Two-stroke free piston engine

Abstract

The utility model discloses a two-stroke free piston engine which comprises two opposite air cylinders and further comprises a swing gear, a first one-way clutch, a second one-way clutch, a first power output piece and a second power output piece. The swing gear is connected with a first power output piece through a first one-way clutch and connected with a second power output piece through a second one-way clutch, a first stroke and a second stroke are correspondingly formed in sequence every time the piston does linear reciprocating motion, in each stroke, one air cylinder does work, and the other air cylinder compresses. The output power of each stroke is guaranteed, and continuous power is output after the power of the two power output pieces is coupled through the transmission unit. In this way, a complex transmission mechanism composed of a push rod, a crankshaft and the like in the prior art can be omitted, linear reciprocating motion of the piston is converted into rotating motion, power in the rotating state is output, and engine efficiency is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of engines, in particular to a two-stroke free piston engine. Background Art

[0002] Hybrid electric vehicles (HEV), plug-in hybrid electric vehicles (PHEV) and range-extended electric vehicles (REEV) are the main technical routes for energy-saving and new energy vehicles. What the three have in common is that they all contain a piston engine with a crankshaft and convert fuel (such as gasoline, diesel, methanol, natural gas, hydrogen, etc.) into mechanical energy. Moreover, HEV, PHEV and REEV all need to maximize the energy conversion efficiency of the engine.

[0003] The power generated by existing piston engines is transmitted to the push rod through the piston, and the push rod is then transmitted to the crankshaft through the crank, which is then converted into rotational motion and output power. Due to the limitations of the push rod and crankshaft, the piston stroke is fixed, so the compression ratio cannot be adjusted and optimized according to power requirements. The thermal efficiency of the system is limited. In addition, when doing work, the push rod will exert a reaction force, and its lateral component will press the piston tightly against the cylinder wall, greatly increasing friction and increasing energy loss.

[0004] When the power stroke just begins, the pressure in the cylinder is the highest, but the crank is close to the top dead center at this time, the push rod's lever arm on the crankshaft is very small, the torque generated is small, and therefore the output power is also small. At the same time, the energy contained in the high-temperature and high-pressure gas is released slowly, and the energy loss caused by gas leakage and heat loss also increases accordingly.

[0005] When the power stroke is about to end, the crank is close to the bottom dead center, and the push rod's lever arm on the crankshaft is smaller. At this time, the pressure in the cylinder is smaller, so the output power is also smaller, which reduces the power density of the engine and increases the fluctuation of the output power.

[0006] In addition, the load between the push rod and the crankshaft, and between the crankshaft and the housing is very large, the friction loss is large, and high-pressure oil is required to lubricate the bearings. At the same time, the oil pump consumes energy, thereby reducing the efficiency of the engine. Summary of the Invention

[0007] To this end, in order to solve the above problems, the present invention provides a two-stroke free piston engine, which can eliminate the complex transmission mechanism composed of push rods and crankshafts in the prior art, and convert the linear reciprocating motion of the piston into rotational motion to output power in a rotational form, while improving engine efficiency.

[0008] To achieve the above purpose, the technical solutions provided by the present invention are as follows:

[0009] The utility model provides a two-stroke free-piston engine, comprising two cylinders arranged opposite to each other, and also comprising a transmission unit; the transmission unit comprises a rocking gear, a first one-way clutch, a second one-way clutch, a first power output member and a second power output member, the first power output member is matched with the first one-way clutch, and the second power output member is matched with the second one-way clutch; the first power output member and the second power output member are both used to transmit engine torque; the pistons of the two cylinders are connected by a push rod, the rocking gear is meshed with the rack on the push rod, and the rocking gear is arranged for fixed-axis rotation; each time the piston makes a linear reciprocating motion, it forms a first stroke and a second stroke in sequence, and in each stroke, there is always one cylinder doing work and the other cylinder compressing, so as to ensure that each Each stroke outputs power and is capable of performing the next stroke; in the first stroke, the push rod drives the rocking gear to rotate in the first direction through the rack, and the rocking gear is connected to the first power output member through the first one-way clutch to ensure that the first power output member transmits torque, and the second one-way clutch is separated synchronously to ensure that the second power output member idles in the same rotation direction as the previous stroke; in the second stroke, the push rod drives the rocking gear to rotate in the second direction opposite to the first direction through the rack, and the rocking gear is connected to the second power output member through the second one-way clutch to ensure that the second power output member transmits torque, and the first one-way clutch is separated synchronously to make the first power output member idle in the same rotation direction as the previous stroke.

[0010] In one embodiment, the swing gear is directly driven to connect to the first power output member via the first one-way clutch, and the swing gear is directly driven to connect to the second power output member via the second one-way clutch.

[0011] Furthermore, the first power output member and the second power output member are output shafts or output wheels for outputting torque respectively.

[0012] In one embodiment, the transmission unit further includes a coupling mechanism, and the first power output member and the second power output member are connected by the coupling mechanism, coupling the power alternately output by the two power output members into a single, continuously output power, and the rotation direction remains unchanged.

[0013] Furthermore, the rocking gear and / or the first power output member and / or the second power output member are connected via the coupling mechanism to couple the power output of every two consecutive strokes and ensure continuous power output, and the power output direction remains unchanged.

[0014] Furthermore, the coupling mechanism includes a coupling gear and a first output gear and a second output gear arranged coaxially, the first power output member includes a first output shaft lockably connected to the first one-way clutch and a first gear fixed on the first output shaft; the second power output member includes a second output shaft lockably connected to the second one-way clutch and a second gear fixed on the second output shaft; the first output gear is driven and connected to the first gear through the coupling gear, and the second output gear is engaged with the second gear.

[0015] Furthermore, the coupling mechanism includes a coupling gear and a first output gear and a second output gear arranged coaxially, the first power output member and the second power output member are both gears, the first one-way clutch is provided between the first power output member and the shaft of the rocking gear, and the second one-way clutch is provided between the second power output member and the shaft of the rocking gear; the first output gear is driven and connected to the first power output member through the coupling gear, and the second output gear is engaged with the second power output member.

[0016] Furthermore, the coupling mechanism includes a transmission gear set, the shaft of the rocking gear is fixedly connected to the transmission gear set, the transmission gear set is driven to connect to the first power output member through the first one-way clutch, and is driven to connect to the second power output member through the second one-way clutch, thereby forming an indirect drive setting.

[0017] Furthermore, the first power output member includes a first output shaft lockably connected to the first one-way clutch and a first gear fixed on the first output shaft; the second power output member includes a second output shaft lockably connected to the second one-way clutch and a second gear fixed on the second output shaft, and the first gear and the second gear are meshed.

[0018] Furthermore, the coupling mechanism includes a coupling gear and a transmission gear set, the shaft of the swing gear is fixedly connected to the transmission gear set, the first power output member is a gear, and the shaft of the swing gear is directly driven and connected to the first power output member through the first one-way clutch; the second power output member includes a second output shaft that can be locked and connected to the second one-way clutch, and a second gear fixed on the second output shaft, and the transmission gear set is driven and connected to the second output shaft through the second one-way clutch; the first power output member is driven and connected to the second gear through the coupling gear.

[0019] The technical solution provided by the utility model has the following beneficial effects:

[0020] The present invention can eliminate the complex transmission mechanism composed of the crankshaft and the like in the prior art, which not only reduces the overall cost, but also realizes the conversion of the linear reciprocating motion of the piston into rotational motion by pushing a single rocking gear to rotate on a fixed axis through a push rod provided with a rack, so as to output power in a rotational form, which is used to drive a rotating generator with stable power generation efficiency, thereby improving the conversion efficiency of mechanical energy into electrical energy, and at the same time improving the engine efficiency. It can also be used as a direct power for driving vehicles such as HEV, PHEV and REEV. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 FIG2 is a partial schematic diagram of a two-stroke free piston engine in the first embodiment in which the second cylinder is in a scavenging state;

[0022] Figure 2 FIG2 is a partial schematic diagram of a two-stroke free piston engine in the first embodiment, in which the first cylinder is in a power stroke state;

[0023] Figure 3 FIG2 is a partial schematic diagram of a two-stroke free piston engine in the first embodiment, in which the first cylinder is in a scavenging state;

[0024] Figure 4 FIG2 is a partial schematic diagram of a two-stroke free piston engine in the first embodiment, in which the second cylinder is in a power stroke state;

[0025] Figure 5 Shown is a connection diagram of a two-stroke free piston engine in Example 1;

[0026] Figure 6 Shown is a connection diagram of a two-stroke free piston engine in the second embodiment;

[0027] Figure 7 Shown is a connection diagram of a two-stroke free piston engine in embodiment three;

[0028] Figure 8 Shown is a connection diagram of a two-stroke free piston engine in Example 4. DETAILED DESCRIPTION

[0029] To further illustrate various embodiments, the present invention is provided with accompanying drawings. These drawings form part of the disclosure of this invention and are primarily used to illustrate the embodiments and, in conjunction with the relevant description in the specification, to explain the operating principles of the embodiments. By referring to these drawings, those skilled in the art will understand other possible implementations and the advantages of this invention. The components in the figures are not drawn to scale, and similar reference numerals are generally used to represent similar components.

[0030] The present invention will now be further described with reference to the accompanying drawings and specific implementation methods.

[0031] Example 1

[0032] Reference Figures 1 to 5 As shown, this embodiment provides a two-stroke free piston engine (hereinafter referred to as the piston engine). The piston engine of this embodiment includes two relatively arranged cylinders, namely a first cylinder 1a and a second cylinder 1b, and the pistons of the first cylinder 1a and the second cylinder 1b are respectively a first piston 2a and a second piston 2b.

[0033] The piston engine also includes a transmission unit, such as Figure 5 The transmission unit shown includes a rocking gear 4, a first one-way clutch 5a, a second one-way clutch 5b, a first power output member 6a, a second power output member 6b, and a coupling mechanism 100. The first power output member 6a engages with the first one-way clutch 5a, and the second power output member 6b engages with the second one-way clutch 5b. Both the first and second power output members 6a and 6b are used to transmit engine torque. The coupling mechanism 100 is a downstream component of the two power output members.

[0034] like Figure 2 and Figure 4 As shown, the first piston 2a of the first cylinder 1a and the second piston 2b of the second cylinder 1b are connected by a push rod 3, and a rack is provided on the push rod 3. The rocking gear 4 is engaged with the rack 31 on the push rod 3, and the rocking gear 4 is set to rotate on a fixed axis so that the rocking gear 4 can rock around its own axis.

[0035] Each time the piston makes a straight line reciprocating motion, it forms the first stroke and the second stroke in sequence. In each stroke, there is always one cylinder doing work and the other cylinder is compressing to ensure that each stroke outputs power and can proceed to the next stroke.

[0036] During the first stroke, the swing gear 4 is connected to the first power output member 6a through the first one-way clutch 5a to ensure that the first power output member 6a transmits torque, and the second one-way clutch 5b is synchronously separated to ensure that the second power output member 6b idles in the same rotation direction as the previous stroke.

[0037] During the second stroke, the swing gear 4 is connected to the second power output member 6b through the second one-way clutch 5b to ensure that the second power output member 6b transmits torque, and the first one-way clutch 5a is synchronously separated to allow the first power output member 6a to idle in the same rotation direction as the previous stroke.

[0038] In this embodiment, the push rod 3 is a linear rod structure. The movement of the piston from one end of the cylinder to the other end of the cylinder is a stroke, one back and forth is a round trip, and two strokes constitute a working cycle.

[0039] First, as Figure 1 As shown in the figure, at the end of the stroke of the previous working cycle, the first piston 2a of the first cylinder 1a moves to the leftmost end of the first cylinder 1a, the air and fuel mixture in the first cylinder 1a is compressed, and the second cylinder 1b completes scavenging, blows out the exhaust gas in the cylinder, and blows in the air and fuel mixture. Figure 2 As shown, when ignition and combustion occur in the first cylinder 1a, the first cylinder 1a is in the power stroke, the pressure in the first cylinder 1a increases, pushing the first piston 2a to move to the right, and pushing the second piston 2b to move to the right through the push rod 3, compressing the air and fuel mixture in the second cylinder 1b. The second cylinder 1b is in the compression stroke, and at this time, the two pistons move synchronously to the right in a straight line to form the first stroke.

[0040] Afterwards Figure 3 As shown, when the second piston 2b of the second cylinder 1b moves to the rightmost end of the second cylinder 1b, the compression stroke ends, the first cylinder 1a performs scavenging, blows out the exhaust gas in the cylinder, and blows in the air and fuel mixture; the air and fuel mixture in the second cylinder 1b is compressed. Figure 4 As shown, when ignition and combustion occur in the second cylinder 1b, the second cylinder 1b enters the power stroke. The pressure in the second cylinder 1b increases, pushing the second piston 2b to the left. This, in turn, pushes the first piston 2a to the left via the push rod 3, compressing the air and fuel mixture in the first cylinder 1a. The first cylinder 1a is in the compression stroke, and at this time, the two pistons move synchronously to the left in a straight line, forming the second stroke. This then enters the next stroke of the working cycle.

[0041] Therefore, one reciprocating linear motion of the piston forms a working cycle, and the next working cycle will be carried out immediately after one working cycle is completed.

[0042] When the piston and the push rod 3 move back and forth in the left and right directions, the rack 31 on the push rod 3 drives the rocking gear 4 to rock and rotate, and in the first stroke, the rack 31 moving to the right drives the rocking gear 4 to rotate clockwise; and in the second stroke, the rack 31 moving to the left drives the rocking gear 4 to rotate counterclockwise, so as to realize the meshing transmission between the rack 31 on the push rod 3 and the rocking gear 4, and convert the reciprocating linear motion of the piston into the fixed-axis rocking rotation of the rocking gear 4.

[0043] like Figure 5As shown, the swing gear 4 rotates on a fixed axis and can swing around its own axis. The swing gear 4 is connected to the first power output member 6a through the first one-way clutch 5a, or is connected to the second power output member 6b through the second one-way clutch 5b. Since the locking directions of the first one-way clutch 5a and the second one-way clutch 5b are set to be opposite to each other, when the swing gear 4 rotates, there is always one power output member in transmission and the other power output member in idling, so as to ensure that the two power output members alternately transmit torque and corresponding idling in the two strokes of one cycle of the piston engine, and the rotation direction of each power output member remains unchanged. In addition, the two power output members can output power independently and are each connected to a load (such as a generator).

[0044] The first one-way clutch 5a is locked during the first stroke, and the clockwise rotating swing gear 4 drives the first power output member 6a to rotate clockwise and transmit power through the first one-way clutch 5a; then the first one-way clutch 5a is disengaged during the second stroke, so that the counterclockwise rotating swing gear 4 is separated from the first power output member 6a, and the first power output member 6a can continue to rotate clockwise without load.

[0045] Synchronously, the second one-way clutch 5b is disengaged during the first stroke, so that the swing gear 4 that has been rotating clockwise is separated from the second power output member 6b, and the second power output member 6b rotates counterclockwise without load; then the second one-way clutch 5b is locked during the second stroke, so that the swing gear 4 that has been rotating counterclockwise drives the second power output member 6b to rotate counterclockwise through the second one-way clutch 5b and transmit torque.

[0046] In summary, the first power output member 6a rotates and outputs torque in the first stroke, but idles in the second stroke with its rotation direction unchanged. The second power output member 6b idles in the first stroke, but outputs torque in the second stroke with its rotation direction unchanged.

[0047] More specifically, Figure 5 As shown, the specific coupling mechanism 100 includes a coupling gear 8 and a first output gear 10 and a second output gear 9 arranged coaxially. The first power output member 6a and the second power output member 6b are connected by the coupling mechanism 100 to couple the power output of every two consecutive strokes and ensure continuous power output, and the power output direction remains unchanged, that is, the piston engine has only one power output and can output power continuously. To achieve this, the two power output members need to be coupled together.

[0048] To be more specific, the first power output member 6a includes a first output shaft 61 that can be locked and connected to the first one-way clutch 5a, and a first gear 62 fixed on the first output shaft 61; the second power output member 6b includes a second output shaft 63 that can be locked and connected to the second one-way clutch 5b, and a second gear 64 fixed on the second output shaft 63. The first output gear 10 is driven by the coupling gear 8 to connect to the first gear 62 of the first power output member 6a, and the second output gear 9 is engaged with the second gear 64 of the second power output member 6b.

[0049] In addition, in this embodiment, the first output shaft 61 and the first gear 62 of the first power output member 6a are fixedly connected and rotate coaxially and in the same direction. Furthermore, the first gear 62 of the first power output member 6a meshes with the coupling gear 8 and rotates in opposite directions, and the coupling gear 8 meshes with the first output gear 10 and rotates in opposite directions.

[0050] The second output shaft 63 of the second power output member 6b and the second gear 64 are fixedly connected and rotate coaxially and in the same direction. The second gear 64 of the second power output member 6b is meshed with the second output gear 9 and rotates in opposite directions.

[0051] The first output gear 10 and the second output gear 9 are coaxially fixedly connected via a shaft 91 to rotate in the same direction.

[0052] During the first stroke, the push rod 3 moving to the right drives the swing gear 4 to rotate clockwise, the first one-way clutch 5a is locked, and the swing gear 4 drives the first power output member 6a to rotate clockwise through the first one-way clutch 5a. The first gear 62 of the first power output member 6a drives the coupling gear 8 to rotate counterclockwise, and the coupling gear 8 drives the first output gear 10 and the second output gear 9 to rotate clockwise and transmit together. At the same time, the second one-way clutch 5b is disengaged, and the second output shaft 63 of the second power output member 6b can rotate counterclockwise without restraint, and the second output gear 9 rotating clockwise drives the second power output member 6b to rotate counterclockwise.

[0053] During the second stroke, the push rod 3 moving to the left drives the swing gear 4 to rotate counterclockwise, the second one-way clutch 5b is locked, and the swing gear 4 drives the second power output member 6b to rotate counterclockwise through the second one-way clutch 5b. The second gear 64 of the second power output member 6b drives the second output gear 9 and the first output gear 10 to rotate clockwise and transmit, and the first output gear 10 drives the coupling gear 8 to rotate counterclockwise; at the same time, the first one-way clutch 5a is disengaged, and the first output shaft 61 can rotate idly clockwise without restraint, that is, the first output gear 10 drives the coupling gear 8 to rotate counterclockwise, and the coupling gear 8 drives the first power output member 6a to rotate idly clockwise together.

[0054] Therefore, during the first stroke, the swing gear 4 drives the first output member 6a to rotate clockwise through the first one-way clutch 5a, the first output member drives the coupling gear 8 to rotate counterclockwise, the coupling gear 8 drives the first output gear 10 to rotate clockwise, the second output gear 9 coaxially connected to the first output gear 10 drives the second output member 6b to rotate counterclockwise, the second output gear 9 and the shaft 91 of the first output gear 10 rotate clockwise and output power; during the second stroke, the swing gear 4 drives the first output member 6b to rotate counterclockwise through the second one-way clutch 5b, the second output member 6b drives the second output gear 9 to rotate clockwise, the first output gear 10 coaxially connected to the second output gear 9 drives the coupling gear 8 to rotate counterclockwise, the coupling gear 8 drives the first output member 6a to rotate clockwise, the second output gear 9 and the shaft 91 of the first output gear 10 rotate clockwise and output power.

[0055] In other words, the shafts 91 of the second output gear 9 and the first output gear 10 are continuously driven to rotate clockwise, maintaining a constant rotational direction or power output direction, thereby achieving power coupling between the two power output components. Simultaneously, whether driving or idling, the rotational direction of all gears and shafts downstream of the two one-way clutches remains constant: the first output component 6a, the second output gear 9, and the first output gear 10 rotate clockwise, while the second output component 6b and the coupling gear 8 rotate counterclockwise. Through power coupling, any shaft and gear downstream of the two one-way clutches—namely, the first output component 6a, the second output component 6b, the coupling gear 8, the second output gear 9, and the first output gear 10—can function as the total output.

[0056] Within a working cycle of the piston engine of this embodiment, the piston engine has a variable stroke and compression ratio. The variable compression ratio allows the use of different fuels to enhance the flexibility and adaptability of the piston engine, promotes HCCI combustion to ensure higher thermal efficiency, and improves the potential for SI-HCCI conversion through the variable compression ratio.

[0057] This embodiment replaces the complex transmission mechanism composed of the crankshaft and the like in the prior art by using a push rod 3 and a transmission unit provided with a rack 31. This not only reduces the number of moving parts, simplifies the transmission structure, and reduces the overall cost, but also eliminates the high-pressure oil-lubricated bearings and the oil pump, thereby reducing energy consumption and improving the energy conversion efficiency of the system. It also effectively reduces the lateral load on the engine piston, thereby reducing the friction loss between the piston and the cylinder wall.

[0058] Moreover, the rack 31 on the push rod 3 drives a single rocking gear 4 to rotate, thereby realizing the conversion of the linear reciprocating motion of the piston of the piston engine into a rotational motion, so as to output power in a rotational form, which is used to drive a rotating generator with stable power generation efficiency, thereby improving the conversion efficiency of mechanical energy into electrical energy, and at the same time improving the engine efficiency. It can also be used as a direct power for driving vehicles such as HEV, PHEV and REEV.

[0059] Of course, in other embodiments, if the transmission unit adopts a dual rocking gear design, and during operation, the two rocking gears need to withstand the huge thrust output by the piston and have large load fluctuations, the technical requirements and costs of the gears, gear shafts, and bearings are high. Arranging two rocking gears between the two cylinders requires more space and the rigidity of the push rod 3 must be increased. However, this embodiment uses a transmission unit with a single rocking gear, which can reduce costs, size and weight, and improve design flexibility.

[0060] In addition, when the piston of the piston engine is around the top dead center, its acceleration is significantly higher, thereby reducing the residence time at high temperature and reducing the heat transfer loss during the combustion process. When the piston of the piston engine is around the bottom dead center, the force arm of the push rod 3 does not decrease, and the output power attenuation is small, so as to achieve small output power fluctuations.

[0061] Compared with the piston engine of the prior art, which has strong vibrations in three axes, namely the x-axis, y-axis and z-axis, the piston engine of this embodiment has strong vibrations only in one direction (i.e., the left and right movement directions of the piston), and the NVH (NVH includes noise, vibration and harshness) characteristics are significantly improved.

[0062] Example 2

[0063] like Figure 6 As shown, embodiment 2 provides a two-stroke free piston engine. The structure of embodiment 2 is substantially the same as that of embodiment 1, except that: the first power output member 6a' and the second power output member 6b' are both gears, a first one-way clutch 5a is provided between the first power output member 6a' and the shaft 41 of the rocking gear 4, and a second one-way clutch 5b is provided between the second power output member 6b' and the shaft 41 of the rocking gear 4. The two power output members alternately transmit torque and corresponding idling in the two strokes of a cycle of the piston engine, and the rotation direction of each power output member remains unchanged, and the two power output members can output power independently and are each connected to a load (such as a generator). Of course, the movement mode of the push rod, the rocking gear 4 and the two cylinders in embodiment 2 is similar to that in embodiment 1. Figures 1 to 4 As shown, it will not be described in detail here.

[0064] In this specific embodiment, the first one-way clutch 5a is arranged between the shaft 41 of the rocking gear 4 and the first power output member 6a', the second one-way clutch 5b is arranged between the shaft 41 of the rocking gear 4 and the second power output member 6b', and the first power output member 6a' is engaged with the coupling gear 8, and the rotation directions are opposite to each other; the coupling gear 8 and the first output gear 10 are engaged, and the rotation directions are opposite to each other; the second power output member 6b' is engaged with the second output gear 9, and the rotation directions are opposite to each other.

[0065] During the first stroke, the swing gear 4 rotates clockwise, the first one-way clutch 5a is locked, and the swing gear 4 drives the first power output member 6a' to rotate clockwise through the first one-way clutch 5a. The first power output member 6a' drives the coupling gear 8 to rotate counterclockwise and transmit. The coupling gear 8 drives the first output gear 10 and the second output gear 9 to rotate clockwise and transmit together. At the same time, the second one-way clutch 5b is disengaged, and the second power output member 6b' can idle without restraint. The second output gear 9 rotating clockwise drives the second power output member 6b' to idle counterclockwise.

[0066] During the second stroke, the swing gear 4 rotates counterclockwise, the second one-way clutch 5b is locked, and the swing gear 4 drives the second power output member 6b' to rotate counterclockwise through the second one-way clutch 5b. The second power output member 6b' drives the second output gear 9 and the first output gear 10 to rotate clockwise and transmit. At this time, the first output gear 10 drives the coupling gear 8 to rotate counterclockwise. At the same time, the first one-way clutch 5a is disengaged, and the first power output member 6a' can idle without restraint. The coupling gear 8 rotating counterclockwise drives the first power output member 6a' to idle clockwise.

[0067] In summary, during the first stroke, the shaft 91 of the second output gear 9 and the first output gear 10 are driven to rotate clockwise; during the second stroke, the shaft 91 of the second output gear 9 and the first output gear 10 are driven to rotate clockwise. In other words, the shaft 91 of the second output gear 9 and the first output gear 10 are continuously driven to rotate clockwise, and their rotation direction or power output direction remains unchanged. This achieves power coupling between the two power output elements. After power coupling, any shaft and gear downstream of the two one-way clutches, namely, the first power output element 6a', the second power output element 6b', the coupling gear 8, the second output gear 9, and the first output gear 10, can serve as the main output shaft.

[0068] Example 3

[0069] like Figure 7As shown, embodiment 3 provides a two-stroke free piston engine. The structure of embodiment 3 is substantially the same as that of embodiment 1, except that the coupling mechanism 100' further includes a transmission gear set 200, which includes gear A, gear B and gear C. Gear A is fixedly mounted on the shaft 41 of the rocking gear 4, and gear A is engaged with gear B and gear C respectively. Gear B is driven to connect to the first power output member 6a through the first one-way clutch 5a, and gear C is driven to connect to the second power output member 6b through the second one-way clutch 5b, thereby forming an indirect drive arrangement. The two power output members alternately transmit torque and corresponding idling in the two strokes of a cycle of the piston engine, and the rotation direction of each power output member remains unchanged. In addition, the two power output members can output power independently and are each connected to a load (such as a generator). Of course, the movement mode of the push rod, rocking gear 4 and two cylinders in embodiment 3 is similar to that in embodiment 1. Figures 1 to 4 As shown, it will not be described in detail here.

[0070] In this specific embodiment, the first power output member 6a includes a first output shaft 61 that can be locked and connected to the first one-way clutch 5a, and a first gear 62 fixed on the first output shaft 61; the second power output member 6b includes a second output shaft 63 that can be locked and connected to the second one-way clutch 5b, and a second gear 64 fixed on the second output shaft 63, and the first gear 62 of the first power output member 6a and the second gear 64 of the second power output member 6b are engaged.

[0071] The swing gear 4 is drivingly connected to the first output shaft 61 of the first power output member 6a through the gear A, the gear B and the first one-way clutch 5a to form a first torque transmission route.

[0072] The swing gear 4 is drivingly connected to the second output shaft 63 of the second power output member 6b through the gear A, the gear C and the second one-way clutch 5b to form a second torque transmission route.

[0073] During the first stroke, the push rod drives the rocking gear 4 and gear A to rotate clockwise together, gear A drives gears B and gear C to rotate counterclockwise at the same time, the first one-way clutch 5a is locked, and gear B drives the first power output member 6a to rotate counterclockwise through the first one-way clutch 5a. At the same time, the second one-way clutch 5b is disengaged, and the second power output member 6b can rotate clockwise without restraint, and the first gear 62 of the first power output member 6a drives the second power output member 6b to rotate clockwise.

[0074] During the second stroke, the push rod drives the rocking gear 4 and gear A to rotate counterclockwise, gear A drives gear B and gear C to rotate clockwise at the same time, the second one-way clutch 5b is locked, and gear C drives the second power output member 6b to rotate clockwise through the second one-way clutch 5b. At the same time, the first one-way clutch 5a is disengaged, and the first power output member 6a can idle without restraint, and the second gear 64 drives the first power output member 6a to idle counterclockwise.

[0075] In summary, during the first stroke, the second output shaft 63 of the second power output member 6b is driven clockwise; during the second stroke, the second power output member 6b is still driven clockwise. In other words, the second power output member 6b is continuously driven clockwise, with its rotational direction unchanged or its power output direction remaining unchanged, to achieve power coupling between the two power output members. Similarly, the first output shaft 61 of the first power output member 6a is continuously driven counterclockwise; and after power coupling, any shaft and gear downstream of the two one-way clutches, namely the first power output member 6a and the second power output member 6b, can serve as the main output shaft, achieving two consecutive alternating strokes, and the swing gear 4 can also continue to swing.

[0076] Example 4

[0077] like Figure 8 As shown, embodiment 4 provides a two-stroke free-piston engine. The structures of embodiment 4 and embodiment 3 are substantially the same, except that: the transmission gear set 200' of this embodiment includes gear D and gear E, wherein gear D is fixed on the shaft 41 of the rocking gear 4, and gear D is engaged with gear E. The first power output member 6a' is the first gear, and the shaft 41 of the rocking gear 4 is directly driven and connected to the first power output member 6a' through the first one-way clutch 5a; the second power output member 6b includes a second output shaft 63 that is lockable and connected to the second one-way clutch 5b, and a second gear 64 fixed on the second output shaft 63, and gear E is driven and connected to the second output shaft 63 of the second power output member 6b through the second one-way clutch 5b; and the second output shaft 63 and the second gear 64 are coaxially fixedly connected, and the first power output member 6a' is driven and connected to the second gear 64 of the second power output member 6b through the coupling gear 8 to achieve power coupling. The two power output members alternately transmit torque and corresponding idling in the two strokes of a cycle of the piston engine, and the rotation direction of each power output member remains unchanged. The two power output members can independently output power and are each connected to a load (such as a generator). Of course, the movement mode of the push rod, the rocking gear 4 and the two cylinders in the fourth embodiment is similar to that in the first embodiment. Figures 1 to 4 As shown, it will not be described in detail here.

[0078] During the first stroke, the first cylinder performs work, the push rod drives the rocking gear 4 and gear D to rotate clockwise, gear D drives gear E to rotate counterclockwise, the first one-way clutch 5a is locked, and the rocking gear 4 drives the first power output member 6a' to rotate clockwise through the first one-way clutch 5a, and the first power output member 6a' drives the coupling gear 8 to rotate counterclockwise and transmit power. At the same time, the second one-way clutch 5b is disengaged. Since the second power output member 6b can idle without restraint, the coupling gear 8 drives the second power output member 6b to idle clockwise.

[0079] It can be seen that the torque transmission route of the first stroke is: the rocking gear 4, the first power output member 6a' and the coupling gear 8 transmit power in sequence.

[0080] During the second stroke, when the second cylinder is working, the push rod drives the rocking gear 4 and gear D to rotate counterclockwise, gear D drives gear E to rotate clockwise, the second one-way clutch 5b is locked, and gear E drives the second power output member 6b to rotate clockwise through the second one-way clutch 5b. The second gear 64 of the second power output member 6b drives the coupling gear 8 to rotate counterclockwise and transmit power. At the same time, the first one-way clutch 5a is disengaged. Since the first power output member 6a' can idle without restraint, the coupling gear 8 drives the first power output member 6a' to idle clockwise.

[0081] It can be seen that the torque transmission route of the second stroke is: the rocking gear 4, gear D, gear E, the second power output member 6b and the coupling gear 8 transmit power in sequence.

[0082] During the first stroke, coupling gear 8 is driven counterclockwise; during the second stroke, coupling gear 8 is still driven counterclockwise. In other words, coupling gear 8 is continuously driven counterclockwise, maintaining a constant rotational direction or power output direction, thereby coupling the power of the two power output members. Through the coupling connection of coupling gear 8, any shaft and gear downstream of the two one-way clutches—the first power output member 6a', the second power output member 6b, and the coupling gear 8—can function as a master output shaft, ensuring consistent rotational direction and continuous power output.

[0083] Although the present invention has been specifically shown and described in conjunction with the preferred embodiments, those skilled in the art should understand that various changes can be made to the form and details of the present invention without departing from the spirit and scope of the present invention as defined by the appended claims, and all of these changes are within the scope of protection of the present invention.

Claims

1. A two-stroke free-piston engine comprising two cylinders arranged opposite to each other, characterized in that: Also includes a transmission unit; The transmission unit includes a swing gear, a first one-way clutch, a second one-way clutch, a first power output member and a second power output member, the swing gear is connected to the first output member through the first one-way clutch, and the swing gear is connected to the second output member through the second one-way clutch; The pistons of the two cylinders are connected by a push rod, the swing gear is engaged with the rack on the push rod, and the swing gear is arranged to rotate on a fixed axis; Each time the piston makes a linear reciprocating motion, it corresponds to the first stroke and the second stroke in sequence, forming a working cycle; when the engine is working in a cycle, the piston pushes the push rod to make a linear reciprocating motion together; In the first stroke, the push rod drives the rocking gear to rotate in the first direction through the rack, and the rocking gear is connected to the first power output member through the first one-way clutch to ensure that the first power output member transmits torque, and the second one-way clutch is synchronously disengaged to ensure that the second power output member idles in the same rotation direction as the previous stroke; In the second stroke, the push rod drives the rocking gear through the rack to rotate in a second direction opposite to the first direction. The rocking gear is connected to the second power output member through the second one-way clutch to ensure that the second power output member transmits torque, and the first one-way clutch is synchronously disengaged to allow the first power output member to idle in the same rotation direction as the previous stroke. The first power output member and the second power output member transmit and output the engine torque alternately, and their respective rotation directions remain unchanged.

2. The two-stroke free piston engine according to claim 1, characterized in that: The transmission unit further includes a coupling mechanism, through which the first power output member and the second power output member are connected, coupling the power alternately output by the two power output members into a single, continuously output power with an unchanged rotation direction.

3. The two-stroke free piston engine according to claim 1, characterized in that: The swing gear is directly driven to connect to the first power output member through the first one-way clutch, and the swing gear is directly driven to connect to the second power output member through the second one-way clutch.

4. The two-stroke free piston engine according to claim 3, characterized in that: The first power output member and the second power output member are output shafts or output wheels for outputting torque respectively.

5. The two-stroke free piston engine according to claim 2, characterized in that: The rocking gear and / or the first power output member and / or the second power output member are connected via the coupling mechanism to couple the power output of every two consecutive strokes and ensure continuous power output with unchanged power output direction.

6. The two-stroke free piston engine according to claim 5, characterized in that: The coupling mechanism includes a coupling gear and a first output gear and a second output gear arranged coaxially. The first power output member includes a first output shaft that can be locked and connected to the first one-way clutch, and a first gear fixed on the first output shaft; the second power output member includes a second output shaft that can be locked and connected to the second one-way clutch, and a second gear fixed on the second output shaft; the first output gear is driven and connected to the first gear through the coupling gear, and the second output gear is engaged with the second gear.

7. The two-stroke free-piston engine according to claim 5, characterized in that: The coupling mechanism includes a coupling gear and a first output gear and a second output gear arranged coaxially. The first power output member and the second power output member are both gears. The first one-way clutch is provided between the first power output member and the shaft of the rocking gear, and the second one-way clutch is provided between the second power output member and the shaft of the rocking gear; the first output gear is driven and connected to the first power output member through the coupling gear, and the second output gear is engaged with the second power output member.

8. The two-stroke free piston engine according to claim 5, characterized in that: The coupling mechanism includes a transmission gear set, the shaft of the rocking gear is fixedly connected to the transmission gear set, the transmission gear set is driven to connect to the first power output member through the first one-way clutch, and is driven to connect to the second power output member through the second one-way clutch, thereby forming an indirect drive setting.

9. The two-stroke free-piston engine according to claim 8, characterized in that: The first power output member includes a first output shaft lockably connected to the first one-way clutch and a first gear fixed to the first output shaft; the second power output member includes a second output shaft lockably connected to the second one-way clutch and a second gear fixed to the second output shaft, and the first gear and the second gear are meshed.

10. The two-stroke free-piston engine according to claim 5, characterized in that: The coupling mechanism includes a coupling gear and a transmission gear set. The shaft of the swing gear is fixedly connected to the transmission gear set. The first power output member is a gear. The shaft of the swing gear is directly driven and connected to the first power output member through the first one-way clutch; the second power output member includes a second output shaft that can be locked and connected to the second one-way clutch, and a second gear fixed on the second output shaft. The transmission gear set is driven and connected to the second output shaft through the second one-way clutch; the first power output member is driven and connected to the second gear through the coupling gear.

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