WO2012029953A1

WO2012029953A1 - Transmission device for riding-type work vehicle

Info

Publication number: WO2012029953A1
Application number: PCT/JP2011/070047
Authority: WO
Inventors: 黒田　智之; 道雄塚本
Original assignee: ヤンマー株式会社
Priority date: 2010-09-03
Filing date: 2011-09-02
Publication date: 2012-03-08
Also published as: CN103080609A; CN103080609B; KR101795539B1; JP2012051531A; JP5723556B2; KR20130140624A

Abstract

The purpose of the present invention is to improve the assemblability of a transmission device and improve the strength of members in a riding-type farm work vehicle such as a rice planter. The transmission device has a transmission case (9). The transmission case (9) has a two-part structure comprising a deep main body (9a) and a shallow lid (9b) and has disposed therein a shaft, gears, and the like. The main body (9a) has a plate-like intermediate member (87) fixed therein, and the intermediate member (87) is used to support the shaft. Because the shaft support span is shortened, the shaft support strength and shaft durability are improved. Because shaft stability is improved, reattachment of the lid (9b) after removal thereof is facilitated. Therefore, maintenance can be performed easily.

Description

Traveling transmission device for riding type work machine

The present invention relates to a traveling transmission for a riding type work machine such as a riding type rice transplanter.

An example of a riding type farm working machine is a riding type rice transplanter. This riding type rice transplanter has a traveling machine body on which an engine is mounted and a seedling planting device disposed behind the traveling machine body, and the seedling planting device is connected to the traveling machine body so as to be movable up and down. The traveling machine body has left and right front wheels and rear wheels, and the power of the engine is transmitted to the front wheels and the rear wheels via the traveling transmission.

The traveling gearbox has a hollow traveling mission case, in which a shaft group, a gear group, a traveling clutch, a differential device (differential device), a brake, and the like are arranged. The traveling mission case is configured to be hollow by fastening a plurality of shell-shaped members with bolts, and a two-part system (two-part system) is disclosed in Patent Document 1. In the two-split method, one end of the shaft is supported by one part, and the other end of the shaft is supported by the other part.

In recent years, passenger type rice transplanters often have an HST (hydrostatic continuously variable transmission) to enhance the driving feeling, and the HST is attached to a driving mission case. Further, since there is a region where transmission efficiency is lowered only with HST, it is widely practiced to install HMT (hydraulic mechanical continuously variable transmission) using both HST and a planetary gear mechanism. HMT has been installed on type rice transplanters from early on and has been highly evaluated in the market.

Furthermore, although the riding type rice transplanter is a wheel traveling type and is steered by turning the front wheel, a front axle device is attached to the traveling mission case, and a differential device is provided inside the traveling mission case. The rotational speed of the left and right front wheels is changed.

JP 2005-160406 A

Now, since the traveling transmission case of the traveling transmission is hermetically sealed, it is inevitable that the traveling transmission case is composed of a plurality of members. However, in the configuration in which the shaft is simply divided into two parts as in the prior art, since the shaft is simply supported at both ends with one end supported by one part and the other end supported by the other part, assembly is troublesome.

In other words, the holes that fit the shafts are provided in the two parts that make up the traveling mission case, and the other parts cannot be fitted into the respective shafts unless the posture of each shaft is accurately held in the one part. In the split method, each shaft has only one end fitted into the hole of one part before assembling. The work of fitting the other part into the shaft becomes troublesome.

In particular, after the traveling mission case is incorporated into a work machine such as a rice transplanter, the shaft is often turned sideways, so that if the other part is removed for maintenance or parts replacement, the shaft tends to collapse due to its own weight. It was more troublesome to fit the other part.

Furthermore, in the simple split method, the shaft is only supported at one end and the other end, so the support span is inevitably lengthened, and the strength against bending is lowered and the durability is lowered. There is a risk.

The present invention has an object to improve such a current situation.

As a means for solving the above problems, the inventors of the present application have completed the invention of each claim. Among these, the invention of claim 1 has a traveling mission case and a shaft group and a gear group disposed therein, and the traveling mission case includes a main body portion having a deep depth and a shallow lid portion covering the main body portion. The shaft group is arranged in a posture intersecting with the opening surfaces of the main body portion and the lid portion, and at least a part of the shaft group is disposed on the main body portion of the traveling mission case. The intermediate member which functions as a bearing for the is fixed.

The invention of claim 2 embodies claim 1 and further comprises an HST to which power from the engine is transmitted and a planetary gear mechanism that constitutes an HMT in combination with the HST. The HST is attached to the outer surface of the bottom portion located on the opposite side of the lid portion of the main body portion in the traveling mission case, and the planetary gear mechanism is connected to the bottom portion of the main body portion in the traveling mission case. And the intermediate member.

The invention of claim 3 embodies claim 1 or 2, and in this invention, an axle device for driving a wheel is attached to each of the main body portion and the lid portion of the traveling mission case, In the traveling mission case, one wheel drive shaft that transmits power to one axle device and the other wheel drive shaft that transmits power to the other axle device are arranged concentrically, and the two wheel drive shafts are different from each other. A differential device for moving is disposed between the main body and the intermediate member.

The invention of claim 4 further embodies claims 1 to 3, and provides a space in which oil can freely flow between the inner periphery of the main body and the outer periphery of the intermediate member in the traveling mission case. Yes.

According to the first aspect of the present invention, since the shaft disposed inside the traveling mission case is supported by the main body and the intermediate member even when the lid is removed, the shaft is accurately positioned at the correct position. Kept in a state. For this reason, even when the other end of the shaft fits into the lid, the lid can be easily fitted, and thus the traveling mission case can be assembled accurately and efficiently. In addition, since the intermediate member can function as a reinforcing member, it contributes to increasing the strength of the traveling mission case.

Also, when the lid is removed for maintenance or parts replacement with the traveling mission case installed in the work implement, the shaft is stably held in place even if the shaft is in a horizontal orientation. Therefore, the lid can be easily reattached. Therefore, it can be said that the present invention is particularly effective for improving workability in maintenance and parts replacement.

Furthermore, if the shaft / gear is removed for maintenance or repair, the traveling mission case often has to be removed from the fuselage when it is a simple divide-by-two method. However, in the present invention, since the depth of the main body part and the intermediate member are included, many of the shafts and gears can be held in the predetermined depth in the main body part. By removing only the lid part until the part is attached to the airframe, it is possible to perform operations such as changing the shaft. Therefore, the frequency with which the traveling mission case is removed during maintenance and repair can be significantly reduced. In this respect, maintenance and repair workability can be improved.

Also, since the support span of the shaft can be shortened by arranging the intermediate member, the strength of the shaft can be increased and the durability can be improved. Further, the shaft can be supported only by the main body portion and the intermediate member, or can be supported only by the intermediate member and the lid portion. Therefore, the freedom of the shaft support structure can be improved. This is also a feature of the present invention.

Now, it is theoretically possible to provide a plurality of bearings on one part that constitutes the traveling mission case. In this case, however, the part must be manufactured as a casting using a mold and then subjected to complicated post-processing. This requires low productivity and high costs. That is, one mold is manufactured for each traveling mission case, and the procedures such as pouring, curing, removing the mold, and cutting of the bearing portion must be taken, resulting in low productivity and high cost. Moreover, since the shaft cannot be set with the gear attached to the shaft, the assembly is also very troublesome.

On the other hand, if a separable intermediate member is provided as in the present invention, it is sufficient to provide a bearing portion for supporting one end of the shaft in the main body portion constituting the traveling mission case. Therefore, die cast products (molded products) manufactured by methods such as pouring into a cavity, solidification, and die removal after separating the molds using molds that can be adhered and separated freely are possible. Can be adopted.

Therefore, the shaft can be stably supported by using the intermediate member while manufacturing the main body (or the lid) with high dimensional accuracy efficiently and at low cost. Therefore, it is possible to increase productivity and contribute to cost reduction. In addition, since the intermediate member can be attached and detached, the shaft can be assembled by a simple procedure in which one end is inserted into the main body while the member such as a gear is attached, and then the intermediate member is set. For this reason, assembly work is also easy.

As described above, combining the HST and the planetary gear mechanism to configure the HMT can ensure high transmission efficiency over a wide range from low speed to high speed, but if the traveling mission case is a simple split system, There is a concern that the support span of the gear mechanism becomes long and the durability is lowered.

On the other hand, when the configuration of claim 2 is adopted, the planetary gear mechanism can be supported by the intermediate member, so that the support stability of the planetary gear mechanism can be significantly improved. In addition, it is easy to dispose the travel clutch between the main body and the intermediate member, which can contribute to the compactness of the travel transmission. Furthermore, since the planetary gear mechanism is held between the main body and the intermediate member, the lid can be attached or detached while the HMT is attached to the traveling mission case. Easy assembly and maintenance.

As described above, a differential device is indispensable for a wheel traveling type work machine, but if the two wheel drive shafts are not stably supported, the durability is lowered. In this regard, if the configuration of claim 3 of the present application is adopted, the differential device is stably held by the main body portion and the intermediate member, and as a result, the two wheel drive shafts are also stably supported. As a result, the durability of the differential device can be improved.

It is normal for oil to collect inside the traveling mission case. In particular, in a working machine having an HST, it is common that the traveling mission case is also used as a tank for hydraulic oil of the HST, and when the working machine includes a hydraulic cylinder and a power steering, The traveling mission case is also used as a tank for these hydraulic oils.

And since the hydraulic oil often becomes high temperature, it is necessary to circulate it inside the traveling mission case and cool it as much as possible. However, if the configuration of claim 4 is adopted, the oil (hydraulic oil) inside the traveling mission case Since the circulation of the oil is not hindered, the oil cooling function is not hindered. Further, since the intermediate member can be reduced in size, the material cost can be suppressed and the travel transmission can be reduced in weight.

It is a side view of the rice transplanter concerning an embodiment. It is a top view of the whole rice transplanter. It is a side view which shows the framework of a traveling machine body. It is a top view which shows the framework of a traveling machine body. It is a side view of the front part of a traveling machine body. (A) is a top view of the front part of a traveling body, (B) is a top view of a traveling mission case. It is a perspective view which shows a driving | running | working mission case and a steering mechanism. It is a perspective view of the principal part. (A) is the perspective view which looked at the traveling mission case from the front, (B) is the isolation | separation top view of a traveling mission case. It is a bottom sectional view of a run mission case. It is a sectional side view of the traveling mission case in the opened state. It is a perspective view which shows a transmission structure. It is a separate perspective view of the principal part. It is a vertical side view of the principal part. It is a side view of a traveling mission case. It is a hydraulic circuit diagram. It is a perspective view which shows the framework of a traveling machine body. It is a hydraulic circuit diagram. FIG. 6 is a separated plan view of a traveling mission case and a member attached to the traveling mission case. It is a figure which shows an raising / lowering mechanism, (A) is the perspective view seen from the right side, (B) is the isolation | separation perspective view seen from the left side. It is a separation perspective view of the important section in the state where piping was displayed. (A) is the isolation | separation perspective view of the principal part in the state which abbreviate | omitted piping, (B) is an isolation | separation side view. (A) is a perspective view of a traveling mission case, (B) is a rear view of the principal part which separated the intermediate member while showing a traveling mission case with a virtual line. It is a transmission system diagram. It is a separate perspective view of the principal part. (A) is the perspective view which looked at the inside of a traveling mission case from back, (B) is the isolation | separation perspective view inside a traveling mission case. It is a side view in the state where a lid part of a run mission case was omitted. It is a plane sectional view showing a travel transmission. It is a partial plane sectional view showing a travel transmission.

Next, an embodiment in which the present invention is applied to a riding type rice transplanter (hereinafter simply referred to as “rice transplanter”) will be described with reference to the drawings. In the following description, the words “front and rear” and “left and right” are used to specify the direction, which is based on the posture of the operator facing the forward direction.

(1). As shown in FIGS. 1 and 2, the rice transplanter includes a traveling machine body 1 that is supported by the left and right front wheels 2 and the left and right rear wheels 3, and a seedling planting device 4 that is disposed behind the traveling machine body 1. have. The front wheel 2 is attached to the traveling machine body 1 so as to be able to turn horizontally, and the rear wheel 3 is attached to the traveling machine body 1 so as to be unable to turn horizontally.

The seedling planting device 4 is connected to the traveling machine body 1 through a lifting link mechanism 6 so as to be lifted and lowered. The seedling planting device 4 is lifted and lowered by rotating the lifting link mechanism 6 with a hydraulic lifting cylinder 5. Although not clearly shown, the seedling planting device 4 has a frame structure, and a rotary planting mechanism 107, a seedling stage 108, a float 109, and the like are provided on the frame structure. A leveling rotor 111 is also provided. The rice transplanter of this embodiment is eight-row planting, and thus has eight planting mechanisms 107. Although not shown, a fertilizer application device can be attached to the rear part of the traveling machine body 1.

As shown in FIGS. 3, 4, and 6, the traveling machine body 1 has a machine body frame 7, and supports the engine 8 at the front part of the machine body frame 7. A traveling mission case 9 is disposed behind the engine 8, and left and right front axle devices 10 are attached to the front portion of the traveling mission case 9 via spacers 114. Is mounted so that it can swivel horizontally. The rear wheel 3 is attached to a rear axle case 12, and the traveling mission case 9 and the rear axle case 12 are connected by a cylindrical connecting frame 11.

For example, as shown in FIG. 4, the body frame 7 includes left and right front side frames 7 a positioned at the front of the traveling body 1, left and right front frames 7 b connected to the front ends of the left and right front side frames 7 a, and left and right front sides. Left and right horizontal middle frames 7c connected to the rear ends of the side frames 7a, left and right rear side frames 7d extending rearward from the middle frames 7c, and left and right horizontal rear frames 7e fixed to the rear ends of the rear side frames 7d The rear frame 7e is supported by the rear axle case 12 via the rear column 7f. A left and right horizontally long stay 12a is fixed to the rear axle case 12, and a rear column 7f is fixed to the stay 12a.

The connecting frame 11 and the middle frame 7c are connected by a first reinforcing frame 121 that is U-shaped in front view and tilted forward in side view. Although not shown, the fuel tank is disposed in a state surrounded by the first reinforcing frame 121 from the front side in a plan view. The first reinforcing frame 121 and the rear axle case 12 are connected by a pair of left and right second reinforcing frames 122. The middle frame 7c projects to the left and right outside of the front side frame 7a, and auxiliary frames are attached to the projecting portion.

The left and right front side frames 7a have two front and rear engine frames 13 each having an opening U shape fixed upward, and the engine frame 13 supports the engine 8. The engine 8 is placed horizontally so that the crankshaft is directed in the left-right direction. The engine 8 and the traveling mission case 9 are connected via a bracket 48. An auxiliary frame 14 having a U shape in plan view is fixed to the engine frame 13 on the front side. The auxiliary frame 14 is also connected to the front frame 7b. Since the engine frame 13 projects below the front side frame 7a, the engine 8 has a low center of gravity, and the crankshaft is positioned below the upper surface of the front side frame 7a.

The engine 8 is covered with a bonnet 15, and spare seedling stands 16 are disposed on the left and right sides of the bonnet 15. A driver's seat 17 is arranged behind the bonnet 15. The traveling machine body 1 has a vehicle body cover (step) 18 on which an operator is placed. Although a fuel tank is arranged below the driver's seat 17, details are omitted. A rotary steering handle 19 is disposed in front of the driver seat 17.

As shown in FIGS. 6 and 7, the front axle device 10 includes a fixed support portion 10a fixed to the front side frame 7a via a bracket, and a rotation support portion attached to the fixed support portion 10a so as to be substantially horizontally rotatable. 10b, and the front wheel 2 is attached to the front axle provided in the rotation support portion 10b. A knuckle arm 20 is fixed to the rotation support portion 10b, and a tie rod 21 is connected to the knuckle arm 20 so as to be relatively rotatable. When the steering handle 19 is rotated, the left and right tie rods 21 simultaneously move in opposite directions via a power steering unit, which will be described later, thereby causing the left and right front wheels 2 to turn horizontally in the same direction. As a result, the rice transplanter is steered.

For example, as shown in FIG. 7, the HST 24 is mounted on the left side surface of the traveling mission case 9. As shown in FIG. 16, the HST 24 has a hydraulic pump 24a driven by the input shaft 25 and a hydraulic motor 24b driven by the hydraulic pump 24a. Power is transmitted to the input shaft 25 from the output shaft 26 of the engine 8 via the belt 27. A cooling fan 28 is fixed to the input shaft 25. The power of the hydraulic motor 24 b is output via the planetary gear mechanism 57. Accordingly, the HST 24 and the planetary gear mechanism 57 cooperate to constitute an HMT (hydraulic mechanical continuously variable transmission).

The power changed by the HST 24 is transmitted to the front wheel 2 via the front axle device 10 via the auxiliary transmission mechanism consisting of a gear group, and the rear axle case 12 via the drive shaft 77 (see, for example, FIG. 17). It is transmitted to the inside and from here to the rear wheel 3. For example, as shown in FIG. 6, a work power shaft 140 ′ protrudes backward from the right side surface of the traveling mission case 9, and the rotation of the work power shaft 140 ′ is performed between the stock case 16 ′ (see FIG. 17) and the PTO. It is transmitted to the seedling planting device 4 via the shaft 140 ″ (see FIG. 1).

Needless to say, the output shaft 26 of the engine 8 and the input shaft 25 and output shaft 36 (see FIG. 10) of the HST 24 are horizontally long and parallel to each other. The HST 24 is arranged so that the hydraulic pump 24a is positioned in front and the hydraulic motor 24b is positioned in rear. The belt 27 is held constant in tension by a tension pulley 29.

The HST 24 incorporates a swash plate for controlling the rate at which the power of the hydraulic pump 24a is transmitted to the hydraulic motor 24b, and this swash plate is driven by rotating the control shaft 30 shown in FIG. 7, for example. Is done. On the other hand, as shown in FIG. 4, a shift pedal 31 is provided on a portion of the control floor on the right side of the traveling mission case 9 in plan view. The rotation angle (depression amount) of the speed change pedal 31 is detected by a potentiometer.

Then, a control motor (not shown) is driven based on the detection signal of the potentiometer, and the control shaft 30 is rotated by a link mechanism (not shown) that is moved by the control motor. The power transmission ratio to 24b changes, and thereby the vehicle speed is adjusted steplessly according to the depression amount of the shift pedal 31.

As shown in FIG. 3, the steering handle 19 rotates about an axis that is inclined with respect to the vertical line in a side view. The steering handle 19 is fixed to an inclined upper handle shaft 32. The upper handle shaft 32 is fixed to the main handle shaft 33 in a vertical posture through a universal joint (not shown). The main handle shaft 33 is built in the handle post 34.

For example, as shown in FIG. 7, a hydraulic power steering unit 35 is attached to the front end portion of the traveling mission case 9, and the rotational torque of the main handle shaft 33 is amplified by the power steering unit 35 and transmitted to the tie rod 21. Is done.

(2). Details of Traveling Mission Case Next, details of a part centering on the traveling mission case 9 will be described with reference to FIG. 8 and subsequent drawings. For example, as shown in FIG. 6A, a pump unit 37 as an example of a hydraulic power source is attached to the right side surface of the mission case 9. In the pump unit 37, a tandem charge pump 37a and an auxiliary pump 37b driven by the input shaft 25 of the HST 24 are arranged.

The input shaft 25 of the HST 24 is always rotating as long as the engine is operated. Therefore, the charge pump 37a is always rotating. The pressure oil generated by the auxiliary pump 37 b is sent to the torque generator 39 of the power steering unit 35 through the first pipe 38. The pressure oil generated by the charge pump 37a is sent to the oil supply port 41 of the HST 24 through the second discharge pipe 40.

A valve unit 42 for controlling the lift cylinder 5 described above is fixed to the rear part of the traveling mission case 9, and the pressure oil discharged from the torque generator 39 of the power steering unit 35 is passed through the third pipe 43. It is sent to the valve unit 42.

For example, as shown in FIG. 9B, the traveling mission case 9 is composed of two members, a main body portion 9a having a deep depth and a lid portion 9b covering the main body portion 9a, and a shaft, gears, and the like are disposed therein. ing. A steering support portion 46 projecting forward is formed in a substantially lower half portion of the front end of the main body 9 a in the traveling mission case 9, and the power steering unit 35 is fixed to the steering support portion 46.

The steering support portion 46 is in a state of protruding from the front surface of the main body portion 9a constituting the traveling mission case 9, and thus has a front end surface and left and right side surfaces. For example, as shown in FIG. 7, a forward projecting portion 47 is formed at the lower end of the steering support portion 46. A bracket 48 is connected to the forward projecting portion 47 with a bolt 49, and the bracket 48 is fixed to the engine 8. is doing.

A receiving port 52 through which surplus oil or leaked oil accumulated in the case of the HST 24 flows is provided on the right side surface of the steering support portion 46, and the discharge port 53 and the receiving port 52 leading to the case of the HST 24 are connected to a metal drain pipe. 54 is connected. Note that the drain pipe 54 may be one in which an air cooler or the like is interposed in the middle thereof.

The traveling mission case 9 also serves as an oil tank, and the hydraulic oil that has flowed into the steering support portion 46 returns to the interior of the traveling mission case 9 (details will be described later). Needless to say, the drain pipe 54 is connected to the HST 24 and the steering support 46 by a joint 55.

For example, as shown in FIG. 9, an oil filter 56 is provided below the charge pump 37 a on the right side surface of the traveling mission case 9, and the oil accumulated in the traveling mission case 9 passes through the oil filter 56 and is charged by the charge pump. It flows into 37a.

Next, the internal structure of the traveling mission case 9 will be briefly described with reference to FIGS. A planetary gear mechanism 57 is provided inside the traveling mission case 9, and the output of the HST 24 is synthesized by the planetary gear mechanism 57 and taken out to the first shaft 58.

As shown in FIG. 11, below the first shaft 58, a first intermediate shaft 59 for backward travel and a second intermediate shaft 60 for forward travel are disposed in a state where they are displaced forward and backward. The front wheel drive shaft 61 and the third intermediate shaft 62 are disposed in a position shifted forward and backward at a portion below the

intermediate shafts

59 and 60, and the rear portion is disposed below the third intermediate shaft 62. A wheel drive shaft 63 is disposed.

A plurality of fixed gears 64 for shifting are fixed to the first shaft 58 in a non-slidable manner, and a sliding gear 65 is attached to the second intermediate shaft 60 by spline fitting. Then, by shifting the shifter shaft 66 and sliding the slidable gear 65 to change the meshing with the fixed gear 64 or to the neutral state, the rice transplanter can be set in a planting mode (low speed forward), a road traveling mode ( There are five modes: high speed advance), seedling mode (neutral), neutral mode, and reverse mode.

The sliding of the shifter shaft 66 is performed by rotating a shift lever (not shown). The first shaft 58 is provided with a traveling clutch 68 such as a ball type. The second intermediate shaft 60 is provided with a multi-plate parking brake 69. Although details are omitted because it is not directly related to the present invention, the travel clutch 68 is automatically engaged when the shift pedal 31 (see FIGS. 2 and 4) is depressed, and parking is performed when the shift pedal 31 is fully returned. The brake 69 works lightly. In addition, the parking brake 69 can be strongly applied by stepping on the brake pedal 70 (see FIG. 3).

As shown in FIG. 10, the front wheel drive shaft 61 is separated into two on the left and right sides at the inner bottom of the traveling mission case 9, and power is transmitted to the front axle device 10 through the respective shafts. The left and right front wheel drive shafts 61 are connected via a differential mechanism 71 (a differential lock device 72 that eliminates the differential relationship between the left and right front wheel drive shafts 61 is also provided).

The rotation of the second intermediate shaft 60 is transmitted from the output gear at the left end of the sheet in FIG. 10 to the differential mechanism 71 and also transmitted to the rear wheel drive shaft 63 via the three flat gears 74 as shown in FIG. The rotation of the rear wheel drive shaft 63 is transmitted to the drive shaft 77 through a pair of bevel gears 76. Of the three spur gears 74, the middle spur gear is loosely supported on the third intermediate shaft 62 at the left end of the paper surface of FIG. 10.

The rotation of the first shaft 58 is transmitted to the third intermediate shaft 62 via three spur gears 75 including an output gear fixed to the right end of the paper surface in FIG. 3 is transmitted from the intermediate shaft 62 to the work output shaft 79 through a pair of bevel gears 78. An intermediate gear of the three flat gears 75 is connected to the parking brake 69 on the second intermediate shaft 60 and is supported idle.

Although not shown, the work output shaft 79 is input to the inter-shaft transmission, from which power is transmitted to the seedling planting device 4 via the PTO shaft. When the fertilizer is provided, power is transmitted from the inter-strain transmission to the fertilizer.

As shown in FIG. 10, a bearing plate 80 for holding the shafts 58 to 63 is arranged inside the main body 9a constituting the traveling mission case 9. The bearing plate 80 is fixed to the main body 9a with bolts. Due to the presence of the bearing plate 80, each shaft can be held in a stable state.

Next, the power steering device will be described. As shown in FIGS. 13 and 14, the power steering unit 35 includes the torque generator (hydraulic motor) 39 described above and a speed reduction mechanism that decelerates the rotation of the output shaft 82 of the torque generator 39. 39 is fastened to the upper surface of the steering support 46 with bolts, and the speed reduction mechanism is arranged in a concave space (that is, a large opening upward) formed on the upper surface of the steering support 46.

As shown in FIG. 13, the speed reduction mechanism of the power steering unit 35 includes a sun gear shaft 83a into which an output shaft (not shown) of the torque generator 39 is inserted and spline-fitted, and a first sun gear carved at the lower end of the sun gear shaft 83a. 83, a first carrier 86 and a second sun gear 85, which support the three first planetary gears 84 and the first planetary gears 84 driven by the first sun gear 83 and have the second sun gear 85 fixed at the center of rotation. And three second planetary gears 87 meshed from the outside, and a second carrier 88 supporting the second planetary gears 87.

As shown in FIG. 14, a steering shaft 89 is integrally provided at the rotation center of the second carrier 88, and the steering shaft 89 is rotatably held by the steering support portion 46 by a bearing 90. That is, the steering support portion 46 is a steering gear box of the power steering unit 35. The steering shaft 89 protrudes downward from the bottom of the steering support 46, and the pitman arm 91 is fixed to the downward protrusion, and the tie rod 21 is connected to the tip of the pitman arm 91 so as to be relatively rotatable. .

The output shaft 82 of the torque generator 39 is transmitted to the three first planetary gears 84 via the first sun gear 83, and the three first planetary gears 84 orbit around the axis of the output shaft in a decelerated state. As a result, the first carrier 86 rotates. When the first carrier 86 rotates, the second planetary gear 87 orbits around the second sun gear 85 in a decelerated state, whereby the second carrier 88 further decelerates and rotates. As a result, the rotation of the output shaft 82 is decelerated in two stages and transmitted to the steering shaft 89. A cylindrical body 92 is arranged on the inner peripheral wall of the empty space of the steering support portion 46, and an internal gear 93 that meshes with the first and second

planetary gears

84, 87 from the outside on the inner peripheral surface of the cylindrical body 92. Is formed.

As indicated by phantom lines in FIG. 14, the receiving port 52 opens toward the empty space in the steering support portion 46, and the drain hole 94 opens toward the traveling mission case 9 in the steering support portion 46. Is forming. Accordingly, surplus oil or leaked oil carried out from the case of the HST 24 returns to the oil sump inside the traveling mission case 9 after coming into contact with the inner surface of the void of the steering support portion 46, gears, or the like. The drain hole 94 is located below the oil level OL of the oil stored in the traveling mission case 9, and therefore the drain hole 94 is always immersed in oil.

And since members such as gears constituting the drain pipe 54, the steering support 46, or the speed reduction mechanism of the power steering unit 35 have higher thermal conductivity than oil, the oil returns to the inside of the traveling mission case 9. To be cooled. Therefore, even if the rice transplanter is used for a long time, the efficiency reduction of the HST 24 can be suppressed.

For example, as shown in FIGS. 9A and 15, a large number of ribs 96 are formed on the left and right side surfaces of the steering support portion 46 so as to protrude outward in the left and right directions (that is, in a direction perpendicular to the opening surface of the main body portion 9a). ing. The ribs 96 cross in the vertical and horizontal directions when viewed from the side. When the power steering unit 35 is operated, a large load is applied to the steering support 46, but high strength is maintained by the presence of the group of ribs 96, and the rib 96 exhibits the function of a cooling fin. The oil cooling effect by can also be improved.

Now, both ends of the drain pipe 54 are fixed to the HST 24 and the steering support portion 46 by joints 55. However, since the drain pipe 54 is fitted tightly to the joint 55, if the length of the drain pipe 54 is short, high accuracy is obtained. If the bending process is not performed, twisting may occur between the end of the drain pipe 54 and the joint 55.

On the other hand, in this embodiment, since the drain pipe 54 is connected to the right side surface far from the HST 24 among the left and right side surfaces of the steering support portion 46, the drain pipe 54 has a receiving port as compared with the case where it is connected to the left side surface. Therefore, the length of the drain pipe 54 is inevitably increased, so that the drain pipe 54 does not need to be bent with high accuracy. Variation in machining accuracy can be absorbed by slight bending deformation. Further, if the length of the drain pipe 54 is long, the air cooling effect is increased accordingly, and the cooling effect is also increased.

The engine 8 of this embodiment is a water-cooled type, and thus has a radiator cooled by a fan. However, the drain pipe 54 can be extended to the vicinity of the fan of the radiator to be forcibly cooled. It is.

(3). First Summary In the above configuration, the traveling machine body 1 is provided with the engine 8, the traveling mission case 9, and the rotary handle type steering device, and the traveling mission case 9 is transmitted with power from the engine 8 to the HST 24. The hydraulic fluid of the HST 24 is supplied from the inside of the traveling mission case 9 and is returned to the traveling mission case 9 through the discharge port 53 after use. In the riding type work machine in which the case 9 is integrally provided with a steering support unit 46 to which the steering device is attached, an accepting port 52 into which the oil discharged from the HST 24 flows into the steering support unit 46, an oil Is provided with a drain hole 94 for allowing the vehicle to flow into the traveling mission case 9. The receiving port 52 of the steering support portion 46 and the discharge port 53 of the HST 24 are connected by a pipe 54.

Generally, the traveling mission case 9 is made of metal and does not reach a high temperature even if the temperature of the HST 24 or the like transfers heat. Therefore, the temperature of the steering support 46 in the traveling mission case 9 is much lower than the temperature of the hydraulic oil. For this reason, in the embodiment, surplus oil and leak oil discharged from the HST 24 are cooled by passing through the steering support portion 46 of the traveling mission case 9. In addition, since the portion of the steering device that enters the steering support portion 46 does not move at high speed and does not reach a high temperature, the oil is cooled by contacting a part of the steering device.

As described above, according to the embodiment, surplus oil and leak oil discharged from the HST 24 can be cooled by using a part of the traveling mission case 9 and the control device, so that the oil temperature of the oil accumulated in the traveling mission case 9 is reduced. It is possible to reduce the cost as much as possible to ensure the transmission efficiency of the HST 24 while keeping the cost low.

Further, the steering device has a hydraulic or electric power steering unit 35, and the steering gear of the power steering unit 35 is disposed inside the steering support portion 46, so that the steering device is configured. The rotational torque of the steering handle 19 is amplified and output to the output shaft 82, and the rotation of the output shaft 82 is decelerated by the steering gear and transmitted to the pitman arm 91. The steering gear is stopped in a state where the steering handle 19 is not rotated, and the speed of the steering gear is low even if it rotates, so that the temperature of the steering gear does not increase. Therefore, since the steering gear functions as an oil heat absorber, the oil cooling effect can be further improved. Further, the steering support portion 46 of the traveling mission case 9 is hollow to accommodate the gear, so that the area where the oil contacts the steering support portion 46 can be increased. The oil cooling effect can be improved.

Further, the steering support portion 46 is formed in a state in which a part of the outer periphery of the traveling mission case 9 protrudes outward, and a large number of fin-like ribs 96 project from the outer surface of the steering support portion 46. Therefore, the presence of the rib 96 can improve the strength of the steering support portion 46, and the surface area of the steering support portion 46 is remarkably increased so that a high air cooling effect can be exhibited, so that the oil cooling function can be further improved. .

The die-cast product is manufactured by a method in which molten metal is filled in a space formed between molds that are in close contact with each other and the mold is removed after the metal is solidified. In this case, the traveling mission case 9 is made of die-cast and faces away from the mounting portion of the HST 24 according to the embodiment. The rib 96 of the steering support portion 46 is formed so as to protrude in a direction perpendicular to the opening surface of the traveling mission case 9, so that the rib 96 protrudes in the relative movement direction of the mold. As a result, the rib 96 can be formed without impairing the ease of die cutting.

When the HST and the steering support portion are connected by a metal drain pipe, the drain pipe is cooled by air, so that the cooling effect of the hydraulic oil can be further improved. As in the embodiment, the receiving port 52 of the steering support portion 46 is It is provided at a location far from the HST 24 on the outer surface of the steering support portion 46. When the discharge port 53 of the HST 24 and the receiving port 52 of the steering support portion 46 are connected by a metal drain pipe 54, the drain pipe 54 is received. Since the steering support portion 46 is entrained when connecting to the port 52 and the length can be increased, it is more effective for cooling the hydraulic oil.

Now, the drain pipe 54 is manufactured by bending a metal pipe with a bender (press brake type bending machine), and both ends thereof are fixed to the HST 24 and the steering support portion 46 by joints. In this case, the metal pipe may be elastically deformed and fitted into the joint, or it may be slightly bent and deformed to absorb the processing error. There are cases where the fitting becomes troublesome and the processing error cannot be absorbed. On the other hand, when configured as in the embodiment, the length of the metal drain pipe 54 can be made as long as possible so that bending deformation at the time of connecting work can be facilitated. Can also absorb.

(4). Details of the Valve Unit Structure Next, details of a portion centering on the valve unit 42 will be described with reference to FIG. 18 and subsequent drawings. For example, as shown in FIG. 19, the traveling mission case 9 is composed of a main body portion 9a having a deep depth and a lid portion 9b that closes the main body portion 9a, and a shaft, a gear, a traveling clutch, a frame, a differential device, etc. Has been placed. The traveling mission case 9 also serves as an oil tank, and hydraulic oil is supplied to the pump unit 37 via an oil filter 56 (see FIG. 18).

As shown in FIG. 18, the pump unit 37 is a tandem type in which a charge pump 37a and an auxiliary pump 37b are arranged in parallel, and both pumps 41a and 41b are driven by the input shaft 25 of the HST 24. The HST 24 is fixed to the main body 9 a of the traveling mission case 9, and the hydraulic pump 41 is fixed to the lid 9 b of the traveling mission case 9.

The oil is sucked into the charge pump 37a and the auxiliary pump 37b through the oil filter 56. The input shaft 25 of the HST 24 is always rotating as long as the engine is operated. Therefore, the charge pump 37a and the auxiliary pump 37b are always rotating. The pressure oil generated by the charge pump 37a is sent to the hydraulic oil supply port of the HST 24 through the second discharge pipe 40. The pressure oil generated by the auxiliary pump 37 b is sent to the power steering unit 35 through the first pipe 38. Excess oil or leak oil discharged from the HST 24 returns to the traveling mission case 9 through the drain pipe 54.

In addition, it is also possible to arrange | position a cooling means between HST24 and a steering support part so that the oil cooler 155 'may be interposed in the middle part of the drain pipe 54, as shown with a dashed-dotted line in FIG.

Steering support 46 is provided on the lower part of the front end surface of the main body 9 a in the traveling mission case 9, and the power steering unit 35 is attached to the steering support 46. Further, the above-described front bracket 24 (see FIG. 6) is coupled to the steering support portion 46 of the main body portion 9a by bolts. The power steering unit 35 includes a hydraulic pump and a steering gear.

For example, as can be clearly understood from FIG. 21, the rear surface of the main body portion 9a constituting the traveling mission case 9 has a lower portion constituting the substantially lower half portion with the upper rear surface 145 constituting the substantially upper half portion positioned in front. The rear surface 146 is located behind, and therefore the rear surface of the main body 9a is uneven. In other words, there is a step between the upper and lower rear surfaces 45 and 46. The valve unit 42 is fixed to the upper rear surface 145, and the connection frame 10 is fixed to the lower rear surface 146. A flange 117a is provided at the front end of the connecting frame 11, and the flange 117a is fastened to the lower rear surface 146 of the traveling mission case 9 with a bolt 117b.

The upper and lower rear surfaces 45 and 46 are formed with voids opened rearward (to equalize the wall thickness as much as possible), and female screw holes 148 are formed in the periphery and boss portions. The valve unit 42 has a main body block 149. As shown in FIG. 22B, a flange 149 a is formed at the lower end of the main body block 149, and this flange 149 a is fixed to the upper rear surface 145 with a headed bolt 150. On the other hand, a recess 151 is formed in the upper portion of the main body block 149 so as to open upward and to the left and right sides. A nut 152 disposed in the recess 151 is provided on a stud bolt 152 ′ protruding from the upper rear surface 145. Screwed in.

The hydraulic oil discharged from the power steering unit 35 is sent to the input port of the valve unit 42 through the third pipe 43, branched from here and sent to the lift cylinder 5 through the fourth pipe 156, and the fifth pipe 157. Is sent to the rolling control device 158 'for the seedling planting device. The elevating cylinder 5 and the traveling mission case 9 are connected by a seventh pipe 159 that is a drain pipe, and the rolling control device 158 'and the traveling mission case 9 are also connected by an eighth pipe 160 that is a drain pipe. .

For example, as shown in FIG. 20, the elevating cylinder 5 is disposed in a posture tilted backward with respect to the vertical line in a side view, and is connected via a bracket 162 so as to tilt in a side view with the base end as a center. Attached to the frame 11. On the other hand, for example, as shown in FIG. 17, the elevating link mechanism 6 includes a top link 163 and a lower link 164, and the rear ends of both

links

63 and 64 are connected to a hitch 165 so as to be relatively rotatable. . Although details are omitted, a seedling planting device is connected to the hitch 165 via a kingpin.

As can be understood from FIG. 17, the front ends of the top link 163 and the lower link 164 are rotatably connected to the left and right rear columns 7 f via horizontally long upper support shafts 166 and lower support shafts 167 (see also FIG. 20). Has been. A longitudinally long drive link 168 is rotatably connected to the rear end portion of the lower link 164 by a horizontally long shaft 169, and the upper end of the auxiliary link 170 protruding obliquely upward from the front end of the lower link 164 is driven. The front end of the link 168 is connected by a horizontally long pin 171, and the pin 171 is passed through the tip of the piston rod 106 a in the elevating cylinder 5.

Therefore, when the piston rod 106a moves backward, the drive link 168 rotates so that the rear end thereof rises, and thereby the seedling planting device 4 rises. The fifth pipe 157 is connected to the front end portion of the elevating cylinder 5, and the seventh pipe 159 is connected to the base end portion of the elevating cylinder 5. That is, the piston rod 106a always moves forward by the weight of the seedling planting device 4, and the piston rod 106a moves backward by sending the pressure oil to the front end portion of the lifting cylinder 5, and the seedling planting device 4 rises. When the pressure oil returns from the fifth pipe 157, the piston rod 106a moves forward and the seedling planting device 4 descends. Therefore, the seedling planting device 4 can be raised and lowered by controlling the supply of pressure oil to the fifth pipe 157.

The seedling planting device 4 is connected to the hitch 165 so that it can roll left and right. Then, by driving the seedling planting device rolling control device 158 ′ based on a signal from a tilt sensor (not shown) in the left / right direction, the planting depth of the seedlings in each row is corrected by correcting the left / right tilt of the seedling planting device 4. Can be equalized.

The valve unit 42 includes a flow dividing valve 174 that divides the flow of pressure oil into the lift cylinder 5 and the seedling plant rolling control device 158 ′, a lift control valve 175 that controls the flow of pressure oil to the lift cylinder 5, and a lift solenoid valve 176. And a pair of electromagnetic control valves 177 for controlling the flow direction of the pressure oil to the elevation control valve 175, and a relief valve 178 for returning the pressure oil to the traveling mission case 9. The diversion valve 174 also corresponds to a control member of the hydraulic equipment.

Supply / stop / return of pressure oil to the lifting / lowering cylinder 5 is selected by moving the sprue of the lifting / lowering control valve 175 in the axial direction by controlling the electromagnetic control valve 177 ON / OFF. The posture in side view is controlled. The electromagnetic control valve 177 is often performed by a signal from a potentiometer (or a tilt sensor: not shown) provided in the traveling machine body 1 or the seedling planting device 4, but can also be driven by a mechanical interlocking means.

In the present embodiment, the lift control valve 175 has a sudden rise port 179, a slowly rise port 180, a slowly descend port 181 and a sudden drop port 182, and the pressure oil supply port and the return port from the lift control valve 175 are provided as these. Ascending and descending control of the seedling planting device 4 is performed accurately by selectively communicating with the other port. The seedling planting device 4 may be manually operated for adjustment, for example. Therefore, the lift control valve 175 is provided with a manual operation rod 183. The manual operation rod 183 can be operated by a person reaching out from the side of the traveling machine body 1.

The seedling planting rolling control device 158 ′ has a rolling cylinder 184 and an electromagnetic valve 185 for controlling the rolling cylinder 184. The rolling cylinder 184 has a pair of piston rods 184a protruding from both ends thereof, and the rolling posture is controlled by changing the protruding state of the piston rod 184a with the neutral position as a boundary.

(5). Second Summary In the above configuration, the traveling mission case 9 is disposed below the vehicle body cover 28, but the periphery of the traveling mission case 9 is a wide dead space. Since the valve unit 42 is fixed to the traveling mission case 9 using a wide dead space below the vehicle body cover 28, the valve unit 42 having a certain size can be arranged without any trouble.

Further, since the valve unit 42 is fixed to the upper rear surface of the traveling mission case 9, the valve unit 42 is protected from below by the traveling mission case 9 itself and the connecting frame 11. For this reason, for example, pebbles jump up. Even if there is, it is protected properly.

Furthermore, in this embodiment, not only the HST 24, the power steering unit 35, the

hydraulic pumps

37a and 37b, and the valve unit 42 are attached to the traveling mission case 9 as hydraulic equipment, but the traveling mission case 9 is also an oil tank. Since it is also used as a unit, hydraulic-related parts and equipment are unitized with the traveling mission case 9 at the center, which reduces the time and labor of assembling the rice transplanter and reducing the management and storage of the parts. it can.

The valve unit 42 can also be provided on the lid portion 9b of the traveling mission case 9, but if provided on the main body portion 9a as in the present embodiment, the lid unit 9b can be removed while the valve unit 42 remains fixed. There is an advantage that it is possible to reduce the trouble of maintenance and replacement of members arranged in the traveling mission case 9. In this embodiment, the valve unit 42 is merely provided with the diversion valve 174 in relation to the seedling plant rolling control device 158 ′. However, the electromagnetic valve 185 of the seedling plant rolling control device 158 ′ is replaced with the valve unit. 42 can also be provided.

In summary, the traveling machine body 1 having the traveling mission case 9, the hydraulic source 37 for driving the hydraulic device 5, and the valve unit 42 for controlling the hydraulic device 5 driven by the hydraulic source 37 are provided. Since the valve unit 42 is attached to the traveling mission case 9, the dead space outside the traveling mission case 9 can be effectively used to arrange the valve unit 42, and the design flexibility can be improved accordingly. Further, since the traveling mission case 9 and the valve unit 42 can be integrated into one unit, the labor for assembling the work machine and the labor for managing and storing the members can be reduced.

The hydraulic device controlled by the valve unit 42 is a lifting cylinder 5 for lifting and lowering the seedling planting device 4 connected to the traveling machine body 1 so as to be movable up and down, and detects the tilting posture of the traveling machine body 1 in the longitudinal direction. Since the lift cylinder 5 is driven by detecting by means and operating the valve unit 42 based on the tilt detection result, in particular, in the rice transplanter, the body cover 18 and the body frame 7 Since there is often no extra space in between, it can be said that it is particularly beneficial to apply the embodiment to a rice transplanter.

Further, in the embodiment, the traveling machine body 1 is supported by the left and right front wheels 2 and the left and right rear wheels 3 so as to be able to travel freely, and the traveling mission case 9 has a pair of left and right that rotatably support the front wheels 2. A front axle device 10 is attached, and a connecting frame 11 extending rearward is fixed. A rear axle case 12 fixed to the connecting frame 11 supports a rear wheel 3 so as to be rotatable. The front axle device 10, a rear axle case 12, and a connecting frame 11, and a body frame 7 is supported. Further, the rear surface of the traveling mission case 9 is viewed from the side so that the lower part is located behind and the upper part is located in front. The connecting frame 11 is fixed to the lower part of the rear surface, and the valve unit 42 is fixed to the upper part.

With this configuration, the traveling mission case 9 can also be used as a strength member of the traveling machine body 1 and can contribute to simplification and weight reduction of the structure of the traveling machine body 1. The valve unit 42 is fixed to the stepped portion of the traveling mission case 9 and is guarded from below by the traveling mission case 9 itself and the connecting frame 11. Therefore, high safety can be ensured.

As the hydraulic source 37,

hydraulic pumps

37a and 37b are generally used, and the

hydraulic pumps

37a and 37b are always rotating as long as the engine 8 is operated. The power of the engine 8 is input into the traveling mission case 9. Therefore, as in the embodiment,

hydraulic pumps

37a and 37b driven by the input shaft 25 to which power is transmitted from the engine 8 are attached to the traveling mission case 9, and the

hydraulic pumps

37a and 37b are connected to the hydraulic power source. 37, when the traveling mission case 9 is also used as a tank of hydraulic oil supplied to the

hydraulic pumps

37a and 37b, the traveling mission case 9 and the

hydraulic pumps

37a and 37b are integrated, Since the traveling mission case 9 functions as an oil tank, the traveling mission case 9 is also used as a hydraulic unit. For this reason, the whole structure can be simplified.

In recent years, riding-type farming machines such as riding-type rice transplanters are often equipped with continuously variable transmissions such as HST24 (hydrostatic continuously variable transmission) to improve running feeling. In this case, the continuously variable transmission 24 is generally attached to the traveling mission case 9, and the power of the engine 8 is transmitted to the input shaft 25 of the continuously variable transmission 24. Then, as in the embodiment, a continuously variable transmission 24 having an input shaft 25 and an output shaft 26 in a horizontally long posture is attached to one of the left and right side surfaces of the traveling mission case 9. The hydraulic pumps 37 a and 37 b driven by the input shaft 25 of the continuously variable transmission 24 are arranged on the other side surface of the transmission case 9, and a hydraulic type is disposed at the front of the traveling transmission case 9. When the power steering unit 35 is attached and the hydraulic oil from the

hydraulic pumps

37a and 37b is supplied to the valve unit 42 via the power steering unit 35, the continuously variable transmission 24 and the hydraulic pressure are supplied. Since the

pumps

37a and 37b are arranged in a distributed manner on both the left and right sides of the traveling mission case 9, the left and right Hydraulic pump 37a and vinegar take, becomes a simple form with no wonder a drive system of 37b.

Since the hydraulic drive type power steering unit 35 is also attached to the traveling mission case 9, the

hydraulic pumps

37a, 37b, the power steering unit 35, and the valve unit 42 are integrated into the traveling mission case 9. As a result, the labor of assembling the work machine and managing parts can be significantly reduced.

(6). Next, details of the travel transmission will be described with reference to FIG. 23 and subsequent drawings. For example, as shown in FIG. 23 (B), the traveling mission case 9 is composed of two shell-like members, which are a main body portion 9a having a deep depth and a lid portion 9b that covers and is shallower than the main body portion 9a. Both are fastened with bolts. Both opening surfaces (fastening surfaces and mating surfaces) are orthogonal to (transverse) the axis of each axis described later.

Next, the transmission system will be described mainly based on FIG. The HST 24 includes a hydraulic pump 24a driven by the input shaft 25 and a hydraulic motor 24b driven by the hydraulic pump 24a. The hydraulic motor 24 b has an output shaft 36. A first drive shaft 241 that rotates concentrically and integrally with the input shaft 25 of the HST 24 is connected to the input shaft 25, and is arranged on a main drive gear 242 fixed to the first drive shaft 241 and on the output shaft 36 so as to be freely rotatable. The driven carrier gear 243 is always meshed.

On the other hand, an internal gear 245 is arranged to swing around the end of the first shaft 58 concentrically with the output shaft 36, while a sun gear 246 is fixed to the output shaft 36 of the HST 24, and the internal gear 245 and the sun gear are fixed. 246 and the planetary gear 247 attached to the driven carrier gear 243 are meshed. Such a planetary gear mechanism and the HST 24 constitute an HMT. The first shaft 58 and the internal gear 245 are interlocked and detachably connected via a ball-type traveling clutch 68.

Next, the mechanical auxiliary transmission mechanism will be described. First to fourth gears 49 to 52 are fixed to the first shaft 58 so as not to be relatively rotatable. In addition, a second intermediate shaft 60 and a first intermediate shaft 59 parallel to the first shaft 58 are disposed inside the traveling mission case 9, and a fifth gear 255 having a different outer diameter from the second intermediate shaft 60. The sixth gear 256 is mounted so as to be slidable in the axial direction without being relatively rotatable, and the seventh gear 257 and the eighth gear 258 are relatively rotated on both the left and right sides with the fifth gear 255 and the sixth gear 256 interposed therebetween. It is fixed impossible. A twelfth gear 268 is engraved at one end of the second intermediate shaft 60, and a multi-plate brake (parking brake) 69 is provided at the other end.

The first intermediate shaft 59 is a reverse rotation idle shaft, and the ninth gear 260 that is always meshed with the first gear 249 and the tenth gear 261 that the sixth gear 256 slides and disengages are fixed so as not to be relatively rotatable. Has been. Since FIG. 24 is shown in an unfolded state, the first shaft 58 and the first intermediate shaft 59 are drawn apart from each other, but actually, as indicated by the arrows, the fifth gear 255 is shown. Meshes with the second gear 250, and the sixth gear 256 can selectively mesh with either the third gear 251 or the tenth gear 261.

In the traveling mission case 9, a left wheel drive shaft 263 and a right wheel drive shaft 264 are arranged in parallel with other shafts. The left and right

wheel drive shafts

63 and 64 are differentially connected to each other by a differential device 266 having a differential case 265, and an eleventh gear 267 and a twelfth gear 268 fixed to the differential case 265 are engaged with each other. That is, power is transmitted from the second intermediate shaft 60 to the left and right

wheel drive shafts

63 and 64. The differential device 266 can be deactivated by the differential lock device 72. The traveling mission case 9 and the left and right front axle devices 10 are connected by an axle housing 270.

Although details are omitted, by sliding the fifth gear 255 and the sixth gear 256, the rice transplanter can be planted in a planting mode (low speed forward), a road traveling mode (high speed forward), a seedling mode (neutral), a neutral mode, There are 5 modes for reverse mode. The sliding operation of the fifth gear 55 and the sixth gear 256 is performed by operating a speed change lever (not shown).

Although it is not directly related to the present invention, the details are omitted. However, when the speed change pedal 31 (see FIGS. 2 and 3) is depressed, the travel clutch 68 is automatically engaged, and when the speed change pedal 31 is fully returned, the brake is applied. 69 works lightly. Further, the brake 69 can be applied strongly by depressing the brake pedal 70 (see FIG. 3).

Furthermore, a third intermediate shaft 62 is disposed inside the traveling mission case 9. A thirteenth gear 275 is fixed on the third intermediate shaft 62 so as not to be relatively rotatable, and a fourteenth gear 276 is rotatably arranged. Power is transmitted to the 14 gear 276. The thirteenth gear 275 meshes with the fourth gear 252 on the first shaft 58 via the seventh gear 257 on the second intermediate shaft 60, so that the HMT output rotation before passing through the auxiliary transmission mechanism is reduced. It is transmitted to the 13th gear 275.

A work output shaft 78 projects rearward from the right side portion of the traveling mission case 9, and power is transmitted to the work output shaft 78 from the third intermediate shaft 62 by a pair of bevel gears 79. The power of the work output shaft 78 is input to the inter-case case 116 ′, from which power is transmitted to the seedling planting device 4 by the PTO shaft 140 ″.

The rear wheel drive second shaft 282 protrudes rearward from the rear surface of the left side slightly from the center in the left width direction in the traveling mission case 9. The rear wheel drive second shaft 282 is transmitted with power from the rear wheel drive shaft 63 via a pair of bevel gears 76. Further, a fifteenth gear 285 that meshes with the fourteenth gear 276 is fixed to the rear wheel drive shaft 63, and the rotation of the rear wheel drive second shaft 282 is driven by a drive shaft 77 that extends in the front-rear direction of the fuselage. It is transmitted to the inside of the rear axle case 12.

(7). Details of Shaft Support Structure As described above, the traveling mission case 9 is composed of the main body portion 9a having a deep depth and the lid portion 9b having a shallow depth, and is conceptually shown in FIG. In addition, an intermediate member 287 extending in the front-rear direction is disposed inside the main body 9a, and is detachably (removably) fixed to a substantially intermediate position in the left-right width direction of the main body 9a. The first shaft 58, the first to fourth intermediate

rotating shafts

53, 54, 74, and 83 and one end of the differential case 265 are rotatably supported by an intermediate member 287 via bearings.

The first drive shaft 241 is not supported by the intermediate member 287, but the first drive shaft 241 can be supported by the intermediate member 287. Specific embodiments of the arrangement of the shaft group, the arrangement of the gear group, and the shaft support structure are shown in FIG. This point will be described next.

The traveling mission case 9 has a shape close to an egg shape in a side view, and a steering support 46 is provided at the lower part of the front end. In the present embodiment, the hydraulic oil used in the HST 24 is returned to the inside of the traveling mission case 9 via the steering support portion 46 (to cool the hydraulic oil).

As shown in FIG. 27, the group of shafts has a posture in which the respective rotation axes extend in the vehicle width direction (left-right direction), and are arranged in the direction from the front to the rear lower part of the traveling mission case 9 as a whole. Is arranged. Specifically, the first drive shaft 241 is disposed at the top and the front, the first shaft 58 is disposed behind the first drive shaft 241, and the second intermediate shaft 60 and the first intermediate shaft are disposed below the first shaft 58. 59 is separated in the front-rear direction, and the

wheel drive shafts

63, 64 and the third intermediate shaft 62 are disposed in the state separated from the front-rear portion below the first intermediate shaft 59. The rear wheel drive shaft 63 is arranged at the rearmost position.

The intermediate member 287 is plate-shaped and extends long along the direction in which the shaft groups are arranged. Therefore, the intermediate member 287 has an appearance that extends long in an oblique direction in a side view. In addition, a large space is provided between the outer peripheral surface of the intermediate member 287 and the inner peripheral surface of the main body 9a in the traveling mission case 9, so that the working oil is a space between the intermediate member 287 of the main body 9a. Can move freely.

As can be understood from FIG. 23 (B), the intermediate member 287 is disposed in a state of being deeply inserted into the main body portion 9a (about the middle position in the axial direction and the lateral width direction). As shown in FIG. 25, a boss portion 289 for fixing the intermediate member 287 is formed on the main body portion 9 a, and the peripheral portion of the intermediate member 287 is fastened to the boss portion 289 with a bolt 290. . The boss portion 289 has a stepped shape projecting inward from the bottom inner surface and wall inner surface of the main body portion 9a, and an aspect projecting inward from the side wall inner surface of the main body portion 9a in an island shape. Is present.

As shown in FIG. 28, the input shaft 25 of the HST 24 and the first drive shaft 241 are connected via a main drive gear 242. Further, the right end portion of the first drive shaft 241 is rotatably supported by the lid portion 9b via a bearing. Further, the first shaft 58 is rotatably supported by the intermediate member 287 at the left and right central portions thereof and the right end portion by the lid portion 9b via bearings. The tooth gear 245 and the sun gear 246 are juxtaposed and loosely fitted, and the sun gear 246 is rotatably supported on the left side wall of the main body portion 9a via a bearing.

Therefore, the first shaft 58 is rotatably supported by the main body portion 9a via the sun gear 246, and is also rotatably supported by the intermediate member 287 and the lid portion 9b. Further, a traveling clutch 68 is formed between the first shaft 58 and the internal gear 245. The internal gear 245 and the traveling clutch 68 are short spans between the main body 9a and the intermediate member 287. Therefore, the support strength of the first shaft 58 is extremely high, and the support stability between the internal gear 245 and the travel clutch 68 is excellent. In addition, since the planetary gear mechanism such as the internal gear 245 and the traveling clutch 68 are arranged close to each other, the traveling transmission can be made compact.

Further, since the posture of the first shaft 58 is firmly held by the main body portion 9a and the intermediate member 287, the lid portion 9b can be accurately aligned. Therefore, it is easy to assemble and maintain. A shifter for connecting and disconnecting the traveling clutch 68 is indicated by reference numeral 92 (see FIGS. 28 and 26B).

The second intermediate shaft 60 and the first intermediate shaft 59 are rotatably supported by the intermediate member 287 and the lid portion 9b via bearings. Since both the intermediate

rotating shafts

53 and 54 can be shortened in length as compared with the case where they are supported by the main body 9a and the lid 9b, the strength against bending can be increased accordingly and the posture stability is also excellent. Therefore, durability can be improved and assembly and maintenance can be facilitated.

By shortening the second intermediate shaft 60 and the first intermediate shaft 59, the space formed between the main body portion 9a and the intermediate member 287 can be accommodated in the planetary gear mechanism that requires space in the radial direction and the differential device 266. Can be used.

As shown in FIGS. 28 and 29, the brake 69 is attached to the inside of the lid portion 9b. And since the main-body part 9a of the driving | running | working mission case 9 is being fixed to the rear axle case 12 with the connection frame 11, the main-body part 9a cannot be removed easily, but the cover part 9b can be removed comparatively easily. Since the brake 69 is overused, the necessity for maintenance and replacement is high. However, in the present embodiment, the brake 69 is attached to the lid portion 9b that can be easily removed, so that the maintenance and replacement of the brake 69 can be easily performed. Although not shown in the figure, the operation member of the brake 69 is provided on the lid portion 9b.

More specifically, in the present embodiment, the main body 9a of the traveling mission case 9 functions as a strength member (frame member) of the traveling machine body 1 by being fixed to the rear axle case 12 by the connecting frame 11. Although the advantage of simplification of the overall structure of the traveling transmission 1 can be obtained by adopting the configuration, the maintenance and replacement of the brake 69 are facilitated while ensuring the advantage.

The fifth gear 255 and the sixth gear 256 provided on the second intermediate shaft 60 are slid by, for example, a shift shifter 292 shown in FIG. The shift shifter 292 is attached to a horizontally long shifter shaft 66, and the shifter shaft 66 is partially exposed on the left side of the main body 9 a in the traveling mission case 9.

The shifter shaft 66 is slidably fitted between the intermediate member 287 and the lid portion 9b. For example, as shown in FIG. 26 (B), the shifter shaft 66 has a plurality of grooves (294) for holding the position, and the groove 294 is pressed by a spring. When the child (eg, ball) is fitted, the shift shifter 292 has five modes: a planting mode (low speed forward), a road traveling mode (high speed forward), a seedling mode (neutral), a neutral mode, and a reverse mode. Held in one of the modes.

Then, as shown in FIG. 26, the intermediate member 287 is provided with an upward hole 295 into which a holder (not shown) for holding a spring and a presser is inserted. Thus, since the shifter shaft 66 can be temporarily supported together with the subtransmission mechanism on the intermediate member 287 that is separable from the main body portion 9a, the assembly of the traveling transmission device is also simplified. This point is one of the advantages of the present embodiment and can be an independent invention (conventionally, since the shift bar is supported by the traveling mission case, the assembly is troublesome).

28, the differential case 265 is rotatably supported by the main body 9a and the intermediate member 287 via a bearing. The main body portion 9a is provided with an inward protruding portion 209c protruding toward the lid portion 9b, and the left end portion of the differential case 265 is rotatably supported by the end portion of the inward protruding portion 209c. Thus, since the differential case 265 is rotatably supported at both ends, the differential case 265 maintains extremely high stability with a short width. In the present embodiment, a differential lock clutch 96 constituting the differential lock device 72 is disposed inside an inwardly protruding portion 209c provided on the main body 9a. Therefore, the differential lock device 72 can be made compact.

The inward projecting portion 209c has a cylindrical shape as a whole, but is partially supported by a notch (not shown) along the width direction and supported by the main body portion 9a near the projecting portion 9c. By connecting the fork portion of the differential lock fork (not shown) to the differential lock clutch 96 through this notch, the differential lock clutch 96 can be slidably operated in the axial direction.

As shown in FIG. 29, the third intermediate shaft 62 is rotatably supported by the intermediate member 287 and the lid portion 9b via a bearing. Since the third intermediate shaft 62 can be shortened compared to the case where it is supported by the main body 9a, the strength and stability can be improved. The rear wheel drive shaft 63 is rotatably supported by the main body 9a and the intermediate member 287. And since the length of the rear-wheel drive shaft 63 is very short, it is possible to ensure extremely high strength and stability.

Now, in order to attach the third intermediate shaft 62 and the work output shaft 78 to the lid portion 9b, there is an empty space 297 having an L-shaped flat cross section and an opening inward of the case and an opening in the rear of the case. . The work output shaft 78 is rotatably supported in the space 297 by two front and rear bearings 288 and is prevented from coming off by a snap ring 299. The driven bevel gear 79 provided on the work output shaft 78 is set to a size that can be removed from the rear opening of the space 297.

More specifically, the driven bevel gear 79 of the third intermediate shaft 62 is spline-fitted to the third intermediate shaft 62 outside the bearing and is located in the space 297 so that the rear opening of the space 297 is open. Therefore, only the bevel gear 79 can be removed from the third intermediate shaft 62. For this reason, the snap ring 299 is removed without removing the lid portion 9b one by one. By removing the work output shaft 78, the two bevel gears 79 can be exchanged.

The work output shaft 78 rotates in proportion to the traveling speed. For this reason, the seedling planting interval (between plants) is basically adjusted by the strain adjustment mechanism built in the strain case 116 '. As a manufacturer, there is a case where it is desired to optionally prepare a specification that slightly changes between stocks relative to reference stocks according to the characteristics of crops and regions. That is, there is a case where a fine adjustment function between stocks may be prepared as an option. In this embodiment, since the work output shaft 78 can be easily removed and the two bevel gears 79 can be replaced, it is possible to easily meet the demand for fine adjustment between the stocks.

Now, in the rice transplanter, the raising / lowering cylinder 5 changes the posture of the seedling planting device 4 so that the planting depth of the seedling is constant even if there is unevenness in the field. In this case, depending on the vehicle speed Changing the operating sensitivity of the elevating cylinder 5 is performed. For this purpose, a sensor for detecting the vehicle speed is required. The vehicle speed sensor may be used for other purposes, such as providing a vehicle speed sensor to alert the operator when the speed is excessive.

In Japanese Patent Laid-Open No. 2000-175525, the rotational speed of the rear wheel drive shaft is detected by the vehicle speed sensor, but the rear wheel drive shaft is often left exposed, so there is a concern that the vehicle speed sensor may become dirty. Is done. If the rear wheel drive shaft and the vehicle speed sensor are covered with a cover, the structure becomes complicated and the cost increases.

On the other hand, in this embodiment, as shown in FIG. 29, a vehicle speed sensor 200 is provided outside the work output shaft 78 in the lid portion 9b, and the vehicle speed is calculated from the rotation speed of the work output shaft 78. It is composed. The work output shaft 78 is provided with a detection gear 201 that rotates with the shaft 78 between the two bearings 88, and detects the vehicle speed by converting the unevenness of the gear into the number of pulses.

In this embodiment, since the vehicle speed sensor 200 is protected by the lid portion 9b, there is no fear of contamination even if a separate cover is not provided. Further, since the side surface of the lid portion 9b is exposed to the outside (right side), the vehicle speed sensor 200 can be easily attached and detached.

The lid 9a can be removed after draining the oil inside the traveling mission case 9, but in this case, the right front wheel is also removed. Accordingly, when the lid portion 9a is removed, the traveling machine body 1 is in a three-wheel supported state, but the traveling machine body 1 can be stably held by being supported by some member. Therefore, even if the whole is not lifted and disassembled with a crane or the like in a maintenance shop, for example, in the user's warehouse or work site, the lid 9b can be removed to perform maintenance and repair inside the traveling mission case 9. . For this reason, the labor required for maintenance and repair can be remarkably reduced.

(8). Third Summary In summary, in the embodiment, the travel mission case 9 includes a shaft group and a gear group disposed therein, and the travel mission case 9 includes a main body portion 9a having a deep depth and the main body portion 9a. The shaft group is arranged in a posture intersecting with the opening surfaces of the main body 9a and the lid 9b, and the traveling mission case 9 Since the intermediate member 287 functioning as a bearing for at least a part of the shaft group is fixed to the main body 9a, the shaft disposed inside the traveling mission case 9 is in a state in which the lid 9b is removed. Is also supported by the main body 9a and the intermediate member 287, and is held in an accurately positioned state. For this reason, even when the other end of the shaft fits into the lid portion 9b, the lid portion 9b can be easily fitted, and therefore the traveling mission case 9 can be assembled accurately and efficiently. In addition, since the intermediate member 287 can function as a reinforcing member, it contributes to increasing the strength of the traveling mission case 9.

Further, when the lid 9b is removed for maintenance or parts replacement with the traveling mission case 9 incorporated in the work machine, the shaft is stably held at a predetermined position even if the shaft is in a horizontal posture. Therefore, it is possible to easily reattach the lid portion 9b, and therefore, it can be said that it is particularly effective for improving workability at the time of maintenance and parts replacement.

Furthermore, when the shaft / gear is removed for maintenance or repair, the traveling mission case 9 often has to be removed from the traveling machine body 1 in the case of the simple halving method. However, in the case of the embodiment, since the depth of the main body portion 9a and the intermediate member 287 are provided, most of the shaft and gear are changed to the deep main body portion 9a. Since it can be held in a predetermined posture, it is possible to perform operations such as shaft replacement by removing only the lid portion 9b until the main body portion 9a is attached to the traveling machine body 1. The frequency with which the traveling mission case 9 is removed can be significantly reduced. In this respect, maintenance and repair workability can be improved.

Moreover, since the support span of the shaft can be shortened by arranging the intermediate member 287, the strength of the shaft can be increased and the durability can be improved. Furthermore, the shaft can be supported only by the main body portion 9a and the intermediate member 287, or can be supported only by the intermediate member 287 and the lid portion 9b, and thus the flexibility of the shaft support structure is improved. it can.

Now, it is theoretically possible to provide a plurality of bearings on one part constituting the traveling mission case 9, but in this case, the parts are manufactured as a casting using a mold and then subjected to complicated post-processing. Because it must be done, productivity is low and cost is high. That is, one mold is manufactured for each traveling mission case 9, and steps such as pouring, curing, removing the mold, and cutting of the bearing portion must be performed, resulting in low productivity and high cost. . Moreover, since the shaft cannot be set with the gear attached to the shaft, the assembly is also very troublesome.

On the other hand, when the separable intermediate member 287 is provided as in the embodiment, it is sufficient that the main body portion 9a constituting the traveling mission case 9 is provided with a bearing portion that supports one end portion of the shaft. Die-cast products (molding) manufactured by methods such as pouring into a cavity, solidification, and die removal after separating the mold using a mold that can be adhered and separated freely. Product).

Thus, the shaft can be stably supported by using the intermediate member 287 while manufacturing the main body 9a (or the lid 9b) with high dimensional accuracy efficiently and at low cost. Therefore, it is possible to increase productivity and contribute to cost reduction. In addition, since the intermediate member 287 can be attached and detached, the shaft can be assembled by a simple procedure in which one end is inserted into the main body portion 9a with a member such as a gear attached thereto and then the intermediate member 287 is set. Therefore, assembly work is easy.

As described above, when the HMT is configured by combining the HST 24 and the planetary gear mechanism, high transmission efficiency can be secured over a wide range from the low speed range to the high speed range, but when the traveling mission case 9 is a simple split system, There is a concern that the support span of the planetary gear mechanism becomes long and the durability is lowered.

In contrast, the embodiment further includes an HST 24 to which power from the engine 8 is transmitted, and a planetary gear mechanism that forms an HMT in combination with the HST 24. The HST 24 includes the traveling mission. The main body 9a of the case 9 is attached to the outer surface of the bottom located on the opposite side of the lid 9b, and the planetary gear mechanism is connected to the bottom of the main body 9a of the traveling mission case 9 and the intermediate member 287. Therefore, the planetary gear mechanism can be supported by the intermediate member 287, and the support stability of the planetary gear mechanism can be remarkably improved. In addition, it is easy to dispose a travel clutch between the main body 9a and the intermediate member 287, which can contribute to the compactness of the travel transmission. Furthermore, since the planetary gear mechanism is held between the main body portion 9a and the intermediate member 287, the lid portion 9b can be attached or detached while the HMT is attached to the traveling mission case 9, and as a result, The traveling mission case 9 can be easily assembled and maintained.

As described above, a differential device is indispensable for a wheel traveling type work machine, but if the two wheel drive shafts are not stably supported, the durability is lowered. In this regard, as in the embodiment, a wheel drive axle device 10 is attached to each of the main body portion 9a and the lid portion 9b of the traveling mission case 9, and the traveling mission case 9 has one axle device 10 attached to it. One wheel drive shaft 263 that transmits power and the other wheel drive shaft 264 that transmits power to the other axle device 10 are arranged concentrically, and the differential device 266 for making the

wheel drive shafts

263 and 264 differential is provided as described above. When the differential device 266 is stably held between the main body 9a and the intermediate member 287 when the main body 9a and the intermediate member 287 are disposed, the two

wheel drive shafts

263 and 264 are also supported stably. As a result, the durability of the differential device 266 can be improved.

It is normal for oil to collect inside the traveling mission case 9. In particular, in a working machine having an HST 24, it is general that the traveling mission case 9 is also used as a hydraulic oil tank of the HST 24, and when the working machine includes a hydraulic cylinder and a power steering, The traveling mission case 9 is also used as a tank for these hydraulic oils.

And since the hydraulic oil often becomes high temperature, it is necessary to circulate inside the traveling mission case 9 and cool it as much as possible. However, as in the embodiment, the inner periphery of the main body 9a in the traveling mission case 9 and the If a space where oil can freely flow is provided between the outer periphery of the intermediate member 287, the circulation of oil (hydraulic oil) inside the traveling mission case 9 is not hindered, which may hinder the oil cooling function. Absent. Further, since the intermediate member 87 can be reduced in size, the material cost can be reduced and the travel transmission can be reduced in weight.

(9). Others The present invention can be embodied in various ways other than the above embodiment. For example, the application target is not limited to the rice transplanter, and can be applied to various riding-type agricultural machines. For example, the specific shapes of the traveling mission case and the intermediate member can be arbitrarily changed as necessary. It is also possible to configure a plurality of intermediate members. In this case, a plurality of intermediate members can be arranged separately in the spreading direction of the opening surface of the main body, or can be arranged separately in the depth direction of the main body (thus, the shaft Can be supported by a plurality of intermediate members.)

When providing a continuously variable transmission, it is not limited to HST, and it is possible to provide a belt type CVT or the like. Moreover, when applying to seedling transplanting machines, such as a rice transplanter, it is also possible to incorporate an inter-strain adjustment device in a traveling mission case. Moreover, this invention is applicable also to other working machines other than a rice transplanter.

Also, the attitude and structure of the traveling mission case, the arrangement position of the HST, etc. can be arbitrarily set as necessary. For example, it is possible to place the engine behind the control floor. Since the power transmission means from the engine to the HST is not limited to a belt, it is possible to transmit power via a gear or to directly connect the output shaft of the engine and the input shaft of the HST.

The structure and function of the valve unit can be selected as necessary. Furthermore, the arrangement position of the valve unit is not limited to the rear surface of the traveling mission case, and can be fixed to other parts such as the side surface of the traveling mission case.

It is also possible to provide a cover that protects the valve unit. In the case where the valve unit is disposed on the stepped portion of the traveling mission case, the stepped portion may be provided on the left or right side surface or the front surface of the traveling mission case.

The invention of the present application is embodied in a riding-type farm work machine such as a rice transplanter and demonstrates its usefulness. Therefore, it can be used industrially.

DESCRIPTION OF SYMBOLS 1 Traveling machine body 4 Seedling device 8 Engine 9 Traveling mission case 9a Main body part 9b Cover part 24 HST as an example of continuously variable transmission
DESCRIPTION OF SYMBOLS 10 Front axle apparatus 11 Connection frame 12 Rear axle case 26 HST input shaft 40 HST output shaft 41 First drive shaft 44 Second drive shaft 45 Internal gear 48 constituting planetary gear mechanism (HMT) 48

Traveling clutch

53, 54 , 74, 83 Intermediate rotating shaft 59 Brake (parking brake)
63, 64 Wheel drive shaft 65 Differential case 66 Differential device 72 Brake pedal 87 Intermediate member

Claims

It has a traveling mission case and a group of shafts and gears arranged inside it,
The traveling mission case has a main body portion having a deep depth and a shallow lid portion covering the main body portion, and the shaft group is disposed in a posture intersecting with the opening surfaces of the main body portion and the lid portion.
The structure
An intermediate member that functions as a bearing for at least a part of the shaft group is fixed to the main body of the traveling mission case.
A traveling transmission for a riding-type work machine.
Furthermore, it has an HST to which power from the engine is transmitted, and a planetary gear mechanism that constitutes an HMT in combination with the HST,
The HST is attached to an outer surface of a bottom portion located on the opposite side of the lid portion of the main body portion in the traveling mission case, and the planetary gear mechanism is connected to the bottom portion of the main body portion and the intermediate member in the traveling mission case. Arranged between
The traveling transmission device for a riding type work machine according to claim 1.
A wheel drive axle device is attached to each of the main body portion and the lid portion of the traveling mission case, and the traveling mission case has one wheel drive shaft for transmitting power to one axle device and the other axle. The other wheel drive shaft that transmits power to the device is arranged concentrically, and a differential device for making the both wheel drive shafts differential is arranged between the main body portion and the intermediate member,
The traveling transmission device for a riding type work machine according to claim 1 or 2.
A space in which oil can freely circulate between the inner periphery of the main body portion and the outer periphery of the intermediate member in the traveling mission case,
The traveling speed change device for a riding type work machine according to any one of claims 1 to 3.