JP3321704B2 - Swivel for construction machinery - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a revolving device for revolving an upper revolving unit mounted on a lower traveling unit of a construction machine such as a hydraulic shovel or a hydraulic crane.

[0002]

2. Description of the Related Art FIG. 6 shows an example of a hydraulic excavator. An upper revolving unit 2 is mounted on a lower traveling unit 1 via a revolving unit described later.
Is mounted so as to be freely rotatable. The turning room 3 of the upper turning body 2 includes a machine room 4, a cab 5, and a counterweight 6.
The working device 7 is attached to the front of the revolving frame 3 so as to be able to descend.

Next, a conventional swivel device shown in FIG. 7 will be described. An inner ring of a turning wheel 8 provided with an internal gear 8 a is fixed to the lower traveling body 1, and a lower flange of a housing 9 and an outer ring of the turning wheel 8 are attached to the turning frame 3. A ring gear 10 provided with a two-stage internal gear is attached to the upper flange of the housing 9, and a hydraulic motor 11 is installed above the ring gear 10.

[0004] An upper tapered roller bearing 13 and a lower tapered roller bearing 14 for supporting the pinion shaft 12 are attached to the inner peripheral wall of the housing 9. The pinion 15 provided at the lower end of the pinion shaft 12 meshes with the internal gear 8 a of the turning wheel 8.

[0005] A sun gear 17 constituting a planetary gear reduction mechanism G is attached to an output shaft 16 of the hydraulic motor 11. In the ring gear 10, a plurality of planetary gears 18, a carrier 19, a sun gear 20, a plurality of planetary gears 21, and a carrier 22 that are linked to the sun gear 17 are provided. The carrier 22 is connected to the upper end of the pinion shaft 12 via a spline 23.

The rotation of the output shaft 16 is transmitted from the sun gear 17 to the planetary gear 18. The planetary gear 18 revolves while rotating around the inner circumference of the ring gear 10, and the revolution is transmitted to the sun gear 20 via the carrier 19. . And the sun gear 20
The planetary gear 21 revolves around the inner circumference of the ring gear 10 while rotating, and the revolution is transmitted from the carrier 22 to the pinion shaft 12 via the spline 23. As described above, the rotation of the hydraulic motor 11 is reduced by two stages by the planetary gear reduction mechanism G, and is transmitted to the pinion shaft 12 as a high torque rotation.

[0007] When the pinion shaft 12 rotates, the pinion 15 revolves while rotating on the inner periphery of the revolving wheel 8, and the revolution is transmitted from the pinion shaft 12 to the revolving frame 3 via the housing 9, and The revolving superstructure 2 performs a revolving operation on the undercarriage 1.

The pinion shaft 12 is provided on the upper small-diameter portion 1.
2a and a lower large-diameter portion 12b are formed in a stepped cylindrical shape. The above-described upper tapered roller bearing 13 includes:
An inner ring 13a fitted to the small diameter portion 12a of the pinion shaft 12, an outer ring 13b attached to the mounting step 9a of the housing 9, and a plurality of tapered rollers 13c interposed between the inner ring 13a and the outer ring 13b. A nut 280 is screwed into the small diameter portion 12a.
The upper tapered roller bearing 13 and the lower tapered roller bearing 14 are fixed by tightening 80.

The lower tapered roller bearing 14 includes an inner ring 14 a fitted to the large diameter portion 12 b of the pinion shaft 12,
The housing 10 includes an outer ring 14b attached to the attachment step 10b of the housing 10, and a plurality of tapered rollers 14c interposed between the inner ring 14a and the outer ring 14b.

A sleeve 24 is mounted between the inner ring 14a of the lower tapered roller bearing 14 and the upper end surface of the pinion 15, and the outer peripheral surface of the sleeve 24 is
Is in contact with the oil seal 25 attached to the oil seal attachment step. Sleeve 24, oil seal 25
Thereby, the lubricating oil filled in the turning device is held. A drain pipe 26 for guiding the lubricating oil in the turning device to the outside is connected to the housing 9. On the inner peripheral wall of the housing 9, there is provided a drain hole 27 composed of a vertical hole opening vertically and a horizontal hole communicating with the drain pipe 26.

[0011]

According to the present invention, a pinion shaft rotated via a reduction gear mechanism is supported by an upper tapered roller bearing and a lower tapered roller bearing mounted on an inner peripheral wall of a housing. Its housing
The outer ring of the upper tapered roller bearing was installed in
Part of the upper tapered roller bearing
Opening on the inner peripheral wall of the housing
In a revolving device of a construction machine in which a vertical hole is provided and an oil seal is arranged between a lower tapered roller bearing and a pinion, a pinion shaft is formed by a nut having an outer diameter larger than an opening of the upper tapered roller bearing. , And the nut shields an area above the opening of the bearing to reduce the opening area between the bearing support and the reduction gear mechanism.

During driving, the planetary gear reduction mechanism G becomes high in temperature due to frictional heat of gears and bearings, and raises the temperature of lubricating oil. The high-temperature lubricating oil is positively reduced by the flow of the lubricating oil as shown by the arrows generated by the pumping action of the tapered roller bearings 13 and 14.
By being sent to the lower part, the heat of the upper part of the reduction mechanism G is transmitted to the lower part of the reduction mechanism G. When the temperature of the upper part of the reduction mechanism G (inside of the ring gear 10) becomes high, the lower part of the reduction gear (the housing 9 holding the tapered bearings 13 and 14) is heated.
Inside) also becomes high temperature.

The material of the oil seal 25 is generally vulnerable to heat, and the service life of a material made of nitrile rubber is greatly reduced when the ambient temperature rises to 70 ° C. or higher. For this reason, when the turning device is continuously used at a high temperature, the oil seal 25 is damaged in a shorter period than the expected service life, the lubricating oil leaks from the lower portion of the turning device, and the speed reduction mechanism G due to insufficient lubricating oil. Galling and seizure occur.

The present invention has been made in view of the above circumstances, and suppresses the flow of lubricating oil in a turning device between upper and lower portions by a simple means, so that the temperature rise in the lower portion of the speed reducer (near an oil seal) can be reduced. The purpose is to do.

[0015]

SUMMARY OF THE INVENTION The present invention relates to a turning device for a construction machine in which a pinion shaft rotated via a reduction gear mechanism is supported by an upper tapered roller bearing and a lower tapered roller bearing mounted in a housing. ,
The upper tapered roller bearing is fixed to a pinion shaft by a nut formed with an outer diameter larger than the opening of the bearing, and the nut is shielded from above the opening of the bearing.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an embodiment of the present invention shown in FIG. 1 will be described. In the figure, the same components as those in FIG. 7 are denoted by the same reference numerals.

The upper tapered roller bearing 13 is fixed to the small diameter portion 12a of the pinion shaft 12 by a nut 28 having an outer diameter larger than the opening of the bearing. The upper part is shielded. Thus, the opening area of the upper tapered roller bearing 13 is reduced, and the flow of the lubricating oil between the upper and lower parts is reduced by largely bending the flow path of the lubricating oil.

In a conventional turning device, as shown in FIG.
High-temperature lubricating oil near the planetary gear reduction mechanism G directly penetrated into the drain hole 27. However, in the turning device of the present invention, the flow of the lubricating oil changes, the opening area between the bearing support portion and the reduction mechanism portion is reduced, and the lubrication of the lower portion of the turning device pushed up by the pumping action of the upper tapered roller bearing 13 is performed. The oil hits the nut 28 and is returned to the drain hole 27 again, so that the flow of the lubricating oil between the upper and lower portions of the turning device is suppressed to a small value.

The lubricating oil in the turning device is cooled mainly by removing heat from the wall surface of the housing 9. In the turning device of the present invention, as shown by an arrow a, the lubricating oil along the housing 9 is cooled. The generation of the positive flow promotes cooling of the lubricating oil.

FIG. 2 shows another embodiment of the present invention in which an annular projection 33a whose outer diameter is larger than the outer diameter of the outer ring 13b of the upper tapered roller bearing 13 is provided on the lower end surface side of the nut 33. FIG. 3 shows another embodiment of the present invention in which an annular projection 29a whose outer diameter is substantially equal to the outer diameter of the outer ring 13b of the upper tapered roller bearing 13 is provided on the upper end surface side of the nut 29. FIG. 4 shows that the outer diameter of the outer ring 1
Another embodiment of the present invention having an annular projection 30a larger than the outer diameter of 3b is shown. Upper tapered roller bearing 13
Above the openings are annular projections 33a, 29a, 30a
Shielded by. In the embodiment of FIG. 4, the opening of the upper tapered roller bearing 13 is wide, but the gap between the outer peripheral surface of the annular projection 30 a and the housing 9 is small, the function is the same, and the oil between the upper and lower parts of the turning device is further reduced. The effect of separating the flow can be expected.

FIG. 5 shows another embodiment of the present invention in which an annular projecting plate 32 is fastened between a nut 31 and an inner ring 13a.

[0022]

According to the present invention, it is expected that the lubricating oil temperature in the vicinity of the oil seal at the lower part of the turning device will be lower by up to about 10 ° C. than the conventional turning device. In the case of an oil seal made of nitrile rubber, the difference of the ambient temperature of 10 ° C. during the continuous operation is a maximum of 100
It is known to have an effect of 0 hours or more. Therefore, in the turning device according to the present invention, the life of the oil seal can be greatly extended as compared with the conventional one.

Further, by lowering the temperature of the lubricating oil at the lower portion of the swivel device, a decrease in viscosity due to a rise in the temperature of the lubricating oil and a change with time such as oxidation are suppressed as compared with the conventional lubricating oil, and the pinion shaft is supported. It also works well for lubrication of the bearing and can prolong the life of the bearing and lubricating oil. Therefore, the durability and reliability of the turning device itself are improved.

In addition, by relaxing the temperature usage conditions,
Sufficient durability can be expected even with an inexpensive oil seal with low heat resistance, which could not be used with conventional swiveling devices. Further, since the opening of the bearing that supports the pinion shaft is not completely closed, the circulation of the lubricating oil necessary for good lubrication of the bearing is ensured. In addition, since the inside of the turning device is not completely separated from the top and bottom, it is not necessary to separately install an oil supply port and an oil discharge port above and below the turning device.

[Brief description of the drawings]

FIG. 1 is a cross-sectional side view showing an embodiment of a turning device for a construction machine according to the present invention.

FIG. 2 is a sectional side view showing another embodiment of the present invention.

FIG. 3 is a sectional side view showing another embodiment of the present invention.

FIG. 4 is a sectional side view showing another embodiment of the present invention.

FIG. 5 is a sectional side view showing another embodiment of the present invention.

FIG. 6 is a side view showing an example of a hydraulic shovel.

FIG. 7 is a sectional side view showing a conventional turning device.

[Explanation of symbols]

 9 Housing 11 Hydraulic motor 12 Pinion shaft 13 Upper tapered roller bearing 14 Lower tapered roller bearing 15 Pinion G planetary gear reduction mechanism 24 Sleeve 25 Oil seal 26 Drain pipe 27 Drain hole 28 Nut 29 Nut 29a Annular projection 30 Nut 30a Annular projection Part 31 Nut 32 Annular protruding plate 33 Nut 33a Annular protruding part

──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Yuji Igawa 650 Kandamachi, Tsuchiura-shi, Ibaraki Prefecture Within Hitachi Construction Machinery Engineering Co., Ltd. In the factory (56) References JP-A-7-4475 (JP, A) JP-A-10-281265 (JP, A) JP-A-4-89150 (JP, U) JP-A-5-90022 (JP, U) (58) Fields surveyed (Int. Cl. ⁷ , DB name) E02F 9/12

Claims (2)

(57) [Claims] 1. A pinion shaft rotated via a reduction gear mechanism is supported by an upper tapered roller bearing and a lower tapered roller bearing mounted on an inner peripheral wall of a housing, and an upper tapered roller shaft in the housing.
The part where the outer ring of the bearing is attached, and the upper taper
Open the housing so that it opens above and below the roller bearing.
In a turning device of a construction machine in which a vertical hole which opens up and down is provided in an inner peripheral wall portion and an oil seal is arranged between a lower taper roller bearing and a pinion, an upper taper roller bearing is provided with an outer portion larger than an opening of the bearing. A turning device for a construction machine, wherein the turning device is fixed to a pinion shaft with a nut having a diameter, the upper portion of the bearing is shielded by the nut, and the opening area between the bearing support portion and the reduction gear mechanism portion is reduced. . 2. A pinion shaft which is rotated via a reduction gear mechanism is supported by an upper tapered roller bearing and a lower tapered roller bearing mounted on an inner peripheral wall of a housing, and an upper tapered roller shaft in the housing.
The part where the outer ring of the bearing is attached, and the upper taper
Open the housing so that it opens above and below the roller bearing.
In a turning device of a construction machine in which a vertical hole which opens up and down is provided in an inner peripheral wall portion and an oil seal is arranged between a lower taper roller bearing and a pinion, an upper taper roller bearing is provided with an outer portion larger than an opening of the bearing. It is fixed to a pinion shaft with a nut having an annular projection with a diameter, shields the upper portion of the bearing opening with the annular projection, and reduces the opening area between the bearing support and the reduction gear mechanism. Construction equipment swivel.