Abstract:
A Moineau stator includes a tube (10) having lobes (3) arranged in a configuration which is adapted to interact with a rotor and formed through a hydroforming process.
Abstract:
A collapsible drive shaft (20) and method of making the same. The collapsible drive shaft (20) includes a tubular member having first (24) and second (22) portions that are integrally formed as a one-piece member. The first portion has splines (26) formed on an exterior surface thereof. The second (22), opposite portion has both outer (Do2) and inner diameters (Di2) that are greater than the outer diameter (Do1) of the first portion. The method includes placing a tubular metal blank into a hydroforming die (70) having a die cavity and expanding the blank by pressurizing the interior of the blank with hydroforming fluid. During the hydroforming process, the first portion of the blank is expanded to form splines while the second portion is expanded to form inner and outer diameters that are greater than the outer diameter of the first portion.
Abstract:
A method for hydroforming a closed channel member (10) that allows the perimeter to be increased, but which maintains a uniform wall thickness throughout, includes the initial step of disposing a closed channel member (10), such as a tube, within a first hydroforming die (11) defining a first die cavity (12a, 13a). The inner surface of the first die cavity (12a, 13a) corresponds in cross sectional shape to the outer surface of the tube throughout some or all of the length thereof. A preliminary hydroforming operation is performed at a high pressure to expand the tube into conformance with the first die cavity (12a, 13a). The preliminary expanded tube is disposed within a second hydroforming die (15) defining a second die cavity (16a, 17a). The inner surface of the second die cavity (16a, 17a) corresponds in cross sectional shape to the desired final shape for the tube. When the second hydroforming die is closed, a final hydroforming operation is performed at a low pressure to deform the tube into conformance with the second die cavity (16a, 17a).
Abstract:
A method for hydroforming a closed channel structural member that allows the perimeter thereto to be increased, but which maintains a relatively uniform wall thickness throughout, includes the initial step of disposing a closed channel structural member, such as a tube, within a first hydroforming die defining a first die cavity. The inner surface of the first die cavity preferably corresponds in cross-sectional shape to the outer surface of the tube throughout some or all of the length thereof, but the perimeter of the first die cavity is somewhat larger than the perimeter of the tube enclosed therein. The tube is preferably supported concentrically within the die cavity. Then, a preliminary hydroforming operation is then performed at a relatively high pressure to expand the tube into conformance with the first die cavity. Throughout most of this expansion, the outer surface of the tube does not engage the inner surface of the die cavity. As a result, as the perimeter of the tube is increased, the wall thickness thereof is decreased uniformly. The preliminarily expanded tube is then disposed within a second hydroforming die defining a second die cavity. The inner surface of the second die cavity corresponds in cross-sectional shape to the desired final shape for the tube. When the second hydroforming die is closed, a final hydroforming operation is performed at a relatively low pressure to deform the tube into conformance with the second die cavity. Because the perimeter of the tube is approximately equal to the perimeter of the second die cavity, the wall thickness of the tube is essentially unchanged by the final hydroforming operation. Consequently, a relatively larger amount of such expansion can occur than would normally be available if it was necessary to account for variations in the wall thickness of the tube resulting from frictional engagement of the tube with the first hydroforming die.