Turbocharger bearing and lubrication system

Claim 2

A turbocharger comprising: a turbine, having a turbine wheel (11), a compressor, having a compressor wheel (10); a shaft (16) having two ends, one end being connected to the turbine wheel and the other end being connected to the compressor wheel; bearing means, for rotatably supporting the shaft; and a housing disposed between the turbine and compressor, the housing supporting the bearing means, characterised in that the bearing means is a ball bearing cartridge bearing.

Claim 3

A turbocharger comprising: a turbine, having a turbine wheel (11) within a turbine housing; a compressor, having a compressor wheel (10) within a compressor housing; a shaft (16) extending between the turbine wheel and the compressor wheel; a centre housing disposed between the turbine housing and the compressor housing and disposed around the shaft (16); and bearing means within the centre housing and supported by a bearing (13), the bearing means rotatably supporting the shaft; characterised by lubrication means (46,50) which are separate from the internal combustion engine lubrication system to lubricate the bearing means.

Claim 4

A turbocharger comprising: a turbine, having a turbine wheel (11) within a turbine housing; a compressor, having a compressor wheel (10) within a compressor housing; a shaft (16) extending between the turbine wheel and the compressor wheel; a centre housing disposed between the turbine housing and the compressor housing and disposed around the shaft (16); and bearing means within the centre housing and supported by a bearing (13), the bearing means rotatably supporting the shaft; characterised by lubrication means (46,50) which are separate from the internal combustion engine lubrication system to lubricate the bearing means.

Claim 5

A turbocharger as claimed in Claim 1 or Claim 2 characterised in that the bearing means includes an inner race (20) rotatable with the shaft (16), a plurality of outer races (14,15) supported by the centre housing and a multiplicity of ball bearings (30,31) disposed between the inner and outer races to allow the inner race (20) to rotate with respect to the outer races (14,15).

Claim 6

A turbocharger as claimed in Claim 3 characterised in that the bearing means includes means (35-37) to preload the ball bearings (30,31) towards the rotatable inner race (20).

Claim 7

A turbocharger as claimed in Claim 3 or 4 characterised by air ventilation means along the surface of the shaft (16) in the form of an air slinger (27), mounted on the inner race (20), freely rotatable within the main housing.

Claim 8

A turbocharger as claimed in 5 characterised in that the ventilation means further comprises a multiplicity of ribs (26) mounted in the annular space between the shaft (16) and the inner race (20), and parallel to the axis of the shaft, to allow air flow longitudinally along the shaft in the annular space between the outer surface of the shaft (16) and the inner surface of the inner race (20), the inner race having one or more apertures (29) near the end of the shaft opposite the air slinger (27), to permit entry of air into the annular space between the shaft and the inner race, to facilitate air flow for cooling the shaft.

Claim 9

A turbocharger as claimed in any of Claims 3 to 6 characterised by a squeeze film damper (54,55) between the outer periphery of the outer races and the inner periphery of the bearing bore within the main housing, to absorb energy and thus dampen any tendency of the bearing assembly and the shaft towards axial angular displacement.

Claim 10

A turbocharger as claimed in Claim 7 characterised in that the squeeze film damper is formed by each of the outer races having an external surface whose general cylindrical shape is reduced to a slight frusto-conical shape.

Claim 11

A turbocharger as claimed in any preceding claim characterised in that the lubrication means has a ribbed exterior (58) to aid in the dissipation of heat.

Claim 12

A turbocharger as claimed in any preceding claim characterised in that the bearing means is a cartridge bearing which comprises: a tubular inner ball bearing race (20) having an internal diameter suitable for fitting around the outside diameter of the turbocharger shaft (16) to be supported, the inner race (20) also having a pair of outwardly disposed grooves (62,63), located on its outside circumference, axially near the ends of the inner race; a multiplicity of ball bearings (30,31) situated circumferentially around the outer diameter of the inner race (20) and within the grooves (62,63) of the inner race; a ball bearing separator (60,61) fittable circumferentially outwards of the external diameter of the inner race (20), the ball bearing separator (60,61) having a series of circular slots about the midpoint of its axial length, the slots being dimensioned to receive the ball bearings and to separate the ball bearings in their orbit around the inner race (20); a pair of outer races (14,15) annularly cylindrically shaped, each having an axially linear outside surface, and having an internal shoulder (34,35) such that the greater diameter of the internal surface is nearer the end outwardly disposed with respect to the ball bearing cartridge assembly, the shoulder allowing the outer races to be slipped directly over the ball bearings (30,31) located within the grooves of the inner race (20) and to continue until the shoulder within the internal diameter of the inner wall of the outer race contacts and bears against the ball bearings, further urging the ball bearings against the groove of the inner race; a spacer assembly (35 - 37) generally of annular piston-like shape, having a parallel sided opening along its length, the opening being greater than the diameter of the inner race, around which the spacer assembly lies, the spacer assembly further having a series of longitudinal bores (36) whose axes are parallel to the axis of the spacer assembly, the bores being radially spaced about the axis of the spacer assembly for axially separating and urging apart the outer races; and a multiplicity of preload springs (37) located within the bores, the preload springs acting to urge contact with the inwardly disposed faces of the outer races (14,15) thereby springingly urging the outer races away from each other and away from the spacer assembly, in order to maintain the force applied to the ball bearings by the bearing pressure of the inner and outer races against the ball bearings.

Claim 13

A self-contained cartridge lubrication system for a turbocharger characterised by a lubrication cartridge housing; a filter assembly, mounted concentrically within the lubrication cartridge housing for filtering lubrication fluid; and an electrically driven pump mounted within the filter assembly for pumping filtered lubricant to the turbocharger.

Claim 14

A self-contained cartridge lubrication system for a turbocharger characterised by a lubrication cartridge housing; a filter assembly, mounted concentrically within the lubrication cartridge housing for filtering lubrication fluid; and an electrically driven pump mounted within the filter assembly for pumping filtered lubricant to the turbocharger.

Claim 15

A ball bearing cartridge comprising: a tubular inner ball bearing race, having an internal diameter suitable for fitting around the outside diameter of the shaft to be supported, the inner race also having a pair of grooves located on its outside diameter axially near the ends of the inner race; a set of ball bearings situated circumferentially around the outer diameter of the inner race and within the grooves of the inner race; a ball bearing separator fittable circumferentially outwards of the external diameter of the inner race, the ball bearing separator having a series of circular slots for receiving and separating the ball bearings in their orbit around the inner race; a pair of outer races annularly cylindrically shaped, having an axially linear outside surface, fittable with a bearing bore, and having an internal surface which is grooved concentrically outwardly towards the end outwardly disposed with respect to the bearing cartridge assembly, the groove allowing the outer race to be slipped directly over the ball bearings until the groove within the internal diameter of the inner wall of the outer race bears against the ball bearings, further urging the ball bearings against the groove of the inner race; a spacer and preload assembly, of generally annular piston like shape, having a generally parallel sided opening along its length the opening being greater in width than the diameter of the inner race circumferentially around which inner race the spacer assembly will lie, the spacer assembly further having a series of longitudinal bores, the axis of the bores being generally parallel to the axis of the spacer assembly, the bores being evenly radially spaced about the axis of the spacer assembly for axially separating the outer races; and a multiplicity of preload springs located within the bores, the preload springs causing urging contact with the inwardly disposed faces of the outer races, for springingly urging the outer races away from each other and away from the spacer assembly, in order to maintain the force applied to the ball bearings by the bearing pressure of the inner and outer races against the ball bearings.

Claim 16

A ball bearing cartridge comprising: a tubular inner ball bearing race, having an internal diameter suitable for fitting around the outside diameter of the shaft to be supported, the inner race also having a pair of grooves located on its outside diameter axially near the ends of the inner race; a set of ball bearings situated circumferentially around the outer diameter of the inner race and within the grooves of the inner race; a ball bearing separator fittable circumferentially outwards of the external diameter of the inner race, the ball bearing separator having a series of circular slots for receiving and separating the ball bearings in their orbit around the inner race; a pair of outer races annularly cylindrically shaped, having an axially linear outside surface, fittable with a bearing bore, and having an internal surface which is grooved concentrically outwardly towards the end outwardly disposed with respect to the bearing cartridge assembly, the groove allowing the outer race to be slipped directly over the ball bearings until the groove within the internal diameter of the inner wall of the outer race bears against the ball bearings, further urging the ball bearings against the groove of the inner race; a spacer and preload assembly, of generally annular piston like shape, having a generally parallel sided opening along its length the opening being greater in width than the diameter of the inner race circumferentially around which inner race the spacer assembly will lie, the spacer assembly further having a series of longitudinal bores, the axis of the bores being generally parallel to the axis of the spacer assembly, the bores being evenly radially spaced about the axis of the spacer assembly for axially separating the outer races; and a multiplicity of preload springs located within the bores, the preload springs causing urging contact with the inwardly disposed faces of the outer races, for springingly urging the outer races away from each other and away from the spacer assembly, in order to maintain the force applied to the ball bearings by the bearing pressure of the inner and outer races against the ball bearings.