A pump housing includes: a slide surface, along which inner and outer gears are slid; a suction guide passage, which is recessed from the slide surface and guides the fuel at a suction side; a discharge passage, which is recessed from the slide surface-and guides the fuel at a discharge side; and a communication groove, which is recessed from the slide surface and is shaped into an arcuate form that extends along a circumcircle of the inner gear. The communication groove is communicated with the suction groove and the discharge passage through two opposite groove end parts, respectively, of the communication groove.

A motor operated compressor includes: a main housing having a motor chamber; a frame provided on one side of the motor chamber and coupled to the main housing; a fixed scroll coupled to one side surface of the frame; an orbiting scroll provided to perform an orbiting movement between the frame and the fixed scroll, and form a compression chamber along with the fixed scroll; a sealing member provided on one side surface of the orbiting scroll to form a back pressure chamber between the orbiting scroll and the frame; and a plate provided between the frame and the fixed scroll and between the frame and the orbiting scroll, where the plate includes a sealing portion at least part of which is positioned between the frame and the fixed scroll; and a sliding portion extended from the sealing portion and positioned between the frame and the orbiting scroll.

A crescent internal gear pump includes a front cover, an end cover, a ring gear and a pinion gear disposed within a gear housing in an eccentric, intermeshing relationship. The housing is disposed intermediate the front cover and the end cover. A crescent is disposed radially intermediate the ring gear and the pinion gear. The crescent partially extends into a correspondingly shaped slot in the end cover. The gear housing, the ring gear, and the pinion gear can have substantially the same thickness. A shim can be disposed intermediate the end cover and the gear housing for establishing a desired clearance therebetween.

A scroll compressor is provided that may include an orbiting scroll having an orbiting wrap, and which performs an orbiting motion; and a fixed scroll having a fixed wrap to form a compression chamber including a suction chamber, an intermediate pressure chamber, and a discharge chamber, by being engaged with the orbiting wrap. A wrap thickness of the fixed wrap may be greater than a wrap thickness of the orbiting wrap within a range which forms the suction chamber. With such a configuration, even if the fixed scroll or the orbiting scroll is thermally-expanded, a transformation of the fixed wrap at a suction side may be prevented. This may prevent a gap between the fixed wrap and the orbiting wrap at an opposite side to the suction side, thereby enhancing compression efficiency.

This co-rotating scroll compressor is provided with: a first side plate (27) which is arranged on the side of a drive-side rotational axis direction (CL1) with respect to a drive-side scroll member (70) and a driven-side scroll member (90), a second side plate (30) fixed at a predetermined gap in the direction of the drive-side rotational axis (CL1) with respect to the first side plate (27), and a center plate (20) arranged between the first side plate (27) and the second side plate (30). The first side plate (27) is fixed to the driven-side scroll member (90), and the center plate (20) is fixed to the drive-side scroll member (70). A synchronization drive mechanism equipped with a crank pin (15) is disposed between the first side plate (27) and second side plate (30) and the center plate (20).

A scroll compressor includes a casing, compression mechanism housed in the casing, and drive shaft. The compression mechanism includes fixed and movable scrolls, and a housing. The housing includes a bearing portion configured to rotatably support the drive shaft, a body portion continuous with the bearing portion and extending radially outward, a pressing portion provided radially outside the body portion to press the casing, and a supporting portion extending from a face of the body portion near the fixed scroll. An end face of the supporting portion near the fixed scroll is a fastening face to which the fixed scroll is fastened. A gap is formed between an inner peripheral surface of the casing and outer peripheral surfaces of the body and supporting portions. An axial length of the gap is greater than or equal to an axial length of an inner peripheral surface of the supporting portion.

A scroll compressor includes a drive bush (22) disposed in one end portion in an axial direction of a main shaft (21) rotated around an axis, and eccentrically rotated, a pair of angular bearings (23 and 24) arranged back-to-back, and respectively clearance-fitted to an outside of the drive bush (22), a compression unit (20) that has a boss portion (26C) which protrudes from an end plate (26A) of a movable scroll and in which the pair of angular bearings (23 and 24) are interference-fitted to an inner peripheral surface of the boss portion, and a preload application unit (30) that applies a preload to the pair of angular bearings (23 and 24) in a direction in which the pair of angular bearings (23 and 24) moves close to each other.

An oil pump includes: a first core in which an inner rotor having external teeth and an outer rotor having internal teeth are housed; a housing having a recess in which the first core is held; a second core disposed in contact with the first core in an axial direction; and a cover having a holding hole in which the second core is held. The first core has a first recess/projection portion formed on a first axial end surface at a side opposite to an axial end surface opposing a bottom wall of the recess. The second core has a second recess/projection portion formed on a second axial end surface that is in contact with the first axial end surface. A gap is formed between opposing surfaces of the housing and the cover in a state where the first and second axial end surfaces are in contact with each other.

A scroll compressor includes a fixed scroll including a fixed scroll lap, and a movable scroll including a movable scroll lap. A first scroll lap is one of the fixed scroll lap and the movable scroll lap. A second scroll lap is an other of the fixed scroll lap and the movable scroll lap. A second thickness of the second scroll lap is larger than a first thickness of the first scroll lap. A first side face gap is formed between an inner line of the first scroll lap and an outer line of the second scroll lap. A second side face gap is formed between an outer line of the first scroll lap and an inner line of the second scroll lap. The second side face gap is larger than the first side face gap.

A low cost scroll device and methods of manufacturing the same are described. The scroll device includes, for example, a drive pin hole and bearing bores machined into a scroll of the scroll device from the same side as the involute of the scroll; idler shaft assemblies with no more than one bearing in the orbiting scroll for mechanically coupling the orbiting scroll to the fixed scroll; and an epoxy coating applied using a process that requires assembly of the scroll device only once.