A valve assembly includes a valve body defining a cylindrical passage therein about an axis. An inlet port is defined in or near a first end of the valve body. First and second outlet ports are defined in the valve body extending radially outward from the cylindrical passage. A cylindrical valve spool having a central passage is positioned within, and sealingly engaged with, the cylindrical passage. The valve spool is moveable along the axis among: a first position wherein the inlet port is in fluid communication with the first outlet port but not the second outlet port, a second position wherein the inlet port is in fluid communication with the second outlet port but not the first outlet port, and an intermediate position between the first and second positions wherein the inlet port is in fluid communication with both of the first and second outlet ports.

An integrally formed piston has a crown portion having an upper crown surface and an undercrown surface. A ring belt extends from the undercrown surface at a periphery thereof. The ring belt includes an uppermost ring land and at least one oil galley contoured to extend around at least two surfaces of the uppermost ring land. The oil galley has an opening at the undercrown surface for receiving a cooling fluid therein for cooling the uppermost ring land. A skirt extends from the undercrown surface and the ring belt and has a plurality of stiffening features arranged in a truss formation. At least one of the plurality of stiffening features has an I-beam cross-section and another of the plurality of stiffening features has a negative draft angle.

An integrally formed piston has a crown portion having an upper crown surface and an undercrown surface. A ring belt extends from the undercrown surface at a periphery thereof. The ring belt includes an uppermost ring land and at least one oil galley contoured to extend around at least two surfaces of the uppermost ring land. The oil galley has an opening at the undercrown surface for receiving a cooling fluid therein for cooling the uppermost ring land. A skirt extends from the undercrown surface and the ring belt and has a plurality of stiffening features arranged in a truss formation. At least one of the plurality of stiffening features has an I-beam cross-section and another of the plurality of stiffening features has a negative draft angle.

The invention is a sealing assembly for equipment with movable shafts—such as coaxial and side port swivels, hydraulic swivels, and rotary control devices—that prevents the loss of a high pressure fluid through the clearance existing between a housing and the shaft. The invention is disclosed in the context of a coaxial swivel that conducts high pressure fluid from a stationary first conduit to a rotating second conduit that has dynamic runout, and may be misaligned relative to the first conduit.

A piston for an internal combustion engine includes a cylindrical piston body defining a longitudinal axis and having a top end and an outer cylindrical surface. A first piston ring groove is formed in the outer cylindrical surface and includes a groove root, an upper surface and a lower surface. The groove root has a variable depth about a circumference of the cylindrical piston body.

A piston assembly for an internal combustion engine includes a cylinder bore and a piston having a plurality of ring grooves, and a ring positioned within a ring groove. The ring includes a cross-section having a lower surface and an outer radial surface that form a scraping corner, an inner radial surface, and an upper surface. The upper surface and the lower surface are generally parallel with one another, and both upper and lower surfaces form a positive first angle with respect to a radial axis, and the outer radial surface forms a second positive angle with respect to a central axis. A constant twist occurs in the ring about a rotational center of the cross-section, the constant twist occurring at each cross-sectional location of the ring about the circumference of the ring and between adjacent free ends of the ring.

Methods and apparatuses for installing a piston ring onto a piston include a piston ring feeder having at least one projection feature and a receiving aperture. Methods include receiving a piston end having a piston groove into the receiving aperture until the piston groove is above piston rings on the piston ring feeder and below projection feature top ends; raising a ring to partially snap into the piston groove with ring ends separated by a first projection feature and the ring wrapped around a second projection feature; raising the piston such that the ring is pulled off the second projection feature while the first projection feature separates the ring ends; and raising the piston such that the first projection feature releases the ring ends and the ring fully snaps into the piston groove to form a gap between the ring ends of the ring seated in the piston groove.

The present invention discloses a piston for an engine. The piston comprises a piston body; wherein, a top land, a first compression ring groove, a second land, a second compression ring groove, a third land, an oil ring groove are disposed in turn on the periphery of the piston body from top to bottom; the ratio of the depth of the first compression ring groove to the depth of the second compression ring groove is less than or equal to 1.0; at least one of annular expansion grooves are disposed on the periphery of the second land and/or the third land, to reduce the intra-cylinder carbon deposition and the hydrocarbon emissions in the exhaust gas emissions of the engine and thus improve the engine efficiency and the overall performance of the engine.

In an engine piston assembly of the present invention, a piston structure, together with a piston ring set matched to the piston structure and an inner wall of a cylinder bore body, forms a crevice passage having at least two annular expansion chambers and also having a function of multistage throttling and expansion. The engine piston assembly of the present invention can not only greatly and effectively reduce the intra-cylinder carbon deposition and the hydrocarbon emissions in the exhaust gas emissions of the engine, but also significantly improve the engine efficiency and the overall performance of the engine, so that the present invention is suitable for wide applications.

The present invention discloses an energy-saving and emission-reducing multistage throttling expansion method for engine. In a crevice passage disposed between the combustion chamber and the crankcase, a multistage throttling is disposed for converting pressure energy of the high-pressure blow-by gas into kinetic energy and momentum, and a multistage expansion is disposed for expanding and dissipating the incoming kinetic energy and momentum of the high-velocity blow-by gas into heat, so that to realize the multistage throttling and expansion method, reduce the leaking of the unburned fuel-air mixture and the burned gas, the hydrocarbon emissions hidden in the intra-cylinder carbon deposition and exhaust gas emissions of the engine, and also improve the engine efficiency and the overall performance of the engine.