A blower assembly includes, but is not limited to, a blower housing defining a blower chamber and including a gas inlet and a gas outlet; a first rotor positioned within the blower chamber and adapted for rotation therein, the first rotor including a first shaft and at least two lobes defining a first lobe profile; and a second rotor positioned within the blower chamber and adapted for rotation therein, the second rotor including a second shaft and at least two lobes defining a second lobe profile, wherein the first and second rotors are formed from a metal having a coefficient of thermal expansion from about 1 (10.sup.−6 in/in*K) to about 13 (10.sup.−6 in/in*K), and wherein at least one of the outer surface of the first rotor, the outer surface of the second rotor, or the blower chamber includes a coating.

Oleophobic and/or philic surface(s) are utilized for oil separation, direction, and/or collection in a refrigeration system. Surfaces of component(s) of a refrigeration system (compressor, oil separator, evaporator, etc.) are produced to be oleophobic or philic. The oleophobic and/or philic surfaces are utilized to direct a flow path of oil within the refrigeration system or to prevent oil connection in an area. Refrigerant phobic and/or lubricant phobic material(s) also may be utilized to help promote separation of refrigerant vapor from refrigerant liquid and/or from oil in refrigeration systems.

A compressor may include a non-orbiting scroll, an orbiting scroll, a bearing housing and first and second discrete keys. The non-orbiting scroll may include a first end plate having a first spiral wrap extending therefrom. The orbiting scroll may include a second end plate having a second spiral wrap extending therefrom and meshingly engaged with the first spiral wrap of the non-orbiting scroll. The bearing housing may support the orbiting scroll. Each of the first and second keys may be slidably engaged in first slots formed in the second end plate of the orbiting scroll and slidably engaged in second slots formed in the first end plate of the non-orbiting scroll or third slots formed in the bearing housing.

A compressor assembly becomes a compressor as a result of a terminal guard being attached. The compressor assembly includes a body, and a terminal guard mounting seat attached to an outer surface of the body. The terminal guard is attachable to the terminal guard mounting seat. A compressor includes the compressor assembly and the terminal guard. The compressor can be manufactured by attaching the terminal guard mounting seat to the outer surface, administering metal spraying to at least part of the outer surface after attaching the terminal guard mounting seat, and attaching the terminal guard to the terminal guard mounting seat after the administering metal spraying.

A compressor includes a casing and a metallic coating. The casing includes a low-pressure casing part covering a low-pressure space and a high-pressure casing part covering a high-pressure space. The metallic coating is formed at least on a part of an outer surface of the casing. The metallic coating includes a low-pressure part coating formed in the low-pressure casing part, a high-pressure part coating formed in the high-pressure casing part, and a welded part coating formed in a welded part. At least either the average thickness of the low-pressure part coating or the average thickness of the welded part coating is greater than the average thickness of the high-pressure part coating.

A low cost scroll device and methods of manufacturing the same are described. The scroll device includes, for example, a drive pin hole and bearing bores machined into a scroll of the scroll device from the same side as the involute of the scroll; idler shaft assemblies with no more than one bearing in the orbiting scroll for mechanically coupling the orbiting scroll to the fixed scroll; and an epoxy coating applied using a process that requires assembly of the scroll device only once.

A compressor may include a shell assembly, a first scroll, a second scroll, a driveshaft, and a bearing. The first scroll includes a first end plate and a first spiral wrap extending from the first end plate. The second scroll includes a second end plate and a second spiral wrap extending from the second end plate. The spiral wraps engage each other to form fluid pockets. The driveshaft may engage one of the scrolls. The bearing supports the driveshaft for rotation relative to the shell assembly. The bearing includes first and second axial ends and an aperture extending through the first and second axial ends. The driveshaft extends through the aperture. The aperture is defined by an inner diametrical surface of the bearing. The inner diametrical surface may include a tapered portion that extends radially outward as the tapered portion extends axially toward the first axial end of the bearing.

An orbiting scroll of a scroll compressor includes a platter wall having a first face including a spiral structure projecting therefrom, a second face having a coupling structure configured to couple the orbiting scroll to a drive mechanism of the scroll compressor, and a circumferential surface connecting the first face to the second face in an axial direction of the platter wall. The orbiting scroll includes a mass reduction feature provided as an inwardly indented channel formed in the circumferential surface. The channel is further configured to form a retaining feature for retaining a rim of a mask during a process of coating the spiral structure of the first face with a surface coating.

A rotary positive displacement pump (1) comprises a pump enclosure (10) and at least one rotating member (20). The pump enclosure (10) has an inlet (12) and an outlet (14). The rotating member (20) is arranged for, when being rotated, causing a transfer of a liquid from the inlet (12) to the outlet (14). The rotary positive displacement pump (1) has internal sliding surfaces (16, 24, 26, 32, 34) that during operation are exposed to the liquid and are exposed to a sliding contact relative to other internal sliding surfaces (16, 24, 26, 32, 34) of the rotary positive displacement pump (1). At least a part of the internal sliding surfaces (16, 24, 26, 32, 34) has a surface region composed by a nitrided or nitrocarburized steel intercalated with a solid lubricant. A method for manufacturing a rotary positive displacement pump is also disclosed.

A rotor for a mud motor includes a core having a first outer shape, and a shell positioned around the core, the shell having a second outer shape that is different from the first outer shape, the second outer shape defining one or more lobes and one or more cavities that are configured to engage a bore of a stator during rotation of the rotor relative to the stator. A thickness of the shell varies as proceeding around the core, from a non-zero minimum thickness to a maximum thickness.