Balancing shaft mechanism and engine assembly

Abstract

The present application belongs to the field of engine technology, and discloses a balance shaft mechanism and an engine assembly. The balance shaft mechanism is arranged below an engine cylinder body. The housing comprises two balance shaft sleeves and a support arranged between the two balance shaft sleeves. Two balance shafts are arranged in the two balance shaft sleeves respectively, and the two balance shafts are in driving connection with an engine crankshaft, so that the two balance shafts can rotate under the driving of the engine crankshaft, and the unbalance amount is generated, thereby reducing the engine vibration. In addition, the two balance shaft sleeves extend along the horizontal direction, and the outer diameters are L. The support has a crankshaft accommodation slot with an opening facing upward, so that the crankshaft can extend into the crankshaft accommodation slot, the height of the engine is reduced, the slot depth of the crankshaft accommodation slot along the vertical direction is H, and H / L is greater than or equal to 1 / 3, so that the engine crankshaft can extend into the deeper part of the crankshaft accommodation slot, and the height of the engine is further reduced.

Description

Technical Field

[0001] This invention relates to the field of engine technology, and more particularly to balance shaft mechanisms and engine assemblies. Background Technology

[0002] To reduce engine vibration, a balance shaft is usually installed in the cylinder block. The balance shaft is generally a shaft with an eccentric weight that rotates synchronously with the crankshaft. The reverse vibration force generated by the eccentric weight, i.e. the imbalance, is equivalent to the imbalance generated by the original moving parts of the engine, thereby reducing engine vibration and achieving a good balance effect for the engine.

[0003] Currently, there are two common arrangements for balance shaft mechanisms. One is to place the balance shaft on the side of the crankshaft and connect the crankshaft and the balance shaft through an intermediate gear. However, this structure is complex, has high friction loss, and poor reliability. The other solution is to place the balance shaft mechanism below the engine block. This structure is simple, but it increases the overall height of the engine. Summary of the Invention

[0004] According to one aspect of the present invention, the present invention provides a balance shaft mechanism to solve the problem that placing the balance shaft mechanism below the engine block in the prior art increases the overall height of the engine.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] Balance shaft mechanism, used to be installed below the engine block;

[0007] include:

[0008] The housing includes two balance shaft sleeves and a support member disposed between the two balance shaft sleeves. Both balance shaft sleeves extend horizontally and have an outer diameter of L. The support member has an upward-opening crankshaft clearance groove for the engine crankshaft to extend into. The vertical groove depth of the crankshaft clearance groove is H, and H / L≥1 / 3.

[0009] There are two balance shafts, each rotatably mounted in a balance shaft sleeve, and both balance shafts are connected to the engine crankshaft drive.

[0010] As a preferred embodiment of the balance shaft mechanism, the housing further includes a rib plate connected between the two balance shaft sleeves, the rib plate being disposed within the crankshaft relief groove and connected to the bottom wall of the crankshaft relief groove.

[0011] As a preferred embodiment of the balance shaft mechanism, the bottom wall of the crankshaft relief groove is provided with an oil leakage hole.

[0012] As a preferred embodiment of the balance shaft mechanism, a bushing is provided inside the balance shaft sleeve, and the balance shaft is rotatably connected to the inner wall of the bushing. The inner wall of the bushing is elliptical, and the major axis of the inner wall of the bushing extends horizontally and the minor axis extends vertically.

[0013] As a preferred embodiment of the balance shaft mechanism, the inner wall of the bushing is provided with an oil groove for storing lubricating oil.

[0014] As a preferred embodiment of the balance shaft mechanism, a bearing is provided inside the balance shaft sleeve and connected to the outer ring of the bearing, the balance shaft is connected to the inner ring of the bearing, and the sleeve and the bearing are respectively connected to the two ends of the balance shaft.

[0015] According to another aspect of the invention, an engine assembly is provided, including the aforementioned balance shaft mechanism, and further comprising:

[0016] Engine block, wherein the balance shaft mechanism is disposed below the engine block;

[0017] An engine crankshaft is connected to the engine block, and the engine crankshaft can extend into the crankshaft relief groove;

[0018] The oil pan is located below the balance shaft mechanism.

[0019] As a preferred embodiment of the engine assembly, the oil pan is equipped with an oil pump, the oil pump is driven by an oil pump gear, the engine crankshaft is equipped with a first sprocket, the first of the two balance shafts is equipped with a second sprocket, the oil pump gear is fixedly connected to a third sprocket, and the first sprocket, the second sprocket and the third sprocket are connected by a chain drive.

[0020] As a preferred embodiment of the engine assembly, the second of the two balance shafts is provided with a transmission gear that meshes with the oil pump gear.

[0021] As a preferred embodiment of the engine assembly, one end of the first of the two balance shafts extends out of the balance shaft sleeve, and the second sprocket is disposed outside the balance shaft sleeve.

[0022] The beneficial effects of this invention are:

[0023] This invention provides a balance shaft mechanism for installation below the engine block. The housing includes two balance shaft sleeves and a support member disposed between the two balance shaft sleeves. Two balance shafts are provided, each rotatably mounted within one of the two balance shaft sleeves, and both balance shafts are drive-connected to the engine crankshaft. This allows the two balance shafts to rotate under the drive of the engine crankshaft, generating an imbalance that can counteract the imbalance generated by the engine, thereby reducing engine vibration. Furthermore, both balance shaft sleeves extend horizontally and have an outer diameter of L. The support member has an upward-opening crankshaft clearance groove to facilitate crankshaft insertion, reducing the overall engine height. The vertical depth of the crankshaft clearance groove is H, where H / L ≥ 1 / 3, resulting in a large groove depth that allows the engine crankshaft to extend deep into the groove, further reducing the overall engine height.

[0024] The present invention also provides an engine assembly including the above-mentioned balance shaft mechanism, and further including an engine block, an engine crankshaft connected to the engine block, and an oil pan disposed below the balance shaft mechanism. The balance shaft mechanism is disposed below the engine block, and the engine crankshaft can extend into the crankshaft relief groove of the balance shaft mechanism. The crankshaft relief groove has a large groove depth so that the engine crankshaft can extend into a deeper part of the crankshaft relief groove, thereby further reducing the overall height of the engine. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the balance shaft mechanism in an embodiment of the present invention;

[0026] Figure 2 yes Figure 1 Sectional view of section AA;

[0027] Figure 3 This is a schematic diagram of the balance shaft structure in an embodiment of the present invention;

[0028] Figure 4 This is a schematic diagram of the bushing structure in an embodiment of the present invention. Figure 1 ;

[0029] Figure 5 This is a schematic diagram of the bushing structure in an embodiment of the present invention. Figure 2 .

[0030] In the picture:

[0031] 1. Housing; 11. Balance shaft sleeve; 111. Bushing; 112. Oil groove; 113. Bearing; 114. Support bearing; 115. Snap ring; 116. Positioning bolt; 117. Fixing bolt; 12. Support component; 13. Relief groove; 131. Oil leakage hole; 14. Rib plate;

[0032] 2. Balance shaft; 21. Second sprocket; 22. Transmission gear; 23. Counterweight. Detailed Implementation

[0033] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, and not all of the structures.

[0034] In the description of this invention, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0035] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0036] In the description of this embodiment, the terms "upper," "lower," "left," and "right," etc., refer to the orientation or positional relationship shown in the accompanying drawings. They are used only for ease of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention. In addition, the terms "first" and "second" are used only for distinction in description and have no special meaning.

[0037] To reduce engine vibration, a balance shaft is usually installed in the cylinder block. There are two common arrangements for the balance shaft mechanism. One is to place the balance shaft next to the crankshaft and connect the crankshaft and the balance shaft through an intermediate gear. However, this structure is complex, has high friction loss, and poor reliability. The other solution is to place the balance shaft mechanism under the engine block. Its structure is simple, but this solution increases the overall height of the engine.

[0038] To address the aforementioned issues, this embodiment provides a balance shaft mechanism to solve the problem that placing the balance shaft mechanism below the engine block in the prior art increases the overall height of the engine, and can be used in the field of engine technology.

[0039] Reference Figures 1-5 The balance shaft mechanism is installed below the engine block. It includes a housing 1 and balance shafts 2. The housing 1 includes two balance shaft sleeves 11 and a support member 12 positioned between the sleeves. Two balance shafts 2 are provided, each rotatably mounted within one of the sleeves 11. Both balance shafts 2 are connected to the engine crankshaft, allowing them to rotate under the crankshaft's drive, generating an imbalance that counteracts the engine's own imbalance, thus reducing engine vibration. Specifically, each balance shaft 2 is equipped with a counterweight 23. When the balance shaft 2 rotates at high speed under the engine crankshaft's drive, the counterweight 23 generates an imbalance that counteracts the engine crankshaft's imbalance, achieving a vibration damping effect.

[0040] Continue to refer to Figures 1-5 Both balance shaft sleeves 11 extend horizontally and have an outer diameter of L. The support member 12 has an upward-opening crankshaft relief groove 13 for the engine crankshaft to extend into. The vertical depth of the crankshaft relief groove 13 is H, where H / L ≥ 1 / 3, thus giving the crankshaft relief groove 13 a greater depth so that the engine crankshaft can extend deeper into the crankshaft relief groove 13, further reducing the overall height of the engine. Specifically, the bottom wall of the crankshaft relief groove 13 can be set lower by increasing the distance between the two balance shaft sleeves 11, thereby increasing the depth of the crankshaft relief groove 13. Optionally, the bottom wall of the crankshaft relief groove 13 is arc-shaped, and the vertical depth of the crankshaft relief groove 13 is the distance from the lowest point of the bottom wall of the crankshaft relief groove 13 to the opening of the crankshaft relief groove 13. In this embodiment, the diameter of the balance shaft sleeve 11 is approximately 62.5 mm, and the engine crankshaft can extend into the crankshaft relief groove 13 by 27 mm, which is approximately 43% of the diameter of the balance shaft sleeve 11.

[0041] Continue to refer to Figures 1-5 The housing 1 also includes a rib 14 connected between the two balance shaft sleeves 11. The rib 14 is disposed in the crankshaft relief groove 13 and connected to the bottom wall of the crankshaft relief groove 13. The rib 14 is used to increase the structural strength between the two balance shaft sleeves 11 and the bottom wall of the crankshaft relief groove 13.

[0042] Continue to refer to Figures 1-5Since the crankshaft relief groove 13 is used for the engine crankshaft to extend into, oil may drip from the engine crankshaft. Therefore, an oil leakage hole 131 is provided on the bottom wall of the crankshaft relief groove 13 to allow the engine oil to escape from the crankshaft relief groove 13.

[0043] Continue to refer to Figures 1-5 A bushing 111 is provided inside the balance shaft sleeve 11. The balance shaft 2 is rotatably connected to the inner wall of the bushing 111. The inner wall of the bushing 111 is elliptical, with its major axis extending horizontally and its minor axis extending vertically. The purpose of the elliptical inner wall of the bushing 111 is that, since the balance shaft mechanism is located below the engine block, the balance shaft 2 mainly serves to reduce the longitudinal vibration of the engine. The longitudinal length of the bushing 111 is relatively low. When the balance shaft 2 rotates at high speed, an imbalance will occur, and the bushing 111 will be longitudinally elongated to make its longitudinal length consistent with its transverse length. This deforms the inner wall of the bushing 111 into a circle or approximately a circle, allowing a uniform thickness oil film to be formed between the bushing 111 and the balance shaft 2, thereby optimizing lubrication and reducing friction loss. Optionally, in order to limit the two bushings 111, a retaining ring 115 is provided on the end face of one bushing 111 to prevent the bushing 111 from moving along the axis of the balance bushing tube 11, and the other bushing 111 is fixed to the housing 1 by a positioning bolt 116 to prevent it from being displaced or rotated.

[0044] Continue to refer to Figures 1-5 The inner wall of the bushing 111 is provided with an oil groove 112 for storing lubricating oil, so that more lubricating oil can be stored in the bushing 111, which is conducive to the formation of oil film and further reduces friction.

[0045] Continue to refer to Figures 1-5 A bearing 113 is installed inside the balance shaft sleeve 11 and connected to the outer ring of the bearing 113. The balance shaft 2 is connected to the inner ring of the bearing 113. The sleeve 111 and the bearing 113 are respectively connected to the two ends of the balance shaft 2. Optionally, a support bearing 114 is provided in the middle part of the balance shaft 2. The outer ring of the support bearing 114 is connected to the balance shaft sleeve 11, and the balance shaft 2 is connected to the inner ring of the support bearing 114.

[0046] This embodiment also provides an engine assembly, which includes the aforementioned balance shaft mechanism. The engine assembly also includes an engine block, an engine crankshaft, and an oil pan. The balance shaft mechanism is disposed below the engine block; the oil pan is disposed below the balance shaft mechanism; the engine crankshaft is connected to the engine block, and the engine crankshaft can extend into the crankshaft relief groove 13. The crankshaft relief groove 13 has a large groove depth so that the engine crankshaft can extend into a deeper part of the crankshaft relief groove 13, thereby further reducing the overall height of the engine.

[0047] Optionally, an oil pump is installed in the oil pan, driven by an oil pump gear. The engine crankshaft is equipped with a first sprocket, and the first of the two balance shafts 2 is equipped with a second sprocket 21. The oil pump gear is fixedly connected to a third sprocket. The first sprocket, the second sprocket 21, and the third sprocket are connected by a chain drive. Thus, when the engine crankshaft rotates, the chain drive synchronously drives the first of the two balance shafts 2 and the oil pump gear to rotate, thereby realizing the transmission connection between the engine crankshaft and the first of the two balance shafts 2.

[0048] Optionally, the second of the two balance shafts 2 is provided with a transmission gear 22, which meshes with the oil pump gear, thereby connecting the second of the two balance shafts 2 to the engine crankshaft. This arrangement saves space as much as possible and simplifies the structure.

[0049] Optionally, one end of the first of the two balance shafts 2 extends out of the balance shaft sleeve 11, and the second sprocket 21 is disposed outside the balance shaft sleeve 11. Similarly, one end of the second of the two balance shafts 2 extends out of the balance shaft sleeve 11, and the transmission gear 22 is disposed outside the balance shaft sleeve 11. Gaskets are provided between the second sprocket 21 and its corresponding bushing 111, and between the transmission gear 22 and its corresponding bushing 111. Fixing bolts 117 are connected to both ends of the two balance shaft sleeves 11 to limit the movement of the second sprocket 21 and the transmission gear 22.

[0050] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art will be able to make various obvious changes, readjustments, and substitutions without departing from the scope of protection of the present invention. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. Balance shaft mechanism, used to be installed below the engine block; Its features are, include: The housing (1) includes two balance shaft sleeves (11) and a support member (12) disposed between the two balance shaft sleeves (11). Both balance shaft sleeves (11) extend horizontally and have an outer diameter of L. The support member (12) has an upward-opening crankshaft relief groove (13) for the engine crankshaft to extend into. The vertical groove depth of the crankshaft relief groove (13) is H, and H / L≥1 / 3. There are two balance shafts (2), which are rotatably installed in two balance shaft sleeves (11) respectively, and both balance shafts (2) are connected to the crankshaft of the engine. The balance shaft sleeve (11) is provided with a bushing (111), and the balance shaft (2) is rotatably connected to the inner wall of the bushing (111). The inner wall of the bushing (111) is elliptical, and the major axis of the inner wall of the bushing (111) extends horizontally and the minor axis extends vertically.

2. The balance shaft mechanism according to claim 1, characterized in that, The housing (1) also includes a rib (14) connected between the two balance shaft sleeves (11), the rib (14) being disposed in the crankshaft relief groove (13) and connected to the bottom wall of the crankshaft relief groove (13).

3. The balance shaft mechanism according to claim 1, characterized in that, The bottom wall of the crankshaft relief groove (13) is provided with an oil leakage hole (131).

4. The balance shaft mechanism according to claim 1, characterized in that, The inner wall of the bushing (111) is provided with an oil groove (112) for storing lubricating oil.

5. The balance shaft mechanism according to claim 1, characterized in that, The balance shaft sleeve (11) is provided with a bearing (113) and is connected to the outer ring of the bearing (113). The balance shaft (2) is connected to the inner ring of the bearing (113). The sleeve (111) and the bearing (113) are respectively connected to the two ends of the balance shaft (2).

6. An engine assembly, characterized in that, Including the balance shaft mechanism as described in any one of claims 1-5, further comprising: Engine block, wherein the balance shaft mechanism is disposed below the engine block; An engine crankshaft is connected to the engine block and is capable of extending into the crankshaft relief groove (13). The oil pan is located below the balance shaft mechanism.

7. The engine assembly according to claim 6, characterized in that, The oil pan is equipped with an oil pump, which is driven by an oil pump gear. The engine crankshaft is equipped with a first sprocket, and the first of the two balance shafts (2) is equipped with a second sprocket (21). The oil pump gear is fixedly connected to a third sprocket. The first sprocket, the second sprocket (21), and the third sprocket are connected by a chain drive.

8. The engine assembly according to claim 7, characterized in that, The second of the two balance shafts (2) is provided with a transmission gear (22) that meshes with the oil pump gear.

9. The engine assembly according to claim 7, characterized in that, One end of the first of the two balance shafts (2) extends out of the balance shaft sleeve (11), and the second sprocket (21) is disposed outside the balance shaft sleeve (11).

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