JP2002173062A - Travel driving device of crawler vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize easiness of assembling and weight reduction of a travel driving device by reducing an external force burden applied to a seed reduction gear by rationalizing a support structure of a sprocket. SOLUTION: In the driving device for a sprocket in a crawler vehicle, an assembly support part 4 of the sprocket 13 in a truck frame is formed to a forked shape along a vertical axis of a body and the sprocket 13 is disposed between the forked part of the truck frame 3. A sprocket shaft 13a is supported by bearing support structure bodies 11, 11' mounted to the truck frame at both sides and a speed reduction gear 15 is assembled to one bearing support structure body 11. An output part 15a of this speed reduction gear 15 is bonded to one end part of the sprocket shaft 13a.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a traveling drive device for a tracked vehicle, which can mainly improve the durability and the maintainability by compactly integrating a traveling drive portion in the tracked vehicle.

[0002]

2. Description of the Related Art Conventionally, for example, a traveling drive in a tracked vehicle is located behind a vehicle body and plays a role of a traveling driving force and a load of an external force load. And the traveling drive (drive reduction gear) is a body frame (track frame).
It is mounted with a cantilever structure.

More specifically, as shown in FIGS. 9 (a) and 9 (b), a traveling drive unit 101 of a crawler belt 100 has a hydraulic motor
The sprocket 104 is fastened and fixed to the casing 103a integral with the output portion of the speed reducer 103 (generally having a planetary gear structure) by bolts 108. The fixed side of the speed reducer 103 is a truck of the vehicle body. A fixed-side base end 103b of the speed reducer 103 is fitted into the drive speed reducer mounting hole 106 provided at the rear end of the frame 105 from the outside, and is fastened and fixed with bolts 107.

[0004]

In such a traveling drive of a tracked vehicle, a large sprocket is mainly used and a large output torque is required, so that a large reduction ratio is required. However, it is difficult to reduce the size and weight. The mounting portion is structurally mounted on the truck frame of the vehicle body in a cantilevered structure as described above. For this purpose, the supporting portion of the driving machine needs to have a structure with high rigidity, and it is generally made tough, and it is inevitable that the supporting portion becomes heavy in weight.

[0005] In addition, a large rolling bearing must be used for the support portion of the sprocket also in the speed reducer portion of the traveling drive, and there is a problem in that the cost is generally increased.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems. The present invention has been made to simplify the support structure of the sprocket and reduce the external load acting on the speed reducer. It is an object of the present invention to provide a traveling drive device for a tracked vehicle capable of reducing weight.

[0007]

Means for Solving the Problems and Action / Effect To achieve the above-mentioned object, a traveling drive device for a tracked vehicle according to the present invention is a drive device for a sprocket in a tracked vehicle, comprising: The sprocket assembly support portion of the frame is formed in a forked shape along the longitudinal axis of the vehicle body, a sprocket is arranged between the forked portions of the track frame, and the sprocket shaft is attached to the track frame on both sides. It is supported by a bearing support structure, and a speed reducer is assembled to one of the bearing support structures, and an output portion of the speed reducer is coupled to one end of the sprocket shaft. .

In the present invention, a sprocket shaft for driving a crawler belt is provided at both ends of a track frame formed in a bifurcated shape as a double-supporting support structure, and the speed reducer is assembled to one bearing support structure at one end of the sprocket shaft. By combining the output units, the power from the motor can be reduced and transmitted in a compact structure.
By doing so, the sprocket is supported by both ends of the shaft, so that the load imposed by external force can be reduced. In addition, since the structure is separated from the speed reducer to which power is transmitted, the rolling bearing mounted on the bearing support structure can be reduced in size and cost. Further, by disposing the speed reducer away from the sprocket, stable speed reduction drive can be performed without receiving an irregular external force, and the structure of the main parts to be assembled can be simplified.

[0009] It is preferable that the built-in support portion of the sprocket has a structure in which a bearing support structure of the sprocket can be inserted from a rear end and supported by a forked structure formed at a rear portion of the track frame. By doing so, there is an effect that the assembly of the sprocket and the traveling speed reducer assembly becomes easy, and the maintenance becomes easy.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, a specific embodiment of a traveling drive device for a tracked vehicle according to the present invention will be described with reference to the drawings.

FIG. 1 is a view showing an embodiment of a crawler traveling type working machine provided with a traveling drive device according to the present invention. FIG. 2 is a longitudinal sectional view of a main part of the traveling drive device, FIG. 3 is a side view taken along the line AA of FIG. 2, and FIG. b) are shown respectively.

In this embodiment, a crawler traveling construction machine applied to a hydraulic excavator 1 will be described.

The traveling drive device 10 according to this embodiment
Are provided at the rear of both the left and right track frames 3 of the lower traveling body 2 in the excavator 1. As shown in FIGS. 4A and 4B, the rear portion of the track frame 3 is bifurcated along the longitudinal axis of the vehicle body at a required interval as the support portion 4 of the driving sprocket 13 of the crawler belt 7. I have. Each of the support portions 4 is provided with a cut 5 on the side surface from the rear end, and the inner end portion 5a is formed in a semicircle with a required radius, and the mounting bolt hole 5 is formed along the semicircular portion.
c are provided at a required pitch. This configuration is formed symmetrically.

A pair of bearing support structures 11 and 11 'each having a mounting portion 11a formed in a flange shape and fitted to the support portion 4 provided at the rear portion of the track frame 3 are provided. The mounting portion 11a is engaged with the semicircular inner ends 5a, 5a of the bifurcated support portion 4 and fastened with bolts 6 for mounting.

The pair of bearing support structures 11, 11 '
Are located in the center of the inward rolling bearing 12 (hereinafter, referred to as
(Hereinafter simply referred to as bearing 12).
As a result, the sprocket shaft 13a is supported on both sides, and is mounted and supported on the rear portion of the track frame 3 so as to sandwich the sprocket 13 between the dual bearing support structures 11, 11 '. The sprocket shaft 13
On the sprocket 13 side of the bearing 12 supporting the a, a seal ring 18 having a rubber lip for sealing the bearing 12 at the outer peripheral tip is attached to the shaft neck portion, and intrusion of earth and sand into the bearing portion from the outside. Has been tried to prevent.

A reduction gear 15 composed of a planetary gear mechanism is integrally mounted on the outer surface of the bearing support structure 11, which is located inside the vehicle body, of the pair of bearing support structures 11, 11 '. The output portion 15a (the carrier in the third-stage reduction gear mechanism) of the speed reducer 15 and the sprocket shaft 13a are connected to each other by a spline joint with the shaft end 13a 'having the same axis. The parts of the speed reducer 15 and the hydraulic motor 16 correspond to the track frame 3
It is covered by a cover 17 attached to the support portion 4 provided at the rear of the device, and is prevented from entering soil from outside and protected against external force.

In the traveling drive device 10 configured as described above, the sprocket 13 for driving the crawler belt 7 has its shaft 13a formed on the track frame 3 on both sides through the bearings 12, 12, and the fork support portion 4, 4 and supported by the bearing support structures 11 and 11 ', sufficient rigidity can be obtained against external forces received during running and during excavation work by the working machine. When assembling, the dual-bearing support structures 11, 11 ', the sprocket 13, and the speed reducer 15 (with the hydraulic motor 16) are made into a unit.
With respect to the support portion 4 of the track frame 3, the notch 5 opened rearward from the opening to the bearing support structure 11,
11 'can be attached so as to be fitted, so that assembly and disassembly can be easily performed, and workability is remarkably improved.

Next, as another embodiment, FIG. 5 is a front view showing an embodiment of a traveling drive device of a lower traveling body provided with a high drive reduction drive, and FIG. 6 is a front view of FIG.
FIG. 7 is a cross-sectional view, FIG. 7 is a plan view taken along line CC of FIG. 5, and FIG. , Respectively.

The traveling drive device 10 according to this embodiment
FIG. 8A is a view similar to FIG.
As shown in (c), the track frame 3 is positioned above the normal type, and the support portion 4 of the sprocket 13A is bifurcated parallel to the rear portion at a required interval.
A, 4A 'are provided, and cutouts 5A, 5A' opening rearward are formed at required positions. The inner ends of the cuts 5A, 5A 'in the support portions 4A, 4A' are formed in a semicircle having a required radius, and mounting bolt holes are formed on the side surfaces along the semicircular inner ends 5a ', 5a ". 5
Many d are provided at a required pitch. The structure of the support portions 4A, 4A 'is formed symmetrically at the rear portions of the left and right track frames 3, 3.

The support portions 4A and 4A 'provided at the rear of the track frame 3 are formed such that the cut 5A' in the outer support 4A 'is smaller in diameter than the cut 5A in the inner support 4A. The center o of the semicircle forming the inner ends 5a ', 5a "of the cuts in the inner and outer support portions is made to coincide with the axis passing in the width direction. These support portions 4A, 4A' Attachment section 11 having a flange-shaped fitting structure with support section 4A 'on the outside.
b ', the bearing support structure 11A' having a smaller diameter than the bearing support structure 11A 'is provided on the inner support portion 4A, and the mounting portion 11b is attached to the inner end portion 5a. ', 5a "and bolt 6
It is fastened by and attached.

The left and right bearing support structures 11A, 11
A ′ is provided with rolling bearings 12A, 12A at the center portion inward (between the support portions), and these bearings 12A, 12A are provided.
A is attached to the rear portion of the track frame 3 so that the sprocket shaft 13a is supported on both sides by A, and is configured to support the sprocket 13A. The reduction gear 15A composed of a planetary gear mechanism is integrally mounted on the outer surface of the bearing support structure 11A located inside,
The output portion 15b (carrier in the third-stage reduction gear mechanism) of the speed reducer 15A and the sprocket shaft 13a are aligned with the sprocket shaft 13a so as to be connected to the shaft end 13a 'by a spline shaft joint. . The speed reducer 15A and the hydraulic motor 16 are covered by a cover 17 attached to the support 4A to prevent intrusion of earth and sand from the outside and protection against external force. On the sprocket 13 side of the bearing 12 that supports the sprocket shaft 13a, a seal ring 18 having a rubber lip that seals the bearing 12A at the outer peripheral end is attached to the shaft neck portion, and the seal ring 18 is externally attached to the bearing portion. To prevent intrusion of earth and sand.

Further, a support shaft 21 is provided below the mounting portion of the sprocket 13A by a pair of bearing blocks 20, 20 for mounting a base on the lower surface of the support portions 4A, 4A '.
Is supported by the lower sprocket 1
The winding angle of the crawler belt 7 suspended around 3A is provided so that the meshing ratio between the sprocket and the crawler belt link becomes appropriate.

The traveling drive device 10A thus configured
In the above, the outer diameter of the sprocket 13A for driving the crawler belt 7 is reduced so that the sprocket 13A is supported at a position higher than the ground contact surface of the crawler belt 7. By doing so, in addition to obtaining the same operational effects as those of the above-described embodiment, the drive shaft can be prevented from entering the ground during traveling or work by moving the drive shaft away from the ground. The effect of preventing the invasion of foreign matter by the object can be enhanced. Also, the sprocket 13
As the diameter of A decreases, the driving torque decreases and the external force load can be reduced, so that the rigidity of the planetary portion support in the planetary gear mechanism of the speed reducer 15A can be reduced, and the sprocket 13
Along with the small diameter of A, the weight can be reduced. In addition, the reduction gear 15A does not require a large reduction ratio as in the related art by reducing the diameter of the sprocket 13A, so that there is an advantage that the reduction gear 15A can be made compact.

The above description has been given of the embodiment applied to the hydraulic excavator. However, the present invention is not limited to this, and can be applied to other crawler traveling type vehicles.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating an embodiment of a crawler traveling type working machine including a traveling drive device according to the present invention.

FIG. 2 is a longitudinal sectional view of a main part of the traveling drive device.

FIG. 3 is a side view as viewed from AA of FIG. 2;

FIG. 4 is a front view (a) and a plan view (b) showing a sprocket-incorporated support portion of the track frame.

FIG. 5 is a front view showing an embodiment of a traveling drive device for a lower traveling body including a high-drive reduction drive.

FIG. 6 is a sectional view taken along line BB of FIG. 5;

FIG. 7 is a plan view taken along the line CC of FIG. 5;

FIG. 8 is a front view (a), a right side view (b), and a rear view (c) showing a sprocket-incorporated support portion of the track frame.

FIGS. 9A and 9B are views showing a conventional drive reduction gear mounting structure, in which FIG. 9A is a longitudinal sectional view and FIG. 9B is a front view.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Hydraulic excavator 3 Track frame 4, 4A, 4A 'Support part 5, 5A, 5A' Cut 5a, 5a ', 5a "Inner end of cut 7 Crawler belt 10, 10A Traveling drive device 11, 11', 11A, 11A ' Bearing support structure 12, 12A Bearing 13, 13A Sprocket 13a Sprocket shaft 15, 15A Reduction gear 15a, 15b Output part of reduction gear 16 Hydraulic motor 17 Cover 20 Bearing block 22 Lower terminal wheel at the end

Claims (2)

[Claims] 1. A drive device for a sprocket in a tracked vehicle, wherein a built-in support portion of the sprocket in a track frame is formed in a forked shape along a longitudinal axis of the vehicle body, and is provided between the forked portions of the track frame. And a sprocket shaft is mounted on both sides of the sprocket shaft and supported by a bearing support structure, and a speed reducer is assembled to one of the bearing support structures, and an output portion of the speed reducer is provided. Is coupled to one end of the sprocket shaft. 2. The built-in support portion of the sprocket has a structure in which a bearing support structure of the sprocket can be inserted and supported from a rear end into a forked structure formed at a rear portion of the track frame. A traveling drive device for a tracked vehicle according to claim 1.