Abstract:
Embodiments of the invention provide a system and method for induction heating a helical rotor of a progressing cavity pump in order to reduce the surface roughness of the rotor. In order to heat the rotor most evenly, it is desired to space the coil as closely around the rotor as possible. The invention provides a mechanism for threading the helical rotor through an induction coil having an interior diameter which is less than the major diameter of the rotor. The induction coil may include one loop and overlapping ends. The rotor to be heated is rotated about its longitudinal axis and advanced axially through the coil as it rotates. The axial speed and rotational speed are synchronized so that the rotor moves one pitch through the coil for each complete rotation.
Abstract:
A method of hardfacing a metal body, including the steps of flame spraying a metallic material onto a surface of the metal body to produce a layer of the metallic material on the metal body and fusing the layer of metallic material to provide a hardfacing layer, is improved by roughening the surface of the metal body prior to the step of flame spraying to provide a mechanical bond between the metal body and the hardfacing layer. The roughening is carried out to achieve a surface roughness adjusted to the thickness of the hardcoating. The surface roughness is preferably 40%-90% of the thickness of the hardfacing layer. A rotor for a progressing cavity pump/motor, including a metallic rotor body having a surface, and a layer of hardfacing on the surface, the hardfacing comprising of fused flame sprayed metallic material, the surface of the rotor body having an average surface roughness of at least substantially 6 mils with irregular protrusions for providing a mechanical bond between the rotor body and the hardfacing.
Abstract:
A method of hardfacing a metal body, including the steps of flame spraying a metallic material onto a surface of the metal body to produce a layer of the metallic material on the metal body and fusing the layer of metallic material to provide a hardfacing layer, is improved by roughening the surface of the metal body prior to the step of flame spraying to provide a mechanical bond between the metal body and the hardfacing layer. The roughening is carried out to achieve a surface roughness adjusted to the thickness of the hardcoating. The surface roughness is preferably 40%-90% of the thickness of the hardfacing layer. A rotor for a progressing cavity pump/motor, including a metallic rotor body having a surface, and a layer of hardfacing on the surface, the hardfacing comprising of fused flame sprayed metallic material, the surface of the rotor body having an average surface roughness of at least substantially 6 mils with irregular protrusions for providing a mechanical bond between the rotor body and the hardfacing.