Engine and methods for removing fuel pump from engine

Abstract

This invention relates to an engine and a method for removing a fuel pump from an engine. A method for removing a fuel pump from an engine includes the steps of: removing a retaining nut connected to a drive shaft of the fuel pump, the drive shaft extending through a central opening in a sprocket, the sprocket being connected to a first chain assembly that drives a camshaft of the engine; and removing the fuel pump from the engine without removing the flywheel housing, the first chain assembly, or the sprocket.

Description

[0001] This application is a divisional application of the invention patent application filed on May 23, 2019, with application number 201980033517.1 (international application number PCT / IB2019 / 054303) and entitled "System and method for a fixed sprocket in an engine". Technical Field

[0002] The present invention generally relates to sprockets driving engine components, and more specifically, to systems and methods for mounting sprockets on an engine to allow removal of sprocket-driven engine components. Background Technology

[0003] In many engine manufacturing processes, engine components such as fuel pumps or air compressors powered by crankshaft-driven sprockets must be installed before the chain system and flywheel housing connected to the engine components are installed. This results in a suboptimal assembly sequence. In many engine repair and maintenance situations, engine components cannot be removed without first removing the engine from the vehicle and then removing the flywheel housing and chain assembly connected to the sprockets. This process incurs significant costs in terms of labor and engine downtime. Therefore, a system and method for solving these problems is desired. Summary of the Invention

[0004] In one embodiment, this disclosure provides a captive sprocket system for an engine, comprising: a sprocket including a first sprocket gear, a second sprocket gear, and a retaining disc having a diameter and a thickness; a cylinder block having a plurality of threaded bosses and a bore with a central opening, the plurality of threaded bosses together forming an axial support surface and a radial positioning surface, the axial support surface and the radial positioning surface being sized to receive the retaining disc of the sprocket to support and position the sprocket; and a plurality of retaining screws configured to be received by the plurality of threaded bosses, each retaining screw having a head with a lower surface, the lower surface covering the retaining disc and retaining the sprocket in the bore when the retaining screw is received by the threaded boss; wherein the thickness of the retaining disc is less than the distance between the lower surface of the head of the retaining screw and the axial support surface formed by the plurality of threaded bosses, and the diameter of the retaining disc is less than the diameter of the radial positioning surface formed by the plurality of threaded bosses, thereby allowing the sprocket to rotate within the bore. In one aspect of this embodiment, the sprocket includes a central opening having a diameter sized to receive a drive shaft of an engine component, either a fuel pump or an air compressor. A variation of this aspect further includes a retaining nut configured to screw onto a threaded end of the drive shaft, the retaining nut having an outer diameter larger than the diameter of the central opening of the sprocket. In another aspect, the first sprocket gear is configured to engage with a first chain assembly coupled to a camshaft of the engine. In a variation of this aspect, the second sprocket gear is configured to engage with a second chain assembly driven by the crankshaft of the engine. Another variation includes a flywheel housing having an inlet / outlet opening that provides access to the retaining nut when the sprocket is held in the hole. In other variations, the flywheel housing further includes an inlet / outlet cover that removably covers the inlet / outlet opening. In another aspect of this embodiment, at least one of the first sprocket, the second sprocket, and the retaining disc is made of a first piece of material, and at least another of the first sprocket, the second sprocket, and the retaining disc is formed of a second piece of material separate from the first piece of material.

[0005] In another embodiment, this disclosure provides a method for removing a fuel pump from an engine, the method comprising the steps of: removing an inlet / outlet cover of a flywheel housing; removing a retaining nut coupled to a drive shaft of the fuel pump, the drive shaft extending through a central opening in a sprocket, the sprocket being coupled to a first chain assembly driving a camshaft of the engine; and removing the fuel pump from the engine without removing the flywheel housing, the first chain assembly, or the sprocket. In one aspect of this embodiment, the retaining nut has an outer diameter larger than the diameter of the central opening in the sprocket. In another aspect, the sprocket includes a first sprocket gear and a second sprocket gear, the first sprocket gear being configured to engage with the first chain assembly, and the second sprocket gear being configured to engage with a second chain assembly driven by the crankshaft of the engine. In a variation of this aspect, the sprocket includes a retaining disc, at least one of the first sprocket gear, the second sprocket gear, and the retaining disc being formed of a first piece of material, and at least another of the first sprocket gear, the second sprocket gear, and the retaining disc being formed of a second piece of material separate from the first piece of material. In another variation, the sprocket includes a retaining disc having a diameter and a thickness, the diameter of the retaining disc being smaller than the diameter of a radially locating surface formed by a plurality of threaded bosses formed on the engine, and the thickness of the retaining disc being smaller than the distance between the lower surface of a plurality of fixing screws connected to the plurality of threaded bosses and the axially supporting surface formed by the plurality of threaded bosses.

[0006] In another embodiment, this disclosure provides an engine comprising: a sprocket including a retaining disc having a diameter and a thickness; a bore having a central opening; a plurality of threaded bosses disposed adjacent to the bore, the plurality of threaded bosses together forming an axial support surface and a radial positioning surface, the axial support surface and the radial positioning surface being sized to receive the retaining disc of the sprocket to support and position the sprocket; and a plurality of retaining screws configured to be received by the plurality of threaded bosses, each retaining screw having a head with a lower surface, the lower surface covering the retaining disc and retaining the sprocket in the bore when the retaining screw is received by the threaded boss; wherein the thickness of the retaining disc is less than the distance between the lower surface of the head of the retaining screw and the axial support surface formed by the plurality of threaded bosses, and the diameter of the retaining disc is less than the diameter of the radial positioning surface formed by the plurality of threaded bosses, thereby allowing the sprocket to rotate within the bore. One aspect of this embodiment also includes a camshaft and a first chain assembly coupled to the camshaft, the sprocket including a first sprocket gear configured to mesh with the first chain assembly to drive rotation of the camshaft. A variation of this aspect further includes a crankshaft and a second chain assembly coupled to the crankshaft, the sprocket including a second sprocket gear configured to mesh with the second chain assembly, the crankshaft driving rotation of the sprocket via the second chain assembly. Another aspect includes a cylinder block, the bore and the plurality of threaded bosses formed on the cylinder block. Yet another aspect of this embodiment includes an engine component having a drive shaft, the sprocket including a central opening having a diameter sized to receive the drive shaft. A variation of this aspect further includes a retaining nut configured to screw onto a threaded end of the drive shaft, the retaining nut having an outer diameter larger than the diameter of the central opening of the sprocket. Another variation includes a flywheel housing having an inlet / outlet opening that provides access to the retaining nut when the sprocket is held in the hole. Attached Figure Description

[0007] The foregoing features and other features of this disclosure, and how they are obtained, will become clearer and the disclosure itself will be better understood by referring to the following description of embodiments of this disclosure in conjunction with the accompanying drawings, wherein:

[0008] Figure 1 This is a perspective view of a sprocket according to one embodiment of the present disclosure;

[0009] Figure 2 It is a three-dimensional view of a part of the cylinder block;

[0010] Figure 3A This is a perspective view of a threaded boss according to one aspect of this disclosure;

[0011] Figure 3B yes Figure 3A Side view of the threaded boss;

[0012] Figure 4 It is supported by Figure 2 The cylinder block bore Figure 1 A 3D view of the sprocket;

[0013] Figure 5 It is supported on a platform with chain components installed. Figure 2 The cylinder block bore Figure 1 A side sectional view of the sprocket;

[0014] Figure 6 It is supported on a platform with chain components installed. Figure 2 The cylinder block bore Figure 1 A 3D view of the sprocket;

[0015] Figure 7 Is with Figure 6 A similar 3D view, but showing the fuel pump installed in the cylinder block;

[0016] Figure 8 It is along Figure 7 The side sectional view taken by line AA;

[0017] Figure 9A Is with Figure 8 Similar side sectional view;

[0018] Figure 9B yes Figure 9A A magnified view of a portion;

[0019] Figure 10 This is a side plan view of a flywheel housing according to one embodiment of the present disclosure;

[0020] Figure 11 It has the inlet and outlet covers removed. Figure 10 Side view of the flywheel housing;

[0021] Figure 12 The fuel pump is installed in the cylinder block. Figure 11 A magnified view of a portion; and

[0022] Figure 13 It removes the fuel pump and Figure 12 A similar view.

[0023] While the invention is susceptible to various modifications and alternatives, specific embodiments have been shown by way of example in the accompanying drawings and are described in detail below. However, the invention is not intended to be limited to the specific embodiments described. Rather, the invention is intended to cover all modifications, equivalents, and alternatives that fall within the scope of the invention as defined in the appended claims. Detailed Implementation

[0024] The terms “connected,” “connected,” and variations thereof are used to include arrangements in which two or more components are in direct physical contact with each other, and arrangements in which two or more components are not in direct contact with each other (e.g., components are “connected” via at least a third component) but still cooperate or interact with each other. Furthermore, the terms “connected,” “connected,” and variations thereof refer to any connection of mechanical parts known in the art, including but not limited to connections made with bolts, screws, threads, magnets, electromagnets, adhesives, friction clamps, welds, snaps, fixtures, etc.

[0025] Throughout this disclosure and claims, references to various components or features are made using numerical terms such as “first” and “second”. Such use is not intended to indicate an order of components or features. Rather, numerical terms are used to assist the reader in identifying the component or feature being referenced and should not be interpreted narrowly as providing a specific order of components or features.

[0026] Figure 1 A sprocket according to one embodiment of the present disclosure is depicted. The sprocket 10 generally includes a first sprocket gear 12, a second sprocket gear 14, and a retaining disc 16. The first sprocket gear 12 includes a generally cylindrical body 13 having an upper surface 18 and a plurality of teeth 20 formed around its periphery. The second sprocket 14 is axially disposed between the first sprocket gear 12 and the retaining disc 16, and includes a generally cylindrical body 22 having an upper surface 24 and a plurality of teeth 26 formed around its periphery. The diameter of the teeth 26 of the second sprocket gear 14 is larger than the diameter of the teeth 20 of the first sprocket gear 12. The second sprocket gear 14 also includes a plurality of openings 28 configured to cooperate with a puller for separating the sprocket 10 from a connectable pump, as described below. The retaining disc 16 includes an upper surface 30, an outer surface 32 defining the diameter of the retaining disc 16, and a lower surface 34. The distance between the upper surface 30 and the lower surface 34 defines the thickness of the retaining disc 16. The diameter of the retaining disc 16 is larger than the diameter formed by the teeth 26 of the second sprocket 14. The first sprocket 12 and the second sprocket 14 include an inner surface 36 defining a central bore 38. The central bore 38 communicates with a central opening 40 of the sprocket 10 and includes a shoulder 42 surrounding the central opening 40.

[0027] It should be understood that in different embodiments, the sprocket 10 may be formed from a single piece of material or may consist of two or more components. For example, in one embodiment, the retaining disc 16 may be manufactured separately from the first sprocket gear 12 and the second sprocket gear 14. This configuration may have the benefit of preventing the retaining disc 16 from interfering with the tooth hardening process of the sprocket gear teeth. In another example, the retaining disc 16 may be manufactured separately to allow for careful control of the thickness and diameter of the retaining disc. In yet another embodiment, the retaining disc 16 may be rigidly mounted to the cylinder block, with an operating clearance at the permanent assembly interface between the retaining disc and the sprocket gear. In this example, the retaining disc 16 may be clamped in place (by a retaining screw described below), and the sprocket gear may rotate freely relative to the retaining disc. In other examples, the retaining disc 16, the first sprocket gear 12, and the second sprocket gear 14 are manufactured separately and assembled together for use.

[0028] Now refer to Figure 2 The sprocket 10 is configured to be disposed within a bore 44 formed in the cylinder block 46 of the engine. The bore 44 forms a central opening 48. A plurality of threaded bosses 50 are disposed within the bore 44 and spaced apart around the periphery of the central opening 48. Figure 3A and 3B The threaded boss 50 is shown in detail.

[0029] like Figure 3A and Figure 3B As shown, each threaded boss 50 includes a generally cylindrical body 52 with a screw opening 54. The screw opening 54 includes a countersunk hole 56 communicating with a threaded hole 58, which is sized to receive a retaining screw, as further described below. Each threaded boss 50 also includes an axial support wall 60 and a radial locating wall 62. Figure 2 As best shown, the axial support walls 60 of the plurality of threaded bosses 50 are located in a common plane and together form an axial support surface for the sprocket 10. The radial locating walls 62 of the plurality of threaded bosses 50 define a diameter that is larger than and concentric with the central opening 48, and together form a radial locating surface.

[0030] Figure 4 A sprocket 10 is shown mounted in a bore 44 of a cylinder block 46. As shown, multiple threaded bosses 50 are fitted with multiple retaining screws 64. In this way, the sprocket 10 is held within the bore 44, as further described below.

[0031] Now refer to Figure 5A cross-sectional view of a sprocket 10 mounted in a bore 44 of a cylinder block 46 is shown. A retaining screw 64 mounted in a threaded boss 50 is shown. A chain assembly 66 operatively engaged with the teeth 26 of a second sprocket gear 14 is shown. Additionally, an adapter 68 is shown, which is mounted to the cylinder block 46 to allow mounting of any of several different engine components, such as a fuel pump (described herein) or an air compressor. The adapter 68 includes a central opening 70 that allows the drive shaft of the engine component (described below) to pass through the adapter 68, the central opening 48 of the bore 44, and the central opening 40 of the sprocket 10. As further described below, the drive shaft of the engine component is fixed to the sprocket 10 and is provided with rotational power (to drive the operation of the engine component) due to the rotation of the sprocket 10.

[0032] Figure 6 This is another view of the sprocket 10 mounted on the cylinder block 46, wherein the chain assembly 66 is coupled between the drive gear assembly 72 of the engine crankshaft (not shown) and the second sprocket gear 14 of the sprocket 10. As shown, the chain assembly 66 includes a first chain guide 74, a second chain guide 76, and a chain tensioner 78, as known in the art. When the engine is assembled and in operation, these components are normally covered by the flywheel housing (described below). It should be noted that in Figure 5 and Figure 6 The fuel pump (i.e., in this example, the engine component driven by the rotation of the sprocket 10) installed in the cylinder block 46 is not shown.

[0033] Figure 7 Is with Figure 6 The view is similar to the previous one, but with a fuel pump 80 mounted on it. As shown, the drive shaft 82 of the fuel pump 80 extends through the central opening 40 of the sprocket 10 and is connected to the sprocket 10 by a retaining nut 84 for rotation, as shown below. Figure 8 , Figure 9A and Figure 9B Further described. As is known in the art, rotation of the engine crankshaft causes rotation of the transmission gear assembly 72, which powers the rotation of the sprocket 10 via the chain assembly 66. When the sprocket 10 is connected to the drive shaft 82 of the fuel pump 80 via the retaining nut 84, rotation of the sprocket 10 causes rotation of the drive shaft 82 to power the operation of the fuel pump 80.

[0034] Now refer to Figure 8 , Figure 9A and Figure 9BThe diagram shows a drive shaft 82 of the fuel pump 80 extending through a central opening 40 into a central bore 38 of the sprocket 10. The drive shaft 82 includes a threaded end that engages with the internal thread of a retaining nut 84. When the retaining nut 84 is tightened onto the drive shaft 82, it presses a washer 86 against the shoulder 42 of the central bore 38, thereby connecting the drive shaft 82 to the sprocket 10. In some embodiments, the washer 86 is omitted.

[0035] like Figure 9B As best shown, when the sprocket 10 is supported by the drive shaft 82 of the fuel pump 80, the sprocket is positioned to rotate freely within the bore 44 of the cylinder block 46. The retaining screw 64 includes a head 88 having a radial flange 90 extending therefrom. The flange 90 has a lower surface 92. The retaining screw 64 also includes a threaded body 94, which is threaded into a threaded hole 58 of the screw opening 54 of the threaded boss 50. Figure 3B As shown, when the retaining screw 64 is fully seated in the threaded boss 50, the thickness of the retaining disc 16 between the upper surface 30 and the lower surface 34 is less than the distance between the lower surface 92 of the flange 90 and the axial support wall 60 of the threaded boss 50. Furthermore, the diameter of the retaining disc 16 defined by the outer surface 32 is less than the diameter of the radial positioning surface formed by the radial positioning wall 62 of the threaded hole 50.

[0036] Now refer to Figure 10 and Figure 11 The image shows a flywheel housing 100 with a main body 102 and an inlet / outlet cover 104. The inlet / outlet cover 104 can be removed by removing the fastener 106, exposing the cavity 108. Figure 10 and Figure 11 The image shows a flywheel housing 100 mounted on the cylinder block 46. Figure 11 In this process, the inlet / outlet cover 104 is removed from the flywheel housing 100. Removal of the inlet / outlet cover 104 exposes the sprocket 10, allowing the fuel pump 80 to be removed as described below. By providing access to the sprocket 10 (specifically, retaining nut 84), the inlet / outlet cover 104 enables the removal of the fuel pump 80 without removing the flywheel housing 100 or the second chain assembly 110 disposed within the cavity 108 and extending between the first sprocket gear 12 and the camshaft gear 112, which drives the camshaft (not shown) due to the rotation of the sprocket 10. In prior art designs, the fuel pump 80 can only be removed by removing the flywheel, flywheel housing, chain assembly driving the camshaft, sprocket, and then the fuel pump. This results in significant engine costs and downtime.

[0037] exist Figure 12In this configuration, the inlet / outlet caps 104 of the flywheel housing 100 are removed, and the fuel pump 80 is installed in the cylinder block 46. A retaining nut 84 is attached to the drive shaft 82 of the fuel pump 80. To remove the fuel pump 80, the chain assembly 110 and chain assembly 66 are held in place, and the retaining nut 84 is unscrewed from the drive shaft 82 using a wrench or other suitable tool. The fuel pump 80 can then be removed from the cylinder block 46, as... Figure 13 As shown in the image.

[0038] While this disclosure has been described as having an exemplary design, further modifications to this disclosure are possible within its spirit and scope. This application is therefore intended to cover any variations, uses, or alterations of this disclosure that utilize its general principles. Furthermore, this application is intended to cover any deviations from this disclosure that fall within the scope of known practices or conventions in the field to which this disclosure pertains.

[0039] As used herein, the modifier “about” when used with quantity includes the value and has the meaning indicated by the context (e.g., it includes at least the degree of error associated with a measurement of a particular quantity). When used in the context of range, the modifier “about” should also be considered to disclose a range defined by the absolute values ​​of its two endpoints. For example, the range “about 2 to about 4” also discloses the range “2 to 4”.

[0040] The connecting lines shown in the various figures contained herein are intended to represent exemplary functional relationships and / or physical connections between various elements. It should be noted that many alternative or additional functional relationships or physical connections may exist in a real system. However, any benefit, advantage, solution to a problem, and any element that causes any benefit, advantage, or solution to occur or become more significant shall not be construed as a critical, necessary, or essential feature or element. Therefore, the scope is limited only by the appended claims, wherein references to elements in the singular form are not intended to mean "one and only one," but rather "one or more," unless expressly stated otherwise. Furthermore, where phrases such as "at least one of A, B, or C" are used in the claims, it is intended that such phrases be interpreted as indicating that in an embodiment A may exist singly, in an embodiment B may exist singly, in an embodiment C may exist singly, or in a single embodiment any combination of elements A, B, or C may exist; for example, A and B, A and C, B and C, or A and B and C.

[0041] In the specific embodiments described herein, references to "one embodiment," "implementation," "example embodiment," etc., indicate that the described embodiment may include specific features, structures, or characteristics, but each embodiment may not necessarily include specific features, structures, or characteristics. Furthermore, these phrases do not necessarily refer to the same embodiment. Additionally, when a specific feature, structure, or characteristic is described in connection with an embodiment, it is proposed that, to the best of the understanding of those skilled in the art who benefit from this disclosure, it is possible to influence these features, structures, or characteristics in conjunction with other embodiments, whether or not explicitly described. Upon reading this specification, those skilled in the art will understand how to implement this disclosure in alternative embodiments.

[0042] Furthermore, regardless of whether an element, component, or method step in this disclosure is expressly recited in the claims, such element, component, or method step is not intended to be made public. No element of any claim herein should be construed in accordance with 35 U.S. C112(f) unless the element is expressly recited using the phrase “means for…”. As used herein, the terms “comprising,” “including,” or any variation thereof are intended to cover non-exclusive inclusions such that a process, method, article, or apparatus that comprises a list of elements does not necessarily include only those elements, but may include other elements not expressly listed or inherent to the process, method, article, or apparatus.

[0043] Related applications

[0044] This application claims priority to U.S. Provisional Application Serial No. 62 / 675,356, filed May 23, 2018, entitled “SYSTEM AND METHOD FOR ACAPTIVESPROCKET IN AN ENGINE,” the entire disclosure of which is expressly incorporated herein by reference.

Claims

1. An engine, the engine comprising: An engine component having a drive shaft that drives the operation of the engine component by rotation of the drive shaft; Camshaft, which includes camshaft gear; The second chain assembly engages with the drive gear assembly of the crankshaft of the engine; A sprocket, comprising one or more sprocket gears, wherein at least one of the one or more sprocket gears engages the second chain assembly such that the sprocket rotates together with the transmission gear assembly, the drive shaft is provided with rotational power due to the rotation of the sprocket, the sprocket includes a body in which a central opening is formed, and wherein, in the event of removal of the engine components, the sprocket can remain on the engine; A retaining nut connects the drive shaft of the engine component to the sprocket, the drive shaft extending through the central opening in the sprocket connected to a first chain assembly that drives the camshaft of the engine, thereby allowing the engine component to be removed without removing the first chain assembly or the sprocket; and A cylinder body having a bore, wherein the sprocket is mounted on the cylinder body and positioned within the bore, and wherein the sprocket is held within the bore by a plurality of retaining screws mounted around the bore to cover a portion of the sprocket. The engine component is a fuel pump, and the engine also includes a flywheel housing having inlet and outlet openings to provide access to the fuel pump, allowing the fuel pump to be removed from the engine without removing the flywheel housing, the first chain assembly, or the sprocket.

2. The engine according to claim 1, wherein, The sprocket includes a first sprocket gear and a second sprocket gear, the first sprocket gear meshing with the first chain assembly, and the second sprocket gear being configured to mesh with the second chain assembly driven by the crankshaft of the engine.

3. The engine according to claim 2, wherein, The sprocket includes a retaining disc, at least one of the first sprocket gear, the second sprocket gear, and the retaining disc is formed from a first piece of material, and at least another of the first sprocket gear, the second sprocket gear, and the retaining disc is formed from a second piece of material separate from the first piece of material.

4. The engine according to claim 2, wherein, The sprocket includes a retaining disc having a diameter and a thickness, the diameter of the retaining disc being smaller than the diameter of a radially locating surface formed by a plurality of threaded bosses formed on the engine, and the thickness of the retaining disc being smaller than the distance between the lower surface of the plurality of fixing screws connected to the plurality of threaded bosses and the axially supporting surface formed by the plurality of threaded bosses.

5. A method for removing a fuel pump from an engine according to claim 1, the method comprising the steps of: Remove the inlet and outlet covers from the flywheel housing; Remove the retaining nut that connects the drive shaft of the fuel pump to the sprocket, the drive shaft extending through a central opening in the sprocket, the sprocket being connected to a first chain assembly that drives the camshaft of the engine; as well as The fuel pump is removed from the engine without removing the flywheel housing, the first chain assembly, or the sprocket.

6. The method according to claim 5, wherein, The retaining nut has an outer diameter larger than the diameter of the central opening in the sprocket.

7. The method according to claim 5, wherein, The sprocket includes a first sprocket gear and a second sprocket gear, the first sprocket gear meshing with the first chain assembly, and the second sprocket gear being configured to mesh with a second chain assembly driven by the crankshaft of the engine.

8. The method according to claim 7, wherein, The sprocket includes a retaining disc, at least one of the first sprocket gear, the second sprocket gear, and the retaining disc is formed from a first piece of material, and at least another of the first sprocket gear, the second sprocket gear, and the retaining disc is formed from a second piece of material separate from the first piece of material.

9. The method according to claim 5, wherein, The sprocket includes a retaining disc having a diameter and a thickness, the diameter of the retaining disc being smaller than the diameter of a radial positioning surface formed by a plurality of threaded bosses formed on the engine, and the thickness of the retaining disc being smaller than the distance between the lower surface of a plurality of fixing screws connected to the plurality of threaded bosses and the axial support surface formed by the plurality of threaded bosses.

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