JP2017180511A - Transmission and driving device including the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a transmission which inhibits foreign objects from entering into the device.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 receives the output rotation having the changed speed to rotate; a labyrinth seal 5 which is formed between the fixed housing 10 and the rotary housing 20 and prevents entry of foreign objects from the outside; and a pocket 60 which is provided communicating with the labyrinth seal 5 and stores the foreign objects entering into the labyrinth seal 5.SELECTED DRAWING: Figure 2

Description

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

  In an endless track vehicle such as a hydraulic excavator, a travel motor is provided on an axle portion of an endless track (crawler belt).

  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 inside the rotating casing, and the planetary gear mechanism decelerates the output rotation of the hydraulic motor provided inside the fixed housing and transmits it to the rotating casing.

JP 2013-199968 A

  In the transmission disclosed in Patent Document 1, a labyrinth seal is formed between the fixed housing and the rotating casing. 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 capable of suppressing foreign matter from entering the inside of the apparatus.

  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 a rotation housing that is rotated by receiving the output rotation that has been changed. A labyrinth seal that is formed between the housing and the rotating housing and prevents entry of foreign matter from the outside, and a pocket that is provided in communication with the labyrinth seal and stores foreign matter that has entered the labyrinth seal. .

  In the first invention, foreign matter that has entered the labyrinth seal can be stored in the pocket.

  In a second aspect of the present invention, the pocket is an annular groove formed in the rotary housing and extending in the axial direction of the rotary housing.

  In the second invention, the pocket is formed in the rotating housing as an annular groove extending in the axial direction of the rotating housing. For this reason, when the rotating housing rotates, a force is applied to the foreign matter stored in the pocket so as to be pressed toward the wall surface on the outer diameter side of the pocket by centrifugal force. Thereby, the foreign material stored in the pocket tends to stay in the pocket.

  According to a third aspect of the present invention, the fixed housing has an annular fixed-side projection that extends toward the rotary housing and faces the rotary housing with a first gap, and the rotary housing is fixed on the radially inner side of the fixed-side projection. The labyrinth seal has a first gap and a second gap, and has an annular rotation-side projection facing the inner peripheral surface of the fixed-side projection with a second gap.

  According to a fourth aspect of the present invention, the pocket has an opening that opens into the first gap, and the radial length of the opening is larger than the radial length of the second gap.

  In the fourth aspect of the invention, it is difficult for foreign matter such as mud to enter the second gap, so that foreign matter such as mud can be prevented from entering the transmission.

  According to a fifth aspect of the invention, the pocket has an opening that opens in the first gap, and when the distance from the outer peripheral surface of the fixed-side protrusion to the outer peripheral surface of the rotation-side protrusion is L1, the opening is rotated. It is formed in the range of L1 / 2 from the outer peripheral surface of a side protrusion part.

  In the fifth invention, the opening of the pocket is formed so as to open to the first gap within the range of L1 / 2 from the outer peripheral surface of the rotation-side protrusion, and therefore, between the outside and the opening of the pocket. A gap with a certain length can be secured. Accordingly, resistance can be given to foreign matter such as mud that is about to enter, so that foreign matter such as mud can reach the opening of the pocket.

  According to a sixth aspect of the invention, the pocket is formed such that the radially inner side surface is flush with the outer peripheral surface of the rotation-side protrusion, or is positioned radially inward of the outer periphery of the rotation-side protrusion. To do.

  In the sixth aspect of the invention, the foreign matter such as mud that has entered through the first gap flows toward the pocket by hitting the outer peripheral surface of the rotation-side protrusion, and therefore, foreign matter such as mud is easily captured in the pocket.

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

  According to the present invention, foreign matter can be prevented from entering the inside of the apparatus.

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

  Hereinafter, with reference to FIG.1 and FIG.2, the transmission 100 which concerns on 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 transmission 100 that changes 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. The fixed-side protrusion 13 is formed to face the rotary housing 20 with a first gap described later. On the proximal end side of the rotating flange portion 29 of the rotating housing 20, it extends toward the fixed housing 10 on the radially inner side of the fixed side protruding portion 13, and has a second gap described later on the inner peripheral surface 13 b of the fixed side protruding portion 13. Opposing annular rotation-side protrusions 23 are formed.

  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 12a of the fixed flange portion 12 where the fixed side protrusion portion 13 is formed and the tip 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 illustrated in FIGS. 1 and 2, the transmission 100 includes a pocket 60 that communicates with the first gap 5 </ b> A of the labyrinth seal 5. The pocket 60 is formed as an annular groove 60 a that opens in the side surface 29 a of the rotary flange portion 29 and extends in the axial direction of the rotary housing 20. By using such an annular groove 60a, the pocket 60 can be formed by simple processing.

  The pocket 60 has an opening 60c that opens into the first gap 5A. The length of the opening 60c in the radial direction is formed to be larger than the length of the second gap 5B. Further, the opening 60c has a range of L1 / 2 from the outer peripheral surface 23a of the rotation-side projection 23 when the distance from the outer peripheral surface 13c of the fixed-side projection 13 to the outer periphery 23a of the rotation-side projection 23 is L1. It is formed so as to open to the first gap 5A.

  Next, the function of the pocket 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. Foreign matter such as mud that has entered from the opening 5D of the labyrinth seal 5 tries to gradually enter the space S through the first gap 5A, the second gap 5B, and the third gap 5C, as indicated by arrows in FIG. To do. For this reason, the transmission 100 is provided with a pocket 60 communicating with the first gap 5A. As a result, foreign matter such as mud that has entered the first gap 5A is stored in the pocket 60, so that foreign matter such as mud can be prevented from entering the space S. Although the pocket 60 is provided so as to communicate with the first gap 5A, the pocket 60 can be communicated with the labyrinth seal 5 and can be stored in the second gap 5B or the third gap 5C as long as it can store foreign matter such as mud. It may be provided.

  Further, when vibration is applied to the transmission 100 due to traveling of a hydraulic excavator, foreign matter such as mud stored in the pocket 60 may come out of the pocket 60. Therefore, in the transmission 100, the pocket 60 is provided in the rotary housing 20. When the rotating housing 20 rotates, a force that is pressed against the outer wall of the pocket 60 by centrifugal force acts on foreign matters such as mud stored in the pocket 60. As a result, even when vibration is applied to the transmission 100, foreign matter such as mud stored in the pocket 60 tends to stay in the pocket 60.

  According to the above embodiment, the following effects are obtained.

  The transmission 100 is provided with a pocket 60 that communicates with the labyrinth seal 5. Thereby, foreign matter such as mud that has entered from the opening 5 </ b> D of the labyrinth seal 5 can be stored in the pocket 60. Therefore, foreign matter such as mud can be prevented from entering the space S, and the floating seal 50 can be prevented from being damaged by the foreign matter. Thereby, it is possible to prevent the floating seal 50 from being damaged and foreign matter from entering the transmission 100.

  In the transmission 100, the pocket 60 is formed in the rotary housing 20 as an annular groove 60 a extending in the axial direction of the rotary housing 20. For this reason, when the rotary housing 20 rotates, a force that is pressed against the outer wall surface of the pocket 60 by centrifugal force acts on foreign matters such as mud stored in the pocket 60. Thereby, foreign matters such as mud stored in the pocket 60 are likely to stay in the pocket 60.

  Further, when foreign matter such as mud jumps out of the pocket 60 into the first gap 5A due to the rotation of the rotary housing 20, the foreign matter such as mud jumps out toward the opening 5D on the radially outer side by centrifugal force. It will be. Therefore, it is possible to prevent foreign matters such as mud from moving toward the radially inner side of the labyrinth seal 5.

  Further, the length of the opening 60c in the radial direction is formed to be larger than the length of the second gap 5B in the radial direction. This makes it difficult for foreign matter such as mud to enter the second gap 5B, so that foreign matter such as mud can be prevented from entering the space S.

  Further, the opening 60c has a range of L1 / 2 from the outer peripheral surface 23a of the rotation-side projection 23 when the distance from the outer peripheral surface 13c of the fixed-side projection 13 to the outer periphery 23a of the rotation-side projection 23 is L1. It is formed so as to open to the first gap 5A. Thereby, a certain length of gap can be secured from the outside to the opening 60c. Therefore, resistance can be given to foreign matter such as mud that is about to enter, so that foreign matter such as mud can reach the pocket 60 later.

  Preferably, the pocket 60 is such that the radially inner side surface 60b of the groove 60a is flush with the outer peripheral surface 23a of the rotation-side protrusion 23 or radially inward of the outer peripheral surface 23a of the rotation-side protrusion 23. Formed. Thereby, foreign matter such as mud that has entered through the first gap 5A flows toward the inside of the pocket 60 by hitting the outer peripheral surface 23a of the rotation-side projection 23 as shown by the arrow in FIG. Foreign matter can be easily captured in the pocket 60. Further, the side surface 60b of the pocket 60 is formed so as to be located radially inward of the outer peripheral surface 23a of the rotation-side protrusion 23, whereby the outer peripheral surface 23a of the rotation-side protrusion 23 and the side surface 60b of the pocket 60 are formed. Since there is a step between them, foreign matter such as mud stored in the pocket 60 can be prevented from flowing out of the pocket 60. The pocket 60 may be formed so that the entire pocket 60 is located on the radially inner side of the outer peripheral surface 23 a of the rotation-side protrusion 23.

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

  The transmission 100 includes a fixed housing 10 in which a drive source (hydraulic motor 1) is accommodated, a speed change mechanism 30 that changes the output rotation of the drive source (hydraulic motor 1), and a speed change output that accommodates the speed change mechanism 30. A labyrinth seal 20 provided between the rotating housing 20 that is rotated by transmission of rotation, a labyrinth seal 5 that is formed between the fixed housing 10 and the rotating housing 20 and prevents foreign matter from entering from the outside, and is provided in communication with the labyrinth seal 5. 5 and a pocket 60 for storing foreign matter that has invaded.

  In this configuration, foreign matter that has entered the labyrinth seal 5 can be stored in the pocket 60. As a result, foreign matter can be prevented from entering the transmission 100.

  Further, the transmission 100 is characterized in that the pocket 60 is an annular groove 60 a formed in the rotary housing 20 and extending in the axial direction of the rotary housing 20.

  In this configuration, the pocket 60 is formed in the rotary housing 20 as an annular groove 60 a extending in the axial direction of the rotary housing 20. For this reason, when the rotary housing 20 rotates, a force that is pressed against the outer wall surface of the pocket 60 by centrifugal force acts on foreign matters such as mud stored in the pocket 60. Thereby, foreign matters such as mud stored in the pocket 60 are likely to stay in the pocket 60.

  Further, in the transmission 100, the fixed housing 10 has an annular fixed-side protruding portion 13 that extends toward the rotating housing 20 and faces the rotating housing 20 with a first gap 5A. The rotating housing 20 includes the fixed-side protruding portion. The labyrinth seal 5 includes an annular rotation-side protrusion 23 that extends toward the fixed housing 10 on the radially inner side of the inner surface 13 and faces the inner peripheral surface 13b of the fixed-side protrusion 13 with a second gap 5B. It has a gap 5A and a second gap 5B.

  Further, in the transmission 100, the pocket 60 has an opening 60c that opens into the first gap 5A, and the radial length of the opening 60c is larger than the radial length of the second gap 5B. Features.

  In this configuration, foreign matter such as mud does not easily enter the second gap 5 </ b> B, and thus foreign matter such as mud can be prevented from entering the transmission 100.

  Further, in the transmission 100, the pocket 60 has an opening 60c that opens into the first gap 5A, and the distance from the outer peripheral surface 13c of the fixed-side protrusion 13 to the outer peripheral surface 23a of the rotation-side protrusion 23 is L1. In this case, the opening 60c is formed within a range of L1 / 2 from the outer peripheral surface 23a of the rotation-side protrusion 23.

  In this configuration, the opening 60c of the pocket 60 is formed so as to open to the first gap 5A within a range of L1 / 2 from the outer peripheral surface 23a of the rotation-side protrusion 23, and therefore the opening of the pocket 60 from the outside. A gap of a certain length can be secured up to 60c. Therefore, resistance can be given to foreign matter such as mud that is about to enter, so that foreign matter such as mud can be delayed from reaching the opening 60c of the pocket 60.

  Further, in the transmission 100, the pocket 60 is positioned such that the radially inner side surface 60 b is flush with the outer peripheral surface 23 a of the rotation-side projection 23 or radially inward of the outer peripheral surface 23 a of the rotation-side projection 23. It is formed.

  In this configuration, foreign matter such as mud that has entered through the first gap 5A flows toward the pocket 60 by colliding with the outer peripheral surface 23a of the rotation-side projection 23, so that foreign matter such as mud is easily captured in the pocket 60. Become.

  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.

  The pocket 60 may have any shape as long as it can hold foreign matter.

  For example, although the pocket 60 is provided in the rotary housing 20, it may be provided in the fixed housing 10. Alternatively, the pocket 60 may be provided in both the fixed housing 10 and the rotary housing 20. Alternatively, an annular groove may be provided in the fixed housing 10 and the bottom of the groove may be communicated with the screw hole 15. In this case, foreign matter such as mud can also be stored in the screw hole 15.

DESCRIPTION OF SYMBOLS 100 ... Transmission, 1 ... Hydraulic motor (drive source), 5 ... Labyrinth seal, 5A ... 1st clearance, 5B ... 2nd clearance, 5C ... 3rd clearance, 5D ... Opening part, 6 ... Car body (external member), 10 ... Fixing housing, 13 ... Fixing-side protrusion, 13a ... Front end surface, 13b ... Inner peripheral surface, 13c ... -Outer peripheral surface, 20 ... Rotating housing, 23 ... Rotating side projection, 23a ... Outer peripheral surface, 30 ... Transmission mechanism, 60 ... Pocket, 60a ... Groove, 60b ... Side, 60c ... opening

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;
A transmission provided with a pocket that is provided in communication with the labyrinth seal and stores foreign matter that has entered the labyrinth seal.   The transmission according to claim 1, wherein the pocket is an annular groove formed in the rotary housing and extending in an axial direction of the rotary housing. The fixed housing has an annular fixed side protrusion that extends toward the rotating housing and faces the rotating housing with a first gap;
The rotating housing has an annular rotating-side protruding portion that extends toward the fixed housing on the radially inner side of the fixed-side protruding portion and faces the inner peripheral surface of the fixed-side protruding portion with a second gap,
The transmission according to claim 2, wherein the labyrinth seal has the first gap and the second gap. The pocket has an opening that opens into the first gap;
The transmission according to claim 3, wherein the radial length of the opening is larger than the radial length of the second gap. The pocket has an opening that opens into the first gap;
When the distance from the outer peripheral surface of the fixed side protrusion to the outer peripheral surface of the rotation side protrusion is L1,
The transmission according to claim 3 or 4, wherein the opening is formed within a range of L1 / 2 from an outer peripheral surface of the rotation-side protrusion.   The pocket is formed such that a radially inner side surface thereof is flush with an outer peripheral surface of the rotation-side protrusion or is positioned radially inward from an outer periphery of the rotation-side protrusion. The transmission according to any one of 3 to 5.   A drive device comprising: the transmission according to any one of claims 1 to 6; and the drive source.

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