Gear pair for a lifting vessel

1. A gear pair for a lifting vessel for a rack and pinion drive for lowering and raising a jack-up leg of the lifting vessel: said gear pair comprising:

two gear units comprising a first gear unit and a second gear unit driving in opposite directions of rotation and configured for engagement with two tooth racks on the jack-up leg, respectively; each said gear unit comprising:

a drive shaft for connection to a drive,

an output shaft for connection to a drive pinion,

a transmission housing, and

a planetary stage mounted in the transmission housing;

the first gear unit comprising a first torque support configured to enable support of the first gear unit on the second gear unit, said first torque support of the first gear unit surrounding the transmission housing of the second gear unit in a spincer-like manner and contacting the transmission housing of the second gear unit symmetrically with respect to a straight line connecting the output shafts of the gear units at two first support points on the first torque support, the two first support points in relation to a first vertical plane extending through the output shaft of the second gear unit and are located offset towards the first gear unit having the first torque support;

the second gear unit comprising a second torque support configured to enable support of the second gear unit on the first gear unit, said second torque support of the second gear unit surrounding the transmission housing of the first gear unit in a spincer-like manner and contacting the transmission housing of the first gear unit symmetrically with respect to a straight line connecting the output shafts of the gear units at two second support points on the second torque support, the two second support points in relation to a second vertical plane extending through the output shaft of the first gear unit and are located offset towards the second gear unit having the second torque support;

the first two support points and the second two support points are located between the first and second vertical planes extending through the output shafts of the gear units.

2. The gear pair of claim 1 , wherein the transmission housing of each said first and second gear units has a ring-shaped cross-section in an area in which the first and second torque supports are mounted or fitted.

3. The gear pair of claim 1 , wherein the first vertical plane and a section between the output shaft of the second gear unit and the first two support points define a first angle in a first range of 5 to 10 degrees and wherein the second vertical plane and a section between the output shaft of the first gear unit and the second two support points define a second angle in a second range of 5 to 10 degrees.

4. The gear pair of claim 1 , wherein the transmission housing of the first gear unit has in a region of maximum diameter a ring-shaped flange for fastening of the first torque support, said second support points of the second torque support of the second gear unit being located on the flange.

5. A rack and pinion drive for lowering and raising of a jack-up leg of a lifting vessel, comprising:

a support structure configured for connection to the lifting vessel and having symmetrical circular recesses on both sides of a line along which the jack-up leg with mounted toothed racks is movable;

a gear pair radially separated from the support structure and rotatable in two horizontally adjacent ones of the recesses, said gear pair including two gear units comprising a first gear unit and a second gear unit driving in opposite directions of rotation and configured for engagement with two tooth racks on the jack-up leg, respectively, each said gear unit comprising:

a drive shaft for connection to a drive,

an output shaft,

a transmission housing, and

at least one planetary stage mounted in the transmission housing,

the first gear unit comprising a first torque support configured to enable support of the first gear unit on the second gear unit, said first torque support of the first gear unit surrounding the transmission housing of the second gear unit in a spincer-like manner and contacting the transmission housing of the second gear unit symmetrically with respect to a straight line connecting the output shafts of the gear units at two first support points on the first torque support, the two first support points in relation to a first vertical plane extending through the output shaft of the second gear unit and are located offset towards the first gear unit having the first torque support;

the second gear unit comprising a second torque support configured to enable support of the second gear unit on the first gear unit, said second torque support of the second gear unit surrounding the transmission housing of the first gear unit in a spincer-like manner and contacting the transmission housing of the first gear unit symmetrically with respect to a straight line connecting the output shafts of the gear units at two second support points on the second torque support, the two second support points in relation to a second vertical plane extending through the output shaft of the first gear unit and are located offset towards the second gear unit having the second torque support;

the first two support points and the second two support points are located between the first and second vertical planes extending through the output shafts of the gear units;

two motors connected to the drive shafts of the first and second gear units; and

two drive pinions connected to the output shafts of the first and second gear units in one-to-one correspondence.

6. The rack and pinion drive of claim 5 , wherein the at least one planetary stage of each of the first and second gear units is one planetary stage, the planetary stage including a planetary carrier, said transmission housings of the first and second gear units mounted on a double bearing of the respective planetary carriers.

7. The rack and pinion drive of claim 5 , wherein the at least one planetary stage of each of the first and second gear units is two planetary stages, the first and second transmission housings mounted on a double bearing of a respective planetary carrier of a respective planetary main stage of the two planetary stages.

8. The rack and pinion drive of claim 5 , wherein the transmission housing of each of the first and the second gear units having a flange on an output side, said drive pinions having each a drive pinion shaft, with the flanges of the transmission housings being each arranged in a region of a spherical roller bearing of the drive pinion shafts.

9. A lifting vessel, comprising a rack and pinion drive, said rack and pinion drive comprising:

a support structure configured for connection to the lifting vessel and having symmetrical circular recesses on both sides of a line along which a jack-up leg with two mounted tooth racks is movable;

a gear pair radially separated from the support structure and rotatable in two horizontally adjacent ones of the recesses, said gear pair including two gear units driving in opposite directions of rotation and configured for engagement with said two tooth racks on the jack-up leg, respectively, each said gear unit comprising:

a drive shaft for connection to a drive,

an output shaft,

a transmission housing, and

at least one planetary stage mounted in the transmission housing,

the first gear unit comprising a first torque support configured to enable support of the first gear unit on the second gear unit, said first torque support of the first gear unit surrounding the transmission housing of the second gear unit in a spincer-like manner and contacting the transmission housing of the second gear unit symmetrically with respect to a straight line connecting the output shafts of the gear units at two first support points on the first torque support, the two first support points in relation to a first vertical plane extending through the output shaft of the second gear unit and are located offset towards the first gear unit having the first torque support;

the second gear unit comprising a second torque support configured to enable support of the second gear unit on the first gear unit, said second torque support of the second gear unit surrounding the transmission housing of the first gear unit in a spincer-like manner and contacting the transmission housing of the first gear unit symmetrically with respect to a straight line connecting the output shafts of the gear units at two second support points on the second torque support, the two second support points in relation to a second vertical plane extending through the output shaft of the first gear unit and are located offset towards the second gear unit having the second torque support;

the first two support points and the second two support points are located between the first and second vertical planes extending through the output shafts of the gear units;

two motors connected to the drive shafts of the first and second gear units; and

two drive pinions connected to the output shafts of the first and second gear units in one-to-one correspondence.

10. The lifting vessel of claim 9 , wherein the at least one planetary stage of each of the first and second gear units is one planetary stage, the planetary stage including a planetary carrier, said transmission housings of the first and second gear units mounted on a double bearing of the respective planetary carriers.

11. The lifting vessel of claim 9 , wherein the at least one planetary stage of each of the first and second gear units is two planetary stages, the first and second transmission housings mounted on a double bearing of a respective planetary carrier of a respective planetary main stage of the two planetary stages.

12. The lifting vessel of claim 9 , wherein the transmission housing of each of the first and the second gear units having a flange on an output side, said drive pinions having each a drive pinion shaft, with the flanges of the transmission housings being each arranged in a region of a spherical roller bearing of the drive pinion shafts.