JP3712142B2 - Hydraulic excavator swivel frame support device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a structure of a turning device that supports an upper turning body on a center frame of a lower traveling body of a construction machine such as a hydraulic excavator.
[0002]
[Prior art]
The structure of a conventional center frame will be described taking a hydraulic excavator composed of a lower traveling body and an upper swing body as an example. First, the hydraulic excavator 20 will be described with reference to FIG. The lower traveling body 21 is provided with left and right crawler frames 3 (left crawler frame 3a, right crawler frame 3b). The left and right crawler frames 3 and the center frame 2 are detachably attached.
This lower traveling body 21 can be moved forward and backward by a traveling motor (not shown). An upper swing body 23 is mounted on the lower traveling body 21 via a swing circle 22. The upper turning body 23 can be turned by a turning motor (not shown). A work machine 30, a machine cab 26, an operator cabin 27, and a counterweight 28 are attached to the turning frame of the upper turning body 23. The work machine 30 includes a boom 31, an arm 33, and a bucket 35, and is driven by each hydraulic cylinder 32, 34, 36.
[0003]
Next, a conventional center frame turning support device of the hydraulic excavator 20 will be described with reference to FIGS.
FIG. 8 is a plan view of the turning device, which is driven by meshing with an internal gear 4a of the inner race and a swing pinion 9a fixed to the output shaft of the turning motor. The swivel device will be described in detail with reference to FIG.
The swing circle 22 is provided with an annular mounting member 12 fixed to the upper surface plate 10 of the center frame 2. An annular inner race 4 is fastened to the annular mounting member 12 with bolts 7. An annular outer race 5 is fastened to the revolving frame 1 of the upper revolving structure 23 with bolts 8 on the outer periphery of the inner race 4. The inner race 4 and the outer race 5 are rotatable with respect to each other via a ball 6 and constitute a swivel bearing.
[0004]
An internal gear 4 a is provided inside the inner race 4, and the internal gear 4 a meshes with a swing pinion 9 a fixed to the output shaft 9 of the swing motor 25 mounted on the swing frame 1.
When the swing pinion 9a is rotated by driving the turning motor 25, the swing pinion 9a is revolved by meshing with the internal gear 4a, and the upper turning body 23 can turn.
[0005]
Next, a center frame of a conventional hydraulic excavator will be described with reference to FIGS. In the center frame 2 shown in FIG. 11, an annular mounting member 12 is fixed to the upper surface plate 10. The annular mounting member 12 and the inner race 4 are fastened by bolts 7. Leg portion upper surface plates 11a, 11a, 11a, 11a extending from the upper surface plate 10 are provided. The upper surface plate 10 and the leg upper surface plates 11a, 11a, 11a, 11a are integrally formed and are provided with bending portions 11b, 11b, 11b, 11b. The center frame 2 is detachably fastened with bolts across the right crawler frame 3a and the left crawler frame 3b.
The P part of the leg upper plate will be described with reference to FIG. The leg upper surface plate 11a extending from the upper surface plate 10 has a box shape by the lower surface plate 13 and the side plates 11e and 11d. 11c is a reinforcing rib.
Thus, the center frame 2 needs to be provided with the annular mounting member 12 to support the slewing bearing, and the upper surface plate 10 has to be formed with legs by bending.
[0006]
Further, the meshing portion between the swing pinion 9a and the internal gear 4a is lubricated with grease.
FIG. 10 shows a configuration of a grease bath for storing grease. An annular plate 14 is welded to the upper surface plate 10 of the center frame 2. A cylindrical grease bath 15 is fastened to the inner peripheral portion of the plate 14 with bolts 16. A seal 17 is attached to the upper end of the grease bath 15 and is in contact with the revolving frame 1, and grease 18 is stored inside.
[0007]
[Problems to be solved by the present invention]
However, the center frame turning support device has the following problems.
(1) Since the annular mounting member 12 is welded to the upper surface plate 10, in order to ensure sufficient strength in this welded portion, the length of the welding leg is lengthened so that stress is not concentrated on the welded portion. It took a lot of production steps such as grinder processing, and the cost was high.
(2) The upper surface plate 10 is bent to form the leg upper surface plate 11a. However, since the upper surface plate 10 is a thick plate, it is difficult to bend and the cost is high.
(3) The conventional grease bath cannot follow the deformation and deflection of the frame due to the bolt tightening, and the bolt may be loosened or the welded portion may be cracked.
Further, due to the bolt tightening structure, the cost is high due to the processing of bolt holes, the number of bolt tightening steps, and the bolts and washers.
[0008]
The present invention pays attention to the above-mentioned conventional problems, and uses a top plate as a thick plate and directly provides a tapped hole for attaching an inner race to the top plate to eliminate the annular mounting member and its welding. In addition, the upper plate of the thick plate and the upper plate of the leg portion of the thin plate are prepared with different materials, each is welded and integrally formed, and bending is applied to the upper plate of the leg portion of the thin plate. An object of the present invention is to provide a highly durable swing frame support device for a hydraulic excavator by eliminating the bending process, reducing the number of manufacturing steps, and facilitating the installation of a grease bath.
[0009]
[Means for Solving the Problems]
In order to achieve the above object, a swing frame support device for a hydraulic excavator according to the present invention includes a center frame coupled to the left and right crawler frames, an inner race fixed to the center frame, and an inner race provided in the inner race . and gear, a swing motor that is attached to the rotating frame of the upper rotating body, is composed with a pinion fixed to the output shaft of the swing motor, the outer race and the ball provided on the rotating frame and the internal gear of the Lee N'naresu and a circular pivot bearing that, by engagement with the internal gear of the pinion and the inner race by the driving of the swing motor a support device of the rotating frame of a hydraulic excavator to pivot driving the upper swing body, the center frame. 2A and forming by fixing the top plate 41 and the leg portion top plate 42, to form a tapped hole in the top plate, front The bolts inner race is obtained by a configuration in which attached to the upper plate.
[0010]
In the above configuration, a spacer 4b is interposed between the upper surface plate 41 and the inner race 4B, and the inner race 4B and the spacer 4b are attached to the upper surface plate 41 with bolts. .
[0011]
Further, in the above structure is obtained by a configuration in which挾着the outer peripheral portion of the bottom plate 51 of the grease bath 50 in an annular groove 53 provided between the inner race 4B and spacers 4b.
[0012]
In the above configuration, the annular seal 55 made of an elastic body is attached to the outer peripheral portion of the bottom plate 51 of the grease bath 50, and between the upper end portion of the inner peripheral side plate 52 of the grease bath 50 and the swivel frame 1. The seal 17 is provided.
[0013]
[Action]
According to the above configuration, the inner plate mounting tap hole is directly provided on the upper surface plate of the center frame, and the upper surface plate and the inner race are directly bolted. Also, the top plate and the leg top plate are made of different materials, the top plate is a thick plate, and the leg top plate is a thin plate. There is no need to form a leg top plate. Further, the butt weld has a short leg length and is easy to weld .
[0014]
Further, the inner race can be made small by inserting a spacer between the inner race and the upper surface plate.
[0015]
An inner race and a spacer are interposed between the upper surface plate of the center frame and the revolving frame, and an outer peripheral portion of the bottom plate of the grease bath is attached to an annular groove provided between the inner race and the spacer. Since the seal is attached to the outer peripheral portion of the bottom plate of the grease bath between the annular seal made of an elastic body and the upper end portion of the inner peripheral side plate of the grease bath and the swivel frame, the strength against deformation and twisting is improved. Improves and simplifies structure.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of a center frame turning support device for a hydraulic excavator according to the present invention will be described with reference to FIGS.
In addition, what attached | subjected the same code | symbol as FIG. 9 thru | or FIG. 12 is the same, and description is abbreviate | omitted.
First, a first embodiment of the center frame turning support device will be described with reference to FIGS. A circle 41b is formed in the center of the upper surface plate 41 of the center frame 2A shown in FIG. A hydraulic swivel joint or the like (not shown) is arranged in the circle 41b. A plurality of tap holes 41a are opened on the outer periphery of the circle 41b. The center frame 2A includes four leg portion upper surface plates 42, 42, 42, and 42 joined to the upper surface plate 41 by welding, and is integrally formed. The upper surface plate 41 and the leg upper surface plates 42, 42, 42, 42 are box-shaped by the lower surface plate 13, the vertical plate 44 shown in FIG. 2, and the side plates (side plates 11d, 11e similar to those shown in FIG. 12). It has a shape and is reinforced with ribs 11c.
[0017]
Next, the joining state of the upper surface plate 41 and the leg portion upper surface plate 42 of the center frame 2A and the supporting state with the turning device will be described in detail with reference to FIGS.
First, the upper surface plate 41 of the center frame 2A shown in FIG. 2 has a thickness T2, and the leg upper surface plate 42 has a thickness T1. The upper surface plate 41 is thicker than the leg upper surface plate 42. The upper surface plate 41 and the leg upper surface plate 42 are butt welded.
A tapped hole 41a for the bolt 7A is formed in the upper surface plate 41, and the inner race 4A of the swing circle 22A is sandwiched between the upper surface plate 41 and the turning frame 1 and fastened by the bolt 7A. In this case, since the outer race 5 is fixed between the upper surface of the upper surface plate 41 and the swivel frame 1, it is necessary to secure a predetermined amount of gap S <b> 3 between the upper surface of the upper surface plate 41 and the bolt 8. Therefore, the height H1 of the inner race 4A is set higher than that of the conventional inner race.
[0018]
FIG. 3 shows another example when the upper surface plate 41A and the leg upper surface plate 42A are butt welded. As shown in this figure, the leg upper surface plate 42A is butt welded at a predetermined angle C with respect to the upper surface plate 41A. In this way, the upper surface plate 41 and the leg upper surface plate 42 can be integrally formed without bending as in the prior art.
[0019]
According to such a structure, if a tapped hole is provided directly on the upper surface plate to attach the inner race, the conventional annular mounting member is not necessary.
Further, since the upper surface plate (thick plate) and the leg portion upper surface plate (thin plate) are welded, there is no need to bend the upper surface plate (thick plate) and form the leg portion as in the conventional case.
[0020]
Next, a second embodiment of the center frame turning support device will be described with reference to FIG.
The same reference numerals as those in FIGS. 1 to 3 in the first embodiment are the same, and the description is omitted. The inner race 4B and the spacer 4b of the swing circle 22B are sandwiched between the upper surface plate 41 and the revolving frame 1 shown in the drawing and fastened with bolts 7A.
According to such a structure, since the inner race 4B can be made small, the manufacturing cost becomes low.
[0021]
Next, a third embodiment of the center frame turning support device will be described with reference to FIGS.
Components with the same reference numerals as those in FIGS. 1 to 4 are the same and will not be described.
The grease bath 50 is formed by welding an inner peripheral side plate 52 to an annular bottom plate 51, the outer peripheral portion of the bottom plate 51 is sandwiched between the inner race 4 </ b> B and the spacer 4 b, and is fastened to the upper surface plate 41 by bolts 54. ing.
FIG. 6 is a detailed view of part A of FIG. The inner race 4B and the spacer 4b are interposed between the upper surface plate 41 of the center frame 2A and the revolving frame 1 shown in the figure, and the grease bath 50 is inserted into the annular groove 53 provided between the inner race 4B and the spacer 4b. The outer periphery of the bottom plate 51 is attached with bolts 54.
An annular seal 55 made of an elastic material such as rubber is attached to the outer periphery of the bottom plate 51 of the grease bath 50.
Further, a seal 17 is attached to the upper end portion of the inner peripheral side plate 52 of the grease bath 50 and brought into contact with the revolving frame 1 to prevent the grease 18 from leaking.
Accordingly, even when the upper surface plate 41 is deformed or bent, the grease bath 50 can follow and the grease bath 50 is not damaged.
[0022]
【The invention's effect】
As described above, according to the pivoting frame supporting device of the hydraulic excavator of the present invention, the upper surface plate and the leg upper surface plate of the center frame are made of different materials, the upper surface plate is a thick plate, and the leg upper surface plate is a thin plate. Since each of them is butt-welded, it is not necessary to bend the thick plate as in the conventional method to form the leg upper surface plate, so that it is easy to manufacture and an annular shape fixed to the conventional upper surface plate. By eliminating the mounting member, durability and economy are improved.
[0023]
In addition, by inserting a spacer between the inner race and the upper surface plate, the inner race can be made smaller, so that the cost is reduced.
[0024]
Furthermore, by holding the grease bath between the inner race and the spacer via an annular sealing member made of an elastic body such as rubber, deformation and deflection are prevented, durability is improved, and the structure is simple and inexpensive. .
[Brief description of the drawings]
FIG. 1 is a perspective view of a center frame according to the present invention.
FIG. 2 is a first embodiment of the center frame turning support device.
FIG. 3 is another explanatory view showing a welded state of the upper surface plate and the leg upper surface plate of the first embodiment.
FIG. 4 is a second embodiment of the center frame turning support device.
FIG. 5 shows a third embodiment of the center frame turning support device.
6 is a detailed view of part A of the grease bath mounting part of FIG. 5; FIG.
FIG. 7 is a side view of a hydraulic excavator.
FIG. 8 is a plan view of a conventional turning device.
9 is a cross-sectional view taken along the line MM in FIG. 6;
FIG. 10 is a configuration diagram of a conventional grease bath.
FIG. 11 is a perspective view of a conventional center frame.
12 is a detailed view of a portion P in FIG. 11. FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Turning frame, 2, 2A ... Center frame, 3 ... Crawler frame, 4, 4A, 4B ... Inner race, 4a ... Internal gear, 4b ... Spacer, 5 ... Outer race, 6 ... Ball, 7, 7A, 8 ... bolt, 9 ... output shaft, 9a ... swing pinion, 10, 41, 41A ... top plate, 11a, 42, 42A ... leg top plate, 12 ... annular mounting member, 11c ... rib, 11d, 11e ... side plate, 17 ... seal, 20 ... hydraulic excavator, 21 ... lower traveling body, 22, 22A, 22B ... swing circle, 23 ... upper turning body, 25 ... turning motor, 50 ... grease bath, 51 ... bottom plate 52 ... inner peripheral side plate, 53 ... annular groove, 55 ... annular seal.

Claims (4)

A center frame connected to the left and right crawler frames, an inner race fixed to the center frame, an internal gear provided on the inner race, a swing motor attached to the swing frame of the upper swing body, and an output of the swing motor A pinion fixed to the shaft, an inner gear of the inner race, an outer race provided on the swivel frame, and an annular swivel bearing formed of balls, and the pinion and the inner race of the inner race driven by a swivel motor A support device for a swing frame of a hydraulic excavator that meshes with a gear to drive a swing of an upper swing body, and the center frame (2A) is formed by fixing an upper surface plate (41) and a leg upper surface plate (42). the tapped hole formed in the upper plate, the turning of the hydraulic excavator, characterized in that it has attached to the inner race to the top plate by bolts Frame of the supporting device. A spacer (4b) is interposed between the upper surface plate (41) and the inner race (4B), and the inner race (4B) and the spacer ( 4b ) are attached to the upper surface plate (41) with bolts . 2. A support device for a swing frame of a hydraulic excavator according to claim 1. Said inner race (4B) and the hydraulic pressure according to claim 2, characterized in that挾着the outer peripheral portion of the bottom plate of the grease bath (50) (51) in an annular groove (53) provided between the spacer 4b) Support device for excavator swivel frame. On the outer peripheral portion of the bottom plate (51) of the grease bath (50), an annular seal (55) made of an elastic body, the upper end portion of the inner peripheral side plate (52) of the grease bath (50), and the swivel frame (1) The support device for the swivel frame of the hydraulic excavator according to claim 3, further comprising a seal (17) attached between the support frame and the hydraulic excavator.

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