Abstract: A down hole motor is used in the oil prospecting industry to drive drill bits for drilling the ground at great depths. The down hole motor (1) includes a drive shaft (5) held in the motor body (3) by an axial thrust bearing (6) and by a radial bearing (7). The radial bearing (7) is a tubular member whose interior surface is coated with an anti-abrasion layer (11) formed by laser-assisted facing directly inside an alloy steel radial bearing body (10). The thickness of the facing layer is then reduced by removing material by the use of a cutting tool. This produces a radial bearing (7) that is relatively insensitive to drilling mud and confers great reliability on the down hole motor (1).

Abstract: The present invention concerns the down hole motors used in the oil prospecting industry to drive drill bits for drilling the ground at great depths. The down hole motor (1) comprises a drive shaft (5) held in the motor body (3) by an axial thrust bearing (6) and by a radial bearing (7). The radial bearing (7) is a tubular member whose interior surface is coated with an anti-abrasion layer (11) formed by laser-assisted facing directly inside an alloy steel radial bearing body (10). The thickness of the facing layer is then reduced by removing material by means of a cutting tool. This produces a radial bearing (7) that is relatively insensitive to drilling mud and confers great reliability on the down hole motor (1).

Abstract: The present invention concerns the down hole motors used in the oil prospecting industry to drive drill bits for drilling the ground at great depths. The down hole motor (1) comprises a drive shaft (5) held in the motor body (3) by an axial thrust bearing (6) and by a radial bearing (7). The radial bearing (7) is a tubular member whose interior surface is coated with an anti-abrasion layer (11) formed by laser-assisted facing directly inside an alloy steel radial bearing body (10). The thickness of the facing layer is then reduced by removing material by means of a cutting tool. This produces a radial bearing (7) that is relatively insensitive to drilling mud and confers great reliability on the down hole motor (1).

Abstract: The present invention concerns the down hole motors used in the oil prospecting industry to drive drill bits for drilling the ground at great depths. The down hole motor (1) comprises a drive shaft (5) held in the motor body (3) by an axial thrust bearing (6) and by a radial bearing (7). The radial bearing (7) is a tubular member whose interior surface is coated with an anti-abrasion layer (11) formed by laser-assisted facing directly inside an alloy steel radial bearing body (10). The thickness of the facing layer is then reduced by removing material by means of a cutting tool. This produces a radial bearing (7) that is relatively insensitive to drilling mud and confers great reliability on the down hole motor (1).

Abstract: Device for resurfacing a concave face (2) of a tubular part (1) by supplying resurfacing material and energy by a laser, comprising a laser source for generating a laser beam (9), resurfacing material delivery means (5) based on hard refractory particles and metal alloy particles, in order to deliver the resurfacing material close to a resurfacing zone (6) on the concave face (2) of the tubular part (1) to be resurfaced, laser beam delivery means (7) and directing means (8) for directing the laser beam (9) into the resurfacing zone (6). The laser source is a diode laser (4) and the laser beam delivery means (7) conduct the latter over a penetration length (L) along a penetration direction and then the directing means (8) deflect the laser beam (9) into a radial direction (II-II) away from the penetration direction, so that the laser source may lie outside the tubular part (1) and the laser beam delivery means (7) may be axially engaged completely or partly in the tubular part (1).