The present utility model discloses a portable four-stroke engine, comprising: an engine body, a flywheel and an oil storage tank, wherein an air valve distribution chamber and a crank shaft chamber are arranged in the engine; a crank shaft is arranged in the crank shaft chamber, and is connected to the flywheel; the oil storage tank is arranged on the engine body, located above the flywheel, and configured to store lubricating oil; a cam and a rocker arm mechanism are arranged in the air valve distribution chamber; and the cam is configured to drive the rocker arm mechanism. The portable four-stroke engine provided by the present utility model has a small volume and therefore has better operation performance.

According to one embodiment, a drive device includes a first piston reciprocatively along a first direction within a first mount plane, a first crankshaft orthogonal to the first mount plane, a first XY separation crank mechanism between the first piston and the first crankshaft, which converts reciprocating motion of the first piston and rotary motion of the first crankshaft into each other, a second piston reciprocatively along a second direction symmetrical to the first direction within a second mount plane symmetrical to the first mount plane about a central reference plane, a second crankshaft orthogonal to the second mount plane, a second XY separation crank mechanism between the second piston and the second crankshaft, which converts reciprocating motion of the second piston and rotary motion of the second crankshaft into each other, and a coupler-synchronizing mechanism which rotates the first and second crankshafts in synchronous with each other.

According to one embodiment, a drive device includes a first piston reciprocatively along a first direction within a first mount plane, a first crankshaft orthogonal to the first mount plane, a first XY separation crank mechanism between the first piston and the first crankshaft, which converts reciprocating motion of the first piston and rotary motion of the first crankshaft into each other, a second piston reciprocatively along a second direction symmetrical to the first direction within a second mount plane symmetrical to the first mount plane about a central reference plane, a second crankshaft orthogonal to the second mount plane, a second XY separation crank mechanism between the second piston and the second crankshaft, which converts reciprocating motion of the second piston and rotary motion of the second crankshaft into each other, and a coupler-synchronizing mechanism which rotates the first and second crankshafts in synchronous with each other.

An internal combustion engine includes a first low-pressure cylinder housing a first low-pressure piston, and a first high-pressure cylinder housing a first high-pressure piston, the first high-pressure cylinder being arranged in upstream fluid communication with the first low-pressure cylinder for providing exhaust gas into the first low-pressure cylinder. The internal combustion engine further includes a second low-pressure cylinder housing a second low-pressure piston, the second low-pressure cylinder being arranged in upstream fluid communication with the first high-pressure cylinder for providing compressed gas into the first high-pressure cylinder, and a second high-pressure cylinder housing a second high-pressure piston, the second high-pressure cylinder being arranged in downstream fluid communication with the first low-pressure cylinder for receiving compressed gas from the first low-pressure cylinder, and further arranged in upstream fluid communication with the second low-pressure cylinder for providing exhaust gas into the second low-pressure cylinder.

An internal combustion engine includes a first low-pressure cylinder housing a first low-pressure piston, and a first high-pressure cylinder housing a first high-pressure piston, the first high-pressure cylinder being arranged in upstream fluid communication with the first low-pressure cylinder for providing exhaust gas into the first low-pressure cylinder. The internal combustion engine further includes a second low-pressure cylinder housing a second low-pressure piston, the second low-pressure cylinder being arranged in upstream fluid communication with the first high-pressure cylinder for providing compressed gas into the first high-pressure cylinder, and a second high-pressure cylinder housing a second high-pressure piston, the second high-pressure cylinder being arranged in downstream fluid communication with the first low-pressure cylinder for receiving compressed gas from the first low-pressure cylinder, and further arranged in upstream fluid communication with the second low-pressure cylinder for providing exhaust gas into the second low-pressure cylinder.

An internal combustion engine, including a combustion chamber with a first aperture; a compression chamber with a second aperture; and a crossover valve comprising an internal chamber, first and second valve seats, a valve head, and first and second valve faces on the valve head, wherein the first aperture allows fluid communication between the combustion chamber and the internal chamber, the second aperture allows fluid communication between the compression chamber and the internal chamber, the first valve face couples to the first valve seat to occlude the first aperture, and the second valve face couples to the second valve seat to occlude the second aperture.

An internal combustion engine, including a combustion chamber with a first aperture; a compression chamber with a second aperture; and a crossover valve comprising an internal chamber, first and second valve seats, a valve head, and first and second valve faces on the valve head, wherein the first aperture allows fluid communication between the combustion chamber and the internal chamber, the second aperture allows fluid communication between the compression chamber and the internal chamber, the first valve face couples to the first valve seat to occlude the first aperture, and the second valve face couples to the second valve seat to occlude the second aperture.

An internal combustion engine includes a first low-pressure cylinder housing a first low-pressure piston, and a first high-pressure cylinder housing a first high-pressure piston, the first high-pressure cylinder being arranged in upstream fluid communication with the first low-pressure cylinder for providing exhaust gas into the first low-pressure cylinder. The internal combustion engine further includes a second low-pressure cylinder housing a second low-pressure piston, the second low-pressure cylinder being arranged in upstream fluid communication with the first high-pressure cylinder for providing compressed gas into the first high-pressure cylinder, and a second high-pressure cylinder housing a second high-pressure piston, the second high-pressure cylinder being arranged in downstream fluid communication with the first low-pressure cylinder for receiving compressed gas from the first low-pressure cylinder, and further arranged in upstream fluid communication with the second low-pressure cylinder for providing exhaust gas into the second low-pressure cylinder.

The disclosure provides a method and an apparatus for acquiring an electronic file. The method for acquiring an electronic file comprises: sending a first request message for acquiring an electronic file to a platform server, wherein the first request message carries a first identifier of an information providing server providing the electronic file; receiving first prompt information returned from the platform server according to the first request message; determining first verification information for identity authentication according to the first prompt information, and sending the first verification information to the platform server; and receiving the electronic file forwarded by the platform server, wherein the electronic file is from the information providing server, and private information in the electronic file is encrypted through a first encryption key of the information providing server. The technical solutions in the disclosed embodiments can effectively protect private information of a user from being leaked by a platform server, thereby ensuring privacy security of the user.

The disclosure provides a method and an apparatus for acquiring an electronic file. The method for acquiring an electronic file comprises: sending a first request message for acquiring an electronic file to a platform server, wherein the first request message carries a first identifier of an information providing server providing the electronic file; receiving first prompt information returned from the platform server according to the first request message; determining first verification information for identity authentication according to the first prompt information, and sending the first verification information to the platform server; and receiving the electronic file forwarded by the platform server, wherein the electronic file is from the information providing server, and private information in the electronic file is encrypted through a first encryption key of the information providing server. The technical solutions in the disclosed embodiments can effectively protect private information of a user from being leaked by a platform server, thereby ensuring privacy security of the user.