Patent ID: 9551595
Date: 2017-01-24
CPC Classifications: G01D

Claim:
1. An induction detecting type rotary encoder comprising: a stator; a rotor disposed opposite the stator, the rotor being rotatable around a rotation axis; a first transmitting coil provided in the stator, the first transmitting coil including a first inner circumference coil and a first outer circumference coil that allow respective currents to flow therethrough in the same rotational direction while being centered on the rotation axis; a second transmitting coil provided in the stator, the second transmitting coil including a second inner circumference coil and a second outer circumference coil that allow respective currents to flow therethrough in different rotational directions while being centered on the rotation axis; a first receiving coil provided in the stator, the first receiving coil being formed in a circular first region at a center of which the rotation axis is positioned; a second receiving coil provided in the stator, the second receiving coil being formed in a circular second region, the second region being disposed over or under the first region in a direction along the rotation axis, a first insulating layer being interposed between the first receiving coil and the second receiving coil; a first magnetic flux coupling body provided in the rotor, the first magnetic flux coupling body being formed in a circular third region at a center of which the rotation axis is positioned; and a second magnetic flux coupling body provided in the rotor, the second magnetic flux coupling body being formed in a circular fourth region, the fourth region being disposed over or under the third region in the direction along the rotation axis, a second insulating layer being interposed between the first magnetic flux coupling body and the second magnetic flux coupling body, wherein the closest distance between the first inner circumference coil and the second magnetic flux coupling body is shorter than the closest distance between the first outer circumference coil and the second magnetic flux coupling body, and the closest distance between the second inner circumference coil and the first magnetic flux coupling body is shorter than the closest distance between the second outer circumference coil and the first magnetic flux coupling body.