JP3904428B2 - Traveling drive device for tracked vehicle - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention is a construction machine, such as a bulldozer or a hydraulic excavator, there is according to the traveling drive apparatus in a construction machine vehicles crawler type working with rough terrain mainly details the durability of the sprocket that drives track with a function of enhancing, to a travel drive apparatus for crawler type vehicles.
[0002]
[Prior art]
Conventionally, a traveling device in a traveling track type construction machine vehicle has an endless crawler belt wound around a sprocket and an idler incorporated in a driving device provided at a required distance before and after the vehicle body, It is supposed to run. The crawler belt includes a plurality of track links arranged on the left and right sides at a predetermined interval, a bush provided therebetween, and a plurality of connection pins inserted into the bushes to connect the track links to each other. A crawler plate is bolted on the left and right track links to form an endless shape.
[0003]
A traveling device having a crawler belt having such a configuration is driven by the sprocket and the crawler bush being sequentially engaged during driving, and the crawler belt is in contact with the bottom of the sprocket while the mesh is engaged. Has been communicated. However, when the crawler belt driven by meshing with the sprocket moves to the ground plane side, the crawler plate touches the ground to support the vehicle body, and is therefore wound around the sprocket (the sprocket on the ground plane side). The push-up force is applied through the bush of the shoe plate (which meshes with the teeth of the shoe).
[0004]
[Problems to be solved by the invention]
For this reason, not only the surface pressure against the bush due to the rotational driving force but also the thrust load generated for supporting the vehicle body and the slipping between the initial position where the bush sequentially engages and the separation from the tooth portion are caused by the sprocket teeth. The load acts greatly. In addition, the earth and sand that is rolled up when traveling on rough terrain enters the meshing area between the sprocket teeth and the bush of the crawler belt, and if the running operation continues, friction with the earth and sand becomes significant, and the teeth of the bush and sprocket teeth are severely worn. Become. In particular, in the type of crawler type vehicles to perform operations repeatedly vigorously move over time as bulldozer, depletion of the sprocket is intensely, are often forced to be replaced.
[0005]
Under these circumstances, in order to reduce the wear on the teeth of the sprocket of the travel drive device, as one way to improve the meshing structure of the crawler bush and the sprocket teeth, it is possible to drive without engaging the bush to the bottom of the tooth. There is an idea to make it. In this way, when the sprocket and the crawler bush are engaged, there is a gap in the root of the tooth even if soil enters, so when the bush engages with the tooth, friction is caused by rubbing with the sand that adheres to the bottom of the tooth. Can be prevented, and friction can be prevented from occurring due to earth and sand, thereby reducing wear. By the way, although the object is different from that of the present invention, according to Japanese Patent Laid-Open No. 10-45056, it is possible to prevent the sprocket tooth bottom and the bush from directly colliding with each other to reduce noise and vibration. For the purpose, there is a prior art as disclosed in a configuration in which a gap is formed in a tooth bottom at a meshing portion between a sprocket and a bush of a crawler belt.
[0006]
In the prior art, in order to form a gap when the tooth bottom of the sprocket is engaged with the bush of the crawler belt, an annular link abutting portion is provided in the housing of the power transmission mechanism including the sprocket. The clearance can be secured by receiving the track link of the crawler belt at the link contact portion.
[0007]
Therefore, in the method of forming a gap when the tooth bottom and bushing are engaged in the tooth part of the procket as disclosed in the above publication, this time, by contact between the earth and sand adhering to the link contact part of the housing and the track link The housing side will be worn, and if the housing is worn, it will naturally be necessary to replace it. Inviting such a situation results in a large loss economically because the power transmission mechanism is replaced.
[0008]
The present invention has been made in view of such circumstances, and rationally configures a sprocket and its mounting structure in a power transmission mechanism that has been conventionally handled as a consumable, and includes a crawler bush and sprocket teeth. the engagement structure, it is an object to provide a traveling driving device for crawler type vehicle which is a high constitutive durable even under sediment penetration.
[0009]
[Means for solving the problems and actions / effects]
To achieve the above purpose, the traveling drive device of crawler type vehicle according to the present invention,
In a traveling drive device for a tracked vehicle including a sprocket having a tooth portion meshing with a bush connecting a crawler belt link,
The sprocket is integrally provided with a flange on the side along the tooth portion, and a flat receiving surface is formed on the outer periphery of the flange to receive and support the non-grounded side surface of the link by surface contact. When the sprocket meshes with the link, the non-grounding side surface of the link abuts against the receiving surface of the flange, and a gap is secured between the bush and the tooth bottom of the sprocket. it is characterized in (first invention).
[0010]
In the present invention, the crawler belt link that is wound around the sprocket and driven by the collar portion provided along the tooth portion of the sprocket provided so as to replace the power transmission mechanism in the crawler travel drive device, By making it contact | abut to a collar part, the bush of a crawler belt will always mesh | engage without contacting the tooth bottom part in the tooth | gear part of a sprocket. The track link because it is received by the flange portion of受支the link at the same time meshes with the bush and the teeth, while the bushing to move in mesh with the sprocket can you to remain not in contact with the tooth bottom.
[0011]
According to the present invention, while maintaining the state in which nothing comes into contact with the track bushing to the tooth bottom of the sprocket can drive each other seen engage, when the sprocket and the crawler belt of the bushing are engaged, even soil intrudes teeth Since there is a gap in the bottom part , when the bushes mesh with the tooth part, it can be prevented from rubbing with the earth and sand adhering to the tooth bottom part to generate large friction, and it prevents wear of the tooth part due to earth and sand and prevents wear. Can be reduced and the durability can be enhanced. Therefore, the sprocket replacement frequency can be reduced to improve the operation efficiency.
[0012]
In addition, a flat receiving surface is formed on the outer periphery of the collar portion, and the non-grounding side surface of the link is supported by surface contact by this receiving surface, so that when the sprocket tooth portion and the bush are engaged, the bush is interposed. The link connected by the connecting pin comes into contact with the receiving surface , the meshing position of the bush with respect to the tooth part is defined, and a gap between the tooth bottom part and the bush is formed at the time of meshing, and the earth and sand at the meshing part It is possible to reduce the rubbing phenomenon due to. In addition, since the thrust load is received by the buttocks, only the traction load is borne at the tooth portion, and it is not necessary to increase the diameter of the bush or to use an expensive material. Will reduce the cost.
[0013]
The sprocket is preferably formed in a toothed manner with an even number of teeth (second invention). In this way, the tooth thickness can be increased, the amount corresponding to wear, in other words, the wear allowance can be increased, and the durability can be improved accordingly.
[0014]
The sprocket may be ring-shaped and divided into a plurality of segments, and the division position may be a half position between the interdental teeth ( third invention). Further, in the third invention, the sprocket segment, where the bush said bush between teeth is two intervening is in the place of one intervening the divided position is provided in a location where the bushing is one mediated It is good to be comprised ( 4th invention). In such a place where two bushes meshing with the tooth part of the sprocket are interposed between the tooth forming parts, either one of the bushes meshes with the tooth to transmit power, and only one bush is interposed between the tooth forming parts. Since the bush that does not directly participate in driving is received in a place where there is no intervention, the bush can be divided without affecting a part with a large load. In addition, since all segments are formed identically, if the assembly reference position is determined in advance, mounting and assembly can be performed reliably without selective combination, so that the sprocket replacement operation can be performed in a short time. is there.
[0015]
Furthermore, the tooth thickness dimension b of the front Symbol sprocket, the relationship between the pitch P of the track link, preferably a b / P ≒ 1 / 3~2 / 3 ( fifth aspect). When forming sprocket teeth, in addition to increasing the thickness by increasing the tooth thickness, it is preferable to increase the tooth thickness in consideration of wear resistance. It is preferable to widen the interval between the tooth forming portions, and since the link pitch is constant, the purpose can be achieved without difficulty by setting within this numerical value from this contradiction event.
[0016]
The sprocket has a stepped shape with an annular protrusion on its inner periphery, and is driven from the outer surface side of the wheel by engaging the annular protrusion with a step formed on the outer periphery of the wheel. The tip of the mounting bolt inserted from the wheel- side mounting hole is screwed and fastened to the screw hole provided in the annular protrusion of the sprocket at a position that matches a large number of mounting holes provided in parallel to the axis. It is preferable that the structure is fixed (the sixth invention). By configuring in this way, as a mounting means for mounting the segment of the divided sprocket to the wheel , the mounting work is facilitated, and the load on the inner peripheral surface and the wheel side is also applied to the load acting on the sprocket after mounting. Since the outer peripheral surface comes into contact with the mounting bolt and no shearing force acts on the mounting bolt, the mounting bolt is securely held.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
Next, a specific embodiment of the travel drive apparatus of the crawler type vehicle according to the present invention will be described with reference to the drawings.
[0018]
And driving front view of a traveling driving device for crawler type vehicle according to the present invention is shown in Figure 1. 2 is a cross-sectional view taken along line AA of FIG. 1, FIG. 3 is an enlarged cross-sectional view showing the main part of the sprocket, and FIG. 4 shows the state of engagement between the sprocket and the crawler belt link. A side view of the main part is shown.
[0019]
Travel drive apparatus 1 of this embodiment consists of track 4 exerted idler (not shown) and the drive wheel 3 wound on both sides of the body frame 2 as a lower traveling body in the crawler type vehicle, the vehicle body frame 2 The crawler belt 4 that is attached and receives power transmitted from an engine (not shown) and is wound around the driving wheel 3 via a reduction gear mechanism is driven. In this configuration, the relationship between the sprocket 15 that transmits power to the link 5 of the crawler belt 4 in the drive wheel 3 and the link 5 of the crawler belt will be described.
[0020]
The driving wheel 3 has a planetary gear speed reduction mechanism 6 supported by the end of the vehicle body frame 2 with a well-known structure, a wheel 10 fixedly supported by the output shaft 7 and rotationally driven, and a concentric circle around the wheel 10. It is comprised with the cyclic | annular sprocket 15 with which it mounts | wears.
[0021]
The wheel 10 is supported by a boss portion 8a of the casing 8 of the planetary gear speed reduction mechanism 6 via a rolling bearing 9, and the output shaft of the planetary gear speed reduction mechanism 6 protrudes outside through the boss portion 8a. 7 (integrated with the carrier) are connected coaxially through a support ring 11 fitted and fixed by a spline key at the end. A large number of sprocket mounting holes 12 are provided at a predetermined radial position near the outer periphery so as to be parallel to the axis at a predetermined pitch.
[0022]
The sprocket 15 is the intermittent teeth of the even-numbered teeth, connecting links 5, between the teeth portion 15a and the tooth portion 15a (corresponding to the valley of the tooth as it were) as shown in FIG. 1 bushing The tooth thickness dimension is increased by alternately forming the locations where one 5b is located and the locations where two 5b are located. And the tooth | gear part 15a which meshes with the bush 5b of the link 5 is set as the structure used as the any one tooth | gear part 15a in the part in which the said two bushes 5b are received. Therefore, as shown in FIG. 4, a clearance s is formed between the tooth surface of the tooth portion 15 a ′ that does not contact the bush 5 b and the bush 5 b.
[0023]
Furthermore, the sprocket 15 has flanges 16 and 16 formed on both the left and right sides of the tooth forming portion, and the inner peripheral portion 17 has a shape that matches the outer peripheral surface 10a of the wheel 10 and is behind the peripheral portion of the wheel 10. An annular protrusion 18 is formed over the entire circumference so as to be positioned in contact with the side surface 10b, and is formed with a so-called step. A large number of screw holes 19 are provided in the annular protrusion 18 so as to coincide with the position of the sprocket mounting hole 12 provided in the wheel 10 so as to be parallel to the axis.
[0024]
Further, a flat receiving surface 20 is formed on the outer periphery of the flange portion 16 of the sprocket 15 so as to receive and support the non-grounding side surface 5a of the link 5 in accordance with the connecting pitch of the crawler belt link 5 meshing with the tooth portion 15a. The height of the receiving surface 20 is set such that a gap t is formed between the lower end of the bush 5b of the meshing link 5 and the bottom surface 15b. A recess 21 is formed between the receiving surfaces 20 so that the adjacent receiving surfaces 20 do not interfere with each other when the links 5 are supported.
[0025]
The tooth thickness dimension b of the tooth portion 15a of the sprocket 15 is set to fall within a range of b / P≈1 / 3 to 2/3 in relation to the pitch P of the crawler belt link 5. If it does in this way, intensity | strength can be raised by enlarging tooth thickness and abrasion resistance can be improved. On the other hand, if the tooth thickness dimension b is increased at a constant diameter, the dimension between the tooth forming parts is narrowed, so that the condition for discharging the earth and sand entering the tooth forming part space is deteriorated. As a compromise for such a contradiction event, it is preferable to set the value within the above range.
[0026]
The sprocket 15 configured as described above is divided into four parts in the present embodiment, and is formed so that it can be easily removed and assembled at the time of replacement accompanying wear of the tooth portion 15a. Further, the divided sprocket segment 15C has a central position between the tooth forming portions where one of the bushes 5b exists between the tooth portion 15a and the tooth portion 15a, as shown in FIG. Has been. And the receiving surfaces 20 and 20 formed in the said collar parts 16 and 16 are positioned so that the one end part may adjoin to a division | segmentation position.
[0027]
The travel drive device 1 of the present embodiment configured as described above receives power from a drive source and is decelerated to a required speed by the planetary gear mechanism 6 so that the sprocket 15 rotates together with the wheel 10. Sprocket 15 wound track 4 hung, when the link 5 is bush 5b of the connecting portion is moved to drive meshes with teeth 15a of the sprocket 15, as one tooth placed (linked with teeth 15a of the sprocket The bush 5b and the tooth portion 15a mesh with each other. Therefore, about the meshing | engagement of the sprocket 15 and the link 5, three tooth parts will substantially mesh with 8 teeth, and motive power is transmitted in the location which contacts and meshes with these tooth parts 15a. However, each tooth portion 15a can have a tooth thickness dimension larger than that of a general sprocket tooth, so that power can be reliably transmitted. And the bush 5b in the position which does not mesh with the tooth part 15a does not receive a driving force directly in the tooth formation space part, but an operation of connecting and moving the link 5 is performed.
[0028]
Further, when the link 5 meshes with the sprocket 15, the non-grounding side surface 5 a of the link 5 is received in contact with the receiving surfaces 20, 20 provided on both side flanges 16, 16 of the sprocket 15. The meshing position of the bush 5b is defined, and as a result, a gap t is always formed between the bush 5b and the tooth bottom surface 15b (corresponding to the tooth bottom portion of the present invention). The rubbing phenomenon can be reduced without rubbing. And since the link 5 wound around the sprocket 15 is always supported and rotated by the receiving surfaces 20 and 20 on both sides of the tooth forming portion, a thrust load is applied to the receiving surface 20. The tooth portion 15a only needs to bear the traction load, and it is not necessary to increase the diameter of the bush 5b or use an expensive material. Therefore, there is an advantage that the production cost on the crawler belt side can be reduced. Of course, the wear resistance of the sprocket 15 is improved and the frequency of replacement can be reduced.
[0029]
When the sprocket 15 is worn out due to long-term use and needs to be replaced, it can be easily removed by releasing the segment 15C of the divided sprocket 15 from the mounting bolt 13 with the wheel 10. In this bolt fastening portion, each mounting bolt 13 can be removed by unscrewing the screw shaft portion 13a from the screw hole 19 provided in the segment 15C of the sprocket 15, and can be operated on the outer surface. It is easy to use and easy to work, and can be easily replaced on site.
[0030]
Next, FIG. 5 shows a cross-sectional view of a principal part showing another embodiment having a different sprocket mounting structure. In this embodiment, the basic configuration is the same as that of the above embodiment, and the attachment structure of the sprocket 15 to the wheel 10 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.
[0031]
In this embodiment, a slightly deep groove 25 is formed in the middle in the width direction on the outer periphery of the wheel 10A that is fixedly supported by the output shaft 7 of the planetary gear speed reduction mechanism 6 and driven to rotate. An annular inner peripheral surface 18a of the sprocket 15A is formed by an inner peripheral surface 26a and an outer peripheral surface 26b of the mounting flange 26 and an outer peripheral surface 27 rearward (relative to the outer surface) from the groove 25. While being received, one side surface (substantially the front surface) of the annular projection 18A protruding inward from the inner peripheral surface thereof is attached to the mounting flange inner surface 26a of the wheel 10 so as to be mounted.
[0032]
The mounting flange 26 of the wheel 10A is provided with a large number of mounting holes 12A at a predetermined pitch on a line drawn with a predetermined radius from the outer surface in parallel with the axis, and the positions of the mounting holes 12A are matched. A screw hole 19 is provided in the annular protrusion 18A of the sprocket 15A. The sprocket 15A is structured to be fastened and fixed by inserting the mounting bolt 13A through the mounting hole 12A provided in the mounting flange 26 of the wheel 10A and screwing it into the screw hole 19 of the annular protrusion 18A. The sprocket 15A is divided into four and can be removed for each segment 15C.
[0033]
In the wheel 10A and the sprocket 15A configured as described above, the mounting flange 26 portion is formed on the outer peripheral portion of the wheel 10A, and the annular protrusion portion 18A on the sprocket 15A side is inserted into the groove portion 25 behind the wheel 10A for positioning. By fastening, the axial length of the mounting bolt 13A can be shortened. Further, since the sprocket 15A is provided with an annular protrusion 18A at an intermediate position on the inner peripheral portion thereof, and is fastened and fixed by bolts at the annular protrusion 18A, an effect of increasing stability can be obtained, and also in terms of weight. There is an advantage that it can be reduced.
[0034]
FIG. 6 is a cross-sectional view of an essential part showing another embodiment having a different sprocket mounting structure. In this embodiment as well, the structure of the mounting portion of the sprocket with respect to the wheel is partially different from that described above. Therefore, the same parts as those of the above-described embodiment are denoted by the same reference numerals and description thereof is omitted.
[0035]
In this embodiment, the outer peripheral portion 10a of the wheel 10B that is fixedly supported by the output shaft 7 of the planetary gear speed reduction mechanism 6 and driven to rotate is formed in a stepped shape on the rear surface side and is a circle drawn with a required radius. In addition, a large number of mounting holes 12 are drilled at a required pitch so as to be parallel to the axis. On the other hand, the inner peripheral surface 17 of the sprocket 15B is provided with an annular protrusion 18B so as to follow the outer peripheral surface 10a of the wheel 10 and to contact the stepped side surface 10b of the wheel 10B at the rear. The annular protrusion 18B is provided with a large number of mounting holes 18c parallel to the axis so as to coincide with the positions of the mounting holes 12 of the wheel 10B.
[0036]
The sprocket 15B and the wheel 10B of this embodiment configured in this way are fitted with the inner peripheral portion 17 of the sprocket 15B on the outer peripheral portion 10a of the wheel 10B, and the mounting holes 12 provided in the wheel 10B and the sprocket 15B are provided. The mounting bolt 13 is inserted through the mounting hole 18c provided in the annular protrusion 18B, and the nut 13A is screwed and fastened with the screw shaft portion 13a at the front end portion of the shaft portion of the mounting bolt 13 that penetrates. ing.
[0037]
In the mounting structure having such a configuration, the mounting bolts 13 are passed through the mounting holes 12 and 18c and fastened by the nut 13A. Therefore, the fastening force can be secured and the mounting can be firmly fixed.
[0038]
As described above, according to the present invention, the sprocket that is configured to be exchangeable when worn by operation is configured to aggregate the portions that wear due to the influence of earth and sand when engaged with the crawler belt link. A drive device that can withstand long-term use can be obtained by replacing only the sprocket without affecting the structure that is difficult to replace.
[Brief description of the drawings]
FIG. 1 is a driving front view of a traveling driving device for crawler type 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 sectional view showing a main part of the sprocket.
FIG. 4 is a side view of the main part showing the meshed state of the sprocket and the crawler belt link.
FIG. 5 is a cross-sectional view of an essential part showing another embodiment in which the sprocket mounting structure is different.
FIG. 6 is a cross-sectional view of an essential part showing another embodiment having a different sprocket mounting structure.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Travel drive device 3 Drive wheel 4 Crawler belt 5 Crawler belt link 5a Link non-grounding side surface 5b Bush 6 Planetary gear mechanism 7 Output shaft 10, 10A, 10B Wheel 11 Support ring 12, 12A, 18c Mounting hole 13, 13A Mounting bolt 15 , 15A, 15B Sprocket 15a Tooth portion 15b Tooth bottom surface 16 鍔 portion 18, 18A, 18B Annular projection 19 Screw hole 20 Receiving surface 25 Groove portion 26 Mounting flange

Claims (6)

In a traveling drive device for a tracked vehicle including a sprocket having a tooth portion meshing with a bush connecting a crawler belt link,
The sprocket is integrally provided with a flange on the side along the tooth portion, and a flat receiving surface is formed on the outer periphery of the flange to receive and support the non-grounded side surface of the link by surface contact. When the sprocket meshes with the link, the non-grounding side surface of the link comes into contact with the receiving surface of the flange, and a gap is secured between the bush and the tooth bottom of the sprocket. traveling drive device of crawler type vehicle according to claim. The sprocket traveling drive device of crawler type vehicle according to claim 1, the number of teeth is formed on the even number of intermittent teeth. The sprocket is divided into a plurality of segments in a ring shape, the division position is traveling drive device for crawler type vehicle according to claim 2, which is to be a half position between the intermittent teeth . Segment of the sprockets, where the bush said bush between teeth is two intervening is in the place of one intervening claim 3, wherein the dividing position to the location where the bushing is one intervening has the configuration provided traveling drive device of crawler type vehicle according to. Tooth thickness dimension b of the sprocket, the relationship between the pitch P of the links, b / P ≒ 1 / 3~2 / 3 a is traveling drive the crawler type vehicle according to any one of claims 1-4 apparatus. The sprocket has a stepped shape with an annular protrusion on its inner periphery, and is driven from the outer surface side of the wheel by engaging the annular protrusion with a step formed on the outer periphery of the wheel. The tip of the mounting bolt inserted from the wheel- side mounting hole is screwed and fastened to the screw hole provided in the annular protrusion of the sprocket at a position that matches a number of mounting holes provided in parallel to the axis. traveling drive device of crawler type vehicle according to any one of claims 1 to 5 which is a fixed configurations.

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