JPH09202258A - Steering device for running work machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simplify the structure of the steering device which can adjust the speeds and rotational directions of the right and left crawlers of the running work machine arbitarily in a stepless manner. SOLUTION: A transmission mechanism transmitting power to the output shafts 21a and 21b of a right and a left running crawler, is formed out of paired right and left epicyclic gear shifting mechanisms 31 and 31 each of which is formed out of a sun gear 40, an epicyclic gear 39, and of a ring gear 42, the power of a running hydraulic transmission means formed out of a hydraulic pump 33, and of a hydraulic motor 34 is transmitted to the sun gear 40, and power from a turning hydraulic type driving means formed out of a second hydraulic pump 36, and of a second hydraulic motor 37, is so designed that it can be transmitted to a pair of ring gears 42 and 42 meshed with the respective epicyclic gears in such a way that their rotating directions are mutually opposite. When the tow pairs of hydraulic pumps 33 and 36 and hydraulic motors 34 and 37 are to be mounted onto a mission case 30, the first hydraulic pump 33 and the second hydraulic pump 36 are disposed along one straight line so as to let the power of an engine be inputted to them through a common shaft 70.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a steering device for a traveling working machine having a pair of left and right traveling crawlers, such as a combine harvester capable of cutting and threshing, and a tractor for agricultural work or civil engineering.

[0002]

2. Description of the Related Art Conventionally, a traveling portion of a traveling working machine such as a combine or a tractor is composed of a pair of left and right traveling crawlers, and each of the left and right traveling crawlers is driven by a set of one hydraulic pump and a hydraulic motor. Configuration, in other words, the left and right traveling crawlers are driven by independent left and right hydraulic drive systems (two pumps, two motors type) to control steering along the crop row during mowing work, and normal straight traveling Executing the control is performed, for example, in Japanese Patent Publication No. 54-34972.
It is disclosed in Japanese Utility Model Laid-Open No. 3-116422.

[0003]

However, according to these configurations, the operator has to operate the left and right hydraulic drive systems separately, and in the case of going straight, the outputs of the left and right hydraulic drive systems are completely eliminated. Must be adjusted to be the same. Also, when the spin turn is performed by driving the outer side of the turn and the inner side of the turn in opposite directions from the slow turn operation in which the running speed on the inside of the turn is slower in the same direction and slower than the running speed on the outside of the turn, both hydraulic pressures are temporarily Since there is an operation to stop the output of the drive system and switch it in reverse,
There was room for improvement in the operability of stepless speed control and smooth direction change.

Therefore, the applicant of the present invention connects the planetary speed change mechanism with a hydraulic drive means for traveling, which comprises a hydraulic pump and a hydraulic motor, and a hydraulic drive means for turning, which also comprises a hydraulic pump and a hydraulic motor. , By inputting the outputs of both hydraulic drive means to another input section of the planetary speed change mechanism,
We have developed a steering system that allows the turning radius to be adjusted steplessly with simple operations and the straight-line speed to be adjusted continuously.

The present invention aims to improve the structure of a steering device of this type.

[0006]

In order to achieve the above-mentioned object, a steering apparatus for a traveling working machine according to the present invention uses a pair of left and right motive power from a hydraulic drive means for traveling composed of a hydraulic pump and a hydraulic motor. While being configured to be transmitted to the output shaft to the pair of left and right traveling crawlers in the traveling work machine via the planetary transmission mechanism, the power from the hydraulic drive means for turning including the hydraulic pump and the hydraulic motor is One planetary speed change mechanism and the other planetary speed change mechanism are transmitted so as to impart rotations in opposite directions to each other, and one of the straight drive mode and the straight drive mode is controlled according to the output adjustment amount of the traveling and turning hydraulic drive means. Of the traveling crawler and the other traveling crawler are configured to be continuously adjustable up to a turning operation in which the rotation directions of the traveling crawler and the other traveling crawler are opposite to each other. , While attached to the transmission case which incorporates the transmission mechanism is the power from the prime mover through one common axis which is configured to transmit to the hydraulic pump.

[0007]

With this structure, the power of the hydraulic drive means for traveling is supplied to the pair of left and right planetary gears while the power from the hydraulic drive means for turning is stopped. If the output shaft is transmitted to a pair of left and right traveling crawlers in the traveling vehicle via the speed change mechanism, straight traveling is executed, and the rotation speed of the left and right traveling crawlers is controlled even if the traveling surface is in a bad condition such as mud. It is easy to drive straight ahead by matching them, and the straight running performance is improved.

Further, during turning, by continuously changing the power rotational speed from the hydraulic drive means for turning consisting of a hydraulic pump and a hydraulic motor, the traveling crawlers on the inside and outside of the turning can be changed steplessly. The speed ratio can be changed arbitrarily (steplessly). That is, by operating the hydraulic drive means for traveling while operating the output of the hydraulic drive means for turning, the speed at which the left and right traveling crawlers are driven in the same direction can be adjusted as desired. As the inner traveling crawler is stopped or driven in the backward direction, the traveling outer crawler can change the speed in the forward direction. As a result, stepless swivel work is performed at any traveling speed and at any turning radius. Therefore, there is an effect that the transition operation can be executed extremely smoothly from a gentle turning having a large turning radius to a sharp turning having a small turning radius.

Further, when the hydraulic drive means for turning is operated with the hydraulic drive means for traveling stopped, the left and right traveling crawlers perform spin-turns with the same rotational speed but opposite rotation directions. The turning speed at that time can be arbitrarily adjusted. In this way, the configuration of the steering device of the traveling work machine is extremely simple because the output operating means of the hydraulic drive means for traveling and the operating means of the hydraulic drive means for turning are all that is required. The effect is that it can be executed by a simple operation, and the operability of changing directions is improved.

By mounting the two pairs of hydraulic pumps and hydraulic motors in both the hydraulic drive means in the transmission case having the transmission mechanism built-in, the location where the power is output from each hydraulic motor to the transmission mechanism is brought close to each other. Can be placed
In addition, the structure of the combination of the hydraulic system and the mechanical system can be made compact so that the hydraulic path from the hydraulic pump to the hydraulic motor is shortened. Further, when two hydraulic pumps arranged in a tandem type are rotationally driven by one common shaft, it is possible to transmit power from a prime mover such as an engine to the two hydraulic pumps with a simple input structure.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Next, an embodiment in which the present invention is applied to a combine will be described. FIG. 1 is a side view of a traveling body 1 of a general-purpose combine, which is a traveling vehicle having a pair of left and right traveling crawlers 2a and 2b. Yes, the threshing device 3 is mounted on the traveling machine body 1, and the handling cylinder 4 in the handling chamber of the threshing device 3 is arranged so that its axis is along the traveling direction of the traveling machine body 1, and below the receiving body. It is provided with a rocking sorting device 5 such as a net and a sheave, and a wind sorting device based on the wind of Kara Min Juan 6, and a paddy tank for storing threshed grains is mounted on the side of the threshing device 3.

The cutting pretreatment device 7 has a rectangular tubular feeder house 9 (having a chain conveyor 9a therein) which is opened at the front part of the threshing device 3 and which can be raised and lowered by a hydraulic cylinder 8 for raising and lowering. A horizontally long bucket-shaped platform 10 continuously provided at the front end of the feeder house 9, a horizontally long scraping auger 11 horizontally provided in the platform 10, a reel 12 with a tine bar at the front upper position thereof, and left and right on the lower surface side of the platform 10. It consists of a cutting blade 14 in the form of a hair clipper arranged in the longitudinal direction. Further, a pair of left and right grass bodies 15 protruding forward are provided at both left and right front portions of the pre-mowing treatment device 7.

The left and right traveling crawlers 2a, 2b are respectively provided with left and right output shafts 21a, 21 of a steering device 20 which will be described later.
Starting wheels 22 and 2 which are rotationally driven by the power output from b
2 and the guide wheel 2 biased rearward to the rear end side of the traveling body 1.
Tracks 24, 24 wound around 3, 23 and each track 2
4, a suspension wheel (lower wheel) 25 supporting the lower inner peripheral surface of the wheel 4.

Next, the structure of the steering device 20 will be described. In the first embodiment shown in FIGS. 2 to 4, a pair of left and right planetary transmission mechanisms 31, 31 to be described later are provided in the mission case 30.
A hydraulic drive means 32 for traveling comprising a first hydraulic pump 33 and a first hydraulic motor 34, and a second hydraulic pump 36.
Also, the hydraulic drive means 35 for turning including the second hydraulic motor 37 is incorporated.

The pair of left and right planetary speed change mechanisms 31, 31 are bilaterally symmetrical, and a plurality (three in the embodiment) on the same radius.
A pair of left and right bracelets 38, 38 on which the planetary gears 39, 39, 39 are rotatably supported, respectively.
It is arranged so as to be opposed to each other on the coaxial line within 0 as appropriate. Sun gear 4 meshing with each of the planetary gears 39
The left and right ends of the sun shaft 41 to which 0 and 40 are fixed are
It is rotatably supported by a bearing located at the center of rotation of the inner side of each of the insides 8 and 38.

The ring gear 42 having the inner teeth on the inner peripheral surface and the outer teeth on the outer peripheral surface has three inner teeth 39, 39, 3
9 are arranged concentrically with the sun shaft 41 so as to mesh with each other.
It is rotatably supported by a bearing on a central shaft 43 protruding outward from the outer surface of the bracelet 38. By changing and adjusting the angle of the rotary swash plate of the variable displacement first hydraulic pump 33 in the hydraulic drive means 32 for traveling, the discharge direction and discharge amount of the pressure oil to the first hydraulic motor 34 are changed. Then, the rotation direction and the rotation speed of the first hydraulic motor 34 are adjustable. Rotational power from the first hydraulic motor 34 is transmitted from the input gear 45 of the input shaft 44 through the gears 46, 47, 48 of the auxiliary transmission mechanism to the sun shaft 4
It is transmitted to the center gear 49 fixed to 1. A brake mechanism (not shown) is provided on the brake shaft 50 to which the gear 48 is attached. In addition, the PTO shaft 5 that transmits the rotational force to the working machine or the like via the gear 51 that meshes with the gear 46.
Output to 2.

The traveling hydraulic drive means 32 is provided.
Is transmitted to the pair of left and right planetary speed change mechanisms 31, 31 via the center gear 49 fixed on the sun shaft 41, and the center shaft 4 of the left bracelet 38 is rotated.
The transmission gear 53 fixed to 3 is meshed with the transmission gear 54 fixed to the left output shaft 21a to output. Similarly,
Transmission gear 53 fixed to the central shaft 43 of the right bracelet 38
Is meshed with the transmission gear 54 fixed to the output shaft 21b on the right side and output (see FIGS. 2 and 4).

By changing and adjusting the angle of the rotary swash plate of the variable displacement second hydraulic pump 36 in the hydraulic drive means 35 for turning, the discharge direction and discharge amount of the pressure oil to the second hydraulic motor 37 can be controlled. Is changed so that the rotation direction and the rotation speed of the second hydraulic motor 37 can be adjusted. Second
Rotational power from the hydraulic motor 37 is transmitted to the pair of transmission gears 56 and 57 attached to the input shaft 55. And FIG.
As shown in FIG. 5, the outer teeth of the left ring gear 42 directly mesh with the transmission gear 56, and the right transmission gear 57 meshes with the reversing gear 59 attached to the reverse rotation shaft 58. It meshes with external teeth.

Therefore, when the left ring gear 42 is reversely rotated at the predetermined rotation speed by the normal rotation of the second hydraulic motor 37, the right ring gear 42 is normally rotated at the same rotation speed as described above. Rotational force from the engine (not shown) is transmitted to the endless chain 60 on the shaft of one hydraulic pump (for example, the shaft 33a of the first hydraulic pump 33 of the hydraulic drive means for traveling) outside the mission case 30. Is transmitted to the shaft 33a of the first hydraulic pump 33 and the second hydraulic pump 3
The shaft 6a of 6 and the chain 61 in the mission case 30
If the power is transmitted by winding (see FIG. 3), only one power transmission position from the engine is required, and the steering device becomes compact.

A single operating lever (not shown) provided on the seat in the control section of the traveling machine body 1 can be moved in two directions, that is, the front-rear direction and the left-right direction, which are orthogonal to each other in plan view. It allows speed adjustment and steering operation to be performed simultaneously. In the embodiment, when the operating lever is erected vertically upward, the neutral position is set. When the operating lever is rotated in the forward direction, the traveling machine body 1 is moved forward, and when rotated in the backward direction, the traveling vehicle body 1 is moved backward and the traveling speed is The operation lever is set so that it becomes faster as the front-rear tilt angle (the tilt angle with respect to the vertical angle) increases. When the operation lever is tilted to the left or right, the traveling machine body 1 is swung in that direction to increase the left-right tilt angle. A method for adjusting the pressure oil discharge direction and the discharge amount of the hydraulic pumps 33, 36 of the traveling hydraulic drive means 32 and the turning hydraulic drive means 35 so that the turning radius becomes smaller (smaller turning). Is.

With this configuration, for example, when the hydraulic drive means 35 for turning is stopped, the rotation of the ring gears 42, 42 on both the left and right sides is stopped and fixed. When the traveling hydraulic drive means 32 is driven in this state, the rotational force from the first hydraulic motor 34 is input to the center gear 49 of the sun shaft 41, and the rotational force is applied to the left and right sun gears 40, 40. To the output shafts 21a and 21b on both the left and right sides through the planetary gear 39 and the arm gear 38 of the planetary transmission mechanism on both the left and right sides at the same rotational speed in the same direction. You can drive straight ahead.

On the contrary, when the traveling hydraulic drive means 32 is stopped, the sun shaft 41 and the sun gears 40 on the left and right sides are fixed. In this case, the brake shaft 50
It is preferred to actuate the braking means to fix the.
In this state, when the turning hydraulic drive unit 35 is driven, for example, in the forward direction, the planetary speed change mechanism including the left planetary gear 39 and the arm gear 38 rotates in the reverse direction, while the right planetary gear 3 is rotated.
9. The planetary speed change mechanism including the arm gear 38 rotates in the normal direction. Therefore, while the left traveling crawler 2a moves backward,
Since the right traveling crawler 2b moves forward, the traveling body 1 spins to the left on the spot.

In FIG. 5, the horizontal axis indicates the horizontal tilt angle of the operating lever, and the vertical axis indicates the traveling speed (m / se) of the left and right traveling crawlers.
c.) is adopted, the solid line and the dotted line show the spin turn state, the solid line A1 and the dotted line a1 show the left traveling crawler 2a, and the solid line B1 and the dotted line b1 show the right traveling crawler 2b. The solid line A1 and the dotted line a1 are forward (+ sign), and the solid line B1 is
The dotted line b1 is backward (-), and indicates that the absolute values of the traveling speeds of the left and right traveling crawlers are the same with respect to the same tilt angle of the operation lever in the left direction or the right direction (turning direction). The solid line and the dotted line are based on the magnitude of the forward tilt angle of the operating lever, that is, the magnitude of the traveling speed. Therefore, the spin turn can be steplessly adjusted at an arbitrary speed by changing the forward tilt angle or the backward tilt angle and the left-right tilt angle of the operation lever.

The alternate long and short dash line in FIG.
In the case where the turning radius is steplessly adjusted at any speed up to a sharp turn, for example, the left and right traveling crawlers 2
When making a right turn from a state in which a and 2b are traveling forward at 1.5 (m / sec.), the left traveling crawler 2a moves to x (m
/ Sec.) (See dashed-dotted line A2) while the right traveling crawler 2b is decelerated by the same value x (m / sec.) As described above (see dashed-dotted line B2). That is, the left traveling crawler 2a travels at 1.5 + x (m / sec.),
The right traveling crawler 2b travels at 1.5-x (m / sec.) And turns right. Also, this acceleration / deceleration x
(M / sec.) Can be adjusted steplessly according to the tilt angle of the operating lever, and a gentle turn can be made like the speed line a2 of the left traveling crawler 2a and the speed line b2 of the right traveling crawler 2b shown by the chain double-dashed line. it can.

In this case, the speed line A of the left traveling crawler 2a
2 and the speed line a2 are large, it is possible to adopt a state of zero speed or a reverse state like the speed line B2 and the speed line b2 of the right traveling crawler 2b. In these cases, neither the traveling hydraulic drive means 32 nor the turning hydraulic drive means 35 has power loss due to slippage of the brake or clutch, and only normal hydraulic power transmission loss of the hydraulic pump and the hydraulic motor. Therefore, the horsepower loss can be significantly reduced.

In this type of steering apparatus, the first hydraulic pump 33 and the first hydraulic motor 3 of the hydraulic drive means 32 for traveling are used.
4 can be set to have a large horsepower (capacity), and the horsepower (capacity) of the second hydraulic pump 36 and the second hydraulic motor 37 of the hydraulic drive means 35 for turning can be set to a small value, thereby improving energy efficiency. Is improved. On the other hand, when the left and right traveling crawlers are separately and independently driven by two sets of hydraulic drive means composed of a hydraulic pump and a hydraulic motor as in the conventional case, both the left and right traveling crawlers are driven at the same speed when going straight. It is necessary to provide a large horsepower (capacity) necessary for driving, and during slow turning, the horsepower (capacity) of the hydraulic drive means inside the turning is surplus, resulting in a large energy loss.

In the second embodiment shown in FIGS. 6 and 7, the input shaft 44 from the first hydraulic motor 33 in the hydraulic drive means 32 for traveling is the output shaft 21a for the left and right traveling crawlers 2a, 2b. 21b is parallel to the input shaft 5 from the second hydraulic motor 3 in the hydraulic drive means 35 for turning.
5 is arranged orthogonal to the input shaft 44, and the input shaft 55
The bevel gear 62 at the tip of the bevel gear 63,
Mesh with 64. The bevel gears 63 and 64 and the transmission gears 65 and 66 that rotate integrally with the bevel gears mesh with the outer teeth of the left and right ring gears 42 and 42, respectively, and the rotational force is transmitted. Therefore, if the bevel gear 63 rotates forward with respect to the normal rotation of the second hydraulic motor 37, the bevel gear 64 rotates reversely,
Therefore, the left ring gear 42 rotates forward and the right ring gear 42
Will rotate in the reverse direction.

The axis of the first hydraulic pump 33 in the hydraulic drive means 32 for traveling and the hydraulic drive means 3 for turning.
5 is arranged parallel to the shaft of the second hydraulic pump 36, the power from the engine is input to the shaft of one hydraulic pump, and the power is transmitted from this shaft to the shaft of the other hydraulic pump by chain winding. Good. In addition, since the meshing relationship of the gears of the planetary speed change mechanism and the hydraulic drive means 32 for traveling is the same as that of the first embodiment, the same reference numerals are given to the same parts, and detailed description of the configuration and operation will be given. Is omitted.

8 and 9 show a third embodiment, in which the axis of the first hydraulic pump 33 in the hydraulic drive means 32 for traveling and the axis of the second hydraulic pump 36 in the hydraulic drive means 35 for turning are shown. Is a common shaft 70, and power is input to the pulley 71 fixed to the common shaft 70 from the engine by a belt 72 or the like. The common shaft 70 is the left and right output shafts 21a protruding from the mission case 30 in the embodiment of FIG.
Although it is parallel to 21b, it may be arranged to be orthogonal. On the other hand, the input shaft 73 from the first hydraulic motor 34 in the hydraulic drive means 32 for traveling and the input shaft 74 from the second hydraulic motor 37 in the hydraulic drive means 35 for turning are the output shafts 21a, It is arranged orthogonal to 21b. Then, the bevel gear pair 76, 77 that faces and meshes with the bevel gear 75 attached to the tip of the input shaft 73 of the traveling hydraulic drive unit 32 rotates integrally with the sun shaft 41.

Then, a pair of left and right planetary transmission mechanisms 31, 3
1 is a left-right symmetrical shape, and a pair of left and right bracelets 38, 38 on which three planetary gears 39, 39, 39 are respectively rotatably supported on the same radius are coaxially arranged in the mission case 30 on a coaxial line. They are spaced apart and face each other. The left and right ends of the sun shaft 41, to which the sun gears 40, 40 meshing with the respective planetary gears 39 are fixed, have two bracelets 38, 38.
Is rotatably supported by a bearing located at the center of its rotation inside.

Further, the ring gear 42 having the inner teeth on the inner peripheral surface and the outer teeth on the outer peripheral surface has the inner teeth of the three 39,3.
9 and 39 are arranged concentrically with the sun shaft 41 so as to mesh with each other, and the ring gear 42 is provided on the sun shaft 41 or on the central shaft 43 protruding outward from the outer surface of the bracelet 38. It is rotatably supported by bearings.

Second in hydraulic drive means 35 for turning
Rotational power from the hydraulic motor 37 is applied to the bevel gear pair 7 in which the bevel gear 78 attached to the tip of the input shaft 74 is arranged to face each other.
A transmission gear 81 that meshes with one of the bevel gears 79 and that rotates integrally with one bevel gear 79 meshes with the outer teeth of the left ring gear 42 shown in FIG. It meshes with the outer teeth of the right ring gear 42.

Therefore, if the bevel gear 79 rotates normally with respect to the normal rotation of the second hydraulic motor 37, the bevel gear 80 rotates reversely, so that the left ring gear 42 rotates normally and the right ring gear 42 rotates reversely. It will be. A pulley 83 is integrally provided with the bevel gear 77 or the sun shaft 41, which meshes with the bevel gear 75 of the traveling input shaft 73, so that the pulley 83 and a rotating force applied to a working machine, etc. Is configured so that the pulley 84 of the PTO shaft 52 that transmits the power is wound around the chain 85 and output.

Then, the hydraulic drive means 32 for traveling
Is transmitted to the pair of left and right planetary speed change mechanisms 31, 31 via the sun shaft 41, and the transmission gear 53 fixed to the central shaft 43 of the left bracelet 38 is connected to the left output shaft 21a. It is output by meshing with the transmission gear 54 fixed to the. Similarly, the transmission gear 53 fixed to the center shaft 43 of the right bracelet 38 is meshed with the transmission gear 54 fixed to the right output shaft 21b to output (see FIGS. 8 and 9).

With this configuration, for example, if the turning hydraulic drive means 35 is stopped, the rotation of the left and right ring gears 42, 42 is stopped and fixed. When the traveling hydraulic drive means 32 is driven in this state, the rotational force from the first hydraulic motor 34 is input to the sun shaft 41 via the bevel gears 75, 76, 77, and the rotational force is applied to both left and right sides. Sun gears 40, 40 in the planetary transmissions 31, 31 of
To the output shafts 2 on both the left and right sides through the planetary gears 39 and the arm gears 38 of the planetary speed change mechanism on the left and right sides.
Since it is equally output to 1a and 21b, it is possible to drive straight ahead.

On the contrary, when the traveling hydraulic drive means 32 is stopped, the sun shaft 41 and the sun gears 40 on the left and right sides are fixed. In this state, when the hydraulic drive means 35 for turning is driven to rotate forward, for example, the planetary speed change mechanism including the left planetary gear 39 and the arm gear 38 rotates forward via the ring gear 42, while the planetary speed change mechanism rotates via the ring gear 42. The planetary gear mechanism including the right planetary gear 39 and the arm gear 38 rotates in the reverse direction. Therefore, the left traveling crawler 2
While “a” moves forward, the right traveling crawler 2b moves backward, so that the traveling body 1 spin-turns to the left on the spot.

Then, the hydraulic drive means 32 for traveling
Of the first hydraulic motor 34 by changing and adjusting the angle of the rotary swash plate of the first hydraulic pump 33 of variable capacity and the second hydraulic pump 36 of variable capacity in the hydraulic drive means 35 for turning. 2 Since the discharge direction and discharge amount of the pressure oil to the hydraulic motor 37 can be respectively changed, the turning radius and the turning speed can be changed steplessly from the gentle turning to the sharp turning in the same manner as in the first embodiment. In addition to being adjustable, the speed of spin turns can also be adjusted steplessly.

In this embodiment, since the lengths of the input shafts 73 and 74 between the bevel gears 75 and 78 from the first hydraulic pump 33 and the second hydraulic pump 37 can be arbitrarily set, the mission case 30 can be made compact. it can. Further, the distance between both hydraulic drive means and the output shaft to the starting wheel 22 can be set arbitrarily. Further, since power is transmitted to the PTO shaft 52 by the chain, there is an advantage that the position of the PTO shaft 52 can be set arbitrarily.

When the traveling speed is equal to or higher than a constant value (predetermined), if the turning operation is performed, the centrifugal force becomes large, and there is a risk that the passenger will be swung to the outside of the turning and fall from the traveling machine body 1. Therefore, when the turning operation is executed when the vehicle speed (running speed) is equal to or higher than a certain level, the discharge amount control of the first hydraulic pump 33 and the discharge amount control of the second hydraulic pump 36 are mechanically controlled so that the running speed is reduced. Alternatively, it is preferable to be configured to be electrically linked. Further, if the hydraulic drive means 32 for traveling is provided with a mechanical or electrical limiting means that prevents the turning operation when the operating lever is in the vicinity of the neutral position (stop position), it is erroneously provided. By touching the operation lever, it is possible to prevent a risk that the operator turns unexpectedly.

Instead of the embodiment of FIG. 2, power is transmitted to the ring gears 42, 42 on both the left and right sides in the same direction and at the same rotational speed through the transmission gear 48 from the hydraulic drive means 32 for traveling, The center gear 49 is omitted, and the sun shaft 41 is divided into left and right so that the left and right sun gears 40, 40 can rotate independently of each other, and the left transmission gear in the turning hydraulic drive means 35. 65 to the left sun axis 41
The right transmission gear 65 may be meshed with a gear (not shown) fixed to the sun gear 41, and the right transmission gear 65 may be meshed with a gear (not shown) fixed to the right sun shaft 41.

It goes without saying that the present invention can be applied not only to agricultural work machines but also to traveling vehicles for civil engineering such as bulldozers.

[Brief description of drawings]

FIG. 1 is a side view of a combine.

FIG. 2 is a power transmission block diagram of the steering apparatus of the first embodiment.

FIG. 3 is a side view of the steering apparatus of the first embodiment.

FIG. 4 is a partial cross-sectional view of a pair of planetary speed change mechanism portions of the steering system of the first embodiment.

FIG. 5 is an explanatory view of the operation of the first embodiment.

FIG. 6 is a power transmission block diagram of the steering system of the first embodiment.

FIG. 7 is a side view of the steering apparatus of the second embodiment.

FIG. 8 is a power transmission block diagram of the steering apparatus of the third embodiment.

FIG. 9 is a side view of the steering apparatus of the third embodiment.

[Explanation of symbols]

 20 Steering device 21a, 21b Output shaft 30 Mission case 31, 31 Planetary speed change mechanism 32 Hydraulic drive means for traveling 33 First hydraulic pump 34 First hydraulic motor 35 Hydraulic drive means for turning 36 Second hydraulic pump 37 Second hydraulic motor 38 Bracelet 39 Planetary gear 40 Sun gear 42 Ring gear 49 Center gear

Claims (1)

[Claims] Claim: What is claimed is: 1. Power from a hydraulic drive means for traveling comprising a hydraulic pump and a hydraulic motor is transmitted to an output shaft to a pair of left and right traveling crawlers in a traveling work machine via a pair of left and right planetary speed change mechanisms. On the other hand, the power from the hydraulic drive means for turning composed of the hydraulic pump and the hydraulic motor is applied to the one planetary speed change mechanism and the other planetary speed change mechanism in opposite directions to each other. According to the output adjustment amount of both the traveling hydraulic drive means and the turning hydraulic drive means, there is no step from the straight traveling to the turning operation in which the rotational directions of the one traveling crawler and the other traveling crawler are opposite to each other. While being adjustable, the hydraulic pumps and hydraulic motors of the traveling and turning hydraulic drive means are mounted in a mission case that incorporates the transmission mechanism, and a common one is provided. Steering system of the traveling working machine, characterized by being configured so as to transmit power from the prime mover to the hydraulic pump via the.