Reciprocating piston heat engine and vehicle
By introducing levers and compensating shaft structures into a reciprocating piston heat engine, the piston thrust is converted into the output torque of the compensating shaft, solving the problem that the piston thrust cannot be effectively converted into torque in traditional heat engines, thus improving thermal efficiency and equipment life.
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- ZHANG YONGZHENG
- Filing Date
- 2026-01-16
- Publication Date
- 2026-07-23
Smart Images
Figure CN2026073028_23072026_PF_FP_ABST
Abstract
Description
A reciprocating piston heat engine and a vehicle
[0001] Cross-references to related applications
[0002] This application is based on Chinese Patent Application No. 2025100708579, filed on January 16, 2025, and claims priority to that Chinese Patent Application, the entire contents of which are incorporated herein by reference. Technical Field
[0003] This invention specifically relates to a reciprocating piston heat engine and a transportation vehicle. Background Technology
[0004] The power-generating process of a traditional reciprocating piston heat engine (including internal combustion engines and external combustion engines) is the process by which the thrust of the piston in the cylinder is converted into torque on the crankshaft. More specifically, it is the tangential component of the total force P along the cylinder centerline that drives the crankshaft to rotate, thus achieving the purpose of doing work, as shown in Figure 7. The mathematical expression for its torque is:
[0005] Mt = Pt·R = P·R·sin(α+β) / cosβFormula 1
[0006] In Formula 1: Mt is the crankshaft output torque, Pt is the tangential force acting on the crank pin, P is the total force exerted by the cylinder cavity on the piston centerline, R is the crankshaft radius, α is the power output shaft rotation angle (here, the power output shaft rotation angle is the crankshaft rotation angle), and β is the connecting rod swing angle. Obviously, Formula 1 is a sine function.
[0007] Here, we choose the gasoline engine in a reciprocating piston heat engine for analysis.
[0008] When analyzing a gasoline engine, we use a typical analytical tool for gasoline engines: the indicator diagram, as shown in Figure 9. We substitute different angles into α according to Formula 1 to obtain the corresponding torque Mt values, plot the points on the indicator diagram, and connect the points to obtain the output torque Mt curve of the gasoline engine.
[0009] Comparing the torque (Mt) curve with the cylinder pressure (P) curve, we found that the initial phase of the torque (Mt) curve is much flatter and has a smaller amplitude than the initial phase of the pressure (P) curve, especially with a significant attenuation in the 0-30° range. The peak torque (Mt) only appears when the crankshaft angle reaches 35°, and even then, it's not a sharp peak; that is, the peak torque (Mt) lags behind the peak cylinder pressure (P) curve by approximately 25°, and its peak height is less than half the peak height of the pressure (P) curve. The torque (Mt) curve is severely distorted compared to the pressure (P) curve. Furthermore, the torque (Mt) curve only touches the pressure (P) curve when the crankshaft angle reaches 50°, after which Mt gradually weakens and moves away. Here, we see that the area enclosed by the torque (Mt) curve and the X and Y axes is considerably smaller than the area enclosed by the cylinder pressure (P) and the X and Y axes, inevitably contributing to a reduction in the thermal efficiency of the gasoline engine. Because the crankshaft does work based on the tangential force acting on the crankpin, and the tangential force exhibits a sinusoidal characteristic {Psin(α+β) / cosβ}, a significant feature of the sine function is that its value is zero at 0°. At 90°, its value is 1. From 0° to 90°, it's a process where the function value gradually increases. In the early stages of the power stroke, when the piston is at top dead center or just after leaving it, the space above the piston is small, the combustion medium exerts strong pressure, and the cylinder pressure P peaks. This is the perfect opportunity for the piston to exert power and push the piston back. However, because the crankshaft angle α is small, the sine of α is also small, and its product with the pressure P is also small. At this time, the piston's thrust is only the thrust on the crankshaft's central axis—the normal force {Pcos(α+β) / cosβ}. The tangential force Pt on the crankpin is very weak. Only after the crankshaft has rotated a considerable angle α does the tangential force acting on the crankpin gradually become apparent, arriving late and missing the optimal power-generating opportunity. The wasted power is carried away by the cooling medium as heat, causing thermal pollution. This phenomenon can be explained by the first law of thermodynamics. This is arguably the real reason why the thermal efficiency of traditional reciprocating piston gasoline engines has stagnated for so long. The conclusion is quite clear: as soon as work begins, a significant portion of the energy is lost immediately. By extension, other types of reciprocating piston heat engines, such as diesel engines and Stirling engines, suffer from the same problem. Therefore, improving the thermal efficiency of reciprocating piston heat engines is an urgent task. Summary of the Invention
[0010] The purpose of this invention is to provide a reciprocating piston heat engine and a vehicle that can convert piston thrust into output torque as much as possible, effectively increasing output torque and improving the combustion efficiency of the reciprocating piston heat engine.
[0011] The technical solution adopted in this invention is:
[0012] A reciprocating piston heat engine includes a cylinder, a piston, a connecting rod, and a crankshaft. The reciprocating piston heat engine also includes a lever and a compensating shaft. The piston is disposed in the inner cavity of the cylinder. One end of the connecting rod is hinged to the piston, the crank is hinged to the connecting rod, and the other end of the connecting rod is hinged to the lever. The lever passes laterally through the compensating shaft with a slide rail, and the lever can slide back and forth within the slide rail of the compensating shaft.
[0013] A vehicle comprising a reciprocating piston heat engine as described above.
[0014] The beneficial effects of this invention are:
[0015] 1. This invention improves the piston's working state by using the compensating shaft as the output end. It transforms the force applied directly to the crankshaft and crank arm in a traditional reciprocating piston heat engine into a force applied to the crankshaft and simultaneously transmitted to the levers, linked to the compensating shaft. The force applied to the crankshaft is merely to maintain inertial rotation and ensure smooth transitions between strokes (e.g., two-stroke, four-stroke) without interruption. The force received through the levers and compensating shaft is the output power of this invention's reciprocating piston heat engine, effectively converting the piston's thrust into the engine's output torque and overcoming the initial combustion knock effect. When the piston thrust is at its maximum, the piston thrust cannot be effectively converted into torque. To avoid unnecessary energy loss, this method can effectively increase the output torque and improve the thermal efficiency of reciprocating piston engines. Due to the increased thermal efficiency and output torque, the heat that the combustion medium in the cylinder needs to remove will inevitably decrease. Therefore, the size and complexity of the required cooling system will also be reduced. This is very beneficial for weight reduction and cost reduction, especially for reciprocating piston engines. Under the same power, emissions are reduced and energy is saved, which is very beneficial to the human living environment.
[0016] 2. In this invention, when the piston moves to the top dead center of the cylinder to begin working, the angle between the connecting rod and the lever is 80°~110°. This can effectively convert the maximum thrust of the piston at the beginning of combustion into a tangential force on the compensating shaft, reducing the impact force on the crankshaft. Especially in the case of knocking, this extends the service life of the equipment and improves the safety and reliability of the heat engine operation. Attached Figure Description
[0017] Figure 1 is a cross-sectional view of a reciprocating piston heat engine in an embodiment of the present invention.
[0018] Figure 2 is a left view of Figure 1.
[0019] Figure 3 is a schematic diagram of a reciprocating piston heat engine in a compressed state according to an embodiment of the present invention.
[0020] Figure 4 is a schematic diagram of a reciprocating piston heat engine in the working state in an embodiment of the present invention.
[0021] Figure 5 is a schematic diagram of a reciprocating piston heat engine in an embodiment of the present invention, where the piston has moved to the bottom dead center of its stroke.
[0022] Figure 6 is a schematic diagram of a reciprocating piston heat engine in the exhaust state in an embodiment of the present invention.
[0023] Figure 7 is a schematic diagram of a traditional reciprocating piston heat engine.
[0024] Figure 8 is a schematic diagram of a reciprocating piston heat engine in an embodiment of the present invention.
[0025] Figure 9 is an indicator diagram of a reciprocating piston heat engine and a conventional reciprocating piston heat engine in an embodiment of the present invention.
[0026] Figure 10 is a schematic diagram of the reciprocating piston heat engine in an embodiment of the present invention.
[0027] In the diagram: 1-Cylinder block; 2-Piston; 3-Connecting rod; 4-Crankshaft; 5-Lever; 6-Compensating shaft; 7-Hinge shaft; 8-Crankshaft; 9-Piston pin; 10-Crankshaft pin. Embodiments of the present invention
[0028] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.
[0029] In the description of this invention, it should be understood that if terms such as "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise" are used to indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, they are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of the stated features. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.
[0030] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection. They can refer to a mechanical connection or an electrical connection. They can refer to a direct connection or an indirect connection through an intermediate medium, and they can refer to the internal communication of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in this invention can be understood according to the specific circumstances.
[0031] Example 1
[0032] A reciprocating piston heat engine, as shown in Figures 1-6, includes a cylinder 1, a piston 2, a connecting rod 3, a crank 4, a lever 5, and a compensating shaft 6. The piston 2 is disposed within the inner cavity of the cylinder 1 and can move up and down along the inner cavity of the cylinder 1. One end of the connecting rod 3 is hinged to the piston 2, and the crank is hinged to the connecting rod 3. The other end of the connecting rod 3 is hinged to one end of the lever 5 outside the cylinder 1 via a hinge pin 7. A transverse slide is provided on the compensating shaft 6, and the slide is arranged radially along the compensating shaft. The other end of the lever 5 passes through the transverse slide on the compensating shaft 6, and the lever 5 can slide back and forth within the slide of the compensating shaft 6. When the piston 2 moves to the bottom dead center of its stroke within the cylinder 1, a combustible mixture or... The liquid allows for air intake; then, under inertia, piston 2 moves upward, entering the compression stroke; after the compression stroke, the combustion stroke begins, during which the combustible mixture explodes, pushing piston 2 towards the bottom dead center of cylinder 1. Connecting rod 3 also moves downward, causing lever 5 to move downward. The downward movement of lever 5 causes it to slide relative to the slide of compensating shaft 6, and simultaneously causes compensating shaft 6 to rotate clockwise around its own axis, thus achieving power output; subsequently, connecting rod 3 continues to rotate around the rotation center of crank 4, pushing piston 2 towards the top dead center of cylinder 1, expelling exhaust gas from the cylinder cavity; then the next cycle begins.
[0033] In the basic structural diagram of Figure 10: the small end of the engine connecting rod 3 is connected to the piston 2 via the piston pin 9, and the large end of the connecting rod 3 is connected to the crankshaft crank 4 via the crank pin 10. The innovation of this invention lies in the fact that a pair of clamping plates with round holes are provided at the lower end of the large end of the connecting rod 3, and are integrated with the connecting rod 3 to form part of the connecting rod. The clamping grooves of the clamping plates facilitate the secure insertion of one end of the lever 5, and then the hinge pin 7 is inserted to form a hinge. The other end of the lever 5 passes through the compensating shaft 6 with a slide rail, and the lever 5 can slide left and right within the slide rail of the compensating shaft 6. The compensating shaft 6 is set on the engine block next to the crankshaft.
[0034] Furthermore, the hinge point between crank 4 and connecting rod 3 is located between the hinge point between piston 2 and connecting rod 3 and the hinge point between lever 5 and connecting rod 3.
[0035] Furthermore, the straight lines of the movement trajectories of the compensation shaft 6 and the piston 2 do not intersect, but are perpendicular to each other.
[0036] Furthermore, when the piston 2 moves to the top dead center of the cylinder 1 (i.e., the piston moves to the innermost end of the cylinder 1's internal stroke), the angle between the connecting rod 3 and the lever 5 is 80°~110°.
[0037] In the preferred embodiment, when the piston 2 moves to the top dead center of the stroke inside the cylinder 1, the angle between the connecting rod 3 and the lever 5 is 90°.
[0038] Furthermore, when the piston 2 moves to the bottom dead center of the cylinder 1 (i.e., when the piston moves to the outermost end of the cylinder 1's internal stroke), the length direction of the connecting rod 3 is consistent with the movement direction of the piston 2.
[0039] Furthermore, crank 4 is connected to crankshaft 8, and the rotation of crank 4 can drive crankshaft 8 to rotate; the hinge point between connecting rod 3 and crank 4 is not on the axis of crankshaft.
[0040] Furthermore, the compensating shaft 6 is connected to an overrunning clutch for driving the wheels;
[0041] The compensating shaft 6 can be used directly as a power output shaft, or the compensating shaft 6 can be connected to a power output shaft via an overrunning clutch.
[0042] Furthermore, the reciprocating piston heat engine also includes an ignition switch, spark plugs, intake valves, exhaust valves, and a high-pressure injection system. The intake valves, exhaust valves, high-pressure injection system, and spark plugs are located on the top of the cylinder block. The ignition switch is connected to the spark plugs via an ignition coil. The intake valves, exhaust valves, and high-pressure injection system are all connected to the control system of the vehicle (i.e., the intake valves, exhaust valves, and high-pressure injection system are all connected to the control system of the automobile or ship).
[0043] Furthermore, each cylinder 1, piston 2, connecting rod 3, and crank 3 form a power unit;
[0044] The reciprocating piston heat engine includes a power output shaft and multiple power units arranged side by side. The compensation shaft 6 of each power unit is connected to the power output shaft through an overrunning clutch. Each compensation shaft 6 transmits power to the power output shaft through the overrunning clutch, and the power output shaft outputs power uniformly.
[0045] The compensation shaft 6 and the power output shaft of each power unit are arranged in the same direction, and the compensation shaft 6 of each power unit are arranged in a staggered phase.
[0046] Example 2
[0047] The vehicle constructed based on Example 1 has even better performance in the defined Example 2.
[0048] A vehicle includes a reciprocating piston heat engine as described above, which drives the vehicle to move.
[0049] The means of transport include, but are not limited to, vehicles and ships, and vehicles include, but are not limited to, cars and motorcycles.
[0050] The working principle of this invention is as follows: Piston 2 moves to the bottom dead center of the cylinder 1, drawing in a combustible gas or liquid mixture, thus achieving intake; under the inertia of crankshaft 8, piston 2 moves to the top dead center of the cylinder 1, achieving compression; then, the combustible gas or liquid mixture ignites and explodes, pushing piston 2 towards the bottom dead center of the cylinder 1, thus performing work; due to inertia, connecting rod 3 continues to rotate around the rotation center of crankshaft 4, pushing piston 2 towards the top dead center of the cylinder 1, expelling exhaust gas from the cylinder 1, thus achieving exhaust; then the next cycle begins. Due to the continuous output of power, the vehicle is driven forward continuously.
[0051] Since the cosine function is exactly the opposite of the sine function, when the power output shaft rotation angle is 0°, the cosine function value is 1, and then the function value gradually decreases as the angle increases. This characteristic is very useful when applied to the piston work in a reciprocating piston heat engine. Therefore, according to the embodiment of the present invention, as shown in Figure 8, the following formula is established for the reciprocating piston heat engine:
[0052] Mt'=P·L·cosα Formula 2
[0053] In Formula 2, Mt' is the torque delivered by the compensating shaft, P is the total force exerted by the cylinder cavity on the piston centerline, L is the lever arm acting on the compensating shaft, and α is the power output shaft angle of a single power unit. Here, the power output shaft angle is the compensating shaft angle, which is typically between 0° and 50°. As the power output shaft angle, it covers the crankshaft angle α during engine operation, which ranges from approximately 0° to 100° and has a fixed correspondence. Here, we will still take a gasoline engine as an example for analysis, and its indicator diagram is shown in Figure 9. It should be noted that in our previous analysis of all operating conditions of the traditional gasoline engine, the objective factors remain unchanged, and the cylinder pressure is still the same P curve. Only the crankshaft, which is the power output end of the gasoline engine, has been changed to the compensating shaft.
[0054] Similarly, in Formula 2, we select different angles within the range of 0 to 50° to obtain the corresponding torque Mt' values. Then, we plot the points on the indicator diagram and connect the points to obtain a torque curve Mt' that is very close to the pressure curve P.
[0055] In Figure 9, we can intuitively observe that the dashed line near the lower edge of the pressure curve P is the output torque curve Mt' on the compensation shaft. Compared with the traditional gasoline engine output torque curve Mt, Mt' is very close to the cylinder pressure curve P. The area enclosed by Mt' and the X and Y axes is much larger than the area enclosed by Mt and the X and Y axes. This is because when the piston just begins to do work at top dead center, the cylinder pressure is high, the cosine function value is large, and the thrust on the compensation shaft is also large, resulting in a higher product. As the piston continues to descend, the cylinder cavity pressure P gradually decreases while the compensation shaft rotation angle α continuously increases, and the function value gradually decreases until the work is finished. Here, the peak value of the piston pressure P in the cylinder cavity and the peak value of the cosine function appear synchronously, achieving a highly efficient conversion of "force" into "torque." This is very beneficial for improving the thermal efficiency of reciprocating piston heat engines.
[0056] This invention abandons the traditional method of using the crankshaft as the power output end. Instead, a hinge is installed at the lower end of the connecting rod big end, and a lever is connected to the hinge. The lever passes through a compensating shaft with a slide rail next to the crankshaft. When the piston does work, the downward movement of the connecting rod drives the hinge downward. The downward movement of the hinge causes the lever to drive the compensating shaft to rotate clockwise, realizing power output. During the exhaust stroke, the hinge, along with the piston's upward movement, causes the lever to drive the compensating shaft to rotate counterclockwise. During the intake stroke, the compensating shaft rotates clockwise again. In the subsequent compression stroke, the compensating shaft rotates counterclockwise again, and so on. To ensure the continuity of power output, an overrunning clutch is installed on the compensating shaft, which can ensure continuous power output in the same direction.
[0057] The addition of a compensating shaft to the device significantly improves the piston's working state, transforming the force previously applied only to the crankshaft into a force applied to the compensating shaft. This changes the sinusoidal relationship of the work done on the crankshaft to a cosine relationship of the work done on the compensating shaft, increasing output torque and improving thermal efficiency under unchanged external conditions.
[0058] In a traditional reciprocating piston heat engine, power output is achieved through the crankshaft itself, while in this invention, power output is achieved through a compensating shaft outside the crankshaft.
[0059] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.
[0060] It should be understood that those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of the appended claims.
Claims
1. A reciprocating piston heat engine comprising a cylinder (1), a piston (2), a connecting rod (3), a crank (4), wherein the reciprocating piston heat engine further comprises a lever (5) and a compensation shaft (6), the piston (2) is arranged in the inner cavity of the cylinder (1), one end of the connecting rod (3) is hinged to the piston (2), the crank is hinged to the connecting rod (3), the other end of the connecting rod (3) is hinged to one end of the lever (5) outside the cylinder (1), the other end of the lever (5) passes through a sliding groove horizontally arranged on the compensation shaft (6), and the lever (5) can slide back and forth in the sliding groove of the compensation shaft (6).
2. The reciprocating piston heat engine of claim 1, wherein: The straight line of the movement track of the compensation shaft (6) does not intersect with the straight line of the movement track of the piston (2).
3. A reciprocating piston heat engine as claimed in claim 1 or 2, wherein: The straight line of the movement track of the compensation shaft (6) is perpendicular to the straight line of the movement track of the piston (2).
4. The reciprocating piston heat engine of claim 2, wherein: When the piston (2) moves to the top dead center in the stroke of the cylinder (1), the included angle between the connecting rod (3) and the lever (5) is 80°-110°.
5. The reciprocating piston heat engine of claim 1, wherein: The crank (4) is connected with a crankshaft, and the crank (4) rotates around the crankshaft.
6. The reciprocating piston heat engine of claim 1, wherein: The compensation shaft (6) is connected with an overrunning clutch.
7. The reciprocating piston heat engine of claim 1, wherein: Each cylinder (1), piston (2), connecting rod (3) and crank (3) form a power unit. The reciprocating piston heat engine comprises a power output shaft and a plurality of power units arranged side by side, and the compensation shaft (6) of each power unit is connected with the power output shaft through an overrunning clutch.
8. The reciprocating piston heat engine of claim 7, wherein: The compensation shaft of each power unit and the power output shaft are arranged in the same direction, and the compensation shafts of the power units are arranged in opposite phases.
9. The reciprocating piston heat engine of claim 1, wherein: The reciprocating piston heat engine further comprises an ignition switch, a spark plug, an intake valve, an exhaust valve and a high-pressure injection system, the intake valve, the exhaust valve, the high-pressure injection system and the spark plug are arranged on the top of the cylinder, and the ignition switch is connected with the spark plug through an ignition coil.
10. A vehicle comprising the reciprocating piston heat engine according to any one of claims 1-9.