Motor assembly and steering apparatus for vehicle having the same

According to embodiments of the present disclosure, it is possible to easily adjust the tension of the belt, and simplify the motor installation structure in the steering system, and share a motor between vehicle types.

CROSS REFERENCE TO RELATED APPLICATION

This application claims priority from Korean Patent Application No. 10-2021-0017984, filed on Feb. 9, 2021, which is hereby incorporated by reference for all purposes as if fully set forth herein.

TECHNICAL FIELD

The present embodiments of the present disclosure relate to a motor assembly and a steering apparatus of a vehicle including the same, more particularly, relate to a motor assembly capable of easily adjusting a belt tension and simplifying the motor installation structure and assembly process in the steering system, and capable of sharing the motor between vehicle models, and a vehicle steering apparatus with the same.

In a structure for transferring the torque of the motor, a belt and a pulley are often used to reduce the torque of the motor to the driven part. In this case, since the belt tension may be loosened, it is necessary to maintain the belt tension to prevent the pulley from spinning.

In particular, a steering apparatus of a vehicle may include a motor for generating a torque to assist a driver's steering torque, or steering a wheel corresponding to a driver's steering torque, or generating a steering reaction force to improve a driver's steering feeling. A general steering apparatus has a structure in which a motor is coupled to a housing eccentrically with respect to a motor shaft, rotates with respect to the housing, and maintains the tension of a belt connecting the motor shaft and a pulley. Alternatively, there may be used a structure in which a pulley supported on the outer surface of the belt is installed, the belt is pressed by the pulley, and the tension of the belt is maintained.

However, in the structure of assembling the motor eccentrically, it is difficult to manufacture since a screw hole having a circumferential slit shape is required to be provided in the housing to rotate the motor. In addition, there is a problem in that it is cumbersome to use a different type of motor for each vehicle model in consideration of interference with peripheral parts and a motor installation space. In addition, the structure including the pulley supported on the outer surface of the belt has a problem in that the number of parts increases and the assembly process is complicated since it is required to further include a pulley as well as a motor.

SUMMARY

In this background, embodiments of the present disclosure provide a motor assembly capable of easily adjusting a belt tension and simplifying the motor installation structure and assembly process in the steering system, and capable of sharing the motor between vehicle models, and a vehicle steering apparatus with the same.

In an aspect of the present disclosure, there is provided a motor assembly including a motor including a motor shaft including a large-diameter portion and a small-diameter portion extending from one end of the large-diameter portion, a first support member formed in a hollow and provided on a first side of an outer surface of the small-diameter portion, and an outer diameter of which decreases from one side to another side, a second support member formed in a hollow shape and provided on a second side of the outer surface of the small-diameter portion, and an outer diameter of which increases from one side to another side, a pulley which is formed in a hollow shape, includes a plurality of slits for cutting an inner surface and an outer surface, and includes, in the inner surface, a first tapered surface supported on an outer surface of the first support member and a second tapered surface supported on an outer surface of the second support member, a nut coupled to one end of the small-diameter portion, a first elastic member provided between the nut and the first support member, and a second elastic member provided between the second support member and the large-diameter portion.

In another aspect of the present disclosure, there is provided a motor assembly including a motor including a motor shaft including a large-diameter portion and a small-diameter portion extending from one end of the large-diameter portion, a support member formed in a hollow shape and provided on an outer surface of the small-diameter portion, the outer diameter of which decreases from one side to another side, a pulley which is formed in a hollow shape, includes a plurality of slits for cutting an inner surface and an outer surface, and includes, in the inner surface, a tapered surface supported on an outer surface of the support member and a step portion formed with a diameter enlarged at an end of the tapered surface and supported by the large-diameter portion, a nut coupled to one end of the small-diameter portion, and an elastic member provided between the nut and the support member.

In another aspect of the present disclosure, there is provided a steering apparatus of a vehicle including the motor assembly, a sliding bar having both ends connected to a tie rod and a knuckle arm, a housing accommodating the sliding bar and coupled to a motor of the motor assembly, a ball nut coupled to an outer surface of the sliding bar via a ball and coupled to a driven pulley, and a belt coupled to a pulley included in the motor assembly and the driven pulley.

In another aspect of the present disclosure, there is provided a steering apparatus of a vehicle including the motor assembly, a steering column including a steering shaft, to which a motor of the motor assembly is coupled, a driven pulley coupled to the steering shaft, and a belt coupled to a pulley included in the motor assembly and the driven pulley.

According to embodiments of the present disclosure, it is possible to easily adjust the tension of the belt, and simplify the motor installation structure in the steering system, and share a motor between vehicle types.

DETAILED DESCRIPTION

FIG.1is an exploded perspective view of a motor assembly according to the present embodiments,FIG.2is a perspective view illustrating an example of use of a motor assembly according to the present embodiments,FIGS.3to4are perspective views of a part of a motor assembly according to the present embodiments,FIG.5is a cross-sectional view of a part of a motor assembly according to the present embodiments,FIG.6is an exploded perspective view of a part of a motor assembly according to the present embodiments,FIG.7is a cross-sectional view of a part of a motor assembly according to the present embodiments,FIG.8is an exploded perspective view of a motor assembly according to the present embodiments,FIG.9is an exploded perspective view of a part of a motor assembly according to the present embodiments,FIG.10is a cross-sectional view of a part of a motor assembly according to the present embodiments,FIG.11is an exploded perspective view of a part of a motor assembly according to the present embodiments,FIG.12is a cross-sectional view of a part of a motor assembly according to the present embodiments, andFIGS.13to14are perspective views of a steering apparatus for a vehicle according to the present embodiments.

First, it will be described an embodiment of the present disclosure with reference toFIGS.1to7.

According to an embodiment, there may be provided a motor assembly100including a motor101including a motor shaft102including a large-diameter portion103and a small-diameter portion104extending from one end of the large-diameter portion, a first support member121formed in a hollow and provided on a first side of an outer surface of the small-diameter portion104, and an outer diameter of which decreases from one side to another side, a second support member122formed in a hollow shape and provided on a second side of the outer surface of the small-diameter portion104, and an outer diameter of which increases from one side to another side, a pulley110which is formed in a hollow shape, includes a plurality of slits310for cutting an inner surface and an outer surface, and includes, in the inner surface, a first tapered surface511supported on an outer surface of the first support member121and a second tapered surface512supported on an outer surface of the second support member122, a nut140coupled to one end of the small-diameter portion104, a first elastic member131provided between the nut140and the first support member121, and a second elastic member132provided between the second support member122and the large-diameter portion103.

Referring toFIGS.1to2, a belt200is supported on the outer surface of the pulley110, as the belt200rotates, and the torque of the motor101is transmitted to the driven part. The pulley110may be formed to be elastically deformed in the radial direction, and to be enlarged or reduced in diameter. The pulley110is enlarged by an elastic force of the first elastic member131and the second elastic member132, so that the belt200is pressed and the tension of the belt200can be maintained.

Referring toFIG.3, the pulley110is formed in a hollow shape, and a plurality of slits310for cutting the inner and outer surfaces are formed in the pulley110. The slit310includes a first slit311formed from one end of the pulley110toward another end of the pulley110and a second slit312formed from the another end of the pulley110toward the end of the pulley110.

The first slit311and the second slit312may be alternately provided. Therefore, the first slit311and the second slit312may be elastically deformed to increase or decrease the width thereof, so that the pulley110can be enlarged or reduced in diameter.

As shown inFIG.3, the first slit311and the second slit312may be formed parallel to an axial direction. Alternatively, as shown inFIG.4, the first slit311and the second slit312may be formed in a spiral shape.

In both cases in which the first slit311and the second slit312are formed parallel to the axial direction and formed in a spiral shape, the pulley110may be enlarged in diameter to press the belt200. In the case that the first slit311and the second slit312are formed is spiral shapes, the rib of the pulley110provided between the first slit311and the second slit312may be supported by the belt200at a wider angle in the circumferential direction, so that it is possible to press the belt200more stably.

Referring toFIG.1andFIG.5, the first support member121and the second support member122are inserted into the inner surface of the pulley110from one side and another side, respectively. The first elastic member131and the second elastic member132elastically support the first support member121and the second support member122, respectively. Accordingly, the belt200is pressed in a direction in which the pulley110is enlarged by the elastic force of the first elastic member131and the second elastic member132.

The motor shaft102of the motor101includes a small-diameter portion104and a large-diameter portion103. The small-diameter portion104is provided to extend from one end of the large-diameter portion103. The nut140is coupled to one end of the small-diameter portion104, and the first elastic member131, the first support member121, the pulley110, the second support member122and the second elastic member132are coupled to the motor shaft102.

The first support member121and the second support member122are formed in a hollow shape, and are provided on a first side and a second side of the outer surface of the small-diameter portion104, respectively.

The first support member121is formed with an outer diameter decreasing from one side to another side. The second support member122is formed with an outer diameter increasing from one side to another side. That is, the first support member121and the second support member122may be symmetrically formed in a direction facing each other.

In the inner surface of the pulley110, there may be provided a first tapered surface511supported on the outer surface of the first support member121and a second tapered surface512supported on the outer surface of the second support member122.

That is, the inner diameter of the pulley110in the portion where the first tapered surface511is formed decreases from one side to another side. In the portion where the second tapered surface512is formed, the inner diameter of the pulley110is formed to increase from one side to another side. The inner surface of the pulley110may have an approximately v-shape.

The first elastic member131is provided between the nut140and the first support member121, is supported by the nut140, and presses the first support member121. The second elastic member132is provided between the second support member122and the large-diameter portion103, is supported by the large-diameter portion103, and presses the second support member122.

In one side of the first support member121and another side of the second support member122, there may be provided a groove recessed in the axial direction for seating the first elastic member131and the second elastic member132, respectively.

Accordingly, the first support member121and the second support member122are pressed in a direction facing each other by the first elastic member131and the second elastic member132, respectively. Since the first support member121and the second support member122are supported by the first tapered surface511and the second tapered surface512of the pulley110, respectively, the belt200is pressed in the direction in which the pulley110is enlarged, and the tension of the belt200is maintained.

In addition, the first elastic member131and the second elastic member132may be compressed or tensioned by moving the nut140forward or backward. Accordingly, it is possible to easily adjust the tension of the belt200by adjusting the elastic force of the first elastic member131and the second elastic member132.

Meanwhile, in order to rotate the belt200by the rotation of the motor shaft102without loss of torque, it is required to prevent the slip between the small-diameter portion104and the inner surface of the first support member121and the second support member122, between the outer surface of the first support member121and the second support member122and the pulley110, and between the outer surface of the pulley110and the belt200.

First, although not shown in the figures, serrations may be formed on the small-diameter portion104and the inner surfaces of the first support member121and the second support member122. That is, the first support member121and the second support member122are coupled to the small-diameter portion104to be slidable in the axial direction but fixed in the circumferential direction to prevent the slip.

As shown inFIGS.6to7, a first groove611elongated in the axial direction may be formed on the outer surface of the small-diameter portion104, and a second groove612elongated in the axial direction may be formed on the inner surface of the second support member122. A support pin620is inserted into the first groove611and the second groove612, and the first support member121and the second support member122are fixed to the small-diameter portion104in the in the circumferential direction so as to prevent the slip.

That is, the support pin620is formed in a substantially rod shape, the radially inner portion of the support pin620is inserted into the first groove611and is supported in the circumferential direction by the small-diameter portion104. The radially outer portion of the support pin620is inserted into the second groove612and is supported by the first support member121and the second support member122in the circumferential direction.

To facilitate coupling in the axial direction, the first groove611may be formed to open up to one end of the small-diameter portion104. The second groove612may be formed to be opened from the first support member121and the second support member122to both ends, respectively.

In addition, the first support member121, the second support member122, and the pulley110may be made of a high friction material, so that there may be prevented the slip between the outer surfaces of the first and second support members121and122and the inner surface of the pulley110.

That is, the first support member121and the second support member122are in close contact with the first tapered surface511and the second tapered surface512, respectively, by the elastic force of the first elastic member131and the second elastic member132. In addition, the first tapered surface511and the second tapered surface512are in close contact with the first support member121and the second support member122by the restoring force of the pulley110. Accordingly, there may be prevented the slip by manufacturing the first support member121and the second support member122and the pulley110with a high friction material.

In addition, similarly to the support pin620, the first groove611and the second groove612, a groove may be formed on the inner circumferential surface of the pulley110and the outer circumferential surfaces of the first support member121and the second support member122so as to fix in the circumferential direction by inserting a pin. In this case, the depth of the groove or the thickness of the pin is required to be designed based on the enlarged diameter of the pulley110.

In addition, it is also possible to prevent slip between the outer surface of the pulley110and the belt by using a toothed belt and forming a groove meshing with the teeth of the belt on the outer peripheral surface of the pulley110. Alternatively, slip may be prevented by increasing the area in which the pulley110and the belt are supported.

Referring toFIG.5andFIG.7, one end and another end of the pulley110are provided with a stepped portion320protruding in a radial direction to prevent the belt200from being separated. The stepped portion320is formed to protrude in a tapered manner, and a v-shaped belt supported on the tapered surface of the stepped portion320is used as the belt200, so that it is possible to prevent the slip by increasing the area in which the outer peripheral surface of the pulley110and the belt200are supported.

Hereinafter, it will be described an embodiment of the present disclosure with reference toFIGS.8to12.

According to an embodiment, there may be provided a motor assembly including a motor101including a motor shaft102including a large-diameter portion103and a small-diameter portion104extending from one end of the large-diameter portion103, a support member820formed in a hollow shape and provided on an outer surface of the small-diameter portion104, the outer diameter of which decreases from one side to another side, a pulley810which is formed in a hollow shape, includes a plurality of slits310for cutting an inner surface and an outer surface, and includes, in the inner surface, a tapered surface1001supported on an outer surface of the support member820and a step portion1002formed with a diameter enlarged at an end of the tapered surface1001and supported by the large-diameter portion103, a nut140coupled to one end of the small-diameter portion104, and an elastic member830provided between the nut140and the support member820.

Compared with the embodiments shown inFIGS.1to7, in the embodiments shown inFIGS.8to12, one support member820and one elastic member830are provided, respectively, and one tapered surface1001is also provided on the inner surface of the pulley810.

The same reference numerals are used for the same components as in the above-described embodiments, and detailed descriptions thereof will be omitted.

A plurality of slits310for cutting the inner and outer surfaces are formed in the pulley810formed in a hollow shape, the pulley810is enlarged by the elastic force of the elastic member830, so that the belt is pressed and the tension of the belt is maintained.

The slit310includes a first slit311formed from an end of the pulley810toward another end, and a second slit312formed from the another end of the pulley810toward the end of the pulley810.

The first slit311and the second slit312may be provided alternately, and the first slit311and the second slit312may be formed parallel to the axial direction (refer toFIG.8) or may be formed in a spiral shape (refer toFIG.9).

Referring toFIGS.8and10, the support member820is inserted into the inner surface of the pulley810from one side. The elastic member830elastically supports the support member820so that the belt is pressed in a direction in which the pulley810is enlarged by the elastic force of the elastic member830.

The support member820is formed to be hollow and is provided on the outer surface of the small-diameter portion104, and the outer diameter of the support member decreases from one side to another side.

The inner peripheral surface of the pulley810is provided with a tapered surface1001supported on the outer surface of the support member820. That is, in the portion where the tapered surface1001is formed, the inner diameter of the pulley810is formed to decrease from one side to another side.

In addition, the inner peripheral surface of the pulley810is provided with a step portion1002supported on the large-diameter portion103of the motor shaft102. The step portion1002is formed by being enlarged in the diameter at an end of the tapered surface1001.

That is, since the end of the tapered surface1001is a portion where the inner diameter of the pulley810is minimized, the step portion1002is formed by being enlarged from the inner peripheral surface of the pulley810at the another side.

The step portion1002is supported by the large-diameter portion103and the another side of the pulley810is supported by the motor shaft102in the axial direction. The elastic member830provided between the nut140and the support member820presses the support member820against the nut140. The belt is pressed in the direction in which the pulley810is enlarged and the tension of the belt is maintained.

Accordingly, since the elastic member830may be compressed or tensioned by moving the nut140forward or backward, it is possible to easily adjust the tension of the belt by adjusting the elastic force of the elastic member830.

Meanwhile, similarly, a serration may be formed to prevent slip between the small-diameter portion104and the inner circumferential surface of the support member820. Alternatively, as shown inFIGS.11to12, a first groove611elongated in the axial direction may be formed on the outer surface of the small-diameter portion104and a second groove612elongated in the axial direction may be formed on the inner surface of the support member820. Accordingly, the support member820may be fixedly coupled to the small-diameter portion104in the circumferential direction by the support pin620inserted into the first groove611and the second groove612, thereby preventing the slip.

In addition, by manufacturing the support member820and the pulley810with a high friction material, there may be prevented the slip between the outer circumferential surface of the support member820and the inner circumferential surface of the pulley810by frictional force.

The support member and the pulley may be fixed in the circumferential direction by forming a groove on the outer surface of the support member820and the inner surface of the pulley810and inserting a pin thereto.

In addition, it is possible to prevent the slip by using a toothed belt and forming a groove on the outer circumferential surface of the pulley810engaged with the tooth of the belt. Alternatively, in order to prevent separation of the belt, a stepped portion320protruding radially from one end and another end of the pulley810may be formed to protrude in a tapered manner, and a v-shaped belt may be used, so that it is also possible to prevent the slip by increasing the area in which the pulley810and the belt200are supported.

According to the motor assembly having such a configuration, the tension of the belt can be easily adjusted by moving the nut forward or backward, so that the belt tension adjustment process can be simplified.

Hereinafter, it will be described an embodiment of the present disclosure with reference toFIG.13.

According to an embodiment, there may be provided a steering apparatus1300of a vehicle including a motor assembly100or800, a sliding bar1320having both ends connected to a tie rod and a knuckle arm, a housing1310accommodating the sliding bar1320and coupled to a motor101, a ball nut1330coupled to an outer surface of the sliding bar1320via a ball and coupled to a driven pulley1340, and a belt200coupled to a pulley110or810and the driven pulley1340.

The steering apparatus1300for a vehicle shown inFIG.13may be a part of a rack-driven power-assisted steering apparatus or a steer-by-wire steering apparatus, and the sliding bar1320, the ball nut1330, the driven pulley1340, and the like are generally the same as those known, and thus detailed descriptions thereof will be omitted.

That is, the motor assembly100according to the embodiments shown inFIGS.1to7or the motor assembly800according to the embodiments shown inFIGS.8to12may be installed in the housing1310, so that the driver's manipulation of the steering wheel may be assisted by the torque of the motor101or the wheel may be steered to correspond to the driver's manipulation of the steering wheel. It is possible to easily adjust the tension of the belt200connecting the pulleys110or810and the driven pulley1340by moving the nut140forward or backward.

Hereinafter, it will be described an embodiment of the present disclosure with reference toFIG.14.

According to an embodiment, there may be provided a steering apparatus1400including a motor assembly100or800, a steering column1410including a steering shaft1420and coupled to a motor101, a driven pulley1430coupled to the steering shaft1420, and a belt200coupled to a pulley110or810and the driven pulley1430.

The steering apparatus1400for a vehicle shown inFIG.14may be a part of a steer-by-wire steering apparatus, and the steering shaft1420, the steering column1410, the driven pulley1430, and the like are generally the same as those known, and thus detailed descriptions thereof will be omitted.

That is, the motor assembly100according to the embodiments shown inFIGS.1to7or the motor assembly800according to the embodiments shown inFIGS.8to12may be is installed in the steering column1410. As a result, it is possible to apply a steering reaction force to the steering shaft1420, and improve the steering feeling of the driver. In addition, it is also possible to easily adjust the tension of the belt140connecting the pulleys110or810and the driven pulley1430by moving the nut140forward or backward.

However, in addition to the embodiments shown inFIGS.13to14, the motor assemblies100and800according to the present embodiments may be applied to other types of steering apparatus having a structure for transferring torque of the motor using a belt.

According to the steering apparatus of a vehicle having such a configuration, there is no need to assemble the motor eccentrically as in the general steering system, and there is no need to rotate the motor in a state coupled to the housing in order to adjust the tension of the belt. Accordingly, it is possible to simplify the motor installation structure and assembly process, and share motors between vehicle models without risk of interference with surrounding.