JP2000129723A - Reduction gear - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a seal member from being worn and damaged at early stages by preventing foreign matter such as chips generated within a housing from entering the seal member. SOLUTION: An upper bearing 22 and a lower bearing 23, for rotatably supporting the output shaft 20 of a reduction gear mechanism 15, are provided on the inner periphery of a housing main body 12 constituting a housing 11. An oil seal 25 sealing the space between the inner periphery of the lower end of the housing main body 12 and a spacer 24 on the output shaft 20 in a liquid- tight fashion is provided on the inner periphery of the lower end of the housing main body 12 and lubricant L for lubricating the reduction gear mechanism 15 is sealed inside the housing 11 by the oil seal 25. The lower bearing 23 placed above the oil seal 25 is filled with a solid polymer 26 made of a resin, e.g. fluororesin.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a speed reducer suitable for use in a turning device such as a hydraulic excavator or a hydraulic crane.

[0002]

2. Description of the Related Art A construction machine such as a hydraulic excavator 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. A turning device for turning the upper revolving unit on the lower traveling unit is provided between the lower revolving unit and the lower traveling unit.

[0003] The turning device is generally equipped with a speed reducer for increasing the output of the rotation source, and the speed reducer is a cylinder having a rotation source provided at an upper end and an upper end. A housing, a speed reduction mechanism provided in the housing, for reducing the rotation of the rotation source, and a pinion extending upwardly and downwardly in the housing and provided at a lower end side, and decelerated by the speed reduction mechanism. An output shaft for outputting rotation and an upper bearing and a lower bearing which are provided between the housing and the output shaft so as to be rotatable within the housing and are separated from each other by an upper bearing and a lower bearing. (Japanese Utility Model Laid-Open No. 4-32347).

In this type of prior art reduction gear, lubricating oil for lubricating each gear constituting the reduction gear is enclosed in a housing. A seal member is fixedly provided on the inner periphery of the housing and located below the lower bearing and in sliding contact with the output shaft. The seal member prevents leakage of lubricating oil from inside the housing. ing.

In another conventional technique, a seal member is disposed at a position between an upper bearing and a lower bearing, and the seal member lubricates a lubricating oil for lubricating a reduction mechanism and a lower bearing. It is known that it is configured to isolate grease.

[0006]

By the way, in the above-mentioned prior art, during operation of the reduction gear, each gear constituting the reduction mechanism rotates while meshing with each other.
Foreign matter such as abrasion powder or dust is mixed in the lubricating oil for lubricating the speed reduction mechanism. Then, the foreign matters settle in the lubricating oil, and pass through gaps formed in the upper bearing and the lower bearing, respectively, and settle on the seal member side disposed below the lower bearing. I do.

For this reason, the lip portion of the seal member that slides on the output shaft may be worn or damaged by the foreign matter, and in this case, there is a problem that lubricating oil may leak from inside the housing.

Also, in the case of other prior arts, the foreign matter mixed in the lubricating oil precipitates on the seal member side through the gap formed inside the upper bearing, so that it is the same as the above-mentioned prior art. Problems arise.

The present invention has been made in view of the above-mentioned problems of the prior art, and can prevent foreign matters such as abrasion powder mixed in lubricating oil in a housing from entering a seal member side. Minimize the resulting wear and damage,
Lubricating oil leakage from inside the housing can be eliminated,
It is an object of the present invention to provide a speed reducer capable of improving the performance and reliability of the device.

[0010]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, a reduction gear transmission according to the present invention comprises: a cylindrical housing having a rotation source disposed on an upper side and an upper side, and a rotation source provided on an upper end side; A reduction mechanism for reducing the rotation of the rotation source, an output shaft extending upward and downward in the housing and provided with a pinion at the lower end, and outputting the rotation reduced by the reduction mechanism; An upper bearing and a lower bearing are provided between the housing and the output shaft so as to be rotatably supported in the housing.

The first aspect of the present invention is characterized in that, between the housing and the output shaft, lubricating oil for lubricating the speed reduction mechanism is sealed in the housing, so that it is lower than the lower bearing. A seal member is provided on the side, and inside at least one of the upper bearing and the lower bearing,
Another object of the present invention is to provide a shielding member which has a self-lubricating ability and prevents foreign substances mixed in the lubricating oil from entering the sealing member side.

With this configuration, even if foreign matter such as abrasion powder generated on the side of the speed reduction mechanism during operation of the speed reduction device or the like enters the lubricating oil and sediments downward, the foreign matter is more likely than the sealing member. Since the shielding member is provided inside the upper bearing or the lower bearing arranged on the upper side, the shielding member can prevent the foreign matter from entering the sealing member side. Further, since the shielding member has a self-lubricating ability, the bearing can always be kept in a lubricated state by the shielding member.

According to the second aspect of the present invention, the upper bearing and the lower bearing are provided between the housing and the output shaft so as to separate lubricating oil for lubricating the speed reduction mechanism and grease for lubricating the lower bearing. A seal member is provided between the upper bearing and a shielding member that has a self-lubricating ability and prevents foreign substances mixed in the lubricating oil from entering the seal member side is provided inside the upper bearing. .

With this configuration, even if foreign matter generated on the side of the speed reduction mechanism during operation of the speed reduction device or the like enters the lubricating oil and is settled downward, it is disposed above the seal member. Since the shield member is provided inside the upper bearing, the shield member can prevent the foreign matter from entering the seal member side. Further, since the shielding member has a self-lubricating ability, the upper bearing can always be kept in a lubricated state by the shielding member.

Further, in the invention according to claim 3, the bearing located above the seal member among the upper bearing and the lower bearing includes an outer ring fitted to the housing, an inner ring fitted to the output shaft, A rolling element that rolls in a gap formed between the outer ring and the inner ring; and the shielding member is made of a polymer material filled in the gap.

With this configuration, the gap between the outer ring and the inner ring constituting the upper bearing (lower bearing) can be filled with the polymer material, and foreign substances mixed in the lubricating oil can be filled inside the bearing. Can be prevented from passing through.

Further, in the invention according to claim 4, the polymer material is impregnated with a lubricant for lubricating between the rolling elements.

[0018] With this configuration, the rolling elements can be maintained in a lubricated state by the lubricant impregnated in the polymer material.

[0019]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a hydraulic excavator according to an embodiment of the present invention;

FIGS. 1 to 4 show a first embodiment of the present invention. In the drawing, reference numeral 1 denotes a lower traveling body of a hydraulic shovel, 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; Engine cover 4 on 3,
A cab box 5 and a counter weight 6 are provided. In addition, the turning frame 3 is provided with a working device 7 for performing excavation work such as earth and sand so as to be able to move up and down.

Reference numeral 8 denotes a turning device provided between the lower traveling unit 1 and the upper turning unit 2, and the turning unit 8 rotates the rotary shaft 9A by supplying and discharging pressure oil from the outside. It is roughly composed of a swing motor 9 as a source and a speed reducer 10 described later.

Reference numeral 10 denotes a reduction gear mounted on the turning device 8. The reduction gear 10 includes a housing 11, a reduction gear mechanism 15, an output shaft 20, and the like, which will be described later. A lubricating oil L for lubricating the components is sealed. And this reduction gear 1
Numeral 0 indicates a configuration in which the rotation of the rotation shaft 9A of the swing motor 9 is reduced and output to the output shaft 20.

Here, the housing 11 has a large-diameter flange portion 12A on the lower end side fixed to the revolving frame 3 and a housing main body 12 arranged upward and downward, and a small-diameter located on the upper end side of the housing main body 12. Ring gear 13 fixed on flange portion 12B and having an internal gear formed on the inner peripheral side
And a cover 14 provided above the ring gear 13 and having the turning motor 9 attached to the upper end.

Reference numeral 15 denotes a reduction gear mechanism which is disposed below the cover 14 and is disposed in the housing 11 and constitutes a reduction mechanism together with the ring gear 13. The reduction gear mechanism 15 is a lower end of a rotating shaft 9A of the turning motor 9. Sun gear 16 provided in
And three planetary gears 17 (only one is shown) that mesh with the sun gear 16 and the ring gear 13 and revolve around the sun gear 16 while rotating around the sun gear 16, and on the inner peripheral side of the planetary gear 17. It is composed of a rotatably provided pin 18, a carrier 19 for rotatably supporting the pin 18 in a state in which the inner peripheral side meshes with a sun gear 16 described later, and the like.

An output shaft 20 is rotatably provided in the housing 11 and outputs rotation reduced by the reduction gear mechanism 15. The output shaft 20 extends upward and downward in the housing 11, and has an upper end. The side is spline-coupled to the inner peripheral side of the carrier 19. And the output shaft 20 is
The lower end protrudes downward from inside the housing body 12 to form a pinion 20A, which meshes with a turning wheel 21 provided on the turning frame 3 side.

Reference numeral 22 denotes an upper bearing located at the upper end side of the output shaft 20 and provided between the housing body 12 and the output shaft 20. The upper bearing 22 is, as shown in FIG.
Between the inner ring 22A, the inner ring 22A, the outer ring 22B, which is radially opposed to the inner ring 22A and is fitted to the inner periphery of the housing body 12, and the inner ring 22A and the outer ring 22B. Plural tapered rollers 22C as rolling elements disposed
And a retainer 22D that rotatably retains each of the tapered rollers 22C.

Reference numeral 23 denotes a lower bearing located at the lower end side of the output shaft 20 and provided between the housing main body 12 and the output shaft 20. The lower bearing 23 is substantially the same as the upper bearing 22. , Inner ring 23A provided by fitting to output shaft 20
And an outer ring 2 fitted to the inner periphery of the housing 11.
3B, a plurality of tapered rollers 23C as rolling elements disposed between the inner ring 23A and the outer ring 23B, and a retainer 23D that rotatably holds the respective tapered rollers 23C. And the lower bearing 23 is the upper bearing 2
2, the output shaft 20 is rotatably supported in the housing body 12.

A spacer 24 is provided between the pinion 20A and the inner ring 23A of the lower bearing 23.
Numeral 4 is fitted and fixed to the output shaft 20, and is configured to axially position the inner ring 23A of the lower bearing 23 between the output shaft 20 and the pinion 20A.

Reference numeral 25 denotes an annular oil seal as a sealing member fixedly provided on the inner periphery of the lower end side of the housing body 12. The oil seal 25 has an oil lip 25A on the upper inner surface and an inner lip 25A. The lower side is a dust lip 25
B, and these lips 25A and 25B are in sliding contact with the outer peripheral side of the spacer 24 provided on the output shaft 20 with interference. The oil lip 25A prevents the lubricating oil L sealed in the housing 11 from leaking to the outside, and the dust lip 25B allows grease or the like adhering between the pinion 20A and the swivel wheel 21 to move into the housing 11. Prevents intrusion.

Reference numeral 26 denotes a polymer material provided inside the lower bearing 23 as a shielding member having a self-lubricating ability. The polymer material 26 comprises an inner ring 23A and an outer ring 23B of the lower bearing 23.
And a solid filler filled in the gap between them.

Here, the polymer material 26 is formed by impregnating a liquid resin material such as polyamide, polyethylene, fluororesin or the like with a lubricant such as grease and performing heating and cooling treatments. The polymer material 26 is disposed above the oil seal 25 together with the lower bearing 23, and foreign matter such as abrasion powder mixed into the lubricating oil L enters the oil seal 25 as described later. And the passage of only the lubricating oil L is allowed.

The speed reducer 10 according to the present embodiment has the above-described configuration. When pressure oil is supplied and discharged from the outside to the swing motor 9 and the rotary shaft 9A is driven to rotate, the rotation of the speed reducer 10 is reduced. The speed is reduced by the reduction gear mechanism 15 in the housing 11, and a high torque rotational force is transmitted to the output shaft 20.

The pinion 20A of the output shaft 20 meshes with the turning wheel 21 of the lower traveling body 1 to revolve while rotating along the turning wheel 21, and the revolving force at this time is transmitted through the housing 11. Is transmitted to the upper revolving superstructure 2 so that the entire upper revolving superstructure 2 performs a revolving motion on the lower traveling superstructure 1. Further, during the operation of the reduction gear transmission 10, the lubricating oil L sealed in the housing 11 by the oil seal 25 lubricates each gear constituting the reduction gear mechanism 15.

When the reduction gear 10 operates, the gears constituting the reduction gear mechanism 15 rotate while meshing with each other, thereby generating foreign substances such as abrasion powder and dust. It mixes and settles on the oil seal 25 side.

Therefore, in the present embodiment, the lower bearing 23
Is disposed above the oil seal 25, and the gap between the inner ring 22 </ b> A and the outer ring 22 </ b> B of the lower bearing 23 is filled with a polymer material 26. As a result, even if foreign matter is generated on the reduction gear mechanism 15 side as described above, the foreign matter can be blocked by the polymer material 26 from passing through the gap between the inner ring 22A and the outer ring 22B.

Thus, according to the present embodiment, foreign matter can be prevented from entering the oil seal 25 by the polymer material 26, and the oil lip 2 of the oil seal 25 can be prevented.
It is possible to eliminate the possibility that the dust 5A and the dust lip 25B may be worn and damaged by foreign substances. The oil seal 25 allows the housing 11 and the spacer 24 on the output shaft 20 side to keep a good seal for a long period of time, preventing leakage of the lubricating oil L from the inside of the housing 11, and Performance, reliability and the like can be improved.

Further, the lower bearing 23 is formed by the polymer material 26.
Since the gap between the inner ring 23A and the outer ring 23B is filled, the possibility that the foreign matter enters the gap between the inner ring 23A and the outer ring 23B can be eliminated. Thus, wear and damage of the lower bearing 23 due to foreign matter can be prevented, and durability and life of the lower bearing 23 can be improved.

Further, since the polymer material 26 is configured to be impregnated with a lubricant such as grease, the inner ring 23A and the outer ring 2
The tapered roller 23C can be smoothly rolled between the lower bearing 3B and the lower bearing 23, whereby the wear and the like generated on the lower bearing 23 can be further reduced, and the performance and the like of the lower bearing 23 can be enhanced.

FIGS. 5 and 6 show a second embodiment of the present invention. The feature of this embodiment is that a lubricating oil for lubricating a speed reduction mechanism is provided between a housing and an output shaft. A seal member is provided between the upper bearing and the lower bearing to isolate grease for lubricating the lower bearing, and the upper bearing has a self-lubricating ability and is mixed in lubricating oil. The object is to provide a shielding member for preventing foreign matter from entering the sealing member side. Note that, in the present embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted.

Reference numeral 31 denotes a housing main body applied to the present embodiment instead of the housing main body 12 constituting the housing 11 according to the first embodiment, and the housing main body 31 is a housing according to the first embodiment. Body 12
Large diameter flange portion 31 formed on the lower end side in substantially the same manner as
A and a small-diameter flange portion 31B formed on the upper end side.

However, on the inner peripheral side of the housing body 31, there is provided an annular projection 31C which is located between the upper bearing 22 and the lower bearing 23 and protrudes radially inward. Is different from that of the embodiment. Also,
In the housing main body 31, lubricating oil L for lubricating the reduction gear mechanism 15 is sealed in a portion above an oil seal 33 described later.

Reference numeral 32 denotes a spacer used in the present embodiment.
The spacer 32 is the spacer 2 according to the first embodiment.
Although substantially formed as a tubular body fitted and fixed to the output shaft 20 in substantially the same manner as 4, an annular flange 32A protrudes radially outward from the lower end side outer periphery. The flange 32A is configured to reduce the gap between the housing main body 31 and the spacer 32 and to minimize leakage of grease or the like that supplies the lower bearing 23 to the outside.

Reference numeral 33 denotes an oil seal as a seal member used in the present embodiment instead of the oil seal 25 according to the first embodiment. The oil seal 33 is provided on the inner peripheral side of the housing main body 31 with an annular projection 31C. It is fixedly provided in a state where it is positioned by the. The oil seal 33 is provided with an oil lip 33A and a dust lip 33B that are in sliding contact with the output shaft 20 to isolate the lubricating oil L on the reduction gear mechanism 15 and the grease on the lower bearing 23. Has become.

Reference numeral 34 denotes the polymer material 2 according to the first embodiment.
6 is a polymer material provided as a shielding member having a self-lubricating ability provided inside the upper bearing 22. The polymer material 34 is provided in a gap between the inner ring 22A and the outer ring 22B of the upper bearing 22. It is configured as a filled solid filler. The polymer material 34 is made of a resin material in which a lubricant such as grease is impregnated similarly to the polymer material 26 according to the first embodiment. The lubricating oil L is prevented from entering the side, and only the lubricating oil L is allowed to pass.

Thus, also in the present embodiment configured as described above, it is possible to obtain substantially the same operation and effect as in the first embodiment.

In the first embodiment, the polymer material 2
Although the configuration is described in which 6 is provided on the lower bearing 23, a configuration in which a polymer material is provided on the upper bearing 22 in addition to the lower bearing 23 may be adopted. Further, the polymer material 26 may be omitted, and a polymer material may be provided on the upper bearing 22 side.

Further, in each embodiment, the case where the turning device is used for a hydraulic excavator has been described as an example. However, the present invention is not limited to this, and the turning device of another construction machine such as a hydraulic crane, or The present invention may be applied to a reduction gear device used other than the turning device.

[0048]

As described above in detail, according to the first aspect of the present invention, an upper bearing and a lower bearing are provided between the housing and the output shaft so as to be spaced apart from each other in the upper and lower directions. A seal member is provided at a position lower than the lower bearing to seal the lubricating oil for lubricating the reduction mechanism in the housing,
Since the inside of at least one of the upper bearing and the lower bearing is provided with a shielding member that has a self-lubricating ability and prevents foreign substances mixed in the lubricating oil from entering the sealing member side, The possibility that the seal member is worn or damaged by foreign matter can be eliminated, and the seal member can keep good sealing between the housing and the output shaft for a long period of time. Then, leakage of the lubricating oil from inside the housing can be prevented, and the performance and reliability of the device can be improved. Further, the bearing can be always kept in a lubricated state by the shielding member, and the durability and the like of the shielding member can be enhanced.

Further, even when the sealing member is disposed between the upper bearing and the lower bearing and the shielding member is provided on the upper bearing, the lubricating oil is provided by the shielding member. It is possible to prevent the mixed foreign matter from entering the seal member side, and it is possible to obtain substantially the same effect as the first aspect of the present invention.

According to the third aspect of the present invention, the shielding member is
Since the upper bearing (lower bearing) is made of a polymer material filled in the gap between the outer ring and the inner ring, there is no danger of foreign matter entering the space formed inside the bearing due to the polymer material. Wear and damage of the bearing due to foreign matter can be prevented, and its durability and life can be improved.

Further, in the invention according to claim 4, since the polymer material is impregnated with a lubricant for lubricating between the rolling elements, the rolling elements are smoothly rolled between the outer ring and the inner ring. The performance of the bearing can be improved.

[Brief description of the drawings]

FIG. 1 is an external view showing a hydraulic excavator to which a turning device according to a first embodiment of the present invention is applied.

FIG. 2 is an enlarged longitudinal sectional view of the turning device in FIG. 1;

FIG. 3 is an enlarged cross-sectional view of a main part showing an upper bearing, a lower bearing, an oil seal, a polymer material, and the like in FIG. 2;

FIG. 4 is a sectional view as seen from the direction of arrows IV-IV in FIG. 3;

FIG. 5 is a longitudinal sectional view showing a turning device according to a second embodiment of the present invention.

FIG. 6 is an enlarged sectional view of an essential part showing an upper bearing, a lower bearing, an oil seal, a polymer material and the like in FIG. 5;

[Explanation of symbols]

 Reference Signs List 9 rotation motor (rotation source) 9A rotation shaft 10 reduction gear 11 housing 15 reduction gear mechanism 20 output shaft 20A pinion 22 upper bearing 22A, 23A inner ring 22B, 23B outer ring 22C, 23C tapered roller (rolling element) 23 lower bearing 25, 33 Oil seal (seal member) 26,34 Polymer material (shielding member)

 ──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Takeshi Kurihara 650, Kandamachi, Tsuchiura-shi, Ibaraki Pref.Hitachi Construction Machinery Co., Ltd. (72) Inventor Yuji Igawa, Tsuchiura-machi, Tsuchiura-shi, Ibaraki 650 Hitachi Construction Machinery Co., Ltd.

Claims (4)

[Claims] 1. A cylindrical housing having a rotation source disposed on an upper side and an upper side and a rotation source provided on an upper end side, a reduction mechanism provided in the housing to reduce the rotation of the rotation source, and a housing inside the housing. A pinion extending upward and downward and provided on a lower end side, for outputting rotation reduced by the reduction mechanism; and the housing and the output shaft for rotatably supporting the output shaft in the housing. A speed reducer comprising an upper bearing and a lower bearing provided apart from each other at an upper portion and a lower portion, wherein a lubricating oil for lubricating the speed reduction mechanism is provided between the housing and an output shaft. A seal member is provided at a position lower than the lower bearing to seal the inside, and at least one of the upper bearing and the lower bearing has a self-lubricating ability and a lubricating oil. Mixed in Reduction gear foreign matter, characterized in that a shielding member for preventing from entering into the sealing member side. 2. A cylindrical housing having a rotation source provided on an upper side and an upper side, and a reduction mechanism provided in the housing and configured to reduce the rotation of the rotation source. A pinion extending upward and downward and provided on a lower end side, for outputting rotation reduced by the reduction mechanism; and the housing and the output shaft for rotatably supporting the output shaft in the housing. A speed reducer comprising an upper bearing and a lower bearing provided apart from each other at an upper portion and a lower portion, between the housing and an output shaft, lubricating oil for lubricating the speed reducing mechanism and the lower portion. A seal member is provided between the upper bearing and the lower bearing to isolate grease for lubricating the side bearing, and the upper bearing has a self-lubricating ability and is mixed in the lubricating oil. Foreign matter is Reduction gear, characterized in that a shielding member for preventing from entering the member. 3. A bearing located above the seal member of the upper bearing and the lower bearing is an outer ring fitted to the housing, an inner ring fitted to the output shaft, and the outer ring and the inner ring. 3. The reduction gear according to claim 1, further comprising a rolling element that rolls in a gap formed between the first and second members, and wherein the shielding member is made of a polymer material filled in the gap. 4. The reduction gear transmission according to claim 3, wherein the polymer material is impregnated with a lubricant for lubricating between the rolling elements.