Patent Description:
A power steering device of a vehicle is a device configured to reduce an angular rotation operating force of a steering wheel, and a power steering method using a hydraulic pressure has been continuously in use. Recently launched vehicles are equipped with motor driven power steering (MDPS) devices to change the steering force according to the driving speed.

Generally, an electric power steering (EPS) motor is attached to a motor driven power steering (MDPS) column to assist a driver's steering.

When the EPS motor is coupled to a shaft of a decelerator of the column to generate torque and drive the decelerator, a member referred to as a "coupler" should be used.

However, in a coupler manufactured by a conventional forging method, it is difficult to implement a shape due to the characteristics of the forging method, and when a location of the coupler is twisted in a manufacturing process, there is a problem that a coupling force with a shaft is difficult to ensure.

Further, a problem in which a noise occurs due to surface contact between the other object and the coupler when the motor is driven has also been indicated.

<CIT> discloses flexible couplings for use in high-speed operations.

An embodiment is directed to providing a coupler manufactured using both a forging method and an injection method.

Problems to be solved by the present invention are not limited to the above-described problems, and purposes and effects understood from solutions and embodiments which will be described below are also included.

One aspect of the present invention provides a coupler including: an inner insertion part including a through hole; and an outer support part configured to surround the outside of the inner insertion part, wherein the inner insertion part includes a connection groove through which the outer support part passes, the outer support part includes at least one projection part configured to protrude in a center direction of the through hole, and the projection part includes a groove part.

The inner insertion part includes a plate-shaped plate having a predetermined thickness and a protruding part in which the through hole is formed.

The plate has a polygonal structure. The polygonal structure of the plate may be provided in a polygonal shape having a multiple of the number of the projection parts.

An outermost point of the plate may be located under the projection part.

Linear gear teeth may be formed on a through surface forming the through hole.

A spiral screw thread may be formed on the through surface forming the through hole.

The outer support part includes a cylindrical outer wall, and the projection part protrudes in an inward direction from the outer wall.

The projection part and the neighboring projection parts may be disposed at the same interval on the outer support part.

An upper surface of the projection part may have an inclined portion which is inclined downward from the projection part.

A side surface of the projection part may be formed of an involute curve.

The inner insertion part may be manufactured using a forging method and the outer support part may be manufactured using an injection method.

Another aspect of the present invention provides a motor assembly including: a rotary shaft; a rotor including a hole in which the rotary shaft is disposed; a stator disposed at an outer side of the rotor; a housing configured to accommodate the rotor and the stator; and a coupler coupled to the rotary shaft, wherein the coupler includes an inner insertion part including a through hole and an outer support part configured to surround the outside of the inner insertion part. The inner insertion part includes a connection groove through which the outer support part passes, the outer support part includes at least one projection part configured to protrude in a center direction of the through hole, and the projection part includes a groove part.

According to an embodiment, both a forging method and an injection method can be used to implement a detailed shape and increase a coupling force.

Further, an additional coupling structure can be added to an inner diameter of a coupler to ensure reliability of the coupling force.

In addition, a structure of a coupling surface can be implemented as an involute shape to reduce a noise which occurs when a rotating direction is changed.

Various useful advantages and effects of the present invention are not limited to the above and may be relatively easily understood in a process of describing exemplary embodiments of the present invention.

Since the present invention may be variously changed and have various embodiments, particular embodiments will be exemplified and described in the drawings. However, the embodiments of the present invention are not limited to the particular embodiments and include all changes, and substitutes as long as they remain within the scope of the invention as defined by the appended claims.

Further, it should be understood that, although the terms "first," "second," and the like may be used herein to describe various elements, the elements are not limited by the terms. The terms are only used to distinguish one element from another. For example, a first element could be termed a second element, and similarly, a second element could be termed a first element without departing from the scope of the present invention. The term "and/or" includes combinations of one or all of a plurality of associated listed items.

Terms used in the present invention are used only to describe the particular embodiments and not to limit the present invention. The singular form is intended to also include the plural form, unless the context clearly indicates otherwise. It should be further understood that the terms "include," "including," "provide," "providing," "have," and/or "having" specify the presence of stated features, integers, steps, operations, elements, components, and/or groups thereof but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.

In the description of the embodiments, when one element is disclosed to be formed "on" or "under" another element, the terms "on" or "under" include both a case in which the two elements are in direct contact with each other and a case in which at least one other element is indirectly disposed between the two elements to be formed. Further, when the terms "on" or "under" is expressed, a meaning of an upward direction and a downward direction with respect to one element may also be included.

Hereinafter, the embodiments will be described in detail with reference to the accompanying drawings, the same reference numerals are applied to the same or corresponding elements, and redundant description thereof will be omitted.

<FIG> clearly illustrate only main characteristic parts to conceptually and clearly understand the present invention, and accordingly, an explanatory diagram may be variously modified, and the scope of the present invention does not have to be limited according to particular shapes shown in the drawings.

<FIG> is a perspective view of a coupler according to an embodiment of the present invention, <FIG> is a view illustrating a configuration of an inner insertion part which is an element of the present invention, <FIG> is a projection view illustrating a state in which the inner insertion part is inserted into an outer support part, and <FIG> is a cross-sectional view of the coupler.

Referring to <FIG>, a coupler <NUM> according to the embodiment of the present invention includes an inner insertion part <NUM> and an outer support part <NUM>.

The inner insertion part <NUM> includes a plate <NUM> and a protruding part <NUM> and may be formed of a metal material.

The plate <NUM> is provided in a plate shape having a predetermined thickness and may be inserted into the outer support part <NUM> not to be exposed to the outside when coupled to the outer support part <NUM>. The plate <NUM> has a polygonal structure to prevent the plate <NUM> from slipping in the outer support part <NUM> when the plate <NUM> is inserted into the outer support part <NUM> and a shaft (not shown) is connected to a through hole <NUM> to rotate.

The plate <NUM> has a polygonal shape. The polygonal structure is provided in a polygonal shape having a multiple of the number of projection parts <NUM>. As an embodiment, when four projection parts <NUM> are configured, the plate <NUM> may be provided in an octagonal structure to increase a supporting force and uniformly distribute an applied load when the load is applied to the projection parts <NUM> of the outer support part <NUM>. Although an example of the octagonal structure is described in the drawing, a dodecagon may be formed when the number of the projection parts <NUM> is four.

Outermost points of the plate <NUM> having the polygonal structure may be located under the projection parts <NUM>. Accordingly, a large weight is applied to the projection parts <NUM> when the projection parts <NUM> are coupled to another object. In this case, the outermost points of the plate <NUM> located at a lower side may increase the supporting force of the projection parts <NUM>. Further, when the outermost points are located under the projection parts <NUM>, since the number of the projection parts <NUM> and the number of the outermost points located between the projection parts <NUM> are entirely the same, the load may be stably distributed.

As an embodiment, the projection part <NUM> and the neighboring projection parts <NUM> may be disposed at the same interval on the outer support part <NUM> , and the inner insertion part <NUM> may be provided in a polygonal structure having two times the number of the projection parts <NUM> disposed on the outer support part <NUM>.

In the above case, the outermost points of the plate <NUM> having a regular polygonal structure may be located under the projection parts <NUM>, and the neighboring outermost points may be located between the projection part <NUM> and the projection part <NUM>. In this case, since the outermost points are located at the same angle in the regular polygonal structure and are each located at a center between the projection part <NUM> and the projection part <NUM>, torque which acts on the projection parts <NUM> may be stably dispersed.

Further, at least one connection groove <NUM> is formed in the inner insertion part <NUM>, and the outer support part may be connected to the connection groove <NUM>. The connection groove <NUM> may increase a coupling force when connecting the outer support part <NUM> and the inner insertion part <NUM> using an injection method.

As an embodiment, a plurality of connection grooves <NUM> may be formed in the plate <NUM> as a plurality of through holes. When the connection grooves <NUM> are formed as the plurality of through holes, elements forming the outer support part <NUM> may be connected to the connection grooves <NUM> through inner sides of the through holes. In this case, a power transferring force due to rotation may be increased.

Although an example in which the connection grooves <NUM> are formed as the through holes is described in the drawing, the present invention is not limited thereto, and the connection grooves <NUM> may be provided to protrude to increase the coupling force with the outer support part <NUM>.

The protruding part <NUM> is provided to protrude from one area in a center of the plate <NUM>, and a through hole <NUM> connected to the shaft (not shown) is formed in the protruding part <NUM>. As an embodiment, the protruding part <NUM> shares a center with the plate <NUM> having the polygonal structure and may be provided in a pipe shape in which the through hole <NUM> is formed.

The outer support part <NUM> includes an accommodation part <NUM>, an outer wall <NUM>, and a projection part <NUM>. The outer support part <NUM> is connected to surround the outside of the inner insertion part <NUM>.

One area of the inner insertion part <NUM> is inserted into the accommodation part <NUM>, and the accommodation part <NUM> may form a lower surface of the outer support part <NUM>. The plate <NUM> of the inner insertion part <NUM> may be inserted into the accommodation part <NUM>. As an embodiment, an outer protruding part <NUM>, into which the plate <NUM> is inserted and which is configured to come into contact with an outer surface of the protruding part <NUM>, may be connected to the accommodation part <NUM>. In this case, an area in which the outer protruding part <NUM> comes into contact with the protruding part <NUM> is not limited.

The outer wall <NUM> is formed to be connected to an end portion of the accommodation part <NUM> and to protrude to one side. As an embodiment, the outer wall <NUM> may form an inner space accommodating one end portion when coupled to the other object and may support the projection parts <NUM>. A shape of the outer wall <NUM> may be transformed according to a shape of the coupled other object and is not limited to the shape in the drawing.

At least one projection part <NUM> configured to protrude in an inward direction from the outer wall <NUM> is disposed on the outer wall <NUM>. The plurality of projection parts <NUM> is provided to stably support coupling with the other object and be located to be spaced apart from each other at the predetermined interval with the neighboring projection part <NUM> to stably support the load and torque.

At least one groove part <NUM> may be formed in the projection part <NUM>. When the outer support part <NUM> is formed through the injection method, the projection part <NUM> may have a drying problem due to a thickness thereof. In order to prevent the above, the groove part <NUM> may be formed in one area of the projection part <NUM>. As an embodiment, the groove part <NUM> may be formed in a downward direction from the upper portion of the projection part <NUM> and located in a center portion of the projection part <NUM>.

An inclined portion <NUM> inclined downward from the projection part <NUM> may be formed on an upper surface of the projection part <NUM>. The inclined portion <NUM> may facilitate the engagement of the projection part <NUM> with the other object.

A process of manufacturing the coupler <NUM> of present invention will be described below with reference to <FIG>.

The inner insertion part <NUM> coupled to the shaft is formed of a metal material and manufactured through a forging method to prevent damage due to a rigidity difference in the case in which a different material is used in coupling to the shaft.

Further, the inner insertion part <NUM> is located at a predetermined location and the outer support part <NUM> is formed through injection. Accordingly, since the shaft and the connection groove <NUM> may ensure rigidity and the shape of the projection part <NUM> coupled to the other object may be easily transformed, an engaging force may be increased.

<FIG> are views illustrating an embodiment of the inner insertion part which is an element of the present invention. Since the through hole <NUM> coupled to the shaft (not shown) is pressed surface-to-surface when a straight-shaped shaft is coupled to the through hole <NUM>, tolerance management is difficult d. Further, when the shaft is inserted, slip may occur.

In order to prevent the above, elements configured to prevent slipping of the through hole <NUM> may be provided.

<FIG> illustrates a case in which linear gear teeth 132a are provided in a longitudinal direction of the through hole <NUM> on a through surface <NUM> forming the through hole <NUM>. In this case, the gear teeth 132a may be formed to be coupled to each other in a matching structure on an outer circumferential surface of the shaft (not shown), and a cylindrical pillar portion may be located to be inserted into the gear teeth 132a by forced fitting.

<FIG> illustrates a case in which a spiral-shaped screw thread 132b is provided on the through surface <NUM> forming the through hole <NUM>. The shaft (not shown) may have the screw thread 132b formed on the outer circumferential surface thereof to be screw-coupled to the inner insertion part <NUM>.

The shaft and the through hole <NUM> may be additionally fixed to a bonding surface through welding to prevent separation after being coupled to each other.

<FIG> are views illustrating the shape of the projection part which is an element in <FIG>.

The projection part <NUM> may have a side surface provided in the shape of a curved surface and may be coupled to the other object to be inserted thereinto. As an embodiment, a side surface of the projection part <NUM> may be formed in an involute shape. A curve provided by an involute curve may be bonded to the other object point-to-point.

A conventional coupler has a structure which comes into contact with the other object surface-to-surface. In this case, a rotating direction of a motor is changed and noises are generated from a coupler surface of the other object and a coupler surface of the motor. However, since the projection part <NUM> provided with the involute curve comes into point contact with the other object, occurrence of noises during a change of the direction of the motor may be reduced.

Meanwhile, hereinafter, a motor assembly including a coupler according to another embodiment of the present invention will be described with reference to the accompanying drawings. However, the description of the same elements as those described in the coupler according to an embodiment of the present invention will be omitted.

<FIG> is an exploded perspective view of a motor assembly including a coupler according to another embodiment of the present invention, and <FIG> is a cross-sectional view of the motor assembly to which the coupler is coupled. In <FIG> and <FIG>, reference numerals the same as those in <FIG> show the same members and detailed descriptions thereof will be omitted.

A motor assembly <NUM> according to another embodiment of the present invention may include a rotary shaft <NUM>, a rotor <NUM> including a hole in which the rotary shaft <NUM> is disposed, a stator <NUM> disposed at an outer side of the rotor <NUM>, a housing <NUM> configured to accommodate the rotor <NUM> and the stator <NUM>, and a coupler <NUM> coupled to the rotary shaft <NUM>.

The rotor <NUM> is disposed in the stator <NUM>. The rotor <NUM> may include a rotor core and a magnet coupled to the rotor core. The rotor <NUM> may be classified into the following types according to a coupling method between the rotor core and the magnet.

The rotor <NUM> may be implemented as a type in which the magnet is coupled to an outer circumferential surface of the rotor core. In the above-type rotor <NUM>, a separate can member may be coupled to the rotor core to prevent separation of the magnet and increase a coupling force. Alternatively, the magnet and the rotor core may be integrally formed by double injection.

The rotor <NUM> may be implemented as a type in which the magnet is coupled to the inside of the rotor core. In the above-type rotor <NUM>, a pocket into which the magnet is inserted into the rotor core may be provided.

The rotor core of the rotor <NUM> may be formed by laminating a plurality of sheet-shaped plates.

The rotor <NUM> may be formed in a shape in which a plurality of pucks forming a skew angle are stacked.

The stator <NUM> causes electric interaction with the rotor <NUM> to induce rotation of the rotor <NUM>. A coil may be wound around the stator <NUM> to cause the interaction between the stator <NUM> and the rotor <NUM>. A specific configuration of the stator <NUM> on which the coil is wound will be described below.

The stator <NUM> may include a stator core including a plurality of teeth. The stator core may be provided with a ring-shaped yoke portion, and the teeth on which coils are wound may be provided on an outer circumferential surface of the yoke portion. The teeth may be provided at a predetermined interval along the outer circumferential surface of the yoke portion. Meanwhile, the stator core may be formed by laminating a plurality of thin sheet-shaped plates. Further, the stator core may be formed of a plurality of divided cores coupled or connected to each other.

The rotary shaft <NUM> may be coupled to the rotor <NUM>. When the electric interaction between the rotor <NUM> and the stator <NUM> occurs due to current supply, the rotor <NUM> rotates, and accordingly, the rotary shaft <NUM> rotates. The rotary shaft <NUM> may be connected to a steering shaft of a vehicle to transfer power to the steering shaft. The rotary shaft <NUM> may be supported by a bearing.

The housing <NUM> may be formed in a cylindrical shape, and the stator <NUM> may be coupled to an inner wall of the housing <NUM>. An upper portion of the housing <NUM> may be implemented in an open state and a lower portion of the housing <NUM> may be implemented in a closed state. A pocket part configured to accommodate the bearing supporting a lower portion of the rotary shaft <NUM> may be provided in the lower portion of the housing <NUM>. A bracket may be coupled to the open upper portion of the housing <NUM>. The bracket may also be provided with a pocket part configured to support an upper portion of the rotary shaft <NUM>. Further, the bracket may include a hole or a groove into which a connector, to which an external cable is connected, is inserted.

The coupler <NUM> may be coupled to an end portion of the rotary shaft <NUM> to transfer a rotating force of the motor. The above embodiments may be used in the coupler <NUM>.

As described above, the motor according to one embodiment of the present invention has been examined with reference to the accompanying drawings.

The above description is only an exemplary description of the present invention, and various changes, various modifications, changes, and substitutions of the present invention may be performed by those skilled in the art within essential characteristics of the embodiments. Accordingly, the disclosed embodiments and the accompanying drawings of the present invention are not for the purpose of limitation but are for describing the present invention, and the scope of the present invention is not limited by the embodiments and the accompanying drawings. The scope of the present invention should be interpreted by the claims which will be described below.

Claim 1:
A coupler comprising:
an inner insertion part (<NUM>); and
an outer support part (<NUM>) configured to surround the outside of the inner insertion part, the outer support part (<NUM>) including a cylindrical outer wall (<NUM>) and a plurality of projection parts (<NUM>),
characterized in that:
the inner insertion part (<NUM>) includes a cylindrical-shaped protruding part (<NUM>) having a through hole (<NUM>) disposed at a center thereof and a polygonal-shaped plate (<NUM>) configured to extend in a radial direction from an outer circumferential surface of the protruding part,
the outer support part (<NUM>) includes an accommodation part (<NUM>) coupled to the plate (<NUM>), the cylindrical outer wall being configured to extend from an edge of the accommodation part, and the plurality of projection parts (<NUM>) being configured to extend toward the protruding part (<NUM>) from an inner side of the outer wall (<NUM>),
the plate (<NUM>) includes a plurality of connection grooves (<NUM>), and
the accommodation part (<NUM>) is partially disposed in the connection groove (<NUM>).