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.

The pump device includes a motor portion that includes a shaft rotating about a central axis and a pump portion that is driven by a motor portion via the shaft. The pump portion includes a pump rotor that rotates along with the shaft and a pump housing that includes an accommodation portion that accommodates the pump rotor. The pump housing includes a pump body that includes a first bearing portion that supports the shaft and a pump cover with an accommodation portion disposed between the pump cover and the pump body. The pump cover includes a flow path through which oil is discharged and suctioned, and includes a second bearing portion that rotatably supports the shaft and that communicates with the flow path. An end portion of the shaft on one side in the axial direction is disposed at the second bearing portion or inside the flow path.

One of a pair of a fixed scroll and an orbiting scroll is the scroll including a step portion provided only at a predetermined position along a spiral direction on a blade bottom surface of a spiral wrap, and the other one of the scrolls is the scroll including a step portion provided only at a predetermined position along a spiral direction on a blade tip surface of a spiral wrap. A blade bottom surface of an end plate of the fixed scroll is set as a reference surface for setting a chip gap between both the scrolls. When a wrap height of the spiral wrap of the orbiting scroll is represented by (L) (Lo, Li) and a wrap height of the spiral wrap of the fixed scroll is represented by (lo, li), L (Lo, Li)>1 (lo, li) is satisfied.

A compressor (20) comprises: a housing assembly (22) having a plurality of ports including a suction port (24) and a discharge port (26); a male rotor (30) mounted for rotation about an axis (500); a female rotor (32) enmeshed with the male rotor and mounted in the housing for rotation about an axis (502) for drawing a flow from the suction port, compressing the flow, and discharging the compressed flow through the discharge port. The housing assembly comprises: a motor case (54); and a cover (60) bearing the suction port. The cover comprises a unitary piece forming: a mounting portion (63) mounted to an adjacent end (55) of the motor case, said adjacent end being large enough to pass the motor; and a fitting portion (62) extending to a rim (66) at the suction port and bearing an external groove (200).

A fluid pump includes a stator. A rotor is rotationally operable with respect to the stator. A drive shaft extends from the rotor to a pump assembly that delivers a fluid from an inlet to an outlet. A pump housing includes an interior cavity that contains the stator, the rotor and the pump assembly. A pump cover is disposed at an end of the pump housing. The pump cover defines an end of the interior cavity. A spring assembly biases the pump cover in an axial direction toward the pump assembly.

A scroll compressor includes a casing, a drive motor arranged in an inner space of the casing, a rotary shaft coupled to the drive motor to rotate, a main frame arranged under the drive motor, a fixed scroll arranged under the main frame, an orbiting scroll engaging with the orbiting scroll to make an orbiting motion, the rotary shaft being inserted into and eccentrically coupled to the orbiting scroll, a first bearing positioned between the main frame and the rotary shaft, and a second bearing positioned between the fixed scroll and the rotary shaft, where a gap between the first and second bearings and the rotary shaft varies with a vertical position. The scroll compressor may prevent the eccentric effect occurring during rotation from deteriorating performance of the bearings, thereby preventing compression performance from being lowered.

A scroll compressor includes fixed and orbiting scrolls, and satisfies at least one of a first condition and a second condition. In the first condition, a first gap between a distal end of the first wrap and the second base changes heading from an outer peripheral side of the first wrap to an inner peripheral side. In the second condition, a second gap between a distal end of the second wrap and the first base changes heading from an outer peripheral side of the second wrap to an inner peripheral side. A rate of change in the first gap in one area is greater than a rate of change in the first gap in another area. A rate of change in the second gap in one area is greater than a rate of change in the second gap in another area.

A vane rotary compressor includes a roller rotatably supported in a cylinder and including a plurality of vane slots formed along a circumferential direction with back pressure chambers formed at one end of each of the vane slots A plurality of vanes are slidably supported in the vane slots protruding toward an inner circumferential surface of the cylinder. A compression space formed by the vanes between the roller and the cylinder includes an inlet port and an outlet port formed at both sides of a contact point between the roller and the cylinder. A vane positioned between the inlet port and the outlet port is configured such that a front gap between a front surface of the vane and the inner circumferential surface of the cylinder is smaller than a rear gap between a rear surface of the vane and an inner surface of the back pressure chamber.

Provided is a gear pump device that enables improvement in volumetric efficiency and manufacturability, and also makes it possible to ensure sealing property and to reduce drive torque. According to the present invention, a sealing mechanism is provided with an annular rubber member, an outer member, and an inner member, wherein: the inner member has, at an end of an outer peripheral wall on the side of an inner gear in the axial direction, a notch which is recessed radially inward of the inner gear so as to form, together with an axial one end face of the inner gear, a depressed part; and the outer member has an insertion part which is disposed within the depressed part and which abuts against the axial one end face of the inner gear so as to constitute a part of a sealing surface on the other side.

A method of treating, tuning, assembling, and/or overhauling a twin rotor device includes applying a coating material on an internal set of working surfaces of the twin rotor device when at least partially assembled. The coating may be factory or field applied to a new or used twin rotor device. The working surfaces may be uncoated or previously coated and may be built-up as the coating material forms a coating on at least some of the working surfaces. Manufacturing variations of a pair of rotors and a housing may be compensated by the coating. One or more performance characteristics of the twin rotor device may be improved by the coating, and variation between a series of twin rotor device may be reduced or substantially eliminated. The coating may reduce internal leakage and increase volumetric efficiency of the twin rotor device. The twin rotor device may be a supercharger 200, a screw compressor 1200, or other twin rotor device.