JP6833437B2 - Seal structure - Google Patents

Description

The present invention relates to a seal structure that prevents foreign matter such as earth and sand from entering the track drive device.

Vehicles such as hydraulic excavators equipped with an endless track zone (hereinafter, also referred to as "infinite track vehicles") are equipped with an endless track drive device that drives the endless track zone. Tracked vehicles are usually planned to run on road surfaces where earth and sand and mud are exposed, and when traveling, a large amount of earth and sand and the like are rolled up. Therefore, the space between the rotating casing and the fixed side housing of the endless track drive device is sealed to prevent foreign matter such as earth and sand from entering.

For example, in the seal structure of the endless track drive device disclosed in Patent Document 1, a floating seal is provided between the rotating casing and the fixed side housing to prevent the hydraulic oil from leaking to the outside, and around the floating seal. A labyrinth seal is provided to prevent the intrusion of foreign matter such as mud.

Japanese Unexamined Patent Publication No. 2013-199968

The labyrinth seal of Patent Document 1 is formed by a gap having a bent cross-sectional shape, and communicates with the outside through an opening directed in the radial direction (see the symbol “41” in FIG. 4 described later). As described above, in the seal structure of Patent Document 1, the opening of the gap between the fixed housing and the rotating casing is directed in the radial direction, and the direction of action of gravity and the opening direction of the gap match.

Therefore, the earth and sand deposited in the space above the opening of the labyrinth seal easily invades into the gap through the opening due to the action of gravity.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a seal structure capable of suppressing foreign matter such as earth and sand from entering the gap between the fixed housing and the rotating casing.

One aspect of the present invention is a seal structure of an endless track drive device for driving an endless track zone of a vehicle, in which a gap path is formed between a rotary casing rotatably provided about a rotation axis and a rotary casing. A fixed housing to be formed, one of the rotating casing and the fixed housing constitutes an outer member whose radial direction perpendicular to the axis of rotation is at least partly located outside the other and the other inside. The outer member constitutes the member, and is a covering portion extending in the axial direction in which the rotation axis extends and extending in the radial direction, and has a covering portion for partitioning at least a part of the gap path, and is more than the outer member. The opening of the crawler path communicating with the outer outer space also relates to a seal structure provided outside in the radial direction with respect to the portion of the covering that extends in the radial direction.

The outer member has an overhanging portion that projects toward the external space in the radial direction, the covering portion and the overhanging portion form a concave deposit portion, and the opening of the gap path is of the covering portion in the radial direction. It may be provided at a position 3/4 or more of the height of the overhanging portion from the portion extending in the axial direction and away from the portion extending in the axial direction in the covering portion.

The opening of the gap may be provided outside the overhang in the radial direction.

The inner member has an extension portion that is arranged outward in the radial direction with respect to the portion of the covering portion that extends in the radial direction, and the opening of the gap path is the portion of the covering portion that extends in the radial direction. It may be partitioned by an extension.

The opening of the gap may be oriented in the axial direction.

The interstitial road may have a radial road extending in the radial direction and an axial road extending in the axial direction.

The seal structure may further include a seal member that is arranged in the gap and contacts each of the outer and inner members.

The outer member may be a fixed housing and the inner member may be a rotating casing.

The outer member may be a rotating casing and the inner member may be a fixed housing.

According to the present invention, since the opening of the gap path between the fixed housing and the rotating casing is provided outside the portion of the covering portion extending in the radial direction in the radial direction, foreign matter such as earth and sand is provided. Can be prevented from entering the gap.

FIG. 1 is a functional block diagram of a tracked vehicle. FIG. 2 is a cross-sectional view showing an example of an endless track driving device according to an embodiment of the present invention. FIG. 3 is an enlarged cross-sectional view showing the vicinity of the gap path shown in FIG. FIG. 4 is an enlarged cross-sectional view showing the vicinity of the gap path according to the prior art. FIG. 5 is an enlarged cross-sectional view showing the vicinity of the gap path according to the modified example. FIG. 6 is an enlarged cross-sectional view showing the vicinity of the gap path according to another modified example.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. It should be noted that the elements shown in each drawing may include elements whose size, scale, etc. are shown differently from those actually shown in order to facilitate understanding.

FIG. 1 is a functional block diagram of the tracked vehicle 100. The endless track vehicle 100 includes an endless track zone 102 and an infinite track drive device 101 that drives the endless track zone 102. The endless track drive device 101 includes a hydraulic motor 103 that produces power for driving the endless track zone 102, and a seal structure 104 that isolates a mechanism for transmitting the power of the hydraulic motor 103 from the outside.

FIG. 2 is a cross-sectional view showing an example of the endless track driving device 101 according to the embodiment of the present invention.

The endless track driving device 101 includes a cylindrical rotating casing 20 that is rotatably provided about the rotation axis O, and a fixed housing 10 that forms a gap path 40 between the rotating casing 20. The rotary casing 20 is rotatably supported by the fixed housing 10 via the bearing 3, and can rotate about the rotation axis O.

An annular rotary flange portion 29 projects from the outer wall portion 22 of the rotary casing 20. A plurality of screw holes 28 are formed in the rotary flange portion 29. A sprocket such as a crawler wheel (not shown) is connected to the rotary flange portion 29 via a bolt screwed into the screw hole 28 and rotates together with the rotary casing 20. Therefore, as the rotating casing 20 rotates, the endless track zone such as the crawler belt that meshes with the sprocket circulates and moves.

An annular fixed flange portion 19 projects from the outer wall portion 12 of the fixed housing 10. A plurality of screw holes 18 are formed in the fixed flange portion 19. The plurality of screw holes 18 are arranged at substantially equal intervals with respect to the circumferential direction of the fixed housing 10. The fixing flange portion 19 is connected to the vehicle frame via a bolt screwed into each screw hole 18.

A hydraulic motor 103 is provided inside the fixed housing 10. Typically, a swash plate type piston pump can be used as the hydraulic motor 103. When hydraulic oil is supplied to the hydraulic motor 103 from a hydraulic source (not shown), the output shaft of the hydraulic motor 103 rotates about the rotation axis O.

A planetary gear mechanism 60 is provided inside the rotating casing 20. The planetary gear mechanism 60 has a first-stage sun gear 61, a first-stage planetary gear 62, a carrier 63, a second-stage sun gear 64, a second-stage planetary gear 65, and a ring gear 66. The output shaft of the hydraulic motor 103 is connected to the first-stage sun gear 61 via the input shaft 14, and the first-stage sun gear 61 rotates together with the output shaft. The rotation of the first-stage sun gear 61 causes the first-stage planetary gear 62 to revolve, and the rotation of the first-stage planetary gear 62 causes the carrier 63 to rotate. When the carrier 63 rotates, the second-stage sun gear 64 that meshes with the carrier 63 rotates, and when the second-stage sun gear 64 rotates, the second-stage planetary gear 65 rotates. When the second-stage planetary gear 65 rotates, the ring gear 66 that meshes with the second-stage planetary gear 65 rotates, and the rotary casing 20 provided integrally with the ring gear 66 also rotates. In this way, the rotational power output from the output shaft of the hydraulic motor 103 is transmitted to the rotary casing 20 by increasing the torque while the rotation is decelerated by the planetary gear mechanism 60.

A cover 8 is attached to the open end 27 of the rotary casing 20, and the rotary casing 20 and the cover 8 define a gear chamber 9 in which the planetary gear mechanism 60 is housed.

A floating seal 50 is provided between the fixed housing 10 and the rotating casing 20. The floating seal 50 includes O-rings 51 and 52 and seal rings 53 and 54. The O-rings 51 and 52 are arranged in close contact with the wall surface 11 of the fixed housing 10 and the inner wall surface 21 of the rotating casing 20, respectively. The seal rings 53 and 54 are pressed by the O-rings 51 and 52, respectively, and are in sliding contact with each other.

When the rotating casing 20 rotates, one of the seal rings 53 and 54 slides on the other. In this way, the seal rings 53 and 54 are basically always in close contact with each other without any gaps to prevent the hydraulic oil in the endless track drive device 101 from leaking to the outside and foreign matter in the endless track drive device 101. Prevents intrusion. The specific configuration of the floating seal 50, which is a type of combination seal, is not particularly limited. Typically, the floating seal 50 can be composed of rubber O-rings 51 and 52 and high-hardness special cast iron seal rings 53 and 54. By adopting a structure in which the metal seal rings 53 and 54 slide together, the floating seal 50 exhibits excellent wear durability against earth and sand and the like.

Next, the configuration in the vicinity of the gap path 40 will be described.

FIG. 3 is an enlarged cross-sectional view showing the vicinity of the gap path 40 shown in FIG.

The gap path 40 according to the present embodiment has a curved cross-sectional shape that forms a labyrinth seal between the fixed housing 10 and the rotating casing 20. Specifically, the gap path 40 has radial paths 42a and 42b extending in the radial direction (that is, the radial direction with respect to the rotation axis O) perpendicular to the rotation axis O, and the rotation axis O (see FIG. 1). Has axial paths 43a, 43b extending in the axial direction Da extending along the line. The gap road 40 of the present embodiment has two radial roads (first radial road 42a and second radial road 42b) and two axial roads (first axial road 43a and second radial road 43b). That is, the gap road 40 extends to the first axial road 43a extending in the axial direction Da, the first radial road 42a connected to the first axial road 43a and extending in the radial direction Dr, and the first radial road 42a. It has a second axial road 43b that is connected and extends in the axial direction Da, and a second radial road 42b that is connected to the second axial road 43b and extends in the radial direction Dr. A first radial path 42a and a first axial path 43a are provided on the rotary flange portion 29.

The opening 41 of the gap path 40 is formed by a first axial path 43a extending in the axial direction Da, and is directed to the axial direction Da. The second radial road 42b opens around the floating seal 50 and is arranged between the O-rings 51 and 52. By bending the gap paths 40 at a plurality of locations to provide the plurality of radial paths 42a and 42b and the plurality of axial paths 43a and 43b in this way, the fixed housing 10 (outer member 31) and the rotary casing 20 (inner member 32) are provided. It is possible to prevent the invasion of earth and sand between the and.

One of the rotating casing 20 and the fixed housing 10 constitutes an outer member 31 in which at least a part is arranged outside the other in the radial direction Dr, and the other constitutes an inner member 32. In this embodiment, the outer member 31 is a fixed housing 10 and the inner member 32 is a rotating casing 20.

The outer member 31 has a covering portion 35 extending in the axial direction Da and extending in the radial direction Dr. The covering portion 35 partitions at least a part of the gap path 40 (in the example shown in FIG. 3, the first axial path 43a, the first radial path 42a, and the second axial path 43b).

By including the portion 35a in which the covering portion 35 extends in the radial direction Dr in this way, the gap path 40 between the outer member 31 (fixed housing 10) and the inner member 32 (rotary casing 20) is made into the radial direction Dr. It can be postponed. As a result, the gap path 40 can be lengthened, and foreign matter such as earth and sand can be suppressed from entering. Further, the covering portion 35 includes not only the portion 35a extending in the radial direction Dr but also the portion 35b extending in the axial direction Da, whereby the gap path 40 between the outer member 31 and the inner member 32 is formed. The labyrinth seal can be complicated, and the invasion of foreign matter such as earth and sand can be effectively suppressed.

The opening 41 of the gap path 40 communicating with the external space S outside the outer member 31 is provided outside the portion 35a of the covering portion 35 extending in the radial direction Dr with respect to the radial direction Dr.

The fixed flange portion 19 included in the outer member 31 forms an overhanging portion 45 projecting toward the external space S in the radial direction Dr. The covering portion 35 and the fixed flange portion 19 form a concave depositing portion H. The opening 41 of the gap path 40 is 3/4 or more of the height of the fixed flange portion 19 from the portion 35b extending in the axial direction Da of the covering portion 35 with respect to the radial direction Dr, and the axial of the covering portion 35. It is provided at a position away from the portion 35b extending in the direction Da. The opening 41 of the gap path 40 of the present embodiment is provided outside the fixed flange portion 19 in the radial direction Dr. As a result, even if foreign matter such as earth and sand is deposited on the depositing portion H, such foreign matter is present at a distance from the opening 41, so that the foreign matter does not enter the opening 41 even if it is affected by gravity.

On the other hand, the inner member 32 has an expansion portion 37 arranged outside the covering portion 35 with respect to the portion 35a extending in the radial direction Dr. The opening 41 (that is, the first axial path 43a) of the gap path 40 is partitioned by a portion 35a of the covering portion 35 extending in the radial direction Dr and an extension portion 37. In the present embodiment, at least a part of the expansion portion 37 that partitions the first axial path 43a is made to bulge in the axial direction Da (particularly, the deposit portion H side (left side in FIG. 3)) as compared with the screw hole 28. It is provided. The outermost radial end of the portion 35a extending in the radial direction Dr of the covering portion 35 is arranged so as to face the expansion portion 37 via the first axial path 43a. .. It should be noted that, of the surfaces on the depositing portion H side (left side in FIG. 3) of the portion of the expansion portion 37 that partitions the first axial road 43a, the surface arranged adjacent to the opening 41 and the radial direction Dr of the covering portion 35. Of the surface of the deposited portion H side (left side in FIG. 3) of the portion 35a extending to the surface, the surface arranged adjacent to the opening 41 exists on the same plane, and in the example shown in FIG. 3, the radial direction. It extends to Dr.

In the present embodiment, the seal members 70a and 70b are arranged in the gap path 40, and the seal members 70a and 70b are provided so as to come into contact with each of the outer member 31 and the inner member 32. The seal members 70a and 70b can be arranged at arbitrary positions in the gap path 40. In the illustrated example, the first seal member 70a is arranged on the first radial path 42a and the second seal is arranged on the second axial path 43b. The member 70b is arranged. From the viewpoint of more reliably preventing foreign matter such as earth and sand from entering around the floating seal 50 through the gap path 40 (that is, the labyrinth seal), the seal members 70a and 70b should completely block the gap path 40. It is preferable that it is provided in. However, the seal members 70a and 70b are not essential, and only one of the seal members 70a and 70b may be provided, or the seal members 70a and 70b may not be provided. Even in such a case, since the gap path 40 constitutes the labyrinth seal and the opening 41 particularly faces the axial direction Da, foreign matter such as earth and sand invades the gap path 40 and invades the periphery of the floating seal 50. You can prevent that.

Next, the operation of the track drive device 101 will be described.

When the track vehicle 100 is traveling, the hydraulic motor 103 rotates the rotating casing 20 via the planetary gear mechanism 60, so that the endless track zone that meshes with the sprocket that rotates with the rotating casing 20 is circulated and moved. On the other hand, the labyrinth seal formed by the gap path 40 prevents foreign matter such as earth and sand from entering around the floating seal 50, and the floating seal 50 prevents foreign matter from entering the gear chamber 9 and the gear chamber. Leakage of hydraulic oil from 9 is prevented.

When the track driving device 101 is used in an environment where earth and sand are present, foreign matter such as earth and sand adheres to the fixed housing 10 and the rotating casing 20. However, according to the seal structure 104 of the endless track drive device 101 according to the above-described embodiment, the intrusion of such foreign matter into the endless track drive device 101 is caused by the gap path 40 (labyrinth seal) and the floating seal 50. Is prevented by.

FIG. 4 is an enlarged cross-sectional view showing the vicinity of the gap path 40 according to the prior art.

Compared to the conventional seal structure 104 (see FIG. 4) in which the gap path 40 opens at the bottom of the deposit portion H in a direction consistent with the direction of gravity, the gap path 40 is separated from the bottom portion of the deposit portion H in the axial direction. The seal structure 104 (see FIGS. 2 and 3) of the present embodiment that opens to Da can more effectively suppress the intrusion of earth and sand into the gap path 40. That is, in the present embodiment, the covering portion 35 is formed on one of the outer member 31 and the inner member 32 (the outer member 31 (fixed housing 10) in the present embodiment), and the other member (inner in the present embodiment). The member 32 (rotary casing 20)) is covered with the covering portion 35. Then, at least a part of the depositing portion H on which the earth and sand can be deposited is partitioned by the covering portion 35, and the opening 41 of the gap path 40 is outside (more preferably) from the bottom of the depositing portion H in the radial direction Dr. By opening at the outside of the depositing portion H), it is possible to prevent foreign matter such as earth and sand from entering the gap path 40 through the opening 41. Further, by setting the direction of the opening 41 of the gap 40 to the axial direction Da and directing the opening 41 in a direction that does not include the gravity direction component, the invasion of foreign matter into the gap 40 is more effectively prevented. be able to.

Further, by forming the covering portion 35 in the fixed housing 10, it is possible to prevent the foreign matter such as earth and sand adhering to the covering portion 35 from being wound up, and to drop such foreign matter by its own weight.

The present invention is not limited to the above-described embodiments and modifications, but may include various aspects to which various modifications that can be conceived by those skilled in the art are added, and the effects produced by the present invention are also described above. It is not limited to the matters of. Therefore, various additions, changes, and partial deletions can be made to the claims and the elements described in the specification without departing from the technical idea and purpose of the present invention.

For example, in the above-described embodiment, the fixed housing 10 constitutes the outer member 31 and the rotating casing 20 constitutes the inner member 32. However, as shown in FIG. 5, the fixed housing 10 constitutes the inner member 32 and the inner member 32 is formed. The rotary casing 20 may constitute the outer member 31. That is, the covering portion 35 may be formed by the rotating casing 20, and in the example shown in FIG. 5, a part of the gap path 40 (that is, the first radial path 42a and the first axial path 43a) is provided in the fixed flange portion 19. There is. In the example shown in FIG. 5, the rotating flange portion 29 forms the overhanging portion 45, and the covering portion 35 and the rotating flange portion 29 form the concave depositing portion H.

In the example shown in FIG. 5, the portion of the fixed flange portion 19 that partitions the first axial path 43a is provided so as to overlap the screw hole 18 in the axial direction Da, and is provided from the screw hole 18 to the deposition portion H. It does not bulge to the side (right side of FIG. 5). The outermost radial end of the portion 35a extending in the radial direction Dr of the covering portion 35 is a portion of the fixed flange portion 19 for partitioning the first axial path 43a via the first axial path 43a. It is arranged so as to face the. It should be noted that, of the surfaces on the depositing portion H side (right side in FIG. 5) of the portion of the fixed flange portion 19 that partitions the first axial path 43a, the surface arranged adjacent to the opening 41 and the radial direction of the covering portion 35. Of the surfaces on the depositing portion H side (right side in FIG. 5) of the portion 35a extending to Dr, the surfaces arranged adjacent to the opening 41 are on the same plane, and in the example shown in FIG. 5, they are radial. Extends in the direction Dr.

Further, as shown in FIG. 6, a gap path 40 (particularly, a first radial path 42a) may be arranged on the back surface side of the screw hole 18. In the example shown in FIG. 6, one side of the screw hole 18 (left side in FIG. 6) is open to the outside, and the other side of the screw hole 18 (right side in FIG. 6) is a gap path 40 (particularly, the first radial path 42a). ) Is open to communicate with. However, the other side of the screw hole 18 (that is, the covering portion 35 side) may be closed by the fixed flange portion 19, and the screw hole 18 does not communicate with the gap path 40 (particularly the first radial path 42a). May be good. A first radial path 42a is formed so as to penetrate the back portion of the fixed flange portion 19 on the other side of the screw hole 18. In the example shown in FIG. 6, the height of the opening 41 (that is, the radial direction from the portion 35b of the covering portion 35 extending in the axial direction Da) while suppressing the increase in the size of the fixed flange portion 19 with respect to the radial direction Dr. The distance to Dr) can be increased. Therefore, it is possible to effectively prevent sediment and the like from entering the gap path 40 from the depositing portion H through the opening 41.

In the example shown in FIG. 6, the portion of the fixed flange portion 19 that partitions the first axial path 43a bulges in the axial direction Da (particularly on the deposit portion H side (right side in FIG. 6)) as compared with the screw hole 18. It is provided so as to do so. Then, the outermost radial end portion of the portion 35a extending in the radial direction Dr of the covering portion 35 is arranged so as to face the fixed flange portion 19 via the first axial path 43a. There is. It should be noted that, of the surfaces on the depositing portion H side (right side in FIG. 6) of the portion of the fixed flange portion 19 that partitions the first axial path 43a, the surface arranged adjacent to the opening 41 and the radial direction of the covering portion 35. Of the surfaces on the depositing portion H side (right side in FIG. 6) of the portion 35a extending to Dr, the surfaces arranged adjacent to the opening 41 are on the same plane, and in the example shown in FIG. 6, they are radial. Extends in the direction Dr.

Further, for example, in the above-described embodiment, the floating seal 50 is provided together with the labyrinth seal (gap path 40), but the floating seal 50 is not necessarily provided. Further, a seal structure other than the floating seal 50 may be provided. Even in such a case, according to the seal structure 104 described above, it is possible to suppress the entry of earth and sand or the like into the gap path 40 between the fixed housing 10 and the rotating casing 20.

3 Bearing 8 Cover 9 Gear chamber 10 Fixed housing 11 Wall surface 12 Outer wall part 14 Input shaft 18 Screw hole 19 Fixed flange part 20 Rotating casing 21 Inner wall surface 22 Outer wall part 27 Opening end 28 Screw hole 29 Rotating flange part 31 Outer member 32 Inner member 35 Cover 37 Expansion 40 Gap Road 41 Opening 42a First Radial Road 42b Second Radial Road 43a First Axial Road 43b Second Axial Road 45 Overhang 50 Floating Seal 51 O Ring 52 O Ring 53 Seal Ring 54 Seal Ring 60 Planetary gear mechanism 61 Sun gear 62 Planetary gear 63 Carrier 64 Sun gear 65 Planetary gear 66 Ring gear 70a First seal member 70b Second seal member 100 Infinite track vehicle 101 Infinite track drive 102 Infinite track band 103 Hydraulic motor 104 Seal structure Da Axial direction Dr Radial direction F Foreign matter H Accumulation part S External space

Claims (8)

It is a seal structure of the endless track drive device that drives the endless track zone of the vehicle.
A rotating casing that is rotatably provided around the axis of rotation,
A fixed housing that forms a gap with the rotating casing.
One of the rotating casing and the fixed housing constitutes an outer member whose radial direction is perpendicular to the rotation axis and at least a part thereof is arranged outside the other, and the other constitutes an inner member.
The outer member
A first covering portion that partitions a portion of the gap path that extends in the axial direction extending the rotation axis, and an end portion of the gap path that extends in the axial direction and is connected in the radial direction. A covering portion including a second covering portion for partitioning an extending portion, the second covering portion extending outward from the outer peripheral surface of the first covering portion in the radial direction, and the first covering portion. And the covering portion, wherein the second covering portion partitions at least a part of the gap path.
Has a projecting portion which projects into the radial direction toward the outer side of the outer space, and
The opening of the gap path communicating with the external space is provided outside the second covering portion in the radial direction.
The first covering portion, the second covering portion, and the overhanging portion form a concave deposit portion.
Among the gap passage, the first is defined by the coating portion and the portion that Mashimasu extending in the axial direction, the first through the covered portion, the seal structure on the opposite side from the depositing unit with respect to the radial direction body. The inner member has an extension portion that is arranged outside the second covering portion in the radial direction.
The opening of the gap is partitioned by the second covering and the extension.
A claim that the surface of the expansion portion arranged adjacent to the opening and the surface of the second covering portion arranged adjacent to the opening are present on the same plane. Item 1. The seal structure according to item 1. The seal structure according to claim 1 or 2, wherein the opening of the gap path is provided outside the overhanging portion in the radial direction. The seal structure according to any one of claims 1 to 3, wherein the opening of the gap path is directed in the axial direction. The seal structure according to any one of claims 1 to 4, wherein the gap path has a radial path extending in the radial direction and an axial path extending in the axial direction. The seal structure according to any one of claims 1 to 5, further comprising a seal member arranged in the gap path and in contact with each of the outer member and the inner member. The seal structure according to any one of claims 1 to 6, wherein the outer member is the fixed housing, and the inner member is the rotating casing. The seal structure according to any one of claims 1 to 6, wherein the outer member is the rotating casing, and the inner member is the fixed housing.

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