A leak-current detecting unit detects a zero-phase current flowing from an electric-motor driving device, which drives an electric motor with electric power from an alternating-current power supply, or the electric motor to a ground, a leak-current control unit that, on the basis of the zero-phase current detected by the leak-current detecting unit, generates a control signal having cyclicity synchronized with the alternating-current power supply, and an anti-phase generating unit that generates an anti-phase current that is in anti-phase to the zero-phase current on the basis of the control signal from the leak-current control unit, and outputs the anti-phase current.

In an outer circumferential portion of an intermediate partition plate, a concave portion is provided at a position at which an upper vane and a lower vane slide. At a lower dead center of an upper piston and a lower piston, 80% or more of the entire length in the sliding direction of the upper vane and the lower vane are accommodated respectively on the inside of an upper cylinder and the inside of a lower cylinder. In the concave portion, a width W with respect the circumferential direction of the intermediate partition plate is greater than a thickness T of the upper vane and the lower vane, and when a depth of the concave portion is D and the entire length of the upper vane and the lower vane is L, D≧0.1×L is satisfied.

A drive includes an inverter power circuit that applies power to an electric motor of a compressor from a direct current (DC) voltage bus. A power factor correction (PFC) circuit outputs power to the DC voltage bus based on input alternating current (AC) power. The PFC circuit includes: (i) a switch having a first terminal, a second terminal, and a control terminal; (ii) a driver that switches the switch between open and closed states based on a control signal; (iii) an inductor that charges and discharges based on switching of the switch; and (iv) a circuit that outputs a signal indicating whether the switch is in the open state or the closed state based on a voltage across the first and second terminals of the switch.

A manufacturing method of an end plate of a pump that can remove a sag includes: punching a workpiece from a plate material, the workpiece being the end plate including a mounting seat including a fastener; forming a pressed trace surface by pressing an outer edge of an outer surface, when a surface, of both front and back surfaces of the punched workpiece, further from a sag formed on a cut end surface is the outer surface, and a surface, of both front and back surfaces of the punched workpiece, nearer to the sag is an inner surface. A section of the pressed trace surface disposed along an outer edge of the mounting seat is a fastening section. A section of the pressed trace surface other than the fastening section is a non-fastening section. A radial width of the fastening section is shorter than that of the non-fastening section.

A manufacturing method of an end plate of a pump that can remove a sag includes: punching a workpiece from a plate material, the workpiece being the end plate including a mounting seat including a fastener; forming a pressed trace surface by pressing an outer edge of an outer surface, when a surface, of both front and back surfaces of the punched workpiece, further from a sag formed on a cut end surface is the outer surface, and a surface, of both front and back surfaces of the punched workpiece, nearer to the sag is an inner surface. A section of the pressed trace surface disposed along an outer edge of the mounting seat is a fastening section. A section of the pressed trace surface other than the fastening section is a non-fastening section. A radial width of the fastening section is shorter than that of the non-fastening section.

A scroll-type fluid machine reduces intrusion of abrasion powders, generated by sliding of a conductor causing an orbiting scroll side and a fixed scroll side to be conducted, into a compression chamber, and improves reliability of a compressor. The scroll-type machine includes a casing, a fixed scroll having a flange surface attached to the casing, and a wrap portion provided at an end plate, an orbiting scroll having a wrap portion provided at the end plate, and provided in an opposed relationship with the fixed scroll, a drive shaft connected through a crank portion to the orbiting scroll, an orbiting bearing, a face seal portion arranged between the orbiting scroll and the fixed scroll, a cooling fan, and an orbiting scroll side conductive brush.

A compressor is provided and may include a shell, a hub, an insert, and at least one collar. The hub may be disposed within the shell and define an axis of rotation. The hub may include an axially extending aperture. The insert may be disposed within the aperture. The at least one collar may be disposed about the hub.

A compressor includes: an annular cylinder; a rotation shaft which is rotated by the motor; a piston which revolves along an inner circumferential surface of the cylinder, and forms a cylinder chamber on the inside of the cylinder; a vane which protrudes to the inside of the cylinder chamber from a vane groove provided in the cylinder, and divides the cylinder chamber into an inlet chamber and a compression chamber by abutting against the piston; and an injection hole which injects a liquid refrigerant to the inside of the compression chamber. The center of the injection hole is disposed to be within a fan-like range of which a center angle is equal to or less than 40° toward a side opposite to a connection position between the compressor housing and the inlet unit from a center line of the vane groove in the circumferential direction of the rotation shaft.

A motor-operated compressor includes a casing having an inner space in which a driving motor, an orbiting scroll and a fixed scroll are accommodated, and a controller provided outside the casing. The casing includes an intake hole formed at a side adjacent to the controller and an exhaust hole formed at a side adjacent to the fixed scroll on the basis of the driving motor. The casing includes a communication passage formed between the casing and a stator of the driving motor, such that a refrigerant introduced into the inner space through the intake hole is introduced into the suction chamber through the driving motor. A back pressure space supporting the orbiting scroll is sealed by oil. The stator has teeth on its inner circumferential surface and protrusions on its outer circumferential surface, each protrusion being located within a width range of each tooth.

A compressor including a gear system configured to be driven by a drive unit, a plurality of compression stages coupled to the gear system, wherein the plurality of compression stages includes at least one centrifugal compression stage and at least one positive displacement compression stage, is provided. Furthermore, an associated method is also provided.