Labyrinth seal with interlocking rotor and seal case insert

1. A labyrinth seal, comprising:

a seal case with an inner-diameter leg encircling a rotation axis;

an insert encircling the rotation axis, the insert having a first side contacting the seal case and a second side facing away from the seal case, the insert forming a second locking leg that extends axially away from the second side;

a slinger encircling the rotation axis and wrapping around the inner-diameter leg to cooperate with the seal case to form a first part of a labyrinth path, the slinger having a second innermost leg that forms a second locking feature protruding radially away from the rotation axis; and

a rotor encircling the rotation axis and cooperating with the insert to form a second part of the labyrinth path, the rotor having a first innermost leg and a first locking leg, wherein the first locking leg (i) is radially farther from the rotation axis than the second locking feature, (ii) extends axially toward the second side of the insert to axially overlap with the second locking leg, and (iii) forms a first locking feature that protrudes radially toward the rotation axis, the first locking feature being axially closer to the first side of the insert than the second locking feature;

wherein:

the first innermost leg and the second innermost leg extend axially toward each other to limit axial movement of the rotor toward the slinger; and

the first locking feature extends radially to overlap with the second locking feature such that the second locking feature, when engaged with the first locking feature, limits axial movement of the rotor away from the insert.

2. The labyrinth seal of claim 1 , the first innermost leg and the second innermost leg cooperating to connect the first part and the second part of the labyrinth path.

3. The labyrinth seal of claim 1 , the first locking feature including a plurality of protruding features spaced apart from each other, disposed at different respective azimuthal locations relative to the rotation axis, and protruding from the first locking leg toward the rotation axis.

4. The labyrinth seal of claim 1 , the rotor being made of polymer.

5. The labyrinth seal of claim 4 , the rotor including a middle section connecting the first innermost leg with the first locking leg.

6. The labyrinth seal of claim 5 , the first innermost leg and the first locking leg being parallel to the rotation axis.

7. The labyrinth seal of claim 4 , the insert being made of polymer.

8. The labyrinth seal of claim 1 , the first locking feature including a continuous rim encircling the rotation axis and protruding from the first locking leg toward the rotation axis.

9. The labyrinth seal of claim 1 , the seal case further including:

an outer-diameter leg; and

an axially oriented leg and a radially oriented leg forming a step, the insert being press fit into the step; each of the axially oriented leg and radially oriented leg being located between the inner-diameter leg and the outer-diameter leg.

10. A roller bearing assembly, comprising:

a bearing cone;

a bearing cup encircling the bearing cone;

a plurality of rollers disposed between the bearing cone and the bearing cup to allow the bearing cone to rotate relative to the bearing cup; and

the labyrinth seal of claim 1 , the seal case further including an outer-diameter leg that (i) encircles the rotation axis, (ii) has a diameter greater than a diameter of the inner-diameter leg, and (iii) is rigidly coupled to the bearing cup;

wherein the rotor and the slinger are mounted on a cylindrical surface of the bearing cone, and the rotor interlocks with the insert to limit axial movement of the rotor toward the plurality of rollers.

11. The roller bearing assembly of claim 10 , the rotor being interference fit onto the bearing cone.

12. A method for sealing a roller bearing, comprising:

press fitting a rotor onto a bearing cone of the roller bearing;

coupling an outer-diameter leg of a seal case to a bearing cup of the roller bearing;

snap fitting an insert, fixed in the seal case, onto the rotor to (i) interlock the insert and rotor to limit axial movement of the rotor in a direction toward rollers disposed between the bearing cone and the bearing cup, and (ii) form a first part of a labyrinth path between the rotor and the insert, wherein said snap fitting comprises moving the seal case, with the insert affixed therein, toward the rotor such that a first locking leg of the insert snaps onto a second locking leg of the rotor; and

press fitting a slinger onto the bearing cone to (i) limit axial movement of the rotor in a direction away from the rollers, and (ii) form a second part of the labyrinth path between an inner-diameter leg of the seal case and the slinger.

13. The method of claim 12 , wherein:

the first locking leg extends toward the rotor and has first locking features protruding radially outward;

the second locking leg extends toward the insert and has second locking features protruding radially inward; and

said moving comprises moving the seal case such that the first locking features are moved axially past the second locking features.

14. The method of claim 12 , further comprising moving the seal case axially toward the bearing cup and rotor to simultaneously perform said coupling and snap fitting.