Crankshaft-free piston type engine

Abstract

The invention belongs to the technical field of engines, and discloses a crankshaft-free piston type engine which comprises at least one air cylinder set, each air cylinder set comprises two air cylinders arranged oppositely, a piston is arranged in each air cylinder, the pistons of the two air cylinders are connected through a push rod, and a load of the engine is in power connection with the push rod; the engine further comprises a reciprocating motion flywheel mechanism, the reciprocating motion flywheel mechanism comprises a sliding block, a sliding rail seat and a flywheel, the sliding block is fixedly installed on the push rod, a sliding rail is arranged on the sliding rail seat, the sliding block is in sliding fit with the sliding rail, the base line of the sliding rail is a closed plane curve, and the sliding rail seat is coaxially and fixedly connected with the flywheel through a connecting shaft. The rotary motion of the piston and the push rod is coupled with the rotary motion of the energy storage flywheel through the sliding rail and sliding block mechanism, the piston and the push rod are driven to do reciprocating linear motion through the rotation inertia moment of the flywheel, an engine is conveniently started, and the inertia moment needed for stable operation is provided for the engine.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of engine, in particular to a crankshaft-free piston engine. BACKGROUND

[0002] The existing vehicle engine is basically a crankshaft connecting rod type internal combustion engine. The crank connecting rod mechanism of the engine is the main moving part for realizing the working cycle and completing the energy conversion of the engine. The crank connecting rod mechanism mainly includes basic parts such as cylinder, piston, connecting rod, crankshaft and flywheel. The linear reciprocating motion of the piston driven by the heat energy generated by fuel combustion is converted into the rotary motion of the crankshaft, so as to convert the heat energy into mechanical energy, and at the same time, the force acting on the piston is converted into the torque output by the crankshaft to drive the rotation of the vehicle wheels. The crankshaft is also connected with the timing belt / chain and cooperates with a certain transmission ratio to ensure the opening and closing time of the intake valve and the exhaust valve, which is an important part of the engine valve train system. The crankshaft and the connecting rod ensure that the piston reaches the top dead center and the bottom dead center, so that the gas in the cylinder reaches the designed compression ratio and the in-cylinder gas burns stably. The flywheel is connected with the crankshaft, and its main function is to store energy and stabilize the engine speed. The flywheel stores energy when the engine does work, and releases energy when the piston does not work (such as when the piston reaches the top dead center and the bottom dead center or the cylinder misfires), so as to maintain the engine speed and ensure the smooth operation of the engine. When the engine starts, the flywheel uses inertia to help the engine continuously increase the speed until the engine ignites and operates.

[0003] The crankshaft has a large volume and an irregular shape, and occupies a large movement space when working, so that the crankshaft engine has a large volume. The crankshaft bearing and the connecting rod bearing adopt bush bearing, and the friction coefficient is larger than that of rolling bearing, and high-pressure lubricating oil is needed, so the energy loss is large. In addition, the piston is deflected and the friction loss of the cylinder wall is increased, which affects the working efficiency of the engine. The crankshaft is a non-axially symmetric part, which rotates at high speed when working, and generates strong multi-dimensional vibration, which causes many NVH problems. In addition, the crank connecting rod mechanism itself has a complex structure and high manufacturing cost.

[0004] To improve engine energy conversion efficiency, increase power density, and reduce NVH (noise, vibration, and harshness) issues, researchers designed a reciprocating free piston engine. This engine eliminates the crankshaft and connecting rod mechanism, using a cylinder to drive a pushrod in reciprocating linear motion, with the load connected to the pushrod. Chinese patent CN103334836A discloses a free piston internal combustion generator with a dual-combustion chamber elliptical cylinder internal combustion module. This module uses a reciprocating linear generator as the load, mounted on the pushrod, to convert the energy output by the piston in the reciprocating linear motion into electrical energy. Chinese patent CN221973641U discloses a free piston engine, which includes two opposing cylinders and a transmission unit. The transmission unit includes two rocker gears, a one-way clutch engaging each rocker gear, and a drive shaft. The pistons of the two cylinders are connected by a push rod with a rack. The rocker gears mesh with the rack, and each rocker gear is connected to its corresponding drive shaft via the one-way clutch, allowing the rocker gears to rotate around a fixed axis. The piston drives the rocker gears through the push rod and rack, converting the reciprocating linear motion of the piston into rocker rotation, and then into rotational motion, outputting rotational power. These two engine structures eliminate or reduce many problems associated with crankshaft connecting rod mechanisms, improving engine thermal efficiency, range extender miniaturization, and NVH (noise, vibration, and harshness).

[0005] However, the aforementioned reciprocating linear engine has the following problems: It cannot be matched with a flywheel that has an energy storage function. Without an energy storage flywheel, the kinetic energy of the flywheel cannot be used to pass through top and bottom dead centers, making engine starting very difficult. It requires multiple forward and reverse accelerations by the electric motor, necessitating significant power and a long time. Without an energy storage flywheel, the flywheel's inertial moment cannot maintain a stable engine speed. When the piston reaches top / bottom dead centers, there is no inertial force to drive the piston back. If a misfire occurs, the engine can easily stop running, resulting in a stall or engine failure, and poor engine stability. Without a crankshaft synchronized with the piston movement, a mechanical timing mechanism cannot be matched, making valve control more complicated and less stable. Lacking mechanical constraints, the piston's dead center position and the gas compression ratio are constantly changing, resulting in large fluctuations in engine torque and poor operational stability. Summary of the Invention

[0006] To address the aforementioned problems, the present invention aims to provide a crankshaftless piston engine with a reasonable structural design and good stability. It utilizes the linear reciprocating motion of the piston and pushrod in the cylinder assembly to output power via the pushrod. A slide rail-slider mechanism couples the rotational motion of the piston and pushrod with the rotational motion of the energy storage flywheel. The rotational inertial torque of the flywheel drives the piston and pushrod in reciprocating linear motion, facilitating engine starting and providing the necessary inertial torque for stable engine operation. The flywheel and piston move synchronously, and a timing mechanism is selectively connected, ensuring stable and reliable valve control. The mechanical action between the slide rail and the slider ensures the piston accurately reaches dead center, maintaining a stable cylinder compression ratio and stable engine operation.

[0007] To achieve the above-mentioned objectives, the present invention adopts the following technical solution:

[0008] A crankshaftless piston engine includes at least one cylinder bank, which includes two opposing cylinders, each containing a piston. The pistons of the two cylinders are connected by a push rod, and the engine load is powered by the push rod. The engine also includes a reciprocating flywheel mechanism, which includes a slider, a slide rail seat, and a flywheel. The slider is fixedly mounted on the push rod, and the slide rail seat is provided with a concave or convex slide rail. The slider slides in contact with the slide rail, and the baseline of the slide rail is a closed planar curve. The slide rail seat and the flywheel are coaxially fixedly connected by a connecting shaft.

[0009] Furthermore, the number of cylinder groups mentioned above is two or more, and the push rods of each cylinder group are linked together through a transmission assembly.

[0010] A crankshaftless piston engine includes multiple cylinders arranged side by side, each cylinder containing a piston, each piston being connected to a push rod, the multiple push rods being linked adjacently via a transmission assembly, and at least one push rod being connected to the engine's load power; the engine also includes a reciprocating flywheel mechanism, the reciprocating flywheel mechanism including a slider, a slide rail seat, and a flywheel, the slider being fixedly mounted on one of the push rods, the slide rail seat being provided with an inwardly concave or outwardly convex slide rail, the slider slidingly engaging with the slide rail, the baseline of the slide rail being a closed planar curve, and the slide rail seat and the flywheel being coaxially fixedly connected via a connecting shaft.

[0011] Furthermore, a starter motor is provided on one side of the flywheel, and the starter motor is connected to the flywheel drive.

[0012] Furthermore, the plane of the slide rail curve is perpendicular to the axis of the connecting shaft. When the slide rail rotates around the connecting shaft, the slider is always at the intersection of the slider and the baseline of the slide rail.

[0013] Furthermore, when the slide rail rotates, the slider, push rod, and piston reciprocate in a linear motion together, while simultaneously sliding relative to each other along the slide rail.

[0014] Furthermore, when the slide rail rotates at a constant speed, the slider moves in a uniform linear motion within the slide rail.

[0015] Furthermore, the planar curve of the aforementioned slide rail, described by its polar coordinate equation, possesses the following characteristics: ; ; Where ρ represents the polar radius of point M, that is, the distance from the pole O to point M; θ represents the angle through which the polar radius rotates, that is, the angle between point M and the polar axis; L represents the path of the slider when it makes reciprocating linear motion, and its length is equal to the length of the piston stroke.

[0016] The polar coordinate equations (1) and (2) represent the locus (ρ,θ) of point M, which is a closed plane curve.

[0017] Furthermore, the motion of the slider and slide rail described above is as follows:

[0018] (1) The slider moves along a fixed horizontal straight line L, and the slide rail rotates clockwise around the pole O; the slide rail rotates clockwise around the pole O at a constant speed, and the slider reciprocates along the horizontal straight line L.

[0019] (2) The slide rail rotates clockwise at a constant speed for one revolution [0, 2π], and the slider moves at a constant speed from the right end to the left end along the upper half of the slide rail in a straight line; the slide rail rotates clockwise for the second revolution [2π, 4π], and the slider moves from the left end to the right end along the lower half of the slide rail in a straight line; the slide rail rotates at a constant speed for two revolutions, and the slider moves at a constant speed in a straight line for one reciprocating motion.

[0020] Furthermore, for the planar curve of the aforementioned slide rail, its polar radius ρ is a linear function of the rotation angle θ. Taking the time derivatives with respect to ρ and θ: ; ; Where ω represents the planar curve rotational speed of the slide rail; L represents the length of the piston stroke. It represents the speed of change of the extreme diameter, that is, the speed of change from the intersection of the plane curve of the slide rail and the straight line L to the extreme point O, and also represents the speed of the slider along the straight line L;

[0021] When θ∈[0, 2π], that is, when the slide rail has rotated for the first time... A negative value indicates that the intersection point of the straight line L and the plane curve of the slide rail moves in the opposite direction of the polar coordinate axis; when θ∈[2π, 4π], that is, when the slide rail has rotated for the second time, A positive value indicates that the intersection point of the straight line L and the plane curve of the slide rail moves in the same direction as the polar coordinate axis; two rotations of the slide rail correspond to one reciprocating linear motion of the slider; continuous rotation of the slide rail causes the slider to make continuous reciprocating linear motion.

[0022] The present invention also provides another type of crankshaftless piston engine, which includes a cylinder and a reciprocating flywheel mechanism. A piston is provided in the cylinder and is connected to one end of a push rod. The reciprocating flywheel mechanism includes a slider, a slide rail seat, and a flywheel. The slider is fixedly mounted on the push rod. The slide rail seat is provided with a concave or convex slide rail. The slider slides in cooperation with the slide rail. The baseline of the slide rail is a closed planar curve. The slide rail seat and the flywheel are coaxially fixedly connected through a connecting shaft.

[0023] Preferably, the other end of the push rod is connected to a return spring.

[0024] The present invention also provides a reciprocating flywheel mechanism with another structure, used in the crankshaftless piston engine of the present invention to replace the original reciprocating flywheel mechanism. It includes at least one sliding block, at least one sliding rail seat, and several gears. The sliding block is arranged on the push rod, and the sliding rail seat is provided with concave or convex sliding rails. Each sliding block corresponds to one sliding rail, and each sliding rail is slidably coupled to each sliding block. The baseline of the sliding rail is a closed planar curve. Each sliding rail is connected to a gear through a coupling shaft. The gears mesh with each other and rotate at the same speed. One of the coupling shafts is the engine power output component.

[0025] Due to the adoption of the technical solution described above, the present invention has the following advantages:

[0026] This invention relates to a crankshaftless piston engine, which incorporates a reciprocating flywheel mechanism. The key technology is the reciprocating / rotational coupling mechanism, which uses a slider and a slide rail to couple the continuous reciprocating linear motion of the piston and pushrod with the continuous rotation of the flywheel. This achieves synchronization between the rotation of the slide rail / flywheel and the reciprocating motion of the piston. Here, "synchronization" means that any angle of rotation of the slide rail / flywheel corresponds to a position of the slider / piston, and vice versa. Therefore, this crankshaftless piston engine possesses a mechanical inertia flywheel mechanism, a mechanical timing mechanism, and a mechanical mechanism that ensures the piston accurately reaches its top and bottom dead centers.

[0027] Compared with crankshaft engines, the crankshaftless piston engine of this invention eliminates the crankshaft connecting rod mechanism, reducing size and increasing power density; it eliminates the need for bearings and high-pressure lubricating oil, reducing energy loss and improving fuel economy; due to the absence of an eccentric rotating mechanism, NVH is greatly improved, making it particularly suitable as a power system for range extenders; the structural design is simpler and more reasonable, and the manufacturing cost is significantly reduced.

[0028] Compared with free piston engines, the crankshaftless piston engine of this invention has the following advantages: 1. It has an inertial flywheel, resulting in good working stability: When the gas in the cylinder burns and the piston outputs huge energy, the flywheel absorbs part of the energy and stabilizes the engine speed; when the engine load suddenly increases, the flywheel releases energy to mitigate the impact of sudden load changes; when the piston reaches dead center, the reciprocating flywheel mechanism uses the flywheel's moment of inertia to push the piston back, maintaining the piston's reciprocating linear motion, and can even complete the next stroke in the event of misfire; 2. It has a timing reference synchronized with the piston movement, greatly reducing the difficulty of control technology, improving system stability, and reducing manufacturing costs; 3. The motion coupling mechanism can ensure that the piston accurately reaches dead center, stabilize the compression ratio of the gas in the cylinder, and reduce fluctuations in output torque; 4. It has an inertial flywheel, which can utilize the flywheel's energy storage function to start the engine more easily. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of one embodiment of the crankshaftless piston engine of the present invention;

[0030] Figure 2 yes Figure 1 A schematic diagram of the main structure of the slider and push rod in the middle;

[0031] Figure 3 yes Figure 1 A side view of the slider and push rod in the diagram;

[0032] Figure 4 yes Figure 1 A bottom view of the slide rail base structure;

[0033] Figure 5 yes Figure 4 A schematic diagram of the cross-sectional structure;

[0034] Figure 6 yes Figure 4 A schematic diagram of the slide rail seat from another angle;

[0035] Figure 7 yes Figure 4 A schematic diagram of one embodiment of the closed plane curve of the slide rail;

[0036] Figure 8 This is a schematic diagram of the slide rail rotating around its central axis and the trajectory of the slider.

[0037] Figure 9 yes Figure 4 A schematic diagram of the closed plane curve of the slide rail in Embodiment 2;

[0038] Figure 10 This is a schematic diagram of the forces acting between the slide rail and the slider;

[0039] Figure 11 This is a schematic diagram of the structure of a second embodiment of the crankshaftless piston engine of the present invention;

[0040] Figure 12 This is a structural schematic diagram of a third embodiment of the crankshaftless piston engine of the present invention;

[0041] Figure 13 This is a structural schematic diagram of the fourth embodiment of the crankshaftless piston engine of the present invention;

[0042] Figure 14 This is a schematic diagram of the structure of a second embodiment of the reciprocating flywheel mechanism in this invention;

[0043] Figure 15 yes Figure 14 A schematic diagram of the structure of the two sliders and the push rod;

[0044] In the diagram: 1 - First cylinder; 2 - First piston; 3 - Slider; 4 - Flywheel; 5 - Connecting shaft; 6 - Slide rail seat; 7 - Second piston; 8 - Second cylinder; 9 - Rack; 10 - Load gear; 11 - Push rod; 12 - Slide rail; 13 - Planar curve; 3 (a, b) - Sliding block; 5 (a, b) - Connecting shaft; 6 (a, b) - Sliding rail; 14 (a, b) - Gear. Detailed Implementation

[0045] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0046] like Figures 1 to 6As shown, the crankshaftless piston engine includes a cylinder bank comprising a first cylinder 1 and a second cylinder 8 arranged opposite each other. The first cylinder 1 and the second cylinder 8 are respectively equipped with a first piston 2 and a second piston 7. The first piston 2 is linked to the second piston 7 via a push rod 11. When the first piston 2 performs its power stroke, the second piston 7 performs its compression stroke, and vice versa. The engine load is powered by the push rod 11, and the load includes, but is not limited to, a linear motor actuator, a rocker gear, and a piston pump. Preferably, a rack 9 is fixed to the side wall of the push rod 11, and a load gear 10 is located on one side of the push rod 11 and meshes with the rack 9 for transmission. When the engine is working, firstly, the first cylinder 1 performs power, pushing the first piston 2 to the right, which in turn pushes the second piston 7 to the right via the push rod 11, compressing the gas in the second cylinder 8. When the first cylinder 1 completes its stroke and reaches right dead center, it performs scavenging. Then, the second cylinder 8 performs power, pushing the second piston 7 to the left. The first piston 2 is pushed to the left by the push rod 11, compressing the gas in the first cylinder 1, thereby causing the first piston 2, the second piston 7, and the push rod 11 to complete one reciprocating motion. The engine also includes a reciprocating flywheel mechanism, which includes a slider 3, a slide rail seat 6, and a flywheel 4. The slider 3 is fixedly mounted on the push rod 11 and moves in a reciprocating linear motion together with the first piston 2, the second piston 7, and the push rod 11. The slide rail seat 6 is coaxially fixedly connected to the flywheel 4 through a connecting shaft 5 and rotates around the shaft. The slide rail seat 6 is provided with a concave or convex slide rail 12, and the slider is provided with a convex or concave structure and slides in cooperation with the slide rail. The slider 3 slides freely relative to the slide rail 12. The baseline of the slide rail 12 is a closed plane curve and is perpendicular to the connecting shaft 5 of the slide rail seat 6. When the slide rail seat 6 rotates around the connecting shaft 5, the slide rail 12 drives the slider 3, which in turn drives the push rod 11 and the first piston 2 and the second piston 7 to move in a reciprocating linear motion, and vice versa.

[0047] The timing belt / chain / gear of the engine of this invention is connected to the flywheel 4 or the connecting shaft 5.

[0048] A starter motor can be installed on one side of the flywheel, and the output end of the starter motor is connected to a drive wheel, which is connected to the flywheel via a transmission.

[0049] The baseline of the slide rail 12 is a closed plane curve 13. The plane curve 13 has an axis O. The axis of the connecting shaft 5 passes through the axis O and is perpendicular to the slide rail plane. The slide rail seat 6 rotates around the connecting shaft 5. The slide rail 12 rotates around the axis O in the slide rail plane. The slider 3 is always at the intersection of the slide rail 12 and the straight line L. The straight line L represents the path of the slider when it makes a reciprocating linear motion.

[0050] When the slide rail rotates, the slider makes a reciprocating linear motion and slides relative to the slide rail, and vice versa; preferably, when the slide rail rotates at a constant speed, the slider makes a constant linear motion within the slide rail.

[0051] When the engine is running, the flywheel rotates at high speed. The flywheel has a certain moment of inertia and kinetic energy, and tends to maintain its current speed. Due to the action of the flywheel, the slide rail tends to maintain a constant speed. If the slider slides at a constant speed, the force between the two is almost zero. If the slider decelerates, the flywheel releases energy, and the slide rail applies a force to maintain the slider speed. The flywheel decelerates and releases energy. If the slider accelerates, the slide rail applies a force to maintain the slider speed, while the flywheel accelerates and stores energy.

[0052] like Figure 7 As shown, the baseline of the slide rail 12 is a closed plane curve 13, which is represented by the following polar coordinate equation: ; ; Where ρ represents the polar radius of any point M on the curve, that is, the distance from the pole O to point M; θ represents the angle through which the polar radius turns, that is, the angle between point M and the polar axis (usually the positive direction of the X-axis); L represents the path of the slider when it makes reciprocating linear motion, and its length is equal to the length of the piston stroke.

[0053] The polar coordinate equations (1) and (2) represent the locus (ρ, θ) of point M, which is a closed plane curve.

[0054] See Figure 8 When the crankshaftless piston engine of the present invention is working, the slider 3 and the slide rail 12 described above have the following movements:

[0055] (1) In actual operation, slider 3 moves along a fixed horizontal straight line L. The extreme diameter ρ represents the distance from slider (point M) to pole O. The slider's trajectory is the straight line segment represented by L. The extreme diameter ρ does not rotate and coincides with the straight line L. The slide rail 12 rotates clockwise around pole O with a rotation angle of θ. The slide rail rotates clockwise around pole O, and the slider moves back and forth along the horizontal straight line L.

[0056] (2) The slide rail rotates clockwise at a constant speed for one revolution [0, 2π], and the slider moves at a constant speed from the right end to the left end along the upper half of the slide rail in a straight line; the slide rail rotates clockwise for a second revolution [2π, 4π], and the slider moves from the left end to the right end along the lower half of the slide rail in a straight line; the slide rail rotates at a constant speed for two revolutions, and the slider moves at a constant speed in a straight line for one reciprocating motion;

[0057] (3) Find the time derivatives of equations (1) and (2) above: ; ; Where ω represents the planar curve rotational speed of the slide rail; L represents the length of the piston stroke. It represents the speed of change of the extreme diameter, that is, the speed of change from the intersection of the plane curve of the slide rail and the straight line L to the extreme point O, and also represents the speed of the slider along the straight line L;

[0058] When θ∈[0, 2π], that is, when the slide rail has rotated for the first time... A negative value indicates that the slider (located at the intersection of the straight line L and the closed plane curve of the slide rail) moves in the opposite direction of the extreme radius ρ, i.e., to the left; when θ∈[2π, 4π], i.e. when the slide rail rotates clockwise for the second time, v is a positive value, indicating that the slider (located at the intersection of the straight line L and the closed plane curve of the slide rail) moves in the same direction as the extreme radius ρ, i.e., to the right; the slide rail rotates two times, corresponding to the slider making one reciprocating linear motion and returning to the starting point; the slide rail makes a continuous rotational motion, causing the slider to make a continuous reciprocating linear motion; according to formulas (3) and (4), if the slide rail rotates at a constant speed, the slider will make a constant linear motion, and vice versa.

[0059] In this invention, the first piston 2, the second piston 7, the push rod 11, and the slider 3 reciprocate linearly, wherein the slider 3 moves along a straight line L; the slider 3 is slidably coupled with the slide rail 12 and remains on the closed plane curve of the slide rail; therefore, the slider is always at the intersection of the straight line L and the slide rail curve: when the slide rail rotates, the slider moves linearly within the slide rail; when the slide rail rotates at a constant speed, the slider moves at a constant speed linearly within the slide rail.

[0060] The present invention can partially adjust the baseline of the slide rail or use different slide rail baselines as needed.

[0061] See Figure 10 At the contact point between the slider and the slide rail, draw the tangent to the closed plane curve of the slide rail; the slider and the slide rail are in contact at this point and are well lubricated, so friction is negligible; the force F between the slider and the slide rail is along the normal direction of the contact point (perpendicular to the tangent); decompose the contact force F, F ρ The component of the force F along line L will push the slider to move along line L; θ The component of the force perpendicular to line L will drive the slide rail to rotate. When the crankshaftless piston engine of this invention is working, if the slider moves at a constant speed and the slide rail rotates at a constant speed, the interaction force between the two is zero. The slider continues to move at a constant speed in a straight line, and the slide rail continues to rotate at a constant speed. If the slider speed decreases, the inertial torque of the flywheel tends to maintain the current rotation speed of the slide rail, and the slide rail exerts a squeezing force on the slider, tending to keep the slider moving at its original speed in a straight line. If the slider speed increases, the slider exerts a force on the slide rail. The tangential component of the force along the contact point of the slide rail drives the slide rail to rotate at an accelerated speed, which in turn drives the flywheel to accelerate and accumulate energy.

[0062] When the engine is running, the piston experiences significant pressure fluctuations from the gas inside the cylinder. Consequently, the force exerted by the piston on the pushrod fluctuates considerably, resulting in large changes in the speed of the pushrod and slider. The flywheel, with its large torque of inertia, possesses a strong ability to maintain its own uniform rotation and functions to stabilize the speed of the slider / pushrod / piston, reducing speed fluctuations. During piston expansion and work, the piston experiences immense pressure and accelerates. The force between the slider and the slide rail drives the slide rail and flywheel to accelerate, accumulating energy and stabilizing the speed of the slider / pushrod / piston.

[0063] Before the slider reaches the top / bottom dead center, the combined force of the piston thrust and the load causes the slider to decelerate rapidly. Finally, upon reaching the dead center, its speed drops to zero. All components undergoing reciprocating or oscillating motion—the piston, pushrod, slider, and load—have zero speed and zero kinetic energy, and there is no inertial force to drive the piston and other components back. However, the flywheel, aided by inertia, tends to maintain a constant speed. After passing the dead center, the slide rail applies a force, causing the slider to return and quickly enter a constant speed motion, preventing the piston / pushrod / load from jamming near the dead center and causing engine shutdown. Driving the slider / piston / pushrod through the dead center only requires the flywheel to release some energy; it does not stop rotating but continues to rotate. As long as the flywheel accumulates enough energy, it can drive the slider through the slide rail to perform multiple reciprocating motions. If a cylinder misfires, the flywheel can drive the slider / piston / pushrod past the top dead center and complete the next stroke, preventing engine shutdown due to misfire and enhancing engine stability.

[0064] When the crankshaftless piston engine of this invention is working, during the stroke, the piston does work, driving the push rod to accelerate, and the slider drives the slide rail and flywheel to accelerate and accumulate energy, thereby stabilizing the slider speed. After the slider reaches the dead point, the flywheel releases energy and uses inertia to drive the slider to move in the opposite direction, maintaining the system's movement and preventing the system from getting stuck at the dead point. This allows the slider to quickly pass through the dead point and accelerate rapidly, maintaining the system's reciprocating cycle and stable operation.

[0065] During engine startup, in the linear motion (stroke) of the slider, the motor drives the slide rail and flywheel to accelerate, and the slide rail drives the slider to accelerate linearly. The flywheel speed increases, accumulating more and more kinetic energy. When the slider reaches the dead center, the speed of the slider, push rod, and piston drops to zero, but the flywheel tends to maintain a constant speed. Using the inertial torque, the slider escapes the predicament of zero speed at the dead center. The flywheel releases some energy, causing the slider, push rod, and piston to accelerate rapidly in the opposite direction, entering the next stroke. The speed of the slider, push rod, and piston increases until they reach the engine ignition speed, starting the engine.

[0066] Comparing formulas (3) and (4) above, the velocity of the slider before it reaches the end is... The speed when leaving the end is The changes are drastic, negatively impacting engine performance and the mechanism. The closed-plane curve of the slide rail shows that it is not smooth at the ends (corresponding to the top / bottom dead centers), hindering smooth system operation. To solve this problem, the closed-plane curve of the slide rail at the ends is replaced with a smooth curve (such as a parabola or arc), as shown below. Figure 9 As shown, at one end, the slider starts from zero speed and accelerates to a constant speed with a certain acceleration; at the other end, the slider decelerates from a constant speed to zero with a certain deceleration. This avoids excessive speed changes at the ends and makes the slide rail curve smooth at the ends, effectively solving the problem. Furthermore, other parts of the slide rail curve can be adjusted appropriately according to the motion patterns and characteristics of the piston and load to make the engine run more smoothly.

[0067] The slide rail has three intersection points of the slide rail curve at 90°, 180° and 270° angles, but this does not affect the normal operation of the reciprocating flywheel: the slider is at 1 / 4, 1 / 2 and 3 / 4 of the stroke and is moving in a straight line. The inertia of the piston and push rod maintains the original speed and direction. The slide rail and flywheel rotate and maintain the original speed. This speed makes the intersection point of the slide rail curve and the straight line L still move along the straight line L with the original speed and direction. As a result, the slider slides along the closed plane curve of the slide rail described by equations (1) and (2) and will not enter the wrong path.

[0068] like Figure 11 , 2As shown in Figure 6, this invention also discloses a crankshaftless piston engine, which includes multiple cylinders arranged side by side. Taking two cylinders as an example, the structure of the engine is described in detail. A first piston 2 and a second piston 7 are respectively installed in the first cylinder 1 and the second cylinder 8. The first piston 2 and the second piston 7 are respectively connected to two push rods 11. One push rod 11 is connected to the load of the engine, the load including but not limited to a linear motor actuator, a rocker gear, and a piston pump. Preferably, racks 9 are fixed on the side walls of both push rods 11, and gears 10 mesh with the racks 9 on the two push rods 11, thereby realizing the linkage between the pistons and push rods. When the engine is working, firstly, the second cylinder 8 performs work, pushing the second piston 7 downwards, which in turn pushes the first piston 2 upwards via the two push rods 11, compressing the gas in the first cylinder 1. Then, the first cylinder 1 performs work, pushing the first piston 2 downwards, which in turn pushes the second piston 7 upwards via the two push rods 11. The piston 7 moves upward, compressing the gas in the second cylinder 8, thereby causing the first piston 2, the second piston 7, and the two push rods 11 to complete one reciprocating motion. The engine also includes a reciprocating flywheel mechanism, which includes a slider 3, a slide rail seat 6, and a flywheel 4. The slider 3 is fixedly mounted on the push rod 11 and moves in a reciprocating linear motion together with the first piston 2, the second piston 7, and the push rod 11. The slide rail seat 6 is coaxially fixedly connected to the flywheel 4 through a connecting shaft 5 and rotates around the shaft. The slide rail seat 6 is provided with a concave or convex slide rail 12, and the slider is provided with a convex or concave structure and slides in cooperation with the slide rail. The slider 3 slides freely relative to the slide rail 12. The baseline of the slide rail 12 is a closed plane curve and is perpendicular to the connecting shaft 5 of the slide rail seat 6. When the slide rail seat 6 rotates around the connecting shaft 5, the slide rail 12 drives the slider 3, which in turn drives the push rod 11, the second piston 7, and the first piston 2 to move in a reciprocating linear motion, and vice versa.

[0069] The push rods of the aforementioned multiple cylinders are connected to each other and linked by a transmission assembly.

[0070] like Figure 12 , 2As shown in Figure 6, this invention also discloses a crankshaftless piston engine, which includes a second cylinder 8 and a reciprocating flywheel mechanism. The second cylinder 8 houses a second piston 7, which is connected to one end of a push rod 11. The other end of the push rod is connected to a return spring (not shown in the figure). The engine further includes a reciprocating flywheel mechanism comprising a slider 3, a slide rail 6, and a flywheel 4. The slider 3 is fixedly mounted on the push rod 11 and reciprocates linearly together with the second piston 7 and the push rod 11. The slide rail seat 6 and the flywheel 4 are coaxially fixedly connected via a connecting shaft 5 and rotate around this shaft. The slide rail seat 6 is provided with a concave or convex slide rail 12, and the slider has a convex or concave structure that slides in cooperation with the slide rail. The slider 3 slides freely relative to the slide rail 12. The baseline of the slide rail 12 is a closed plane curve and is perpendicular to the connecting shaft 5 of the slide rail seat 6. When the slide rail seat 6 rotates around the connecting shaft 5, the slide rail 12 drives the slider 3, which in turn drives the push rod 11 and the second piston 7 to perform reciprocating linear motion, and vice versa. The above technical solution applies the reciprocating flywheel mechanism of this invention to a single-cylinder reciprocating linear engine, facilitating engine starting, maintaining stable engine operation, and driving the piston back to its position and compressing the gas in the cylinder, either alone or together with a return spring.

[0071] like Figure 13 As shown, the present invention is a crankshaftless piston engine, which includes two cylinder banks, the structure of which is similar to... Figures 1 to 6 The cylinder group structure and working method are the same. The reciprocating flywheel mechanism is used in a four-cylinder four-stroke engine. Through transmission components such as push rods, racks and pinions and load gear 10, the four pistons are linked. In each stroke, there is always one cylinder for intake, one cylinder for compression, one cylinder for power, and one cylinder for exhaust. The reciprocating flywheel mechanism can be connected to any one of the cylinders.

[0072] If the strength of the slide rail and slider can withstand the load, the connecting shaft 5 directly serves as the engine power output shaft, outputting torque, further simplifying the crankshaftless piston engine. Due to the influence of component size and material strength, the slide rail / slider cannot withstand the load generated by the piston's work. Therefore, this invention also provides a reciprocating flywheel mechanism with another structure for use in the crankshaftless piston engine of this invention, replacing the original reciprocating flywheel mechanism. This mechanism uses several slide rail / slider assemblies to share the load; it includes at least one sliding block, at least one sliding rail seat, and several gears. The sliding block is arranged on a push rod, and the sliding rail seat is provided with concave or convex sliding rails. Each sliding block corresponds to one sliding rail, and each sliding rail is slidably coupled to each sliding block. The baseline of the sliding rail is a closed planar curve. Each sliding rail is connected to a gear through a connecting shaft. The gears mesh with each other and rotate at the same speed. One of the connecting shafts is the engine power output component. See also Figure 14 , 15 This will be explained in detail using a two-rail / slider assembly as an example.Figure 14 In the middle, the push rod 11 is provided with sliding blocks 3a and 3b, whose motion trajectories are La and Lb, respectively; Figure 15 In this configuration, sliding rails 6a and 6b are slidably coupled to sliding blocks 3a and 3b, respectively. Sliding rail 6a is connected to gear 14a via shaft 5a, and sliding rail 6b is connected to gear 14b via shaft 5b. Gears 14a and 14b mesh (directly or indirectly) and rotate synchronously. Shafts 5a and 5b, and gears 14a or 14b are power output components of the engine, thus dividing the load generated by the piston thrust in two and halving the stress on the slider. Because the baseline of the sliding rails is symmetrical, gears 14a and 14b mesh directly or via an idler gear.

[0073] The parts of this invention not described in detail are prior art. Although the invention has been specifically shown and introduced in conjunction with preferred embodiments, there are many methods and approaches to implement this technical solution. The above description is only a preferred embodiment of the invention and is not intended to limit the invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the invention should be included within the protection scope of the invention.

Claims

1. A crankshaftless piston engine, characterized in that: It includes at least one cylinder group, which includes two cylinders arranged opposite each other. Each cylinder has a piston, and the pistons of the two cylinders are connected by a push rod. The load of the engine is powered by the push rod. The engine also includes a reciprocating flywheel mechanism, which includes a slider, a slide rail seat, and a flywheel. The slider is fixedly mounted on the push rod, and a slide rail is provided on the slide rail seat. The slider slides in contact with the slide rail, and the baseline of the slide rail is a closed planar curve. The slide rail seat and the flywheel are coaxially fixedly connected by a connecting shaft.

2. The crankshaftless piston engine according to claim 1, characterized in that: The number of cylinder groups is two or more, and the push rods of each cylinder group are linked together through a transmission assembly.

3. A crankshaftless piston engine, characterized in that: It includes multiple cylinders arranged side by side, each cylinder containing a piston, each piston being connected to a push rod, the multiple push rods being linked together via a transmission assembly, and at least one push rod being connected to the load power of the engine; the engine also includes a reciprocating flywheel mechanism, the reciprocating flywheel mechanism including a slider, a slide rail seat, and a flywheel, the slider being fixedly mounted on one of the push rods, the slide rail seat being provided with a slide rail, the slider slidingly engaging with the slide rail, the baseline of the slide rail being a closed planar curve, and the slide rail seat and the flywheel being coaxially fixedly connected via a connecting shaft.

4. The crankshaftless piston engine according to claim 1, 2 or 3, characterized in that: It also includes one or more of the following features: (1) A starter motor is provided on one side of the flywheel, and the starter motor is connected to the flywheel drive; (2) The plane of the slide rail is perpendicular to the axis of the connecting shaft. When the slide rail rotates around the connecting shaft, the slider is always at the intersection of the slider and the baseline of the slide rail. When the slide rail rotates, the slider, push rod and piston move together in a reciprocating linear motion and slide relative to each other along the slide rail, so that the rotation of the slide rail and the reciprocating linear motion of the slider and piston are synchronous. (3) The timing belt, timing chain or timing gear is connected to the flywheel drive.

5. The crankshaftless piston engine according to claim 1 or 3, characterized in that: The planar curve of the slide rail, described by its polar coordinate equation, has the following characteristics: ； ； Where ρ represents the polar radius of point M, that is, the distance from the pole O to point M; θ represents the angle through which the polar radius rotates, that is, the angle between point M and the polar axis; L represents the path of the slider when it makes reciprocating linear motion, and its length is equal to the length of the piston stroke. The polar coordinate equations (1) and (2) represent the locus (ρ,θ) of point M, which is a closed plane curve.

6. The crankshaftless piston engine according to claim 5, characterized in that: The closed plane curve of the slide rail is replaced by a smooth curve at the end, so that the slider can accelerate from zero speed to uniform speed at one end. At the other end, the slider decelerates from a constant speed to zero.

7. The crankshaftless piston engine according to claim 5, characterized in that: It also includes one or more of the following features: (1) The slider moves along a fixed horizontal straight line L, and the slide rail rotates clockwise around the pole O with a rotation angle of θ; the slide rail rotates clockwise around the pole O, and the slider reciprocates along the horizontal straight line L. (2) The slide rail rotates clockwise at a constant speed for one revolution [0, 2π], and the slider moves at a constant speed from the right end to the left end along the upper half of the slide rail in a straight line; the slide rail rotates clockwise for a second revolution [2π, 4π], and the slider moves from the left end to the right end along the lower half of the slide rail in a straight line; the slide rail rotates at a constant speed for two revolutions, and the slider moves at a constant speed in a straight line for one reciprocating motion; (3) Find the time derivatives with respect to ρ and θ: ； ； Where ω represents the planar curve rotational speed of the slide rail; L represents the length of the piston stroke. It represents the speed of change of the extreme diameter, that is, the speed of change from the intersection of the plane curve of the slide rail and the straight line L to the extreme point O, and also represents the speed of the slider along the straight line L; When θ∈[0, 2π], that is, when the slide rail has rotated for the first time... A negative value indicates that the intersection point of the straight line L and the plane curve of the slide rail moves in the opposite direction of the polar coordinate axis; when θ∈[2π, 4π], that is, when the slide rail has rotated for the second time, A positive value indicates that the intersection point of the straight line L and the plane curve of the slide rail moves in the same direction as the polar coordinate axis; two rotations of the slide rail correspond to one reciprocating linear motion of the slider; continuous rotation of the slide rail causes the slider to make continuous reciprocating linear motion.

8. A crankshaftless piston engine, characterized in that: It includes a cylinder and a reciprocating flywheel mechanism. The cylinder contains a piston, which is connected to one end of a push rod. The reciprocating flywheel mechanism includes a slider, a slide rail seat, and a flywheel. The slider is fixedly mounted on the push rod, and a slide rail is provided on the slide rail seat. The slider and the slide rail slide together. The baseline of the slide rail is a closed planar curve. The slide rail seat and the flywheel are coaxially fixedly connected through a connecting shaft.

9. A reciprocating flywheel mechanism, characterized in that: It includes at least one sliding block, at least one sliding rail seat, and several gears. The sliding block is arranged on a push rod, and the sliding rail seat is provided with a sliding rail. Each sliding block corresponds to one sliding rail, and each sliding rail is slidably coupled to each sliding block. The baseline of the sliding rail is a closed planar curve. Each sliding rail is connected to a gear through a coupling shaft. The gears mesh with each other and rotate at the same speed. One of the coupling shafts is an engine power output component.

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