Vehicles of travel

Abstract

DEPCT65 The objective is to provide a mode of transportation that can prevent wear and tear on the ring. The synchronizer, even when the synchronizer ring is not immersed in the vehicle oil (1), includes: Engine (3); gearbox (5), which is the enclosure that houses the gears for transmitting power from the engine; and the supply pipe. Oil (60) which is placed in the space for the cover of the gearbox housing, the oil supply pipe that supplies oil from From the outside of the gearbox housing to the inside of the gearbox housing, the power transmission device incorporates the gear teeth and synchronizer rings. The oil filler(28) that comes into contact with the gear tube includes: the main tubular body(62) which contains the oil. Recirculating; oil discharge port (64) in which oil is discharged; and pilot section (66) which is used to guide the oil. The oil is discharged from the drain port to the area between the gear teeth and the synchronizer ring. -----------------------------------------------------------

Description

Vehicles in motion

[0001] The present invention relates to a traveling vehicle.

[0002] Conventionally, a vehicle equipped with a case that houses an engine and a power transmission device that transmits power from the engine has been widely known (see Patent Document 1). The power transmission device is, for example, a forward / reverse switching device that switches the vehicle between forward and reverse. The power transmission device has a gear and a synchronizer ring that contacts the gear. When the driver switches gears, the shifter pushes the synchronizer ring toward the gear, causing the gear and the synchronizer ring to come into contact. Friction generated by this contact causes the rotational speeds of the gear and the synchronizer ring to match, and rotation of the shaft is transmitted to the gear via the synchronizer ring.

[0003] Generally, oil (transmission oil) is stored in the case. By immersing at least a portion of the power transmission device (especially the synchronizer ring) in oil, the oil gets into the gap between the gear and the synchronizer ring. The oil reduces friction between the gear and the synchronizer ring, suppressing wear on the synchronizer ring.

[0004] Japanese Patent Application Laid-Open No. 2004-168228

[0005] The oil in the case becomes very hot when the vehicle is driven, so if there is a large amount of oil, there is a problem that damage from heat increases and costs increase.On the other hand, if there is a small amount of oil, the synchronizer ring located at the top of the case becomes less immersed in oil, which increases the risk of wear on the synchronizer ring.

[0006] Therefore, an object of the present invention is to provide a running vehicle that can suppress wear of a synchronizer ring even when the synchronizer ring is not immersed in oil.

[0007] A traveling vehicle according to the present disclosure includes an engine, a case that houses a power transmission device that transmits power from the engine, and a supply pipe disposed in the housing space of the case and that supplies oil from the outside of the case to the inside of the case. The power transmission device includes a gear and a synchronizer ring that contacts the gear. The supply pipe has a tubular main body through which the oil flows, an outlet through which the oil is discharged, and a guide portion that guides the oil discharged from the outlet to between the gear and the synchronizer ring. According to this aspect, the oil supplied by the supply pipe is guided between the gear and the synchronizer ring by the guide portion, so that the oil is applied to the contact surface of the synchronizer ring that contacts the gear. Therefore, even when the synchronizer ring is not immersed in oil, lubrication between the gear and the synchronizer ring can be maintained, and wear of the synchronizer ring can be suppressed.

[0008] According to a preferred aspect, the guide portion is cylindrical. The guide portion extends from the main body portion toward a gap between the gear and the synchronizer ring. The discharge port is provided at an end of the guide portion in the extending direction. The guide portion discharges oil from the discharge port facing the gear in the extending direction of the guide portion. Because the guide portion extends toward a gap between the gear and the synchronizer ring, the discharged oil can be accurately applied between the gear and the synchronizer ring. This makes it possible to maintain lubrication between the gear and the synchronizer ring.

[0009] According to a preferred embodiment, the outlet is positioned above the central axis of the shaft on which the gear is mounted, thereby allowing oil to be applied to the upper side of the gear, which is less likely to be immersed in oil, and maintaining lubrication between the gear and the synchronizer ring.

[0010] According to a preferred embodiment, the main body extends in a vertical direction so as not to overlap the central axis of the shaft. In a cross section perpendicular to the central axis of the shaft, the extension direction of the guide portion is inclined with respect to the vertical direction so that the angle between the extension direction of the guide portion and an imaginary line passing through the center of the outlet and the central axis of the shaft is less than 30 degrees. This allows oil to be discharged toward the gear axis (i.e., the central axis of the shaft) when the main body and the central axis of the main shaft do not overlap. This makes it easier for oil to reach not only the radially outer contact surface between the gear and the synchronizer ring, but also the radially inner contact surface between the gear and the synchronizer ring. This makes it easier to lubricate the contact surface between the gear and the synchronizer ring.

[0011] According to a preferred aspect, the power transmission device includes a mechanical forward / reverse switching device that switches the traveling vehicle between forward and reverse. The gear is a gear of the forward / reverse switching device. When performing work using the traveling vehicle (e.g., agricultural work), switching between forward and reverse occurs frequently, so the number of gear changes of the forward / reverse switching device is greater than the number of gear changes of the transmission. For this reason, the synchronizer ring that contacts the gear of the forward / reverse switching device is more susceptible to wear than the synchronizer ring that contacts the gear of the transmission. Therefore, by guiding oil between the gear of the forward / reverse switching device and the synchronizer ring, wear of the synchronizer ring, which is more susceptible to wear, can be suppressed.

[0012] According to a preferred aspect, the forward / reverse switching device includes a forward gear and a reverse gear as the gears. The synchronizer ring includes a first synchronizer ring that contacts the forward gear and a second synchronizer ring that contacts the reverse gear. The guide portion includes a first guide portion that guides the oil between the forward gear and the first synchronizer ring, and a second guide portion that guides the oil between the reverse gear and the second synchronizer ring. Because oil is applied to both the first synchronizer ring that contacts the forward gear and the second synchronizer ring that contacts the reverse gear, wear on both synchronizer rings can be suppressed.

[0013] According to a preferred embodiment, the vehicle includes a transmission that changes the speed of power from the engine and transmits it to the drive wheels. The case includes a first housing chamber that houses the forward / reverse switching device, a second housing chamber that houses the transmission, and a case wall portion that is located between the first housing chamber and the second housing chamber and separates the first housing chamber from the second housing chamber. The supply pipe supplies the oil to the first housing chamber. While the oil is being supplied, the oil level in the first housing chamber becomes higher than before the oil was supplied. This makes it easier for at least a portion of the synchronizer ring of the forward / reverse switching device to be immersed in oil. As a result, wear on the synchronizer ring can be further reduced.

[0014] According to a preferred aspect, the case wall has an opening penetrating the first housing chamber and the second housing chamber. The vehicle has a shaft disposed in the first housing chamber and rotated by power from the engine, and a bearing into which the shaft is inserted. The bearing is fixed to the case wall so as to close the opening. Because the bearing is fixed so as to close the opening, the flow rate of oil flowing from the first housing chamber to the second housing chamber through the opening is limited. This makes it easier for oil to accumulate in the first housing chamber even though the case wall has an opening, and makes it easier for at least a portion of the synchronizer ring of the forward / reverse switching device to be immersed in oil. As a result, wear on the synchronizer ring can be further suppressed.

[0015] According to a preferred embodiment, the bearing has an inner ring, an outer ring, rolling elements, and a seal portion that seals the gap between the inner ring and the outer ring. This makes it more difficult for oil to pass between the inner ring and the outer ring compared to a bearing without a seal portion, further limiting the flow rate of oil flowing from the first housing chamber to the second housing chamber. This makes it easier to store oil in the first housing chamber, making it easier for at least a portion of the synchronizer ring of the forward / reverse switching device to be immersed in oil. As a result, wear on the synchronizer ring can be further suppressed.

[0016] According to a preferred embodiment, the seal is disposed closer to the first housing chamber than the rolling elements. Because oil accumulates closer to the first housing chamber than the seal, it is easier for oil to accumulate in the first housing chamber, and at least a portion of the gear of the forward / reverse switching device is more likely to be immersed in oil, compared to when the seal is located farther from the rolling elements. As a result, wear on the synchronizer ring can be further reduced.

[0017] According to a preferred embodiment, the openings include a first opening to which the bearing without the seal is fixed and a second opening to which the bearing with the seal is fixed. The first opening is located below the second opening. This improves oil circulation between the first and second housing chambers in the lower area where oil is likely to accumulate.

[0018] According to a preferred embodiment, the opening further includes a third opening to which the bearing without the seal is fixed. The third opening is located above the second opening. This allows oil to flow more easily into the second housing chamber through the third opening than through the second opening. This prevents excessive oil from accumulating in the first housing chamber.

[0019] According to a preferred embodiment, the openings include a fourth opening disposed above the synchronizer ring. The fourth opening is open without the bearing being fixed thereto. This allows oil accumulated above the synchronizer ring to more easily flow into the second housing chamber. This prevents more oil than necessary from accumulating in the first housing chamber.

[0020] FIG. 1 is a left side view of a traveling vehicle according to an embodiment. FIG. 2 is a perspective view of a control device according to an embodiment, viewed from the upper left rear side. FIG. 3 is a rear view of the control device according to an embodiment. FIG. 4 is a rear view of the control device according to an embodiment. FIG. 5 is a left side view of the control device according to an embodiment. FIG. 6 is a left side view of the control device according to an embodiment. FIG. 7 is an enlarged view of a shuttle lever and a guide plate according to an embodiment. FIG. 8 is an enlarged view of a guide plate according to an embodiment. FIG. 9 is an enlarged view of a steering unit according to an embodiment. FIG. 10 is a B-B cross-sectional view of the case according to an embodiment in FIG. 11. FIG. 11 is an A-A cross-sectional view of the case according to an embodiment in FIG. 10. FIG. 12 is a CC cross-sectional view of the case according to an embodiment in FIG. 10. FIG. 13 is a D-D cross-sectional view of the case according to an embodiment. FIG. 14 is a perspective view for explaining a bearing according to an embodiment. FIG. 15 is a diagram for explaining the movement of a transmission unit. FIG. 16 is a diagram for explaining the movement of a transmission unit.

[0021] Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. In the following description of the drawings, identical or similar parts are designated by identical or similar reference numerals. However, it should be noted that the drawings are schematic, and the dimensional ratios and the like may differ from those of the actual parts. Therefore, specific dimensions and the like should be determined with reference to the following description. Furthermore, parts in the drawings may have different dimensional relationships and ratios. In this specification and the drawings, elements having substantially the same functions and configurations are designated by the same reference numerals to avoid redundant description, and elements not directly related to the present invention are not shown.

[0022] (1) Schematic Configuration of Traveling Vehicle 1 The schematic configuration of the traveling vehicle 1 will be described mainly in Fig. 1 and Fig. 2. Fig. 1 is a side view of the traveling vehicle according to the embodiment. Fig. 2 is a perspective view of the steering device according to the embodiment as seen from the upper left rear side. In this embodiment, a tractor is exemplified as the traveling vehicle 1.

[0023] Arrow X shown in the drawings indicates the width direction of the traveling vehicle 1, arrow Y indicates the front-rear direction of the traveling vehicle 1, and arrow Z indicates the up-down direction of the traveling vehicle 1. Arrow X1 indicates the right direction of the traveling vehicle 1, and arrow X2 indicates the left direction of the traveling vehicle 1. Arrow Y1 indicates the forward direction (forward direction) of the traveling vehicle 1, and arrow Y2 indicates the rearward direction (reverse direction) of the traveling vehicle 1. Arrow Z1 indicates the upward direction of the traveling vehicle 1, and arrow Z2 indicates the downward direction of the traveling vehicle 1. The direction from the center of the traveling vehicle 1 in the width direction X to the right or left is referred to as the outward direction, and the direction from the right or left side of the traveling vehicle 1 in the width direction X to the center is referred to as the inward direction. Therefore, the center of the traveling vehicle 1 in the width direction X is sometimes referred to as the "inner side of the vehicle," and the right and left sides of the center in the width direction X are sometimes referred to as the "outer side of the vehicle."

[0024] As shown in Figures 1 and 2, the traveling vehicle 1 has a vehicle body 2 that can travel. The vehicle body 2 has an engine 3, a case 5, a case cover member 6, and a steering device 10. The engine 3 is a diesel engine. The engine 3 is located at the front of the traveling vehicle 1 and is covered by a hood. The engine 3 may be an electric motor or a hybrid type having a diesel engine and an electric motor. The case 5 has a flywheel housing, a clutch housing, and a transmission case. The flywheel housing is connected to the rear of the engine 3 and houses a flywheel. The clutch housing is connected to the rear of the flywheel housing and houses a clutch that intermittently transmits the power of the engine 3 transmitted via the flywheel. The transmission case is connected to the rear of the clutch housing. The case 5 houses a power transmission device that transmits power from the engine 3. The power transmission device may include a forward / reverse switching device 20 and a transmission 30. In this embodiment, the case 5 houses a forward / reverse switching device 20 that switches the traveling vehicle between forward and reverse, and a transmission 30 that changes the speed of power from the engine 3 and transmits it to the drive wheels. The forward / reverse switching device 20 has a forward gear 25 and a reverse gear 26 as gears. The case 5 is disposed below the steering device 10 in the up-down direction Z.

[0025] The case cover member 6 covers the upper part of the case 5. When viewed from above the vehicle, the case cover member 6 has a main body portion 6a that overlaps with the upper part of the case 5, and side portions 6b that are arranged outside the main body portion 6a in the width direction X. The upper surface of the main body portion 6a is located higher than the upper surfaces of the side portions 6b (see Figures 2-4). The driver's feet are placed on the case cover member 6. The case cover member 6 is located forward of the driver's seat 9 in the fore-and-aft direction Y. It is also located rearward of the control console 12 in the fore-and-aft direction Y.

[0026] As shown in FIG. 1 , the traveling vehicle 1 has a traveling device 8 that supports a body 2 so that it can travel. The traveling device 8 is a wheel-type traveling device that has a plurality of front wheels 8A provided at the front of the body 2 and a plurality of rear wheels 8B provided at the rear of the body 2. The plurality of front wheels 8A include a left front wheel supported on the left side of a front axle case supported in front of the engine 3, and a right front wheel supported on the right side of the front axle case. The plurality of rear wheels 8B include a left rear wheel supported on the left side of a case 5 (such as a transmission case), and a right rear wheel supported on the right side of the case 5. The traveling device 8 may be a semi-crawler type traveling device (a traveling device that has the front wheels 8A and a crawler-type traveling mechanism used instead of the rear wheels 8B).

[0027] The front wheels 8A are steerable wheels that can be steered by moving the cylinder rod of a steering cylinder arranged in front of the front axle case. By steering the front wheels 8A, the direction of the vehicle body 2 can be changed (the vehicle body can be steered). The steering cylinder is composed of a hydraulic cylinder. Of the front wheels 8A and rear wheels 8B, at least the rear wheels 8B are drive wheels, and power output from the transmission 30 is transmitted to the drive wheels. A driver's seat 9 where the driver sits is mounted at the rear of the vehicle body 2. A control device 10, partially covered by a control cover 11, is provided in front of the driver's seat 9.

[0028] (2) Details of the Steering Device 10 and the Forward / Reverse Switching Device 20 Details of the steering device 10 and the forward / reverse switching device 20 will be described mainly with reference to FIGS. 3 to 11 . FIGS. 3 and 4 are rear views of the steering device according to the embodiment. However, in FIG. 4 , some components (such as the case cover member 6, pedal 17, support pipe 18, and cover member 124) are omitted from FIG. 3 . FIGS. 5 and 6 are left side views of the steering device according to the embodiment. In FIG. 6 , some components (such as the case cover member 6, pedal 17, support pipe 18, and cover member 124) are omitted from FIG. 5 . FIG. 7 is an enlarged view of a shuttle lever and a guide plate according to the embodiment. FIG. 8 is an enlarged view of a guide plate according to the embodiment. FIG. 9 is an enlarged view of a steering unit according to the embodiment. FIG. 10 is a cross-sectional view of the case according to the embodiment taken along line B-B in FIG. 11 . FIG. 11 is a cross-sectional view of the case according to the embodiment taken along line A-A in FIG. 10 . FIG. 12 is a cross-sectional view of the case according to the embodiment taken along line C-C in FIG. 10 . FIG. 13 is a cross-sectional view of the case according to the embodiment taken along line D-D in FIG. 10 . Fig. 14 is a perspective view for explaining a bearing according to an embodiment. Fig. 15 is a diagram for explaining the movement of a transmission part. Fig. 16 is a diagram for explaining the movement of a transmission part. It should be noted that in each figure, some members may be omitted as appropriate.

[0029] As shown in FIGS. 1-6 , the control device 10 includes a control console 12, a shuttle lever 13, a guide plate 14, a transmission unit 15, a steering unit 16, pedals 17, and a support pipe 18. As shown in FIG. 1 , the control console 12 includes a fixed bracket 122 and a cover member 124. The fixed bracket 122 is erected on the vehicle body 2 (case 5). The transmission unit 15 and the steering unit 16 are supported by the fixed bracket 122. As shown in FIG. 3 , the fixed bracket 122 includes a first side wall 1221 and a second side wall 1222 facing the first side wall. The first side wall 1221 and the second side wall 1222 are disposed outward of the transmission unit 15 in the width direction X. The first side wall 1221 and the second side wall 1222 are plate-shaped members extending in the up-down direction Z.

[0030] The first side wall 1221 and the second side wall 1222 are arranged side by side in the width direction X (arranged opposite each other in the width direction X). The first side wall 1221 is arranged on the left side of the center of the vehicle body 2 in the width direction X, and the second side wall 1222 is arranged on the right side of the center of the vehicle body 2 in the vehicle width direction. The first side wall 1221 and the second side wall 1222 are connected by a first connecting member 1223 and a second connecting member 1224.

[0031] The left end of the first connecting member 1223 is fixed to the first side wall 1221, and the right end of the first connecting member 1223 is fixed (connected) to the second side wall 1222. The first connecting member 1223 has a through-hole 1223a through which the steering post 164 passes, and the steering controller 166 is fixed thereto.

[0032] The left end of the second connecting member 1224 is fixed to the first side wall 1221, and the right end of the second connecting member 1224 is fixed (connected) to the second side wall 1222. The second connecting member 1224 secures the first side wall 1221 and the second side wall 1222 at the front portions of the first side wall 1221 and the second side wall 1222, respectively.

[0033] The fixed bracket 122 has a third side wall 1225 that supports the oil tank 168. The third side wall 1225 is fixed to an upper part of the second side wall 1222. The fixed bracket 122 has a fixed plate 1226. A through hole is formed in the fixed plate 1226. The transmission unit 15 (specifically, the shuttle shaft 152 and the support cylinder 153) is inserted into the through hole. The fixed plate 1226 is fixed to the first side wall 1221. The cover member 124 covers the rear side of the steering controller 166. The cover member 124 is connected to the first side wall 1221 and the second side wall 1222.

[0034] The shuttle lever 13 is a member that switches the traveling direction of the vehicle body 2. By operating the shuttle lever 13 forward or backward, the operation of the shuttle lever 13 is transmitted to the forward / reverse switching device 20 via the transmission unit 15. This switches the traveling direction (travel direction) of the vehicle body 2 between the forward direction and the reverse direction. As shown in FIGS. 3 to 8, the shuttle lever 13 has a lever body 131 and a grip 132 connected to an upper end 131a of the lever body 131.

[0035] The guide plate 14 guides the shuttle lever 13. The guide plate 14 is a single plate-shaped member. The guide plate 14 is rectangular in top view (see FIG. 8 ). The guide plate 14 extends in the width direction X. The guide plate 14 has a guide hole 142 and an insertion hole 144. The guide hole 142 is a hole into which the shuttle lever 13 (the lower end 131b of the lever main body 131) is inserted, and is a through-hole that passes through the guide plate 14. By combining the guide hole 142 and the insertion hole 144 in a single guide plate 14, the space required for the control device 10 can be saved.

[0036] When viewed from above on the guide plate 14, the guide hole 142 has an arc-shaped arc portion 142A and a protrusion 142B that protrudes in the width direction X from the center of the arc portion 142A in the front-rear direction Y. The insertion hole 144 is a through-hole that penetrates the guide plate 14 and into which the transmission part 15 is inserted. By inserting the transmission part 15 into the insertion hole 144, the transmission part 15 can be fixed. The insertion hole 144 is located more inward in the width direction X than the guide hole 142.

[0037] As shown in FIGS. 3 to 8 , the guide plate 14 extends from the inside to the outside in the width direction X. An end 141 of the guide plate 14 in the width direction X is located outside the first side wall 1221 in the width direction X. This ensures the length of the guide plate 14 in the width direction X even if the length in the width direction X from the first side wall 1221 to the second side wall 1222 is reduced to increase the space under the driver's feet. Therefore, the space under the driver's feet can be increased without affecting the operation of the shuttle lever 13. The arc portion 142A may be located outside the first side wall 1221.

[0038] The guide plate 14 is supported by a support member 145. The guide plate 14 is fixed to the support member 145. As a result, the position of the guide plate 14 is not fixed via a side wall (e.g., the first side wall 1221) that constitutes the control device 10. Therefore, the position of the guide plate 14 can be freely designed without being affected by the position of the first side wall 1221. Furthermore, the support member 145 extends from the support body 146 to the control device 10. Therefore, the guide plate 14 is not fixed via a side wall (e.g., the first side wall 1221) that constitutes the control device 10. Therefore, the guide plate 14 is not composed of a member that is fixed to the first side wall 1221 and extends in the up-down direction Z. Therefore, the position of the guide plate 14 can be freely designed without being affected by the position of the first side wall 1221.

[0039] Generally, when an existing guide plate is fixed to the first side wall 1221, the guide plate is usually composed of a first portion extending upward in the vertical direction Z from the first side wall 1221, and a second portion extending inward in the width direction X from the upper end of the first portion. Therefore, in order to ensure the length of the second portion that guides the shuttle lever, the length in the width direction X from the first side wall 1221 to the second side wall 1222 cannot be made shorter than necessary.

[0040] On the other hand, because the guide plate 14 according to this embodiment is not fixed to the first side wall 1221, it can extend further outward in the width direction X than the first side wall 1221. Therefore, even if the length in the width direction X from the first side wall 1221 to the second side wall 1222 is reduced in order to increase the space under the driver's feet, the length of the guide plate 14 in the width direction X can be ensured. This allows the space under the driver's feet to be increased without affecting the operation of the shuttle lever 13.

[0041] The support member 145 is fixed to a support body 146 located forward of the steering device 10 in the front-to-rear direction Y. The support body 146 is disposed inside the hood. The support body 146 is not fixed to the case 5. The support member 145 has a first support member 145A to which the guide plate 14 is directly fixed, and a second support member 145B that supports the guide plate 14 via the first support member 145A.

[0042] The first support member 145A is a plate-shaped member. The first support member 145A has, at its rear side in the front-rear direction Y, a first end 145Ae1 that is arc-shaped and extends along the steering post 164, and a second end 145Ae2 that extends from the first end 145Ae1 in the rear direction Y2 (see FIG. 8 ). The first support member 145A may abut against the steering post 164. The left side 145AL of the first support member 145A is longer in the front-rear direction Y than the right side 145AR. As a result, even if a force in the right direction X1 is applied to the guide plate 14 by operating the shuttle lever 13, for example, the right side 145AR (second end 145Ae2) abuts against the steering post 164, preventing the guide plate 14 from moving. Therefore, the guide plate 14 can be firmly fixed. Furthermore, the outer end of the right side 145AR in the width direction X extends rearward in the front-rear direction Y. As a result, even if a force in the left direction X2 is applied to the guide plate 14, the right side portion 145AR comes into contact with the steering post 164, so that the guide plate 14 can be prevented from moving.

[0043] The guide plate 14 is fixed to the first support member 145A on the inside in the width direction X. Specifically, the first support member 145A is fixed to the guide plate 14 with bolts and nuts on the outside in the width direction X. Therefore, the guide plate 14 is fixed above the left side portion 145AL of the first support member 145A. The first support member 145A is fixed to the second support member 145B with bolts and nuts in front of the first support member 145A.

[0044] The second support member 145B is a member extending in the front-rear direction Y. The second support member 145B is fixed to the first support member 145A by bolts and nuts at a rear portion of the second support member 145B. The second support member 145B is fixed to the support body 146 by bolts and nuts at a front portion of the second support member 145B.

[0045] 4, 6, 15, 16, etc., the transmission unit 15 is a member that transmits the operation of the shuttle lever 13 to the forward / reverse switching device 20. In the longitudinal direction Y, the transmission unit 15 is located forward of the cover member 124. This makes it possible to further increase the space under the driver's feet.

[0046] The transmission unit 15 has a mounting member 151, a shuttle shaft 152, a support cylinder 153, an interlocking rod 154, a connecting member 155, a shuttle arm 156, and an engaging portion 157. The mounting member 151 is a member attached to the shuttle lever 13. Specifically, the lever body 131 is fixed to the left end of the mounting member 151. Specifically, the lever body 131 is fixed to the left end of the mounting member 151. The mounting member 151 is supported on the shuttle shaft 152 by a bolt and a nut. The mounting member 151 (i.e., the shuttle lever 13) can swing in the up-down direction Z around the bolt as an axis.

[0047] The shuttle shaft 152 can be rotated around the axial advance direction by the shuttle lever 13. An upper portion 152A of the shuttle shaft 152 protrudes upward from the support cylinder 153. The upper portion 152A is inserted into the insertion hole 144. The upper portion 152A is attached to the mounting member 151 and supports the mounting member 151. A lower portion 152B of the shuttle shaft 152 protrudes downward from the support cylinder 153. The lower portion 152B is bent in the width direction X. An end of the lower portion 152B is connected to the interlocking rod 154.

[0048] The support tube 153 is disposed vertically so as to extend in the up-down direction Z. The support tube 153 is located between the first side wall 1221 and the second side wall 1222 in the width direction X. The support tube 153 is located between the second connecting member 1224 and the cover member 124 in the front-rear direction Y. The support tube 153 is inserted into a through-hole formed in the fixing plate 1226 and is fixed via the fixing plate 1226. Therefore, the support tube 153 is fixed to the fixing bracket 122.

[0049] The interlocking rod 154 is a member extending in the front-to-rear direction Y. A front end 154A of the interlocking rod 154 is connected to the shuttle shaft 152 by a bolt and a nut. A rear end 154B of the interlocking rod 154 is connected to a connecting member 155 by a bolt and a nut. Therefore, the interlocking rod 154 is connected to the shuttle arm 156 via the connecting member 155. The connecting member 155 connects the interlocking rod 154 and the shuttle arm 156. An inner end of the connecting member 155 is connected to the interlocking rod 154 by a bolt and a nut. An outer end of the connecting member 155 is directly fixed to the shuttle arm 156.

[0050] The shuttle arm 156 extends in the vertical direction Z. The shuttle arm 156 has an arm body 156A and an arm tube 156B. The upper end of the arm body 156A is fixed to the connecting member 155. The arm body 156A also rotates in accordance with the rotation of the connecting member 155. The lower end of the arm body 156A is fixed to the engaging portion 157. The arm body 156A is inserted into the arm tube 156B. The arm tube 156B is not connected to the connecting member 155, but is connected to the case 5. The engaging portion 157 is a member that abuts against the shift fork 21. The engaging portion 157 is fixed to the arm body 156A. The shift fork 21 moves in accordance with the movement of the engaging portion 157. The engaging portion 157 is fixed to the arm body 156A on the inside in the width direction X, and engages with the shift fork 21 (third fork portion 213) on the outside in the width direction X.

[0051] The steering unit 16 has a steering wheel 162, a steering post 164, a steering controller 166, and an oil tank 168. The steering wheel 162 is a member operated by the driver. The steering wheel 162 is a member for operating the steering of the vehicle body 2, and is manually operated by the driver. The steering post 164 supports the steering wheel 162 and the steering controller 166. A steering shaft (axis) is inserted into the steering post 164. The steering post 164 transmits operation by the steering wheel 162 to the steering controller 166 via the steering shaft.

[0052] The steering controller 166 controls the steering of the traveling vehicle 1 by operating the steering wheel 162. The steering controller 166 is hydraulic. The steering controller 166 is a valve that controls a steering cylinder. The steering controller 166 is a rotary valve that is operated by the steering wheel 162 to control the flow rate of hydraulic oil and switch the direction of the hydraulic oil. In other words, the steering controller 166 is a valve that can output hydraulic oil that transmits the steering of the steering wheel 162. The steering controller 166 outputs hydraulic oil according to the amount of operation of the steering wheel 162 from a port corresponding to the operation direction. The hydraulic oil output from the steering controller 166 is sent to the steering cylinder and moves the cylinder rod of the steering cylinder. As a result, the left and right front wheels are steered according to the rotation of the steering wheel 162.

[0053] 4, 6, and 9, a plurality of hydraulic hoses (first hose H1 to fourth hose H4) are connected to the steering controller 166. The first hose H1 is a hydraulic hose that supplies hydraulic oil discharged from a hydraulic pump P equipped in the traveling vehicle 1 to the steering controller 166. The hydraulic pump P is provided inside the hood. The hydraulic pump P is driven by the power of the engine 3.

[0054] The second hose H2 is a hydraulic hose that supplies (discharges) hydraulic oil (transmission oil) to the case 5 that stores the hydraulic oil. The second hose H2 has a first hose section H2A from the steering controller 166 to the oil tank 168 and a second hose section H2B from the oil tank 168 to the case 5. The second hose H2 corresponds to a flow path that connects the steering controller 166 and a tank port T. Hydraulic oil flows through the second hose H2. The tank port T is the case 5. More specifically, the tank port T is a first housing chamber 51 (and a second housing chamber 52) that will be described later.

[0055] As shown in Figure 9, the oil tank 168 is disposed midway along the second hose H2B. The oil tank 168 stores hydraulic oil when the engine 3 of the traveling vehicle 1 is stopped. The oil tank 168 also stores hydraulic oil when the engine 3 is running. The oil tank 168 is disposed below the steering handle 162. This allows the length of the flow path of the second hose section H2B to be shortened.

[0056] The oil tank 168 has an inlet 168A and an outlet 168B. The inlet 168A is an inlet through which hydraulic oil flows into the oil tank 168. The outlet 168B is an outlet through which hydraulic oil flows out of the oil tank 168. The outlet 168B is located at a higher position than the inlet 168A. As shown in FIG. 9 , the outlet 168B may be located inside the oil tank 168. Specifically, a cylindrical portion 1682 having the outlet 168B may be located inside the oil tank 168. In this case, the upper end of the cylindrical portion 1682 corresponds to the outlet 168B. The cylindrical portion 1682 extends from a lower surface 168L of the oil tank 168 toward an upper surface 168U. When the hydraulic oil stored in the oil tank 168 exceeds the height of the outlet 168B, it flows from the outlet 168B into the second hose H2 by gravity.

[0057] The oil tank 168 has a space 168s in which hydraulic oil is stored. In the oil tank 168, a lower surface 168L of the space 168s is positioned higher than an inlet H2Ain through which hydraulic oil flows from the steering controller 166 into the flow path (second hose H2). By providing the oil tank 168, the steering controller 166 can be placed in a hydraulic pressure maintaining state.

[0058] The third hose H3 and the fourth hose H4 are connected to a steering cylinder. The third hose H3 is a hydraulic hose for left turning. The steering cylinder is actuated to steer the left front wheel and the right front wheel to the left by hydraulic oil flowing through the third hose H3. The fourth hose H4 is a hydraulic hose for right turning. The steering cylinder is actuated to steer the left front wheel and the right front wheel to the left by hydraulic oil flowing through the fourth hose H4.

[0059] The pedals 17 are operated by the driver's feet. As shown in Figures 2, 3, and 5, the pedals 17 are arranged outward in the width direction X from the control console 12. The pedals 17 include a clutch pedal 171, a first brake pedal 172, and a second brake pedal 173.

[0060] The clutch pedal 171 is a pedal for operating the clutch. The clutch pedal 171 has a pedal plate portion 171a and a pedal body 171b. One end of the pedal plate portion 171a is connected to the support pipe 18. The other end of the pedal plate portion 171a is connected to the pedal body 171b. The pedal body 171b is the part that is stepped on by the sole of the driver's foot when the driver operates the clutch pedal.

[0061] The first brake pedal 172 and the second brake pedal 173 are pedals for operating brakes that brake the traveling device 8. The first brake pedal 172 has a pedal plate portion 172a and a pedal body 172b. One end of the pedal plate portion 172a is connected to the support pipe 18. The other end of the pedal plate portion 172a is connected to the pedal body 172b. The second brake pedal 173 has a similar configuration to the first brake pedal 172. The pedal body 172b is the part that is stepped on by the sole of the driver's foot when the driver operates the pedal.

[0062] The clutch pedal 171 is disposed to the left of the control console 12. The first brake pedal 172 and the second brake pedal 173 are disposed to the right of the control console 12. The second brake pedal 173 is disposed to the right of the first brake pedal 172. The support pipe 18 is a pipe that supports the pedals 17. The support pipe 18 is fixed (connected) to the control console 12. The support pipe 18 is a pipe that extends in the width direction X.

[0063] As shown in Figures 10 and 11, the case 5 has a first storage chamber 51 that houses the forward / reverse switching device 20, a second storage chamber 52 that houses the transmission 30, and a third storage chamber 53 that houses the clutch.

[0064] The first storage chamber 51 is disposed between the second storage chamber 52 and the third storage chamber 53 in the front-rear direction Y. The first storage chamber 51 is disposed below the control device 10. Therefore, the forward / reverse switching device 20 is disposed below the control device 10.

[0065] The case 5 has an upper case portion 51A, a lower case portion 51B, a left case portion 51C, a right case portion 51D, a first case wall portion 55, and a second case wall portion 56. The upper case portion 51A is located above the first storage chamber 51. Therefore, the upper case portion 51A is the portion located above the space that forms the first storage chamber 51. The lower case portion 51B is located below the first storage chamber 51. The left case portion 51C is located on the left side of the first storage chamber 51. The right case portion 51D is located on the right side of the first storage chamber 51.

[0066] The case 5 has a through-hole 51Aa that penetrates the case upper portion 51A and into which the transmission unit 15 is inserted. Specifically, the arm body 156A is inserted into the through-hole 51Aa. Compared to inserting the transmission unit 15 from the side of the case 5, it is no longer necessary to bring the transmission unit 15 all the way to the side of the case 5. This allows for more foot space. Furthermore, it is no longer necessary to provide a cover that is long in the width direction X under the driver's feet to cover the transmission unit 15. This allows for more foot space. Furthermore, the distance of the transmission unit 15 from the shuttle lever 13 to the forward / reverse switching device 20 can be shortened, thereby improving the shifting feel. Since the shifting feel is improved by shortening the length of the transmission unit 15 rather than by increasing the rigidity of the transmission unit 15, costs can be reduced.

[0067] As shown in FIG. 5 , the pedal 17 (e.g., the clutch pedal 171) is disposed closer to the driver's seat 9 than the through-hole 51Aa in the front-rear direction Y. Specifically, the rear end of the pedal body 171b is disposed closer to the driver's seat 9 than the through-hole 51Aa in the front-rear direction Y. Furthermore, the rear end of the pedal body 171b is disposed closer to the driver's seat 9 than the transmission unit 15 itself in the front-rear direction Y. When the pedal 17 is operated, the pedal 17 is less likely to come into contact with the transmission unit 15 inserted into the through-hole 51Aa, thereby increasing the space under the driver's feet. Note that the pedal 17 may be disposed closer to the driver's seat than the through-hole 51Aa and the transmission unit 15 when the driver is not operating the pedal 17 (normal state). When the driver presses the pedal, the through-hole 51Aa and the transmission unit 15 may be disposed closer to the driver's seat than the pedal 17.

[0068] As shown in FIGS. 2 and 5 , the front end of the case cover member 6 may be located behind the through-hole 51Aa (and the transmission unit 15) in the longitudinal direction Y. More specifically, the front end of the main body 6a of the case cover member 6 may be located behind the through-hole 51Aa (and the transmission unit 15) in the longitudinal direction Y. Therefore, it can be seen that the case cover member 6 does not cover the transmission unit 15. Since the transmission unit 15 does not need to be disposed between the case 5 and the case cover member 6 to extend to the side surface of the case 5, the case cover member can be disposed closer to the case 5 (i.e., lower) in the vertical direction Z, thereby increasing the space under the driver's feet. Note that the front end of the side portion 6b of the case cover member 6 may or may not be located behind the through-hole 51Aa (and the transmission unit 15) in the longitudinal direction Y.

[0069] As shown in FIGS. 3 and 4 , the through hole 51Aa and the transmission unit 15 may be located inside the first side wall 1221 and the second side wall 1222 in the width direction X. This prevents the driver's foot from hitting the transmission unit 15. The transmission unit 15 may also be located inside the side portion 6b of the case cover member 6 in the width direction X. The transmission unit 15 may also be located inside the outer end of the main body portion 6a of the case cover member 6 in the width direction X. The pedal 17 (e.g., clutch pedal 171) may also be located inside the main body portion 6a of the case cover member 6 in the width direction X. This configuration ensures a sufficient distance in the width direction X between the pedal 17 (e.g., clutch pedal 171) and the transmission unit 15.

[0070] The first case wall 55 is located between the first housing chamber 51 and the second housing chamber 52. The first case wall 55 separates the first housing chamber 51 and the second housing chamber 52. The second case wall 56 is located between the first housing chamber 51 and the third housing chamber 53. The second case wall 56 separates the first housing chamber 51 and the third housing chamber 53. The first housing chamber 51 houses the forward / reverse switching device 20. The forward / reverse switching device 20 includes a shift fork 21, a main shaft 22, a shifter 23, a fork rod 24, a forward gear 25, a reverse gear 26, a coupling 27, and a synchronizer ring 28.

[0071] The shift fork 21 can be moved via the transmission unit 15 by operating the shuttle lever. The shift fork 21 is attached to a fork rod 24. The shift fork 21 has a pair of first fork portions 211 (211U, 211L), a second fork portion 212, and a third fork portion 213. The first fork portion 211 is connected to the shifter 23. As a result, the shifter 23 moves together with the movement of the shift fork 21 (first fork portion 211).

[0072] The pair of first fork portions 211 includes an upper fork portion 211U disposed on the upper side and a lower fork portion 211L disposed on the lower side. The pair of first fork portions 211 extend from the second fork portion 212. Specifically, the upper fork portion 211U extends upward from the second fork portion 212. The lower fork portion 211L extends inward from the second fork portion 212 in the width direction X. The second fork portion 212 is located between the pair of first fork portions 211. A through hole is formed in the second fork portion 212, into which the fork rod 24 is inserted.

[0073] The third fork portion 213 engages with the transmission part 15. The third fork portion 213 is connected to the upper fork portion 211U of the pair of first fork portions 211. Specifically, the third fork portion 213 is connected to the upper end of the upper fork portion 211U. As a result, the third fork portion 213 engaged with the transmission part 15 is positioned on the upper side, which allows the length of the transmission part 15 to be shortened. As a result, deterioration of the gear shift feeling can be suppressed.

[0074] A shifter 23, a forward gear 25, a reverse gear 26, a coupling 27, and a synchronizer ring 28 are attached to the main shaft 22. That is, the forward gear 25, the reverse gear 26, the coupling 27, and the synchronizer ring 28 are inserted into the main shaft 22. A central axis (rotation axis) 22c of the main shaft 22 is closer to the upper case 51A than to the lower case 51B. This allows the distance from the transmission unit 15 inserted into the case 5 to the forward / reverse switching device 20 to be shortened.

[0075] The synchronizer ring 28 is used to synchronize the rotation of the gears. The synchronizer ring 28 has a first synchronizer ring 281 that contacts the forward gear 25 and a second synchronizer ring 282 that contacts the reverse gear 26. The shifter 23 and the coupling 27 are arranged between the first synchronizer ring 281 and the second synchronizer ring 282.

[0076] The shifter 23 is movable along the main shaft 22 between the forward gear 25 and the reverse gear 26. The shifter 23 changes the connection (mesh) between the forward gear 25 and the reverse gear 26. Specifically, as shown in FIG. 12 , a coupling 27 is disposed radially inside the shifter 23. When the shifter 23 starts to move in one direction (for example, the forward direction Y1), the coupling 27 presses the first synchronizer ring 281 against the forward gear 25. Due to frictional force generated in the forward gear 25, the rotation of the coupling 27, which rotates integrally with the main shaft 22, begins to be transmitted to the synchronizer ring 28 and the forward gear 25. The forward gear 25 meshes with a gear attached to a shaft different from the main shaft 22. The forward gear 25 is designed so that the shaft rotates as a result of the rotation of the gear, thereby rotating the drive wheels so that the traveling vehicle 1 moves forward.

[0077] Similarly, when the shifter 23 starts to move in the other direction (for example, the backward direction Y2), the coupling 27 presses the second synchronizer ring 282 against the reverse gear 26. Frictional force generated in the reverse gear 26 causes the rotation of the coupling 27 to begin to be transmitted to the synchronizer ring 28 and the reverse gear 26. The synchronizer ring 28 is engaged with a reverse gear attached to a shaft different from the main shaft 22. The synchronizer ring 28 is designed so that the shaft rotates as a result of the rotation of the reverse gear, thereby rotating the drive wheels so that the vehicle 1 moves backward. The synchronizer ring 28 may be pressed toward the forward gear 25 or the reverse gear 26 by a synchronizer key disposed between the coupling 27 and the shifter 23.

[0078] The transmission 30 has a main transmission unit and an auxiliary transmission unit. The main transmission unit changes and outputs (changes speed) the rotation input from the propeller shaft. The auxiliary transmission unit changes and outputs (changes speed) the rotation input from the main transmission unit.

[0079] As shown in FIGS. 10 to 13 , the traveling vehicle 1 has a supply pipe 60 that supplies oil (hydraulic oil) from the outside of the case 5 to the inside of the case 5. The supply pipe 60 is arranged in the storage space (first storage chamber 51) of the case 5. The supply pipe 60 supplies oil to the first storage chamber 51. In the embodiment, the supply pipe 60 is a pipe through which oil that has flowed through the second hose H2 passes. More specifically, the oil that has flowed through the second hose portion H2B flows through the supply pipe 60. Oil (hydraulic oil) discharged from a hydraulic device (specifically, the steering controller 166) is supplied (discharged) to the inside of the case 5.

[0080] The supply pipe 60 has a main body 62, an outlet 64, and a guide 66. The main body 62 is a tubular member through which oil flows. The main body 62 may be a circular pipe. In this embodiment, the main body 62 extends parallel to the central axis (rotation axis) 22c of the main shaft 22. Therefore, the main body 62 extends from the first case wall 55 along the front-rear direction Y (forward direction Y1). As shown in FIG. 10 , the main body 62 extends so as not to overlap the central axis 22c of the main shaft 22 in the up-down direction Z. Specifically, the main body 62 is disposed closer to the second hose H2 than the central axis 22c of the main shaft 22. The shorter distance from the second hose H2 to the supply pipe 60 allows oil to be applied to the gears more quickly.

[0081] The oil is discharged from the discharge port 64. The discharge port 64 may be provided in the guide portion 66. The discharge port 64 is disposed above the main shaft 22. This allows the oil to be applied to the upper side of the gear, which is less likely to be immersed in oil, and makes it possible to maintain lubrication between the gear and the synchronizer ring 28.

[0082] The guide portion 66 guides the oil discharged from the discharge port 64 between the gear and the synchronizer ring 28. This allows the oil to be applied to the contact surface of the synchronizer ring 28 that comes into contact with the gear. Therefore, even if the synchronizer ring 28 is not immersed in oil, lubrication between the gear and the synchronizer ring 28 can be maintained, and wear of the synchronizer ring 28 can be suppressed.

[0083] The guide portion 66 may be cylindrical. The guide portion 66 may be a nozzle. The guide portion 66 extends from the main body portion 62 toward the space between the gear and the synchronizer ring 28. An outlet 64 is provided at the end of the guide portion 66 in the extending direction. This allows the discharged oil to be accurately applied between the gear and the synchronizer ring 28. This makes it possible to maintain lubrication between the gear and the synchronizer ring 28.

[0084] In this embodiment, the extension direction of the guide portion 66 (the vertical direction Z in FIG. 12 ) is perpendicular to the extension direction of the main body portion 62 (the front-rear direction Y in FIG. 12 ). Therefore, the guide portion 66 extends perpendicular to the central axis 22 c of the main shaft 22. Furthermore, in a cross section perpendicular to the central axis 22 c of the main shaft 22 (i.e., a cross section taken along the width direction X and the vertical direction Z (see FIG. 10 )), the extension direction of the guide portion 66 is inclined with respect to the vertical direction Z so that the angle between the extension direction of the guide portion 66 and an imaginary line passing through the center of the discharge port 64 and the central axis 22 c of the main shaft 22 is less than 30 degrees. This allows oil to be discharged toward the axis of the gear (i.e., the central axis of the main shaft 22) when the main body portion 62 and the central axis 22 c of the main shaft 22 do not overlap in the vertical direction Z. Therefore, oil can more easily reach not only the radially outer contact surface between the gear and synchronizer ring 28, but also the radially inner contact surface between the gear and synchronizer ring 28. This makes it easier to lubricate the contact surface between the gear and synchronizer ring 28. In FIG. 10, the imaginary line and the extending direction of the guide portion 66 coincide with each other, so the angle is 0 degrees. In addition, the guide portion 66 may extend above the axis of the gear or below the axis of the gear, taking into consideration how the oil is applied.

[0085] It is desirable that the discharge port 64 be located close to the synchronizer ring 28 (and the gear) so that a large amount of oil can be applied to the synchronizer ring 28. For example, it is desirable that the distance from the discharge port 64 to the synchronizer ring 28 be shorter than the distance from the synchronizer ring 28 to the central axis 22c of the main shaft 22. It is also desirable that the guide portion 66 be located far enough away from the synchronizer ring 28 (and the gear) that the supply pipe 60 does not come into contact with the synchronizer ring 28 (or the gear) due to the vibration of the supply pipe 60 caused by the driving of the traveling vehicle 1.

[0086] In this embodiment, the guide portion 66 has a first guide portion 661 and a second guide portion 662. The first guide portion 661 guides oil to between the forward gear 25 and the first synchronizer ring 281. The first guide portion 661 extends from the main body portion 62 toward the forward gear 25. A first outlet 641 facing between the forward gear 25 and the first synchronizer ring 281 is provided at an end of the first guide portion 661 in the extending direction. The second guide portion 662 guides oil to between the reverse gear 26 and the second synchronizer ring 282. The second guide portion 662 extends from the main body portion 62 toward between the reverse gear 26 and the second synchronizer ring 282. A second outlet 642 facing between the reverse gear 26 and the second synchronizer ring 282 is provided at an end of the second guide portion 662 in the extending direction.

[0087] The first guide portion 661 is disposed upstream of the downstream end of the supply pipe 60. The downstream end of the supply pipe 60 is sealed. The first guide portion 661 is disposed downstream of the second guide portion 662.

[0088] As shown in FIG. 13 , the first case wall 55 has an opening 550 below the supply pipe 60 that penetrates the first housing chamber 51 and the second housing chamber 52. The opening 550 may include a first opening 551, a second opening 552, a third opening 553, and a fourth opening 554. The first opening 551 is located lowermost than the other openings. The second opening 552 is located higher than the first opening 551. The third opening 553 is located higher than the second opening 552. The fourth opening 554 is located higher than the third opening 553. Also, as shown in FIG. 13 , the fourth opening 554 is located higher than the synchronizer ring 28 (the upper end of the synchronizer ring 28).

[0089] The traveling vehicle 1 has a shaft 70 and a bearing 58. The shaft 70 is disposed in the first housing chamber 51 and rotates by power from the engine 3. The shaft 70 is inserted into the bearing 58. The bearing 58 is fixed to the first case wall portion 55 so as to close the opening 550.

[0090] In this embodiment, as shown in FIG. 13 , the shaft 70 includes a first shaft 71, a second shaft 72, and the above-mentioned main shaft 22. A gear is attached to each shaft. The bearing 58 includes a first bearing 581, a second bearing 582 (second bearing 582A, second bearing 582B), and a third bearing 583 (third bearing 583A, third bearing 583B). The first bearing 581 is fixed to the first case wall 55 so as to close the first opening 551. Similarly, the second bearing 582 is fixed to the first case wall 55 so as to close the second opening 552, and the third bearing 583 is fixed to the first case wall 55 so as to close the third opening 553. The first shaft 71 is inserted into the first bearing 581, the second shaft 72 is inserted into the second bearing 582, and the main shaft 22 is inserted into the third bearing 583. It should be noted that the bearing 58 is not fixed to the fourth opening 554 .

[0091] 14, the bearing 58 has an inner ring 58I, an outer ring 58O, and rolling elements 58R. A shaft 70 is inserted inside the inner ring 58I. The rolling elements 58R are rollers or balls. The rolling elements 58R are disposed between the inner ring 58I and the outer ring 58O. The bearing 58 may have a cage that determines the position of the rolling elements 58R.

[0092] As shown in Figures 13 and 14B, the second bearing 582A may have a seal portion 582S in addition to an inner ring 582I, an outer ring 582O, and a rolling element 582R. The seal portion 582S seals the gap between the inner ring 582I and the outer ring 582O. The seal portion 582S is positioned closer to the first housing chamber 51 than the rolling element 582R. The seal portion 582S is not positioned closer to the second housing chamber 52 than the rolling element 582R. Therefore, the second bearing 582A has the seal portion 582S positioned on only one side. Note that the first bearing 581, the second bearing 582B, and the third bearing 583 do not have seal portions.

[0093] 10, 11 and 13, the oil level when the engine is stopped is S1, and the oil level when the engine is running is S2. The oil in the case 5 circulates between the hydraulic device (steering controller 166) and the case 5.

[0094] Specifically, when the engine 3 is operating and rotating, the oil stored in the second housing chamber 52 is supplied to the hydraulic equipment. As a result, oil is supplied from the second housing chamber 52 to the hydraulic equipment. The oil in the second housing chamber 52 decreases slightly, causing the oil level in the second housing chamber 52 to drop slightly. Note that because the capacity of the second housing chamber 52 for storing oil is larger than the capacity of the first housing chamber 51, there is little difference in the oil level fluctuation between when the engine 3 is rotating and when it is stopped.

[0095] The supply of oil from the second housing chamber 52 to the hydraulic equipment causes oil to be supplied (discharged) from the hydraulic equipment to the first housing chamber 51. When the engine 3 is rotating, oil (hydraulic oil) from the steering controller 166 is supplied to the first housing chamber 51 through the outlet 64. As a result, the oil level in the first housing chamber 51 rises to S2 while the engine 3 is rotating. While oil is being supplied, the oil level in the first housing chamber 51 becomes higher than before the oil was supplied. Furthermore, oil preferentially accumulates in the first housing chamber 51. Therefore, even if the center axis 22c of the main shaft 22 is close to the case upper portion 51A, the synchronizer ring 28 attached to the main shaft 22 is easily immersed in the oil accumulated in the first housing chamber 51, thereby reducing the amount of oil used.

[0096] The higher the rotation speed of the engine 3, the greater the amount of oil supplied to the first housing chamber 51, and the faster the oil level rises in the first housing chamber 51. On the other hand, the lower the rotation speed of the engine 3, the less the amount of oil supplied to the first housing chamber 51, and the slower the oil level rises in the first housing chamber 51.

[0097] Oil is supplied to the first storage chamber 51 through the supply pipe 60. Assume here that the supply pipe 60 does not have a guide portion 66, and the discharge port 64 is directly provided on the main body portion 62. The oil flowing through the main body portion 62 of the supply pipe 60 has a velocity component along the main body portion 62. Therefore, the oil discharged from the discharge port 64 of the main body portion 62 has a velocity component in the extension direction of the main body portion 62 (the forward direction Y1 in FIG. 12 ), and is discharged forward of the discharge port 64 (to the left in FIG. 12 ). Here, the viscosity of the oil in the case 5, which has been heated by driving the traveling vehicle 1, is lower than that of oil at a lower temperature. Therefore, the velocity of the oil flowing through the supply pipe 60 increases, and the oil is discharged further forward. In particular, in the case of two discharge ports 64, the pressure inside the upstream discharge port 64 is higher than that of the downstream discharge port 64, and therefore the oil flows faster and is more likely to be discharged further forward. Even if the gear and synchronizer ring 28 are positioned so that the oil discharge path passes between them, the discharge path changes depending on whether the oil temperature is high or low, which can result in oil not being applied to the contact surface of the synchronizer ring 28. The synchronizer ring 28 attached to the main shaft 22 is not immersed in oil until the oil level rises to S2, making it susceptible to damage. Furthermore, even when the oil level rises to S2, only a portion of the synchronizer ring 28 is immersed in oil, so it is preferable to apply oil to the portion not immersed in oil.

[0098] As described above, the guide portion 66 guides the oil discharged from the discharge port 64 to the gear. Therefore, the oil supplied by the supply pipe 60 is guided between the gear and the synchronizer ring 28 by the guide portion 66, so that the oil is applied to the contact surface of the synchronizer ring 28 that comes into contact with the gear. Therefore, even if the synchronizer ring 28 is not immersed in oil, lubrication between the gear and the synchronizer ring 28 can be maintained, and wear of the synchronizer ring 28 can be suppressed. Furthermore, wear of not only the synchronizer ring 28 but also the gear can be suppressed.

[0099] Furthermore, an outlet 64 is provided at the end of the cylindrical guide portion 66 in the extension direction (the front-rear direction Y in FIGS. 11 and 12 ). Because the guide portion 66 extends toward the gap between the gear and the synchronizer ring 28, oil that has flowed inside the cylindrical guide portion 66 is discharged toward the gap between the gear and the synchronizer ring 28. This allows the oil to be accurately applied to the gap between the gear and the synchronizer ring 28.

[0100] Furthermore, the gear to which oil is guided by the guide portion 66 is the gear of the forward / reverse switching device 20. When work (for example, farming) is performed using the traveling vehicle 1, switching between forward and reverse occurs frequently, so the number of gear changes in the forward / reverse switching device 20 is greater than the number of gear changes in the transmission 30. For this reason, the synchronizer ring 28 that contacts the gear of the forward / reverse switching device 20 is more susceptible to wear than the synchronizer ring 28 that contacts the gear of the transmission 30. Therefore, by guiding oil between the gear of the forward / reverse switching device 20 and the synchronizer ring 28, wear on the synchronizer ring 28, which is more susceptible to wear, can be reduced.

[0101] Even if the gears of the transmission 30 are not immersed in oil, the synchronizer rings of the transmission 30 are sufficiently lubricated by splashes of oil stored in the second housing chamber 52.

[0102] The guide portion 66 also has a first guide portion 661 that guides oil between the forward gear 25 and the first synchronizer ring 281, and a second guide portion 662 that guides oil between the reverse gear 26 and the second synchronizer ring 282. Because oil is applied to both the first synchronizer ring 281 that contacts the forward gear 25 and the second synchronizer ring 282 that contacts the reverse gear 26, wear on both synchronizer rings 28 can be suppressed.

[0103] On the other hand, because the first case wall portion 55 is provided with the opening 550, oil flows from the first housing chamber 51 to the second housing chamber 52 through the opening 550. As a result, when the engine 3 is rotating, the oil level in the second housing chamber 52 drops to S2, but the oil does not run out of the second housing chamber 52.

[0104] Here, because the bearing 58 is fixed so as to close the opening 550, the flow rate of oil flowing from the first housing chamber 51 to the second housing chamber 52 through the opening 550 is restricted. As a result, even though the first case wall portion 55 has the opening 550, oil can easily be stored in the first housing chamber 51, and at least a portion of the synchronizer ring 28 can easily be immersed in oil.

[0105] The second bearing 582A also has a seal portion 582S. This makes it more difficult for oil to pass between the inner ring 582I and the outer ring 582O compared to a bearing 58 (e.g., the first bearing 581) that does not have a seal portion 58S, further limiting the flow rate of oil flowing from the first housing chamber 51 to the second housing chamber 52. This makes it easier for oil to accumulate in the first housing chamber 51, making it easier for at least a portion of the synchronizer ring 28 to be immersed in oil. In particular, when the oil becomes hot due to the driving of the traveling vehicle 1, the viscosity of the oil decreases, making it easier for oil to flow from the first housing chamber 51 to the second housing chamber 52 through the opening 550. Therefore, by limiting the oil flow rate using the seal portion 582S, it is possible to maintain a high oil level in the first housing chamber 51 even when the oil is hot.

[0106] Furthermore, when the engine 3 rotation speed is low, the amount of oil supplied to the first housing chamber 51 is small, and the speed at which the oil level rises in the first housing chamber 51 is slow. Therefore, by limiting the flow rate of oil flowing from the first housing chamber 51 to the second housing chamber 52 using the bearing 58, oil can be more easily stored in the first housing chamber 51 even when the engine rotation speed is low. As a result, at least a portion of the synchronizer ring 28 can be more easily immersed in oil.

[0107] Even when the bearing 58 has the seal portion 58S, oil passes through the gap between the shaft 70 and the bearing 58 and the gap between the first case wall portion 55 and the bearing 58, and flows from the first housing chamber 51 to the second housing chamber 52 through the opening 550. Furthermore, when the seal portion 58S does not seal the gap between the inner ring 58I and the outer ring 58O, oil flows through the inside of the bearing 58 into the second housing chamber 52, although the flow rate is small.

[0108] Furthermore, the seal portion 582S of the second bearing 582 is disposed closer to the first housing chamber 51 than the rolling element 582R. Because oil accumulates closer to the first housing chamber 51 than the seal portion 582S, it is easier for oil to accumulate in the first housing chamber 51 (the oil level tends to rise more quickly) compared to when the seal portion 582S is farther away from the rolling element 582R. This makes it easier for at least a portion of the synchronizer ring 28 to be immersed in oil.

[0109] The first opening 551, to which the first bearing 581 without the seal portion 58S is fixed, is located below the second opening 552 to which the second bearing 582 with the seal portion 582S is fixed. This improves oil circulation between the first housing chamber 51 and the second housing chamber 52 on the lower side where oil is likely to accumulate. This prevents the continued use of oil with deteriorated performance (e.g., high-temperature oil) in one of the first housing chamber 51 and the second housing chamber 52. On the other hand, by making it difficult for oil to leak from the second opening 552, which is likely to be located higher than the oil level in the second housing chamber 52, it is possible to make it easier for oil to accumulate in the first housing chamber 51.

[0110] Additionally, a third bearing 583 that does not have a seal portion 58S is fixed to the third opening 553. The third opening 553 is located above the second opening 552. This allows oil to more easily flow into the second housing chamber 52 through the third opening 553 than through the second opening 552. This prevents more oil than necessary from accumulating in the first housing chamber 51.

[0111] Furthermore, the fourth opening 554 is disposed above the synchronizer ring 28. The fourth opening 554 is open without the bearing 58 being fixed thereto. As a result, since the bearing 58 is not fixed thereto, oil that accumulates above the synchronizer ring 28 is more likely to flow out into the second housing chamber 52 than through the third opening 553. Because the oil that accumulates above the synchronizer ring 28 does not contribute to the lubrication of the synchronizer ring 28, it is possible to further prevent more oil than necessary from accumulating in the first housing chamber 51.

[0112] When the engine 3 is stopped, oil is not supplied from the second housing chamber 52 to the hydraulic equipment. Therefore, oil is not supplied from the hydraulic equipment to the first housing chamber 51. While the engine 3 is stopped, oil flows from the first housing chamber 51 to the second housing chamber 52 through the second opening 552 and the third opening 553. As a result, the oil level in the first housing chamber 51 drops to S1.

[0113] (3) Movement of Transmission Unit 15 The movement of the transmission unit 15 will be explained mainly with reference to Figures 15 and 16. In Figure 15, the shuttle lever 13 is in the neutral position. In this neutral position, the shuttle lever 13 (the lower end 131b of the lever body 131) is positioned at the protrusion 142B of the guide hole 142. In this case, the shuttle lever 13 cannot be operated forward or backward. Furthermore, when the shuttle lever 13 is in the neutral position, the forward / reverse switching device 20 is in a power disconnection state (i.e., the shifter 23 is not connected to either the forward gear 25 or the reverse gear 26), and no power is output from the transmission 30 to the traveling device 8.

[0114] In the neutral position, the shuttle lever 13 can swing upward against the biasing force of the spring. When the shuttle lever 13 is swung upward from the neutral position, the shuttle lever 13 moves from the protrusion 142B of the guide hole 142 to the arc portion 142A. When the shuttle lever 13 is swung upward, the shuttle lever 13 can move within the arc portion 142A of the guide hole 142. Therefore, the shuttle lever 13 can swing back and forth.

[0115] When the shuttle lever 13 is moved in the direction F1 (rearward direction Y2) along the arc portion 142A, the shuttle lever 13 is moved from the neutral position to the forward position. When the shuttle lever 13 is in the forward position, the forward / reverse switching device 20 is in a state in which it transmits forward power, and the traveling direction of the vehicle body 2 is switched to the forward direction.

[0116] Specifically, when the shuttle lever 13 is operated in the F1 direction, the upper portion 152A of the shuttle shaft 152 rotates in the F2 direction, and the lower portion 152B of the shuttle shaft 152 moves in the F3 direction. This causes the interlocking rod 154 to move in the F4 direction (rearward direction Y2), and the connecting member 155 and the shuttle arm 156 rotate in the F5 direction and the F6 direction, respectively. The rotation of the shuttle arm 156 causes the engaging portion 157 to move in the F7 direction, and the shift fork 21 moves in the F8 direction (forward direction Y1) along the main shaft 22. As a result, the shifter 23 connects with the forward gear 25, and the forward / reverse switching device 20 switches to a state in which it transmits forward power.

[0117] On the other hand, when the shuttle lever 13 is moved in the direction R1 (rearward direction Y2) along the arc portion 142A, the shuttle lever 13 is moved from the neutral position to the reverse position. When the shuttle lever 13 is in the reverse position, the forward / reverse switching device 20 is in a state where it transmits reverse power, and the traveling direction of the vehicle body 2 is switched to the reverse direction.

[0118] Specifically, when the shuttle lever 13 is operated in the R1 direction, the upper portion 152A of the shuttle shaft 152 rotates in the R2 direction, and the lower portion 152B of the shuttle shaft 152 moves in the R3 direction. This causes the interlocking rod 154 to move in the R4 direction (rearward direction Y2), and the connecting member 155 and the shuttle arm 156 rotate in the R5 direction and the R6 direction, respectively. The rotation of the shuttle arm 156 causes the engaging portion 157 to move in the R7 direction, and the shift fork 21 moves in the R8 direction (rearward direction Y2) along the main shaft 22. As a result, the shifter 23 connects with the reverse gear 26, and the forward / reverse switching device 20 switches to a state in which it transmits reverse power.

[0119] (4) Other Embodiments Although the present invention has been described in detail using the above-described embodiments, it is clear to those skilled in the art that the present invention is not limited to the embodiments described herein. The present invention can be implemented in modified and altered forms without departing from the spirit and scope of the present invention as defined by the claims. Therefore, the description in this specification is intended to be illustrative and does not have any limiting meaning on the present invention.

[0120] For example, in the above description, the guide portion 66 may be provided by bending the downstream end portion of the supply pipe 60 toward the gear side. This reduces the number of steps required to process the supply pipe 60 compared to when the first guide portion 661 and the first discharge port 641 are formed.

[0121] In the above description, the guide portion 66 may extend vertically downward from the main body portion 62. Because the guide portion 66 causes the oil to be discharged vertically downward, the discharged oil is less likely to have a horizontal velocity component. Therefore, the discharged oil is more likely to reach the gear facing the discharge port without shifting horizontally (e.g., forward in FIG. 12 ). Because the oil can be applied to the desired location regardless of the oil temperature, lubrication between the gear and the synchronizer ring 28 can be maintained.

[0122] In the above description, the supply pipe 60 has two discharge ports 64, but this is not limited to this. The supply pipe 60 may have one discharge port 64. The supply pipe 60 may spray oil from one discharge port 64 onto spaces between multiple gears and multiple synchronizer rings 28. The supply pipe 60 may also have three or more discharge ports 64. The supply pipe 60 may have a number of guide portions 66 corresponding to the number of discharge ports 64. The supply pipe 60 may have a number of discharge ports 64 and a number of guide portions 66 corresponding to the number of synchronizer rings 28 to which oil is to be sprayed.

[0123] In the above description, only the second bearing 582A has the seal portion 582S, but this is not limited to this. At least one of the other bearings 58 (the first bearing 581, the second bearing 582B, and the third bearing 583) may have the seal portion 58S. Furthermore, the second bearing 582A does not have to have the seal portion 582S.

[0124] Furthermore, in the second bearing 582A, the seal portion 582S is disposed closer to the first housing chamber 51 than the rolling element 582R, but this is not limited to this. The seal portion 582S may be disposed closer to the second housing chamber 52 than the rolling element 582R, rather than being disposed closer to the first housing chamber 51. Alternatively, the seal portion 582S may be disposed on both the first housing chamber 51 side and the second housing chamber 52 side with respect to the rolling element 582R. This makes it possible to further restrict the flow rate of oil flowing from the first housing chamber 51 to the second housing chamber 52 through the second opening 552.

[0125] In the above description, oil is applied from the supply pipe 60 between the gear of the forward / reverse switching device and the synchronizer ring 28, but this is not limitative. Oil may also be applied between a gear other than the gear of the forward / reverse switching device 20 (for example, a gear of the transmission 30) and the synchronizer ring 28.

[0126] For example, although the oil tank 168 is disposed below the steering controller 166 in the above embodiment, the present invention is not limited to this. For example, the oil tank 168 may be provided inside the hood.

[0127] In the above description, the steering controller 166 has been given as an example of the hydraulic device, but the hydraulic device may be another hydraulic device or may have another hydraulic device.

[0128] The entire contents of Japanese Patent Application No. 2019-019206, filed on February 5, 2019, are incorporated herein by reference.

[0129] A running vehicle can be provided in which wear of the synchronizer ring can be suppressed even when the synchronizer ring is not immersed in oil.

[0130] DESCRIPTION OF SYMBOLS 1: Traveling vehicle 2: Vehicle body 3: Engine 5: Case 6: Case cover member 8: Traveling device 9: Driver's seat 10: Control device 11: Control cover 12: Control platform 13: Shuttle lever 14: Guide plate 15: Transmission section 16: Steering section 17: Pedal 18: Support pipe 20: Forward / reverse switching device 22: Main shaft 25: Forward gear 26: Reverse gear 30: Transmission device 51: First storage chamber 51Aa: Through hole 52: Second storage chamber 53: Third storage chamber 55: First case wall 56: Second case wall 58: Bearing 60: Supply pipe 62: Main body 64: Discharge port 66: Guide section 70: Shaft 550: Opening 551: First opening 552: Second opening 553: Third opening 554: Fourth opening 581: First bearing 582: Second bearing 583: Third bearing 661: First guide portion 662: Second guide portion

Claims

DEPCT651. A motor vehicle comprising: an engine; a gearbox housing which encloses the power transmission equipment for transmitting power from the engine; and an oil supply pipe located in the enclosure of the gearbox, an oil supply pipe that supplies oil from the outside of the gearbox to the inside of the gearbox, where the power transmission equipment, including the gears and synchronizer rings, are in contact with the gears; and the oil supply pipe comprising: a tubular main body in which the oil circulates; an oil discharge port where the oil is discharged; and a guide element that guides the oil supplied from the oil discharge port to the area between the gears and synchronizer rings.

2. A motor vehicle under claim 1, in which the guide element is tubular, extends from the main body to the area between the gears and synchronizer rings, and the oil discharge port is located at one end in the direction of the extended guide element.

3. A motor vehicle under claim 1 or 2, in which the oil discharge port is located above the center axis of the shaft where the gears are attached.4.A traveling vehicle under claim 3, in which the main body extends without overlapping the center axis of the axle in the vertical direction, and the extension of the pilot section is tilted relative to the vertical direction such that the angle formed by an imaginary line drawn through the center of the discharge port and the center axis of the axle with respect to the extension of the pilot section is less than 30 degrees on a cross-section perpendicular to the center axis of the axle.

5. Any traveling vehicle under claims 1 through 4, in which the traveling vehicle incorporates, in part, a power transmission device, a mechanical forward / reverse switching device used to switch the forward and reverse movement of the traveling vehicle, and a gear as a gear of the forward / reverse switching device. 6.The vehicle under claim 5, where the forward / reverse switching device incorporates the forward and reverse gears as part of the gearbox, the synchronizer rings incorporate the first synchronizer ring in contact with the forward gear and the second synchronizer ring in contact with the reverse gear, and the pilot parts incorporate the first pilot part which guides oil to the area between the forward gear and the first synchronizer ring and the second pilot part which guides oil to the area between the reverse gear and the second synchronizer ring.7.A vehicle under claim 5 or 6, which also includes a gear shifting device used to shift power from the engine and transmit power to the drive wheels, in which the gearbox housing includes: the first enclosure which encloses the forward / reverse shifting device; the second enclosure which encloses the gear shifting device; and the gearbox wall located between the first and second enclosures; the gearbox wall separating the first and second enclosures; the fuel supply pipe supplying fuel to the first enclosure; and, while supplying fuel, in the first enclosure, the fuel surface is higher than before the fuel supply.

8. A vehicle under claim 7, in which there are provided openings that pass through the first and second enclosures in the gearbox wall, the vehicle includes: the shafts located in the first enclosure; the shafts that rotate under engine power; and the bearings in which the shafts are inserted; and the bearings attached to the gearbox wall to cover the openings. 9.

10. A vehicle under claim 9, where the bearing incorporates the inner ring, outer ring, rolling body, and sealing element used to close the area between the inner and outer rings.

11. A vehicle under claim 9 or 10, where the opening incorporates: the first opening which houses the bearing without the sealing element; and the second opening which houses the bearing with the sealing element, and the first opening is located lower downward from the second opening.

12. A vehicle under claim 11, where the opening also incorporates the third opening which houses the bearing without the sealing element, and the third opening is located upper upward from the second opening. 13.The vehicle travels according to claim 12, where the opening also includes a fourth opening positioned upwards from the synchronizer ring, and the fourth opening is open without a bearing mounted there-----------------------------------------------------------;.