Key for producing connection against relative rotation

Abstract

The invention relates to a key (10) for producing a rotationally fixed connection between two annular components (2, 3). The key (10) has: a longitudinal extension direction (L); a first engagement section (11) for engaging with the first annular component (2); and a second engagement section (12) for engaging with a second annular component (3). The first engagement section (11) has a flat contact surface (13.1; 13.2) for engaging with the first annular component (2); the second engagement section (12) has a curved contact surface (14) for engaging with the second annular component (3). The invention further relates to an assembly (1) for torque transmission, comprising two ring-shaped components (2, 3) and such a key (10).

Description

Technical Field

[0001] This invention relates to a key for establishing a connection between two annular members that resists relative rotation. Furthermore, this invention relates to an assembly for torque transmission having two annular members and such a key. Background Technology

[0002] Wind turbines include a rotor, which is typically mechanically connected to a generator via a transmission assembly. Within the transmission assembly, different concentrically arranged annular members are connected to each other by means of a key to resist relative rotation for torque transmission. With conventional keys, the high loads present in wind turbines often result in unacceptably high loads in the annular members or the key itself. Therefore, the object of this invention is to provide a key for establishing a rotation-resistant connection between two annular members, which optimizes the load characteristics in both the annular members and the key. Summary of the Invention

[0003] This objective is achieved by the key claimed in claim 1 for establishing a connection between two annular members that resists relative rotation. These annular members may be integrally annular in shape. The annular members may be arranged concentrically with each other. For example, a first annular member is radially disposed within a second annular member. The annular members may be designed for use in wind turbines (e.g., transmission assemblies of wind turbines). The transmission assemblies may be disposed in the torque transmission path between the rotor and generator of a wind turbine. The annular members may each have a diameter of several meters. One of these annular members may be a bearing ring of a bearing in the transmission assembly of a wind turbine. This bearing may be, for example, a spherical roller bearing. The second annular member may be a hollow shaft, which may be designed as a flange. These two annular members and the key may together constitute an assembly for torque transmission. This assembly may have a circumferential direction that extends circumferentially along the annular members. Furthermore, the assembly may have a radial direction that extends radially along the annular members. Additionally, the assembly may have an axial direction that extends axially along the annular members. The key can have a generally elongated shape, in which the extension direction, i.e. the main extension direction, is greater than the length of the key in the spatial direction perpendicular to the main extension direction.

[0004] The key of the present invention has a longitudinal extending direction. If the key is installed as intended to establish a connection between annular members that resists relative rotation, the longitudinal extending direction of the key may be arranged parallel to the radial direction or have at least one component arranged parallel to the aforementioned radial direction. The longitudinal extending direction of the key may be its primary extending direction. Furthermore, the key has: a first engagement section for engaging with a first annular member; and a second engagement section arranged along the longitudinal extending direction after the first engagement section for engaging with a second annular member. The engagement sections of the key and the annular members can mate with each other such that the key can be connected to the annular members via a clearance fit or an interference fit through its respective engagement section. Here, the key may be formed in one piece from a single material (e.g., ferritic material or other materials), wherein a first region of the key may form the first engagement section, and another region of the key may form the second engagement section. In an alternative embodiment, the key is formed from multiple components, which may be made of different materials. These multiple components may be securely connected to each other, for example, by material locking, form locking, and / or friction locking. The bond can be heat-treated and / or surface-treated, such as nitriding, to increase wear resistance.

[0005] The first engagement section of the key has a flat contact surface for engaging with the first annular member. In one embodiment, the first engagement section has two flat contact surfaces arranged parallel to each other, which may each have a rectangular shape, for example. On the other hand, the second engagement section has a curved contact surface for engaging with the second annular member. Here, the flat and curved contact surfaces of the first and second engagement sections can be designed such that the second engagement section allows the key to rotate relative to the second annular member about a rotation axis extending in the longitudinal direction of the key. On the other hand, the first engagement section with the flat contact surface can prevent such rotation of the key relative to the first annular member. Thus, the key can be designed such that it is self-aligning under load. In this way, relative movement between the first and second annular members can be achieved, and local elastic and plastic deformations are reduced. As a result, a key for establishing a connection between two annular members that resists relative rotation can be provided, which improves the load characteristics of the key and the annular members under load.

[0006] In one embodiment, the first interlocking section is designed as a cuboid to form two parallel, flat contact surfaces. Besides the two parallel, flat contact surfaces that form the sides of the cuboid, the cuboid interlocking section can have other parallel and flat bottom and top surfaces. On the other hand, the end faces of the cuboid—which, in addition to the flat contact surfaces, can also be arranged between the bottom and top surfaces—can be formed in a rounded manner. Therefore, the first interlocking section can have a cuboid shape with rounded end faces. In an alternative embodiment, the first interlocking section has only one flat contact surface, while all other contact surfaces of the first interlocking section can be formed curvedly. Alternatively, the second interlocking section can be designed as a column to form curved contact surfaces. Thus, for example, the peripheral side of the column section can form the curved contact surface. In addition to the peripheral side, the column section can also have a bottom and a top surface, wherein the top surface of the column section can coincide with the bottom surface of the cuboid section. If the key is installed as specified to establish a rotation-resistant connection between the two annular members, the two parallel, flat contact surfaces of the first interlocking section can be arranged parallel to the aforementioned axial direction of the annular members. This design allows for the provision of a key with a self-aligning design in a particularly simple manner.

[0007] In one embodiment, the first interlocking segment has a total contact area for interlocking with the first annular member, which is smaller than the total contact area of ​​the second interlocking segment for interlocking with the second annular member. The total contact area can be the area of ​​either the first or second interlocking segment that remains in contact with the first or second annular member during specified operation to transmit force. For example, it can be the entire surface of the first or second interlocking segment. Similarly, it can be all or part of the circumferential surface of the first or second annular segment, excluding the bottom and top surfaces of each segment from the total contact area. Because the total contact area of ​​the first interlocking segment is designed to be smaller than that of the second interlocking segment, the force applied to the annular member by the key during specified operation is distributed over a larger area in the second interlocking segment than in the first interlocking segment. As a result, this generates less stress in the second annular member than in the first annular member. The key thus formed, especially when the first annular member is designed to be more robust than the second annular member, for example, with a higher yield strength, can provide optimized load characteristics in the annular member.

[0008] In one embodiment, the second interlocking section has unloading grooves for adjusting the stiffness of the key. The unloading grooves may run along the circumferential direction of the key, for example, along the circumferential direction of a cylindrical section of the key, extending in part or throughout the circumference of the key. The unloading grooves may have angular cross-sections, such as square or rectangular cross-sections, and alternatively or additionally, circular, such as semi-circular cross-sections. Combinations of such cross-sectional shapes are also possible. The key may have one, two, three, or more unloading grooves, which may be partially arranged in the first interlocking section in addition to the second interlocking section. By providing unloading grooves, the local stiffness of the key can be reduced, thereby optimizing, for example, reducing overall and alternatively or additionally homogenizing, the loads occurring in the annular member and the key under load.

[0009] In one embodiment, the key has an undercut in the transition region from the first interlocking section to the second interlocking section. For example, this undercut is formed in the transition region from the flat contact surface of the first interlocking section to the curved contact surface of the cylindrical interlocking section. Here, the transition from the first interlocking section to the undercut and from the undercut to the second interlocking section can be formed continuously, for example, continuously and differentially. By providing the undercut and the continuous, for example, rounded transition from the first interlocking section to the second interlocking section, the stress distribution in the transition region, for example, the transition region from the flat contact surface to the curved contact surface, can be improved, for example, by reducing or homogenizing the overall stress distribution.

[0010] In one embodiment, the second interlocking section has a bulge extending in the longitudinal direction. Along the longitudinal direction of the key, the bulge may initially increase in the second interlocking section from one end toward the first interlocking section, and then decrease again toward the opposite end. The bulge may be designed to be symmetrical, such that its maximum value is approximately centered in the second interlocking section along the longitudinal direction. In terms of cross-section, the bulge may form a substantially parabolic or sinusoidal profile. The bulge may extend circumferentially over the entire circumference of the second interlocking section and alternatively or additionally only over a segment of the circumference of the second interlocking section. The bulge may impart convexity to the second interlocking section (e.g., a curved contact surface) extending in the longitudinal direction. By providing the bulge, the load distribution in the key and in the hole of the second annular member in which the key is received can be optimized, for example, by reducing the overall load distribution and alternatively or additionally homogenizing it. In one embodiment, the bulge may also be omitted to reduce cost.

[0011] In one embodiment, the flat contact surface of the first interlocking section may have a ridge. This ridge may run transversely to the longitudinal extension direction of the key. If the key is installed as specified, the ridge may, for example, run parallel to the axial direction of the annular member. The ridge may be designed to be symmetrical, rising initially from one end of the flat contact surface and then lowering again towards the other end. The maximum ridge may be formed approximately in the middle of the contact surface. In cross-section, the ridge may have a parabolic or alternatively sinusoidal profile. The ridge may impart a convexity to the flat contact surface transverse to the longitudinal extension direction. If the first interlocking section has the aforementioned two flat contact surfaces arranged parallel to each other, each contact surface may have this ridge. By providing this ridge on the flat contact surface, the stress distribution in the key and in the groove of the first interlocking section of the first annular member in which the key is received can be improved, for example, by reducing the overall stress distribution and alternatively or additionally homogenizing it. In one embodiment, the ridge may also be omitted to reduce cost.

[0012] The present invention also relates to a torque transmission assembly according to one of the above embodiments, having two annular members and a key. A first engaging section of the key can engage with a first annular member, and a second engaging section of the key can engage with a second annular member for transmitting torque between the annular members. The first annular member may have a rectangular groove for receiving the first engaging section, and the second annular member may have a circular hole for receiving the second engaging section. Here, the first annular member may have higher strength than the second annular member. Regarding the design, advantages, and benefits of the various components and members, reference is made to the above statements in conjunction with the key used to establish a connection resistant to relative rotation between the two annular members. Attached Figure Description

[0013] Figure 1 The schematic diagram illustrates a component for torque transmission according to an embodiment of the present invention.

[0014] Figure 2 The illustration schematically shows an embodiment of the invention from Figure 1 The key to the components used for torque transmission in the system.

[0015] Figures 3A and 3B schematically illustrate the situation from... Figure 1 The connection between the ring-shaped component and the key in the component.

[0016] Figure 4 It shows the passage from Figure 1 A schematic cross-sectional view of the annular component and key in the structure. Detailed Implementation

[0017] Figure 1A torque transmission assembly 1 according to an embodiment of the present invention is shown. In this embodiment, assembly 1 is a torque transmission assembly for a wind turbine. In this embodiment, assembly 1 is disposed in a transmission mechanism assembly arranged in the torque transmission path between the wind turbine rotor and the generator. Assembly 1 is designed for torque transmission between first and second annular members 2, 3. Assembly 1 has a bearing 4, which in this embodiment is designed as a spherical roller bearing. The spherical roller bearing 4 includes an inner ring 5 and an outer ring 2, which are arranged concentrically with each other and are supported by rollers 6 in a manner that allows them to rotate relative to each other. In this embodiment, the spherical roller bearing 4 has two rows of rollers between the inner ring 5 and the outer ring 2. Each roller 6 is arranged sequentially between the inner ring 5 and the outer ring 2 along the circumferential direction U of assembly 1. These roller rows are also arranged sequentially along the axial direction A of assembly 1. Along the radial direction R of component 1, the inner ring 5 is positioned in front of the rollers 6, which are radially arranged inside the outer ring 2.

[0018] In this embodiment, the outer ring 2 of the bearing 4 forms a first annular member 2. Here, the outer ring 2 is formed by three components arranged sequentially and connected to each other along the axial direction A. A first annular member 2.1 is located in the middle, having a substantially constant diameter. Along the axial direction A, another component 2.2 or 2.3 is arranged before and after component 2.1, respectively, wherein the diameter decreases linearly along the axial direction A from the end adjacent to the middle component 2.1 toward the end furthest away. Thus, each of the components 2.2 and 2.3 of the outer ring 2 forms an inclined support surface for one row of rollers in the bearing 4. Here, the two inclined support surfaces of the outer ring 2 are opposite each other. In addition to the inclined support surfaces of the outer ring 2, the rollers 6 of these roller rows are supported on the inner ring 5 of the bearing 4 by correspondingly formed support surfaces.

[0019] Furthermore, component 1 includes a second annular member 3, which, in the present case, is positioned as a hollow shaft in the torque transmission path between the wind turbine rotor and the generator. In the present case, the second annular member 3 is designed as an intermediate flange for fastening another component of the aforementioned transmission mechanism assembly. In this embodiment, the first and second annular members 2 and 3 have different strengths. Thus, in this embodiment, the first annular member, i.e., the outer ring 2 of the bearing 4, is formed of a strong material, currently bearing steel. On the other hand, in the present case, the second annular member 3 is formed of a material with lower mechanical strength, having a lower yield strength than the material of the first annular member 2. In the present case, the second annular member 3 is a casting made of cast iron. In the present case, the first annular member 2 has a yield strength that is, for example, two, three, four, or five times that of the yield strength of the second annular member 3.

[0020] Furthermore, component 1 includes a plurality of keys 10 for establishing a rotation-resistant connection between the first annular member 2 (i.e., the outer ring 2 of the bearing 4) and the second annular member 3 arranged radially outward relative to it. In this embodiment, component 1 includes two keys 10, wherein the first key 10 is disposed between part 2.2 of the outer ring 2 and the hollow shaft 3, and the second key 10 is disposed between part 2.3 of the outer ring 2 and the hollow shaft 3. Within the scope of this embodiment, component 1 includes only these two keys, and there are no other keys 10 between the annular members 2 and 3. These keys 10 are designed to be identical to each other and can be arranged at any circumferential position of component 1. The design of the keys 10 is described below.

[0021] As from Figure 2 As can be seen, key 10 has a longitudinal extension direction L, a first engagement section 11, and a second engagement section 12. The longitudinal extension direction L is the main extension direction of key 10. The first engagement section 11 is designed to engage with the first annular member 2, i.e., the outer ring 2 of bearing 4 in the present case. The second engagement section 12 is designed to engage with the second annular member 3, i.e., the flange 3 in the present case. (As seen from...) Figure 2As can be seen, in this embodiment, the first interlocking section 11 is designed as a substantially cuboid and has two parallel, flat contact surfaces 13.1 and 13.2 for interlocking with the first annular member 2. Here, the opposing end faces 13.3 and 13.4 of the first interlocking section 11 are designed as arcs. Therefore, the first interlocking section 11 has an overall cuboid shape with rounded end faces. Following the first interlocking section 11 along the longitudinal extension direction L of the key 10, a second interlocking section 12 is provided. In this embodiment, the second interlocking section has an overall cylindrical shape and a curved contact surface 14 for interlocking with the second annular member 3. More precisely, the cylindrical interlocking section 12 has a circular cross-section and forms a curved peripheral surface 14 for interlocking with the second annular member 3 as a contact surface. Here, the second interlocking section 12 has a length along the longitudinal extension direction L, which is two, three, four, or five times the length of the first interlocking section 11 along the longitudinal extension direction L.

[0022] In this embodiment, the key 10 is formed from a single piece of material. For this purpose, a cylindrical bar is used as the starting component, which is shortened to the key length, i.e., the sum of the lengths of the first and second interlocking segments 11, 12 along the longitudinal extension direction L. For example, the bar already has a diameter corresponding to the nominal diameter of the cylindrical interlocking segment 12. The component is then milled to mill two parallel contact surfaces 13.1 and 13.2 in the cylindrical starting component and to form the first interlocking segment 11. Further optimizations can then be introduced into the geometry of the key 10, which are referred to below. Figure 2 and Figure 4 To describe.

[0023] As shown in Figure 3A, the second annular member 3 has a circular hole 7 for receiving the second engagement section 12 of the key 10. In this embodiment, the hole 7 is designed to receive the entire second engagement section 12 of the respective key 10, while the first engagement sections 11 of the key 10 extend from the circular hole 7. Rectangular grooves 8 are formed in the first annular member 2, more precisely, in components 2.2 and 2.3 of the outer ring 2 of the bearing 4, for receiving the first engagement sections 11 of the respective key 10. Here, these grooves 8 are oriented along the axial direction A of the assembly 1, and thereby perpendicular to the radial direction R and the circumferential direction U of the assembly. The parallel flat contact surfaces 13.1 and 13.2 of the first engagement sections 11 engage with the parallel side surfaces of the respective grooves 8. Here, these grooves 8 are designed such that the contact surfaces 13.1 and 13.2, the end faces 13.3 and 13.4, and thus the entire first mating section 11, are completely accommodated in their respective grooves 8. Here, the circular hole 7 of the second annular member 3, the rectangular groove 8 of the first annular member 2, and the key 10 mate with each other such that the longitudinal extension direction L of the key 10 is aligned parallel to the radial direction R of the assembly 1 in the prescribed installed state. Furthermore, these members mate with each other such that the key 10 is connected to the first annular member 2 and the second annular member 3 by means of a clearance fit or an interference fit, respectively.

[0024] Figure 4 A schematic cross-sectional view through component 1 is shown, in which the first and second annular members 2 and 3, and key 10 are visible. Furthermore, in... Figure 4As can be seen, the key 10 has a first engagement section 11, which is arranged in a rectangular groove 8 of the first annular member 2; and a second engagement section 12, which is arranged in a circular hole 7 of the second annular member 3. In addition to the design already described, the key 10 in this embodiment has modifications for optimizing strength, as disclosed below. In the transition region from the first engagement section 11 to the second engagement section 12, more precisely, in the transition from the parallel, flat contact surfaces 13.1 and 13.2 to the cylindrical peripheral surface 14, undercuts 15.1 and 15.2 are formed, respectively. Here, undercuts 15.1 and 15.2 are respectively rounded to form a continuous, currently continuously differentiable transition from the first engagement section 11 with flat contact surfaces 13.1 and 13.2 to the second engagement section 12 with the cylindrical peripheral surface 14. Furthermore, the second interlocking section 12, in its current form, approximately halfway along its longitudinal extension direction L, has an unloading groove 16, which in this embodiment has a semi-circular cross-section. In this embodiment, the unloading groove 16 is designed to be circumferential and thus extends along the entire circumferential side surface 14 of the key 10 in the circumferential direction. The unloading groove 16 adjusts the local stiffness of the key 10 and thereby optimizes the load in the key 10 under load.

[0025] Furthermore, in this embodiment, the second interlocking section 12 has a bulge (not shown in these figures) formed along the longitudinal extension direction L of the key 10. This bulge is designed such that it extends over the entire circumferential direction 14 of the second interlocking section 12. The bulge is formed symmetrically with respect to the second interlocking section 12 along the longitudinal extension direction L, and therefore, the maximum value of the bulge along the longitudinal extension direction L is approximately located midway between the beginning and end of the second interlocking section 12. This imparts a convexity to the circumferential surface 14 of the column interlocking section 12 along the longitudinal extension direction L. Furthermore, the parallel flat contact surfaces 13.1 and 13.2 of the first interlocking section 11 also have bulges that are transverse to the longitudinal extension direction L and extend along the axial direction A of the assembly 1 in the installed state of the key 10. Consequently, the parallel flat contact surfaces 13.1 and 13.2 of the first interlocking section 13 also each have a convexity that faces the direction of the groove 8 of the first annular member 2. The bulge is also designed to be symmetrical, and thus its maximum value along the axial direction A is approximately located midway between the beginning and end of the respective contact surfaces 13.1 and 13.2. The bulge, and the accompanying convexity of the flat contact surfaces 13.1 and 13.2 and the curved contact surface 14, optimizes the stress distribution in the key 10, the circular hole 7, and the rectangular groove 8.

[0026] As can be seen from these figures, the annular members 2 and 3 and the key 10 are also designed such that the total contact area between the first interlocking section 11 and the first annular member 2—in the present case, the sum of contact surfaces 13.1 and 13.2—is smaller than the total contact area between the second interlocking section 12 and the second annular member 3 (in the present case, the circumferential surface 14). Because the total contact area between the second interlocking section 12 and the second annular member 3 is larger, the stress introduced by the key 10 into the second annular member 3 is much less than the stress introduced into the first annular member 2. The resulting advantage is that the load generated by the key 10 in the second annular member 3 is less than the load generated in the first annular member 2. Since the second annular member 3, as described above, has a lower yield strength than the first annular member 2, this provides a torque transmission assembly 1 with load characteristics optimized for the respective components.

[0027] List of reference numerals

[0028] 1 Components for torque transmission

[0029] 2. First annular component, outer ring

[0030] Components of the first annular member (2.1, 2.2, 2.3)

[0031] 3 Second ring component

[0032] 4 bearings

[0033] 5 Inner Circle

[0034] 6 rollers

[0035] 7. Circular holes

[0036] 8 Rectangular grooves

[0037] 10 keys

[0038] 11 First Interlocking Section

[0039] 12 Second Interlocking Section

[0040] 13.1, 13.2 Flat contact surfaces

[0041] 13.3, 13.4 Circular end faces

[0042] 14. Circumferential surface of the column

[0043] 15.1, 15.2 Undercut

[0044] 16 Unloading trench

[0045] L longitudinal extension direction

[0046] Axial direction

[0047] R radial direction

[0048] U circumferential direction

Claims

1. A key (10) for establishing a connection resisting relative rotation between two annular members (2, 3), wherein, The key (10) has: a longitudinal extending direction (L); a first engagement section (11) for engaging with the first annular member (2); and a second engagement section (12) arranged along the longitudinal extending direction (L) after the first engagement section for engaging with the second annular member (3), wherein the first engagement section (11) has a flat contact surface (13.1; 13.2) for engaging with the first annular member (2); and the second engagement section (12) has a curved contact surface (14) for engaging with the second annular member (3).

2. The key (10) according to claim 1, characterized in that, The first interlocking section (11) is designed as a cuboid to form two parallel flat contact surfaces (13.1, 13.2), and the second interlocking section (12) is designed as a column to form the curved contact surface (14).

3. The key (10) according to any one of the preceding claims, characterized in that, The first interlocking section (11) has a total contact area for interlocking with the first annular member (2), and the total contact area of ​​the first interlocking section is smaller than the total contact area of ​​the second interlocking section (12) for interlocking with the second annular member (3).

4. The key (10) according to any one of the preceding claims, characterized in that, The second interlocking section (12) has an unloading groove (16) for adjusting the stiffness of the key (10).

5. The key (10) according to any one of the preceding claims, characterized in that, The key (10) has an undercut (15.1; 15.2) in the transition region from the first interlocking segment (11) to the second interlocking segment (12).

6. The key (10) according to any one of the preceding claims, characterized in that, The second interlocking section (12) has a bulge extending in the longitudinal direction (L), which gives the curved contact surface (14) a convexity extending in the longitudinal direction (L).

7. The key (10) according to any one of the preceding claims, characterized in that, The flat contact surface (13.1; 13.2) of the first interlocking section (11) has a bulge that runs transversely to the longitudinal extension direction (L), the bulge giving the flat contact surface (13.1; 13.2) a convexity that runs transversely to the longitudinal extension direction (L).

8. An assembly (1) for torque transmission, having two annular members (2, 3) and a key (10) according to any one of the preceding claims, wherein, The first engagement section (11) of the key (10) engages with the first annular member (2) and the second engagement section (12) of the key (10) engages with the second annular member (3) for transmitting torque between the annular members (2, 3).

9. The component (1) according to claim 8, characterized in that, The first annular member (2) has a rectangular groove (8) for receiving the first interlocking section (11), and the second annular member (3) has a circular hole (7) for receiving the second interlocking section (12).

10. The component (1) according to claim 8 or 9, characterized in that, The first annular member (2) has higher strength than the second annular member (3).

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