Gear wheel and planetary transmission comprising same

Abstract

The invention relates to a transmission, in particular a planetary transmission, comprising a sun gear and a wind turbine with a rotatably arranged nacelle, wherein the toothing of the sun gear has an interruption in such a way that a first toothing region of the toothing is spaced apart from a second toothing region of the toothing in the axial direction, wherein a defined break point is arranged between the first toothing region and the second toothing region in the axial direction.

Description

[0001] GEAR AND PLANETARY GEAR WITH THIS

[0002] Description:

[0003] The invention relates to a transmission, in particular a planetary transmission, with a sun gear and a wind turbine with a rotatably arranged nacelle.

[0004] It is generally known that a planetary gear train has a sun gear that meshes with planetary gears that mesh with a ring gear.

[0005] From DE 10 2017 107 892 A1, a locking device is known as the closest prior art.

[0006] A wind turbine is known from AT 512 436 A1.

[0007] The invention is therefore based on the object of efficiently operating a device driven by a planetary gear, in particular a wind turbine.

[0008] According to the invention, the object is achieved in the transmission according to the features specified in claim 1 and in the wind turbine according to the features specified in claim 15.

[0009] Important features of the invention in the transmission, in particular planetary transmission, with a sun gear, in particular with a rotatably arranged sun gear, are that the toothing of the sun gear has an interruption such that a first toothing region of the toothing is spaced apart from a second toothing region of the toothing in the axial direction, wherein a predetermined breaking point is arranged in the axial direction between the first toothing region and the second toothing region, in particular wherein the axial direction is aligned parallel to the axis of rotation of the sun gear. The advantage here is that the device with the transmission can be operated efficiently. In the event of an overload, the first sun gear is destroyed and thus the part of the device driven by the transmission is protected from overload. For example, this is a large and therefore very expensive ring gear.For repairs, only the first sun gear of the gearbox, i.e., the smallest sun gear in the gearbox, needs to be replaced. The downstream gear stages and the ring gear can then continue to be used. Especially in wind turbines, where the ring gear is complex to install and thus incurs high costs not only for manufacturing but also for assembly, repairing or replacing the first sun gear of a multi-stage gearbox is cost-effective and thus ensures efficient operation of the entire system throughout its service life, including repairs.

[0010] In an advantageous embodiment, the predetermined breaking point is designed as a constriction, with the smallest outer diameter of the predetermined breaking point being smaller than the root diameter of the gearing. The advantage here is that the predetermined breaking point can be easily manufactured as a constriction.

[0011] In an advantageous embodiment, the predetermined breaking point is formed as a section of a rotating body whose axis of rotational symmetry is aligned coaxially with the axis of rotation of the sun gear, wherein the curve generating the rotating body is a semicircle or a semi-ellipse. The advantage here is that with a generating curve with a semicircle, production is very simple and with a generating curve with a semi-ellipse the predetermined breaking point can be designed more precisely than with a design with a semicircle. In any case, however, the predetermined breaking point is concave. The axial position of the point of the predetermined breaking point which has the smallest outer diameter is preferably arranged axially centrally, so that starting from this point the outer diameter increases in both axial directions. With a design with a semi-ellipse, no or only a few fragments are generated in the event of an overload.In an advantageous embodiment, the rotating body is concavely shaped and / or the outer diameter of the rotating body section increases strictly monotonically with increasing axial distance from the narrowest point of the rotating body, i.e., the axial position at which the rotating body has the smallest outer diameter. It is advantageous that the predetermined breaking point breaks essentially axially centrally.

[0012] In an advantageous embodiment, the gearing is designed as a straight gear. This is advantageous because it enables simple and cost-effective production.

[0013] In an advantageous embodiment, a shaft is connected to the sun gear in a rotationally fixed manner, with the gearing meshing with an internal gearing of the shaft. This is advantageous because the sun gear also functions as a gear coupling component. While the shaft is connected to the first sun gear in a rotationally fixed manner, compensation is achieved if the rotational axes of the shaft and the first sun gear are not aligned.

[0014] In an advantageous embodiment, the shaft has an internally toothed blind hole into which the sun gear teeth are partially inserted. This provides an easy-to-establish connection.

[0015] In an advantageous embodiment, the sun gear has a collar on its side axially remote from the shaft, in particular a cylindrical section whose outer diameter is smaller than the root circle diameter of the toothing and larger than the smallest outer diameter of the predetermined breaking point, in particular wherein the collar is axially spaced from the predetermined breaking point. It is advantageous in this case that the toothing is spaced from the thrust washer and is thus protected. In addition, the end face of the first sun gear can be designed as a flat surface, so that the radially directed recesses machined into the thrust washer form channels through which oil that has axially passed through the thrust washer can be guided.

[0016] In an advantageous embodiment, the first sun gear is a solid part, in particular, the first sun gear is not a hollow part. This is advantageous because no oil can flow through the first sun gear in the axial direction, thus forcing a radial outflow. The oil thus flows through the hollow second sun gear and then the thrust washer, where it is then redirected in the radial direction and flows out. This not only improves lubrication but also spreads out waste heat, thus reducing peak temperatures in the transmission and improving heat dissipation to the environment.

[0017] In an advantageous embodiment, the material of the first sun gear is formed without gaps and / or continuously and / or uniformly in the area covered by the predetermined breaking point in the axial direction and / or in the area arranged in the axial direction between the first gearing area and the second gearing area, radially within the smallest outer diameter of the predetermined breaking point. This provides the advantage of a well-defined point for the overload and of the fact that, thanks to the corresponding semi-elliptical design, the number of fragments is negligible or even zero.

[0018] For this purpose, the semi-ellipse has a major semi-axis, in particular the main axis, which is at least twice the length of the minor semi-axis, in particular the minor axis.

[0019] In an advantageous embodiment, the first sun gear meshes with planetary gears which mesh with an internally toothed ring gear, wherein the planetary gears are rotatably mounted on a planet carrier which has an internally toothed bore into which the teeth of a second sun gear are partially inserted. The advantage here is that a high gear ratio can be achieved in a small space. In an advantageous embodiment, the second sun gear has an axially continuous recess, in particular one located centrally. The advantage here is that material can be saved, the dynamics of the transmission are increased, the moment of inertia is reduced, and lubrication and cooling are improved due to the oil flowing through axially. However, in contrast to the second sun gear, the first sun gear is not hollow, but designed as a solid part. This is the only way to achieve a well-defined predetermined breaking point.This means that oil cannot flow through the first sun gear and the heat dissipation must be achieved by the oil surrounding the second toothing area and the oil flowing through the predetermined breaking point designed as a constriction.

[0020] In an advantageous embodiment, the second sun gear is hollow. This has the advantage of saving material, increasing the dynamics of the transmission, reducing the moment of inertia, and improving lubrication and cooling due to the axially flowing oil. However, unlike the second sun gear, the first sun gear is not hollow, but rather constructed as a solid component. This is the only way to achieve a well-defined predetermined breaking point. Therefore, oil cannot flow through the first sun gear, and heat must be dissipated by the oil surrounding the second gearing area and the oil flowing through the predetermined breaking point, which is designed as a constriction.

[0021] In an advantageous embodiment, a thrust washer is accommodated in the first planetary carrier, which axially limits the first sun gear, in particular the collar of the first sun gear. Advantageously, the thrust washer is made of a hardened material, thus reducing friction. Furthermore, the radially directed channels are traversed by oil, which is also pumped by centrifugal force and forms a hydrodynamic cushion for the first sun gear. Thus, the axial limitation is achieved with minimal effort and friction despite the different speeds.

[0022] In an advantageous embodiment, the thrust washer is held in the first planet carrier by force, in particular by means of a snap ring. This provides the advantage of a simple and cost-effective fastening method.

[0023] In an advantageous embodiment, the first planet carrier has an axially continuous stepped bore, wherein the thrust washer bears against a first step of the stepped bore, in particular wherein a bearing of a first planet bears against a second step of the stepped bore. This is advantageous in that a secure fastening of the thrust washer can be achieved. In addition, the first sun gear bears against the thrust washer on the side of the thrust washer facing away from the first step. The thrust washer is thus pressed against the first step and is thus securely held. This is advantageous in that efficient operation can be achieved because the first sun gear is kept at a distance from the second sun gear, i.e. the central gear of the second planetary gear stage, by a thrust washer which has a greater hardness than the end face of the second sun gear.The material of the thrust washer is therefore of different hardness compared to the material of the second sun gear, in particular which is made of the same material as the first sun gear.

[0024] In an advantageous design, the thrust washer is made of steel and nitrided. This is advantageous because it allows for simple manufacturing and low friction values.

[0025] In an advantageous design, the thrust washer has a centrally located, axially continuous hole. This is advantageous because lubricating oil passes through the hole, thus without the influence of centrifugal force. Because the radial clearance disappears, the centrifugal force also disappears.

[0026] In an advantageous embodiment, one or more depressions are formed on the side of the thrust washer facing the first sun gear, each extending from the centrally arranged, axially through hole to the radially outer edge of the thrust washer, in particular such that a channel is formed which is delimited by the thrust washer and the first sun gear, in particular wherein the depressions and / or channels are regularly spaced from one another in the circumferential direction. The advantage here is that lubricating oil passes through the hole and can then be conveyed radially. In this way, the planets, which are arranged at a non-negligible radial distance, can be easily lubricated, in particular their needle bearings; this is because the planets are mounted by means of needle bearings which are pushed onto bolts of the planet carrier.

[0027] In an advantageous design, the channel cross-section initially increases and then decreases with increasing radial distance. The advantage here is that the channel cross-section, which increases with increasing radial distance up to a maximum value, creates a buffer volume that allows for continuous outflow at an even greater radial distance, even with inconsistent filling with lubricating oil, since the channel cross-section decreases again from the maximum value as the radial distance continues to increase. The channel then opens at this largest radial distance to the planets, particularly their bearings.

[0028] In an advantageous embodiment, the transmission has more than two planetary gear stages arranged in series. This is advantageous because a high gear ratio can be achieved.

[0029] Important features of the wind turbine with a rotatably arranged nacelle in which a generator is arranged are that the wind turbine has a gearbox driven by an electric motor according to one of the preceding claims, the output shaft of which is connected in a rotationally fixed manner to a pinion which is in engagement with a gear ring, in particular wherein the toothing of the pinion is in engagement with the external toothing of a gear ring, in particular wherein the rotational position of the gear ring is and / or determines the rotational position of the nacelle, in particular wherein the gearbox is connected to the nacelle and the rotational position of the nacelle, in particular relative to the gear ring, is controllable by the rotational position of the gear ring relative to the gearbox.

[0030] The advantage here is that the first sun gear is destroyed in the event of overload. This protects the ring gear and prevents it from being destroyed by overload. A costly replacement of the ring gear is thus avoidable. Further advantages arise from the subclaims. The invention is not limited to the combination of features of the claims. Those skilled in the art will recognize further possible combinations of claims and / or individual claim features and / or features of the description and / or the figures, in particular from the problem and / or the problem posed by comparison with the prior art.

[0031] The invention will now be explained in more detail using schematic illustrations:

[0032] Figure 1 shows a planetary gear according to the invention in a sectional view.

[0033] Figure 2 shows a sun gear 1 of the planetary gear in an oblique view.

[0034] Figure 3 shows the sun gear 1 in a sectional view.

[0035] As shown in the figures, a shaft 5, in particular the input shaft of the planetary gear, is rotatably mounted via a bearing 2 accommodated in a housing part, in particular bearing flange 9.

[0036] A shaft seal 4, which is also accommodated in the bearing flange 2, seals towards the shaft 5.

[0037] Thus, bearing 2 is sealed with oil from the interior of the planetary gear.

[0038] To provide the bearing mount for the bearing 2 and the shaft seal mount for the shaft seal 4, the bearing flange has a hollow cylindrical support section projecting into the interior of the planetary gear.

[0039] The bearing 2 and the shaft seal 4 are spaced apart from each other in the axial direction, in particular in the direction of the axis of rotation of the shaft 5.

[0040] A channel 3 extending radially through the hollow cylindrical support section allows oil to be filled at the outer circumference of the hollow cylindrical support section. Another radial channel 6 is arranged diametrically opposite the first channel 3 on the hollow cylindrical section. This prevents oil overfilling.

[0041] The shaft 5 is connected in a rotationally fixed manner to a first sun gear 1. For this purpose, the first sun gear 1 has a toothing that is interrupted in the axial direction, i.e., in the direction of the rotational axis of the first sun gear 1. Thus, the first sun gear 1 has a first toothing region 20 and a second toothing region 21 spaced apart in the axial direction from the first toothing region 20. Both toothing regions (20, 21) have the same number of teeth, modules, and parameters of the involute toothing; only the tip diameter differs, since the first toothing region 20 has a smaller tip diameter than the second toothing region 21. In addition, the first toothing region has an introduction chamfer, in particular chamfered tip regions, at its end region axially remote from the second toothing region 21.The tip diameter of the first toothing area 20 is therefore monotonically increasing with decreasing distance to the second toothing area 21.

[0042] The second toothing area 21 is in engagement with the toothing of first planets 7, which in turn are in engagement with an internally toothed first ring gear 8, which is connected in a rotationally fixed manner to the bearing flange 9. The first planets 7 are rotatably arranged on a first planet carrier 11, which drives further gear stages.

[0043] For this purpose, a second sun gear 12 is inserted into the first planet carrier 11 with its running gear teeth in an internally toothed area of ​​the first planet carrier 11, with the running gear teeth being continuously constructed. Thus, the second sun gear 12 is connected to the first planet carrier 11 in a rotationally fixed manner.

[0044] On the side of the first planet carrier 11 axially facing the first sun gear 1, a first thrust washer 10 is accommodated, the outer diameter of which is larger than the tip diameter of the second toothing area of ​​the first sun gear 1.

[0045] The second sun gear 12 is in engagement with second planet gears 13, which in turn are in engagement with the internally toothed ring gear 8 or alternatively, in further embodiments according to the invention, with another ring gear.

[0046] The second planetary gears 13 are rotatably mounted on a second planetary carrier 16, which in turn is connected to a third sun gear 15 in a rotationally fixed manner, in that its running teeth are in turn inserted into an internally toothed region of the second planetary carrier 16. The first sun gear 1 is not hollow, in particular, but rather a solid part.

[0047] The second sun gear 12, however, is axially hollow throughout, in particular as a hollow part. The clear inner diameter of the second sun gear 12 is in particular larger than the smallest outer diameter of the predetermined breaking point 30 of the first sun gear 1, which is designed as a constriction.

[0048] The tip diameter of the second toothing area 21 is larger than the clear inner diameter of the hollow second sun gear 12.

[0049] Thus, the maximum transmittable torque of the first sun gear 1 is determined by the predetermined breaking point 30. In particular, this maximum transmittable torque is at least five or ten times smaller than the maximum transmittable torque through the second sun gear 12.

[0050] In this way, it is ensured that if the gearbox is overloaded, the first sun gear 1 is destroyed - but not other parts of the gearbox.

[0051] A second thrust washer 14 is accommodated in the second planet carrier 16, which axially limits the second sun gear 12.

[0052] The first thrust washer 10 axially limits the first sun gear 1.

[0053] The first sun gear 1 has a collar 31 on its axial end region facing the first thrust washer 10, so that the axial end face of the first gear 1, which can run against the thrust washer 10, has an outer diameter which is smaller than the tip diameter of the second toothing region 21 of the first sun gear 1.

[0054] The predetermined breaking point 30 is designed as a constriction whose smallest outer diameter is smaller than the smallest root diameter of the first toothing area 20 and also smaller than the smallest root diameter of the second toothing area 21. As can be seen in Figure 3, the predetermined breaking point 30 has a rounded portion with a semicircular cross-section. This allows for simple manufacturing using a radius.

[0055] Particularly advantageous, however, is a fillet that has a semi-elliptical fillet instead of a semi-circular fillet. This is because, especially when the fillet is designed as a rotational body section with a semi-elliptical rounded cross-section, the maximum transmittable torque can be specified as precisely as possible, and in the event of predetermined failure, a negligible or at least minimal number of particles breaking off in the event of overload can be achieved.

[0056] In this way, the first sun gear 1 is broken and the input shaft 5 can rotate freely relative to the output shaft of the gearbox, but there are only a few metal particles in the oil-filled interior of the gearbox, so that when repairing, i.e. replacing, the first sun gear 1, simply replacing the first sun gear 1 is sufficient to enable recommissioning.

[0057] The gear mechanism according to the invention is preferably used in a yaw angle adjustment mechanism of a wind turbine, in particular in an arrangement for rotating the nacelle of the wind turbine. An electric motor drives the input shaft 5, and while the output shaft is thereby rotated only slowly, a sufficiently high torque is generated for adjusting the yaw angle of the wind turbine. If, during operation, the yaw angle adjustment requires a torque that exceeds a threshold value, for example because the yaw angle adjustment mechanism is blocked, the torque transmitted through the first sun gear 1 exceeds the threshold value and destroys the first sun gear 1 at the predetermined breaking point 30. Thus, further parts, in particular those that are more expensive to manufacture, are protected, since after the destruction of the first sun gear 1, the output shaft of the gear mechanism is arranged to rotate freely.This causes the nacelle to align itself according to the air resistance and the wind turbine can be shut down.

[0058] The output shaft of the gearbox is non-rotatably connected to a pinion, which meshes with a ring gear. Thus, by controlling the electric motor driving the input shaft 5, the angle of rotation of the ring gear and thus of the wind turbine nacelle can be adjusted. Preferably, the outer diameter of the ring gear is at least five times larger than the outer diameter of the pinion, which is non-rotatably connected to the output shaft. In the event of overload, the expensively manufactured ring gear is protected by the destruction of the first sun gear 1, which is arranged in the input direction, at the predetermined breaking point 30.

[0059] In further embodiments of the invention, several gear motors according to the invention are arranged in the wind turbine, all of which act on the same gear ring, in particular for rotating the nacelle.

[0060] List of reference symbols

[0061] 1 sun gear

[0062] 2 camps

[0063] 3 channel

[0064] 4 Shaft seal

[0065] 5 Wave

[0066] 6 channel

[0067] 7 Planetary gear

[0068] 8 ring gear

[0069] 9 Bearing flange

[0070] 10 thrust washer

[0071] 11 planet carrier

[0072] 12 second sun gear

[0073] 13 second planet gear

[0074] 14 second thrust washer

[0075] 15 third sun gear

[0076] 20 first gearing area

[0077] 21 second gearing area

[0078] 30 predetermined breaking point

[0079] 31 Bund

Claims

Patent claims:

1. A gear mechanism, in particular a planetary gear mechanism, comprising a first sun gear (1), in particular comprising a first rotatably arranged sun gear (1), wherein the toothing of the first sun gear (1) has an interruption such that a first toothing region (20) of the toothing is spaced apart from a second toothing region (21) of the toothing in the axial direction, wherein in the region arranged in the axial direction between the first toothing region (20) and the second toothing region (21), the smallest outer diameter of the first sun gear (1) is smaller than the root circle diameter of the toothing, in particular wherein the toothing is designed as spur toothing, in particular wherein the axial direction is aligned parallel to the axis of rotation of the first sun gear (1).

2. Gearbox according to claim 1, characterized in that the predetermined breaking point (30) is designed as a constriction, wherein the smallest outer diameter of the predetermined breaking point (30) is smaller than the root diameter of the toothing.

3. Transmission according to one of the preceding claims, characterized in that the predetermined breaking point (30) is formed as a section of a rotary body whose rotational symmetry axis is aligned coaxially with the rotational axis of the first sun gear (1), wherein the curve generating the rotary body is a semicircle or a semi-ellipse.

4. Gearbox according to one of the preceding claims, characterized in that the rotating body is concavely shaped and / or the outer diameter of the rotating body section increases strictly monotonically with increasing axial distance to the narrowest point of the rotating body, i.e. to that axial position at which the rotating body has the smallest outer diameter.

5. Gearbox according to one of the preceding claims, characterized in that the toothing is designed as straight toothing.

6. Gearbox according to one of the preceding claims, characterized in that a shaft (5) is rotationally connected to the first sun gear (1) in that the toothing is in engagement with an internal toothing of the shaft (5) and / or that the shaft (5) has an internally toothed blind hole into which the toothing of the first sun gear (1) is partially inserted.

7. Gearbox according to one of the preceding claims, characterized in that the first sun gear (1) has a collar (31) on its side axially remote from the shaft (5), that is to say has a cylindrical section whose outer diameter is smaller than the root circle diameter of the toothing and larger than the smallest outer diameter of the predetermined breaking point (30), in particular wherein the collar (31) is axially spaced from the predetermined breaking point (30).

8. Transmission according to one of the preceding claims, characterized in that the first sun gear (1) is a solid part, in particular wherein the first sun gear (1) is not a hollow part.

9. Gearbox according to one of the preceding claims, characterized in that in the area covered by the predetermined breaking point (30) in the axial direction and / or in the area arranged in the axial direction between the first toothed area (20) and the second toothed area (21), radially inside the smallest outer diameter of the predetermined breaking point (30), the material of the first sun gear (1) is formed without gaps and / or continuously and / or uniformly.

10. Transmission according to one of the preceding claims, characterized in that the first sun gear (1) is in engagement with planetary gears which are in engagement with an internally toothed ring gear (8), the planetary gears being rotatably mounted on a planet carrier (11) which has an internally toothed bore into which the toothing of a second sun gear (12) is partially inserted.

11. Transmission according to claim 10, characterized in that the second sun gear (12) has an axially continuous, in particular centrally arranged recess and / or that the second sun gear (12) is hollow.

12. Transmission according to claim 10 or 11, characterized in that a thrust washer (10) is accommodated in the first planet carrier (11), which axially delimits the first sun gear, in particular the collar (31) of the first sun gear (1).

13. Transmission according to claim 12, characterized in that the thrust washer (10) is arranged axially between the first sun gear (1) and the second sun gear (12), in particular - wherein the thrust washer (10) has an axially continuous, in particular centrally arranged, hole and / or wherein the thrust washer (10) is made of steel and is nitrided and / or wherein one or more depressions are formed on the side of the thrust washer (10) facing the first sun gear (1), each extending from the centrally arranged, axially continuous hole to the radially outer edge of the thrust washer (10), in particular such that a channel (3, 6) delimited by the thrust washer (10) and the first sun gear (1), in particular the collar (31), is formed, in particular wherein the depressions and / or channels are regularly spaced from one another in the circumferential direction, in particular wherein the channel cross-section initially increases and then decreases with increasing radial distance, in particular wherein the hole opens into the depression and / or into the channel (3, 6), in particular such that lubricating oil entering through the hole can flow through the channel (3,6) is conveyed radially outwards., 14. Transmission according to one of the preceding claims, characterized in that the transmission has more than two planetary gear stages arranged in series.

15. Wind turbine with a rotatably arranged nacelle in which a generator is arranged, wherein the wind turbine has a gearbox driven by an electric motor according to one of the preceding claims, the output shaft of which is connected in a rotationally fixed manner to a pinion which is in engagement with a gear ring, in particular wherein the toothing of the pinion is in engagement with the external toothing of a gear ring, in particular wherein the rotational position of the gear ring is and / or determines the rotational position of the nacelle, in particular wherein the gearbox is connected to the nacelle and the rotational position of the nacelle, in particular relative to the gear ring, is controllable by the rotational position of the gear ring relative to the gearbox.

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