US 4,799,808 A · Compact seal

Abstract

A compact seal assembly fits into the end of a bearing and effectively retains grease within the bearing while excluding contaminants, notwithstanding operation of the bearing within a hostile environment. The seal assembly includes a shield having an axial mounting portion which fits over the inner race of the bearing and an outwardly directed flange, as well as a smooth sealing surface on both. The seal has a case which fits into the outer face of the bearing and an elastomeric sealing element which establishes several barriers along the sealing surface of the shield. The first barrier exists at a pumping labyrinth which encircles, but is spaced outwardly from the axial segment of the sealing surface where it is exposed to the interior of the bearing. The labyrinth contains wedge-shaped cavities which pump the grease back toward the interior of the bearing. The next barrier is along a primary dirt lip which actually contacts the axial portion of the sealing surface, it being urged against that surface by a garter spring. Another barrier exists along a secondary dirt lip which contacts the radial portion of the sealing surface, that is the portion on the flange of the shield. The primary dirt lip lies between the pumping labyrinth and the secondary dirt lip, with these portions of the sealing element being separated by grooves. Rings of grease occupy the grooves, and this grease extends outwardly to and adheres to the sealing surface so as to establish still more barriers along the sealing surface.

Claims20

Dependent claims

In combination with a sealing surface that exists around an axis of rotation and has a generally axially directed portion and a generally radially directed portion, a seal for establishing a barrier with the sealing surface so as to isolate a region generally between two components, one of which carries the seal and the other the sealing surface, when relative rotation about the axis of rotation exists between the two components, said seal comprising a labyrinth having a first face presented toward, yet spaced from the axially directed portion of the sealing surface and a second face presented toward the isolated region;

a first dirt lip extended toward and bearing against the axially directed portion of the sealing surface;
and a second dirt lip extended toward and bearing against the generally radially directed portion of the sealing surface, the first dirt lip being located between the labyrinth and the second dirt lip.

A seal assembly mounted about an axis of rotation and comprising:

a shield formed from a generally rigid material and having a generally axially directed portion and a generally radially directed portion which projects outwardly from the axially directed portion, the shield having a sealing surface located along the axially directed portion where it is presented away from the axis of rotation and also along the radially directed portion;
and a seal including a case formed from a generally rigid material, a labyrinth attached to the case and encircling the sealing surface along the axial portion thereof, but being spaced outwardly from the sealing surface, first and second flexible dirt lips attached to the case and contacting the sealing surface, with the first dirt lip being located between the second dirt lip and the labyrinth, each dirt lip where it contacts the sealing surface being oblique to the sealing surface and further being inclined away from the labyrinth, so that an increase in pressure of sufficient magnitude in the region of the labrinth will cause at least the first dirt lip to separate from the sealing surface and vent the region by the labyrinth, the two dirt lips forming part of a flexible seal element which is bonded to the seal case and has a groove located between the two lips, with the groove opening toward the radial portion of the shield.

A seal assembly mounted about an axis of rotation and comprising:

a shield formed from a generally rigid material and having a generally axially directed portion and a generally radially directed portion which projects outwardly from the axially directed portion, the shield having a sealing surface located along the axially directed portion where it is presented away from the axis of rotation and also along the radially directed portion;
and a seal including a case formed from a generally rigid material, a labyrinth attached to the case and encircling the sealing surface along the axial portion thereof, but being spaced outwardly from the sealing surface, first and second flexible dirt lips attached to the case and contacting the sealing surface, with the first dirt lip being located between the second dirt lip and the labyrinth, the first lip contacting the sealing surface along the axial portion of the shield and the second lip contacting the sealing surface along the radial portion of the shield.

Dependencies are inferred from the claim text.

Compact seal

Life of this patent

Compact seal

Life of this patent

Abstract

Claims20