US 11,598,653 B2Granted

Rotational angle detection apparatus and rotating machine apparatus

AssigneeTDK Corporation

InventorsMasaki Nagata, Kazuya Watanabe, Hiraku Hirabayashi

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Abstract

A rotational angle detection apparatus is provided with a magnet disposed so as to be rotatable integrally with an axis of rotation, having a substantially circular shape when viewed along the axis of rotation, and including a magnetization vector component in a direction orthogonal to the axis of rotation; a magnetic sensor that outputs a sensor signal on the basis of change in a magnetic field accompanying rotation of the magnet; and a rotational angle detector that detects a rotational angle of the rotating body on the basis of the sensor signal output by the magnetic sensor; wherein the magnet has a curved inclined surface with a concave shape along the axis of rotation from a prescribed position on the outer side in a radial direction toward the axis of rotation, and when a circular virtual plane orthogonal to the axis of rotation and centered at the axis of rotation is established at a position opposed to the curved inclined surface, the magnetic sensor is disposed at a position at which the amplitudes of a magnetic field intensity Hr in a radial direction and a magnetic field intensity Hθ in a circumferential direction on the virtual plane are substantially the same, and the magnetic field intensities Hr and Hθ in the radial direction and/or the circumferential direction is output as the sensor signal.

Claims13

Dependent claims

A rotational angle detection apparatus comprising:

a magnet located to be rotatable integrally with an axis of rotation accompanying rotation of a rotating body, wherein the magnet has a substantially circular shape when viewed along the axis of rotation, and wherein the magnet includes a magnetization vector component in a direction orthogonal to the axis of rotation;
and
a magnetic sensor that outputs a sensor signal based on change in a magnetic field accompanying rotation of the magnet, wherein
the magnet has a first magnet section and a second magnet section that is integrated with the first magnet section;
the first magnet section is positioned on a first axial end of the magnet;
the second magnet section is positioned on a second axial end of the magnet, wherein the first axial end of the magnet is opposite to the second axial end of the magnet;
the first magnet section includes a first surface substantially orthogonal to the axis of rotation and a curved inclined surface;
the second magnet section includes a second surface, which is substantially orthogonal to the axis of rotation and is opposed to the first surface of the first magnet section;
the second magnet section further includes a side surface, which is connected with an outer perimeter of the second surface;
the side surface of the second magnet section is substantially parallel to the axis of rotation;
the side surface of the second magnet section includes a first edge that is positioned on one side of the axial direction of the axis of rotation and a second edge that is positioned on the other side of the axial direction of the axis of rotation;
in a cross section of the magnet taken along the axis of rotation, the curved inclined surface includes a first end that is connected with the outer perimeter of the first surface of the first magnet section and a second end that is positioned farther from the axis of rotation than the first end;
the second end is connected with the second magnet section at a position closer to the axis of rotation than the second edge of the side surface of the second magnet section;
the curved inclined surface is sloped while curving in a concave shape toward the axis of rotation;
and
in a cross section of the magnet taken along the axis of rotation, the magnetic sensor is located in a region that is enclosed by a first virtual plane parallel to the axis of rotation and including the side surface of the second magnet section, a second virtual plane orthogonal to the axis of rotation and including the first surface of the first magnet section, a part of an outer perimeter of the second magnet section and the curved inclined surface of the first magnet section;
and
the part of the outer perimeter is connected between the second end of the curved inclined surface and the second edge of the side surface.

15 more elements

A rotational angle detection apparatus comprising:

a magnet located to be rotatable integrally with an axis of rotation accompanying rotation of a rotating body, wherein the magnet has a circular shape when viewed along the axis of rotation, and wherein the magnet includes a magnetization vector component in a direction orthogonal to the axis of rotation;
and
a magnetic sensor that outputs a sensor signal based on change in a magnetic field accompanying rotation of the magnet, wherein
the magnet has a first magnet section and a second magnet section that is integrated with the first magnet section;
the first magnet section is positioned on a first axial end of the magnet;
the second magnet section is positioned on a second axial end of the magnet, wherein the first axial end of the magnet is opposite to the second axial end of the magnet;
the first magnet section includes a first surface orthogonal to the axis of rotation and a curved inclined surface;
the second magnet section includes a second surface, which is orthogonal to the axis of rotation and is opposed to the first surface of the first magnet section;
the second magnet section further includes a side surface, which is connected with an outer perimeter of the second surface;
the second magnet section includes a notch in which a portion of the first magnet section side of the side surface is cut away;
the side surface of the second magnet section is parallel to the axis of rotation;
the side surface of the second magnet section includes a first edge that is positioned on one side of the axial direction of the axis of rotation and a second edge that is positioned on the other side of the axial direction of the axis of rotation;
in a cross section of the magnet taken along the axis of rotation, the curved inclined surface includes a first end that is connected with the outer perimeter of the first surface of the first magnet section and a second end that is positioned farther from the axis of rotation than the first end;
the notch is connected between the second edge of the side surface and the second end of the curved inclined surface;
the curved inclined surface is sloped while curving in a concave shape toward the axis of rotation;
and
in a cross section of the magnet taken along the axis of rotation, the magnetic sensor is located in a region that is enclosed by a first virtual plane parallel to the axis of rotation and including the side surface of the second magnet section, a second virtual plane orthogonal to the axis of rotation and including the first surface of the first magnet section, a surface connected between the second edge and the second end and the curved inclined surface of the first magnet section.

14 more elements

A rotational angle detection apparatus comprising:

a magnet located to be rotatable integrally with an axis of rotation accompanying rotation of a rotating body, wherein the magnet has a circular shape when viewed along the axis of rotation, and wherein the magnet includes a magnetization vector component in a direction orthogonal to the axis of rotation;
and
a magnetic sensor that outputs a sensor signal based on change in a magnetic field accompanying rotation of the magnet, wherein
the magnet has a first magnet section and a second magnet section that is integrated with the first magnet section;
the first magnet section is positioned on a first axial end of the magnet;
the second magnet section is positioned on a second axial end of the magnet, wherein the first axial end of the magnet is opposite to the second axial end of the magnet;
the first magnet section includes a first surface orthogonal to the axis of rotation and a curved inclined surface;
the second magnet section includes a second surface, which is orthogonal to the axis of rotation and is opposed to the first surface of the first magnet section;
the second magnet section further includes a side surface, which is connected with an outer perimeter of the second surface;
the second magnet section has a protrusion protruding toward the first magnet section side;
the protrusion includes an outer side surface that is flush with the side surface of the second magnet section, an end surface that is connected with an end of the outer side surface on the first magnet section side and substantially orthogonal to the axis of rotation and an inner side surface that is connected with an end of the end surface on the axis of rotation and substantially parallel to the axis of rotation;
the side surface of the second magnet section is parallel to the axis of rotation;
the side surface of the second magnet section includes a first edge that is positioned on one side of the axial direction of the axis of rotation and a second edge that is positioned on the other side of the axial direction of the axis of rotation;
in a cross section of the magnet taken along the axis of rotation, the curved inclined surface includes a first end that is connected with the outer perimeter of the first surface of the first magnet section and a second end that is positioned farther from the axis of rotation than the first end;
the curved inclined surface is sloped while curving in a concave shape toward the axis of rotation;
and
in a cross section of the magnet taken along the axis of rotation, the magnetic sensor is located in a region that is enclosed by a first virtual plane parallel to the axis of rotation and including the side surface of the second magnet section, a second virtual plane orthogonal to the axis of rotation and including the first surface of the first magnet section, the end surface and the inner side surface of the protrusion and the curved inclined surface of the first magnet section.

14 more elements

Dependencies are inferred from the claim text.

Facts

Application: 17/825,715Filed 26 May 2022 · continuation
Priority: JP JP2016-04862211 Mar 2016
Published: US 2022/0282996 A18 Sep 2022
Granted: 7 Mar 2023
Term ends: Not estimatedThe source records don’t support an estimate.

Classification5 codes

G01D 5/2033
By influencing the self-induction of one or more coils: controlling the saturation of a magnetic circuit by means of a movable element, e.g. a magnet
G01D 5/145
Using Hall-effect devices: influenced by the relative movement between the Hall device and magnetic fields
G01D 5/16
Influencing the magnitude of a current or voltage: by varying resistance
G01D 2205/77
Position sensors comprising a moving target with particular shapes, e.g. of soft magnetic targets: specific profiles

Family

Application15/450,273Parent of this continuation · filed 6 Mar 2017
Application16/876,251Parent of this continuation · filed 18 May 2020
US 10,697,801 B2Parent of this continuation · filed 30 Jun 2020
US 2022/0282996 A1Pre-grant publication · published 8 Sep 2022
US 11,371,863 B2Parent of this continuation
US 2017/0261349 A1Published application
US 2020/0284616 A1Published application
US 11,598,653 B2This patent

From the US filing history. Foreign family members aren’t listed.