A fuel system component used to supply a fuel to a fuel tank or used to discharge the fuel from the fuel tank comprises a first resin layer; and a second resin layer formed in a similar color to that of the first resin layer and configured to include a welding portion that is welded to the first resin layer and an exposed portion that is not adjacent to or in contact with the first resin layer. A belt-like portion is formed on a first resin layer-side surface of the exposed portion to be parallel to a boundary between the welding portion and the exposed portion and is configured to include at least one of a concave and a convex extended intermittently or continuously.

A drive shaft is for selectively connecting a drive input to an output. The drive shaft has a tubular portion, a first diaphragm member, and a second diaphragm member displaced axially along the shaft from the first diaphragm member. The first and second diaphragm members each are formed with two axial ends. At least one undulation extends radially of the ends. The tubular portion connects the first and second diaphragm members. The first and second diaphragm members and the tubular portion are formed of fiber-reinforced polymer matrix composites. The first and second diaphragm members are connected to first and second axial ends of the tubular portion through a mechanical connection at joints. There is also a method of forming a drive shaft.

A high torque polymer fittings useful in fluid handling systems. The fittings are especially useful for fluid handling fittings having diameters of one inch or greater. Various embodiments of the fittings disclosed accommodate specialized wrenches for securing the fittings, the wrenches being used to tighten the fittings to a desired torque.

A drive shaft is for selectively connecting a drive input to an output. The drive shaft has a tubular portion, a first diaphragm member, and a second diaphragm member displaced axially along the shaft from the first diaphragm member. The first and second diaphragm members each are formed with two axial ends. At least one undulation extends radially of the ends. The tubular portion connects the first and second diaphragm members. The first and second diaphragm members and the tubular portion are formed of fiber-reinforced polymer matrix composites. The first and second diaphragm members are connected to first and second axial ends of the tubular portion through a mechanical connection at joints. There is also a method of forming a drive shaft.

A drive shaft is for selectively connecting a drive input to an output. The drive shaft has a tubular portion, a first diaphragm member, and a second diaphragm member displaced axially along the shaft from the first diaphragm member. The first and second diaphragm members each are formed with two axial ends. At least one undulation extends radially of the ends. The tubular portion connects the first and second diaphragm members. The first and second diaphragm members and the tubular portion are formed of fiber-reinforced polymer matrix composites. The first and second diaphragm members are connected to first and second axial ends of the tubular portion through a mechanical connection at joints. A method of forming a drive shaft is also disclosed.

A high torque polymer fittings useful in fluid handling systems. The fittings are especially useful for fluid handling fittings having diameters of one inch or greater. Various embodiments of the fittings disclosed accommodate specialized wrenches for securing the fittings, the wrenches being used to tighten the fittings to a desired torque.

A fuel system component used to supply a fuel to a fuel tank or used to discharge the fuel from the fuel tank comprises a first resin layer; and a second resin layer formed in a similar color to that of the first resin layer and configured to include a welding portion that is welded to the first resin layer and an exposed portion that is not adjacent to or in contact with the first resin layer. A belt-like portion is formed on a first resin layer-side and conically shaped surface of the exposed portion of the second resin layer at a distance from a boundary between the welding portion and the exposed portion and is configured to include at least one of a concavity and a convexity extended intermittently or continuously.

A mechanical system for an aerospace application includes a drive input connected to a first axial end of a first diaphragm member, and a drive output connected to a second axial end of a second diaphragm member. The drive output is an aerospace component. The first and second diaphragm members are formed with two axial ends and at least one undulation extending radially of the axial ends. The at least one undulation is intermediate the ends. A tubular portion connects the first and second diaphragm members. The first and second diaphragm members and the tubular member are formed of fiber reinforced polymer matrix composites. The first and second diaphragm members are connected to axial ends of the tubular member by welding of the axial ends of the tubular portion to one of the inner ends of each of said first and second diaphragm members. The aerospace component is a propeller.