A rotor assembly and a compressor are provided. The rotor assembly has a crankshaft, a rotor core, a balance weight and an oil baffle shield. The rotor core is provided with a vent hole. The vent hole extends through the rotor core along an axial direction of the rotor core. The balance weight is located at one end of the rotor core approximate to an oil sump of the compressor. The oil baffle shield is arranged to cover the balance weight and is provided with a central opening. The crankshaft extends through the central opening. An accommodating space is defined between the oil baffle shield and the rotor core. The accommodating space is communicated with the vent hole.

A method of manufacturing a two-piece counterweight for a scroll compressor is provided. The method includes molding an outer plate, and molding a base having a first opening configured to receive a scroll compressor drive shaft having a longitudinal axis. The method further includes configuring the base for assembly and attachment to the drive shaft. The method also includes attaching the outer plate to the base such that the outer plate is axially offset from the base. In a particular embodiment of this method, the base and outer plate are molded from powdered metal. In certain embodiments, the base and outer plate include one or more openings aligned to permit attachment by inserting a mechanical fastener through the aligned openings. In alternate embodiments, the base and outer plate are attached via brazing or welding.

An electric compressor includes an electric motor, and a motor controller configured to drive the electric motor. The motor controller includes a high voltage circuit board on which switching elements are mounted, a low voltage circuit board on which a control circuit controlling switching operation of the switching elements is mounted, an input connector, an output connector, and a current sensor. The high voltage circuit board and the low voltage circuit board are stacked with each other. The output connector is integrated with a detection busbar that provides electrical connection between the high voltage circuit board and the low voltage circuit board, and through which detection signals indicative of the output current are output to the control circuit.

PROBLEM TO BE SOLVED To improve controllability of a motor including a stator with two-split structure.

SOLUTION
A motor 400 includes a stator 460 disposed to surround an outer circumference of a rotor 440 which rotates integrally with a drive shaft 420. The stator 460 includes an inner core 462 having multiple protrusions 462B radially outwardly extending from an outer circumferential surface of a cylindrical portion 462A, and a cylindrical outer core 464 having its inner circumferential surface side attached to a top of the protrusion 462B. A connection portion (first connection portion 462F) as a part for connecting a side surface (first side surface 462D) of the protrusion 462B at an upstream side in a rotating direction of the rotor 440 and an outer circumferential surface of the cylindrical portion 462A has a rounded shape. A connection portion (second connection portion 462G) as a part for connecting a side surface (second side surface 462E) of the protrusion 462B at a downstream side in the rotating direction of the rotor 440 and the outer circumferential surface of the cylindrical portion 462A has a rounded shape. A radius r1 of the rounded shape of the first connection portion 462F is greater than a radius r2 of the rounded shape of the second connection portion 462G.

An electric compressor, an inverter manufacturing equipment and an inverter manufacturing method to prevent soldering defects and damage to elements, wherein an inverter includes a circuit board on which a plurality of elements are mounted and a frame coupled to the circuit board, wherein the frame includes a support plate, a side plate projecting from the support plate toward the circuit board, an array plate on which switching elements connected to the circuit board are arranged, and a connection bar connecting the support plate and the array plate.

A roots blower includes driving and driven rotors that rotate while intermeshing with each other, driving and driven shafts fixed at the shaft centers of the driving and driven rotors, respectively, a driving gear attached to the end of the driving shaft, a driven gear that is attached to the end of the driven shaft and intermeshes with the driving gear, a rotor chamber that houses the driving and driven rotors, a gear chamber that houses the driving and driven gears, and driving and driven bearings that rotatably support the driving and driven shafts, respectively. The driving and driven gears are lubricated by a grease.

A motor-driven compressor with a housing and an electric motor includes a stator that includes a stator core including a yoke and teeth, an insulator including an insulator base in contact with an end face of the yoke, and three-phase windings, each being wound around the corresponding teeth in a concentrated manner so as to form coils. The winding of each phase forms connection wires locked on an outer circumferential surface of the insulator base. Each connection wire connects adjacent coils of the corresponding phase. The outer circumferential surface includes a locking surface including accommodation grooves, each accommodating the corresponding connection wire, and a non-locking surface that does not lock the connection wires. The stator core includes an engagement recess that engages with part of a jig. The engagement recess is located radially outward from the insulator base on the end face and located radially outward from the non-locking surface.

A vacuum pump which can decompose depositions by radicals and effectively exhaust them is provided. The vacuum pump including a casing, a stator disposed on an inner side of the casing, and a shaft rotatably supported with respect to the stator and also including a cylindrical rotor rotatably enclosed together with the shaft in the casing, in which an electrode portion, which is a part of a radical generating device that generates radicals, is disposed in the casing.

A split power gerotor pump includes a rotational axis, a shaft, an inner gerotor, an eccentric pocket, and an outer gerotor. The inner gerotor is rotationally fixed on the shaft, rotatable about the rotational axis, and includes n first lobes. The eccentric pocket is rotatable about the rotational axis, and includes a cylindrical bore with a center radially offset from the rotational axis and an outer surface, disposed radially outside of the cylindrical bore and arranged for direct engagement with a gear or a rotor for an electric motor. The outer gerotor includes a cylindrical outer surface installed in the cylindrical bore and n+1 second lobes.

Systems to drive a downhole pump include an enclosure body with a magnetically transparent wall. A magnetic driver or a stationary member with coil windings in slots is disposed outside the enclosure body. A magnetic follower or a movable member with one or more permanent magnets is disposed inside the enclosure body such that the magnetic follower or movable member is exposed to a different environment compared to the magnetic driver or stationary member. The magnetic driver and magnetic follower, or the stationary member and movable member, are separated by a gap containing at least a portion of the magnetically transparent wall. A prime mover is operatively coupled to the magnetic driver. A rod couples the magnetic follower or the movable member to the downhole pump. Movement of the rod with the magnetic follower or the movable member operates the pump.