Patent Description:
Motors are apparatuses configured to convert electrical energy to mechanical energy to obtain rotational forces and are widely used for vehicles, home appliances, industrial machines, and the like. Particularly, the motor may be used in a device for securing steering stability of a vehicle. For example, the motor may be used as a vehicle motor in an electronic power steering (EPS) system or the like. The document <CIT> provides an example of a motor and electric power steering apparatus.

The motor may include a housing, a shaft, a stator disposed in the housing, a rotor installed on an outer circumferential surface of the shaft, and the like. In this case, an electrical interaction may be induced between the stator and the rotor so that the rotor may rotate. In addition, the shaft is also rotated due to the rotation of the rotor.

The motor may detect a position of the rotor to control the rotor. Accordingly, the motor may further include a sensing magnet and a circuit board on which a sensor configured to detect the sensing magnet is disposed in order to detect the position of the rotor.

In this case, a distance between the sensing magnet and the sensor is very important to satisfy sensing performance. However, it is difficult to maintain the distance due to size limitation demanded by users of the motor in a shaft direction (longitudinal direction of the shaft).

Meanwhile, a plurality of magnets are installed on the rotor, and the rotor may be formed as a surface permanent magnet (SPM) type rotor in which magnets are attached to a surface of a rotor core.

Cans may be used for the rotor to prevent separation and rust generation of the magnets.

The cans may be provided as two members so that the cans may be inserted from an upper side and a lower side to completely cover the magnets in a state in which the magnets are attached to the rotor core.

However, due to an assembly tolerance of the cans, a certain gap may be formed between the two members, and a problem may occur that the magnets are exposed and rust is generated due to the gap.

However, although the gap can be minimized in a case in which a thickness of the member is as thin as <NUM> T, it is difficult to secure rigidity when the motor is driven at a high speed.

In addition, in a case in which the thickness of the member is formed to be as thick as <NUM> T, since the rigidity of the can is increased, assemblability thereof can be lowered. In addition, when the cans are press-fitted so that end portions come into contract with each other, there is a problem in that the magnets are broken due to overload applied to the cans.

Accordingly, there is a need for a can capable of preventing generation of the gap and also capable of securing the rigidity.

The present invention is directed to providing a motor in which a hole is formed in a cover disposed to cover an opening of a housing and a sensor is disposed in the hole to secure a predetermined distance between the sensor and a sensing magnet so that the sensing performance is secured and a size in a shaft direction is reduced.

The present invention is directed to providing a motor in which an elastic structure capable of elastically supporting a rotor core is implemented on caps formed to have a predetermined thickness to prevent generation of a gap between the caps and secure rigidity regardless of an assembly tolerance.

Objectives to be solved by the present invention 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.

One aspect of the present invention provides a motor according to claims <NUM> to <NUM>. The motor includes a housing, a cover disposed to cover the housing, a stator disposed in the housing, a rotor disposed inside the stator, a shaft disposed in a central portion of the rotor, a sensing magnet disposed on an end portion of the shaft, and a circuit board including a sensor configured to detect the sensing magnet, wherein the sensor is disposed in a hole formed in the cover.

The motor may further include a sealing member disposed to cover the sensor.

The hole may include a first region and a second region which have different inner diameters, the inner diameter of the first region may be greater than the inner diameter of the second region, and the sealing member may be disposed around the first region.

In a state in which the circuit board is coupled to the cover, the sealing member may be applied on the sensor through the hole and cured.

The sensing magnet may be disposed to face the sensor with the sealing member disposed between the sensing magnet and the sensor.

One surface of the sensing magnet may be in contact with the sealing member.

The rotor may include a rotor unit including a rotor core and a plurality of magnets disposed on an outer circumferential surface of the rotor core to be spaced apart from each other, and a pair of cans which cover an upper portion and a lower portion of the rotor unit, wherein the cans may include plate parts having a plate shape, sidewall parts protruding from outer circumferential surfaces of the plate parts in a shaft direction, and at least two protruding parts protruding from each of the plate parts, and the protruding part may protrude toward the rotor core.

The protruding part may be formed in the can by cutting and pressing one region of the plate part.

The plate part may include a hole formed in a central portion, and a radius from a center (C) of the rotor to an inner circumferential surface of the plate part may be smaller than a distance to the outer circumferential surface of the rotor core.

The protruding part may include a connecting part which is bent and extends from the plate part and a support part extending from the connecting part, and the support part may be in contact with one side of the rotor core.

As the support part is pressed by the rotor core, one region at which the support part meets the connecting part may be in line contact with the rotor core.

The sum of lengths of the sidewall parts of the pair of cans in the shaft direction may be greater than a length of the rotor core in the shaft direction.

The at least two protruding parts may be disposed to be rotationally symmetrical with respect to a center.

A thickness of the can may be in a range of <NUM> to <NUM> T.

According to embodiments, in a motor having an above-described configuration, a hole is formed in a cover disposed to cover an opening of a housing, and a sensor is disposed in the hole, and thus a size of the motor in a shaft direction can be reduced.

In this case, a sealing force can be improved using a sealing member disposed to cover a sensor in the hole.

In addition, a sensing magnet is disposed to be in contact with the sealing member to secure a distance between the sensor and the sensing magnet so that constant quality for sensing performance can be maintained.

Meanwhile, in the motor, an elastic structure capable of elastically supporting a rotor core is implemented in caps formed to have a predetermined thickness, generation of a gap can be prevented between the caps and rigidity can also be secured regardless of an assembly tolerance.

However, the technical spirit of the present invention is not limited to some embodiments which will be described and may be realized using various other embodiments, and at least one component of the embodiments may be selectively coupled, substituted, and used to realize the technical spirit within the range of the technical spirit.

In addition, unless clearly and specifically defined otherwise by context, all terms (including technical and scientific terms) used herein can be interpreted as having meanings customary 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 for limiting 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 possible combinations of 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 of 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 motor according to an embodiment, <FIG> is a cross-sectional view illustrating the motor according to the embodiment, and <FIG> is an enlarged view illustrating a region A of <FIG>. In this case, <FIG> is the cross-sectional view taken along line A-A of <FIG>. In addition, in <FIG>, a y direction is referred to as a shaft direction, and an x direction is referred to as a radial direction.

Referring to <FIG>, a motor <NUM> according to the embodiment may include a housing <NUM> in which an opening is formed at one side, a cover <NUM> disposed on the housing <NUM>, a stator <NUM> disposed in the housing <NUM>, a rotor <NUM> disposed inside the stator <NUM>, a shaft <NUM> configured to rotate along with the rotor <NUM>, a sensing magnet <NUM> disposed at an end portion of one side of the shaft <NUM>, and a circuit board <NUM> disposed above the cover <NUM>. In addition, the motor <NUM> may further include a sealing member <NUM> disposed to cover a sensor <NUM> disposed on the circuit board <NUM>. In this case, the sensor <NUM> disposed on the circuit board <NUM> of the motor <NUM> may detect the sensing magnet <NUM> to detect rotation of the shaft <NUM>. In this case, the term "inside" may be referred to as a direction toward a center C in the radial direction, and the term "outside" may be referred to as a direction opposite to the term "inside.

Meanwhile, the motor <NUM> may further include a busbar (not shown) disposed on the stator <NUM> or a busbar terminal disposed on an insulator <NUM> of the stator <NUM>. In addition, the busbar or the busbar terminal may be electrically connected to a coil <NUM> of the stator <NUM>.

The housing <NUM> and the cover <NUM> may form an exterior of the motor <NUM>. In addition, the housing <NUM> may be coupled to the cover <NUM> to form an accommodation space. Accordingly, as illustrated in <FIG>, the rotor <NUM>, the stator <NUM>, the shaft <NUM>, and the like may be disposed in the accommodation space. In this case, the shaft <NUM> may be rotatably disposed in the accommodation space. Accordingly, the motor <NUM> may further include a bearing <NUM> disposed on the shaft <NUM>.

The housing <NUM> may be formed in a cylindrical shape. In addition, the stator <NUM>, the rotor <NUM>, the shaft <NUM>, and the like may be accommodated in the housing <NUM>. In this case, the shape or material of the housing <NUM> may be variously changed. For example, the housing <NUM> may be formed of a metal material which firmly withstands even at high temperature.

The cover <NUM> may be disposed on an open surface of the housing <NUM>, that is, an upper portion of the housing <NUM>, to cover the opening of the housing <NUM>.

<FIG> is a perspective view illustrating the cover of the motor according to the embodiment, and <FIG> is a cross-sectional view illustrating the cover of the motor according to the embodiment. In this case, <FIG> is the cross-sectional view taken along line B-B of <FIG>.

Referring to <FIG> and <FIG>, the cover <NUM> may include a hole <NUM>.

The hole <NUM> may be formed to pass through the cover <NUM> in the shaft direction. In this case, a center C of the hole <NUM> may be disposed to be virtually collinear with a center C of the shaft <NUM>.

The hole <NUM> may include a first region <NUM> and a second region <NUM> having different inner diameters. As illustrated in <FIG>, an inner diameter D1 of the first region <NUM> is greater than an inner diameter D2 of the second region <NUM>. In addition, the first region <NUM> may be disposed above the second region <NUM> in consideration of the sealing member <NUM>.

The stator <NUM> may be supported by an inner circumferential surface of the housing <NUM>. In addition, the stator <NUM> may be disposed outside the rotor <NUM>. That is, the rotor <NUM> may be disposed inside the stator <NUM>.

Referring to <FIG>, the stator <NUM> may include a stator core <NUM>, the coil <NUM> wound around the stator core <NUM>, and an insulator <NUM> disposed between the stator core <NUM> and the coil <NUM>.

The coil <NUM> configured to generate a rotating magnetic field may be wound around the stator core <NUM>. In this case, the stator core <NUM> may be formed of one core or formed of a plurality of split cores coupled to each other.

In addition, the stator core <NUM> may be formed in a form in which a plurality of thin steel plates are stacked but is not necessarily limited thereto. For example, the stator core <NUM> may be formed as one single component.

The stator core <NUM> may include a yoke (not shown) having a cylindrical shape and a plurality of teeth (not shown) protruding in the radial direction from the yoke. In addition, the coil <NUM> may be wound around the tooth.

The insulator <NUM> insulates the stator core <NUM> from the coil <NUM>. Accordingly, the insulator <NUM> may be disposed between the stator core <NUM> and the coil <NUM>.

Accordingly, the coil <NUM> may be wound around the tooth <NUM> of the stator core <NUM> on which the insulator <NUM> is disposed.

The rotor <NUM> may be disposed inside the stator <NUM>. In addition, the rotor <NUM> may include a hole formed in a central portion so that the shaft <NUM> is inserted into the hole. Accordingly, the shaft <NUM> may be coupled to the hole of the rotor <NUM>. In this case, the rotor <NUM> may be rotatably disposed inside the stator <NUM>.

<FIG> is a perspective view illustrating the rotor of the motor according to the embodiment, and <FIG> is an exploded perspective view illustrating the rotor of the motor according to the embodiment.

Referring to <FIG> and <FIG>, the rotor <NUM> may include a rotor unit <NUM> including a rotor core <NUM> and a plurality of magnets <NUM> disposed on outer circumferential surface of the rotor core <NUM> to be spaced apart from each other and a pair of cans <NUM> for covering an upper portion and a lower portion of the rotor unit. In this case, end portions the pair of cans <NUM> may be formed to be in contact with each other to prevent foreign materials from being introduced into the rotor unit <NUM>.

In this case, the cans <NUM> may be formed to have the same shape. Accordingly, since the cans <NUM> disposed on the upper portion and the lower portion of the rotor unit <NUM> can be shared, a production cost can be reduced.

Accordingly, the cans <NUM> may be disposed to surround the rotor unit <NUM> to prevent separation of the magnets <NUM> of the rotor unit <NUM> and generation of rust thereon.

Referring to <FIG>, the rotor unit <NUM> may include the rotor core <NUM> and the plurality of magnets <NUM> disposed on the outer circumferential surface of the rotor core <NUM> to be spaced apart from each other at preset intervals. In this case, the magnets <NUM> may be referred to as rotor magnets or drive magnets.

The rotor core <NUM> may be formed in a form, in which a plurality of circular thin steel plates are stacked, or in a single cylindrical form. Accordingly, the rotor core <NUM> may be formed to have a predetermined length L1 in the shaft direction. In this case, the length of the rotor core <NUM> may be referred to as a first length.

In addition, a hole to which the shaft <NUM> is coupled may be formed at a center C of the rotor core <NUM>.

The magnets <NUM> may be disposed on the outer circumferential surface of the rotor core <NUM> to be spaced apart from each other at the preset intervals. In this case, the magnets <NUM> may be attached to the outer circumferential surface of the rotor core <NUM> using an adhesive member such as glue. As illustrated in <FIG>, two magnets <NUM> may be vertically disposed to form a skew. In addition, the plurality of magnets <NUM> in which the skew is formed may be disposed on the outer circumferential surface of the rotor core <NUM> in a circumferential direction. In this case, the term "skew" may denote that the magnet <NUM> disposed on an upper portion and the magnet <NUM> disposed on the lower portion are misaligned in the shaft direction.

The cans <NUM> may be formed to have a cup shape in which a hole is formed in a central portion and may be disposed to cover the upper portion and the lower portion of the rotor unit <NUM>. In this case, the can <NUM> may be referred to as a cap.

The can <NUM> may protect the rotor unit <NUM> from external shocks and physical and chemical stimuli while preventing foreign materials from being introduced into the rotor unit <NUM>.

In this case, a thickness of the can <NUM> may be in the range of <NUM> to <NUM> T. For example, in a case in which the thickness of the can <NUM> is as thin as <NUM> T, it is difficult to secure rigidity when the motor <NUM> is driven at a high speed. Accordingly, in the motor <NUM>, the can <NUM> may be formed to have a thickness of <NUM> to <NUM> T to secure the rigidity. In this case, in a case in which the rotor core <NUM> is formed in a form in which a plurality of plates are stacked, a thickness of the plate may be <NUM> T.

In addition, in the motor <NUM>, protruding parts <NUM> are formed on the cans <NUM> to elastically support the rotor core <NUM> to overcome an assembly limitation related to the length L1 of the rotor core <NUM> in the shaft direction so that the end portions of the pair of cans <NUM> may be in contact with each other. Accordingly, in the motor <NUM>, through the protruding parts <NUM> formed on the cans <NUM>, assemblability of the rotor <NUM> and versatility of the can <NUM> can be improved.

<FIG> is a perspective view illustrating the can of the motor according to the embodiment, <FIG> is a plan view illustrating the can of the motor according to the embodiment, and <FIG> is a cross-sectional view taken along line C-C of <FIG>.

Referring to <FIG>, the can <NUM> may include a plate part <NUM> disposed above or under the rotor unit <NUM>, a sidewall part <NUM> protruding from an outer circumferential surface of the plate part <NUM> in the shaft direction, and the protruding parts <NUM> formed on the plate part <NUM> to protrude toward the rotor unit <NUM>. In this case, the plate part <NUM>, the sidewall part <NUM>, and the protruding parts <NUM> may be integrally formed.

The plate part <NUM> may be formed as a circular plate in which a hole 421a is formed in a central portion. In this case, the hole 421a may be formed in a circular shape having a predetermined radius R. Accordingly, the radius R from a center C of the rotor <NUM> or a center C of the plate part <NUM> to an inner circumferential surface of the plate part <NUM> may be smaller than a distance to the outer circumferential surface of the rotor core <NUM>. Accordingly, the protruding parts <NUM> formed on the plate part <NUM> to protrude toward the rotor unit <NUM> may be in contact with an upper surface or lower surface of the rotor core <NUM>.

As illustrated in <FIG>, the plate part <NUM> may be formed in a ring shape when viewed from above.

The plate part <NUM> may be disposed to cover a part of the rotor core <NUM> and the magnets <NUM>. For example, from the center C of the rotor <NUM>, a distance to the inner circumferential surface of the plate part <NUM> is smaller than the distance to the outer circumferential surface of the rotor core <NUM>.

The sidewall part <NUM> may be formed on the outer circumferential surface of the plate part <NUM> to protrude in the shaft direction.

The sidewall part <NUM> may be formed to have a predetermined length L2 in the shaft direction. In this case, the length L2 of the sidewall part <NUM> in the shaft direction may be based on a lower surface of the plate part <NUM>. In this case, the length L2 of the sidewall part <NUM> in the shaft direction may be referred to as a second length. In addition, the length L2 of the sidewall part <NUM> in the shaft direction may be greater than half of the length L1 of the rotor core <NUM> in the shaft direction.

For example, since the sum of the lengths L2 of the sidewall parts <NUM> of the pair of cans <NUM> in the shaft direction may be greater than the length L1 of the rotor core <NUM> in the shaft direction, the end portions of the pair of cans <NUM> may be disposed to be in contact with each other.

The sidewall part <NUM> may be formed in a cylindrical shape.

The sidewall part <NUM> may be disposed outside the magnets <NUM>. Accordingly, the sidewall part <NUM> prevents the magnets <NUM> from moving in the radial direction. That is, the sidewall part <NUM> may support outer side surfaces of the magnets <NUM> in corresponding to a centrifugal force due to rotation of the rotor <NUM>.

At least two protruding parts <NUM> are formed on the plate part <NUM>. In addition, the plurality of protruding parts <NUM> may be disposed to be spaced apart from each other at predetermined intervals in a circumferential direction of the plate part <NUM>. For example, three protruding parts <NUM> may be disposed to be spaced apart from each other at intervals of <NUM>° about the center C. Accordingly, when the can <NUM> is disposed on the rotor unit <NUM>, the can <NUM> can be prevented from being inclined in the shaft direction due to the protruding parts <NUM>.

Meanwhile, in a case in which an even number of the protruding parts <NUM> are disposed, the protruding parts <NUM> may be symmetrically disposed with respect to the center C. In addition, at least of a pair of protruding parts <NUM> may be disposed to be rotationally symmetrical with respect to the center C. As illustrated in <FIG>, four protruding parts <NUM> may be disposed to be rotationally symmetrical with respect to the center C at intervals of <NUM>°.

The protruding parts <NUM> are formed on one surface of the plate part <NUM> to protrude toward the rotor core <NUM>. In this case, the protruding part <NUM> may be formed by cutting and pressing one region of the plate part <NUM>. Accordingly, when the can <NUM> is fitted onto the rotor unit <NUM>, a part of the protruding part <NUM> is in contact with the rotor core <NUM> to elastically support the rotor core <NUM>.

Referring to <FIG>, the protruding part <NUM> may include a connecting part 423a that is bent and extends from the plate part <NUM> and a support part 423b extending from the connecting part 423a. In this case, the support part 423b may be disposed to be spaced apart from the plate part <NUM> by a predetermined distance.

Accordingly, since the connecting part 423a is disposed to be inclined with respect to one surface of the plate part <NUM>, and the support part 423b extends from the connecting part 423a to be spaced apart from the plate part <NUM> by the predetermined distance, the protruding part <NUM> may be implemented to have an elastic structure supporting the rotor core <NUM>. In this case, the protruding length L3 of the protruding part <NUM> in the shaft direction may be based on the lower surface of the plate part <NUM>.

When the rotor unit <NUM> is coupled to the can <NUM>, as illustrated in <FIG>, the support part 423b may be in contact with one side of the rotor core <NUM>. For example, in the case of the can <NUM> disposed on the upper portion of the rotor unit <NUM>, the support part 423b of the can <NUM> may be in contact with the upper surface of the rotor core <NUM>.

Accordingly, even when an assembly tolerance occurs due to coupling of the rotor unit <NUM> and the can <NUM> in the shaft direction, the assembly tolerance may be compensated by as much as the protruding length L3 of the protruding part <NUM> from the plate part <NUM> in the shaft direction.

Accordingly, since the length L2 of the sidewall part <NUM> in the shaft direction is greater than half of the length L1 of the rotor core <NUM> in the shaft direction, the end portions of the pair of cans <NUM> may be in contact with each other. In this case, even in a case in which the half of the length L1 of the rotor core <NUM> in the shaft direction is greater than a length in which the protruding length L3 of the protruding part <NUM> is subtracted from the length L2 of the sidewall part <NUM> in the shaft direction based on the plate part <NUM>, since compensation may be performed by as much as the protruding length L3 of the protruding part <NUM>, the upper surface or the lower surface of the rotor core <NUM> may be disposed to press the protruding part <NUM>. Accordingly, the end portions of the pair of cans <NUM> may be in contact with each other. In addition, the end portions of the cans <NUM> which are in contact with each other may be fixed by an adhesive member or through welding.

<FIG> is a view illustrating one example of an arrangement relationship between the rotor core and the protruding part of the can in the rotor of the motor according to the embodiment.

Referring to <FIG>, in a case in which half of the length L1 of the rotor core <NUM> in the shaft direction is smaller than a length in which the protruding length L3 of the protruding part <NUM> is subtracted from the length L2 of the sidewall part <NUM> in the shaft direction, the protruding part <NUM> is disposed to be spaced apart from the rotor core <NUM> in the shaft direction. In this case, the end portions of the pair of cans <NUM> may be disposed to be in contact with each other.

<FIG> is a view illustrating another example of an arrangement relationship between the rotor core and the protruding part of the can in the rotor of the motor according to the embodiment.

Referring to <FIG>, in a case in which a length in which the protruding length L3 of the protruding part <NUM> is subtracted from the length L2 of the sidewall part <NUM> in the shaft direction is the same as half of the length L1 of the rotor core <NUM> in the shaft direction, the protruding part <NUM> is in contact with the upper surface or the lower surface of the rotor core <NUM>. In this case, the end portions of the pair of cans <NUM> may be disposed to be in contact with each other.

<FIG> is a view illustrating still another example of an arrangement relationship between the rotor core and the protruding part of the can in the rotor of the motor according to the embodiment.

Referring to <FIG>, in a case in which half of the length L1 of the rotor core <NUM> in the shaft direction is greater than a length in which the protruding length L3 of the protruding part <NUM> is subtracted from the length L2 of the sidewall part <NUM> in the shaft direction, the rotor core <NUM> presses the protruding part <NUM>. In this case, even when the protruding part <NUM> is disposed on the plate part <NUM> to protrude by as much as the protruding length L3 of the protruding part <NUM>, the end portions of the pair of cans <NUM> may be disposed to be in contact with each other.

In this case, since the support part 423b of the protruding part <NUM> is pressed by the rotor core <NUM>, one region at which the support part 423b meets the connecting part 423a may be in line contact with the rotor core <NUM>.

The shaft <NUM> may be disposed in the housing <NUM> to be rotatable by the bearing <NUM>. In addition, the shaft <NUM> may be rotated along with the rotor <NUM> in conjunction with rotation of the rotor <NUM>.

The sensing magnet <NUM> may be disposed on the end portion of one side of the shaft <NUM>. In this case, the sensing magnet <NUM> may be disposed to be spaced apart from the sensor <NUM> of the circuit board <NUM> by a predetermined spacing distance D.

In addition, one side of the sensing magnet <NUM> may be disposed to be in contact with the sealing member <NUM>. Accordingly, when the cover <NUM> on which the circuit board <NUM> is disposed is coupled to the housing <NUM>, since the spacing distance D between the sensor <NUM> and the sensing magnet <NUM> can be secured due to the sealing member <NUM>, sensing performance of the motor <NUM> can be maintained with constant quality.

Referring to <FIG> and <FIG>, the circuit board <NUM> may be disposed on the cover <NUM>. In this case, the circuit board <NUM> may be a printed circuit board (PCB).

In addition, the sensor <NUM> may be mounted on the circuit board <NUM>. In this case, the sensor <NUM> may be disposed on the circuit board <NUM> to face the sensing magnet <NUM> so as to have the predetermined spacing distance D from the sensing magnet <NUM>. In this case, the sensor <NUM> may be provided as a Hall integrated circuit (IC). In addition, the sensor <NUM> may detect changes in an N-pole and an S-pole of the sensing magnet <NUM> to generate a sensing signal.

Accordingly, the sensor <NUM> of the circuit board <NUM> may detect a magnetic force of the sensing magnet <NUM> installed to be rotatable in conjunction with the rotor <NUM> to allow a present position of the rotor <NUM> to be checked.

The sealing member <NUM> may be disposed on the circuit board <NUM> to cover the sensor <NUM>. In this case, the sealing member <NUM> may be formed of a material having an elastic force.

The sealing member <NUM> may be applied on the sensor <NUM> through the hole <NUM> and cured. For example, in a state in which the circuit board <NUM> is coupled to the cover <NUM>, the sealing member <NUM> may be applied on the sensor <NUM> through the hole <NUM> and cured. In addition, the cover <NUM> on which the circuit board <NUM> and the sealing member <NUM> are installed may be coupled to the housing <NUM>.

In this case, an example, in which the sealing member <NUM> is applied on the sensor <NUM> and cured, is described, but the present invention is not necessarily limited thereto. For example, the sealing member <NUM> provided as a separate part may also be disposed to cover the sensor <NUM>. Accordingly, since a curing time of the sealing member <NUM> in a coating type can be reduced due to the sealing member <NUM> provided as the separate part, productivity can be improved.

Meanwhile, the sealing member <NUM> may be disposed around the hole <NUM> to secure a sealing force between the housing <NUM> and the cover <NUM>.

Referring to <FIG>, the sealing member <NUM> may be disposed around the first region <NUM> of the hole <NUM>. Accordingly, the sensing magnet <NUM> may be disposed to be in contact with a lower portion of the sealing member <NUM>. In addition, the predetermined spacing distance D between the sensor <NUM> and the sensing magnet <NUM> can be maintained by the sealing member <NUM>.

While the present invention has been described with reference to the exemplary embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the scope of the invention as defined by the appended claims.

Claim 1:
A motor comprising:
a housing (<NUM>);
a cover (<NUM>) disposed to cover the housing (<NUM>);
a stator (<NUM>) disposed in the housing (<NUM>);
a rotor (<NUM>) disposed inside the stator (<NUM>);
a shaft (<NUM>) disposed in a central portion of the rotor (<NUM>);
a sensing magnet (<NUM>) disposed on an end portion of the shaft (<NUM>); and
a circuit board (<NUM>) including a sensor (<NUM>) configured to detect the sensing magnet (<NUM>),
wherein the sensor (<NUM>) is disposed in a hole (<NUM>) formed in the cover (<NUM>),
characterized in that the rotor further includes :
a rotor unit (<NUM>) including a rotor core (<NUM>) and a plurality of magnets (<NUM>) disposed on an outer circumferential surface of the rotor core (<NUM>) to be spaced apart from each other; and
a pair of cans (<NUM>) which cover an upper portion and a lower portion of the rotor unit (<NUM>) in the shaft direction,
wherein the cans (<NUM>) include plate parts (<NUM>) having a plate shape, sidewall parts (<NUM>) protruding from outer circumferential surfaces of the plate parts (<NUM>) in the shaft direction, and at least two protruding parts (<NUM>) protruding from each of the plate parts (<NUM>), and
the protruding part (<NUM>) protrudes toward the rotor core (<NUM>),
wherein the protruding parts (<NUM>) elastically support the rotor core (<NUM>).