JP2011063246A - Friction type driving device and inverted pendulum type mobile body using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To always provide a driving force (rotational force) to at least drive disk assemblies 52L, 52R in contact with the ground more than drive rollers, and minimize the slippage between the drive rollers and the drive disk assemblies 52L, 52R. <P>SOLUTION: The drive rollers 60L, 60R are formed of hourglass-shaped rollers the diameters of which are reduced from the axial ends toward the centers thereof, respectively. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a friction type driving device and an inverted pendulum type moving body, and more particularly to a friction type driving device used as a traveling unit and an inverted pendulum type moving body using the same.

  As a traveling drive device for an omnidirectional mobile body, a plurality of annular rollers and a driven roller that is arranged in the annular direction of the annular body and is rotatable around an axis in a tangential direction of the annular body at its own position. Each of each of the left and right drive disks, a main wheel including a driven roller), left and right drive disks (rotating members) disposed on both the left and right sides in the axial direction of the main wheel so as to be rotatable around its own central axis. And a plurality of drive rollers (drive rollers) that are arranged to be rotatable about an axis that forms a twisted relationship with the central axis of the drive disk and that have an outer peripheral surface that contacts the outer peripheral surface of the driven roller. There exists a drive device (for example, patent document 1).

  This friction drive is used as a traveling unit of a single-wheel inverted pendulum type moving body, and left and right drive disks are supported rotatably from the frame of the inverted pendulum type moving body, and the left and right drive rollers are driven rollers. The main wheel is supported so as to be able to rotate (revolve) so as to be sandwiched from the left and right.

  In the inverted pendulum type moving body using this friction type driving device, the drive roller is pressed against the driven roller, and the rotation of the drive disk is transmitted from the drive roller to the driven roller by the friction between the drive roller and the driven roller. When the drive disks are driven to rotate in the same direction and at the same speed, the main wheels revolve, and when the left and right drive disks are driven to rotate in different directions or at different speeds, the main wheels revolve. The driven roller rotates (rotates about the axis in the tangential direction of the annular body) or the main wheel does not revolve, and the driven roller rotates and can move (run) diagonally in the front, rear, left, and right directions.

International Publication No. 2008/13279 Pamphlet

  In the friction type driving device as described above, at least one pair of left and right drive rollers always contacts the driven roller that is grounded at the lowermost portion, and at least the driven roller that is in the grounded state always has a propulsive force than the drive roller. It is necessary to be set to give (rotational force).

  In addition, in order to obtain an accurate movement (movement direction) according to the control target of the main wheel and to reduce power loss, sliding between the outer peripheral surfaces of the drive roller and the driven roller is reduced as much as possible. It is necessary.

  The problem to be solved by the present invention is that at least the driven roller in contact with the ground is always given a propulsive force (rotational force) from the drive roller, and the sliding between the drive roller and the driven roller is reduced as much as possible. It is to be.

  A frictional drive device according to the present invention includes a main body including an annular body and a plurality of driven rollers that are arranged in a ring direction of the annular body and are rotatable about a tangential axis of the annular body at each of the arrangement positions. A wheel, left and right drive disks arranged to rotate about its own center axis on both left and right sides in the axial direction of the main wheel, and each of the left and right drive disks twisted with respect to the center axis of the drive disk A friction drive device having a plurality of drive rollers that are arranged so as to be rotatable around an axis that forms the relationship, and that have an outer peripheral surface that is in contact with the outer peripheral surface of the driven roller. Each of the disk members is configured by an assembly of a plurality of disk members rotatably attached to each other, and the disk members are located in the middle of those at the end portions in the axial direction of the roller shafts. Outer diameter smaller toward the part.

The inverted pendulum type moving body according to the present invention includes the friction drive device according to the above-described invention as a traveling unit.
Vertical pendulum type moving body.

  According to the friction type drive device of the present invention, the drive roller is constituted by an assembly of disk members, and the disk member has a smaller outer diameter toward the center than at the end in the axial direction of the roller shaft. The assembly of disk members has a drum shape as a whole, and the contact area between the outer peripheral surfaces of the drive roller and the driven roller is enlarged in the axial direction of the drive roller. As a result, an area where the drive roller contacts the outer peripheral surface of the driven roller as viewed in the ring direction of the main wheel is enlarged, and a setting in which the drive roller always comes into contact with the grounded driven roller can be obtained satisfactorily.

  As a result, the driven roller that is in contact with the ground is always given a propulsive force (rotational force) from the drive roller, and the contact area is expanded to reduce slippage between the drive roller and the driven roller. Power transmission efficiency is improved.

  Since the drive roller is in line contact with the outer peripheral surface of the driven roller in the absence of elastic deformation, the above-described effect is achieved so that the hourglass curvature formed by the disk member aggregate matches the curvature of the outer peripheral surface of the driven roller. Becomes prominent.

The front view which shows one Example of the inverted pendulum type mobile body which contains the friction type drive device by this invention as a traveling unit. The longitudinal cross-sectional view of the friction-type drive device by a present Example. The side view of the principal part of the friction type drive device by a present Example. The enlarged front view of the principal part of the friction type drive device by a present Example. The front view of the drive roller used for the friction type drive device by a present Example. The front view of the drive roller used for the friction type drive device by other Examples.

  Embodiments of a friction type driving device and an inverted pendulum type moving body according to the present invention will be described below with reference to FIGS. Note that the vertical three-dimensional coordinate axes in the vertical direction, the front-rear direction, and the horizontal direction are defined as illustrated according to the moving direction of the moving body.

  First, an overall configuration of an inverted pendulum type moving body including the friction type driving device according to the present embodiment as a traveling unit will be described with reference to FIG.

  The inverted pendulum type moving body has a column-shaped frame 10. A traveling unit 40 (friction type driving device) and left and right steps 12L and 12R are attached to the lower part of the frame 10. A handle bar 14 is attached to the top of the frame 10. Left and right grip members 16L and 16R are attached to the left and right ends of the handle bar 14, respectively.

  The traveling unit 40 is of a single wheel type and is located between a left side wall 18L and a right side wall 18R formed in the lower part of the frame 10, and uses a gyroscope and a load sensor (not shown) built in the frame 10. Under the standing control of the inverted pendulum, the frame 10 is kept in an upright position, and as a unicycle, it runs in all directions, front, rear, left, right, and diagonal.

  Next, details of the traveling unit 40 (friction type driving device) according to the present embodiment will be described with reference to FIGS.

  The left side wall portion 18L and the right side wall portion 18R are formed with cylindrical portions 20L and 20R that protrude to the opposite sides. Inside the cylindrical portions 20L and 20R, ring-shaped mount members 46L and 46R are concentrically fixed to each other with a center axis A together with ring members 42L and 42R and mounting bolts 44.

  The left and right mount members 46L, 46R also serve as outer races for the cross roller bearings 48L, 48R, and inner races 50L, 50R for the cross roller bearings 48L, 48R are rotatably provided inside the mount members 46L, 46R. . The cross roller bearings 48L and 48R are rolling bearings capable of handling a radial load and an axial load (thrust load).

  Left and right drive disk assemblies 52L and 52R are fixedly connected to the inner races 47L and 47R together with internal gear members 80L and 80R of wave gear devices 72L and 72R described later. That is, the coupling body of the internal gear members 80L, 80R and the drive disk assemblies 52L, 52R is supported by the cross roller bearings 48L, 48R so as to be rotatable around the same central axis as the central axis A from the frame 10.

  The drive disk assemblies 52L and 52R include disk-shaped disk members 54L and 54R that are directly connected to the internal gear members 80L and 80R, and a frustoconical outer peripheral member 56L that is fixed to the outer peripheral portion of the disk members 54L and 54R. , 56R.

  The outer peripheral portions of the disk members 54L, 54R and the outer peripheral members 56L, 56R are symmetrical with respect to the central axes of the left and right drive disk assemblies 52L, 52R at equal intervals in the circumferential direction. The left and right drive rollers 60L and 60R are rotatably supported by roller support shafts 58L and 58R at a plurality of positions rotationally symmetrical as a center line.

  The left and right drive rollers 60L and 60R are arranged in such a manner that the axial direction of the roller shafts 58L and 58R extends in a direction perpendicular to one virtual plane that is neither parallel nor orthogonal to the central axis of the drive disk assemblies 52L and 52R. As a result, the rotation surface is arranged in a plane parallel to one virtual plane that is neither parallel nor orthogonal to the central axis of the drive disk assemblies 52L, 52R.

  In other words, the left and right roller shafts 58L and 58R are symmetrically arranged and extend in the axial direction that forms a twisted relationship with respect to the central axis A, respectively. As a result, the left and right drive rollers 60L and 60R supported by the left and right roller shafts 58L and 58R are bilaterally symmetrical and have the same inclined arrangement as the helical gear teeth.

  The drive disk assemblies 52L and 52R only need to support a plurality of drive rollers 60L and 60R with a predetermined direction, and the drive disk assemblies 52L and 52R can be disc-shaped, It may have any shape such as a head cone.

  The structure of the drive rollers 60L and 60R will be described in detail later.

  Electric motors 64L and 64R are disposed further inside the left and right inner races 50L and 50R. In the left and right electric motors 64L and 64R, outer housings 66L and 66R each including a stator coil (not shown) are fixed to the left and right mount members 46L and 46R by ring members 42L and 42R. The left and right electric motors 64L and 64R are both concentric with the central axis A and have rotor shafts 70L and 70R extending in a direction approaching each other in the axial direction.

  Wave plugs 74L and 74R of the left and right wave gear devices 72L and 72R are fixedly connected to the tip portions of the rotor shafts 70L and 70R. The wave gear devices 72L and 72R have a well-known structure. The left and right electric motors 64L and 64R are arranged concentrically with the central axis A, and have high elliptical wave plugs 74L and 74R as input members. Wave flanges 76L, 76R fitted and fitted to the outer peripheral surfaces of the wave plugs 74L, 74R, and a thin-walled cylindrical flexible cylinder with a flange that has friction engagement with the outer peripheral surfaces of the wave bearings 76L, 76R and has outer teeth on the outer peripheral surface The external teeth members 78L and 78R and the high-rigidity ring-shaped internal teeth members 80L and 80R having internal teeth that mesh with the external teeth of the flexible external teeth members 78R and 78L. The internal gear members 80L and 80R are output members, and are fixedly connected to the left and right drive disk assemblies 52L and 52R by the bolts 45 as described above.

  As a result, the output rotations of the left and right electric motors 64L and 64R are decelerated by the left and right wave gear devices 72L and 72R, and individually transmitted to the left and right drive disk assemblies 52L and 52R.

  The left and right drive disk assemblies 52L, 52R support the main wheel 84 on the same or approximate center axis as the center axis A so as to be sandwiched from both the left and right sides by an annular roller group of left and right drive rollers 60L, 60R. ing. In other words, the main wheel 84 is the same as the central axis A from the left and right drive disk assemblies 52L and 52R so as to be sandwiched between the left and right sides by a group of rollers arranged in an annular shape by the left and right drive rollers 60L and 60R. Alternatively, it is supported on an approximate center axis without axis, and can rotate (revolve) around its own center.

  The main wheel 84 includes an endless annular ring body 86 formed of a prismatic body, a plurality of inner sleeves 88 fitted and mounted on the outer periphery of the ring body 86, and ball bearings 90 on the outer periphery of each inner sleeve 88. It comprises a plurality of driven rollers 92 that are rotatably mounted.

  The driven roller 92 is a grounding roller, and is configured by a metal cylindrical portion 92A that fits with the ball bearing 90 and a rubber cylindrical portion 92B that is vulcanized and bonded to the outer periphery of the metal cylindrical portion 92A. Yes.

  A plurality of driven rollers 92 are provided in the annular direction (circumferential direction) of the annular body 86 together with the inner sleeve 88, and can be rotated (rotated) around a tangential axis of the annular body 86 at the position where the driven roller 92 is disposed.

  The left and right drive rollers 60L and 60R come into contact with the outer peripheral surface of the rubber cylindrical portion 92B of the driven roller 92 that forms the substantial outer peripheral surface of the main wheel 84 with the outer peripheral surface, and the drive disk assemblies 52L and 52R rotate by friction. (Propulsion force) is transmitted to the driven roller 92.

  Regarding the relationship (number) between the driven roller 92 and the left and right drive rollers 60L, 60R, at least one set of the left and right drive rollers 60L, 60R is always in contact with the driven roller 92 that is grounded at the lowest portion. 60L and 60R are set so that a propulsive force (rotational force) is always applied to at least the driven roller 92 in a grounded state.

  The left and right drive rollers 60L and 60R are each in the rotational direction around the central axis (ring center) of the main wheel 84, more precisely, in the tangential direction at the contact point of the drive rollers 60L and 60R with the driven roller 92. Thus, it is rotatably arranged around a central axis extending in a direction that is neither orthogonal nor parallel.

  That is, the left and right drive rollers 60L and 60R are each inclined with respect to the rotation direction (revolution direction) around the central axis of the main wheel 84, and have a torsional relationship with the rotation axis of the drive disk assemblies 52L and 52R. The rotation axis is formed and has a rotation plane along one virtual plane that is neither parallel nor orthogonal to the central axis of the drive disk assemblies 52L and 52R.

  In other words, the center axis of each of the left and right drive rollers 60L and 60R is inclined at an angle with respect to the radial line of the annular body 86 corresponding to the central axis of the driven roller 92, and at the same time, the center line of the annular body 86 contacts. It is inclined at an angle with respect to the virtual plane. Due to this three-dimensional inclination of the central axis, the arrangement of the drive rollers 60L, 60R in the drive disk assemblies 52L, 52R can be compared, in other words, the teeth of a “helical bevel gear” placed on a conical surface at a certain angle. It is similar to the inclination of (tooth trace). Please refer to the pamphlet of International Publication No. 2008/139740 if you need more detailed explanation about this.

  In this embodiment, if the left and right drive disk assemblies 52L and 52R have different rotational directions or (and) rotational speeds by the left and right electric motors 64L and 64R, the circumference (by the rotational force of the drive disk assemblies 52L and 52R) With respect to the force in the tangential) direction, a component force in a direction perpendicular to this force acts on the contact surface between the left and right drive rollers 60L, 60R and the driven roller 92. Due to this component force, a force that twists the driven roller 92 acts on the outer surface of the driven roller 92, and the driven roller 92 rotates (rotates) around its own central axis.

  The rotation of the driven roller 92 is determined by the rotational speed difference between the left and right drive disk assemblies 52L and 52R. For example, when the left and right drive disk assemblies 52L and 52R are rotated in the opposite directions at the same speed, the main wheel 84 does not revolve at all, and only the driven roller 92 rotates. As a result, a driving force in the left-right direction is applied to the main wheel 84, and the inverted pendulum moving body moves in the left-right direction (true lateral movement).

  On the other hand, when the rotation directions and rotation speeds of the left and right drive disk assemblies 52L and 52R are the same, the driven roller 92 does not rotate, the main wheel 84 revolves, and the inverted pendulum moving body 10 Move forward (straight) or reverse.

  Thus, the inverted pendulum moving body moves in all directions on the road surface by independently controlling the rotation speed and rotation direction of the left and right drive disk assemblies 52L and 52R by the left and right electric motors 64L and 64R. Can do.

  Details of the left and right drive rollers 60L and 60R according to the present embodiment will be described with reference to FIGS.

  The drive rollers 60L and 60R are configured by an assembly of a plurality of disk members 61L and 61R that are rotatably attached to the roller shafts 58L and 58R, respectively. That is, the drive rollers 60L and 60R are configured by a plurality of disk members 61L and 61R that are skewed to the roller shafts 58L and 58R. The disk members 61L and 61R have smaller outer diameters toward the central portions 602L and 602R than at the end portions 601L and 601R in the axial direction of the roller shafts 58L and 58R. Thereby, the aggregate | assembly of the disk members 61L and 61R, ie, the drive rollers 60L and 60R, has comprised the hourglass shape (hourglass shape).

  In a state where there is no elastic deformation, the drive rollers 60L and 60R are in line contact with the outer peripheral surface of the driven roller 92, and the hourglass shape (outer peripheral surface) of the drive rollers 60L and 60R (an assembly of the disk members 61L and 61R) in this line contact. The curvature of the shape) matches the curvature of the outer peripheral surface of the driven roller 92 in the same line contact.

  As described above, when the drive rollers 60L and 60R have the hourglass shape, the contact area between the outer peripheral surfaces of the drive rollers 60L and 60R and the driven roller 92 is expanded in the axial direction of the drive rollers 60L and 60R. The plurality of disk members 61L and 61R constituting the drive rollers 60L and 60R are individually rotated without contacting the driven roller 92 and causing slippage.

  As a result, as viewed in the ring direction of the main wheel 84, the area where the drive rollers 60L and 60R are in contact with the outer peripheral surfaces of the driven rollers 92L and 92R is enlarged.

  As a result, the driven roller 92 that is in contact with the ground can be surely set so that the drive rollers 60L and 60R are in contact with each other. The driven roller 92 that is in the grounded state is always more thrust than the drive rollers 60L and 60R. (Rotational force) is applied.

  Further, by increasing the contact area between the drive rollers 60L, 60R and the driven roller 92, slip between the drive rollers 60L, 60R and the driven roller 92 is reduced, and the transmission efficiency of the propulsive force due to friction is improved.

  The enlargement of the contact area matches the curvature of the hourglass shape of the drive rollers 60L and 60R with the curvature of the outer peripheral surface of the driven roller 92 in line contact with the outer peripheral surface of the driven roller 92 without any elastic deformation. It becomes more remarkable.

  As shown in FIG. 5, the drive rollers 60 </ b> L and 60 </ b> R are illustrated in addition to the outer peripheral surface of the rotating arc surface that is continuous in the axial direction (bus line direction) by the assembly of the disk members 61 </ b> L and 61 </ b> R with the tapered outer peripheral surface. As shown in FIG. 6, it may be an outer peripheral surface shape that changes stepwise in the axial direction (busbar direction) by an assembly of the disk members 63L and 63R with straight outer peripheral surfaces.

  When the drive rollers 60L and 60R have an outer peripheral surface shape that changes stepwise in the axial direction (bus line direction), the outer peripheral corners (edge portions) of the disc members 63L and 63R are rubber cylinders of the driven roller 92. Under the elastic deformation of the portion 92B, the rubber cylindrical portion 92B is caught, and the slip between the drive rollers 60L and 60R and the driven roller 92 is further reduced. As a result, the transmission efficiency of the propulsive force due to the friction between the drive rollers 60L and 60R and the driven roller 92 is further improved.

  A plurality of circumferential grooves may be formed on the outer peripheral surfaces of the drive rollers 60L and 60R, and the edge portions of the circumferential grooves are elastically deformed by the rubber cylindrical portion 92B of the driven roller 92. By biting into 92B, further effects can be expected.

10 Frame 12L, 12R Step 14 Handlebar 42L, 42R Mount member 52L, 52R Drive disk assembly 58L, 58R Roller shaft 60L, 60R Drive roller 61L, 61R Disk member 63L, 63R Disk member 64L, 64R Electric motor 72L, 72R Wave motion Gear device 84 Main wheel 86 Annular body 92 Driven roller

Claims (2)

A main wheel including an annular body and a plurality of drive disk assemblies 52L and 52R which are arranged in the annular direction of the annular body and are rotatable around a tangential axis of the annular body at the respective arrangement positions; The left and right drive disks, which are rotatably arranged around their own central axis on both left and right sides in the axial direction of the main wheel, and each of the left and right drive disks have a twist relationship with respect to the central axis of the drive disk. A friction type driving device having a plurality of drive rollers arranged so as to be rotatable about an axis and having an outer peripheral surface contacting the outer peripheral surface of the drive disk assembly 52L, 52R,
The drive roller is constituted by an assembly of a plurality of disk members each rotatably attached to a single roller shaft, and the disk member is located at a center portion from the end portion in the axial direction of the roller shaft. Friction type drive device whose outer diameter becomes smaller toward   An inverted pendulum type moving body including the friction type driving device according to claim 1 as a traveling unit.

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