WO2024056204A1

WO2024056204A1 - Gear wheel and planetary transmission comprising same

Info

Publication number: WO2024056204A1
Application number: PCT/EP2023/025361
Authority: WO
Inventors: Rafael RODARTE; Ramon de Assis; Antonio Ventriglia VIEIRA
Original assignee: Sew-Eurodrive Gmbh & Co. Kg
Priority date: 2022-09-13
Filing date: 2023-08-01
Publication date: 2024-03-21
Also published as: DE102023003162A1; DE102022003370B3

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

GEAR AND PLANETARY GEAR WITH THIS

Description:

The invention relates to a gearbox, in particular a planetary gearbox, with a sun wheel and a wind turbine with a rotatably arranged nacelle.

It is well known that a planetary gear has a sun gear meshing with planetary gears meshing with a ring gear.

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

A wind turbine is known from AT 512 436 A1.

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

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.

Important features of the invention in the transmission, in particular planetary gear, 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 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 can be operated efficiently with the gearbox. In the event of an overload, the first sun gear is destroyed and the part of the device driven by the gear is therefore protected from overload. For example, this is a large and therefore very expensive sprocket. For repairs, only the first sun gear of the transmission needs to be replaced, i.e. the smallest sun gear of the transmission. The downstream gear stages and the ring gear can then continue to be used. Particularly in the case of a wind turbine in which the ring gear is installed in a complex manner and therefore incurs high costs not only due to production but also due to assembly, the repair or replacement of a first sun gear of a multi-stage gearbox is cost-effective and thus ensures efficient operation of the entire system over its service life including repairs.

In an advantageous embodiment, the predetermined breaking point is designed as a narrowing, with the smallest outside diameter of the predetermined breaking point being smaller than the root diameter of the toothing. The advantage here is that the predetermined breaking point can be easily produced as a constriction.

In an advantageous embodiment, the predetermined breaking point is formed as a rotating body section, the axis of rotational symmetry of which is aligned coaxially with the rotational axis of the sun gear, the curve generating the rotating body being a semicircle or a semi-ellipse. The advantage here is that with a generating curve with a semicircle the production is very simple and with a generating curve with a semi-ellipse the predetermined breaking point can be made more well-defined than with a version with a semicircle. In any case, the predetermined breaking point is concave. The axial position of that point of the predetermined breaking point which has the smallest outside diameter is preferably arranged axially centrally, so that the outside diameter increases in both axial directions starting from this point. When designed 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 to the narrowest point of the rotating body, i.e. to the axial position at which the rotating body has the smallest outer diameter. The advantage here is that the predetermined breaking point breaks essentially axially in the middle.

In an advantageous embodiment, the toothing is designed as a straight toothing. The advantage here is that simple, cost-effective production is possible.

In an advantageous embodiment, a shaft is connected to the sun gear in a rotationally fixed manner, in that the toothing is in engagement with an internal toothing of the shaft. The advantage here is that the sun gear also functions as a toothed coupling part. Although the shaft is connected to the first sun gear in a rotationally fixed manner, compensation is achieved when the axes of rotation of the shaft and the first sun gear are not aligned.

In an advantageous embodiment, the shaft has an internally toothed blind hole into which the teeth of the sun gear are partially inserted. The advantage here is that a connection that is easy to establish is provided.

In an advantageous embodiment, the sun gear has a collar on its side axially remote from the shaft, in particular a cylindrical section, the outer diameter of which is smaller than the root diameter of the toothing and larger than the smallest outer diameter of the predetermined breaking point, in particular with the collar being axially spaced is from the breaking point. The advantage here is that the teeth are spaced apart from the thrust washer and are therefore protected. In addition, the end face of the first sun gear can be designed as a flat surface, so that the radially directed depressions incorporated into the thrust washer form channels through which oil that has passed axially through the thrust washer can be guided.

In an advantageous embodiment, the first sun gear is a solid part, in particular the first sun gear is not a hollow part. The advantage here is that no oil can flow through the first sun gear in the axial direction and thus a radial one Flowing out is forced. The oil therefore flows through the hollow second sun gear and then through the thrust washer, where it is then deflected in the radial direction and flows out. This not only improves lubrication, but also spreads lost heat, so that peak temperatures in the gearbox are reduced and heat dissipation to the environment is improved.

In an advantageous embodiment, 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 toothing area and the second toothing area, the material of the first sun gear is gap-free and/or radially within the smallest outer diameter of the predetermined breaking point continuously formed and/or evenly executed. The advantage here is that a well-defined point is available for the overload and that the number of fragments is negligible or even zero due to the appropriate semi-elliptical design.

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

In an advantageous embodiment, the first sun gear is in engagement with planet gears which are in engagement with an internally toothed ring gear, the planet gears being 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 area of space. In an advantageous embodiment, the second sun gear has an axial, continuous, in particular centrally arranged recess. The advantage here is that material can be saved, the dynamics of the transmission are increased, the moment of inertia is reduced and the lubrication and cooling are improved as a result of the oil flowing through axially. However, in contrast to the second sun wheel, the first sun wheel is not hollow, but is designed as a solid part. This is the only way to achieve a well-defined breaking point. However, oil cannot flow through the first sun gear and the heat dissipation must be effected by the oil surrounding the second toothing area and the oil flowing through the predetermined breaking point designed as a constriction.

In an advantageous embodiment, the second sun gear is designed to be hollow. The advantage here is that material can be saved, the dynamics of the transmission are increased, the moment of inertia is reduced and the lubrication and cooling are improved as a result of the oil flowing through axially. However, in contrast to the second sun wheel, the first sun wheel is not hollow, but is designed as a solid part. This is the only way to achieve a well-defined breaking point. However, oil cannot flow through the first sun gear and the heat dissipation must be effected by the oil surrounding the second toothing area and the oil flowing through the predetermined breaking point designed as a constriction.

In an advantageous embodiment, a thrust washer is accommodated in the first planet carrier, which axially limits the first sun gear, in particular the collar of the first sun gear. The advantage here is that the thrust washer is made of a hardened material and thus the friction is reduced. In addition, the radially directed channels are flowed through with oil, which is also conveyed by centrifugal force and forms a hydrodynamic cushion for the first sun gear. This means that the axial limitation is achieved with little effort and friction despite the different speeds.

In an advantageous embodiment, the thrust washer is held non-positively in the first planet carrier, in particular by means of a snap ring. The advantage is that a simple and cost-effective fastening method can be used.

In an advantageous embodiment, the first planet carrier has an axially continuous stepped bore, wherein the thrust washer rests against a first stage of the stepped bore, in particular wherein a bearing of a first planet rests against a second stage of the stepped bore. The advantage here is that the thrust washer can be securely fastened. In addition, the first sun gear rests against the thrust washer on the side of the thrust washer facing away from the first stage. This means that the thrust washer is pressed against the first stage and is therefore held securely. The advantage here is that efficient operation can be achieved since 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 that has a greater hardness than the end face of the second sun gear. The material of the thrust washer is therefore different in hardness compared to the material of the second sun gear, in particular which is made of the same material as the first sun gear.

In an advantageous embodiment, the thrust washer is made of steel and treated with nitriding. The advantage here is that simple production and low coefficients of friction can be achieved.

In an advantageous embodiment, the thrust washer has a centrally arranged, axially continuous hole. The advantage here is that lubricating oil passes through the hole, i.e. without the influence of centrifugal force. Because the radial distance disappears here, the centrifugal force also disappears.

In an advantageous embodiment, one or more recesses are formed on the side of the thrust washer facing the first sun gear, each of which extends from the centrally arranged, axially continuous hole to the radially outer edge of the thrust washer, in particular in such a way that one of the thrust washer and the first Sun wheel limited channel is formed, 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. That way they're not on Planets arranged with vanishing radial distance can be easily lubricated, especially their needle bearings; because the planets are mounted using needle bearings that are pushed onto bolts on the planet carrier.

In an advantageous embodiment, the channel cross section initially increases and then decreases as the radial distance increases. The advantage here is that the channel cross-section, which increases up to a maximum value with increasing radial distance, creates a buffer volume that enables a constant outflow at an even larger radial distance even when filled with lubricating oil unsteadily, since the channel cross-section decreases again from the maximum value when the radial distance continues to increase. The channel then opens at this greatest radial distance towards the planets, especially towards their bearings.

In an advantageous embodiment, the transmission has more than two planetary gear stages arranged in series. The advantage is that a high gear ratio can be achieved.

Important features of the wind turbine with a rotatably arranged nacelle, in which a generator is arranged, are that the wind turbine has a transmission 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 connected to a ring gear is in engagement, 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/determines the rotational position of the nacelle, in particular wherein the gear is connected to the nacelle and the rotational position of the nacelle is in particular relative to the sprocket, can be controlled by the rotational position of the sprocket related to the gearbox.

The advantage is that the first sun gear is destroyed if it is overloaded. This means the ring gear is protected and cannot be destroyed by overloading. A costly replacement of the sprocket can therefore be avoided. Further advantages result from the subclaims. The invention is not limited to the combination of features of the claims. For the person skilled in the art, further sensible combination options of claims and/or individual claim features and/or features of the description and/or the figures arise, in particular from the task and/or the task posed by comparison with the prior art.

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

A planetary gear according to the invention is shown in a sectional view in FIG.

In Figure 2, a sun gear 1 of the planetary gear is shown in an oblique view.

In Figure 3, the sun gear 1 is shown in a sectional view.

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

A shaft sealing ring 4, which is also accommodated in the bearing flange 2, seals against the shaft 5.

The bearing 2 is thus sealed with oil from the interior of the planetary gear.

To provide the bearing receptacle for the bearing 2 and the shaft seal receptacle for the shaft seal ring 4, the positioning flange has a hollow cylindrically shaped support section which projects into the interior of the planetary gear.

The bearing 2 and the shaft sealing ring 4 are spaced apart from one another in the axial direction, in particular in the direction of the axis of rotation of the shaft 5.

A channel 3 running radially through the hollow cylindrical support section enables oil to be filled on the outer circumference of the hollow cylindrical support section. Another radially continuous channel 6 is arranged diametrically opposite the first channel 3 on the hollow cylindrical section. This means that overfilling with oil can be avoided.

The shaft 5 is connected to a first sun gear 1 in a rotationally fixed manner. For this purpose, the first sun gear 1 has teeth that are interrupted in the axial direction, that is to say in the direction of the axis of rotation of the first sun gear 1. Thus, the first sun gear 1 has a first toothing region 20 and a second toothing region 21 which is spaced apart from the first toothing region 20 in the axial direction. Both toothing areas (20, 21) have the same number of teeth, modules and parameters of the involute toothing; only the tip circle diameter is different, since the first toothing area 20 has a smaller tip circle diameter than the second toothing area 21. In addition, the first toothing area has an insertion chamfer at its end area axially remote from the second toothing area 21, in particular beveled head areas. The tip circle diameter of the first toothing area 20 therefore increases monotonically as the distance to the second toothing area 21 decreases.

The second toothing region 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 non-rotatably connected to the bearing flange 9. The first planets 7 are rotatably arranged on a first planet carrier 11, which drives further gear stages.

For this purpose, a second sun gear 12 with its running teeth is inserted into an internally toothed area of the first planet carrier 11 in the first planet carrier 11, the running teeth being manufactured uninterrupted. The second sun gear 12 is thus connected to the first planet carrier 11 in a rotationally fixed manner.

On its side of the first planet carrier 11 that faces axially towards the first sun gear 1, a first thrust washer 10 is accommodated, the outer diameter of which is larger than the tip circle diameter of the second toothing region of the first sun gear 1.

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 exemplary embodiments according to the invention, with another ring gear.

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

The second sun gear 12, however, is axially continuously hollow, in particular as a hollow part. The clear inside diameter of the second sun gear 12 is in particular larger than the smallest outside diameter of the predetermined breaking point 30 of the first sun gear 1, which is designed as a narrowing.

The tip circle diameter of the second toothing region 21 is larger than the clear inside diameter of the hollow second sun gear 12.

The maximum transferable torque of the first sun gear 1 is therefore determined by the predetermined breaking point 30. In particular, this maximum transferable torque is at least five or ten times smaller than the maximum torque that can be passed through the second sun gear 12.

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

A second thrust washer 14 is accommodated in the second planet carrier 16, which axially delimits the second sun gear 12.

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

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 abut the thrust washer 10, has an outer diameter that is smaller than the tip circle diameter of the second toothing region 21 of the first sun gear 1.

The predetermined breaking point 30 is designed as a constriction, the smallest outer diameter of which is smaller than the smallest root diameter of the first toothing area 20 and is 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 rounding which is semicircular in cross section. This enables simple production using a radius.

However, a rounding which has a semi-elliptical rounding instead of the semicircular rounding is particularly advantageous. Particularly when the rounding is designed as a rotating body section with a semi-ellipse-shaped rounded cross-section, a maximum transferable torque can be specified as precisely as possible and, in the event of a predetermined break, a vanishing or at least as minimal number of particles breaking off can be achieved in the event of an overload.

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 transmission, but there are only a few metal particles in the oil-filled interior of the transmission, so that when the first sun gear 1 is repaired, i.e. replaced, there is only one Replacing the first sun gear 1 is sufficient to enable recommissioning.

The transmission 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. For this purpose, an electric motor drives the input shaft 5 and the output shaft is therefore only rotated slowly, but a sufficiently high torque is generated for the yaw angle adjustment 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 passed through the first sun gear 1 exceeds the threshold value and destroys the first sun gear 1 at the predetermined breaking point 30. This means that further ones are particularly more expensive to produce Parts protected because after the destruction of the first sun gear 1, the output shaft of the transmission is arranged to rotate freely. This then aligns the nacelle according to the air resistance and the wind turbine can go out of operation.

The output shaft of the gearbox is connected in a rotationally fixed manner to a pinion, which is in mesh with a ring gear. Thus, by controlling the electric motor driving the driving shaft 5, the angle of rotation of the ring gear and thus the nacelle of the wind turbine 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 driving shaft. In the event of an overload, the expensively manufactured ring gear is protected by destroying the first sun gear 1 arranged in a driving manner at the predetermined breaking point 30.

In further exemplary embodiments according to the invention, several geared motors according to the invention are arranged in the wind turbine, all of which act on the same gear ring, in particular to rotate the nacelle.

Reference symbol list

1 sun gear

2 warehouses

3 channel

4 shaft seal

5 wave

6 channel

7 planetary gear

8 ring gear

9 bearing flange

10 thrust washer

11 planet carriers

12 second sun gear

13 second planetary gear

14 second thrust washer

15 third sun wheel

20 first gear area

21 second gear area

30 breaking point

31 frets

Claims

Patent claims:

1. Transmission, in particular planetary gear, with a first sun gear (1), in particular with a first rotatably arranged sun gear (1), the toothing of the first sun gear (1) having an interruption such that a first toothing region (20) of the toothing of a second toothing region (21) of the toothing is spaced apart 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 outside diameter of the first sun gear (1) is smaller than the root diameter of the Gearing is, in particular wherein the gearing is designed as straight gearing, in particular wherein the axial direction is aligned parallel to the axis of rotation of the first sun gear (1).

2. Transmission according to claim 1, characterized in that the predetermined breaking point (30) is designed as a narrowing, the smallest outer diameter of the predetermined breaking point (30) being 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 rotating body, the axis of rotational symmetry of which is aligned coaxially with the axis of rotation of the first sun gear (1), the curve generating the rotating body being a semicircle or a semi-ellipse is.

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

5. Transmission according to one of the preceding claims, characterized in that the teeth are designed as straight teeth.

6. Transmission according to one of the preceding claims, characterized in that a shaft (5) is rotatably 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 teeth of the first sun gear (1) are partially inserted.

7. Transmission 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), i.e. has a cylindrical section, the outer diameter of which is smaller than the root diameter the toothing and larger than the smallest outside diameter of the predetermined breaking point (30), in particular where 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. Transmission 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 toothing area (20) and the second toothing area (21). , radially within the smallest outer diameter of the predetermined breaking point (30), the material of the first sun gear (1) is formed without gaps and/or uninterrupted and/or is made uniform.

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

11. Transmission according to claim 10, characterized in that the second sun gear (12) has an axial, continuous, in particular centrally arranged

Has 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 limits 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 on the side of the thrust washer facing the first sun gear (1) ( 10) one or more recesses are formed, each of which extends from the centrally arranged, axially continuous hole to the radially outer edge of the thrust washer (10), in particular in such a way that one of the thrust washer (10) and the first sun gear (1), in particular the collar (31), a limited channel (3, 6) 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 in the recess and/or opens into the channel (3, 6), in particular so that lubricating oil that has entered through the hole is conveyed radially outwards through the channel (3, 6).

14. Transmission according to one of the preceding claims, characterized in that the transmission has more than two serially arranged planetary gear stages.

15. Wind turbine with a rotatably arranged nacelle in which a generator is arranged, the wind turbine having a transmission 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 ring gear, in particular, wherein the toothing of the pinion is in engagement with the external toothing of a gear rim, in particular wherein the rotational position of the gear rim is and/determines the rotational position of the gondola, in particular wherein the gear is connected to the gondola and the rotational position of the gondola in particular relative to the gear rim the rotational position of the ring gear related to the gearbox can be controlled.