CN114458471A

CN114458471A - Cylinder block assembly for engine and engine

Info

Publication number: CN114458471A
Application number: CN202011226593.5A
Authority: CN
Inventors: 吴恢栋; 李寒磊; 侯俊朋
Original assignee: Jiangsu Changfa Agricultural Equipment Co Ltd
Current assignee: Jiangsu Changfa Agricultural Equipment Co Ltd
Priority date: 2020-11-07
Filing date: 2020-11-07
Publication date: 2022-05-10

Abstract

A cylinder block assembly for an engine includes a cylinder block having an intake side, an exhaust side, a block front side, and a block rear side. The cylinder body comprises a crankshaft mounting hole, a main oil duct and an oil suction opening, the crankshaft mounting hole is located between the air inlet side and the air outlet side and is provided with a first central shaft, the main oil duct is provided with a central shaft parallel to the first central shaft, the oil suction opening is used for sucking lubricating oil, and the main oil duct and the oil suction opening are located on two opposite sides of the crankshaft mounting hole respectively. According to the cylinder body assembly, the oil suction port and the main oil gallery are respectively positioned at the two opposite sides of the crankshaft mounting hole, so that the oil way is simple to arrange, and a good lubricating effect can be obtained.

Description

Cylinder block assembly for engine and engine

Technical Field

The invention relates to the technical field of engine cooling, in particular to a cylinder block assembly for an engine.

Background

Engines need to dissipate heat through engine cooling systems during the energy conversion process, and in the early days, engines were cooled primarily by air convection. As the power density of engines continues to increase and emissions and energy conservation technologies are considered, the engine blocks, if not cooled as necessary to operate in the optimum temperature range, tend to pre-ignite and deflagrate, causing damage to the engine components by subjecting them to additional shock loads. Meanwhile, the lubrication condition of the engine is deteriorated, and the normal clearance of the moving part is damaged, so that the friction and the abrasion of parts are caused, the working efficiency is finally reduced, and the service life is shortened.

In the prior art, a main oil gallery is typically provided in the cylinder block for lubricating the associated components of the cylinder block assembly. In order to introduce oil in the oil pan into the main oil gallery, the cylinder block assembly further includes an oil strainer located in the oil pan. The oil in the oil pan is sucked into the main oil gallery through the oil strainer. The cylinder body is provided with an oil suction port connected with an engine oil strainer. The existing oil suction port and the main oil gallery are both arranged on the same side of the cylinder body, and the arrangement can cause the main oil gallery to be not arranged easily.

Disclosure of Invention

The invention aims to provide a cylinder block assembly for an engine, which has a simple structure and a better lubricating effect.

In order to realize the purpose, the following technical scheme is provided:

according to one aspect of the present invention, a cylinder block assembly for an engine is provided that includes a cylinder block having an intake side, an exhaust side, a block front side, and a block rear side. The cylinder body comprises a crankshaft mounting hole, a main oil duct and an oil suction opening, the crankshaft mounting hole is located between the air inlet side and the air outlet side and is provided with a first central shaft, the main oil duct is provided with a central shaft parallel to the first central shaft, the oil suction opening is used for sucking lubricating oil, and the main oil duct and the oil suction opening are located on two opposite sides of the crankshaft mounting hole respectively.

Preferably, the cylinder block assembly further includes an oil strainer located below the cylinder block and a mount fixing the oil strainer to the cylinder block, the mount being provided with a first connecting passage communicating oil passages of the intake side and the exhaust side and a second connecting passage communicating the oil strainer with the oil suction port.

Preferably, the first connecting channel and the second connecting channel are vertically arranged and are separately arranged.

Preferably, the main oil gallery is located at an exhaust side, the oil suction port is located at an air inlet side, the cylinder block further comprises an oil filter arranged at the air inlet side and an oil cooler arranged at the air outlet side, and the cylinder block comprises a first oil passage flowing into the oil filter, a second oil passage flowing out of the oil filter and connected with the first connecting channel, a third oil passage flowing into the oil cooler and connected with the first connecting channel, and a fourth oil passage flowing out of the oil cooler and connected with the main oil gallery.

Preferably, the first oil path, the second oil path and the third oil path are all L-shaped, the second oil path and the third oil path are located in the same plane, and the plane where the first oil path is located is perpendicular to the plane where the second oil path and the third oil path are located.

Preferably, the plane of the second oil path and the plane of the third oil path are perpendicular to the first central axis.

Preferably, the cylinder block further includes a first balance shaft mounting hole having a central shaft parallel to the first central shaft, a second balance shaft mounting hole having a central shaft parallel to the first central shaft, and a camshaft mounting hole having a central shaft parallel to the first central shaft, the first balance shaft mounting hole, the camshaft mounting hole, and the main oil gallery are located on the same side of the cylinder block, and the second balance shaft mounting hole and the main oil gallery are located on opposite sides of the cylinder block.

Preferably, the camshaft mounting hole is located above the main oil gallery, and the first balance shaft mounting hole is located below the main oil gallery.

Preferably, the cylinder block further includes a first branch oil passage connecting the main oil gallery and the camshaft mounting hole, and a second branch oil passage connecting the main oil gallery and the crankshaft mounting hole, and the first branch oil passage and the second branch oil passage are located on the same plane.

Preferably, the cylinder block further includes a third branch oil passage connecting the second branch oil passage and the second balance shaft mounting hole, and the third branch oil passage and the first branch oil passage are located on the same plane.

According to another aspect of the present invention, there is also provided an engine including the cylinder block assembly described above.

According to the cylinder body assembly, the oil suction port and the main oil gallery are respectively positioned at the two opposite sides of the crankshaft mounting hole, so that the oil way is simple to arrange, and a good lubricating effect can be obtained.

Drawings

The invention is described in further detail below with reference to the following figures and detailed description:

FIG. 1 is a partially exploded view of the cylinder block assembly of the present invention.

FIG. 2 is a perspective view of the cylinder block assembly mounting water pump of the present invention.

FIG. 3 is a perspective view of the cylinder block assembly mounting oil cooler of the present invention.

FIG. 4 is a perspective view of the cylinder block assembly mounting cooling conduit of the present invention.

FIG. 5 is a perspective view of the cylinder block assembly mounting oil pump of the present invention.

FIG. 6 is a front view of the cylinder block assembly mounting oil pump, mount and oil strainer of the present invention.

FIG. 7 is a schematic view of the cylinder block assembly of the present invention without the mount and oil strainer.

Fig. 8 is a sectional view taken along the line "a-a" in fig. 7.

Fig. 9a is a perspective view of a cooling duct.

Fig. 9b is a front view of the cooling duct.

FIG. 9c is a cross-sectional view taken along line "B-B" in FIG. 9B.

FIG. 10 is a partial cross-sectional view of a cylinder block assembly.

Fig. 11 is a sectional view taken along the line "C-C" in fig. 10.

FIG. 12 is a perspective view of the mounting block and oil filter assembled.

FIG. 13 is a perspective view of another angle of the mount and oil filter assembly.

FIG. 14 is a cross-sectional view of the mount and oil filter assembled.

Fig. 15 is a cross-sectional view taken along line "D-D" in fig. 14.

Fig. 16 is a sectional view taken along line "E-E" in fig. 14.

Detailed Description

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.

For the sake of simplicity, the drawings only schematically show the parts relevant to the present invention, and they do not represent the actual structure as a product. In addition, in order to make the drawings concise and understandable, components having the same structure or function in some of the drawings are only schematically illustrated or only labeled. In this document, "one" means not only "only one" but also a case of "more than one".

It should be further understood that the term "and/or" as used in this specification and the appended claims refers to and includes any and all possible combinations of one or more of the associated listed items.

In this context, it is to be understood that, unless otherwise explicitly stated or limited, the terms "mounted," "connected," and "connected" are to be construed broadly and may include, for example, a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

In addition, in the description of the present application, the terms "first," "second," and the like are used only for distinguishing the description, and are not intended to indicate or imply relative importance.

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following description will be made with reference to the accompanying drawings. It is obvious that the drawings in the following description are only some examples of the invention, and that for a person skilled in the art, without inventive effort, other drawings and embodiments can be derived from them.

Referring to fig. 1 to 6, the present invention discloses a cylinder block assembly 100 including a cylinder block 1, a cooling pipe 2 fixed to the cylinder block 1, a water pump 3 fixed to the cylinder block 1, an oil cooler 4 fixed to the cylinder block 1, an oil strainer 5, a mount 6 fixing the oil strainer 5 to the cylinder block 1, and an oil pump 7. The cylinder block 1 is provided with an intake side 13, an exhaust side 14, a block front side 11 and a block rear side 12. The water pump 3 and the oil pump 7 are provided on the front side 11 of the cylinder block, the oil cooler 4 is provided on the exhaust side 14, the oil strainer 5 and the mount 6 are provided on the lower side of the cylinder block 1, and the cooling duct 2 is provided on the rear side 12 of the cylinder block. Preferably, a suction port (not numbered) of the oil strainer 5 is provided in an intermediate region below the cylinder block 1. The longitudinal direction in the present invention is a direction of the cylinder block 1 along the first center axis 1941 (see below), and is also a front-rear direction of the cylinder block 1. The lateral direction in the present invention is a direction perpendicular to the first center axis 1941, and is also a left-right direction of the cylinder block 1.

The cylinder block assembly 100 in the present embodiment is a part of an engine. In addition to including cylinder block assembly 100, engines typically include an oil pan, cylinder head housing, turbocharger, and fuel injection system, among other things.

The cylinder block 1 includes a crankshaft mounting hole 194 provided with a first center shaft 1941, a main oil gallery 185 provided with a center shaft parallel to the first center shaft 1941, a camshaft mounting hole 191 provided with a center shaft parallel to the first center shaft 1941, a first balance shaft mounting hole 193 provided with a center shaft parallel to the first center shaft 1941, and a second balance shaft mounting hole 192 provided with a center shaft parallel to the first center shaft 1941. A camshaft mounting hole 191 is provided above the main oil gallery 185, and a first balance shaft mounting hole 193 is provided below the main oil gallery 185. The first and second balance

shaft mounting holes

193 and 192 are located on opposite sides of the crankshaft mounting hole 194, respectively. The first balance shaft mounting hole 193, the camshaft mounting hole 191, and the main oil gallery 185 are located on the same side of the cylinder block. Preferably, the first balance shaft mounting hole 193, the camshaft mounting hole 191, and the main oil gallery 185 are located on the exhaust side 14 of the cylinder block, and the second balance shaft mounting hole 192 is located on the intake side 13 of the cylinder block. The center axis of the main oil gallery 185 is closer to the center of the cylinder block 1 than the center axes of the camshaft mounting hole 191 and the first balance shaft mounting hole 193.

The water pump 3 is provided above the cylinder block 1, and the oil pump 7 is provided below the cylinder block. The intake side 12 of the cylinder block 1 is also provided with an oil filter mount 124, and an oil filter (not shown) is fixed to the oil filter mount 124.

Referring to fig. 7 to 9c, the cylinder block assembly 100 includes cooling water lines and cylinders 16 disposed between the cooling water lines. The cooling water line includes a first water path 171 located on the intake side 13, a second water path 172 located on the exhaust side 14, and a third water path 173 connecting the first water path 171 and the second water path 172 and located on the rear side 12 of the cylinder. The cooling water line is provided around the cylinder block 16, and can cool the cylinder block 1.

The cylinder block 1 is further provided with an oil cooler mount 15 on the exhaust side 14, and the oil cooler mount 15 is provided on the second water passage 172. This arrangement makes it possible to cause cooling water to flow into the oil cooler 4 (see fig. 3) to cool the oil (lubricating oil) flowing through the oil cooler. The cylinder block assembly 100 further includes a cooling duct 2 fixed to the block rear side 12, and a third water passage 173 is provided in the cooling duct 2. In the present embodiment, since the first and

second water passages

171 and 172 are provided in the cylinder block 1, the first and

second water passages

171 and 172 may be referred to as a cylinder block water passage. Since the third water passage 173 is provided in the cooling duct 2, the third water passage 173 may also be referred to as a cooling duct water passage. The third water passage 173 in the present embodiment is fixed to the cylinder block 1 by assembling, but in other embodiments, the third water passage 173 may be directly provided in the cylinder block 1.

The cooling pipe 2 is elongated and placed on the upper side of the cylinder block 1. The cooling pipe 2 includes a first connection port 1731 at one end of the third water path 173 and connected to the first water path 171, and a second connection port 1732 at the other end of the third water path 173 and connected to the second water path 172. The first connection port 1731 and the second connection port 1732 are both rectangular, and the height of the first connection port 1731 is smaller than the height of the second connection port 1732. Increasing the height of the second connection port 1732 allows the cooling water flowing through the second connection port 1732 to better flow into the oil cooler 4.

The first and

second water paths

171 and 172 are disposed in parallel and perpendicular to the third water path 173. The first and

second water paths

171 and 172 extend in parallel to the first central axis 1941. The cooling water pipeline includes water inlet and return water mouth (not numbered) of all locating the cylinder body front side, and water inlet and return water mouth all are linked together with water pump 3.

The cylinder block 1 further includes a cylinder jacket chamber surrounding the cylinder and communicating with the first water passage 171. The cylinder 1 includes a first cylinder 161 and a second cylinder 162 which is far from the front side 11 of the cylinder body than the first cylinder 161, and the cylinder jacket cavity includes a first cylinder jacket cavity 1612 surrounding the first cylinder 161 and a second cylinder jacket cavity 1622 surrounding the second cylinder 162. The cooling water pipe further includes a first communication hole 1611 connecting the first cylinder jacket chamber 1612 and the first water passage 171, and a second communication hole 1621 connecting the second cylinder jacket chamber 1622 and the first water passage 171. The aperture of the first communication hole 1611 is smaller than the aperture of the second communication hole 1621. This arrangement can make the amount of cooling water flowing into the first cylinder jacket cavity 1622 and the second cylinder jacket cavity 1612 almost the same.

The cylinder block 1 further includes a third cylinder 163 located closer to the block front side 11 than the first cylinder 161 and a fourth cylinder 164 located farther from the block front side 11 than the second cylinder 162. The cylinder jacket cavities also include a third cylinder jacket cavity 1632 surrounding the third cylinder 163 and a fourth cylinder jacket cavity 1642 surrounding the fourth cylinder 164. The cooling water line further includes a third communication hole 1631 connecting the third cylinder jacket chamber 1632 and the first water passage 171, and a fourth communication hole 1641 connecting the fourth cylinder jacket chamber 1642 and the first water passage 171. The first communication hole 1611 has an aperture equal to that of the third communication hole 1631, and the second communication hole 1621 has an aperture equal to that of the fourth communication hole 1641.

The second water path 172 is disposed in non-communication with the cylinder jacket chamber, and the third water path 173 is disposed in non-communication with the cylinder jacket chamber. This arrangement allows the cooling water path to flow through the cylinder jacket cavity and move up and into the cylinder head to form a water path (not shown). Meanwhile, the cooling water flowing out from the water pump 3 moves around the cylinder through the cooling water path and enters the water pump 3 again to form another water path, so that a good cooling effect can be achieved on the cylinder block 1. Although the number of cylinders in the present embodiment is four, other numbers of cylinders are also within the scope of the present invention.

Referring to fig. 10 to 16, the oil pump 7 rotates to suck oil in an oil pan (not shown) into an oil passage in the cylinder block 1 through the strainer 6. The cylinder block 1 is also provided with an oil suction port 1811 at the intake side 13 for sucking in lubricating oil and connected to the oil strainer 6. The mount 6 is provided with a first connecting passage 623 communicating oil passages of the intake side 13 and the exhaust side 14 and a second connecting passage 611 communicating the oil strainer 6 with the oil suction port 1811. Preferably, the first connection channel 623 and the second connection channel 611 are vertically disposed. The oil suction opening 1811 is located at the intake side 13 (fig. 5).

An oil filter (not shown) is provided on the intake side 13, and the oil cooler 4 is provided on the exhaust side 14. The cylinder block 1 includes a first oil passage 182 that flows into the oil filter, a second oil passage 183 that flows out from the oil filter and is connected to the first connecting passage 623, a third oil passage 184 that flows into the oil cooler 4 and is connected to the first connecting passage 623, and a fourth oil passage 188 that flows out from the oil cooler 4 and is connected to the main oil passage 185. The fourth oil passage 188 is disposed perpendicular to the main oil passage 185. The first oil path 182, the second oil path 183 and the third oil path 184 are all in an L shape, the second oil path 183 and the third oil path 184 are located on the same plane, and the plane where the first oil path 182 is located is perpendicular to the plane where the second oil path 183 and the third oil path 184 are located.

The first oil passage 182 includes a first longitudinal section 1821 having a central axis parallel to a first central axis 1941, and a first transverse section 1822 perpendicular to the first longitudinal section 1821 and extending to the intake side 13 and communicating with the oil filter. The second oil path 183 includes a second lateral section 1832 flowing from the oil filter into the cylinder block 1 and a first vertical section 1831 extending perpendicularly to and downward from the second lateral section 1832 and connected to the first connecting passage 623. The third oil path 184 includes a second vertical section 1841 flowing from the first connecting passage 623 into the cylinder block 1 and a third lateral section 1842 perpendicular to the second vertical section and flowing into the oil cooler 4. The fourth oil passage 188 extends in a direction perpendicular to the first center axis 1941 and is provided in a lateral direction. The fourth oil passage 188 connects the oil cooler 4 and the main oil gallery 185 such that the oil (or lubricating oil) in the oil cooler 4 flows into the main oil gallery 185 through the main oil gallery 185. Since the oil cooler 4 is supplied with cooling water, the cooling water can cool the oil flowing through the oil cooler 4. One end of the first connecting passage 623 is provided with a first extension 621 extending vertically, and the other end is provided with a second extension 622 extending vertically. The first extension 621 is connected to the second vertical section 1841, and the second extension 622 is connected to the first vertical section 1831.

The cylinder block 1 further includes a first branch oil passage 1862 connecting the main oil gallery 185 and the camshaft mounting hole 191, a second branch oil passage 1862 connecting the main oil gallery 185 and the crankshaft mounting hole 194, a third branch oil passage 1863 connecting the second branch oil passage 1862 and the second balance shaft mounting hole 192, and a fourth branch oil passage (not shown) connecting the main oil gallery 185 and the first balance shaft mounting hole 193. The first branch oil passage 1861, the second branch oil passage 1862, and the third branch oil passage 1863 are located on the same plane. The central axes of the first branch oil passage 1861 and the second branch oil passage 1862 are positioned on the same straight line and are disposed obliquely. The first branch oil passage 1861 and the second branch oil passage 1862 have the same diameter, and this arrangement enables the first branch oil passage 1861 and the second branch oil passage 1862 to be processed at one time. The center axis of the third branch oil passage 1863 is located in the lateral direction. Since the fourth branch oil passage and the third branch oil passage 1863 are not located on the same plane, the fourth branch oil passage is not seen in the cross-sectional view of fig. 11.

The cylinder block 1 is also provided with a vertically disposed fifth oil passage 181, and an oil suction port 1811 is provided at an end of the fifth oil passage 181. The other end of the fifth oil passage 181 is connected to the oil pump 7. When the oil pump 7 is operated, oil in an oil pan (not shown) flows into the oil strainer, then flows into the second connecting passage 611 of the mount 6, then flows into the vertical section 612, and then flows into the fifth oil passage 181. The vertical section 612 may be considered as a part of the second connection channel 611. Subsequently, the oil flows into the oil pump 7, and the oil flowing out of the oil pump 7 flows into the first oil passage 182. The oil flowing out of the first oil passage 182 flows into an oil filter (not shown), and then the oil flowing out of the oil filter flows into the second oil passage 183. Subsequently, the oil in the second oil passage 183 flows into the first connecting passage 623 and then into the third oil passage 184. The oil in the third oil passage 184 flows into the oil cooler 4, and the oil flowing out of the oil cooler 4 flows into the fourth oil passage 188 and then into the main oil passage 185. The main oil gallery 185 is disposed in a longitudinal direction, and the engine oil in the main oil gallery 185 flows into the crankshaft mounting hole 194, the camshaft mounting hole 191, the first balance shaft mounting hole 193, and the second balance shaft mounting hole through the respective branch oil passages, respectively, to lubricate the respective components.

The mounting seat 6 is square. The mount 6 includes a link 61, a second link 62 connected to the first link 62 and vertically disposed, a third link 63 connected to the first link 62 and vertically disposed, a fourth link 64 connected to the second link 62 and vertically disposed, and a fifth link 65 connecting the first link 61 and the fourth link 64. The first link 61, the second link 62, the fourth link 64, and the third link 63 are connected in sequence, thereby forming a square shape. One end of the fifth link 65 is connected to the midpoint of the first link 61 and the other end is connected to the midpoint of the fourth link 64. The first connecting passage 623 is provided to the second link 62, and the second connecting passage 611 is provided to the first link 61. The first link 61 and the fourth link 64 are arranged in parallel, and the second link 62, the third link 63 and the fifth link 65 are arranged in parallel. One end of the oil strainer 5 is fixed to the first link 61 by means of assembly. Although the mounting seat 6 in this embodiment is provided as described above, in other embodiments, it may be provided in other forms, such as a triangular shape.

Since the temperature of the intake side 13 of the cylinder block 1 is lower than the temperature of the exhaust side 14, the components are mounted as much as possible on the intake side of the cylinder block 1. Since the mounting area of the intake side is limited, the oil cooler is mounted on the exhaust side of the cylinder block, so that the number of parts mounted on the intake side can be reduced, and the mounting area can be saved. The oil flowing through the oil cooler 4 is cooled by introducing cooling water into the oil cooler 4. A cooling water path is provided around the cylinder 16 to cool the cylinder 16. A cooling water path is provided around the cylinder 16 to cool the cylinder 16. Through setting up oil cooler 4 in the exhaust side, but make full use of limited organism space increases the engine oil cooling area and simultaneously can the rational distribution cooling water endless cylinder block for the engine can obtain better cooling effect.

It will be apparent to those skilled in the art that various modifications and variations can be made to the above-described exemplary embodiments of the present invention without departing from the spirit and scope of the invention. Thus, it is intended that the present invention cover the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.

Claims

1. A cylinder block assembly for an engine, the cylinder block assembly including a cylinder block provided with an intake side, an exhaust side, a block front side and a block rear side, characterized in that the cylinder block includes a crankshaft mounting hole provided with a first center shaft between the intake side and the exhaust side, a main oil gallery provided with a center shaft parallel to the first center shaft, and an oil suction port for sucking lubricating oil, the oil suction port and the main oil gallery being located at opposite sides of the crankshaft mounting hole, respectively.

2. The cylinder block assembly according to claim 1, further comprising a strainer located below the cylinder block and a mount fixing the strainer to the cylinder block, the mount being provided with a first connecting passage communicating oil passages of an intake side and an exhaust side and a second connecting passage communicating the strainer with an oil suction port.

3. The cylinder block assembly of claim 2, wherein the first connecting passage and the second connecting passage are vertically disposed and are separately disposed.

4. The cylinder block assembly of claim 2, wherein the main oil passage is located at an exhaust side, the oil suction port is located at an intake side, the cylinder block further comprises an oil filter provided at the intake side, and an oil cooler provided at the exhaust side, and the cylinder block comprises a first oil passage flowing into the oil filter, a second oil passage flowing out from the oil filter and connected to the first connecting passage, a third oil passage flowing into the oil cooler and connected to the first connecting passage, and a fourth oil passage flowing out from the oil cooler and connected to the main oil passage.

5. The cylinder block assembly of claim 4, wherein the first oil passage, the second oil passage, and the third oil passage are all "L" shaped, the second oil passage and the third oil passage are located in the same plane, and the plane in which the first oil passage is located is perpendicular to the plane in which the second oil passage and the third oil passage are located.

6. The cylinder block assembly of claim 5, wherein the second and third oil passages lie in a plane that is perpendicular to the first central axis.

7. The cylinder block assembly of claim 1, wherein the cylinder block further includes a first balance shaft mounting hole having a center axis parallel to the first center axis, a second balance shaft mounting hole having a center axis parallel to the first center axis, and a camshaft mounting hole having a center axis parallel to the first center axis, the first balance shaft mounting hole, the camshaft mounting hole and the main oil gallery being located on a same side of the cylinder block, the second balance shaft mounting hole and the main oil gallery being located on opposite sides of the cylinder block.

8. The cylinder block assembly of claim 7, wherein the camshaft mounting bore is located above the main oil gallery and the first balance shaft mounting bore is located below the main oil gallery.

9. The cylinder block assembly of claim 7, wherein the cylinder block further includes a first branch oil passage connecting the main oil gallery and the camshaft mounting bore and a second branch oil passage connecting the main oil gallery and the crankshaft mounting bore, the first branch oil passage and the second branch oil passage being located on a same plane.

10. The cylinder block assembly of claim 9, wherein the cylinder block further includes a third branch oil passage connecting the second branch oil passage and the second balance shaft mounting hole, the third branch oil passage and the first branch oil passage being located on the same plane.

11. An engine comprising a cylinder block assembly according to any one of claims 1 to 10.