System and method for pre-loading bearings
AssigneeTesla, Inc.
InventorsScott Michael Graves, Luke Ottaway, Ian Felder
Life of this patent
Estimating the term…
Abstract
A drive unit is disclosed that includes case portions, a gasket interposed between the case portions, shafts, bearings having respective bearing races, and a bearing shim plate. One shaft includes an input oil tube which provides a fluid pathway between the bearing shim plate and a rotor of the drive unit. Interposed between bearings, and the bearing shim plate, are shims. An approach for sizing shims for use with a drive unit is also disclosed, the approach including determining the distance from a mating flange of a case portion, to different bearing races, selecting shims based on the determined distances, and attaching the bearing shim plate to the case portion with shims interposed therebetween.
Claims20
A method of selecting shims for use in an electric drive unit comprising a first bearing, a second bearing, a first gear shaft positioned within the first bearing and the second bearing, a first case portion holding the first bearing and defining a mating flange, a second case portion holding the second bearing, and a bearing shim plate, wherein the first case portion is attached to the second case portion with a gasket interposed between the first case portion and the second case portion, the method comprising:
- determining a first distance from the mating flange of the first case portion to a first bearing race of the first bearing;
- selecting a first shim based on the first distance from the mating flange of the first case portion to the first bearing race of the first bearing to apply a first axial pre-load to the first bearing and the second bearing;
- and
- attaching the bearing shim plate to the first case portion with the first shim interposed between a bearing shim plate gasket and the first bearing race, with the bearing shim plate gasket interposed between the bearing shim plate and the first shim, and with the bearing shim plate gasket further interposed between the bearing shim plate and the first case portion.
An electric drive unit comprising:
- a first bearing;
- a second bearing;
- a first gear shaft positioned within the first bearing and the second bearing;
- a first case portion holding the first bearing and defining a mating flange;
- a second case portion holding the second bearing;
- a gasket;
- a bearing shim plate gasket;
- a first shim selected based on a first distance from the mating flange of the first case portion to a first bearing race of the first bearing to apply a first axial pre-load to the first bearing and the second bearing;
- and
- a bearing shim plate attached to the first case portion with the first shim interposed between the bearing shim plate gasket and the first bearing race, with the bearing shim plate gasket interposed between the bearing shim plate and the first shim, and with the bearing shim plate gasket further interposed between the bearing shim plate and the first case portion;
- wherein the first case portion is attached to the second case portion holding the second bearing with the gasket interposed between the first case portion and the second case portion holding the second bearing.
An electric drive unit comprising:
- a first bearing having a first bearing race;
- a second bearing;
- a third bearing having a third bearing race;
- a fourth bearing;
- a first gear shaft positioned within the first bearing and the second bearing;
- a second gear shaft positioned within the third bearing and the fourth bearing;
- a first case portion holding the first bearing and the third bearing, and defining a mating flange;
- a second case portion holding the third bearing and the fourth bearing;
- a gasket;
- a bearing shim plate gasket;
- a first shim;
- a second shim;
- a bearing shim plate:
- attached to the first case portion with the first shim interposed between the bearing shim plate gasket and the first bearing race, with the bearing shim plate gasket interposed between the bearing shim plate and the first shim, and with the bearing shim plate gasket further interposed between the bearing shim plate and the first case portion;
- and
- attached to the first case portion with the second shim interposed between the bearing shim plate gasket and the third bearing race, with the bearing shim plate gasket interposed between the bearing shim plate and the second shim, and with the bearing shim plate gasket further interposed between the bearing shim plate and the first case portion;
- wherein the first case portion is attached to the second case portion holding the third bearing and the fourth bearing with the gasket interposed between the first case portion and the second case portion holding the third bearing and the fourth bearing;
- wherein the first shim applies a first axial pre-load to the first bearing and the second bearing;
- and
- wherein the second shim applies a second axial pre-load to the third bearing and the fourth bearing.
Dependencies are inferred from the claim text.