Multi-link crankshaft negative offset power transmission device and opposed multi-link double crankshaft internal combustion engine

Abstract

The multi-link crankshaft negative offset power transmission device and the opposed multi-link double crankshaft internal combustion engine adopt a multi-link transmission structure, and the center negative offset of its crankshaft is arranged on one side of the piston running center line. The crankshaft angle occupied by the piston during reciprocating motion is not equal, and the compression stroke occupies a crankshaft angle greater than 180°; the power stroke occupies a crankshaft angle less than 180°. The conversion of piston force into dimensionless torque of the crankshaft is greatly improved, and the crankshaft angle when the maximum dimensionless torque value is generated is closer to the top dead center. The multi-link transmission structure reduces the deviation angle between the upper connecting rod and the cylinder axis during piston movement, especially the deviation angle of the two-thirds stage of the power stroke with a large cylinder explosion pressure is smaller, so that the friction power consumption generated by the side pressure between the piston and the cylinder is reduced to a very small level. The crankshaft rotates at a constant speed and the power stroke is faster than the compression stroke.

Description

Technical Field

[0001] The invention relates to a power transmission device, in particular to a multi-link crankshaft negative offset power transmission device and an opposed multi-link double crankshaft internal combustion engine. Background Art

[0002] The various piston reciprocating engine power transmission mechanisms that have been disclosed so far all convert the reciprocating motion of the piston into rotational motion through a crank-connecting rod mechanism and a crankshaft, and the crankshaft is driven by the piston connecting rod to do work. From the perspective of converting chemical energy into mechanical energy, the effective thermal efficiency of a traditional crankshaft connecting rod structure engine is usually 30% to 40%, and up to about 50%. Only no more than half of the fuel energy is used to make the engine do effective work, and the energy conversion efficiency is not high. One of the main reasons is that the inherent defects of the traditional crankshaft connecting rod as a power transmission mechanism lead to the inability to effectively convert power. Especially in the first quarter of the stroke at the beginning of the power stroke, although the piston in the crankshaft connecting rod mechanism is under the action of the high pressure of the gas, the connecting rod and the crank arm are almost in a straight line. At this time, the tangential force on the crankshaft is very small and cannot effectively drive the crankshaft to rotate; the maximum value of the dimensionless torque converted by the piston force is 1.04, and the point where the maximum value is generated is 75 degrees of crankshaft rotation angle away from the top dead center. Taking a gasoline engine as an example, the conversion loss reaches 80% of the effective heat.

[0003] When the traditional single crankshaft connecting rod mechanism is working, there is alternating lateral pressure between the engine piston and the cylinder wall, which affects the friction power consumption between the piston and the cylinder. According to statistics, the friction power consumption of the piston-connecting rod system can account for 75% of the entire engine mechanical loss, and the friction power consumption of the cylinder liner-piston ring accounts for 75% of the piston-connecting rod system, resulting in low thermal efficiency.

[0004] The German patent (EP-0292603) introduces a multi-link piston internal combustion engine, which has the following structural features: the piston is connected to the crank by upper and lower connecting rods, the end point of the outward extension section of the upper connecting rod at the hinge of the upper and lower connecting rods is hinged to a swing rod, and the other end of the swing rod is supported on the eccentric block of the engine cylinder. The lateral force of the piston is reduced, the friction loss is reduced, and the maximum torque value per unit piston pressure is increased from 1.04 of the single crankshaft connecting rod to about 1.3. However, its shortcomings are that firstly, the center line of the piston movement intersects with the center line of the crankshaft, which limits the increase in the maximum torque value per unit piston pressure. Secondly, the upper and lower connecting rods are hinged, and the structure of the outer extension section at the lower end of the upper connecting rod and the hinge of a swing rod is complex and the strength of the mechanism is insufficient. Finally, the working stroke of the best embodiment is greater than 180 degrees of crankshaft rotation, and the thermal efficiency is not greatly improved. Summary of the invention

[0005] The purpose of the present invention is to provide a multi-link crankshaft negative offset power transmission device and an opposed multi-link double crankshaft internal combustion engine, which adopts a multi-link transmission structure, and its crankshaft center is negatively offset and arranged on one side of the piston running center line, the crankshaft angles occupied by the piston during reciprocating motion are not equal, the compression stroke occupies a crankshaft angle greater than 180°; the power stroke occupies a crankshaft angle less than 180°, and the crankshaft rotates at a constant speed and the power stroke is faster than the compression stroke. From the kinematic and dynamic analysis of the well-known traditional single crankshaft connecting rod mechanism, it is concluded that the dimensionless tangential force acting on the crank pin is completely consistent with the dimensionless speed of the piston in terms of size and sign, the piston moves fast in the power stroke and its dimensionless speed is high, which means that the dimensionless tangential force is large; the fast power stroke movement speed also means that the cylinder block and cylinder head maintain high temperature for a short time during the power stroke combustion, and the heat dissipation is small, and the heat loss is small, thereby improving the effective thermal efficiency of the engine.

[0006] The technical solution adopted by the present invention to solve the technical problem is: comprising a piston, the piston is connected to one end of an upper connecting rod through a piston pin, the other end of the upper connecting rod is hinged to one end of a lower connecting rod through a first hinge shaft, the other end of the lower connecting rod is connected to a crank of a crankshaft through a crank pin, and the crankshaft is arranged on one side of a piston motion center line L;

[0007] A third hinge shaft is arranged on the lower connecting rod, the third hinge shaft is hinged to one end of the rocker, and the other end of the rocker is hinged to the rocker seat through a fourth hinge shaft;

[0008] During the piston compression stroke, the crank pin is closer to the piston motion center line L, and during the piston power stroke, the crank pin is farther from the piston motion center line L;

[0009] During the piston compression stroke, the crankshaft crank rotates through a greater angle than during the piston power stroke;

[0010] The angle β formed by the line C1A between the center C1 of the first articulated shaft and the center A of the crank pin and the line CA between the center C of the third articulated shaft and the center A of the crank pin is 5°-30°;

[0011] When the center A of the crank pin rotates to the line OB between the center O of the crankshaft's main shaft and the center B of the fourth articulated shaft, the angle γ formed by the line CB between the center C of the third articulated shaft and the center B of the fourth articulated shaft and the line CA between the center C of the third articulated shaft and the center A of the crank pin is the minimum reverse transmission angle, and the angle of γ is 2°-49°.

[0012] The ratio of the length of the line C1A between the center C1 of the first articulated shaft and the center A of the crank pin to the length of the line CA between the center C of the third articulated shaft and the center A of the crank pin is 1:1-1.5:1;

[0013] During the working stroke of the piston, from the position where the crank and crankshaft center line OA are collinear and non-coincident with the line CA to the position where the crank and crankshaft center line OA rotate 65°, the angle δ between the center line DC1 of the upper connecting rod and the piston movement center line L is always ≤10°.

[0014] The ratio of the length of the line C1A between the center C1 of the first articulated shaft and the center A of the crank pin to the length of the line CA between the center C of the third articulated shaft and the center A of the crank pin is 1:1-1.35:1. The ratio of the length of the line C1A between the center C1 of the first articulated shaft and the center A of the crank pin to the length of the line CA between the center C of the third articulated shaft and the center A of the crank pin is 1:1. The angle β formed by the line C1A between the center C1 of the first articulated shaft and the center A of the crank pin and the line CA between the center C of the third articulated shaft and the center A of the crank pin is 10°-20°. The angle β formed by the line C1A between the center C1 of the first articulated shaft and the center A of the crank pin and the line CA between the center C of the third articulated shaft and the center A of the crank pin is 15°. The angle of the minimum reverse transmission angle γ is 2°-35°. The minimum reverse transmission angle γ is 2°.

[0015] An opposed multi-link double crankshaft internal combustion engine comprises a group of first cylinder bodies and a group of second cylinder bodies opposed to each other, each of the first cylinder body and the second cylinder body cooperates with a group of multi-link crankshaft negative bias power transmission devices, pistons are installed in the first cylinder body and the second cylinder body, the piston movement center lines L of the pistons in each group of the first cylinder body and the second cylinder body are located in the same plane, the pistons in the first cylinder body and the pistons in the second cylinder body work in opposite directions, the crankshafts of the multi-link crankshaft negative bias power transmission devices corresponding to the first cylinder body and the second cylinder body are respectively arranged on different sides of the plane where the center lines L of the piston movement are located, the crankshafts of the multi-link crankshaft negative bias power transmission devices corresponding to the first cylinder body and the second cylinder body have the same rotation direction, synchronous gears are installed on the two groups of crankshafts, the two groups of synchronous gears are meshed with the central intermediate gear, the center of the central intermediate gear is located on the plane where the center lines L of the piston movement are located, and the central intermediate gear is connected to the output shaft.

[0016] An opposed multi-link double crankshaft internal combustion engine comprises a group of first cylinder bodies and a group of second cylinder bodies opposed to each other, each of the first cylinder body and the second cylinder body cooperates with a group of multi-link crankshaft negative bias power transmission devices as described in claim 1, pistons are installed in the first cylinder body and the second cylinder body, the piston movement center lines L of the pistons in each group of the first cylinder body and the second cylinder body are located in the same plane, the pistons in the first cylinder body and the pistons in the second cylinder body work in opposite directions, the crankshafts of the multi-link crankshaft negative bias power transmission devices corresponding to the first cylinder body and the second cylinder body are arranged on the same side of the plane where the center lines L of the pistons are located, the crankshafts of the multi-link crankshaft negative bias power transmission devices corresponding to the first cylinder body and the second cylinder body rotate in opposite directions, synchronous gears are installed on the two groups of crankshafts, the two groups of synchronous gears are meshed with each other, and one group of synchronous gears is connected to the output shaft.

[0017] The positive effects of the present invention are: a multi-link transmission structure is adopted, and the center negative offset of its crankshaft is arranged on one side of the piston running center line. The crankshaft angles occupied by the piston during reciprocating motion are not equal, and the compression stroke occupies a crankshaft angle greater than 180°; the power stroke occupies a crankshaft angle less than 180°. The conversion of piston force into dimensionless torque of the crankshaft is greatly improved, and the crankshaft angle when the maximum dimensionless torque value is generated is closer to the top dead center. The use of a multi-link transmission structure reduces the deviation angle between the upper connecting rod and the cylinder axis during piston movement, especially the deviation angle of the two-thirds stage of the power stroke with a large cylinder explosion pressure is smaller, so that the friction power consumption generated by the side pressure between the piston and the cylinder is reduced to a very small level. The crankshaft rotates at a constant speed and the power stroke is faster than the compression stroke. From the kinematic and dynamic analysis of the known traditional single crankshaft connecting rod mechanism, it is concluded that the dimensionless tangential force acting on the crank pin is exactly the same as the dimensionless speed of the piston in terms of magnitude and sign. The piston moves fast in the power stroke and its dimensionless speed is high, which means that the dimensionless tangential force is large; the fast power stroke movement speed also means that the cylinder block and cylinder head maintain high temperature for a short time during the power stroke combustion, and the heat dissipation is small, resulting in small heat loss. The fast power stroke movement speed means that the fast combustion expansion speed can reduce the tendency of detonation and increase the engine compression ratio. Thereby improving the effective thermal efficiency of the engine. The center negative offset of the crankshaft is arranged on one side of the piston running center line, so that the piston stroke is greater than the traditional single crankshaft connecting rod mechanism, and the crankshaft size can be reduced when making engines with the same cylinder diameter and displacement. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the structural principle of the multi-link crankshaft negative bias power transmission device of the present invention; Figure 2 It is a comparison diagram of the modified torque curve when the minimum reverse transmission angle γ of the present invention is 25°, the torque curve of the conventional non-biased crank-connecting rod mechanism, and the modified torque curve when the minimum reverse transmission angle γ of the present invention is 12°; Figure 3It is a comparison diagram of the torque curves of the crankshaft of the multi-link type crankshaft negative bias power transmission device of the present invention when the crankshaft is positively biased and negatively biased; Figure 4 It is a schematic diagram of the structural principle of the first embodiment of the present invention; Figure 5 is a torque curve diagram of the first embodiment of the present invention; Figure 6 It is a schematic diagram of the structural principle of the second embodiment of the present invention; Figure 7 is a torque curve diagram of the second embodiment of the present invention; Figure 8 It is a schematic diagram of the structural principle of the third embodiment of the present invention; Fig. 9 is a torque curve diagram of the third embodiment of the present invention; Fig.10 Schematic diagram of the structure principle of the fourth embodiment of the present invention; Fig.11 is a torque curve diagram of the fourth embodiment of the present invention; Fig.12 Schematic diagram of the structure principle of the fifth embodiment of the present invention; Fig.13 is a torque curve diagram of the fifth embodiment of the present invention; Fig.14 is a schematic diagram of the structural principle of Embodiment 6 of the present invention; Fig.15 is a torque curve diagram of embodiment 6 of the present invention; Fig.16 Schematic diagram of the structure principle of the seventh embodiment of the present invention; Fig.17 is a torque curve diagram of Embodiment 7 of the present invention; Fig.18 is a schematic diagram of the structural principle of Embodiment 8 of the present invention; Fig.19 is a torque curve diagram of the eighth embodiment of the present invention; Fig. 20 is a schematic diagram of the structural principle of Embodiment 9 of the present invention; Fig.21 is a torque curve diagram of Embodiment 9 of the present invention; Fig. 22 is a schematic diagram of the structural principle of Embodiment 10 of the present invention; Fig.23 is a torque curve diagram of the tenth embodiment of the present invention; Fig.24 is a schematic diagram of the structural principle of the eleventh embodiment of the present invention; Fig.25 is a torque curve diagram of the eleventh embodiment of the present invention; Fig.26 is a schematic diagram of the structural principle of Embodiment 12 of the present invention; Fig. 27 is a torque curve diagram of the twelfth embodiment of the present invention; Fig.28 This is one of the schematic diagrams of the structural principle of the opposed multi-link double crankshaft internal combustion engine of the present invention; Fig.29 This is the second schematic diagram of the structural principle of the opposed multi-link double crankshaft internal combustion engine described in the present invention. DETAILED DESCRIPTION

[0019] The multi-link crankshaft negative bias power transmission device described in the present invention is as follows: Figure 1As shown, it includes a piston 1, the piston 1 is connected to one end of an upper connecting rod 3 through a piston pin 2, the other end of the upper connecting rod 3 is hinged to one end of a lower connecting rod 5 through a first hinge shaft 4, the other end of the lower connecting rod 5 is connected to the crank of a crankshaft 7 through a crank pin 6, and the crankshaft 7 is arranged on one side of the piston movement center line L;

[0020] A third hinge shaft 8 is provided on the lower connecting rod 5, the third hinge shaft 8 is hinged to one end of a rocker 9, and the other end of the rocker 9 is hinged to a rocker seat 11 through a fourth hinge shaft 10;

[0021] During the compression stroke of the piston 1, the crank pin (6) is closer to the piston motion center line L, and during the power stroke of the piston 1, the crank pin (6) is farther from the piston motion center line L;

[0022] During the compression stroke of the piston 1, the angle through which the crank of the crankshaft 7 rotates is greater than the angle through which the crank of the crankshaft 7 rotates during the power stroke of the piston 1;

[0023] The angle β formed by the line C1A between the center C1 of the first articulated shaft 4 and the center A of the crank pin 6 and the line CA between the center C of the third articulated shaft 8 and the center A of the crank pin 6 is 5°-30°;

[0024] When the center A of the crank pin 6 rotates to the line OB between the main shaft center O of the crankshaft 7 and the center B of the fourth articulated shaft 10 (at this time the center A of the crank pin 6 is located at point E), the angle γ formed by the line CB between the center C of the third articulated shaft 8 and the center B of the fourth articulated shaft 10 and the line CA between the center C of the third articulated shaft 8 and the center A of the crank pin 6 is the minimum reverse transmission angle, and the angle of γ is 2°-49°.

[0025] Figure 1 OACBO constitutes a crank rocker unit. The well-known crank rocker mechanism is that the crank actively rotates, and the rocker passively follows the swing, and the transmission angle is ∠ACB. In this case, the minimum transmission angle is usually required to be ≥40°, and the minimum transmission angle occurs when the crank OA is parallel to the body OB. This angle must be greater than 0° to ensure the normal operation of the mechanism.

[0026] The present invention is that the piston actively reciprocates, and the third articulated shaft of the lower connecting rod is transmitted to the rocker through the upper connecting rod D-C1, and the crank passively rotates. The transmission direction of the crank rocker mechanism is opposite to that of the known crank rocker mechanism, so the present invention calls this angle the reverse transmission angle. The minimum reverse transmission angle γ is Figure 1 The center point A of the crank pin 6 coincides with point E, that is, the angle ∠EC3B ( Figure 1The angle formed by the line between the center C1 of the first articulated shaft 4 and the center A of the crank pin 6 (referred to as C1A) and the line between the center C of the third articulated shaft 8 and the center A of the crank pin 6 (referred to as CA) is β, and C1A divided by CA is called the side length ratio k of the lower connecting rod;

[0027] When the length of crank OA is r, the length of crank pin and third articulated shaft is L, the length of rocker CB is y, and the distance between rocker swing center B and crank rotation center O is x, the formula of minimum reverse transmission angle γ is obtained according to the cosine theorem:

[0028]

[0029]

[0030] by Figure 1 For example, Figure 1 As shown, Figure 1 r = 2.00 cm; L = 5.30 cm; y = 3.5 cm; x = 4.592 cm; β = 15°; k = 1.2.

[0031] According to the above size ratio, we can get Figure 1 Medium γ = 25°.

[0032] Figure 1 The piston force F acts on the first hinge axis C1 of the lower connecting rod through the upper connecting rod, and the rocker force acts on the third hinge axis of the lower connecting rod through the rocker BC from the point B fixed to the body. The common point of action of the above two forces must be found first, and then the tangential force of the crankshaft point A is calculated from the common point force of the lower connecting rod. According to the synthesis and decomposition of the forces, the common point of action of the upper connecting rod force and the rocker force is the intersection point C2 of the straight line where the extension line of the rocker BC coincides with the upper connecting rod DC1. Point C2 changes position on the straight line where the upper connecting rod DC1 coincides with the rotation of the crank OA. When the piston is at the top dead center, the crank OA and the C2A line segment are straightened and collinear, represented by the OS line segment, and the angle ∠AOS is called the crankshaft angle.

[0033] δ is the angle between the piston motion centerline L and the upper connecting rod DC1. Without considering friction and inertia, a schematic diagram of engine torque decomposition is made. The combustion gas pressure F acts on the piston and is transmitted to the crank journal through the upper connecting rod, lower connecting rod and rocker to obtain the crankshaft torque T, which is expressed as:

[0034]

[0035] As mentioned above, the stroke of the multi-link crankshaft negative bias power transmission device is greater than that of the traditional single crankshaft connecting rod mechanism. For comparison, the stroke ratio of the piston stroke of the traditional single crankshaft connecting rod mechanism is 1, and the stroke ratio of the multi-link crankshaft negative bias power transmission device is divided by twice the crank 0-A length (2r), and the stroke ratio is calculated and multiplied by the calculated torque to obtain the corrected torque value. Continuing to calculate according to the above size ratio, assume the unit crank length and unit piston pressure (F = 1; r = 1), such as Figure 2 As shown, when the minimum reverse transmission angle γ = 25°, the modified torque curve of the present invention is plotted by a graphical method, represented by a solid line; the torque curve of the conventional non-biased crank-connecting rod mechanism is represented by a dotted line; when γ = 12°, the modified torque curve of the present invention is plotted by the above steps and methods, represented by a dotted line. Figure 2 It can be seen that as the minimum reverse transmission angle becomes smaller, the maximum output torque becomes larger, and the maximum point is closer to the top dead center, which are 1.823 and 2.16 respectively, both of which are greater than the maximum value of 1.058 of the traditional unbiased crank-connecting rod mechanism.

[0036] Figure 1 The middle curve W is the motion trajectory of the first articulated axis C1 point, in which the disconnected dotted line part represents the power stroke trajectory, and the continuous solid line part represents the compression stroke trajectory. It can be seen that the distance between the first half of the power stroke and the piston motion centerline is very small, that is, the angle δ between the piston motion centerline L and the upper connecting rod DC1 is very small, and the piston side pressure is very small. It is precisely at this time that the combustion pressure of the working medium in the combustion chamber is very large. Although the angle δ between the piston motion centerline L and the upper connecting rod DC1 in the second half of the power stroke and the compression stroke becomes larger, it is still smaller than the angle of the traditional single crankshaft. Moreover, the pressure in the cylinder is not large at this time, so the technical solution provided by the present invention solves the problem of large friction work paid by the engine piston.

[0037] Figure 3 The dotted line indicates Figure 1 The structure shown rotates counterclockwise, i.e., the torque curve of the crankshaft positive offset arrangement, and the power stroke is greater than 180° crankshaft rotation angle; the solid line indicates Figure 1 The torque curve of the structure shown rotates clockwise, that is, the crankshaft negative offset arrangement, and the power stroke is less than 180° crankshaft rotation angle. It is obvious from the curve that the crankshaft negative offset arrangement is significantly better than the crankshaft positive offset arrangement, and Figure 2 By comparison, it can also be seen that the maximum torque of the positive offset crankshaft arrangement is also inferior to that of the traditional single crankshaft connecting rod mechanism.

[0038] Use the same method as above to make different γ angles, β angles and different proportional dimensions of connecting rod C1A and connecting rod CA, and examine their modified torque curves.

[0039] Table 1

[0040]

[0041]

[0042] Compared with the traditional single crankshaft connecting rod mechanism, the multi-link crankshaft negative bias power transmission device greatly increases the maximum value of the correction torque and makes the crankshaft rotation angle where the maximum value of the correction torque occurs closer to the top dead center. The minimum reverse transmission angle γ is inversely proportional to the maximum value of the correction torque; although the maximum torque increases as the ratio of C1A to CA increases, the increase in the maximum value of the correction torque is small; the β angle is inversely proportional to the maximum value of the correction torque, but the change is small. Reasonable setting of the ratio of C1A to CA, combined with the size of the β angle, facilitates the installation of the first and third articulated shafts, and the crankshaft has good splash lubrication on the cylinder block.

[0043] Embodiment 1:

[0044] The piston 1 is connected to one end of an upper connecting rod 3 through a piston pin 2, the other end of the upper connecting rod 3 is hinged to one end of a lower connecting rod 5 through a first hinge shaft 4, the other end of the lower connecting rod 5 is connected to the crank of a crankshaft 7 through a crank pin 6, and the crankshaft 7 is arranged on one side of the piston movement center line L;

[0045] A third hinge shaft 8 is provided on the lower connecting rod 5, the third hinge shaft 8 is hinged to one end of a rocker 9, and the other end of the rocker 9 is hinged to a rocker seat 11 through a fourth hinge shaft 10;

[0046] When the crankshaft 7 is located on the right side of the piston movement center line L, the crankshaft 7 rotates in a clockwise direction; when the crankshaft is located on the left side of the piston movement center line L, the crankshaft 7 rotates in a counterclockwise direction;

[0047] When the piston reciprocates, the crankshaft angle occupied by the piston compression stroke is greater than the crankshaft angle occupied by the piston power stroke;

[0048] The ratio of the length of the line C1A between the center C1 of the first articulated shaft 4 and the center A of the crank pin 6 to the length of the line CA between the center C of the third articulated shaft 8 and the center A of the crank pin 6 is 1.2:1;

[0049] The angle β formed by the line C1A between the center C1 of the first articulated shaft 4 and the center A of the crank pin 6 and the line CA between the center C of the third articulated shaft 8 and the center A of the crank pin 6 is 5°;

[0050] When the center A of the crank pin 6 rotates to the line OB between the main shaft center O of the crankshaft 7 and the center B of the fourth articulated shaft 10, the angle γ formed by the line CB between the center C of the third articulated shaft 8 and the center B of the fourth articulated shaft 10 and the line CA between the center C of the third articulated shaft 8 and the center A of the crank pin 6 is the minimum reverse transmission angle, and the angle γ is 2°.

[0051] Embodiment 2:

[0052] The piston 1 is connected to one end of an upper connecting rod 3 through a piston pin 2, the other end of the upper connecting rod 3 is hinged to one end of a lower connecting rod 5 through a first hinge shaft 4, the other end of the lower connecting rod 5 is connected to the crank of a crankshaft 7 through a crank pin 6, and the crankshaft 7 is arranged on one side of the piston movement center line L;

[0053] A third hinge shaft 8 is provided on the lower connecting rod 5, the third hinge shaft 8 is hinged to one end of a rocker 9, and the other end of the rocker 9 is hinged to a rocker seat 11 through a fourth hinge shaft 10;

[0054] When the crankshaft 7 is located on the right side of the piston movement center line L, the crankshaft 7 rotates in a clockwise direction; when the crankshaft is located on the left side of the piston movement center line L, the crankshaft 7 rotates in a counterclockwise direction;

[0055] When the piston reciprocates, the crankshaft angle occupied by the piston compression stroke is greater than the crankshaft angle occupied by the piston power stroke;

[0056] The ratio of the length of the line C1A between the center C1 of the first articulated shaft 4 and the center A of the crank pin 6 to the length of the line CA between the center C of the third articulated shaft 8 and the center A of the crank pin 6 is 1.2:1;

[0057] The angle β formed by the line C1A between the center C1 of the first articulated shaft 4 and the center A of the crank pin 6 and the line CA between the center C of the third articulated shaft 8 and the center A of the crank pin 6 is 5°;

[0058] When the center A of the crank pin 6 rotates to the line OB between the main shaft center O of the crankshaft 7 and the center B of the fourth articulated shaft 10, the angle γ formed by the line CB between the center C of the third articulated shaft 8 and the center B of the fourth articulated shaft 10 and the line CA between the center C of the third articulated shaft 8 and the center A of the crank pin 6 is the minimum reverse transmission angle, and the angle γ is 12°.

[0059] Embodiment three:

[0060] The piston 1 is connected to one end of an upper connecting rod 3 through a piston pin 2, the other end of the upper connecting rod 3 is hinged to one end of a lower connecting rod 5 through a first hinge shaft 4, the other end of the lower connecting rod 5 is connected to the crank of a crankshaft 7 through a crank pin 6, and the crankshaft 7 is arranged on one side of the piston movement center line L;

[0061] A third hinge shaft 8 is provided on the lower connecting rod 5, the third hinge shaft 8 is hinged to one end of a rocker 9, and the other end of the rocker 9 is hinged to a rocker seat 11 through a fourth hinge shaft 10;

[0062] When the crankshaft 7 is located on the right side of the piston movement center line L, the crankshaft 7 rotates in a clockwise direction; when the crankshaft is located on the left side of the piston movement center line L, the crankshaft 7 rotates in a counterclockwise direction;

[0063] When the piston reciprocates, the crankshaft angle occupied by the piston compression stroke is greater than the crankshaft angle occupied by the piston power stroke;

[0064] The ratio of the length of the line C1A between the center C1 of the first articulated shaft 4 and the center A of the crank pin 6 to the length of the line CA between the center C of the third articulated shaft 8 and the center A of the crank pin 6 is 1.2:1;

[0065] The angle β formed by the line C1A between the center C1 of the first articulated shaft 4 and the center A of the crank pin 6 and the line CA between the center C of the third articulated shaft 8 and the center A of the crank pin 6 is 5°;

[0066] When the center A of the crank pin 6 rotates to the line OB between the main shaft center O of the crankshaft 7 and the center B of the fourth articulated shaft 10, the angle γ formed by the line CB between the center C of the third articulated shaft 8 and the center B of the fourth articulated shaft 10 and the line CA between the center C of the third articulated shaft 8 and the center A of the crank pin 6 is the minimum reverse transmission angle, and the angle γ is 49°.

[0067] Embodiment 4:

[0068] The piston 1 is connected to one end of an upper connecting rod 3 through a piston pin 2, the other end of the upper connecting rod 3 is hinged to one end of a lower connecting rod 5 through a first hinge shaft 4, the other end of the lower connecting rod 5 is connected to the crank of a crankshaft 7 through a crank pin 6, and the crankshaft 7 is arranged on one side of the piston movement center line L;

[0069] A third hinge shaft 8 is provided on the lower connecting rod 5, the third hinge shaft 8 is hinged to one end of a rocker 9, and the other end of the rocker 9 is hinged to a rocker seat 11 through a fourth hinge shaft 10;

[0070] When the crankshaft 7 is located on the right side of the piston movement center line L, the crankshaft 7 rotates in a clockwise direction; when the crankshaft is located on the left side of the piston movement center line L, the crankshaft 7 rotates in a counterclockwise direction;

[0071] When the piston reciprocates, the crankshaft angle occupied by the piston compression stroke is greater than the crankshaft angle occupied by the piston power stroke;

[0072] The ratio of the length of the line C1A between the center C1 of the first articulated shaft 4 and the center A of the crank pin 6 to the length of the line CA between the center C of the third articulated shaft 8 and the center A of the crank pin 6 is 1.2:1;

[0073] The angle β formed by the line C1A between the center C1 of the first articulated shaft 4 and the center A of the crank pin 6 and the line CA between the center C of the third articulated shaft 8 and the center A of the crank pin 6 is 30°;

[0074] When the center A of the crank pin 6 rotates to the line OB between the main shaft center O of the crankshaft 7 and the center B of the fourth articulated shaft 10, the angle γ formed by the line CB between the center C of the third articulated shaft 8 and the center B of the fourth articulated shaft 10 and the line CA between the center C of the third articulated shaft 8 and the center A of the crank pin 6 is the minimum reverse transmission angle, and the angle γ is 2°.

[0075] Embodiment five:

[0076] The piston 1 is connected to one end of an upper connecting rod 3 through a piston pin 2, the other end of the upper connecting rod 3 is hinged to one end of a lower connecting rod 5 through a first hinge shaft 4, the other end of the lower connecting rod 5 is connected to the crank of a crankshaft 7 through a crank pin 6, and the crankshaft 7 is arranged on one side of the piston movement center line L;

[0077] A third hinge shaft 8 is provided on the lower connecting rod 5, the third hinge shaft 8 is hinged to one end of a rocker 9, and the other end of the rocker 9 is hinged to a rocker seat 11 through a fourth hinge shaft 10;

[0078] When the crankshaft 7 is located on the right side of the piston movement center line L, the crankshaft 7 rotates in a clockwise direction; when the crankshaft is located on the left side of the piston movement center line L, the crankshaft 7 rotates in a counterclockwise direction;

[0079] When the piston reciprocates, the crankshaft angle occupied by the piston compression stroke is greater than the crankshaft angle occupied by the piston power stroke;

[0080] The ratio of the length of the line C1A between the center C1 of the first articulated shaft 4 and the center A of the crank pin 6 to the length of the line CA between the center C of the third articulated shaft 8 and the center A of the crank pin 6 is 1.2:1;

[0081] The angle β formed by the line C1A between the center C1 of the first articulated shaft 4 and the center A of the crank pin 6 and the line CA between the center C of the third articulated shaft 8 and the center A of the crank pin 6 is 30°;

[0082] When the center A of the crank pin 6 rotates to the line OB between the main shaft center O of the crankshaft 7 and the center B of the fourth articulated shaft 10, the angle γ formed by the line CB between the center C of the third articulated shaft 8 and the center B of the fourth articulated shaft 10 and the line CA between the center C of the third articulated shaft 8 and the center A of the crank pin 6 is the minimum reverse transmission angle, and the angle γ is 12°.

[0083] Embodiment six:

[0084] The piston 1 is connected to one end of an upper connecting rod 3 through a piston pin 2, the other end of the upper connecting rod 3 is hinged to one end of a lower connecting rod 5 through a first hinge shaft 4, the other end of the lower connecting rod 5 is connected to the crank of a crankshaft 7 through a crank pin 6, and the crankshaft 7 is arranged on one side of the piston movement center line L;

[0085] A third hinge shaft 8 is provided on the lower connecting rod 5, the third hinge shaft 8 is hinged to one end of a rocker 9, and the other end of the rocker 9 is hinged to a rocker seat 11 through a fourth hinge shaft 10;

[0086] When the crankshaft 7 is located on the right side of the piston movement center line L, the crankshaft 7 rotates in a clockwise direction; when the crankshaft is located on the left side of the piston movement center line L, the crankshaft 7 rotates in a counterclockwise direction;

[0087] When the piston reciprocates, the crankshaft angle occupied by the piston compression stroke is greater than the crankshaft angle occupied by the piston power stroke;

[0088] The ratio of the length of the line C1A between the center C1 of the first articulated shaft 4 and the center A of the crank pin 6 to the length of the line CA between the center C of the third articulated shaft 8 and the center A of the crank pin 6 is 1.2:1;

[0089] The angle β formed by the line C1A between the center C1 of the first articulated shaft 4 and the center A of the crank pin 6 and the line CA between the center C of the third articulated shaft 8 and the center A of the crank pin 6 is 30°;

[0090] When the center A of the crank pin 6 rotates to the line OB between the main shaft center O of the crankshaft 7 and the center B of the fourth articulated shaft 10, the angle γ formed by the line CB between the center C of the third articulated shaft 8 and the center B of the fourth articulated shaft 10 and the line CA between the center C of the third articulated shaft 8 and the center A of the crank pin 6 is the minimum reverse transmission angle, and the angle γ is 49°.

[0091] Embodiment seven:

[0092] The piston 1 is connected to one end of an upper connecting rod 3 through a piston pin 2, the other end of the upper connecting rod 3 is hinged to one end of a lower connecting rod 5 through a first hinge shaft 4, the other end of the lower connecting rod 5 is connected to the crank of a crankshaft 7 through a crank pin 6, and the crankshaft 7 is arranged on one side of the piston movement center line L;

[0093] A third hinge shaft 8 is provided on the lower connecting rod 5, the third hinge shaft 8 is hinged to one end of a rocker 9, and the other end of the rocker 9 is hinged to a rocker seat 11 through a fourth hinge shaft 10;

[0094] When the crankshaft 7 is located on the right side of the piston movement center line L, the crankshaft 7 rotates in a clockwise direction; when the crankshaft is located on the left side of the piston movement center line L, the crankshaft 7 rotates in a counterclockwise direction;

[0095] When the piston reciprocates, the crankshaft angle occupied by the piston compression stroke is greater than the crankshaft angle occupied by the piston power stroke;

[0096] The ratio of the length of the line C1A between the center C1 of the first articulated shaft 4 and the center A of the crank pin 6 to the length of the line CA between the center C of the third articulated shaft 8 and the center A of the crank pin 6 is 1.2:1;

[0097] The angle β formed by the line C1A between the center C1 of the first articulated shaft 4 and the center A of the crank pin 6 and the line CA between the center C of the third articulated shaft 8 and the center A of the crank pin 6 is 15°;

[0098] When the center A of the crank pin 6 rotates to the line OB between the main shaft center O of the crankshaft 7 and the center B of the fourth articulated shaft 10, the angle γ formed by the line CB between the center C of the third articulated shaft 8 and the center B of the fourth articulated shaft 10 and the line CA between the center C of the third articulated shaft 8 and the center A of the crank pin 6 is the minimum reverse transmission angle, and the angle γ is 2°.

[0099] Embodiment eight:

[0100] The piston 1 is connected to one end of an upper connecting rod 3 through a piston pin 2, the other end of the upper connecting rod 3 is hinged to one end of a lower connecting rod 5 through a first hinge shaft 4, the other end of the lower connecting rod 5 is connected to the crank of a crankshaft 7 through a crank pin 6, and the crankshaft 7 is arranged on one side of the piston movement center line L;

[0101] A third hinge shaft 8 is provided on the lower connecting rod 5, the third hinge shaft 8 is hinged to one end of a rocker 9, and the other end of the rocker 9 is hinged to a rocker seat 11 through a fourth hinge shaft 10;

[0102] When the crankshaft 7 is located on the right side of the piston movement center line L, the crankshaft 7 rotates in a clockwise direction; when the crankshaft is located on the left side of the piston movement center line L, the crankshaft 7 rotates in a counterclockwise direction;

[0103] When the piston reciprocates, the crankshaft angle occupied by the piston compression stroke is greater than the crankshaft angle occupied by the piston power stroke;

[0104] The ratio of the length of the line C1A between the center C1 of the first articulated shaft 4 and the center A of the crank pin 6 to the length of the line CA between the center C of the third articulated shaft 8 and the center A of the crank pin 6 is 1.2:1;

[0105] The angle β formed by the line C1A between the center C1 of the first articulated shaft 4 and the center A of the crank pin 6 and the line CA between the center C of the third articulated shaft 8 and the center A of the crank pin 6 is 15°;

[0106] When the center A of the crank pin 6 rotates to the line OB between the main shaft center O of the crankshaft 7 and the center B of the fourth articulated shaft 10, the angle γ formed by the line CB between the center C of the third articulated shaft 8 and the center B of the fourth articulated shaft 10 and the line CA between the center C of the third articulated shaft 8 and the center A of the crank pin 6 is the minimum reverse transmission angle, and the angle γ is 12°.

[0107] Embodiment nine:

[0108] The piston 1 is connected to one end of an upper connecting rod 3 through a piston pin 2, the other end of the upper connecting rod 3 is hinged to one end of a lower connecting rod 5 through a first hinge shaft 4, the other end of the lower connecting rod 5 is connected to the crank of a crankshaft 7 through a crank pin 6, and the crankshaft 7 is arranged on one side of the piston movement center line L;

[0109] A third hinge shaft 8 is provided on the lower connecting rod 5, the third hinge shaft 8 is hinged to one end of a rocker 9, and the other end of the rocker 9 is hinged to a rocker seat 11 through a fourth hinge shaft 10;

[0110] When the crankshaft 7 is located on the right side of the piston movement center line L, the crankshaft 7 rotates in a clockwise direction; when the crankshaft is located on the left side of the piston movement center line L, the crankshaft 7 rotates in a counterclockwise direction;

[0111] When the piston reciprocates, the crankshaft angle occupied by the piston compression stroke is greater than the crankshaft angle occupied by the piston power stroke;

[0112] The ratio of the length of the line C1A between the center C1 of the first articulated shaft 4 and the center A of the crank pin 6 to the length of the line CA between the center C of the third articulated shaft 8 and the center A of the crank pin 6 is 1.2:1;

[0113] The angle β formed by the line C1A between the center C1 of the first articulated shaft 4 and the center A of the crank pin 6 and the line CA between the center C of the third articulated shaft 8 and the center A of the crank pin 6 is 15°;

[0114] When the center A of the crank pin 6 rotates to the line OB between the main shaft center O of the crankshaft 7 and the center B of the fourth articulated shaft 10, the angle γ formed by the line CB between the center C of the third articulated shaft 8 and the center B of the fourth articulated shaft 10 and the line CA between the center C of the third articulated shaft 8 and the center A of the crank pin 6 is the minimum reverse transmission angle, and the angle γ is 49°.

[0115] Embodiment ten:

[0116] The piston 1 is connected to one end of an upper connecting rod 3 through a piston pin 2, the other end of the upper connecting rod 3 is hinged to one end of a lower connecting rod 5 through a first hinge shaft 4, the other end of the lower connecting rod 5 is connected to the crank of a crankshaft 7 through a crank pin 6, and the crankshaft 7 is arranged on one side of the piston movement center line L;

[0117] A third hinge shaft 8 is provided on the lower connecting rod 5, the third hinge shaft 8 is hinged to one end of a rocker 9, and the other end of the rocker 9 is hinged to a rocker seat 11 through a fourth hinge shaft 10;

[0118] When the crankshaft 7 is located on the right side of the piston movement center line L, the crankshaft 7 rotates in a clockwise direction; when the crankshaft is located on the left side of the piston movement center line L, the crankshaft 7 rotates in a counterclockwise direction;

[0119] When the piston reciprocates, the crankshaft angle occupied by the piston compression stroke is greater than the crankshaft angle occupied by the piston power stroke;

[0120] The ratio of the length of the line C1A between the center C1 of the first articulated shaft 4 and the center A of the crank pin 6 to the length of the line CA between the center C of the third articulated shaft 8 and the center A of the crank pin 6 is 1.2:1;

[0121] The angle β formed by the line C1A between the center C1 of the first articulated shaft 4 and the center A of the crank pin 6 and the line CA between the center C of the third articulated shaft 8 and the center A of the crank pin 6 is 15°;

[0122] When the center A of the crank pin 6 rotates to the line OB between the main shaft center O of the crankshaft 7 and the center B of the fourth articulated shaft 10, the angle γ formed by the line CB between the center C of the third articulated shaft 8 and the center B of the fourth articulated shaft 10 and the line CA between the center C of the third articulated shaft 8 and the center A of the crank pin 6 is the minimum reverse transmission angle, and the angle γ is 12°.

[0123] Embodiment eleven:

[0124] The piston 1 is connected to one end of an upper connecting rod 3 through a piston pin 2, the other end of the upper connecting rod 3 is hinged to one end of a lower connecting rod 5 through a first hinge shaft 4, the other end of the lower connecting rod 5 is connected to the crank of a crankshaft 7 through a crank pin 6, and the crankshaft 7 is arranged on one side of the piston movement center line L;

[0125] A third hinge shaft 8 is provided on the lower connecting rod 5, the third hinge shaft 8 is hinged to one end of a rocker 9, and the other end of the rocker 9 is hinged to a rocker seat 11 through a fourth hinge shaft 10;

[0126] When the crankshaft 7 is located on the right side of the piston movement center line L, the crankshaft 7 rotates in a clockwise direction; when the crankshaft is located on the left side of the piston movement center line L, the crankshaft 7 rotates in a counterclockwise direction;

[0127] When the piston reciprocates, the crankshaft angle occupied by the piston compression stroke is greater than the crankshaft angle occupied by the piston power stroke;

[0128] The ratio of the length of the line C1A between the center C1 of the first articulated shaft 4 and the center A of the crank pin 6 to the length of the line CA between the center C of the third articulated shaft 8 and the center A of the crank pin 6 is 1.0:1;

[0129] The angle β formed by the line C1A between the center C1 of the first articulated shaft 4 and the center A of the crank pin 6 and the line CA between the center C of the third articulated shaft 8 and the center A of the crank pin 6 is 15°;

[0130] When the center A of the crank pin 6 rotates to the line OB between the main shaft center O of the crankshaft 7 and the center B of the fourth articulated shaft 10, the angle γ formed by the line CB between the center C of the third articulated shaft 8 and the center B of the fourth articulated shaft 10 and the line CA between the center C of the third articulated shaft 8 and the center A of the crank pin 6 is the minimum reverse transmission angle, and the angle γ is 2°.

[0131] Embodiment 12:

[0132] The piston 1 is connected to one end of an upper connecting rod 3 through a piston pin 2, the other end of the upper connecting rod 3 is hinged to one end of a lower connecting rod 5 through a first hinge shaft 4, the other end of the lower connecting rod 5 is connected to the crank of a crankshaft 7 through a crank pin 6, and the crankshaft 7 is arranged on one side of the piston movement center line L;

[0133] A third hinge shaft 8 is provided on the lower connecting rod 5, the third hinge shaft 8 is hinged to one end of a rocker 9, and the other end of the rocker 9 is hinged to a rocker seat 11 through a fourth hinge shaft 10;

[0134] When the crankshaft 7 is located on the right side of the piston movement center line L, the crankshaft 7 rotates in a clockwise direction; when the crankshaft is located on the left side of the piston movement center line L, the crankshaft 7 rotates in a counterclockwise direction;

[0135] When the piston reciprocates, the crankshaft angle occupied by the piston compression stroke is greater than the crankshaft angle occupied by the piston power stroke;

[0136] The ratio of the length of the line C1A between the center C1 of the first articulated shaft 4 and the center A of the crank pin 6 to the length of the line CA between the center C of the third articulated shaft 8 and the center A of the crank pin 6 is 1.5:1;

[0137] The angle β formed by the line C1A between the center C1 of the first articulated shaft 4 and the center A of the crank pin 6 and the line CA between the center C of the third articulated shaft 8 and the center A of the crank pin 6 is 15°;

[0138] When the center A of the crank pin 6 rotates to the line OB between the main shaft center O of the crankshaft 7 and the center B of the fourth articulated shaft 10, the angle γ formed by the line CB between the center C of the third articulated shaft 8 and the center B of the fourth articulated shaft 10 and the line CA between the center C of the third articulated shaft 8 and the center A of the crank pin 6 is the minimum reverse transmission angle, and the angle γ is 2°.

[0139] According to the correction torque diagrams of embodiments 1 to 10, it is known that the maximum correction torque is inversely proportional to the minimum reverse transmission angle γ; the crankshaft angle at which the maximum correction torque occurs is proportional to the minimum reverse transmission angle γ. The smaller the minimum reverse transmission angle γ, the larger the maximum correction torque, and the smaller the crankshaft angle at which the maximum correction torque occurs, the closer to the top dead center. The maximum correction torque changes less when the angle β changes.

[0140] As mentioned above, to ensure that the mechanism can operate, the minimum reverse transmission angle γ must be greater than 0°, but when the angle γ is close to 0°, the torque curve rises very steeply and the piston acceleration is very large. Therefore, the seventh embodiment is the best embodiment, and its maximum correction torque is larger, and the crankshaft angle at which the maximum correction torque occurs is closer to the top dead center. The ratio of C1A to CA and the angle β meet the minimum installation distance between the first articulated shaft and the third articulated shaft.

[0141] Combining Table 1 with Example 11 and Example 12, although the maximum torque increases when the ratio of C1A to CA increases, the maximum torque changes slightly after correction. Under the condition of meeting the minimum installation distance between the first articulated axis and the third articulated axis, the ratio of the connecting rod C1A to CA is minimized to reduce the β angle. The preferred solution is: the ratio of the connecting rod C1A to CA is 1:1.

[0142] The combustion pressure of the engine during the power stroke is very high near the top dead center. As the piston moves downward, the pressure gradually decreases. When the crankshaft angle is 65°-100°, the pressure is one order of magnitude lower than the maximum pressure near the top dead center. Figure 1 The motion trajectory of the first articulated axis C1 is an arc, and the arc of the power stroke trajectory is smaller than that of the compression stroke trajectory. Although the angle δ between the center line DC1 of the upper connecting rod 3 and the center line L of the piston movement is large when the C1 point is at the bottom dead center, the pressure in the cylinder is small, the piston force is also small, and the pressure on the piston side is not large. The friction work is reduced and the overall efficiency of the engine is improved.

[0143] The crankshaft rotation angles occupied by the pistons of the multi-link crankshaft negative bias power transmission device described in the present invention are not equal during reciprocating motion, the compression stroke occupies a crankshaft rotation angle greater than 180°; the power stroke occupies a crankshaft rotation angle less than 180°, which makes the difference in the reciprocating acceleration of the pistons large, and the reciprocating inertia force is difficult to be fully balanced by the centrifugal inertia force of the crankshaft counterweight. In order to solve the above problems, the present invention preferably arranges the pistons of the two sets of multi-link crankshaft negative bias power transmission devices symmetrically, which effectively solves the problem of motion balance, reduces vibration, and increases the life of the engine. The specific structure is as follows:

[0144] The opposed multi-link double crankshaft internal combustion engine of the present invention is as follows: Fig.28 As shown, it includes a group of first cylinders 21 and a group of second cylinders 21 facing each other, each of the first cylinders 21 and the second cylinders 21 cooperates with a group of multi-link crankshaft negative bias power transmission devices according to claim 1, pistons 1 are installed in the first cylinders 21 and the second cylinders 21, the piston movement center lines L of the pistons 1 in each group of the first cylinders 21 and the second cylinders 21 are located in the same plane, the pistons in the first cylinders 21 and the second cylinders 21 work in opposite directions, and the first cylinders 21 and the second cylinders 21 correspond to each other. The crankshafts 7 of the multi-link crankshaft negative bias power transmission device are respectively arranged on different sides of the plane where the center line L of each piston movement is located. The crankshafts 7 of the multi-link crankshaft negative bias power transmission device corresponding to the first cylinder body 21 and the second cylinder body 21 have the same rotation direction. Synchronous gears 23 are installed on both sets of crankshafts 7. Both sets of synchronous gears 23 are meshed with the center intermediate gear 24, so that the pistons 1 in the two cylinder bodies reach the top dead center synchronously. The center of the center intermediate gear 24 is located on the plane where the center line L of each piston movement is located, and the center intermediate gear 24 is connected to the output shaft. The advantage of this solution is that due to the two cylinder bodies being opposed, the reciprocating inertial force is completely balanced, and the upper and lower rotating crankshafts can be completely balanced by adjusting the crankshaft counterweight, so that the vibration is reduced to a very low level. In particular, the connection of the center intermediate gear 24 with the output shaft makes the power output stable and the noise reduced.

[0145] The opposed multi-link double crankshaft internal combustion engine of the present invention is as follows: Fig.29As shown, it includes a group of first cylinder bodies 21 and a group of second cylinder bodies 21 facing each other, each of the first cylinder body 21 and the second cylinder body 21 cooperates with a group of multi-link crankshaft negative bias power transmission devices according to claim 1, pistons 1 are installed in the first cylinder body 21 and the second cylinder body 21, the piston movement center lines L of the pistons 1 in each group of the first cylinder body 21 and the second cylinder body 21 are located in the same plane, the pistons in the first cylinder body 21 and the pistons in the second cylinder body 21 work in opposite directions, the crankshafts 7 of the multi-link crankshaft negative bias power transmission devices corresponding to the first cylinder body 21 and the second cylinder body 21 are respectively arranged on the same side of the plane where the center lines L of the piston movement are located, the crankshafts 7 of the multi-link crankshaft negative bias power transmission devices corresponding to the first cylinder body 21 and the second cylinder body 21 rotate in opposite directions, and synchronous gears 23 are installed on the two groups of crankshafts 7, and the two groups of synchronous gears 23 are meshed with each other, so that the pistons 1 in the two cylinder bodies reach the top dead center synchronously, and one group of synchronous gears 23 is connected to the output shaft. The advantage of this solution is that due to the two opposing cylinders, the reciprocating inertia forces are completely balanced, and the left and right rotating crankshafts can be completely balanced by adjusting the crankshaft counterweights, so that the vibration is reduced to a very low level, and the crankshaft can be splash lubricated.

Claims

1. A multi-link crankshaft negative bias power transmission device, comprising a piston (1), characterized in that: The piston (1) is connected to one end of an upper connecting rod (3) through a piston pin (2), the other end of the upper connecting rod (3) is hinged to one end of a lower connecting rod (5) through a first hinge shaft (4), the other end of the lower connecting rod (5) is connected to a crank of a crankshaft (7) through a crank pin (6), and the crankshaft (7) is arranged on one side of a piston movement center line L; A third hinge shaft (8) is provided on the lower connecting rod (5), the third hinge shaft (8) is hinged to one end of a rocker (9), and the other end of the rocker (9) is hinged to a rocker seat (11) via a fourth hinge shaft (10); During the compression stroke of the piston (1), the crank pin (6) is closer to the piston movement center line L, and during the power stroke of the piston (1), the crank pin (6) is farther from the piston movement center line L; During the compression stroke of the piston (1), the crankshaft (7) rotates at a greater angle than the crankshaft (7) rotates at during the power stroke of the piston (1); The angle β formed by the line C1A between the center C1 of the first articulated shaft (4) and the center A of the crank pin (6) and the line CA between the center C of the third articulated shaft (8) and the center A of the crank pin (6) is 5°-30°; When the center A of the crank pin (6) rotates to the line OB between the main axis center O of the crankshaft (7) and the center B of the fourth articulated shaft (10), the angle γ formed by the line CB between the center C of the third articulated shaft (8) and the center B of the fourth articulated shaft (10) and the line CA between the center C of the third articulated shaft (8) and the center A of the crank pin (6) is the minimum reverse transmission angle, and the angle γ is 2°-49°.

2. The multi-link crankshaft negative bias power transmission device according to claim 1, characterized in that: The ratio of the length of the line C1A between the center C1 of the first articulated shaft (4) and the center A of the crank pin (6) to the length of the line CA between the center C of the third articulated shaft (8) and the center A of the crank pin (6) is 1:1-1.5:

1.

3. The multi-link crankshaft negative bias power transmission device according to claim 1, characterized in that: During the working stroke of the piston (1), during the process from the position where the crank (7) and the crankshaft center line OA are collinear and non-coincident with the line CA to the position where the crank (7) and the crankshaft center line OA rotate 65°, the angle δ between the center line DC1 of the upper connecting rod (3) and the piston movement center line L is always ≤10°.

4. The multi-link crankshaft negative bias power transmission device according to claim 1, characterized in that: The ratio of the length of the line C1A between the center C1 of the first articulated shaft (4) and the center A of the crank pin (6) to the length of the line CA between the center C of the third articulated shaft (8) and the center A of the crank pin (6) is 1:1-1.35:

1.

5. The multi-link crankshaft negative bias power transmission device according to claim 1, characterized in that: The ratio of the length of the line C1A between the center C1 of the first articulated shaft (4) and the center A of the crank pin (6) to the length of the line CA between the center C of the third articulated shaft (8) and the center A of the crank pin (6) is 1:

1.

6. The multi-link crankshaft negative bias power transmission device according to claim 1, characterized in that: The angle β formed by the line C1A between the center C1 of the first articulated shaft (4) and the center A of the crank pin (6) and the line CA between the center C of the third articulated shaft (8) and the center A of the crank pin (6) is 10°-20°.

7. The multi-link crankshaft negative bias power transmission device according to claim 1, characterized in that: The angle β formed by the line C1A between the center C1 of the first articulated shaft (4) and the center A of the crank pin (6) and the line CA between the center C of the third articulated shaft (8) and the center A of the crank pin (6) is 15°.

8. The multi-link crankshaft negative bias power transmission device according to claim 1, characterized in that: The minimum reverse transmission angle γ is 2°-35°.

9. The multi-link crankshaft negative bias power transmission device according to claim 1, characterized in that: The minimum reverse transmission angle γ is 2°.

10. An opposed multi-link double crankshaft internal combustion engine, characterized in that: The invention comprises a group of first cylinders (21) and a group of second cylinders (21) which are opposite to each other, each of the first cylinders (21) and the second cylinders (21) cooperates with a group of multi-link crankshaft negative bias power transmission devices according to claim 1, pistons (1) are installed in the first cylinders (21) and the second cylinders (21), the piston movement center lines L of the pistons (1) in each group of the first cylinders (21) and the second cylinders (21) are located in the same plane, the pistons in the first cylinders (21) and the pistons in the second cylinders (21) work in opposite directions, and the first cylinders (21) and the second cylinders (21) work in opposite directions. The crankshafts (7) of the multi-link crankshaft negative bias power transmission devices corresponding to the cylinder bodies (21) are respectively arranged on different sides of the plane where the center line L of each piston movement is located. The crankshafts (7) of the multi-link crankshaft negative bias power transmission devices corresponding to the first cylinder body (21) and the second cylinder body (21) have the same rotation direction. Synchronous gears (23) are installed on both sets of crankshafts (7). Both sets of synchronous gears (23) are meshed with the central intermediate gear (24). The center of the central intermediate gear (24) is located on the plane where the center line L of each piston movement is located. The central intermediate gear (24) is connected to the output shaft.

11. An opposed multi-link double crankshaft internal combustion engine, characterized in that: The invention comprises a group of first cylinders (21) and a group of second cylinders (21) which are opposite to each other, each of the first cylinders (21) and the second cylinders (21) cooperates with a group of multi-link crankshaft negative bias power transmission devices according to claim 1, a piston (1) is installed in each of the first cylinders (21) and the second cylinders (21), the piston movement center lines L of the pistons (1) in each group of the first cylinders (21) and the second cylinders (21) are located in the same plane, and the pistons in the first cylinders (21) and the second cylinders (21) are in a mutually opposite relationship. The power directions are opposite, the crankshafts (7) of the multi-link crankshaft negative bias power transmission devices corresponding to the first cylinder body (21) and the second cylinder body (21) are both arranged on the same side of the plane where the center line L of each piston movement is located, the crankshafts (7) of the multi-link crankshaft negative bias power transmission devices corresponding to the first cylinder body (21) and the second cylinder body (21) rotate in opposite directions, and synchronous gears (23) are installed on the two sets of crankshafts (7), the two sets of synchronous gears (23) are meshed with each other, and one set of synchronous gears (23) is connected to the output shaft.

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