Planetary gear mechanism

Abstract

To provide a planetary gear mechanism capable of reducing stirring loss.SOLUTION: In a planetary gear mechanism 11, a second supply passage 62 supplies a lubrication oil to a sun gear 22. A fifth duct line 75 discharges the lubrication oil in a housing 29 to the outside. A first wall surface passage S1 is formed between a planetary gear 23 and a first wall surface 33f of a carrier column 33 of a planetary carrier 25 and the lubrication oil flows thereinto from the sun gear 22 side. A carrier column passage 38 is formed on the carrier column 33 and discharges the lubrication oil flowing into the first wall surface passage S1 to the outside of the planetary carrier 25. A first wall surface inner periphery side passage 36 is formed at the planetary carrier 25 and discharges the lubrication oil from the inner periphery side of the carrier column passage 38 to the outside of the planetary carrier.SELECTED DRAWING: Figure 6A

Description

[Technical Field]

[0001] The present invention relates to a planetary gear mechanism. [Background technology]

[0002] Planetary gear mechanisms are used in transmissions and the like. The planetary gear mechanism includes a sun gear, multiple planetary gears arranged around the sun gear, and a ring gear arranged around the multiple planetary gears, and the multiple planetary gears are supported by a planetary carrier (see Patent Document 1). In the planetary gear mechanism shown in Patent Document 1, lubricating oil for lubricating the tooth surfaces is supplied toward the sun gear, and the lubricating oil flows toward the outside of the planetary carrier as the planetary gears rotate. The planetary gear mechanism shown in Patent Document 1 uses helical gears, and the lubricating oil for lubricating the tooth surfaces flows along the rotation axis, so the lubricating oil is supplied from the upstream side of the flow direction.

[0003] In addition, in order to improve the dischargeability of lubricating oil and ensure the strength of the planetary carrier, a planetary gear mechanism has been disclosed in which the gap between the planetary carrier and the planetary gear tooth surface is increased in the direction in which the lubricating oil flows (see Patent Document 2).

[0004] On the other hand, in construction machinery where both forward and reverse rotations are frequently used, supplying lubricant in accordance with the rotation of the helical gear in one direction may result in insufficient lubrication of the tooth surfaces when the helical gear is rotated in the opposite direction. For this reason, a planetary gear mechanism has been disclosed that switches the direction in which lubricant is discharged onto the tooth surfaces of the helical gear based on the rotation direction of the helical gear (see Patent Document 3). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-112127 [Patent Document 2] Japanese Patent Application Publication No. 2023-134028 [Patent Document 3] Japanese Patent Publication No. 2023-134027 Summary of the Invention [Problem to be solved by the invention]

[0006] In recent years, the need for electrification has led to a demand for high-speed rotation, but this has increased the impact of mixing loss, so there is a demand for reducing mixing loss.

[0007] An object of the present disclosure is to provide a planetary gear mechanism that can reduce stirring loss. [Means for solving the problem]

[0008] The planetary gear mechanism according to the present disclosure includes a sun gear, multiple planetary gears, multiple shafts, a planetary carrier, a housing, a supply passage, a discharge passage, a wall surface passage, a wall surface inner peripheral side passage, and a carrier pillar passage. The multiple planetary gears are arranged around the sun gear and mesh with the sun gear. The multiple shafts rotatably support the multiple planetary gears. The planetary carrier has carrier pillars arranged between the planetary gears and supports the multiple shafts. The housing houses the sun gear, the multiple planetary gears, the multiple shafts, and the planetary carrier. The supply passage supplies lubricating oil toward the sun gear. The discharge passage discharges lubricating oil from within the housing to the outside. The wall surface passage is formed between the planetary gears and the wall surface of the carrier pillar of the planetary carrier, and lubricating oil flows into it from the sun gear side. The wall surface inner peripheral side flow passage is formed in the planetary carrier and discharges the lubricating oil from the inner peripheral side of the carrier pillar flow passage toward the outside of the planetary carrier. The carrier pillar flow passage is formed in the carrier pillar and discharges the lubricating oil that has flowed into the wall surface flow passage to the outside of the planetary carrier. [Effects of the Invention]

[0009] According to the present disclosure, it is possible to provide a planetary gear mechanism that can reduce stirring loss. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a schematic diagram showing a drive system of a work machine according to an embodiment of the present disclosure. [Figure 2A] FIG. 2 is a cross-sectional view showing a planetary gear mechanism according to an embodiment of the present disclosure. [Figure 2B] FIG. 2B is an enlarged view showing the vicinity of the sun gear in FIG. 2A. [Figure 3A] 1 is a diagram of a planetary gear unit according to an embodiment of the present disclosure, viewed from a first direction along an axis. [Figure 3B] FIG. 10 is a diagram of the planetary gear unit according to the embodiment of the present disclosure, viewed from a second direction along the axis. [Figure 4] FIG. 2 is a side view of the planetary gear unit according to the embodiment of the present disclosure, viewed from a direction perpendicular to the axis. [Figure 5A] FIG. 3B is a cross-sectional view of the planetary gear unit taken along the arrow B in FIG. 3A. [Figure 5B] FIG. 3B is a cross-sectional view of the planetary gear unit taken along the line CC in FIG. 3A. [Figure 6A] FIG. 5B is a cross-sectional view of the planetary gear unit taken along the arrows DD in FIG. 5A. [Figure 6B] FIG. 5B is a cross-sectional view of the planetary gear unit taken along the arrows between E and E in FIG. 5A. [Figure 6C] FIG. 5B is a cross-sectional view of the planetary gear unit taken along the arrows in the FF section of FIG. 5A. [Figure 7] FIG. 2 is a perspective view of a planetary carrier according to an embodiment of the present disclosure. [Figure 8] FIG. 1 is a block diagram illustrating a lubrication system according to an embodiment of the present disclosure. [Figure 9] (a) A schematic diagram showing the positional relationship between the opening for discharging lubricating oil and the gear when the planetary gear mechanism is viewed along a first direction, and (b) a schematic diagram showing the positional relationship between the opening for discharging lubricating oil and the gear when the planetary gear mechanism is viewed along a second direction. [Figure 10] FIG. 2 is a perspective view of a planetary carrier according to an embodiment of the present disclosure. [Figure 11] FIG. 2 is a side view of a planetary carrier according to an embodiment of the present disclosure. [Figure 12] FIG. 4A is a schematic side view showing the state in which the sun gear and the planetary gears are meshed, and FIG. 4B is a schematic view of the sun gear and the planetary gears as viewed along a first direction. [Figure 13] FIG. 4 is a flowchart illustrating a control operation of the lubrication system according to the embodiment of the present disclosure. [Figure 14A] FIG. 10 is a cross-sectional view of a planetary gear unit and a sun gear according to a modified example of the embodiment of the present disclosure. [Figure 14B] FIG. 10 is a partially enlarged perspective view of a planetary carrier according to a modified example of the embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0011] A planetary gear mechanism according to an embodiment of the present disclosure will be described with reference to the drawings. The planetary gear mechanism according to the present embodiment is used in, for example, the drive system of a work machine.

[0012] <Configuration> (Overview of drive system 2 of work machine 1) FIG. 1 is a schematic diagram showing a drivetrain 2 of a work machine 1. The drivetrain 2 of the work machine 1 has an engine 3, a torque converter 4, a transmission 5, a transfer 6, axles 7a and 7b, a pair of rear tires 8, and a pair of front tires 9. The engine 3 is, for example, a diesel engine. Driving force generated by the engine 3 is transmitted to the torque converter 4. The torque converter 4 transmits the driving force generated by the engine 3 to the transmission 5.

[0013] The transmission 5 reduces the driving force of the engine 3 transmitted via the torque converter 4 and transmits it to the transfer 6. A planetary gear mechanism 11 (described later) of this embodiment is used as a reducer for the transmission 5, for example.

[0014] The transfer 6 distributes the driving force transmitted from the transmission 5 to the front and rear axles 7a, 7b. A pair of rear tires 8 is connected to the rear axle 7a. The pair of rear tires 8 rotates by the power from the engine 3 distributed to the rear axle 7a. A pair of front tires 9 is connected to the front axle 7b. The pair of front tires 9 rotates by the power from the engine 3 distributed to the front axle 7b.

[0015] (Planetary gear mechanism 11) FIG. 2A is a cross-sectional view showing the planetary gear mechanism 11 of this embodiment.

[0016] The planetary gear mechanism 11 includes an input shaft 21, a sun gear 22, a plurality of planetary gears 23, a pinion shaft 24 (shaft), a planetary carrier 25, a ring gear 26, a fixing member 27, an output shaft 28, and a housing 29. Power is input to the input shaft 21. The sun gear 22 is fixed to the input shaft 21. The plurality of planetary gears 23 are arranged around the sun gear 22 and mesh with the sun gear 22. The plurality of pinion shafts 24 rotatably support the plurality of planetary carriers 25. The planetary carrier 25 supports the plurality of pinion shafts 24. The ring gear 26 is arranged around the plurality of planetary gears 23. The fixing member 27 fixes the ring gear 26 to the housing 29. The output shaft 28 outputs power that has been reduced in speed by the sun gear 22, the plurality of planetary gears 23, the planetary carrier 25, and the ring gear 26. The housing 29 accommodates the sun gear 22, the plurality of planetary gears 23, the planetary carrier 25, the ring gear 26, and the fixed member 27.

[0017] (input shaft 21) Power is input to the input shaft 21. In FIG. 1, power from the engine 3 is input via a torque converter 4. The input shaft 21 is a cylindrical member. The input shaft 21 is inserted into a housing 29. The input shaft 21 is rotatably supported relative to the housing 29 by a bearing 51 arranged in the housing 29. In FIG. 2A, the central axis of the input shaft 21 is indicated as O. The input shaft 21 is arranged coaxially with an output shaft 28, which will be described later. Among directions parallel to the central axis O, a direction from the input shaft 21 toward the output shaft 28 is defined as a first direction A1, and a direction opposite to the first direction A1, from the output shaft 28 toward the input shaft 21, is defined as a second direction A2. The input shaft 21 has a main body 111 and an end 112. The end 112 is arranged at the end of the main body 111 on the first direction A1 side. A sun gear 22 is formed at the end 112 of the input shaft 21. FIG. 2B is an enlarged view showing the vicinity of the sun gear 22. The end portion 112 is formed to have a smaller outer diameter than the main body portion 111. A step is formed between the main body portion 111 and the end portion 112. The main body portion 111 has an end face 111a perpendicular to the central axis O at the step portion.

[0018] (Sun gear 22) The sun gear 22 is fixed to the tip of the input shaft 21. The sun gear 22 is arranged coaxially with the input shaft 21. The sun gear 22 is arranged around an end 112 of the input shaft 21, which is arranged inside a housing 29. The sun gear 22 rotates together with the input shaft 21 about an axis O. The sun gear 22 is a helical gear. The sun gear 22 has a tooth surface 22a including helical teeth 22b. The helical teeth 22b of the sun gear 22 are indicated by a two-dot chain line in Figures 2A and 2B. The helical teeth 22b are inclined with respect to the axis O.

[0019] (Planetary Gear 23) FIG. 3A is a front view of the sun gear 22, the planetary gears 23, and the planetary carrier 25 viewed from a first direction A1 along the axis O. FIG. 3B is a rear view of the sun gear 22, the planetary gears 23, and the planetary carrier 25 viewed from a second direction A2 along the axis O. FIG. 4 is a side view of the sun gear 22, the planetary gears 23, and the planetary carrier 25. FIG. 5A is a cross-sectional view of the sun gear 22, the planetary gears 23, the pinion shafts 24, and the planetary carrier 25 taken along lines B-B in FIG. 3A. FIG. 5B is a cross-sectional view of the sun gear 22, the planetary gears 23, the pinion shafts 24, and the planetary carrier 25 taken along lines C-C in FIG. 3A. FIG. 6A is a cross-sectional view of the sun gear 22, the planetary gears 23, the pinion shafts 24, and the planetary carrier 25 taken along lines D-D in FIG. 5A. Fig. 6B is a cross-sectional view of the sun gear 22, planetary gears 23, pinion shafts 24, and planetary carrier 25 taken along the arrows E-E in Fig. 5A. Fig. 6C is a cross-sectional view of the sun gear 22, planetary gears 23, pinion shafts 24, and planetary carrier 25 taken along the arrows F-F in Fig. 5A.

[0020] The multiple planetary gears 23 are disposed on the outer periphery of the sun gear 22 and mesh with the sun gear 22. In this embodiment, as shown in FIG. 3A, three planetary gears 23 are provided. The planetary gears 23 are helical gears. As shown in FIG. 2A, the planetary gears 23 have tooth surfaces 23a including helical teeth 23b. The helical teeth 23b of the planetary gears 23 are indicated by two-dot chain lines in FIG. 2A. The helical teeth 23b are inclined with respect to the axis O. The planetary gears 23 are rotatably supported by the pinion shaft 24. The planetary gears 23 rotate about an axis parallel to the axis O.

[0021] (Pinion shaft 24) As shown in Fig. 2A, the pinion shaft 24 is inserted into the center of the planetary gear 23. A bearing 52 is disposed around the pinion shaft 24. The planetary gear 23 is disposed around the bearing 52. The bearing 52 allows the planetary gear 23 to rotate relative to the pinion shaft 24. As shown in Fig. 6A, a pinion shaft 24 is provided for each planetary gear 23. In this embodiment, three pinion shafts 24 are provided corresponding to the three planetary gears 23.

[0022] (Planetary Carrier 25) The planetary carrier 25 supports a plurality of pinion shafts 24. As shown in Fig. 2A, the plurality of pinion shafts 24 are fixed to the planetary carrier 25. Fig. 7 is a perspective view of the planetary carrier 25. As shown in Figs. 4, 5A, and 7, the planetary carrier 25 has a first carrier disc 31, a second carrier disc 32, a plurality of carrier pillars 33, a first carrier boss 34, and a second carrier boss 35.

[0023] The first carrier disk 31 is disk-shaped. As shown in FIGS. 2A, 5A, and 5B, first ends 241 (ends on the second direction A2 side) of the multiple pinion shafts 24 are fixed to the first carrier disk 31. The first carrier disk 31 is disposed on the second direction A2 side of the multiple planetary gears 23. A through hole is formed in the first carrier disk 31 along the central axis O, and the input shaft 21 is inserted into the through hole.

[0024] The second carrier disk 32 is disk-shaped. Second ends 242 (ends on the first direction A1 side) of the multiple pinion shafts 24 are fixed to the second carrier disk 32. The second carrier disk 32 is disposed on the first direction A1 side of the multiple planetary gears 23. A through hole is formed in the second carrier disk 32 along the central axis O, and the output shaft 28 is inserted into the through hole.

[0025] As shown in Figures 5A and 5B, the multiple carrier pillars 33 are arranged between the first carrier disk 31 and the second carrier disk 32. The multiple carrier pillars 33 connect between the first carrier disk 31 and the second carrier disk 32. As shown in Figures 6A to 6C, the carrier pillars 33 are arranged between the planetary gears 23 adjacent to each other in the circumferential direction H.

[0026] As shown in FIGS. 5A and 5B, the carrier column 33 has a first end 331 connected to the first carrier disc 31 and a second end 332 connected to the second carrier disc 32.

[0027] Three carrier pillars 33 are formed on the planetary carrier 25. The three carrier pillars 33 are shaped so as to be rotationally symmetrical about the axis O.

[0028] 6A to 6C, each carrier pillar 33 is formed to extend radially outward from the central axis O along the outer edges of the planetary gears 23 on both sides in the circumferential direction. Note that the radial direction is perpendicular to the central axis O and includes directions approaching the central axis O and directions away from the central axis O.

[0029] In the following description, when distinguishing between the multiple planetary gears 23, the upper right planetary gear 23 shown in Fig. 6A will be referred to as 23c, the upper left planetary gear 23 as 23d, and the lower planetary gear 23 as 23e. In the drawing, 23c, 23d, and 23e are indicated in parentheses after the reference numeral 23.

[0030] Furthermore, in the following description, when distinguishing between multiple carrier pillars 33, the carrier pillar 33 between planetary gears 23c and 23d will be referred to as 33c, the carrier pillar 33 between planetary gears 23d and 23e will be referred to as 33d, and the carrier pillar 33 between planetary gears 23e and 23c will be referred to as 33e, as shown in Fig. 6A. In the figure, 33c, 33d, and 33e are shown in parentheses after the reference numeral 33.

[0031] Of the rotation directions of the planetary gear 23 as viewed along the first direction A1, the left rotation direction is indicated by arrow G1 (see FIG. 6A), and the right rotation direction is indicated by arrow G2 (see FIG. 6C). Also, as shown in FIG. 6A, of the circumferential direction H about the axis O, the left circumferential direction is indicated by arrow H1, and the right circumferential direction is indicated by arrow H2. Of the rotation directions of the sun gear 22, the left rotation direction is indicated by arrow L (see FIG. 6C), and the right rotation direction is indicated by arrow R (see FIG. 6A).

[0032] Since the carrier pillars 33c, 33d, and 33e have the same shape, the carrier pillar 33c will be taken as an example for explanation.

[0033] 5A and 5B, the carrier pillar 33c is formed so as to be inclined with respect to the axis O. In the circumferential direction, the position of the first end 331 of the carrier pillar 33c is disposed on the right circumferential direction H2 side of the position of the second end 332.

[0034] 5A and 5B, the carrier pillar 33c gradually moves away from the planetary gear 23d from the second end 332 toward the first end 331. A first wall surface 33f on the left circumferential direction H1 side of the carrier pillar 33c is inclined so as to move away from the planetary gear 23d from the second end 332 toward the first end 331. The carrier pillar 33c gradually moves away from the planetary gear 23c from the first end 331 toward the second end 332. A second wall surface 33g on the right circumferential direction H2 side of the carrier pillar 33c is inclined so as to move away from the planetary gear 23c from the first end 331 toward the second end 332.

[0035] 6A to 6C, carrier pillar 33d has a shape obtained by rotating carrier pillar 33c 120 degrees to the left in the circumferential direction H1 around axis O. Carrier pillar 33e has a shape obtained by rotating carrier pillar 33c 240 degrees to the left in the circumferential direction H1 around axis O.

[0036] 4, the first carrier boss 34 protrudes in the second direction A2 from the first carrier disc 31. The input shaft 21 is inserted into the inside of the first carrier boss 34, as shown in FIG. 2A.

[0037] As shown in Fig. 4, the second carrier boss 35 protrudes in the first direction A1 from the second carrier disc 32. The output shaft 28 is inserted into the inside of the second carrier boss 35, as shown in Fig. 2A.

[0038] 2A, the first carrier boss 34 is rotatably supported on the housing 29 via a bearing 53. The second carrier boss 35 is rotatably supported on the housing 29 via a bearing 54.

[0039] (Ring gear 26) 2A, the ring gear 26 is disposed around the planetary gears 23. The ring gear 26 has an annular shape. The inner peripheral surface of the ring gear 26 is formed with a tooth surface 26a having helical teeth that mesh with the helical teeth 23b of the planetary gears 23. The ring gear 26 is fixed to a housing 29 via a fixing member 27.

[0040] (Fixing member 27) The fixed member 27 is annular. The fixed member 27 is disposed on the outer periphery of the ring gear 26. The fixed member 27 is fixed to a housing 29, which will be described later. The fixed member 27 meshes with teeth disposed on the outer periphery of the ring gear 26. This connects the ring gear 26 to the housing 29 so that the ring gear 26 cannot rotate relative to the housing 29.

[0041] (output shaft 28) As shown in FIG. 2A , the output shaft 28 is disposed coaxially with the input shaft 21 (on the central axis O). The output shaft 28 meshes with the planetary carrier 25 via spline teeth. The output shaft 28 is rotatably supported relative to the housing 29 by a plurality of bearings 55 disposed in the housing 29. Through holes are formed in the second carrier disk 32 and the second carrier boss 35 (described later) of the planetary carrier 25 along the axis O. The output shaft 28 is inserted into these through holes and fixed to the second carrier disk 32 and the second carrier boss 35.

[0042] (Housing 29) The housing 29 accommodates the sun gear 22, the planetary gears 23, the pinion shafts 24, the planetary carrier 25, the ring gear 26, and the fixed member 27. The input shaft 21 and the output shaft 28 are inserted into the housing 29.

[0043] As shown in FIG. 2A, the housing 29 has a first support portion 41, a second support portion 42, a third support portion 43, and a fourth support portion 44.

[0044] The first support portion 41 is disposed on the second direction A2 side of the first carrier disk 31 of the planetary carrier 25. The first support portion 41 has a wall portion 411 and a protrusion 412. The wall portion 411 is disposed parallel to the first carrier disk 31. The wall portion 411 is disposed around the first carrier boss 34 of the planetary carrier 25. The protrusion 412 protrudes from the wall portion 411 in the second direction A2. A through hole into which the input shaft 21 is inserted is formed in the protrusion 412. A bearing 51 is disposed between the input shaft 21 and the inner wall of the through hole of the protrusion 412. This allows the housing 29 to rotatably support the input shaft 21. The wall portion 411 has a through hole aligned with the axis O. The first carrier boss 34 is inserted into this through hole. A bearing 53 is disposed between the inner wall of the through hole of the wall portion 411 and the first carrier boss 34 of the planetary carrier 25. As a result, the first support portion 41 rotatably supports the first carrier boss .

[0045] The second support portion 42 is arranged to cover the first direction A1 side of the second carrier disk 32 and the radial outside of the ring gear 26. The second support portion 42 has a wall portion 421 and an outer edge portion 422. The wall portion 421 is arranged on the first direction A1 side of the second carrier disk 32. The wall portion 421 has a through hole along the axis O. The second carrier boss 35 is inserted into this through hole. The second support portion 42 rotatably supports the second carrier boss 35. A bearing 54 is arranged between the inner wall of the through hole of the wall portion 421 and the second carrier boss 35.

[0046] The outer edge portion 422 extends in the second direction A2 from the outer peripheral end of the wall portion 421. The end of the outer edge portion 422 on the second direction A2 side is connected to the outer peripheral portion of the wall portion 411.

[0047] The first support portion 41 rotatably supports the first carrier boss 34 , and the second support portion 42 rotatably supports the second carrier boss 35 , so that the planetary carrier 25 is rotatably supported by the housing 29 .

[0048] The third support portion 43 is disposed on the first direction A1 side of the second support portion 42. The third support portion 43 is fixed to the second support portion 42. The third support portion 43 has a through hole along the axis O. The output shaft 28 is inserted into the through hole. A plurality of bearings 55 are disposed between the inner wall of the through hole and the output shaft 28. In this way, the third support portion 43 rotatably supports the output shaft 28.

[0049] The fourth support portion 44 is disposed on the first direction A1 side of the third support portion 43. The fourth support portion 44 is fixed to the third support portion 43. The fourth support portion 44 has a through hole along the axis O. The output shaft 28 is inserted into the through hole.

[0050] (Lubricant flow path and lubricant flow) The work machine 1 has a lubrication system 10 that lubricates the gears of a planetary gear mechanism 11. Figure 8 is a block diagram showing the configuration of the lubrication system 10. The lubrication system 10 has a pump 12, a switching valve 13, a rotation sensor 14, and a controller 15.

[0051] The pump 12 supplies lubricating oil from a tank 16 that stores lubricating oil to the planetary gear mechanism 11. The planetary gear mechanism 11 is provided with a first supply flow path 61 and a second supply flow path 62 (described later) that supply lubricating oil to the gears. The switching valve 13 switches the supply of lubricating oil between the first supply flow path 61 and the second supply flow path 62. The rotation sensor 14 detects information for determining the rotation direction of the gears. The controller 15 controls the pump 12 and the switching valve 13. The controller 15 controls the switching valve 13 based on the detection information of the rotation sensor 14.

[0052] The switching valve 13 switches the flow path for supplying the lubricating oil sent from the pump 12 between a first supply flow path 61 and a second supply flow path 62. As shown in FIG. 8 , the pump 12 and the tank 16 are connected by a first pipe 71. The switching valve 13 and the pump 12 are connected by a second pipe 72. A third pipe 73 and a fourth pipe 74 are connected to the switching valve 13. The third pipe 73 is connected to the first supply flow path 61 of the planetary gear mechanism 11. The fourth pipe 74 is connected to the second supply flow path 62 of the planetary gear mechanism 11.

[0053] The switching valve 13 switches the connection destination of the second pipeline 72 between a third pipeline 73 and a fourth pipeline 74. When the switching valve 13 connects the second pipeline 72 and the third pipeline 73, the lubricating oil is supplied to the first supply flow path 61 of the planetary gear mechanism 11. When the switching valve 13 connects the second pipeline 72 and the fourth pipeline 74, the lubricating oil is supplied to the second supply flow path 62 of the planetary gear mechanism 11.

[0054] The planetary gear mechanism 11 and the tank 16 are connected by a fifth pipe line 75 (discharge flow path). The fifth pipe line 75 discharges the lubricating oil in the housing 29 to the outside. As shown in FIG. 8 and FIG. 2A, the lubricating oil discharged from the planetary gear mechanism 11 passes through the fifth pipe line 75 and is returned to the tank 16.

[0055] Next, a description will be given of the first supply passage 61 and the second supply passage 62 that supply lubricating oil to the sun gear 22. As shown in FIG.

[0056] The first supply flow path 61 is disposed on the second direction A2 side of the sun gear 22. The first supply flow path 61 is formed to discharge lubricating oil toward the tooth surface 22a of the sun gear 22. The first supply flow path 61 is disposed in the input shaft 21. As shown in FIG. 2B , the first supply flow path 61 includes a first portion 611, a plurality of second portions 612, and a plurality of third portions 613.

[0057] The first portion 611 is disposed along the central axis of the main body 111 of the input shaft 21. The multiple second portions 612 are formed radially outward from the end of the first portion 611 on the first direction A1 side. The third portion 613 is formed in the first direction A1 from the radially outer end of each second portion 612, and has an opening 61a in the end surface 111a of the main body 111. As shown in FIG. 2B , the opening 61a is disposed to face the helical tooth 22b of the sun gear 22 in the direction along the axis O. The opening 61a is disposed to overlap with the tooth surface 22a when viewed along the first direction A1.

[0058] FIG. 9(a) is a schematic diagram showing the positional relationship between the gears and the openings that discharge lubricating oil when the planetary gear mechanism 11 is viewed along the first direction A1. In FIG. 9(a) and FIG. 9(b) described later, the openings are enlarged for clarity. As shown in FIG. 9(a), the openings 61a of the multiple third portions 613 are arranged circumferentially around the axis O. The openings 61a are arranged at equal intervals around the axis O. The number of openings 61a is set to the same number as the number of planetary gears 23. The lubricating oil supplied from the first portion 611 in the first direction A1 is divided into multiple second portions 612, passes through the third portion 613, and is discharged from the multiple openings 61a toward the tooth surfaces 22a.

[0059] As shown in Fig. 2A, the second supply flow path 62 is arranged on the first direction A1 side of the sun gear 22. The second supply flow path 62 is formed to discharge lubricating oil toward the tooth surface 22a of the sun gear 22. As shown in Fig. 2A, the second supply flow path 62 is arranged in the output shaft 28 and the housing 29. The second supply flow path 62 has a first portion 621, a second portion 622, a third portion 623, a fourth portion 624, a fifth portion 625, and a sixth portion 626.

[0060] The first portion 621 is disposed on the fourth support portion 44. The first portion 621 is formed from the outer surface of the fourth support portion 44 to the output shaft 28. The second portion 622 is a groove formed circumferentially on the outer peripheral surface of the output shaft 28. The first portion 621 is connected to the second portion 622, which is also a groove. The third portion 623 is formed from the second portion 622 toward the central axis of the output shaft 28. The fourth portion 624 is formed from the end of the third portion 623 on the center side to near the end face 28a of the output shaft 28 on the second direction A2 side, as shown in FIG. 2B. The fifth portion 625 is formed from the end of the fourth portion 624 on the second direction A2 side toward the radially outward direction. The sixth portion 626 is formed from the radially outer end of the fifth portion 625 in the second direction A2. The sixth portion 626 has an opening 62a in the end face 28a of the output shaft 28 on the second direction A2 side. As shown in Fig. 2B, the opening 62a is disposed so as to face the helical teeth 22b of the sun gear 22 in the direction along the axis O. The opening 62a is disposed so as to overlap with the tooth surface 22a when viewed in the second direction A2. Fig. 9(b) is a schematic diagram showing the positional relationship between the openings that discharge lubricating oil and the gears when the planetary gear mechanism 11 is viewed in the second direction A2. As shown in Fig. 9(b), the opening 62a is disposed at one location on the end face 28a of the output shaft 28.

[0061] The lubricating oil passes through the first portion 621, the second portion 622, the third portion 623, the fourth portion 624, the fifth portion 625 and the sixth portion 626 and is discharged from the opening 62a towards the tooth surface 22a.

[0062] Next, the flow of the lubricating oil discharged from the first supply passage 61 or the second supply passage 62 toward the sun gear 22 in the planetary carrier 25 will be described.

[0063] The lubricating oil is discharged from the above-mentioned first supply passage 61 or second supply passage 62 (Figure 2A) toward the sun gear 22 side, and flows through the first wall surface passage S1 (Figure 6A) and the second wall surface passage S2 (Figure 6C) toward the outer periphery of the planetary carrier 25 due to centrifugal force.

[0064] As shown in FIGS. 6A to 6C, the first wall surface flow passages S1 are flow passages formed between the first wall surface 33f on the left circumferential direction H1 side of each carrier pillar 33 and the planetary gear 23 arranged on the left circumferential direction H1 side of each carrier pillar 33. The spacing between the first wall surface flow passages S1 is indicated by d1. The first wall surface flow passages S1 have an inlet S10 for lubricating oil on the central axis O side. The inlet S10 is a space formed between the end of the first wall surface 33f of the carrier pillar 33 on the central axis O side and the planetary gear 23 on the left circumferential direction H1 side.

[0065] 6A to 6C, the second wall surface flow passages S2 are flow passages formed between the second wall surface 33g on the right circumferential direction H2 side of each carrier pillar 33 and the planetary gear 23 arranged on the right circumferential direction H2 side of each carrier pillar 33. The spacing between the second wall surface flow passages S2 is indicated by d2. The second wall surface flow passages S2 have a lubricating oil inlet S20 on the central axis O side. The inlet S20 is a space formed between the end of the second wall surface 33g of the carrier pillar 33 on the central axis O side and the planetary gear 23c on the right circumferential direction H2 side.

[0066] Taking carrier pillar 33c of the three carrier pillars 33 as an example, as shown in FIGS. 6A to 6C, a first wall surface flow path S1 is formed between carrier pillar 33c and planetary gear 23d arranged on the left circumferential direction H1 side of carrier pillar 33c. Due to the inclination of first wall surface 33f of carrier pillar 33, first wall surface flow path S1 is formed such that the distance d1 gradually increases from second end 332 to first end 331 of carrier pillar 33c, as shown in FIGS. 5A and 5B. Of first wall surface flow path S1, the portion on the first end 331 side is indicated as flow path portion S11, and the portion on the second end 332 side is indicated as flow path portion S12. Carrier pillar 33 is formed such that the distance d1 is wider in flow path portion S11 than in flow path portion S12.

[0067] Due to the inclination of the second wall surface 33g of the carrier pillar 33, the second wall surface flow path S2 is formed so that the distance d2 gradually increases from the first end 331 toward the second end 332. Of the second wall surface flow path S2, the portion on the first end 331 side is indicated as flow path portion S21, and the portion on the second end 332 side is indicated as flow path portion S22. The carrier pillar 33 is formed so that the distance d2 is wider in flow path portion S22 than in flow path portion S21.

[0068] The position of the DD cross section shown in Fig. 5A is a position cutting the side of the first end 331 of the carrier pillar 33. Therefore, Fig. 6A shows the cross section on the side of the first end 331 of the carrier pillar 33. As shown in Fig. 6A, the spacing d1 of the first wall surface flow passages S1 in the DD cross section is wider than the spacing d2 of the second wall surface flow passages S2.

[0069] The position of the E-E cross section shown in Fig. 5A is a position cutting through the center of the carrier pillar 33. Therefore, Fig. 6B shows a cross section at the center of the carrier pillar 33. As shown in Fig. 6B, the spacing d1 of the first wall surface flow paths S1 in the E-E cross section is equal to the spacing d2 of the second wall surface flow paths S2.

[0070] The position of the FF cross section shown in Fig. 5A is a position cutting the side of the second end 332 of the carrier pillar 33. Therefore, Fig. 6C shows a cross section on the side of the second end 332 of the carrier pillar 33. As shown in Fig. 6C, the spacing d2 of the second wall surface flow passages S2 in the FF cross section is wider than the spacing d1 of the first wall surface flow passages S1.

[0071] 7, the first carrier disk 31 is formed with a plurality of first wall surface inner-periphery-side flow passages 36. The second carrier disk 32 is formed with a plurality of second wall surface inner-periphery-side flow passages 37. The first wall surface inner-periphery-side flow passages 36 and the second wall surface inner-periphery-side flow passages 37 discharge lubricating oil from the sun gear 22 side to the outside of the planetary carrier 25 before it flows into the first wall surface flow passage S1 and the second wall surface flow passage S2. The first wall surface inner-periphery-side flow passages 36 and the second wall surface inner-periphery-side flow passages 37 discharge lubricating oil from the radially inner sides of the first wall surface flow passage S1 and the second wall surface flow passage S2 to the outside of the planetary carrier 25.

[0072] 2A and 7, the first wall surface inner peripheral side flow passage 36 has an inner opening 36a on the surface of the first carrier disk 31 facing the second carrier disk 32 (the surface on the first direction A1 side). The inner opening 36a is formed on the edge of a through hole in the first carrier disk 31 into which the input shaft 21 is inserted. As shown in FIG. 2A, the first wall surface inner peripheral side flow passage 36 has an outer opening 36b on the surface of the first carrier disk 31 opposite to the second carrier disk 32 (the surface on the second direction A2 side). The outer opening 36b is formed at a position farther from the central axis O than the inner opening 36a.

[0073] As shown in Fig. 7, six first wall surface inner peripheral flow passages 36 are formed in the first carrier disk 31 along the circumferential direction. The six inner openings 36a are arranged at equal intervals on a concentric circle centered on the central axis O. As shown in Fig. 3A, the six outer openings 36b are arranged at equal intervals centered on the central axis O.

[0074] 2A, the second wall surface inner peripheral side flow passage 37 has an inner opening 37a on the surface of the second carrier disk 32 facing the first carrier disk (the surface on the second direction A2 side). The inner opening 37a is formed on the edge of a through hole in the second carrier disk 32 into which the output shaft 28 is inserted. The second wall surface inner peripheral side flow passage 37 has an outer opening 37b on the surface of the second carrier disk 32 opposite to the first carrier disk 31 (the surface on the second direction A2 side). The outer opening 37b is formed at a position farther from the central axis O than the inner opening 37a.

[0075] As shown in Fig. 7, six second wall surface inner peripheral flow passages 37 are formed in the second carrier disk 32 along the circumferential direction. The six inner openings 37a are arranged concentrically at equal intervals around the central axis O. As shown in Fig. 3B, the six outer openings 37b are arranged at equal intervals around the central axis O.

[0076] The inner openings 36a of the first wall surface inner periphery side flow passages 36 and the inner openings 37a of the second wall surface inner periphery side flow passages 37 are arranged opposite to each other in the direction along the central axis O.

[0077] 6A to 6C, the inner opening 37a of the second wall surface inner periphery-side flow passage 37 is disposed closer to the central axis O than the inlet S10 of the first wall surface flow passage S1 and the inlet S20 of the second wall surface flow passage S2. Note that in FIGS. 6A to 6C, the inner opening 37a is located on the far side of the sun gear 22 in the plane of the drawing and is therefore hidden by the sun gear 22, but is depicted by a solid line to indicate its position. Note that, although not shown, the inner opening 36a of the first wall surface inner periphery-side flow passage 36 is also disposed closer to the central axis O than the inlet S10 of the first wall surface flow passage S1 and the inlet S20 of the second wall surface flow passage S2.

[0078] In this way, by positioning the inner openings 36a and 37a radially inward from the inlets S10 and S20, the lubricating oil can be discharged to the outside of the planetary carrier 25 before flowing from the sun gear 22 side into the first wall surface flow path S1 or the second wall surface flow path S2.

[0079] As described above, by providing the first wall surface inner peripheral flow passage 36 and the second wall surface inner peripheral flow passage 37, it is possible to prevent more lubricating oil than necessary from flowing into the first wall surface flow passage S1 or the second wall surface flow passage S2, thereby reducing stirring loss.

[0080] The planetary carrier 25 is formed with a carrier pillar flow path 38 that discharges the lubricating oil that has flowed into the first wall surface flow path S1 or the second wall surface flow path S2 to the outside of the planetary carrier 25.

[0081] Fig. 10 is a perspective view of the planetary carrier 25. Fig. 10 is a diagram showing the carrier pillar flow paths 38 formed in the planetary carrier 25. Fig. 11 is a side view of the planetary carrier 25.

[0082] 10, a plurality of carrier pillar flow paths 38 are provided, and are formed as flow paths extending from the wall surface of each carrier pillar 33 to the first carrier disk 31. In this embodiment, three carrier pillar flow paths 38 are provided.

[0083] Each carrier pillar flow path 38 has a first flow path portion 81, a second flow path portion 82, and a third flow path portion 83. The first flow path portion 81 is formed in the carrier pillar 33 along the central axis O. As shown in FIG. 6A, the first flow path portion 81 is arranged near the outer periphery of the planetary carrier 25. As shown in FIG. 10, the first flow path portion 81 has discharge side openings 81a in the first carrier disk 31. As shown in FIGS. 3A and 10, the three discharge side openings 81a are arranged at equal intervals on concentric circles centered on the central axis O.

[0084] As shown in FIG. 6A , the second flow path portion 82 is formed from a first wall surface 33f on the left circumferential direction H1 side of the carrier pillar 33 to the first flow path portion 81. The second flow path portion 82 has a first inlet-side opening 82a on the first wall surface 33f. The first inlet-side opening 82a faces the first wall surface flow path S1. The first inlet-side opening 82a faces the flow path portion S11, in which the spacing d1 of the first wall surface flow paths S1 is wide. As shown in FIG. 11 , the first inlet-side opening 82a is formed at a position closer to the first carrier disk 31 than to the second carrier disk 32. The first inlet-side opening 82a is formed at a first end portion 331 of the carrier pillar 33. As shown in FIG. 6A , the first inlet-side opening 82a is formed at a position on the first wall surface 33f closer to the end on the central axis O side than to the end on the outer circumferential side of the planetary carrier 25. The second flow path portion 82 extends outward from the first inlet side opening 82a and connects to the first flow path portion 81. The second flow path portion 82 connects the first wall surface flow path S1 and the first flow path portion 81. The second flow path portion 82 connects the first inlet side opening 82a and the first flow path portion 81, which is disposed on the outer diameter side of the first inlet side opening 82a, so that the lubricating oil that has flowed into the first inlet side opening 82a flows toward the first flow path portion 81 by centrifugal force.

[0085] 6A, the lubricating oil that has flowed into the first wall surface flow passage S1 flows from the first inlet side opening 82a into the second flow passage portion 82, then flows into the first flow passage portion 81, and is discharged from the discharge side opening 81a. Of the lubricating oil that has flowed into the first wall surface flow passage S1, the lubricating oil that does not flow into the first inlet side opening 82a is discharged to the outside of the planetary carrier 25 through the first wall surface flow passage S1.

[0086] As shown in FIG. 6C , the third flow path portion 83 is formed from the second wall surface 33g on the right circumferential direction H2 side of the carrier pillar 33 to the first flow path portion 81. The third flow path portion 83 has a second inlet side opening 83a on the second wall surface 33g. The second inlet side opening 83a faces the second wall surface flow path S2. The second inlet side opening 83a faces the flow path portion S22, in which the spacing d2 of the second wall surface flow paths S2 is wide. As shown in FIG. 11 , the second inlet side opening 83a is formed at a position closer to the second carrier disk 32 than to the first carrier disk 31. The second inlet side opening 83a is formed at the second end portion 332 of the carrier pillar 33. As shown in FIG. 6C , the second inlet side opening 83a is formed at a position on the second wall surface 33g closer to the end on the central axis O side than to the end on the outer circumferential side of the planetary carrier 25. The third flow path portion 83 extends outward from the second inlet side opening 83a and connects to the first flow path portion 81. The third flow path portion 83 connects the second wall surface flow path S2 and the first flow path portion 81. The third flow path portion 83 connects the second inlet side opening 83a and the first flow path portion 81, which is disposed on the outer diameter side of the second inlet side opening 83a, so that the lubricating oil that has flowed into the second inlet side opening 83a flows toward the first flow path portion 81 by centrifugal force.

[0087] 6C, the lubricating oil that has flowed into the second wall surface flow passage S2 flows from the second inlet side opening 83a into the third flow passage portion 83, then flows into the first flow passage portion 81, and is discharged from the discharge side opening 81a. Of the lubricating oil that has flowed into the second wall surface flow passage S2, the lubricating oil that does not flow into the second inlet side opening 83a is discharged to the outside of the planetary carrier 25 through the second wall surface flow passage S2.

[0088] In this way, by providing a carrier pillar flow path 38 that discharges the lubricating oil that has flowed into the first wall surface flow path S1 and the second wall surface flow path S2, which are flow paths formed between the wall surface of the carrier pillar 33 and the planetary gear 23, to the outside of the planetary carrier 25, it is possible to further reduce stirring loss.

[0089] 10 and 11, the second flow path portion 82 is disposed closer to the first carrier disk 31, and the third flow path portion 83 is disposed closer to the second carrier disk 32. Therefore, the second flow path portion 82 and the third flow path portion 83 are spaced apart in the direction along the central axis O. Therefore, only the second flow path portion 82 is shown in FIG. 6A, only the third flow path portion 83 is shown in FIG. 6C, and neither is shown in FIG. 6B.

[0090] (Rotation sensor 14) 8 detects information for determining the rotation direction of the sun gear 22. The rotation sensor 14 transmits the detected information to the controller 15. As the rotation sensor 14, for example, a rotary encoder can be used.

[0091] Other information for determining the rotation direction of the sun gear 22 may be information about the rotation direction of the input shaft 21 or the output shaft 28, or information about the position of the forward / reverse selector lever of the work machine 1. When the forward / reverse selector lever is in the forward position, it can be determined that the sun gear 22 rotates in a predetermined direction, and when it is in the reverse position, it can be determined that the sun gear 22 rotates in the direction opposite to the predetermined direction.

[0092] (Controller 15) The controller 15 includes a processor such as a CPU. The processor performs processing for controlling the pump 12 and the switching valve 13. The controller 15 includes a storage device. The storage device includes a memory such as a RAM or a ROM, and an auxiliary storage device such as an HDD (Hard Disk Drive) or an SSD (Solid State Drive). The storage device stores data and programs for controlling the pump 12 and the switching valve 13.

[0093] The controller 15 controls the switching valve 13 based on the detection information of the rotation sensor 14. Upon receiving the detection information of the rotation sensor 14, the controller 15 determines the rotation direction of the sun gear 22, and switches the switching valve 13 according to the determined rotation direction to discharge the lubricating oil from the first supply flow path 61 or the second supply flow path 62.

[0094] Next, the rotation of the helical gear and the flow of lubricant will be described to explain why the controller 15 switches the flow path for discharging lubricant. Fig. 12(a) is a schematic side view showing the sun gear 22 and planetary gears 23 in mesh. For ease of understanding, the size and shape of the planetary gear 23 are different from those in Fig. 2A. Fig. 12(b) is a schematic view of the sun gear 22 and planetary gears 23 as viewed along the first direction A1.

[0095] When the sun gear 22 rotates in the counterclockwise rotation direction L shown in FIG. 12(b), the planetary gears 23 rotate in the clockwise rotation direction G2. Due to the shape of the helical teeth 22b of the sun gear 22 and the shape of the helical teeth 23b of the planetary gears 23, the lubricant flows on the tooth surfaces 22a and 23a in the first direction A1 shown in FIG. 12(a). The lubricant flows from the first end 331 side of the carrier post 33 toward the second end 332 side, as shown in FIG. 5A. As the planetary gears 23 rotate in the clockwise rotation direction G2, the lubricant flows from the inlet S20 into the second wall surface flow passage S2, as shown in FIG. 6C. Furthermore, a portion of the lubricant flows toward the second end 332 side into the second wall surface inner circumference side flow passage 37 through the inner opening 37a before flowing into the inlet S20 and is discharged from the outer opening 37b.

[0096] The lubricating oil that flows into the second wall surface flow passage S2 flows into the carrier pillar flow passage 38 from the second inlet side opening 83a. More specifically, the lubricating oil that flows into the second wall surface flow passage S2 flows into the third flow passage portion 83 from the second inlet side opening 83a. The lubricating oil that flows into the third flow passage portion 83 flows into the first flow passage portion 81 and is discharged to the outside of the planetary carrier 25 from the discharge side opening 81a. Furthermore, the lubricating oil that flows into the second wall surface flow passage S2 but does not flow into the second inlet side opening 83a is discharged toward the outside of the planetary carrier 25 through the second wall surface flow passage S2. The discharge direction of the lubricating oil is indicated by a thick arrow in FIG. 6C.

[0097] The lubricating oil moves toward the second end 332 and flows into the second wall surface flow passage S2 as the planetary gear 23 rotates, mainly flowing through the flow passage portion S22 of the second wall surface flow passage S2. Since the second wall surface flow passage S2 has a wide gap d2 formed therein, the lubricating oil is easily discharged from the flow passage portion S22. Furthermore, since the second inlet side opening 83a opens into the flow passage portion S22, the lubricating oil easily flows into the third flow passage portion 83. In this way, the lubricating oil can be efficiently discharged to the outside of the planetary carrier 25, thereby reducing rotation loss due to the lubricating oil.

[0098] As shown in FIGS. 5A and 5B, the flow path portion S21 of the second wall surface flow path S2 is located upstream in the lubricant flow direction and receives a small amount of lubricant, so there is no need to widen the flow path spacing d2. Therefore, by making the spacing d2 of the flow path portion S21 narrower than that of the flow path portion S22, the cross-sectional area of ​​the carrier pillars 33 can be increased, thereby ensuring the strength of the planetary carrier 25. Furthermore, as shown in FIG. 6C, when the planetary gear 23 rotates in the clockwise rotation direction G2, the lubricant present in the first wall surface flow path S1 is pushed back toward the inner periphery (the side toward the axis O) by the rotation of the planetary gear 23, so that the flow of lubricant toward the outer periphery is unlikely to occur. Therefore, by narrowing the spacing d1 of the flow path portion S11 of the first wall surface flow path S1 and increasing the cross-sectional area of ​​the carrier pillars 33, the strength of the planetary carrier 25 can be ensured.

[0099] On the other hand, when the sun gear 22 rotates in the clockwise rotation direction R shown in FIG. 12(b), the plurality of planetary gears 23 rotate in the counterclockwise rotation direction G1. Due to the shape of the helical teeth 22b of the sun gear 22 and the shape of the helical teeth 23b of the planetary gears 23, the lubricating oil flows on the tooth surfaces 22a and 23a in the second direction A2 shown in FIG. 12(a). The lubricating oil flows from the second end 332 of the carrier post 33 toward the first end 331 shown in FIG. 5A. As the planetary gears 23 rotate in the counterclockwise rotation direction G1, the lubricating oil that has moved toward the first end 331 flows from the inlet S10 into the first wall surface flow passage S1 as shown in FIG. 6A. Furthermore, a portion of the lubricating oil that has flowed toward the first end 331 flows into the first wall surface inner circumference side flow passage 36 through the inner opening 36a before flowing into the inlet S10 and is discharged from the outer opening 36b.

[0100] The lubricating oil that flows into the first wall surface flow path S1 flows into the carrier pillar flow path 38 from the first inlet side opening 82a. More specifically, the lubricating oil that flows into the first wall surface flow path S1 flows into the second flow path portion 82 from the first inlet side opening 82a. The lubricating oil that flows into the second flow path portion 82 flows into the first flow path portion 81 and is discharged to the outside of the planetary carrier 25 from the discharge side opening 81a. Furthermore, the lubricating oil that flows into the first wall surface flow path S1 but does not flow into the first inlet side opening 82a is discharged toward the outside of the planetary carrier 25 through the first wall surface flow path S1. The discharge direction of the lubricating oil is indicated by a thick arrow in FIG. 6A.

[0101] The lubricating oil moves toward the first end 331 and flows into the first wall surface flow passage S1 as the planetary gear 23 rotates, mainly flowing through the flow passage portion S11 of the first wall surface flow passage S1. Since the flow passage portion S11 has a wide interval d1 formed in the first wall surface flow passage S1, the lubricating oil is easily discharged. Furthermore, since the first inlet side opening 82a opens into the flow passage portion S11, the lubricating oil easily flows into the second flow passage portion 82. In this way, the lubricating oil can be efficiently discharged to the outside of the planetary carrier 25, thereby reducing rotation loss due to the lubricating oil.

[0102] As shown in FIGS. 5A and 5B, the flow path portion S12 of the first wall surface flow path S1 is located upstream in the lubricant flow direction and receives a small amount of lubricant, so there is no need to widen the flow path spacing d1. Therefore, by making the spacing d1 of the flow path portion S12 narrower than that of the flow path portion S11, the cross-sectional area of ​​the carrier pillars 33 can be increased, thereby ensuring the strength of the planetary carrier 25. Furthermore, as shown in FIG. 6A, when the planetary gear 23 rotates in the counterclockwise direction G1, the lubricant present in the second wall surface flow path S2 is pushed back toward the inner periphery (the side toward the axis O) by the rotation of the planetary gear 23, so that the lubricant is less likely to flow toward the outer periphery. Therefore, by making the spacing d2 of the flow path portion S21 of the second wall surface flow path S2 narrower than the spacing d1 of the flow path portion S11, the cross-sectional area of ​​the carrier pillars 33 can be increased, thereby ensuring the strength of the planetary carrier 25.

[0103] When sun gear 22 rotates in counterclockwise direction L, lubricating oil flows in first direction A1, so by supplying lubricating oil from the second direction A2 side of sun gear 22, which is the upstream side of the flow direction, toward first direction A1, it is possible to constantly supply lubricating oil onto tooth surfaces 22a, 23a. When sun gear 22 rotates in clockwise direction R, lubricating oil flows in second direction A2, so by supplying lubricating oil from the first direction A1 side of sun gear 22, which is the upstream side of the flow direction, toward second direction A2, it is possible to constantly supply lubricating oil onto tooth surfaces 22a, 23a.

[0104] Therefore, when the controller 15 determines that the rotation direction of the sun gear 22 is the left rotation direction L based on the detection information from the rotation sensor 14, the controller 15 drives the switching valve 13 to connect the second pipe line 72 and the third pipe line 73. As a result, the lubricating oil supplied from the tank 16 by the pump 12 is discharged toward the tooth surface 22a of the sun gear 22 from the opening 61a of the first supply flow path 61 located on the second direction A2 side of the sun gear 22.

[0105] Furthermore, when the controller 15 determines that the rotation direction of the sun gear 22 is the clockwise rotation direction R based on the detection information from the rotation sensor 14, the controller 15 drives the switching valve 13 to connect the second pipe line 72 to the fourth pipe line 74. As a result, the lubricating oil supplied from the tank 16 by the pump 12 is discharged toward the tooth surface 22a of the sun gear 22 from the opening 62a of the second supply flow path 62 located on the first direction A1 side of the sun gear 22.

[0106] <Operation> Next, a description will be given of the control operation of the lubrication system 10 of this embodiment. Fig. 13 is a flow chart showing the control operation of the lubrication system 10 of this embodiment.

[0107] First, in step S101, the controller 15 drives the pump 12.

[0108] Next, in step S102, the controller 15 receives the detection information of the rotation sensor 14.

[0109] Next, in step S103, the controller 15 determines, based on the received detection information, the rotation direction of the sun gear 22. For example, the controller 15 determines, based on the detection information, whether the rotation direction of the sun gear 22 is the left rotation direction L.

[0110] If it is determined in step S103 that the rotation direction is the left rotation direction L, the control proceeds to step S104.

[0111] In step S104, the controller 15 drives the switching valve 13 to connect the second pipe 72 and the third pipe 73, and the control ends. As a result, the lubricating oil supplied from the tank 16 by the driving of the pump 12 is discharged toward the tooth surface 22a of the sun gear 22 from the opening 61a of the first supply passage 61 located on the second direction A2 side of the sun gear 22. The discharged lubricating oil flows in a direction (first direction A1) from the first end 331 side toward the second end 332 side. As the planetary gear 23 rotates in the clockwise rotation direction G2, the lubricating oil that has flowed toward the second end 332 side mainly flows into the passage portion S22 of the second wall surface passage S2 via the inlet S20, as shown in FIG. 6C . Furthermore, some of the lubricating oil that has flowed toward the second end 332 side flows into the second wall surface inner circumference side passage 37 via the inner opening 37a before flowing into the inlet S10 and is discharged from the outer opening 37b.

[0112] The lubricating oil that flows into the second wall surface flow path S2 through the inlet S20 flows from the second wall surface flow path S2 through the second inlet side opening 83a into the third flow path portion 83. The lubricating oil that flows into the third flow path portion 83 flows into the first flow path portion 81 and is discharged from the discharge side opening 81a to the outside of the planetary carrier 25. In addition, the lubricating oil that does not flow into the second inlet side opening 83a is discharged to the outside of the planetary carrier 25 through the second wall surface flow path S2.

[0113] On the other hand, if it is determined in step S103 that the rotation direction is not the left rotation direction L, it can be determined that the rotation direction is the right rotation direction R, and the control proceeds to step S105.

[0114] In step S105, the controller 15 drives the switching valve 13 to connect the second pipe 72 and the fourth pipe 74, and the control ends. As a result, the lubricating oil supplied from the tank 16 by the driving of the pump 12 is discharged from the opening 62a of the second supply passage 62 located on the first direction A1 side of the sun gear 22 toward the tooth surface 22a of the sun gear 22. The discharged lubricating oil flows in a direction (second direction A2) from the second end 332 side toward the first end 331 side. As the planetary gear 23 rotates in the counterclockwise rotation direction G1, the lubricating oil that has flowed toward the first end 331 side flows from the inlet S10 into the first wall surface passage S1, as shown in FIG. 6A . Furthermore, a portion of the lubricating oil that has flowed toward the first end 331 side flows into the first wall surface inner circumference side passage 36 through the inner opening 36a before flowing into the inlet S10 and is discharged from the outer opening 36b.

[0115] The lubricating oil that flows into the first wall surface flow path S1 through the inlet S10 flows from the first wall surface flow path S1 through the first inlet side opening 82a into the second flow path portion 82. The lubricating oil that flows into the second flow path portion 82 flows into the first flow path portion 81 and is discharged from the discharge side opening 81a to the outside of the planetary carrier 25. In addition, the lubricating oil that does not flow into the first inlet side opening 82a passes through the first wall surface flow path S1 and is discharged to the outside of the planetary carrier 25.

[0116] The rotation sensor 14 constantly detects information relating to the rotation direction of the sun gear 22 and transmits it to the controller 15. Therefore, the rotation direction is determined each time detection information is received. For example, if the rotation direction of the sun gear 22 determined based on the previously received detection information matches the rotation direction of the sun gear 22 determined based on the currently received detection information, the controller 15 does not drive the switching valve 13 and maintains the same state.

[0117] (Features, etc.) 6A, the planetary gear mechanism 11 of this embodiment includes a first wall surface flow passage S1 formed between the carrier post 33 and the planetary gear 23 and into which lubricating oil flows from the sun gear 22 side, a first wall surface inner circumference side flow passage 36 (see FIG. 7) formed in the planetary carrier 25 and which discharges the lubricating oil from the inner circumference side of the first wall surface flow passage S1 toward the outside of the planetary carrier 25, and a carrier post flow passage 38 formed in the planetary carrier 25 and which discharges the lubricating oil that has flowed into the first wall surface flow passage S1 to the outside of the planetary carrier 25. This allows the lubricating oil that has flowed into the first wall surface flow passage S1 to be discharged to the outside of the planetary carrier 25 via the carrier post flow passage 38, thereby reducing stirring loss. A portion of the lubricating oil before flowing into the first wall surface flow passage S1 can be discharged to the outside of the planetary carrier 25 via the first wall surface inner circumference side flow passage 36. Furthermore, the lubricating oil that has flowed into the first wall surface flow passage S1 but has not flowed into the carrier pillar flow passages 38 can be discharged via the first wall surface flow passage S1 to the outside of the planetary carrier 25. In this way, the lubricating oil supplied toward the sun gear 22 through a plurality of flow passages can be discharged to the outside of the planetary carrier 25, thereby reducing stirring loss.

[0118] 6A, in the planetary gear mechanism 11 of this embodiment, when the planetary gear 23 rotates in the left rotation direction G1 (first direction), the lubricating oil flows into the first wall surface flow passage S1, and the carrier post flow passage 38 is formed in the first wall surface 33f on the left circumferential direction H1 side (first circumferential direction side) of the carrier post 33 and has a first inlet side opening 82a into which the lubricating oil flows from the first wall surface flow passage S1. As a result, the lubricating oil that has flowed into the first wall surface flow passage S1 can flow into the carrier post flow passage 38 via the first inlet side opening 82a and be discharged to the outside of the planetary carrier 25.

[0119] In the planetary gear mechanism 11 of this embodiment, as shown in Fig. 2A, the planetary gear 23 has helical teeth. Rotation of the planetary gear 23 in the counterclockwise rotation direction G1 pushes lubricating oil from the second carrier disc 32 side to the first carrier disc 31 side in the axial direction of the planetary gear 23. As shown in Fig. 10, the first inlet side opening 82a is formed at a position closer to the first carrier disc 31 than the second carrier disc 32. In this way, because the first inlet side opening 82a is provided on the side where the lubricating oil flows due to the helical teeth, the lubricating oil flowing into the first wall surface flow path S1 can efficiently flow into the carrier post flow path 38.

[0120] 5A, in the planetary gear mechanism 11 of the present embodiment, the first wall surface 33f is formed at an incline so that the distance between the planetary gear 23 and the first wall surface 33f in the first wall surface flow path S1 is wider on the first carrier disc 31 side than on the second carrier disc 32 side in the direction along the central axis O. In this way, by increasing the distance d1 of the first wall surface flow path S1 on the side where the lubricating oil flows, it is possible to make it easier to discharge the lubricating oil.

[0121] 10 , the planetary gear mechanism 11 of this embodiment has a discharge side opening 81a in the first carrier disk 31, a first flow path portion 81 formed in the carrier pillar 33 along the axial direction of the planetary gear 23, and a second flow path portion 82 formed from the first inlet side opening 82a to the first flow path portion 81. This allows the lubricating oil that has flowed into the first inlet side opening 82a to be discharged to the outside of the planetary carrier 25.

[0122] In the planetary gear mechanism 11 of this embodiment, as shown in FIG. 6C , the planetary gear 23 is rotatable in a clockwise rotation direction G2 (second direction) opposite to the counterclockwise rotation direction G1. The planetary gear mechanism 11 further includes a second wall surface flow path S2 formed between the carrier post 33 and the planetary gear 23 disposed on the right circumferential direction H2 side (second circumferential direction side) of the carrier post 33 opposite to the counterclockwise circumferential direction H1. When the planetary gear 23 rotates in the clockwise rotation direction G2, the lubricating oil flows into the second wall surface flow path S2. The carrier post flow path 38 is formed in the second wall surface 33g on the right circumferential side of the carrier post 33 and has a second inlet side opening 83a into which the lubricating oil flows from the second wall surface flow path S2. This allows the lubricating oil that has flowed into the second wall surface flow path S2 to be discharged to the outside of the planetary carrier 25 via the carrier post flow path 38. Of the lubricating oil that has flowed into the second wall surface flow passages S2, the lubricating oil that has not flowed into the carrier pillar flow passages 38 can be discharged via the second wall surface flow passages S2 to the outside of the planetary carrier 25. Regardless of whether the planetary gear 23 rotates forward or backward, the lubricating oil supplied toward the sun gear 22 through the multiple flow passages can be discharged to the outside of the planetary carrier 25, thereby reducing stirring loss.

[0123] 6C , in the planetary gear mechanism 11 of the present embodiment, rotation of the planetary gear 23 in the clockwise rotation direction G2 pushes lubricating oil from the first carrier disc 31 side to the second carrier disc 32 side in the axial direction of the planetary gear 23. The second inlet side opening 83a is formed in a position on the second wall surface 33g closer to the second carrier disc 32 than to the first carrier disc 31. In this way, because the second inlet side opening 83a is provided on the side where the lubricating oil flows due to the helical teeth, the lubricating oil that flows into the second wall surface flow path S2 can efficiently flow into the carrier post flow path 38.

[0124] 5A, in the planetary gear mechanism 11 of this embodiment, the second wall surface 33g is formed at an incline so that the distance d2 between the planetary gear 23 and the second wall surface 33g in the second wall surface flow path S2 is wider in the axial direction on the second carrier disc 32 side than on the first carrier disc 31 side. In this way, by increasing the distance d2 of the second wall surface flow path S2 on the side where the lubricating oil flows, it is possible to make it easier to discharge the lubricating oil.

[0125] In the planetary gear mechanism 11 of this embodiment, the carrier pillar flow path 38 has a third flow path portion 83 formed from the second inlet side opening 83a to the first flow path portion 81. This allows the lubricating oil that has flowed into the second inlet side opening 83a to be discharged to the outside of the planetary carrier 25.

[0126] <Other embodiments> Although one embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, and various modifications are possible within the scope of the gist of the invention. In particular, the multiple embodiments and modifications described in this specification can be arbitrarily combined as necessary.

[0127] (A) In the above embodiment, the discharge side opening 81a of the carrier pillar flow path 38 is formed in the first carrier disk 31, but it may also be formed in the second carrier disk 32, or it may be formed in both the first carrier disk 31 and the second carrier disk 32.

[0128] (B) In the above embodiment, the carrier post flow passages 38 are formed in a hole-like shape. However, this is not limiting and they may be groove-like, as long as they are configured to discharge the lubricating oil that has flowed into the first wall surface flow passages S1 and the second wall surface flow passages S2. FIG. 14A is a cross-sectional view showing the planetary carrier 25 and the sun gear 22 in which groove-like carrier post flow passages 38' are formed. FIG. 14A is a cross-sectional view taken at the same position as FIG. 6A. FIG. 14B is a perspective view of the carrier post 33 in which the carrier post flow passages 38' are formed. As shown in FIG. 14A, the carrier post flow passages 38' are formed in each of the first wall surface 33f and the second wall surface 33g of the carrier post 33 along the central axis O. As shown in FIG. 14B, the carrier post flow passages 38' are concave grooves formed in the first wall surface 33f and the second wall surface 33g of the carrier post 33. Also, as shown in FIG. 14B, the carrier post flow passages 38' have openings 38a' in the first carrier disk 31.

[0129] (C) In the above embodiment, the planetary gear 23 rotates in both the counterclockwise rotation direction G1 and the clockwise rotation direction G2, so the first inlet opening 82a is formed in the first wall surface flow passage S1 and the second inlet opening 83a is formed in the second wall surface flow passage S2. However, this is not limited to this. For example, if the planetary gear 23 rotates mainly in the counterclockwise rotation direction G1 and infrequently in the clockwise rotation direction G2, or if it rotates only in the counterclockwise rotation direction G1, the amount of lubricant passing through the second wall surface flow passage S2 is small, so the second inlet opening 83a need not be formed in the second wall surface flow passage S2, and the third flow passage portion 83 need not be formed. In this case, the lubricant flows in the first direction A1 due to the helical teeth, so only the first wall surface inner circumference side flow passage 36 may be provided, and the second wall surface inner circumference side flow passage 37 may not be provided. Furthermore, the second supply flow passage 62 may not be provided, and the controller 15 does not need to switch the lubricant supply direction.

[0130] (D) In the planetary gear mechanism 11 of the above embodiment, three planetary gears 23 and three carrier pillars 33 are arranged, but this is not limitative and four or more may be arranged.

[0131] (E) In the above embodiment, the ring gear 26 is fixed to the housing 29, the sun gear 22 and the planetary gears 23 rotate relative to the housing 29, and power is input to the sun gear 22 and output from the planetary carrier 25, but this is not limiting. For example, the planetary carrier 25 may be fixed to the housing 29, the sun gear 22 and the ring gear 26 may be rotated, and power may be output from the ring gear.

[0132] (F) In the above embodiment, the first wall surface flow path S1 has a distance d1 that gradually increases from the second end 332 side toward the first end 331 side, but this is not limited thereto and the distance may increase in stages. Similarly, the second wall surface flow path S2 has a distance d2 that gradually increases from the first end 331 side toward the second end 332 side, but this is not limited thereto and the distance may increase in stages.

[0133] (G) In the above embodiment, the first wall surface flow path S1 and the second wall surface flow path S2 are formed so that the spacing between them is different on the first end 331 side and the second end 332 side, but this is not limited to this, and for example, the spacing between them may be the same on the first end 331 side and the second end 332 side.

[0134] (H) In the above embodiment, helical teeth are used for the sun gear 22, planetary gears 23, and ring gear 26, but they are not limited to helical teeth.

[0135] (I) Examples of the work machine 1 in the above embodiment include a wheel loader provided with front and rear tires, a forklift, etc., but are not limited to these, and examples include an excavator and a bulldozer with crawler tracks.

[0136] (J) In the above embodiment, the planetary gear mechanism 11 is applied to the work machine 1, but it is not limited to work machines and can be applied to any configuration that has a planetary gear. [Industrial Applicability]

[0137] According to the present disclosure, it is possible to provide a planetary gear mechanism that can reduce stirring loss. [Explanation of symbols]

[0138] 11: Planetary gear mechanism 20: Planetary gear unit 23: Planetary gear 24: Pinion shaft 25: Planetary Carrier 29: Housing 36: First wall inner circumferential flow path 37: 2nd wall inner circumferential flow path 38: Carrier pillar flow path S1: First wall flow channel S2: Second wall flow channel

Claims

1. Sun gear and a plurality of planetary gears disposed around the sun gear and meshing with the sun gear; a plurality of shafts that rotatably support the plurality of planetary gears; a planetary carrier having a carrier pillar disposed between the planetary gears and supporting the plurality of shafts; a housing that accommodates the sun gear, the plurality of planetary gears, the plurality of shafts, and the planetary carrier; a supply flow path for supplying lubricating oil toward the sun gear; a discharge flow path for discharging the lubricating oil in the housing to the outside; a wall surface flow path formed between the planetary gear and a wall surface of the carrier pillar of the planetary carrier, into which lubricating oil flows from the sun gear side; a wall surface inner peripheral side flow passage formed in the planetary carrier, for discharging lubricating oil from an inner peripheral side of the wall surface flow passage toward an outside of the planetary carrier; a carrier pillar flow path formed in the carrier pillar for discharging lubricating oil that has flowed into the wall surface flow path to the outside of the planetary carrier.

2. the wall surface flow passage has at least a first wall surface flow passage formed between the carrier pillar and the planetary gear arranged on a first circumferential direction side in the circumferential direction of the carrier pillar, When the planetary gear rotates in a first direction, lubricating oil flows into the first wall surface flow path, The carrier pillar flow path is formed in a first wall surface of the carrier pillar on the first circumferential direction side, and has a first inlet side opening into which lubricating oil flows from the first wall surface flow path.

2. The planetary gear mechanism according to claim 1.

3. The planetary carrier includes: a first carrier disk supporting first ends of the plurality of shafts; a second carrier disk supporting second ends of the shafts opposite the first ends and disposed opposite the first carrier disk, the carrier posts connect the first carrier disk and the second carrier disk; the planetary gear has helical teeth, the rotation of the planetary gear in the first direction forces lubricating oil from the second carrier disc side to the first carrier disc side in the axial direction of the planetary gear, the first inlet side opening is formed at a position closer to the first carrier disk than to the second carrier disk; 3. A planetary gear mechanism according to claim 2.

4. the first wall surface is formed at an incline so that a gap between the planetary gear and the first wall surface in the first wall surface flow path is wider on the first carrier disk side than on the second carrier disk side in the axial direction; 4. The planetary gear mechanism according to claim 3.

5. The carrier pillar channel is a first flow path portion having a discharge side opening in at least one of the first carrier disk and the second carrier disk and formed in the carrier post along the axial direction of the planetary gear; a second flow path portion formed from the first inlet side opening to the first flow path portion, 4. A planetary gear mechanism according to claim 3.

6. the planetary gear is rotatable in a second direction opposite to the first direction; the wall surface flow passage further includes a second wall surface flow passage formed between the carrier pillar and the planetary gear arranged on a second circumferential direction side of the carrier pillar opposite to the first circumferential direction, When the planetary gear rotates in the second direction, the lubricating oil flows into the second wall surface flow path, The carrier pillar flow path is formed in a second wall surface of the carrier pillar on the second circumferential direction side, and has a second inlet side opening into which the lubricating oil flows from the second wall surface flow path.

3. A planetary gear mechanism according to claim 2.

7. The planetary carrier includes: a first carrier disk supporting first ends of the plurality of shafts; a second carrier disk supporting second ends of the shafts opposite the first ends and disposed opposite the first carrier disk, the carrier posts connect the first carrier disk and the second carrier disk; the planetary gear has helical teeth, the rotation of the planetary gear in the second direction forces lubricating oil from the first carrier disc side to the second carrier disc side in the axial direction of the planetary gear, the second inlet side opening is formed in the second wall surface at a position closer to the second carrier disk than to the first carrier disk.

7. A planetary gear mechanism according to claim 6.

8. the second wall surface is inclined so that a distance between the planetary gear and the second wall surface in the second wall surface flow path is wider on the second carrier disk side than on the first carrier disk side in the axial direction.

8. A planetary gear mechanism according to claim 7.

9. The carrier pillar channel is a first flow path portion having a discharge side opening in at least one of the first carrier disk and the second carrier disk and formed in the carrier post along the axial direction of the planetary gear; a second flow path portion formed from the first inlet opening to the first flow path portion; a third flow path portion formed from the second inlet side opening to the first flow path portion, 9. A planetary gear mechanism according to claim 7 or 8.

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