An Oldham coupling structure for a scroll compressor decreases Oldham coupling pressure loading without increasing compressor diameter or significantly increasing orbiting scroll or Oldham coupling inertia. The Oldham coupling key height and area are increased by recessing the key face into the ring portion of the Oldham coupling, increasing the key height and adding pads to the involute side of the orbiting scroll base plate to extend the key slot, potentially resulting in reduced compressor diameter and/or reduced orbiting scroll and Oldham coupling inertia.

A scroll compressor includes fixed and movable scrolls, and a drive part. The fixed scroll has a fixed-side end plate, a fixed-side lap, and a thrust sliding portion surrounding the first lap. The movable scroll has a movable-side end plate and a movable-side lap. The drive part revolves the movable scroll so that refrigerant in a compression chamber formed by the fixed-side lap and movable-side lap is compressed. A back-pressure space which communicates with the compression chamber for at least a prescribed period in a revolution cycle is formed at the back face side of the movable scroll. A first oil channel supplied with oil from a space is formed in a first angle region of the fixed-side end plate. A communication channel formed in a second angle region communicates with the compression chamber. A second oil channel communicating with the back-pressure space is formed in the second angle region.

A compressor (10) includes a compression mechanism (18) and a driveshaft (62) that drives the compression mechanism (18). The driveshaft (62) may include a first axially extending passage (94), a second axially extending passage (96), and a lubricant distribution passage (100). The first and second axially extending passages (94, 96) may be radially offset from each other and may intersect each other at an overlap region (98). The first and second axially extending passages (94, 96) are in fluid communication with each other at the overlap region (98). The lubricant distribution passage (100) may extend from the first axially extending passage (94) through an outer diametrical surface of the driveshaft (62). The lubricant distribution passage (100) may be disposed at a first axial distance (D1) from a first axial end (90) of the driveshaft (62). A first axial end of the overlap region (98) may be disposed at a second axial distance (D2) from the first axial end (90) of the drive shaft (62). The first axial distance (D1) is greater than the second axial distance (D2).

A two-stage rotary compressor for gas, in particular air. The compressor comprises a bottom plate and a head enclosing between them two compression stages. The compressor is characterized in that an interconnection device is arranged between the two compression stages, said device being suited to establish a communication “in series” or “in parallel”, to be selected by the manufacturer, between said two compression stages.

To be as lightweight and compact, for example for automotive technology, a scroll compressor further includes an axial guide that supports the movable compressor body to prevent movements in the direction parallel to a centre axis of the stationary compressor body and, in the event of movements, guides it in the direction transverse to the centre axis. A coupling prevents the movable compressor body from rotating freely. The axial guide supports a compressor body base, which carries the scroll vane, of the second compressor body against an axial support face, in that the axial support face abuts a sliding body such that it is slidable transversely to the centre axis. The sliding body is slidable transversely to the centre axis, on a carrier element that is arranged in the compressor housing.

Disclosed are a method and a device for balancing crankshaft deformation e, a crankshaft with counterweights determined according to the method, and a scroll compressor using the crankshaft. The method includes: determining a component centrifugal force required by a counterweight to overcome the crankshaft deformation caused by both an orbiting scroll centrifugal force and a gas force; and determining the counterweight according to the component centrifugal force. The counterweight is arranged on the crankshaft.

A method of operating a vacuum pump system, the method including the steps of: operating a primary vacuum pump having a variable speed motor; connecting at least two secondary vacuum pumps in parallel with said primary vacuum pump; dividing the secondary vacuum pumps in groups, each group including at least one secondary vacuum pump; and assigning a priority for each of said groups. The method further includes the steps of measuring the inlet pressure p1, comparing the measured inlet pressure p1 with a predetermined pressure value p0, and if p1 is higher than p0, starting the secondary vacuum pump at a first predetermined startup load S.sub.startup,1 if it includes a fixed speed motor, and/or starting the secondary vacuum pump at a second predetermined startup load S.sub.startup,2, if it includes a variable speed motor.

Apparatus, e.g., including a pump or rotary device, having a discharge casing and a discharge casing insert. The discharge casing may be configured with a discharge flow pathway for providing a flow of effluent being pumped and discharged, the discharge flow pathway having a discharge flow pathway wall, the discharge casing also configured with a discharge casing insert borehole that passes from an outer surface of the discharge casing through the discharge flow pathway wall. The discharge casing insert may include a discharge casing Venturi plug portion to be received in the discharge casing insert borehole and arranged in the discharge flow pathway, the discharge casing Venturi plug portion configured with a restricted discharge flow pathway for providing a partial obstruction in the discharge flow pathway and the flow of the effluent being pumped and discharged.

A pumping installation includes at least one first positive-displacement machine and one second positive-displacement machine, as well as a control module, in which installation a gas is evacuated from an enclosed volume by means of the first positive-displacement machine and/or the second positive-displacement machine. The pumping installation includes at least one control valve controlled by the control module and a pressure sensor for sensing the value of the pressure at the outlet of the first positive-displacement machine and/or a temperature sensor for sensing the value of the temperature at the outlet of the first positive-displacement machine in order to control the flow of gas between the enclosed volume and the outlet of the pumping installation.

A scroll compressor according to the present invention includes a casing, an orbiting member provided within the casing and performing an orbiting motion, a non-orbiting member forming a compression chamber together with the orbiting member, the compression chamber having a suction chamber, an intermediate pressure chamber and a discharge chamber, a communication passage configured to bypass a refrigerant of the compression chamber into the casing, an opening/closing valve assembly configured to open and close the communication passage, and a switching valve assembly configured to operate the opening/closing valve assembly, the switching valve assembly being provided outside the casing and connected to the opening/closing valve assembly, whereby an installation of the bypass hole can result in prevention of over-compression and an installation of a control valve for varying a capacity outside the casing can result in reduction of costs for the control valve.