WO2019013514A1

WO2019013514A1 - Actuator system for electric vehicle

Info

Publication number: WO2019013514A1
Application number: PCT/KR2018/007772
Authority: WO
Inventors: 최윤용; 홍정표
Original assignee: 드라이브텍 주식회사
Priority date: 2017-07-11
Filing date: 2018-07-10
Publication date: 2019-01-17
Also published as: KR101784875B1

Abstract

An actuator system for an electric vehicle is disclosed. According to an embodiment of the present invention, the actuator system for the electric vehicle comprises: an actuator motor having a rotary shaft; a speed reduction part detachably coupled to the rotary shaft, reducing the speed of rotation power transmitted from the rotary shaft so as to form a set reduction ratio, and including a fork driving shaft rotating according to the speed-reduced rotation power, and a linearly moving part coupled to the fork driving shaft so as to linearly move the fork driving shaft according to the rotational direction of the fork driving shaft; and a shift part including a shift fork detachably coupled to the linearly moving part so as to linearly move according to a linear movement of the linearly moving part, and a sleeve coupled to the shift fork and linearly moving at a set position according to the linear movement of the shift fork so as to be coupled to and released from a first-stage gear or a second-stage gear such that a first-stage shift gear or a second-stage shift gear is implemented.

Description

Actuator system for electric vehicles

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an actuator system for an electric vehicle, and more particularly, to an actuator system for an electric vehicle having a small-sized system and high output performance.

Generally, an internal combustion engine such as a gasoline engine or a diesel engine used as a prime mover in an automobile uses fossil fuel as a power source by burning the fuel in the cylinder.

Recently, global environmental problems have become a global concern, and environmental regulations have been strengthened especially in developed countries. Especially, exhaust gas regulations related to automobiles and fuel efficiency regulations have been expanded.

The development trend of automobiles has been studied in order to develop vehicles with less pollution instead of the current gasoline and heavy oil as the main fuel which are seriously affecting air pollution. As a result of these researches, there is a growing interest in electric vehicles, which are low in noise and do not emit any exhaust gas at all.

An electric vehicle uses a secondary battery (a battery) as a driving power source. Instead of a conventional gasoline or diesel engine, a driving motor is driven by a high voltage and a high current outputted from a battery, And transmits it to the wheel through the transmission device so as to rotate the wheel.

Since a typical electric vehicle has excellent characteristics of a driving motor, the performance of a vehicle required by a decelerator having a single gear ratio or a two-speed change of the first and second speeds can be obtained.

However, when the speed reducer is used alone, the capacity of the driving motor must be relatively increased. Therefore, a two-speed transmission system is used in order to operate the driving motor as efficiently as possible.

In this case, systems for automatically performing shifts between first and second gears have been developed for the sake of the driver's convenience. In this method, an actuator for shifting is installed in a transmission mechanism, and the transmission mechanism (generally, a shift fork a shift fork is constituted by a shaft to which the shift fork linearly moves and a sleeve which is coupled to the shift fork and linearly moved to be engaged with and disengaged from the first or second gear).

A system in which such a transmission mechanism is shifted by the force of an actuator is shown in Fig.

1 is disclosed in Korean Patent No. 10-0194729 (registered on Feb. 10, 1999).

1, a conventional shift actuator system for an electric vehicle includes a transmission mechanism 100 and a sensing means for sensing whether or not the gears of the transmission mechanism 100 are meshed with each other for automatically shifting the two- (50) for rotating and stopping the transmission in accordance with a signal of the sensing means, the transmission means being operable to change the direction of rotation of the transmission mechanism (100) by the motor (50) And a moving means for moving the moving means.

The moving means includes a ball skew 61 rotating as the motor 50 and a rod 60 screwed with the ball skew 61 and coupled with the transmission mechanism 100, A ball skew flow 61 which is transmitted in accordance with the rotation of the motor 50 and a rod 61 which is integrally coupled to the ball skew flow 61 and is engaged with the transmission mechanism 100.

The conventional shift actuator system for an electric vehicle has a structure in which the ball skew 61 is rotated in accordance with the rotation of the motor 50 and the rod 60 coupled with the transmission mechanism 100 by the rotation of the ball skew 61 And moves along the subsidiary shaft 90 so that the two-speed shifting of the first speed and the second speed is performed.

However, when the electric vehicle adopting such a conventional electric vehicle shift actuator system is shifted in a state of running on a steep sloping road or in a state where it exceeds the weight of the electric vehicle, the load applied to the electric vehicle The rod 60 coupled with the transmission mechanism 100 is not normally moved along the sub-shaft 90 due to the rotation of the ball squeeze flow 61 due to the reverse rotation Can not be achieved. This is because the ball skew 61 has precise control characteristics but can not deliver a large transfer force and the capacity of the motor 50 is not large enough to overcome the reverse load generated from the drive wheel.

Accordingly, the conventional shift actuator system for an electric vehicle needs to shift the gears of the transmission 100 in order to overcome the load generated when the vehicle is running on a road with a steep slope or in a state where the load weight is exceeded, There is a problem that the capacity of the motor 50 for the motor must be increased. Therefore, the space utilization of the electric vehicle can not be efficiently performed, and the production cost is increased.

Also, since the bulky ball skew 61 is used to transmit the force of the motor 50, the space utilization of the electric vehicle can not be efficiently utilized and the production cost increases.

It is to be understood that the matters described as the background art of the present invention are only for improving the understanding of the technology as the background of the present invention, and it is accepted that they correspond to the conventional art already known to those skilled in the art It should not be accepted.

An actuator system for an electric vehicle in which a capacity of a motor used for a shift is reduced while generating a high output is proposed.

The solution of the present invention is not limited to the above-mentioned solutions, and other solutions not mentioned can be clearly understood by those skilled in the art from the following description.

An actuator system for an electric vehicle according to an embodiment of the present invention includes an actuator motor having a rotation axis, a speed reducer for reducing the rotational force of the actuator motor, a speed reducing mechanism for reducing the rotational force of the actuator motor, And a transmission portion that linearly moves in accordance with the linear motion converted by the modular deceleration portion to form a one-stage speed ratio or a two-speed speed ratio, wherein the modulated deceleration portion is detachably attached to the actuator motor and the transmission portion And the modular decelerating portion is detachably coupled to the rotary shaft of the actuator motor so as to reduce the rotational force of the actuator motor decelerated in the decelerator at a predetermined reduction ratio, Reduction gears and detachable to the driven shafts. A first reduction gear which is engaged with the first reduction gear to form a first reduction gear ratio and rotates the slave shaft in accordance with the first reduction gear ratio and a second reduction gear which is detachably coupled to the follower shaft, A second reduction gear that is detachably coupled to the fork drive shaft and meshes with the second reduction gear to form a two-stage reduction ratio and rotates the fork drive shaft according to the two-stage reduction ratio; Wherein the fork driving shaft includes a straight moving portion which is coupled to the fork driving shaft and linearly moves the fork driving shaft in accordance with the rotating direction of the fork driving shaft, the speed changing portion is detachably coupled to the linear moving portion of the modulated speed reducing portion, A shift fork that linearly moves in accordance with the linear movement, and a shift fork which is engaged with the shift fork, La is a straight line movement at the set position is coupled and released in first gear or second gear comprises a sleeve (sleeve) of the first-stage shift speed or two-speed stage to be implemented.

The reduction ratio by the first reduction gear and the first reduction gear and the reduction ratio by the second reduction gear and the second reduction gear may be the same or different from each other.

According to another aspect of the present invention, there is provided an actuator system for an electric vehicle, comprising: an actuator motor having an axis of rotation; a modular decelerator for decelerating a torque of the actuator motor and converting the decelerated torque into a linear motion; Wherein the modular deceleration portion is detachably coupled to the actuator motor and the transmission portion, and the modulated deceleration portion is connected to the actuator motor and the transmission portion, A primary pulley detachably coupled to a rotary shaft of the actuator motor to reduce the rotational force of the actuator motor at a predetermined reduction ratio, the primary pulley being detachably coupled to a rotary shaft of the actuator motor; A second pulley which is connected to the first pulley by a belt or a chain, And a straight moving portion coupled to the fork driving shaft and linearly moving the fork driving shaft according to the rotating direction of the fork driving shaft, wherein the diameter of the first pulley is smaller than the diameter of the second pulley Wherein the transmission portion includes a shift fork detachably engaged with the linear moving portion of the modular deceleration portion and linearly moving in accordance with a linear movement of the linear moving portion, And a sleeve which is linearly moved at a predetermined position in accordance with the movement so as to engage and disengage from the first gear or the second gear so that the one-gear position or the two-position gear position is realized.

The fork drive shaft and the linear moving part may be formed into a trapezoidal screw connection.

The actuator motor rotates the rotary shaft in normal and reverse directions.

According to the actuator system for an electric vehicle according to the embodiment of the present invention, since the decelerator for generating a high output by decelerating the rotational force of the actuator motor is provided, the actuator motor necessary for shifting of the electric vehicle can be miniaturized and high output can be generated, The load that is generated when the vehicle is running on the road of the load weight or when the vehicle is running while the load weight is exceeded can be overcome so that the shift can be normally performed.

Further, according to the actuator system for an electric vehicle according to the embodiment of the present invention, the deceleration unit for generating a high output by decelerating the rotational force of the actuator motor is modularized, and the modular deceleration unit is detachable to the actuator motor and the shift fork, The actuator motor and the deceleration section can be selected according to the capacity, so that various designs of the actuator system of the electric vehicle can be made.

1 is a diagram showing a configuration of a conventional shift actuator system for an electric vehicle.

2 is a diagram illustrating a configuration of an actuator system for an electric vehicle according to an embodiment of the present invention.

3 is a diagram illustrating a configuration of an actuator system for an electric vehicle according to another embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

Embodiments of the present invention are provided to more fully describe the present invention to those skilled in the art, and the following embodiments may be modified in various other forms, The present invention is not limited to the following embodiments. Rather, these embodiments are provided so that this disclosure will be more thorough and complete, and will fully convey the concept of the invention to those skilled in the art.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms "a", "an," and "the" include plural forms unless the context clearly dictates otherwise. Also, " comprise " and / or " comprising " when used herein should be interpreted as specifying the presence of stated shapes, numbers, steps, operations, elements, elements, and / And does not preclude the presence or addition of one or more other features, integers, operations, elements, elements, and / or groups. As used herein, the term " and / or " includes any and all combinations of one or more of the listed items.

Although the terms first, second, etc. are used herein to describe various elements, regions and / or regions, it should be understood that these elements, components, regions, layers and / Do. These terms do not imply any particular order, top, bottom, or top row, and are used only to distinguish one member, region, or region from another member, region, or region. Thus, the first member, region or region described below may refer to a second member, region or region without departing from the teachings of the present invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings schematically showing embodiments of the present invention. In the figures, for example, variations in the shape shown may be expected, depending on manufacturing techniques and / or tolerances. Accordingly, embodiments of the present invention should not be construed as limited to any particular shape of the regions illustrated herein, including, for example, variations in shape resulting from manufacturing.

The actuator system for an electric vehicle according to the embodiment of the present invention can reduce the size of the actuator motor required for shifting of the electric vehicle and generate a high output so that the actuator system can be operated on a road with a steep slope, It is possible to overcome the generated load (reverse load generated from the drive wheel, etc.) and to make the shift to be performed normally.

Further, the actuator system for an electric vehicle according to the embodiment of the present invention modularizes the deceleration unit that decelerates the rotational force of the actuator motor to generate high output, and allows the modular deceleration unit to be detachable to the actuator motor and the shift fork, Allowing the actuator motor and deceleration section to be selected to suit a wide range of applications.

Further, the actuator system for an electric vehicle according to the embodiment of the present invention allows the manual transmission system to be changed to the automatic transmission system at a low cost by coupling the modular decelerator to the sleeve of the actuator motor and the manual transmission system.

The actuator system for an electric vehicle according to an embodiment of the present invention can be roughly classified into a gear train deceleration system and a pulley system according to a method of decelerating a rotational force of an actuator motor.

Hereinafter, an actuator system for an electric vehicle employing the gear thermal deceleration system and an actuator system for an electric vehicle employing a pulley system will be described with reference to FIGS. 2 and 3, respectively.

2, an actuator system for an electric vehicle according to an embodiment of the present invention includes an actuator motor 200, a fork drive shaft (not shown) that rotates the actuator motor at a predetermined reduction ratio and rotates in accordance with the reduced rotational force And a linear moving part 300 coupled to the fork driving shaft 312 and linearly moving the fork driving shaft 312 in accordance with the rotational direction of the fork driving shaft 312; And a transmission portion that is detachably coupled to the moving portion 300 and linearly moves in accordance with the linear movement of the straight line moving portion 300 to form a one-stage speed ratio or a two-speed speed ratio.

The actuator motor 200 has a rotation axis 210 projecting to the side. The actuator motor 200 can rotate the rotary shaft 210 in the forward and reverse directions.

At this time, the output of the actuator motor 200 is not transmitted directly to the deceleration section through the rotary shaft 210, but may be decelerated through the multi-stage planetary gear reducer 220 and then transmitted to the deceleration section.

The decelerating portion is detachably coupled to the rotating shaft 210. The decelerating portion decelerates the rotational force transmitted from the rotational shaft 210 at a predetermined reduction ratio and rotates in accordance with the rotational direction of the fork driving shaft 312, The rotation of the rotary shaft 210 is converted to a linear motion after decelerating the rotational motion of the rotary shaft 210 according to the set reduction ratio through the linear movement unit 300 that linearly moves the rotary shaft 312.

At this time, the fork driving shaft 312 and the linear moving part 300 can be formed into a trapezoidal screw connection.

Since the fork driving shaft 312 and the linear moving part 300 are in a trapezoidal threaded manner, the fastening force between the fork driving shaft 312 and the straight moving part 300 is strengthened as compared with the ball screw connecting method, The power transmission efficiency can be maximized. In addition, the volume of the fork driving shaft 312 and the straight-line moving part 300 can be reduced as compared with the ball screw coupling method, thereby making it possible to reduce the manufacturing cost and utilize the space efficiently.

The deceleration section further includes a first reduction gear 302, a second reduction gear 306, a second reduction gear 308, and a second reduction gear 310.

The first reduction gear 302 is detachably coupled to the rotary shaft 210.

The first type reduction gear 306 is fixedly or detachably coupled to the driven shaft 304 and meshes with the first reduction gear 302 to form a first reduction gear ratio, 304).

The second reduction gear 308 is fixedly or detachably coupled to the driven shaft 304 and rotates in accordance with the rotation of the driven shaft 304.

The second type reduction gear 310 is fixedly or detachably coupled to the fork drive shaft 312 and meshes with the second reduction gear 308 to form a two-stage reduction gear ratio, (312).

At this time, the reduction ratio by the first reduction gear 302 and the first reduction gear 306 and the reduction ratio by the second reduction gear 308 and the second reduction gear 310 may be the same or different from each other .

In one embodiment of the present invention, the deceleration section is exemplified by the two-stage deceleration structure, but the present invention is not limited to this, and it may have a multi-stage deceleration structure of two or more stages. Also, although the deceleration structure of the deceleration portion is exemplified as a gear train type, the present invention is not limited thereto, and a one-stage or multi-stage deceleration structure can be realized by using the planetary gear type.

The output of the actuator motor 200 is input to the rotary shaft 210 or the output of the actuator 200 is decelerated in the multi-stage planetary gear reducer 220. That is, the deceleration unit may be a gear train type or a planetary gear type structure. You can receive input in one state.

On the other hand, when the deceleration portion is implemented by the planetary gear system, the deceleration portion may be replaced by a multi-stage planetary gear reducer 220 coupled to the output side of the actuator motor 200. [ In this case, the linear moving part 300 may be coupled to the rotating rotary shaft 210 according to the output of the multi-stage planetary gear reducer 220. Accordingly, the linear moving part 300 linearly moves along the rotating direction of the rotating shaft 210 according to the output of the multi-stage planetary gear reducer 220. In this structure, the rotary shaft 210 and the linear moving part 300 can be formed into a trapezoidal screw connection.

When the multi-stage planetary gear system is selected, the actuator system according to the embodiment of the present invention can be used in a two-wheel electric vehicle and a scooter that require a small load and a small size, and an electric wheel chair for a disabled person.

In the deceleration unit according to the embodiment of the present invention, the driven shaft 304 and the fork drive shaft 312 may be rotatably installed at both ends of a housing (not shown) of the deceleration unit, It is possible.

These decelerating portions can be produced by modularization. That is, the decelerating portion is detachably mountable to the actuator motor 200, and can be detachably attached to the speed changing portion.

Accordingly, in the embodiment of the present invention, since the decelerating portion of the detachable structure is provided, other decelerating portions having different decelerating ratios can be installed and replaced.

The first reduction gear 302 is detachable to the rotary shaft 210 and the second reduction gear 306 and the second reduction gear 308 are detachably attached to the driven shaft 304 Since the second type reduction gear 310 has a structure that is detachable to the fork drive shaft 312, the second type reduction gear 306, the second type reduction gear 306, The second reduction gear 306, the second reduction gear 308 and the second reduction gear 308 having gear ratios different from those of the second reduction gear 308 and the second reduction gear 310, respectively, Can be selectively replaced with the longitudinal reduction gear (310).

The transmission portion includes a shift fork 510 detachably coupled to the linear portion 300 of the reduction portion and linearly moving along the linear movement of the linear portion 300, (Not shown) or a second gear (not shown) in a linear position in accordance with the linear movement of the shift fork 510, And includes a sleeve 520 to allow a single speed stage to be implemented.

At this time, an input shaft 600 is installed at the center of the slit portion 520, and the input shaft 600 can receive a driving force from a driving motor (not shown).

According to the configuration of the present invention, the actuator system for an electric vehicle according to an embodiment of the present invention achieves downsizing of the system and facilitates detachment by implementing the deceleration unit in a modular manner .

Further, the actuator system for an electric vehicle according to an embodiment of the present invention adopts a modular deceleration unit that converts the rotational motion of the actuator motor 200 into a linear motion, thereby minimizing the capacity of the actuator motor 200, .

3 is a view illustrating an actuator system for an electric vehicle according to another embodiment of the present invention.

Referring to FIG. 3, an actuator system for an electric vehicle according to an embodiment of the present invention includes an actuator motor 200, an actuator motor 200 for rotating the actuator motor 200 at a predetermined reduction ratio, A deceleration portion coupled to the fork drive shaft 740 and the fork drive shaft 740 and including a linear movement portion 700 for linearly moving the fork drive shaft 740 in accordance with the rotation direction of the fork drive shaft 740; And a transmission portion that is coupled to a straight line of the reduction portion in a detachable manner and which linearly moves in accordance with the linear movement of the linear portion 700 to form a one-stage transmission ratio or a two-stage transmission ratio.

The actuator motor 200 has a rotation axis 210 projecting to the side. The actuator motor 200 can rotate the rotary shaft 210 in the forward and reverse directions. At this time, the output of the actuator motor 200 may be transmitted after being decelerated through the multi-step planetary gear reducer 220, rather than being transmitted directly to the deceleration portion through the rotary shaft 210.

The decelerating portion is detachably coupled to the rotating shaft 210. The decelerating portion decelerates the rotational force transmitted from the rotational shaft 210 at a predetermined reduction ratio and rotates in accordance with the rotational direction of the fork driving shaft 740, The linear motion of the rotary shaft 210 is converted to a linear motion after decelerating the rotational motion of the rotary shaft 210 according to the set reduction ratio.

At this time, the fork drive shaft 740 and the linear moving part 700 can be formed into a trapezoidal screw connection.

Since the fork driving shaft 740 and the linear moving part 700 have a trapezoidal screw connection, the fastening force between the fork driving shaft 740 and the straight moving part 700 is strengthened as compared with the ball screw connecting method, The power transmission efficiency can be maximized. In addition, the volume of the fork driving shaft 740 and the straight-line moving part 700 can be reduced as compared with the ball screw coupling method, thereby reducing the manufacturing cost and effectively utilizing the space.

The decelerator includes a primary pulley 710 detachably coupled to the rotary shaft 210, a first pulley 710 fixedly or detachably coupled to the fork drive shaft 740, and a secondary pulley 730 connected to a belt or chain 720. [

In this case, the diameter of the first pulley 710 may be smaller than the diameter of the second pulley 730.

It is preferable that the first pulley 710 and the second pulley 730 are implemented as a fixed type rather than a variable type. The first pulley 710 and the second pulley 730 can be used as long as they are rotatable in connection with the chain or belt 720. That is, the first pulley 710 and the second pulley 730 may be a sprocket connected to the chain or a pulley that can be connected to a belt or chain.

In the deceleration unit according to another embodiment of the present invention, both ends of the fork drive shaft 740 may be rotatably installed in a housing (not shown) of the deceleration unit, and one end may be rotatably supported.

Accordingly, in another embodiment of the present invention, since the decelerating portion of the detachable structure is provided, other decelerating portions having different decelerating ratios can be installed and replaced.

Further, since the first pulley 710 is detachable to the rotating shaft 210 in the pulley type decelerating portion and the second pulley 730 is detachable to the fork driving shaft 740, It is possible to selectively replace the first pulley 710 and the second pulley 730 having diameters different from those of the respective first pulleys 710 and the second pulleys 730.

The transmission portion includes a shift fork 510 detachably coupled to the linear portion 700 of the reduction portion and linearly moving along the linear movement of the linear portion 700, (Not shown) or a second gear (not shown) in a linear position in accordance with the linear movement of the shift fork 510, And includes a sleeve 520 to allow a single speed stage to be implemented.

According to another embodiment of the present invention, the actuator system for an electric vehicle according to another embodiment of the present invention achieves downsizing of the system and facilitates detachment by implementing the deceleration unit in a modular manner .

In addition, the actuator system for an electric vehicle according to another embodiment of the present invention adopts a modular deceleration unit for converting the rotary motion of the rotary actuator motor 200 into a linear motion, thereby minimizing the capacity of the actuator motor 200, Lt; / RTI >

Claims

An actuator motor having a rotary shaft, a decelerator for decelerating the rotational force of the actuator motor, a modular decelerator for decelerating a rotational force of the actuator motor decelerated by the decelerator and converting the decelerated rotational force into a linear motion, Speed transmission ratio or a two-speed transmission ratio,

Wherein the modulated deceleration portion is detachably coupled to the actuator motor and the transmission portion,

Wherein the modular decelerating portion includes a first reduction gear which is detachably coupled to a rotation shaft of the actuator motor so as to reduce the rotational force of the actuator motor decelerated by the reduction gear at a predetermined reduction ratio and is detachably coupled to the rotation shaft of the actuator motor A first reduction gear that is detachably coupled to the driven shaft and meshes with the first reduction gear to form a first reduction gear ratio and rotates the slave shaft according to the first reduction gear ratio, Wherein the fork drive shaft is detachably coupled to the fork drive shaft and is engaged with the second reduction gear to form a two-stage reduction ratio, and the fork drive shaft is rotated according to the two- A second type reduction gear; and a second type reduction gear, coupled to the fork drive shaft, A straight line moving portion that linearly moves the drive shaft,

Wherein the transmission portion includes a shift fork detachably engaged with the linear moving portion of the modular deceleration portion and linearly moving in accordance with the linear movement of the linear moving portion, and a shift lever coupled to the shift fork, And a sleeve that is linearly moved at a predetermined position to be engaged with and disengaged from the first gear or the second gear so that the one-gear position or the two-position gear position is realized.
The method according to claim 1,

Wherein the reduction ratio by the first reduction gear and the first reduction gear and the reduction ratio by the second reduction gear and the second reduction gear are the same or different from each other.
The actuator motor has a rotation axis, a modular deceleration section that decelerates the rotational force of the actuator motor and converts it into a linear motion, and a linear motion according to the linear motion converted by the modulated deceleration section to form a one- or two- And a transmission portion

Wherein the modulated deceleration portion is detachably coupled to the actuator motor and the transmission portion,

Wherein the modular decelerating portion includes a primary pulley detachably coupled to a rotary shaft of the actuator motor to reduce the rotary force of the actuator motor at a predetermined reduction ratio and detachably coupled to a rotary shaft of the actuator motor, A second pulley detachably connected to the fork drive shaft and connected to the first pulley by a belt or a chain; a second pulley coupled to the fork drive shaft, Wherein the first pulley has a diameter that is less than the diameter of the second pulley,

Wherein the transmission portion includes a shift fork detachably engaged with the linear moving portion of the modular deceleration portion and linearly moving in accordance with the linear movement of the linear moving portion, and a shift lever coupled to the shift fork, And a sleeve that is linearly moved at a predetermined position to be engaged with and disengaged from the first gear or the second gear so that the one-gear position or the two-position gear position is realized.
The method according to claim 1 or 3,

Wherein the fork drive shaft and the linear movement portion form a trapezoidal screw connection.
The method according to claim 1 or 3,

And the actuator motor rotates the rotary shaft in normal and reverse directions.