JP2008131894A - Tilling shaft supporting structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a tilling shaft supporting structure which can prevent weeds or the like from twining around on a tilling final shaft. <P>SOLUTION: A protector 500 for covering the lower portion of a chain case 333 is disposed on the chain case 333. The chain case 333 is covered with the main body portion 510 of the protector 500, while the free end portion of an extension piece 520 extended from the main body portion 510 to the tilling final shaft 111 is adjacent to the outer peripheral surface of the tilling final shaft 111. Only at a prescribed portion around the axis of the tilling final shaft 111, the outer peripheral surface of the tilling final shaft 111 is surrounded with the free end portion of the extension piece 520. Herein, when weeds or the like twine around the tilling final shaft 111 with the rotation of the tilling final shaft 111, the weeds or the like to twine around are contacted with the free end portion of the extension piece 520 and are raked off. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a support structure for a tillage shaft applied to a tractor.

  A transmission case accommodating the transmission mechanism and capable of storing oil, a bearing member provided in the transmission case, a bearing member installed in the bearing member, and an oil seal member are supported in a freely rotatable and liquid-tight manner around the axis. A tilling final shaft having a connecting flange provided on the downstream side in the transmission direction of the shaft main body, and a tilling claw shaft connected to the tilling final shaft through the connecting flange so as not to rotate relative to the tilling shaft. There has been proposed a support structure for a tilling shaft that is provided and that covers a lower portion of the transmission case with a protector (see Patent Document 1 below).

  The support structure of the tilling shaft described in Patent Document 1 covers the lower part of the transmission case with the protector, thereby preventing the lower part of the transmission case that easily comes into contact with soil on the ground during tilling from being worn. Yes.

By the way, the tilling final shaft is rotationally driven by transmitting the power from the PTO shaft provided in the vehicle main unit through the transmission mechanism, but weeds etc. are present on the shaft main body of the tilling final shaft at the time of tilling. It may wind up. In particular, if weeds wind around the sliding part between the transmission case and / or bearing member and the tilling final shaft, resistance to the rotation of the tilling final shaft will occur, increasing the load on the engine and transmission mechanism. Will do.
JP 2002-281802 A

  This invention is made | formed in view of the said prior art, and makes it one object to provide the support structure of a tilling shaft which can prevent winding of weed etc. to a tilling final shaft.

  A support structure for a tillage shaft according to the present invention includes a transmission case that stores an oil transmission mechanism that can store oil, a bearing member that is provided in the transmission case, a bearing member that is installed in the bearing member, and an oil seal member. A tillable final shaft having a shaft body that is rotatable and liquid-tightly supported around the axis, and a connecting flange provided on the downstream side in the transmission direction of the shaft body, and relative to the tilling final shaft via the connecting flange. A tilling shaft support structure including a tilling claw shaft that is non-rotatably coupled and a protector that covers a lower portion of the transmission case, and the protector includes a main body portion that covers the transmission case, and a main body portion. An extending piece extending toward the tilling final axis and having a free end close to the outer peripheral surface of the tilling final axis, and the extending piece has the free end at the front. It is characterized in that only are configured so as to surround the outer peripheral surface of the tilling final shaft in the axial about a predetermined range of tilling final shaft.

According to the support structure of the tillage shaft having the above configuration, the transmission mechanism is accommodated in the transmission case capable of storing oil. The transmission case is provided with a bearing member, and the shaft main body of the tilling final shaft is supported by the bearing member via the bearing member and the oil seal member so as to be rotatable about the axis and in a liquid-tight manner. The tilling final shaft is provided with a connecting flange on the downstream side in the transmission direction of the shaft body, and the tilling claw shaft is connected to the tilling final shaft through the connecting flange so as not to rotate relative to the tilling final shaft.
On the other hand, the transmission case is provided with a protector that covers a lower portion of the transmission case. And while a transmission case is covered by the main-body part of a protector, the free end part of the extension piece extended toward the tilling final axis from the main-body part is adjoining to the outer peripheral surface of a tilling final axis. And only in a predetermined range around the axis of the tilling final axis, the outer peripheral surface of the tilling final axis is surrounded by the free end of the extending piece.
Here, when weeds or the like are to be wound around the tillage final shaft as the tillage final shaft is rotated, the weeds or the like that are to be wound come into contact with the free end of the extended piece and are scraped off (scraper). Effect occurs).

  In this way, the free end of the extending piece extending from the protector that covers the lower part of the transmission case surrounds only within a predetermined range around the axis of the tilling final axis, so that weeds can be wrapped around the tilling final axis. Can be prevented. In addition, an increase in the number of parts can be prevented by scraping weeds or the like using a protector that covers the lower portion of the transmission case.

  Preferably, the connection flange has a tapered region whose outer diameter is reduced toward the upstream side in the transmission direction, and the free end portion of the extending piece is configured to be close to the tapered region. .

In this case, in the taper region of the connecting flange, the outer diameter is reduced toward the upstream side in the transmission direction, and therefore, the movement toward the upstream side in the transmission direction with respect to weeds and the like to be wound around the tilling final shaft is prevented. Prompted.
Thereby, the weeds etc. which are going to wind with rotation of a tilling final axis | shaft can be moved to the direction of the free end part of the extension piece of a protector. Therefore, the scraping action such as weeds by the protector can be obtained more effectively.

  More preferably, the bearing member has a downstream side in the transmission direction protruding from the transmission case to the downstream side in the transmission direction, and the connection flange has an extension part that is close to the transmission case. The taper region is formed, and the first labyrinth is formed in cooperation with the protrusion of the bearing member.

In this case, the first labyrinth is formed by the protruding portion of the bearing member that protrudes downstream in the transmission direction from the transmission case and the extending portion that is close to the transmission case from the connection flange. At this time, a taper region is formed in the extending portion to move weeds or the like to be wound as the tillage final shaft rotates in the direction of the free end of the extending piece of the protector.
Therefore, by forming the first labyrinth, weeds, mud, etc. that have moved in the direction of the free end of the extending piece of the protector on the taper region can enter from between the bearing member and the connecting flange. Can be prevented.

  More preferably, the upstream end surface in the transmission direction of the extending portion is configured to cooperate with the end surface of the opposing fixing member to form a second labyrinth.

In this case, the second labyrinth is formed by the upstream end surface in the transmission direction of the extending portion of the connecting flange and the end surface of the opposing fixing member.
Therefore, by forming the second labyrinth, weeds, mud, etc. that have moved on the taper region toward the free end of the extension piece of the protector, the extension part of the connecting flange and the fixing member facing this It is possible to prevent intrusion from between the end surfaces of the wings and to effectively prevent the weeds and the like from being wound around the tilling final shaft and mud etc. together with the first labyrinth.

  Preferably, the bearing member has a downstream side in the transmission direction protruding from the transmission case to the downstream side in the transmission direction, and a boss portion extending radially outward is provided in the protruding portion. The flange has an extending portion that is close to the transmission case, and the extending portion forms the tapered region, and an outer periphery of a region of the protruding portion that is located downstream of the boss portion in the transmission direction. The labyrinth is formed in cooperation with the surface, the downstream end surface facing the downstream side in the transmission direction of the boss portion, and the outer peripheral surface.

In this case, using the boss portion provided in the protruding portion protruding from the bearing member, the downstream end surface and the outer peripheral surface facing the downstream side in the transmission direction of the boss portion, and the downstream side in the transmission direction from the boss portion of the protruding portion The labyrinth is formed by the outer peripheral surface of the region located at the position and the extending portion that is close to the transmission case from the connecting flange. At this time, a taper region is formed in the extending portion to move weeds or the like to be wound as the tillage final shaft rotates in the direction of the free end of the extending piece of the protector.
Therefore, by forming a labyrinth using the boss part, weeds, mud, etc. that have moved on the taper area in the direction of the free end of the protector are prevented from entering between the bearing member and the connecting flange. can do.

  More preferably, an uneven labyrinth is formed on the downstream end face of the boss part and the upstream end face of the extension part.

In this case, a labyrinth having a more complicated shape is formed between the boss portion and the extending portion.
Therefore, weeds, mud, and the like that have moved on the taper region toward the free end of the extending piece of the protector can be more effectively prevented from entering between the bearing member and the connecting flange.

  Preferably, it is configured such that a space portion exists in at least a part of a region where the protector and the transmission case face each other.

In this case, a space part is provided in a part of area | region where a protector and a transmission case oppose.
Therefore, even if mud or the like has entered from the free end of the extended piece of the protector, it will be preferentially stored in the space, and it will invade the oil seal member that is vulnerable to intrusion of mud or the like. It can prevent and improve durability.

  More preferably, the protector is a discharge port whose inner end portion communicates with the space portion and whose outer end portion opens toward the rear side of the vehicle, and is contracted toward the outer end portion from the inner end portion. It is comprised so that the discharge port made into the diameter may be formed.

In this case, when mud etc. penetrate | invades into the space part of a protector, mud etc. are discharged | emitted from the discharge port opened to the vehicle rear side. Here, since the diameter of the discharge port is reduced from the inner end portion toward the outer end portion, mud or the like hardly enters from the outer end portion of the discharge port to the inner end portion side (that is, in the space portion). Mud etc. are easily discharged from the end portion to the outer end portion (that is, outside).
Therefore, even if mud or the like enters from the free end of the extended piece of the protector, the mud or the like that has entered can be effectively discharged from the discharge port.

  Preferably, the extending piece is configured to be detachably connected to the main body.

In this case, the main body portion and the extending piece of the protector are configured separately and can be attached and detached.
Therefore, when the free end portion of the extended piece is worn, the increase in the maintenance cost can be suppressed by replacing only the extended piece of the protector. On the other hand, when the body part of the protector is worn, the same effect can be obtained by replacing only the body part of the protector. In addition, by attaching an extension piece to an existing protector (without an extension piece), the protector of the present invention can be realized by diverting the existing protector. The presence or absence of the extended piece 520 can also be made selectable.

  More preferably, the extension piece is configured to be connected to the main body portion so that the position thereof can be adjusted.

In this case, the extension piece of the protector is mounted with its position adjusted with respect to the main body.
Therefore, the free end of the extended piece can be brought as close as possible to the outer peripheral surface of the tilling final shaft regardless of the design error of the protector. Further, even when the free end portion of the extended piece is worn, the scraping action of weeds or the like can be sustained for a longer period by adjusting the position again and appropriately positioning the extended piece.

  According to the support structure of the tillage shaft according to the present invention, the free end portion of the extending piece extending from the protector that covers the lower portion of the transmission case surrounds only within a predetermined range around the axis of the tillage final shaft. It is possible to prevent weeds and the like from being wound around the final shaft. In addition, an increase in the number of parts can be prevented by scraping weeds or the like using a protector that covers the lower portion of the transmission case.

Hereinafter, preferred embodiments of a support structure for a tillage shaft according to the present invention will be described with reference to the accompanying drawings.
FIG. 1 is a side view showing a tractor A to which a first embodiment of a support structure for a tillage shaft according to the present invention is applied.

A tractor A shown in FIG. 1 includes a tractor main body 200 and a rotary cultivator 300 attached to the tractor main body 200.
In the tractor main body 200, a bonnet 6 is disposed at the front of a main body that suspends front and rear wheels 1 and 2 in the front and rear, and a drive source (here, an engine) 5 is disposed inside the bonnet 6. . A steering handle 10 is disposed in front of the driver's seat 11.

A mission case 50 is disposed behind the drive source 5, and the power from the drive source 5 is transmitted to the mission case 50 to change the speed, and the drive force is transmitted to the rear wheel 2 and the front wheel 1. It is configured.
The rotary cultivator 300 is mounted on a work machine mounting device 220 provided at the rear of the tractor main unit 200 via a coupling mechanism 210 provided in the device 220.
The work implement mounting device 220 includes a top link 221 and a pair of left and right lower links 222. The lower link 222 is connected via a lift rod 224 to a lift arm 223 provided on a side in the vehicle width direction of a hydraulic case 51 disposed on the transmission case 50.
The rotary tiller 300 can be turned up and down via the lift rod 224 and the lower link 222 when the lift arm 223 is turned up and down by expansion and contraction of a hydraulic cylinder (not shown) in the hydraulic case 51. ing.

  Further, the rotary tiller 300 is driven by a part of the power from the drive source 5 being transmitted to the rotary tiller 300 via the universal joint 16 from the PTO shaft 15 protruding from the rear surface of the transmission case 50. It is configured.

2 and 3 are developed sectional views of the power transmission structure of the rotary tiller shown in FIG. 2 is a developed sectional view of the power transmission structure on the upstream side in the transmission direction, and FIG. 3 is a developed sectional view of the power transmission structure on the downstream side in the transmission direction, continuing from FIG.
As shown in FIGS. 1 to 3, the rotary tiller 300 includes an input shaft 310, a power transmission shaft 320, a rotor case 330, a tilling unit 340, and a tilling cover 150 that covers the tilling unit 340. ing.
The input shaft 310 is configured to be operatively connected to the PTO shaft 15 provided in the apparatus via the universal joint 16, and the power from the drive source 5 is transmitted to the PTO shaft 15 and the universal joint. 16 is transmitted.

  The power transmission shaft 320 is configured such that power from the input shaft 310 is transmitted by the first transmission mechanism 350, and is operatively connected to the input shaft 310 via the first transmission mechanism 350. .

Specifically, the first transmission mechanism 350 includes a bevel gear box 351 and first and second bevel gears 352 and 353.
The bevel gear box 351 supports the input shaft 310 so as to be rotatable around an axis, and also supports one end portion of the power transmission shaft 320 disposed so as to be orthogonal to the input shaft 310 so as to be rotatable around the axis. is doing.
The first bevel gear 352 is accommodated in the bevel gear box 351 and is externally fixed to the input shaft 310. The second bevel gear 353 is accommodated in the bevel gear box 351 and is externally fitted and fixed to one end side of the power transmission shaft 320 so as to mesh with the first bevel gear 352.

  The rotor case 330 is disposed at the outer ends of the pair of left and right main beams 331 and 332 provided on both sides of the transmission mechanism 350 in the vehicle width direction and the pair of left and right main beams 331 and 332, respectively. The supporting members 333 and 334 are provided.

Specifically, the support member 333 disposed on the one main beam 331 is a chain case here, and the support member 334 disposed on the other main beam 332 is a side frame here. It is said that.
The one main beam 331 is disposed so as to connect one side surface of the bevel gear box 351 and the upper end portion of the chain case 333, and the power transmission shaft 320 is internally provided. The other main beam 332 is disposed so as to connect the other side surface of the bevel gear box 351 and the upper end portion of the side frame 334.

The chain case 333 has an upper end supporting the other end portion of the power transmission shaft 320 so as to be rotatable about its axis, and a bearing member 101 provided at the lower end is a tilling shaft 110 constituting the tilling portion 340. One end portion side is supported through a bearing member 410 and an oil seal member 420 so as to be rotatable about the axis and in a liquid-tight manner. The bearing member 101 according to the present embodiment is a bearing case separated from the chain case 333 and is fixed to the chain case 333 by welding or the like, but is integrally formed with the chain case 333. Also good.
Here, the oil seal member 420 is for preventing leakage of the lubricating oil in the chain case 333.
Further, in the side frame 334, the bearing member 101 at the lower end portion supports the other end portion of the tilling shaft 110 so as to be rotatable about the axis.

The tilling part 340 includes a tilling shaft 110 and a tilling claw 120.
The tillage shaft 110 is configured such that the power from the power transmission shaft 320 is transmitted by the second transmission mechanism 360, and is operatively connected to the power transmission shaft 320 via the second transmission mechanism 360. Yes.

Specifically, the second transmission mechanism 360 includes first and second sprockets 361 and 362 and a chain 363.
The first sprocket 361 is externally fitted and fixed to the other end of the power transmission shaft 320, and the second sprocket 362 is externally fixed to the one end of the tillage shaft 110. The chain 363 is wound around the first and second sprockets 361 and 362.
Further, the tilling claw 120 is provided on the tilling claw shaft 112 constituting the tilling shaft 110 so as not to rotate relative to the axis by using a fixing member BL1.

  With this configuration, the rotary cultivator 300 allows the power transmitted from the input shaft 110 to the power transmission shaft 320 via the first transmission mechanism 350 to pass through the second transmission mechanism 360. This is transmitted to the tilling shaft 110, whereby the tilling claw 120 on the tilling shaft 110 is rotationally driven around the axis.

Next, the support structure 100 for the tillage shaft 110 according to the present embodiment will be described in detail with reference to FIG.
The tilling shaft 110 includes a tilling final shaft 111 and a tilling claw shaft 112 as shown in FIG.

The tilling final shaft 111 includes a shaft body 111a and a connecting flange 111b.
The shaft main body 111a is supported in a fluid-tight manner so as to be rotatable about an axis through the bearing member 410 and the oil seal member 420 installed on the bearing member 101, and the connecting flange 111b is transmitted to the shaft main body 111a. It is provided downstream in the direction (inward in the vehicle width direction).
Further, the tilling claw shaft 112 is connected to the tilling final shaft 111 so as not to rotate relative to the tilling final shaft 111 via the connecting flange 111b constituting the tilling final shaft 111.

Further, as shown in FIG. 3, an opening 333 a is provided on the downstream side of the chain case 333 in the transmission direction of the bearing member 101.
The shaft main body 111a is supported by a hollow holder 430 attached to the opening 333a formed in the chain case 333 via the bearing member 410 and the oil seal member 420 so that the shaft main body 111a is rotatable and liquid-tight around the axis. .
Specifically, the bearing member 410 and the oil seal member 420 are provided between the second sprocket 362 and the connection flange 111b, and the oil seal member 420 is disposed in the vehicle width direction of the bearing member 410. In the direction (downstream in the transmission direction).

In the present embodiment, the bearing member 101 has a protruding portion 101a that is protruded downstream in the transmission direction from the chain case 333 in the transmission direction. The connecting flange 111b has a plate portion extending radially outward from the shaft body 111a and an extending portion 111c extending from the outer peripheral edge of the plate portion in a direction approaching the chain case 333. Here, the extending portion 111c forms a tapered region 111ct whose outer diameter is reduced toward the upstream side in the transmission direction of the shaft body 111a (inward in the vehicle width direction), and the protruding portion 101a of the bearing member 101. To form the first labyrinth.
Furthermore, the transmission direction upstream end surface 111d of the extending portion 111c is configured to cooperate with the opposing end surface 152a of the fixing member to form a second labyrinth. In the present embodiment, the fixing member includes the side plate 151 of the tillage cover 150 and the tilling cover side member 152 (here, the hinge plate 152 connected to the side plate 151) connected to the side plate 151. The end surface 152 a of the member is a downstream end surface of the hinge plate 152.
With such first and second labyrinths, the installation space P of the bearing member 410 and the oil seal member 420 is configured to be blocked from the outside.

Here, in the present embodiment, as shown in FIG. 3, a protector 500 that covers a lower portion of a chain case 333 that is a transmission case is provided. Here, FIG. 4 is the figure which looked at the protector 500 of FIG. 3 from the transmission direction downstream side.
As shown in FIGS. 3 and 4, the protector 500 includes a main body 510 that covers the chain case 333, and extends from the main body 510 toward the tilling final shaft 111, and a free end portion of the tilling final shaft 111. And an extended piece 520 close to the outer peripheral surface. As shown in FIG. 4, the extending piece 520 is configured such that the free end portion surrounds the outer peripheral surface of the tilling final shaft 111 only in a predetermined range around the axis of the tilling final shaft 111. . Various ranges can be set as long as the surrounding range is not the entire circumference.

According to the tilling shaft support structure 100 configured as described above, the chain case 333 is covered by the main body 510 of the protector 500, while the free end portion of the extending piece 520 extending from the main body 510 toward the tilling final shaft 111. Is close to the outer peripheral surface of the tilling final shaft 111. The outer peripheral surface of the tilling final shaft 111 is surrounded by the free end portion of the extending piece 520 only in a predetermined range around the axis of the tilling final shaft 111.
Here, when weeds or the like are to be wound around the cultivation final shaft 111 as the cultivation final shaft 111 is rotated, the weeds or the like to be wound are surrounded only within a predetermined range around the axis of the cultivation final shaft 111. It comes into contact with the free end of the locating piece 520 and is scraped off (scraper action occurs).

  Thus, the free end of the extended piece 520 extending from the protector 500 that covers the lower portion of the chain case 333 surrounds only within a predetermined range around the axis of the tilling final shaft 111, so that Winding of weeds can be prevented. In addition, an increase in the number of parts can be prevented by scraping weeds or the like using the protector 500 that covers the lower part of the chain case 333.

  In the present embodiment, the free end portion of the extending piece 520 is configured to be close to the tapered region 111ct.

In this case, in the taper region 111ct of the extending portion 111c extending from the connecting flange 111b, the outer diameter of the shaft body 111a is reduced toward the upstream side in the transmission direction. Accompanying weeds and the like move in a direction approaching the free end 520 of the protector 500.
Thereby, the weeds etc. which are going to wind with rotation of the tilling final axis | shaft 111 can be moved to the direction of the free end part of the protector 500. FIG. Therefore, the scraping action of weeds and the like by the extending piece 520 of the protector 500 can be obtained more effectively.

  In addition, the second labyrinth formed by the end surface of the fixing member (in this embodiment, the downstream end surface of the hinge plate 152) and the upstream end surface in the transmission direction of the extending portion 111c of the coupling flange 111b causes the taper region 111ct to be Can be prevented from entering between the hinge plate 152 and the extending portion 111c of the connecting flange 111b, such as weeds and mud that have moved in the direction of the free end of the extending piece 520 of the protector 500. . In addition, even if mud or the like has entered beyond the second labyrinth, the bearing member 410 and the first labyrinth formed by the extending portion 111c of the connecting flange 111b and the protruding portion 101a of the bearing member 101 It is possible to prevent mud or the like from entering the installation space P of the oil seal member 420 and to reliably block the installation space P from the outside.

In the present embodiment, the space 500 is configured to exist in at least a part of a region where the protector 500 and the chain case face each other.
In addition, as shown in FIG. 4, the protector 500 includes a discharge port 540 having an inner end communicating with the space 530 and an outer end opened to the vehicle rear side, from the inner end. A discharge port 540 having a reduced diameter is formed toward the outer end.

  In this case, even if mud or the like temporarily enters from the free end portion of the extension piece 520 of the protector 500 by providing the space portion 530 in a part of the region where the protector 500 and the chain case 333 oppose each other. Therefore, it is preferentially stored in the space portion 530, and it is possible to improve the durability by preventing the oil seal member 420 which is vulnerable to intrusion of mud or the like.

Moreover, when mud or the like enters the space portion 530 of the protector 500, the mud or the like is discharged from the discharge port 540 opened to the vehicle rear side. Here, since the discharge port 540 is reduced in diameter from the inner end portion toward the outer end portion, mud or the like enters the inner end portion side (that is, in the space portion 530) from the outer end portion of the discharge port 540. It is difficult to remove mud or the like from the inner end portion to the outer end portion (that is, outside).
Therefore, even if mud or the like enters from the free end of the extending piece 520 of the protector 500, the mud or the like that has entered can be effectively discharged from the discharge port 540.

Next, a second embodiment according to the present invention will be described. FIG. 5 is a cross-sectional view showing a schematic configuration of a support structure for a tillage shaft according to a second embodiment of the present invention. In the present embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted.
This embodiment is different from the first embodiment in that a protruding portion 101a of the bearing member 101 is provided with a boss portion 101b extending radially outward, and an extending portion 111c of the connecting flange 111b is The outer peripheral surface of a region located on the downstream side in the transmission direction of the boss portion 101b and the downstream end surface and the outer peripheral surface facing the downstream side in the transmission direction of the boss portion 101b while forming the tapered region 111ct. Labyrinth is formed in cooperation with. At this time, an uneven labyrinth is formed on the downstream end surface of the boss portion 101b and the upstream end surface of the extending portion 111c. More specifically, a protrusion is provided on the downstream end face of the boss 101b, and a recess corresponding to the protrusion is provided on the upstream end face of the extension 111c. In addition, the shape of the said protrusion part and a recessed part is not restricted to the aspect shown in FIG.

In this case, using the boss portion 101b provided on the protruding portion 101a protruding from the bearing member 101, the downstream end surface and the outer peripheral surface facing the downstream side in the transmission direction of the boss portion 101b, and the boss portion of the protruding portion 101a. A labyrinth is formed by the outer peripheral surface of the region located on the downstream side in the transmission direction from 101b and the extending portion 111c approaching the chain case 333 from the connecting flange 111b. In addition, the protrusion formed on the downstream end surface of the boss 101b and the recess formed on the upstream end of the extending portion 111c are engaged with each other, so that the space between the boss 101b and the extending portion 111c is engaged. Thus, a labyrinth having a more complicated (intricate) shape is formed.
The extending portion 111c is formed with a tapered region 111ct that moves weeds or the like to be wound with the rotation of the tilling final shaft 111 in the direction of the free end of the extending piece 520 of the protector 500.

  In this way, by forming a labyrinth using the boss portion 101b, weeds and mud that have moved in the direction of the free end of the extending piece 520 of the protector 500 on the tapered region 111ct are separated from the bearing member 101. Intrusion from between the connecting flange 111b can be prevented. At this time, intrusion of mud and the like can be more effectively prevented by making the shape of the labyrinth more complicated.

Subsequently, a third embodiment according to the present invention will be described. FIG. 6 is a cross-sectional view showing a schematic configuration of a support structure for a tillage shaft according to a third embodiment of the present invention. In the present embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted.
The present embodiment is different from the first embodiment in that the extended piece 520 of the protector 500 is detachably connected to the main body 510, and the extended piece 520 is connected to the main body 510. It is connected so that position adjustment is possible.
More specifically, for example, a connection hole 560 is provided in both the main body 510 and the extending piece 520, and both are fixed to the connection hole 560 by a connection member 550 such as a screw. Here, at least one of the main body 510 and the connecting hole 560 of the extending piece 520 is a long hole whose position of the connecting member 550 can be adjusted in the transmission direction (vehicle width direction) of the shaft main body 111a. Can be realized.

  In this case, the main body 510 and the extension piece 520 of the protector 500 are configured separately and can be attached and detached. In addition, the extension piece 520 of the protector 500 is mounted with its position adjusted with respect to the main body 510.

Thus, by making the extended piece 520 of the protector 500 detachable, when the free end portion of the extended piece 520 is worn, only the extended piece 520 of the protector 500 is replaced, so that the maintenance cost can be reduced. The rise can be suppressed. On the other hand, when the main body 510 of the protector 500 is worn, the same effect can be obtained by replacing only the main body 510 of the protector 500. Further, by attaching the extension piece 520 to the existing protector 500 (without the extension piece 520), the protector 500 of the present embodiment is realized by diverting the existing protector (by performing only minor processing). In addition to reducing the manufacturing cost, the presence or absence of the extended piece 520 can be selected according to the specification.
Further, by making it possible to adjust the position of the extended piece 520 of the protector 500, the free end portion of the extended piece 520 can be used as the outer peripheral surface (taper region 111ct) of the tilling final shaft 111 regardless of the design error of the protector 500. As close as possible. Further, even when the free end portion of the extended piece 520 is worn, the scraping action of weeds and the like can be sustained for a longer period by re-adjusting the position and properly positioning (in other words, the extended piece 520 exchange cycles can be lengthened).

As mentioned above, although embodiment which concerns on this invention was described, this invention is not limited to the said embodiment, A various improvement, change, and correction are possible within the range which does not deviate from the meaning.
For example, in the above-described embodiment, the tilling shaft 110 is inward in the vehicle width direction with respect to the second transmission mechanism 360 (chain case 333) (in other words, the downstream side in the transmission direction in the tilling final shaft 111 is inward in the vehicle width direction). The side rotary type tiller has been explained, but the tillage shafts are provided on both sides of the second transmission mechanism (chain case) in the vehicle width direction (in other words, the upstream side in the transmission direction of the tillage final shaft is outward in the vehicle width direction). The present invention can also be applied to a center rotary type tiller.

It is a side view which shows the tractor to which 1st Embodiment of the support structure of the tilling shaft which concerns on this invention is applied. It is an expanded sectional view of the power transmission structure of the power transmission direction upstream of the rotary tiller shown in FIG. It is an expanded sectional view of the power transmission structure in the transmission direction downstream side of the rotary cultivator shown in FIG. It is the figure which looked at the protector 500 of FIG. 3 from the transmission direction downstream side. It is sectional drawing which shows schematic structure of the support structure of the tilling shaft which concerns on 2nd Embodiment of this invention. It is sectional drawing which shows schematic structure of the support structure of the tilling shaft which concerns on 3rd Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 ... Support structure of tilling shaft 110 ... Tilling shaft 112 ... Tilling claw shaft 101 ... Bearing member 101a ... Projection part 101b ... Boss part 111 ... Tilling final shaft 111a ... Shaft body 111b ... Connection flange 111c ... Extension part 111ct ... Tapered area
333 ... Chain case (transmission case) 360 ... Second transmission mechanism (transmission mechanism)
410: Bearing member 420 ... Oil seal member
DESCRIPTION OF SYMBOLS 500 ... Protector 510 ... Main-body part 520 ... Extension piece 530 ... Space part 540 ... Discharge port 550 ... Connection member 560 ... Connection hole

Claims (10)

A transmission case accommodating the transmission mechanism and capable of storing oil, a bearing member provided in the transmission case, a bearing member installed in the bearing member, and an oil seal member are supported in a freely rotatable and liquid-tight manner around the axis. A tilling final shaft having a connecting shaft provided on the downstream side in the transmission direction of the shaft body, and a tilling claw shaft connected to the tilling final shaft through the connecting flange so as not to rotate relative to the tilling shaft; A support structure for a tillage shaft including a protector that covers a lower portion of the transmission case,
The protector has a main body portion that covers the transmission case, and an extending piece that extends from the main body portion toward the tilling final shaft and whose free end portion is close to the outer peripheral surface of the tilling final shaft,
The extending piece is configured so that the free end portion surrounds the outer peripheral surface of the tilling final shaft only within a predetermined range around the axis of the tilling final shaft. The connecting flange has a tapered region whose outer diameter is reduced as it goes upstream in the transmission direction;
The tiller shaft support structure according to claim 1, wherein a free end portion of the extending piece is adjacent to the tapered region. In the bearing member, the downstream side in the transmission direction protrudes from the transmission case to the downstream side in the transmission direction,
The connection flange has an extending portion that is close to the transmission case;
The tiller shaft support structure according to claim 2, wherein the extending portion forms the tapered region and forms a first labyrinth in cooperation with the protruding portion of the bearing member.   The tiller shaft support structure according to claim 3, wherein an end surface on the upstream side in the transmission direction of the extending portion cooperates with an end surface of the opposing fixing member to form a second labyrinth. The bearing member has a downstream side in the transmission direction protruding from the transmission case to the downstream side in the transmission direction, and a boss portion extending radially outward is provided in the protruding portion,
The connection flange has an extending portion that is close to the transmission case;
The extending portion forms the tapered region, and an outer peripheral surface of a region of the projecting portion located on the downstream side in the transmission direction from the boss portion, and a downstream end surface and an outer periphery facing the downstream side in the transmission direction of the boss portion. The tiller shaft support structure according to claim 2, wherein the labyrinth is formed in cooperation with the surface.   6. The support structure for a tillage shaft according to claim 5, wherein an uneven labyrinth is formed on a downstream end surface of the boss portion and an upstream end surface of the extending portion.   The tiller shaft support structure according to any one of claims 1 to 6, wherein a space portion exists in at least a part of a region where the protector and the transmission case face each other.   The protector is a discharge port having an inner end communicating with the space portion and an outer end opened to the rear side of the vehicle, the discharge diameter being reduced from the inner end toward the outer end. The support structure for the tillage shaft according to claim 7, wherein an outlet is formed.   The tiller shaft support structure according to any one of claims 1 to 8, wherein the extending piece is detachably connected to the main body.   The tiller shaft support structure according to claim 9, wherein the extending piece is connected to the main body portion so as to be adjustable in position.

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