| 摘要 |
<p>A seal for closing an annular space between two machine components, such as the races of an antifriction bearing, includes a case (26) which is pressed into the outer component and a shield (28) which is pressed over the inner component and has axial (38, 44) and radial walls (40, 42). The case (26) carries an elastomeric seal element (30) which establishes multiple fluid barriers along the shield (28). To this end, the seal element (30) has a mounting portion (46) which lies along the axial wall (42) of the shield (28), creating a labyrinth which is enhanced with wedge-shaped pumping cavities (54). The seal element (30) also has a contact lip portion (48) attached to the mounting portion at a groove (66) which opens generally away from the axis. The lip portion has two edges - a radially directed one along the axial wall of the shield and an axially directed one along the radial wall. The groove (66) contains a garter spring (33) which bears against the side walls (70, 72) of the groove (66), yet is remote from the bottom wall. The spring (33), which has its cross-sectional center offset from the radial edge toward the mounting portion urges the axially directed edge against the radial wall of the shield and the radially directed edge against the axial wall, thus establishing two more dynamic fluid barriers. Another elastomeric seal element (32) may be bonded to the shield (28) and its has a lip (80) which contacts the case (26), forming still another dynamic fluid barrier.</p> |
