WO2025129386A1

WO2025129386A1 - Cylinder head assemblies for internal combustion engines

Info

Publication number: WO2025129386A1
Application number: PCT/CN2023/139455
Authority: WO
Inventors: Xiang GUO; Chang Mei
Original assignee: Cummins Inc
Current assignee: Cummins Inc
Priority date: 2023-12-18
Filing date: 2023-12-18
Publication date: 2025-06-26
Anticipated expiration: 2026-06-18

Abstract

Cylinder head assemblies for internal combustion engines are disclosed that include a camshaft carrier and a pedestal for a rocker lever engaged to the cylinder head with a fastener through the pedestal. A lubrication fluid flow path is provided around the fastener to fluidly connect a fluid gallery between the camshaft carrier and the cylinder head and a fluid passage in the pedestal.

Description

CYLINDER HEAD ASSEMBLIES FOR INTERNAL COMBUSTION ENGINES

Field of the Invention:

The present invention relates generally to internal combustion engines, and more particularly to cylinder head assemblies for internal combustion engines that include camshaft carriers and pedestals for rocker levers mounted to cylinder heads.

BACKGROUND

Internal combustion engines may employ rocker levers and one or more camshafts to control opening and closing of intake valves and/or exhaust valves. Some engines employ cam-in-block designs, which can lead to a reduction in strength and stiffness in the block, additional mass, and service challenges. Other engines employ overhead camshaft support structures, but require drillings in the cylinder head to deliver lubrication fluid to the rocker lever. Therefore, further improvements in this technological area are needed.

SUMMARY

The present disclosure includes cylinder head assemblies for internal combustion engines that include a camshaft carrier and pedestal for a rocker lever engaged to the cylinder head with a fastener through the pedestal. In an embodiment, a lubrication fluid flow path is provided around the fastener to fluidly connect a fluid gallery located between the camshaft carrier and the cylinder head and a fluid passage in the pedestal.

In an embodiment, a cylinder head assembly for an internal combustion engine is provided. The cylinder head assembly includes a cylinder head having an upper deck and a fire deck. The cylinder head assembly also includes a camshaft carrier configured to support at least one camshaft. The camshaft carrier includes a support surface positionable against the upper deck of the cylinder head, and a fluid gallery along the support surface that is spaced from the upper deck. The cylinder head assembly also includes a pedestal configured to support at least one rocker lever. The pedestal includes a hole extending therethrough for receiving a fastener that secures the pedestal to the upper deck, and the hole is in fluid communication with the fluid gallery. The pedestal also includes a fluid passage in fluid communication with the hole that extends into the pedestal for delivering lubrication fluid from the fluid gallery to the rocker lever.

In an embodiment, a cylinder head assembly for an internal combustion engine includes a cylinder head having an upper deck and a fire deck, a camshaft carrier configured to support at least one camshaft, a pedestal configured to support at least one rocker lever, and a fastener extending through a hole of the pedestal to secure the pedestal to the upper deck. The camshaft carrier includes a support surface positioned against the upper deck of the cylinder head. The fastener extends through the hole of the pedestal to secure the pedestal to the upper deck. The camshaft carrier includes an engagement part positioned between the pedestal and the upper deck so that engagement of the fastener to the upper deck clamps the engagement part of the camshaft carrier between pedestal and the upper deck.

This summary is not intended to identify key or essential features of the claimed subject matter, nor is it intended to be used as an aid in limiting the scope of the claimed subject matter. Further embodiments, forms, objects, features, advantages, aspects, and benefits shall become apparent from the following description and drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The description herein makes reference to the accompanying drawings wherein like numerals refer to like parts throughout the several views, and wherein:

FIG. 1 is a schematic perspective view of an internal combustion engine including an engine block and a cylinder head assembly.

FIG. 2 is a schematic elevation view of a portion of the cylinder head assembly of FIG. 1.

FIG. 3 is a section view of the cylinder head assembly of FIG. 1 along a part of a lubrication fluid flow path.

FIG. 4 is an enlarged section view of the lubrication fluid flow path of FIG. 3.

FIG. 5 is a schematic view of a portion of a bottom side of an embodiment of a camshaft carrier that can be used with the cylinder head assembly of FIG. 1.

FIG. 6 is a schematic view of a portion of a lubrication flow path for another embodiment camshaft carrier that can be used with the cylinder head assembly of FIG. 1.

DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS

For the purposes of promoting an understanding of the principles of the invention, reference will now be made to the embodiments illustrated in the drawings and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended, any alterations and further modifications in the illustrated embodiments, and any further applications of the principles of the invention as illustrated therein as would normally occur to one skilled in the art to which the invention relates are contemplated herein.

Referring to FIGs. 1-4, a cylinder head assembly 30 for an internal combustion engine 10 is provided. Cylinder head assembly 30 includes a cylinder head 32 having an upper deck 34 and a fire deck 36. Cylinder head assembly 30 also includes a camshaft carrier 50 configured to support at least one camshaft 52. Camshaft carrier 50 includes a support surface 54 positionable against upper deck 34 of cylinder head 32, and a fluid gallery 56 along support surface 54 that is spaced from upper deck 34. Cylinder head assembly 30 also includes a pedestal 80 configured to support at least one rocker lever 82. Pedestal 80 includes a hole 84 extending therethrough for receiving a fastener 100 that secures pedestal 80 to upper deck 34, and hole 84 is in fluid communication with fluid gallery 56. Pedestal 80 also includes a fluid passage 86 in fluid communication with hole 84 that extends into pedestal 80 for delivering lubrication fluid from fluid gallery 56 to rocker lever 82.

In an embodiment, cylinder head assembly 30 for internal combustion engine 10 includes cylinder head 32 having upper deck 34 and fire deck 36, camshaft carrier 50 configured to support at least one camshaft 52, pedestal 80 configured to support at least one rocker lever 82, and fastener 100 extending through hole 84 of pedestal 80 to secure pedestal 80 to upper deck 34. Camshaft carrier 50 includes support surface 54 positioned against upper deck 34 of cylinder head 32. Fastener 100 extends through hole 84 of pedestal 80 to secure pedestal 80 to upper deck 34. Camshaft carrier 50 includes an engagement part 70 positioned between pedestal 80 and upper deck 34 so that engagement of fastener 100 to upper deck 34 clamps engagement part 70 of camshaft carrier 50 between pedestal 80 and upper deck 34.

Referring to FIG. 1, internal combustion engine 10 is shown with an engine block 12 and cylinder head assembly 30 mounted on engine block 12. Engine block 12 includes multiple combustion chambers (not shown) for housing pistons. The pistons reciprocate in the combustion chambers to rotate a crankshaft (not shown) in response to combustion of a charge (air-fuel mixture) in the combustion chambers.

Cylinder head assembly 30 includes cylinder head 32 and multiple components mounted on cylinder head 32 that work in conjunction with the pistons and crankshaft to control the combustion in the combustion chambers. For example, multiple support systems 40 can be mounted to cylinder head 32. Support systems 40 include pedestals 80 to support rocker levers 82 and camshaft carriers 50 to support camshaft 52.

Cylinder head 32 includes upper deck 34 and fire deck 36. Fire deck 36 includes a lower flame surface mounted directly or indirectly on engine block 12. An intake path 38 can be provided between upper deck 34 and fire deck 36. Upper deck 34 provides a platform for mounting of support systems 40 to cylinder head 32.

In an embodiment each support system 40 includes a pair of pedestals 80 that each support two rocker levers 82. Referring further to FIG. 2, each rocker lever 82 is mounted its corresponding pedestal 80 with a respective one of the fasteners 80 extending through the pedestal 80 and engaged to upper deck 34 of cylinder head 32. Each support system 34 also includes camshaft carrier 50 engaged to cylinder head 32 with fasteners 100 through the corresponding pedestal 80, as discussed further below.

Referring further to FIGs. 3-4, fastener 100 extends through hole 84 of pedestal 80 to threadingly engage bore 38 in upper deck 34 of cylinder head 32. Fastener 100 includes a head 102 at a proximal end of fastener 100, a first shaft portion 104 extending distally from head 102, and a second shaft portion 106 extending distally from first shaft portion 104. In an embodiment, first shaft portion 104 is non-threaded and second shaft portion 106 is threaded. In an embodiment, second shaft portion 106 threadingly engages bore 38 in upper deck 34 of cylinder head 32.

In the illustrated embodiment, fastener 100 extends through a seat 110. Seat 110 is mounted to pedestal 80 with fastener 100 extending through seat 110 and hole 84 of pedestal 80. In an embodiment, seat 110 has a spherical shape that is complementary to receptacle 88 of rocker lever 82 allow pivoting of rocker lever 82. For example, rocker lever 82 pivots about seat 110 in response to cam lobe 58 of camshaft 52 acting on roller 90 of rocker lever 82.

Pedestal 80 includes fluid passage 86 in fluid communication with and extending from hole 84. Hole 84 is sized relative to first portion 104 of fastener 100 so that fluid can flow from fluid gallery 56, through hole 84 around first portion 104 of fastener 100, and into fluid passage 86. Fluid passage 86 provides lubrication fluid to rocker lever 82 to facilitate movement of rocker lever 82 and/or for operation or movement of one or more components coupled to rocker lever 82, such as valves, tappets, etc.

Camshaft carrier 50 includes a base portion 62 and a support arm 64 extending from base portion 62. Base portion 62 includes support surface 54 and fluid gallery 56 facing upper deck 34 of cylinder head 32. Support arm 64 is configured to rotatably support camshaft 52. Base portion 62 includes a channel 66 in support surface 54. A seal 68 in channel 66 sealingly engages camshaft carrier 50 against upper deck 34 of cylinder head 32. In an embodiment, seal 68 is an elastomer-type seal, but any suitable sealing material for seal 68 is contemplated.

In an embodiment, engagement part 70 of base portion 62 of camshaft carrier 50 extends between pedestal 80 and upper deck 34. In an embodiment, engagement part 70 is a flange, lip, or recessed part of base portion 62 that extends around hole 84 and bore 38 between upper deck 34 and a lower surface of pedestal 80 oriented toward upper deck 34.

In an embodiment, fluid gallery 56 is defined at least in part by engagement part 70 and is in fluid communication with hole 84. In an embodiment, support surface 54 of camshaft carrier 50 extends along base portion 62 and engagement part 70. In an embodiment, fluid gallery 56 is recessed relative to and extends along support surface 54 along base portion 62 and engagement part 70.

Fastener 100 clamps engagement part 70 of base portion 62 between bottom surface 94 of pedestal 80 and upper deck 34 of cylinder head 32 when fastener 100 is engaged to upper deck 34 of cylinder head 32. In an embodiment, fastener 100 fixes pedestal 80 and camshaft carrier 50 to upper deck 34 of cylinder head 30.

In an embodiment, fastener 100 extends through hole 84 of pedestal 80 and second portion 106 of fastener 100 is engaged to upper deck 34 of cylinder head 32. Fastener 100 clamps bottom surface 94 of pedestal 80 against engagement part 70 of camshaft carrier 50 to sealingly engage support surface 54 of camshaft carrier 50 against upper deck 34. A lubrication fluid flow path is thereby formed that extends from fluid gallery 56, through hole 84 around fastener 100, and into fluid passage 86.

Referring to FIG. 5, a schematic bottom view of an embodiment of camshaft carrier 50 is shown looking toward support surface 54. Fluid gallery 56 extends along support surface 54 between multiple locations that align with holes 84 of multiple pedestals 80. Each location receives a fasteners 100 to secure camshaft carrier 50 against upper deck 34 and the multiple pedestals 80.

In the illustrated embodiment, fluid gallery 56 includes a distribution portion 130 extending along camshaft carrier 50 between multiple hole portions 132. Hole portions 132 each surround a corresponding hole 84 of the multiple pedestals 80. Fluid gallery 56 also includes branches 134 that each fluidly connect distribution portion 130 with a corresponding hole portion 132. Lubrication fluid is distributed through fluid gallery 56 to each of the locations for holes 84 to flow into corresponding fluid passages 86.

Referring to FIG. 6, another embodiment of camshaft carrier 50 is shown and designated as camshaft carrier 50’ . Camshaft carrier 50’ includes a fluid gallery 56’s imilar to fluid gallery 56 discussed above, except fluid gallery 56’ includes a second distribution portion 140 connected to distribution portion 130 with one or more crossing portions 152.

Fluid gallery 56’ is configured for a dual overhead cam structure with the first and second distribution portions 130, 140 extending along the exhaust camshaft side 142 and the intake camshaft side 144, respectively. First distribution portion 130 is connected to cam bore galleries 146 with cam bore branches 154 and to brake galleries 148 with brake branches 156 for the exhaust camshaft side 142. Second distribution portion 140 is connected to cam bore galleries 150 for the intake camshaft side 144 with cam bore branches 158.

Various aspects of the present disclosure are contemplated. According to one aspect, a cylinder head assembly for an internal combustion engine is provided. The cylinder head assembly includes a cylinder head having an upper deck and a fire deck. The cylinder head assembly also includes a camshaft carrier configured to support at least one camshaft. The camshaft carrier includes a support surface positionable against the upper deck of the cylinder head, and a fluid gallery along the support surface that is spaced from the upper deck. The cylinder head assembly also includes a pedestal configured to support at least one rocker lever. The pedestal includes a hole extending therethrough for receiving a fastener that secures the pedestal to the upper deck, and the hole is in fluid communication with the fluid gallery. The pedestal also includes a fluid passage in fluid communication with the hole that extends into the pedestal for delivering lubrication fluid from the fluid gallery to the rocker lever.

In an embodiment, the cylinder head assembly includes the fastener positionable in the hole of the pedestal, and the hole is configured to maintain a fluid flow path from the fluid gallery to the fluid passage with the fastener positioned in the hole.

In a further embodiment, the fluid gallery extends around the fastener between the pedestal and the upper deck of the cylinder head.

In a further embodiment, the fluid gallery extends along the camshaft carrier between multiple pedestals. Each of the multiple pedestals has a hole therethrough for receiving a fastener that secures the pedestal to the upper deck, and each of the holes is in fluid communication with the fluid gallery.

In a further embodiment, the fluid gallery includes a distribution portion extending along the camshaft carrier, hole portions that around the holes of the pedestals, and branches connecting the distribution portion to respective ones of the hole portions.

In a further embodiment, the fluid galley includes a second distribution portion parallel to the distribution portion. The distribution portions distribute lubrication fluid to respective ones of first and second camshafts.

In a further embodiment, the fastener includes a head and a shaft extending from the head. The shaft includes a first portion positionable through the hole of the pedestal and a second portion extending from the first portion. The fluid flow path from the fluid gallery to the fluid passage extends through the hole between the first portion of the fastener and the pedestal. The second portion of the fastener is configured to threadingly engage the upper deck of the cylinder head.

In yet a further embodiment, the cylinder head assembly includes a spherically-shaped seat between the head and the pedestal, and the rocker lever pivotably supported on the spherically-shaped seat.

In an embodiment, the camshaft carrier includes a base portion and a support arm extending from the base portion. The base portion includes the support surface and the fluid gallery, and the support arm is configured to support the at least one camshaft.

In a further embodiment, the base portion of the camshaft carrier includes a channel in the support surface. A seal in the channel sealingly engages the camshaft carrier against the upper deck of the cylinder head.

In a further embodiment, an engagement part of the base portion of the camshaft carrier extends between the pedestal and the upper deck. The fastener clamps the engagement part of the base portion between the pedestal and the upper deck of the cylinder head when the fastener is engaged to the upper deck.

In still a further embodiment, the fastener fixes the pedestal and the camshaft carrier to the upper deck of the cylinder head.

In an embodiment, with the fastener in the hole of the pedestal engaged to the upper deck of the cylinder head, the fastener engages the pedestal against the camshaft carrier to sealingly engage the support surface of the camshaft carrier against the upper deck to form a lubrication fluid flow path extending from the fluid gallery of the camshaft carrier, through the hole of the pedestal around the fastener, and into the fluid passage of the pedestal.

According to another aspect, a cylinder head assembly for an internal combustion engine includes a cylinder head having an upper deck and a fire deck, a camshaft carrier configured to support at least one camshaft, a pedestal configured to support at least one rocker lever, and a fastener extending through a hole of the pedestal to secure the pedestal to the upper deck. The camshaft carrier includes a support surface positioned against the upper deck of the cylinder head. The fastener extends through the hole of the pedestal to secure the pedestal to the upper deck. The camshaft carrier includes an engagement portion positioned between the pedestal and the upper deck so that engagement of the fastener to the upper deck clamps the engagement portion of the camshaft carrier between pedestal and the upper deck.

In an embodiment, the cylinder head assembly includes a seat secured to the pedestal by the fastener, and the rocker lever is pivotably supported on the pedestal by the seat.

In a further embodiment, the fastener includes a head securing the seat against the pedestal and a shaft extending from the head. The shaft includes a first portion extending through the hole of the pedestal and a second portion extending from the first portion. The second portion is threadingly engaged the upper deck of the cylinder head.

In an embodiment, the camshaft carrier defines a fluid gallery along the support surface, the pedestal defines a fluid passage for delivering fluid to the rocker lever, and the hole in the pedestal defines a space around the fastener that fluidly connects the fluid gallery and the fluid passage.

In a further embodiment, the fluid gallery extends around the fastener between the pedestal and the cylinder head.

In an embodiment, the camshaft carrier includes a base portion and a support arm extending from the base portion. The support surface extends along the base portion, and the support arm is configured to support the at least one camshaft.

In an embodiment, the camshaft carrier includes a channel in the support surface. A seal in the channel sealingly engaged to the cylinder head by the fastener.

In an embodiment, the cylinder head assembly includes the at least one camshaft engaged to the camshaft carrier, and the rocker lever engaged to the pedestal with fastener.

According to another aspect of the present disclosure, an internal combustion engine is provided that includes a cylinder head assembly according to any one or combination of embodiments disclosed herein.

While the invention has been illustrated and described in detail in the drawings and foregoing description, the same is to be considered as illustrative and not restrictive in character, it being understood that only certain exemplary embodiments have been shown and described and that all changes and modifications that come within the spirit of the inventions are desired to be protected. In reading the claims, it is intended that when words such as “a, ” “an, ” “at least one, ” or “at least one portion” are used there is no intention to limit the claim to only one item unless specifically stated to the contrary in the claim. When the language “at least a portion” and/or “a portion” is used the item can include a portion and/or the entire item unless specifically stated to the contrary.

Claims

A cylinder head assembly for an internal combustion engine, the cylinder head assembly comprising:

a cylinder head including an upper deck and a fire deck;

a camshaft carrier configured to support at least one camshaft, the camshaft carrier including:

a support surface positionable against the upper deck of the cylinder head; and

a fluid gallery along the support surface, the fluid gallery spaced from the upper deck; and

a pedestal configured to support at least one rocker lever, the pedestal including:

a hole extending therethrough for receiving a fastener that secures the pedestal to the upper deck, the hole in fluid communication with the fluid gallery; and

a fluid passage extending into the pedestal for delivering lubrication fluid to the rocker lever, the fluid passage in fluid communication with the hole to receive lubrication fluid from the fluid gallery.
The cylinder head assembly of claim 1, further comprising:

the fastener positionable in the hole of the pedestal, wherein the hole is configured to maintain a fluid flow path from the fluid gallery to the fluid passage with the fastener positioned in the hole.
The cylinder head assembly of claim 2, wherein the fluid gallery extends around the fastener between the pedestal and the upper deck of the cylinder head.
The cylinder head assembly of claim 3, wherein the fluid gallery extends along the camshaft carrier between multiple pedestals, each of the multiple pedestals having a hole therethrough for receiving a fastener that secures the pedestal to the upper deck, each of the holes in fluid communication with the fluid gallery.
The cylinder head assembly of claim 4, wherein the fluid gallery includes:

a distribution portion extending along the camshaft carrier;

hole portions that around the holes of the pedestals; and

branches connecting the distribution portion to respective ones of the hole portions.
The cylinder head assembly of claim 5, wherein the fluid galley includes a second distribution portion parallel to the distribution portion, the distribution portions distributing lubrication fluid to respective ones of first and second camshafts.
The cylinder head assembly of claim 2, wherein the fastener includes:

a head;

a shaft extending from the head, the shaft including:

a first portion positionable through the hole of the pedestal, the fluid flow path from the fluid gallery to the fluid passage extending through the hole between the first portion of the fastener and the pedestal; and

a second portion extending from the first portion, the second portion being configured to threadingly engage the upper deck of the cylinder head.
The cylinder head assembly of claim 7, further comprising:

a spherically-shaped seat between the head and the pedestal; and

the rocker lever pivotably supported on the spherically-shaped seat.
The cylinder head assembly of claim 1, wherein the camshaft carrier includes:

a base portion, the base portion including the support surface and the fluid gallery; and

a support arm extending from the base portion, the support arm configured to support the at least one camshaft.
The cylinder head assembly of claim 9, wherein the base portion of the camshaft carrier includes a channel in the support surface, and further comprising a seal in the channel for sealingly engaging the camshaft carrier against the upper deck of the cylinder head.
The cylinder head assembly of claim 9, wherein:

an engagement part of the base portion of the camshaft carrier extends between the pedestal and the upper deck; and

the fastener clamps the engagement part of the base portion between the pedestal and the upper deck of the cylinder head when the fastener is engaged to the upper deck.
The cylinder head assembly of claim 11, wherein the fastener fixes the pedestal and the camshaft carrier to the upper deck of the cylinder head.
The cylinder head assembly of claim 1, wherein:

with the fastener in the hole of the pedestal engaged to the upper deck of the cylinder head, the fastener engages the pedestal against the camshaft carrier to sealingly engage the support surface of the camshaft carrier against the upper deck to form a lubrication fluid flow path extending from the fluid gallery of the camshaft carrier, through the hole of the pedestal around the fastener, and into the fluid passage of the pedestal.
An internal combustion engine comprising the cylinder head assembly of any of claims 1-13.
A cylinder head assembly for an internal combustion engine, the cylinder head assembly comprising:

a cylinder head including an upper deck and a fire deck;

a camshaft carrier configured to support at least one camshaft, the camshaft carrier including a support surface positioned against the upper deck of the cylinder head;

a pedestal configured to support at least one rocker lever, the pedestal including a hole extending therethrough; and

a fastener extending through the hole of the pedestal to secure the pedestal to the upper deck of the cylinder head, wherein the camshaft carrier includes an engagement part positioned between the pedestal and the upper deck so that engagement of the fastener to the upper deck of the cylinder head clamps the engagement part of the camshaft carrier between pedestal and the upper deck.
The cylinder head assembly of claim 15, further comprising a seat secured to the pedestal by the fastener, and further comprising the rocker lever pivotably supported on the pedestal by the seat.
The cylinder head assembly of claim 16, wherein the fastener includes:

a head securing the seat against the pedestal; and

a shaft extending from the head, the shaft including:

a first portion extending through the hole of the pedestal; and

a second portion extending from the first portion, the second portion threadingly engaged the upper deck of the cylinder head.
The cylinder head assembly of claim 15, wherein:

the camshaft carrier defines a fluid gallery along the support surface:

the pedestal defines a fluid passage for delivering fluid to the rocker lever; and

the hole in the pedestal defines a space around the fastener that fluidly connects the fluid gallery and the fluid passage.
The cylinder head assembly of claim 18, wherein the fluid gallery extends around the fastener between the pedestal and the cylinder head.
The cylinder head assembly of claim 15, wherein the camshaft carrier includes:

a base portion, the support surface extending along the base portion; and

a support arm extending from the base portion, the support arm configured to support the at least one camshaft.
The cylinder head assembly of claim 15, wherein the camshaft carrier includes a channel in the support surface, and further comprising a seal in the channel sealingly engaged to the cylinder head by the fastener.
The cylinder head assembly of claim 15, further comprising:

the at least one camshaft engaged to the camshaft carrier; and

the rocker lever engaged to the pedestal with fastener.
An internal combustion engine comprising the cylinder head assembly of any of claims 15-22.