Patent Application
20120251234
This disclosure relates to a connection device for a drive assembly. In one example, the disclosure relates to an input shaft used to couple a gearbox and an auxiliary device, such as a generator.
Gas turbine engines for aircraft typically include a gearbox that rotationally drives one or more auxiliary devices. One such auxiliary device that is commonly driven by a gearbox is a generator. It is desirable to disconnect the generator from the gearbox in the event of a generator failure so that the gearbox is not damaged. One typical disconnect device is a clutch arranged between a journal shaft of the generator and a rotor shaft.
The journal shaft is typically supported relative to the generator housing by one or more bearings. The input shaft is typically rigidly supported by the journal bearing, for example as an integral part, such that when the clutch disconnects the rotor shaft from the journal shaft, the generator bearings still are significantly loaded by the continued rotation of the input shaft by the gearbox. This can lead to premature bearing wear and failure from the lack of lubrication from the generator, which is not rotationally driven.
A connection device includes a first member having first splines. A second member includes a locking feature and is supported relative to the first member. The first splines and the locking feature are circumferentially aligned with one another in an insertion position. A stop is provided between the first and second members to provide a secured position in which the first splines and locking feature are circumferentially misaligned with one another. A fastening element interconnects and retains the first and second members in the secured position.
A drive assembly includes first and second shafts. The second shaft has a bore with internal splines. An input shaft has first and second ends. The first end is coupled to the first shaft in a slip-fit relationship. The second end includes first splines engaging the internal splines. A locking member is supported by the second end. The locking member is moveable between insertion and secured positions. The secured position axially retains the input shaft to the second shaft. The insertion position is configured to permit installation of the second shaft into the bore.
A method of making a connection includes inserting a connection device having first and second members into a splined bore of a shaft. A fastener is tightened to connect the first and second members to one another. The second member rotates relative to the first member in response to the tightening step. A locking feature on the second member is misaligned relative to a locating feature on the shaft in response to the rotating step to axially retain the connection device to the shaft.
The disclosure can be further understood by reference to the following detailed description when considered in connection with the accompanying drawings wherein:
A drive assembly 10 is illustrated in
The generator 16 includes a rotor shaft 28 selectively connected to the journal shaft 36 via a disconnect device, such as a clutch 34. The journal shaft 36 is rotationally supported within a generator housing 32 by a bearing 38. A stator 30 is arranged within the generator housing 32 and generates electrical current in response to the rotational drive imparted to the rotor 28 from the gearbox 12 through an input shaft 40.
The input shaft 40 is shown in more detail in
A locking member 46 includes a protrusion 68 that is received in a corresponding recess 66 in the second end 44. The locking member 46 includes a threaded hole 62. A fastening element 60, such as a bolt with a washer 64, is threadingly received in the threaded hole 62 to secure the locking member 46 to the second end 44. One or more notches 70 (two shown in the example) are provided on the second end 44. Corresponding pins 72 extend from the locking feature 46 and are received in the notches 70.
The locking member 46 includes a locking feature 63 that is provided by splines of a similar configuration to those of the second splines 56, for example. The locking member 46 has an insertion position (
The secured position axially retains the input shaft 40 to the drive shaft 22. Referring to
With continuing reference to
The second end 44 is axially secured to and supported by the drive shaft 22 rather than on the journal shaft 36. As a result, the typically large loads on the bearings 84, 86 following generator disconnect can be significantly reduced.
The drive shaft 22 is hollow such that lubrication within the gearbox 12 is conveyed through this hollow shaft. The connection device can be used also as a plug 92 if desired, as illustrated in
Although an example embodiment has been disclosed, a worker of ordinary skill in this art would recognize that certain modifications would come within the scope of the claims. For that reason, the following claims should be studied to determine their true scope and content.
