JPH01132473A - Hydraulic steering device - Google Patents

Abstract

PURPOSE:To reduce the size of a hydraulic motor by mounting a mechanical brake on the output shaft of the hydraulic motor and when a high trailing force is generated at just one track of a vehicle to apply a large torque to the output shaft, sharing this torque with the mechanical brake to bear. CONSTITUTION:The output from a prime mover (a) is transmitted separately to a hydraulic pump (c) and a torque converter (d) by a PTO device (b). The output from the torque converter (d) is transmitted to a transmission (e) and so on while the output from the hydraulic pump (c) is transmitted to a hydraulic motor (m) and so on. In such constitution, a brake disc 11 is firmly attached to the output shaft 1 of the hydraulic motor (m) and a braking device 10 having a braking member 12 is mounted on a part 13 of a vehicle. When the output shaft 1 is required to bear a high torque because large trailing force is generated at just one track of the vehicle, the revolution of the brake disc 11 is braked. Thus the torque of the output shaft 1 may be shared with the braking device 10.

Description

[Detailed Description of the Invention] (Industrial Application Field) This invention relates to a steering device for a tracked vehicle that runs on tracks, and in particular, the invention relates to a steering device for a tracked vehicle that runs on tracks, and in particular, the rotation of a hydraulic morph is controlled by one of the gear devices disposed on the left and right output shafts. It is suitable for use in a bulldozer that is equipped with a steering device that steers the vehicle in a manner that increases and decreases the amount of the vehicle.

(Prior art) In a steering system for a tracked vehicle that runs on tracks, the rotation of a hydraulic motor is applied to one of the gear devices disposed on the left and right output shafts, while being reduced to the other. The third diagram is an explanatory diagram of power transmission for a vehicle with a conventional steering device that performs steering.
As shown in the figure.

In the figure, the output of the prime mover a is divided into two inputs: P, T, O, and the hydraulic pump C and the torque converter d, and the output from the torque converter d is sent to the transmission e and the small bevel gear f. , large bevel gear g, left and right main shafts and h'
are transmitted to the respective ring gears il and iR' as inputs of the left planetary gear set i and the right planetary gear set i'. On the other hand, the pressure oil from the hydraulic pump C drives a hydraulic motor m via a pipe l, and the output of the hydraulic motor m is transmitted by a bevel gear q to a left bevel gear r and a right bevel gear r' to a left gear S and a right gear, respectively. Drive S'. The gear 10 that rotates together with the sun gear i of the left planetary gear device i is the left gear S.
Since it meshes with the sun gear i, the rotation of the left bevel gear 5 is
can be conveyed to. Similarly, the sun gear i of the right planetary gear set i′
Gear i51', which rotates as one with s', is the right gear S
' Because it meshes with .

The rotation of right bevel gear r' is transmitted to sun gears i,'. The outputs of the left and right planetary gear devices i and i' are a left output shaft j and a right output shaft j' that rotate together with planetary carriers ic and io' that respectively support a plurality of planetary gears iP and iP'. are transmitted to the left and right brake devices k and ', respectively, and to the left and right sprockets p and n', respectively, via the left and right final reduction gears n and n'.

When a vehicle equipped with such a steering device is traveling straight, the hydraulic motor m is in a neutral position, the bevel gear q is fixed, and the sun gears i, and i,' are fixed, so the driving force distributed by the output of the transmission e to the left and right main shafts and h' at the same rotation speed via the large bevel gear g is applied to the left and right planetary gear units i and Since the output from i' has the same rotational speed and is transmitted to the left and right output shafts j and j', respectively, the vehicle moves straight.

When the vehicle turns, when the hydraulic motor m is operated to rotate the bevel gear q, the left and right bevel gears r and r' rotate in opposite directions, so the sun gears is and i of the left and right planetary gear units i and i', ' rotate in opposite directions, and the left and right planetary gear units j and i' act as a differential gear unit, so the rotational speed of the left and right output shafts j and j' is increased compared to the above-mentioned straight-ahead movement, and the rotation speed of the left and right output shafts j and i' is increased while the other The vehicle decelerates and turns.

(Problems to be Solved by the Invention) In order to explain the problems in the hydraulic steering system shown in FIG. 3 above, the following symbols are defined.

The number of teeth of sun gear 18 and i,' are both a.

Ring gears iR and i,1' have the same number of teeth.

The meshing of the left gear S and the gear tit, and the meshing of the right gear S' and the gear i8. ρ h The reduction ratios of the left and right final reduction gears n and n' are both ρ 1゜ Reduction ratio in the meshing of bevel gear q with left bevel gear r and right bevel gear r' Both ratios are ρ2° and the torque of the left sprocket p is T t .

Torque of right sprocket p' is T R.

The torque of left bevel gear r is Tr.

The torque of the right bevel gear r' is Tr.

given that.

pII a + b ρ1 ρ, l a+b ρ1 Therefore, the torque T of the output shaft of the hydraulic motor m is T, =-(T
-Tr・) ρ 2 ρga・ρ1・ρ2 a+b Therefore, if T t, = T *, then TII=O.

If T L q" T +t, then T1≠0, and considering only the turning of the vehicle, the track on one side of the tracked vehicle only needs to have a traction force of about 0.45W, where W is the vehicle weight. (TL = TR) in the above equation (3) is 0
．． The torque is equivalent to 45W, and the capacity of the hydraulic motor at this time is (T L - T R) in equation (3) as 0.
．． Any torque may be used as long as it corresponds to the morph output shaft torque calculated as a torque equivalent to 45W. However, in operations where a very large load is applied to one side of the earthwork board, such as when rolling stones with a bulldozer, a traction force of about 1.4 times the vehicle weight W is required only on one side of the belly band.
(Tt~T+t) in equation (3) is a torque equivalent to 1.4W, and the capacity of the hydraulic motor is compared to the capacity required for turning.

1,410.45L-, which is a major problem in that it requires approximately three times the capacity.

(Means and effects for solving the problems) This invention has been made in view of the above points, and is equipped with a mechanical brake on the output shaft of a hydraulic motor, which is useful for only one side of the track, such as when lifting stones. When a traction force is generated and the hydraulic motor output shaft is required to bear a large torque load, the mechanical brake is operated and the torque that should be borne by the motor output shaft is borne by the mechanical brake, thereby increasing the capacity of the hydraulic motor. This allows the vehicle to be held down to the extent necessary for turning.

(Example) Next, embodiments of the present invention will be described based on the drawings.

Components in FIG. 1 that have the same functions as those in FIG. 3 described above are designated by the same reference numerals, and detailed description thereof will be omitted. A brake device Z 10 is provided, which includes a brake disc 11 fixed to the output shaft 1 of a hydraulic motor m, and a brake member 12 fixed to a part 13 of the vehicle body. When a large traction force is generated only in the crawler track and the output shaft 1 of the hydraulic motor m needs to bear a large torque, the above (3) is achieved by operating the brake device 10 to brake the rotation of the brake disc 11. ) in the formula (T L
The output shaft torque T of the hydraulic motor m, which is calculated as a torque corresponding to approximately 1.4 W, is shared by the brake device 10, and the capacity of the hydraulic motor m is equal to the torque (TL-T , l) should have a capacity corresponding to the output shaft torque calculated as a torque corresponding to approximately 0.45W.

This makes it possible to use a small hydraulic motor with a capacity that is about 1/3 that of a conventional one.

FIG. 2(a) shows another embodiment, in which the same reference numerals are used for parts having the same functions as those in FIG. 1, and detailed explanation thereof will be omitted. What differs from the one in FIG. 1 is the arrangement of gears in the left and right planetary gear sets 20 and 20', in which inputs from the left and right main shafts and h' are transmitted to sun gears 20s and 20,', respectively. The rotation of the left gear S is controlled by the ring gear 20. which is meshed with the left gear S. is transmitted to the internal gear 2 (L++) via the external gear 20R2, and these two rotations are combined by the planetary gear 20 and transmitted from the planetary carrier 20c to the left output shaft j as an output. Since the items marked with ' are the same as those described above on the left side, their explanation will be omitted.The operation of the brake device 10 in the embodiment of FIG. 2(a) is the same as that of the brake device in the embodiment of FIG. Since it is similar to the device 10, detailed explanation will be omitted.

FIG. 2(b) shows yet another embodiment, in which the same reference numerals are used for the same functions as those in FIG. 1, and detailed explanation thereof will be omitted. The output from the transmission e is transmitted to the large bevel gear 32 via the small bevel gear 31, and this rotation is transmitted from a plurality of shaft-shaped planetary carriers 30c fixed to the large bevel gear 32 to the left planetary gear unit 30 and the right planetary gear unit 30. It becomes an input to the planetary gear system 30' (planetary carrier 30.
is the planetary carrier common to the left and right planetary gear sets 30 and 30'). Further, the bevel gear 33 provided on the output shaft 1 of the hydraulic motor m is the left bevel gear 34 provided on the outer periphery of the left ring gear 34. The left internal gear 34□ provided on the inner circumference of the left ring gear 34 meshes with the left planetary gear 30F, and the left planetary gear 30F meshes with the planetary carrier 30c. The left sun gear 30. Since the input from the planetary carrier 30c and the rotational force from the left ring gear 34 are meshed with the left planetary gear 30F,
are combined and transmitted from the left sun gear 303 to the left output shaft j as an output. The symbols on the right side of the figure with '' are also the same as those described above on the left side, so the explanation will be omitted.

The operation of the brake device 10 in the embodiment shown in FIG. 2(b) is similar to that of the brake device 10 in the embodiment shown in FIG.
Since it is the same as 0, detailed explanation will be omitted.

(Effects of the Invention) The present invention is constructed as described in detail above, and is a steering device for a tracked vehicle that runs on crawlers, in which the rotation of a hydraulic motor is controlled by a gear device disposed on left and right output shafts. The vehicle is equipped with a steering device that steers the vehicle by adding to one side and decreasing to the other, when the vehicle performs work that generates a very large traction force on one side of the track, such as stone-raising work. By applying this invention to a vehicle, the capacity of the hydraulic motor can be reduced to about 1/3 of that of a vehicle without the application, thereby reducing the weight and volume of the entire vehicle and significantly reducing the price. It has the excellent effect of being able to

[Brief explanation of the drawing]

Figure 1 is an explanatory drawing of an embodiment of the present invention, Figure 2 (
A) and (b) are explanatory drawings of different embodiments, respectively, and FIG. 3 is of the prior art. 1... Hydraulic morph output shaft, 10... Brake device. 11... Brake disc, 12... Brake member. Patent applicant Komatsu Ltd. Representative (patent attorney) Osamu Matsuzawa

Claims (1)

[Claims] A steering device for a tracked vehicle that runs on tracks,
In a steering device that steers a vehicle by applying rotation of a hydraulic motor to one of gear devices installed on the left and right output shafts and reducing it to the other, a brake device is installed on the output shaft of the hydraulic motor. A hydraulic steering device characterized by being provided with.