Patent Description:
As is well known, as a traveling apparatus that makes a traveling body such as an inspection robot travel by use of rotation torque of a driving apparatus such as a motor, there exist a wheel-traveling type in which a wheel is made to make contact with a road surface or the like so that a traveling body is made to travel and an endless-track traveling type in which an endless track formed of a crawler belt or a caterpillar is made to make contact with a road surface or an apparatus to be inspected so that a traveling body is made to travel.

In the case of the wheel-traveling type in which a wheel is made to make contact with a road surface or the like so that traveling is performed, there exist, for example, a four-wheel independent driving type in which in order to make a traveling body such as a robot stably travel in a level difference or the like on a travel surface, all of four wheels that are provided at the front and rear sides of the traveling body are driven by respective independent driving power sources and a front-and-rear wheels synchronous driving type in which respective timing pulleys are provided on the front and rear wheels of a traveling body and a timing belt is mounted across the front and rear timing pulleys so that the front and rear wheels are driven in synchronization with each other (For example, refer to Patent Document <NUM>).

In addition, there has been proposed a traveling apparatus in which as a traveling body for traveling through a narrow gap, the wheel-traveling type is utilized, two or more wheels are arranged at the front and rear sides of the traveling body in such a way that each one of the wheels is in series with one another, the width of the traveling body is as large as the width of the wheel, and an apparatus such as a control box provided with a control board is mounted in a space existing between the front and rear wheels (for example, refer to Patent Document <NUM>).

Furthermore, in the endless-track traveling type, there has been proposed a traveling apparatus in which a negative pressure is made to occur in a decompression chamber of a traveling body and hence a crawler belt made of a flexible member, wound over the front and rear pulleys, is pressed to the wall face so that traveling is performed (for example, refer to Patent Document <NUM>). In addition, in the endless-track traveling type, there has been proposed a mechanism in which the respective tread faces of crawler shoes arranged along a crawler belt are prevented from being folded in a valley manner (for example, refer to Patent Document <NUM>).

Patent Document <NUM>, according to its abstract, relates to a crawler vehicle having a chain drive with two closed chains which are arranged spaced apart in the vehicle transverse direction and which are guided in each case at a first end around a drive wheel and at a second end around a guide wheel, and which are designed to be supported against the ground in a ground-side chain section between the drive wheel and the guide wheel. According to the invention, in each case at least one support rail which extends in the vehicle longitudinal direction is arranged between the drive wheels and the guide wheels, which support rail is designed to bear permanently against a contact section of the respective ground-side chain section. The invention also relates to the use in particular for snow-going crawler vehicles, for example piste grooming vehicles.

Patent Document <NUM>, according to its abstract, relates to a vacuum wall crawler having at least one vacuum track unit comprising: - a track frame; - two pulleys provided in opposite ends of the track frame, and defining a wheelbase; - an endless track arranged to circulate on the two pulleys, and comprising a flexible band, said flexible band comprising a plurality of apertures, and having a thickness; - a vacuum distribution box provided in said track frame wherein the vacuum distribution box is in communication with a portion of the apertures to distribute a vacuum to the portion of apertures as the endless track circulates, where the thickness of the flexible band is <NUM>-<NUM>% of the wheel base, W.

Patent Document <NUM>, according to its abstract, states that to attract the wall surface having a step difference and projecting and recessed parts with the sufficient attractive force, and to move freely, both ends of a center shaft are respectively equipped with frames freely to turn. Both ends of each frame are respectively equipped with crawler belt devices freely to turn. Four crawler belt devices each having a magnet inside of an endless crawler belt thereof are driven in pairs by two motors provided for each frame. Two crawler belt devices provided in each frame are connected to each other by an elastic connecting means, and when one crawler belt device is floated on the travelling surface, it is returned by the elastic force of a coil spring. Four crawler belt devices are oscillated mutually at a predetermined degree of freedom of rotation, and adhered to the travelling surface. Even in the case where each crawler belt device rides on a step difference part and is separated from the travelling surface temporarily, it is returned to the travelling surface immediately by the energizing force of the elastic connecting means, and adhered to the travelling surface again.

In the case of the conventional traveling apparatus disclosed in Patent Document <NUM>, in order to travel through a narrow gap, an apparatus such as a control box is disposed between the front and rear wheels so that the thickness thereof is reduced; however, due to a recess or a protrusion existing in a traveling surface, the bottom plain of the main body of the traveling apparatus makes contact with the traveling surface during traveling and hence the traveling apparatus may become unable to travel or a large vibration may occur in the traveling apparatus. In order to solve these problems, it is desired to increase the diameter of the wheel; however, when the diameter of the wheel is increased, the traveling apparatus becomes larger as a whole and hence it becomes difficult to reduce the thickness thereof.

In the case of the endless-track traveling type utilizing a crawler belt, in order to travel stably, it is required that the portion, of the crawler belt, that should make contact with a traveling surface is pressed to the traveling surface by at least three pulleys; thus, the number of components such as a pulley and the like increases and the traveling apparatus is upsized inevitably.

The present invention has been implemented in order to solve the foregoing problems in conventional traveling apparatuses; the objective thereof is to provide an endless-track traveling apparatus that can be downsized and can stably travel.

In addition, the objective of the present invention is to provide a traveling body such as an inspection robot that can be downsized and can stably travel.

According to the present disclosure, an endless-track traveling apparatus and a traveling body as defined in the independent claims are provided. Further embodiments of the claimed invention are defined in the dependent claims. Although the claimed invention is only defined by the claims, the below embodiments, examples, and aspects are present for aiding in understanding the background and advantages of the claimed invention.

In an endless-track traveling apparatus according to the present invention, there is provided a planar member that is disposed in a space surrounded by the endless track and has a flat portion that makes contact with an inner circumferential surface of at least one of two portions, of the endless track existing between the first pulley and the second pulley, that face each other; the flat portion of the planar member makes contact with the inner circumferential surface of the endless track at a position at the traveling subject side with respect to a virtual straight line that connects a vertex, at the traveling subject side, in the outer circumferential surface of the first pulley and a vertex, at the traveling subject side, in the outer circumferential surface of the second pulley; at least part of the outer circumferential surface, of the endless track, that faces the inner circumferential surface being in contact with the flat portion of the planar member makes contact with the traveling subject. As a result, the endless-track traveling apparatus can be downsized and thinned; on top of that, even when there is an obstacle caused by a groove or the like existing in the traveling subject, the endless-track traveling apparatus can suppress vibration so as to travel smoothly.

<FIG> is a perspective view illustrating the overall configuration of a traveling body provided with an endless-track traveling apparatus according to Embodiment <NUM> of the present invention. A traveling body <NUM>, illustrated in <FIG>, that is provided with an endless-track traveling apparatus according to Embodiment <NUM> is configured as an inspection robot for a large-size electric power generator. In <FIG>, the traveling body <NUM> configured as an inspection robot for an electric power generator includes a sensor mounting unit <NUM>, as an apparatus mounting unit, that is equipped with a sensor, a camera, and the like for inspection, a first endless-track traveling apparatus <NUM> equipped with a crawler belt <NUM> as an endless track, and a second endless-track traveling apparatus <NUM> equipped with a crawler belt <NUM>.

As illustrated in <FIG>, the first endless-track traveling apparatus <NUM>, the second endless-track traveling apparatus <NUM>, and the sensor mounting unit <NUM> are arranged in parallel with one another in a direction substantially perpendicular to a forward direction F and a backward direction B of the traveling body <NUM>. First coupling members <NUM>, <NUM>, and <NUM> are arranged between a sidewall portion of a base portion <NUM> in the first endless-track traveling apparatus <NUM> and one of the sidewall portions of a case <NUM> of the sensor mounting unit <NUM> so as to mechanically couple the first endless-track traveling apparatus <NUM> and the sensor mounting unit <NUM>.

Second coupling members <NUM>, <NUM>, and <NUM> are arranged between a sidewall portion of a base portion <NUM> in the second endless-track traveling apparatus <NUM> and the other one of the sidewall portions of the case <NUM> of the sensor mounting unit <NUM> so as to mechanically couple the second endless-track traveling apparatus <NUM> and the sensor mounting unit <NUM>.

Each of the first coupling members <NUM>, <NUM>, and <NUM> and the second coupling members <NUM>, <NUM>, and <NUM> can bend at the substantially central portion in its longitudinal direction.

The sensor mounting unit <NUM> is supported by the first endless-track traveling apparatus <NUM> through the intermediary of the first coupling members <NUM>, <NUM>, and <NUM> and is supported by the second endless-track traveling apparatus <NUM> through the intermediary of the second coupling members <NUM>, <NUM>, and <NUM>; the bottom plain of the sensor mounting unit <NUM> faces a traveling surface R via a gap. The first endless-track traveling apparatus <NUM> and the second endless-track traveling apparatus <NUM> are configured in such a way as to be in linearly symmetrical with each other with respect to the forward direction F and the backward direction B; each one thereof forms the endless-track traveling apparatus according to Embodiment <NUM> of the present invention.

The traveling body <NUM>, configured in such a way as described above, advances straight in the forward direction F or in the backward direction B by rotating the crawler belt <NUM>, as an endless track, of the first endless-track traveling apparatus <NUM> and the crawler belt <NUM>, as an endless track, of the second endless-track traveling apparatus <NUM> at the same rotation speed and in the same direction.

The respective rotation directions of the crawler belt <NUM> of the first endless-track traveling apparatus <NUM> and the crawler belt <NUM> of the second endless-track traveling apparatus <NUM> are set to be opposite to each other so that turning operation is performed; the respective rotation directions thereof are set to be the same as each other and the respective rotation speeds thereof are set to be different from each other so that clockwise traveling or anticlockwise traveling can be performed. For example, in the case where while traveling in the forward direction F is performed, the rotation speed of the crawler belt <NUM> of the first endless-track traveling apparatus <NUM> is made to be lower than the rotation speed of the crawler belt <NUM> of the second endless-track traveling apparatus <NUM>, clockwise traveling can be performed; in the case where the rotation speed of the crawler belt <NUM> of the second endless-track traveling apparatus <NUM> is made to be lower than the rotation speed of the crawler belt <NUM> of the first endless-track traveling apparatus <NUM>, anticlockwise traveling can be performed.

Next, the endless-track traveling apparatus according to Embodiment <NUM> of the present invention will be explained in detail. <FIG> is an exploded perspective view of the endless-track traveling apparatus according to Embodiment <NUM> of the present invention and corresponds to the second endless-track traveling apparatus <NUM> in <FIG>. As described above, the first endless-track traveling apparatus <NUM> and the second endless-track traveling apparatus <NUM> in <FIG> are configured in such a way as to be in linearly symmetrical with each other with respect to the forward direction F and the backward direction B; however, because each of the first endless-track traveling apparatus <NUM> and the second endless-track traveling apparatus <NUM> is configured substantially in the same manner, the second endless-track traveling apparatus <NUM> will be explained here.

In <FIG>, the second endless-track traveling apparatus <NUM> is provided with the base portion <NUM> and a covering portion <NUM>. The base portion <NUM> is provided with a top portion <NUM> and side portions <NUM>, <NUM>, <NUM>, and <NUM> that each extend downward from the respective edges at the four ends of the top portion <NUM>. The covering portion <NUM> makes contact with the respective endfaces of the side portions <NUM>, <NUM>, <NUM>, and <NUM> of the base portion <NUM> so as to cover the bottom portion of the base portion <NUM>.

In the top portion <NUM> of the base portion <NUM>, there is formed a rectangular through-hole <NUM> for exposing one of the portions (the upper portion in <FIG>), of the crawler belt <NUM>, that face each other to the outside from the base portion <NUM>. In the covering portion <NUM>, there are formed a rectangular through-hole <NUM> for exposing the other one of the portions (the lower portion in <FIG>), of the crawler belt <NUM>, that face each other from the covering portion <NUM>, a through-hole <NUM> for exposing an aftermentioned permanent magnet 37a, and a through-hole <NUM> for exposing an aftermentioned permanent magnet 37c.

A driving-side pulley axle unit 34a is provided with a driving-side pulley axle 34a1 that supports a driving-side pulley 33a as a first pulley, a driving-side pulley axle holding body 34a2 that pivotably holds the driving-side pulley axle 34a1, and a bevel gear 34a3 fixed on the driving-side pulley axle 34a1. The driving-side pulley axle 34a1 of the driving-side pulley axle unit 34a is inserted into the central through-hole of the driving-side pulley 33a that is fixed on the driving-side pulley axle 34a1 in such a way as to rotate integrally with the driving-side pulley axle 34a1.

A driven-side pulley axle unit 34b is provided with a driven-side pulley axle 34b1 that supports a driven-side pulley 33b, as a second pulley, and a driven-side pulley axle holding body 34b2 that holds the driven-side pulley axle 34b1. The driven-side pulley axle 34b1 of the driven-side pulley axle unit 34b is inserted into the central through-hole of the driven-side pulley 33b that is pivotably held by the driven-side pulley axle holding body 34b2, through the intermediary of the driven-side pulley axle 34b1.

A motor <NUM> fixed to the base portion <NUM> drives a bevel gear 34a4, through the intermediary of a speed reducing mechanism <NUM>. The bevel gear 34a4 is engaged with the foregoing bevel gear 34a3; the bevel gear 34a4 drives and rotates the driving-side pulley 33a, through the intermediary of the bevel gear 34a3 and the driving-side pulley axle 34a1. A control board <NUM> equipped with a control circuit for controlling the motor <NUM> and the like is fixed inside the base portion <NUM>.

The crawler belt <NUM> that is made of rubber and forms an endless track is wound over an outer circumferential surface 33a1 of the driving-side pulley 33a and an outer circumferential surface 33b1 of the driven-side pulley 33b; while the driven-side pulley 33b is rotated by rotation of the driving-side pulley 33a, the crawler belt <NUM> travels over the driving-side pulley 33a and the driven-side pulley 33b.

<FIG> is an explanatory view of the endless-track traveling apparatus according to Embodiment <NUM> of the present invention. In <FIG> and <FIG>, a planar member <NUM> is disposed in the space surrounded by the crawler belt <NUM> as an endless track. The planar member <NUM> has a flat portion 32a that makes contact with the inner circumferential surface of one of the two portions (the lower portion in each of <FIG> and <FIG>), of the crawler belt <NUM> existing between the driving-side pulley 33a and the driven-side pulley 33b, that face each other.

The flat portion 32a of the planar member <NUM> makes contact with the inner circumferential surface of the crawler belt <NUM> at a position at a traveling subject <NUM> side with respect to a virtual straight line X1 that connects a vertex A1, at the traveling subject <NUM> (e.g., a traveling surface) side, in the outer circumferential surface 33a1 of the driving-side pulley 33a and a vertex B1, at the traveling subject <NUM> side, in the outer circumferential surface 33b1 of the driven-side pulley 33b. Accordingly, the crawler belt <NUM> is pressed from the inside to the outside by the planar member <NUM> and is exposed to the outside through the through-hole <NUM> provided in the covering portion <NUM> so as to make contact with the traveling subject <NUM>.

The planar member <NUM> disposed inside the crawler belt <NUM> is provided with the flat portion 32a that makes contact with the inner circumferential surface of the driving-side pulley 33a, a first inclination portion 32b1 connected with one of the end portions of the flat portion 32a, and a second inclination portion 32b2 connected with the other one of the end portions of the flat portion 32a. The first inclination portion 32b1 is formed in such a way that the distance between the first inclination portion 32b1 and the inner circumferential surface of the crawler belt <NUM> becomes larger as the first inclination portion 32b1 approaches the driving-side pulley 33a more. The second inclination portion 32b2 is formed in such a way that the distance between the second inclination portion 32b2 and the inner circumferential surface of the crawler belt <NUM> becomes larger as the second inclination portion 32b2 approaches the driven-side pulley 33b more.

In <FIG>, the permanent magnet 37a is fixed inside the base portion <NUM> and is disposed in such a way as to be exposed to the outside of the covering portion <NUM> through the through-hole <NUM> provided in the covering portion <NUM>. Similarly, the permanent magnet 37c is fixed inside the base portion <NUM> and is disposed in such a way as to be exposed to the outside of the covering portion <NUM> through the through-hole <NUM> provided in the covering portion <NUM>. A permanent magnet 37b is fixed to the flat portion 32a of the planar member <NUM> and is disposed inside the crawler belt <NUM>.

Next, there will be explained the operation of the traveling body <NUM> provided with the first endless-track traveling apparatus <NUM> and the second endless-track traveling apparatus <NUM>, which are each configured in such a manner as described above, at a time when the traveling body <NUM> is configured as an inspection robot for an electric power generator. The traveling body <NUM> travels through a gap between the rotor and the stator core of the electric power generator so as to perform inspection of the electric power generator. <FIG> is an explanatory view illustrating a usage state of a traveling body provided with the endless-track traveling apparatus according to Embodiment <NUM> of the present invention.

In <FIG> and <FIG>, the traveling body <NUM> inserted into the space between a rotor <NUM> and a stator core <NUM> of the electric power generator travels in the axle direction of the electric power generator, by means of the first endless-track traveling apparatus <NUM> and the second endless-track traveling apparatus <NUM>, and performs inspection of the inside of the electric power generator by use of various kinds of sensors and a camera mounted in the sensor mounting unit <NUM>. The permanent magnets 37a, 37b, 37c provided inside the first endless-track traveling apparatus <NUM> and the permanent magnets 37a, 37b, 37c provided inside the second endless-track traveling apparatus <NUM> are attracted by the stator core <NUM> as the traveling subject formed of a magnetic material; as a result, each of the first endless-track traveling apparatus <NUM> and the second endless-track traveling apparatus <NUM> can travel while adhering to the stator core <NUM> as the traveling subject, without dropping at any position in the circumferential direction of the electric power generator.

In this situation, the permanent magnets 37a, 37b, 37c provided in the first endless-track traveling apparatus <NUM> and the permanent magnets 37a, 37b, 37c provided in the second endless-track traveling apparatus <NUM> are attracted by the stator core <NUM>, without making contact with the stator core <NUM>. Because the permanent magnet 37b is attracted by the stator core <NUM>, each of the crawler belts <NUM> and <NUM> provided in the first endless-track traveling apparatus <NUM> and the second endless-track traveling apparatus <NUM>, respectively, makes contact with the stator core <NUM> while being pressed to the stator core <NUM>. When in this situation, the motor <NUM> is driven, each of the crawler belts <NUM> and <NUM> travels while being folded at the respective outer circumferential surfaces of the driving-side pulley 33a and the driven-side pulley 33b, so that each of the crawler belts <NUM> and <NUM> can enter the electric power generator in the axle direction and can travel therein.

As is well known, the stator of the electric power generator has the stator core <NUM> configured with magnetic steel sheets, a coil <NUM> inserted into two or more slots formed at even intervals in the stator core <NUM>, and a resin member <NUM> for pressing the coil <NUM>.

Because due to attractive force of each of the permanent magnets 37a, 37b, and 37c that are attracted by the stator core <NUM>, each of the crawler belts <NUM> and <NUM> is pressed to the stator core <NUM> and is driven while making contact with the stator core <NUM>, the first endless-track traveling apparatus <NUM> and the second endless-track traveling apparatus <NUM> travel on the inner circumferential surface of the stator core <NUM> of the electric power generator. The traveling body <NUM> as an inspection robot for the electric power generator travels without straying away from the inner circumferential surface of the stator core <NUM> configured with magnetic steel sheets; then, the traveling body <NUM> travels while determining whether or not any abnormality exists in the electric power generator, by use of the sensor or the like mounted in the sensor mounting unit <NUM>. In this situation, the traveling direction is adjusted by the difference between the respective speeds of the crawler belts <NUM> and <NUM> of the first endless-track traveling apparatus <NUM> and the second endless-track traveling apparatus <NUM>, respectively, so that the traveling body <NUM> travels while performing rectilinear correction.

No attractive force to be produced by each of the permanent magnets 37a, 37b, and 37c occurs on the resin member <NUM> inserted into the slot of the stator core <NUM>; therefore, when the first endless-track traveling apparatus <NUM> and the second endless-track traveling apparatus <NUM> of the traveling body <NUM> travel on the stator core <NUM> configured with magnetic steel sheets, they can travel without dropping from the stator. It may be allowed that in order to facilitate the travel of each of the first endless-track traveling apparatus <NUM> and the second endless-track traveling apparatus <NUM>, a guide member is mounted on the protrusion portion of the stator core <NUM> of the electric power generator so that there is provided a mechanism for preventing the traveling body <NUM> from dropping from the stator core <NUM>.

In such a way as described above, the inspection on the electric power generator is performed by making the traveling body <NUM> travel in the axle direction of the electric power generator; when the travel in the axle direction of the electric power generator ends, the traveling body <NUM> is pulled out from the electric power generator and the circumferential position in the electric power generator is changed; then, the traveling body <NUM> is made to travel in the axle direction of the electric power generator. In such a way as described above, the inspection by means of the traveling body <NUM> is performed over the all circumference of the electric power generator.

<FIG> is a cross-sectional view of the endless-track traveling apparatus according to Embodiment <NUM> of the present invention at a time when it travels; <FIG> illustrates a traveling-direction cross section of the second endless-track traveling apparatus <NUM>. <FIG> is a partial cross-sectional view of the endless-track traveling apparatus according to Embodiment <NUM> of the present invention at a time when it travels. As illustrated in each of <FIG> and <FIG>, with regard to the stator core <NUM>, configured with magnetic steel sheets, of the electric power generator, two or more magnetic protrusion portions 5a, 5b, 5c, 5d, 5e, 5f, and <NUM> exist at even intervals in the stator core <NUM> in the axle direction, when described in detail; respective cooling spaces are formed between the magnetic protrusion portions 5a, 5b, 5c, 5d, <NUM>, 5f, and <NUM>. The respective magnetic protrusion portions 5a, 5b, 5c, 5d, 5e, 5f, and <NUM> are arranged continuously and at predetermined intervals in the stator core in the axle direction; although the radial-direction height of the stator core is one and the same, there exist portions whose axle-direction widths are different from one another.

In order to make the traveling body <NUM> travel in the electric power generator configured in such a way as described above, it is required that the traveling body <NUM> travels in such a way that the first endless-track traveling apparatus <NUM> and the second endless-track traveling apparatus <NUM> are prevented from being trapped by the respective spaces existing between the magnetic protrusion portions 5a, 5b, 5c, 5d, 5e, 5f, and <NUM>. Therefore, as described above, in the endless-track traveling apparatus according to Embodiment <NUM> of the present invention, the flat portion 32a of the planar member <NUM> presses the crawler belt <NUM>, from the inside to the outside thereof, to the traveling surface. Because of this configuration, the inner circumferential surface of the crawler belt <NUM> makes contact with the flat portion 32a of the planar member <NUM> in the range of the length dimension of the flat portion 32a of the planar member <NUM>.

In this situation, the length dimension of the flat portion 32a of the planar member <NUM> has a magnitude that covers at least three adjacent magnetic protrusion portions among the magnetic protrusion portions 5a, 5b, 5c, 5d, 5e, 5f, and <NUM> existing side by side in the axle direction on the inner circumferential surface of the stator core <NUM>. Accordingly, because the crawler belt <NUM> makes parallel contact with the surface of the stator core <NUM> at three or more points, the endless-track traveling apparatus can be downsized and can travel stably.

It may be also allowed that other three or more pulleys are arranged between the driving-side pulley 33a and the driven-side pulley 33b inside the crawler belt <NUM> so that the inside of the crawler belt <NUM> is held by the three or more pulleys; however, in that case, it is required to enlarge the diameter of the pulley or to provide a great number of pulleys in consideration of the case where the size of each of the respective cooling spaces existing between the magnetic protrusion portions 5a, 5b, 5c, 5d, 5e, 5f, and <NUM> is larger than the size of a single pulley. As a result, it becomes difficult to dispose the control board <NUM> or the endless-track traveling apparatus is upsized because the thickness or the overall length thereof becomes larger.

When the thicknesses of the first endless-track traveling apparatus <NUM> and the second endless-track traveling apparatus <NUM> increase, it may become impossible to insert the traveling body <NUM> into the space between the rotor <NUM> and the stator core <NUM> of the electric power generator; moreover, when the thicknesses of the first endless-track traveling apparatus <NUM> and the second endless-track traveling apparatus <NUM> increase, interference with the retaining ring of the electric power generator may occur at the position where the traveling body <NUM> is inserted into the electric power generator and hence it becomes impossible to insert the traveling body <NUM> into the electric power generator; therefore, it becomes impossible to perform inspection on the electric power generator.

As described above, the traveling body according to Embodiment <NUM> of the present invention makes it possible to downsize and thin the first endless-track traveling apparatus <NUM> and the second endless-track traveling apparatus <NUM>; moreover, the endless-track traveling apparatuses are not trapped in the space in the traveling surface so as to become unable to travel and hence the endless-track traveling apparatuses can travel stably; therefore, detection of an abnormality or the like by the sensor does not become impossible.

Meanwhile, it is conceivable that in order to prevent the travel from becoming difficult due to friction or hooking between the crawler belt <NUM> and the planar member <NUM>, the output torque of the motor <NUM> is increased; however, in order to increase the output torque of the motor <NUM>, the motor <NUM> should be upsized. As a result, the endless-track traveling apparatus is upsized.

Accordingly, in the endless-track traveling apparatus according to Embodiment <NUM> of the present invention, in order to prevent the crawler belt <NUM> from becoming difficult to travel due to friction between the crawler belt <NUM> and the planar member <NUM>, coating processing for decreasing the friction coefficient is applied to the surface, of the flat portion 32a of the planar member <NUM>, that makes contact with the crawler belt <NUM>. As a result, the friction resistance between the crawler belt <NUM> and the flat portion 32a of the planar member <NUM> is suppressed and hence the travel of the crawler belt <NUM> is facilitated, so that it is made possible to downsize the endless-track traveling apparatus without upsizing the motor. It may be allowed that instead of applying the coating processing to the flat portion 32a, a sheet formed of a low-friction material is pasted on the surface, of the flat portion 32a, that makes contact with the crawler belt <NUM>.

Furthermore, two or more teeth for transferring torque are provided in each of the outer circumferential surfaces 33a1 and 33b1 of the driving-side pulley 33a and the driven-side pulley 33b, respectively, and recess portions 31a1 for engaging with these teeth are provided in the crawler belt <NUM>; however, in some cases, the recess portion 31a1 of the crawler belt <NUM> is hooked to the end portion of the planar member <NUM> and hence the travel of the crawler belt <NUM> becomes difficult.

Therefore, in the endless-track traveling apparatus according to Embodiment <NUM> of the present invention, the first inclination portion 32b1 and the second inclination portion 32b2 that gradually part from the crawler belt <NUM> are formed at both the respective end portions of the planar member <NUM>. This configuration makes it possible to prevent the recess portion 31a1 of the crawler belt <NUM> from being hooked to the end portion of the planar member <NUM> and hence the travel of the crawler belt <NUM> is facilitated, so that it is made possible to downsize the endless-track traveling apparatus without upsizing the motor. It may be allowed that the foregoing coating processing is applied to at least each of the surfaces, of the first inclination portion 32b1 and the second inclination portion 32b2, that face the crawler belt <NUM> or the sheet formed of a low-friction material is pasted thereon.

It is required that in order to prevent slipping, the friction coefficient of the surface, of the crawler belt <NUM>, that makes contact with the traveling surface is made large. In contrast, the surface, of the crawler belt <NUM>, at the side where the engagement with the teeth provided in the driving-side pulley 33a and the driven-side pulley 33b is implemented requires a high strength so that stable engagement with the teeth is performed. Thus, in the endless-track traveling apparatus according to according to Embodiment <NUM> of the present invention, the hardness of the rubber, of the crawler belt <NUM>, at the side where contact with the traveling surface is implemented is made low so that the friction coefficient is increased, and the hardness of the rubber, of the crawler belt <NUM>, at the side where the engagement with the teeth provided in the driving-side pulley 33a and the driven-side pulley 33b is implemented is made high, so that the foregoing stable engagement is performed.

In the foregoing explanation, the second endless-track traveling apparatus <NUM> illustrated in <FIG> has mainly be described; however, the first endless-track traveling apparatus <NUM> is formed in the same manner.

As described above, in the endless-track traveling apparatus according to Embodiment <NUM> of the present invention, the size of the motor is not enlarged; thus, the endless-track traveling apparatus can be thinned and downsized. Thus, the inspection robot as a traveling body equipped with the endless-track traveling apparatus can perform stable travel even for the cooling groove in the stator core of the electric power generator, and the motor size does not become large; therefore, the robot becomes thin and small-size.

<FIG> is a cross-sectional view of an endless-track traveling apparatus according to Embodiment <NUM> of the present invention at a time when it travels. In <FIG>, the stator core <NUM> of an electric power generator is situated at the upper side of the drawing; the rotor <NUM> is situated at the lower side of the drawing. The endless-track traveling apparatus according to Embodiment <NUM> of the present invention is provided with a first planar member <NUM> and a second planar member <NUM> that are each formed in the same manner as the planar member in the endless-track traveling apparatus according to foregoing Embodiment <NUM>.

In <FIG>, with the crawler belt <NUM> in contact with the surface of the rotor <NUM> of the electric power generator, the second endless-track traveling apparatus <NUM> travels in the axle direction of the electric power generator. The first planar member <NUM> corresponds to the planar member <NUM> in the endless-track traveling apparatus <NUM> according to Embodiment <NUM> and is provided at the side, in the crawler belt <NUM>, that faces the stator core <NUM> of the electric power generator. The second planar member <NUM> is provided at the side, in the crawler belt <NUM>, that faces the rotor <NUM> of the electric power generator.

In each of <FIG> and foregoing <FIG>, the first planar member <NUM> has a flat portion 321a that makes contact with the inner circumferential surface of one of the two portions (the upper portion in <FIG>), of the crawler belt <NUM> existing between the driving-side pulley 33a and the driven-side pulley 33b, that face each other.

The flat portion 321a of the first planar member <NUM> makes contact with the inner circumferential surface of the crawler belt <NUM> at a position at the traveling subject <NUM> side with respect to the virtual straight line X1 that connects the vertex A1, at the traveling subject <NUM> (e.g., a traveling surface) side, in the outer circumferential surface 33a1 of the driving-side pulley 33a and the vertex B1, at the traveling subject <NUM> side, in the outer circumferential surface 33b1 of the driven-side pulley 33b. Accordingly, the crawler belt <NUM> is pressed from the inside to the outside by the first planar member <NUM> and is exposed to the outside through the through-hole <NUM> provided in the covering portion <NUM> so as to make contact with the traveling subject <NUM>.

The first planar member <NUM> disposed inside the crawler belt <NUM> is provided with the flat portion 321a that makes contact with the inner circumferential surface of the driving-side pulley 33a, a first inclination portion 321b1 connected with one of the end portions of the flat portion 321a, and a second inclination portion 321b2 connected with the other one of the end portions of the flat portion 321a. The first inclination portion 321b1 is formed in such a way that the distance between the first inclination portion 321b1 and the inner circumferential surface of the crawler belt <NUM> becomes larger as the first inclination portion 321b1 approaches the driving-side pulley 33a more. The second inclination portion 321b2 is formed in such a way that the distance between the second inclination portion 321b2 and the inner circumferential surface of the crawler belt <NUM> becomes larger as the second inclination portion 321b2 approaches the driven-side pulley 33b more.

The second planar member <NUM> has a flat portion 322a that makes contact with the inner circumferential surface of the other one of the two portions (the lower portion in <FIG>, the upper portion of <FIG>), of the crawler belt <NUM> existing between the driving-side pulley 33a and the driven-side pulley 33b, that face each other.

The flat portion 322a of the second planar member <NUM> makes contact with the inner circumferential surface of the crawler belt <NUM> at a position at a traveling subject <NUM> side with respect to a virtual straight line X2 that connects a vertex A2, at the traveling subject <NUM> (e.g., a traveling surface) side, in the outer circumferential surface 33a1 of the driving-side pulley 33a and a vertex B2, at the traveling subject <NUM> side, in the outer circumferential surface 33b1 of the driven-side pulley 33b. Accordingly, the crawler belt <NUM> is pressed from the inside to the outside by the second planar member <NUM> and is exposed to the outside through the through-hole <NUM> provided in the base portion <NUM> so as to make contact with the traveling subject <NUM>.

The second planar member <NUM> disposed inside the crawler belt <NUM> is provided with the flat portion 322a that makes contact with the inner circumferential surface of the driving-side pulley 33a, a first inclination portion 322b1 connected with one of the end portions of the flat portion 322a, and a second inclination portion 322b2 connected with the other one of the end portions of the flat portion 322a. The first inclination portion 322b1 is formed in such a way that the distance between the first inclination portion 322b1 and the inner circumferential surface of the crawler belt <NUM> becomes larger as the first inclination portion 322b1 approaches the driving-side pulley 33a more. The second inclination portion 322b2 is formed in such a way that the distance between the second inclination portion 322b2 and the inner circumferential surface of the crawler belt <NUM> becomes larger as the second inclination portion 322b2 approaches the driven-side pulley 33b more.

The endless-track traveling apparatus according to Embodiment <NUM> of the present invention configured in such a manner as described above is utilized, for example, as illustrated in foregoing <FIG>, as one of a pair of endless-track traveling apparatuses of the traveling body <NUM> configured as an inspection robot for an electric power generator.

Even in the case where while, as Embodiment <NUM>, traveling on the inner circumferential surface of the stator core <NUM> of the electric power generator, the traveling body according to Embodiment <NUM> of the present invention drops, for some causes, from the inner circumferential surface of the stator core <NUM> to the outer circumferential surface of the rotor <NUM>, the crawler belt <NUM> can travel on the surface of the rotor <NUM>, because the second planar member <NUM> is provided at the side, of the crawler belt <NUM>, that faces the rotor <NUM> and hence the crawler belt <NUM> protrudes toward the rotor <NUM> through the through-hole <NUM> of the base portion <NUM>.

Accordingly, when the endless-track traveling apparatus according to Embodiment <NUM> is utilized as the traveling apparatus of a traveling body configured as an inspection robot for an electric power generator, the traveling body can travel on the surface of the rotor even when a failure such as dropping from the stator core occurs; on top of that, a thin and small-size traveling body can be obtained.

In the endless-track traveling apparatus according to Embodiment <NUM> of the present invention, the respective crawler belts protrude at one and the other one of the surfaces that are in a front-and-back relation; therefore, there can be obtained not only a traveling body as an inspection robot for an electric power generator but also a traveling body that can travel in a narrow place while performing switching between the front surface and the back surface of the endless-track traveling apparatus.

In the endless-track traveling apparatus <NUM>, illustrated in <FIG>, according to Embodiment <NUM> of the present invention, the respective crawler belts protrude at one and the other one of the surfaces that are in a front-and-back relation; however, it may be allowed that the first planar member <NUM> and the second planar member <NUM> are integrally fixed to each other and that a switching apparatus is provided for switching the respective setting positions of the first planar member <NUM> and the second planar member <NUM> so that the crawler belt <NUM> protrudes through only one of the surfaces, as may be necessary. Alternatively, it may be allowed to provide a switching apparatus for switching the setting positions of each of the first planar member <NUM> and the second planar member <NUM>.

In the endless-track traveling apparatus according to Embodiment <NUM> of the present invention, each of the first planar member <NUM> and the second planar member <NUM> is configured in the same manner as the planar member <NUM> in the endless-track traveling apparatus according to Embodiment <NUM>; the crawler belt <NUM> in the endless-track traveling apparatus according to Embodiment <NUM> is configured in the same manner as the crawler belt <NUM> in the endless-track traveling apparatus according to Embodiment <NUM>.

Claim 1:
An endless-track traveling apparatus comprising:
a first pulley (33a) and a second pulley (33b) that are arranged in such a way that the respective center axes thereof are in parallel with each other;
a motor (<NUM>) that drives at least one of the first pulley (33a) and the second pulley (33b); and
an endless track (<NUM>) that is wound over an outer circumferential surface of the first pulley (33a) and an outer circumferential surface of the second pulley (33b), that is driven by the at least one of the pulleys rotated by being driven by the motor (<NUM>), and that travels over the first pulley (33a) and the second pulley (33b),
wherein an outer circumferential surface of the endless track (<NUM>) is configured such that it makes contact with a traveling subject (<NUM>) so that based on the travel of the endless track (<NUM>), the endless-track traveling apparatus travels on the traveling subject (<NUM>),
wherein there is provided a planar member (<NUM>) that is disposed in a space surrounded by the endless track (<NUM>) and has a flat portion (32a) that makes contact with an inner circumferential surface of at least one of two portions, of the endless track (<NUM>) existing between the first pulley (33a) and the second pulley (33b), that face each other,
wherein the flat portion (32a) of the planar member (<NUM>) makes contact with the inner circumferential surface of the endless track (<NUM>) at a position at the traveling subject side with respect to a virtual straight line (X1) that connects a vertex (A1), at the traveling subject side, in the outer circumferential surface (33a1) of the first pulley (33a) and a vertex(B1), at the traveling subject side, in the outer circumferential surface (33b1) of the second pulley (33b),
wherein at least part of the outer circumferential surface, of the endless track (<NUM>), that faces the inner circumferential surface being in contact with the flat portion (32a) of the planar member (<NUM>) is configured such that it makes contact with the traveling subject (<NUM>),
characterized in that the endless track (<NUM>) is formed in such a way that the hardness of the inner circumferential surface is larger than the hardness of the outer circumferential surface.