A vacuum pump rotor comprises at least one displacement element arranged on a rotor shaft. The rotor shaft comprises at least one shaft end for a bearing element to be arranged thereon. The rotor element, the at least one displacement element and the at least one shaft end are made from aluminum or an aluminum alloy.

A vacuum pump screw rotor, comprising at least two helical displacer elements on a rotor shaft. The at least two displacer elements have different pitches, but the pitches of each displacer element are constant. Furthermore, the displacer elements each have a helical recess, each having a contour that remains the same over its entire length. Hereby, a suction-side displacer element has a recess having an asymmetric contour, and a pressure-side displacer element has a recess having a symmetrical contour.

A method of casting an assembly is provided that includes forming a structural insert, over-molding the structural insert with a temporary core, and positioning the over-molded structural insert within a cavity of a casting die. The over-molded structural insert is cast within a part, to form the assembly, and the temporary core is removed. The method may also include a temporary core configured to define an alloy flash trim location or locating features to position the structural insert within the cavity of the casting die. Further, the temporary core may define shared features with the structural insert. The part and structural insert may be dissimilar materials such as a part of an aluminum alloy material and a structural insert of a steel alloy material.

A screw vacuum pump comprises a housing forming a pumping chamber, wherein the housing is made of aluminum or an aluminum alloy. Further provided are two screw rotors arranged in the pumping chamber, each screw rotor comprising at least one displacer element having a helical recess for forming a plurality of windings, wherein the at least one displacer element is made of aluminum or an aluminum alloy. Between the region in which prevail 5% to 30% of the outlet pressure and a pressure-side end of the rotor (pump outlet), at least six, particularly at least eight, and with particular preference at least ten windings are provided.

Oil pumps having wear-resistant coatings applied thereto and methods of applying the coatings are disclosed. The oil pump may include an aluminum housing that defines a cavity. A steel rotor may be disposed within the cavity and configured to rotate therein such that a portion of the steel rotor contacts the aluminum housing. A metal coating (e.g., steel) may cover at least a portion of the aluminum housing in a region that is configured to be contacted by the steel rotor. An integrated oil pump and engine cover is disclosed including an aluminum body having a peripheral wall defining a cavity. The peripheral wall may form a portion of the oil pump housing and the cavity may receive a steel rotor. A wear-resistant coating (e.g., steel) may cover at least a portion of the peripheral wall in a region that is configured to be contacted by the steel rotor.

A structural frame is provided. The structural frame includes a bottom surface, first and second cylinder block sidewall engaging surfaces, the first and second cylinder block sidewall engaging surfaces positioned above the bottom surface at a height that is above a centerline of a crankshaft support included in a cylinder block when the structural frame is coupled to the cylinder block.

An insert that can be positioned in a gap between a first front face of a cylinder liner, the first front face facing a cylinder head, and a second front face of the cylinder head, the second front face facing the cylinder liner. The insert includes at least one compressible material.

A compressor includes a cylinder including a cylinder chamber, a piston movably arranged relative to the cylinder in the cylinder chamber, and a sliding member slideable against the cylinder and the piston in the cylinder chamber. The cylinder and the piston are constructed from an AlSi alloy having a Si content exceeding 12.6 wt %, which is a eutectic point. The sliding member is constructed from steel and has a surface layer including a sliding surface slideable against the cylinder and the piston. The surface layer is treated so as to have greater hardness than hardness of proeutectic Si contained in the AlSi alloy, and the surface layer has hardness of at least Hv 1000 in the sliding surface.

A 2-cycle, direct-injection diesel engine configured to accommodate low cetane diesel and jet fuels. The engine includes combustion chambers having surfaces which are operable at high temperatures during engine operation to increase the combustion rate of low cetane fuels. The engine is further configured to reduce starting times in cold and/or low pressure situations such as those experienced during attempts to restart a plane engine at relatively high altitudes.

A linear compressor is provided that may include a shell including a refrigerant suction inlet, a cylinder provided in the shell, a piston reciprocated in the cylinder, a suction muffler movable together with the piston, the suction muffler defining a refrigerant passage, a suction guide provided at one side of the piston to guide a refrigerant suctioned through the refrigerant suction inlet to the suction muffler, a back cover coupled to the suction guide, and a coupling guide provided in a space defined by the suction guide and the back cover to maintain a coupling force between the suction guide and the back cover.