Centrifugal compressor with improved lubrication system for gear-type transmission

Abstract

A centrifugal supercharger includes a case presenting a compressor chamber and a transmission chamber. An impeller in the compressor chamber is mounted to a shaft that extends into the transmission chamber. The impeller shaft is drivingly connected to a power input shaft by intermeshing gears provided on the shafts. A portion of the transmission chamber defines a fluid reservoir in which lubrication fluid is held. The intermeshing gears, as well as the bearing assemblies supporting the shafts, are located outside the fluid reservoir portion of the transmission chamber. A rotatable fluid-propelling element partly submerged in the lubrication fluid contained within the reservoir portion ensures that sufficient but not excessive lubrication fluid is supplied to the intermeshing gears and the bearing assemblies. A dedicated lubricant reserve system ensures that the required operating level of fluid is provided to, and maintained in, the reservoir portion.

1 . A centrifugal supercharger having self-contained transmission lubrication, said centrifugal supercharger comprising:
 a case presenting a compressor chamber and a transmission chamber,   said transmission chamber having a fluid reservoir portion;   lubrication fluid contained entirely within the transmission chamber and filling only the fluid reservoir portion thereof;   a rotatable impeller in the compressor chamber;   a gear-type transmission operable to drivingly connect the impeller to a power source,   said transmission including an impeller shaft that extends from the transmission chamber into the compression chamber to support the impeller,   said transmission including an input shaft that projects from the transmission chamber outside the case for connection to the power source,   said transmission including a drive gear and a driven impeller gear mounted within the transmission chamber respectively on the input and impeller shafts,   said gears being drivingly connected to spin the impeller shaft at a faster rotational speed than the input shaft,   said transmission being located at least partly in the transmission chamber but at least substantially outside the fluid reservoir portion thereof; and   a lubrication slinger disc rotatably mounted in the transmission chamber and extending into the fluid reservoir portion,   said transmission causing rotation of the lubrication slinger disc when driven by the power source, with the lubrication slinger disc being operable when rotated to propel lubrication fluid from the fluid reservoir portion to the transmission located within the transmission chamber.   
   
   
       2 . The centrifugal supercharger as claimed in  claim 1 ,
 said transmission defining a ratio of input-to-impeller shaft speed in the range of 1:3 to 1:6.   
   
   
       3 . The centrifugal supercharger as claimed in  claim 1 ,
 said gears drivingly intermeshing with one another and presenting corresponding diameters,   said disc presenting a disc rotation axis spaced apart from an axis of the drive gear and presenting a disc diameter,   said disc diameter being no larger than the drive gear diameter to thereby compactly position the disc relative to the transmission,   said disc diameter being larger than the impeller gear diameter to extend below the gears into the fluid reservoir portion for propelling lubrication fluid.   
   
   
       4 . The centrifugal supercharger as claimed in  claim 1 ,
 said impeller shaft causing rotation of the lubrication slinger disc when driven by the power source, with the slinger disc being rotatable at a speed no greater than the impeller.   
   
   
       5 . The centrifugal supercharger as claimed in  claim 1 ,
 said fluid reservoir portion of the transmission chamber being positioned below the transmission located within the transmission chamber, such that rotation of the lubrication slinger disc causes lubrication fluid in the fluid reservoir portion to be slung upwardly to the transmission.   
   
   
       6 . The centrifugal supercharger as claimed in  claim 5 ,
 said transmission chamber being generally teardrop-shaped in cross-section, with the fluid reservoir portion being wider in cross-section than any other portion of the transmission chamber.   
   
   
       7 . The centrifugal supercharger as claimed in  claim 1 ,
 each of said shafts being rotatably supported by respective pairs of bearing assemblies that are located within the transmission chamber, which are lubricated by the slinger disc.   
   
   
       8 . The centrifugal supercharger as claimed in  claim 1 ,
 said disc and said impeller presenting respective rotation axes spaced apart from one another,   said lubrication slinger disc being rotatably supported by a pair of bearing assemblies,   said case presenting multiple pairs of opposed aligned mounting sockets, with said pair of bearing assemblies being selectively received in one of the pairs of mounting sockets.   
   
   
       9 . The centrifugal supercharger as claimed in  claim 1 ,
 said disc including circumferential teeth that intermesh with the impeller gear so that the disc is in driving contact with the impeller shaft.   
   
   
       10 . The centrifugal supercharger as claimed in  claim 1 ,
 said slinger disc being outside the driving connection between the impeller and power source so that at least substantially no driving power is transferred to the impeller by the disc.   
   
   
       11 . The centrifugal supercharger as claimed in  claim 1 ,
 said lubrication slinger disc being the sole pump that lubricates the transmission.   
   
   
       12 . The centrifugal supercharger as claimed in  claim 1 ,
 said slinger disc presenting an outer circumferential surface,   said slinger disc having an outer surface speed of at least about  3 , 500  feet per minute during rotation of the impeller.   
   
   
       13 . The centrifugal supercharger as claimed in  claim 1 ,
 said disc presenting an outer, generally circular surface that engages the impeller gear so that rotation of the impeller gear effects rotation of the disc.   
   
   
       14 . The centrifugal supercharger as claimed in  claim 1 ,
 said impeller shaft presenting a cantilevered section that extends from the transmission chamber into the compression chamber,   said impeller being mounted on the cantilevered section.