| 摘要 |
<p>The invention provides an oil seal for a valve stem which can be installed to a place having a narrow installation space even if a back pressure seal lip is provided, can stably exclude an influence of a back pressure to a main seal lip, by means of the back pressure seal lip, and can achieve a reduction of a change in an oil leaking amount. The oil seal for a valve stem is provided with a reinforcing ring (10) having an inclined portion (13) formed on an inner peripheral side of a radially extending portion (12) and extending toward a cam side (A), and a main seal portion (30) having a main seal lip (31) slidably brought into close contact with a valve stem (3) and extending toward the cam side (A), and a back pressure seal lip (40) positioned on a cylinder side (B) in relation to the main seal lip (31), the main seal portion (30) is positioned on the cam side (A) in relation to the radially extending portion (12), and the back pressure seal lip (40) is positioned on the cylinder side (B) in relation to an inner peripheral end portion (14) of the inclined portion (13).</p> |
