Abstract: The present application relates to apparatus (400, 500) for measuring an impedance of an electrical load (300) that is configured to be coupled to a controlled current source (200). The apparatus (400, 500) comprises a first coupling node (402) configured to be coupled to a first terminal (302) of the load (300) and a second coupling node (404) configured to be coupled to a second terminal (304) of the load (300). The apparatus further comprises a transformer (406) having a primary winding (408) and a secondary winding (410) and a capacitance (412) connected in series between a first terminal (414) of the secondary winding (410) and the first coupling node (402). A second terminal (416) of the secondary winding (410) is connected to the second coupling node (404).

Abstract: A centrifugal compressor impeller includes a plurality of blades on a front side that extend from a first axial side to an outer radial end of the impeller. The centrifugal impeller includes a back side having a nonlinear backwall. The backwall can include a flat area hear a bore of impeller, a flat area near a tip of the impeller, and a convex surface between the flat areas of the bore and the tip. In some forms the impeller further includes a concave surface between the convex surface and the tip to form an s-shape. A transition or inflection point can denote the change from convex to concave. The convex and/or concave surfaces can take any variety of forms such as constant radius sections and/or compound curves.

Abstract: A compressor system can include a lubricant injection system useful to supply lubricant to an airend. The compressor system can include a variable lubricant flow valve which can be regulated by a controller on the basis of operating conditions of the compressor system. In one form the compressor system also includes an oil separator and/or an oil cooler with or without a them al control valve. The controller can have one or more modes of operation, including a mode in which the controller regulates the flow of lubricant to the airend to increase an internal flow area of the valve when the airend is operated at an unloaded or loaded condition. In some forms the controller can regulate the lubricant flow valve and/or the thermal control valve and/or the lubricant cooler.

Abstract: Integrally geared centrifugal compressor systems are described that include eccentric cartridges that house bearings and seals to maintain rotor concentricity for a variety of pinons integrated in a fixed gearbox design to provide multiple impeller speeds with a single gearbox design. In an aspect, a system includes, but is not limited to, a pinion configured to be rotated by a bull gear about a rotational axis; a rotor coupled to the pinion; and an eccentric cartridge configured to house a bearing assembly through which the rotor extends to support rotation of the rotor, the eccentric cartridge having an outer surface and an inner surface, wherein the inner surface is eccentric relative to the outer surface to align the rotational axis with a center axis of the bearing assembly.

Abstract: A dynamic compressor includes an impeller having impeller vanes disposed around a hub, a shroud, and a diffuser having a shroud surface adjacent to the shroud and a hub surface adjacent to the hub, wherein the diffuser is circumferentially disposed around the impeller. The diffuser includes a plurality of diffuser vanes extending from the hub surface to the shroud surface, each having a vane leading edge and a vane trailing edge. The diffuser includes a centrifugal acceleration stabilizer ring formed in the shroud surface located in a vaneless region defined between an impeller trailing edge and the vane leading edge. The centrifugal acceleration stabilizer ring stabilizes the flow of the fluid by changing the circumferentially-flowing high velocity fluid flow exiting the impeller into a radially-flowing high velocity fluid flow before entering the diffuser, improving the efficiency of the dynamic compressor.

Abstract: A hand-held power tool is provided that includes a motive source, a user interface, and one or more sensors. The motive source includes a printed circuit board (PCB) configured to support electrical components of the motive source. The user interface is movable between a plurality of mode positions to select one of a plurality of operational modes of the motive source. And one or more sensors are mounted on the PCB and are configured to detect the plurality of mode positions of the user interface.

Abstract: A compressor is disclosed which can include a first stage and a second stage. In one form the compressor includes contact cooled compressor stages. The compressor can include a rod useful to inject a lubricant for purposes of cooling/lubricating/sealing the rotating components of the compressor. In one form the rod is an elongate rod with openings which permit a lubricant such as oil to be injected. The injected oil can be atomized via the openings. The rod can be positioned in the interstage space between the first and second stages, and can include a variety of openings.

Abstract: An impact tool is provided which includes a drive source configured to rotate an output drive. A hammer is movable in a first direction to apply a rotational impact force on an anvil which rotates the output drive. A first hammer angle sensor set to a first signal channel and located proximate to a surface of the hammer. A plurality of regularly spaced targets are located on the surface of the hammer. Each of the plurality of regularly spaced targets are detectable by the first hammer sensor. And detection of one or more of the plurality of regularly spaced targets by the first hammer sensor indicates movement of the hammer.

Abstract: The present disclosure is directed to a screw compressor system having a compressor housing with a pair of screw rotors rotatably supported within a compression chamber. Lubricant is injected into a compression chamber at a first volume ratio and at a second volume ratio greater than the first volume ratio to increase the sealing and lubrication between the screw rotors and rotor bores in the compressor housing as well as to increase heat transfer from a compressed working fluid in the compression chamber.

Abstract: Systems and methods form induction rotors by performing isostatic pressing (HIP) to weld clad to a shaft, which allows for scaling the manufacturing of solid steel rotors, as compared to conventional techniques. In examples, the rotors are designed for high-speed motors and may include recessed short circuit rings and/or end rings. An exemplary process molds an alloy powder into cladding such that heretofore unachievable rotor designs are achievable according to systems and methods described herein. In examples, a thin source-layer is introduced to welding zones, thereby enriching and strengthening the resulting joint at welding zones. The source-layer may be introduced by adding an intermediate layer comprising the source material between the materials being welded. The reduced alloy-depletion welding disclosed herein strengthens the welding area joints and provides for the manufacture of component designs, which were previously unachievable due to alloy-depletion weaknesses and environmental constraints.

Abstract: A power tool is provided that, in one version, includes a front housing that supports an output drive, and a back cap located opposite the front housing. The back cap receives at least one fastener of the plurality of fasteners. A motor housing supports a motor and is located between the front housing and the back cap. The motor includes a rotor that is configured to rotate about a motor axis to drive rotation of the output drive. The fastener is disposed through the back cap, and secures to the front housing coupling the front housing, the motor housing, and the back cap together.

Abstract: A compressed air drying system is provided for removing moisture from compressed air. The dryer operates in two modes in response to the demand for compressed air. In a first mode of operation, a refrigeration compressor runs continuously and the speed of a condenser fan is varied to maintain a constant cooling temperature. In a second mode of operation, the refrigeration compressor runs intermittently between on and off periods. As result, the cooling temperature fluctuates during the second mode of operation.

Abstract: The present disclosure is directed to a dryer system for drying compressed gas discharged from a compressor. The dryer system includes a refrigeration drying system operable for removing moisture from the compressed gas and a desiccant drying system with a desiccant wheel located in series downstream of the refrigeration drying system operable for removing additional moisture from the compressed gas.

Abstract: A filter for compressed air systems is provided. The filter includes a filter housing with a filter therein between an air inlet and an air outlet. Compressed air flowing between the air inlet and the air outlet passes through the filter housing and the filter element. A base is removably fastened to the filter housing which may be separated from the filter housing to allow the filter element to be removed and replaced.

Abstract: An air drying unit for compressed air systems is provided. The air drying unit has a precooler/reheater, a main cooler and a moisture separator. Incoming air is cooled to cause moisture within the compressed air to condense, which is then separated to dry the compressed air. The precooler/reheater, main cooler and moisture separator are designed as an integral unit that does not require pipes to connect the components together. Instead, compressed air flows through the sealed unit through passages therein between the precooler/reheater, main cooler and moisture separator.

Abstract: Illustrative embodiments of ratchet tools are disclosed. In one embodiment, a ratchet tool may comprise a handle extending along a handle axis and housing a motor, a head coupled to the handle at a first end of the handle, the head supporting an output shaft configured to be driven by the motor to rotate about an output axis, the output axis being substantially perpendicular to the handle axis, a ratchet mechanism coupled between the handle and the output shaft, the ratchet mechanism configured to restrict rotation of the output shaft in a first direction and to allow rotation of the output shaft in a second direction opposite the first direction, and a direction control configured to switch the first direction associated with the ratchet mechanism between a clockwise and a counterclockwise direction, the direction control being coupled to the handle and spaced apart from the head along the handle axis.

Abstract: Compressed air dryer systems are described. In an aspect, a system includes, but is not limited to, a plurality of dryer modules and a controller operable to regulate a run-time of each of the plurality of dryer modules. Each dryer module is configured to direct a portion of cooling medium past a stream of compressed air. Each dryer module includes a temperature sensor in thermal communication with the portion of cooling medium, and a chiller configured to reduce a temperature of the portion of cooling medium based on the sensed temperature and a temperature set-point. The controller communicatively is coupled with the plurality of dryer modules and operable to monitor a plurality of run-times. Each run-time is associated with a corresponding dryer module. The controller is further operable to direct operation of each dryer module based on its run-time by modifying the temperature set-point of the dryer module.