To provide a seal member having a magnetic encoder which integrally has a magnetic encoder section and a seal lip section while excellently expressing the magnetic property of the magnetic encoder section and the sealing property of the seal lip section, and to provide an effective manufacturing method of the same.
A seal member 10 having a magnetic encoder is configured to seal an annular space formed between two members 2 and 4 which rotate in a relatively coaxial manner. The encoder includes a reinforcement ring 11 which is fitted onto one member 4 among the two members; and a magnetic ring 12 which is fixedly attached to the reinforcement ring to constitute the magnetic encoder and has an annular seal lip section 15. The magnetic ring includes a multipole magnet section 13 composed of a magnetic rubber material gm containing magnetic powder, a contraction 14 having a cross sectional width smaller than a thickness dimension of the multipole magnet section, and the seal lip section integrally formed with the multipole magnet section via the contraction 14.
Okumura Kimitoshi
Shuko Okimoto