JP2015020565A - Trochoid drive mechanism - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simplify a steering mechanism and a drive wheel mechanism, and to move a locus which is approximate to a trochoid curve by contact point movement, for achieving off-road stable travel in all orientations.SOLUTION: A trochoid drive mechanism 1 comprises: four action parts 20 respectively having an axle 22 to whose tip end a wheel 23 is fixed; a motion mechanism part 30 for moving the axle 22 on a ground by gyrating movement; and an inclination mechanism part 40 for inclining a turning central axis of the gyrating movement. Each of the wheels 23 moves with a locus in which a contact point between it and the ground is approximate to a trochoid curve by the gyrating movement.

Description

  The present invention relates to a trochoid drive mechanism that performs omnidirectional movement in a trajectory approximate to a trochoid curve.

  When considering holonomic omnidirectional movement in a plane, the trajectory along the trochoidal curve is effective as a geometric solution for linear movement by a continuous rotating mechanism. The inventor has proposed a holonomic omnidirectional movement type described in Patent Documents 1 and 2. Such Patent Documents 1 and 2 are mechanisms for steering and following a complete solution of a trochoid curve. Further, in Patent Document 2, a large step is formed by tilting a large-diameter wheel at a large camber angle. The trochoid drive mechanism of the driven wheel turning type which has the ability to get over is proposed.

WO2011 / 155485 JP 2012-246961 A

  In addition, the present inventor previously applied a trochoid drive mechanism related to wheel drive wheels as a response to a single-shaft multi-wheel configuration for operation on rough terrain and maximizing the scaffolding (Japanese Patent Application No. 2012-120065). As suggested. By the way, since the analysis regarding the performance evaluation of the trochoid traveling system described in Patent Documents 1 and 2 and the prior application has not been performed, the inventor has now been traveling on a horizontal plane with the main drive shaft as a normal line. I tried to analyze.

  In considering the application to rough terrain in the above analysis, since the horizontality fluctuates on rough terrain, Patent Documents 1 and 2 and the prior application that are designed to always draw a trochoidal curve at the ground contact point. In the described trochoid running system, the following geometrical analysis was performed to determine how the fluctuation affects the running trajectory stability during running on rough terrain.

  FIG. 1 is a diagram for explaining the change of the ground contact point and the fluctuation of the traveling direction of the wheel W, and shows a front view, a plan view (Top View), and a side view (Side View). First, the z axis is set in the main drive axis direction. Further, the virtual ground plane is the xy plane, and the virtual ground point of the wheel W is the origin. Here, the x-axis is set in the tangential direction of the wheel W. At this time, the rotation center of the traveling track is always on the y-axis of the same orthogonal coordinate system. Under this condition, the terrain property is defined as a fluctuation of the two-degree-of-freedom posture of the ground plane with respect to the main drive shaft. In this mechanism, rotation around the z-axis corresponds to a change in the steering angle Ψ, and rotation around the x-axis corresponds to a change in the camber angle θ, which does not change the ground contact point. In this coordinate system, the fluctuation around the x axis is defined as the change Δθ of the camber angle θ as the horizontal fluctuation, but the ground point does not change due to this change, and only the ground contact point depends on the fluctuation angle Δλ around the y axis. Will move. At this time, if the moved ground point is the phase angle fluctuation Δφ of the wheel W, the following relationship is established.

tanΔλ = tanΔφcos (θ + Δθ)
At this time, the fluctuation angle ΔΨ of the steering angle Ψ is defined as follows.

tanΔΨ = tanΔφsin (θ + Δθ)
From both equations, it can be seen that the horizontal fluctuation due to uneven terrain affects the traveling as a straight-running fluctuation angle in the relationship of the following expression with respect to the fluctuation angles (Δθ, Δλ) of two degrees of freedom.

tanΔΨ = tanΔλtan (θ + Δθ)
Here, if the unevenness in the z-axis direction of the irregular ground is sufficiently small compared to the radius r of the wheel W, Δλ≈0 and Δθ≈0, so the above equation is expressed as follows.

tanΔΨ ≒ Δλ (tanθ + Δθ)
In the case of this drive system, the x axis that is a virtual ground line is a system that rotates around the main drive axis with respect to the physical stationary system, and fluctuations derived from this rotation are the angle Δξ formed by the main drive axis and the ground plane. Can be approximated as follows.

(Δλ, Δθ) ≒ (Δξsinωt, Δξcosωt)
By substituting this into the above equation, the fluctuation ΔΨ in the traveling direction can be obtained, and the traveling locus of the ground contact point under various conditions can be simulated. In the simulation, assuming that the main drive shaft is inclined about the y-axis (for example, Δλ = π / 60) and the steering operation is performed at a predetermined camber angle, the larger the camber angle is, the more the original traveling direction is. It was found that it has a larger movement component in the y-axis direction with respect to the x-axis direction. In addition, it was found that when the steering operation is not performed, the vehicle does not stop and has a slight movement component in the y-axis direction. Further, when the ground contact surface is tilted by Δξ, in the vicinity of the camber angle θ≈0, the frequency of the fluctuation ΔΨ in the traveling direction is about ω / π and the amplitude is about (Δξ) ^2. On the other hand, when θ is sufficiently large, the frequency is ω / 2π. The amplitude value is governed by Δξtanθ. Therefore, from the viewpoint of minimizing the fluctuation ΔΨ in the traveling direction, it is desirable that the camber angle θ is close to 0 and the main drive shaft is kept in the normal direction with respect to the (macro) slope average.

  That is, when going straight at high speed, it is desirable to adjust the vehicle body posture with a suspension or the like so that the main drive shaft is perpendicular to the ground contact surface with the camber angle being small, that is, with the wheel set up. On the other hand, the step response force in this case is limited to the conventional wheel operation capability. By the way, in order to utilize the rough terrain traveling ability of the present mechanism, it is desirable to perform control to correct the traveling direction fluctuation while performing a large camber angle operation. On the other hand, it is possible to configure a simple steering mechanism that enables omnidirectional movement by actively tilting the main drive shaft by utilizing this characteristic in reverse.

  From the above analysis results, the inventor found that in the mode of operation with a large camber angle, even when the steering mechanism is eliminated from the conventional mechanism, the main drive shaft is tilted so that the phase is approximately 90 °. The knowledge that it can be operated as an omnidirectional traveling system that travels in a trochoidal track was obtained. This is also considered to be a promising mechanism configuration that enables a significant simplification of the mechanism when applied to a traveling system having a large camber angle single-shaft single-wheel configuration by inverted pendulum control.

  The present invention has been made in view of the above knowledge, and simplifies the steering mechanism and the drive wheeling mechanism, and realizes stable traveling on rough terrain in all directions by moving the contact point of the track approximated to the trochoid curve. An object of the present invention is to provide a trochoid drive mechanism.

  The present invention includes at least one action portion having an axle having a wheel fixed to the tip, a motion mechanism portion for causing the axle to shave on the action surface, and a tilting center axis of the razor motion. A trochoid drive mechanism including a tilting mechanism portion to be moved. According to the present invention, the axle of the action portion performs a razor motion by the motion mechanism portion, so that the wheel at the tip draws a trajectory that approximates a trochoid curve while moving the ground point on the action surface. Since the wheel is fixed to the axle, the wheel is also rotationally restrained in the slashing motion. In this state, when the turning center axis of the razor movement is tilted by the tilting mechanism unit, the camber angle is biased on the working surface in relation to the tilt direction of the turning center axis, and the rotation phase Proceed in the 90 ° direction. If the inclination direction can be indicated in all directions, the wheel can travel in all directions.

  Further, in the present invention, the steering mechanism and the drive wheel mechanism are compared with Patent Documents 1 and 2 and the prior application, although there is some inaccuracy in time trajectory accuracy as a trochoid curve and vertical movement of the center of gravity of the mechanism. Can be simplified. In addition, by adjusting the amount of inclination, it is possible to control the omnidirectional speed, it has excellent ability to ride on uneven terrain, such as having the ability to climb over steps that can climb stairs, and personal mobile and interpersonal services that coexist with people who move by walking The mechanism is expected to be highly useful as a robot traveling system.

  In addition, the present invention includes a main body, and a plurality of the action portions are provided in the main body, and the tilt mechanism tilts each turning center axis of the plurality of action portions by the same angle. According to this structure, each action part translates in the same direction. Therefore, this rough terrain traveling property is highly valuable in application to a working vehicle such as a construction machine that requires a complex movement in translation and rotation in all directions.

  Further, according to the present invention, the motion mechanism section causes the axles of the plurality of action sections to shave in the same phase. According to this configuration, one can be a drive source and the other can be a driven structure, so that the structure can be simplified.

  Further, the present invention is characterized in that the axle is provided with a universal joint at an upper portion and a ball joint is interposed in the middle of the shaft. According to this configuration, the axle can be supported with a simple structure.

  Further, the present invention is characterized in that the tilting mechanism portion makes the side surface of the wheel substantially grounded to the working surface when stationary. According to this configuration, it is possible to shift to a state in which the wheel side face is substantially or completely grounded (side-down) when stationary, thereby obtaining a structure for obtaining stationary stability. In particular, in the case of a mechanism characterized by operation with a large camber angle close to 90 °, application to an omnidirectional traveling body employing a magnet wheel is expected. In addition, the structure supports the mechanism so that it stands upright on the axle with all sides of the vehicle fully grounded when stationary, so it repeats moving and stationary with a combination of high grounding stability and fine adjustment in all directions. It is thought that it will bring an advantage to the application to such crane cars.

  In the present invention, the wheel is made of a magnet. According to this configuration, in the case of a mechanism characterized by operation and stationary at a large camber angle close to 90 °, application to a wall-mounted mobile robot or the like by using a magnet wheel is expected.

  Further, the present invention is characterized in that the wheel is provided with an engaging member that protrudes in a radial direction at least at one place in the circumferential direction on the surface on the axle side. According to this configuration, slipping down can be suppressed by increasing the engagement with the tread when climbing over the stairs.

  ADVANTAGE OF THE INVENTION According to this invention, the trochoid drive mechanism which simplified the steering mechanism and the drive wheel formation mechanism can be provided.

It is a figure explaining the fluctuation | variation of a grounding point and the moving direction of the wheel W, The front view (Front View), the top view (Top View), and the side view (Side View) are shown. It is a schematic perspective view which shows one Embodiment of the trochoid drive mechanism which concerns on this invention. It is a partial side sectional view showing one embodiment of a main part, an action part, and an exercise mechanism part. It is a partial side sectional view showing one embodiment of an inclination mechanism part. It is a figure explaining the transition of the contact point of a wheel, (a) is a figure in case a turning center is in a vertical direction, (b) is a figure in case the turning center is shifted in a horizontal direction. It is a figure which shows one Embodiment of the structure of the wheel which suppresses sliding at the time of going over stairs as much as possible, (a) is a top view, (b) is a side view.

  Hereinafter, an embodiment in which a trochoid drive mechanism according to the present invention is applied to a propulsion mechanism including wheels will be described with reference to the drawings. FIG. 2 is a schematic perspective view showing an embodiment of the trochoid drive mechanism according to the present invention.

  In the present embodiment, the trochoid drive mechanism 1 includes a main body 10 that is composed of four layers in the vertical direction and in which substantially circular plate-like bodies are stacked. In FIG. 2, the uppermost plate-like body is omitted for convenience of explanation. The four-layered plate-like bodies are respectively arranged at a required interval, and are the ceiling plate 11, the upper drive plate 12, the intermediate plate 13 and the lower drive plate 14 from the upper side. 3 shows the ceiling plate 11, the upper drive plate 12, the intermediate plate 13, and the lower drive plate 14. The ceiling plate 11, the upper drive plate 12, the intermediate plate 13 and the lower drive plate 14 each have a required shape and are structurally supported in association with each other as follows.

  The trochoid drive mechanism 1 further includes an action unit 20, a motion mechanism unit 30, and a tilt mechanism unit 40. FIG. 3 is a partial side cross-sectional view showing an embodiment of the main body 10, the action part 20, and the motion mechanism part 30. FIG. 4 is a partial side cross-sectional view showing an embodiment of the tilt mechanism unit 40. In the present embodiment, as shown in FIG. 2, the action portion 20 and the motion mechanism portion 30 are disposed at four substantially equal positions in the circumferential direction of the main body 10. The four action parts 20 and the movement mechanism part 30 have the same structure. Note that one of the motion mechanism units 30 serves as a drive source, and the structure is different in part from the remaining three on the driven side. In FIG. 3, only one action part 20 and movement mechanism part 30 are shown for convenience of explanation.

  The action unit 20 is supported by the upper drive plate 12 and the lower drive plate 14. The action portion 20 is fixed to the upper drive plate 12 at the upper end portion, and is supported by the lower drive plate 14 at a substantially central portion via a joint described later. The action part 20 is attached to the upper drive plate 12, the axle 21 having a circular cross section extending from the top 21 to the lower side of the lower drive plate 14, and the axle 22 at the lower end thereof. And a wheel 23 having a required diameter. The action part 20 has a universal joint 24 interposed between the top part 21 and the axle 22. Further, a ball joint 25 is interposed between the axle 22 and the lower drive plate 14.

  As shown in FIG. 3, the universal joint 24 has yokes 241 and 242 having U-shaped portions facing each other in a crossing manner, and the yokes 241 and 242 are connected by a cross pin 243. On the other hand, the yoke 242 is configured to be tiltable in a free direction. The ball joint 25 connects the joint portion 252 with the spherical tubular body 251 in which a circular hole for fitting the axle 22 is formed, the joint portion 252 having a spherical cavity surrounding a part of the spherical tubular body 251 inside, and the joint portion 252. And a fixing portion 254 that is fixed to the lower drive plate 14 via the arm 253. According to this configuration, when the lower drive plate 14 moves in the left-right direction with respect to the upper drive plate 12 as described later, the axle 22 is bent and inclined by the universal joint 24.

  FIG. 3 shows an exercise mechanism 30 serving as a drive source. The motion mechanism unit 30 is mounted with a motor 32 as a drive unit at a suitable position on the top surface of the ceiling plate 11 via a frame 31. A gear 321 is integrally attached to the output shaft of the motor 32. The rotational force of the motor 32 causes the ceiling plate 11 and the intermediate plate 13 to rotate on a horizontal plane by the gear 33 to the shaft 38 constituting the motion mechanism unit 30. The gear 33 is attached to the upper end of the shaft 34 and meshes with the gear 321. The shaft 34 is loosely fitted in the hole 111 of the ceiling plate 11 so as to be rotatable. One end of, for example, a plate-like first turning member 35 having a required length rotatable around the shaft 34 is connected to the lower portion of the shaft 34. The other end of the first turning member 35 is movably connected to a shaft 36 that is loosely fitted in the hole 121 of the upper drive plate 12. One end of, for example, a plate-like second turning member 37 having a required length rotatable around the shaft 36 is connected to the lower portion of the shaft 36. The other end of the turning member 37 is movably connected to a shaft 38 that is loosely fitted in the hole 131 of the intermediate plate 13. Therefore, the shaft 34 to the shaft 38 constitute a two-stage crank. The shafts 34, 36, and 38 are provided with unillustrated positioning members that restrict movement in the vertical direction.

  The positions of the shafts 34, 36, and 38 are set so that the first and second turning members 35 and 37 face the same direction (in phase) around the shaft 36. The first and second swiveling members 35 and 37 each have a ratio of dimensions from one end to the other end, more specifically, the dimension between the shafts 34 and 36 of the first swiveling member 35 and the second swiveling member. The ratio between the 37 shafts 36 and 38 is set to a predetermined ratio.

  In the above structure, when the motor 32 is driven, the gear 33 receives the rotational force from the gear 321 and turns around the shaft 36. By this turning operation, the intermediate plate 13 also turns synchronously with a turning diameter corresponding to the predetermined ratio. The ratio of the turning diameters of the upper drive plate 12 and the intermediate plate 13 defines the angle θ (see FIG. 5A) of the razor movement (swing motion) with respect to the turning center axis of the axle 22 of the action portion 20. The wheel 22 is not a free wheel, but functions as a driving wheel on which rotational restraint force is applied. Therefore, the wheel 23 stands at a camber angle corresponding to the angle θ and moves the ground point around the turning center axis. The other three driven sides of the motion mechanism unit 30 have a structure in which the motor 32 and the gears 321 and 33 are omitted. The four motion mechanism sections 30 are oriented so that their rotational phases coincide.

  FIGS. 5A and 5B are diagrams for explaining the transition of the ground contact point of the wheel 22. FIG. 5A is a diagram when the turning center is in the vertical direction, and FIG. 5B is a diagram when the turning center is shifted in the horizontal direction. That is, in a state where the steering is not turned off as shown in FIG. 5A, the axle 22 moves with a predetermined angle around the turning center axis Oc, that is, the angle θ corresponding to the predetermined ratio described above. I do. In FIG. 5A, the radius of the wheel 23 is set so that the distance from the contact point of the wheel 23 to the point where the turning center axis Oc intersects the contact surface coincides with the radius of the arc drawn by the contact point. It is preferable. In this way, even if a razor movement is performed without turning off the steering wheel, one round of rolling of the wheel 23 coincides with one round of the grounding point, and no twist is generated. The same applies to the wheel 23 '.

  Next, returning to FIG. 4, the structure of the tilt mechanism unit 40 will be described. The tilting mechanism 40 is for shifting the intermediate plate 13 and the lower drive plate 14 in the left-right direction. In the present embodiment, the lower drive plate 14 is shifted in the left-right direction with respect to the intermediate plate 13. ing. By this sliding operation, the axis center Oc of the slashing motion is equivalently tilted (see FIG. 5B), and the trochoid drive mechanism 1 is moved in the horizontal direction, more specifically, with respect to the tilt direction of the shaft center Oc. It can be moved in the direction advanced in the 90 ° rotation direction on the horizontal plane.

  In FIG. 4, windows 132 and 141 are formed in the intermediate plate 13 and the lower drive plate 14 as necessary. The tilt mechanism unit 40 includes a relay plate 41 arranged in parallel between the intermediate plate 13 and the lower drive plate 14. Linear sliders 42 and 43 are arranged on the upper and lower surfaces of the relay plate 41 in the form of a cross-beam. That is, between the lower surface of the intermediate plate 13 and the upper surface of the relay plate 41, a pair of linear sliders 42 parallel to the left-right direction are disposed at the front and rear (paper surface direction in FIG. 4) side position. In this embodiment, the linear slider 42 includes a guide member 42g having a predetermined length provided on the intermediate plate 13 side and a moving member 42s provided on the relay plate 41 side.

  On the other hand, a pair of linear sliders 43 parallel to the front-rear direction are disposed between the lower surface of the relay plate 41 and the upper surface of the lower drive plate 14 at the left and right side positions thereof. In this embodiment, the linear slider 43 includes a guide member 43g having a predetermined length provided on the lower drive plate 14 side and a moving member 43s provided on the relay plate 41 side.

  Servo motors 44 and 47 as drive units are fixed substantially at the center of the upper and lower surfaces of the relay plate 41. Instead of the servo motors 44 and 47, a motor or an electromagnetic solenoid may be used. In this embodiment, a pinion gear 45 is integrally fixed to the output shaft of the servo motor 44. A rack 46 extends from the intermediate plate 13 in the left-right direction, and the pinion gear 45 and the rack 46 are engaged with each other. Furthermore, in this embodiment, a pinion gear 48 is integrally fixed to the output shaft of the servo motor 47. A rack 49 extends from the lower drive plate 14 in the front-rear direction, and the pinion gear 48 and the rack 49 are engaged with each other.

  Therefore, when the servo motor 44 is driven, the pinion gear 45 rotates and slides on the rack 46 in the horizontal direction, so that the relay plate 41 integral with the servo motor 44 slides in the horizontal direction with respect to the intermediate plate 13. To do. When the servo motor 47 is driven, the pinion gear 48 rotates to slide the rack 49 in the front-rear direction, so that the lower drive plate 14 slides in the front-rear direction with respect to the relay plate 41. As a result, both the servo motors 44 and 47 are driven, so that the lower drive plate 14 can slide with respect to the intermediate plate 13 in the front-rear and left-right directions by a desired amount. When the servo motors 44 and 47 are powered on and locked, the wheel 23 stops at a certain camber angle. On the other hand, when the servo motors 44 and 47 are turned off, the lock is released, the tilting posture of the axle 22 is released, and as a result of returning to the vertical direction, the wheel 22 is in contact with the ground contact surface (work surface). become.

  The indicator 50 includes an operation button 51 for instructing to turn on the power, a joystick 52 capable of instructing movement in all directions, and an antenna 53 for transmitting instruction contents by radio waves, for example. The joystick 52 generates voltages in directions orthogonal to each other according to the tilt amount. In FIG. 3, the control unit 60 installed on the ceiling board 11 receives the instruction content from the indicator 50 and gives a predetermined drive instruction to the motor 32 and the servomotors 44 and 47. The motor 32 may have a variable rotation speed according to the instruction content. As the rotational speed increases, the moving speed also increases. In addition, it is preferable that the servo motors 44 and 47 adjust the amount of horizontal displacement in accordance with the amount of tilt of the joystick 52 and make the amount of tilt of the turning center axis Oc variable. The greater the tilt amount, the greater the change in camber angle during one round of movement of the ground contact point of the wheel 23, and the moving speed increases. In addition, although the highly accurate straight traveling performance of the traveling trajectory per round as a trochoidal curve is somewhat reduced, the straight traveling performance when the traveling direction is viewed in a macro manner is maintained.

  FIG. 5B shows a tilt side phase position (shown by a broken line) and a phase position on the opposite side (shown by a solid line) of only the wheel 23 when the turning center axis Oc is tilted. FIG. As shown in the figure, at the tilt side phase position, the camber angle is slightly reduced and the wheel 23 is raised, and it can be seen that the steering direction proceeds with a larger radius of curvature, while the phase on the opposite side from the tilt side. At the position, it can be seen that the wheel 23 is further laid down at the maximum camber angle and proceeds in the steering direction with the minimum radius of curvature. The arc drawn by the grounding point of the wheel 23 on the grounding surface draws a trajectory contracted in an elliptical shape when viewed from the grounding surface in the left-right direction in FIG. 5B, and the apparent curvature and line in the grounding surface. The speed is not uniform and a pseudo-trochoid curve is drawn. In other words, a moving force in the direction of the paper surface of FIG. 5 is generated and proceeds in that direction. As shown in FIG. 5B, the grounding point moves up and down as viewed from the direction of the axis Oc due to the inclination of the turning center axis Oc. Therefore, the trochoid drive mechanism 1 has its center of gravity turned around the grounding point. Although the vertical movement occurs periodically, such vertical movement is greatly absorbed by the structure in which the axle 22 is slidable by the ball joint 25.

  In FIG. 5A, the wheel 23 ′ has a different wheel radius (larger) than the wheel 23. As shown in the figure, it can be seen that as the wheel radius becomes larger (or smaller), the length of the axle 22 is correspondingly shorter (or longer).

  Further, as described in FIG. 5 and the operation of the servo motors 44 and 47, the trochoid drive mechanism 1 can keep the wheel 23 in contact with the ground when stationary, and operates at a large camber angle during operation. It is. Therefore, if the wheel 23 is formed of a magnet, it can be applied to a traveling body including a magnet adsorption type wheel that travels on a metal (magnetic body) wall surface or the like. The metal wall surface may be a vertical wall or a three-dimensional wall surface such as a metal pipe or an inner wall of a metal container, and can be applied for various inspections. In addition, in order to ensure the operation to stand up to the required camber angle against the magnetic force from the solid grounding posture at rest, the solid grounding posture is restricted and is in a slightly upright state, i.e. point grounding. It is desirable to maintain the posture. For example, a method of structurally restricting the return of the axle 22 in the normal direction with an interference member such as a stopper can be considered.

  In addition, the trochoid drive mechanism 1 is provided with rough terrain compatibility and also has a step-over function. Stepping over the step slides up to the stair nosing in a point contact state, and in this state the tip of the wheel slightly advances in the traveling direction, but slides down from the nose with the wheel rotation and gradually proceeds with further wheel rotation. To do. However, the step over the step is caused by the point contact engagement of the wheel with the nose of the staircase, so there is a possibility that the step will slide down. FIGS. 6A and 6B are diagrams showing an embodiment of a wheel structure that suppresses slipping when climbing over stairs as much as possible. FIG. 6A is a top view and FIG. 6B is a side view. The engaging member 231 is provided on the upper surface side of the wheel 23, has an angular shape, and a spherical body is formed at the tip in this embodiment. As can be seen from FIG. 6A, the engaging member 231 is exposed outward from the peripheral surface of the wheel 23 to the extent that it does not contact the grounding surface during the traveling operation. Moreover, although the number of the engagement members 231 may be one or a required number, in this embodiment, three engagement members 231 are equally provided in the circumferential direction. The spherical body portion at the tip of the engaging member 231 has a gap with the upper surface of the wheel 23, and this gap is used to make it easy to catch on the nose of the tread surface of the staircase. Further, by providing a spherical body at the tip of the engaging member 231, the floor reaction force can be stably utilized by contacting the tread surface of the staircase, and the spherical body of the engaging member 231 has a large friction coefficient such as resin. If the material is used, the engagement with the tread surface is further enhanced, and sliding is further suppressed. Further, the engaging member 231 may be a shaped object that can ensure contact with the tread surface instead of the spherical body provided at the tip.

  In the present embodiment, the two-stage crank is adopted as the structure for performing the slashing motion. However, the present invention is not limited to this, and various structures can be adopted. For example, an aspect in which the truncated cone is supported upside down and rotatably supported, and an axle having a wheel at the lower end is attached to one place on the peripheral surface of the truncated cone, so that the truncated cone can be tilted.

DESCRIPTION OF SYMBOLS 1 Trochoid drive mechanism 10 Main body 20 Action part 22 Axle 23 Wheel 231 Engagement member (engagement part)
24 Universal joint 25 Ball joint 30 Motion mechanism part 32 Motors 35, 37 First and second pivot shafts 40 Tilt mechanism part 41 Relay plates 42, 42, linear sliders 44, 47 Servo motors 45, 48 Pinion gears 46, 49 Rack

Claims (7)

At least one working part with an axle having a wheel fixed at the tip;
A motion mechanism that causes the axle to shave on the working surface;
A trochoid drive mechanism comprising: an inclination mechanism part for inclining a turning center axis of the razor movement. 2. The trochoid drive mechanism according to claim 1, further comprising: a main body, wherein the main body includes a plurality of the action portions, and the tilt mechanism portion tilts each turning center axis of the plurality of action portions by the same angle. The trochoid drive mechanism according to claim 2, wherein the motion mechanism section causes the axles of the plurality of action sections to shave in the same phase. The trochoid drive mechanism according to any one of claims 1 to 3, wherein the axle includes a universal joint at an upper portion thereof, and a ball joint is interposed in the middle of the shaft. The trochoid drive mechanism according to any one of claims 1 to 4, wherein the tilting mechanism portion makes the side surface of the wheel substantially grounded to the working surface when stationary. The trochoid drive mechanism according to claim 1, wherein the wheel is made of a magnet. The trochoid according to any one of claims 1 to 6, wherein the wheel includes an engagement member that is provided on a surface on the axle side and protrudes in a radial direction at least at one place in a circumferential direction. Drive mechanism.