KR102817206B1 - motor assembly for driving apparatus of electric side step - Google Patents

Abstract

The present invention relates to a motor assembly of an electric side step driving device, and one embodiment of the present invention provides a motor assembly of an electric side step driving device, including a housing member including a first housing and a second housing, a shaft disposed within the housing member and rotating integrally with a rotor and an input gear, a bearing disposed between the rotor and the input gear and coupled with the second housing to support rotation of the shaft, and an oil seal coupled with the second housing between the bearing and the input gear, wherein the input gear, the bearing, and the oil seal are press-fitted into the second housing while coupled to the shaft and disposed in the second housing.

Description

Motor assembly for driving apparatus of electric side step

Embodiments of the present invention relate to a motor assembly of an electric side step driving device, and more particularly, to a motor assembly of an electric side step driving device with improved assembling properties and durability.

Side steps are generally used for the convenience of getting in and out of vehicles with high garages such as pickup trucks and large SUVs. Side steps are installed to protrude outward from the bottom of the vehicle door. However, if the side steps are installed to protrude at all times, unnecessary air resistance is caused while driving, which increases the risk of rear-end collisions, and there is a problem that it is difficult to provide sufficient foothold area when getting in and out of the vehicle.

Accordingly, an electric side step equipped with a drive device to protrude the footrest outward only when necessary has been developed and provided. The electric side step is configured so that the footrest automatically protrudes outward or returns inward to the vehicle body depending on the opening and closing of the vehicle door. A board that functions as a footrest is provided on the inside of the vehicle body to prevent interference with obstacles during driving, and the board protrudes outward only when the vehicle door is opened to assist smooth boarding and disembarkation.

The electric side step driving device is configured to convert the driving force of the motor into high-torque rotational force including a plurality of gears and transmit it to the output shaft, and as the link member connected to the board by the output shaft rotates, the board protrudes outward from the vehicle body or is retracted into the vehicle body. At this time, the motor as the power source is configured to include a shaft forming a rotational axis, a rotor connected to the shaft and rotating, a commutator, and an input gear, and the input gear meshes with the gear of the driving device to transmit rotational force to the driving device.

In general, motors are provided with oil seals adjacent to the locations where gears are arranged to prevent lubricating material applied to the gears from flowing into the internal commutator. However, conventional motors have had problems in that the oil seals come into contact with bearings inside the motor, interfering with the rotation of the bearings, and in that the oil seals are deformed due to friction, preventing the oil seals from maintaining stable sealing force.

Embodiments of the present invention are intended to solve the above-mentioned problems and/or limitations, and to provide a motor assembly of an electric side step driving device with improved durability and assemblability.

However, these tasks are exemplary and the scope of the present invention is not limited thereby.

One embodiment of the present invention provides a motor assembly of an electric side step driving device, comprising: a housing member including a first housing and a second housing; a shaft disposed within the housing member and rotating integrally with a rotor and an input gear; a bearing disposed between the rotor and the input gear and coupled with the second housing to support rotation of the shaft; and an oil seal coupled with the second housing between the bearing and the input gear, wherein the input gear, the bearing, and the oil seal are press-fitted into the second housing while coupled to the shaft and disposed in the second housing.

In one embodiment of the present invention, the oil seal may be provided to have a width smaller than that of the bearing, and an edge of the oil seal may be arranged to contact the outer ring of the bearing.

In one embodiment of the present invention, the oil seal includes a first bulkhead portion arranged to be in contact with the housing, an extension portion extending from the first bulkhead portion toward the shaft, and a second bulkhead portion connected to the extension portion and arranged to be in contact with the shaft, wherein the height of the first bulkhead portion in a direction parallel to the shaft may be higher than that of the second bulkhead portion.

In one embodiment of the present invention, the edge of the first bulkhead portion contacts one end of the outer ring of the bearing, and the area of contact between the first bulkhead portion and the bearing may be less than half the area of one end of the outer ring of the bearing.

In one embodiment of the present invention, the oil seal is provided such that the outer peripheral surface is in contact with the housing and the inner peripheral surface is in contact with the shaft, and a groove open in the bearing direction may be formed.

In one embodiment of the present invention, the rotor includes a core portion having a central hole that is fitted into the shaft and a plurality of slots that are arranged radially based on the central hole, and a bobbin portion that is fitted to one end of the core portion and on which a coil is wound, and the bobbin portion may have a plurality of coupling portions that are fitted corresponding to each of the plurality of slots.

In one embodiment of the present invention, at least one of the plurality of connecting portions may have a fixing projection formed on a surface in contact with the slot and protruding toward the slot.

In one embodiment of the present invention, the plurality of coupling parts include an inner coupling part coupled to the inside of the slot and a coil support part connected to the inner coupling part, and a step may be formed between the coil support part and the inner coupling part.

In one embodiment of the present invention, the fixing projection may be formed on one surface of the inner coupling portion adjacent to the coil support portion.

In one embodiment of the present invention, the bobbin portion has a separated first bobbin portion and a second bobbin portion, and the first bobbin portion and the second bobbin portion can be fittedly connected to the core portion along the longitudinal direction of the shaft.

In one embodiment of the present invention, the shaft may have at least one first stamping projection formed on an outer surface of an area coupled with the rotor and protruding with a predetermined width and length, and at least one second stamping projection formed on an outer surface of an area coupled with the gear and protruding with a predetermined width and length, and the first stamping projection may have a first inclined area formed at an angle from the outer surface in one area, and the second stamping projection may have a second inclined area formed at an angle from the outer surface in one area.

In one embodiment of the present invention, the first inclined region and the second inclined region may have a length 10 to 40 times longer than the height protruding from the outer surface.

In one embodiment of the present invention, the first inclined region may be formed at an end of the first stamping projection adjacent to one end of the shaft, and the second inclined region may be formed at an end of the second stamping projection adjacent to the other end opposite to one end of the shaft.

Other aspects, features and advantages other than those described above will become apparent from the following drawings, claims and detailed description of the invention.

According to the problem solving means of the present invention described above, in the motor assembly of the electric side step driving device according to the embodiments of the present invention, when the bearing is coupled to the housing member, the oil seal can be stably seated in the housing by press-fitting the bearing and the oil seal together, and interference between the bearing and the oil seal can be prevented. In addition, by improving interference between the bearing and the oil seal, a motor assembly with improved durability and assembling ability can be provided.

In addition, embodiments of the present invention can improve the bonding strength between the bobbin and the core and enhance the durability and assemblability of the rotor by providing a plurality of fixing projections capable of stably supporting the core on the bobbin coupled with the core of the rotor.

In addition, embodiments of the present invention can reduce manufacturing costs, facilitate the manufacturing process, and improve assembling efficiency by having the same size of the stage where the bearing, commutator, and rotor are combined on the shaft that serves as the rotation axis.

In addition, embodiments of the present invention can reduce the press force deviation during assembling of a bearing, a commutator, or a rotor by improving the shape of the stamping projection of the shaft, and can improve the assembling performance.

In addition, embodiments of the present invention can reduce noise during motor operation by improving brushes in contact with the commutator.

Of course, the scope of the present invention is not limited by these effects.

FIG. 1 is a perspective view illustrating a motor assembly of an electric side step driving device according to one embodiment of the present invention.
Fig. 2 is a cross-sectional view of the motor assembly of the electric side step driving device of Fig. 1 taken along line II-II.
Figure 3 is an enlarged cross-sectional view showing part A of Figure 2.
Figure 4 is a drawing showing the process of assembling an oil seal and bearing into a second housing.
FIG. 5 is a drawing illustrating a rotor of a motor assembly according to one embodiment of the present invention.
FIG. 6 is a drawing illustrating a shaft of a motor assembly according to one embodiment of the present invention.

Hereinafter, the following embodiments will be described in detail with reference to the attached drawings. When describing with reference to the drawings, identical or corresponding components are given the same drawing reference numerals and redundant descriptions thereof will be omitted.

The present embodiments can be subject to various transformations, and specific embodiments are illustrated in the drawings and described in detail in the detailed description. The effects and features of the present embodiments, and the methods for achieving them, will become clear with reference to the contents described in detail below together with the drawings. However, the present embodiments are not limited to the embodiments disclosed below, and can be implemented in various forms.

In the drawings, parts irrelevant to the description are omitted in order to clearly explain the present invention, and similar parts are given similar drawing reference numerals throughout the specification.

In the examples below, the terms first, second, etc. are not used in a limiting sense but are used for the purpose of distinguishing one component from another.

In the examples below, singular expressions include plural expressions unless the context clearly indicates otherwise.

In the examples below, terms such as “include” or “have” mean that a feature or component described in the specification exists, and do not exclude in advance the possibility that one or more other features or components may be added.

In the examples below, when it is said that a part such as a unit, region, or component is located above or on another part, this includes not only the case where it is directly above the other part, but also the case where another unit, region, or component is interposed in between.

In the examples below, terms such as connect or combine do not necessarily imply a direct and/or fixed connection or combination of two members, unless the context clearly indicates otherwise, and do not exclude the presence of another member between the two members.

In the drawings, the sizes of components may be exaggerated or reduced for convenience of explanation. For example, the sizes and thicknesses of each component shown in the drawings are arbitrarily shown for convenience of explanation, and therefore the following embodiments are not necessarily limited to what is shown.

The terms “above,” “upper,” “below,” and “lower” used in this specification are only used to easily describe the relationship between each component depicted in the drawings, and do not limit the direction in which each component is arranged.

FIG. 1 is a perspective view illustrating a motor assembly (10) of an electric side step driving device according to one embodiment of the present invention, and FIG. 2 is a cross-sectional view of the motor assembly (10) of the electric side step driving device of FIG. 1 taken along line II-II.

Referring to FIGS. 1 and 2, a motor assembly (10) of an electric side step driving device according to one embodiment of the present invention may include a housing member (100), a shaft (200), a rotor (300), an input gear (400), a bearing (500), an oil seal (600), and a commutator (700).

The housing member (100) forms the outer appearance of the motor assembly (10) and may have an accommodation space inside. The housing member (100) may include a first housing (110) and a second housing (120). The first housing (110) and the second housing (120) may be combined to form the outer appearance of the motor assembly (10) and may each have an accommodation space extending in the height direction (z direction).

A portion of a shaft (200) and a rotor (300) coupled with the shaft (200) may be placed in the internal receiving space of the first housing (110), and a stator (310) surrounding the rotor (300) may also be placed. A first coupling member coupled with one end of the shaft may be placed at one end of the receiving space of the first housing (110), and the first coupling member may be, for example, a rotary bearing. The first housing (110) may have an opening connected to the internal receiving space, and the shaft (200) may pass through the opening.

In the internal accommodation space of the second housing (120), the remaining portion of the shaft (200) that is not accommodated in the first housing (110) and the input gear (400), bearing (500), and oil seal (600) coupled with the shaft (200) may be arranged. In addition, an electric side step driving device connected to the input gear (400) may be arranged in the accommodation space of the second housing (120). The electric side step driving device has a plurality of gears and can receive the driving force of the motor assembly (10) from the input gear (400) to reduce the rotation speed. That is, the electric side step driving device can convert high-speed rotational force generated from the motor assembly (10) into low-speed, high-torque rotational force and output it, thereby driving a board that serves as a foothold of the electric side step.

The second housing (120) may include an opening connected to an internal receiving space, and a shaft (200) may pass through the opening. The opening of the second housing (120) may be coupled with the opening of the first housing (110). In one embodiment, the opening of the second housing (120) may be fitted into the opening of the first housing (110). When the opening of the second housing (120) and the opening of the first housing (110) are coupled, the receiving space of the second housing (120) may be connected to the receiving space of the first housing (110) to form one internal space extending in the longitudinal direction (z direction).

A shaft (200), a rotor (300), a stator (310), an input gear (400), a bearing (500), an oil seal (600), a commutator (700), and a brush (710) can be placed in the above internal space.

The shaft (200) may be arranged to extend in the longitudinal direction (z direction) of the internal space, and may be arranged at the center of the width direction (y direction) of the internal space. A rotor (300), an input gear (400), a bearing (500), an oil seal (600), and a commutator (700) may be fitted and coupled to the shaft (200), and may serve as a rotational axis on which the rotor (300), the input gear (400), the bearing (500), and the commutator (700) rotate.

Specifically, the shaft (200) can be coupled with the rotor (300) and can rotate together with the rotor (300) by the rotational force generated from the rotor (300). In addition, the shaft (200) can be coupled with the input gear (400) and can rotate together with the input gear (400). That is, the rotor (300) and the input gear (400) can rotate around the same axis, and the rotational force generated from the rotor (300) can be transmitted to the input gear (400) through the shaft (200).

A bearing (500) may be placed between the rotor (300) and the input gear (400). The bearing (500) may be provided such that the inner ring is connected to the shaft (200) and the outer ring is connected to the second housing (120). The bearing (500) may be press-fitted and fixed to the second housing (120). The bearing (500) may play a role in fixing the shaft (200) in a fixed position and supporting the rotational movement of the shaft (200). The bearing (500) may be provided as a rotational bearing having the same size as the first coupling member coupled to one end of the shaft (200), but is not limited thereto.

An oil seal (600) may be placed between the input gear (400) and the bearing (500) to prevent the lubricating material applied to the input gear (400) from moving toward the bearing (500). The oil seal (600) may be placed between the input gear (400) and the bearing (500) so as to be adjacent to the bearing (500). The oil seal (600) may be provided so that its inner surface is connected to the shaft (200) and its outer surface is connected to the second housing (120), and may be press-fitted and fixed to the second housing (120).

In one embodiment, the width of the oil seal (600) may be provided to be smaller than the width of the bearing (500). Here, the width means the length in the width direction (y direction) in the cross section shown in FIG. 2. In addition, the oil seal (600) may be formed such that the length in the height direction (z direction) of the inner peripheral surface is shorter than the length in the height direction (z direction) of the outer peripheral surface.

Meanwhile, the oil seal (600) may have a groove formed between the inner and outer surfaces, and the groove may be formed to be open toward the bearing (500). The oil seal (600) may have a groove that is open toward the bearing (500), so that the edge may contact the outer ring of the bearing (500), and other areas other than the edge may not contact the bearing (500).

According to one embodiment of the present invention, a motor assembly (10) is provided with an oil seal (600) that comes into contact with a bearing (500) so that it comes into contact only with the outer ring of the bearing (500), so that the oil seal (600) can be combined with the bearing (500) without interfering with the rotational movement of the bearing (500), and deformation and wear of the oil seal (600) are reduced, thereby improving the durability of the oil seal (600).

With further reference to FIGS. 3 and 4 below, the combination of the bearing (500) and the oil seal (600) and the second housing (120) will be described in detail.

Figure 3 is a cross-sectional view showing an enlarged portion of part A of Figure 2, and Figure 4 is a drawing showing the process of assembling an oil seal (600) and a bearing (500) to a second housing (120).

Referring to FIG. 3, a bearing (500) fitted into a shaft (200) and assembled with a second housing (120) may be arranged such that the inner surface of the inner ring contacts the shaft (200) and the outer surface of the outer ring (510) contacts the second housing (120). At this time, the bearing (500) may be press-fitted and fixed to the shaft (200), and the inner ring of the bearing (500) may be provided to rotate together with the shaft (200). In addition, the bearing (500) may be press-fitted and fixed to the second housing (120), and the outer ring of the bearing (500) may be stably seated in the second housing (120).

Meanwhile, an oil seal (600) may be arranged on one side of the bearing (500). The oil seal (600) may be inserted into the second housing (120) while being fitted to the shaft (200), and may be arranged such that a plurality of protrusions formed on the inner surface contact the shaft (200) and the outer surface contacts the second housing (120). The oil seal (600) may be arranged to seal the space between the shaft (200) and the second housing (120) on one side of the bearing (500), thereby blocking foreign substances flowing in from the input gear (400) toward the bearing (500).

The width of the oil seal (600) may be formed to be a value smaller than the width of the bearing (500). At this time, the second housing (120) may have two steps on the inner surface where the bearing (500) and the oil seal (600) are arranged so as to be combined with the bearing (500) and the oil seal (600). Specifically, the second housing (120) may have a first step (122) that contacts the edge of the outer ring of the bearing (500) so as to support the bearing (500) in the longitudinal direction (z direction), and may have a second step (123) that has a width smaller than that of the first step (122) so as to support the oil seal (600).

In one embodiment, the oil seal (600) may include a first bulkhead portion (610) extending in the longitudinal direction (z direction) and in contact with the second housing (120), an extension portion (620) extending from the first bulkhead portion (610) toward the shaft (200), and a second bulkhead portion (630) connected to the extension portion (620) and in contact with the shaft (200). A groove (640) may be formed between the first bulkhead portion (610) and the second bulkhead portion (630).

The height (h1) of the first bulkhead portion (610) in the direction parallel to the shaft, i.e., in the longitudinal direction (z direction), may be higher than the height (h2) of the second bulkhead portion (630). Therefore, when the bearing (500) and the oil seal (600) come into contact, the edge (611) of the oil seal may come into contact with one end of the outer ring (510) of the bearing (500), and at this time, the second bulkhead portion (630) may not come into contact with the bearing (500).

Looking at the contact portion (B) where the bearing (500) and the oil seal (600) shown in Fig. 3 come into contact, one end of the first baffle portion (610) forming the edge (611) of the oil seal (600) is formed so that its width becomes narrower as it goes toward the bearing (500). The edge (611) of the oil seal (600) can come into contact with a part of one end of the outer ring (510) of the bearing (500), and the edge (611) can be placed only on one end of the outer ring (510) of the bearing (500).

In one embodiment, the area where the edge (611) of the oil seal (600) and one end of the outer ring (510) of the bearing (500) come into contact may be less than or equal to half the area of one end of the outer ring (510) of the bearing (500). Specifically, the width of the edge (611) of the oil seal (600) in contact with the bearing (500) may be less than or equal to 1/3 of the width of the outer ring of the bearing (500). At least a portion of one end of the outer ring of the bearing (500) that does not come into contact with the edge (611) may come into contact with the first step (122).

Referring to FIG. 4, the bearing (500) and the oil seal (600) can be coupled to the shaft (200) and pressed together into the second housing (120). A second coupling member (210) to which the other end of the shaft (200) is coupled can be arranged at one end of the second housing (120), and the shaft (200) can be coupled with the second coupling member (210) after being inserted into the second housing (120).

A first coupling member, a rotor (300), a commutator (700), a bearing (500), an oil seal (600), and an input gear (400) can be fitted and coupled to a shaft (200), and the shaft (200) can be inserted and installed into a second housing (120) in a state in which it is coupled with the above components. The bearing (500) and the oil seal (600) coupled with the shaft (200) can be in a state in which they are coupled by being in contact with each other.

The second housing (120) can apply heat to the area where the bearing (500) and the oil seal (600) are seated to form a thermal expansion section (H), and the bearing (500) and the oil seal (600) can be pressed in and seated at the same time. At this time, the bearing (500) and the oil seal (600) can be inserted into the interior of the second housing (120) together in a combined state, and after being inserted into the interior of the second housing (120), the bearing (500) can be stopped and fixed at a position where it contacts the first step (122), and the oil seal (600) can be stopped and fixed at a position where it contacts the second step (123).

When the oil seal (600) is fitted and combined into the shaft (200), the groove (640) may be arranged so that it is open toward the bearing (500), and the edge (611) may be arranged so that it comes into contact with the outer ring (510) of the bearing (500). Accordingly, when the shaft (200) is inserted into the second housing (120), the bearing (500) that is strongly fixed to the shaft (200) may be pushed together by the force of being inserted into the second housing (120), so that the oil seal (600) may be easily inserted into the fixed position of the second housing (120). The bearing (500) inserted into the second housing (120) comes into contact with the first step (122) and becomes a hard stop, and the oil seal (600) may be smoothly inserted until it comes into contact with the second step (123).

According to one embodiment of the present invention, a motor assembly (10) is provided with an outer diameter of an oil seal (600) smaller than an outer diameter of a bearing (500), and an edge (611) of the oil seal (600) is pressed into a second housing (120) by contacting an outer ring (510) of the bearing (500), thereby preventing the oil seal (600) from interfering with the rotational movement of the bearing (500) and preventing the oil seal (600) from being deformed by pressure. In addition, the assembling properties of the bearing (500) and the oil seal (600) can be improved, and wear of the bearing (500) and the oil seal (600) can be prevented, thereby providing a motor assembly (10) with increased durability.

FIG. 5 is a drawing illustrating a rotor (300) of a motor assembly (10) according to one embodiment of the present invention.

Referring to FIG. 5, a rotor (300) of a motor assembly (10) according to one embodiment of the present invention may include a core portion (320) and a bobbin portion (330). The core portion (320) may extend to a predetermined length along the longitudinal direction (L) of the shaft (200) and may have a center hole portion (321) that is fitted into the shaft (200) and a plurality of slots (322) that are arranged radially based on the center hole portion (321). The center hole portion (321) and each slot (322) may be connected by a connecting portion.

The bobbin part (330) may include a first bobbin part (330-1) and a second bobbin part (330-2). The first bobbin part (330-1) and the second bobbin part (330-2) may be fitted to the core part (320) along the longitudinal direction (L) of the shaft (200). The first bobbin part (330-1) and the second bobbin part (330-2) may be formed to have the same structure.

The first bobbin part (330-1) and the second bobbin part (330-2) are fitted and connected on both sides of the core part (320) with the core part (320) as the center, so as to cover the upper and lower surfaces of the core part (320). At this time, the core part (320) connected to the bobbin part (330) may have the outer surfaces of the plurality of slots (322) exposed to the outside.

In one embodiment, the first bobbin part (330-1) and the second bobbin part (330-2) may have a plurality of coupling members that are fit-fitted into each of the plurality of slots (322). The plurality of coupling members may include an inner coupling member (331) that is coupled to the inside of the slot (322) and a coil support member (332) that is connected to the inner coupling member (331).

The inner joint (331) is coupled with the inner surface of the slot (322) to support the slot (322) from the inside. The inner joint (331) may have two coupling surfaces arranged parallel to the slot (322). The coupling surfaces may be coupled with two extension surfaces surrounding the connection portion of the core portion (320).

The coil support (332) can be connected to the inner coupling portion (331) and can be formed to protrude in a direction away from the core portion (320) along the longitudinal direction (L) of the shaft (200). The coil support (332) can play a role in supporting the coil wound around each slot (322) so that it does not come off.

In one embodiment, a step (333) may be formed between the coil support (332) and the inner coupling portion (331). The step (333) may be coupled with an end of the slot (322) when the bobbin portion (330) is fitted and coupled to the core portion (320). The bobbin portion (330) may be stably coupled with the slot (322) by having the inner coupling portion (331) and the step (333), and may prevent the core portion (320) from being separated from the bobbin portion (330).

In one embodiment, at least one of the plurality of connecting portions may be formed with a fixing projection (334) protruding toward the slot (322) on a surface that comes into contact with the slot (322). Specifically, at least one of the steps (333) formed between the coil support portion (332) and the inner connecting portion (331) may be formed with a fixing projection (334) protruding in the longitudinal direction (L).

In one embodiment, the fixed projections (334) may be provided in multiple numbers in one joint, but is not limited thereto.

In one embodiment, the fixing projections (334) may be formed on a plurality of coupling portions that are arranged symmetrically among the plurality of coupling portions. For example, in the case of a bobbin portion (330) having ten coupling portions, the fixing projections (334) may be formed on five coupling portions, and the fixing projections (334) may be arranged symmetrically. In another embodiment, the fixing projections (334) may be formed on all of the plurality of coupling portions. However, the number and arrangement of the coupling portions on which the fixing projections (334) are formed are not limited to the above-described embodiments, and any number and arrangement are all possible.

The fixed projection (334) is formed on one surface of the inner joining portion (331) adjacent to the coil support portion (332), and can serve as a guide to stably support and settle the plurality of slots (322) when the core portion (320) and the bobbin portion (330) are joined. In addition, when the core portion (320) and the bobbin portion (330) are joined, the fixed projection (334) can prevent the bobbin portion (330) from being separated from the core portion (320).

Meanwhile, the bobbin part (330) can be manufactured by injection molding, and each of the coil support parts (332) can be provided with a gate into which material is injected when manufacturing the bobbin part (330). The gate can be provided in an inlet groove (335) that is introduced toward the core part (320) along the longitudinal direction (L) of the shaft (200) at one end of each coil support part (332). The bobbin part (330) can prevent the coil from being damaged by the gate when winding the coil by providing the gate in the inlet groove (335) and preventing it from protruding outward from the coil support part (332), and can reduce the risk of an operator's hand being injured by a sharp part of the gate.

FIG. 6 is a drawing illustrating a shaft (200) of a motor assembly (10) according to one embodiment of the present invention.

Referring to Fig. 6, a shaft (200) may be extended in the longitudinal direction with a predetermined length and may have one end (E1) and the other end (E2) opposite to the one end (E1). The shaft (220) may have two steps whose width becomes narrower from the one end (E1) to the other end (E2).

The shaft (200) may include one or more first stamping protrusions (221) protruding from the outer surface to have a predetermined width and length. Here, the width refers to a length extending along the circumferential direction of the shaft (200), and the length refers to a length extending along the longitudinal direction of the shaft (200). The first stamping protrusion (221) may have a first inclined region (S1) formed to be inclined from the outer surface in one area. At this time, the first inclined region (S1) may be formed at an end of the first stamping protrusion (221) adjacent to one end (E1) of the shaft (200).

A rotor (300) can be fitted and combined in a region where a first stamping projection (221) is formed in the shaft (200). The rotor (300) is inserted from one end (E1) of the shaft (200) and is press-fitted to be fixed in the region where the first stamping projection (221) is formed, thereby being combined with the shaft (200). The first stamping projection (221) can serve to fix the rotor (300) so that it does not come off. That is, when the rotor (300) rotates, the shaft (220) is combined with the rotor (300) through the first stamping projection (221), so that they can rotate together.

The first inclined area (S1) of the first stamping projection (221) can play a role in reducing the deviation of the pressing force when the rotor (300) is pressed in. The first stamping projection (221) has the first inclined area (S1), so that the rotor (300) can be pressed in using a constant pressing force.

Meanwhile, the shaft (200) may include one or more third stamping protrusions (222) protruding from the outer surface to have a predetermined width and length. The third stamping protrusions (222) may be formed on the same step as the step where the first stamping protrusions (221) are formed among the steps formed on the shaft (200), and may be arranged spaced apart from the first stamping protrusions (221). The third stamping protrusions (222) may be arranged at a position closer to the other end (E2) than the first stamping protrusions (221).

The third stamping projection (222) may have a third inclined region (S2) formed to be inclined from the outer surface in one area. At this time, the third inclined region (S2) may be formed at an end of the third stamping projection (222) adjacent to the other end (E2) of the shaft (200).

A commutator (700) can be fitted and combined in the area where the third stamping projection (222) is formed on the shaft (200). The commutator (700) is inserted into the other end (E2) of the shaft (200) and is press-fitted to be fixed in the area where the third stamping projection (222) is formed, thereby being combined with the shaft (200). The third stamping projection (222) can play a role in fixing the commutator (700) so that it does not come off.

The third inclined area (S2) of the third stamping projection (222) can play a role in reducing the deviation of the pressing force when pressing the commutator (700). The third stamping projection (222) has the third inclined area (S2), so that the commutator (700) can be pressed in using a constant pressing force.

In addition, the shaft (200) may include one or more second stamping protrusions (223) protruding from the outer surface to have a predetermined width and length. The second stamping protrusions (223) may be formed on a different step from the step where the first stamping protrusions (221) and the third stamping protrusions (222) are formed among the steps formed on the shaft (200). The diameter of the step where the second stamping protrusions (223) are formed may be smaller than the diameter of the step where the first stamping protrusions (221) and the third stamping protrusions (222) are formed.

The second stamping projection (223) may have a second inclined region (S3) formed to be inclined from the outer surface in one area. At this time, the second inclined region (S3) may be formed at an end of the second stamping projection (223) adjacent to the other end (E2) of the shaft (200).

An input gear (400) can be fitted and combined in an area where a second stamping projection (223) is formed in the shaft (200). The input gear (400) is inserted from the other end (E2) of the shaft (200) and can be combined with the shaft (200) by being press-fitted so as to be fixed in an area where a second stamping projection (223) is formed. The second stamping projection (223) can play a role in fixing the input gear (400) so that it does not come off, and the shaft (220) and the input gear (400) are combined through the second stamping projection (223) so that they can rotate together.

The second inclined area (S3) of the second stamping projection (223) can play a role in reducing the deviation of the pressing force when the input gear (400) is pressed in. The second stamping projection (223) has the second inclined area (S3), so that the input gear (400) can be pressed in using a constant pressing force.

The first inclined region (S1), the second inclined region (S3), and the third inclined region (S2) may be provided to have a length that is 10 to 40 times longer than the height protruding from the outer surface, respectively. The motor assembly (10) has the first inclined region (S1), the second inclined region (S3), and the third inclined region (S2), and by providing the inclination of each inclined region to be gentle, the pressing force can be constantly adjusted when press-fitting a component into the shaft (200), and the assembling efficiency can be improved.

Meanwhile, the rotor (300), bearing (500), and commutator (700) can be pressed into one step having the same diameter among the steps formed on the shaft (200). The motor assembly (10) has the same size of the steps into which the rotor (300), bearing (500), and commutator (700) are pressed into the shaft (200), and by forming the first stamping projection (221) and the third stamping projection (222), the manufacturing cost of the shaft (200) can be reduced, and the assembly of the rotor (300), bearing (500), and commutator (700) can be facilitated.

In addition, the motor assembly (10) according to one embodiment of the present invention can fix the bearing (500) by press-fitting it into the shaft (200) with a predetermined size of press force. The predetermined size may be determined by the axial force received by the first coupling member and the bearing (500). For example, the size of the press force at which the bearing (500) is press-fitted into the shaft (200) may be 300 kgf or more and 600 kgf or less. When the motor assembly (10) press-fits the bearing (500) into the shaft (200), the press force is large enough to stably couple the bearing (500) without it coming off, but the press force does not cause damage to the bearing (500), thereby stably fixing the bearing (500) to the shaft (200) and allowing the bearing (500) to stably support the shaft (200), the rotor (300), and the commutator (700).

Meanwhile, as an example, the brush (710) in contact with the commutator (700) of the motor assembly (10) may have a mass ratio of copper and carbon of 1:1.5 to 1:2. For example, the brush (710) may have a copper content of 30% or more, and a carbon content provided corresponding thereto may be 60% or more, but is not limited thereto.

In addition, the brush (710) may be provided so that the contact area with the commutator (700) has one of the values between 25 mm ² and 45 mm ² . In order to reduce noise of the brush (710), the conventional motor assembly increased the carbon content, but there was a problem that the current flow was poor due to the increase in the carbon content. The motor assembly (10) according to one embodiment of the present invention has the copper mass of the brush (710) at 30% to 40% of the total mass, and by increasing the contact area between the brush (710) and the commutator (700), the current flow can be improved and noise can also be reduced.

Although the present invention has been described with reference to one embodiment shown in the drawings, this is merely exemplary, and those skilled in the art will understand that various modifications and variations of embodiments are possible from this. Accordingly, the true technical protection scope of the present invention should be determined by the technical idea of the appended patent claims.

10: Motor assembly of electric side step drive device
100 : Housing Absence
110 : 1st Housing
120: Second Housing
200 : Shaft
300 : Rotor
400 : Input Gear
500 : Bearing
600 : Oil seal
700 : Stopper
710 : Brush

Claims (13)

A housing member comprising a first housing and a second housing;
A shaft disposed within the housing member and rotating integrally with the rotor and input gear;
A bearing disposed between the rotor and the input gear and coupled with the second housing to support rotation of the shaft;
An oil seal is included between the bearing and the input gear, and is coupled with the second housing;
The above input gear, the bearing and the oil seal are pressed into the second housing while being coupled to the shaft and placed in the second housing,
The above rotor
A core portion having a central hole that is fitted into the shaft and a plurality of slots that are arranged radially based on the central hole;
A bobbin portion connected to one end of the core portion and having a coil wound thereon;
The above bobbin part has a plurality of connecting parts that are fitted and connected to each of the plurality of slots,
A motor assembly of an electric side step drive device, wherein at least one of the plurality of connecting parts has a fixed projection formed on a surface in contact with the slot and protruding toward the slot. In the first paragraph,
A motor assembly of an electric side step drive device, wherein the oil seal is provided to have a width smaller than that of the bearing, and an edge of the oil seal is positioned to contact the outer ring of the bearing. In the first paragraph,
The above oil seal
A first bulkhead portion arranged to be in contact with the second housing;
An extension extending from the first bulkhead portion toward the shaft;
A second bulkhead portion connected to the above extension portion and arranged to be in contact with the shaft;
A motor assembly of an electric side step drive device, wherein the height of the first bulkhead portion in a direction parallel to the shaft is higher than that of the second bulkhead portion. In the third paragraph,
The edge of the above first bulkhead portion comes into contact with one end of the outer ring of the bearing,
A motor assembly of an electric side step driving device, wherein the area of contact between the first bulkhead and the bearing is less than half of the area of one end of the outer ring of the bearing. In the first paragraph,
The above oil seal is provided so that its outer surface is in contact with the second housing, its inner surface is in contact with the shaft, and a motor assembly of an electric side step driving device is formed with a groove open in the bearing direction. delete delete In the first paragraph,
The above plurality of coupling members include an inner coupling member coupled to the inside of the slot and a coil support member connected to the inner coupling member,
A motor assembly of an electric side step driving device, wherein a step is formed between the coil support portion and the inner coupling portion. In Article 8,
A motor assembly of an electric side step driving device, wherein the above-mentioned fixed projection is formed on one surface of the inner joining portion adjacent to the above-mentioned coil support portion. In the first paragraph,
The above bobbin part has a separated first bobbin part and a second bobbin part,
A motor assembly of an electric side step driving device, wherein the first bobbin portion and the second bobbin portion are fitted and connected to the core portion along the longitudinal direction of the shaft. In the first paragraph,
The shaft has at least one first stamping projection formed on the outer surface of the area coupled with the rotor to protrude with a predetermined width and length, and at least one second stamping projection formed on the outer surface of the area coupled with the input gear to protrude with a predetermined width and length.
The above first stamping projection has a first inclined region formed inclined from the outer surface in one area,
A motor assembly of an electric side step driving device, wherein the second stamping projection has a second inclined area formed to be inclined from the outer surface in one area. In Article 11,
A motor assembly of an electric side step driving device, wherein the first inclined region and the second inclined region have a length that is 10 to 40 times longer than the height protruding from the outer surface. In Article 11,
The above first inclined region is formed at an end of the first stamping projection adjacent to one end of the shaft,
A motor assembly of an electric side step driving device, wherein the second inclined region is formed at an end adjacent to the other end of the second stamping projection facing one end of the shaft.

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