초록 ▼

A connection of a tube to a machine includes a plurality of rolled grooves in a region of contact between the collet of a compression fitting and the tube. The grooves reduce the occurrence of fretting of the tube surface while a region of residual compressive stress formed in the tube proximate the

A connection of a tube to a machine includes a plurality of rolled grooves in a region of contact between the collet of a compression fitting and the tube. The grooves reduce the occurrence of fretting of the tube surface while a region of residual compressive stress formed in the tube proximate the bottom of each groove by the rolling process serves to counteract the stress concentration created by the grooves. In one embodiment a single groove formed in a thread pattern extends from above collet to within the area of contact.

대표청구항 ▼

1. A connection (10) to a machine (14) comprising:a fitting (16) adapted to be connected to a machine (14) and adapted to receive an end of a tube for attachment thereto, the fitting comprising a collet (18) and a nut (24) for compressing the collet onto the outside surface of a tube; a tube (12) ha

1. A connection (10) to a machine (14) comprising:a fitting (16) adapted to be connected to a machine (14) and adapted to receive an end of a tube for attachment thereto, the fitting comprising a collet (18) and a nut (24) for compressing the collet onto the outside surface of a tube; a tube (12) having an end (30) disposed within the fitting and having an area (32) in contact with the collet; and a plurality of grooves (36) formed on the outside surface (28) of the tube proximate the collet and a region of residual compressive stress in the tube proximate a radially inner surface of each of the plurality of grooves, wherein a first (44) of the plurality of grooves is located in an area of the tube not in contact with the collet proximate an end of the collet opposed the machine.