Bearing assembly including bearing support ring configured to reduce thermal warping during use, bearing apparatuses using the same, and related methods

A bearing apparatus for use in a subterranean drilling system, comprising:

• a first bearing assembly including,
• a plurality of first superhard bearing elements distributed circumferentially about an axis and having a plurality of substantially coplanar superhard bearing surfaces;
• and
• a first support ring having the plurality of first superhard bearing elements mounted within recesses that terminate at a first depth in the first support ring, the first support ring including,
• at least one thermal-warping-reducing feature configured to reduce a radial moment, compared to if the at least one thermal-warping-reducing feature were absent from the support ring, the radial moment being thermally induced in the first support ring when the support ring and the plurality of first superhard bearing elements are exposed to operational temperature conditions, the at least one thermal-warping-reducing feature configured to increase compliance of the first support ring and to allow the plurality of first superhard bearing elements to move out of plane by about 0.02 degrees to 0.2 degrees responsive to the radial moment, the at least one thermal-warping-reducing feature including a slot extending into the support ring to at least the first depth;
• and
• a second bearing assembly including a plurality of second superhard bearing elements generally opposing the plurality of first superhard bearing elements of the first bearing assembly and distributed circumferentially about the axis.

A motor assembly for use in a subterranean drilling system, comprising:

• a motor operable to apply torque to a rotary drill bit;
• and
• a bearing apparatus operably coupled to the motor, the bearing apparatus including a rotor and a stator;
• and
• wherein at least one of the rotor or the stator comprises:
• a plurality of superhard bearing elements distributed circumferentially about an axis, each of the plurality of superhard bearing elements including a superhard bearing surface, the superhard bearing surfaces of the plurality of superhard bearing elements being substantially coplanar with each other;
• and
• a support ring having a plurality of recesses each extending inwardly and terminating at a first depth, each of the plurality of superhard bearing elements mounted at least partially within a corresponding one of the plurality of recesses, the support ring including,
• a plurality of radially-extending slots formed in the support ring, each of the plurality of radially-extending slots disposed between immediately circumferentially adjacent ones of the plurality of superhard bearing elements, each of the plurality of radially-extending slots extending into the support ring to at least the first depth, thereby increasing compliance of the support ring.

A method of operating a bearing apparatus in a subterranean drilling system, comprising:

• providing a first bearing assembly including,
• a plurality of first superhard bearing elements distributed circumferentially about an axis, each of the plurality of superhard bearing elements including a superhard bearing surface, the superhard bearing surfaces of the plurality of superhard bearing elements being substantially coplanar with each other;
• and
• a first support ring having a plurality of recesses each extending inwardly and terminating at a first depth, each of the plurality of first superhard bearing elements mounted at least partially within a corresponding one of the plurality of recesses, the support ring including,
• a plurality of radially-extending slots formed in the support ring, each of the plurality of radially-extending slots disposed between immediately circumferentially adjacent ones of the plurality of superhard bearing elements, each of the plurality of radially-extending slots extending into the support ring to at least the first depth;
• providing a second bearing assembly including,
• a plurality of second superhard bearing elements generally opposing the plurality of first superhard bearing elements of the first bearing assembly and distributed circumferentially about the axis;
• operating the bearing apparatus under hydrodynamic operational conditions in which a fluid film develops between the plurality of first superhard bearing elements and the plurality of second superhard bearing elements that prevents contact therebetween;
• and
• wherein the plurality of radially-extending slots increase compliance of the first support ring.