Tracked vehicles

Abstract

It must be capable of overcoming obstacles that exceed the radius of the drive wheel or idler wheel. [Solution] A tracked vehicle 1 comprising a vehicle body 3, a tracked running gear 5 suspended on the vehicle body 3, and a motor 7 that provides driving force to the tracked running gear 5, wherein the tracked running gear 5 comprises a shaft 51 that is rotated by the driving force, a drive wheel 52 and two idler wheels 53, 54 arranged at equal intervals in the circumferential direction of the shaft 51 with respect to the shaft 51, a transmission member (sprockets 512, 521 and chain 13) that transmits driving force from the shaft 51 to the drive wheel 52 and rotates the drive wheel 52, and a track 55 that is wrapped around the drive wheel 52 and the idler wheels 53, 54 and driven by the rotating drive wheel 52, and when the tracked running gear 5 comes into contact with an obstacle S, the tracked running gear 5 rotates around the shaft 51 by the shaft 51 that is rotated by the driving force.

Description

Technical Field

[0001] The present invention relates to a crawler-type traveling vehicle including a vehicle body, a crawler-type traveling device suspended from the vehicle body, and a drive source that applies a driving force to the crawler-type traveling device.

Background Art

[0002] When a vehicle travels on uneven ground such as snow or mud, it is required to reduce the ground pressure so that the vehicle does not sink into the snow or mud. For this reason, vehicles traveling on uneven ground are generally vehicles equipped with a crawler-type traveling device capable of reducing the ground pressure (for example, a snow vehicle, etc., hereinafter referred to as a crawler-type traveling vehicle).

[0003] As the crawler-type traveling device, for example, a triangular crawler traveling device disclosed in Patent Document 1 and Patent Document 2 is known. The crawler traveling device disclosed in Patent Document 1 and Patent Document 2 includes a crawler, a starting wheel that applies a driving force to the crawler, two idler wheels located below the starting wheel, and an idler that rotatably supports the driving wheel and the idler wheels, and the crawler is wound around the starting wheel and the two idler wheels.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] A crawler-type traveling vehicle equipped with the above-described triangular crawler-type traveling device travels on uneven ground. However, when there are obstacles or steps (hereinafter collectively referred to as obstacles) on the ground surface to be traveled that are larger than the radius of the starting wheel or the idler wheel, there is a problem that the vehicle cannot overcome the obstacles.

[0006] The present invention aims to solve the above-mentioned problems and to provide a tracked vehicle capable of overcoming obstacles exceeding the radius of the drive wheel or idler wheel. [Means for solving the problem]

[0007] To solve the above problems, the tracked vehicle of the present invention has the following configuration.

[0008] (1) A tracked vehicle comprising a vehicle body, a tracked running gear suspended on the vehicle body, and a drive source that provides driving force to the tracked running gear, wherein the tracked running gear comprises a shaft that is rotated by the driving force, a drive wheel and two idler wheels arranged at equal intervals in the circumferential direction of the shaft with respect to the shaft, a transmission member that transmits the driving force from the shaft to the drive wheel to rotate the drive wheel, and a track that is wrapped around the drive wheel and the idler wheel and driven by the rotating drive wheel, and is characterized in that when the tracked running gear comes into contact with an obstacle, the tracked running gear rotates around the shaft by the shaft that is rotated by the driving force.

[0009] (2) In the tracked vehicle described in (1), it is preferable that the transmission member comprises a first gear provided on the shaft and a second gear provided on the drive wheel that is smaller than the first gear, and that the gear ratio of the first gear to the second gear is the same as the ratio of the maximum distance from the center of the shaft to the outer surface of the track to the minimum distance from the center of the drive wheel to the outer surface of the track. [Effects of the Invention]

[0010] According to the tracked vehicle described above, it is possible to overcome obstacles that exceed the radius of the drive wheel or idler wheel. [Brief explanation of the drawing]

[0011] [Figure 1]This is a side view of a tracked vehicle according to this embodiment. [Figure 2] This is a bottom view (viewed from the bottom of the paper in Figure 1) of the tracked vehicle according to this embodiment. [Figure 3] This is a front view of the tracked vehicle according to this embodiment (viewed from the left side of the page in Figure 1). [Figure 4] This is an enlarged view of the tracked running gear 5. [Figure 5] Figures (a)-(d) show how a tracked vehicle overcomes an obstacle S on the ground surface G. [Figure 6] This is a side view of a tracked vehicle showing one of its four tracked running gears overcoming an obstacle. [Figure 7] This diagram shows one of the four tracked running gears of a tracked vehicle overcoming an obstacle, viewed from the front of the vehicle in the direction of travel (left side in Figure 6). [Figure 8] This figure shows a modified version of a tracked running gear. [Figure 9] This is a cross-sectional view AA in Figure 4. [Modes for carrying out the invention]

[0012] Embodiments of the tracked vehicle according to the present invention will be described in detail with reference to the drawings. Figure 1 is a side view of the tracked vehicle 1 according to this embodiment. In Figure 1, the left side of the paper is the front of the tracked vehicle 1. Figure 2 is a bottom view of the tracked vehicle 1 according to this embodiment (viewed from the bottom of the paper in Figure 1). Figure 3 is a front view of the tracked vehicle 1 according to this embodiment (viewed from the left side of the paper in Figure 1). Figure 4 is an enlarged view of the tracked vehicle 5. Note that the drawings used in this explanation are simplified for illustrative purposes and do not accurately represent the shape, dimensions, etc.

[0013] The tracked vehicle 1 according to this embodiment (hereinafter simply referred to as "vehicle 1") mainly consists of a vehicle body 3 and four tracked running gears 5A, 5B, 5C, and 5D, as shown in Figures 1-3. In the following description, the tracked running gears 5A, 5B, 5C, and 5D will be simply referred to as "tracked running gear 5" unless otherwise specified.

[0014] Body 3 is equipped with a driver's cab (not shown) for operating vehicle 1. Motors 7A, 7B, 7C, and 7D, which provide driving force to the tracked running gears 5A, 5B, 5C, and 5D, are fixed to body 3. In the following description, motors 7A, 7B, 7C, and 7D will be simply referred to as motor 7 unless otherwise specified.

[0015] The motor 7 comprises a main body 71, an output shaft 72 extending from the main body 71, and a sprocket 73 fixed to the output shaft 72. A chain 11 is wrapped around the sprocket 73. As a result, the motor 7 can transmit driving force to the tracked running gear 5 via the chain 11. In other words, the motor 7 is a drive source that provides driving force to the tracked running gear 5. More specifically, motor 7A is a drive source for the tracked running gear 5A, motor 7B is a drive source for the tracked running gear 5B, motor 7C is a drive source for the tracked running gear 5C, and motor 7D is a drive source for the tracked running gear 5D.

[0016] The crawler traveling devices 5A, 5B, 5C, and 5D are suspended from the vehicle body 3 by axle suspension type suspensions 9A and 9B. The front-back direction position of the crawler traveling devices 5A, 5B, 5C, and 5D with respect to the vehicle body 3 is not particularly limited. However, it is preferable that the crawler traveling devices 5A and 5B on the front side in the traveling direction (the left side of the paper surface in FIGS. 1 and 2) do not protrude forward beyond the leading end of the vehicle body 3, so that there is no so-called overhang. This makes it easier for the vehicle 1 to cross over the obstacle S. Also, the height direction position (the vertical direction of the paper surface in FIG. 1) of the crawler traveling devices 5A, 5B, 5C, and 5D with respect to the vehicle body 3 is not particularly limited. However, it is preferable that the vehicle body 3 is located above the center of the crawler traveling devices 5A, 5B, 5C, and 5D (the center of the shaft body 51 described later). This makes it easier for the vehicle 1 to cross over the obstacle S.

[0017] The crawler traveling device 5 mainly includes a shaft body 51, a driving wheel 52, two idler wheels 53 and 54, and a crawler 55, and is formed in a substantially triangular shape. Also, the size of the crawler traveling device 5 is not particularly limited. For example, the height H (see FIG. 3) is about the same size as the height of the vehicle body 3 and is about 1 m. Also, the width W (see FIG. 3) is about 200 mm.

[0018] The shaft body 51 is rotatably supported on the axle 91 via a bearing 92 (see FIG. 9). Also, the shaft body 51 is provided with a sprocket 511 and a sprocket 512 (an example of a transmission member and a first gear) coaxially. The above-described chain 11 is wound around the sprocket 511.

[0019] The driving wheel 52 and the two idler wheels 53 and 54 are arranged at equal intervals in the circumferential direction of the shaft body 51. Also, the distance from the center CL11 of the shaft body 51 to the center CL12 of the driving wheel 52, the distance from the center CL11 of the shaft body 51 to the center CL13 of the idler wheel 53, and the distance from the center CL1 of the shaft body 51 to the center CL14 of the idler wheel 54 are all the same, and they are arranged in a substantially equilateral triangle.

[0020] As shown in Figure 9, the hub 15 is mounted on the outside of the vehicle 1 in a manner that covers the tracked running gear 5, so as to pivotally support the drive wheel 52 and the two idler wheels 53 and 54 from the shaft 51, in order to maintain the distance between the drive wheel 52 and the two idler wheels 53 and 54. Note that the hub 15 shown in Figure 9 is omitted in other drawings.

[0021] The hub 15 is rotatably supported at the axial end of the axle 91 via a bearing 93. The hub 15 also rotatably supports the drive wheel 52 via a bearing 151 and the idler wheel 53 (54) via a bearing 152 on the radially outer side of the axle 91. As a result, during the rotation and revolution movements of the tracked running gear 5 (details will be described later), the drive wheel 52 and the idler wheels 53, 54 can rotate while maintaining their distance from each other.

[0022] A bearing 93 is interposed between the axle 91 and the hub 15, and bearings 151 and 152 are interposed between the hub 15 and the drive wheel 52 and idler wheel 53 (54). This design ensures that the tracked running gear 5 operates smoothly whether it is rotating or revolving (details will be described later). However, a restricting member may be provided to prevent the tracked running gear 5 from mistakenly revolving around the axle 51 during rotation. Examples of such restricting members include friction transmission members such as clutches.

[0023] The drive wheel 52 is equipped with a sprocket 521 (an example of a transmission member and a second gear) on its inner side in the width direction of the vehicle 1. The position of the sprocket 521 in the width direction of the vehicle 1 is the same as that of the sprocket 512, and a chain 13 (an example of a transmission member) is wrapped around the sprockets 512 and 521. The track 55 is made of rubber, for example, and is wrapped around the drive wheel 52 and two idler wheels 53 and 54.

[0024] The tracked running gear 5, configured as described above, can operate as follows: The shaft 51 receives driving force from the motor 7 via the chain 11 through the sprocket 511. This causes the shaft 51 to rotate. The rotating shaft 51 then receives driving force transmitted from the sprocket 512 via the chain 13 through the sprocket 521. This causes the drive wheel 52 to rotate around its own axis, driving the track 55. The idler wheels 53 and 54 rotate around their own axes in response to the driving force of the track 55. In the following description, the rotation of the drive wheel 52 and the idler wheels 53 and 54 around their respective axes is referred to as the rotational movement of the tracked running gear 5.

[0025] Furthermore, the tracked running gear 5 can rotate as a single unit around the axle 51, that is, the drive wheel 52 and idler wheels 53, 54 can also rotate around the axle 51. In the following description, the rotation of the drive wheel 52 and idler wheels 53, 54 around the axle 51 is referred to as the orbital motion of the tracked running gear 5.

[0026] The tracked running gear 5 can overcome obstacles S by automatically switching between the above-mentioned rotational and revolutionary movements. Specifically, this will be explained using Figures 5(a)-(d), 6, and 7. Figures 5(a)-(d) show the tracked running gear 5 overcoming obstacles S on the ground surface G. In Figure 5, the left direction of the paper is the direction of travel for the tracked running gear 5. Figure 6 is a view from the side of vehicle 1 showing one of the four tracked running gears 5, 5A, overcoming obstacles S. In Figure 6, the left direction of the paper is the direction of travel for vehicle 1. Figure 7 is a view from the front of vehicle 1 in the direction of travel (left side of the paper in Figure 6) showing one of the four tracked running gears 5, 5A, overcoming obstacles S.

[0027] As shown in Figure 5(a), when vehicle 1 travels on uneven ground G, it moves by the rotation of the tracked running gear 5. Then, as shown in Figure 5(b), when the tracked running gear 5 comes into contact with an obstacle S on the ground G, the drive of the tracks 55 is stopped by the obstacle S, making it impossible for the tracked running gear 5 to rotate. As a result, the tracked running gear 5 automatically switches to orbital movement, and as shown in Figures 5(c)-(d), the tracked running gear 5 overcomes the obstacle S by orbiting. Then, as shown in Figure 5(d), once the obstacle S has been overcome and there are no more obstacles in the direction of travel of the tracked running gear 5 that would stop the drive of the tracks 55, vehicle 1 can once again move by the rotation of the tracked running gear 5.

[0028] As described above, when the tracked running gear 5 comes into contact with an obstacle S, the shaft 51, which is rotated by the driving force of the motor 7, causes the tracked running gear 5 to rotate around the shaft 51 (i.e., the tracked running gear 5 revolves), making it possible for the vehicle 1 to overcome obstacles S that exceed the radius of the drive wheels 52 or idler wheels 53, 54.

[0029] Furthermore, in the tracked running gear 5, the gear ratio of sprocket 512 and sprocket 521 is the same as the ratio of the maximum distance R2 from the center of the shaft 51 to the outer surface of the track 55 to the minimum distance R1 from the center of the drive wheel 52 to the outer surface of the track 55. This makes it possible to make the speed of the revolution (i.e., the speed at which the drive wheel 52 and idler wheels 53, 54 rotate around the shaft 51 as the center of rotation) and the speed of the rotation (i.e., the speed at which the track 55 is driven by the drive wheel 52) the same. Because the speed of the revolution and the speed of the rotation are the same, even if some of the four tracked running gears 5A, 5B, 5C, and 5D are performing revolutionary movements to overcome obstacles S, while the others are performing rotational movements, the vehicle 1's running speed does not fluctuate, and it is possible to smoothly overcome obstacles S.

[0030] Specifically, as shown in Figures 6 and 7, if, among the tracked running gears 5A, 5B, 5C, and 5D, only tracked running gear 5A performs an orbital motion to overcome the obstacle S, while the other tracked running gears 5B, 5C, and 5D make contact with the ground surface G and perform a rotational motion, then since the speed of the orbital motion and the rotational motion of tracked running gear 5 are the same, it is possible to smoothly overcome the obstacle S without any fluctuation in the vehicle 1's travel speed.

[0031] The steering method of vehicle 1 is not particularly limited, but for example, it is possible to use a pivot turning type, a super pivot turning type, a front-wheel steering type, a front and rear wheel steering type, an articulated type, etc.

[0032] A pivot turning system is a method of turning the vehicle 1 in place by driving one of the left or right tracks 55 (for example, driving one of the tracks 55 of the tracked running gears 5A and 5C, and the tracks 55 of the tracked running gears 5B and 5D). A super pivot turning system is a method of turning the vehicle 1 in place by driving the left and right tracks 55 in opposite directions at a constant speed (for example, driving the tracks 55 of the tracked running gears 5A and 5C and the tracks 55 of the tracked running gears 5B and 5D in opposite directions at a constant speed).

[0033] Front-wheel steering refers to a system in which the vehicle 1 is steered by manipulating the steering angle of the tracked running gears 5A and 5B on the front side of the vehicle body 3. Front and rear wheel steering refers to a system in which the vehicle 1 is steered by manipulating the steering angle of the tracked running gears 5A and 5B on the front side of the vehicle body 3, as well as manipulating the steering angle of the tracked running gears 5C and 5D on the rear side of the vehicle body 3.

[0034] An articulated steering system is a method in which the front and rear of the vehicle body 3 are connected by hinges or the like so that they can bend to the left and right, and the vehicle 1 is steered by manipulating the direction of this bending.

[0035] (A modified example of a tracked running gear) Next, regarding the tracked running gear 10, which is a modified version of the tracked running gear 5, we will explain only the differences from the tracked running gear 5 using Figure 8. Figure 8 is a diagram showing the modified tracked running gear 10.

[0036] As shown in Figure 8, the tracked running gear 10 is equipped with idler wheels 56 between the drive wheel 52 and the idler wheel 53, between the idler wheel 53 and the idler wheel 54, and between the idler wheel 54 and the drive wheel 52. These idler wheels 56 are auxiliary wheels that rotate in conjunction with the drive of the track 55. These idler wheels 56 are biased to the track 55 using known methods, maintaining the tension of the track 55. For example, although an elastic member 57 is used in Figure 8, it can be replaced with a hydraulic cylinder or an electric cylinder.

[0037] As described above, the tracked vehicle 1 according to this embodiment is (1) A tracked vehicle 1 comprising a vehicle body 3, a tracked running gear 5 suspended on the vehicle body 3, and a drive source (e.g., a motor 7) that provides driving force to the tracked running gear 5, wherein the tracked running gear 5 comprises a shaft 51 that is rotated by the driving force, a drive wheel 52 and two idler wheels 53, 54 arranged at equal intervals in the circumferential direction of the shaft 51 with respect to the shaft 51, a transmission member (e.g., sprockets 512, 521 and a chain 13) that transmits driving force from the shaft 51 to the drive wheel 52 and rotates the drive wheel 52, and a track 55 that is wrapped around the drive wheel 52 and the idler wheels 53, 54 and driven by the rotating drive wheel 52, and is characterized in that when the tracked running gear 5 comes into contact with an obstacle S, the tracked running gear 5 rotates around the shaft 51 by the shaft 51 that is rotated by the driving force.

[0038] (2) In the tracked vehicle 1 described in (1), it is preferable that the transmission member comprises a first gear (e.g., sprocket 512) provided on the shaft 51 and a second gear (e.g., sprocket 521) provided on the drive wheel 52 that is smaller than the first gear (sprocket 512), and that the gear ratio of the first gear (sprocket 512) and the second gear (sprocket 521) is the same as the ratio of the maximum distance R2 from the center of the shaft 51 to the outer surface of the track 55 to the minimum distance R1 from the center of the drive wheel 52 to the outer surface of the track 55.

[0039] According to the tracked vehicle 1 described above, it is possible to overcome obstacles S that exceed the radius of the drive wheel 52 or idler wheels 53, 54.

[0040] The embodiments described above are merely illustrative and do not limit the present invention in any way. Therefore, the present invention can naturally be improved and modified in various ways without departing from its essence. For example, although the track 55 is described as being made of rubber, it may be made of metal. Also, although sprockets 512, 521 and a chain 13 are used as members that transmit driving force from the shaft 51 to the drive wheel 52, they may be replaced with pulleys and a rubber belt, or the driving force may be transmitted by gear drive in which the gears on the shaft 51 and the gears on the drive wheel 52 are directly meshed.

[0041] Although the hub 15 is described as being attached from the outside of the vehicle 1, it is not limited to this and may be configured to be attached from the inside of the tracked running gear 5. In this case, by attaching a known steering device, it becomes possible to easily configure a front-wheel steering system or a front and rear wheel steering system.

[0042] Furthermore, while the distance from the center CL11 of the shaft 51 to the center CL12 of the drive wheel 52, the distance from the center CL11 of the shaft 51 to the center CL13 of the idler wheel 53, and the distance from the center CL11 of the shaft 51 to the center CL14 of the idler wheel 54 were assumed to be the same, they are not limited to this and may be variable. In particular, during the orbital movement of the tracked running gear 5, it is expected that a load will be placed on the tracks 55 when overcoming obstacles. In such cases, it is conceivable to make the aforementioned distance variable in order to relieve the load on the tracks 55 while enabling smooth orbital movement.

[0043] Furthermore, although the tracked vehicle 1 according to this embodiment is equipped with four tracked running gears 5A, 5B, 5C, and 5D, it may be equipped with four or more tracked running gears. [Explanation of symbols]

[0044] 1. Tracked vehicles 3. Vehicle Body 5A Tracked Running Gear 5B Tracked Running Gear 5C Tracked Running Gear 5D Tracked Running Gear 7. Motor (an example of a drive source) 13. Chain (an example of a transmission member) 51 Axis 52 Drive wheel 53 Idle Wheel 54 Idle Wheel 55 Tracks 512 Sprocket (Example of a transmission member and first gear) 521 Sprocket (an example of a transmission member and second gear)

Claims

1. A tracked vehicle comprising a vehicle body, a tracked running gear suspended on the vehicle body, and a drive source that provides driving force to the tracked running gear, The aforementioned tracked running gear, A shaft body rotated by the aforementioned driving force, Centered around the aforementioned shaft, the drive wheel and two idler wheels are arranged at equal intervals in the circumferential direction of the shaft, A transmission member that transmits the driving force from the shaft to the drive wheel and rotates the drive wheel, A track is wrapped around the drive wheel and the idler wheel, and is driven by the rotating drive wheel. To be equipped, When the tracked running gear comes into contact with an obstacle, the shaft, which is rotated by the driving force, causes the tracked running gear to rotate around the shaft. A tracked vehicle characterized by [feature].

2. In the tracked vehicle described in claim 1, The aforementioned transmission member is The shaft body comprises a first gear, The drive wheel is equipped with a second gear smaller than the first gear, To be equipped, The gear ratio of the first gear and the second gear is the same as the ratio of the maximum distance from the center of the shaft to the outer surface of the track to the minimum distance from the center of the drive wheel to the outer surface of the track. A tracked vehicle characterized by [feature].

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