JP2001059525A - Self-aligning roller bearing for swing drive device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a self-aligning roller bearing for a swing drive device capable of reducing total cost by reducing the number of part items required to be assembled in the device for lubricating the lower self-aligning roller bearing of the two of upper and lower self-aligning roller bearings for supporting an output shaft of a planet gear speed reduction mechanism in the swing drive device and reducing man-hours for assembly of the device. SOLUTION: An oil seal 6 having aligning property is attached on at least one side and assembled in a planet gear speed reduction mechanism so as to face downward, and a sealing space to seal grease G for lubricating lower self-aligning roller bearing 42 for supporting an output shaft 36 is partitioned by an upper seal 42a and the oil seal 6 integrated with the bearing 42 to dispense with a conventional spacer and a lower seal, they by attaining reduction of the number of part items by unitizing the oil seal 6 against the bearing 42, reduction of man-hours of assembly of the device, and the miniaturization of the device.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a self-aligning roller bearing for a swing drive device used in, for example, a mini hydraulic excavator.

[0002]

2. Description of the Related Art In general, a swing drive device used in a mini-hydraulic shovel or the like generally reduces the rotation of a drive source such as a hydraulic motor by a planetary gear speed reduction mechanism, and the speed reduction mechanism fixes a casing to a swing body, and The output shaft is provided with a pinion gear, and the pinion gear meshes with a ring gear fixedly arranged on the vehicle body side, thereby turning the revolving body.

FIG. 3 is a cross-sectional view of a main part of an example of the structure of such a turning drive device. In this example, a two-stage planetary gear mechanism is used, in which 30 is a casing fixed to the revolving unit T, 31a and 31b are sun gears,
32a and 32b are planetary gears meshing with the respective sun gears 31a and 31b, and 33a and 33b are respective planetary gears 32a and 3b.
2b is supported by shafts 33c and 33d, and 34a and 34b are internal gears meshing with the planetary gears 32a and 32b, respectively. The first-stage sun gear 31a has a rotating shaft ( Input shaft) 35. The second-stage carrier 33b is connected to the output shaft 36 by key groove fitting or the like.
Is decelerated and transmitted to the output shaft 36. And
A pinion gear 37 is provided at the lower end of the output shaft 36,
A ring gear 38 on which the pinion gear 37 is fixedly arranged.
The pinion gear 37 is rotated by the driving of the rotating shaft 35, and the revolving body T is revolved.

The output shaft 36 is rotatably supported by the casing 30 via two upper and lower self-aligning roller bearings 41, 42. The two self-aligning roller bearings 41, 4 are provided.
By making the span between the two relatively large, it is considered to withstand a radial load F acting on the shaft end of the output shaft 36 from one side via a pinion gear 37 provided in a cantilever shape at the lower end thereof. .

[0005] Of the self-aligning roller bearings 41 and 42, the upper bearing 41 is lubricated integrally with the planetary gear mechanism.
The grease G is sealed between the upper seal 42a inserted between the shaft 30 and the output shaft 36 and the lower seal 42b provided integrally with the spacer 42c at the lower end of the casing 30.

[0006]

In the above-described conventional rotary drive device, the upper seal 42a and the lower seal 42a are used to seal the lubricating grease G of the lower spherical roller bearing 42. The side seal 42b is required, which causes an increase in the number of parts and an increase in the number of assembly steps.

An object of the present invention is to provide an upper and lower shaft for supporting the output shaft of a planetary gear reduction mechanism for such a turning drive.
Among the individual spherical roller bearings, the number of parts that need to be incorporated into the device for lubrication of the lower spherical roller bearings is reduced, and the assembly cost of the device is reduced, reducing the total cost. It is an object of the present invention to provide a self-aligning roller bearing for a swing drive device that can achieve a reduction in the size of the device.

[0008]

In order to achieve the above object, a self-aligning roller bearing for a slewing drive device according to the present invention uses a planetary gear reduction mechanism having a casing fixed to a slewing body for rotating a drive source. In a turning drive device for turning the revolving body by reducing the speed and engaging a pinion gear fixed to a vertical output shaft of the planetary gear reduction mechanism with a ring gear, two upper and lower automatic adjustments supporting the output shaft are provided. A self-aligning roller bearing for a slewing drive device used on a lower side of the roller bearings, wherein an oil having a centering property is provided on at least one of axial ends of one of inner and outer rings of the bearing. A seal is mounted on the planetary gear reduction mechanism so that an end face of the oil seal on the mounting side faces downward.

According to the present invention, the lower self-aligning roller bearing which supports the output shaft of the planetary gear reduction mechanism of the turning drive device has a centering property on the lower end face side in a state of being assembled into the device. The intended purpose is to be achieved by integrating the oil seal.

That is, in the lower spherical roller bearing of the upper and lower spherical roller bearings for supporting the output shaft, conventionally, a space for enclosing grease for lubrication is formed. Upper and lower seals are used. Of these, the upper seal requires a suitable span between the upper and lower self-aligning roller bearings. From the viewpoint of securing the grease amount for the spherical roller bearing, it is desirable to provide it at a position separated from the bearing.However, the lower seal is integrated into the bearing from the beginning to form a unit. As a result, it is possible to reduce the number of parts of the swing drive device and the number of assembling steps without requiring a spacer and a lower seal separately from the bearing, and further to eliminate the need for the spacer. To Reducing the axial dimension I, it can contribute to downsizing of the apparatus.

Here, the oil seal used in the self-aligning roller bearing of the present invention is supposed to be eccentric because the bearing has eccentricity. The structure disclosed in Japanese Patent Application Laid-Open No. 4-29130 can be suitably used, and by adopting this structure, the output shaft is radially connected to the shaft end from one side through a pinion gear provided in a cantilever shape at the tip thereof. The sealing performance can be effectively maintained against the axial eccentricity of the inner race caused by receiving the load.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an axially parallel sectional view showing the configuration of the embodiment of the present invention. A plurality of spherical rollers 3 as rolling elements are rotatably arranged between the inner ring 1 and the outer ring 2. The inner race 1 has a double-row raceway surface, and the raceway surface of the outer race 2 forms a part of a spherical surface whose center of curvature is the bearing center. The spherical rollers 3 are held by holders 4a and 4b so as to be arranged at equal intervals in the circumferential direction for each raceway surface of the inner ring 1. In addition, 5
Is a floating guide wheel.

The self-aligning roller bearing has an oil seal 6 attached to only one end face thereof. That is, on one end side of the inner ring 1, a seal surface 11 with which a seal lip described later of the oil seal 6 is in sliding contact is formed, and the seal surface 11 is a straight cylindrical surface. A fitting groove 21 for fitting the oil seal 6 is formed at one end of the outer ring 2.

[0014] The oil seal 6 is formed of
Has a structure equivalent to that disclosed in the above publication, and is mainly composed of a metal core 61, a rubber elastic member 62 integrated with the metal core 61, and a garter spring 63. . The core metal 61 is generally annular and has a substantially L-shaped cross section, and its outer diameter surface is formed in the fitting groove 21 of the outer ring 2.
Is attached to the outer ring 2 so as to be along the bottom surface (inner peripheral surface).

The elastic member 62 has a seal lip 62a, a flexible portion 62b, and a lip waist portion 62c. The main lip M, which is in sliding contact with the seal surface 11 of the inner ring 1 over the entire circumference, is provided on the seal lip 62a. An auxiliary lip S that is also in sliding contact with the seal surface 11 over the entire circumference is formed, and a garter spring 63 is fitted on the outer peripheral side of the main lip M. The flexible portion 62b is interposed between the metal core 61 and the seal lip 62a,
Is inclined in a direction of a small diameter from the inner periphery of the cored bar 61 toward the inside in the axial direction, and the tip thereof is connected to the lip waist portion 62c. The lip waist portion 62c plays a role of reinforcing the seal lip 62a, and a reinforcing ring 64 made of a material having relatively high rigidity is integrated with a side surface portion thereof.

According to the configuration of the oil seal 6 described above, when the inner ring 1 is eccentric due to its centering action due to the inclination or eccentricity of the shaft into which the inner ring 1 is fitted, the flexible portion 62b expands and contracts in the radial direction. As a result, the seal lip 62a is displaced following the eccentricity, and the seal lip 62a is displaced while remaining substantially circular due to the presence of the reinforcing ring 64 of the lip waist portion 63c. Even when the eccentricity is equal to or more than the interference, a substantially uniform contact pattern over the entire circumference with respect to the seal surface 11 is maintained. Accordingly, even when the inner ring 1 is largely eccentric or inclined, the eccentricity can be effectively followed, and the sealing performance can be always maintained in accordance with the aligning action of the self-aligning roller bearing.

Now, the above embodiment of the present invention will be described with reference to FIG.
Is used as a lower self-aligning roller bearing 42 that supports the output shaft 36 of the planetary gear reduction mechanism in the turning drive device exemplified in (1), and is incorporated in the device such that the mounting end surface of the oil seal 6 faces downward. . That is, FIG. 2 is a cross-sectional view of a main part in which the embodiment of the present invention is adopted as the lower self-aligning roller bearing 42 of the output shaft 36. In the embodiment of the present invention, The outer ring 2 is press-fitted into the output shaft 36, and is incorporated into the device while being fitted into the casing 30 of the planetary gear reduction mechanism. Upper spherical roller bearing 4
1 is the same as the conventional one. The upper seal 42a for partitioning the upper end of the grease sealed space of the lower self-aligning roller bearing 42 is the same as the conventional upper seal 42a. However, by adopting the embodiment of the present invention, the conventional lower seal 42a is used. The grease G for lubricating the lower self-aligning roller bearing 42 becomes unnecessary because the lubrication roller 42b and the spacer 42c become unnecessary.
It is sealed in a space partitioned by the upper seal 42a and the oil seal 6 integrated with one end surface of the bearing 42.

As a result, by employing the embodiment of the present invention shown in FIG. 1, the number of components constituting the turning drive device is reduced, the number of assembling steps can be reduced, and the total cost can be reduced. Becomes possible. Moreover, since the upper seal 42a is the same as the conventional one, the amount of grease G for lubricating the lower spherical roller bearing 42 is secured, and the oil seal 6 has a high eccentric follow-up function. Therefore, even if a high radial load acts on the end face of the output shaft 36, the sealing performance can be maintained. Also, a bearing 4 is used instead of the lower seal 42b and the spacer 42c.
The use of the oil seal 6 integrated with the apparatus 2 is also effective in reducing the axial dimension (height) of the apparatus.

In the above-described embodiment, the lower seal 4
Although the bearing 42 having only the seal 2b is disclosed, the upper seal 42a may be disposed in the bearing 42 in order to further reduce the number of parts and the number of assembling steps.

[0020]

According to the present invention, the lower self-aligning roller bearing of the upper and lower bearings that support the output shaft of the planetary gear reduction mechanism of the turning drive device faces downward when incorporated into the device. Alignment only at the end (eccentricity tracking)
In order to form a sealed space for grease for lubricating the bearing, a lower seal among the seals incorporated on the upper and lower sides of the bearing in this type of conventional device is provided because the oil seal having Is not required, the number of parts can be reduced, and the man-hours required for assembling the device can be reduced, and the size of the device can be reduced by unitizing the self-aligning roller bearing and the oil seal.

[Brief description of the drawings]

FIG. 1 is an axially parallel sectional view of an embodiment of the present invention.

FIG. 2 is a sectional view of a main part of a turning drive device incorporating an embodiment of the present invention.

FIG. 3 is a sectional view of a main part of a conventional turning drive device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Inner ring 11 Seal surface 2 Outer ring 21 Fitting groove 3 Spherical roller 4a, 4b Cage 5 Floating guide ring 6 Oil seal 61 Core metal 62 Elastic member 62a Seal lip 62b Flexible part 62c Lip waist 63 Garter spring 64 Reinforcing ring 30 Planet Gear reduction mechanism casing 36 Output shaft 37 Pinion gear 41 Upper spherical roller bearing 42 Lower spherical roller bearing 42a Upper seal 42b Lower seal G Grease

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Yoshiaki Horiuchi 3-5-8 Minamisenba, Chuo-ku, Osaka-shi, Osaka Inside Koyo Seiko Co., Ltd. (72) Inventor Hiroyoshi Ito 3-5-2 Minamisenba, Chuo-ku, Osaka-shi, Osaka No. 8 F-term in Koyo Seiko Co., Ltd. (Reference) 2D015 DA02 DA04 3J006 AE06 3J012 AB01 AB13 BB03 BB05 EB01 FB11 HB04 3J016 AA05 BB03 CA03

Claims (1)

[Claims] The rotation of a drive source is reduced by a planetary gear reduction mechanism having a casing fixed to a revolving body, and a pinion gear fixed to a vertical output shaft of the planetary gear reduction mechanism is meshed with a ring gear. Thus, in the turning drive device for turning the turning body, the upper and lower two self-aligning roller bearings supporting the output shaft are self-aligning roller bearings for a turning drive device used on a lower side, wherein the bearing An oil seal having a centering property is mounted on at least one of both axial ends of one of the inner and outer races, and the planetary gear reduction is performed such that an end face on the mounting side of the oil seal faces downward. A self-aligning bearing for a turning drive, wherein the self-aligning bearing is incorporated into a mechanism.