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EP-4345325-B1 - DRIVE SHAFT WITH NON-CYLINDRICAL SHAPE AND SPACED REINFORCEMENTS

EP4345325B1EP 4345325 B1EP4345325 B1EP 4345325B1EP-4345325-B1

Inventors

  • GURVICH, MARK R.
  • REED, Brayton
  • Schaefer, Joyel
  • KING, MICHAEL J.

Dates

Publication Date
20260506
Application Date
20230816

Claims (15)

  1. A drive shaft comprising: a drive shaft body extending between axial ends and having an axial cross-sectional shape, which includes a plurality of undulations (32, 52, 62) increasing a drive shaft body diameter through an infinite number of diameters across at least 15% of an axial length between the axial ends, and there being at least one reinforcing belt (65, 72, 82, 92, 102, 96, 204, 210) associated with adjacent ones of said plurality of undulations, wherein said plurality of undulations (32, 52, 62) are provided by a plurality of increased diameter sections which are axially spaced along an axial length of the drive shaft between axial ends, and with smaller diameter intermediate portions, characterised in that said reinforcing belt (65, 72, 82, 92, 102, 96, 204, 210) includes a plurality of reinforcing belts positioned on said intermediate portions, and preferably wherein said plurality of reinforcing belts are also positioned on said plurality of undulations.
  2. The drive shaft as set forth in claim 1, wherein said reinforcing belt (65, 72, 82, 92, 102, 96, 204, 210) includes a plurality of reinforcing belts positioned on said plurality of undulations.
  3. The drive shaft as set forth in any preceding claim, wherein said plurality of undulations (32, 52, 62) extending along a non-zero angle relative to a circumferential direction defined relative to a drive axis of said drive shaft, such that they form a spiral with a spiral smaller diameter intermediate portion.
  4. The drive shaft as set forth in claim 3, wherein said at least one reinforcing belt (65, 72, 82, 92, 102, 96, 204, 210) is positioned on said intermediate portion.
  5. The drive shaft as set forth in claim 4, wherein said at least one reinforcing belt is a plurality of reinforcing belts also positioned on said enlarged undulations.
  6. The drive shaft as set forth in claim 3, wherein said at least one reinforcing belt (65, 72, 82, 92, 102, 96, 204, 210) is a plurality of reinforcing belts positioned on said enlarged undulations.
  7. The drive shaft as set forth in any preceding claim, wherein the undulations extending along a non-zero angle relative to a circumferential direction defined relative to a drive axis of said drive shaft to form portions such that there are distinct and separate portions of said undulations formed along a non-zero angle with intermediate portions
  8. The drive shaft as set forth in claim 7, wherein said at least one reinforcing belt (65, 72, 82, 92, 102, 96, 204, 210) includes a plurality of reinforcing belts positioned on said intermediate portions.
  9. The drive shaft as set forth in claim 8, wherein said plurality of reinforcing belts are also positioned on said plurality of undulation portions.
  10. The drive shaft as set forth in claim 8, wherein said at least one reinforcing belt (65, 72, 82, 92, 102, 96, 204, 210) includes a plurality of reinforcing belts positioned on said plurality of undulation portions.
  11. The drive shaft as set forth in any preceding claim, wherein said at least one reinforcing belt (65, 72, 82, 92, 102, 96, 204, 210) is on an outer periphery of said drive shaft body, and preferably wherein there being an outer drive shaft body wrapped over said at least one reinforcing belt.
  12. The drive shaft as set forth in any preceding claim, wherein said at least one reinforcement belt (65, 72, 82, 92, 102, 96, 204, 210) is on an inner periphery of said drive shaft body.
  13. The drive shaft as set forth in any preceding claim, wherein said drive shaft body and said at least one reinforcement belt (65, 72, 82, 92, 102, 96, 204, 210) are formed of a fiber-reinforced polymer-matrix composite.
  14. A drive shaft comprising: a drive shaft body extending between axial ends and having an axial cross-sectional shape which includes undulations increasing a drive shaft body diameter through an infinite number of diameters across at least 15% of an axial length between the axial ends, and said undulation extending along a non-zero angle relative to a circumferential direction defined relative to a drive axis of said drive shaft, such that the undulations form a spiral with an intermediate smaller diameter spiral portion, and there being at least one reinforcing belt (65, 72, 82, 92, 102, 96, 204, 210) associated with at least one of said undulations and said intermediate portion, wherein there being at least one reinforcing belt (65, 72, 82, 92, 102, 96, 204, 210) including a plurality of reinforcing belts associated with both said undulations and said intermediate portion.
  15. The drive shaft as set forth in claim 14, wherein there are a plurality of spaced undulation portion with intermediate smaller diameter portions that do not extend along a non-zero angle.

Description

BACKGROUND This application relates to drive shafts having non-cylindrical shapes. Drive shafts are known and utilized to connect any number of driven components to transfer loads, and mainly, torsional loads. Among many known typical examples of such applications are drive shafts to transfer torque from an engine of main rotor to a tail rotor in rotorcraft configurations. Historically, drive shafts have had a cylindrical tubular portion with constant cross-section along the shaft length extending between diaphragms at each ends. The diaphragms allow flexibility under bending and axial load, as the drive axes and positions between the drive input and the driven component may vary during service or have some unavoidable misalignments. Drive shafts have also been proposed that have undulations that can enhance bending and axial flexibility, i.e., provide an alternative to the use of relatively expensive diaphragms. DE 629 625 relates to an angular drive between two shafts. US 11 273 610 relates to composite driveshafts. SUMMARY A drive shaft is provided in claim 1 and includes a drive shaft body extending between axial ends and having an axial cross-sectional shape, which includes a plurality of undulations increasing a drive shaft body diameter through an infinite number of diameters across at least 15% of an axial length between the axial ends. There is at least one reinforcing belt associated with adjacent ones of the plurality of undulations. A drive shaft is provided in claim 14 and includes a drive shaft body extending between axial ends and having an axial cross-sectional shape which includes undulations increasing a drive shaft body diameter through an infinite number of diameters across at least 15% of an axial length between the axial ends. The undulations extend along a non-zero angle relative to a circumferential direction defined relative to a drive axis of the drive shaft, such that the undulations form a spiral with an intermediate smaller diameter spiral portion. There is at least one reinforcing belt associated with at least one of the undulations and the intermediate portion. These and other features may be best understood from the following drawings and specification. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1A shows an axial cross-section of a first embodiment having a first type undulation.Figure 1B shows an axial cross-section of a second embodiment having a second type undulation.Figure 1C shows an axial cross-section of a third embodiment having a third type undulation.Figure 2A shows an axial cross-section of the first embodiment having a first option for reinforcing belts.Figure 2B shows an axial cross-section of the first embodiment having a second reinforcement belt option.Figure 2C shows an axial cross-section of the first embodiment having a third reinforcement belt option.Figure 3A shows an axial cross-section of the second embodiment having a first option for reinforcing belts.Figure 3B shows an axial cross-section of the second embodiment having a second reinforcement belt option.Figure 3C shows an axial cross-section of the second embodiment having a third reinforcement belt option.Figure 3D shows an axial cross-section of the second embodiment with a fourth reinforcement belt option.Figure 4A shows an axial cross-section of the third embodiment having a first option for reinforcing belts.Figure 4B shows an axial cross-section of the third embodiment having a second reinforcement belt option.Figure 4C shows an axial cross-section of the third embodiment having a third reinforcement belt option.Figure 5 schematically shows a method of forming a reinforcement belt.Figure 6A shows a fragment of an axial cross-section of a drive shaft wall with a reinforcement belt option.Figure 6B shows a fragment of an axial cross-section of a drive shaft wall with another reinforcement belt option.Figure 6C shows a fragment of an axial cross-section of a drive shaft wall with another reinforcement belt option.Figure 6D shows a fragment of an axial cross-section of a drive shaft wall with another reinforcement belt option.Figure 6E shows a fragment of an axial cross-section of a drive shaft wall with another reinforcement belt option.Figure 7A shows a fragment of an axial cross-section of a drive shaft wall with another reinforcement belt option.Figure 7B shows a fragment of an axial cross-section of a drive shaft wall with another reinforcement belt option.Figure 7C shows a fragment of an axial cross-section of a drive shaft wall with another reinforcement belt option.Figure 7D shows a fragment of an axial cross-section of a drive shaft wall with another reinforcement belt option.Figure 8 show a fragment of an axial cross-section of a drive shaft wall with yet another reinforcement belt option.Figure 9 shows a fiber feature of the reinforcement belts. DETAILED DESCRIPTION A drive assembly 20 is illustrated in Figure 1A as an axial cross-sectional view for connecting a drive input 22 to a compo