Balance mechanism and engine

Abstract

The invention provides a balance mechanism and an engine, the balance mechanism comprises a balance shaft, the axial direction of the balance shaft is parallel to the axial direction of a crankshaft of a horizontally opposed two-cylinder engine; the axial direction of the crankshaft is parallel to or the same as the Y-axis direction; the two cylinders are located on the two sides of the crankshaft in the X-axis direction respectively and distributed in the Y-axis direction at intervals. The balance shaft is used for being connected with the crankshaft through the preset gear assembly, so that when the crankshaft rotates, the balance shaft is driven to rotate in the direction opposite to the rotating direction of the crankshaft at the same rotating speed; the balance assembly comprises a bevel gear assembly and a balance part, and the bevel gear assembly is connected with the balance shaft and the balance part, so that the rotating axis of the balance part is parallel to or the same as the Z-axis direction; the two balance assemblies are distributed in the axial direction of the balance shaft. The two balance parts are oppositely arranged in the X-axis direction, and the rotation directions of the two balance parts are opposite, so that the two balance parts generate force in the X-axis direction to balance the reciprocating inertia force of the two cylinders correspondingly.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of engines, in particular to a balancing mechanism and an engine. BACKGROUND

[0002] Horizontal opposed engine: the engine pistons are evenly distributed on both sides of the crankshaft, moving left and right in the horizontal direction, so as to reduce the overall height of the engine, shorten the length, and lower the vehicle's center of gravity, making the vehicle ride more smoothly.

[0003] For horizontal two-cylinder opposed engines, due to the presence of the misalignment value, the first-order reciprocating inertia torque is unbalanced, resulting in a large torsional torque in the misalignment direction. SUMMARY

[0004] The main purpose of the present application is to provide a balancing mechanism and an engine to solve the problem of first-order reciprocating inertia torque imbalance of horizontal two-cylinder opposed engines without increasing the imbalance in the other two directions.

[0005] In order to achieve the above-mentioned purpose, according to one aspect of the present application, a balancing mechanism is provided, which comprises: a balancing shaft, the axial direction of the balancing shaft is parallel to the axial direction of the crankshaft of the horizontal two-cylinder opposed engine; the axial direction of the crankshaft is parallel or identical to the Y-axis direction; the two cylinders are respectively located on both sides of the crankshaft along the X-axis direction and are spaced apart along the Y-axis direction; a preset gear assembly, the balancing shaft is connected to the crankshaft through the preset gear assembly, so that when the crankshaft rotates around its central axis, the balancing shaft rotates around its central axis in the opposite direction of the rotation direction of the crankshaft at the same speed; a balancing assembly, the balancing assembly comprises a bevel gear assembly and a balancing part, the bevel gear assembly is connected to the balancing shaft and connected to the balancing part, so that the balancing shaft drives the balancing part to rotate through the bevel gear assembly, and the rotation axis of the balancing part is parallel or identical to the Z-axis direction; the balancing assembly is two, the two balancing assemblies are distributed along the axial direction of the balancing shaft; the balancing parts of the two balancing assemblies are oppositely arranged along the X-axis direction and have opposite rotation directions, so that the two balancing parts both generate a force along the X-axis direction to balance the reciprocating inertia forces of the two cylinders respectively.

[0006] Further, the preset gear assembly comprises a starting gear, an intermediate gear set and an ending gear; the starting gear is connected to the crankshaft, and the central axis of the starting gear coincides with the central axis of the crankshaft; the ending gear is connected to the balancing shaft, and the central axis of the ending gear coincides with the central axis of the balancing shaft; the starting gear is in meshing transmission with the ending gear through the intermediate gear set; the speed ratio of the starting gear to the ending gear is 1:1.

[0007] Further, the bevel gear assembly comprises a first bevel gear and a second bevel gear; the first bevel gear is connected with the balance shaft, and the central axis of the first bevel gear coincides with the central axis of the balance shaft; the first bevel gear and the second bevel gear are engaged with each other, so that the rotation axis of the second bevel gear is parallel or identical to the Z-axis direction; the balance part is connected with the second bevel gear.

[0008] Further, the preset central plane is perpendicular to the Y-axis direction; the two cylinders are respectively located on two sides of the preset central plane along the Y-axis direction, and the distances from the two cylinders to the preset central plane are equal; the two balance assemblies are respectively located on two sides of the preset central plane.

[0009] Further, the distances from the two balance assemblies to the preset central plane are equal. And / or, the weights of the balance parts of the two balance assemblies are equal.

[0010] Further, the two balance assemblies form a balance unit; the balance unit is at least one.

[0011] Further, the balance part is arranged around the rotation axis thereof, and the balance part has two ends arranged at intervals along the circumferential direction thereof.

[0012] Further, the angle between the two ends of the balance part is 180 degrees.

[0013] Further, the balance assembly further comprises a support shaft, the central axis of the support shaft is the rotation axis of the balance part, and the balance part is rotatably sleeved on the support shaft.

[0014] According to another aspect of the present application, an engine is provided, which comprises a crankshaft and the above-mentioned balance mechanism.

[0015] By applying the technical solution of the present application, the balance mechanism comprises a balance shaft, a preset gear assembly and a balance assembly; the axial direction of the balance shaft is parallel to the axial direction of the crankshaft of the horizontally-opposed two-cylinder engine; the axial direction of the crankshaft is parallel or identical to the Y-axis direction. The two cylinders are respectively located on two sides of the crankshaft along the X-axis direction, and the two cylinders are distributed at intervals along the Y-axis direction.

[0016] The balance shaft is connected with the crankshaft through the preset gear assembly, so that when the crankshaft rotates around the central axis thereof, the balance shaft is driven by the preset gear assembly to rotate around the central axis thereof in the direction opposite to the rotation direction of the crankshaft and at the same rotation speed as the crankshaft.

[0017] The balance assembly comprises a bevel gear assembly and a balance part; the bevel gear assembly is connected with the balance shaft, and the bevel gear assembly is connected with the balance part, so that the balance shaft drives the balance part to rotate through the bevel gear assembly, and the rotation axis of the balance part is parallel or identical to the Z-axis direction.

[0018] The two balance assemblies are distributed along the axial direction of the balance shaft, and the balance portions of the two balance assemblies are oppositely arranged along the X-axis direction and rotate in opposite directions, so that the two balance portions generate forces along the X-axis direction to balance the reciprocating inertial forces of the two cylinders respectively.

[0019] When the balance shaft drives the two balance portions to rotate, the balance portions generate a force along the X-axis direction and a force along the Y-axis direction during the rotation because the rotation axes of the balance portions are parallel to or the same as the Z-axis direction. Since the two balance portions are oppositely arranged along the X-axis direction and rotate in opposite directions, the forces along the Y-axis direction of the two balance portions are opposite in direction and equal in size, so that the forces along the Y-axis direction of the two balance portions can be offset to avoid generating additional unbalance in the Y-axis direction.

[0020] The two cylinders are a left cylinder and a right cylinder, and the left-right direction is the X-axis direction. The left cylinder generates a reciprocating inertial force to the left, and the right cylinder generates a reciprocating inertial force to the right. The force along the X-axis direction of one balance portion is to the right to balance the reciprocating inertial force to the left of the left cylinder, and the force along the X-axis direction of the other balance portion is to the left to balance the reciprocating inertial force to the right of the right cylinder.

[0021] The balance mechanism of the present application is used to solve the problem of first-order reciprocating inertial torque imbalance of the horizontally-opposed two-cylinder engine without increasing the imbalance in other two directions. BRIEF DESCRIPTION OF DRAWINGS

[0022] The drawings accompanying the specification of the present application serve to provide further understanding of the present application, and the illustrative embodiments of the present application and their descriptions serve to explain the present application, and do not constitute improper limitations on the present application. In the drawings:

[0023] Fig. 1 A structural schematic diagram of an embodiment of the balance mechanism according to the present application is shown;

[0024] Fig. 2 A schematic diagram of a preset center surface according to the present application is shown;

[0025] Fig. 3 A top view of the balance mechanism according to the present application is shown.

[0026] Among the above drawings, the following reference signs are included:

[0027] 10, balance shaft;

[0028] 20, preset gear assembly; 21, initial end gear; 221, first intermediate gear; 222, second intermediate gear; 23, terminal end gear;

[0029] 30, balancing assembly; 31, bevel gear assembly; 311, first bevel gear; 312, second bevel gear; 32, balancing part; 33, supporting shaft;

[0030] 200, crankshaft; 201, shaft body; 210, left cylinder; 220, right cylinder; 230, preset center plane. DETAILED DESCRIPTION

[0031] It should be noted that the embodiments and features in the embodiments in the present application can be combined with each other without conflict. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0032] It should be noted that the following detailed description is exemplary and is intended to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the present application belongs.

[0033] It should be noted that the terms used herein are only for the purpose of describing the specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, the singular form is intended to include the plural form unless the context clearly indicates otherwise, and it should also be understood that when the terms "comprise" and / or "include" are used in the specification, they indicate the presence of a feature, step, operation, device, component, and / or combination thereof.

[0034] The present application provides a balancing mechanism, please refer to Figs. 1 to 3 The balancing mechanism includes a balancing shaft 10, a preset gear assembly 20, and a balancing assembly 30. The axial direction of the balancing shaft 10 is parallel to the axial direction of the crankshaft 200 of the horizontally opposed two-cylinder engine. The axial direction of the crankshaft 200 is parallel or identical to the Y-axis direction. The two cylinders are located on both sides of the crankshaft 200 along the X-axis direction, and are spaced apart along the Y-axis direction. The two cylinders refer to two cylinders.

[0035] The balancing shaft 10 is connected to the crankshaft 200 through the preset gear assembly 20, so that when the crankshaft 200 rotates around its central axis, the balancing shaft 10 is driven by the preset gear assembly 20 to rotate around its central axis in the opposite direction of the rotation direction of the crankshaft 200 at the same speed as the crankshaft 200. The central axis of the crankshaft 200 refers to the central axis of the shaft body 201 of the crankshaft 200.

[0036] The balance assembly 30 comprises a bevel gear assembly 31 and a balance part 32; the bevel gear assembly 31 is connected with the balance shaft 10, and the bevel gear assembly 31 is connected with the balance part 32, so that the balance shaft 10 drives the balance part 32 to rotate through the bevel gear assembly 31, and the rotation axis of the balance part 32 is parallel or identical to the direction of the Z axis; that is, the rotation axis of the balance part 32 is perpendicular to the central axis of the balance shaft 10.

[0037] The balance assembly 30 is two, and the two balance assemblies 30 are distributed along the axial direction of the balance shaft 10; the balance parts 32 of the two balance assemblies 30 are oppositely arranged along the X axis direction, and the rotation directions of the balance parts 32 of the two balance assemblies 30 are opposite, so that the two balance parts 32 all generate forces along the X axis direction to balance the reciprocating inertial forces of the two cylinders respectively.

[0038] When the balance shaft 10 drives the two balance parts 32 to rotate, since the rotation axis of the balance part 32 is parallel or identical to the direction of the Z axis, each balance part 32 will generate a component force along the X axis direction and a component force along the Y axis direction during rotation. Since the two balance parts 32 are oppositely arranged along the X axis direction and the rotation directions are opposite, the directions of the Y axis direction component forces of the two balance parts 32 are opposite and the sizes are equal, so the Y axis direction component forces of the two balance parts 32 can be offset to avoid generating additional unbalance in the Y axis direction.

[0039] The two cylinders are a left cylinder 210 and a right cylinder 220, and the left-right direction is the X axis direction; the left cylinder 210 generates a left reciprocating inertial force, and the right cylinder 220 generates a right reciprocating inertial force. The X axis direction component force of one balance part 32 is a right component force, which is used to balance the left reciprocating inertial force of the left cylinder 210; the X axis direction component force of the other balance part 32 is a left component force, which is used to balance the right reciprocating inertial force of the right cylinder 220.

[0040] It should be noted that the reciprocating inertial force of the cylinder refers to the reciprocating inertial force generated by the piston connecting rod of the cylinder.

[0041] Specifically, the two balance assemblies 30 are arranged in one-to-one correspondence with the two cylinders, so that the balance part 32 of each balance assembly 30 is used to balance the reciprocating inertial force of the corresponding cylinder.

[0042] The balance mechanism of the application is used to solve the problem of first-order reciprocating inertial torque imbalance of the horizontally opposed two-cylinder engine, without increasing the imbalance in other two directions. That is, the balance mechanism of the application is a first-order balance mechanism.

[0043] In this embodiment, the preset gear assembly 20 includes a starting gear 21, an intermediate gear set, and a terminal gear 23. The starting gear 21 is connected to the crankshaft 200, and the central axis of the starting gear 21 coincides with the central axis of the crankshaft 200, so that the crankshaft 200 drives the starting gear 21 to rotate around its central axis. The starting gear 21 meshes with the terminal gear 23 through the intermediate gear set, so that the starting gear 21 drives the terminal gear 23 to rotate around its central axis. The terminal gear 23 is connected to the balance shaft 10, and the central axis of the terminal gear 23 coincides with the central axis of the balance shaft 10, so that the terminal gear 23 drives the balance shaft 10 to rotate around its central axis. The speed ratio of the starting gear 21 to the terminal gear 23 is 1:1, so that the balance shaft 10 and the crankshaft 200 rotate at the same speed.

[0044] Specifically, the starting gear 21 is mounted on the crankshaft 200; the ending gear 23 is mounted on the balance shaft 10.

[0045] like Fig. 1 As shown, the intermediate gear set includes a first intermediate gear 221 and a second intermediate gear 222. The central axes of the starting gear 21, the first intermediate gear 221, the second intermediate gear 222, and the ending gear 23 are all parallel. The first intermediate gear 221 meshes with the starting gear 21, the first intermediate gear 221 meshes with the second intermediate gear 222, and the second intermediate gear 222 meshes with the ending gear 23. The speed ratio between the starting gear 21 and the first intermediate gear 221 is 2:1, the speed ratio between the first intermediate gear 221 and the second intermediate gear 222 is 1:2, and the speed ratio between the second intermediate gear 222 and the ending gear 23 is 1:1.

[0046] The starting gear 21 and the first intermediate gear 221 rotate in opposite directions, the first intermediate gear 221 and the second intermediate gear 222 rotate in opposite directions, and the second intermediate gear 222 and the terminal gear 23 rotate in opposite directions; therefore, the starting gear 21 and the terminal gear 23 rotate in opposite directions.

[0047] In the embodiment, the bevel gear assembly 31 comprises a first bevel gear 311 and a second bevel gear 312; the first bevel gear 311 is connected with the balance shaft 10, and the central axis of the first bevel gear 311 coincides with the central axis of the balance shaft 10, so that the balance shaft 10 drives the first bevel gear 311 to rotate around the central axis of the first bevel gear 311; the first bevel gear 311 and the second bevel gear 312 are engaged with each other, and the central axis of the first bevel gear 311 is perpendicular to the central axis of the second bevel gear 312, so that the first bevel gear 311 drives the second bevel gear 312 to rotate around the central axis of the second bevel gear 312, and the rotation axis of the second bevel gear 312 is parallel or identical to the Z-axis direction. The balance part 32 is connected with the second bevel gear 312, so that the second bevel gear 312 drives the balance part 32 to rotate around the central axis of the second bevel gear 312.

[0048] Specifically, the first bevel gear 311 is sleeved on the balance shaft 10.

[0049] In the embodiment, the preset central plane 230 is perpendicular to the Y-axis direction; the two cylinders are respectively located on the two sides of the preset central plane 230 along the Y-axis direction; the distances from the two cylinders to the preset central plane 230 are equal along the Y-axis direction; and the two balance assemblies 30 are respectively located on the two sides of the preset central plane 230.

[0050] Optionally, the distances from the two balance assemblies 30 to the preset central plane 230 are equal along the Y-axis direction.

[0051] Optionally, the weights of the balance parts 32 of the two balance assemblies 30 are equal; and the masses of the balance parts 32 of the two balance assemblies 30 are equal.

[0052] In actual use, the distances of the balance assemblies 30 to the preset central plane 230 along the Y-axis direction and the weights of the balance parts 32 can be adjusted according to actual needs, as long as the purpose that the Y-axis direction components of the two balance parts 32 can offset each other and the two balance parts 32 can balance the left reciprocating inertial force of the left cylinder 210 and the right reciprocating inertial force of the right cylinder 220 respectively can be achieved. Preferably, the distances of the two balance assemblies 30 to the preset central plane 230 along the Y-axis direction are equal, and the weights of the balance parts 32 of the two balance assemblies 30 are equal, which can certainly meet the above purpose.

[0053] Optionally, the two balance assemblies 30 are arranged in one-to-one correspondence with the two cylinders; and the positions of the two balance assemblies 30 correspond to the positions of the corresponding cylinders along the Y-axis direction.

[0054] Optionally, the two balance assemblies 30 form a balance unit; and the balance unit is at least one. When the balance unit is multiple, the balance assemblies 30 of the multiple balance units are distributed along the axial direction of the balance shaft 10.

[0055] In the embodiment, the balancing part 32 is a block structure, that is, the balancing part 32 is a balancing block.

[0056] In the embodiment, the balancing part 32 is arranged around the rotation axis thereof, and the balancing part 32 has two ends arranged at intervals along the rotation circumferential direction thereof. That is, a preset ring is arranged around the rotation axis of the balancing part 32, and the balancing part 32 is a part of the preset ring along the circumferential direction of the preset ring.

[0057] Optionally, the balancing part 32 is a half-ring structure, that is, the balancing part 32 is half of the preset ring along the circumferential direction of the preset ring, that is, the angle between the two ends of the balancing part 32 along the circumferential direction of the preset ring is 180 degrees.

[0058] Since the balancing part 32 has two ends arranged at intervals along the rotation circumferential direction thereof, the two ends of the balancing part 32 must be open; as shown in the figure, the relative arrangement of the two balancing parts 32 along the X-axis direction means that the openings of the two balancing parts 32 are arranged relative to each other along the X-axis direction. Fig. 3

[0059] In the embodiment, the balancing assembly 30 further comprises a support shaft 33, the central axis of the support shaft 33 is the rotation axis of the balancing part 32, and the balancing part 32 is rotatably sleeved on the support shaft 33.

[0060] Specifically, the second bevel gear 312 is rotatably sleeved on the support shaft 33, and the central axis of the second bevel gear 312 coincides with the central axis of the support shaft 33.

[0061] The application also provides an engine comprising the crankshaft 200 and the balancing mechanism described above. Specifically, the engine is a horizontally opposed two-cylinder engine.

[0062] From the above description, it can be seen that the above-mentioned embodiments of the application achieve the following technical effects:

[0063] In the balancing mechanism provided by the application, the balancing mechanism comprises a balancing shaft 10, a preset gear assembly 20 and a balancing assembly 30; the axial direction of the balancing shaft 10 is parallel to the axial direction of the crankshaft 200 of the horizontally opposed two-cylinder engine; the axial direction of the crankshaft 200 is parallel or identical to the Y-axis direction. The two cylinders are respectively located on the two sides of the crankshaft 200 along the X-axis direction, and the two cylinders are distributed at intervals along the Y-axis direction.

[0064] The balancing shaft 10 is connected with the crankshaft 200 through the preset gear assembly 20, so that when the crankshaft 200 rotates around its central axis, the balancing shaft 10 is driven by the preset gear assembly 20 to rotate around its central axis in the opposite direction to the rotation direction of the crankshaft 200 at the same rotation speed as the crankshaft 200.

[0065] ​The balance assembly 30 comprises a bevel gear assembly 31 and a balance part 32; the bevel gear assembly 31 is connected with the balance shaft 10, and the bevel gear assembly 31 is connected with the balance part 32, so that the balance shaft 10 drives the balance part 32 to rotate through the bevel gear assembly 31, and the rotation axis of the balance part 32 is parallel or identical to the Z-axis direction.

[0066] The balance assembly 30 is two, and the two balance assemblies 30 are distributed along the axial direction of the balance shaft 10; the balance parts 32 of the two balance assemblies 30 are oppositely arranged along the X-axis direction, and the rotation directions of the balance parts 32 of the two balance assemblies 30 are opposite, so that the two balance parts 32 all generate forces along the X-axis direction to balance the reciprocating inertial forces of the two cylinders respectively.

[0067] When the balance shaft 10 drives the two balance parts 32 to rotate, since the rotation axis of the balance part 32 is parallel or identical to the Z-axis direction, each balance part 32 generates a component force along the X-axis direction and a component force along the Y-axis direction during rotation. Since the two balance parts 32 are oppositely arranged along the X-axis direction and the rotation directions are opposite, the directions of the Y-axis direction component forces of the two balance parts 32 are opposite and the sizes are equal, so the Y-axis direction component forces of the two balance parts 32 can be offset to avoid generating additional unbalance in the Y-axis direction.

[0068] The two cylinders are a left cylinder 210 and a right cylinder 220, and the left-right direction is the X-axis direction; the left cylinder 210 generates a left reciprocating inertial force, and the right cylinder 220 generates a right reciprocating inertial force. The X-axis direction component force of one balance part 32 is a right component force to balance the left reciprocating inertial force of the left cylinder 210; and the X-axis direction component force of the other balance part 32 is a left component force to balance the right reciprocating inertial force of the right cylinder 220.

[0069] The balance mechanism of the application is used to solve the problem of first-order reciprocating inertial torque imbalance of the horizontally-opposed two-cylinder engine without increasing the imbalance in other two directions.

[0070] The balance mechanism of the application realizes the direction conversion of force through the bevel gear assembly 31 to balance the first-order reciprocating inertial torque, realizes the good NVH (noise, vibration, and sound roughness) performance of the overall engine, and has compact overall structure arrangement, reduces the overall boundary, and improves the power transmission efficiency and use reliability of the engine.

[0071] The balance mechanism of the application can realize a certain balance rate without increasing the overall size of the whole machine. According to the weight requirement of the whole machine and the NVH performance of the engine, the required balance rate is realized. It can be seen that the balance mechanism of the application has compact structure, does not increase the size of the whole machine, is light in weight, and can meet the design of different balance rates according to the space of the whole machine.

[0072] It is to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting. It will be apparent to those skilled in the art that various modifications and variations can be made in the present application without departing from the spirit or scope of the application. Thus, it is intended that the present application cover modifications and variations of this application provided they come within the scope of the appended claims and their equivalents.

[0073] Spatially relative terms, such as "beneath", "below", "lower", "above", "upper" and the like, can be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if a device described is turned over in use, a downwardly position element or feature can then be oriented upwardly. Thus, the example term "below" can encompass both an orientation of below and above. The device can be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly. Likewise, descriptions of movement along and around various axes includes various unusual orientations and assay configurations.

[0074] The specific embodiments of the present application have been shown and described in order to illustrate the application. It will be understood, however, that the application can be practiced in other embodiments and that modifications and variations can be made to the disclosed embodiments without departing from the spirit and scope of the underlying principles.

Claims

1. A balancing mechanism, characterized by, The application relates to a balance shaft (10) which is axially parallel to the crankshaft (200) of a horizontally-opposed two-cylinder engine; the axial direction of the crankshaft (200) is parallel or identical to the Y-axis direction; the two cylinders are respectively located on the two sides of the crankshaft (200) along the X-axis direction and are spaced along the Y-axis direction. A preset gear assembly (20) is used for connecting the balance shaft (10) with the crankshaft (200) so that when the crankshaft (200) rotates around its central axis, the balance shaft (10) is driven to rotate around its central axis in the opposite direction of the rotation direction of the crankshaft (200) at the same speed. A balance assembly (30) comprises a bevel gear assembly (31) and a balance part (32); the bevel gear assembly (31) is connected with the balance shaft (10) and the balance part (32) so that the balance shaft (10) drives the balance part (32) to rotate through the bevel gear assembly (31) and the rotation axis of the balance part (32) is parallel or identical to the Z-axis direction. The balance assembly (30) is two; the two balance assemblies (30) are distributed along the axial direction of the balance shaft (10); the balance parts (32) of the two balance assemblies (30) are oppositely arranged along the X-axis direction and rotate in opposite directions so that the two balance parts (32) both generate forces along the X-axis direction to balance the reciprocating inertial forces of the two cylinders respectively. The preset gear assembly (20) comprises a starting gear (21), an intermediate gear set and a terminal gear (23); the starting gear (21) is connected with the crankshaft (200) and its central axis is coincident with the central axis of the crankshaft (200); the terminal gear (23) is connected with the balance shaft (10) and its central axis is coincident with the central axis of the balance shaft (10); the starting gear (21) is in mesh transmission with the terminal gear (23) through the intermediate gear set; the speed ratio of the starting gear (21) to the terminal gear (23) is 1:

1.

2. The counterbalance mechanism of claim 1, wherein, The bevel gear assembly (31) comprises a first bevel gear (311) and a second bevel gear (312); the first bevel gear (311) is connected with the balance shaft (10) and its central axis is coincident with the central axis of the balance shaft (10); the first bevel gear (311) and the second bevel gear (312) are in mesh with each other so that the rotation axis of the second bevel gear (312) is parallel or identical to the Z-axis direction; the balance part (32) is connected with the second bevel gear (312).

3. The counterbalance mechanism of claim 1, wherein, A preset central plane (230) is perpendicular to the Y-axis direction; the two cylinders are respectively located on the two sides of the preset central plane (230) along the Y-axis direction and the distances of the two cylinders to the preset central plane (230) are equal; the two balance assemblies (30) are respectively located on the two sides of the preset central plane (230).

4. The counterbalance mechanism of claim 1, wherein, ​ 5. The counterbalance mechanism according to claim 4, wherein, the distance from the two counterbalance assemblies (30) to the preset center plane (230) is equal; and / or the weight of the counterbalance portions (32) of the two counterbalance assemblies (30) is equal.

6. Counterbalance mechanism according to claim 4 or 5, characterized in that The two counterbalance assemblies (30) form a counterbalance unit; the counterbalance unit is at least one.

7. The counterbalance mechanism of claim 1, wherein, The counterbalance portion (32) is disposed around its rotation axis, and the counterbalance portion (32) has two ends spaced apart along its circumference.

8. The counterbalance mechanism of claim 7, wherein, The angle between the two ends of the counterbalance portion (32) is 180 degrees.

9. The counterbalance mechanism of claim 1, wherein, The counterbalance assembly (30) further comprises a support shaft (33), the central axis of the support shaft (33) is the rotation axis of the counterbalance portion (32), and the counterbalance portion (32) is rotatably sleeved on the support shaft (33).

10. An engine characterized by, The counterbalance mechanism according to any one of claims 1 to 9 and a crankshaft (200).

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