JPH053798Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field This invention relates to a rotating reducer having a structure that prevents grease in an oil tank from entering the rotating reducer of a branch rotating body from a shaft penetrating portion.

BACKGROUND TECHNOLOGY In general, construction and cargo handling machines in which the upper rotating body can fully rotate relative to the lower traveling body are shown in FIG.
As shown in the reference in FIG. 5, the upper revolving body 11 is
The outer ring 5 is attached to the upper surface of the center of the main frame of the lower traveling body 12 on the upper rotating body 11 side, and the inner ring 4 having an internal gear is attached to the lower traveling body 12 side. There is. The upper rotating body 11 is provided with a swing device 2 whose input shaft is driven by power such as a hydraulic motor, and whose output shaft end meshes with an internal gear of an inner ring 4 of a swing bearing 3. A pinion 6 is fixedly installed, and when the pinion 6 rotates, the upper rotating body 11 is rotated by the reaction force.

In the above structure, the upper revolving body 11, which has a large weight and inertial force, is started and stopped entirely by the pinion 6 and the internal gear of the inner ring 4 that meshes with the pinion 6. Therefore, a strong load is frequently applied to the tooth surfaces of both teeth, and they also slide against each other along the tooth row, so in order to improve their durability, a conventional method has been used, as shown in Fig. 5. The outer periphery of the flange of a cover 7 made of a thin steel plate having a protrusion in the center and a flange-like outer periphery is fixed to the mounting member of the swing bearing 3 on the upper surface of the lower running body 12, and Between the internal gear and the protrusion of the cover 7,
An open annular oil tank 8 is formed to ensure the movement width of the pinion 6, and this oil tank 8 is filled with an appropriate amount of grease to lubricate the tooth surfaces. On the other hand, as shown in the cross-sectional view of FIG. 6, the structure near the output shaft end of the swing reducer 2 that constitutes the swing device 1 is such that the output shaft is supported by a bearing built into the casing of the swing reducer 2. The inside of the casing, including the bearings, is sealed and the internal components are protected with separate lubricating oil, so naturally there is a gap between the stationary casing and the rotating output shaft as shown in Figure 7. An oil seal 19 having lips a and b as shown in the enlarged view of the main part is provided to prevent internal lubricating oil from flowing out and foreign matter from entering from the outside.

Problems to be Solved by the Invention In the swing device having the above structure, the oil seal 19 and the pinion 6 are located relatively close to each other in view of the strength of the swing reducer output shaft.
The internal gear of the slewing bearing meshes with the pinion in an oil tank filled with grease.
Grease is pushed out around the meshing teeth, and the grease that is pushed out to the oil seal side of the swing reducer pushes the lip of the oil seal open and enters the casing of the swing reducer, providing special lubrication inside. Not only does it mix with oil and deteriorate its properties, but if the amount of intruding oil increases further, it can cause accidents such as lubricating oil spouting out from openings such as the oil level gauge of the swing reduction gear.

It is an object of the present invention to provide a structure for an output shaft penetrating portion that prevents such accidents and allows the swing reducer to withstand long-term use.

Means for Solving the Problems In order to solve the above problems, this invention takes the following steps. In other words, (a) In the output shaft penetration part of the swing reducer, the outer periphery of the sleeve that rotates with the output shaft or the sleeve part that is integrated with the output shaft and the bearing that is fixed to the swing reducer body and supports the output shaft. A sleeve and a retainer are provided so that they are in contact with the output shaft penetrating portion on the inner circumference of the retainer with a small gap, and (b) the sleeve rotates together with the sleeve in an annular space formed by the outer circumferential surface of the sleeve and the retainer. An oil seal is provided with a lip that abuts on the inner circumferential wall surface of the retainer on the side farthest from the minute gap.

Function The grease filled in the oil tank for tooth surface lubrication is forcefully pushed out toward the periphery of the teeth due to the engagement between the pinion and the internal gear, and a portion of the grease is pushed out toward the periphery of the teeth. The oil starts to spray towards the seal and tries to get inside, but due to the small gap between the outer circumference of the sleeve and the inner circumference of the retainer,
The force is reduced, and since the lip of the oil seal is at the farthest position from the minute gap, it is not directly hit by the jet of grease, and the grease pushes the lip apart and enters the inside of the swing reducer. There will be no intrusion.

Embodiment An embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a cross-sectional view showing the main parts of the drive part in the swing device 1. The swing device 2 is equipped with an oil level gauge 16, an air breather 17, etc. on the upper part, and decelerates the rotational input of a hydraulic motor (not shown). This is a rotating reducer that transmits information to the output shaft 14 through the flange part of its casing, and as described above, the upper rotating body 1
It is fixed to the frame of 1. The output shaft 14 is pivotally supported by a bearing 15 held in the casing of the swing reducer 2 and the retainer 13, and a pinion 6 that meshes with an internal gear provided on the inner ring 4 of the swing bearing 3 is fixedly installed at the shaft end. The end face of the pinion 6 and the bearing 1
A sleeve 10, which is fitted onto the output shaft 14 and rotates therewith, is press-fitted between the output shaft 14 and the output shaft 14. Reference numeral 9 denotes an oil seal, which is encircled in the inner space of the retainer 13 and is made of an elastic material and has lips a, as shown in FIG. 2, which is an enlarged view of part A.
The lips a and b rotate together with the sleeve 10, and the lips a and b always slide in contact with the inner wall of the retainer 13, preventing the lubricating oil in the casing of the swing reducer 2 from flowing out, and preventing grease from flowing from the outside. Prevents foreign matter such as dust from entering.

Note that 5, 7, 8, and 12 respectively indicate the outer ring, cover, oil tank, and lower running body of the swing bearing 3, as in the conventional swing device described above, and the sleeve 10 indicates the output shaft 14 or the pinion. It is also possible that it is configured integrally with 6.

As mentioned above, both lips a and b are made of oil-resistant elastic material and are always in line contact with the inner wall of the retainer 13, but the contact pressure is due to their own elastic force and the second lip. As shown in the figure, this is due to the elastic force of coil springs d and d which are wound in an annular manner from the outer periphery.

In addition, the retainer 13 forms an annular space with the outer circumferential surface of the sleeve 10 so as to enclose the oil seal 9, and the flange portion e is connected to the sleeve 1.
It is arranged so as to bite into the stepped portion of the outer periphery of No. 0, and faces each other with a minute gap B in between. In Fig. 2, the minute gap B is a hook-shaped linear gap, but it may also be in the shape of a broken line or a curved line. It is necessary to be placed in position.

The operation of the swing reduction gear of this invention having the above configuration will be explained.

In conventional reduction gears, the pinion 6 and the internal gear provided in the inner ring 4 of the swing bearing 3, which mesh in an oil-immersed state, spray grease around the teeth as the meshing progresses, and some of the droplets are Naturally, the part enters the inside from the boundary between the sleeve and the retainer, expands the lip a of the oil seal 19, enters the space c formed by the lips a and b, increases the internal pressure of the space c, and finally When the lips a and b are opened up and down, the grease enters the casing of the swing reducer along with dust, degrading the lubricating oil inside, and causing damage to internal components and other accidents. In the structure of this invention, the strongly sprayed grease droplets are generally generated as a type of intermittent pulsating pressure, so while passing through the minute gap B, the spray pressure is reduced due to the labyrinth effect. , Furthermore, this minute gap B and the lips a and b of the oil seal 9
Since the lip b is located at the farthest position from the lip b, grease droplets do not directly collide with the lip b, thus maintaining good sealing performance.

FIG. 3 shows a second embodiment in which the structure of the oil seal used in this invention is different, and like FIG. 2,
FIG. 2 is an enlarged sectional view of section A in FIG. 1;

The oil seal 18 used in this figure is inserted into the sleeve 10 at its inner periphery, and has lips a and b on its outer periphery that make line contact with the inner wall of the retainer 13, just like the oil seal 9. However, lip a exerts contact pressure only by the elastic force of the elastic material that is its component, and lip b exerts contact pressure by the coil spring d as described above.
Contact pressure is added by this, and the action and effect are the same as in Example 1. In addition, since there are various combinations of structure, materials used, shape, etc. for oil seals depending on the operating conditions, the oil seals are not limited to oil seals 9 and 18, and it goes without saying that it is effective to select an oil seal that suits the various conditions.

Note that the smaller the minute gap B, the better the results will be obtained, but this is because the relative dynamic position between the sleeve 10 and the retainer 13 changes as the swing reducer is used for a long time. ,
It is necessary to take these into account and determine the minimum dimensions that will not directly interfere with the
The shape of the minute gap is made into a hook shape, a broken line shape, or a curved shape to reduce the force of the sprayed grease, and the lip of the oil seal is placed at the farthest position from this minute gap. Due to differences in structure and assembly procedure, the shape and arrangement of the sleeve, retainer, and oil seal shown in the embodiments are not limited.

Effects of the invention In the swinging device equipped with the swing reducer according to this invention, while the swinging body is swinging, the engagement between the pinion and the internal gear causes the grease in the oil tank to be sprayed in the direction of the oil seal located in the immediate vicinity of the pinion. too,
The force of the grease droplets is reduced by the small gap between the retainer and the sleeve, and since the lip of the oil seal is located far away from the small gap, the grease does not directly hit the lip. Grease does not push the lip open and enter the rotating reducer together with dust, so the special lubricating oil inside can withstand long-term operation without being contaminated.

[Brief explanation of drawings]

Figure 1 is a sectional view of the main parts of the swing reducer of this invention.
2 is an enlarged sectional view of the A section in FIG. 1, FIG. 3 is an enlarged sectional view of the A section in FIG. 1 showing another embodiment, and FIG.
FIG. 5 is a side view and a perspective view of the essential parts showing the structure of the swing device, FIG. 6 is a sectional view of the main parts of a conventional swing reduction gear, and FIG. 7 is an enlarged sectional view of section C in FIG. 6. 2...Swivel reducer, 3...Swivel bearing, 6
...Pinion, 7...Cover, 8...Oil tank, 9,
18, 19...oil seal, 10...sleeve, 13...retainer.

Claims (1)

[Scope of utility model registration request] The retainer and sleeve are arranged so as to face each other with a small gap in the shape of a hook, a broken line, or a curve between the flange part of the retainer through which the output shaft of the swing reducer passes and the outer peripheral part of the sleeve that rotates together with the output shaft. A rotating speed reducer for a rotating body, characterized in that an oil seal is provided in an annular space formed by an inner surface of a retainer and an outer circumferential surface of a sleeve, with a lip provided on the side farthest from the minute gap.