Spherical fluid-film bearing
A spherical fluid-film bearing for supporting a rotating shaft includes a first bearing element and a second bearing element positioned along the rotating shaft in opposite orientations. Each bearing element also includes a rotor having bearing surface formed as a spherical segment. Additional stabilizing features may be included in the spherical fluid-film bearing, including mechanical springs, hydraulic pistons and a high pressure lubrication system.
1 . A spherical fluid-film bearing for supporting a rotating shaft having an axis, comprising:
a first bearing element comprising:
a first rotor coupled to the rotating shaft and having a first bearing surface formed as a spherical segment running true to rotation around the shaft axis;
a plurality of first shoe segments having a first shoe surface complementary to the first bearing surface;
a first base ring retaining the plurality of first shoe segments around the first rotor, reacting against a thrust reaction plate; and
a first oil film between the first rotor and the plurality of first shoe segments; and
a second bearing element comprising:
a second rotor coupled to the rotating shaft and having a second bearing surface formed as a spherical segment also running true to rotation around the shaft axis;
a plurality of second shoe segments having a second shoe surface complementary to the second bearing surface;
a second base ring retaining the plurality of second shoe segments around the second rotor, reacting against the thrust reaction plate; and
a second oil film between the second rotor and the plurality of second shoe segments;
wherein the first bearing element and the second bearing element are facing in opposite directions along the rotating shaft.
2 . The spherical fluid-film bearing of claim 1 , wherein the first base ring and the second base ring each abut the thrust reaction plate, and further comprise a recess for receiving a spring for exerting force along the axis to urge the first base ring and the second base ring apart from each other.
3 . The spherical fluid-film bearing of claim 2 , wherein the spring is a coil spring or a Belleville spring.
4 . The spherical fluid-film bearing of claim 1 , further comprising:
a plurality of first hydraulic pistons extending through the first base ring to the plurality of first shoe segments, wherein the plurality of first hydraulic pistons corresponding to the plurality of first shoe segments; and
a plurality of second hydraulic pistons extending through the second base ring to the plurality of second shoe segments, wherein the plurality of second hydraulic pistons corresponding to the plurality of second shoe segments.
5 . The spherical fluid-film bearing of claim 4 , further comprising:
one or more sensors to detect operating conditions of the bearing and any equipment connected to the rotating shaft; and
a processing component for controlling the first and second hydraulic pistons in response to input from the sensors.
6 . The spherical fluid-film bearing of claim 1 , further comprising:
a high-pressure lubrication (HPL) system for supplying pressurized oil to the first oil film and the second oil film.
7 . The spherical fluid-film bearing of claim 6 , wherein the HPL system further comprises a plurality of channels in each bearing element.
8 . The spherical fluid-film bearing of claim 1 , wherein the plurality of first shoe segments and the plurality of second shoe segments are configured to pivot independently at a pivot point between each shoe segment and a respective base ring.
9 . The spherical fluid-film bearing of claim 8 , wherein an angle between the axis of the rotating shaft and the pivot point for each shoe segment may be changed based on the load experienced by the bearing.
10 . The spherical fluid-film bearing of claim 1 , wherein the plurality of first shoe segments form a convex spherical surface complementary to the first bearing surface and the plurality of second shoe segments form a hemispherical convex surface complementary to the second bearing surface.
11 . The spherical fluid-film bearing of claim 10 , wherein the convex spherical surface comprises a friction-minimizing material.
12 . The spherical fluid-film bearing of claim 1 , wherein the first base ring and the second base ring are between the first rotor and the second rotor.
13 . The spherical fluid-film bearing of claim 12 , wherein the first base ring and the second base ring have an inner diameter sized to provide clearance for the rotating shaft.
14 . The spherical fluid-film bearing of claim 13 , further comprising at least one oil seal between the first and second base rings and the rotating shaft.
15 . The spherical fluid-film bearing of claim 1 , further comprising a housing, where the first base ring and the second base ring are coupled to the housing.
16 . The spherical fluid-film bearing of claim 1 , wherein a length and a width of the first shoe surface and the second shoe surface are approximately equal.
17 . The spherical fluid-film bearing of claim 1 , further comprising six first shoe segments and six second shoe segments.
18 . The spherical fluid-film bearing of claim 1 , further comprising eight first shoe segments and eight second shoe segments.