WO2015072511A1

WO2015072511A1 - Rice planting machine

Info

Publication number: WO2015072511A1
Application number: PCT/JP2014/080058
Authority: WO
Inventors: 健奥村; 憲和松尾; 翔一中村; 黒田　智之; 市川　祐介
Original assignee: ヤンマー株式会社
Priority date: 2013-11-13
Filing date: 2014-11-13
Publication date: 2015-05-21
Also published as: KR20160083112A; KR101798108B1; CN105705000B; CN105705000A

Abstract

Provided is a rice planting machine that can improve durability of a drive transfer mechanism by reducing pitting and chipping of teeth occurring in an intermediate gear by reducing deflection in an intermediate axle within a rear axle case. In a rice planting machine which transfers mechanical power to a rear axle case from an engine via a transmission case, an intermediate gear is provided as a reduction mechanism within the rear axle case, and a bearing that supports the intermediate axle, mating with the intermediate gear, and a bearing holder for holding the bearing are also provided. The bearing holder is affixed to the rear axle case using a plurality of bolts and a plurality of reamer bolts.

Description

Rice transplanter

The present invention relates to a bearing structure in a rear axle case of a rice transplanter.

A general rice transplanter employs a four-wheel drive system that drives front wheels and rear wheels by transmitting power from an engine to a front axle case and a rear axle case via a mission case (for example, Patent Document 1). reference). An intermediate gear for speed reduction is arranged in the rear axle case, and power from the transmission case is transmitted to the axle of the rear wheel via the intermediate gear.

JP 2011-162135 A

When the axle load is large, the intermediate shaft that supports the intermediate gear that transmits power in the rear axle case is bent, causing pitching and chipping in the intermediate gear. In some cases, the durability was reduced and the power transmission efficiency was reduced.
An object of the present invention is to provide a rice transplanter that reduces the pitching and tooth missing generated in the intermediate gear by reducing the deflection of the intermediate shaft, thereby improving the durability of the power transmission mechanism.

The rice transplanter of the present invention is a rice transplanter that transmits power from an engine to a rear axle case through a transmission case, and an intermediate gear serving as a speed reduction mechanism is provided in the rear axle case, and the intermediate shaft into which the intermediate gear is fitted. And a bearing holder for holding the bearing. The bearing holder is fixed to the rear axle case using a plurality of bolts and a plurality of reamer bolts.

The bearing holder is made of cast iron.

According to the present invention, even when the axle load is large, it is possible to reduce the deflection of the intermediate shaft, and it is possible to reduce pitching and missing teeth generated in the intermediate gear.

It is a side view of a rice transplanter. It is a top view of a rice transplanter. It is a skeleton figure which shows the transmission mechanism of a rear axle case. It is a perspective view which shows a rear axle case. It is a figure which shows a bearing holder. It is a perspective view which shows attachment of the bearing holder using a reamer bolt. It is sectional drawing which shows the fixation structure of the speed-reduction mechanism in a rear axle case. It is a figure which shows a leveling apparatus. It is an expanded sectional view which shows the transmission part of a leveling apparatus. It is sectional drawing of a transmission case. It is an expanded sectional view which shows the effect show | played by the enlarged diameter part of a joint. It is a figure which shows another embodiment of the labyrinth structure of a transmission case and a joint. It is a figure which shows another embodiment of the protection structure provided in opening of a transmission case. It is an expanded sectional view showing a bearing structure in a support arm of a leveling device. It is an expanded sectional view which shows the effect show | played by the protection member of a side case.

The rice transplanter 1 will be described with reference to the accompanying drawings.
The rice transplanter 1 includes a traveling machine body 2, a work machine 3, and a lifting link mechanism 4.

The traveling machine body 2 includes a vehicle body frame 11, an engine 12, a transmission 13, a front axle 14, a rear axle 15, a driving operation unit 16, a front wheel 17, and a rear wheel 18.

The body frame 11 is a main structure of the rice transplanter 1. The body frame 11 forms the skeleton of the rice transplanter 1 and is equipped with an engine 12 and the like.

The engine 12 is a power source that generates power by burning fuel. The engine 12 can change a driving | running state by an operator operating the shift pedal 21 grade | etc.,.

The transmission 13 is a power transmission device that performs forward / reverse switching and shifting of the rice transplanter 1. The transmission 13 includes a continuously variable transmission using hydraulic oil as a power transmission medium. The continuously variable transmission can convert part or all of the input rotational power into hydraulic oil pressure, and output the hydraulic oil pressure again as rotational power. The transmission 13 is housed in the mission case 22.

The front axle 14 is a power transmission device that transmits the power of the engine 12 to the front wheels 17. The power of the engine 12 is input to the front axle 14 via the transmission 13. The front axle 14 is provided with a steering device, and the operator can steer the front wheels 17 by operating the handle 23. The front axle 14 is housed in a front axle case 24.

The rear axle 15 is a power transmission device that transmits the power of the engine 12 to the rear wheel 18. The power of the engine 12 is input to the rear axle 15 via the transmission 13. The rear axle 15 is housed in a rear axle case 25.

In the driving operation unit 16, the driver's seat 26 is disposed so as to face the handle 23, and the operator operates the handle 23 and the like while sitting on the driver's seat 26. In addition to the shift pedal 21 and the handle 23 described above, various operation tools for operating the rice transplanter 1 and the like are arranged in the driving operation unit 16.

The work machine 3 includes a seedling stage 31, a planting mechanism 32, and a float 33.

The seedling stage 31 is a seedling supply device that supplies seedlings to the planting mechanism 32. The seedling mat placed on the seedling placing table 31 is appropriately sent to the planting mechanism 32 by the vertical feeding mechanism. The seedling stage 31 is slidably mounted on a rail provided on the planting frame, and reciprocates in the left-right direction in accordance with the operation of the planting mechanism 32. In this way, the seedling stage 31 can supply seedlings to the planting mechanism 32.

The planting mechanism 32 is a seedling planting device for planting a seedling in a field.
The planting mechanism 32 includes an inter-plant change device 41, a planting center case 42, a planting bevel case 43, a rotary case 44, and a planting arm 45.
The power from the inter-strain change device 41 is transmitted to the planting bevel case 43 through the planting center case 42. Then, power is transmitted to the rotary cases 44 provided on the left and right of the planting bevel case 43. By rotating the planting arm 45 provided on the rotary case 44 together with the rotary case 44, it is possible to take seedlings from the seedling mount 31 and plant them in the field.

The float 33 is a planting depth adjusting device that raises and lowers the working machine 3 to adjust the planting depth of the seedlings. The float 33 is also a support device for the seedling mount 31 and the planting mechanism 32 described above. The float 33 includes a center float 33a disposed in the center portion of the work machine 3, and side floats 33b disposed on both sides of the center float 33a. The position sensor provided in the center float 33a moves up and down the work implement 3 to an appropriate height in conjunction with the control device of the traveling machine body 2. Furthermore, since the center float 33a and the side float 33b have a smooth bottom surface in contact with the field, it is possible to level the field. Thus, the center float 33a and the side float 33b which comprise the float 33 can adjust the planting depth of a seedling by raising and lowering the working machine 3 while leveling the field.

The elevating link mechanism 4 includes an upper link 51, a lower link 52, and a hydraulic actuator (not shown).

The upper link 51 and the lower link 52 are connecting devices that connect the traveling machine body 2 and the work machine 3. The upper link 51 and the lower link 52 are also lifting devices that lift and lower the work machine 3. By extending and contracting the hydraulic actuator in response to an instruction from the above-described control device, the posture of the upper link 51 and the lower link 52 can be changed, and the work implement 3 can be moved up and down based on an operation by an operator or a signal from a position sensor. .

As described above, the rice transplanter 1 performs the planting work by the planting mechanism 32 while traveling by driving the front wheels 17 and the rear wheels 18 with the power of the engine 12.

As shown in FIG. 3, the rear wheel 18 is driven by transmitting power from the engine 12 to the rear axle case 25 via the transmission case 22.
The rear input shaft 61 extends from the mission case 22 toward the rear rear axle case 25. The rear axle case 25 includes a case 62 formed in a substantially cylindrical shape from one end of the extended rear input shaft 61 along both left and right directions, and gear cases 63 formed on both left and right ends thereof. The side surface of the gear case 63 is open, and the rear axle case 25 can be sealed by attaching a lid 63a to the opening surface.

In the case 62, power is transmitted from the rear input shaft 61 to the side clutch shafts 65 provided in the left and right directions via the

bevel gears

64a and 64b. The side clutch shaft 65 extends into the gear case 63. A side clutch 66 is provided in the middle of the side clutch shaft 65, and a gear 67 is fixed to the end portion thereof. In the gear case 63, power is transmitted to the intermediate shaft 69 via an intermediate gear 68 that meshes with the gear 67.
An intermediate gear 68 is fixed to the intermediate shaft 69, and an intermediate shaft gear 70 is formed on the outer peripheral surface at the side of the fitting portion with the intermediate gear 68. The intermediate shaft gear 70 meshes with a final gear 71 fixed to the axle 72. The axle 72 extends from the gear case 63 toward the aircraft side. One end (extension side) of the axle 72 is fixed to the rear wheel 18, and the rear wheel 18 is driven by the rotation of the axle 72.
As described above, power is transmitted from the rear input shaft 61 to the side clutch shaft 65 in the case 62, and the gear 67, the intermediate gear 68, the intermediate shaft gear 70, and the final gear 71 are transferred from the side clutch shaft 65 in the gear case 63. Power is transmitted to the axle 72 through the via.

By providing the intermediate gear 68 and the intermediate shaft gear 70, the rotational speed of the axle 72 can be changed with respect to the rotational speed of the side clutch shaft 65. Here, by reducing the number of teeth of the intermediate shaft gear 70 with respect to the number of teeth of the final gear 71, the number of rotations of the intermediate shaft gear 70 is increased with respect to the number of rotations of the axle 72. That is, the intermediate gear 68 and the intermediate shaft gear 70 are provided as the speed reduction mechanism 73.

As shown in FIG. 4, in order to support the speed reduction mechanism 73 in the gear case 63,

bearings

81 and 82 that support the intermediate shaft 69 and a bearing holder 91 that holds the bearing 81 are provided.
As shown in FIG. 5, the bearing holder 91 has a shape in which the right side of a plate formed in a substantially rectangular shape in a side view is curved toward the center thereof. A hole 92 for supporting the bearing 81 is provided at the center of the bearing holder 91, and a through hole 93 for fixing to the gear case 63 is appropriately provided around the hole 92. In the present embodiment, six through holes 93 are provided.

The intermediate gear 68 is fitted to the intermediate shaft 69. A bearing 81 is attached to the end of the intermediate shaft 69 on the inner side of the machine body, and a bearing 82 is attached to the end of the outer side of the machine body (wheel side). By fixing the

bearings

81 and 82 to a bearing holder 91 fixed to the inner side of the gear case 63 and a bearing holder (not shown) integrally formed to the outer side of the gear case 63, the intermediate gear 68 is fixed. The intermediate shaft gear 70 is rotatably supported in the gear case 63.

As shown in FIG. 4, the bearing holder 91 is fixed to the gear case 63 using four bolts 95 and two reamer bolts 94. In accordance with the arrangement of the through holes 93, bolt holes 94 a and 95 a are provided in the gear case 63.

The bearing holder 91 is fixed to the gear case 63 by using the reamer bolt 94 and the bolt 95 in the bolt holes 94a and 95a, respectively.
In FIG. 4, four

bolts

95, 95... Are used at the four corners of the substantially rectangular shape of the bearing holder 91, and the two

reamer bolts

94, 94 are located at positions where there are spaces other than the four corners in the shape of the bearing holder 91. Although the state in use is shown in the figure, the number and the arrangement are not limited to this.

As shown in FIGS. 6 and 7, the reamer bolt 94 is a bolt having a positioning function. In the present embodiment, by using the reamer bolt 94 in the bolt hole 94a, it is possible to improve the mounting accuracy of the bearing holder 91 with respect to the gear case 63 and improve the fastening force.

The reamer bolt 94 has a slightly larger bolt diameter than the hole diameter of the through hole 93 and can be lightly driven and tightened, so that the mounting accuracy when positioning the bearing holder 91 is high.
Further, since a lateral force is received as a shearing force, a displacement between the bearing holder 91 and the rear axle case 25 is prevented. Also, deformation due to external force can be prevented.

Further, the reamer bolt 94 can be positioned as compared with the case where a knock pin or the like is used, and the bearing holder 91 can be fixed to the gear case 63 as a bolt, so that the limited space of the bearing holder 91 is effectively utilized. can do.

As described above, the fastening force can be improved by using the reamer bolt 94. For this reason, the load sharing in the bearing holder 91 and the gear case 63 as a whole can be reduced, and the rigidity can be increased. By increasing the rigidity, the deflection of the bearing holder 91 and the gear case 63 can be reduced. Therefore, it is possible to prevent pitching and chipping that may occur in the intermediate shaft gear 68 and the intermediate shaft gear 70 by reducing the deflection of the intermediate shaft 69 supported by the bearing holder 91 and the gear case 63.

The bearing holder 91 is preferably made of cast iron from the viewpoint of productivity. In the present embodiment where high strength and rigidity are required, the bearing holder 91 is cast using ductile cast iron. Thus, by using the cast iron bearing holder 91, damage (pitching and chipping) of the intermediate shaft 69 and the intermediate gear 68 can be suppressed more effectively.
In particular, ductile cast iron is cast iron in which the shape of graphite is made spherical to improve strength and ductility, and has excellent tensile strength and elongation, and has strength several times that of general cast iron. Therefore, the displacement between the bearing holder 91 and the rear axle case 25 can be reduced, and deformation due to external force can also be reduced.

As described above, by fixing the bearing holder 91 to the gear case 63 using the reamer bolt 94, the number of bolts can be increased even in a limited space of the bearing holder 91, and the fastening force can be improved. Can do.

Next, with reference to FIGS. 8 to 15, the leveling device provided in the rice transplanter will be described.

As shown in FIGS. 8 and 9, in the leveling device 100, a part of the power from the rear input shaft 61 is branched to the leveling transmission shaft 99 via the rear axle case 25, and the input is coupled to the leveling transmission shaft 99. It is transmitted to the drive shaft 103 that extends toward both sides of the transmission case 102 via the shaft 101 and the transmission case 102 that receives the input of the input shaft 101. A plurality of leveling rotors 104 are fixed to the drive shaft 103. The drive shaft 103 is formed in a quadrangular shape when viewed in cross section, and the leveling rotor 104 is fixed to the drive shaft 103 so as not to rotate relative to the drive shaft 103 by engaging with a rectangular opening at the center of the leveling rotor 104.
The drive shaft 103 is a rotor input shaft 105 that protrudes laterally from both side surfaces of the transmission case 102, a rotor drive shaft 106 that is connected to the rotor input shaft 105 and extends to both sides, and the rotor input shaft 105 and the rotor drive. A joint 107 connecting the shaft 106 is used. Connection between the rotor input shaft 105 and the joint 107 of the rotor drive shaft 106 is realized by spline fitting.

As shown in FIG. 9, in the transmission case 102, a bevel gear 108 is provided at the end of the input shaft 101 that is interlocked with the leveling transmission shaft 99, and the bevel gear 109 that meshes with the bevel gear 108 is provided in the middle of the rotor input shaft 105. Fixed to the part. Power is transmitted to the rotor input shaft 105 through these

bevel gears

108 and 109. As the rotor input shaft 105 rotates, the rotor drive shaft 106 is driven through the joint 107, and the leveling rotor 104 rotates.

As shown in FIGS. 9 and 10, the transmission case 102 includes a main body 110 and a lid 112. The main body 110 has an opening through which the input shaft 101 passes, and rotatably supports the input shaft 101 on the inner periphery of the opening, and the opening 111 through which the drive shaft 103 (rotor input shaft 105) passes is provided on both side surfaces. Have. The lid 112 rotatably supports the drive shaft 103 (rotor input shaft 105) and closes the opening 111 of the main body 110.

The main body 110 is formed as an integral box-shaped member having an opening through which the input shaft 101 penetrates and an opening 111 through which the drive shaft 103 penetrates, and an accommodating portion 110a for accommodating the

bevel gears

108 and 109 therein, and an input It is formed as a cylindrical member having an opening through which the shaft 101 passes, and includes a cylindrical portion 110b extending forward (rear axle case 25 side) from the accommodating portion 110a. The main body 110 is integrally formed so as to include the accommodating portion 110a and the cylindrical portion 110b.
An oil seal 120 that seals the inside of the transmission case 102 and

bearings

121 and 121 that rotatably support the input shaft 101 are disposed in order from the opening side on the inner peripheral surface of the cylindrical portion 110b.

The lid 112 seals the internal space of the main body 110 by closing the openings 111 provided on both side surfaces of the main body 110. An O-ring 122 is provided between the outer surface of the lid 112 and the inner surface of the main body 110. A through portion through which the rotor input shaft 105 penetrates is provided at the center of the lid 112, and a boss portion 113 that protrudes laterally from both side surfaces of the lid 112 is integrally provided along the through portion. . An oil seal 123 for sealing the inside of the transmission case 102 and a bearing 124 for rotatably supporting the rotor input shaft 105 are disposed in order from the opening side on the inner peripheral surface of the boss portion 113, and the oil seal 123 is A retaining ring 125 for fixing is provided.

By configuring the transmission case 102 with the main body 110 and the lid 112 that closes the opening 111 of the main body 110, the rigidity of the main body 110 molded integrally can be increased. By forming the main body 110 in a seamless integrated structure in this way, torque when torque fluctuation occurs in the input shaft 101 supported by the main body 110 via the bearing 121 is not applied to the main body 110. Deformation of the main body 110 can be prevented. That is, it is possible to minimize the influence on the main body 110 due to the backlash caused by the input shaft 101 accompanied by torque fluctuation or the backlash caused by the unbalance of the shaft provided in the transmission path by the rotational movement. Therefore, it is possible to prevent the sealing performance of the transmission case 102 from being impaired due to the deformation of the main body 110.
Further, by integrally molding the main body 110, it is not necessary to assemble the main body 110 when assembling the transmission case 102, and the assembly position within the main body 110 is determined at the time of molding. The positioning accuracy of each component when assembling the transmission case 102 by assembling the components can be increased.
Further, the lid 112 has a seamless high-rigidity structure, a bearing 124 for supporting the drive shaft 103 (rotor input shaft 105), and a boss portion 113 protruding to the side of the main body 110. By being provided integrally with the lid 112, even when torque fluctuation occurs in the rotor input shaft 105, it is absorbed by the entire transmission case 102 including the lid 112 having high rigidity and the main body 110 to which the lid 112 is fixed. Can do. Thereby, the influence which the play by the rotor input shaft 105 has on the cover 112 can be made as small as possible. Therefore, the sealing property of the lid 112 can be secured, and the bearing 124 can be prevented from being damaged.

As shown in FIG. 9, the end portion of the joint 107 on the transmission case 102 side covers the outer end portion of the boss portion 113 and extends from the outer end portion of the boss portion 113 toward the inner side of the transmission case 102. It is provided to do. In other words, the inner end portion of the joint 107 is provided with an enlarged diameter portion 107 a that is larger than the outer diameter of the rotor input shaft 105, and the outer peripheral portion of the enlarged diameter portion 107 a is the protruding end portion of the boss portion 113. Has been extended to overlap.
Thus, the path to the oil seal 123 is formed in a labyrinth shape by placing the opening portion of the enlarged diameter portion 107a of the joint 107 over the boss portion 113 of the transmission case 102.

Also, the transmission case 102 is filled with lubricating oil. Accordingly, by confirming that the lubricating oil has leaked from the transmission case 102, it is possible to confirm damage to the lips of the oil seals 120 and 123 of the transmission case 102. By detecting and treating the breakage of the oil seals 120 and 123 at an early stage, breakage of the

bearings

121 and 124, the

bevel gears

108 and 109, and the like disposed on the inside thereof can be prevented.

As shown in FIG. 10, an oil hole 115 is formed on the upper surface of the main body 110 of the transmission case 102, and a nipple 116 for closing the oil hole 115 is attached. The transmission case 102 is filled with lubricating oil. Accordingly, by confirming that the lubricating oil has leaked from the transmission case 102, it is possible to confirm damage to the lips of the oil seals 120 and 123 of the transmission case 102. By detecting and treating the breakage of the oil seals 120 and 123 at an early stage, breakage of the

bearings

121 and 124, the

bevel gears

108 and 109, and the like disposed on the inside thereof can be prevented.
Further, a drain (not shown) for taking out the internal lubricating oil is provided at the lower rear surface of the main body 110, and the internal lubricating oil can be easily discharged and replaced.
The transmission case 102 may be filled with grease instead of the lubricating oil.

As shown in FIG. 10, the protection member 117 is fixed to the outer periphery of the cylindrical portion 40 a of the main body portion 40. The protection member 117 protects the periphery of the connecting portion between the input shaft 101 and the leveling transmission shaft 99, and covers the leveling transmission shaft 99 connected to the input shaft 101 and a universal joint provided between them. Protect.
The protective member 117 is a bellows-shaped protective boot, and is fixed using a clip 118 around the cylindrical portion 110 b extending toward the front of the main body 110. Since the cylindrical portion 110b extends forward from the front surface of the housing portion 110a formed in a box shape, the length of the cylindrical portion 110b can be used as it is as a fixing portion of the clip 118, and is protected. The fixing length of the member 87 can be increased. Thereby, the protection member 117 can be attached more firmly, and it can prevent that it falls out and a clearance gap is vacant. Therefore, mud and foreign matter do not enter the transmission case 102 from the protective member 87 side, and occurrence of problems due to the intruder can be prevented.

As shown in FIG. 11, dust and other foreign matter wound up by the rotation of the leveling rotor 104 and entering between the transmission case 102 and the leveling rotor 104 are collected near the leveling rotor 104, and then transmitted from the leveling rotor 104 side. Proceed toward the case 102 side.
Therefore, the path entering the inside from the open portion of the inner end portion of the joint 107 toward the opening of the boss portion 113 is opposite to the traveling direction of the foreign matter (the direction from the outer side to the inner side of the transmission case 102). And the penetration | invasion direction which goes to the oil seal 123 from the outer side edge part of the boss | hub part 113 becomes the reverse direction further. In this way, by providing the joint 107, the path reaching the oil seal 123 of the transmission case 102 has a labyrinth structure that is opposite to the traveling direction of the foreign matter.

As described above, a part of the joint 107 that connects the rotor input shaft 105 and the rotor drive shaft 106 is the enlarged diameter portion 107a, and the enlarged diameter portion 107a is provided so as to cover the boss portion 113 of the transmission case 102. It is possible to effectively prevent impurities from entering the oil seal 123 of the transmission case 102.
Furthermore, since the path of the contaminants is physically blocked by the enlarged diameter portion 107a of the joint 107, the amount of contaminants reaching the inner end of the joint 107 can be reduced. At the same time, the foreign matter advances along the outer periphery of the joint 107 arranged as a rotating body, and when the foreign matter exceeds the diameter-expanded portion 107a, the centrifugal force of rotation acts in the direction in which the foreign matter separates from the joint 107. By doing so, it is also possible to expect the effect of shaking off foreign matters from the joint 107.

As shown in FIG. 11, the transmission case 102 is fixed to the drive shaft 103 so as not to rotate. That is, the drive shaft 103 rotates relative to the boss portion 113 of the transmission case 102 that is fixed so as not to rotate. As a result, a sliding portion 126 is formed between the inner peripheral surface of the joint 107 and the outer peripheral surface of the boss portion 113.
Even when impurities enter the gap between the joint 107 and the boss portion 113, the impurities can be crushed by the sliding portion 126. Therefore, even if impurities enter the inside of the joint 107, it can be prevented from being crushed by the scraper effect of the sliding portion 126 and reaching the oil seal 123, and entangled with the drive shaft 103.

FIG. 12 shows another embodiment of the labyrinth structure of the transmission case 102 and the joint 107.
As shown in FIG. 12, by providing a protrusion 130 that further expands the diameter at the inner end of the expanded diameter portion 107 a of the joint 107, it functions as a physical obstacle for preventing foreign objects from reaching the open portion of the joint 107. Can be made. Further, by providing the groove 131 on the outer peripheral surface of the boss portion 113 in the sliding portion 96, fine impurities after being crushed by the sliding portion 126 can be temporarily stored.
As described above, by making the labyrinth structure between the transmission case 102 and the joint 107 more complicated, it is possible to further reduce the amount of contaminants reaching the oil seal 123.

FIG. 13 shows another embodiment of the protective structure provided in the opening of the transmission case 102 (boss portion 113).
As shown in FIG. 13, the joint 107 is not provided with the enlarged diameter portion 107 a, but is provided with an extension portion 132 that extends the open end of the boss portion 113 radially outward, and the outer periphery of the rotor input shaft 105. A plate 133 is provided. The plate member 103 is a disk-like member fixed to the outer periphery of the rotor input shaft 105 and is disposed so as to face the extended portion 132 of the boss portion 113. As described above, the plate material 133 prevents the foreign matter traveling from the leveling rotor 104 side, and the opening of the boss portion 113 is provided by providing a path intruding between the plate material 133 and the extending portion 132 in the radial direction. It is possible to reduce the amount of contaminants reaching up to. Further, the plate member 133 rotates relative to the extending portion 132 of the boss portion 113 by rotating with the rotation of the rotor input shaft 105. In other words, the foreign matter that has entered between the plate member 133 and the extending portion 132 of the boss portion 113 can be ground.

As shown in FIG. 14, a cylindrical side case 140 is provided at the support portion of the drive shaft 103 in the support arm 135.
The side case 140 houses a bearing 141 that rotatably supports the drive shaft 103 and an oil seal 142 that is disposed on both sides of the bearing 141. In the side case 140, a collar 143 having an opening corresponding to the cross-sectional shape of the drive shaft 103 and having a circular outer peripheral surface is fixed to the drive shaft 103, and a bearing 141 and an oil seal are provided on the outer peripheral surface of the collar 143. 142 is fixed.

Protective members 146 formed in a plate-like disk shape are provided at both end portions of the collar 143. The protection member 146 is provided in contact with the outer end of the collar 143. The protection member 146 is fixed to the drive shaft 103 and is configured to be rotatable with the rotation of the drive shaft 103.

Both side ends of the side case 140 extend outward from both side ends of the collar 143. The protection member 146 extends from the outer end of the collar 143 toward the outside of the outer end of the side case 140, extends radially outward from the side case 140, and further extends toward the inside of the side case 140. Is issued. In other words, the protection member 146 is provided so as to be recessed toward the inside of the side case 140 along the axial direction of the drive shaft 103, and is extended outward in the axial direction from the recessed center portion 146a. And an outer peripheral portion 146b formed by being bent into a crank shape so as to cover the outer end of the side case 140.
Thus, by providing the protection members 146 at the openings at both ends of the side case 140, the path to the oil seal 142 is formed in a labyrinth shape.

As shown in FIG. 15, dust and other foreign matter wound up by the rotation of the leveling rotor 104 and invading between the side case 140 and the leveling rotor 104 are collected in the vicinity of the leveling rotor 104, and then the side from the leveling rotor 104 side. Proceed toward the case 140 side.
Accordingly, the path from the opening at the inner end of the protective member 146 to the inside and toward the opening of the side case 140 is in the opposite direction to the traveling direction of the foreign matter (the direction from the outside of the side case 140 to the inside). . And the penetration | invasion direction which goes to the oil seal 142 from the outer side edge part of the side case 140 turns into the reverse direction further. In this way, by providing the protective member 146, the path reaching the oil seal 142 of the side case 140 has a labyrinth structure that is opposite to the traveling direction of the foreign matter.
Further, when the foreign matter advances from the leveling rotor 104 along the drive shaft 103 toward the central portion 146a of the protection member 146 and further reaches the outer peripheral portion 146b from the central portion 146a, it is necessary to exceed the recess of the central portion 146a. There is. That is, the protection member 146 having a concave shape at the center can provide resistance to the progress of the impurities.

As described above, by providing the protection members 146 so as to cover the openings at both ends of the side case 140 from the outside, it is possible to effectively prevent foreign substances from entering the oil seal 142 of the side case 140.
The protective member 146 can be rotated with respect to the side case 140 by being fixed to the drive shaft 103 (rotor drive shaft 106). Thereby, the foreign substance which entered between the inner peripheral surface of the protective member 146 and the outer peripheral surface of the side case 140 from the open part of the protective member 146 can be finely crushed.

A grease hole 147 and a grease nipple 148 that closes the grease hole 147 are provided on the upper surface of the side case 140. The internal space surrounded by the oil seal 142 in the side case 140 is filled with grease. By filling the grease in this way, even when the lip of the oil seal 142 is damaged, the effect of preventing the intrusion into the inside by the grease can be expected.

A donut-shaped retaining ring 65 is provided outside the oil seal 142. The retaining ring 65 is fixed to the inner peripheral surface of the side case 140 and positions the oil seal 142. The retaining ring 145 can provide an additional labyrinth structure in the side case 140.

The present invention can be used for a bearing structure in a rear axle case of a rice transplanter.

1: Rice transplanter, 2, traveling machine body, 15: rear axle, 18: rear wheel, 25: rear axle case, 62: case, 63: gear case, 68: intermediate gear, 69: intermediate shaft, 70: intermediate shaft gear, 72 : Axle 73: Reduction mechanism 81: Bearing 121: Bearing holder 92: Hole 93: Through hole 94: Reamer bolt 95: Bolt rod

Claims

In rice transplanters that transmit power from the engine to the rear axle case through the mission case,
An intermediate gear serving as a speed reduction mechanism is provided in the rear axle case, a bearing that supports an intermediate shaft to which the intermediate gear is fitted, and a bearing holder that holds the bearing are provided.
The rice transplanter, wherein the bearing holder is fixed to the rear axle case using a plurality of bolts and a plurality of reamer bolts.
The rice transplanter according to claim 1, wherein the bearing holder is made of cast iron.