US 11,703,079 B2
Bearing element with a smooth continuous profile
Kenneth Bischof, Arden, NC (US); and Zachary Ashton, Arden, NC (US)
Assigned to BorgWarner Inc., Auburn Hills, MI (US)
Appl. No. 17/255,171
Filed by BORGWARNER INC., Auburn Hills, MI (US)
PCT Filed Jun. 28, 2018, PCT No. PCT/US2018/040074
§ 371(c)(1), (2) Date Dec. 22, 2020,
PCT Pub. No. WO2020/005262, PCT Pub. Date Jan. 2, 2020.
Prior Publication US 2021/0262522 A1, Aug. 26, 2021
Int. Cl. F16C 17/02 (2006.01); F16C 17/18 (2006.01); F01D 25/16 (2006.01); F16C 17/26 (2006.01)
CPC F16C 17/028 (2013.01) [F01D 25/166 (2013.01); F16C 17/18 (2013.01); F16C 17/26 (2013.01); F16C 2360/24 (2013.01)] 18 Claims
OG exemplary drawing
 
1. A bearing element for use in a turbocharger comprising:
an inner surface having a smooth profile and comprising a plurality of sections, each section having a taper portion between a first arc-span point and a second arc-span point, a constant-radius portion between the second arc-span point and a third arc-span point, and a transition portion between the third arc-span point and a fourth arc-span point; and
an inner-surface radius dimension that changes from an inner-diameter major dimension at the first arc-span point to an inner-diameter minor dimension at the second arc-span point and changes from the inner-diameter minor dimension at the third arc-span point to the inner-diameter major dimension at the fourth arc-span point;
wherein:
the inner surface having the smooth profile comprises a continuous surface at the first, second, third, and fourth arc-span points; and
the fourth arc-span point of a first section adjoins the first arc-span point of a subsequent section, and the inner-surface radius dimension decreases at a constant rate per degree of angular direction through at least half of the taper portion.
 
6. A bearing element for use in a turbocharger comprising:
an inner surface configured to receive a cylindrical shaft, the inner surface having a smooth profile and comprising a plurality of sections, each section having a taper portion between a first arc-span point and a second arc-span point, a constant-radius portion between the second arc-span point and a third arc-span point, and a transition portion between the third arc-span point and a fourth arc-span point;
an inner-surface radius dimension that changes from an inner-diameter major dimension at the first arc-span point to an inner-diameter minor dimension at the second arc-span point and changes from the inner-diameter minor dimension at the third arc-span point to the inner-diameter major dimension at the fourth arc-span point;
a first angular distance between the first arc-span point and the second arc-span point; and
a second angular distance between the third arc-span point and the fourth arc-span point, the second angular distance being larger than the first angular distance; wherein:
the inner surface having the smooth profile comprises a continuous surface at the first, second, third, and fourth arc-span points; and
the fourth arc-span point of a first section adjoins a first arc-span point of a subsequent section; and the inner-surface radius dimension decreases at a constant rate per degree of angular direction through at least half of the taper portion.
 
17. A turbocharger bearing system comprising:
a first bearing element having:
an inner surface configured to receive a cylindrical shaft, the inner surface having a smooth profile and comprising a plurality of sections, each section having a taper portion between a first arc-span point and a second arc-span point, a constant-radius portion between the second arc-span point and a third axe-span point, and a transition portion between the third arc-span point and a fourth arc-span point;
an inner-surface radius dimension that changes from an inner-diameter major dimension at the first arc-span point to an inner-diameter minor dimension at the second arc-span point and changes from the inner-diameter minor dimension at the third arc-span point to the inner-diameter major dimension at the fourth arc-span point;
a first angular distance between the first arc-span point and the second arc-span point; and
a second angular distance between the third arc-span point and the fourth arc-span point, the first angular distance being larger than the second angular distance; wherein:
the inner surface having the smooth profile comprises a continuous surface at the first, second, third, and fourth arc-span points; and
the fourth arc-span point of a first section adjoins the first arc-span point of a subsequent section; and
a second bearing element configured to receive the cylindrical shaft; at least one of the first and second bearing elements comprises a bearing element having a varying ID-major dimension along a longitudinal axis; and the other of the first and second bearing elements comprises a bearing element having a constant ID-major dimension along the longitudinal axis.