Hydraulic tank for hydraulic clearance adjustment

Abstract

A rocker arm assembly includes an engine brake compartment assembly. The engine brake compartment assembly is movable between a retracted position and an extended position. An engine brake compartment assembly includes a body including a lower chamber and an upper chamber. The engine brake compartment assembly further includes a plunger partially disposed within the lower chamber, where the plunger includes an outer shoulder disposed on a side of the plunger; and a locking pin configured to extend into the lower chamber and engage the outer shoulder of the plunger. The engine brake compartment assembly further includes an actuation pin disposed within the upper chamber and extending downwardly into the inner housing disposed within the lower chamber; and a ball check valve assembly disposed within the plunger and configured to selectively enable hydraulic fluid to enter the interior chamber of the plunger.

Description

[0001] Cross-reference to related applications

[0002] This application claims the benefit of U.S. Provisional Application No. 63 / 342,519, filed on May 16, 2022, the entire contents of which are incorporated herein by reference. Background Art

[0003] The present disclosure relates generally to variable valve actuation and, more particularly, to an improved hydraulic chamber for lash adjustment.

[0004] Internal combustion engines typically use a mechanical, electrical, or hydro-mechanical valve actuation system to actuate the engine valves. These systems may include a combination of a camshaft, rocker arms, and pushrods that are driven by the rotation of the engine's crankshaft. In a typical valve train assembly used with a compression engine brake, the exhaust valve is actuated by a rocker arm that engages the exhaust valve via a valve bridge. The rocker arm rocks in response to a cam on a rotating camshaft and presses down on a valve bridge, which itself presses down on the exhaust valve to open the exhaust valve. BRIEF DESCRIPTION OF THE DRAWINGS

[0005] The following drawings are included to illustrate certain aspects of the present disclosure and should not be considered to be exclusive embodiments. The disclosed subject matter is capable of considerable modification, substitution, combination, and equivalents in form and function without departing from the scope of the present disclosure.

[0006] Figure 1 A perspective view of a valve train assembly including a rocker arm assembly according to one or more aspects of the present disclosure is shown, the rocker arm assembly including an intake rocker arm assembly, an exhaust rocker arm assembly, and an engine brake rocker arm assembly.

[0007] Figure 2 According to one or more aspects of the present disclosure Figure 1 0024] A second perspective view of a valve train assembly of FIG. 1 and shown with the intake rocker arms and associated intake valves removed for illustrative purposes.

[0008] Figure 3 According to one or more aspects of the present disclosure, Figure 1 A cross-sectional view of an engine brake compartment assembly of an engine brake rocker arm assembly. DETAILED DESCRIPTION

[0009] Illustrative embodiments of the present invention are described in detail herein. For the sake of clarity, not all features of an actual implementation may be described in this specification. Of course, it should be understood that in the development of any such actual implementation, many implementation-specific decisions may be made to achieve specific implementation goals, and these decisions may vary between implementations. Furthermore, it should be understood that such development work may be complex and time-consuming, but remains a routine task for those of ordinary skill in the art who benefit from this disclosure.

[0010] Throughout this disclosure, reference numerals followed by alphabetical characters refer to specific instances of elements, and individual reference numerals refer to elements generally or generically. Thus, as an example (not shown in the drawings), reference number "1a" refers to instances of a class of reference numbers, which may be collectively referred to as reference number "1", and any one of which may be collectively referred to as reference number "1". In the drawings and description, like numbers are intended to refer to like elements.

[0011] As used herein, the terms "couple" or "coupled" are intended to mean an indirect connection or a direct connection. Thus, if a first device is coupled to a second device, such connection may be through a direct connection, or through an indirect electrical connection or coupling via other devices and connected shafts.

[0012] In order to facilitate a better understanding of the present disclosure, the following examples of specific embodiments are given. The following examples should never be understood to limit or define the scope of the present disclosure. The embodiments described below with respect to one implementation are not intended to be limiting.

[0013] The present disclosure provides a dedicated rocker arm for engine braking that acts on the exhaust valve. Figure 1 to Figure 2 , a partial view of a valve train assembly constructed according to an example of the present disclosure is shown and generally identified by the reference numeral 10. The partial valve train assembly 10 can utilize engine braking and is shown as being configured for use in a three-cylinder bank portion of a six-cylinder engine. However, it should be understood that the present teachings are not limited to this. In this regard, the present disclosure can be used for any valve train assembly or other suitable valve train that utilizes engine braking. The partial valve train assembly 10 can be supported in a valve train carrier 12 and can include three rocker arms for each cylinder.

[0014] Specifically, each cylinder may include an intake valve rocker arm assembly 14, an exhaust valve rocker arm assembly 16, and an engine brake rocker arm assembly 18. The exhaust valve rocker arm assembly 16 and the engine brake rocker arm assembly 18 cooperate to control the opening of the exhaust valve and are collectively referred to as dual exhaust valve rocker arm assemblies 20, although each rocker arm assembly is a dedicated rocker arm that acts on a single valve. The intake valve rocker arm assembly 14 is configured to control the movement of the intake valves 22, 24. The exhaust valve rocker arm assembly 16 is configured to control the exhaust valve movement in the drive mode. The engine brake rocker arm assembly 18 is configured to act on one of the two exhaust arms in the engine braking mode, as will be described herein. The rocker arm shaft 26 is received by the valve train carrier 12 and supports the rotation of the exhaust valve rocker arm assembly 16 and the engine brake rocker arm assembly 18.

[0015] Continue to refer Figure 1 to Figure 2 , the exhaust rocker arm assembly 16 may generally include an exhaust rocker arm 28, a valve bridge 30, and a sleeve assembly 32. A lever 34 may be pivotally coupled to the valve bridge 30 such that during a braking event, the engine brake rocker arm 36 does not transmit motion to the valve bridge 30. In an alternative embodiment, the valve bridge 30 may operate without the lever 34. The engine brake rocker arm assembly 18 may include a coupling portion (such as Figure 3 1 and 10. The rocker arm 26 may include an engine brake rocker arm 36 having a plurality of pistons 102 (shown in FIG. 1 ) and a plurality of pistons 102 (shown in FIG. 1 ). The valve bridge 30 engages a first exhaust valve 38 and a second exhaust valve 40 associated with a cylinder of the engine. The engine brake rocker arm 36 may include an engine brake compartment assembly (described further below) configured to switch between a drive mode and an engine braking mode. In general, the engine brake compartment assembly has a plunger movably disposed in a cylinder. In an embodiment, the plunger may include an engagement portion (such as an electronic foot (e-foot)) operable to engage the valve bridge 30. The rocker arm shaft 26 may define an oil supply passage 41, wherein a cylinder of the engine brake compartment assembly may be supplied with pressurized fluid from the oil supply passage 41 to extend or retract the plunger.

[0016] The camshaft 42 includes an exhaust main lift cam lobe 44 and an engine brake cam lobe 46. The exhaust rocker arm 28 has a first roller 48. The engine brake rocker arm 36 has a second roller 50. The first roller 48 rotatably engages the exhaust main lift cam lobe 44. As will be described in more detail herein, the second roller 50 is configured to selectively rotatably engage the engine brake cam lobe 46. The exhaust rocker arm 28 rotates about the rocker arm shaft 26 based on the lift profile of the exhaust main lift cam lobe 44. The engine brake rocker arm 36 rotates about the rocker arm shaft 26 based on the lift profile of the engine brake cam lobe 46.

[0017] Figure 3A cross-sectional view of an engine brake nacelle assembly 100 and an engine brake rocker arm 36 according to one or more aspects of the present disclosure is shown. The present disclosure contemplates the use of a combined dual exhaust valve rocker arm assembly 20 (reference Figure 1 ) or a separate dedicated engine brake rocker arm assembly 18 (reference Figure 1 to Figure 2 ) and an engine brake compartment assembly 100. The engine brake compartment assembly 100 may be configured to transition between a retracted position and an extended position, wherein in the retracted position, the engine brake compartment assembly 100 does not engage a valve bridge (such as Figure 1 to Figure 2 ), and in the extended position, the engine brake compartment assembly 100 can selectively engage the valve bridge to open the second exhaust valve 40 (refer to Figure 2 In one or more embodiments, the exhaust valve rocker arm assembly 16 (refer to Figure 1 to Figure 2 ) can be deactivated before starting to activate the engine brake compartment assembly 100 in the engine brake rocker arm 36. The engine brake compartment assembly 100 can be of any suitable size, height, shape, and any combination thereof. In addition, the engine brake compartment assembly 100 can include any suitable material, such as metal, non-metal, polymer, composite material, and any combination thereof. As shown in the figure, the engine brake compartment assembly 100 can be disposed at the valve end of the engine brake rocker arm 36 that is operable to engage with the second exhaust valve 40.

[0018] In the previous embodiment, the engine brake compartment assembly 100 may require active mechanical adjustment of the clearance between the plunger 102 of the engine brake compartment assembly 100 and the second exhaust valve 40. The present embodiment of the engine brake compartment assembly 100 can be achieved by connecting the engine brake compartment assembly 100 to the rocker arm shaft 26 (refer to Figure 1 to Figure 2 ) to eliminate this problem by providing automatic clearance adjustment.

[0019] The engine brake compartment assembly 100 may include a body 104, a plunger 102, a check ball valve assembly 106, an actuating pin 108, and a locking pin 110. In an embodiment, the body 104 may be disposed within a hole at the valve end of the engine brake rocker arm 36. The body 104 may serve as a hole / housing in the body of the rocker arm 36. The body 104 may be configured to accommodate and / or contain components of the engine brake compartment assembly 100. As shown, the body 104 may include a lower chamber 112 and an upper chamber 114. In an embodiment, the upper chamber 114 may be disposed above the lower chamber 112. The body 104 may be configured to receive hydraulic fluid supplied by the rocker shaft 26, wherein the rocker shaft 26 is disposed to pass through a central hole 116 of the engine brake rocker arm 36. In an embodiment, the hydraulic fluid may enter both the upper chamber 114 and the lower chamber 112.

[0020] As shown, the plunger 102 can be disposed within the body 104 and disposed in at least a portion of the lower chamber 112. The plunger 102 can be configured to translate along the length of the lower chamber 112 and can partially extend outward beyond the lower chamber 112. The plunger 102 can be disposed at least partially around an internal housing 118 that is configured to provide a seat for a check ball valve assembly 106 within the plunger 102. The internal housing 118 can include one or more ports 120 configured to enable fluid communication between the lower chamber 112 and an internal chamber 122 of the plunger 102. For example, there can be an internal chamber 122 disposed within the interior of the plunger 102 that houses the check ball valve assembly 106.

[0021] The check ball valve assembly 106 can be configured to selectively allow hydraulic fluid to enter the internal chamber 122 to translate the plunger 102 from the retracted position to the extended position. As shown, the check ball valve assembly 106 can be configured to sit against an internal shoulder 124 provided by the bottom end of the internal housing 118. Hydraulic fluid can be introduced into the internal housing 118, flow through the check ball valve assembly 106 and flow into the internal chamber 122. As shown, the actuating pin 108 can extend downward and push against the ball of the check ball valve assembly 106, thereby unseating the ball from the internal shoulder 124. When the check ball valve assembly 106 is seated, fluid can be allowed to flow freely into and out of the internal chamber 122. During operation, the actuating pin 108 can be actuated to translate upward and remove the force applied to the check ball valve assembly 106. Thus, the check ball valve assembly 106 can sit against the internal shoulder 124 and prevent fluid communication.

[0022] The engine brake compartment assembly 100 may also include a first spring 126 disposed within the interior chamber 122 configured to bias the plunger 102 downwardly into the extended position. In an embodiment, both the first spring 126 and the introduction of hydraulic fluid into the interior chamber 122 may actuate the plunger 102 to move to the extended position.

[0023] The plunger 102 may include a cutout along a side of the plunger 102 that defines an external shoulder 128. The external shoulder 128 may be configured to receive the locking pin 110. In an embodiment, the locking pin 110 may be disposed within the body 104 and may be configured to extend into the lower chamber 112 to engage the external shoulder 128 of the plunger 102. The locking pin 110 may be configured to inhibit translation of the plunger 102 and lock the plunger 102 in place relative to the lower chamber 112. The locking pin 110 may utilize a second spring 130 to bias the locking pin 110 toward the lower chamber 112.

[0024] In an embodiment, the engine brake rocker arm 36 may include a first oil passage 132, a second oil passage 134, and a third oil passage 136. Each of the first oil passage 132, the second oil passage 134, and the third oil passage 136 may fluidly couple the center hole 116 to the engine brake compartment assembly 100. The first oil passage 132 may be configured to provide fluid communication between the upper chamber 114 and the center hole 116. The second oil passage 134 may be configured to provide fluid communication between the space in the lower chamber 112 and the center hole, which space is defined by the plunger 102 and the locking pin 110. Both the first oil passage 132 and the second oil passage 134 may be actuated by an oil control valve disposed further upstream to provide a hydraulic fluid flow. For example, the oil control valve may be disposed in or upstream of the rocker shaft 26. The third oil passage 136 may be configured to provide fluid communication between the lower chamber 112 and the center hole 116.

[0025] When hydraulic fluid is introduced into the upper chamber 114 via the first oil passage 132, pressure may act on the actuation pin 108 to translate the actuation pin 108 upward, thereby removing the force applied to the check ball valve assembly 106. There may be a third spring 138 disposed within the upper chamber 114 that is configured to bias the actuation pin 108 downward to unseat the check ball valve assembly 106. As pressure increases, the upward translation of the actuation pin 108 may compress the third spring 138 and close or seat the check ball valve assembly 106. When the check ball valve 106 is seated against the internal shoulder 124, any hydraulic fluid present within the internal chamber 122 may be trapped therein and may be prevented from flowing outwardly.

[0026] When hydraulic fluid is introduced into the space in the lower chamber 112 via the second oil passage 134, pressure may act on the locking pin 110 to translate and retract the locking pin 110 from the plunger 102, thereby unseating from the external shoulder 128. Removing the locking pin 110 from the plunger 102 may allow the plunger to translate along the lower chamber 112 and extend outwardly.

[0027] In an embodiment, hydraulic fluid can flow into the lower chamber 112 via the third oil passage 136 and then into the plunger 102 through one or more ports 120 of the internal housing 118. Such flow can be controlled independently of the flow of the first oil passage 132 and the second oil passage 134, wherein the oil control valve can control the flow. When the check ball valve assembly 106 is unseated, hydraulic fluid can freely enter and leave the internal chamber 122. In this state, operation of the engine brake rocker arm 36 can provide a change in the clearance between the plunger 102 and the second exhaust valve 40 (refer to Figure 1 to Figure 2). For example, in the event that an upward force is applied to the plunger 102 when the plunger 102 is engaged with the second exhaust valve 40, the force will be transferred to the hydraulic fluid in the internal chamber 122. The plunger 102 can be retracted a specific distance, which depends on the amount of hydraulic fluid that leaves the internal chamber 122 due to the applied force. When the check ball valve assembly 106 is seated, the volume of the hydraulic fluid within the internal chamber 122 does not change. In this state, the engine brake rocker arm 36 can provide a relatively more rigid operation because the applied upward force may not cause translation of the plunger 102.

[0028] Therefore, the disclosed system and method are well suited to obtain the mentioned purposes and advantages and those inherent therein. The specific embodiments disclosed above are illustrative only, because the teachings of the present disclosure can be modified and practiced in different but equivalent ways, which is obvious to those skilled in the art who benefit from the teachings herein. In addition, except as described in the appended claims, it is not intended to limit the details of the construction or design shown herein. Therefore, it is obvious that the specific illustrative embodiments disclosed above can be changed, combined or modified, and all such changes are considered to be within the scope of the present disclosure. The system and method disclosed illustratively herein can be appropriately practiced in the absence of any element not specifically disclosed herein and any optional element disclosed herein. Although the composition and method are described with the terms "including", "containing" or "comprising" various components or steps, the composition and method can also be "essentially composed of various components and steps" or "composed of various components and steps". All numbers and ranges disclosed above can vary by a certain amount. Whenever a numerical range with a lower limit and an upper limit is disclosed, any number and any inclusive range falling within the range are specifically disclosed. In particular, each value range disclosed herein (in the form of "from about a to about b", or equivalently, "from about a to b", or equivalently, "about ab") should be understood to set forth each number and range encompassed within the broader value range. In addition, the terms in the claims have their plain, ordinary meaning unless otherwise explicitly and clearly defined by the patentee. In addition, the indefinite articles "a" or "an" used in the claims are defined herein to mean one element or more than one element that it introduces.

Claims

1. A rocker arm assembly, comprising: rocker arms, including valve ends; as well as an engine brake compartment assembly disposed at the valve end, the engine brake compartment assembly being movable between a retracted position and an extended position, wherein in the retracted position the engine brake compartment assembly does not engage the valve bridge, and in the extended position the engine brake compartment assembly selectively engages the valve bridge to open the first exhaust valve, the engine brake compartment assembly comprising: A body, comprising a lower chamber and an upper chamber; a plunger partially disposed within the lower chamber, wherein the plunger includes an external shoulder disposed on a side of the plunger; a locking pin configured to extend into the lower chamber and engage the external shoulder of the plunger; an actuation pin disposed within the upper chamber and extending downwardly into an inner housing disposed within the lower chamber, wherein the plunger is disposed about the inner housing and configured to translate relative to the inner housing; and A check ball valve assembly is disposed within the plunger, the check ball valve assembly being configured to selectively enable hydraulic fluid to enter an internal chamber of the plunger, wherein the check ball valve assembly is further configured to seat against a bottom end of the inner housing.

2. The rocker arm assembly according to claim 1, wherein: The rocker arm also includes a central hole configured to receive a rocker shaft, wherein the rocker shaft is disposed through the central hole of the rocker arm.

3. The rocker arm assembly according to claim 2, wherein: The rocker arm also includes: a first oil passage configured to provide fluid communication between the upper chamber and the central bore; and A second oil passage is configured to provide fluid communication between a space defined by the plunger and the locking pin and the central bore. 4 . The rocker arm assembly of claim 3 , further comprising an oil control valve configured to provide hydraulic fluid flow through the first oil passage and through the second oil passage.

5. The rocker arm assembly according to claim 3, wherein: The rocker arm also includes a third oil passage configured to provide fluid communication between the lower chamber and the central bore.

6. The rocker arm assembly according to claim 1, wherein: The engine brake compartment assembly also includes a first spring disposed within the interior chamber, the first spring configured to bias the plunger downwardly to the extended position.

7. The rocker arm assembly according to claim 6, wherein: The engine brake compartment assembly also includes a second spring disposed within the upper chamber, the second spring configured to bias the actuation pin downward to unseat the check ball valve assembly.

8. The rocker arm assembly according to claim 1, wherein: The inner housing includes one or more ports configured to allow fluid communication between the lower chamber and the interior chamber of the plunger.

9. The rocker arm assembly according to claim 1, wherein: The rocker arm also includes a cam end opposite the valve end, the cam end including a roller configured to engage an engine braking cam lobe of a camshaft.

10. A valve train assembly comprising: first exhaust valve; Second exhaust valve; as well as A dual exhaust valve rocker arm assembly is configured to selectively open a first engine valve and a second engine valve, the dual exhaust valve rocker arm assembly comprising: a first rocker arm including a valve end; and an engine brake compartment assembly disposed at the valve end, the engine brake compartment assembly being movable between a retracted position and an extended position, wherein in the retracted position the engine brake compartment assembly does not engage the valve bridge, and in the extended position the engine brake compartment assembly selectively engages the valve bridge to open the first exhaust valve, the engine brake compartment assembly comprising: A body, comprising a lower chamber and an upper chamber; a plunger partially disposed within the lower chamber, wherein the plunger includes an external shoulder disposed on a side of the plunger; a locking pin configured to extend into the lower chamber and engage the external shoulder of the plunger; an actuation pin disposed within the upper chamber and extending downwardly into an inner housing disposed within the lower chamber, wherein the plunger is disposed about the inner housing and configured to translate relative to the inner housing; and A check ball valve assembly is disposed within the plunger, the check ball valve assembly being configured to selectively enable hydraulic fluid to enter an internal chamber of the plunger, wherein the check ball valve assembly is further configured to seat against a bottom end of the inner housing.

11. The valve train assembly according to claim 10, wherein: The first rocker arm also includes a central hole configured to receive a rocker shaft, wherein the rocker shaft is disposed through the central hole of the first rocker arm.

12. The valve train assembly according to claim 11, wherein: The first rocker arm further comprises: a first oil passage configured to provide fluid communication between the upper chamber and the central bore; and A second oil passage is configured to provide fluid communication between a space defined by the plunger and the locking pin and the central bore. 13 . The valvetrain assembly of claim 12 , further comprising an oil control valve configured to provide hydraulic fluid flow through the first oil passage and through the second oil passage.

14. The valve train assembly according to claim 12, wherein: The first rocker arm also includes a third oil passage configured to provide fluid communication between the lower chamber and the central bore.

15. The valve train assembly according to claim 10, wherein: The engine brake compartment assembly also includes a first spring disposed within the interior chamber, the first spring configured to bias the plunger downwardly to the extended position.

16. The valve train assembly according to claim 15, wherein: The engine brake compartment assembly also includes a second spring disposed within the upper chamber, the second spring configured to bias the actuation pin downward to unseat the check ball valve assembly.

17. The valve train assembly according to claim 10, wherein: The inner housing includes one or more ports configured to allow fluid communication between the lower chamber and the interior chamber of the plunger.

18. The valve train assembly according to claim 10, wherein: The first rocker arm also includes a cam end opposite the valve end, the cam end including a roller configured to engage an engine braking cam lobe of a camshaft.

19. The valvetrain assembly of claim 10, further comprising a second rocker arm configured to engage both the first exhaust valve and the second exhaust valve via the valve bridge.

20. The valvetrain assembly of claim 10, further comprising a valve bridge operatively associated with the first exhaust valve and the second exhaust valve.

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