Abstract: A scroll-type displacement machine, e.g. scroll compressor, has fixed and orbiting scrolls and an Oldham ring to prevent relative rotation between scrolls. A drive module positioned between the orbiting scroll and drive shaft incorporates an eccentric drive system and first and second counterweights for dynamic balancing. The motor, motor bearings, and motor shaft (i.e., drive shaft) are packaged as a separate, modular unit (e.g. “off-the-shelf” motor) that attaches to the compressor frame. The machine is configured as a high-side machine with a low-pressure port at a radial outer portion of the fixed scroll and a high-pressure port or discharge port located in the floor of the orbiting scroll at its axis, with high pressure flow passing over and around the eccentric drive bearing and drive mechanism. The Oldham ring is distributed on a lateral or radial plane of the scroll pair with a portion surrounding a portion of the fixed scroll and another portion surrounding a portion of the orbiting scroll.

Abstract: A refrigeration system with at least three compressors connected in a circuit. Each compressor has a housing with an oil sump. The oil sump is adapted to contain oil that defines an oil level. A supply line supplies refrigerant and entrained oil to each of the at least three compressors. The oil sump of each compressor has at least one oil port. Each oil port is disposed at an elevation that is equal to or minimally higher than the level of oil to promote equalization of oil levels in each compressor. There are a plurality of separate conduits which are not directly connected, but connected through the oil sumps of separate compressors. At least one compressor includes an oil sump extension having connections for the separate conduits. Each oil port is connected to the separate conduits or an oil sump extension. Each separate conduit connects a pair of compressors.

Abstract: A method of operating a refrigeration system having at least three compressors, in which each compressor has an oil sump with oil at an oil level. The method includes separately connecting the oil sumps of the at least three compressors. Each separate connection allows oil flow only between the oil sumps of two of said compressors thereby preventing bypass flow. The method further includes flowing oil between oil sumps of the at least three compressors and along the separate connections to tend to equalize the oil levels among the oil sumps of the at least three compressors.

Abstract: A refrigeration system with at least three compressors connected in a circuit. Each compressor has a housing with an oil sump. The oil sump is adapted to contain oil that defines an oil level. A supply line supplies refrigerant and entrained oil to each of the at least three compressors. The oil sump of each compressor has at least one oil port. Each oil port is disposed at an elevation that is equal to or minimally higher than the level of oil to promote equalization of oil levels in each compressor. There are a plurality of separate conduits which are not directly connected, but connected through the oil sumps of separate compressors. At least one compressor includes an oil sump extension having connections for the separate conduits. Each oil port is connected to the separate conduits or an oil sump extension. Each separate conduit connects a pair of compressors.

Abstract: A scroll-type displacement machine, e.g. scroll compressor, has fixed and orbiting scrolls and an Oldham ring to prevent relative rotation between scrolls. A drive module positioned between the orbiting scroll and drive shaft incorporates an eccentric drive system and first and second counterweights for dynamic balancing. The motor, motor bearings, and motor shaft (i.e., drive shaft) are packaged as a separate, modular unit (e.g. “off-the-shelf” motor) that attaches to the compressor frame. The machine is configured as a high-side machine with a low-pressure port at a radial outer portion of the fixed scroll and a high-pressure port or discharge port located in the floor of the orbiting scroll at its axis, with high pressure flow passing over and around the eccentric drive bearing and drive mechanism. The Oldham ring is distributed on a lateral or radial plane of the scroll pair with a portion surrounding a portion of the fixed scroll and another portion surrounding a portion of the orbiting scroll.

Abstract: A scroll compressor with unfastened thrust plate includes a compressor housing and scroll compressor bodies disposed in the compressor housing. The scroll bodies include a fixed scroll body and a moveable scroll body. The fixed and moveable scroll bodies have respective bases and respective scroll ribs that project from the respective bases. The scroll ribs mutually engage. The moveable scroll body is movable relative to the fixed scroll body for compressing fluid. An upper bearing member provides axial thrust support to the moveable scroll compressor body through a bearing support via an unfastened thrust plate that is located between the upper bearing member and the moveable scroll body. The unfastened thrust plate has no means of attachment to the upper bearing member or to the moveable scroll body.

Abstract: A method of operating a refrigeration system having at least three compressors, in which each compressor has an oil sump with oil at an oil level. The method includes separately connecting the oil sumps of the at least three compressors. Each separate connection allows oil flow only between the oil sumps of two of said compressors thereby preventing bypass flow. The method further includes flowing oil between oil sumps of the at least three compressors and along the separate connections to tend to equalize the oil levels among the oil sumps of the at least three compressors.

Abstract: The drive connection between an eccentric pin and a slider block in a scroll compressor is angled such that any vertical force between the two will drive the slider block away from the orbiting scroll member. In this manner, manufacturing tolerances will not result in any drive connection which can have a net vertical force driving the slider block toward the orbiting scroll member.

Abstract: Scroll compressors are provided with vapor injection or by-pass ports that will allow greater flow of refrigerant through the port than was the case in the prior art. The prior art has typically utilized a single injection port having a diameter equal to or slightly larger than the thickness of the scroll wrap. In this way, the scroll wrap is able to prevent or restrict cross-flow leakage from the port from passing between the two compression chambers. However, this single port has also limited the amount of refrigerant that can be returned. In one embodiment, the present invention utilizes a plurality of ports generally spaced along the length of the wrap such that cross-flow can still be prevented while providing a greater cross-sectional flow area into or out of the compression chambers. In another embodiment, the several ports may be replaced by a single elongated port.

Abstract: An abradable coating is formed on portions of the flank wall of the wraps of a scroll compressor. The radially outer portions of the flank wall are left uncoated, and can bear a force between the scroll wraps. In this manner, the load is not transferred through a coated portion, but rather through the uncoated portion. As the scroll wraps move relative to each other at run-in, the abradable coating wears away leaving a tight fit between the flank walls at the radially inner locations.

Abstract: A scroll compressor is provided with a generally spiral wrap having an abradable or conformable coating on radially inner portions of its tip. The coating is not applied to radially outer portions. During operation of the scroll compressor, the coating will eliminate tip gap leakage adjacent radially inner, higher discharge pressure portions of the compression process. The outer, non-coated portions will bear the axial load, and ensure the coating will not wear away to an undue amount.

Abstract: A screw compressor includes a housing and a screw rotor disposed in the housing and rotatable relative to the housing for compressing a refrigerant, the housing and the screw rotor having a rest condition, and an operating condition wherein at least one of the housing and the rotor deflect from the rest condition, and structure for at least one of reducing deflection from the rest condition and evenly distributing deflection from the rest condition when the rotor is in the operating condition, whereby clearance between the housing and the rotor is optimized in the operating condition.

Abstract: A scroll compressor having a hybrid wrap is defined to have its wrap origin offset from a drive center of both the orbiting and non-orbiting scroll members. The offset is selected in a direction such that it eliminates extremes in the torque curve relative to shaft rotation. In this way, torque reversal is generally eliminated.

Abstract: A screw compressor includes a housing and a screw rotor disposed in the housing and rotatable relative to the housing for compressing a refrigerant, the housing and the screw rotor having a rest condition, and an operating condition wherein at least one of the housing and the rotor deflect from the rest condition, and structure for at least one of reducing deflection from the rest condition and evenly distributing deflection from the rest condition when the rotor is in the operating condition, whereby clearance between the housing and the rotor is optimized in the operating condition.

Abstract: A rotor for a screw rotor machine includes a shaft and a plurality of lobes disposed on the shaft, each of the lobes extending radially outward from the shaft and having a tip surface, a rear surface and a transition section disposed between the tip surface and the rear surface, the transition section having an arcuate portion, a middle portion and a short radius portion, the arcuate portion being concave in shape so as to open away from the shaft and transition the tip surface into the middle portion.