A rotation detection sensor, which is a wheel-speed sensor, has a detection unit placed in a metal capped cylindrical casing and a holder fit in an opening of the casing. A flange is provided along the entire edge of the opening of the casing. Between the flange and the holder, a viscoelastic liquid gasket is entirely applied. The edge of the opening of the casing and the exposed part of the holder are covered with a resin portion. Thus, the viscoelastic liquid gasket smoothly enters the gap between the casing and the holder to ensure the gap is closed. Moreover, since the viscoelastic liquid gasket is quickly cured owing to its solvent which is speedily volatilized, the gasket exhibits a good workability. Then, after the solvent is volatilized, a rubber-based elastic sealing material is produced. The sealing material thus withstands any temperature change without problem, it never occurs that the sealing material melts to leak out, and the sealing between the casing and the holder can be ensured.
A rotation sensor includes a rotation detector mounted on a holder which is in turn inserted in a casing through its opening. A cover is formed by molding a resin so as to cover the opening of the casing and the portion of the holder protruding from the opening of the casing. A pair of relay terminals extend through a base portion of the holder and a gap defined in the holder, are fixed to a support wall, and connected to respective lead pieces of the detector. A resin cover is formed by molding a resin. When forming the cover, pressure is applied to the holder, thereby causing the holder to bulge axially in the holder. This in turn pushes the relay terminals in the axial direction. But since the relay terminals are fixed to the support wall, the support wall will absorb such pushing force, thereby preventing such pushing from being transmitted to the detector. In order to more effectively absorb such pushing force, the relay terminals may be provided with bent portions in the gap.
