A molten metal pump includes an impeller, a pump base housing at least partially enclosing the impeller, a shaft connected to the impeller, a motor connected to the shaft, a motor mount plate for supporting the motor; and a post for connecting the motor mount plate to the pump base housing. The molten metal pump can include a connector that connects the post to the motor mount plate. The molten metal pump can include a socket for connecting the shaft to the motor. The shaft can comprise an assembly including an elongated metal rod having a first end and a second end and a metal non-circular drive member attached at the second end of the elongated metal rod. The impeller can include a cap member having a plurality of generally polygonally shaped inlet openings communicating with internal passages of the impeller, each inlet opening having an inner wall and an outer wall, the outer wall being longer than the inner wall, each inlet opening also including a leading wall and a trailing wall, the leading wall and the trailing wall each interconnecting the inner wall and the outer wall and each being inclined such that an uppermost edge of each wall precedes a lowermost edge of each wall in a first rotational direction.

A transmission shaft and a roller comprising a pair of connectable portions (M, F) for connecting a transmission shaft (5, 8) and a roller (4, 7) to be driven by torque exerted through the transmission shaft (5, 8). The pair of connectable portions (M, F) comprise a male portion (M) provided on one of the transmission shaft (5, 8) and roller (4, 7) and a complementary female portion (F) provided on the other of the roller (4, 7) and transmission shaft (5, 8). The male portion (M) has a longitudinal axis of rotation (X) and tapers inwardly from a proximal end to a distal end. The male portion (M) has a non-circular cross section.

A gear unit includes: a first gear and a second gear which are disposed about a first axis; an input shaft disposed so as to be rotatable about the first axis; and an intermediate gear disposed between the first gear and the second gear. The intermediate gear is disposed about a second axis tilted with respect to the first axis. The intermediate gear includes an inner ring portion and an outer ring portion disposed so as to be rotatable relative to the inner ring portion. The inner ring portion is configured to be rotated with rotation of the input shaft. The outer ring portion is configured to mesh with the first gear and the second gear.

A molten metal pump includes an impeller, a pump base housing at least partially enclosing the impeller, a shaft connected to the impeller, a motor connected to the shaft, a motor mount plate for supporting the motor; and a post for connecting the motor mount plate to the pump base housing. The molten metal pump can include a connector that connects the post to the motor mount plate. The molten metal pump can include a socket for connecting the shaft to the motor. The shaft can comprise an assembly including an elongated metal rod having a first end and a second end and a metal non-circular drive member attached at the second end of the elongated metal rod. The impeller can include a cap member having a plurality of generally polygonally shaped inlet openings communicating with internal passages of the impeller, each inlet opening having an inner wall and an outer wall, the outer wall being longer than the inner wall, each inlet opening also including a leading wall and a trailing wall, the leading wall and the trailing wall each interconnecting the inner wall and the outer wall and each being inclined such that an uppermost edge of each wall precedes a lowermost edge of each wall in a first rotational direction.

A molten metal pump includes an impeller, a pump base housing at least partially enclosing the impeller, a shaft connected to the impeller, a motor connected to the shaft, a motor mount plate for supporting the motor; and a post for connecting the motor mount plate to the pump base housing. The molten metal pump can include a connector that connects the post to the motor mount plate. The molten metal pump can include a socket for connecting the shaft to the motor. The shaft can comprise an assembly including an elongated metal rod having a first end and a second end and a metal non-circular drive member attached at the second end of the elongated metal rod. The impeller can include a cap member having a plurality of generally polygonally shaped inlet openings communicating with internal passages of the impeller, each inlet opening having an inner wall and an outer wall, the outer wall being longer than the inner wall, each inlet opening also including a leading wall and a trailing wall, the leading wall and the trailing wall each interconnecting the inner wall and the outer wall and each being inclined such that an uppermost edge of each wall precedes a lowermost edge of each wall in a first rotational direction.

A torque limiter including a first body and a second body extending about a central axis. The first body supports first limiter teeth and the second body supports second limiter teeth. The first and second limiter teeth define an engaged configuration and a release configuration. The torque limiter includes limited-retaining means retaining the first and second limiter teeth in the engaged configuration thereof when the torque is less than a transmission torque limit and yielding when the torque exceeds the transmission torque limit. The limited-retaining means include an inner limited-retaining element having an outer contact surface, and an outer limited-retaining element having an inner contact surface mating with the outer contact surface. The inner and outer limited-retaining elements having a retaining configuration wherein the inner limited-retaining element is clamped into the outer limited-retaining element, and a yielded configuration wherein the inner limited-retaining element is loosened from the outer limited-retaining element.