Rotational speed sensor with membrane
AssigneesNissan Motor Co., Ltd., Unisia Jecs Corporation, Nisshinbo Industries, Inc.
InventorsJunichi Onishi, Hideyuki Shibuya, Tadayuki Kuze
Life of this patent
Estimating the term…
Abstract
To prevent the adhesion or penetration of iron filings or other magnetically permeable material, thereby avoiding a short-circuit of the magnetic circuit and ensuring an accurate output signal, a membrane comprised of a non-magnetic material covers the bottom of a casing facing a rotor, and a protuberance of a length at least equal to the maximum air gap between the membrane and the rotor is integrally molded to a portion of the membrane.
Claims12
A two-polepiece type rotational speed sensor including a pickup component positioned to face a rotor affixed integrally to a rotating member of a vehicle, said pickup component comprising a housing having a solid floor, a bobbin mounted within said housing, a coil wrapped around a circumference of the bobbin, a layered body comprising a permanent magnet and two plates sandwiching said permanent magnet, said layered body being inserted into the center of the bobbin, and a non-magnetic elastic membrane uniformly affixed to a bottom surface of the floor of said housing, said membrane having at least one integrally formed protuberance of a thickness at least equal to a maximum air gap between the membrane and the rotor.
A two-polepiece type rotational speed sensor including a pickup component positioned to face a rotor affixed integrally to a rotating member of a vehicle, said pickup component comprising a housing having a solid floor, a bobbin mounted within said housing, a coil wrapped around a circumference of the bobbin, a layered body comprising a permanent magnet and two polepieces sandwiching said permanent magnet, said layered body being inserted into the center of the bobbin, and a non-magnetic elastic membrane uniformly affixed to a bottom surface of the floor of said housing, said membrane having a thickness at least equal to a maximum air gap between an end of each of said two polepieces and the rotor.
A two-polepiece type rotational speed sensor including a pickup component positioned to face a rotor affixed integrally to a rotating member of a vehicle, said pickup component comprising a housing having a solid floor, a bobbin mounted within said housing, a coil wrapped around a circumference of the bobbin, a layered body comprising a permanent magnet and two polepieces sandwiching said permanent magnet, said layered body being inserted into the center of the bobbin, and a non-magnetic elastic membrane uniformly affixed around a side surface of said housing facing said rotor.
Dependencies are inferred from the claim text.