Rotor gear mounting assembly for a generator and method

A rotor gear mounting assembly for a generator includes a rotor shaft comprising a first end and a second end. Also included is a magnetic member arrangement operatively coupled to the rotor shaft proximate at least one of the first end and the second end. Further included is a hub portion of the magnetic member arrangement. Yet further included is a rotor gear operatively coupled to the hub portion.

BACKGROUND OF THE INVENTION

The present invention relates to generators, and more particularly to a rotor gear mounting assembly, as well as a method of mounting a rotor gear to a generator.

Electrical generators typically include a rotor shaft that is driven for rotation and which carries a plurality of field coils or permanent magnets. The generator may include a gear train to drive other components, such as a hydraulic pump, for example, which may be employed to cool the generator or other components of a system. The gear train includes a drive gear that is typically press-fit directly onto the rotor shaft. Direct mounting of the drive gear to the rotor shaft dictates that the drive gear includes a diameter at least as large as that of the rotor shaft, thereby posing packaging challenges.

BRIEF DESCRIPTION OF THE INVENTION

According to one embodiment, a rotor gear mounting assembly for a generator includes a rotor shaft comprising a first end and a second end. Also included is a magnetic member arrangement operatively coupled to the rotor shaft proximate at least one of the first end and the second end. Further included is a hub portion of the magnetic member arrangement. Yet further included is a rotor gear operatively coupled to the hub portion.

According to another embodiment, a method of mounting a rotor gear to a generator is provided. The method includes operatively coupling a magnetic member arrangement to an outer surface of a rotor shaft proximate an end of the rotor shaft. The method also includes operatively coupling a rotor gear to a hub portion of the magnetic member arrangement.

DETAILED DESCRIPTION OF THE INVENTION

Referring toFIGS. 1 and 2, selected portions of a generator10are illustrated. The generator10may be a high speed, variable frequency generator for starting a turbine engine and generating electric current when being driven by the turbine engine, for example.

In the illustrated embodiment, the generator10includes a dynamoelectric portion12having a rotor shaft14that is rotatable about a central axis16. A rotor18is mounted on the rotor shaft14to be driven about the central axis16within a stator22(shown in part). The rotor18includes a plurality of magnetic members24, such as field coils or permanent magnets, circumferentially spaced about the rotor18relative to the central axis16. The general arrangement of dynamoelectric machines is known and may vary from that shown in the illustrated examples.

The rotor shaft14includes an end region26having a shaft outer surface28that includes an outer diameter30, also referred to herein as a first diameter. It is to be appreciated that although a single end region is illustrated, the rotor shaft14includes a first end and a second end. It is contemplated that the embodiments described herein may be employed at the first end and/or the second end.

Disposed proximate the end region26is a magnetic member arrangement32that comprises or houses the plurality of magnetic members24described above. The magnetic member arrangement32includes a main portion34and a hub portion36. The main portion34is operatively coupled to the shaft outer surface28of the rotor shaft14proximate the end region26. The operative coupling between the components is typically facilitated by a threaded engagement of the main portion34with the rotor shaft14. To assist a user with locating and positioning of the magnetic member arrangement32during installation or removal of the magnetic member arrangement32, a shaft pilot component38is included. The shaft pilot component38comprises a diameter that corresponds to a magnetic member pilot component40which comprises a matching diameter.

The hub portion36is integrally formed with the main portion34and connected thereto with a connecting wall42that extends radially inwardly from the main portion34to the hub portion36. The hub portion36is disposed axially beyond the end region26of the rotor shaft14and is circular in geometry. The hub portion includes a hub outer surface42that includes an outer diameter44, also referred to herein as a second diameter. As shown, the second diameter, or outer diameter44, is less than the first diameter, or outer diameter30. More particularly, the outer diameter of the hub portion36is smaller than the outer diameter of the rotor shaft14. Such a configuration advantageously permits coupling of a gear of smaller dimensions, which may be beneficial in certain applications.

A rotor gear46is included as part of a gear train for interacting with one or more other gears (not illustrated) to drive additional components. The type and number of gears that may interact with the rotor gear46may vary based on the particular application of use. Additionally, the additional component(s) driven directly or indirectly by the rotor gear46may vary, with one example being a hydraulic pump that includes a pump gear that interacts with the rotor gear46. However, it is to be understood that numerous other components may benefit from mechanical interaction with the rotor gear46.

The rotor gear46is operatively coupled to the hub outer surface42of the hub portion36. The operative coupling between the components is typically facilitated by a threaded engagement of the rotor gear46with the hub portion36. To assist a user with locating and positioning of the rotor gear46during installation or removal of the rotor gear46, a hub pilot component48is included. The hub pilot component48comprises a diameter that corresponds to a rotor gear pilot component50which comprises a matching diameter.

A method of mounting a rotor gear to a generator100is also provided, as illustrated inFIG. 3and with reference toFIGS. 1 and 2. The generator10and components included for mounting of the rotor gear46to the hub portion36have been previously described and specific structural components need not be described in further detail. The method of mounting a rotor gear to a generator100includes operatively coupling102a magnetic member arrangement to an outer surface of a rotor shaft proximate an end of the rotor shaft. The rotor gear is operatively coupled104to a hub portion of the magnetic member arrangement. As described in detail above, the operative coupling of the magnetic member arrangement to the rotor shaft and of the rotor gear to the hub portion is typically facilitated by a threaded engagement between the respective components.