JP2938786B2 - Swivel - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a swivel device which is provided in a construction machine such as a hydraulic shovel, a hydraulic crane or the like, and which is preferably used for swiveling an upper swing body on a lower traveling body of the construction machine.

[0002]

2. Description of the Related Art A construction machine such as a hydraulic shovel or a hydraulic crane generally includes a lower traveling body for traveling on a road surface and an upper revolving body provided with a working device and the like. By operating a turning device provided between the vehicle and the traveling body, a turning operation is performed on the lower traveling body.

FIG. 13 to FIG. 15 show an example in which this type of conventional swivel device is used for a hydraulic shovel.

In the drawing, reference numeral 1 denotes a lower traveling body, 2 denotes an upper revolving body mounted on the lower traveling body 1 so as to be pivotable, and the upper revolving body 2 has a revolving frame 3; 3
A machine room 4, an operator's cab 5, a counterweight 6, and the like are provided above. Reference numeral 7 denotes a working device mounted on the revolving frame 3 so as to be able to move up and down, and the working device performs excavation work of earth and sand.

[0005] Reference numeral 8 denotes a turning device provided on the turning frame 3. As shown in FIG. 14, the turning device 8 is supplied with pressurized oil from the outside to rotate the output shaft 9 A. The turning device 8 transmits the rotation of the hydraulic motor 9 to the lower traveling body 1, and causes the turning frame 3 and the like to pivot with respect to the lower traveling body 1.

Reference numeral 10 denotes a housing constituting the main body of the turning device 8. The housing 10 has a small-diameter flange portion 11A formed at the upper end and a large-diameter flange portion 11B formed at the lower end, and a large-diameter flange portion. 11B is provided on the housing main body 11 fixed to the revolving frame 3, a small-diameter flange portion 11A of the housing main body 11, a ring gear 12 having an internal gear 12A formed on the inner peripheral side, and provided above the ring gear 12. And a cover 13 to which the hydraulic motor 9 is attached on the upper end side. Here, the housing main body 11 has a mounting step 11C to which an upper bearing 27 described later is mounted on the upper inner peripheral side, and a mounting step 11D to which the lower bearing 29 is mounted on the lower inner peripheral side. I have.

Reference numeral 14 denotes a reduction gear mechanism which is disposed below the cover 13 and is disposed in the housing 10 and constitutes a reduction mechanism together with the ring gear 12.
Consists of a first-stage planetary gear mechanism 15 and a second-stage planetary gear mechanism 20, which will be described later.
Thus, two-stage deceleration is performed.

Reference numeral 15 denotes a first-stage planetary gear mechanism. The planetary gear mechanism 15 includes a sun gear 16 spline-coupled to an output shaft 9A of the hydraulic motor 9, and an internal gear 12A of the sun gear 16 and the ring gear 12. , And revolve around the sun gear 16 while revolving around itself.
(Only one is shown) and a carrier 19 that rotatably supports each planetary gear 17 via a pin 18 and transmits the revolution of each planetary gear 17 to a sun gear 21 described later.

Reference numeral 20 denotes a second-stage planetary gear mechanism located below the first-stage planetary gear mechanism 15.
Is a sun gear 21 meshing with the internal gear of the carrier 19.
A plurality of planetary gears 22, 22,... (Only one is shown) meshing with the sun gear 21 and the internal gear 12A of the ring gear 12 and revolving around the sun gear 21 while rotating around the sun gear 21; 22 is rotatably supported via a pin 23, and the revolution of each of the planetary gears 22 is described below with a pinion shaft 25.
And a carrier 24 that transmits the power to the carrier.

Reference numeral 25 denotes an upper bearing 2 in the housing body 11.
7 and a pinion shaft as an output shaft rotatably supported via a lower bearing 29. The pinion shaft 25 has a small diameter portion 25A on the upper side and a large diameter portion 2 on the lower side.
5B. A spline 25C is formed on the outer periphery of the upper end side of the pinion shaft 25, and the spline 25C is spline-coupled to the carrier 24.

Reference numeral 26 denotes a pinion provided at the lower end of the pinion shaft 25. The pinion 26 projects from the inside of the housing body 11 to the lower surface side of the turning frame 3, and has internal teeth of an inner ring 33 constituting a turning wheel 32 described later. 33A.

Reference numeral 27 denotes an upper bearing provided between the housing main body 11 and the small diameter portion 25A of the pinion shaft 25. The upper bearing 27 includes an outer ring fitted to the mounting step 11C of the housing main body 11, and a pinion. A self-aligning roller bearing including an inner ring fitted to the small diameter portion 25A of the shaft 25 and a plurality of cylindrical rollers provided between the inner ring and the outer ring is used.

Reference numeral 28 denotes an annular retaining ring which is located between the carrier 24 of the planetary gear mechanism 20 and the upper bearing 27 and is fitted to the small diameter portion 25A of the pinion shaft 25. The retaining ring 28 is a pinion shaft. The positioning of the upper bearing 27 in the axial direction 25 is performed.

Reference numeral 29 denotes a large diameter portion 25B of the housing body 11 and the pinion shaft 25 which is located below the upper bearing 27.
And a lower bearing provided between the lower bearing 29 and the lower bearing 29.
Includes an outer ring fitted to the mounting step portion 11D of the housing body 11, an inner ring fitted to the large diameter portion 25B of the pinion shaft 25, and a plurality of cylindrical rollers disposed between the inner ring and the outer ring. A self-aligning roller bearing including a cage (not shown) for rollingly holding each of the cylindrical rollers is used.

Reference numeral 30 denotes a stepped cylindrical retainer provided between the pinion 26 and the lower bearing 29 and provided at the lower end of the housing main body 11. The retainer 30 is provided at the lower end surface of the housing main body 11. Bolt tightened, mounting step 1
1D supports the outer ring of the lower bearing 29.

Reference numeral 31 denotes an annular oil seal made of a resin material such as rubber fixed to the inner peripheral side of the retainer 30. The inner peripheral edge (lip portion) of the oil seal 31 is attached to the pinion shaft 25 with appropriate elasticity. Sliding contact liquid-tight.
Then, the oil seal 31 is connected to each of the planetary gear mechanisms 1 described above.
Lubricating oil L for lubricating the respective gears constituting 5, 20
Is sealed in the housing body 11, and the grease G described later is used.
It has become isolated from.

Reference numeral 32 denotes a turning wheel provided on the lower surface side of the turning frame 3. The turning wheel 32 includes an inner ring 33 provided on a round body 1 A provided at the center of the lower traveling body 1 and a turning wheel. An outer ring 34 fixed to the lower surface of the frame 3;
And a plurality of steel balls 35 (only one is shown) for smoothly rotating (turning) the outer ring 34 and the inner ring 33 between the inner ring 33 and the inner teeth 33 </ b> A of the inner ring 33. The above-mentioned pinion 26 is engaged.

Accordingly, the torque of the hydraulic motor 9 is transmitted to the pinion shaft 25 and the pinion 26 via the reduction gear mechanism 14.
The pinion 26 revolves around the inner periphery of the inner ring 33 while being engaged with the internal teeth 33A. Then, the revolving force is transmitted to the turning frame 3 via the housing 10 and the like, whereby the turning frame 3 performs a turning operation on the lower traveling body 1 via the turning wheel 32.

Reference numeral 36 denotes a grease bus provided on the inner peripheral side of the revolving wheel 32. The grease bus 36 is disposed on the inner peripheral surface of the round body 1A in a concave annular shape over the entire circumference. And
The grease bath 36 is filled with gel-like grease G, and the grease G constantly lubricates the meshing portion between the pinion 26 and the internal teeth 33A of the inner race 33.

The turning device 8 according to the prior art has the above-described configuration. When pressure oil is supplied to the hydraulic motor 9 from the outside, the output shaft 9A rotates, and this rotation is performed by the first stage planetary gear mechanism 15. Are transmitted from the sun gear 16 to each planetary gear 17, and each planetary gear 17 revolves while rotating around the inner periphery of the ring gear 12, and this revolving is performed by the sun gear of the second stage planetary gear mechanism 20 via the carrier 19. 21. Then, the rotation of the sun gear 21 causes each planetary gear 22 to revolve while rotating on the inner periphery of the ring gear 12, and this revolution is transmitted from the carrier 24 to the pinion shaft 25 via the spline 25 </ b> C. In this manner, the rotation of the hydraulic motor 9 is reduced by two steps by the reduction gear mechanism 14 including the planetary gear mechanisms 15 and 20, and the rotation of the pinion shaft 25 becomes high torque.
Is transmitted to

When the pinion shaft 25 rotates, the pinion 26 meshes with the internal teeth 33A to revolve around the inner periphery of the revolving wheel 32 while revolving. The revolution revolves from the pinion shaft 25 via the housing body 11. The upper revolving structure 2 is transmitted to the frame 3 and performs a revolving operation on the lower traveling structure 1.

Here, during the operation of the turning device 8 as described above, the lubricating oil L filled in the housing body 11 usually lubricates the gears constituting the planetary gear mechanisms 15 and 20 and the like. The grease G held in the grease bath 36 lubricates the meshing portion between the pinion 26 and the internal teeth 33A of the inner race 33.

[0023]

The pinion 2
The meshing portion of the inner ring 33 and the internal teeth 33A of the inner ring 33 is structurally located substantially directly below the lower bearing 29, and the upper end of the meshing portion and the lip portion of the oil seal 31 are extremely close to each other. . On the other hand, since the grease G in the grease bath 36 is filled in each tooth groove of the pinion 26 and the internal teeth 33A of the inner ring 33, the pump action by the engagement of the pinion 26 and the internal teeth 33A of the inner ring 33 causes As shown by an arrow A in FIG. 15, high-pressure grease G is ejected from the meshing portion so as to be pushed to the oil seal 31 side.

For this reason, when the lip portion of the oil seal 31 is deformed or broken by the ejection pressure of the grease G and a gap is formed between the oil seal 31 and the pinion shaft 25, the ejected grease G is directed from the gap toward the lower bearing 29. Leaked out
Further, by entering into the housing 11 through a gap between the inner ring and the outer ring of the lower bearing 29, the grease G
And the lubricating oil L filled in the housing 11 are mixed,
The properties of the lubricating oil L deteriorate early. As a result, the durability of the planetary gear mechanisms 15, 20 and the like lubricated by the lubricating oil L is impaired, and there is a problem that stable operation of the turning device 8 cannot be compensated for a long time.

The present invention has been made in view of the above-mentioned problems of the prior art, and a lubricating oil for lubricating a reduction mechanism and the like in a housing and a grease for lubricating a meshing portion between a pinion and a turning wheel are mixed. It is an object of the present invention to provide a swivel device capable of reliably preventing the turning operation.

[0026]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a housing having a lower end attached to an upper revolving body and a rotation source provided at an upper end, and provided in the housing. One or more stages of reduction mechanism for reducing the rotation of the rotation source, an output shaft projecting downward from the housing and outputting the rotation reduced by the reduction mechanism, provided at the lower end side of the output shaft, A pinion that meshes with a revolving wheel that rotatably supports the upper revolving structure with respect to the lower traveling structure; and a housing and an output shaft that are separated upward and downward to rotatably support the output shaft in the housing. It is applied to a swivel device consisting of an upper bearing and a lower bearing provided between them.

The first aspect of the present invention is characterized in that a lubricating oil for lubricating the speed reduction mechanism in the housing is provided between the upper bearing and the lower bearing. An oil seal is provided to separate the grease lubricating the meshing portion, and a barrier is provided inside the lower bearing to prevent grease extruded from the meshing portion between the pinion and the turning ring from flowing toward the oil seal. That is, a member is provided.

Further, according to the invention of claim 2, the lower bearing includes an outer ring fitted to the housing, an inner ring fitted to the output shaft, and a gap formed between the inner ring and the outer ring. A rolling element that rolls in the inside, and the barrier member is made of a polymer material filled in the gap.

Further, the invention according to claim 3 is that the polymer material is formed by impregnating a resin material with a lubricant supplied to the rolling elements.

Furthermore, the invention of claim 4 is that a grease holding space for holding the grease is formed between the polymer material and the rolling element.

[0031]

According to the first aspect of the invention, when the rotation of the rotation source is transmitted to the output shaft via the speed reduction mechanism, the pinion provided at the lower end of the output shaft meshes with the turning wheel, and the turning wheel is moved. By rotating, the upper revolving unit performs a revolving operation with respect to the lower revolving unit. At this time, grease for lubricating the meshing portion between the pinion and the slewing wheel is ejected toward the lower bearing by the meshing between the pinion and the slewing ring, but the lubricating oil for lubricating the speed reduction mechanism and the like in the housing is: Grease sealed in the housing by an oil seal provided between the upper bearing and the lower bearing, and grease spouted toward the lower bearing is oiled by a barrier member provided inside the lower bearing. Since the outflow to the seal side is prevented, the lubricating oil in the housing and the grease can be reliably prevented from being mixed, and the grease ejected may damage or deform the oil seal. Can be prevented.

According to the second aspect of the invention, the grease spouted toward the lower bearing due to the meshing of the pinion and the turning ring is inserted into the gap formed between the outer ring and the inner ring of the lower bearing. By being blocked by the filled polymer material, outflow to the oil seal side is prevented.

According to the third aspect of the invention, the rolling elements are lubricated by the lubricant impregnated in the polymer material, so that the lower bearing can be properly lubricated.

Further, according to the structure of the fourth aspect, the grease spouted toward the lower bearing due to the meshing of the pinion and the turning ring is blocked by the polymer material filled in the gap of the lower bearing. At this time, a part of the grease is held in the grease holding space formed between the polymer material and the rolling element to lubricate the lower bearing, and therefore the lubricant impregnated in the grease and the polymer material is used. Thus, lubrication of the lower bearing can be promoted.

[0035]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. In this embodiment, the same components as those of the above-described conventional technology are denoted by the same reference numerals,
The description is omitted.

First, FIGS. 1 to 6 show a first embodiment of the present invention.

In the figure, reference numeral 41 denotes a housing 1 according to the prior art.
0 shows a housing main body applied to the present embodiment in place of the housing main body 11 constituting the housing main body 11.
Is substantially the same as the housing body 11 described in the related art,
A small-diameter flange portion 41A formed on the upper end side, a large-diameter flange portion 41B formed on the lower end side, a mounting step portion 41C provided on the upper inner peripheral side to which the upper bearing 27 is attached, and provided on the lower inner peripheral side. And a mounting step 41D to which a lower bearing 43 to be described later is mounted.
It differs from the prior art in that a seal mounting portion 41E to which an oil seal 42 described later is mounted is formed between 1C and 41D.

Reference numeral 42 denotes an oil seal located between the upper bearing 27 and the lower bearing 43 and mounted on the seal mounting portion 41E of the housing body 41.
The pinion shaft 2 is formed in an annular shape from a resin material such as rubber, and has an inner peripheral edge portion (lip portion) having appropriate elasticity.
5 in liquid-tight contact with the planetary gear mechanism 15, 2
A lubricating oil L for lubricating the gears and the like that constitute the zero is sealed in the housing main body 41.

Reference numeral 43 denotes a lower portion of the housing main body 41 and the large diameter portion 25B of the pinion shaft 25 which are located below the upper bearing 27.
A lower bearing 43 is provided between the outer ring 43A fitted to the mounting step portion 41D of the housing body 41 and a pinion shaft, in substantially the same manner as the lower bearing 29 according to the related art. Inner ring 43 fitted to the large-diameter portion 25B
B, a plurality of cylindrical rollers 43C, 43C,... As rolling elements disposed between the outer ring 43A and the inner ring 43B, and a retainer 43D that rotatably holds the cylindrical rollers 43C. Although configured as spherical roller bearings,
Gap 43E formed between outer ring 43A and inner ring 43B
This is different from the prior art in that a polymer material 44 as a barrier member is filled therein.

Here, a method of filling the polymer material 44 into the gap 43E of the lower bearing 43 will be described below with reference to FIGS.

First, as shown in FIG. 4, a lower bearing 43 including an outer ring 43A, an inner ring 43B, respective cylindrical rollers 43C, and a retainer 43D is prepared.

Next, as shown in FIG. 5, a pair of push plates 45, 46 are fitted to both ends of the lower bearing 43 in the axial direction, and bolts having the push plates 45, 46 inserted into the respective center portions are inserted. 47
The outer ring 43A and the inner ring 43B
Is closed in a liquid-tight manner. Here, the gap 43 of the lower bearing 43 in the push plate 45
A nipple 45A is erected at one position corresponding to E, and a through hole 45B communicating with the gap 43E is formed in the center of the nipple 45A.

Then, the injection nozzle 48 is attached to the nipple 45A.
And the gap 43E is filled with a liquid polymer material P, which is a raw material of the polymer material 44, while being pressurized through the injection nozzle 48.

Here, the above-mentioned polymer material P contains a resin material such as polyamide, polyethylene and fluororesin and a lubricant such as grease as main components, and is subjected to a heating and cooling treatment so that a lubricant is internally formed. Is cured in a state of being impregnated.

Next, a heating and cooling process is performed on the lower bearing 43 in which the polymer material P is filled in the gap 43E, and the polymer material P is hardened, so that the polymer as shown in FIG. The lower bearing 43 filled with the material 44 can be obtained.

As described above, the lower bearing 43 filled with the polymer material 44 is provided between the housing main body 41 and the pinion shaft 25 just above the pinion 26 and is provided together with the upper bearing 27. The shaft 25 is rotatably supported.

This embodiment has the above-described configuration, and its basic operation is not particularly different from that of the prior art.

According to this embodiment, however, the grease G in the grease bus 36 is pushed out from the meshing portion between the pinion 26 and the internal teeth 33A of the inner ring 33 when the turning device is operated, and the arrow shown in FIG. A, even if the oil is injected toward the lower bearing 43 as shown by A, the lubricating oil L filled in the housing main body 41 is removed by the oil seal 42 provided between the upper bearing 27 and the lower bearing 43. Grease G sealed in the inside 41 and spouted toward the lower bearing 43
Is the polymer material 4 filled in the gap 43E of the lower bearing 43.
4 prevents outflow to the oil seal 42 side. Therefore, the grease G that has been jetted out of the housing body 41
In addition, it is possible to reliably prevent the oil seal 42 from entering the inside and prevent the oil seal 42 from being damaged or deformed by the grease G that has been jetted out.

As a result, the properties of the lubricating oil L filled in the housing main body 41 can be prevented from being deteriorated at an early stage, and the housing main body 41 lubricated by the lubricating oil L can be prevented.
The smooth operation of each of the planetary gear mechanisms 15 and 20 and the upper bearing 27 can be compensated for a long time.

On the other hand, in the lower bearing 43, the lubricant impregnated in the polymer material 44 is gradually supplied to the rolling surface of each cylindrical roller 43C by centrifugal force and heat generated by the rotation of the lower bearing 43. The smooth operation of the lower bearing 43 can be compensated for a long period of time by properly lubricating the lower bearing 43.

Further, according to the present embodiment, the gap 43
By using the lower bearing 43 in which the polymer material 44 is filled in E, as in the case of the swivel device 8 according to the related art, the lower bearing 43 protrudes below the housing body 11 and is disposed between the lower bearing 29 and the pinion 26. Retainer 3 supporting oil seal 31
0 can be eliminated, so that the axial dimension of the large diameter portion 25B of the pinion shaft 25 can be reduced by the amount of the retainer 30. As a result, the size of the entire turning device can be reduced, and the pinion 26 and the inner teeth 3 of the inner ring 33 can be formed.
The radial load (meshing reaction force) acting on the pinion shaft 25 by meshing with the 3A can be reduced, and the life of the lower bearing 43 can be extended.

Also, by mounting an oil seal 42 on a seal mounting portion 41E provided on the housing body 41,
Since the retainer 30 according to the prior art is not required, it is possible to contribute to a reduction in manufacturing cost by reducing the number of parts and the number of assembly steps.

Next, FIGS. 7 to 12 show a second embodiment of the present invention. In this embodiment, the same components as those in the above-described first embodiment are denoted by the same reference numerals, and description thereof will be omitted.

In the figure, reference numeral 51 denotes a polymer material as a barrier member according to the present embodiment. The polymer material 51 is substantially the same as the polymer material 44 according to the first embodiment, and has a gap between the lower bearings 43. By filling and closing the inside 43E, the grease G spouted from the meshing portion between the pinion 26 and the internal teeth 33A of the inner ring 33 causes the oil seal 4 to pass through the lower bearing 43.
The structure is such that it can be prevented from flowing out to the two sides. However, the polymer material 51 according to the present embodiment is different from each of the cylindrical rollers 43C.
A plurality of grease holding spaces 52, 52,... For holding a part of the grease G ejected and assisting lubrication of each of the cylindrical rollers 43C are formed.

Here, a method of filling the lower bearing 43 with the polymer material 51 having the respective grease holding spaces 52 will be described.
This will be described below with reference to FIGS.

First, as shown in FIG. 9, a molten liquid wax 54 is stored in a container 53, and this wax 54 is stored.
After the entire lower bearing 43 is immersed therein, the lower bearing 43 is pulled up and cooled.

Thus, each cylindrical roller 4 of the lower bearing 43 is
3C, the retainer 43D, and the surface of the gap 43E have the structure shown in FIG.
As shown in FIG. 0, a wax coating 55 is formed by solidifying the liquid wax 54 attached thereto.

Next, as shown in FIG.
A pair of push plates 45 and 46 are fitted and fixed to both ends in the axial direction, and the polymer is passed through the injection nozzle 48 connected to the nipple 45A of the push plate 45 with the gap 43E closed in a liquid-tight manner. The liquid polymer material P as a raw material of the material 51 is filled in the gap 43E while being pressurized.

By heating the lower bearing 43 in which the polymer material P is filled in the gap 43E, the polymer material P is hardened and the wax coating 55 is formed.
Is melted and removed. As a result, as shown in FIG. 12, grease holding spaces 52, 52,... Corresponding to the thickness of the wax film 55 are formed on the surface portions of the cylindrical rollers 43C, the retainers 43D, and the gaps 43E. Then, by cooling the lower bearing 43, the lower bearing 43 filled with the polymer material 51 having a plurality of grease holding spaces 52 is provided.
Is manufactured.

The present embodiment has the above-described configuration, and its basic operation is not particularly different from that of the first embodiment.

However, according to the present embodiment, a part of the grease G spouted from the meshing portion between the pinion 26 and the internal teeth 33A of the inner ring 33 during the operation of the swivel device causes the polymer 51
Are held in the respective grease holding spaces 52 formed in.
The grease G held in each grease holding space 52 lubricates the rolling surface and the like of each cylindrical roller 43C in cooperation with the lubricant impregnated in the polymer material 51. 43 can be more effectively lubricated.

Further, the grease G once held in each grease holding space 52 is reliably held in each grease holding space 52 by its high viscosity. Even if it does, it does not come off from the periphery of each cylindrical roller 43C. For this reason,
Even when the lower bearing 43 is in a relatively low temperature state when the turning device is started or the like and the lubricant impregnated in the polymer material 51 is not supplied to each cylindrical roller 43C, the lower bearing 43 is retained in each grease retaining space 52. The rolling surface of each cylindrical roller 43C can be appropriately lubricated by the grease G thus obtained.

In each of the above embodiments, the polymer material 44,
Although the case where 51 is filled in the gap 43E of the lower bearing 43 has been described as an example, the present invention is not limited to this. For example, a polymer material is formed separately from the lower bearing 43,
The polymer material may be fitted to the lower bearing 43 to close the gap 43E.

In each of the above embodiments, the case where a self-aligning roller bearing is applied as the lower bearing 43 has been described as an example.
The present invention is not limited to this. For example, other bearings such as tapered roller bearings and angular ball bearings may be applied.

Further, in each of the above embodiments, the turning device having the two-stage reduction gear mechanism 14 has been described as an example. However, the present invention is not limited to this, and the present invention is not limited to this. It may be used for a turning device having a gear mechanism.

Further, in each of the above embodiments, the case where the turning device is used for a hydraulic excavator has been described as an example. However, the turning device can be used as a turning device of another construction machine such as a hydraulic crane.

[0067]

As described above in detail, according to the first aspect of the present invention, the oil seal for separating the grease from the lubricating oil for lubricating the reduction mechanism and the like provided in the housing is provided by the upper bearing and the lower bearing. And between the lower bearing,
Because it was configured to provide a barrier member that blocks grease spouting toward the lower bearing from the meshing portion between the pinion and the turning wheel,
The ejected grease flows out of the lower bearing toward the oil seal, thereby reliably preventing the grease from entering the housing and mixing with the lubricating oil. Therefore, it is possible to prevent the properties of the lubricating oil filled in the housing from being deteriorated at an early stage, and it is possible to compensate for a long period of time a smooth operation of the reduction mechanism and the like lubricated by the lubricating oil. In addition, since the grease ejection pressure does not directly act on the oil seal, it is possible to reliably prevent the oil seal from being deformed or damaged, and to prevent leakage of the lubricating oil filled in the housing.

According to the second aspect of the present invention, the gap formed between the outer ring and the inner ring constituting the lower bearing is filled with a polymer material to form a barrier member, whereby the lower bearing is formed. It is not necessary to provide an oil seal between the oil seal and the pinion, and the axial dimension of the output shaft can be reduced by the amount of the oil seal and the members supporting the oil seal. As a result, it is possible to reduce the size of the entire swivel device, reduce the radial load (meshing reaction force) acting on the output shaft due to the meshing between the pinion and the swivel wheel, and reduce the lower bearing. Life can be extended.

Further, according to the third aspect of the present invention, since the rolling elements are lubricated by the lubricant impregnated in the polymer material, the lower bearing can be properly lubricated.

Further, according to the structure of the fourth aspect, by forming a grease holding space between the polymer material and the rolling element, a part of the grease spouted from the meshing portion between the pinion and the revolving wheel is greased. Since it can be held in the holding space, lubrication of the lower bearing can be promoted by the held grease and the lubricant impregnated in the polymer material.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing a turning device according to a first embodiment of the present invention.

FIG. 2 is a partially broken longitudinal sectional view showing an enlarged view of a lower bearing and the like in FIG. 1;

FIG. 3 is a cross-sectional view as seen from a direction indicated by arrows III-III in FIG. 2;

FIG. 4 is a longitudinal sectional view showing a configuration of a lower bearing filled with a polymer material in a method of filling the lower bearing in FIG. 2 with a polymer material.

5 is a longitudinal sectional view showing a state in which the lower bearing in FIG. 4 is filled with a polymer material.

FIG. 6 is a longitudinal sectional view showing a lower bearing filled with a polymer material.

FIG. 7 is a longitudinal sectional view showing a lower bearing and the like according to a second embodiment of the present invention at the same position as in FIG. 2;

FIG. 8 is a cross-sectional view as seen from the direction of arrows VIII-VIII in FIG.

FIG. 9 is a longitudinal sectional view showing a state in which the lower bearing is immersed in a liquid wax in the method of filling the lower bearing in FIG. 7 with a polymer material.

FIG. 10 is an enlarged longitudinal sectional view showing a state in which a wax film is formed on a lower bearing.

FIG. 11 is an enlarged longitudinal sectional view showing a state where the lower bearing of FIG. 10 is filled with a polymer material.

FIG. 12 is an enlarged longitudinal sectional view showing a lower bearing filled with a polymer material having a grease holding space.

FIG. 13 is an external view showing a hydraulic excavator to which a conventional turning device is applied.

FIG. 14 is a longitudinal sectional view showing a conventional turning device.

FIG. 15 is a longitudinal sectional view of the same position as FIG. 2 showing a lower bearing and the like in FIG. 14;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Housing 14 Reduction gear mechanism (reduction mechanism) 25 Pinion shaft (output shaft) 26 Pinion 27 Upper bearing 32 Slewing ring 41 Housing body 42 Oil seal 43 Lower bearing 43A Outer ring 43B Inner ring 43C Cylindrical roller (rolling element) 43E Gap 44, 51 Polymer material (barrier member) 52 Grease holding space

Continuation of the front page (72) Inventor Yuji Igawa 650, Kunitachicho, Tsuchiura-shi, Ibaraki Pref. Hitachi Construction Machinery Co., Ltd. Tsuchiura Plant (56) References JP-A-7-4475 (JP, A) JP, U) (58) Fields investigated (Int. Cl. ⁶ , DB name) E02F 9/12 F16C 33/66

Claims (4)

(57) [Claims] 1. A housing having a lower end attached to an upper revolving structure and a rotation source provided on an upper end, a one-stage or plural-stage reduction mechanism provided in the housing and configured to reduce the rotation of the rotation source. An output shaft projecting downward from the housing and outputting rotation reduced by the speed reduction mechanism; and a swivel provided at a lower end of the output shaft to support the upper swing body so as to swing with respect to the lower traveling body. A swivel comprising a pinion meshing with a wheel, and an upper bearing and a lower bearing provided between the housing and the output shaft at a distance above and below to rotatably support the output shaft within the housing. In the device, an oil seal is provided between the upper bearing and the lower bearing to separate lubricating oil for lubricating the reduction mechanism in the housing from grease for lubricating a meshing portion between the pinion and the turning wheel. Provided, the turning device is inside the lower bearing, characterized in that grease is extruded from the meshing portion between the pinion and the turning wheels provided with barrier member to prevent the outflow toward the oil seal. 2. The lower bearing includes an outer ring fitted to the housing, an inner ring fitted to the output shaft, and a rolling element rolling in a gap formed between the inner ring and the outer ring. The turning device according to claim 1, further comprising: a barrier member formed of a polymer material filled in the gap. 3. The swivel device according to claim 2, wherein the polymer material is formed by impregnating a resin material with a lubricant supplied to the rolling elements. 4. Between the polymer material and the rolling element,
The turning device according to claim 2 or 3, wherein a grease holding space for holding the grease is formed.