Actuator and vehicle transmission including the same

Provided are an actuator and a vehicle transmission including the same. The actuator includes a magnet gear unit which transmits a driving force and a driving unit which drives the magnet gear unit. The magnet gear unit includes a first magnet, a second magnet disposed outside the first magnet to face the first magnet, and a pawl member inserted in parallel between the first magnet and the second magnet. The driving unit includes a circular rotor on a central axis, and any one of the first magnet, the second magnet or the pawl member is mounted to the rotor; a third magnet mounted along a circumference of the rotor: and a stator including an annular core having a plurality of protrusions that face the third magnet and coils connected to the protrusions.

CROSS REFERENCE TO RELATED APPLICATION

This application claims priority from Korean Patent Application No. 10-2017-0184576 filed on Dec. 29, 2017, the disclosure of which is incorporated herein by reference in its entirety.

BACKGROUND

1. Field of the Disclosure

The present disclosure relates to an actuator and a vehicle transmission including the same, and more particularly, to an actuator having a magnet gear and a vehicle transmission including the actuator.

2. Description of the Related Art

Generally, vehicle transmissions change gear ratios to maintain the torque of an engine constant based on the speed of a vehicle. To change the gear ratios of a transmission, a driver operates a shift lever of the transmission. The driver may change the gear ratios by selecting a gear by operating the shift lever disposed adjacent to the driver's seat.

Transmissions are categorized into a manual transmission and an automatic transmission. The manual transmission allows a driver to manually select a gear such as a first, second, third, fourth, etc. gear based on the speed of a vehicle. The automatic transmission allows an engine control unit (ECU) of the vehicle to automatically control gears based on the speed of the vehicle, the engine load, the amount of throttle valve opening, etc.

The automatic transmission generally includes a park (P) gear to park the vehicle, a reverse (R) gear to back the vehicle, a neutral (N) gear to disconnect the output of the engine from being transmitted to a driving wheel, and a drive (D) gear to drive the vehicle forward. The driver selects each gear using a shift lever, and typical types of shift levers are a lever type and a dial type. In addition, there is a vehicle type in which each gear is provided in the form of a button.

A common lever type is configured to arrange gears in a row in the order of P-R-N-D and a lever is moved in substantially a linear direction to select each gear. Recently, in certain lever types, the shift lever is not fixed at the P-R-N-D positions, but the lever is configured to return to a preset position after being tilted according to the operation by the driver. The transmission may select a gear in such a manner that P, R. N and D are changed sequentially according to the tilting direction of the lever.

On the other hand, the dial type is configured such that the P, R. N and D gears are disposed around a dial that rotates within a predetermined angle range and a specific point of the dial is positioned at each of the P, R. N and D gears to select a gear.

FIG. 14illustrates an example of a vehicle transmission1of the dial type in the related art. Referring toFIG. 14, the dial-type vehicle transmission1of the related art includes a detent unit F1, an automatic return unit F2, a shift lock unit F3, and a deceleration unit F4as separate elements. The dial-type vehicle transmission1of the related art requires various parts to implement each unit, and the parts are packaged together within a housing. Thus, it is difficult to miniaturize the transmission. In addition, a shift method based on a general gear structure may have the problem of noise generated as the gears are operated.

Therefore, there is a need to develop a novel actuator having a more simplified and smaller configuration and a vehicle transmission including the actuator by improving the complicated mechanical power transmission structure of the conventional vehicle transmission1.

SUMMARY

Aspects of the present disclosure provide an actuator which reduces the number of parts required by improving the power transmission structure of a conventional vehicle transmission and includes a magnet gear for reducing shift noise. Aspects of the present disclosure also provide a vehicle transmission which simplifies the mechanism for implementing detent torque, shift lock and automatic return functions by including an actuator having a magnet gear. However, aspects of the present disclosure are not limited to exemplary embodiments set forth herein. The above and other aspects of the present disclosure will become more apparent to one of ordinary skill in the art to which the present disclosure pertains by referencing the detailed description of the present disclosure given below.

According to an aspect of the present disclosure, an actuator may include a magnet gear unit which transmits a driving force and a driving unit which drives the magnet gear unit. The magnet gear unit may include a first magnet; a second magnet disposed outside the first magnet to face the first magnet; and a pawl member inserted in parallel between the first magnet and the second magnet. The driving unit may include a circular rotor on a central axle to which any one of the first magnet, the second magnet or the pawl member is mounted, a third magnet mounted along a circumference of the rotor, and a stator including an annular core having a plurality of protrusions that face the third magnet and coils connected to the protrusions.

The rotor may be rotated as an attractive force or a repulsive force is exerted on the third magnet by a magnetic force generated when a current is applied to the coils. In addition, any one of the first magnet, the second magnet or the pawl member which is disposed between the other two of the first magnet, the second magnet and the pawl member may be accelerated or decelerated relative to the rotor based on a magnet gear transmission ratio, which is defined as a ratio of the number of magnetic pole pairs included in the second magnet to the number of magnetic pole pairs included in the first magnet.

Further, the third magnet may include a plurality of magnetic poles that correspond to the number of the protrusions, and each of the first magnet and the second magnet may include at least one pair of magnetic poles, wherein polarities of the first magnet, the second magnet and the third magnet may be arranged alternatingly.

The actuator may further include a shaft inserted into the central axle of the rotor. In addition, the pawl member may include a magnetic body on a surface inserted in parallel between the first magnet and the second magnet.

According to another aspect of the present disclosure, a vehicle transmission may include a knob which may be rotated to select any one of a plurality of gears associated with operation modes of a transmission, and a magnet gear unit which may be interlocked with the knob and may provide a driver with a feel of operating the knob when the driver rotates the knob. The magnet gear unit may include a first magnet, a second magnet disposed outside the first magnet to face the first magnet, and a pawl member inserted in parallel between the first magnet and the second magnet, wherein the first magnet, the second magnet, and the pawl member may be rotatable about the same center as the knob.

The pawl member may include a magnetic body provided on a surface inserted in parallel between the first magnet and the second magnet. In addition, any one of the first magnet, the second magnet, or the pawl member may be interlocked with the knob.

Furthermore, the vehicle transmission may include a driving unit which generates holding torque, wherein the driving unit may include a circular rotor on a central axle to which any one of the first magnet, the second magnet or the pawl member which is not interlocked with the knob is mounted, a third magnet mounted along a circumference of the rotor, and a stator including an annular core having a plurality of protrusions that face the third magnet and coils connected to the protrusions.

A holding force may be generated between the third magnet and the stator by a magnetic force generated when a first holding current is applied to the coils or by connection of the coils, and the other two of the first magnet, the second magnet and the pawl member which are not interlocked with the knob may be fixed to provide the feel of operating the knob when the knob is rotated.

Meanwhile, a holding force may be generated between the third magnet and the stator by a magnetic force generated when a second holding current is applied to the coils when there is no brake operation of the driver in a parking gear and may prevent the rotation of the knob.

In addition, the vehicle transmission may further include a shaft inserted into the central axle of the rotor.

According to another aspect of the present disclosure, a vehicle transmission may include a knob which may be rotated to select any one of a plurality of gears associated with operation modes of a transmission, a magnet gear unit which transmits a driving force to the knob when an interlocking condition is satisfied, and a driving unit which drives the magnet gear unit. The magnet gear unit may include a first magnet, a second magnet disposed outside the first magnet to face the first magnet, and a pawl member inserted in parallel between the first magnet and the second magnet. The driving unit may include a circular rotor on a central axle to which any one of the first magnet, the second magnet or the pawl member is mounted, a third magnet mounted along a circumference of the rotor, and a stator including an annular core having a plurality of protrusions that face the third magnet and coils connected to the protrusions.

Further, the pawl member may include a magnetic body provided on a surface thereof, and the pawl member may be inserted in parallel between the first magnet and the second magnet. The rotor may be rotated as an attractive force or a repulsive force is exerted on the third magnet by a magnetic force generated when a current is applied to the coils. When the rotor is rotated, any one of the first magnet, the second magnet or the pawl member which is disposed between the other two may be accelerated or decelerated relative to the rotor based on the number of magnetic pole pairs included in each of the first magnet and the second magnet and the number of pawl pieces included in the magnetic body.

In particular, the knob may be interlocked with any one of the first magnet, the second magnet or the pawl member which is not mounted on the central axle of the rotor.

Meanwhile, the knob may be rotated to return to the parking gear when a condition for returning from a non-parking gear to the parking gear is satisfied. In addition, when a shift condition is satisfied in an autonomous driving mode, the knob may be rotated to select a gear corresponding to the shift condition. Further, a unit angle at which the knob is rotated to select a gear may be determined by a multiple of an angle obtained by dividing 360° by any one of the number of magnetic pole pairs included in the first magnet, the number of magnetic pole pairs included in the second magnet, or the number of pawl pieces included in the magnetic body.

Meanwhile, the third magnet may include a plurality of magnetic poles that correspond to the number of the protrusions, and each of the first magnet and the second magnet may include at least one pair of magnetic poles, wherein polarities of the first magnet, the second magnet and the third magnet may be arranged alternatingly.

In addition, the vehicle transmission may further include a shaft inserted into the central axle of the rotor. The vehicle transmission may further include a sensor unit which detects a gear selected by rotation of the knob. In particular, the sensor unit may include at least one gear which is rotated by the rotation of the knob, a magnet gear which is interlocked with the at least one gear and rotated at a speed higher than a speed of the at least one gear, and a sensor which detects a change in magnetic force of the magnet gear.

DETAILED DESCRIPTION

Advantages and features of the present disclosure and methods of accomplishing the same may be understood more readily by reference to the following detailed description of exemplary embodiments and the accompanying drawings. The present disclosure may, however, be embodied in many different forms and should not be construed as being limited to the exemplary embodiments set forth herein. Rather, these exemplary embodiments are provided to make this disclosure thorough and complete and fully convey the concept of the disclosure to those skilled in the art, and the present disclosure will only be defined by the appended claims. Like reference numerals refer to like elements throughout the specification. In some exemplary embodiments, well-known processes, structures, and technologies will not be specifically described in order to avoid ambiguous interpretation of the present disclosure.

Exemplary embodiments of the disclosure are described herein with reference to cross-section and/or schematic illustrations that are illustrations of exemplary embodiments of the disclosure. As such, variations from the shapes of the illustrations as a result, for example, of manufacturing techniques and/or tolerances, are to be expected. Thus, exemplary embodiments of the disclosure should not be construed as limited to the particular shapes of regions illustrated herein but are to include deviations in shapes that result, for example, from manufacturing. In addition, each component illustrated in figures of the present disclosure may have been enlarged or reduced for ease of description. Like numbers refer to like elements throughout.

Hereinafter, a vehicle transmission according to exemplary embodiments of the present disclosure will be described with reference to the attached drawings.

FIG. 1Ais a perspective view illustrating the exterior of a vehicle transmission1according to an exemplary embodiment of the present disclosure. The vehicle transmission1may be installed between a center fascia and a console box of a vehicle to enable a driver to perform a gear shift operation. However, the present disclosure is not limited thereto, and the vehicle transmission1may be installed at various positions to which the driver can easily access.

Referring toFIG. 1A, a knob100may be exposed on one side of an upper housing500to allow the driver to rotate the knob100to select a desired gear. The knob100may include a display device (not illustrated) which displays a plurality of selectable gears or a currently selected gear. The position of the display device (not illustrated) may be fixed while an outer surface of the knob100is rotated to select a gear. However, the knob100and the display device (not illustrated) may also be rotated together.

Referring toFIG. 1A, in the vehicle transmission1, the knob100may be exposed to the interior space (e.g., a cabin) of the vehicle, and the upper housing500and a lower housing600which house various elements for implementing a gear shift function or a shift lock function may be accommodated within the vehicle body to reduce the space occupied by the vehicle transmission1in the vehicle, thereby improving space utilization.

As illustrated inFIG. 1B, a lever-type shift handle, instead of the knob100, may also be connected to the vehicle transmission1according to the exemplary embodiment of the present disclosure. However, any component that enables the driver to operate gears may be connected to the vehicle transmission1, and a stow position function that allows the lever to be disposed inside a console rather than in a parking gear when the vehicle is turned off may be added depending on the type of lever that is connected. Therefore, the shift handle may be prevented from being exposed when the vehicle is turned off, and unexpected accidents potentially caused by inadvertent operation of gears, which is unexpected by the driver, may be prevented.

FIG. 2is an exploded perspective view of the vehicle transmission1according to the exemplary embodiment of the present disclosure. Referring toFIG. 2, the vehicle transmission1may include the knob100, a sensor unit200, a magnet gear unit300, a driving unit400, the upper housing500, and the lower housing600.

The knob100may be a member that is rotated to select any one of a plurality of gears associated with operation modes of a transmission, and the sensor unit200may be provided to detect a gear that is selected by the rotation of the knob100. Since the rotation angle of the knob100may be detected by the sensor unit200, gears may be shifted as selected.

The upper housing500of the vehicle transmission1according to the exemplary embodiment of the present disclosure may include a pawl member aperture510through which an extension member341of a pawl member340may be exposed. The knob100may be interlocked with the extension member341of the pawl member340, which may be exposed through the pawl member aperture510, to select a gear.

FIG. 3is a perspective view illustrating a longitudinal section of the vehicle transmission1with the knob100removed, taken along line3-3ofFIG. 1A.FIG. 4is a plan perspective view of the vehicle transmission1with the knob100and the upper housing500removed according to the exemplary embodiment of the present disclosure. Referring toFIGS. 3 and 4, the extension member341to be interlocked with the knob100may extend from the pawl member340which may be an element of the magnet gear unit300. An end of the extension member341connected to the knob100may include a polygonal cross-section or a spline and may be coupled to a groove (not illustrated) of the knob100which may correspond to the shape of the cross-section or the spline. Therefore, without slipping, the knob100may rotate to select a gear while forming an accurate rotation angle with the pawl member340.

FIG. 5illustrates the sensor unit200of the vehicle transmission1according to the exemplary embodiment of the present disclosure. Referring toFIGS. 2 through 5, the sensor unit200may include at least one first gear210which may be interlocked with the pawl member340, a magnet whose position may be adjusted according to the gear movement of the sensor unit200, a second gear220which may be engaged with the first gear210, a sensor230which may detect a change in the magnetic force of the magnet, and a printed circuit board (PCB)240on which the sensor230may be installed. To interlock the first gear210of the sensor unit200with the pawl member340, a ring-shaped gear that is engaged with the first gear210may be coupled to the extension member341of the pawl member340.

The second gear220may be rotated by the first gear210which may rotate when the pawl member340is rotated by the rotation of the knob100. Accordingly, the position of the magnet may be changed, and thus the magnetic force may be changed. In addition, the second gear220may also include a magnet. On the PCB240, circuit elements and electronic components for detecting the rotation angle of the knob100and changing or controlling a gear ratio that corresponds to a selected gear may be printed and mounted.

The sensor230may be a sensor, such as a Hall sensor, for detecting a change in magnetic force and may detect a selected gear through a change in magnetic force caused by the rotation of the second gear220. The second gear220may be rotated at a speed higher than that of the first gear210, and the resolution of the sensor230for detecting a change in magnetic force may be increased to enable more accurate detection and control of gears.

FIG. 6Ais an exploded perspective view of an actuator2included in the vehicle transmission1ofFIG. 2.FIG. 6Bis an exploded perspective view of an actuator2according to another exemplary embodiment of the present disclosure. Referring toFIGS. 6A and 6B, the actuators2may each include a magnet gear unit300which may transmit a driving force and a driving unit400which may drive the magnet gear unit300.

In the actuators2of the vehicle transmissions1according to the exemplary embodiments of the present disclosure, the magnet gear unit300and the driving unit400may be integrated as a single module to implement detent torque, shift lock and automatic return functions. Therefore, the number of parts required may be reduced and assemblability may be improved, compared with the dial-type vehicle transmission1in the related art. The magnet gear unit300may include a first magnet310, a second magnet320disposed outside the first magnet310to face the first magnet310, and the pawl member340inserted between the first magnet310and the second magnet320to be rotatable.

Further, the pawl member340may include a magnetic body350on a surface inserted between the first magnet310and the second magnet320to transmit the influence of a magnetic force induced by the driving unit400with the first magnet310or the second magnet320.

The driving unit400may include a stator420and coils430which may generate a magnetic force by applying a current to transmit a driving force to the magnet gear unit300, a third magnet410which may face the stator420and may be affected by the generated magnetic force, and a rotor440on which the third magnet410may be mounted along a circumference.

In the driving unit400of the actuator2according to the exemplary embodiment ofFIG. 6A, the stator420and the third magnet410may face each other along an outer circumference of the stator420. However, the stator420and the third magnet410may also face each other along an inner circumference of the stator420as in the exemplary embodiment ofFIG. 6B. The stator420and the third magnet410may be arranged in any manner as long as the third magnet410may be affected by the magnetic force generated by the stator420.

The driving unit400may include a connector450for supplying power and transmitting a signal. Referring toFIG. 3, the connector450to which a plug is connected may be provided at the position of the upper housing500in the exemplary embodiment of the present disclosure. However, the configuration or format of the connector450is not limited as long as a current may be applied to the coils430of the stator420.

Referring toFIGS. 2, 6A and 6B, the magnet gear unit300may further include a fix core330that surrounds the second magnet320. The fix core330may physically fix the position of the magnet320or transmit holding currents H1and H2applied to the stator420to the second magnet320.

In addition, referring toFIG. 6B, the fix core330may extend in a direction that faces the upper housing500to contact an inner surface of the upper housing500and may fix the position of the second magnet320more stably. Further, part of an extending surface of the fix core330may be open to allow the elements of the vehicle transmission1to be effectively received and interconnected in the housing.

The surface that extends to face the upper housing500may include threaded bores for screws, but the coupling component is not limited to the threaded bores. In addition, the fix core330may be structured to be coupled to the upper housing600in the exemplary embodiment of the present disclosure. However, the shape and structure of the fix core330are not limited thereto as long as the fix core330may stably fix the position of the second magnet320. The magnet gear unit300and the driving unit400of the actuators2according to the exemplary embodiments of the present disclosure may be integrated to mount the first magnet310on a central axle442of the rotor440to transmit a driving force and a holding force. Since the fix core330may fix the position of the second magnet320more stably as described above, the rotor440rotated to drive the magnet gear unit300and the pawl member340rotated at a speed lower or higher than that of the rotor440to transmit a driving force may be driven more precisely and stably.

The driving principle of the actuator2will now be described in more detail in relation to the detent torque, shift lock and automatic return functions in addition to the gear shift function of the vehicle transmission1according to the exemplary embodiment of the present disclosure.

When the knob100is rotated to select a gear by an external force applied by the driver, the driver may be provided with a feel of operating the knob100to allow the driver to recognize the selection of the gear. The magnet gear unit300of the vehicle transmission1according to the exemplary embodiment of the present disclosure may be interlocked with the knob100and may provide the driver with the feel of operating the knob100when the driver rotates the knob100to select a gear.

FIG. 7illustrates the magnet gear unit300of the vehicle transmission1according to the exemplary embodiment of the present disclosure. Referring toFIG. 7, each of the first magnet310and the second magnet320of the magnet gear unit300may include at least one pair of magnetic poles, and the polarities of the magnetic poles may be arranged alternately with each other. In addition,FIGS. 8 and 6A and 6Billustrate pawl pieces351that is included in the magnetic body350provided on the surface of the pawl member340inserted between the first magnet310and the second magnet320. The pawl member340may include the pawl pieces351arranged at equal angles (e.g., at regular angular intervals) and corresponding to the number of magnetic pole pairs included in the second magnet320.

Therefore, the pawl pieces351may transmit a driving force or a constraint force to the knob100interlocked with the pawl member340under the influence of the magnetic force generated between the first magnet310and the second magnet320.

In particular, the pawl member340may be affected by a constraint force generated between the first magnet310whose rotation may be restricted by a holding force generated by the driving unit400and the second magnet320which may be fixed by the fix core330. Therefore, when the driver rotates the knob100interlocked with the pawl member340, the pawl member340may provide the driver with the feel of operating the knob100.

The driving unit400of the vehicle transmission1according to the exemplary embodiment of the present disclosure may apply the first holding current H1to the stator420to generate the holding torque. Referring toFIG. 9illustrating the driving unit400of the vehicle transmission1according to the exemplary embodiment of the present disclosure, the stator420may include an annular core421having a plurality of protrusions422and the coils430connected to (or wound around) the protrusions422to receive a current.

FIG. 10illustrates the rotor440of the driving unit400of the vehicle transmission1according to the exemplary embodiment of the present disclosure. Referring toFIGS. 9 and 10, the third magnet410may be mounted along a circumference441of the rotor440. The third magnet410may be placed to face the protrusions422of the stator420to be affected by a magnetic force generated by a current applied to the coils430. In addition, the third magnet410may include a plurality of magnetic poles that correspond to the number of the protrusions422of the stator420, and the polarities of the magnetic poles may be arranged alternatingly with each other.

Since the first magnet310may be mounted on the central axle442of the rotor440as described above, the driving force or the constraint force of the driving unit400may be transmitted to the magnet gear unit300. In particular, a holding force may be generated between the third magnet410and the stator420by a magnetic force generated when the first holding current H1is applied to the coils430, and a constraint force for restricting rotation may be transmitted to the rotor440on which the third magnet410is mounted and concurrently to the first magnet310mounted on the central axle442of the rotor440.

Therefore, a force for restricting the rotation of the pawl member340that include the magnetic body350may be generated by a magnetic force generated between the fixed first magnet310and the second magnet320, and the pawl member340rotated by an external force applied by the operation of the knob100by the driver may provide the driver with the feel of operating the knob100.

The stator420may generate a holding torque in the third magnet410in response to the first holding current H1, and the rotor440on which the third magnet410is mounted and the first magnet310mounted on the rotor440may be held by the holding torque.

Therefore, to provide the driver who selects a gear with the feel of operating the knob100, the knob100may be rotated when an external force exceeding the holding torque is applied. The holding torque may also be generated by the connection of the coils430.

Referring toFIGS. 9 and 10, a shaft aperture443into or through which a shaft610may be inserted or pass may be formed in the central axle442of the rotor440. In particular, referring to the longitudinal sectional view ofFIG. 3, the shaft610according to the exemplary embodiment of the present disclosure may include a distal end connected to the lower housing600, may pass through the central axle442of the rotor440to be accommodated in a hollow (e.g., a cavity) of the pawl member340and the internal space of the extension member341, and may serve as the axis of rotation about which the pawl member340and the rotor440may stably rotate.

Referring toFIGS. 6A and 6B, the pawl member340may include the hollow. Referring to the longitudinal sectional view ofFIG. 3, the central axle442of the rotor440, the first magnet310and the shaft610may be inserted into the hollow. In particular, referring to the plan perspective view ofFIG. 4, the hollow may allow the shaft610to be inserted up to an inner circumferential surface of the extension member341. Thus, the pawl member340and the rotor440may be stably rotated about the shaft610.

In addition, referring toFIGS. 2 and 3, a cylindrical bush360that surrounds an outer circumferential surface of the extension member341may be further provided to support the rotational movement of the pawl member340.

Meanwhile, a unit angle (e.g., an angle increment) at which the knob100may be rotated to select a gear may be determined by at least one of the number of magnetic pole pairs included in the first magnet310, the number of magnetic pole pairs included in the second magnet320, and the number of the pawl pieces351included in the magnetic body350.

FIG. 11is a plan view of the vehicle transmission1with the knob100and the upper housing500removed according to the exemplary embodiment of the present disclosure, in which part of a surface constituting the pawl member340is illustrated as being open for ease of description.

When the number of magnetic pole pairs included in the second magnet320of the vehicle transmission1is M, the number of the pawl pieces351included in the magnetic body350may also be M as illustrated in the plan view ofFIG. 11, and the unit angle at which the knob100may be rotated to select a gear may be a multiple of an angle obtained by dividing 360° by M.

The direction and magnitude of detent torque generated with respect to the angle at which the knob100is rotated to select a gear and the magnitude of the shift lock are illustrated in the graph ofFIG. 12. Referring toFIG. 12. a torque that is substantially in a sine wave form is generated between unit angles at which the knob100is rotated to select a gear. Referring again to the plan view ofFIG. 11. one magnetic pole pair of the second magnet320may be disposed between the pawl pieces351of the pawl member340. Therefore, a change in magnetic flux generated between the first magnet310and the second magnet320may cause the sine wave torque to be generated in the space between the pawl pieces351when the knob100is rotated to select a gear.

In particular, when the knob100is rotated by about ¼ of the unit angle, the change in magnetic flux may become the maximum, and thus the magnitude of the torque generated may become the maximum. When the knob100is rotated by about ½ of the unit angle, the change in magnetic flux may become zero, and thus the magnitude of the torque generated may become zero. Then. at the moment when the knob100is rotated by more than about ½ of the unit angle. the direction of each magnetic pole pair of the second magnet320disposed at an angle formed between the pawl pieces351may be reversed from N to S or from S to N. Accordingly. the direction of the torque generated may also be reversed. Therefore, when the knob100forms a rotation angle exceeding about ½ of the unit angle, a torque may be generated in a direction in which the knob100is rotated to select a gear, thus enabling the driver to recognize the selection of the gear.

In the exemplary embodiment of the present disclosure, the pawl pieces351may be inserted between the first magnet310and the second magnet320, and M pawl pieces351may be provided to correspond to the M magnetic pole pairs included in the second magnet320. Thus, the sine wave torque may be generated according to a multiple of an angle obtained by dividing 360° by M. and the unit angle at which the knob100is rotated may be determined to be the multiple of the angle obtained by dividing 360° by M.

However, the number of the pawl pieces351may not correspond to the number of magnetic pole pairs included in the second magnet320but may correspond to the number of magnetic pole pairs included in the first magnet310. Additionally, the pawl pieces351may also be disposed not between the first magnet310and the second magnet320but at an innermost or outermost position. Thus, the unit angle at which the knob100is rotated to select a gear may be determined according to the angular period of the sine wave torque generated. Therefore, the unit angle at which the knob100is rotated to select a gear may be determined by a multiple of an angle obtained by dividing 360° by any one of the number of magnetic pole pairs included in the first magnet310, the number of magnetic pole pairs included in the second magnet320, and the number of the pawl pieces351included in the magnetic body350.

An automatic vehicle transmission may require the shift lock function as a safety measure that maintains gear shifting locked to prevent sudden acceleration of the vehicle when the driver does not operate the brake in the parking gear. To this end, the vehicle transmission1according to the exemplary embodiment of the present disclosure may apply the second holding current H2to the stator420when the driver does not operate the brake in the parking gear.

On the same principle that the detent torque is generated, the third magnet410may be fixed by a magnetic force generated by the second holding current H2, and the fixed third magnet410may restrict the rotation of the rotor440. which, in turn. restricts the rotation of the first magnet310mounted on the central axle442of the rotor440. Therefore, the rotation of the knob100may be prevented by the torque generated in the pawl member340disposed between the fixed first magnet310and the second magnet320. In addition, when the state of preventing the rotation of the knob100is not maintained by an external force, the stator420may rotate the rotor440by applying a current, thereby moving the knob100to a preset position.

FIG. 12is a graph illustrating the direction and the range of magnitude of a torque generated in a shift lock state in the vehicle transmission1according to the exemplary embodiment of the present disclosure. Referring toFIG. 12, the torque generated when there is no brake operation by the driver in the parking gear may be expressed as a dot on the graph at a rotation angle of 0° that corresponds to a park (P) gear. The magnitude of the second holding current H2may be greater than that of the first holding current H1to prevent the knob100from being rotated even when the driver applies more than a certain force.

In addition, the actuator2of the vehicle transmission1according to the exemplary embodiment of the present disclosure may return the knob100to the parking gear when a condition for returning from a non-parking gear to the parking gear is satisfied. For example, when the driver turns off the vehicle in a drive (D) gear or inputs a particular operation, the driving unit400may be driven to automatically return the knob100to the parking gear by rotating the knob100.

In the exemplary embodiment. reverse (R). neutral (N) and D may be non-parking gears in which the vehicle may be driven, and P may be a parking gear in which the driving of the vehicle is restricted. When a condition for returning from a non-parking gear to the parking gear is satisfied, the vehicle transmission1according to the exemplary embodiment of the present disclosure may rotate the rotor440by applying a current to the stator420of the driving unit400, and the magnet gear unit300driven by the driving unit400may return the interlocked knob100to the parking gear by rotating the knob100at a speed lower or higher than the rotation speed of the rotor440.

In particular, the number of the protrusions422of the stator420may correspond to the number of magnetic poles of the third magnet410arranged to face the protrusions422with the polarities of the magnetic poles alternating with each other. The magnetic force generated in response to a current applied to the stator420may create an attractive force or a repulsive force between the protrusions422and the third magnet410, and thereby may rotate the rotor440.

Since a magnet gear transmission ratio may be defined as a ratio of the number of magnetic pole pairs included in the second magnet320to the number of magnetic pole pairs included in the first magnet310, each of the first magnet310and the second magnet320may include at least one magnetic pole pair, and the pawl member340may be rotated at a speed lower or higher than that of the rotor440by the magnet gear transmission ratio.

When the rotor440is rotated, the first magnet310mounted on the central axle442of the rotor440may also be rotated at the same speed as the rotor440. Accordingly, the pawl member340may be rotated at a speed lower or higher than the rotor440by the magnet gear transmission ratio between the rotated first magnet310and the fixed second magnet320, and thereby may return the knob100to the parking gear.

FIG. 13is a graph illustrating the direction and magnitude of a torque generated when the knob100is returned to the parking gear when a condition for returning from a non-parking gear to the parking gear is satisfied in the vehicle transmission1according to the exemplary embodiment of the present disclosure. Referring toFIG. 13, the vehicle transmission1may generate a torque of constant magnitude in the same direction to return the knob100to a position that corresponds to a rotation angle of 0° when a condition for returning from a non-parking gear (R, N or D) to the parking gear (P) is satisfied.

In the exemplary embodiment, the knob100may be returned to the parking gear when a condition for returning from a non-parking gear to the parking gear is satisfied. However, the knob100may also be returned to a previous gear when a faulty operation of the knob100occurs while the vehicle is being driven. In order to prevent another gear from being selected while the vehicle is being driven in the D gear, the actuator2may return the knob100to the D gear, which is a previous gear, when the knob100is rotated by the driver's faulty or inadvertent operation.

In addition, when a shift condition is satisfied in an autonomous driving mode, the knob100may be rotated to select a gear that corresponds to the shift condition. The actuator2and the knob100may be interlocked based on various shift conditions. In addition, althoughFIG. 13has been described above using the vehicle transmission1according to the exemplary embodiment of the present disclosure as an example, it also is applicable to the actuator2according to the exemplary embodiment, and the actuator2may output a torque having a predetermined period in a predetermined direction as illustrated inFIG. 13.

In the actuator2and the vehicle transmission1including the same according to the exemplary embodiment of the present disclosure, the pawl member340may be inserted between the first magnet310and the second magnet320. However, the position where the pawl member340is inserted is not limited thereto, and the pawl member340may also be inserted outside the second magnet320or may be inserted inside the first magnet310.

When the pawl member340is inserted at the outermost position, it may include a hollow that may accommodate the central axle442of the rotor440, the first magnet310and the second magnet320. In this case. the knob100may be interlocked with the second magnet320to implement the detent torque, shift lock and automatic return functions described above. When the pawl member340is inserted at the innermost position, the position of the pawl member340may be fixed, the second magnet320may be mounted on the central axle442of the rotor440, and the knob100may be interlocked with the first magnet310to implement the detent torque, shift lock and automatic return functions.

In summary, the positions of the first magnet310, the second magnet320and the pawl member340are not limited to the exemplary embodiment of the present disclosure. When the knob100is interlocked with any one of the first magnet310, the second magnet320and the pawl member340, the interlocked component may be disposed between the two non-interlocked components among the first member310, the second member320and the pawl member340.

In addition, any one of the first magnet310, the second magnet320and the pawl member340which is not interlocked with the knob100may be mounted on the central axle442of the rotor440. When the central axle442of the rotor440is disposed at the innermost position, any one of the first magnet310, the second magnet320and the pawl member340which is disposed at the outermost position may be fixedly installed to implement the detent torque, shift lock and automatic return functions.

On the same principle, when the central axle442of the rotor440is disposed at the outermost position, any one of the first magnet310, the second magnet320and the pawl member340which is disposed at the innermost position may be fixedly installed to implement the detent torque, shift lock and automatic return functions.

Exemplary embodiments of the present disclosure may provide at least one of the following advantages. Since a magnet gear may be used, actuator noise may be reduced, compared with a conventional actuator using a general gear. A dial-type shift operation may improve utilization of the space inside a vehicle. The noise generated when gears are shifted may be reduced and assemblability may be improved by reducing the number of parts required. The mechanism for implementing detent torque, shift lock, and automatic return functions may be simplified compared with methods in the related art. The effects of the exemplary embodiments are not restricted to the one set forth herein. The above and other effects of the exemplary embodiments will become more apparent to one of daily skill in the art to which the exemplary embodiments pertain by referencing the claims.

While the present disclosure has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those of ordinary skill in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the present disclosure as defined by the following claims. The exemplary embodiments should be considered in a descriptive sense only and not for purposes of limitation. The scope of the present disclosure is defined by the following claims, rather than by the above-described detailed description. The meanings and scope of the claims, and all modifications or modified shapes, which are derived from equivalent concepts thereof, should be understood as being included in the scope of the present disclosure.