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 dry vacuum pump has a stator (2) and two rotors (5) that are accommodated in at least one compression chamber (3) of the stator (2), the rotors (5) being configured to rotate synchronously in opposite directions so as to drive a gas to be pumped between an intake and a delivery of the vacuum pump. The rotors (5) and the compression chamber (3) of the stator (2) are coated with a nickel-phosphorus coating (11) comprising between 9% and 14% phosphorus and having a thickness greater than 20 μm, the nickel-phosphorus coating (11) having undergone a hardening heat treatment comprising a step of heating to a treatment temperature greater than 250° C. for a treatment duration greater than one hour, so as to have a hardness greater than 700 HV.

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.

The invention relates to a screw compressor comprising a compressor housing (11) having two rotor screws (1, 2) mounted axially parallel therein, which mesh with each other in a compression space (18), can be driven by a drive and are synchronized with each other in their rotational movement, wherein the rotor screws (1, 2) each have a single-part or multi-part base body (24) with two end faces (5a, 5b, 5c, 5d) and a profiled surface (12a, 12b) extending therebetween, and shaft ends (30) projecting beyond the end faces (5a, 5b, 5c, 5d), wherein at least the profiled surface (12a, 12b) is formed in multiple layers, comprising a first, inner layer (3) and a second, outer layer (4), wherein the first, inner layer (3) and the second, outer layer (4) both comprise or are formed from a thermoplastic synthetic material, wherein particles (25) or pores (32) supporting a running-in process are embedded in the second, outer layer (4) and the thermoplastic synthetic material defines a matrix for receiving the particles (25) or for forming the pores (32).

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.

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.

A compressor includes a casing, a compression mechanism, and a motor that drives the compression mechanism. The casing is configured to cover an internal space. The internal space includes a first space and a second space larger than the first space. The casing has a first casing part covering the first space and a second casing part covering the second space. At least one of the first space and the second space is a high-pressure space configured to contain high-pressure fluid. A metallic coating may be formed on an outer surface of at least the first casing part. Alternatively, a resin coating may be formed on an outer surface of the casing.

A method for treating a surface of a machine part, the method including the steps of: applying a pattern onto the surface of the machine part by means of a laser; and applying a coating onto the patterned surface

A drive device for a motor vehicle, having at least one drive unit and one coolant circuit for controlling the temperature of the at least one drive unit, in which at least one coolant pump is arranged in the coolant circuit for circulating an aqueous coolant in the coolant circuit. The coolant pump is designed as a screw spindle pump, in which one or more internal components are provided with a coating. The coating is designed to intentionally abrade during operation of the screw pump, thereby transferring the coating to uncoated components, while also retaining sufficient coating on the originally coated component.

A compressor includes a casing, a compression mechanism, and a motor that drives the compression mechanism. The casing is configured to cover an internal space. The internal space includes a first space and a second space larger than the first space. The casing has a first casing part covering the first space and a second casing part covering the second space. At least one of the first space and the second space is a high-pressure space configured to contain high-pressure fluid. A metallic coating may be formed on an outer surface of at least the first casing part. Alternatively, a resin coating may be formed on an outer surface of the casing.