Bore and shaft assembly

1. An assembly for a turbocharger comprising:

a labyrinth seal formed by a plurality of slots of a rotatable shaft and a plurality of seal rings, each seal ring received by a respective one of the plurality of slots, the shaft and seal rings positioned in a bore wherein the bore comprises a longitudinal axis extending generally from an inner end to an outer end of the bore and a seat defined inwardly by a step and outwardly by a chamfer that extends radially inward over an outward axial distance to an outer plateau radius of an outer plateau proximate the outer end of the bore where the step resists inward movement of the shaft in the bore and where the chamfer resists outward movement of the shaft in the bore while allowing for removal of the shaft and the plurality of seal rings from the bore via radial contraction of at least one of the seal rings to the radius of the outer plateau as the at least one ring traverses axially across the chamfer.

2. A system for a turbomachine, the system comprising:

a bore that comprises a longitudinal axis extending generally from an inner end to an outer end of the bore, an inner seat disposed proximate to the inner end at an inner seat radius, an outer plateau at an outer plateau radius and an outer seat disposed proximate to the outer end, inward the outer plateau, at an outer seat radius wherein the outer seat radius exceeds the inner seat radius and the outer plateau radius, wherein the inner seat comprises a step that defines an inner end of the inner seat and wherein the outer seat comprises a step that defines an inner end of the outer seat;

a rotatable shaft, insertably positionable in the bore, that comprises an inner slot and an outer slot;

an outer seal ring, positionable on the shaft, configured for receipt by the outer slot and configured to seat in the outer seat of the bore; and

an inner seal ring, positionable on the shaft, configured for receipt by the inner slot, configured with an axial width to bridge the outer plateau and the outer step to prevent seating of the inner seal ring in the outer seat of the bore and configured to seat in the inner seat of the bore wherein the inner seal ring resists axial outward flow of lubricant for lubricating the rotatable shaft.

3. The system of claim 2 wherein the axial width of the inner seal ring exceeds an axial width of the outer seat of the bore.

4. The system of claim 2 further comprising a shaft assembly that comprises the inner seal ring received by the inner slot of the shaft and the outer seal ring received by the outer slot of the shaft.

5. The system of claim 2 further comprising a labyrinth seal that comprises the inner seal ring received by the inner slot of the shaft and seated in the inner seat of the bore and the outer seal ring received by the outer slot of the shaft and seated in the outer seat of the bore.

6. The system of claim 2 wherein the inner step resists axial inward movement of the inner seal ring.

7. The system of claim 2 wherein the outer step resists axial inward movement of the outer seal ring.

8. The system of claim 2 wherein the inner step resists axial inward movement of the inner seal ring and wherein the outer step resists axial inward movement of the outer seal ring.

9. The system of claim 2 wherein the bore comprises a chamfer that extends radially inward over an outward axial distance to the outer plateau radius to resist axial outward movement of the outer seal ring.

10. The system of claim 9 wherein the chamfer allows for removal of the outer seal ring from the outer seat by reducing the radius of the outer seal ring to the radius of the outer plateau upon outward axial movement of the shaft.

11. The system of claim 2 wherein the inner step resists axial inward movement of the inner seal ring and a chamfer that extends radially inward over an outward axial distance to the outer plateau radius wherein the chamfer resists axial outward movement of the outer seal ring.

12. The system of claim 2 wherein the outer seat of the bore comprises a step to resist axial inward movement of outer seal ring and a chamfer that extends radially inward over an outward axial distance to the outer plateau radius to resist axial outward movement of the outer seal ring.

13. A turbocharger comprising:

a compressor comprising a compressor housing and a compressor wheel mounted in the compressor housing;

a turbine comprising a turbine housing and a turbine wheel mounted in the turbine housing;

a rotatable shaft connecting the compressor wheel to the turbine wheel;

a center housing disposed between and mounted to the compressor and turbine housings, the center housing defining a bore that receives the shaft therethrough;

wherein the bore comprises:

a longitudinal axis extending generally from an inner end to an outer end of the bore;

an outer plateau proximate the outer end at an outer plateau radius;

an outer seat disposed inward the outer plateau at an outer seat radius wherein the outer seat comprises an inner end;

an inner seat having an axial width, the inner seat disposed inward the outer seat at an inner seat radius wherein the outer seat radius exceeds the inner seat radius and the outer plateau radius, wherein the inner seat comprises a step that defines an inner end of the inner seat and wherein the outer seat comprises a step that defines the inner end of the outer seat;

and further comprising:

an inner seal ring having an axial width, the inner seal ring disposed inwardly adjacent the inner seat, wherein the axial width of the inner seal ring exceeds an axial width defined between the step of the outer seat and the outer plateau and to thereby allow the inner seal ring to bridge the outer seat and wherein the inner seal ring resists axial outward flow of lubricant for lubricating the rotatable shaft.