Rotational angle sensing device and assembling method thereof
AssigneeDenso Corporation
InventorsTakashi Kawashima, Takashi Hamaoka, Takao Ban
Life of this patent
Estimating the term…
Abstract
A magnet is provided to one of two members, which make relative rotation therebetween. First and second Hall elements are arranged adjacent to each other and are provided to the other one of the two members. A magnetic sensing surface of the first Hall element is generally perpendicular to a magnetic sensing surface of the second Hall element, and a relative rotational angle between the two members is determined through the first and second Hall elements based on a magnetic flux, which is generated by a magnetic flux generating portion of the magnet and passes through the first and second Hall elements toward a magnetic flux attracting portion of the magnet.
Claims10
A rotational angle sensing device for measuring a relative rotational angle between two members, which make relative rotation therebetween, the rotational angle sensing device comprising:
- a magnet that is provided to one of the two members and is configured into one of a ring shape and a circular disk shape, wherein a center of an outer peripheral edge circle, which is defined by an outer peripheral edge of the magnet, substantially coincides with a rotational axis of the relative rotation, and the magnet includes a magnetic flux generating portion and a magnetic flux attracting portion, which are diametrically opposed to each other;
- and
- first and second magnetic sensing elements that are arranged adjacent to each other and are provided to the other one of the two members, wherein a magnetic sensing surface of the first magnetic sensing element is generally perpendicular to a magnetic sensing surface of the second magnetic sensing element, and the relative rotational angle between the two members is determined through the first and second magnetic sensing elements based on a magnetic flux, which is generated by the magnetic flux generating portion and passes through the first and second magnetic sensing elements toward the magnetic flux attracting portion.
A method for assembling a rotational angle sensing device, the method comprising:
- installing two coaxial magnets, each of which is configured into one of a ring shape and a circular disk shape and has a magnetic flux generating portion and a magnetic flux attracting portion that are diametrically opposed to each other, wherein the magnetic flux generating portion and the magnetic flux attracting portion of one of the two magnets are axially aligned with the magnetic flux attracting portion and the magnetic flux generating portion, respectively, of the other one of the two coaxial magnets;
- installing first and second magnetic sensing elements to a predetermined location where magnetic fluxes of the two magnets are substantially cancelled with each other, so that a remaining magnetic flux in the predetermined location becomes substantially zero, wherein the first and second magnetic sensing elements are arranged adjacent to each other and have magnetic sensing surfaces, respectively, which are generally perpendicular to each other;
- and
- re-installing the one of the two coaxial magnets in such a manner that the magnetic flux generating portion and the magnetic flux attracting portion of the one of the two coaxial magnets are axially aligned with the magnetic flux generation portion and the magnetic flux attracting portion, respectively, of the other one of the two coaxial magnets.
A rotational angle sensing device for measuring a relative rotational angle between two members, which make relative rotation therebetween, the rotational angle sensing device comprising:
- a magnet that is provided to one of the two members and is configured into one of a ring shape and a circular disk shape, wherein a center of an outer peripheral edge circle, which is defined by an outer peripheral edge of the magnet, substantially coincides with a rotational axis of the relative rotation, and the magnet includes a magnetic flux generating portion and a magnetic flux attracting portion, which are diametrically opposed to each other;
- and
- first and second magnetic sensing elements that are arranged with respect to each other so that only one accommodating space is required for accommodating the first and second magnetic sensing elements and are provided to the other one of the two members, wherein a magnetic sensing surface of the first magnetic sensing element is generally perpendicular to a magnetic sensing surface of the second magnetic sensing element, and the relative rotational angle between the two members is determined through the first and second magnetic sensing elements based on a magnetic flux, which is generated by the magnetic flux generating portion and passes through the first and second magnetic ensing elements toward the magnetic flux attracting portion.
Dependencies are inferred from the claim text.