not shown but not limited to a motor not shown and the second opening 16 is configured to receive a driven axel such as but not limited to an impeller shaft not shown u s pat no 5 634 770 herein incorporated for reference shows a molten metal pump with a motor and impeller the coupling 10 includes a first upper cavity 22 defined in part by the first opening 14 which is configured to receive the motor output shaft not shown with reference to fig3 the coupling 10 further includes a key way 24 disposed in the first upper cavity 22 and at least one opening 26 three are shown for a fastener such as but not limited to a set screw in the depicted embodiment the key way 24 is parallel but not limited to to the longitudinal axis 50 and receives a key to facilitate attaching the motor output shaft not shown to the coupling 10 the openings 26 are disposed perpendicular e g radial to the longitudinal axis 50 as earlier indicated the openings 26 receive fasteners which will allow the motor output shaft not shown to be attached into place within the first upper cavity 22 of the coupling 10 with further reference to fig1 there is an upper intermediate cavity 28 disposed adjacent to the first upper cavity 22 the upper intermediate cavity 28 has but is not limited to a larger diameter than the first upper cavity 22 and has but is not limited to a smaller diameter than that of the intermediate cavity 44 which is disposed on the other side of.