Rolling bearing temperature measurement system in a railway axle-box and associated method

A method for making a system for measuring the temperature of a rolling bearing in a railway axle-box, comprising the steps of:

• making a first hole externally on a cover of the railway axle-box, with the cover removed from the axle-box, on the side of an edge of the cover facing towards the rolling bearing, the first hole being made in radial direction with respect to a symmetry axis (A) of the bearing;
• making on the cover edge, with cover removed from the axle-box, a second hole having smaller diameter than the first hole, the second hole being made in axial direction with respect to the symmetry axis (A) of the bearing, i.e. parallel to the bearing axis, so as to be in use facing towards an outer ring of the bearing cooperating in use in abutment against the cover edge, and so that the second hole opens into the first hole;
• making, by molding a synthetic plastic material, a cup-shaped body delimited by a bottom wall and by a lateral wall perpendicular to the bottom wall and provided with a through hole, preferably co-molding into the cup-shaped body a leaf spring which projects into the cup-shaped body in front of the through hole;
• driving with interference the cup-shaped body in the first hole, with the through hole aligned and coaxial with the second hole, which is thus put in direct communication with the inside of the cup-shaped body, with a free end of the leaf spring arranged facing the second hole;
• with cover removed from the axle-box,
• mounting a temperature probe axially sliding in the second hole inserting it through an end of the second hole opposite to the first hole, to make a first end of the probe, provided with at least one electrical connecting cable overhangly insert into the cup-shaped body and leaving a second end of the probe, opposite to the first one, projecting from the edge of the axle-box cover out of the second hole;
• with the cover removed from the axle-box,
• passing through the first hole, coupling a shoulder element integrally on the first end of the probe, the shoulder element being adapted to cooperate with the leaf spring for elastically deforming it when the second end of the probe is pushed in a fully retracted position into the second hole;
• and
• mounting the cover closing the axle-box, so that the cover edge abuts against the outer ring of the bearing pushing the probe in the retracted position.