Patent Description:
<CIT> discloses a sensing device according to the preamble of claim <NUM>. In an electronic power steering (EPS) system, an electronic control unit drives a motor according to driving conditions to secure turning stability and provide quick reinforcing force so that a driver can stably travel.

An EPS system includes a sensor assembly configured to measure a torque, a steering angle, and the like of a steering shaft to provide a proper torque. The sensor assembly may include a torque sensor configured to measure a torque applied to the steering shaft and an index sensor configured to measure an angular acceleration of the steering shaft. In addition, the steering shaft may include an input shaft connected to a handle, an output shaft connected to a power transmission structure at a side of a wheel, and a torsion bar which connects the input shaft and the output shaft.

The torque sensor measures a torsion degree of the torsion bar to measure a torque applied to the steering shaft. In addition, the index sensor detects rotation of the output shaft to measure an angular acceleration of the steering shaft. In the sensor assembly, the torque sensor and the index sensor may be disposed to be integrally formed.

The torque sensor may include a housing, a rotor, a stator including a stator tooth, and a collector and measure the torque.

In this case, the torque sensor may have a magnetic type structure in which the collector is provided to be disposed outside the stator tooth.

However, when an external magnetic field is generated, since the collector serves as a passage of the magnetic field in the structure, there is a problem in that the collector affects a magnetic flux value of a Hall integrated circuit (IC). Accordingly, a problem occurs in that an output value of the torque sensor is changed and thus the torsion degree of the torsion bar cannot be measured accurately.

Particularly, since many electric devices are used in a vehicle, a torque sensor is frequently affected by an external magnetic field, and thus there is a need for a torque sensor which is not affected by an external magnetic field.

The present invention is directed to providing a sensing device capable of avoiding magnetic interference of an external magnetic field generated from the outside when a torque is measured.

Specifically, the present invention is directed to providing a sensing device in which a collector is disposed between stator teeth to prevent the collector from serving as a passage of external magnetic fields.

In addition, the present invention is directed to providing a sensing device in which a magnet is rotatably disposed between stator teeth to charge the stator teeth.

Obj ectives to be solved by embodiments are not limited to the above-described objectives, and other objectives which are not described above will be clearly understood by those skilled in the art from the following specification.

The first angle may be the same as a third angle formed by two ends of the second tooth based on the stator center.

The third angle may be an angle formed by two end points, which overlap a center of a height formed between an upper surface and a lower surface of the magnet in a radial direction, of the second tooth.

The second angle may be an angle formed by two end points, which overlap a center of a height formed between an upper surface and a lower surface of the magnet in a radial direction, of the first tooth, and the third angle may be an angle formed by two end points, which overlap the center of the height formed between the upper surface and the lower surface of the magnet in the radial direction, of the second tooth.

At least a portion of the rotor may be disposed in the stator,.

The first angle may be the same as the third angle.

In the first tooth, a width of an upper surface is less than a width of a lower surface in a circumferential direction.

The first stator tooth may include the first body, the plurality of first teeth may extend from the first body, the second stator tooth may include the second body, and the plurality of second teeth may extend from the second body.

A length of the first tooth may be different from a length of the second tooth.

Two ends of the first tooth and two ends of the second tooth may overlap in the radial direction based on the center of the stator.

The sensing device may include a first collector and a second collector which are disposed between the first body of the first stator tooth and the second body of the second stator tooth and spaced apart from each other, sensors disposed between the first collector and the second collector, and a circuit substrate connected to the sensors.

The first collector may include a first collector body facing the sensor and a first extension extending from the first collector body, the second collector may include a second collector body facing the sensor and a second extension extending from the second collector body, and the first extension and the second extension may not overlap in the radial direction.

Each of the first collector body and the second collector body may include a flat surface, the sensor may be disposed between the first collector body and the second collector body, and the sensor may overlap the magnet in an axial direction.

The sensors may include a first sensor and a second sensor, the first collector body may include a first-<NUM> collector body disposed at one side of the first extension to face the first sensor and a first-<NUM> collector body disposed at the other side of the first extension to face the second sensor, and the second collector body may include a second-<NUM> collector body disposed at one side of the second extension to face the first sensor and a second-<NUM> collector body disposed at the other side of the second extension to face the second sensor.

The first sensor and the second sensor may be disposed to face each other based on the center of the stator.

The sensing device may further include a housing coupled to the circuit substrate, the first collector may include a first bracket protruding from the first extension, the second collector may include a second bracket protruding from the second extension, and the first bracket and the second bracket may be coupled to the housing.

The first bracket may be disposed to protrude outward from the first extension, and the second bracket may be disposed to protrude inward from the second extension.

The housing may include a first protruding part and a second protruding part which extend in the axial direction, and the sensor may be disposed between the first protruding part and the second protruding part.

The first protruding part may be disposed inside the first extension, and the second protruding part may be disposed outside the second extension.

The first protruding part may include a third protruding part protruding in the axial direction and coupled to the first bracket, and the second protruding part may include a fourth protruding part protruding in the axial direction and coupled to the second bracket.

In a sensing device according to embodiments having the above-described structure, since a pair of collectors are disposed between a pair of stator teeth and sensors are disposed between the collectors, when a torque is measured, magnetic interference of an external magnetic field generated from the outside can be prevented or minimized.

Since a first tooth of a first stator tooth and a second tooth of a second stator tooth are disposed to overlap in a radial direction and a magnet is rotated between the first tooth and the second tooth, the first tooth and the second tooth can be charged in different poles.

There is an advantage of increasing a magnitude of a collected flux.

There is an advantage of easily coupling the stator tooth to a stator body.

There is an advantage of easily coupling the collector to a housing.

Various and useful advantages and effects of the embodiments are not limited to the above-described contents and will be more easily understood from descriptions of the specific embodiments.

In addition, unless clearly and specifically defined otherwise, all terms (including technical and scientific terms) used herein can be interpreted as having customary meanings to those skilled in the art, and meanings of generally used terms, such as those defined in commonly used dictionaries, will be interpreted by considering contextual meanings of the related technology.

In addition, the terms used in the embodiments of the present invention are considered in a descriptive sense and not to limit the present invention.

In the present specification, unless clearly indicated otherwise by the context, singular forms include the plural forms thereof, and in a case in which "at least one (or one or more) among A, B, and C" is described, this may include at least one combination among all combinations which can be combined with A, B, and C.

In addition, in descriptions of components of the present invention, terms such as "first," "second," "A," "B," "(a)," and "(b)" can be used.

The terms are only to distinguish one element from another element, and an essence, order, and the like of the element are not limited by the terms.

In addition, it should be understood that, when an element is referred to as being "connected or coupled" to another element, such a description may include both a case in which the element is directly connected or coupled to another element and a case in which the element is connected or coupled to another element with still another element disposed therebetween.

In addition, in a case in which any one element is described as being formed or disposed "on or under" another element, such a description includes both a case in which the two elements are formed or disposed in direct contact with each other and a case in which one or more other elements are interposed between the two elements. In addition, when one element is described as being disposed "on or under" another element, such a description may include a case in which the one element is disposed at an upper side or a lower side with respect to another element.

Hereinafter, example embodiments of the invention will be described in detail with reference to the accompanying drawings. Components that are the same or correspond to each other will be denoted by the same reference numerals regardless of the figure numbers, and redundant descriptions will be omitted.

<FIG> is a perspective view illustrating a sensing device according to an embodiment, <FIG> is an exploded perspective view illustrating the sensing device illustrated in <FIG>, and <FIG> is a cross-sectional perspective view illustrating the sensing device taken along line A-A of <FIG>. In <FIG> and <FIG>, a z-direction denotes an axial direction, and a y-direction denotes a radial direction. In addition, the axial direction is perpendicular to the radial direction.

Referring to <FIG>, a sensing device <NUM> according to the embodiment may include a stator <NUM>, a rotor <NUM> of which one portion is disposed in the stator <NUM>, a first collector <NUM> disposed in the stator <NUM>, a second collector <NUM> disposed to be spaced apart from the first collector <NUM> in the radial direction in the stator <NUM>, sensors <NUM> disposed between the first collector <NUM> and the second collector <NUM>, a circuit substrate <NUM> electrically connected to the sensors <NUM>, a housing <NUM> coupled to the circuit substrate <NUM>, a first member <NUM>, and a second member <NUM>.

In this case, the stator <NUM> may be connected to an output shaft (not shown), and the rotor <NUM> of which at least one portion is rotatably disposed in the stator <NUM> may be connected to an input shaft (not shown) but is not necessarily limited thereto.

In this case, the rotor <NUM> may be rotatably disposed with respect to the stator <NUM>. In addition, the second collector <NUM> may be disposed inside the first collector <NUM> in the radial direction. In this case, the term "inside" may denote a direction of being disposed toward a center C in the radial direction, and the term "outside" may denote a direction opposite to "inside".

<FIG> is a perspective view illustrating the stator of the sensing device according to the embodiment, <FIG> is an exploded perspective view illustrating the stator of the sensing device according to the embodiment, and <FIG> is a cross-sectional view illustrating the stator of the sensing device according to the embodiment.

The stator <NUM> may be connected to the output shaft (not shown) of a steering shaft.

Referring to <FIG>, the stator <NUM> may include a stator holder <NUM>, a stator body <NUM>, a first stator tooth <NUM>, and a second stator tooth <NUM>.

The stator holder <NUM> may be connected to an output shaft of an electric steering system. Accordingly, the stator holder <NUM> may rotate in conjunction with rotation of the output shaft. The stator holder <NUM> may be formed in a cylindrical shape. In addition, the stator holder <NUM> may be formed of a metal material but is not necessarily limited thereto, and the stator holder <NUM> may also be formed of another material in consideration of a predetermined strength or more to be fixedly fitted to the output shaft.

The stator holder <NUM> may include a groove <NUM>. The groove <NUM> is concavely formed in an outer circumferential surface of the stator holder <NUM>. The groove <NUM> is disposed along the outer circumferential surface of the stator holder <NUM>. The second member <NUM> (see <FIG>) is inserted into the groove <NUM>.

The stator holder <NUM> may be coupled to the stator body <NUM>.

The stator body <NUM> may be disposed on an end portion of one side of the stator holder <NUM>. The stator body <NUM> may be coupled to the stator holder <NUM> through an insert-injection method using a synthetic resin like a resin. A main gear 121a may be formed in an outer circumferential surface of the stator body <NUM>. The main gear 121a transmits a torque of the stator <NUM> to a first gear <NUM> and a second gear <NUM>.

The first stator tooth <NUM> and the second stator tooth <NUM> may be disposed to be spaced apart from each other in the radial direction. In addition, the first stator tooth <NUM> and the second stator tooth <NUM> may be fixed to the stator body <NUM>. The first stator tooth <NUM> includes a first body <NUM> and first tooth <NUM>. The second stator tooth <NUM> includes a second body <NUM> and second tooth <NUM>.

<FIG> is a perspective view illustrating the stator body of the stator, <FIG> is a plan view illustrating the stator body of the stator, and <FIG> is a cross-sectional view illustrating the stator body of the stator.

Referring to <FIG>, the stator body <NUM> includes an inner part <NUM>, an outer part <NUM>, and a partition plate <NUM>. Each of the inner part <NUM> and the outer part <NUM> has a cylindrical shape. The outer part <NUM> is disposed to be spaced outward from the inner part <NUM> in the radial direction. The partition plate <NUM> connects the inner part <NUM> and the outer part <NUM>. The inner part <NUM>, the outer part <NUM>, and the partition plate <NUM> may be integrally formed. The stator holder <NUM> may be coupled to an inner side of the inner part <NUM>. A space S may be formed between the outer part <NUM> and the inner part <NUM>. The partition plate <NUM> may be formed in a plate shape. The partition plate <NUM> may be disposed between the inner part <NUM> and the outer part <NUM>.

As illustrated in <FIG>, the space S may be divided into a first space S1 and a second space S2 by the partition plate <NUM>. A magnet <NUM> may be disposed in the first space S1, and the sensors <NUM> may be disposed in the second space S2. The partition plate <NUM> may be disposed under a reference line L1, and the reference line L1 is a virtual horizontal line passing through a center of the outer part <NUM> in the axial direction.

Meanwhile, the partition plate <NUM> may include first holes <NUM> and second holes <NUM>. The first holes <NUM> and the second holes <NUM> are for arranging the first stator tooth <NUM> and the second stator tooth <NUM>.

Referring to <FIG>, the first body <NUM> and the second body <NUM> may be disposed in the first space S1. The first tooth <NUM> and the second tooth <NUM> may be disposed in the second space S2.

The plurality of first holes <NUM> may be formed to be spaced apart from each other in a circumferential direction. In addition, the first tooth <NUM> is disposed in the second space S2 by passing through the first holes <NUM>. In this case, the number of the first holes <NUM> is the same as the number of first teeth <NUM>. The first hole <NUM> may be disposed close to an inner circumferential surface of the outer part <NUM>. As illustrated in <FIG>, the first hole <NUM> may be formed in the partition plate <NUM> to be in contact with the inner circumferential surface of the outer part <NUM>.

The plurality of second holes <NUM> may be formed to be spaced apart from each other in the circumferential direction. In this case, the second hole <NUM> may be disposed to be spaced outward from the first hole <NUM> in the radial direction. In addition, the second tooth <NUM> is disposed in the second space S2 by passing through the second holes <NUM>. In this case, the number of the second holes <NUM> is the same as the number of second teeth <NUM> of the second stator tooth <NUM>. The second hole <NUM> may be disposed close to an outer circumferential surface of the inner part <NUM>. As illustrated in <FIG>, the second hole <NUM> may be formed in the partition plate <NUM> to be in contact with the outer circumferential surface of the inner part <NUM>.

The first stator tooth <NUM> and the second stator tooth <NUM> may be disposed between the outer circumferential surface of the inner part <NUM> and the inner circumferential surface of the outer part <NUM> of the stator body <NUM>. In this case, each of the first stator tooth <NUM> and the second stator tooth <NUM> may be formed of a metal material to be charged by rotation of the magnet <NUM>.

In addition, the first stator tooth <NUM> may be fixed to the inner circumferential surface of the outer part <NUM> by an adhesive member (not shown) such as a glue, and the second stator tooth <NUM> may be fixed to the outer circumferential surface of the inner part <NUM> by an adhesive member (not shown) such as a glue but are not necessarily limited thereto. For example, the first stator tooth <NUM> and the second stator tooth <NUM> may be fixed to the stator body <NUM> by coupling members (not shown), through caulking methods, or the like.

<FIG> is a view illustrating coupling of the first stator tooth and the second stator tooth and the stator body.

Referring to <FIG> and <FIG>, a boss <NUM> is disposed to extend downward from the partition plate <NUM>. A sidewall of the boss <NUM> and the outer part <NUM> are spaced apart from each other to form a first slot U1. The first tooth <NUM> is inserted into the first slot U1 and passes through the first hole <NUM> to be positioned in the second space S2. In addition, another sidewall of the boss <NUM> and the inner part <NUM> are spaced apart from each other to form a second slot U2. The second tooth <NUM> is inserted into the second slot U2 and passes through the second hole <NUM> to be positioned in the second space S2.

In a process in which the first stator tooth <NUM> is coupled to the stator body <NUM>, the first slot U1 guides the first tooth <NUM> to the first hole <NUM> so that the first stator tooth <NUM> is easily coupled to the stator body <NUM>.

In a process in which the second stator tooth <NUM> is coupled to the stator body <NUM>, the second slot U2 guides the first tooth <NUM> to the second hole <NUM> so that the second stator tooth <NUM> is easily coupled to the stator body <NUM>.

<FIG> is a view illustrating a state in which the first tooth is inserted into the first hole.

Referring to <FIG>, in the first tooth <NUM>, a width W2 of a lower surface in the circumferential direction is greater than a width W1 of an upper surface in the circumferential direction. In this case, the lower surface is a surface adjacent to the first body <NUM>, and the upper surface is a surface opposite to the lower surface. When viewed from the front, the first tooth <NUM> may have a trapezoidal shape. Such a shape of the first tooth <NUM> is for inducing a difference in magnetic flux density to guide a magnetic flux to flow toward the first body <NUM> and also for increasing a coupling force between the first stator tooth <NUM> and the stator body <NUM>.

In addition, a width W3 of the first hole <NUM> may be greater than the width W1 of the upper surface of the first tooth <NUM> in the circumferential direction and smaller than the width W2 of the lower surface of the first tooth <NUM> in the circumferential direction. This is for fitting the first tooth <NUM> into the first hole <NUM>. While the first tooth <NUM> is inserted into the first hole <NUM> toward the second space S2, a side surface of the first tooth <NUM> is inserted into the first hole <NUM> along an inner wall of the first hole <NUM>. In this process, the side surface of the first tooth <NUM> is press-fitted to the inner wall of the first hole <NUM> so that a coupling force is increased.

Meanwhile, an upper surface of the first body <NUM> may be in contact with a lower surface of the partition plate <NUM>.

Although not illustrated in the drawing, the second tooth <NUM> and the second hole <NUM> may also be coupled through a method which is the same as the above-described method that the first tooth <NUM> is coupled to the first hole <NUM>.

<FIG> is a view illustrating a protrusion of the stator body for fixing the first and second bodies, and <FIG> is a view illustrating a fusing process of the protrusion of the stator body.

In <FIG>, a symbol "I" denotes an inward direction toward a center of the stator, and in <FIG>, a symbol "O" denotes an outward direction opposite to the inward direction.

Referring to <FIG> and <FIG>, the stator body <NUM> includes a first protrusion <NUM> and a second protrusion <NUM>. The first protrusion <NUM> is disposed to protrude from a lower end of the inner part <NUM> in the axial direction. The first protrusion <NUM> is disposed along the inner part <NUM> having an annular shape. The second protrusion <NUM> is disposed to protrude from a lower end of the outer part <NUM> in the axial direction. The second protrusion <NUM> is disposed along the outer part <NUM> having an annular shape.

The first protrusion <NUM> has an outer circumferential surface 126a and an inner circumferential surface 126b. The inner circumferential surface 126b is continuous with an inner wall of the outer part <NUM>. The outer circumferential surface 126a may be inclined with respect to the inner circumferential surface 126b. The outer circumferential surface 126a may be disposed obliquely in a direction from the lower end of the outer part <NUM> toward a lower end of the inner circumferential surface 126b. When fusion is in progress in the axial direction like in a direction F of <FIG>, the first protrusion <NUM> is deformed to cover a lower end of the first body <NUM>. The first protrusion <NUM> prevents the first stator tooth <NUM> from being separated from the stator body <NUM> in the axial direction.

The second protrusion <NUM> has an outer circumferential surface 127a and an inner circumferential surface 127b. The inner circumferential surface 127b is continuous with an inner wall of the inner part <NUM>. The outer circumferential surface 127a may be inclined with respect to the inner circumferential surface 127b. The outer circumferential surface 127a may be disposed obliquely in a direction from the lower end of the inner part <NUM> toward a lower end of the inner circumferential surface 127b. When fusion is in progress in the axial direction like in the direction F of <FIG>, the second protrusion <NUM> is deformed to cover a lower end of the second body <NUM>. The second protrusion <NUM> prevents the second stator tooth <NUM> from being separated from the stator body <NUM> in the axial direction.

<FIG> is a side view illustrating the first stator tooth, and <FIG> is a side view illustrating the second stator tooth.

Referring to <FIG> and <FIG>, the first stator tooth <NUM> may include the first body <NUM> having a ring shape and a plurality of first teeth <NUM> spaced apart from each other and protruding from the first body <NUM> in the axial direction. For example, the first teeth <NUM> may be disposed to be spaced apart from each other in the circumferential direction and may extend upward from an upper side of the first body <NUM>. The first body <NUM> and the plurality of first teeth <NUM> may be integrally formed. In this case, the first body <NUM> may be referred to as a first tooth body.

The first tooth <NUM> may be formed in a shape of which a lower side is wide and an upper side is narrow. For example, when the first tooth <NUM> is viewed in the radial direction, a width of the lower side is greater than a width of the upper side. As illustrated in <FIG>, the first tooth <NUM> may be formed in a trapezoidal shape.

In addition, since the first tooth <NUM> passes through the first hole <NUM>, the upper surface of the first body <NUM> may be in contact with the lower surface of the partition plate <NUM>.

Referring to <FIG> and <FIG>, the second stator tooth <NUM> may include the second body <NUM> having a ring shape and a plurality of second teeth <NUM> spaced apart from each other and protruding from the second body <NUM> in the axial direction. For example, the second teeth <NUM> may be disposed to be spaced apart from each other in the circumferential direction and may extend upward from an upper side of the second body <NUM>. The second body <NUM> and the plurality of second teeth <NUM> may be integrally formed. In this case, the second body <NUM> may be referred to as a second tooth body.

The second tooth <NUM> may be formed in a shape of which a lower side is wide and an upper side is narrow. For example, when the second tooth <NUM> is viewed in the radial direction, in the second tooth <NUM>, a width of the lower side is greater than a width of the upper side. As illustrated in <FIG>, the second tooth <NUM> may be formed in a trapezoidal shape.

In addition, since the second tooth <NUM> passes through the second hole <NUM>, an upper surface of the second body <NUM> may be in contact with the lower surface of the partition plate <NUM>.

Referring to <FIG>, a height H1 of the first body <NUM> is smaller than a height H2 of the first tooth <NUM> on the basis of an upper surface 131a of the first body <NUM>. In addition, referring to <FIG>, a height H3 of the second body <NUM> is smaller than a height H4 of the second tooth <NUM> on the basis of an upper surface 141a of the second body <NUM>. In addition, the height H1 of the first body <NUM> may be the same as the height H3 of the second body <NUM>, and the height H2 of the first tooth <NUM> may be the same as the height H4 of the second tooth <NUM>. However, the present invention is not limited thereto, and the height H2 of the first tooth <NUM> may also be different from the height H4 of the second tooth <NUM>.

<FIG> is a plan view illustrating the first stator tooth, the second stator tooth, and the magnet.

Referring to <FIG>, the first stator tooth <NUM> is disposed outside the second stator tooth <NUM>. In this case, based on the center C, the first stator tooth <NUM> may be formed to have a first radius R1, and the second stator tooth <NUM> may be formed to have a second radius R2. The first radius R1 is greater than the second radius R2.

When viewed in the radial direction (y-direction), the first tooth <NUM> and the second tooth <NUM> may be disposed to overlap in the radial direction. Such an arrangement of the first tooth <NUM> and the second tooth <NUM> has an effect of reducing magnetic flux leakage.

<FIG> is a view illustrating a first pole and a second pole of the magnet.

Referring to <FIG>, the magnet includes first poles 230A and second poles 230B. The first pole 230A and the second pole 230B may be alternately disposed in a circumferential direction of the magnet.

The first poles 230A and the second poles 230B may respectively include N-pole areas NA and S-pole areas SA. Each of the first pole 230A and the second pole 230B may have a multilayer structure in which the N-pole area NA and the S-pole area SA are positioned at inner and outer sides thereof. In the first pole 230A, the N-pole area NA may be disposed at a relatively outer side, and the S-pole area SA may be disposed inside the N-pole area NA. In the second pole 230B, the N-pole area NA may be disposed at a relatively inner side, and the S-pole area SA may be disposed outside the N-pole area NA.

The N-pole area NA of the first pole 230A and the S-pole area SA of the second pole 230B are disposed adjacent to each other. The S-pole area SA of the first pole 230A and the N-pole area NA of the second pole 230B are disposed adjacent to each other.

When the magnet <NUM> rotates so that the first tooth <NUM> approaches the S-pole area SA and is charged with an S-pole, since the second tooth <NUM> approaches the N-pole area NA, the second tooth <NUM> is charged with an N-pole. Alternatively, when the magnet <NUM> rotates so that the first tooth <NUM> approaches the N-pole area NA and is charged with an N-pole, since the second tooth <NUM> approaches the S-pole area SA, the second tooth <NUM> is charged with an S-pole. Accordingly, the sensors <NUM> may measure an angle using a magnetic field applied through the first collector <NUM> and the second collector <NUM>.

In the sensing device according to the embodiment, the first tooth <NUM> and the second tooth <NUM> overlap in the radial direction. Two ends of the second tooth <NUM> may overlap the first tooth <NUM>. For example, positions and sizes of the first tooth <NUM> and the second tooth <NUM> may be designed so that a first angle Θ1, a second angle Θ2, and a third angle Θ3 are the same.

The first angle Θ1 denotes an angle formed by two ends of the first pole 230A based on the stator center C. For example, in a case in which there are eight first poles 230A and eight second poles 230B, the first angle Θ1 may be <NUM>°.

<FIG> is a view illustrating the second angle Θ2.

<FIG> is a view illustrating the third angle Θ3.

Referring to <FIG> and <FIG>, the second angle Θ2 denotes an angel formed by two ends P1 of the first tooth <NUM> based on the stator center C. A reference point G used when the two ends P1 of the first tooth <NUM> are defined in the axial direction will be described below. The reference point G corresponds to a point, which corresponds to a middle point of a height H1 of a body <NUM> of the magnet <NUM>, of the first tooth <NUM> when the first tooth <NUM> is disposed to face the body <NUM> of the magnet <NUM>. The height H1 of the body <NUM> of the magnet <NUM> denotes a height between an upper surface 231a and a lower surface 231b of the magnet <NUM> in the axial direction. An angle Θ4 between the first tooth <NUM> and another first tooth <NUM> at the reference point G may be the same as the second angle Θ2.

Referring to <FIG> and <FIG>, the third angle Θ3 denotes an angle formed by two ends P2 of the second tooth <NUM> based on the stator center C. A reference point G used when the two ends P2 of the second tooth <NUM> are defined in the axial direction will be described below. The reference point G corresponds to a point, which corresponds to the middle point of the height H1 of the body <NUM> of the magnet <NUM>, of the second tooth <NUM> when the second tooth <NUM> is disposed to face the body <NUM> of the magnet <NUM>. An angle Θ5 between the second tooth <NUM> and another second tooth <NUM> at the reference point G may be the same as the third angle Θ3.

<FIG> is a graph showing a flux with respect to the first angle Θ1, the second angle Θ2, and the third angle Θ3.

Referring to <FIG>, it may be seen that in a state in which the second angle Θ2 and the third angle Θ3 are set to be the same, as the second angle Θ2 and the third angle Θ3 become closer to the first angle Θ1, a flux magnitude increases, and as the second angle Θ2 and the third angle Θ3 become farther away from the first angle Θ1, the flux magnitude decreases. It may be seen that, in a case in which sizes and positions of the first tooth <NUM> and the second tooth <NUM> are arranged so that the second angle Θ2 and the third angle Θ3 are the same as the first angle Θ1, the flux magnitude of the first and second stator tooth <NUM> and <NUM> is the largest.

<FIG> is an exploded perspective view illustrating the rotor.

Referring to <FIG> and <FIG>, the rotor <NUM> may include a rotor holder <NUM>, a rotor body <NUM>, and the magnet <NUM>. The rotor holder <NUM>, the rotor body <NUM>, and the magnet <NUM> may be integrally formed.

The rotor holder <NUM> may be connected to the input shaft of the electric steering system. Accordingly, the rotor holder <NUM> may be rotated in conjunction with rotation of the input shaft. The rotor holder <NUM> may be formed in a cylindrical shape. In addition, an end portion of the rotor holder <NUM> may be coupled to the rotor body <NUM>. The rotor holder <NUM> may be formed of a metal material but is not necessarily limited thereto, and the rotor holder <NUM> may also be formed of another material in consideration of a predetermined strength or more to be fixedly fitted to the input shaft.

The rotor <NUM> may include a protrusion <NUM> of the rotor holder <NUM>. The protrusion <NUM> may be disposed to extend from an outer circumferential surface of the rotor holder <NUM> in the radial direction.

The rotor body <NUM> is disposed at one side of the outer circumferential surface of the rotor holder <NUM>. The rotor body <NUM> may be an annular member. A groove <NUM> may be disposed in an inner circumferential surface of the rotor body <NUM>. The groove <NUM> is a groove into which the protrusion of the rotor holder <NUM> is inserted.

The magnet <NUM> is coupled to the rotor body <NUM>. When the rotor holder <NUM> rotates, the magnet <NUM> is rotated in conjunction with the rotation of the rotor holder <NUM>.

<FIG> is a view illustrating the magnet <NUM>, and <FIG> is a plan view illustrating the magnet <NUM>.

Referring to <FIG> and <FIG>, the magnet <NUM> may include the body <NUM> having a ring shape and a protrusion <NUM> protruding from an upper surface of the body <NUM>. The protrusion <NUM> may be provided as a plurality of protrusions <NUM>. The protrusion <NUM> may include a first part 232a and a second part 232b. The first part 232a protrudes upward from the upper surface of the body <NUM>. The second part 232b may be disposed to protrude from the first part 232a in a radial direction of the magnet <NUM>. The second part 232b may protrude inward further than an inner circumferential surfaceof the body <NUM>. The protrusion <NUM> is for improving a coupling force to the rotor body <NUM>. The first part 232a prevents slip between the rotor body <NUM> and the magnet <NUM> in a rotation direction, and the second part 232b prevents separation of the rotor body <NUM> and the magnet <NUM> in the axial direction.

<FIG> is a perspective view illustrating an arrangement of the magnet <NUM> with respect to the first stator tooth and the second stator tooth.

Referring to <FIG>, the magnet <NUM> is disposed between the first tooth <NUM> and the second tooth <NUM>. The body <NUM> of the magnet <NUM> is disposed to face the first tooth <NUM> and the second tooth <NUM>. The protrusions <NUM> of the magnet <NUM> are disposed above the first tooth <NUM> and the second tooth <NUM>.

<FIG> is a view illustrating the collectors, <FIG> is a view illustrating the collectors disposed between the first stator tooth and the second stator tooth, and <FIG> is a view illustrating positions of the sensors and positions of the collectors.

Referring to <FIG> and <FIG>, the collectors may include the first collector <NUM> and the second collector <NUM>. The first collector <NUM> and the second collector <NUM> collect a flux of the stator <NUM>. In this case, the first collector <NUM> and the second collector <NUM> may be formed of a metal material and disposed to be spaced apart from each other in the radial direction.

The first collector <NUM> may include first collector bodies <NUM> and a first extension <NUM>. The first extension <NUM> extends from the first collector bodies <NUM>. The first collector bodies <NUM> may include a first-<NUM> collector body 310A and a first-<NUM> collector body 310B. The first-<NUM> collector body 310A is disposed at one side of the first extension <NUM>. The first-<NUM> collector body 310B is disposed at the other side of the first extension <NUM>. Each of the first-<NUM> collector body 310A and the first-<NUM> collector body 310B may include a flat surface. The first extension <NUM> may include a curved surface having a predetermined curvature.

The second collector <NUM> may have second collector bodies <NUM> and a second extension <NUM>. The second extension <NUM> extends from the second collector bodies <NUM>. The second collector bodies <NUM> may include a second-<NUM> collector body 410A and a second-<NUM> collector body 410B. The second-<NUM> collector body 410A is disposed at one side of the second extension <NUM>. And the second-<NUM> collector body 410B is disposed at the other side of the second extension <NUM>. Each of the second-<NUM> collector body 410A and the second-<NUM> collector body 410B may include a flat surface. The second extension <NUM> may include a curved surface having a predetermined curvature.

The first-<NUM> collector body 310A and the second-<NUM> collector body 410A are disposed to overlap in the radial direction. The first-<NUM> collector body 310B and the second-<NUM> collector body 410B are disposed to overlap in the radial direction. The first extension <NUM> and the second extension <NUM> do not overlap in the radial direction.

The sensor <NUM> detects a change in magnetic field occurring between the stator <NUM> and the rotor <NUM>. The sensor <NUM> may be a Hall integrated circuit (IC). The sensor <NUM> detects an amount of magnetization of the stator <NUM> which occurs due to an electric interaction between the magnet <NUM> of the rotor <NUM> and the stator <NUM>. The sensing device <NUM> measures a torque on the basis of the detected amount of magnetization.

The sensors <NUM> may include a first sensor 500A and a second sensor 500B. The first sensor 500A and the second sensor 500B may be disposed at opposite sides around the center C of the stator.

The first sensor 500A is disposed between the first-<NUM> collector body 310A and the second-<NUM> collector body 410A. The first-<NUM> collector body 310A may be disposed outside the first sensor 500A. The second-<NUM> collector body 410A may be disposed inside the first sensor 500A.

The second sensor 500B is disposed between the first-<NUM> collector body 310B and the second-<NUM> collector body 410B. The first-<NUM> collector body 310B may be disposed outside the second sensor 500B. The second-<NUM> collector body 410B may be disposed inside the second sensor 500B.

The first extension <NUM> may include a plurality of first brackets <NUM>. The first brackets <NUM> may be disposed to extend inward from an upper surface of the first extension <NUM>. The second extension <NUM> may include a plurality of second brackets <NUM>. The second brackets <NUM> may be disposed to extend inward from an upper surface of the second extension <NUM>. Each of the first bracket <NUM> and the second bracket <NUM> may include a hole. The first bracket <NUM> and the second bracket <NUM> are to be coupled to the housing.

<FIG> is a view illustrating the circuit substrate.

Referring to <FIG>, the first sensor 500A and the second sensor 500B are disposed on the circuit substrate. The first sensor 500A and the second sensor 500B are disposed in a state in which the first sensor 500A and the second sensor 500B stand upward on the circuit substrate <NUM>. The first sensor 500A and the second sensor 500B are disposed to face each other.

<FIG> is a perspective view illustrating the housing when viewed from above, and <FIG> is a perspective view illustrating the housing when viewed from below.

Referring to <FIG>, <FIG>, and <FIG>, the housing may include a housing body <NUM>, a first protruding part <NUM>, a second protruding part <NUM>, third protruding parts <NUM>, and fourth protruding parts <NUM>.

The housing body <NUM> has a plate shape which includes an upper surface and a lower surface and of which upper and lower portions are open. A hole <NUM> is disposed at a central portion thereof. The stator holder <NUM> is positioned inside the hole <NUM>.

The first protruding part <NUM> is disposed along a circumference of the hole <NUM>. The first protruding part <NUM> protrudes from the upper surface of the housing body <NUM>.

The second protruding part <NUM> is disposed along the circumference of the hole <NUM>. The second protruding part <NUM> protrudes from the upper surface of the housing body <NUM>.

The first protruding part <NUM> and the second protruding part <NUM> may be disposed on the same circumference. In addition, the first protruding part <NUM> and the second protruding part <NUM> may be disposed to be spaced apart from each other in the circumferential direction. Holes <NUM> may be disposed between the first protruding part <NUM> and the second protruding part <NUM> in the circumferential direction. Two holes <NUM> may be disposed. The holes <NUM> are holes through which the sensors pass.

The circuit substrate <NUM> is installed on a lower surface <NUM> of the housing body <NUM>. A first cover <NUM> may be coupled to a lower side of the housing body <NUM> to cover the circuit substrate <NUM>.

The first protruding part <NUM> may include the third protruding parts <NUM>. The third protruding parts <NUM> protrude upward from an upper surface of the first protruding part <NUM>. The plurality of third protruding parts <NUM> may be provided.

The second protruding part <NUM> may include the fourth protruding parts <NUM>. The fourth protruding parts <NUM> protrude upward from an upper surface of the second protruding part <NUM>. The plurality of fourth protruding parts <NUM> may be provided.

The third protruding parts <NUM> are to be coupled to the first brackets <NUM>. The fourth protruding parts <NUM> are to be coupled to the second brackets <NUM>.

Holes <NUM> in which the first gear <NUM> and the second gear <NUM> are disposed may be disposed in the housing body <NUM>.

<FIG> is a view illustrating the housing in which the collectors and the sensors are disposed.

Referring to <FIG>, the first collector <NUM> and the second collector <NUM> are coupled to the housing <NUM>.

The first extension <NUM> is disposed outside the first protruding part <NUM>. The first bracket <NUM> is coupled to the third protruding part <NUM>. The third protruding part <NUM> is press-inserted into the hole formed in the first bracket <NUM>. After the press-insertion, the third protruding part <NUM> may be fused.

The second extension <NUM> is disposed inside the second protruding part <NUM>. The second bracket <NUM> is coupled to the fourth protruding part <NUM>. The fourth protruding part <NUM> is press-inserted into the hole formed in the second bracket <NUM>. After the press-insertion, the fourth protruding part <NUM> is fused.

The first sensor 500A is disposed between the first-<NUM> collector body 310A and the second-<NUM> collector body 410A.

The second sensor 500B is disposed between the first-<NUM> collector body 310B and the second-<NUM> collector body 410B.

The first gear <NUM> and the second gear <NUM> may be rotatably disposed on an upper surface <NUM> of the housing body <NUM>. The first gear <NUM> or the second gear <NUM> is engaged with the main gear 121a of the stator body <NUM>. A second cover <NUM> may be disposed at an upper side, at which the first gear <NUM> and the second gear <NUM> are disposed, of the housing body <NUM>. The second cover <NUM> is coupled to the housing body <NUM>.

<FIG> is a cross-sectional view illustrating a connector housing and a pin of the housing.

Referring to <FIG>, the housing <NUM> includes a connector housing <NUM> and a pin <NUM>. The pin <NUM> electrically connects the circuit substrate <NUM> and an external cable. One side of the pin <NUM> is connected to the circuit substrate <NUM> disposed at a lower side of the housing <NUM>. The other side of the pin <NUM> is exposed inside the connector housing <NUM>. An entrance of the connector housing <NUM> may be perpendicular to the axial direction. The pin <NUM> may have a shape bent in a "┐" shape.

<FIG> is a view illustrating the first member and the second member, and <FIG> is a view illustrating the first member and the second member installed in the stator holder.

Referring to <FIG> and <FIG>, the first member <NUM> is for preventing a sidewall of the hole <NUM> of the housing body <NUM> from being worn and for preventing coaxial misalignment of the sensing device. As described above, the first tooth <NUM> and the second tooth <NUM> are disposed to overlap in the radial direction. In addition, the sensors <NUM> are disposed between the first tooth <NUM> and the second tooth <NUM> in the radial direction. Accordingly, in a case in which shaking occurs in the radial direction, since distances between the first tooth <NUM>, the sensors <NUM>, and the second tooth <NUM> are changed, the sensing device may be damaged critically, or a performance problem of the sensing device may occur.

The first member <NUM> may be a member having a ring shape. The first member <NUM> may include a body <NUM> and a flange part <NUM>. The body <NUM> is a cylindrical member. The body <NUM> may be disposed along an inner wall of the hole <NUM> of the housing body <NUM>. The body <NUM> is disposed between the outer circumferential surface of the stator holder <NUM> and the inner wall of the hole <NUM> of the housing body <NUM>. The flange part <NUM> has a shape extending from a lower end of the body <NUM> in the radial direction. The flange part <NUM> is disposed to be contactable with the lower surface of the housing body <NUM>. In addition, the flange part <NUM> may be disposed to cover one portion of the first cover <NUM>. In addition, the first member <NUM> may be formed of a metal material.

A lower surface of the flange part <NUM> may be in contact with an upper surface of the second member <NUM>.

The first member <NUM> physically separates the hole <NUM> of the housing body <NUM> from the stator holder <NUM> when the stator holder <NUM> rotates, and thus the first member <NUM> serves to prevent the inner wall of the hole <NUM> of the housing body <NUM> from being worn when the stator holder <NUM> rotates. As a result, the first member <NUM> secures coaxial rotation of the stator holder <NUM>.

The housing <NUM> is hooked on the main gear 121a of the stator body <NUM> and thus is not separated upward from the stator <NUM> in the axial direction. However, the housing <NUM> may be separated downward from the stator <NUM>. The second member <NUM> serves to prevent the housing <NUM> from being separated downward from the stator <NUM>. The second member <NUM> may have a c-ring shape. The second member <NUM> may be formed of a metal material. The second member <NUM> may be formed of an elastically deformable material.

The second member <NUM> is coupled to the groove <NUM> of the stator holder <NUM>. The groove <NUM> is concavely formed along the outer circumferential surface of the stator holder <NUM>. The second member <NUM> is positioned under the lower surface of the housing body <NUM> in a state in which the second member <NUM> is coupled to the stator holder <NUM>. In addition, the second member <NUM> may be disposed under the first member <NUM> to support the lower surface of the flange part <NUM> of the first member <NUM>.

<FIG> is a view illustrating the first gear <NUM> and the second gear <NUM> which are engaged with the main gear 121a.

Referring to <FIG> and <FIG>, the sensing device <NUM> includes the first gear <NUM> and the second gear <NUM> which are sub-gears engaged with the main gear 121a. The main gear 121a, the first gear <NUM>, the second gear <NUM>, and third sensors <NUM> are for measuring an angle of the steering shaft.

The main gear 121a is engaged and rotated with the first gear <NUM> and the second gear <NUM>. The main gear 121a is disposed on the outer circumferential surface of the stator body <NUM>. The first gear <NUM> and the second gear <NUM> are rotatably disposed on the housing body <NUM>. Gear ratios between the main gear 121a, the first gear <NUM>, and the second gear <NUM> are predetermined. For example, in a case in which a total angle of the main gear 121a is <NUM>°, the first gear <NUM> may be designed to rotate <NUM> times and the second gear <NUM> may be designed to rotate <NUM> times when the main gear 121a rotates <NUM> times. In this case, the total angle is an angle calculated by accumulating rotation of the main gear 121a when all the gears return to a state before rotating.

Magnets may be disposed on the first gear <NUM> and the second gear <NUM>. The magnets are disposed to face the third sensors <NUM>. The third sensors <NUM> are mounted on the circuit substrate.

<FIG> is a view illustrating a directionality of an external magnetic field with respect to the stator tooth, <FIG> is a view illustrating a state in which the sensor avoids an external magnetic field having a z-axis directionality, and <FIG> is a view illustrating a state in which the first and second stator teeth avoid an external magnetic field having a y'-axis directionality.

Referring to <FIG>, an external magnetic field greatly affects the sensing device in the z-axis direction which is the axial direction and the y'-axis direction perpendicular to the z-axis direction. In this case, the y'-axis direction denotes a direction toward the sensor <NUM>, which is the radial direction perpendicular to the axial direction.

Referring to <FIG>, the sensor <NUM> of the sensing device according to the embodiment is disposed in a state in which the sensor <NUM> stands in the z-axis direction. Accordingly, an area of the sensor <NUM> when viewed in the z-axis is much smaller than an area of the sensor <NUM> when viewed in the y'-axis direction. Accordingly, the sensing device according to the embodiment has an advantage in that an effect of the external magnetic field on the sensor <NUM> is small in the z-axis direction.

Referring to <FIG>, when the state in which the sensor <NUM> stands in the z-axis direction is considered, a circumferential magnetic field in the y'-axis direction may greatly affect the sensor <NUM>. However, since the circumferential magnetic field in the y'-axis direction is induced along the first stator tooth <NUM> and the second stator tooth <NUM>, the circumferential magnetic field flows without affecting the sensor <NUM>. Accordingly, the sensing device according to the embodiment has an advantage in that an effect of the external magnetic field on the sensor <NUM> is also small even in the y'-axis direction.

<FIG> is a graph showing a comparison of an amount of change in angle with respect to an external magnetic field in the z-axis direction between a comparative example and an example.

Referring to <FIG>, in the case of the comparative example, a sensing device has a structure in which a stator tooth is vertically disposed and a sensor is horizontally disposed, and it may be seen that, as an external magnetic field in a z-axis direction increases, an amount of change in angle increases linearly, and thus the measured angle is greatly changed according to the external magnetic field.

Conversely, in the case of the example, it may be seen that, even when an external magnetic field in a z-axis direction increases, a change in angle barely occurs, and thus the angle is barely affected by the external magnetic field.

<FIG> is a graph showing a comparison of an amount of change in angle with respect to the external magnetic field in the y'-axis direction between the comparative example and the example.

Referring to <FIG>, in the case of the comparative example, the sensing device has the structure in which the stator tooth is vertically disposed and the sensor is horizontally disposed, and it may be seen that, as an external magnetic field in the y'-axis direction increases, an amount of change in angle increases linearly, and thus the measured angle is greatly changed according to the external magnetic field.

Claim 1:
A sensing device comprising:
a stator (<NUM>) including a stator body (<NUM>), first stator teeth (<NUM>) and second stator teeth (<NUM>), wherein the first stator teeth (<NUM>) and second stator teeth (<NUM>) are fixed to the stator body (<NUM>); and
a rotor (<NUM>) including a magnet (<NUM>),
wherein the magnet (<NUM>) is ring shaped and includes a plurality of first poles (230A) and second poles (230B),
wherein the first poles (230A) and the second poles (230B) are alternately disposed in a circumferential direction of the magnet (<NUM>),
wherein the ring shaped magnet (<NUM>) and the stator (<NUM>) are rotatably with respect to each other,
wherein the first and second poles (230A, 230B) are radially disposed between the first stator teeth (<NUM>) and the second stator teeth (<NUM>),
wherein the second stator teeth (<NUM>) are disposed in a direction towards a center (C) axis of the first stator teeth (<NUM>),
wherein the first stator teeth (<NUM>) overlap the second stator teeth (<NUM>) in a radial direction from a center (C) axis of the stator (<NUM>),
wherein a vertex of a first angle (Θ1) lies on the center (C) axis of the stator (<NUM>), wherein the first angle (Θ1) extends between two circumferential ends of each of the first poles (230A),
characterized in that
a second angle (Θ2) comprises the same vertex, and
that the first angle (Θ1) is the same as the second angle (Θ2) which extends between two circumferential ends (P1, P2) of a first tooth (<NUM>; <NUM>) of the first or second stator teeth (<NUM>; <NUM>), which overlaps one of the first poles (230A) in a radial direction, wherein said first tooth (<NUM>; <NUM>) has a trapezoidal shape.