Lubrication system and planetary gear mechanism

Abstract

To provide a planetary gear mechanism which can lubricate a tooth surface sufficiently to enable reduction of stirring loss.SOLUTION: A lubrication system 10 of a planetary gear mechanism 11 has a sun gear 22 including a helical tooth 22b. The lubrication system 10 includes a supply passage 61, a supply passage 62, and a controller 15. The supply passage 61 is disposed at one side of both sides of the sun gear 22 in a direction along a rotation axis O of the sun gear 22 and formed toward a tooth surface 22a of the sun gear 22. The supply passage 62 is disposed at the other side of both sides of the sun gear 22 and formed toward the tooth surface 22a of the sun gear 22. The controller 15 switches discharge of a lubrication oil to the tooth surface 22a of the sun gear 22 between the supply passage 61 and the supply passage 62 based on a rotation direction of the sun gear 22.SELECTED DRAWING: Figure 3

Description

[Technical Field]

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

[0002] In recent years, the need for electrification has led to a demand for high-speed rotation in planetary gear mechanisms used in transmissions, etc. Helical gears are used in planetary gear mechanisms to reduce noise caused by high-speed rotation and improve transmission torque.

[0003] In a planetary gear mechanism using helical gears as shown in Patent Document 1, the lubricating oil that lubricates the tooth surfaces flows along the rotation axis, so the lubricating oil is supplied from the upstream side in the flow direction. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-112127 Summary of the Invention [Problem to be solved by the invention]

[0005] However, in high-speed rotations where both forward and reverse rotations are frequently used, such as in construction machinery, supplying lubricant only in accordance with rotation of the helical gear in one direction can result in insufficient lubrication of the tooth surfaces when the helical gear is rotated in the opposite direction.On the other hand, if lubricant is supplied so that sufficient lubrication is achieved in both forward and reverse rotations, the amount of lubricant will be excessive, resulting in significant agitation loss.

[0006] The present disclosure aims to provide a lubrication system and planetary gear mechanism that can sufficiently lubricate the tooth surfaces and reduce stirring loss in a planetary gear mechanism using helical gears that are frequently used in both forward and reverse rotation. [Means for solving the problem]

[0007] A first aspect of the lubrication system according to the present disclosure is a lubrication system for a planetary gear mechanism having a helical gear, and includes a first lubricant supply passage, a second lubricant supply passage, and a controller. The first lubricant supply passage is disposed on one of both sides of the helical gear in a direction along the rotation axis of the helical gear and extends toward the tooth flanks of the helical gear. The second lubricant supply passage is disposed on the other of both sides of the helical gear and extends toward the tooth flanks of the helical gear. The controller switches the discharge of lubricant to the tooth flanks of the helical gear between the first lubricant supply passage and the second lubricant supply passage based on the rotation direction of the helical gear.

[0008] A planetary gear mechanism according to a second aspect of the present disclosure includes a first lubricating oil supply passage and a second lubricating oil supply passage. The first lubricating oil supply passage is disposed on one of the two sides of the helical gear in a direction along the rotation axis of the helical gear and extends toward the tooth flank of the helical gear. The second lubricating oil supply passage is disposed on the other side of the helical gear and extends toward the tooth flank of the helical gear. [Effects of the Invention]

[0009] According to the present disclosure, it is possible to provide a lubrication system and a planetary gear mechanism that can sufficiently lubricate the tooth surfaces and reduce stirring loss in a planetary gear mechanism using helical gears that are frequently used in both forward and reverse rotation. [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 2] FIG. 1 is a block diagram illustrating a lubrication system according to an embodiment of the present disclosure. [Figure 3] FIG. 2 is a cross-sectional view showing a planetary gear mechanism according to an embodiment of the present disclosure. [Figure 4] FIG. 4 is an enlarged view showing the vicinity of the sun gear in FIG. 3. [Figure 5] (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 6] 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 7] FIG. 4 is a flowchart illustrating a control operation of the lubrication system according to the embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0011] A planetary gear mechanism and a lubrication system having the planetary gear mechanism according to an embodiment of the present disclosure will be described with reference to the drawings. The planetary gear mechanism of 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 case 6, axles 7a and 7b, a pair of front tires 8, and a pair of rear 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 front tires 8 are connected to the front axle 7a. The pair of front tires 8 are rotated by the power from the engine 3 distributed to the front axle 7a. A pair of rear tires 9 are connected to the rear axle 7b. The pair of rear tires 9 are rotated by the power from the engine 3 distributed to the rear axle 7b.

[0015] The work machine 1 has a lubrication system 10 that lubricates the gears of a planetary gear mechanism 11. Figure 2 is a block diagram showing the configuration of the lubrication system 10. The lubrication system 10 has the planetary gear mechanism 11, a pump 12, a switching valve 13, a rotation sensor 14, and a controller 15.

[0016] The pump 12 supplies lubricating oil from a tank 16 that stores lubricating oil to the planetary gear mechanism 11. As will be described in detail later, the planetary gear mechanism 11 is provided with multiple supply paths that supply lubricating oil to the gears. The switching valve 13 switches the supply of lubricating oil between the multiple supply paths. 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.

[0017] (Planetary gear mechanism 11) FIG. 3 is a cross-sectional view showing the planetary gear mechanism 11 of this embodiment.

[0018] The planetary gear mechanism 11 comprises an input shaft 21 (an example of a first shaft), a sun gear 22 (an example of a helical gear), multiple planetary gears 23, a pinion shaft 24, a planetary carrier 25, a ring gear 26 (an example of a helical gear), a fixed member 27, an output shaft 28 (an example of a second shaft), and a housing 29.

[0019] 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. 3, 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 portion 112. The end portion 112 is arranged at the end of the main body 111 on the first direction A1 side. FIG. 4 is an enlarged view showing the vicinity of the sun gear 22. The end portion 112 is formed to be smaller than the outer diameter of the main body 111. A step is formed between the main body 111 and the end 112. The main body 111 has an end face 111a perpendicular to the central axis O at the step.

[0020] 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 dashed double-dashed lines in Figures 3 and 4. The helical teeth 22b are inclined with respect to the axis O.

[0021] As shown in FIG. 3, multiple planetary gears 23 are arranged around the sun gear 22. In this embodiment, three planetary gears 23 are provided, as shown in FIG. 5(a) described later. The planetary gears 23 are helical gears. As shown in FIG. 3, 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. 3. 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 around a direction parallel to the axis O.

[0022] 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. 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.

[0023] The planetary carrier 25 supports a plurality of pinion shafts 24. The plurality of pinion shafts 24 are fixed to the planetary carrier 25. 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.

[0024] The first carrier disk 31 is disk-shaped. 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.

[0025] 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.

[0026] The plurality of planetary gears 23 are disposed between the first carrier disk 31 and the second carrier disk 32. The plurality of carrier pillars 33 connect between the first carrier disk 31 and the second carrier disk 32. The carrier pillars 33 are disposed between the planetary gears 23 in the circumferential direction.

[0027] 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.

[0028] 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 second carrier boss 35.

[0029] The first carrier boss is rotatably supported by the housing 29 via a bearing 53. The second carrier boss is rotatably supported by the housing 29 via a bearing .

[0030] The ring gear 26 is disposed around the planetary gears 23. The ring gear 26 is annular. 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.

[0031] 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. The fixed member 27 meshes with teeth disposed on the outer periphery of the ring gear 26.

[0032] The output shaft 28 is disposed coaxially (on the central axis O) with the input shaft 21. The output shaft 28 is engaged 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 arranged in the housing 29. Each of the planetary carrier 25 and the second carrier disk 32 has a through hole formed 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.

[0033] The housing 29 accommodates the sun gear 22 , the plurality of planetary gears 23 , the pinion shaft 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 .

[0034] 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.

[0035] The first support portion 41 is disposed on the second direction A2 side of the first carrier disk 31. The first support portion 41 has a wall portion 411 and a protruding portion 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. The protruding portion 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 protruding portion 412. A bearing 51 is disposed between the inner wall of the through hole in the protruding portion and the input shaft 21. 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 in the wall portion 411 and the first carrier boss 34. This allows the first support portion 41 to rotatably support the first carrier boss 34.

[0036] 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.

[0037] 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.

[0038] 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 .

[0039] 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.

[0040] 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.

[0041] (Supply route 61~64) Next, a description will be given of the supply passages 61-64 that supply lubricating oil to the sun gear 22, the planetary gears 23, and the ring gear 26. The planetary gear mechanism 11 further has the supply passages 61-64.

[0042] The supply passage 61 is disposed on the second direction A2 side of the sun gear 22. The supply passage 61 is formed to discharge lubricating oil toward the tooth surface 22a of the sun gear 22. The supply passage 61 is disposed in the input shaft 21. As shown in FIG. 4 , the supply passage 61 includes a first portion 611, a plurality of second portions 612, and a plurality of third portions 613.

[0043] 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. 4, 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.

[0044] FIG. 5(a) 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 along the first direction A1. In FIG. 5(a) and FIG. 5(b) described later, the openings are enlarged for clarity. As shown in FIG. 5(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 surface 22a. The supply path 61 corresponds to an example of a first lubricating oil supply path. The openings 61a correspond to an example of a first discharge port.

[0045] The supply passage 62 is disposed on the first direction A1 side of the sun gear 22. The supply passage 62 is formed to discharge lubricating oil toward the tooth surface 22a of the sun gear 22. As shown in FIG. 3 , the supply passage 62 is disposed in the output shaft 28 and the housing 29. The supply passage 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. 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. 4. 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. 4, 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. 5(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. 5(b), the opening 62a is disposed at one location on the end face 28a of the output shaft 28.

[0046] 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 toward the tooth surface 22a. The supply path 62 corresponds to an example of a second lubricating oil supply path. The opening 62a corresponds to an example of a second discharge port.

[0047] The supply passage 63 is disposed on the second direction A2 side of the ring gear 26. The supply passage 63 is formed to discharge lubricating oil toward the tooth surface 26a of the ring gear 26. The supply passage 63 is disposed in the housing 29. The supply passage 63 is disposed in the wall portion 411 of the first support portion 41. The supply passage 63 is formed from the outer surface to the inner surface of the wall portion 411. The supply passage 63 is disposed parallel to the axis O. The supply passage 63 has an opening 63a on the inner surface of the wall portion 411. The opening 63a is disposed to face the inner helical teeth of the ring gear 26 in the direction along the axis O. The opening 63a is disposed to overlap with the tooth surface 26a when viewed along the first direction A1. As shown in FIG. 5(a), the opening 63a is provided, for example, at one location at the top of the tooth surface 26a of the ring gear 26. The supply passage 63 corresponds to an example of a first lubricant supply passage or a third lubricant supply passage. The opening 63a corresponds to an example of a first discharge port.

[0048] The supply passage 64 is disposed on the first direction A1 side of the ring gear 26. The supply passage 64 is formed to discharge lubricating oil toward the tooth surface 26a of the ring gear 26. The supply passage 64 is disposed in the housing 29. The supply passage 64 is disposed in the wall portion 421 of the second support portion 42. The supply passage 64 is formed from the outer surface to the inner surface of the second support portion 42. The supply passage 64 has a first portion 641 and a second portion 642. The first portion 641 is disposed perpendicular to the axis O from the outer peripheral surface of the wall portion 421 toward the inside (the direction of the axis O). The second portion 642 is disposed from the inner end of the first portion 641 toward the second direction A2. The second portion 642 has an opening 64a in the inner peripheral surface of the wall portion 421. The opening 64a is disposed to face the inner helical teeth of the ring gear 26 in the direction along the axis O. The opening 64a faces the opening 63a in the direction along the axis O. The opening 64a is arranged to overlap with the tooth surface 26a when viewed along the second direction A2. As shown in FIG. 5(b), the opening 64a is provided, for example, at one location on the uppermost part of the tooth surface 26a of the ring gear 26. The supply passage 64 corresponds to an example of a second lubricating oil supply passage or a fourth lubricating oil supply passage. The opening 64a corresponds to an example of a second discharge port.

[0049] (Switching valve 13) The switching valve 13 switches the supply path that supplies the lubricating oil sent from the pump 12 to the gears. 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 supply paths 61 and 63 of the planetary gear mechanism 11. The fourth pipe 74 is connected to the supply paths 62 and 64 of the planetary gear mechanism 11.

[0050] 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 supply paths 61 and 63 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 supply paths 62 and 64 of the planetary gear mechanism 11.

[0051] The planetary gear mechanism 11 and the tank 16 are connected by a fifth pipe line 75. As shown in FIGS. 2 and 3, the lubricating oil discharged from the planetary gear mechanism 11 is returned to the tank 16.

[0052] (Rotation sensor 14) The rotation sensor 14 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.

[0053] 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.

[0054] (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.

[0055] The controller 15 controls the switching valve 13 based on the detection information of the rotation sensor 14. When the controller 15 receives the detection information of the rotation sensor 14, it 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 supply path 61 and the supply path 63, or the supply path 62 and the supply path 64.

[0056] The rotation of the helical gear and the flow of lubricating oil will now be described. Fig. 6(a) is a schematic side view showing the state in which the sun gear 22 and the planetary gear 23 are meshed. To make the explanation easier to understand, the size and shape of the planetary gear 23 are different from those in Fig. 3. Fig. 6(b) is a schematic view of the sun gear 22 and the planetary gear 23 as viewed along the first direction A1.

[0057] When the sun gear 22 rotates in the direction of arrow L, which is counterclockwise as shown in Fig. 6(b), the shape of the helical teeth 22b of the sun gear 22 and the shape of the helical teeth 23b of the planetary gear 23 cause the lubricating oil to flow on the tooth surfaces 22a and 23a in the first direction A1 shown in Fig. 6(a). On the other hand, when the sun gear 22 rotates in the direction of arrow R, which is clockwise as shown in Fig. 6(b), the lubricating oil flows on the tooth surfaces 22a and 23a in the second direction A2.

[0058] Therefore, when the sun gear 22 rotates in the counterclockwise rotation direction L, the lubricating oil can be supplied from the second direction A2 side of the sun gear 22, which is the upstream side of the flow direction, toward the first direction A1, thereby allowing the lubricating oil to be constantly supplied onto the tooth surfaces 22a, 23a. When the sun gear 22 rotates in the clockwise rotation direction R, the lubricating oil can be supplied from the first direction A1 side of the sun gear 22, which is the upstream side of the flow direction, toward the second direction A2, thereby allowing the lubricating oil to be constantly supplied onto the tooth surfaces 22a, 23a.

[0059] Furthermore, between the ring gear 26 and the planetary gear 23, when the sun gear 22 rotates in the left rotation direction L, the lubricating oil flows in the first direction A1, and when the sun gear 22 rotates in the right rotation direction R, the lubricating oil flows in the second direction A2.

[0060] Therefore, when the controller 15 determines that the rotation direction of the sun gear 22 is the counterclockwise 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 from the opening 61a of the supply passage 61 located on the second direction A2 side of the sun gear 22 toward the tooth surface 22a of the sun gear 22. In addition, the lubricating oil supplied from the tank 16 by the pump 12 is discharged from the opening 63a of the supply passage 63 located on the second direction A2 side of the ring gear 26 toward the tooth surface 26a of the ring gear 26.

[0061] 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 and the fourth pipe line 74. As a result, the lubricating oil supplied from the tank 16 by the pump 12 is discharged from the opening 62a of the 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 lubricating oil supplied from the tank 16 by the pump 12 is discharged from the opening 64a of the supply passage 64 located on the first direction A1 side of the ring gear 26 toward the tooth surface 26a of the ring gear 26.

[0062] <Operation> Next, a description will be given of the control operation of the lubrication system 10 of this embodiment. Fig. 7 is a flow chart showing the control operation of the lubrication system 10 of this embodiment.

[0063] First, in step S101, the controller 15 drives the pump 12. Next, in step S102, the controller 15 receives the detection information of the rotation sensor .

[0064] 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.

[0065] If it is determined in step S103 that the rotation direction is the left rotation direction L, the control proceeds to step S104.

[0066] In step S104, the controller 15 drives the switching valve 13 to connect the second pipeline 72 and the third pipeline 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 from the opening 61a of the supply path 61 located on the second direction A2 side of the sun gear 22 toward the tooth surface 22a of the sun gear 22. In addition, the lubricating oil supplied from the tank 16 by the driving of the pump 12 is discharged from the opening 63a of the supply path 63 located on the second direction A2 side of the ring gear 26 toward the tooth surface 26a of the ring gear 26.

[0067] 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.

[0068] 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 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 lubricating oil supplied from the tank 16 by the driving of the pump 12 is discharged from the opening 64a of the supply passage 64 located on the first direction A1 side of the ring gear 26 toward the tooth surface 26a of the ring gear 26.

[0069] 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.

[0070] (Features, etc.) (1) The lubrication system 10 of this embodiment is a lubrication system 10 for a planetary gear mechanism 11 having a sun gear 22 (an example of a helical gear) including helical teeth 22b, and includes a supply path 61 (an example of a first lubricant supply path), a supply path 62 (an example of a second lubricant supply path), and a controller 15. The supply path 61 is disposed on one of both sides of the sun gear 22 in a direction along the rotation axis O of the sun gear 22, and is formed toward the tooth surface 22a of the sun gear 22. The supply path 62 is disposed on the other of both sides of the sun gear 22, and is formed toward the tooth surface 22a of the sun gear 22. The controller 15 switches the discharge of lubricant oil to the tooth surface 22a of the sun gear 22 between the supply path 61 and the supply path 62, based on the rotation direction of the sun gear 22.

[0071] By switching between supply path 61 and supply path 62 in accordance with the rotation of sun gear 22, an appropriate amount of lubricating oil can be supplied from the upstream side of the direction in which lubricating oil flows by sun gear 22, regardless of the direction in which sun gear 22 rotates. This allows sufficient lubrication of tooth surface 22a of sun gear 22, and reduces stirring loss.

[0072] (2) In the lubrication system 10 of the embodiment, the supply passage 61 has an opening 61a (an example of a first discharge port). The opening 61a is arranged to overlap with the tooth surface 22a of the sun gear 22 when viewed from the direction along the rotation axis O, and the lubricating oil is discharged through the opening 61a. The supply passage 62 has an opening 62a (an example of a second discharge port). The opening 62a is arranged to overlap with the tooth surface 22a of the sun gear 22 when viewed from the direction along the rotation axis O, and the lubricating oil is discharged through the opening 61a.

[0073] This allows the tooth surface 22a of the sun gear 22 to be lubricated by the lubricating oil discharged from the opening 61a or the opening 62a.

[0074] (3) The lubrication system 10 of the embodiment further includes an input shaft 21 (an example of a first shaft) and a plurality of planetary gears 23. A 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 supply passage 61 has a plurality of openings 61a through which lubricating oil is discharged. The plurality of openings 61a are arranged in the input shaft 21.

[0075] As a result, when the sun gear 22 rotates in the counterclockwise direction L, the space between the sun gear 22 and the planetary gears 23 can be lubricated by the lubricating oil.

[0076] (4) In the lubrication system 10 of the embodiment, the openings 61a are arranged at equal intervals in the circumferential direction. The number of the openings 61a is equal to or greater than the number of the planetary gears 23.

[0077] This allows sufficient lubricating oil to be supplied between the sun gear 22 and the plurality of planetary gears 23.

[0078] (5) The lubrication system 10 of the embodiment further includes a planetary carrier 25, a housing 29, and an output shaft 28 (an example of a second shaft). The planetary carrier 25 rotatably supports the plurality of planetary gears 23. The housing 29 rotatably supports the planetary carrier 25. The output shaft 28 is fixed to the planetary carrier 25 and is arranged coaxially with the input shaft 21. The supply passage 62 has an opening 62a through which lubricating oil is discharged. The opening 62a is arranged in the output shaft 28.

[0079] As a result, when the sun gear 22 rotates in the clockwise direction R, lubricating oil can be supplied between the sun gear 22 and the planetary gears 23.

[0080] (6) The lubrication system 10 of the embodiment further includes a plurality of planetary gears 23, a ring gear 26, a supply passage 63 (an example of a third lubricant supply passage), and a supply passage 64 (an example of a fourth lubricant supply passage). The plurality of planetary gears 23 are arranged around the sun gear 22 and mesh with the tooth surface 22a of the sun gear 22. The ring gear 26 is arranged around the plurality of planetary gears 23 and meshes with the plurality of planetary gears 23. The supply passage 63 is arranged on one of both sides of the ring gear 26 in the direction along the rotation axis O and is formed toward the tooth surface 26a of the ring gear 26. The supply passage 64 is arranged on the other side of the ring gear 26 and is formed toward the tooth surface 26a of the ring gear 26.

[0081] This allows an appropriate amount of lubricating oil to be supplied between the sun gear 22 and the multiple planetary gears 23, and between the multiple planetary gears 23 and the ring gear 26, regardless of whether the sun gear 22 rotates in the left rotation direction L or the right rotation direction R.

[0082] (7) The lubrication system 10 of this embodiment is a lubrication system 10 for a planetary gear mechanism 11 having a ring gear 26 (an example of a helical gear) with helical teeth, and includes a supply path 63 (an example of a first lubricant supply path), a supply path 64 (an example of a second lubricant supply path), and a controller 15. The supply path 63 is arranged on one of both sides of the ring gear 26 in a direction along the rotation axis O of the ring gear 26, and is formed toward the tooth surface 26a of the ring gear 26. The supply path 64 is arranged on the other of both sides of the ring gear 26, and is formed toward the tooth surface 26a of the ring gear 26. The controller 15 switches the discharge of lubricant to the tooth surface 26a of the ring gear 26 between the supply path 63 and the supply path 64 based on the rotation direction of the ring gear 26.

[0083] By switching between supply path 63 and supply path 64 in accordance with the rotation of ring gear 26, lubricating oil can be supplied from the upstream side of the direction in which lubricating oil flows by ring gear 26, regardless of the direction in which ring gear 26 rotates. This allows sufficient lubrication of tooth surface 26a of ring gear 26, making it possible to reduce stirring loss.

[0084] (8) In the lubrication system 10 of the embodiment, the supply passage 63 is arranged to overlap the tooth surface 26a of the ring gear 26 when viewed from the direction along the rotation axis O, and has an opening 63a (an example of a first discharge port) through which the lubricating oil is discharged. The supply passage 64 is arranged to overlap the tooth surface 26a of the ring gear 26 when viewed from the direction along the rotation axis O, and has an opening 64a (an example of a second discharge port) through which the lubricating oil is discharged.

[0085] This allows the tooth surface 26a of the ring gear 26 to be lubricated by the lubricating oil discharged from the opening 63a or the opening 64a.

[0086] (9) The lubrication system 10 of the embodiment further includes a sun gear 22, a plurality of planetary gears 23, a planetary carrier 25, and a housing 29. The plurality of planetary gears 23 are arranged around the sun gear 22 and mesh with the sun gear 22. The planetary carrier 25 rotatably supports the plurality of planetary gears 23. A ring gear 26 (an example of a helical gear) is arranged around the plurality of planetary gears 23 and meshes with the plurality of planetary gears 23. The supply passage 63 and the supply passage 64 are each arranged in the housing 29.

[0087] This allows sufficient lubrication between the ring gear 26 and the planetary gears 23.

[0088] (10) The planetary gear mechanism 11 of this embodiment includes a supply passage 61 (an example of a first lubricating oil supply passage) and a supply passage 62 (an example of a second lubricating oil supply passage). The supply passage 61 is arranged on one of both sides of the sun gear 22 (an example of a helical gear) in a direction along the rotation axis O of the sun gear 22, and is formed toward the tooth surface 22a of the sun gear 22. The supply passage 62 is arranged on the other of both sides of the sun gear 22, and is formed toward the tooth surface 22a of the sun gear 22.

[0089] By discharging lubricating oil from either supply path 61 or supply path 62 in accordance with the rotation of sun gear 22, regardless of the direction of rotation of sun gear 22, it is possible to supply lubricating oil from the upstream side of the direction in which the lubricating oil flows due to sun gear 22. This makes it possible to sufficiently lubricate tooth surface 22a of sun gear 22 and reduce stirring loss.

[0090] (11) The planetary gear mechanism 11 of this embodiment includes a supply passage 63 (an example of a first lubricating oil supply passage) and a supply passage 64 (an example of a second lubricating oil supply passage). The supply passage 63 is arranged on one of both sides of the ring gear 26 (an example of a helical gear) in the direction along the rotation axis O of the ring gear 26, and is formed toward the tooth surface 26a of the ring gear 26. The supply passage 64 is arranged on the other of both sides of the ring gear 26, and is formed toward the tooth surface 26a of the ring gear 26.

[0091] By discharging lubricating oil from either supply path 63 or supply path 64 in accordance with the rotation of ring gear 26, regardless of the direction of rotation of ring gear 26, lubricating oil can be supplied from the upstream side of the direction in which lubricating oil flows due to ring gear 26. This allows sufficient lubrication of tooth surface 26a of ring gear 26, making it possible to reduce stirring loss.

[0092] <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.

[0093] (A) In the above embodiment, the supply channel 61 has three openings 61a, but this is not limitative and the number may be four or more, or two or less.

[0094] Although the supply path 62 has only one opening 62a, the present invention is not limited to this and may have a plurality of openings 62a.

[0095] (B) In the above embodiment, the lubricating oil is discharged from one opening 63a on the first direction A1 side to the tooth surface 26a of the ring gear 26, but the lubricating oil may be discharged from multiple openings. Also, the lubricating oil is discharged from one opening 64a on the second direction A2 side to the tooth surface 26a of the ring gear 26, but the lubricating oil may be discharged from multiple openings.

[0096] (C) In the above embodiment, the openings 61a and 62a are arranged to overlap with the tooth surface 22a of the sun gear 22 when viewed along the axis O, but this is not limiting. It is sufficient that the lubricating oil discharged from the openings 61a and 62a is supplied to the tooth surface 22a.

[0097] Furthermore, the openings 63a and 64a are arranged so as to overlap with the tooth surface 26a of the ring gear 26 when viewed along the axis O, but this is not limitative. It is sufficient that the lubricating oil discharged from the openings 63a and 64a is supplied to the tooth surface 26a.

[0098] (D) 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.

[0099] (E) In the planetary gear mechanism 11 of the above embodiment, three planetary gears 23 are arranged, but this is not limitative and four or more planetary gears may be arranged.

[0100] (F) 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 tracks. [Industrial Applicability]

[0101] The lubrication system and planetary gear mechanism of the present disclosure can provide the effect of sufficiently lubricating the tooth surfaces and reducing stirring loss. [Explanation of symbols]

[0102] 10: Lubrication system 15: Controller 22: Sun gear 22a: Tooth surface 61: Supply route 62: Supply route

Claims

1. 1. A lubrication system for a planetary gear mechanism having helical gears, comprising: a first lubricating oil supply passage disposed on one of both sides of the helical gear in a direction along the rotation axis of the helical gear and formed toward a tooth surface of the helical gear; a second lubricating oil supply passage disposed on the other of the two sides of the helical gear and formed toward the tooth surface of the helical gear; a controller that switches the discharge of lubricating oil onto the tooth surfaces of the helical gear between the first lubricating oil supply path and the second lubricating oil supply path based on a rotation direction of the helical gear.

2. the first lubricant oil supply passage has a first discharge port from which the lubricant oil is discharged, the first discharge port is arranged to overlap with the tooth surface of the helical gear when viewed from a direction along the rotation shaft, the second lubricant supply passage has a second discharge port from which the lubricant is discharged, the second discharge port is disposed so as to overlap with the tooth surface of the helical gear in a direction along the rotation axis. The lubrication system of claim 1 .

3. a first shaft to which the helical gear is fixed as a sun gear; a plurality of planetary gears arranged around the helical gear and meshing with the tooth surfaces of the helical gear; the first lubricant supply passage has a plurality of first discharge ports from which the lubricant is discharged, the plurality of first outlet ports are arranged in the first shaft; The lubrication system of claim 1 .

4. The first discharge ports are arranged at equal intervals in the circumferential direction, the number of the first discharge ports is equal to or greater than the number of the planetary gears; The lubrication system of claim 3 .

5. a planetary carrier that rotatably supports the plurality of planetary gears; a housing that rotatably supports the planetary carrier; a second shaft fixed to the planetary carrier and arranged coaxially with the first shaft, the second lubricant supply passage has a second discharge port from which the lubricant is discharged, The second outlet is disposed in the second shaft. The lubrication system of claim 3 .

6. a plurality of planetary gears arranged around the helical gear serving as a sun gear and meshing with the tooth surfaces of the helical gear; a ring gear disposed around the plurality of planetary gears and meshing with the plurality of planetary gears; a third lubricating oil supply passage disposed on one of both sides of the ring gear in a direction along the rotation axis and formed toward a tooth surface of the ring gear; a fourth lubricating oil supply passage disposed on the other of the two sides of the ring gear and formed toward the tooth surface of the ring gear, the controller switches the discharge of lubricating oil onto the tooth surface of the helical gear between the third lubricating oil supply path and the fourth lubricating oil supply path based on the rotation direction of the helical gear. The lubrication system of claim 1 .

7. Sun gear and a plurality of planetary gears arranged around the sun gear and meshing with the sun gear; a planetary carrier that rotatably supports the plurality of planetary gears; a housing that rotatably supports the planetary carrier, the helical gear is disposed around the plurality of planetary gears and meshes with the plurality of planetary gears; The first lubricant supply passage and the second lubricant supply passage are each disposed in the housing. The lubrication system of claim 1 .

8. A planetary gear mechanism having a helical gear, a first lubricating oil supply passage disposed on one of both sides of the helical gear in a direction along the rotation axis of the helical gear and formed toward a tooth surface of the helical gear; a second lubricating oil supply passage disposed on the other of the two sides of the helical gear and formed toward the tooth surface of the helical gear, the first lubricant oil supply passage has a first discharge port from which the lubricant oil is discharged, the first discharge port is arranged to overlap with the tooth surface of the helical gear when viewed from a direction along the rotation shaft, the second lubricant supply passage has a second discharge port from which the lubricant is discharged, the second discharge port is disposed so as to overlap with the tooth surface of the helical gear in a direction along the rotation axis, the first discharge port is open along the rotation axis so as to face the tooth surface, The second discharge port is open along the rotation axis so as to face the tooth surface. Planetary gear mechanism.

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