| 摘要 |
<p>21042 TITLE APPARATUS AND METHOD FOR HYDRAULICALLY FORMING JOINTS BETWEEN TUBES AND TUBE SHEETS A swaging apparatus for expanding a tube disposed within a tube sheet to form a leak-proof joint, the apparatus including a mandrel body for insertion in the tube. The body defines 2 pair of oppositely directed ramps. A pair of seal members that define the ends of an annular volume within which pressurized hydraulic fluid flows between the mandrel and the tube are movable axially along the ramps, the seals preferably being of the O-ring type. When the mandrel is being inserted, the seals are disposed at the smaller ends of the ramps so as to minimize frictional resistance to the insertion. The seal that is inserted first will tend to move, under frictional forces, to the small end of the ramp, being returned to the large end by the force of the hydraulic fluid during a subsequent swaging operation. The other seal member, however, is urged toward the small end of the corresponding ramp by a spring that is overcome by hydraulic forces once the swaging begins.</p> |
