Polygonal profile coupling for pump in lubrication assembly

Abstract

The invention relates to a lubrication assembly (1) comprising two pumps (10, 20), the shafts (11, 21) of which are coupled for rotation via at least one polygonal profile coupler (40).

Description

Technical Field

[0001] The invention relates to a rotary coupling between two rotary pumps of a lubrication assembly of an aircraft turbomachine. Background Art

[0002] Pumps in lubrication assemblies of aircraft turbomachines are usually stacked and the shafts of these pumps are coupled for rotation to obtain a rotary drive. One known way to achieve this coupling is to couple via splines.

[0003] Splines are machined by electro-erosion or broaching. These operations are long and complex. Sometimes the splines are so small that they require the use of small, deformed tools, which makes machining almost impossible. Summary of the invention

[0004] One object of the present invention is to obtain a lubrication assembly that is easier to manufacture. To this end, the present invention proposes a lubrication assembly for an aircraft turbine, the lubrication assembly comprising:

[0005] A first pump, the first pump comprising a first shaft;

[0006] a second pump, the second pump comprising a second shaft;

[0007] Characterized in that the first shaft and the second shaft are mechanically coupled via at least one polygonal profile coupling.

[0008] Polygon profile couplings can be machined by milling (concave) or turning (convex). Therefore, polygon profile couplings are easier to manufacture than spline couplings.

[0009] Polygonal profile couplings are known to the person skilled in the art, in particular from parts 1 and 2 of the standard DIN 32711.

[0010] According to one embodiment, the first shaft and the second shaft are coupled for rotation via the at least one polygonal profile coupling.

[0011] According to an embodiment, the second shaft is mechanically coupled to the first shaft by a coupling element comprising a first end forming a male portion of a first polygonal profile coupling and the first shaft comprising a first end forming a female portion of said first polygonal profile coupling.

[0012] According to an embodiment, the convex portion and the concave portion are separated from each other.

[0013] The fact that the convex and concave portions are separated allows the gap between the convex and concave portions to absorb misalignment of the axis.

[0014] According to a preferred embodiment, the present invention relates to a lubrication assembly for an aircraft turbomachine, the lubrication assembly comprising:

[0015] A first pump, the first pump comprising a first shaft;

[0016] a second pump, the second pump comprising a second shaft, the second shaft being mechanically coupled to the first shaft via a coupling element;

[0017] Characterized in that the coupling element comprises a first end forming a male portion of a first polygonal profile coupling, the first shaft comprises a first end forming a female portion of the first polygonal profile coupling, the male portion and the female portion being separated from each other.

[0018] According to an embodiment, the profile of the first end of the coupling element and the profile of the first end of the first shaft satisfy the following equation:

[0019] x(α)=[R m -e·cos(n·α)]·cos(n·α)-n·e·sin(n·α)·sin(α)

[0020] y(α)=[R m -e·cos(n·α)]·sin(n·α)+n·e·sin(n·α)·cos(α)

[0021] Where α is a variable, x and y are Cartesian coordinates, and R m is the first parameter, e is the second parameter, and n is a third integer parameter greater than or equal to 3.

[0022] R for the first end of the coupling element m and e than R for the first end of the first shaft m and e are small, so that the concave portion is wider than the convex portion. n for the first end of the coupling element has the same value as n for the first end of the first shaft.

[0023] According to an embodiment, the male and female parts of the first polygonal profile coupling have three sides. The male and female parts are essentially triangular with rounded corners. Therefore, in the equation, n=3.

[0024] According to an embodiment, the male and female portions of the first polygonal profile coupler are spaced at least 10 μm apart.

[0025] According to an embodiment, the coupling element is integral with the second shaft.

[0026] According to an embodiment, the second shaft comprises a first end connected to the second end of the coupling element.

[0027] According to an embodiment, the coupling element is a different component than the second shaft.

[0028] According to an embodiment, the coupling element comprises a second end forming a male portion of a second polygonal profile coupling and the second shaft comprises a first end forming a female portion of said second polygonal profile coupling, said male portion and said female portion being separate from each other.

[0029] According to an embodiment, the profile of the second end of the coupling element and the profile of the first end of the second shaft satisfy the following equation:

[0030] x(α)=[R m -e·cos(n·α)]·cos(n·α)-n·e·sin(n·α)·sin(α)

[0031] y(α)=[R m -e·cos(n·α)]·sin(n·α)+n·e·sin(n·α)·cos(α)

[0032] Where α is a variable, x and y are Cartesian coordinates, and R m is the first parameter, e is the second parameter, and n is a third integer parameter greater than or equal to 3.

[0033] R for the second end of the coupling element m and e than the R of the first end of the second shaft m n for the second end of the coupling element has the same value as n for the first end of the second shaft.

[0034] According to an embodiment, the male and female parts of the second polygonal profile coupling have three sides.

[0035] According to an embodiment, the male and female portions of the second polygonal profile coupling are spaced at least 10 μm apart.

[0036] According to an embodiment, the first pump and the second pump are vane pumps.

[0037] According to an embodiment, the first pump and the second pump are connecting rod type vane pumps or gerotor pumps.

[0038] According to an embodiment, the lubrication assembly further comprises a third pump comprising a third shaft, the third shaft being mechanically coupled to the second shaft via another coupling element, wherein the other coupling element comprises another first end forming a convex portion of another polygonal profile coupling, the second shaft comprising a second end forming a concave portion of the other polygonal profile coupling, the convex portion and the concave portion of the other polygonal profile coupling being separated from each other.

[0039] The invention also provides an aircraft comprising a lubrication assembly as described herein. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Other features and advantages of the present invention will become apparent from the following detailed description, for understanding of which reference is made to the accompanying drawings, in which:

[0041] - Figure 1 is a schematic diagram of a lubrication assembly according to the present invention,

[0042] - Figure 2 is a schematic diagram of another lubrication assembly according to the present invention,

[0043] - Figure 3 is a cross-sectional view of a polygonal profile connector according to the present invention,

[0044] - Figure 4 is a cross-sectional view of a polygonal profile according to the present invention, and

[0045] - Figure 5 is a cross-sectional view of another polygonal profile according to the present invention. DETAILED DESCRIPTION

[0046] The present invention has been described using specific embodiments and with reference to the accompanying drawings, but the present invention is not limited thereto. The figures or drawings described are only illustrative and not restrictive. In addition, the functions described may be performed by structures other than those described herein.

[0047] In the context of this document, the terms “first” and “second” are only used to distinguish various elements, and do not mean that there is an order between these elements.

[0048] In the drawings, the same or similar elements may have the same reference numbers.

[0049] Figure 1 A lubrication assembly 1 according to an embodiment of the invention is shown. The lubrication assembly comprises a first pump 10 and a second pump 20, the first pump 10 comprising a first shaft 11 and the second pump 20 comprising a second shaft 21. The shafts 11, 21 are mechanically coupled so that one shaft can rotate the other shaft. The coupling is achieved by a coupling element 30, which comprises a first end 31 and a second end 32 opposite the first end 31.

[0050] The first shaft 11 comprises a first end 12. The second shaft 21 comprises a first end 22 and a second end 23. The first end 31 of the coupling element 30 engages in the first end 12 of the first shaft 11. Thus, the first end 31 of the coupling element 30 forms the convex portion 41 of the first polygonal profile coupling 40 (refer to Figure 3 ), the first end 12 of the first shaft 11 forms the concave portion 42 of the first polygonal profile connector 40.

[0051] according to Figure 1 In the embodiment shown, the second end 32 of the coupling element 30 engages in the first end 22 of the second shaft 21. Thus, the second end 32 of the coupling element 30 forms the convex portion 41 of the second polygonal profile coupling 40 (refer to Figure 3 Description), the first end portion 22 of the second shaft 21 forms the concave portion 42 of the second polygonal profile coupling 40.

[0052] exist Figure 2 In the embodiment shown, the second end 32 of the coupling element 30 is joined to the first end 22 of the second shaft 21 , so that the coupling element 30 and the second shaft 21 form a single piece.

[0053] The lubrication assembly 1 may include a third pump, a fourth pump, etc. The pumps are stacked and the shafts of the pumps are coupled for rotation via a polygonal profile coupling 40. For example, the third shaft of the third pump may be mechanically coupled to the second end 23 of the second shaft 22 by another coupling element comprising another first end. The other first end forms the male part of another polygonal profile coupling, and the second end 23 of the second shaft 22 forms the female part of the other polygonal profile coupling.

[0054] The pumps 10 , 20 are preferably vane pumps, such as connecting rod pumps or gerotor pumps.

[0055] Figure 3 4 is an example of a coupling 40 using a polygonal profile between a convex portion 41 and a concave portion 42 that are separated from each other. Figure 3 The connector 40 shown can be the first polygonal profile connector (corresponding to the reference numerals 12 and 31), the second polygonal profile connector and / or other polygonal profile connectors of the present disclosure. The fact that the convex portion 41 and the concave portion 42 are separated means that the convex portion 41 and the concave portion 42 are not attached to each other. In addition, although the convex portion 41 and the concave portion 42 can be in contact when driven, when stationary, there is a space 45 around the convex portion 41, which separates the convex portion 41 from the concave portion 42. The distance 46 between the convex portion 41 and the concave portion 42 can be at least 10 μm, preferably at least 100 μm. The distance 46 is measured in a cross section, for example when the convex portion 41 and the concave portion 42 are aligned on the same axis.

[0056] Figure 4 A triangular polygonal outline with Cartesian coordinates (x, y) and polar coordinates (r, Φ) is shown. Typically, a polygonal outline is defined by the following equation in Cartesian coordinates:

[0057] x(α)=[R m-e·cos(n·α)]·cos(n·α)-n·e·sin(n·α)·sin(α)

[0058] y(α)=[R m -e·cos(n·α)]·sin(n·α)+n·e·sin(n·α)·cos(α)

[0059] In polar coordinates, this equation translates to

[0060]

[0061] α is a variable, R m is the first parameter, e is the second parameter, and n is the third parameter. n is an integer greater than or equal to 3. Figure 4 (Triangular polygon outline) requires n to be 3, Figure 5 (Quadrangular polygonal profile) requires n to be 4. α varies to follow the curve of the polygonal profile. n is the same for the convex portion 41 and the concave portion 42. R of the convex portion 41 is m and e is greater than R of the concave portion 42 m In other words, the concave portion 42 has a wider profile than the convex portion 41.

[0062] In other words, the invention relates to a lubrication assembly 1 comprising two pumps 10 , 20 , the shafts 11 , 21 of which are coupled for rotation via at least one polygonal profile coupling 40 .

[0063] The present invention has been described above in conjunction with specific embodiments, which are illustrative and should not be considered as restrictive. In general, the present invention is not limited to the examples shown and / or described above. The use of the verb "include", "comprise" or any other variant and their variations can never exclude the presence of elements other than those mentioned. The use of the indefinite article "a", "an" or the definite article "the" to introduce elements does not exclude the presence of a plurality of these elements. The reference numerals in the claims do not limit the scope of the claims.

Claims

1. A lubrication assembly (1) for an aircraft turbine, the lubrication assembly comprising: A first pump (10), comprising a first shaft (11); A second pump (20), the second pump comprising a second shaft (21); Characterized in that the first shaft (11) and the second shaft (21) are mechanically coupled via at least one polygonal profile coupling (40).

2. The lubrication assembly according to claim 1, wherein: The first shaft (11) and the second shaft (21) are coupled for rotation via the at least one polygonal profile coupling (40).

3. The lubrication assembly according to claim 1 or 2, wherein: The second shaft (21) is mechanically coupled to the first shaft (11) via a coupling element (30), wherein the coupling element (30) comprises a first end (31) forming a male portion (41) of a first polygonal profile coupling (40), and the first shaft (11) comprises a first end (12) forming a female portion (42) of the first polygonal profile coupling (40).

4. Lubrication assembly according to the preceding claim, wherein: The convex portion (41) and the concave portion (42) are separated from each other.

5. The lubrication assembly according to claim 3 or 4, wherein: The profile of the first end (31) of the coupling element (30) and the profile of the first end (12) of the first shaft (11) satisfy the following equation: x(a)=[R m -e·cos(n·α)]·cos(n·α)-n·e·sin(n·α)·sin(α) y(a)=[R m -e·cos(n·α)]·sin(n·α)+n·e·sin(n·α)·cos(α) Where α is a variable, x and y are Cartesian coordinates, and R m is the first parameter, e is the second parameter, and n is a third integer parameter greater than or equal to 3.

6. The lubrication assembly according to any one of claims 3 to 5, wherein: The male and female portions of the first polygonal profile coupler (40) have three sides.

7. A lubrication assembly according to any one of claims 3 to 6, wherein: The convex and concave portions of the first polygonal profile coupler (40) are spaced at least 10 μm apart.

8. A lubrication assembly according to any one of claims 3 to 7, wherein: The coupling element (30) is integral with the second shaft (21).

9. Lubrication assembly according to the preceding claim, wherein: The second shaft (21) comprises a first end (22) coupled to a second end (32) of the coupling element (30).

10. The lubrication assembly according to any one of claims 3 to 7, wherein: The coupling element (30) is a separate component from the second shaft (21).

11. Lubrication assembly according to the preceding claim, wherein The coupling element (30) comprises a second end (32) forming a male portion (41) of a second polygonal profile coupling (40), and the second shaft (21) comprises a first end (22) forming a female portion (42) of the second polygonal profile coupling (40), the male portion (41) and the female portion (42) being separated from each other.

12. Lubrication assembly according to the preceding claim, wherein The profile of the second end (32) of the coupling element (30) and the profile of the first end (22) of the second shaft (21) satisfy the following equation: x(a)=[R m -e·cos(n·α)]·cos(n·α)-n·e·sin(n·α)·sin(α) y(a)=[R m -e·cos(n·α)]·sin(n·α)+n·e·sin(n·α)·cos(α) Where α is a variable, x and y are Cartesian coordinates, and R m is the first parameter, e is the second parameter, and n is a third integer parameter greater than or equal to 3.

13. A lubrication assembly according to any one of the preceding claims, wherein: The first pump (10) and the second pump (20) are vane pumps. Preferably, the first pump and the second pump are connecting rod vane pumps or cycloid pumps.

14. Lubrication assembly according to any one of the preceding claims, further comprising a third pump, the third pump comprising a third shaft, the third shaft being mechanically coupled to the second shaft (21) by a further coupling element, wherein The other coupling element comprises another first end forming a male part of another polygonal profile coupling, the second shaft (21) comprises a second end (23) forming a female part of the other polygonal profile coupling, the male and female parts of the other polygonal profile coupling being separated from each other.

15. An aircraft comprising a lubrication assembly according to any one of the preceding claims.

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