Coupler element shapes for inductive position sensors

Patent metadata

Field	Value
Publication number	US-11519752-B2
Application number	US-201916570216-A
Country	US
Kind code	B2
Filing date	Sep 13, 2019
Priority date	Sep 14, 2018
Publication date	Dec 6, 2022
Grant date	Dec 6, 2022

Abstract

In accordance with one embodiment of the present disclosure, an inductive position sensor assembly is provided. The inductive sensor assembly includes a sensor and a coupler element. The sensor includes a transmitter coil having an inner diameter and an outer diameter and a receiver coil positioned within the outer diameter of the transmitter coil. The coupler element has a geometric continuous curve shape. The coupler element is positioned within the outer diameter of the transmitter coil such that a maximum diameter of the geometric continuous curve shape is the outer diameter of the transmitter coil. When the coupler element is moved, the geometric continuous curve shape of the coupler element modify an inductive coupling between the transmitter coil and the receiver coil.

First claim

What is claimed is:

1. An inductive sensor assembly comprising:
a sensor assembly comprising:
a transmitter coil having an inner diameter and an outer diameter,
a receiver coil positioned within the outer diameter of the transmitter coil,

a coupler element having at least a layer of a magnetic material to induce eddy currents and having a continuous curve shape, the continuous curve shape having at least two transition portions that each are arcuate having a radius of curvature which extends inward towards a center point and at least a pair of lobes connected by the at least two transition portions, the coupler element positioned within the outer diameter of the transmitter coil such that a maximum diameter of the continuous curve shape is the outer diameter of the transmitter coil,
wherein when the coupler element is moved, the continuous curve shape of the coupler element modifies an inductive coupling between the transmitter coil and the receiver coil, and
wherein a shape of the continuous curve shape of the coupler element is defined by a first equation:

{

x
⁡

(
θ
)

=

(

a
+

b
*

cos
⁡

(

N
⁢

⁢
θ

)

)

*

cos
⁡

(
θ
)

y
⁡

(
θ
)

=

(

a
+

b
*

cos
⁡

(

N
⁢

⁢
θ

)

)

*

sin
⁡

(
θ
)

,

0
≤
θ
≤

360
⁢
°

where “N” is equal to a number of poles in the sensor assembly, “a” is a diameter of the coupler element, “b” is a difference between a middle radius of the continuous curve shape of the coupler element and a maximum and/or minimum radius of the continuous curve shape of the coupler element, and “θ” is a variable of a plotted point having an angle with respect to the center point to define the continuous curve shape.

2. The inductive sensor assembly of claim 1 , wherein:
an outermost portion of each one of the at least a pair of lobes is the maximum parameter of the continuous curve shape of the coupler element and defined by a second equation: cos (N θ)=1.

3. The inductive sensor assembly of claim 2 , wherein:
the radius of curvature of the at least two transition portions of the coupler element positioned between each lobe of the at least a pair of lobes is the minimum parameter of the continuous curve shape of the coupler element and defined by a third equation: cos (N θ)=−1.

4. The inductive sensor assembly of claim 3 , wherein:
the at least a pair of lobes of the continuous curve shape of the coupler element is four lobes interconnected to form a four-pole coupler element, each lobe of the four lobes having the outermost portion that extends outwardly from the center point by an equal length, and the at least two transition portions are four transition portions positioned between each of the four lobes and is defined by the minimum parameter determined from the third equation.

5. The inductive sensor assembly of claim 3 , wherein:
the at least a pair of lobes of the continuous curve shape of the coupler element is three lobes interconnected to form a three-pole coupler element, each lobe of the three lobes having the outermost portion that extends outwardly from the center point by an equal length, and the at least two transition portions are three transition portions positioned between each of the three lobes and is defined by the minimum parameter via the third equation.

6. The inductive sensor assembly of claim 1 , wherein the receiver coil is a two-part receiver coil.

7. The inductive sensor assembly of claim 1 , wherein the movement of the coupler element is rotational.

8. The inductive sensor assembly of claim 1 , wherein the movement of the coupler element is linearly.

9. The inductive sensor assembly of claim 1 , wherein the continuous curve shape of the coupler element compensates for a plurality of high order harmonic components found in a waveform of a receiving signal.

10. The inductive sensor assembly of claim

Assignees

• Ksr Ip Holdings Llc

Inventors

• Shao Lingmin

Classifications

• G01D5/2053 Primary

  by a movable non-ferromagnetic conductive element · CPC title

• G01D5/24438

  Special design of the sensing element or scale · CPC title

• G01D5/2066 Primary

  by movement of a single coil with respect to a single other coil · CPC title

• G01D2205/73

  Targets mounted eccentrically with respect to the axis of rotation · CPC title

• G01D2205/77

  Specific profiles · CPC title