Fastener device for a rotating group of a turbomachine

Abstract

The invention relates to a fastener for a rotating set of a turbomachine. The turbomachine comprises a casing and a rotating set supported for rotation within the casing about an axis. The rotating set comprises a rotor shaft, an impeller and a fastener clamping the impeller to the rotor shaft. The fastener is unitary and comprises a head and a shank. The shank comprises a guiding feature on an arcuate surface facing radially outwardly relative to the axis. The shank is received in the impeller and attached to the rotor shaft with the guiding feature guided to an arcuate inner radial surface of the impeller. The head abuts an axial surface of the impeller for axially clamping the impeller to the rotor shaft.

Claims

1. A turbine, comprising: shell; A rotating assembly supported for rotation about an axis within the housing, the rotating assembly including a rotor shaft, an impeller, fasteners, and a collar, the rotor shaft including a shoulder, the collar being accommodated on the rotor shaft, and the impeller being spaced apart from the rotor shaft along the axis; The fastener is integral and includes a head and a shank. The shank includes a first guide feature on an arcuate surface, a second guide feature on another arcuate surface, and an attachment portion. The arcuate surfaces are radially outward relative to the axis, and the other arcuate surface is also radially outward relative to the axis. The shank is received in the impeller and attached to the rotor shaft via the attachment portion. The first guide feature is guided to an arcuate inner radial surface of the impeller, and the second guide feature is guided to another arcuate inner radial surface of the rotor shaft. The head abuts the axial surface of the impeller for axially clamping the impeller to the rotor shaft. The second guide feature is axially spaced from the first guide feature and axially spaced from the attachment portion. The head is adjacent to the axial surface of the impeller to clamp both the impeller and the collar against the shoulder of the rotor shaft.

2. The turbine of claim 1, wherein the attachment portion is threaded and threadedly attached to the rotor shaft.

3. The turbine of claim 2, wherein the first guide feature and the attachment portion are axially spaced apart at opposite ends of the shank.

4. The turbine of claim 3, wherein the first guide feature is adjacent to the head.

5. The turbine of claim 1, wherein the first guide feature is an annular surface that extends continuously around the axis.

6. The turbine of claim 1, wherein the first guide feature includes a tapered portion located at its end.

7. The turbine of claim 1, wherein the arcuate surface of the shank is orthogonal to the axial direction, and wherein the arcuate inner radial surface is orthogonal to the axial direction.

8. The turbine of claim 1, wherein the rotor shaft includes a projecting end that projects axially from the shoulder; It also includes a thrust disc, which is housed on the protruding end of the rotor shaft; and The head abuts the axial surface of the impeller to clamp the impeller, the collar, and the thrust disc against the shoulder of the rotor shaft.

9. The turbine of claim 1, further comprising an electric motor having a motor rotor fixed to the rotor shaft.

10. An electric compressor device, comprising: shell; A rotating assembly supported for rotation about an axis within the housing, the rotating assembly including a rotor shaft, an impeller, fastening devices, and a collar, the rotor shaft including a shoulder, the collar being accommodated on the rotor shaft, and the impeller being spaced apart from the rotor shaft along the axis; An electric motor that drives the rotating assembly to rotate within the housing about the axis; The fastener device includes a fastener received in a bore of the impeller and a bore of the rotor shaft. The fastener is integral and includes a head and a shank. The shank includes a first guide feature on an arcuate surface, a second guide feature on another arcuate surface, and an attachment portion. The other arcuate surface is radially outward relative to the axis. The shank is received in the bore of the impeller and threadedly attached to the bore of the rotor shaft via the attachment portion. The first guide feature is guided to an arcuate inner radial surface of the impeller, and the second guide feature is guided to another arcuate inner radial surface of the rotor shaft. The head abuts an axial surface of the impeller for axially clamping the impeller to the rotor shaft. The second guide feature is axially spaced from the first guide feature and axially spaced from the attachment portion. The head abuts the axial surface of the impeller to clamp both the impeller and the collar against the shoulder of the rotor shaft.

11. The electric compressor device of claim 10, wherein the impeller is a compressor impeller, and the fastening device is a first fastening device that attaches the compressor impeller to a first end of the rotor shaft; and It also includes a turbine impeller and a second fastener assembly, the second fastener assembly attaching the turbine impeller to a second end of the rotor shaft; The second fastener device includes a second fastener that is received in a first hole of the turbine impeller and a second hole at a second end of the rotor shaft. The second fastener is integral and includes a head and a shank. The shank includes at least one third guide feature that is radially outward relative to the axial direction. The shank is received in the hole of the turbine impeller and threadedly attached to the second hole of the rotor shaft. The third guide feature is guided to an arcuate inner radial surface of the turbine impeller. The head of the second fastener abuts the axial surface of the turbine impeller for axially clamping the turbine impeller to the rotor shaft.

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