Support assembly
A support assembly includes a casing having an internal assembly seat and a cylindrical seat formed on an axially inner side of the internal assembly seat, a bearing unit mounted within the internal assembly seat of the casing and including a stationary radially outer ring inserted in the assembly seat of the casing and comprising an axially internal annular surface and a rotating radially inner ring. A sealing device interposed between the two rings includes a first shield interference fitted onto a radially outer surface of the radially inner ring and a second shield arranged on an axially inner side of the first shield and interference fit onto the cylindrical seat of the casing. A spacer is positioned axially between the radially outer ring and the second shield, and may be formed separately from or integrally with the second shield.
1 . A support assembly comprising:
a bearing unit having an axis of rotation;
a casing having an axially inner end and an axially outer end spaced apart along the axis of rotation, the casing comprising an internal assembly seat and a cylindrical seat formed on an axially inner side of the internal assembly seat, the bearing unit being mounted within the internal assembly seat of the casing, the bearing unit comprising:
a stationary radially outer ring inserted in the assembly seat of the casing and comprising an axially inner annular surface; and
a rotating radially inner ring;
a sealing device comprising:
a first shield interference fitted onto a radially outer surface of the radially inner ring; and
a second shield arranged on an axially inner side of the first shield and interference fit onto the cylindrical seat of the casing; and
a spacer positioned axially between the radially outer ring and the second shield, the spacer being slidable axially inward along the casing in response to a misalignment of the bearing unit within the assembly seat of the casing.
2 . The support assembly of claim 1 , wherein;
the spacer comprises an open ring shape with an opening separating two annular ends of the open ring;
the spacer is received within the assembly seat of the casing in a position axially inward of the radially outer ring; and
an axially outer surface of the spacer abuts the axially inner annular surface of the radially outer ring.
3 . The support assembly of claim 2 , wherein;
the spacer further comprises a radially external surface comprising one of a conical shape or spherical shape; and
the radially external surface is configured to slide axially inward along the assembly seat of the casing so that the spacer contacts the second shield due to the misalignment of the bearing unit within the assembly seat of the casing.
4 . The support assembly of claim 3 , wherein the second shield is slidable in an axially inward direction along the cylindrical seat of the casing by up to 2 mm when the spacer pushes against the second shield due to the misalignment of the bearing unit within the assembly seat of the casing.
5 . The support assembly of claim 3 , wherein the spacer is separated from the first shield by a radial distance of at least 2 mm.
6 . The support assembly of claim 2 , wherein the spacer is separated from the second shield by an axial distance of at least 1 mm.
7 . The support assembly of claim 6 , wherein the spacer comprises a hardness of at least 80 Shore D.
8 . The support assembly of claim 2 , wherein the spacer further comprises a pair of holes opposite the opening.
9 . The support assembly of claim 2 , wherein the spacer is made of a metallic material.
10 . The support assembly of claim 2 , wherein the spacer is made of polyether ether ketone.
11 . The support assembly of claim 1 , wherein the second shield is made of polyether ether ketone.
12 . The support assembly of claim 1 , wherein assembly seat of the casing has a concave shape.
13 . The support assembly of claim 1 , wherein the bearing unit includes a plurality of balls between the radially outer ring and the radially inner ring.
14 . The support assembly of claim 1 , wherein the first shield and the spacer define a radial gap therebetween.
15 . A support assembly comprising:
a bearing unit having an axis of rotation;
a casing having an axially inner end and an axially outer end spaced apart along the axis of rotation, the casing comprising an internal assembly seat and a cylindrical seat formed on an axially inner side of the internal assembly seat, the bearing unit being mounted within the internal assembly seat of the casing, the bearing unit comprising:
a stationary radially outer ring inserted in the assembly seat of the casing and comprising an axially inner annular surface; and
a rotating radially inner ring; and
a sealing device comprising:
a first shield interference fitted onto a radially outer surface of the radially inner ring; and
a second shield arranged on an axially inner side of the first shield and interference fit onto the cylindrical seat of the casing, the second shield comprising:
a cylindrical portion mounted onto the cylindrical seat of the casing;
a shaped flange portion extending radially inward from the cylindrical portion; and
a spacer formed integrally with an axially outer end of the cylindrical portion, wherein the spacer extends axially outward from the cylindrical mounting portion and beyond an axially outer surface of the shaped flange portion.
16 . The support assembly of claim 15 , wherein;
the spacer further comprises a radially inner surface;
a radial distance between the radially inner surface of the spacer and the first shield is at least 2 mm; and
an axial distance between the spacer and the radially outer ring is at least 1 mm.
17 . The support assembly of claim 15 , wherein the second shield is slidable in an axially inward direction along the cylindrical seat of the casing by up to 2 mm when the radially outer ring pushes against the spacer due to a misalignment of the bearing unit within the assembly seat of the casing.
18 . The support assembly of claim 17 , wherein the second shield comprises a hardness of at least 80 Shore D.
19 . A support assembly comprising:
a bearing unit having an axis of rotation;
a casing having an axially inner end and an axially outer end spaced apart along the axis of rotation, the casing comprising an internal assembly seat and a cylindrical seat formed on an axially inner side of the internal assembly seat, the bearing unit being mounted within the internal assembly seat of the casing, the bearing unit comprising:
a stationary radially outer ring inserted in the assembly seat of the casing and comprising an axially inner annular surface; and
a rotating radially inner ring; and
a sealing device comprising:
a first shield interference fitted onto a radially outer surface of the radially inner ring; and
a second shield arranged on an axially inner side of the first shield and interference fit onto the cylindrical seat of the casing, the second shield comprising:
a cylindrical portion mounted onto the cylindrical seat of the casing;
a shaped flange portion extending radially inward from the cylindrical portion; and
a spacer formed integrally with an axially outer end of the cylindrical portion and a radially outer end of the shaped flange portion, the spacer comprising:
a corner; and
a radially outer edge extending from the corner to a radially inner end, wherein an axial thickness of the radially outer edge increases in a radially outward direction from the radially inner end to the corner.
20 . The support assembly of claim 19 , wherein the second shield is slidable in an axially inward direction along the cylindrical seat of the casing by up to 2 mm when the radially outer ring pushes against the spacer due to a misalignment of the bearing unit within the assembly seat of the casing.
21 . The support assembly of claim 20 , wherein the first shield comprises a radially outer end separated from the radially inner end of the radially outer edge of the spacer by a radial distance.
22 . The support assembly of claim 21 , wherein the spacer comprises a hardness of at least 80 Shore D.
23 . The support assembly of claim 21 , wherein the spacer is separated from the radially outer ring an axial distance of at least 1 mm.