Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
  • F04B39/00—Component parts, details, or accessories, of pumps or pumping systems specially adapted for elastic fluids, not otherwise provided for in, or of interest apart from, groups F04B25/00 - F04B37/00
  • F04B39/02—Lubrication
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
  • F04B39/00—Component parts, details, or accessories, of pumps or pumping systems specially adapted for elastic fluids, not otherwise provided for in, or of interest apart from, groups F04B25/00 - F04B37/00
  • F04B39/02—Lubrication
  • F04B39/0223—Lubrication characterised by the compressor type
  • F04B39/023—Hermetic compressors
  • F04B39/0238—Hermetic compressors with oil distribution channels
  • F04B39/0246—Hermetic compressors with oil distribution channels in the rotating shaft
  • F04B39/0253—Hermetic compressors with oil distribution channels in the rotating shaft using centrifugal force for transporting the oil
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
  • F04B53/00—Component parts, details or accessories not provided for in, or of interest apart from, groups F04B1/00 - F04B23/00 or F04B39/00 - F04B47/00
  • F04B53/18—Lubricating

Definitions

• the present invention relates to an airtight compressor, and more specifically to an airtight compressor of the type comprising a centrifugal pump for bringing oil to moving parts of the compressor.
• a compressor has the function of raising the pressure of a certain volume of fluid to a pressure necessary to perform a certain work.
• hermetic compressors that generally comprise a sealed housing that defines an oil reservoir and an oil pump means responsible for bringing the reservoir oil to the moving parts of the compressor.
• Oil pumps known in the art comprise an oil pickup tube having an oil inlet. For the capture, the centrifugal effect is relied upon, and the rotation of the pump forces the oil that enters the hole against the pipe walls, promoting the pressure increase and, consequently, its rise.
• the pumping energy required for lubrication is obtained from the rotation and of pump diameter.
• a lower compressor speed is defined for the best compressor performance applied to the refrigeration system, this speed tends to be as low as possible, with the oil pump being the main limiting factor for lowering the speed.
• the pump inlet bore diameter generates a pressure equalization region, rendering this region inactive.
• the pressure increase from centrifugation only occurs in the radius regions larger than the inlet.
• a large diameter inlet will impair pump performance at low revs.
• the radius or diameter of the pump in the oil outlet region is critical to pump efficiency. This is because the oil path through the shaft to this exit hole must take into account the parabolic shape acquired by the oil in its centrifugation, and no protrusion can intercept this parable (in the event of an intercept, the oil flow would simply interrupted).
• the pump design plays a large role in compressor performance, and there is a need for a pump suitable for a compressor running at low rpm.
• an airtight compressor comprising a casing enclosing the compressor component parts, an oil reservoir at the bottom of the casing, a cylinder block incorporating a bearing to support a vertical axis to which it is fitted.
• a rotor is mounted, and a centrifugal pump that carries oil to the moving parts of the compressor, with the vertical axis extending axially beyond the rotor to form a free end at its lower portion, the free end being sized to be received at a corresponding end of the centrifugal pump, at least a portion of the inner wall of the pump end and at least a portion of the outer wall of the shaft assuming a juxtaposed condition upon receipt.
• the free end of the vertical axis extends axially only sufficiently to allow attachment of the pump end, and in a preferred embodiment the free end of the vertical axis extends. not more than 6 mm.
• the free end has a machined portion of reduced outside diameter to facilitate pump end assembly.
• Mounting between the free end of the shaft and the corresponding end of the pump is preferably accomplished by an interference fit, but alternative means such as gluing could also be used.
• Figure 1 - Figure 1 shows a cross-sectional view showing a conventional airtight compressor with a known prior art pumping solution
• Figure 2 - Figure 2 illustrates a sectional view showing a conventional airtight compressor with another known prior art pumping solution
• Figure 3 - Figure 3 illustrates a sectional view showing a hermetically sealed compressor. with the pumping solution provided by the present invention.
• FIG. 4 - Figure 4 shows a detailed sectional view of the oil pump of the present invention mounted to the compressor shaft.
• FIGS 1 and 2 illustrate compressors with known prior art pumping solutions.
• oil pump 1 is inserted into motor rotor 2.
• Pump 1 has one end 3 inserted in oil 4 disposed in a housing reservoir 5 and the other end 6 inserted in rotor 2.
• This configuration creates a clear path for the oil, but restricts the region available for fixing the 7 shaft and pump.
• axis 7 is continuous to the upper end 6 of the pump.
• pump 1 is inserted into shaft 7, with shaft 7 extending to the end of rotor 2.
• This configuration improves the region available for fixing shaft 7, but the oil passage diameter ends. compromised so that the pump can be inserted into the shaft.
• the present invention can come up with a pumping solution capable of ensuring a suitable diameter for oil passage, an optimization of the repression height, and a simplified mounting medium for the oil pump.
• the shaft 7 extends slightly beyond the rotor 2, leaving a free end 8 for mounting the centrifugal pump 1.
• free end 8 has only the extension n. to allow the pump to be mounted 1. This is due to the need not to extend the shaft 8 too much, which would lead to unnecessary material use, increasing the final cost to the compressor. Thus, in a preferred embodiment of the present invention, the free end extension 8 does not exceed 6 mm.
• one end of pump 1 is immersed in oil 4, said end further comprising an inlet port 9 at its most extreme portion.
• the other end 12 of the pump 1 is sized to receive the free end 8 of the shaft 7, the outer wall of the shaft and the inner wall of the pump being juxtaposed after engagement.
• a free end portion of shaft 7 is machined to reduce its outer diameter, such machined portion being for receiving the pump mounting end.
• the mounting of the pump 1 to the free end 8 of the shaft 7 is performed by an interference fit, without the use of glues or adhesives.
• the assembly of the pump 1 at the free end 8 of the shaft 7 is accomplished by gluing.
• the present invention by mounting the pump 1 external to the shaft a and the rotor, ensures a suitable setback height, whereby the inlet orifice is naturally closer to the shaft.
• pump assembly 1 since pump assembly 1 does not take up any extension of shaft 7 internal to the rotor, the entire shaft interference region is available, and the lower end The thrust bearing 13 can be brought very close to the oil (see figure 3) so that the orifice 11 is at a setback height H easily reached even at low rotation.
• the pump mounting configuration of the present invention achieves, by simple and economical construction, an effective pumping solution for a compressor running at low rpm.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Compressor (AREA)
• Structures Of Non-Positive Displacement Pumps (AREA)

Priority Applications (7)

Applications Claiming Priority (2)

Publications (1)

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Family Applications (1)

Country Status (10)

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Citations (9)

Family Cites Families (8)

• 2009
  • 2009-07-24 BR BRPI0902430-1A patent/BRPI0902430A2/pt not_active IP Right Cessation
• 2010
  • 2010-07-26 CN CN2010800375873A patent/CN102483052A/zh active Pending
  • 2010-07-26 SG SG2012005237A patent/SG177748A1/en unknown
  • 2010-07-26 KR KR1020127002084A patent/KR20120034759A/ko not_active Withdrawn
  • 2010-07-26 MX MX2012001053A patent/MX2012001053A/es not_active Application Discontinuation
  • 2010-07-26 IN IN706DEN2012 patent/IN2012DN00706A/en unknown
  • 2010-07-26 US US13/386,829 patent/US20120189437A1/en not_active Abandoned
  • 2010-07-26 JP JP2012520867A patent/JP2013500415A/ja active Pending
  • 2010-07-26 WO PCT/BR2010/000257 patent/WO2011009186A1/pt not_active Ceased
  • 2010-07-26 EP EP10752711A patent/EP2458213A1/en not_active Withdrawn

Patent Citations (9)

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