Abstract: A four-stroke engine includes a case which is comprised of a first case half and a second case half connected with each other at a parting plane which goes through centerline of a crankshaft and is perpendicular to centerline of a cylinder. A first bearing seat is divided into a first upper bearing seat half and a first lower bearing seat at the parting plane. A second bearing seat is divided into a second upper bearing seat half and a second upper bearing seat half at the parting plane. The first upper bearing scat half and the second upper bearing scat half are integrally molded on the first case half, and the first lower bearing seat half and the second lower bearing seat half are integrally molded on the second case half. An outer side surface of the first case half and a side cover form a valve-operating chamber for accommodating a valve-operating mechanism.

Abstract: A crankcase scavenging mechanism for a four-stroke engine is disclosed. A valve operating chamber is assembled from a cylinder head and a cylinder head cover and is communicated with a crankcase. The cylinder head cover is arranged on the top of the cylinder head and is provided with a gas-oil separating cavity on the top thereof. A passage is communicated with the valve operating chamber. The gas-oil separating cavity is connected with a partition plate to form an oil-gas separation chamber. The oil-gas separation chamber is provided with a one-way valve thereon. The one-way valve is installed in a one-way valve hole. A passage above the one-way valve is provided with an inclined orifice, one end of which is blocked by a plug, the other end of which is communicated with the cylinder head and is further communicated with a suction tube through a cylinder head communication passage. An oil-returning hole is formed between the inclined orifice of the passage and the oil-gas separation chamber.

Abstract: The present invention relates to a gasoline generator, belongs to the technical field of motive power equipment. Wherein the gasoline engine set in an enclosed case, a permanent magnet generator is mounted on the engine housing, handle tray mounted on the fore end surface of cool air suction cover, suction cover is joined to the engine housing handle tray, joined to the suction cover, together forms the main cooling air channel for the motive power. The present invention provides a simple, compact and rational structure. Air guide plate and the cool air suction cover envelop all the high temperature parts of the engine and the generator, exhaust pipe and muffler as a whole. Cool air sucked in by the suction fan provides specific and adequate cooling for the above units/parts and then exhausted out of chamber through outlet slots.

Abstract: The present invention relates to a cooling system for an engine inside a power generator, in the field of the power generator, which mainly includes a cool air suction hood, an engine housing side cover, an engine housing, a cool air cooling fan, an exhaust pipe; the cool air suction hood is jointed to the engine housing side cover, the left air guide plate and the right air guide plate on the upper of the engine secured to the engine housing, thus form two main cooling and ventilating chambers A and B on the left and right upper portion of the engine. An engine bottom air guide plate is secured to the bottom of engine housing side cover and forms the bottom cooling and ventilating chamber C of the engine with the side cover and an engine crank case rear cover. The engine crank case rear cover, the above-mentioned members, a heat insulation chamber body, a sealing ring and a heat insulation chamber rear hood form a double chamber cooling means of the secondary cooling cycle chamber D.

Abstract: The present invention relates to a cooling system for an engine inside a power generator, in the field of the power generator, which mainly includes a cool air suction hood, an engine housing side cover, an engine housing, a cool air cooling fan, an exhaust pipe; the cool air suction hood is jointed to the engine housing side cover, the left air guide plate and the right air guide plate on the upper of the engine secured to the engine housing, thus form two main cooling and ventilating chambers A and B on the left and right upper portion of the engine. An engine bottom air guide plate is secured to the bottom of engine housing side cover and forms the bottom cooling and ventilating chamber C of the engine with the side cover and an engine crank case rear cover. The engine crank case rear cover, the above-mentioned members, a heat insulation chamber body, a sealing ring and a heat insulation chamber rear hood form a double chamber cooling means of the secondary cooling cycle chamber D.