The rice-letting machine 1 will be described with reference to the accompanying drawings.
The plowing machine 1 includes a traveling machine 2, a working machine 3, and a lifting link mechanism 4. As shown in Fig.
The traveling vehicle 2 includes a body frame 11, an engine 12, a transmission 13, a front axle 14, a rear axle 15, a driving operation portion 16, front wheels 17 and rear wheels 18 Respectively.
The body frame 11 is the main structure of the herbicide 1. The vehicle body frame 11 constitutes the skeleton of the herringbone unit 1, and the engine 12 and the like are mounted thereon.
The engine 12 is a power source for generating power by combustion of fuel. The engine 12 can change the operating state by operating the speed change pedal 21 or the like by the operator.
The transmission 13 is a power transmission device that performs forward and reverse switching or shifting of the peristaltic device 1. The transmission (13) is provided with a continuously variable transmission device using hydraulic oil as a power transmission medium. The continuously-variable shifting device may convert part or all of the input rotational force to the hydraulic pressure of the operating oil, and output the hydraulic pressure of the operating oil again as the rotational driving force. The transmission (13) is accommodated in the transmission case (22).
The front axle 14 is a power transmission device for transmitting 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. On the other hand, the front axle 14 is provided with a steering device, so that the operator can steer the front wheel 17 by operating the steering wheel 23. [ The freon axle 14 is accommodated in the front axle case 24.
The rear axle 15 is a power transmission device that transmits the power of the engine 12 to the rear wheels 18. [ The power of the engine 12 is input to the rear axle 15 via the transmission 13. The rear axle 15 is accommodated in the rear axle case 25.
The driver's seat 26 is disposed so as to face the handle 23 in the driver's operating section 16 and the operator operates the handle 23 or the like while the driver is seated in the driver's seat 26. [ The operating section 16 is provided with various operating ports for operating the operation of the perforator 1 in addition to the above-described transmission pedal 21 and the handle 23. [
The working machine 3 is composed of a seedling rack 31, a food processor 32 and a float 33.
The seedling rack 31 is a seedling feeder for feeding the seedling to the feeding mechanism 32. The seedling mats mounted on the seedling rack 31 are sent to the feeding mechanism 32 appropriately by the vertical feeding mechanism. The seedling tray 31 is slidably mounted on a rail provided on the food frame, and reciprocates in the lateral direction in accordance with the operation of the food rack 32. In this manner, the seedling rack 31 can feed the seedling to the food rack 32.
The eating utensil 32 is a kind of aeration apparatus for eating a seedling in a field.
The eating utensil 32 includes a bodied period changing device 41, a food center case 42, a food bevel case 43, a rotary case 44 and a food arm 45.
The power from the bobbin period changing device 41 is transmitted to the beaten bevel case 43 through the feeding center case 42. [ Power is transmitted to the rotary case 44 provided on the right and left sides of the food bevel case 43. The food arm 45 provided in the rotary case 44 together with the rotary case 44 rotates to pick up the seedlings from the seedling rack 31 and to put the seedlings in the package.
The float 33 is a depth control device for adjusting the depth of the food part of the seedling aerator by raising and lowering the working machine 3. The float 33 is also a supporting device for the seedling bearing 31 or the eating tool 32 described above. The float 33 is constituted by a center float 33a disposed in the center portion of the working machine 3 and a side float 33b disposed on both sides of the center float 33a. The position sensor provided on the center float 33a elevates and lowers the working machine 3 to a proper height in cooperation with the control device of the traveling base 2. Since the center float 33a and the side float 33b are smoothly formed on the lower surface in contact with the package, the package can be grounded. As described above, the center float 33a and the side float 33b constituting the float 33 can stop the packing and elevate the working machine 3 to adjust the depth of the food portion of the seedling.
The lifting link mechanism 4 is composed of an upper link 51, a lower link 52, and a hydraulic actuator (not shown).
The upper link 51 and the lower link 52 are coupling devices for connecting the traveling base 2 and the working machine 3. [ The upper link 51 and the lower link 52 are also elevating apparatuses for elevating and lowering the working machine 3. The posture of the upper link 51 and the lower link 52 is changed by extending and contracting the hydraulic actuator in response to the instruction of the control device described above and the operation of the operator 3 or the operation of the worker 3 .
As described above, the herbicide 1 drives the front wheel 17 and the rear wheel 18 by the power of the engine 12 and travels while running the cooking operation by the cooking device 32. [
The rear wheel 18 is driven by transmitting power from the engine 12 to the rear axle case 25 through the transmission case 22 as shown in Fig.
The rear input shaft 61 extends from the transmission case 22 toward the rear axle case 25 at the rear side. The rear axle case 25 is constituted by a case 62 formed in a substantially cylindrical shape along both left and right directions from one end of the extended rear input shaft 61 and a gear case 63 formed at both left and right ends thereof. The gear case 63 is open on the side surface, and the rear axle case 25 can be sealed by mounting the lid 63a on the opening surface.
Power is transmitted from the rear input shaft 61 through the bevel gears 64a and 64b to the side clutch shaft 65 provided in both left and right directions in the case 62. [ The side clutch shaft 65 extends into the gear case 63. A side clutch 66 is provided at an intermediate portion of the side clutch shaft 65 and a gear 67 is fixed to an end portion thereof. In the gear case 63, power is transmitted to the intermediate shaft 69 via the intermediate gear 68 meshing with the gear 67.
The intermediate gear 68 is fixed to the intermediate shaft 69 and the intermediate shaft gear 70 is formed on the outer peripheral surface on 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 inside of the gear case 63 toward the side of the gas. One end (extended 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 and the intermediate gear 65 are rotated in the gear case 63 from the side clutch shaft 65, 68, the intermediate shaft gear 70, and the final gear 71, as shown in Fig.
The number of revolutions of the axle 72 can be changed with respect to the number of revolutions of the side clutch shaft 65 by providing the intermediate gear 68 and the intermediate shaft gear 70. [ Here, the number of teeth of the intermediate shaft gear 70 is made smaller than the number of teeth of the final gear 71, so that the number of revolutions of the intermediate shaft gear 70 is increased with respect to the number of revolutions of the axle 72. That is, the intermediate gear 68 and the intermediate shaft gear 70 are provided as the deceleration mechanism 73.
4, in order to support the decelerating mechanism 73 in the gear case 63, bearings 81 and 82 for supporting the intermediate shaft 69 and bearing holders 91 for holding the bearings 81 ).
As shown in Fig. 5, the bearing holder 91 has a shape in which the right side of the plate formed in a substantially rectangular shape when viewed from the side 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 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 mounted on the inner side of the intermediate shaft 69 and a bearing 82 is mounted on the outer side of the vehicle (wheel side). The bearings 81 and 82 are fixed to the bearing holder 91 fixed to the inside of the casing of the gear case 63 and the bearing holder (not shown) formed integrally on the outside of the casing of the gear casing 63, The gear 68 and the intermediate shaft gear 70 are rotatably supported in the gear case 63.
4, the bearing holder 91 is fixed to the gear case 63 by using four bolts 95 and two reamer bolts 94. As shown in Fig. Bolt holes 94a and 95a are provided in the gear case 63 in accordance with the arrangement of the through holes 93. [
The bearing holder 91 is fixed to the gear case 63 by using the reamer bolts 94 and the bolts 95 in the bolt holes 94a and 95a, respectively.
4, four bolts 95 占 쏙옙 占 are used for the four corners of the substantially rectangular shape of the bearing holder 91 and two reamer bolts 94 占 4 are formed in the shape of the bearing holder 91 But the present invention is not limited to this number and arrangement.
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, the mounting accuracy of the bearing holder 91 with respect to the gear case 63 can be enhanced and the fastening force can be improved.
Since the reamer bolt 94 is slightly larger in diameter than the diameter of the through hole 93 and can be lightly inserted and tightened, the mounting accuracy in positioning the bearing holder 91 is high.
Further, since the lateral force is received as the shearing force, the bearing holder 91 and the rear axle case 25 are prevented from being displaced. It is also possible to prevent deformation due to external force.
Further, the reamer bolt 94 can not only position the reamer bolt 94 but also can fix the bearing holder 91 to the gear case 63 as a bolt, as compared with the case of using a knock pin or the like, ) Can effectively utilize the limited space.
As described above, by using the reamer bolt 94, the fastening force can be improved. Therefore, the unevenness of the load sharing in the entire bearing holder 91 and the gear case 63 can be reduced, and the rigidity can be improved. By improving the rigidity, the warp of the bearing holder 91 and the gear case 63 can be reduced. Therefore, the warpage of the intermediate shaft 69 supported by the bearing holder 91 and the gear case 63 is reduced to prevent pitching and tooth damage that may occur in the intermediate shaft gear 68 and the intermediate shaft gear 70 .
The bearing holder 91 is preferably made of a cast iron in terms of productivity, and cast in the present embodiment using a spheroidal graphite cast iron in which high strength and rigidity are required. As described above, by using the bearing holder 91 made of cast iron, damage (pitching and tooth damage) of the intermediate shaft 69 and the intermediate gear 68 can be more effectively suppressed.
In particular, the spheroidal graphite cast iron is spherical graphite, which is improved in strength and ductility, and is excellent in tensile strength and elongation, and has strength of several times that of ordinary cast iron. Therefore, the displacement between the bearing holder 91 and the rear axle case 25 can be reduced, and the deformation due to the external force can 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.
Next, with reference to Figs. 8 to 15, the stopper provided in the pasture stage will be described.
8 and 9, in the stopping device 100, a part of the power from the rear input shaft 61 is diverted to the stopping coaxial part 99 via the rear axle case 25, and the stopping coaxial part 99 And is transmitted to a drive shaft 103 extending toward both sides of the transmission case 102 through an input shaft 101 connected to the transmission case 102 and a transmission case 102 receiving the input of the input shaft 101. A plurality of stationary rotors 104 are fixed to the drive shaft 103. The drive shaft 103 is formed in a rectangular shape in section and is engaged with a rectangular opening at the center of the stationary rotor 104 so that the stationary rotor 104 is fixed so as not to rotate relative to the drive shaft 103.
The drive shaft 103 includes a rotor input shaft 105 projecting sideways from both sides of the transmission case 102, a rotor drive shaft 106 connected to the rotor input shaft 105 and extending to both sides, a rotor input shaft 105, And a joint 107 for connecting the rotor drive shaft 106 to each other. The connection between the rotor input shaft 105 and the joint 107 of the rotor drive shaft 106 is realized by spline coupling.
9, inside the transmission case 102, a bevel gear 108 is provided at the end of the input shaft 101 linked to and connected to the stop transmission shaft 99, and is engaged with the bevel gear 108 And the bevel gear 109 is fixed to the intermediate portion of the rotor input shaft 105. Power is transmitted to the rotor input shaft 105 through the bevel gears 108 and 109. With the rotation of the rotor input shaft 105, the rotor drive shaft 106 is driven through the joint 107 to rotate the stop rotor 104.
9 and 10, the transmission case 102 is constituted by a main body 110 and a lid 112. As shown in Fig. The main body 110 has an opening through which the input shaft 101 passes and rotatably supports the input shaft 101 at the inner periphery of the opening and has an opening (not shown) through which the drive shaft 103 (the rotor input shaft 105) 111 on both sides. The cover 112 supports the drive shaft 103 (the rotor input shaft 105) in a rotatable manner and blocks 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 passes and an opening 111 through which the drive shaft 103 passes, and a bevel gear 108 占 109 And a cylindrical portion 110b which is formed as a cylindrical member having an opening through which the input shaft 101 passes and which extends from the receiving portion 110a to the front side (the rear axle case 25 side). The main body 110 is integrally molded so as to include the accommodating portion 110a and the cylindrical portion 110b.
An oil seal 120 for sealing the inside of the transmission case 102 and bearings 121 and 121 for rotatably supporting the input shaft 101 are arranged in order on the inner circumferential surface of the cylindrical portion 110b from the opening side.
The lid 112 seals the inner space of the main body 110 by blocking the openings 111 provided on both sides 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 body 110. A boss portion 113 projecting sideways from both sides of the lid 112 is integrally provided along the penetration portion of the lid 112 at a central portion thereof through which the rotor input shaft 105 passes. 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 arranged on the inner peripheral surface of the boss 113 in this order from the opening side, A snap ring 125 for fixing the oil seal 123 is provided.
The rigidity of the integrally formed main body 110 can be increased by constructing the transmission case 102 by the main body 110 and the lid 112 covering the opening 111 of the main body 110. [ By forming the main body 110 integrally with the main body 110 as described above, the torque when the torque fluctuation occurs on the input shaft 101 supported by the main body 110 through the bearing 121 is not applied to the main body 110 So that deformation of the main body 110 can be prevented. That is, the effect of the rattling caused by the input shaft 101 accompanied by the torque variation or the rattling caused by the unbalance of the shaft provided in the electric path on the main body 110 can be minimized. Therefore, it is possible to prevent the hermeticity of the transmission case 102 from being damaged due to the deformation of the main body 110.
In addition, since the main body 110 is integrally formed, the assembly of the main body 110 becomes unnecessary when assembling the transmission case 102, and the assembling position in the main body 110 is determined at the time of molding. It is possible to increase the precision of positioning of the respective components when assembling the inner case of the main body 110 and assembling the transmission case 102.
The cover 112 is made of a highly rigid structure having no joints and is configured to hold the bearing 124 for supporting the drive shaft 103 (rotor input shaft 105) The lid 112 having high rigidity and the lid 112 having the lid 112 fixed to the main body 110 are also provided integrally with the lid 112, The transmission case 102 can be absorbed by the entirety of the transmission case 102. Thus, the influence of the rattling caused by the rotor input shaft 105 on the lid 112 can be minimized. Therefore, the hermeticity of the lid 112 can be ensured, and damage to the bearing 124 can be prevented.
9, the end of the joint 107 on the transmission case 102 side covers the outer end of the boss 113 and extends from the outer end of the boss 113 to the end of the transmission case 102 So as to extend toward the inside. In other words, at the inner end of the joint 107, there is provided a enlarged diameter portion 107a whose diameter is enlarged compared to the outer diameter of the rotor input shaft 105, and the outer peripheral portion of the enlarged diameter portion 107a And extend to overlap the ends.
The path to the oil seal 123 is formed in a labyrinth shape by disposing the open portion of the enlarged diameter portion 107a of the joint 107 on the boss portion 113 of the transmission case 102 as described above.
The transmission case 102 is filled with lubricating oil. Thus, by confirming the leakage of the lubricating oil from the inside of the transmission case 102, it is possible to confirm the damage of the oil seals 120, 123 of the transmission case 102 at the lips. It is possible to prevent breakage of the bearings 121, 124 and the bevel gears 108, 109 disposed on the inside of the oil seals 120, 123 by detecting and treating the oil seals 120, 123 at an early stage.
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 blocking the oil hole 115 is mounted. Then, the transmission case 102 is filled with lubricating oil. Thus, by confirming the leakage of the lubricating oil from the inside of the transmission case 102, it is possible to confirm the damage of the oil seals 120, 123 of the transmission case 102 at the lips. It is possible to prevent breakage of the bearings 121, 124, bevel gears 108, 109 and the like disposed on the inside of the oil seals 120, 123 by early detection and treatment of breakage of the oil seals 120, 123.
Further, a drain (not shown) for taking out the lubricating oil from the inside is provided at the lower portion of the rear surface of the main body 110, and the lubricating oil therein can be easily discharged and replaced.
On the other hand, grease may be charged into the transmission case 102 instead of lubricating oil.
10, the protective member 117 is fixed to the outer periphery of the cylindrical portion 40a of the main body portion 40. As shown in Fig. The protection member 117 protects the periphery of the connection portion between the input shaft 101 and the stopping transmission shaft 99 and includes a stopping coaxial shaft 99 connected to the input shaft 101 and a universal joint provided therebetween, .
The protective member 117 is a bellows-shaped protective boot and is fixed using a clip 118 around a cylindrical portion 110b extending toward the front of the main body 110. [ The length of the cylindrical portion 110b can be used as a fixed portion of the clip 118 because the cylindrical portion 110b extends forward from the front surface of the receiving portion 110a formed in a box shape, The fixed length of the protective member 87 can be made longer. As a result, the protection member 117 can be mounted more firmly, and it is possible to prevent a gap or a gap from being generated. Therefore, mud or foreign matter does not enter into the interior of the transmission case 102 from the side of the protection member 87, and the inconvenience caused by such intrusion can be prevented.
The foreign matter such as straw infiltrating between the transmission case 102 and the stationary rotor 104 is gathered in the vicinity of the stationary rotor 104, And is then moved from the stop rotor 104 side toward the transmission case 102 side.
Therefore, the path from the opening of the inner end of the joint 107 to the inside thereof and toward the opening of the boss 113 is opposite to the traveling direction of the foreign object (the direction from the outside to the inside of the transmission case 102) . Further, the direction of intrusion from the outer end of the boss portion 113 toward the oil seal 123 is again the opposite direction. Thus, by providing the joint 107, the path of the transmission case 102 to the oil seal 123 is a labyrinth structure that is opposite to the traveling direction of the foreign object.
As described above, a part of the joint 107 connecting the rotor input shaft 105 and the rotor drive shaft 106 is made to be a diameter enlarged portion 107a, and the enlarged diameter portion 107a is formed in the boss portion 113 of the transmission case 102 It is possible to effectively prevent foreign matter from entering the oil seal 123 of the transmission case 102. [
Since the path of the foreign object is physically blocked by the enlarged diameter portion 107a of the joint 107, the amount of foreign matter reaching the inner end portion of the joint 107 can be reduced. At the same time, the foreign object is moved along the outer periphery of the joint 107 arranged as the rotating body, and when the foreign object passes over the enlarged diameter portion 107a, the foreign object makes the centrifugal force of the rotation in the direction away from the joint 107, It is also expected that the foreign matter is removed from the body 107.
As shown in Fig. 11, the transmission case 102 is fixed to the drive shaft 103 in a non-rotatable manner. That is, the drive shaft 103 rotates with respect to the boss portion 113 of the transmission case 102 fixed to be non-rotatable. Thus, the sliding portion 126 is formed between the inner circumferential surface of the joint 107 and the outer circumferential surface of the boss portion 113.
Further, even when the foreign matter intrudes into the gap between the joint 107 and the boss portion 113, the sliding portion 126 can crush the impurities. Therefore, even if foreign matter intrudes into the joint 107, it can be prevented from reaching the oil seal 123 by being crushed by the scraper effect of the sliding portion 126, thereby preventing it from sticking to the drive shaft 103 can do.
12 shows another embodiment of the labyrinth structure of the transmission case 102 and the joint 107. Fig.
A protrusion 130 whose diameter is widened at the inner end portion of the enlarged diameter portion 107a of the joint 107 is provided so that the physical obstacle for not allowing the foreign object to reach the opening portion of the joint 107 As shown in Fig. By providing the groove 131 in the outer circumferential surface of the boss portion 113 in the sliding portion 96, the small contaminant after being crushed by the sliding portion 126 can be temporarily collected.
As described above, by further complicating the labyrinth structure between the transmission case 102 and the joint 107, the amount of foreign matter reaching the oil seal 123 can be further reduced.
Fig. 13 shows another embodiment of the protection structure provided in the opening of the transmission case 102 (boss portion 113).
13, the joint 107 is not provided with the enlarged portion 107a, but the extended portion 132 extending outward in the radial direction is provided at the open end of the boss portion 113, and the rotor input shaft 105, A plate member 133 is provided on the outer periphery of the plate member 133. The plate member 103 is a disc-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, foreign matter moving from the stationary rotor 104 side is blocked by the plate member 133, and a path penetrating between the plate member 133 and the extending portion 132 is provided toward the radial direction, It is possible to reduce the amount of foreign matter reaching the opening of the opening 113. The plate member 133 rotates relative to the extension portion 132 of the boss portion 113 by rotating together with the rotation of the rotor input shaft 105. That is, the foreign substance intruding between the plate member 133 and the extended portion 132 of the boss unit 113 can be crushed.
As shown in Fig. 14, a side case 140, which is formed in a cylindrical shape, is provided on the support portion of the drive shaft 103 in the support arm 135. Fig.
The side case 140 accommodates a bearing 141 for rotatably supporting the drive shaft 103 and an oil seal 142 disposed on both sides of the bearing 141. A collar 143 having an opening corresponding to the sectional shape of the driving shaft 103 and having a circular outer circumferential surface is fixed to the driving shaft 103 in the side case 140, The bearing 141 and the oil seal 142 are fixed.
At both side ends of the collar 143, a protective member 146 formed in a plate-like disc shape is provided. The protective member 146 is provided in contact with the outer end of the collar 143. The protective member 146 is fixed to the drive shaft 103 and configured to be rotatable together with the rotation of the drive shaft 103. [
Both side ends of the side case 140 extend outwardly from both side ends of the collar 143. The protection member 146 extends outward from the outer end of the side case 140 from the outer end of the collar 143 and extends outward in the radial direction from the side case 140, Lt; / RTI > In other words, the protective member 146 has a central portion 146a which is recessed toward the inner side of the side case 140 along the axial direction of the drive shaft 103, and a central portion 146c which extends axially outward from the concave central portion 146a And an outer peripheral portion 146b formed to be bent in a crank shape so as to cover the outer end of the side case 140. [
Thus, by providing the protective 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.
The foreign matter such as straw infiltrating between the side case 140 and the stationary rotor 104 is gathered near the stationary rotor 104, And is then moved from the stop rotor 104 side toward the side case 140 side.
The path of the foreign object entering from the opening of the inner end of the protection member 146 toward the opening of the side case 140 is opposite to the traveling direction of the foreign object (the direction from the outside to the inside of the side case 140) to be. The direction of infiltration from the outer end of the side case 140 toward the oil seal 142 is again the opposite direction. Thus, by providing the protective member 146, the path of the side case 140 to the oil seal 142 is a labyrinth structure that is opposite to the traveling direction of the foreign object.
The foreign object moves from the stopper rotor 104 along the drive shaft 103 toward the central portion 146a of the protective member 146 and reaches the outer peripheral portion 146b from the central portion 146a, It is necessary to go over the recess. That is, the protection member 146 having a concave shape at the center can impart resistance to the progress of the foreign object.
As described above, it is possible to effectively prevent foreign matter from entering the oil seal 142 of the side case 140 by providing the protection members 146 so as to cover the openings at both ends of the side case 140 from the outside .
The protective member 146 is fixed to the drive shaft 103 (the rotor drive shaft 106), so that the protective member 146 can be rotated with respect to the side case 140. Accordingly, the foreign object intruding between the inner circumferential surface of the protective member 146 and the outer circumferential surface of the side case 140 can be crushed from the opening of the protective member 146.
On the upper surface of the side case 140, there are provided a grease nipple 148 which covers the grease hole 147 and the grease hole 147. The inner space surrounded by the oil seal 142 in the side case 140 is filled with grease. By charging the grease in this manner, even when the lip of the oil seal 142 is broken, an effect of preventing intrusion into the inside by the grease can be expected.
A donut-shaped snap ring 65 is provided on the outer side of the oil seal 142. The snap ring 65 is fixed to the inner circumferential surface of the side case 140 and positions the oil seal 142. By the snap ring 145, an additional labyrinth structure can be provided in the side case 140.
