The invention relates to a port plate 10, 11 that is used as a valve plate or a bearing plate. The port plate 10, 11 comprises a fluid blocking surface section 15 and a fluid passage surface section 13, 14 that is arranged within said at least one fluid blocking surface section 15. Structural reinforcement elements 12, 19 are arranged within the fluid passage orifice of the fluid passage surface section 13, 14.

Control systems and feedback assemblies for hydraulic axial displacement machines, such as pumps and motors. The control systems and feedback assemblies can have enhanced adjustability.

A plunger pump fluid end in which the suction valve and seat is aligned with the plunger and the fluid end housing is constructed with multiple modules. Modules are held in a rigid assembly by staybolts that connect to the power end of the plunger pump. Said staybolts pass though bores in the central fluid module and the suction seat module and bound by a conventional threaded nut. Packing box modules are bound to the central fluid module by bolts that also pass through separate bores in the same central module. A suction valve spring retainer/plunger spacer within the plunger bore of the assembly shields the intersection of the plunger bore and the discharge bore from destructive erosion damage.

A plunger pump fluid end in which the suction valve and seat is aligned with the plunger and the fluid end housing is constructed with multiple modules. Modules are held in a rigid assembly by staybolts that connect to the power end of the plunger pump. Said staybolts pass though bores in the central fluid module and the suction seat module and bound by a conventional threaded nut. Packing box modules are bound to the central fluid module by bolts that also pass through separate bores in the same central module. A suction valve spring retainer/plunger spacer within the plunger bore of the assembly shields the intersection of the plunger bore and the discharge bore from destructive erosion damage.

A bearing attachment system for a pump product having a seal carrier and a cover plate. The attachment system is configured to produce a force deflection curve that provides a clamping force on a pair of tapered roller bearings such that a tight bearing endplay on the tapered roller bearings is maintained through a full range of manufacturing tolerances. The geometric shape of the cover plate and the top surface of the seal carrier provide the desired deflection characteristics.

A fluid end having its fluid flow bores sealed without threading a retaining nut into the walls of each bore. The fluid ends may be assembled using a plurality of different kits that each comprise a fluid end body, a component, a retainer element, and a fastening system. The retainer element holds the component within each of the bores formed in the fluid end body and the fastening system secures the retainer element to the body. The fastening system comprises a plurality of externally threaded studs, washers and nuts in some embodiments. In other embodiments, the fastening system comprises a plurality of screws.

A fluid end having its fluid flow bores sealed without threading a retaining nut into the walls of each bore. The fluid ends may be assembled using a plurality of different kits that each comprise a fluid end body, a component, a retainer element, and a fastening system. The retainer element holds the component within each of the bores formed in the fluid end body and the fastening system secures the retainer element to the body. The fastening system comprises a plurality of externally threaded studs, washers and nuts in some embodiments. In other embodiments, the fastening system comprises a plurality of screws.

A plunger pump fluid end assembly design in which the suction valve and seat is aligned with the plunger and the fluid end housing is constructed with multiple modules. Modules are held in a rigid assembly by staybolts that connect to the power end of the plunger pump. Said staybolts pass though bores in the central fluid module and the suction seat module and bound by a conventional threaded nut. Packing box modules are bound to the central fluid module by bolts that also pass through separate bores in the same central module. A suction valve spring retainer/plunger spacer within the plunger bore of the assembly shields the intersection of the plunger bore and the discharge bore from destructive erosion damage.

A plunger pump fluid end assembly design in which the suction valve and seat is aligned with the plunger and the fluid end housing is constructed with multiple modules. Modules are held in a rigid assembly by staybolts that connect to the power end of the plunger pump. Said staybolts pass though bores in the central fluid module and the suction seat module and bound by a conventional threaded nut. Packing box modules are bound to the central fluid module by bolts that also pass through separate bores in the same central module. A suction valve spring retainer/plunger spacer within the plunger bore of the assembly shields the intersection of the plunger bore and the discharge bore from destructive erosion damage.

An electro hydrostatic actuator comprises a hydraulic pump driven by an electric motor to supply hydraulic fluid to a hydraulic actuator. The pump comprises an inlet and an outlet for the hydraulic fluid and an active flow path arranged therebetween such that, in an active mode of operation when the pump is driven by the electric motor, hydraulic fluid is actively drawn in through the inlet and exhausted out through the outlet. The pump further comprises a bypass flow path arranged to open between the inlet and outlet such that, in a damping mode of operation when the pump is not driven by the electric motor, hydraulic fluid is able to pass through the pump along the bypass flow path between the inlet and outlet.