Patent Publication Number: US-2023150569-A1

Title: Steering apparatus

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     The present application claims priority to Korean Patent Application No. 10-2021-0157315, filed Nov. 16, 2021, the entire contents of which is incorporated herein for all purposes by this reference. 
     TECHNICAL FIELD 
     One embodiment of the present disclosure relates to a steering apparatus, and in more detail, a steering apparatus which supports a steering wheel of a vehicle to effectively adjust a length of the steering wheel in a narrow space. 
     BACKGROUND 
     In general, a steering apparatus is installed in a vehicle and supports the steering wheel to transmit steering of a wheel according to a rotation of the steering wheel. Specifically, the steering apparatus effectively transmits a steering angle of the steering wheel to the steering of the wheel. 
     The steering apparatus can also adjust a distance between a driver and the steering wheel according to a preferred environment of the driver. 
     In the conventional steering apparatus, a change in stroke according to the length adjustment of the steering wheel is limited by an installation space of the steering apparatus. 
     In addition, in the conventional steering apparatus, a screw bar for guiding a movement of a tube of the steering apparatus protrudes to the rear when a vehicle crash occurs, and thus, there is a problem in that an injury occurs due to collision between the screw bar and the driver. 
     That is, there is a need for a steering apparatus capable of having a large change in stroke in a limited space of the vehicle. 
     In addition, there is a need for a steering apparatus capable of reducing the problem of injury caused by a collision between a driver and the steering apparatus even when a vehicle crash occurs. 
     SUMMARY 
     One embodiment of the present disclosure provides a steering apparatus capable of improving responsiveness of stroke control and greatly adjusting variability of the stroke in a compact installation space. 
     According to an aspect of the present disclosure, there is provided a steering apparatus including: an outer tube elongated in one direction; a middle tube of which at least a portion is inserted into the outer tube; an inner tube partially inserted into the middle tube; a steering shaft partially inserted into the inner tube and partially movable in a longitudinal direction of the outer tube together with the inner tube; a motor configured to provide power so that the middle tube and the inner tube move in the longitudinal direction of the outer tube; a first transport guide disposed along the longitudinal direction of the outer tube and supported by the outer tube; a second transport guide separated from the first transport guide and disposed along the longitudinal direction of the outer tube; and a speed reducer supported by the first transport guide and the second transport guide and configured to decelerate power supplied by the motor and transmit decelerated power. 
     The speed reducer may include a worm rotated by the motor, a first gear engaged with the worm and supported by the first transport guide, and a second gear engaged with the first gear and supported by the second transport guide. 
     The first transport guide and the second transport guide may be formed with spirals in different directions. 
     The speed reducer may further include a deceleration guide which is disposed between the first transport guide and the first gear and movable along the spiral of the first transport guide. 
     The speed reducer may further include a housing in which the first gear and the second gear are accommodated. 
     The steering apparatus may further include a first outer guide hole of which one region is formed in the outer tube to be open along the longitudinal direction of the outer tube. 
     The speed reducer may include a support portion of which one region passes through the first outer guide hole and is coupled to the middle tube. 
     The steering apparatus may further include a second outer guide hole disposed to be spaced apart from the first outer guide hole and having one region formed to be open along the longitudinal direction of the outer tube, and a middle guide hole formed to be open in the middle tube so that the second outer guide hole and at least one region face each other. 
     The steering apparatus may further include a guide block portion having one side moving along the second transport guide and the other side being disposed to pass through the second outer guide hole and the mid guide hole and supported by the inner tube. 
     The guide block portion may include a guide block moving along the second transport guide, and a slider supporting the inner tube so that the inner tube moves together with the guide block. 
     According to another aspect of the present disclosure, there is provided a steering apparatus including: an outer tube elongated in one direction; a middle tube of which at least a portion is inserted into the outer tube; an inner tube partially inserted into the middle tube; a steering shaft partially inserted into the inner tube and partially movable along a longitudinal direction of the outer tube together with the inner tube; a motor configured to provide power so that the middle tube and the inner tube move along the longitudinal direction of the outer tube; a speed reducer configured to decelerate power supplied by the motor and transmit decelerated power; a first transport guide disposed to engage with one side of the speed reducer to guide a movement of the speed reducer; and a second transport guide disposed to be spaced apart from the first transport guide to engage with the other side of the speed reducer and together moving when the speed reducer moves to guide a movement of the inner tube. 
     The steering apparatus may further include a first outer guide hole of which one region is formed in the outer tube to be open along the longitudinal direction of the outer tube, and a support portion having one side connected to the speed reducer and the other side passing through the first outer guide hole to be coupled to the middle tube and moving the middle tube together when the speed reducer. 
     The steering apparatus may further include a second outer guide hole disposed to be spaced apart from the first outer guide hole and having one region formed to be open along the longitudinal direction of the outer tube, a middle guide hole formed to be open in the middle tube so that the second outer guide hole and at least one region face each other, an inner guide hole formed to be open in the inner tube such that the middle guide hole and at least one region face each other, and a guide block portion having one side moving along the second transport guide and the other side coupled to passing through the second outer guide hole, the middle guide hole, and the inner guide hole to move the inner tube. 
     The first transport guide and the second transport guide may be arranged to extend in different directions about the speed reducer. 
     According to one embodiment of the present disclosure, the steering apparatus can increase the transport distance of the inner tube to the same length and also increase its speed, so that it can effectively control the variability of the stroke and has a great effect on the degree of freedom of the installation space. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    illustrates a perspective view of a steering apparatus according to one embodiment of the present disclosure. 
         FIG.  2    illustrates an enlarged view when a housing of the speed reducer portion of  FIG.  1    is projected. 
         FIG.  3    illustrates an enlarged view of the speed reducer portion of  FIG.  1   . 
         FIG.  4    illustrates a state in Which a stroke of the steering apparatus according to one embodiment of the present disclosure is reduced. 
         FIG.  5    is an enlarged view of a guide block portion of  FIG.  1   . 
         FIG.  6    is an enlarged view illustrating an area between an inner tube and the speed reducer of  FIG.  1   . 
         FIG.  7    illustrates a part of a cross-sectional view along a longitudinal direction of a first transport guide. 
         FIGS.  8  and  9    illustrate a stroke adjustment process of the steering apparatus according to one embodiment of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     Hereinafter, with reference to the accompanying drawings, one embodiment of the present disclosure will be described in detail so that a person having ordinary knowledge in the technical field to which the present disclosure belongs can easily implement it. The present disclosure may be implemented in several different forms and is not limited to the embodiments described herein. 
     It is noted that the drawings are schematic and not drawn to scale. Relative dimensions and proportions of parts in the drawings are illustrated exaggerated or reduced in size for clarity and convenience in the drawings, and any dimensions are illustrative only and not limiting. Moreover, the same reference numerals are used to indicate like features to the same structural element or part appearing in two or more drawings. 
     An embodiment of the present disclosure specifically represents an ideal embodiment of the present disclosure. As a result, various modifications of the diagram are expected. Accordingly, the embodiment is not limited to a specific shape of the illustrated area, and includes, for example, a shape modification by manufacturing. 
     Hereinafter, as illustrated in  FIGS.  1  to  9   , an outer tube  100 , a middle tube  200 , an inner tube  300 , a steering shaft  400 , a motor  500 , a first transport guide  600 , a second transport guide  700 , and a speed reducer  800  will be described. 
     The outer tube  100  is elongated in one direction. In addition, the outer tube  100  is formed in a hollow inside and may form the outer shape of a steering apparatus  101 . 
     At least a portion of the middle tube  200  may be inserted into the outer tube  100 . Specifically, the middle tube  200  may be arranged side by side along a longitudinal direction of the outer tube  100 , and at least a portion of the middle tube  200  may be inserted into the hollow outer tube  100 . Moreover, the middle tube  200  may be drawn in and out along the longitudinal direction of the outer tube  100 . 
     The middle tube  200  may be slidably supported into the outer tube  100 . 
     The steering shaft  400  is partially inserted in the inner tube  300  and a portion of the steering shaft  400  may be moved together with the inner tube  300 . A portion of the steering shaft  400  is inserted into the inner tube  300  and may be moved along the longitudinal direction of the outer tube  100  together when the inner tube  300  moves. 
     A steering wheel is installed at an end of the steering shaft  400 , and thus, a driver can perform steering by manipulating the steering wheel. 
     The motor  500  provides power so that the middle tube  200  and the inner tube  300  move along the longitudinal direction of the outer tube  100 . The motor  500  may provide power for movements of the middle tube  200  and the inner tube  300  so that the stroke of the steering apparatus  101  is changed. 
     The first transport guide  600  is disposed along the longitudinal direction of the outer tube  100 , and is supported by the outer tube  100 . Specifically, the first transport guide  600  may be disposed outside the outer tube  100  in a direction parallel to the longitudinal direction of the outer tube  100 . In addition, one end of the first transport guide  600  may be supported on the outer tube  100 . 
     One end of the first transport guide  600  may be supported in the form of a cantilever by an outer support region protruding from the outer tube  100  in a circumferential direction. 
     The outer support region of the outer tube  100  may be disposed in a direction opposite to an end portion of the steering shaft  400  in which the steering wheel is installed. 
     Moreover, the first transport guide  600  may guide the transport of the middle tube  200  and the inner tube  300 . 
     The second transport guide  700  is spaced apart from the second transport guide  700  and disposed along the longitudinal direction of the outer tube  100 . Specifically, the second transport guide  700  may be disposed on the outside of the outer tube  100  to be spaced apart from the first transport guide  600 . 
     In addition, the second transport guide  700  may guide the transport of the inner tube  300 . 
     For example, a center of the second transport guide  700  and a center of the first transport guide  600  may be disposed parallel to each other. 
     The speed reducer  800  is supported by the first transport guide  600  and the second transport guide  700 . Moreover, the speed reducer  800  decelerates and transmits the power provided by the motor  500 . Specifically, the speed reducer  800  may receive the power from the motor  500 , move along the first transport guide  600 , and rotate the second transport guide  700 . 
     The first transport guide  600  and the second transport guide  700  may be arranged to extend in different directions about the speed reducer  800 . 
     By such a configuration, in the steering apparatus  101  according to one embodiment of the present disclosure, the inner tube  300  as well as the middle tube  200  can move along the longitudinal direction of the outer tube  100 , and thus, it is possible to effectively adjust the stroke of the steering apparatus  101 . 
     Specifically, the speed reducer  800  is supported by the first transport guide  600  and the second transport guide  700 , and is moved along the first transport guide  600  according to the power of the motor  500 , and the second transport guide  700  can be effectively rotated. 
     In addition, the speed reducer  800  of the steering apparatus  101  according to one embodiment of the present disclosure may include a worm  820 , a first gear  830 , and a second gear  840  as illustrated in  FIG.  2   . 
     The worm  820  may be rotated by the motor  500 . Specifically, the worm  820  may be formed on an output shaft of the motor  500  and rotate together according to a rotational force of the motor  500 . Moreover, the output shaft of the motor  500  may be disposed in a direction perpendicular to the first transport guide  600 . 
     The first gear  830  may be supported by the first transport guide  600 . In addition, a portion of an outer periphery of the first gear  830  may engage with the worm  820  so that the first gear rotates according to the rotation of the worm  820 . That is, a rotation direction of the first gear  830  may be rotated about a central axis of the first transport guide  600 . 
     The second gear  840  may be disposed so that an outer periphery thereof engages with the first gear  830 . In addition, the second gear  840  may be supported by the second transport guide  700 . That is, the second gear  840  may be rotated by the first gear  830 . 
     Moreover, when the second gear  840  is rotated by the first gear  830 , the second transport guide  700  may be rotated. 
     Therefore, the speed reducer  800  includes the worm  820 , the first gear  830 , and the second gear  840 , and thus, the power of the motor  500  may be transferred to the second gear  840  spaced apart from the first transport guide  600  to rotate the second transport guide  700 . 
     In addition, in the first transport guide  600  and the second transport guide  700  according to one embodiment of the present disclosure, as illustrated in  FIGS.  1  and  4   , spirals in different directions may be formed. 
     For example, the first transport guide  600  may have a right-handed spiral. In addition, the second transport guide  700  may have a left-handed spiral. 
     Specifically, one end of the first transport guide  600  may be disposed to be adjacent to one end of the outer tube  100 . One end of the second transport guide  700  may support the second gear  840 , and the other end of the second transport guide  700  may be disposed adjacent to the other end of the outer tube  100 . 
     In this case, the other end of the outer tube  100  may be in a direction relatively adjacent to a position at which the steering wheel of the steering shaft  400  is supported. 
     In addition, a length of each of the first transport guide  600  and the second transport guide  700  may be formed to be relatively shorter than a length of the outer tube  100  as illustrated in  FIG.  4   . 
     In addition, the speed reducer  800  of the steering apparatus  101  according to one embodiment of the present disclosure, as illustrated in  FIG.  7   , may further include a deceleration guide  860 . 
     The deceleration guide  860  may be disposed between an outer peripheral surface of the first transport guide  600  and a center of the first gear  830 . In addition, a groove is formed on an inner peripheral surface of the deceleration guide  860  in a direction in which the deceleration guide  860  engages with the spiral formed on the first transport guide  600 , and thus, the deceleration guide  860  may move along the longitudinal direction of the first transport guide  600 . The outer periphery of the deceleration guide  860  may engage with the first gear  830 , and thus, rotate together according to the rotation of the first gear  830 . 
     That is, according to the rotation of the first gear  830  rotated by the worm  820 , the deceleration guide  860  moves the spiral of the outer periphery of the first transport guide  600  along the longitudinal direction of the first transport guide  600 . 
     At this time, as illustrated in  FIGS.  2  and  4   , the motor  500  for rotating the worm  820  may also be moved along the longitudinal direction of the first transport guide  600 . In addition, the second gear  840  is also rotated by the first gear  830 , and the second gear  840  and the second transport guide  700  may also be moved along the longitudinal direction of the first transport guide  600 . 
     Accordingly, the speed reducer  800  may receive rotational power from the motor  500  and move along the longitudinal direction of the first transport guide  600 . In addition, when the speed reducer  800  moves along the longitudinal direction of the first transport guide  600 , the second transport guide  700  may also move along the longitudinal direction of the first transport guide  600 . 
     Specifically, as illustrated in  FIG.  8   , the speed reducer  800  of the steering apparatus  101  according to one embodiment of the present disclosure may further include a rotation guide  870  which is disposed between the second gear  840  and the second transport guide  700 . 
     The rotation guide  870  may rotate the second transport guide  700  when the second gear  840  is rotated. Specifically, a spiral is not formed at one end of the second transport guide  700  coupled to the rotation guide  870 , and thus, the rotation guide  870  rotates together with the second gear  840  when the second gear  840  rotates to rotate the second transport guide  700 . 
     In addition, the speed reducer  800  according to one embodiment of the present disclosure may further include a housing  810 , as illustrated in  FIG.  3   . 
     The housing  810  may accommodate the first gear  830  and the second gear  840 . In addition, the housing  810  forms the outer shape of the speed reducer  800 , and may secure a space in which the first gear  830  and the second gear  840  engage with each other and maintain a distance therebetween. Alternatively, the housing  810  may also accommodate at least a portion of the worm  820  formed on the output shaft of the motor  500 . 
     In addition, according to one embodiment of the present disclosure, the steering apparatus  101  may further include a first outer guide hole  110 . 
     The first outer guide hole  110  may be opened in one region of the outer tube  100  along the longitudinal direction of the outer tube  100 . Specifically, the first outer guide hole  110  may be formed to face the first transport guide  600 . 
     In addition, according to one embodiment of the present disclosure, the speed reducer  800  of the steering apparatus  101  may further include a support portion  850 , as illustrated in  FIG.  6   . 
     One region of the support portion  850  may be coupled to the middle tube  200  through the first outer guide hole  110 . Specifically, the support portion  850  may connect the housing  810  and the middle tube  200 . 
     The support portion  850  may allow the middle tube  200  and the speed reducer  800  to move together. 
     For example, a portion of the housing  810  is formed to extend through the first outer guide hole  110  and may be coupled to the middle tube  200 . Alternatively, a separate support portion  850  is connected between the housing  810  and the middle tube  200  so that the middle tube  200  is also moved when the speed reducer  800  is moved along the first transport guide  600 . 
     In addition, the steering apparatus  101  according to one embodiment of the present disclosure may include a second outer guide hole  120  and a middle guide hole  210  as illustrated in  FIGS.  1  to  9   . 
     The second outer guide hole  120  may be spaced apart from the first outer guide hole  110 . In addition, one region on the outer tube  100  may be formed to be open along the longitudinal direction of the outer tube  100 . Specifically, the second outer guide hole  120  may be formed to face the second transport guide  700 . 
     In addition, one region of the second outer guide hole  120  may be disposed relatively adjacent to the other end of the outer tube  100  and one region of the first outer guide hole  110 . 
     The middle guide hole  210  may be formed to be open on the middle tube  200 . Moreover, the middle guide hole  210  may be formed such that at least one region faces the second outer guide hole  120 . 
     In addition, the steering apparatus  101  according to one embodiment of the present disclosure may further include a guide block portion  900  as illustrated in  FIGS.  5  and  7  to  9   . 
     The guide block portion  900  is arranged such that one side moves along the second transport guide  700 , and the other side passes through the second outer guide hole  120  and the middle guide hole  210  to support the inner tube  300 . Specifically, one side of the guide block portion  900  may move along the spiral of the second transport guide  700 , and the other side may be supported by the inner tube  300  to move together with the inner tube  300 . 
     That is, when the guide block portion  900  moves along the second transport guide  700 , the inner tube  300  may be moved together. 
     In addition, the steering apparatus  101  according to one embodiment of the present disclosure may further include an inner guide hole  310 . 
     The inner guide hole  310  may be formed to be open to the inner tube  300  so that one region faces the middle guide hole  210 . 
     Moreover, the other side of the guide block portion  900  may be supported by one region of the steering shaft  400  through the inner guide hole  310 . 
     Specifically, the steering shaft  400  includes a first shaft  410  in which one region is disposed in the outer tube  100 , and a second shaft  420  which is inserted into one region of the first shaft  410  and disposed inside the inner tube  300  and supports the steering wheel. 
     The second shaft  420  may be movable along a longitudinal direction of the first shaft  410  and may be rotatably supported in the inner tube  300 . When the second shaft  420  rotates, the first shaft  410  may also rotate. 
     In addition, the guide block portion  900  according to one embodiment of the present disclosure may include a guide block  910  and a slider  920  as illustrated in  FIGS.  8  and  9   . The guide block  910  may move along the second transport guide  700 . Specifically, a groove engaged with the spiral of the second transport guide  700  is formed on an inner periphery of the guide block  910 , and when the second transport guide  700  is rotated by the second gear  840 , the guide block  910  may move along the second transport guide  700 . 
     The slider  920  supports the inner tube  300  to move together with the guide block  910 . Specifically, the slider  920  is supported by the inner tube  300  so that the slide  902  moves together with the inner tube  300  when the guide block  910  moves along the second transport guide  700 . 
     In addition, the slider  920  is formed with a locking groove  921  to be lock-coupled to one end of an inner diameter of the inner guide hole  310 , and the region facing the outer periphery of the second shaft  420  is the second shaft  420  may be formed to contact and support one region of the second shaft  420 . 
     Accordingly, the slider  920  may support the inner tube  300  and the second shaft  420  so that not only the inner tube  300  but also the second shaft  420  are drawn into and out from the outer tube  100  along the longitudinal direction of the outer tube  100 . 
     In addition, one region of one side of the inner tube  300  facing the middle guide hole  210  according to one embodiment of the present disclosure may include an inner protrusion  320  protruding toward the middle guide hole  210 . 
     The inner protrusion  320  may prevent the inner peripheral surface of the middle guide hole  210  from colliding with the guide block portion  900 . 
     In addition, the guide block portion  900  according to one embodiment of the present disclosure may further include a connection member  930 . 
     The connection member  930  is disposed between the slider  920  and the guide block  910  to connect the slider  920  and the guide block  910 . 
     In addition, one end of the first transport guide  600  of the steering apparatus  101  according to one embodiment of the present disclosure is cantilevered to the inner tube  300 , the other end of the second transport guide  700  is disposed relatively adjacent to one end of the outer tube  100  than the other end of the inner tube  300 , and thus, it is possible to prevent the driver from being injured by the first transport guide  600  and the second transport guide  700  when a vehicle impact occurs. 
     By such a configuration, the inner tube  300  and the steering shaft  400  of the steering apparatus  101  according to one embodiment of the present disclosure move when the speed reducer  800  moves along the first transport guide  600 , and also move according to the movement of the guide block portion  900  which is moved when the second transport guide  700  is rotated. 
     That is, according to a specific arrangement structure of the speed reducer  800  and the first transport guide  600  and the second transport guide  700 , the inner tube can have the steering apparatus  101  having a great stroke. 
     In other words, the inner tube  300  may be moved along the first transport guide  600  according to the power provided by the motor  500 , and also moved by the guide block portion  900  moving along the second transport guide  700  according to the rotation of the second transport guide  700 . 
     In the inner tube  300  of the steering apparatus  101  according to one embodiment of the present disclosure, the movement stroke may be increased, and the speed thereof may also be increased. 
     Hereinafter, an operation process of the steering apparatus  101  according to one embodiment of the present disclosure will be described with reference to  FIGS.  8  to  9   . 
     The driver operates an operation button (not illustrated) or the like in a direction of shortening the stroke according to the need for adjusting the stroke length of the steering apparatus  101 . Accordingly, the motor  500  is operated. 
     The worm  820  rotates in one direction according to the power provided by the motor  500 . When the worm  820  is rotated, the first gear  830  engaged therewith is rotated. At this time, the deceleration guide  860  rotates along the spiral of the first transport guide  600 . Accordingly, the speed reducer  800  is moved in a direction in which the speed reducer  800  closer to one end of the outer tube  100  along the longitudinal direction of the first transport guide  600 . 
     In addition, the middle tube  200  connected to the support portion  850  of the speed reducer  800  is also moved in a direction closer to one end of the outer tube  100 . At this time, the inner tube  300  connected to the second transport guide  700  and the guide block portion  900  is also moved in the direction closer to one end of the outer tube  100 . 
     When the first gear  830  is rotated, the second gear  840  meshed therewith is also rotated, and the second transport guide  700  is moved together with the speed reducer  800  along the longitudinal direction of the first transport guide  600  and rotated by the second gear  840 . 
     The guide block  910  is transported in a direction adjacent to the speed reducer  800  along the spiral of the second transport guide  700 , and moves the inner tube  300  in the direction closer to one end of the outer tube  100 . 
     When the user operates the operation button (not illustrated) or releases the operation button, the current stroke of the steering apparatus  101  can be maintained. 
     Alternatively, when the user operates the operation button (not illustrated) in a different direction or in a different mode, the steering apparatus  101  may be operated in a direction in which the stroke is extended. 
     Accordingly, the inner tube  300  moving together with the second shaft  420  on which the steering wheel may be moved by not only the second transport guide  700  moving along the longitudinal direction of the first transport guide  600 , but also the movement of the guide block portion  900  according to the rotation of the second transport guide  700 . 
     Accordingly, the inner tube  300  may be transported a double distance so that the inner tube  300  can be moved not only in the longitudinal direction of the first transport guide  600  but also in the longitudinal direction of the second transport guide  700  through the same straight distance. 
     The steering apparatus  101  according to one embodiment of the present disclosure may vary the inner tube  300  and the steering shaft  400  have a large stroke in a narrow space, and may improve a variable speed. Therefore, the driver can be transferred to have a quick response to the stroke control of the steering apparatus  101  can reduce the fatigue for the control. 
     In addition, the steering apparatus  101  according to one embodiment of the present disclosure can perform effective stroke variation even in a compact space. 
     Although the embodiment of the present disclosure has been described with reference to the accompanying drawings, those skilled in the art to which the present disclosure belongs will be able to understand that the present disclosure may be implemented in other specific forms without changing its technical idea or essential characteristics. 
     Therefore, the embodiments described above are to be understood as illustrative and not restrictive in all respects, the scope of the present disclosure is indicated by the following claims, and all changes or modifications derived from the meaning and scope of the claims and their equivalents should be construed as being included in the scope of the present disclosure. 
     DETAILED DESCRIPTION OF MAIN ELEMENTS 
       
     
       
         
           
               
               
               
               
             
               
                   
               
             
            
               
                 100: 
                 outer tube 
                 101: 
                 steering apparatus 
               
               
                 110: 
                 first outer guide hole 
                 120: 
                 second outer guide hole 
               
               
                 200: 
                 middle tube 
                 210: 
                 middle guide hole 
               
               
                 300: 
                 inner tube 
                 310: 
                 inner guide hole 
               
               
                 400: 
                 steering shaft 
                 500: 
                 motor 
               
               
                 600: 
                 first transport guide 
                 700: 
                 second transport guide 
               
               
                 800: 
                 speed reducer 
                 810: 
                 housing 
               
               
                 820: 
                 worm 
                 830: 
                 first gear 
               
               
                 840: 
                 second gear 
                 850: 
                 support portion 
               
               
                 860: 
                 deceleration guide 
                 900: 
                 guide block portion 
               
               
                 910: 
                 guide block 
                 920: 
                 slider