JP2017116055A - Transmission and driving device including the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a transmission which prevents foreign objects from entering into a labyrinth seal.SOLUTION: A transmission 100 includes: a fixed housing 10 in which a hydraulic motor 1 is housed; a transmission mechanism 30 which changes a speed of output rotation of the hydraulic motor 1; a rotary housing 20 which houses the transmission mechanism 30 and rotates in response to transmission of the output rotation with a changed speed; a labyrinth seal 5 which is formed between the fixed housing 10 and the rotary housing 20 and prevents foreign objects from entering from the exterior part; and a cover member 60 which covers an exterior part side opening part 5D of the labyrinth seal 5.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a transmission and a drive device including the transmission.

  In a crawler type work machine such as a hydraulic excavator, a traveling motor is provided on an axle portion of a crawler belt (an endless track).

  Patent Document 1 includes a transmission having a cylindrical rotating housing that is connected to a sprocket that meshes with a crawler belt and rotates with respect to a fixed housing, and the transmission and the sprocket rotate together to drive the crawler belt. A travel motor is disclosed.

  In the above transmission, a planetary gear mechanism is provided in the rotary housing, and the planetary gear mechanism decelerates the output rotation of the hydraulic motor provided in the fixed housing and transmits it to the rotary housing.

JP 2013-199968 A

  In the transmission disclosed in Patent Document 1, a labyrinth seal is formed between the fixed housing and the rotating housing. This labyrinth seal has a cross-sectional clearance bent in a crank shape, and prevents foreign matters such as mud from entering. However, foreign matter such as mud may pass through the labyrinth seal and enter the inside of the apparatus during long-term use, and a countermeasure against further foreign matter intrusion has been demanded.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a transmission that can prevent foreign matter from entering the labyrinth seal and a drive device including the transmission.

  According to a first aspect of the present invention, there is provided a fixed housing in which a drive source is accommodated, a speed change mechanism that changes the output rotation of the drive source, a speed change mechanism that accommodates the speed change mechanism, and that is rotated by transmission of the changed output rotation. A labyrinth seal that is formed between the outer housing and the rotary housing and prevents foreign substances from entering from outside, and a cover member that covers an opening on the outside of the labyrinth seal.

  In the first invention, the cover member covers the opening on the outside of the labyrinth seal.

  The second invention is characterized in that the cover member is attached to the rotating housing.

  In the second invention, since the cover member is attached to the rotating housing, the cover member rotates together with the rotating housing. This prevents foreign matter such as mud from entering the labyrinth seal from accumulating on the cover member. Therefore, foreign matter such as mud can be prevented from entering the labyrinth seal from the opening of the cover member.

  According to a third aspect of the present invention, the fixed housing has a mounting portion that protrudes from the outer peripheral surface and is attached to an external member, and an annular fixed-side protrusion that is formed on the mounting portion and extends toward the rotating housing. The housing has an annular rotation-side protrusion that extends toward the fixed housing on the radially inner side of the fixed-side protrusion, and the labyrinth seal faces the front surface of the fixed-side protrusion and the opposite surface of the rotation housing that faces the front surface. And a second gap that is formed between the inner peripheral surface of the fixed-side projection and the outer peripheral surface of the rotation-side projection and is substantially perpendicular to the first gap. Features.

  In the third invention, the labyrinth seal is formed as a gap bent by the first gap and the second gap substantially orthogonal to the first gap. Thereby, it is possible to prevent foreign matter such as mud from entering the inside of the apparatus.

  According to a fourth aspect of the present invention, the cover member has a cylindrical portion that covers the opening, and a flange portion that is provided at the base end of the cylindrical portion and is attached to the rotating housing. The cylindrical portion of the cover member is a fixed-side protrusion. It arrange | positions with a predetermined | prescribed clearance gap between the outer peripheral surfaces of these.

  In the fourth invention, a further labyrinth seal is formed by the gap between the cylindrical portion of the cover member and the outer peripheral surface of the fixed-side protrusion. Thereby, it can prevent more that a foreign material penetrate | invades into the inside of an apparatus.

  According to a fifth aspect of the present invention, the cylindrical portion of the cover member has a tip that faces the external member with a predetermined gap.

  In the fifth invention, a further labyrinth seal is formed by the gap between the tip of the cylindrical portion of the cover member and the external member. Thereby, it can further prevent that a foreign material penetrate | invades into the inside of an apparatus.

  According to a sixth aspect of the invention, the cover member is configured to be separable.

  In the sixth invention, since the cover member is configured to be separable, processing and maintenance can be easily performed.

  The seventh invention is characterized by comprising any one of the first to sixth transmissions and a drive source.

  According to the present invention, foreign matter can be prevented from entering the labyrinth seal.

FIG. 1 is a cross-sectional view of a transmission according to a first embodiment of the present invention. FIG. 2 is a partial cross-sectional view of a main part of the transmission according to the first embodiment of the present invention. FIG. 3 is a partial cross-sectional view of a main part of a transmission according to the second embodiment of the present invention.

<First Embodiment>
Hereinafter, with reference to FIG.1 and FIG.2, the transmission 100 which concerns on 1st Embodiment of this invention is demonstrated.

  The transmission 100 is used, for example, in a travel motor that is provided on an axle portion of a crawler work machine such as a hydraulic excavator and drives a crawler belt. The travel motor as a drive device includes a hydraulic motor 1 as a drive source and a speed reducer 100 that decelerates the output rotation of the shaft 31 of the hydraulic motor 1.

  The transmission 100 includes a cylindrical rotary housing 20 that rotates with respect to the fixed housing 10. A sprocket (not shown) is connected to the outer peripheral surface of the rotary housing 20. When the rotary housing 20 and the sprocket rotate together, a crawler belt (not shown) that meshes with the sprocket circulates and the vehicle travels.

  The fixed housing 10 and the rotating housing 20 are disposed inside a path through which the crawler belt circulates. The rotary housing 20 is rotatably supported via the bearing 3 with respect to the fixed housing 10 connected to the vehicle body 6 as an external member, and rotates about the rotary shaft O.

  The hydraulic motor 1 is provided inside the main body 11 of the fixed housing 10. The hydraulic motor 1 is, for example, a swash plate type piston motor. The drive source may be other than the hydraulic motor, and for example, an electric motor may be used. The fixed housing 10 includes a fixed flange portion 12 that protrudes from the outer peripheral surface of the main body portion 11 and is attached to the vehicle body 6. A plurality of screw holes 15 are formed in the fixed flange portion 12. The fixed flange portion 12 corresponds to an attachment portion.

  As shown in FIG. 1, a transmission mechanism 30 is accommodated in the rotary housing 20. The transmission mechanism 30 is a planetary gear mechanism. The speed change mechanism 30 includes a sun gear 32 provided on the shaft 31 of the hydraulic motor 1, an inner gear 33 provided on the inner wall of the rotary housing 20, a plurality of planetary gears 34 that mesh with both the sun gear 32 and the inner gear 33, and each planetary gear. A planetary carrier 35 that supports the planetary carrier 34, a second-stage sun gear 36 that meshes with the planetary carrier 35, and a plurality of planetary gears 37 that mesh with both the sun gear 36 and the inner gear 33. The transmission mechanism 30 decelerates the output rotation of the shaft 31 of the hydraulic motor 1 and transmits it to the rotary housing 20.

  A disc-shaped open end cover 2 that closes the open end 20a is detachably attached to the inner periphery of the open end 20a of the rotary housing 20.

  A gear chamber 4 that houses the speed change mechanism 30 is defined by the inner surface of the rotating housing 20, the outer surface of the main body 11 of the fixed housing, and the open end cover 2. The gear chamber 4 is filled with lubricating oil that lubricates the transmission mechanism 30.

  The rotary housing 20 is formed with a rotary flange portion 29 projecting annularly from the outer peripheral surface 22. A plurality of screw holes 28 are formed in the rotating flange portion 29. The sprocket described above is fastened to the rotating flange portion 29 by screwing a bolt (not shown) into the screw hole 28, and rotates together with the rotating housing 20.

  The fixed housing 10 further includes an annular fixed protrusion 13 formed on the fixed flange portion 12 and extending toward the rotary housing 20. On the proximal end side of the rotation flange portion 29 of the rotation housing 20, an annular rotation-side protrusion 23 that extends toward the fixed housing 10 is formed radially inside the fixed-side protrusion 13.

  A floating seal 50 is provided between the fixed housing 10 and the rotary housing 20. The floating seal 50 includes O-rings 51 and 52 that are respectively attached to a seal surface 14 formed on the fixed flange portion 12 of the fixed housing 10 and an inner peripheral surface 21 of the rotation-side protrusion 23 of the rotary housing 20, and an O-ring. Seal rings 53 and 54 supported via 51 and 52, respectively. The floating seal 50 seals the hydraulic oil in the transmission 100 so that the hydraulic oil in the transmission 100 does not leak to the outside when the seal rings 53 and 54 are in sliding contact with each other when the rotary housing 20 rotates. To prevent intrusion. A space S is defined by the sealing surface 14 of the fixed housing 10, the inner peripheral surface 21 of the rotating housing 20, and the floating seal 50.

  A labyrinth seal 5 is formed between the fixed housing 10 and the rotating housing 20 to prevent foreign matters such as mud from entering the outside of the floating seal 50. The labyrinth seal 5 is formed by a gap between the end surfaces of the fixed housing 10 and the rotating housing 20 facing each other.

  FIG. 2 is an enlarged cross-sectional view of the vicinity of the labyrinth seal 5. As shown in FIG. 2, the labyrinth seal 5 includes a first gap 5 </ b> A formed between the distal end surface 13 a of the fixed side protrusion 13 and the side surface 29 a of the rotation flange portion 29 where the rotation side protrusion 23 is formed. A second gap 5B formed between the inner peripheral surface 13b of the fixed-side protrusion 13 and the outer peripheral surface 23a of the rotation-side protrusion 23 and substantially orthogonal to the first gap 5A, and substantially orthogonal to the second gap 5B; And a third gap 5C that is formed between the side surface 12b of the fixed flange portion 12 where the fixed side protrusion portion 13 is formed and the distal end surface 23b of the rotation side protrusion portion 23 and opens into the space S. Note that the side surface 29 a of the rotating flange portion 29 corresponds to a facing surface that faces the tip surface 13 a of the fixed-side protruding portion 13.

  The first gap 5A has an opening 5D that opens to the outside. The labyrinth seal 5 is formed in a gap bent in a crank shape by the first gap 5A, the second gap 5B, and the third gap 5C. Thereby, it is possible to prevent foreign matters such as mud from entering the space S and to prevent the floating seal 50 from being damaged by the foreign matters. That is, it is possible to prevent the floating seal 50 from being damaged and foreign matter from entering the transmission 100.

  As shown in FIGS. 1 and 2, the transmission 100 includes a cover member 60 that is attached to the rotary housing 20 and covers the opening 5 </ b> D of the labyrinth seal 5. As shown in FIG. 2, the cover member 60 includes a cylindrical portion 61 that covers the opening 5D, and a flange portion 62 that is provided at the base end of the cylindrical portion 61 and is attached to the rotating flange portion 29 of the rotating housing 20 by a bolt. Have.

  The cylindrical portion 61 is disposed with a predetermined gap C between the cylindrical portion 61 and the outer peripheral surface 13 c of the fixed-side protruding portion 13. Further, the cylindrical portion 61 is disposed so that the front end 61a thereof faces the vehicle body 6 with a predetermined gap D. In addition, you may comprise the cover member 60 so that division | segmentation is possible. Thereby, processing, maintenance, etc. can be performed easily. Furthermore, the cover member 60 is divided into a plurality of parts in the radial direction of the cylindrical portion 61 (direction perpendicular to the rotation axis O), so that the cover member 60 can be attached and detached without removing the rotary housing 20. it can. This improves the workability during assembly and maintenance.

  Next, the function of the cover member 60 will be described.

  As described above, the transmission 100 is used for a traveling motor such as a hydraulic excavator. For this reason, the transmission 100 is often used in an environment where foreign matter such as mud is easily applied. When there is no cover member 60, foreign matter such as mud is directly applied to the opening 5 </ b> D of the labyrinth seal 5, so foreign matter such as mud easily enters the labyrinth seal 5. Therefore, the transmission 100 is provided with a cover member 60 that covers the opening 5D. Thereby, it is possible to prevent foreign matters such as mud from entering the labyrinth seal 5 from the opening 5D.

  A foreign substance such as mud tries to enter the space S through a route indicated by an arrow in FIG. As described above, the cylindrical portion 61 is disposed with a predetermined gap C between the cylindrical portion 61 and the outer peripheral surface 13c of the fixed-side protruding portion 13, and the tip 61a of the cylindrical portion 61 is opposed to the vehicle body 6 with a predetermined gap D. Be placed. By setting these gaps C and D to narrow predetermined gaps, it is possible to prevent intrusion of foreign matters such as mud. Thereby, intrusion of foreign matters such as mud into the labyrinth seal 5 can be further prevented.

  When foreign matter such as mud accumulates on the outer peripheral surface 61 b of the cylindrical portion 61 of the cover member 60, the accumulated foreign matter falls on the outer peripheral surface 13 c of the fixed-side protrusion 13 and enters through a gap with the inner peripheral surface of the cylindrical portion 61. There is a risk that. However, in the transmission 100, as described above, since the cover member 60 is attached to the rotary housing 20, the cover member 60 rotates together with the rotary housing 20. As a result, even if foreign matter such as mud accumulates on the outer peripheral surface 61b of the cylindrical portion 61 of the cover member 60, mud and the like accumulated by the rotation of the cover member 60 can be blown away. Therefore, foreign matter such as mud is less likely to accumulate on the outer peripheral surface 61b of the cylindrical portion 61, so that the possibility that foreign matter such as mud enters from the gap C and the gap D can be reduced.

  According to the above 1st Embodiment, there exist the following effects.

  The transmission 100 includes a cover member 60 that covers the opening 5D. Therefore, foreign matter such as mud can be prevented from entering from the opening 5D.

  Further, in the transmission 100, the labyrinth seal 5 is formed as a gap whose cross-sectional shape is bent by a first gap 5A and a second gap 5B substantially orthogonal to the first gap 5A. Thereby, it is possible to prevent foreign matters such as mud from entering the space S and to prevent the floating seal 50 from being damaged by the foreign matters. For this reason, it is possible to prevent the floating seal 50 from being damaged and foreign matter from entering the transmission 100.

  Further, in the transmission 100, the cylindrical portion 61 of the cover member 60 is disposed with a predetermined gap C between the cylindrical portion 61 and the outer peripheral surface 13c of the fixed-side protruding portion 13. In the transmission 100, by setting the gap C to a narrow predetermined gap, entry of foreign matter such as mud is prevented, and foreign matter such as mud can be prevented from reaching the opening 5D. Further, since a zigzag gap, that is, a labyrinth seal, is formed by the gap C and the labyrinth seal 5 (the first gap 5A, the second gap 5B, and the third gap 5C), foreign matter enters the space S. Can be prevented more.

  The cylindrical portion 61 of the cover member 60 is disposed so that the front end 61a thereof faces the vehicle body 6 with a predetermined gap D. Therefore, entry of foreign matter such as mud is also prevented by the gap D, and foreign matter such as mud can be further prevented from reaching the opening 5D. Further, in addition to the bent zigzag gap formed by the gap C and the labyrinth seal 5, a further bent zigzag gap, that is, a further labyrinth seal is formed by the gap D. Thereby, it is possible to further prevent foreign matters from entering the space S.

Second Embodiment
A transmission 200 according to a second embodiment of the present invention will be described with reference to FIG. Below, it demonstrates centering on a different point from the said 1st Embodiment, the same code | symbol is attached | subjected to the structure same as the transmission 100 of 1st Embodiment, and description is abbreviate | omitted.

  The transmission 200 shown in FIG. 3 is different from the transmission 100 according to the first embodiment in that the cover member 60 is attached to the fixed housing 10.

  FIG. 3 is a cross-sectional view of the main part of the transmission 200. In the transmission 200, the fixed housing 10 is formed so as to protrude from the outer peripheral surface of the main body 11 and is attached to the vehicle body 6, and an annular fixed side that is formed on the fixed flange 112 and extends toward the rotary housing 20. And a protrusion 113. In addition, on the proximal end side of the rotation flange portion 29 of the rotation housing 20, an annular rotation-side protrusion 123 that extends toward the fixed housing 10 and radially outside the fixed-side protrusion 113 is formed.

  A labyrinth seal 105 is formed between the fixed housing 10 and the rotary housing 20 in order to prevent foreign matters such as mud from entering the floating seal 50. The labyrinth seal 105 includes a first gap 105A formed between the distal end surface 123a of the rotation-side protrusion 123 and the side surface 112a of the fixed flange portion 112 where the fixed-side protrusion 113 is formed, and the rotation-side protrusion 123. A second gap 105B formed between the inner peripheral surface 123b and the outer peripheral surface 113a of the fixed-side protrusion 113 and substantially orthogonal to the first gap 105A, and substantially orthogonal to the second gap 105B, the tip of the fixed-side protrusion 113 A third gap 105 </ b> C that is formed between the surface 113 b and the inner diameter side surface 29 b of the rotary housing 20 where the rotation-side protrusion 123 is formed and opens into the space S. The side surface 112 a of the fixed flange portion 112 corresponds to a facing surface that faces the front end surface 123 a of the rotation-side protrusion 123.

  The first gap 105A has an opening 105D that opens to the outside. The labyrinth seal 105 is formed in a gap bent in a crank shape by the first gap 105A, the second gap 105B, and the third gap 105C. Thereby, it is possible to prevent foreign matters such as mud from entering the space S and to prevent the floating seal 50 from being damaged by the foreign matters. That is, it is possible to prevent the floating seal 50 from being damaged and foreign matter from entering the transmission 200.

  The cover member 60 is attached to the fixed housing 10 so as to cover the opening 105D of the labyrinth seal 105. Thereby, it can prevent that foreign materials, such as mud, penetrate | invade from opening part 105D.

  The cylindrical portion 61 of the cover member 60 is disposed with a predetermined gap E between the cylindrical portion 61 and the outer peripheral surface 123c of the rotation-side projection 123 of the rotary housing 20. Further, the cylindrical portion 61 is disposed so that the tip 61a thereof faces the rotating flange portion 29 of the rotating housing 20 with a predetermined gap F.

  According to the above 2nd Embodiment, there exist the following effects.

  The transmission 200 includes a cover member 60 that covers the opening 105D. Even if the cover member 60 is simply fixed to the fixed housing 10 in the transmission 100 shown in FIG. 1 and FIG. 2, the front end 61a of the cylindrical portion 61 is located in the vicinity of the opening 5D, so that the opening 5D cannot be covered. For this reason, in the transmission 200, the rotation-side protrusion 123 is formed so as to be positioned on the radially outer side of the fixed-side protrusion 113, so that the opening 105D of the labyrinth seal 105 is on the fixed housing 10 side, that is, the cylindrical portion. 61 is formed on the base end side. Thereby, the opening part 105D can be covered with the cylindrical part 61 of the cover member 60, and foreign substances such as mud can be prevented from entering from the opening part 105D.

  In the transmission 200, the labyrinth seal 105 is formed as a gap that is bent by a first gap 105A and a second gap 105B that is substantially orthogonal to the first gap 105A. Thereby, it is possible to prevent foreign matters such as mud from entering the space S and to prevent the floating seal 50 from being damaged by the foreign matters. That is, it is possible to prevent the floating seal 50 from being damaged and foreign matter from entering the transmission 200.

  Further, in the transmission 200, the cylindrical portion 61 of the cover member 60 is disposed with a predetermined gap E between the cylindrical portion 61 and the outer peripheral surface 123 c of the rotation-side protruding portion 123. In the transmission 200, by setting the gap E to a narrow predetermined gap, entry of foreign matter such as mud is prevented, and foreign matter such as mud can be prevented from reaching the opening 105D. In addition, a zigzag gap that is bent by the gap E and the labyrinth seal 105 (the first gap 105A, the second gap 105B, and the third gap 105C), that is, a further labyrinth seal is formed, so that foreign matter enters the space S. Can be prevented more.

  The cylindrical portion 61 of the cover member 60 is disposed so that the tip 61 a thereof faces the rotating flange portion 29 with a predetermined gap F. Therefore, foreign matter such as mud is prevented from entering by the gap F, and foreign matter such as mud can be further prevented from reaching the opening 105D. Further, in addition to the bent zigzag gap formed by the gap E and the labyrinth seal 105, a further bent zigzag gap, that is, a further labyrinth seal is formed by the gap F. Thereby, it is possible to further prevent foreign matters from entering the space S.

  The cylindrical portion 61 may be configured to cover only a part of the opening 105D in the circumferential direction. For example, by configuring the cylindrical portion 61 to cover the upper side of the opening 105D, it is possible to prevent foreign matters such as mud deposited on the upper portion of the fixed flange portion 112 from dropping and entering from the opening 105D. By making the cylindrical portion 61 cover only a part of the opening portion 105D in the circumferential direction, the cover member 60 can be reduced in weight and cost can be reduced. Further, the cover member 60 can be easily attached.

  The configuration, operation, and effect of the embodiment of the present invention configured as described above will be described together.

  The transmissions 100 and 200 house the fixed housing 10 in which the drive source (hydraulic motor 1) is housed, the speed change mechanism 30 that changes the output rotation of the drive source (hydraulic motor 1), the speed change mechanism 30, and the speed change. The rotating housing 20 that is rotated by the output rotation being transmitted, the labyrinth seals 5 and 105 that are formed between the fixed housing 10 and the rotating housing 20 and prevent foreign matter from entering from the outside, and the outside of the labyrinth seals 5 and 105 And a cover member 60 that covers the side openings 5D and 105A.

  In this configuration, the cover member 60 covers the openings 5 </ b> D and 105 </ b> A on the outside of the labyrinth seals 5 and 105. Thereby, it is possible to prevent foreign matter from entering the labyrinth seals 5 and 105.

  Further, the transmission 100 is characterized in that the cover member 60 is attached to the rotary housing 20.

  In this configuration, since the cover member 60 is attached to the rotary housing 20, the cover member 60 rotates together with the rotary housing 20. This prevents foreign matter such as mud from entering the labyrinth seal 5 from accumulating on the cover member 60. Therefore, foreign matter such as mud can be prevented from entering the labyrinth seal from the opening of the cover member 60.

  Further, in the transmission 100, the fixed housing 10 is formed on the mounting portion (fixed flange portion 12) that protrudes from the outer peripheral surface and is attached to the external member (vehicle body 6), and the mounting portion (fixed flange portion 12). An annular fixed-side protrusion 13 extending toward the housing 20, and the rotary housing 20 includes an annular rotation-side protrusion 23 extending toward the fixed housing 10 on the radially inner side of the fixed-side protrusion 13. The labyrinth seal 5 includes a first gap 5A formed between the front end surface 13a of the fixed side protrusion 13 and the opposite surface (side surface 29a) of the rotary housing 20 that faces the front end surface 13a, and the fixed side protrusion. 13, and a second gap 5 </ b> B that is formed between the inner circumference surface 13 b of the rotation side projection portion 23 and the outer circumference surface 23 a of the rotation-side protrusion 23 and is substantially orthogonal to the first gap 5 </ b> A.

  In this configuration, the labyrinth seal 5 is formed as a gap that is bent by the first gap 5A and the second gap 5B that is substantially orthogonal to the first gap 5A. Thereby, it can prevent that foreign materials, such as mud, penetrate | invade into the apparatus (transmission 100) inside.

  Further, in the transmission 100, the cover member 60 includes a cylindrical portion 61 that covers the opening 5 </ b> D, and a flange portion 62 that is provided at the base end of the cylindrical portion 61 and is attached to the rotary housing 20. The cylindrical portion 61 is arranged with a predetermined gap C between the cylindrical portion 61 and the outer peripheral surface 13c of the fixed-side protruding portion 13.

  According to this configuration, a further labyrinth seal is configured by the gap C between the cylindrical portion 61 of the cover member 60 and the outer peripheral surface 13 c of the fixed-side protruding portion 13. Thereby, it can prevent more that a foreign material penetrate | invades into the apparatus (transmission 100) inside.

  Further, in the transmission 100, the cylindrical portion 61 of the cover member 60 has a tip 61a facing the external member (vehicle body 6) with a predetermined gap D.

  According to this structure, the further labyrinth seal is comprised by the clearance gap D between the front-end | tip 61a of the cylindrical part 61 of the cover member 60, and an external member (vehicle body 6). Thereby, it is possible to further prevent foreign matters from entering the device (transmission 100).

  Further, in the transmissions 100 and 200, the cover member 60 is configured to be separable.

  According to this configuration, since the cover member 60 is configured to be separable, processing and maintenance can be easily performed.

  The embodiment of the present invention has been described above. However, the above embodiment only shows a part of application examples of the present invention, and the technical scope of the present invention is limited to the specific configuration of the above embodiment. Absent.

  For example, the cover member in the second embodiment may be configured to cover only the upper surface side of the opening 105D. Further, the gap D and the gap F need not be provided as long as the gap C and the gap E can prevent foreign matter from entering.

  In the above embodiment, the traveling motor is described as an example of the driving device. However, the driving device may be a motor that drives a turning motor, a winch, or the like.

100, 200 ... Transmission, 1 ... Hydraulic motor (drive source), 5, 105 ... Labyrinth seal, 5A, 105A ... First gap, 5B, 105B ... Second gap, 5C , 105C: third gap, 5D, 105D: opening, 6: vehicle body (external member), 10: fixed housing, 12, 112: fixed flange portion (mounting portion), 13 , 113... Fixed side protrusion, 13 a. Tip surface, 13 b. Inner peripheral surface, 13 c. Outer peripheral surface, 20... Rotating housing, 23. ..Outer peripheral surface, 29... Rotating flange, 29a .. Side surface (opposing surface), 30... Transmission mechanism, 60 .. Cover member, 61. 61b ... outer peripheral surface, 62 ... flange, C, D, E, F ... gap

Claims (7)

A fixed housing that houses the drive source;
A speed change mechanism that changes the output rotation of the drive source;
A rotating housing that houses the speed change mechanism and that is rotated by the output rotation being transmitted,
A labyrinth seal that is formed between the fixed housing and the rotating housing and prevents entry of foreign matter from the outside;
And a cover member covering an opening on the outside of the labyrinth seal.   The transmission according to claim 1, wherein the cover member is attached to the rotary housing. The fixed housing is
A mounting portion that protrudes from the outer peripheral surface and is attached to an external member;
An annular fixed-side protrusion formed on the mounting portion and extending toward the rotating housing,
The rotating housing is
An annular rotation-side protrusion extending toward the fixed housing on the radially inner side of the fixed-side protrusion,
The labyrinth seal is
A first gap formed between the distal end surface of the fixed-side protrusion and the opposed surface of the rotating housing facing the distal end surface;
3. A second gap formed between an inner peripheral surface of the fixed-side protrusion and an outer peripheral surface of the rotation-side protrusion, and having a second gap substantially orthogonal to the first gap. The described transmission. The cover member is
A cylindrical portion covering the opening;
A flange portion provided at a base end of the cylindrical portion and attached to the rotary housing;
The transmission according to claim 3, wherein the cylindrical portion of the cover member is disposed with a predetermined gap between the cylindrical portion and the outer peripheral surface of the fixed-side protrusion.   The transmission according to claim 4, wherein the cylindrical portion of the cover member is opposed to the external member at a tip end thereof with a predetermined gap.   The transmission according to any one of claims 1 to 5, wherein the cover member is configured to be separable.   The drive device provided with the transmission as described in any one of Claim 1 to 6, and the said drive source.