JP4149192B2 - Traveling drive device for tracked vehicle - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a traveling drive device for a construction machine vehicle, such as a bulldozer or a hydraulic excavator, which mainly works on rough terrain, and more specifically relates to the durability of a sprocket for driving a crawler track. The present invention relates to a traveling drive device for a tracked vehicle having a function to enhance.
[0002]
[Prior art]
Conventionally, a traveling device in a track-type construction machine vehicle travels with a crawler belt formed in an endless shape wrapped around a sprocket and an idler incorporated in a driving device provided at a predetermined distance before and after the vehicle body. Have been to. The crawler belt includes a plurality of track links (hereinafter simply referred to as links) arranged on the left and right sides at predetermined intervals, bushes provided therebetween, and a plurality of connection pins inserted into the bushes to connect the links to each other. And a crawler plate is bolted on each of the left and right links to form an endless shape.
[0003]
As shown in FIG. 5, the traveling device including the crawler belt having such a configuration is driven by the sprocket 101 assembled to the drive wheel 100 of the driving device and the bush 108 of the crawler belt 105 being sequentially meshed during traveling. In the engagement, the bush 108 provided on the connecting pin 107 for connecting the link 106 of the crawler belt 105 and the teeth 102 of the sprocket 101 are engaged to transmit power. However, when the crawler belt 105 engaged with the sprocket 101 is moved to the ground surface side, the crawler plate is in contact with the ground and supports the vehicle body, so that the crawler belt 105 is wound around the sprocket 101 (the ground surface side). The push-up force acts through the bush 108 of the crawler belt 105 (which meshes with the sprocket teeth).
[0004]
[Problems to be solved by the invention]
For this reason, the tooth portion 102 of the sprocket 101 has not only the surface pressure against the bush 108 due to the rotational driving force but also the thrust load generated for supporting the vehicle body, the initial position where the bush 108 is sequentially engaged, and the tooth portion 102. The load due to slippage when moving away from the machine acts greatly. Further, the earth and sand to be rolled up when traveling on rough terrain enters into the meshing portion between the tooth portion 102 of the sprocket 101 and the bush 108 of the crawler belt 105, and the friction with the earth and sand becomes remarkable when the running operation is continued. The tooth portion 102 is worn heavily. In particular, in a tracked vehicle such as a bulldozer that repeatedly moves violently over a long period of time, the sprocket 101 is very worn out and often has to be replaced. Therefore, the replacement of the sprocket has a problem that not only the cost of the replacement part but also a lot of manpower is required for the replacement, and the work vehicle cannot be used during that time, so that the construction period is delayed.
[0005]
In addition, since the tooth portion 102 of the sprocket 101 of such a traveling drive device has a general sprocket tooth shape as shown in FIG. 5, in the meshed state with the bush 108 of the crawler belt 105, When the tooth portion 102 of the sprocket 101 and the bush 108 of the crawler belt 105 are engaged with each other during traveling, if the earth and sand may enter the link 106, the bush 108 and the tooth portion 102 are engaged. When fitting, rubbing with earth and sand will cause a large friction. Moreover, in the conventional sprocket teeth, the backlash at the meshing part between the tooth surface and the bushing is large, so if the driving operation that frequently moves forward and backward continues, the friction caused by the sand that enters the meshing part Since the occurrence of this is intense, tooth wear is severe and the power transmission function may be reduced, and the frequency of replacement is increased, so that it is required to improve durability.
[0006]
SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and is intended to improve the durability of a sprocket and to improve the ease of exchanging wear members and the transmission force transmission function of a sprocket. Is intended to provide.
[0007]
[Means for solving the problems and actions / effects]
In order to achieve the above-described object, a traveling drive device for a tracked vehicle according to the present invention includes:
In a traveling drive device for a tracked vehicle,
Teeth in the sprocket, while being slightly smaller tooth thickness than the arc length between the meshing track of the bush, on the side surface of the teeth is provided with a groove discharge mid-season in centripetal direction, the teeth of the groove sprocket It is characterized in that it is formed so as to expand from the original toward the mounting portion side .
[0008]
According to the present invention, the tooth thickness of the sprocket tooth portion of the power transmission mechanism in the crawler belt driving device is allowed to mesh with the mesh space portion between the bushes in the crawler belt link that is wound and driven. Therefore, the earth and sand that penetrates and adheres to the crawler belt link during driving acts to be pushed out when engaged with the sprocket teeth, and the non-contacting of the crawler plate is caused at this time. The earth and sand pushed to the ground side is discharged in the axial direction through the groove provided on the side surface of the tooth portion without being compacted by the tooth tip and the surface of the shoe plate. Therefore, it is possible to prevent the sand and sand from being engaged with the meshing surface of the bush and the tooth portion, thereby preventing the wear of both of them from becoming serious, and it is possible to increase the operational efficiency by reducing the replacement frequency of the sprocket. In addition, the tooth strength is increased by increasing the tooth thickness, and the gap between the bush and the tooth surface is small during forward and backward reversal operation during traveling, so that the reverse rotation can be instantaneously driven with less so-called play. As a traveling drive device for a work machine that frequently repeats advancing and retracting operations, there is an effect that the mobility can be improved.
[0009]
The groove of the exhaust dog days provided in the tooth portion side surface of the sprocket, so toward the mounting portion side is formed so as to be widened from the tooth root, engagement between the teeth and the track links of the sprocket When the earth and sand that penetrates into the link is discharged by the pressing force of the tooth tip on the non-ground surface side of the crawler belt, it is quickly discharged by reducing the resistance to the discharge side. The effect that the frictional resistance in the meshing part by earth and sand can be reduced is acquired.
[0010]
The sprocket may be composed of a plurality of segments divided at intermediate positions at which the bushes and teeth of the crawler belt do not mesh with each other, and may be detachably attached to the drive wheels ( second invention). In addition, the sprocket segment preferably includes a mounting portion that can be bolted from the outside to a hook-shaped mounting portion formed on the drive wheel ( third invention). This makes it easy to assemble or replace, sometimes has the effect of partially replacing the segments, and reducing manufacturing costs.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Next, a specific embodiment of the traveling drive device for a tracked vehicle according to the present invention will be described with reference to the drawings.
[0012]
FIG. 1 is a side view of a drive unit of a traveling drive device for a tracked vehicle according to the present invention. 2 is a sectional view taken along the line AA in FIG. 1, and FIG. 3 is an enlarged plan view taken along the line BB in FIG.
[0013]
A travel drive device 1 according to this embodiment includes a crawler belt 3 wound around an idler (not shown) and drive wheels 2 on both sides of a body frame as a lower traveling body in a tracked vehicle (not shown). The crawler belt 3 which is attached and receives the power transmitted from the engine (not shown) and is wound around the drive wheel 2 via the reduction gear mechanism 6 is driven. In this configuration, the relationship between the sprocket 20 that transmits power to the link 4 of the crawler belt 3 in the drive wheel 2 and the link 4 of the crawler belt will be described.
[0014]
The drive wheel 2 has a planetary gear speed reduction mechanism 6 supported at the end of the vehicle body frame with a well-known structure, a wheel 8 fixedly supported by the output shaft 7 and rotationally driven, and an outer periphery of the wheel 8 in a bowl shape. It is comprised with the cyclic | annular sprocket 20 with which the mounting part 8a formed is mounted | worn with a concentric circle.
[0015]
The wheel 8 is supported by a boss 6b of a casing 6a of the planetary gear reduction mechanism 6 via a rolling bearing 6c, and the output shaft of the planetary gear reduction mechanism 6 protrudes outside through the boss 6b. 7 (integrated with the carrier) are connected coaxially through a support ring 9 fitted and fixed by a spline key at the end. A plurality of sprocket mounting holes 11 are provided at a required radial position so as to be parallel to the axis at a predetermined pitch in the mounting portion 8a formed in a bowl shape.
[0016]
The sprocket 20 has a plurality of teeth, and as shown in FIG. 1, a bush that connects the link 4 between the tooth portion 21 and the tooth portion 21 (corresponding to a tooth valley). The locations where one 5 is located and the locations where two 5 are located are formed alternately so that the tooth thickness is increased. And the tooth part 21 which meshes with the bush 5 is set as the structure used as the part in which any one tooth part 21 and the bush 5 are received in the part in which the said bush 5 is received two. Therefore, as shown in FIG. 1, the bush 5 that does not contact the tooth portion 21 and the tooth surface are associated with each other so that a gap s that does not hinder driving is formed.
[0017]
The tooth portion 21 of the sprocket 20 has a tooth thickness dimension T that is slightly smaller than the arc length obtained by subtracting the diameter of the bush 5 from one pitch of the pin that substantially connects the link 4 of the crawler belt 3. It is formed flat. And the groove | channel 22 for earth removal of the width | variety is suitably formed in the side surface center part of the tooth | gear part 21 on both sides | surfaces. The groove 22 has a shape that widens from the tooth base toward the center of the wheel 8 (centripetal direction), so that earth and sand can be easily discharged.
[0018]
As shown in FIG. 1, the sprocket 20 of the present embodiment thus formed is formed into an intermittent tooth shape every two teeth, and is divided at an intermediate position in the tooth intermediate portion 23 to obtain four pieces. It consists of a combination of segments. Therefore, each sprocket segment 20a consists of the same shape. Each of the sprocket segments 20a has a stepped inner peripheral portion, and a rear side stepped portion of the hooked mounting portion 25 of the inner peripheral portion of the mounting portion 8a formed in the hooked shape of the wheel 8. A sprocket mounting hole 11 provided on the engagement surface of the hook-shaped mounting portion 8a of the wheel 8 by engaging with the outer periphery, and mounting of the mounting portion 25 provided at a pitch matching the sprocket mounting hole 11 Through a hole, a nut 27 is screwed into a fastening bolt 26 inserted from the rear surface and fastened and fixed.
[0019]
The travel drive device 1 of the present embodiment configured as described above receives power from the drive source and is decelerated to a required speed by the planetary gear mechanism 6, and the sprocket 20 rotates together with the wheel 8. The wound crawler belt 3 is driven to run. When the link 4 of the crawler belt 3 moves and the bush 5 of the connecting portion engages with the tooth portion 21 of the sprocket 20 and is driven, each tooth portion 21 except the spur tooth portion 24 of the sprocket has teeth in the rotational direction. The bush 5 meshes with the surface. Accordingly, with regard to the meshing between the sprocket 20 and the link 4 (bush 5), the four teeth are substantially meshed with the eight teeth, and the power is generated at the position where these teeth 21 are brought into contact with each other. Is transmitted. However, since each tooth portion 21 can have a tooth thickness dimension larger than that of a general sprocket tooth, power can be transmitted reliably. The bush 5 in a position where it does not mesh with the tooth portion 21 does not receive a driving force directly in the tooth forming space portion (intermittent portion 24), but an operation of connecting and moving the link 4 is performed.
[0020]
Thus, when the link 4 of the crawler belt 3 meshes with the tooth portion 21 of the sprocket 20, for example, even if the earth and sand are intruded and adhered to the non-grounding surface side of the crawler belt 3, particularly the space inside the link 4. Since the tooth thickness T of the tooth portion 21 of the sprocket 20 is increased and the gap when engaged with the bushes 5 and 5 positioned in the front and rear in the rotational direction is small, the earth and sand in the space portion in the link 4 is the tooth portion. Since the soil removal grooves 22 are provided on both side surfaces of the material 21, they are pushed back to the shoe plate 3 a side by the tooth tips 21 a and are pushed out along the soil removal grooves 22. Since the groove 22 has a shape that extends from the tooth root toward the center of the wheel 8, the earth and sand in the link inner space portion is easily pushed out when subjected to a pressing force, and the discharged soil is consolidated inside the groove 22. Never happen. Therefore, earth and sand can be reduced between the bush 5 and the tooth bottom 23, and the bush 5 and the tooth surface can be prevented from rubbing against each other by the earth and sand.
[0021]
Further, since the tooth portion 21 of the sprocket 20 is formed with a tooth thickness T larger than usual, the strength is increased, and it can be driven with a radial load and a traction load without any trouble. Therefore, it is not necessary to increase the diameter of the bush 5b or use an expensive material, and there is an advantage that the production cost on the crawler belt side can be reduced. Of course, the wear resistance of the sprocket 20 is improved and the frequency of replacement can be reduced.
[0022]
When the tooth portion 21 of the sprocket 20 is worn away and needs to be replaced after a long period of use, it is easy to disengage the divided sprocket segment 20a from the mounting bolt 26 and nut 27 to the wheel 8. Can be removed. In the fastening portion by the bolt 26 and the nut 27, each nut 27 is loosened on the front surface so that the fastening 20 can be released and the sprocket segment 20a can be removed. It can be easily replaced on site.
[0023]
FIG. 4 is an enlarged front view of the main part showing another embodiment of the sprocket. In this embodiment, the basic configuration is the same as that of the above embodiment, and the sprocket structure is partially different. Therefore, the same structural parts as those of the above embodiment are denoted by the same reference numerals as those described above, and the description thereof is omitted.
[0024]
In this embodiment, the sprocket 20A is formed with an interval between every other tooth, and a plurality of (e.g., 8) sprocket segments 20b divided at the intermediate position of each interval are configured. Each of these sprocket segments 20b is a stepped mounting portion 25 formed on the inner peripheral portion as in the above-described embodiment, and a stepped portion on the back is formed in a bowl shape formed on the outer periphery of the wheel 8. The bolts 26 and nuts 27 are fastened and fixed through the mounting holes provided so as to be engaged with the mounting portions 8a and match the sprocket mounting holes 11 provided on the wheel 8 side.
[0025]
Since the sprocket 20A of such an embodiment is substantially the same as the sprocket 20 of the above-described embodiment, the same effects as those of the above-described embodiment are achieved. In addition, in sprocket 20A of this embodiment, since sprocket segment 20b for every tooth is combined, even if the situation where it breaks by any chance should arise, it can respond by exchanging only the part concerned. There is. Further, since all the sprocket segments 20b are divided and formed on the basis of the tooth portion 21, the sprocket segments 20b can be produced under the same conditions in manufacturing, and there is also an advantage that handling on the work becomes easy.
[0026]
As described above, according to the present invention, in a sprocket that is configured to be exchangeable when worn by operation, a portion that wears under the influence of earth and sand during meshing drive with a crawler belt link (bush) is strengthened and discharged. Since the earth function is added, it is possible to obtain a traveling drive device that can withstand long-term use and extend the replacement time.
[Brief description of the drawings]
FIG. 1 is a side view of a drive unit of a traveling drive device for a tracked vehicle according to the present invention.
FIG. 2 is a cross-sectional view taken along the line AA of FIG.
FIG. 3 is an enlarged plan view taken along the line BB of FIG. 1;
FIG. 4 is an enlarged front view of a main part showing another embodiment of the sprocket.
FIG. 5 is a diagram illustrating a drive unit of an example of a travel drive device in a conventional tracked vehicle.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Travel drive device 2 Drive wheel 3 Crawler belt 3a Crawler plate 4 Crawler belt link 5 Bush 6 Planetary gear mechanism 8 Wheel 8a Mounting part 11 Sprocket mounting hole 20, 20A Sprocket 20a, 20b Sprocket segment 21 Sprocket tooth part 21a Tooth tip 22 Exhaust Groove for earth 23 Tooth bottom 25 Sprocket mounting part 26 Bolt

Claims (3)

In a traveling drive device for a tracked vehicle,
The tooth portion (21 ) of the sprocket (20) has a tooth thickness slightly smaller than the arc length between the bushes (5) of the meshed crawler belts, and the side surface of the tooth portion (21) is used for soil removal in the centripetal direction. The groove (22) is provided, and the groove (22) is formed to expand from the tooth base of the sprocket (20) toward the mounting portion (25). apparatus. The sprocket (20) is composed of a plurality of segments divided at an intermediate position where the bush (5) of the crawler belt and the tooth portion do not mesh with each other, and is detachably attached to the drive wheel (2). Item 2. A travel drive device for a tracked vehicle according to item 1 . The track-type vehicle according to claim 2 , wherein the sprocket segment includes a mounting portion that can be bolted from the outside to a hook-shaped mounting portion (25) formed on the drive wheel (2). Travel drive device.

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