A method for evacuating a process space by initially evacuating the process space to a pressure limit value using two compressors operated in parallel, and on reaching or undershooting the pressure limit value, the process space is subsequently evacuated using the two compressors operated in series.

A compressor, more particularly, a scroll compressor provides structures that may enhance centrifugal stiffness at a contact point between a fixed scroll and an orbiting scroll. The compressor may include an orbiting scroll having an orbiting scroll wrap wound around a radial-direction inner area from a radial-direction outer area; and a fixed scroll having a fixed scroll wrap wound around the radial-direction inner area from the radial-direction outer area. A surfacing part may be configured to narrow a distance between the orbiting scroll wrap and the fixed scroll wrap may be formed in a predetermined section of the orbiting scroll or fixed scroll wrap.

An electric compressor includes a housing, a drive shaft, a motor, a movable scroll, and a fixed block. The fixed block is fixed to the housing and disposed between the motor and the movable scroll. The motor includes a stator and a rotor. The rotor has an introduction passage that is formed through the rotor in an axial direction of the drive shaft. The drive shaft includes a balance weight that is disposed between the fixed block and the motor and extends to a position where the balance weight covers at least a part of the introduction passage in a radial direction of the drive shaft in a view in the axial direction. The introduction passage includes a first passage located outward of the balance weight in a circumferential direction of the rotor and the drive shaft, and a second passage facing the balance weight in the axial direction.

A sheet-shaped check valve 23 which opens and closes the injection passage 21 is placed in the check valve chamber 22, an injection discharge passage 21b portion connected to the compression chamber 13 of the injection passage 21 and the check valve chamber 22 open from an outer surface of the fixed scroll 11, a lid body 25 is attached to openings of the injection discharge passage 21b and the check valve chamber 22 such that the check valve 23 is sandwiched between the openings and the lid body 25, and the injection discharge passage 21b and the check valve chamber 22 are hermetically closed, thereby forming the injection passage 21. According to this, it is possible to provide a reliable, efficient and inexpensive compressor with an injection mechanism.

The present disclosure describes a rotary pulsation generator having a simple structure capable of transferring fluid while implementing low noise and low vibration and having high flow of fluid and high pressure suction and discharge functions. According to the present disclosure, fluid is transferred by adjusting a width and interval of pulsation while reducing vibration caused by eccentric rotation of a rotor.

According to one embodiment, a compressor includes cylinders, a rotating shaft, bearings, discharge valve mechanisms, and mufflers. As to the mufflers, an outer contour of the muffler chamber is defined by each of an end face part which is a face part on one end side of the muffler in an axial direction of the rotating shaft, a brim part which is a face part on the other end side in the axial direction, and a side face part which joins the end face part and the brim part to each other in a cylindrical form in the circumferential direction of the rotating shaft, and one of the mufflers includes a concave part formed by denting each of the end face part and the side face part toward the inside of a muffler chamber.

A rotary compressor includes a casing including an oil reservoir configured to store lubricating oil inside, and a compression mechanism including a reciprocator and a support. The reciprocator defines a compression chamber and reciprocating along a first direction. The support has a support surface configured to support the reciprocator. The support surface includes a first groove and a second groove formed therein. The first groove extends along a second direction intersecting with the first direction and is configured to transfer the lubricating oil to the second groove. The second groove extends from a center of the first groove toward the compression chamber along the first direction.

According to one embodiment, a rotary shaft of a rotary compressor includes a first connection shaft and a second connection shaft. The first connection shaft has a cross-sectional shape including a first outer surface, a second outer surface, and a third outer surface. L1 represents a distance from an intersecting point located on one end side where the first outer surface and the second outer surface intersect each other to the rotation center, L2 represents a distance from an intersecting point located on an other end side where the first outer surface and the second outer surface intersect each other, to the rotation center, and L3 represents a distance from the third outer surface to the rotation center, a relationship of L1>L3≥L2 is satisfied.

A compressor includes a motor, a balance weight and a partition. The motor includes a rotor having a first end surface and a second end surface. The balance weight is disposed on the first end surface or the second end surface. The partition is disposed on the first end surface or the second end surface. The rotor has a through hole extending from the first end surface to the second end surface. The partition divides, from the through hole, at least one of a front region and a rear region. The front region is located in front of a front edge of the balance weight in a rotational direction of the rotor. The rear region is located behind a rear edge of the balance weight in the rotational direction of the rotor.

A fluid delivery device has a primary pump and a main pump fluidically connected to the primary pump. The primary pump can be driven by a primary pump input shaft, the main pump can be driven by a main pump input shaft, and the primary pump input shaft and the main pump input shaft are mechanically coupled to a common drive shaft of the fluid delivery device. The primary pump is in the form of a non-compensated gear pump or a centrifugal pump and the main pump is in the form of a compensated internal gear pump.