Patent ID: 11913455
Assignee: DANFOSS COMMERCIAL COMPRESSORS
Field: Engines, pumps, turbines (Mechanical engineering)
Classification: CPC F | IPC F

Claim 0:
1. A scroll compressor including:
a hermetic outer shell provided with a suction inlet configured to supply the scroll compressor with refrigerant gas to be compressed and a discharge outlet configured to discharge compressed refrigerant gas,
a compression unit including at least a first scroll element and a second scroll element, the second scroll element being configured to perform an orbiting movement relative to the first scroll element during operation of the scroll compressor,
a drive shaft which is vertically orientated and which is configured to cooperate with the second scroll element,
an upper bearing arrangement and a lower bearing arrangement configured to rotatably support the drive shaft within the hermetic outer shell,
a centrifugal oil pump including a pick-up tube attached to a lower end portion of the drive shaft and provided with an oil inlet arranged at a lower end of the pick-up tube, the oil inlet being immersed in an oil sump arranged in a bottom section of the hermetic outer shell, the centrifugal oil pump being configured to deliver, during operation of the scroll compressor, oil to the compression unit and to the upper and lower bearing arrangements,
wherein the scroll compressor further includes a static fairing member secured to a non-rotating part of the scroll compressor, the static fairing member including a static tubular part which is at least partially immersed in the oil sump and which surrounds the pick-up tube with a predetermined distance such that a gap is formed between the inner surface of the static tubular part and the outer surface of the pick-up tube, a minimal radial distance (Dr) between the inner surface of the static tubular part and the outer surface of the pick-up tube is between 0.5 and 5 mm,
wherein the lower bearing arrangement comprises a radial bearing housing configured to rotatably support the lower end portion of the drive shaft, the radial bearing housing including an inner radial bearing surface surrounding the outer surface of the lower end portion of the drive shaft,
wherein the lower bearing arrangement further comprises upper and lower axial thrust bearings configured to limit an axial movement of the drive shaft during operation, and a pressurized oil chamber which is fluidly connected to the centrifugal oil pump, the pressurized oil chamber being at least partially delimited by the outer surface of the lower end portion of the drive shaft, the inner radial bearing surface and the upper and lower axial thrust bearings,
wherein the inner radial bearing surface has a first inner diameter and the radial bearing housing further includes an inner circumferential surface having a second inner diameter which is greater than the first inner diameter,
wherein the radial bearing housing further includes an inner frustoconical surface located between the inner radial bearing surface and the inner circumferential surface and diverging towards the inner circumferential surface, and
wherein a radial opening of the drive shaft faces the frustoconical surface.