JP6601233B2 - Traveling device - Google Patents

Description

  The present invention relates to a traveling device for a crawler type vehicle such as a hydraulic excavator.

  For example, a crawler type vehicle such as a hydraulic excavator is configured by an upper turning body having an attachment and a lower traveling body on which the upper turning body is rotatably mounted around a vertical axis. The lower traveling body includes a sprocket and idler wheels over which a crawler (crawler belt) is passed.

  The traveling device that drives the sprocket includes a motor unit and a speed reduction unit. The motor unit includes a travel motor (hydraulic motor) and a fixed casing in which the travel motor is accommodated, and the fixed casing is fixed to a crawler frame (lower frame) of the lower traveling body.

  The speed reduction unit includes a speed reduction mechanism and a rotating casing that houses the speed reduction mechanism. The rotational force of the travel motor decelerated by the speed reduction mechanism is transmitted to the sprocket via the rotation-side casing.

  The stationary casing and the rotating casing are connected to each other through a bearing at one end in the axial direction, and a floating seal is provided inside the ends facing each other with a gap therebetween. Yes. The floating seal is provided to prevent leakage of lubricating oil inside the rotating casing and intrusion of mud, water, and the like from the outside.

  As is well known, a floating seal is composed of a ring metal part called a seal ring and a rubber O-ring, and a set of two is used, and one O-ring is pressed against a fixed peripheral surface. The metal member and the metal member that presses the other O-ring against the peripheral surface of the rotation side are in close contact with each other to slide, thereby sealing the inside of the rotation side casing without hindering the rotation of the rotation side casing.

  However, if muddy water adheres to the O-ring of the floating seal and the mud dries due to the influence of operating heat of the speed reduction mechanism, etc., the O-ring is damaged by repeated running operation, the sealing performance is deteriorated and lubricating oil leaks. There is a fear. And when lubricating oil leaks from a rotation side casing, there exists a possibility that the smooth operation | movement of a traveling apparatus cannot be obtained.

  Therefore, conventionally, an O-ring is inserted into the gap between the two casings located outside the floating seal, and lubricating oil (grease) is filled between the floating seal and the O-ring so that the mud to the floating seal is filled. There is known one in which adhesion of water or water is prevented (see Patent Document 1).

  However, the O-ring inserted into the gap between the two casings is in sliding contact with the peripheral surface that rotates during the traveling operation. For this reason, it is difficult to reliably prevent outflow of the lubricating oil filled outside the floating seal by the O-ring, and there is an inconvenience that the effect of preventing the intrusion of muddy water or the like is reduced early.

  In addition, if mud that has entered the gap between the two casings adheres to the O-ring, the O-ring may be deteriorated, as in the case where mud adheres to the O-ring of the floating seal described above.

JP-A-8-74289

  In view of the above points, an object of the present invention is to provide a traveling device that has improved durability by reliably preventing a decrease in sealing performance of a floating seal.

In order to achieve this object, the present invention provides a stationary casing fixed to a lower frame of a crawler type traveling body and sealed inside, a rotating casing that rotates with respect to the stationary casing, and both casings. In a crawler-type vehicle traveling device that includes a floating seal provided inside ends facing each other with a gap therebetween, and the crawler-type vehicle travels around an outer periphery of the rotating casing. A labyrinth seal portion is provided outside the floating seal in the gap between the side casing and a first seal and a second seal disposed inside the first seal at a position outside the labyrinth seal portion. And a lubricating oil supply passage for guiding the lubricating oil to be filled between the two seals. The first seal is elastic to the rotating casing. To contact, and impervious direction to prevent the passage of one-way fluid along the rotation axis direction of the rotating side casing, and flow allowable direction to permit passage of fluid towards the opposite direction of the fluid through the reverse direction Is set, and the seal lip of the first seal is located on the outer side of the first seal from the second seal side with the direction from the outer side of the first seal toward the second seal as the flow blocking direction. The lubricating oil supply path extends toward the fixed casing side, and the upstream end is opened in the sealed interior of the lower frame. .

  According to the present invention, a labyrinth seal portion, a first seal, and a second seal are provided in a gap between the stationary casing and the rotating casing located outside the floating seal, and further, the first is provided via a lubricating oil supply path. By filling lubricating oil (such as grease) between the seal and the second seal, leakage of lubricating oil inside the rotating casing and entry of mud, water, etc. from the outside are prevented.

  That is, the labyrinth seal part provides flow resistance to mud, water, and the like, and reduces the flow rate of mud, water, and the like that enters the gap between the stationary casing and the rotating casing.

  In addition, the first seal prevents the flow of mud, water, and the like in the direction from the outside of the first seal toward the second seal by setting the seal lip. At this time, since the lubricating oil (such as grease) is filled between the first seal and the second seal, the pressure inside the space between the first seal and the second seal is increased. Intrusion of mud, water or the like into the space between the first seal and the second seal is reliably prevented.

  Further, the direction in which the seal lip of the first seal is directed from the second seal side toward the outside of the first seal is set as a flow allowable direction. According to this, by supplying a large amount of lubricating oil between the first seal and the second seal, the lubricating oil can flow out to the outside of the first seal and try to enter from the outside of the first seal. The action of pushing back mud with lubricating oil is obtained.

  And since the upstream end which becomes the injection port of the lubricating oil supply path for supplying the lubricating oil between the first seal and the second seal opens in the sealed inside of the lower frame, the lubricating oil is lubricated when the lubricating oil is injected. Mud and water do not enter the oil supply path, and fresh lubrication can be supplied between the first seal and the second seal.

  As described above, according to the present invention, it is possible to provide a traveling device with improved durability by reliably preventing a decrease in sealing performance due to a floating seal.

  In the present invention, it is preferable that the gap between the second seal and the floating seal is filled with lubricating oil. According to this, even if mud or water or the like tries to enter the space between the second seal and the floating seal, it is blocked by the lubricating oil filled in the space, so mud or water or the like to the floating seal. Can be more reliably prevented.

Moreover, in this invention, it is preferable to provide the 2nd seal | sticker of the same structure as a 1st seal | sticker. That is, the second seal is elastically abutted on the rotation side casing to prevent passage of fluid in one direction along the rotation axis direction of the rotation side casing , and the flow prevention direction. A seal lip is provided that has a flow-permitting direction that allows passage of fluid in the opposite direction.

  In this case, as a first aspect, the direction of the seal lip of the second seal from the first seal side toward the first seal is defined as the flow blocking direction as the direction from the first seal side toward the first seal. For example, it is set so as to be in a distribution allowable direction.

  According to this, when lubricating oil is supplied between the first seal and the second seal and the lubricating oil overflows from between the first seal and the second seal, the lubricating oil flows to the floating seal side. Instead, it flows out of the first seal. Thereby, sufficient internal pressure can be given with lubricating oil between the 1st seal and the 2nd seal. Therefore, intrusion of mud, water, etc. from the outside of the first seal between the first seal and the second seal can be prevented, and the lubricating oil overflowing from between the first seal and the second seal is It is possible to push back mud, water, and the like from the outside of the first seal toward the first seal, and reliably prevent mud, water, and the like toward the floating seal.

  Further, as a second aspect, the flow of the seal lip of the second seal is such that the direction from the first seal side to the floating seal is the flow blocking direction in the direction from the floating seal side to the first seal. For example, setting may be made so as to be in an allowable direction. At this time, the contact pressure of the seal lip of the second seal with the rotating casing is smaller than the contact pressure of the seal lip of the first seal with the rotating casing.

  According to this, when the lubricating oil is supplied between the first seal and the second seal and the lubricating oil overflows from between the first seal and the second seal, the overflowing lubricating oil first becomes the second It flows between the second seal and the floating seal through the seal. Thereafter, when the filling of the lubricating oil between the second seal and the floating seal is completed (between the second seal and the floating seal is filled with the lubricating oil), from between the first seal and the second seal. The overflowing lubricating oil flows out to the outside through the first seal.

  By filling the space between the second seal and the floating seal with the lubricating oil, adhesion of mud, water or the like to the floating seal is prevented. And mud, water, etc. which go to the 1st seal can be pushed back by the lubricating oil which flows outside the 1st seal.

  Furthermore, the completion of filling of the lubricating oil between the second seal and the floating seal can be determined from the outside by the lubricating oil flowing out from between the first seal and the second seal to the outside of the first seal. Therefore, the lubricating oil can be reliably filled between the second seal and the floating seal, and excessive supply of the lubricating oil can be prevented.

The schematic side view of a hydraulic excavator. The figure which shows the traveling apparatus of 1st Embodiment of this invention. Explanatory sectional drawing of the principal part of the traveling apparatus of 1st Embodiment. Explanatory sectional drawing of the principal part of the traveling apparatus of 2nd Embodiment. Explanatory sectional drawing of the principal part of the traveling apparatus of 3rd Embodiment.

  The traveling device of the first embodiment of the present invention is provided in the hydraulic excavator shown in FIG.

  As shown in FIG. 1, the excavator has an upper swing body 2 mounted on a lower traveling body 1 so as to be rotatable about a vertical axis, and the upper swing body 2 includes a boom 3, an arm 4, and a bucket 5. A work (excavation) attachment 6 is mounted.

  The lower traveling body 1 is configured by attaching a sprocket 8 on one of the front and rear sides of a crawler frame 7 (lower frame) and an idler wheel 9 on the opposite side and spanning a crawler 10 therebetween.

  The sprocket 8 is driven by the traveling device shown in FIG. As shown in FIG. 2, the traveling device includes a motor unit MU on the fixed side and a speed reduction unit GU on the rotation side.

  The motor unit MU includes a travel motor 11 such as a hydraulic motor and a stationary casing 12 in which the travel motor 11 is accommodated. The stationary casing 12 is fixed to the crawler frame 7, and the traveling motor 11 is disposed inside the crawler frame 7. The inside of the crawler frame 7 where the traveling motor 11 is located is sealed in a watertight manner to prevent entry of foreign matters such as water, mud, and dust.

  The speed reduction unit GU includes a speed reduction mechanism (not shown) that reduces the rotational force of the traveling motor 11 and a rotation side casing 13 in which the speed reduction mechanism is accommodated. To the sprocket 8.

  As shown in FIG. 3, the stationary casing 12 and the rotating casing 13 are coupled via bearings 14 and 15 at one end in the axial direction. A labyrinth seal portion 16 and a floating seal 17 are provided between the stationary casing 12 and the rotating casing 13. Further, a first seal 18 and a second seal 19 are provided at positions outside the labyrinth seal portion 16.

  The floating seal 17 includes annular metal members 20 and 21 and rubber O-rings 22 and 23. One metal member 20 presses the O-ring 22 against the inner peripheral surface of the stationary casing 12. The other metal member 21 presses the O-ring 23 against the inner peripheral surface of the rotating casing 13. The metal members 20 and 21 are slidably in close contact with each other, and when the rotating casing 13 rotates, the metal member 21 attached to the rotating casing 13 is attached to the rotating casing 13. 20 slidably rotates.

  The labyrinth seal portion 16 is a narrow space that is bent and formed by a cylindrical rotation-side convex portion 24 of the rotation-side casing 13 and an annular recess 25 corresponding to the rotation-side projection 24 with a gap.

  The stationary casing 12 is provided with a retainer 26 for attaching the first seal 18 and the second seal 19. Thereby, the first seal 18 and the second seal 19 are disposed between the retainer 26 and the sleeve 27 attached to the outer peripheral surface of the rotation-side convex portion 24 of the rotation-side casing 13.

  Here, the first seal 18 and the second seal 19 will be described. The first seal 18 is integrally provided with a base 28 and a seal lip 29. The base portion 28 of the first seal 18 is formed in a block shape, and is adhered and fixed to the retainer 26 of the stationary casing 12.

  The seal lip 29 of the first seal 18 elastically contacts the outer peripheral surface of the sleeve 27 of the rotation-side convex portion 24 of the rotation-side casing 13. The sleeve 27 is provided to prevent the seal lip 29 from being worn.

  A recess 30 is formed between the base 28 of the first seal 18 and the seal lip 29. The recess 30 gives a function like a check valve to the seal lip 29, and the flow direction of the fluid can be set by the direction of the recess 30 (direction of the seal lip 29).

  That is, since the seal lip 29 elastically contacts the sleeve 27 of the rotation-side convex portion 24, the fluid flowing in the direction toward the concave portion 30 (the direction toward the leading edge of the seal lip 29) And the sleeve 27 of the rotation-side convex portion 24 are difficult to pass. Further, when the fluid pressure in the concave portion 30 is higher than the opposite side of the concave portion 30, the seal lip 29 strongly presses against the sleeve 27 of the rotation-side convex portion 24. Thereby, the fluid flowing toward the concave portion 30 of the first seal 18 cannot pass between the seal lip 29 and the rotation-side convex portion 24.

  On the other hand, when the fluid strikes the seal lip 29 from the opposite side of the recess 30, the seal lip 29 is bent by the recess 30, and the fluid passes between the seal lip 29 and the sleeve 27 of the rotation-side convex portion 24.

  The second seal 19 has the same configuration as that of the first seal 18, and is elastically applied to a base portion 31 that is bonded and fixed to the retainer 26 of the stationary casing 12 and a sleeve 27 that is included in the rotating convex portion 24 of the rotating casing 13. A seal lip 32 that comes into contact with each other, and a recess 33 formed between the base portion 31 and the seal lip 32, and depending on the direction of the recess 33 (the direction of the seal lip 32), Can be set.

  As described above, in each of the first seal 18 and the second seal 19, the direction in which the fluid is directed toward the recesses 30 and 33 is the flow blocking direction, and the opposite direction is the flow allowable direction. And as shown in FIG. 3, the 1st seal | sticker 18 and the 2nd seal | sticker 19 are provided with the recessed parts 30 and 33 facing both outside.

  According to this, when muddy water invades from the outside, the flow of muddy water toward the second seal 19 is blocked by the first seal 18. Even if the muddy water exceeds the first seal 18, the muddy water flowing toward the floating seal 17 is blocked by the first seal 18.

  Further, lubricating oil such as grease is filled between the floating seal 17 and the second seal 19 and between the first seal 18 and the second seal 19. Lubricating oil between the floating seal 17 and the second seal 19 is filled during assembly manufacture. Lubricating oil between the first seal 18 and the second seal 19 is filled using the lubricating oil supply path 34.

  The lubricating oil supply path 34 passes through the fixed casing 12 and the crawler frame 7, and an upstream end serving as a lubricating oil inlet 35 opens inside the crawler frame 7. Since the inside of the crawler frame 7 is in a sealed state, the crawler frame 7 is formed so that mud, water, and the like are difficult to enter. Therefore, intrusion of mud, water and the like from the lubricating oil inlet 35 into the lubricating oil supply path 34 is prevented.

  The lubricating oil is filled between the floating seal 17 and the second seal 19 and between the first seal 18 and the second seal 19, so that even if muddy water enters from the outside, the floating seal 17 There is no space in which muddy water can enter between the second seal 19 and between the first seal 18 and the second seal 19. Therefore, intrusion of mud, water, etc. is prevented by the lubricating oil.

  Further, when the lubricating oil is injected through the lubricating oil supply passage 34 to increase the lubricating oil between the first seal 18 and the second seal 19, the flow is blocked by the second seal 19. The lubricating oil flows out through the first seal 18 that is allowed to flow. Due to the flow of the lubricating oil at this time, the outer muddy water is pushed back and the muddy water is prevented from adhering to the first seal 18, so that the first seal 18 can be prevented from being damaged by the mud adhering.

  Next, a second embodiment of the present invention will be described. The traveling device of the second embodiment is also provided in the hydraulic excavator shown in FIG. 1, and the schematic configuration is as shown in FIG.

  Compared with the traveling device of the first embodiment shown in FIG. 3, as shown in FIG. 4, the traveling device of the second embodiment differs in the direction of the recesses 30 and 33 between the first seal 18 and the second seal 19. ing. That is, the second seal 19 is provided with the recess 33 facing inward (on the side opposite to the recess 30 of the first seal 18).

  Furthermore, in the second embodiment, the seal lip 29 of the first seal 18 abuts the outer peripheral surface of the sleeve 27 of the rotation-side convex portion 24 of the rotation-side casing 13 with stronger elasticity than the seal lip 32 of the second seal 19. ing. Other configurations are the same as those of the traveling device of the first embodiment.

  According to the traveling device of the second embodiment, the following operation is obtained. Referring to FIG. 4, when lubricating oil is injected between the first seal 18 and the second seal 19 via the lubricating oil supply path 34, the lubricating oil passes through the second seal 19 toward the floating seal 17. . This is because the pressure of the seal lip 32 of the second seal 19 on the sleeve 27 is smaller than that of the seal lip 29 of the first seal 18.

  As a result, first, the lubricating oil is filled between the floating seal 17 and the second seal 19.

  Thereafter, when the space between the floating seal 17 and the second seal 19 is filled with lubricating oil, and the internal pressure between the floating seal 17 and the second seal 19 rises, the concave portion 33 side of the second seal 19 is pressurized and the second seal 19 is pressurized. The pressure contact force of the seal lip 32 of the two seal 19 is increased. When no more lubricating oil can flow between the floating seal 17 and the second seal 19, the lubricating oil flows out to the outside via the first seal 18.

  The lubricating oil flows out of the first seal 18 so that the space between the floating seal 17 and the second seal 19 and the space between the first seal 18 and the second seal 19 are filled with the lubricating oil. This makes it possible to prevent excessive supply of lubricating oil.

  Furthermore, also in the traveling device of the second embodiment having the above configuration, the same effect as that of the first embodiment can be obtained. That is, since the direction of the concave portion 30 (the leading edge of the seal lip 29) of the first seal 18 is directed outward, it is possible to prevent the intrusion into the inside with respect to the flow of mud, water, etc. from the outside. . Moreover, since the lubricating oil is filled between the floating seal 17 and the second seal 19 and between the first seal 18 and the second seal 19, there is no space for intrusion of muddy water. And since the flow of lubricating oil is formed toward the outside of the first seal 18 from between the first seal 18 and the second seal 19, the muddy water flowing toward the first seal 18 can be pushed back.

  In each of the above embodiments, an example in which the first seal 18 and the second seal 19 are provided in the stationary casing 12 has been described, but the present invention is not limited thereto. Therefore, a third embodiment shown in FIG. 5 can be given.

  In the third embodiment, as shown in FIG. 5, the first seal 18 and the second seal 19 are provided on the rotation-side casing 13. The rotation side casing 13 includes a retainer 36, and the first seal 18 and the second seal 19 are fixed to the retainer 36.

  The lubricating oil supply passage 37 passes through the fixed casing 12 and is opened at the outer surface of the fixed casing 12, and this opening is used as an inlet 38.

  The first seal 18 is provided with the recess 30 facing outward. In FIG. 5, the second seal 19 shows the concave portion 33 facing outward as in the case of the first seal 18. However, the present invention is not limited to this, and the concave portion 33 can also be provided facing inward. . Even if comprised in this way, the effect similar to each embodiment mentioned above can be acquired.

  7 ... Crawler frame (lower frame), 10 ... Crawler, 12 ... Fixed casing, 13 ... Rotating casing, 16 ... Labyrinth seal, 17 ... Floating seal, 18 ... First seal, 19 ... Second seal, 29, 32: Seal lip, 34, 37: Lubricating oil supply passage.

Claims (4)

A fixed casing that is fixed to the lower frame of the crawler type traveling body and sealed inside, a rotating casing that rotates with respect to the fixed casing, and ends that face each other with a gap between them. In a traveling device for a crawler-type vehicle that includes a floating seal provided on the inner side and hangs a crawler on the outer periphery of the rotating casing.
A labyrinth seal portion is provided outside the floating seal in the gap between the stationary casing and the rotating casing;
A first seal, a second seal disposed inside the first seal, and a lubricating oil supply passage for guiding the lubricating oil filled between the two seals are provided at an outer position of the labyrinth seal portion,
The first seal is elastically abutted against the rotation side casing to prevent passage of fluid in one direction along the rotation axis direction of the rotation side casing , and a direction opposite to the flow prevention direction. A seal lip that is set with a flow allowable direction that allows passage of fluid toward
The seal lip of the first seal has a direction from the outer side of the first seal toward the second seal as the flow blocking direction, and a direction from the second seal side toward the outer side of the first seal is the flow allowable direction. Set to be
The lubricating oil supply path extends toward the fixed casing, and has an upstream end opened in a sealed interior of the lower frame.   The traveling device according to claim 1, wherein the gap between the second seal and the floating seal is filled with lubricating oil. The second seal is elastically abutted against the rotation side casing to prevent passage of fluid in one direction along the rotation axis direction of the rotation side casing , and a direction opposite to the flow prevention direction. A seal lip that is set with a flow allowable direction that allows passage of fluid toward
The seal lip of the second seal is set so that the direction from the first seal side toward the floating seal is the flow blocking direction, and the direction from the floating seal side toward the first seal is the flow allowable direction. The traveling device according to claim 1, wherein the traveling device is provided. The second seal is elastically abutted against the rotation side casing to prevent passage of fluid in one direction along the rotation axis direction of the rotation side casing , and a direction opposite to the flow prevention direction. A seal lip that is set with a flow allowable direction that allows passage of fluid toward
The seal lip of the second seal is set so that the direction from the floating seal side to the first seal is the flow blocking direction, and the direction from the first seal side to the floating seal is the flow allowable direction. ,
Further, the contact pressure of the seal lip of the second seal with the rotating casing is smaller than the contact pressure of the seal lip of the first seal with the rotating casing. Or the traveling apparatus of 2.