A hydraulic rotary machine includes a plurality of pistons, a cylinder block accommodating the pistons, a shaft penetrating through the cylinder block, a swash plate making the pistons reciprocate to expand and contract a capacity chamber of the cylinder, a casing accommodating the cylinder block, a front cover closing an opened end of the casing, an extending portion formed in the front cover and extending along the shaft towards the cylinder block, and a first slide bearing provided between the extending portion and the cylinder block. The first slide bearing is fixed to the extending portion or the cylinder block by a pin member.

A method of pumping produced liquids from the depths of a wellbore during a reset stroke and a power stroke of a pump located downhole, wherein the pump comprises an upper barrel, a lower barrel, an upper plunger within the upper barrel, a lower plunger within the lower barrel, an upper ported intake sub with an upper outlet check valve and an upper intake check valve, a dual ported mandrel, and a lower ported intake sub with a lower intake check valve and a lower outlet check valve.

A power end includes a monolithic core with a base having a surface configured to mount to a fluid end of the reciprocating pump and a plurality of extensions integral to the base. Each extension of the plurality of extensions includes a ring portion that defines an opening configured to receive a crankshaft of the reciprocating pump. The power end also includes a plurality of plates separate from the monolithic core. Each plate of the plurality of plates extends between a pair of adjacent of extensions of the plurality of extensions to enclose the monolithic core.