 104. The fuel injector 116 is supplied with a fuel that readily ignites at air pressures and temperatures achieved near a top of a compression stroke of the piston 106 within the cylinder bore 104. The fuel may include, for example, diesel, bio-diesel, dimethyl either (DME), kerosene, seed oils, and other fuels with similarly high cetane indices known by persons with ordinary skill in the art. The fuel injector 116 receives fuel via a fuel pump 200 (shown in
Referring now to
The fuel pump 200 also includes a remanufactured yoke 400 removably coupled to the pump housing 202 and pivotable about a yoke axis 402. Specifically, a core yoke 300 (as shown in
The remanufactured yoke 400 pivots about the yoke axis 402 but does not rotate about pump axis 206. The position of the remanufactured yoke 400 may be selectively adjustable to a range of angular positions between and inclusive of a minimum pump displacement and a maximum pump displacement, as per application requirements. An end cover portion 220 of the pump housing 202 has an intake port (not shown) through which actuating fluid enters piston cavities 222 and an output port 224 through which fluid exits the piston cavities 222.
Referring now to
Referring now to
The base 406 and the sidewall 408 together define a receiving space 410. The opening 412 may be formed by any material removal process, for example, drilling, milling, or laser processing. Further, the base 406 defines an opening 412 to at least partially receive a coupling member 414 (shown in
The sidewall 408 defines a pair of raised portions 422. Further, the sidewall 408 defines an inner surface 424 facing the receiving space 410 and an outer surface 426 opposite the inner surface 424. Furthermore, the inner surface 424 of the sidewall 408 defines a notch 428 proximal to the opening 412 in the base 406. Specifically, the notch 428 is defined on the inner surface 424 of one of the raised portions 422 of the sidewall 408. The notch 428 is in communication with the receiving space 410 and surrounds the opening 412. The notch 428 may be formed by any material removal process, for example, by drilling, milling, or laser processing,
Further, the remanufactured yoke 400 has a pair of posts 430 for supporting the remanufactured yoke 400 in a manner allowing pivoting about the yoke axis 402 (see
Referring now to
It should be noted that the wear plate 436 is made of a material that is similar in material properties, such as hardness, surface cleanliness, and surface texture, to the predetermined layer of material L1 that is removed from the core yoke 300. The wear plate 436 is made of a metallic material having a Rockwell hardness value of at least 45, without any limitations. In some examples, the wear plate 436 may have a Rockwell hardness value of 48 or 54, without any limitations. It should be noted that a hardness and the material of the wear plate 436 may vary based on application requirements. Further, the Rockwell hardness value of the wear plate 436 may be at least equal to or greater than a Rockwell hardness value of the body 404. In some examples, the Rockwell hardness value of the wear plate 436 may be at least equal to or greater than a Rockwell hardness value of the predetermined layer of material L1. In some examples, the wear plate 436 may be made of cast iron.
Further, the wear plate 436 defines a cut-out 438 to at least partially receive the coupling member 414 therein. The cut-out 438 has an arcuate shape herein. It should be noted that, when the wear plate 436 is received within the body 404, the wear plate 436 is rotated by 180 degrees from the orientation that is shown in
The wear plate 436 is annular in shape. Specifically, the wear plate 436 includes an annular body 440. The annular body 440 defines an inner plate surface 442 and an outer plate surface 444. The cut-out 438 in the wear plate 436 is defined at the outer plate surface 444. The wear plate 436 also defines a second central opening 446. The second central opening 446 is in communication with the inner plate surface 442.
Referring now to
The coupling member 414 is a dowel herein. Specifically, the coupling member 414 includes a metallic dowel. However, the coupling member 414 may include any other type of fastening member that couples the wear plate 436 with the body 404 to prevent any relative rotational movement therebetween. It should be noted that the wear plate 436 and the coupling member 414 may include a design different from what is illustrated and explained in this disclosure, as per application requirements. Further, the yoke 400 may include additional components in addition to those explained herein.
Referring now to
Furthermore, when the coupling member 414 is coupled with the body 404 and the wear plate 436, a portion of the coupling member 414 is received within and engages with the cut-out 438 of the wear plate 436 to prevent a rotation of the wear plate 436 with respect to the body 404. Moreover, when the coupling member 414 is coupled with the body 404 and the wear plate 436, a portion of the coupling member 414 is received within the opening 412 in the body 404. In some examples, the coupling member 414 may be coupled with the base 406 of the body 404 by an interference fit. In other examples, the coupling member 414 may have external threads (not shown) and a slot (not shown) formed in its exposed end, the slot being sized to accommodate a screwdriver blade for rotating the coupling member, and the base 406 may have internal threads (not shown) to removably couple the coupling member 414 with the base 406.
It is to be understood that individual features shown or described for one embodiment may be combined with individual features shown or described for another embodiment. The above described implementation does not in any way limit the scope of the present disclosure. Therefore, it is to be understood although some features are shown or described to illustrate the use of the present disclosure in the context of functional segments, such features may be omitted from the scope of the present disclosure without departing from the spirit of the present disclosure as defined in the appended claims.
The present disclosure is related to the remanufactured yoke 400. The remanufactured yoke 400 includes the wear plate 436 that can be disposed after removal of the damaged portions 302 from the initial/core yoke 300. For example, when a top surface of the core yoke 300 becomes worn or damaged, the wear plate 436 may be installed to allow reuse of the core yoke 300 as the remanufactured yoke 400. Specifically, the layer of material L1 containing the damaged portions 302 may be removed from the core yoke 300 on initial salvage reclaim, after which the wear plate 436 and the coupling member 414 may be coupled with the body 404.
Further, the wear plate 436 and/or the coupling member 414 may be replaced once damaged. Thus, the wear plate 436 may act as a sacrificial component that can be replaced on damage. This approach may reduce service and maintenance costs, as only the wear plate 436 may have to be replaced instead of replacing the entire yoke. The wear plate 436 has a simple design and is easy to assemble, which may improve serviceability and maintenance of the fuel pump 200. Further, the wear plate 436 includes the cut-out 438 that acts as an alignment feature for accurately positioning the wear plate 436 relative to the body 404, thereby eliminating requirement of alignment features in the wear plate 436 or additional tools/techniques for alignment.
At step 804, the predetermined layer of material L1 is removed from the base 406 of the body 404. At step 806, the coupling member 414 is received within the base 406. At step 808, the wear plate 436 having the thickness T2 corresponding to the thickness T1 of the predetermined layer of material L1 removed from the base 406 is provided.
At step 810, the wear plate 436 is disposed within the receiving space 410 defined by the base 406 and the sidewall 408, such that the wear plate 436 contacts the base 406 of the body 404 and the coupling member 414. At step 812, the rotational movement of the wear plate 436 relative to the body 404 is prevented based on receipt of the coupling member 414 within the wear plate 436 and the base 406.
The method 800 further includes a step (not shown) at which the opening 412 is provided in the base 406 of the body 404. Further, the wear plate 436 defines the cut-out 438. Furthermore, the step of disposing the wear plate 436 within the receiving space 410 defined by the base 406 and the sidewall 408 further includes a step (not shown) at which the cut-out 438 in the wear plate 436 is aligned with the coupling member 414. The wear plate 436 includes the annular body 440. The annular body 440 defines the inner plate surface 442 and the outer plate surface 444. The cut-out 438 in the wear plate 436 is defined at the outer plate surface 444. Further, the wear plate 436 is made of the metallic material having the Rockwell hardness value of at least 45.
Further, the sidewall 408 defines the inner surface 424 facing the receiving space 410 and an outer surface 426 opposite the inner surface 424. Furthermore, the method 800 includes a step (not shown) at which the notch 428 is provided on the inner surface 424 of the sidewall 408 to allow receipt of the coupling member 414 within the opening 412 in the base 406. The notch 428 is proximal to the opening 412 in the base 406.
The method 800 described herein may be cost effective, simple, and a time-effective method of remanufacturing the yoke 400, without requiring additional/complex set-ups.
It may be desirable to perform one or more of the steps shown in
Unless explicitly excluded, the use of the singular to describe a component, structure, or operation does not exclude the use of plural such components, structures, or operations or their equivalents. The use of the terms “a” and “an” and “the” and “at least one” or the term “one or more,” and similar referents in the context of describing the invention (especially in the context of the following claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. The use of the term “at least one” followed by a list of one or more items (for example, “at least one of A and B” or one or more of A and B″) is to be construed to mean one item selected from the listed items (A or B) or any combination of two or more of the listed items (A and B; A, A and B; A, B and B), unless otherwise indicated herein or clearly contradicted by context. Similarly, as used herein, the word “or” refers to any possible permutation of a set of items. For example, the phrase “A, B, or C” refers to at least one of A, B, C, or any combination thereof, such as any of: A; B; C; A and B; A and C; B and C; A, B, and C; or multiple of any item such as A and A; B, B, and C; A, A, B, C, and C; etc.
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 work machine, systems and methods without departing from the spirit and scope of the disclosure. Such embodiments should be understood to fall within the scope of the present disclosure as determined based upon the claims and any equivalents thereof.
