Transmission, especially for wind power installations

• US 6,607,464 B1
• Filed: 06/21/2002
• Issued: 08/19/2003
• Est. Priority Date: 12/23/1999
• Status: Expired due to Term

• Current Assignee: ZF Friedrichshafen AG (Zeppelin - Stiftung der Stadt Friedrichshafen)
• Original Assignee: Lohmann & Stolterfoht GmbH (Robert Bosch GmbH)
• Inventors: Berger, Günter, Bauer, Gerhard
• Primary Examiner(s): Estremsky, Sherry
• Assistant Examiner(s): Lewis, Tisha D.
• Application Number:
  US10/169,041
• Time in Patent Office: 424 Days
• Field of Search: 475/269, 475/286, 475/302, 475/317, 475/323, 475/325, 475/248, 475/249
• US Class Current: 475/269
• CPC Class Codes: F03D 15/00 Transmission of mechanical power
• CPC Class Codes: F03D 15/10 using gearing not limited to rotary motion, e.g. with oscillating or reciprocating members
• CPC Class Codes: F05B 2260/40311 of the epicyclic, planetary or differential type
• CPC Class Codes: F16H 1/46 Systems consisting of a plurality of gear trains each with orbital gears, i.e. systems having three or more central gears
• CPC Class Codes: F16H 2001/289 comprising two or more coaxial and identical sets of orbital gears, e.g. for distributing torque between the coaxial sets
• CPC Class Codes: F16H 2200/2097 comprising an orbital gear set member permanently connected to the housing, e.g. a sun wheel permanently connected to the housing
• CPC Class Codes: F16H 37/0833 with arrangements for dividing torque between two or more intermediate shafts, i.e. with two or more internal power paths F16H3/72 takes precedence
• CPC Class Codes: F16H 37/10 at both ends of intermediate shafts F16H37/0806 takes precedence
• CPC Class Codes: Y02E 10/72 Wind turbines with rotation axis in wind direction

Abstract

A transmission, especially for wind power installations includes a planetary stage on the input side that is mounted upstream of at least one gear stage. The planetary stage includes at least two power-splitting planetary gears that are mounted in parallel. A differential gear that is mounted downstream of the power-splitting planetary gears compensates for an unequal load distribution between the individual planetary gears caused by their parallel disposition.

Claims

1. A transmission, in particular for wind power installations, comprising:

a transmission case,

an input shaft and an output shaft supported in the transmission case,

an input-side planetary stage disposed between the input shaft and the output shaft and having at least two power-splitting planetary gears of equal dimensions and being connected in parallel, the planetary stage further comprising two sun shafts; and

at least one passive differential gear stage implemented as a differential planetary gear and connected downstream of the planetary stage, said at least one differential gear stage including a sun wheel, a hollow wheel and a planet carrier, wherein one of the two sun shafts is operatively connected with the sun wheel of the differential gear stage and the other of the two sun shafts is operatively connected with the hollow wheel of the differential gear stage, and wherein the planet carrier of the differential gear stage forms an output section operatively connected to the output shaft.

2. The transmission of claim 1, wherein the planetary stage includes exactly two planetary gears that are connected in parallel and arranged sequentially.

3. The transmission of claim 1, the planetary stage further comprising a common planet carrier, wherein the planetary stage is connected with the input, shaft via the common planet carrier.

4. The transmission of claim 1, and further comprising a spur gear stage, wherein the output shaft is arranged with an axial offset relative to the drive shaft, said offset provided by the spur gear stage.

5. The transmission of claim 1, and further comprising an intermediate shaft and a spur wheel supported by the intermediate shaft and arranged between the input shaft and the output shaft.

6. The transmission of claim 1, wherein the passive differential gear stage is arranged coaxially with respect to the two sun shafts.

7. The transmission of claim 1, and further including an intermediate spur gear stage, wherein the, passive differential gear stage is arranged with an axial offset relative to the two sun shafts, said offset provided by the intermediate spur gear stage.

8. The transmission of claim 2, wherein the sun shaft of a first of the planetary gears together with the sun shaft of a second of the planetary gears form a coaxial hollow shaft arrangement.

9. The transmission of claim 7, wherein the intermediate spur gear stage includes two first spur wheels of identical diameter and arranged side-by-side, and two second spur wheels of identical diameter, with the first spur wheels being arranged coaxially with respect to the two sun shafts, and each of the first spur wheels being connected with a respective one of the two sun shafts, the first spur wheels engaging with the second spur wheels, the second spur wheels cooperating with the passive differential gear stage that is arranged coaxially with respect to the corresponding second spur wheels.

10. A transmission, in particular for wind power installations, comprising:

a transmission case;

an input shaft and an output shaft supported in the transmission case;

an input-side planetary stage disposed between the input shaft and the output shaft and having at least two power-splitting planetary gears of equal dimensions and being connected in parallel, the planetary stage further comprising two sun shafts; and

at least one active differential gear stage having a sun wheel and implemented as a differential planetary gear which, on one hand, splits the power equally between the two sun shafts connected to the differential gear stage and, on the other hand, contributes to an overall gear ratio of the transmission through an asymmetric connection of the planetary stage, whereby the sun wheel forms an output section operatively connected to the output shaft.

11. The transmission of claim 10, wherein the planetary stage includes exactly two planetary gears that are connected in parallel and arranged sequentially.

12. The transmission of claim 10, and further comprising a spur gear stage, wherein the output shaft is arranged with an axial offset relative to the drive shaft, said offset provided by the spur gear stage.

13. The transmission of claim 10, and further comprising at least one spur gear stage being connected downstream of the differential gear stage.

14. The transmission of claim 10, wherein each of the two planetary gears includes a planet carrier, a sun wheel and a hollow wheel, and wherein the asymmetric connection between the planetary stage and the differential gear stage is implemented in that on a first of the two planetary gears disposed on an input side of the planetary stage, the hollow wheel is grouped with the planet carrier which is secured to the transmission case and with the sun wheel which is located on the output-side of the planetary stage, and on the second planetary gear disposed on the input side of the planetary stage, the planet carrier is grouped with the hollow wheel which is secured to the transmission case and with the sun wheel which is located on the output side of the planetary stage, whereby the sun wheel of the first planetary gear is operatively connected to the hollow wheel of the differential gear stage and the sun wheel of the second planetary gear is operatively connected to the planet carrier of the differential gear stage.

15. A transmission, in particular for wind power installations, comprising:

a transmission case;

an input shaft and an output shaft supported in the transmission case;

an input-side planetary stage disposed between the input shaft and the output shaft and having at least two power-splitting planetary gears of equal dimensions and being connected in parallel, the planetary stage further comprising two sun shafts; and

at least one active differential gear stage implemented as a differential spur gear pair with opposing helical gears that is softly supported in the axial direction, the differential spur gear pair further including two differential spur wheels, wherein the differential spur gear pair splits the load equally between the two connected sun shafts and contributes to a total gear ratio of the transmission, and wherein one of the two sun shafts is operatively connected with one of the differential spur wheels and the other sun shaft is operatively connected with the other differential spur wheel.

16. The transmission of claim 15, wherein the planetary stage includes exactly two planetary gears that are connected in parallel and arranged sequentially.

17. The transmission of claim 15, wherein the planetary stage includes a common planet carrier and is connected with the input shaft via the common planet carrier.

18. The transmission of claim 15, further comprising an axially soft coupling arranged coaxially between the differential spur gear pair and a coaxial spur wheel disposed on an output side of the differential gear stage, said coupling providing the axially soft support of the differential spur gear pair.

19. The transmission of claim 15, wherein the differential spur gear pair and the corresponding differential spur wheels that each are connected with a respective one of the two sun shafts provide a geared-up transmission ratio with respect to one another.

20. The transmission of claim 16, wherein the sun shaft of a first of the planetary gears together with the sun shaft of a second of the planetary gears form a coaxial hollow shaft arrangement.

21. The transmission of claim 19, and further comprising an additional spur gear stage disposed between the differential spur wheels and the differential spur gear pair, said additional spur gear stage providing a geared-up transmission ratio.

22. A transmission in particular for wind power installations comprising:

a transmission case;

an input shaft and an output shaft supported in the transmission case;

an input-side planetary stage disposed between the input shaft and the output shaft and having at least two power-splitting planetary gears of equal dimensions and being connected in parallel,

at least one active differential gear stage connected downstream of the power-splitting planetary gears for equalizing an uneven load distribution between each of the parallel connected power-splitting planetary gears.