Compact labyrinth-type seal

A seal for creating between two components, one of which rotates relative to the other about an axis of rotation, a barrier to the passage of a grease-type lubricant and contaminants, said seal having an axis that coincides with the axis of rotation when the seal is installed on one of the components, said seal comprising:

• a generally rigid seal case;
• a circular first labyrinth having a circumferentially extending face that is presented toward the axis of rotation and at least one end face that is located at an angle with respect to the circumferentially extending face;
• a circular second labyrinth carried by the seal case and being spaced from the first labyrinth, the second labyrinth having at least one groove that opens axially away from the first labyrinth;
• and a flexible dirt lip carried by the seal case and being located between first and second labyrinths, the dirt lip extending inwardly toward the axis of rotation, and having a contact face which, when the dirt lip is unrestrained, possesses a diameter less than the diameter of the circumferentially extending face of the first labyrinth.

In combination with a pair of machine components which are arranged such that one will rotate relative to the other about an axis of rotation, the one component being hollow and the other component being received in the hollow component and carrying a sealing surface that has a generally axially directed portion and a generally radially directed portion, a seal for isolating within the hollow component a region that contains a grease-type lubricant, said seal comprising:

• a generally rigid seal case attached to the hollow component such that a static seal exists between the case and the hollow component;
• a primary labyrinth attached to the seal case and having a circumferentially extending face that is presented toward and surrounds the axial portion of the sealing surface, yet is spaced outwardly from the axial portion, and an end face that is presented toward and exposed to the isolated region;
• a secondary labyrinth attached to the seal case and presented toward, but being spaced from, the radial portion of the sealing surface, the secondary labyrinth having a groove which opens toward the radially directed portion of the sealing surface;
• and a flexible dirt lip attached to the seal case and being located between the primary and secondary labyrinths, the dirt lip being directed generally away from the primary labyrinth and contacting the sealing surface.