Testing of planetary gear without planet carrier bearing

Abstract

The invention relates to a test bench (1) for testing a planetary transmission (2). In order to use a test bench (1) for a planetary transmission (2) without a planet carrier bearing, the invention proposes that the test bench (1) has a central bearing unit (3), wherein the central bearing unit (3) is configured to rotatably mount a planet carrier (4) of a first stage of the planetary transmission (2), wherein the central bearing unit (3) is further configured to center a ring gear (5) of the planetary transmission (2) relative to the planet carrier (4).

Description

TECHNICAL FIELD

[0001] The invention relates to a test bench for testing a planetary transmission. The invention also relates to a test device having a test bench of this type and a planetary transmission to be tested. Furthermore, the invention relates to a method for testing a planetary transmission by means of a test bench of this type or a method for operating a test device of this type. Furthermore, the invention also relates to a use of a test bench. BACKGROUND

[0002] Modern planetary transmissions, in particular in the case of wind farms, are partly developed as modules in integrated systems. In the case of systems of this type, the transmissions partly no longer have any planet carrier bearings in the slow running level. These planetary transmissions are also referred to as planet carrier bearing-free planetary transmissions. They cannot therefore be tested as independent modules on test benches known hitherto and can only be tested on dedicated test benches in the system, which is very costly in terms of investment. The same applies to future servicing of planet carrier bearing-free planetary transmissions. Without this system, these cannot be tested on test benches, for example standard wind power transmission test benches.

[0003] Up to now, testing has been carried out in a complex manner in the system or the planetary transmissions have had dedicated planet carrier bearings.

[0004] Transmission testing is to be understood as meaning, in particular, testing in which at least rotational movement, torque, bending moment or a combination thereof is applied to the transmission, in particular a planetary transmission. These loads are also referred to as test loads.

[0005] CN 110 220 699 A discloses a test bench for testing a planetary transmission. In the case of this test bench, the ring gear and the planet carrier of the planetary transmission are fixed in a manner that cannot move and a shaft provided for introducing a test torque and coupled to the sun shaft is guided with play through the planet carrier, with the result that the load acting on the planet carrier fixed in motion can be measured by means of strain gauges fastened to the planet carrier. SUMMARY

[0006] One object on which the invention is based is to specify a testing option for planet carrier bearing-free planetary transmissions.

[0007] This object is achieved by the test bench, the method and the use of the test bench according to the application. Preferred refinements are specified in the dependent claims and in the following description, which can represent an aspect of the application individually or in combination. If a feature is shown in conjunction with another feature, this is merely for the sake of simplifying the illustration of the application and does not mean that the feature cannot be an improvement of the application even without the other feature.

[0008] The test bench has a central bearing unit, wherein the central bearing unit is configured to rotatably mount a planet carrier of a first stage of a planetary transmission, wherein the central bearing unit is further configured to center a ring gear of the planetary transmission relative to the planet carrier. Furthermore, this object is achieved by a test device having a test bench of this type and a planetary transmission to be tested, wherein the central bearing unit rotatably mounts a planet carrier of a first stage of the planetary transmission to be tested, wherein the central bearing unit centers a ring gear of the planetary transmission to be tested relative to the planet carrier. Furthermore, this object is achieved by a method of testing a planetary transmission by means of a test bench of this type or of operating a test device of this type, wherein a test load is transmitted from the ring gear to a housing of the central bearing unit by means of a flange.

[0009] At least one stage of the planetary transmission is formed in particular by the planetary transmission, so that the stage can be configured as a planetary gear stage.

[0010] The application is based, inter alia., on the finding that, by using the proposed central bearing unit, planetary transmissions without planet carrier bearings can also be tested and inspected. Here, the planetary transmission provided for testing can be configured as a planetary transmission without planet carrier bearings. As a result of the possibility of mounting the first stage, the test bench or the test device is particularly suitable for measurements and tests on planetary transmissions without planet carrier bearings. The central bearing unit is an external device of the test bench for the transmission. The central bearing unit mounts the planet carrier of the first stage of the planetary transmission to be tested. Furthermore, the central bearing unit centers the corresponding ring gear or the respective ring gear relative to the planet carrier or the respective planet carrier during the testing of a plurality of planetary transmissions. The flange serves for attaching the ring gear in order to transmit a test load from the ring gear to a stationary part of the central bearing unit, such as, for example, a housing of the central bearing unit. The flange is therefore arranged between the central bearing unit and the planetary transmission. Here, the flange can be assigned to the transmission or to the central bearing unit. Furthermore, as an alternative, the flange can also be configured as a separate component which is not assigned to the transmission nor to the central bearing unit. The test load is likewise supported via the flange. The test load can be formed, for example, by a torque, a weight load and / or a bending moment. Here, the return of the torque from the ring gear into the surrounding structure takes place in an advantageous manner via the housing of the central bearing unit and from there further into the closed frame of the electric machine of the test bench or into the base, in particular into the base of the central bearing unit.

[0011] The central bearing unit has in particular at least one rolling bearing. The central bearing unit preferably has at least two rolling bearings which are spaced apart from one another in the axial direction. The central bearing unit can thus support high radial and / or axial forces.

[0012] Complex complete system tests can be dispensed with. For this purpose, by means of the proposed test bench or test device, an already existing test bench can be retrofitted in a simple manner with a central bearing unit and can be used for testing modern transmissions without a planet carrier bearing. The space requirement between the support systems is halved and the weight to be handled is likewise reduced by more than half. The central bearing unit is thus part of the test bench and does not need to be exchanged for a planet transmission to be tested.

[0013] The arrangement of the test bench, the test device and the method are suitable in a particular way for planet transmissions of wind power plants. The production quantity of these transmissions is relatively large and the requirements for reliability are particularly high due to the arrangement of the planet transmissions in the tower of a wind power plant. Furthermore, there are a number of requirements with regard to qualification, which require tests under specified boundary conditions. These boundary conditions can be set on the test bench or the test device, the result being that the test bench or the test device is suitable and advantageous to a particular extent for measurements and tests on planet transmissions for wind power applications.

[0014] In the case of an advantageous refinement of the application, the test bench is configured in a back-to-back arrangement. By means of this arrangement, two planet transmissions can be tested at the same time. In the case of a back-to-back design, the test bench is configured symmetrically and / or mirror-inverted with respect to the central bearing unit. In this case, the central bearing unit is also configured symmetrically. The ring gear is mounted on both sides of the central bearing unit, respectively, with the test bench having one flange on the housing of the central bearing unit on both sides in order to attach the planet carrier. As an alternative, the flanges can also be arranged on the planet transmission, in particular on the planet carrier, and the planet carrier can be connected to the central bearing unit. A two-machine electric machine is thus also provided for the back-to-back arrangement, between which two machines the two planet transmissions and the central bearing unit are advantageously arranged symmetrically. It is noted here that the electric machine does not necessarily have to be connected to the base, but can also be coupled and tested in the form of a hybrid drive (transmission-generator combination). In this case, the drive torque is not returned via the base, but via the housing.

[0015] In the case of this arrangement, the torque return from the ring gear into the surrounding structure also takes place in a favorable manner via the housing of the central bearing unit and from there further into the closed frame of the electric machine of the test bench or into the base, in particular into the base of the central bearing unit. In this back-to-back arrangement, the main support torque can be eliminated via the housing of the central bearing unit by the counter-support torque of the second unit being measured. In this way, only the drive and braking torque of the electric machine is supported via the base in addition to the weight load.

[0016] One aspect of the application relates to the use of a test bench, which can be constructed and improved as described above, for measuring and / or testing a planetary transmission without any planet carrier bearing. BRIEF DESCRIPTION OF DRAWINGS

[0017] In the following, the application will be described and explained in more detail on the basis of exemplary embodiments shown in the drawings, in which:

[0018] Figure 1 a test bench is shown, and

[0019] Figure 2 a test setup is shown. DETAILED DESCRIPTION

[0020] Figure 1 A test bench 1 for testing a planetary transmission 2 (not shown here) without any planet carrier bearing is shown. A central bearing unit 3 is provided for connecting to and centering the planetary transmission 2. Since the centering makes rotation possible, it is also called rotatable centering, or simply mounting. A flange 6 on the central bearing unit 3 or on the planetary transmission 2 is used, inter alia, for the further connection of the central bearing unit 3 to the planetary transmission 2. The flange 6 connects the ring gear 5 (not shown here) of the planetary transmission 2 to the central bearing unit 3. Thereby, the torque from the ring gear 5 of the planetary transmission can be returned via the housing of the central bearing unit 3 into the base 7. Furthermore, the test bench 1 has an electric machine 21 with which the planetary transmission 2 can be loaded with torque.

[0021] Figure 2 A test device 10 on the test bench 1 is shown. In order to avoid repetitions, reference is made to the description regarding Figure 1 and in Figure 1The name introduced in the middle. The planetary gear 2 is connected to the electrical machine 21 via a test bench transmission 22. However, the presence of the test bench transmission 22 is merely optional and this transmission does not have to be part of the test device 10. If the electrical machine 21 covers the required torque and rotational speed range as far as its construction is concerned, the test bench transmission 22 can be dispensed with. This is the case, in particular, in medium-speed electrical machines. A concentric attachment of the electrical machine 21 is then also possible. The other side of the planetary gear 2 is connected to the central bearing unit 3, as a result of which the planet carrier 4 is rotatably mounted. The ring gear 5 of the planetary gear 2 is connected to the central bearing unit 3 with a flange 6 and, via this flange, can also ensure that the torque is returned as far as possible into the base 7.

[0022] The construction shown corresponds to a back-to-back arrangement, in which case two planetary gears 2 can be tested. Here, the test bench 10 has a symmetrical structure, as a result of which there is also a second electrical machine 21 and a second test bench transmission 22. The central bearing unit 3, in which the planet carriers 4 of the two planetary gears 2 are mounted, is located centrally. As a result, the two planetary gears 2 are connected to one another via the central bearing unit 3.

[0023] In summary, the invention relates to a test bench for testing a planetary gear. In order to use the test bench for a planetary gear which does not have any planet carrier bearings, it is proposed that the test bench has a central bearing unit which is configured to rotatably mount a planet carrier of a first stage of the planetary gear and which is also configured to center a ring gear of the planetary gear relative to the planet carrier. Furthermore, the invention relates to a test device having a test bench of this type and a planetary gear to be tested, the central bearing unit rotatably mounting a planet carrier of a first stage of the planetary gear to be tested and centering a ring gear of the planetary gear to be tested relative to the planet carrier. Furthermore, the invention relates to a method for testing a planetary gear using a test bench of this type or to a method for operating a test device of this type, in which a test load is transmitted from the ring gear to a housing of the central bearing unit by means of a flange.

Claims

1. A test stand (1) for testing a planetary gear (2), the test stand (1) having a central bearing unit (3) configured to rotatably mount a first-stage planet carrier (4) of the planetary gear (2), the central bearing unit (3) further configured to center a gear ring (5) of the planetary gear (2) relative to the planet carrier (4).

2. The test bench (1) according to claim 1, wherein the central bearing unit (3) has at least two rolling bearings spaced apart from each other in the axial direction for supporting radial force and / or axial force.

3. The test bench (1) according to claim 1 or 2, wherein the test bench (1) is configured as a back-to-back device for simultaneously testing two planetary gears (2) arranged in a mirror-reversed manner with respect to the central bearing unit (3).

4. A testing apparatus (10) having a test bench (1) according to any one of claims 1 to 3 and a planetary gear (2) to be tested, wherein the central bearing unit (3) rotatably mounts the first stage planet carrier (4) of the planetary gear (2) to be tested, and the central bearing unit (3) centers the gear ring (5) of the planetary gear (2) to be tested relative to the planet carrier (4).

5. The test apparatus (10) according to claim 4, wherein the test apparatus (10) is configured to be arranged back to back.

6. The test apparatus (10) according to claim 4 or 5, wherein the planetary gear (2) to be tested is configured as a planetary gear without a planet carrier bearing.

7. The test apparatus (10) according to claim 4 or 5, wherein the planetary gear (2) to be tested has a first stage and at least one other stage connected to the first stage in a torque transmission manner.

8. The test apparatus (10) according to claim 6, wherein the planetary gear (2) to be tested has a first stage and at least one other stage connected to the first stage in a torque transmission manner.

9. A method for testing a planetary gear (2) using a test bench (1) according to any one of claims 1 to 3 or for operating a test apparatus (10) according to any one of claims 4 to 8, wherein the test load is transmitted from the gear ring (5) to the housing of the central bearing unit (3) by means of a flange (6).

10. The method according to claim 9, wherein the torque is returned from the gear ring (5) to the base (7) of the central bearing unit (3) via the housing of the central bearing unit (3).

11. The method according to claim 9 or 10, wherein the flange (6) is arranged between the central bearing unit (3) and the planetary gear (2).

12. Use of a test bench (1) according to any one of claims 1 to 3 for measuring and / or testing on a planetary transmission without planetary carrier bearings.

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