US Patent 11459832 Couplings for well pumping components

A coupling for joining a downhole pump to a sucker rod string is disclosed. The coupling includes a core having a first end, a central portion, and a second end. The first end and the second end each have an end surface. The first end tapers linearly inwards from the central portion to the first end surface. The second end has a rounded edge along the second end surface. The coupling is made from a spinodally-hardened copper-nickel-tin alloy and has a sliding coefficient of friction of less than 0.4 when measured against carbon steel.