JPH0137000Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a fully hydraulic wheel shovel driven by a hydraulic motor.

[Conventional technology]

Wheel-type hydraulic excavators can be divided into mechanical wheel excavators and fully hydraulic wheel excavators depending on their traveling drive system.

First, the former mechanical wheel shovel is
It has the configuration shown in the figure.

That is, in the figure, 1 is a running body, and the running body 1 has a pair of left and right front wheels 2, 2 and rear wheels 3, 3 for running, a front axle 4, a rear axle 5, and an appropriate suspension mechanism etc. It generally consists of a truck frame 6 attached via means. A revolving body 7 is installed on the traveling body 1 via a turning device 8, so that the revolving body 7 can turn with respect to the traveling body 1. The revolving body 7 includes an engine 9;
A hydraulic pump 10 etc. driven by is provided. The hydraulic pump 10 is a hydraulic power source for driving actuators such as a hydraulic motor (not shown) for rotationally driving the swing device 8 and hydraulic cylinders (not shown) attached to various parts of the front (not shown). becomes.

In this mechanical wheel shovel, the driving force of the traveling means consisting of the front wheels 2 and rear wheels 3 is directly transmitted to the upper bevel gear 13 by the power of the engine 9 via the clutch 11 and the transmission mechanism 12. A rotation transmission shaft 14 provided on the output side of the upper bevel gear 13 is connected to a lower bevel gear 16 attached to the truck frame 6 via a center joint 15 provided at the center of rotation of the rotating device 8. A front wheel rotation transmission shaft 17 and a rear wheel rotation transmission shaft 18 are attached to the lower bevel gear 16, and the other ends of each of the front wheel rotation transmission shafts 17 and rear wheel rotation transmission shafts 18 are connected to the front axle via universal joints, respectively. 4 and the rear axle 5.

The mechanical wheel shovel configured in this manner has the advantage of good power transmission efficiency because it is mechanically directly connected. On the other hand,
Since the clutch 11, upper bevel gear 13, etc. are required, the structure becomes complicated and large, resulting in relatively high manufacturing costs and troublesome maintenance. Also, during excavation work, the vehicle body is stopped and the engine 1 is driven to drive the hydraulic pump 10.
Since the machine rotates and excavates with the front end, there is a disadvantage that the reaction force of the front end acts on the clutch 11, brake, etc., shortening their lifespan.

On the other hand, in order to improve these drawbacks, a fully hydraulic wheel shovel shown in FIG. 2 is also known.

In this figure, the same components as in FIG. 1 are given the same reference numerals and their explanations are omitted.
The all-hydraulic wheel shovel is driven by a hydraulic motor 20 attached to the track frame 6 of the traveling body 1. A transmission mechanism 21 is connected to the hydraulic motor 20, and a front wheel rotation transmission shaft 17 and a rear wheel rotation transmission shaft 18 are connected to the transmission mechanism 21. Said hydraulic motor 20
Hydraulic pump 1 installed on rotating body 7 supplies pressure oil to
0 via the directional valve 22. For this purpose, a center joint 23 is provided between the traveling body 1 and the rotating body 7 so as to be located on the central axis of rotation within the rotating device 8 .

FIG. 3 shows a specific configuration of the center joint 23. In the figure, 30 is a truck frame 6.
The inner cylinder 30 has an outer cylinder 32 connected to the rotating body 7 via a pin 31 and a bearing 33.
are rotatably fitted. The outer cylinder 32 is provided with oil supply/discharge ports 34, 35, and circumferential grooves 36, 37 communicating with the oil supply/discharge ports 34, 35. In addition, a hydraulic motor 20 is installed in the inner cylinder 30.
The oil passage 38 of the traveling hydraulic motor system connected to the
39 is bored, and each oil passage 38, 39 opens into a circumferential groove 36, 37, respectively. Further, a disk 40 is fixed to the upper end of the inner cylinder 30 with bolts 41, and a flange member 42 is fastened to the disk 40 with bolts 43, and the flange member 42 is connected to a rod 45 via a key 44. connected. A collar 46 is rotatably fitted to the rod 45, a connecting member 47 is attached between the collar 46 and the outer cylinder 32, and the collar 46 rotates around the rod 45 together with the outer cylinder 32. can do. A brake fluid supply port 48 is bored in the collar 46, and the collar 46 is further provided with a brake fluid supply port 48.
A circumferential groove 4 communicating with the supply port 48 is provided on the inner circumferential surface of the
9 is formed. Further, a communication hole 50 is bored in the rod 45, one end of the communication hole 50 opens into the circumferential groove 49, and the other end opens into the brake pipe 50.
1 is installed. Therefore, when the rotating body 7 rotates, the outer cylinder 32 and the collar 46 also rotate at the same time.

The above-mentioned all-hydraulic wheel shovel has a simpler traveling mechanism than a mechanical one, and can function as a brake and clutch simply by switching the directional control valve 22, reducing the front reaction force. In addition, the influence of the hydraulic pump 10 can be eliminated.
If the flow rate is increased and the hydraulic motor 20 is made larger,
It has the advantage of providing large torque.

[Problem that the invention attempts to solve]

However, in the case of a fully hydraulic wheel shovel, the center joint 23 usually has oil passages 38 and 39 for the hydraulic motor system for travel, as well as an oil passage for the brake and a steering system as shown in FIG. Control system oil passages are provided, such as a pressure oil passage for switching the transmission mechanism 21, a pressure oil passage for operating the outrigger during excavation, and the like.

However, although the center joint 23 is required to have a small diameter due to constraints such as its installation space, the oil passage 38 of the hydraulic motor system for traveling,
39 plays a major role. As a result, the flow area of the oil passages 38 and 39 that supply pressure oil to the hydraulic motor 20 also becomes relatively narrow due to the relationship with the control system oil passage. Therefore, in the pressure oil supply system from the hydraulic pump 10, the oil passages 38 and 39 become constricted parts, resulting in a large pressure loss in the hydraulic circuit and a disadvantage that the driving force transmission efficiency is significantly reduced. Ta.

The present invention was developed in view of the shortcomings of the above-mentioned conventional technologies, and by installing the travel hydraulic motor on the upper revolving structure side, the travel hydraulic motor system oil passage in the center joint is eliminated, and the hydraulic circuit is It is an object of the present invention to provide a fully hydraulic wheel shovel that reduces pressure loss as much as possible.

[Means for solving problems]

In order to achieve the above object, the present invention includes a traveling body that runs on wheels, a vehicle installed on the traveling body,
a revolving body in which an engine is provided; a revolving device provided between the traveling body and the revolving body; In a fully hydraulic wheel shovel equipped with a swivel joint provided in between,
A hydraulic pump driven by the engine and a direction switching valve for switching the direction of pressure oil from the hydraulic pump are provided in the revolving body, and a hydraulic pump is provided in the revolving body almost directly above the center joint. A hydraulic motor for traveling is provided at the swivel joint and is supplied with and discharged pressure oil from a hydraulic pump via the directional switching valve, and a rotating shaft attached to the hydraulic motor is passed through the swivel joint so as to rotate downward. The tip of the rotating shaft is connected to a transmission mechanism provided on the traveling body, and the swivel joint is provided with only an oil passage for a control system.

[Effect]

With this configuration, in addition to the hydraulic pump driven by the engine, the upper rotating body is provided with a traveling hydraulic motor to which pressure oil is supplied from the hydraulic pump via the directional control valve. Therefore, the hydraulic pump and the hydraulic motor can be placed in close proximity, and a large flow of pressure oil can be efficiently supplied to the hydraulic motor without pressure loss. In addition, unlike an engine, a hydraulic motor can be installed vertically directly above the center joint without any restrictions on the installation direction, so the rotating shaft of the hydraulic motor can be installed directly above the center joint without using a bevel gear. It can be provided vertically through it. Furthermore, since the center joint only needs to be provided with an oil passage for the control system, the center joint can be further downsized.

〔Example〕

Hereinafter, embodiments of the present invention will be described in detail with reference to FIGS. 4 and 5. In addition, in the same figure,
Components that are the same as those in FIGS. 1 and 2 are designated by the same reference numerals and their explanations will be omitted.

However, the basic configuration of this embodiment is a fully hydraulic wheel shovel that uses a simple-structure traveling hydraulic motor as the traveling drive system, similar to that shown in FIG. That is, 61 is a hydraulic motor of this embodiment provided in the revolving body 7, and the hydraulic motor 61 is located on the center axis of rotation of a center joint 63, which will be described later.
It is provided on 1A. In addition, the hydraulic motor 61
Unlike the engine 9, there are no restrictions on the installation location or installation orientation, and vertical installation is also possible.

62 is a rotating shaft attached to the output shaft of the hydraulic motor 61, and the rotating shaft 62 is connected to the center joint 63.
extends vertically downward through the rotation axis of the
It is connected to a transmission mechanism 65 via a bevel gear 64 provided on the track frame 6. A front wheel rotation transmission shaft 66 and a rear wheel rotation transmission shaft 67 are connected to the transmission mechanism 65, and the front wheel rotation transmission shaft 66 and the rear wheel rotation transmission shaft 67 are respectively connected to the front axle 4 and the rear wheel rotation transmission shaft 67 via universal joints. It is connected to the rear axle 5.

Here, pressure oil from the hydraulic pump 10 is supplied to the hydraulic motor 61 via the directional switching valve 22, whereby the hydraulic motor 61 is rotationally driven. In order to enable the rotating body 7 to rotate while the hydraulic motor 61 is stopped, the switching valve for operating the hydraulic motor 61 out of the directional switching valves 22 is of a center-open type, so that no oil lock occurs within the hydraulic motor 61. I try not to. In addition, the clutch valve, etc. that automatically opens when the vehicle is stopped, is operated by a hydraulic motor 6.
1 also makes it possible to turn when the vehicle is stopped.

Next, FIG. 5 shows the specific structure of the center joint 63 as in this embodiment, and 70 is an inner cylinder fixed to the track frame 6 at the center axis of rotation of the revolving body 7. An outer cylinder 71 is fitted into the outer cylinder 71, and a bearing 72 is interposed between the outer cylinder 71 and the inner cylinder 70, so that the outer cylinder 71 can rotate around the inner cylinder 70. A hydraulic motor 61 is installed on the upper end flange portion 71A of the outer cylinder 71.
The rotating shaft 62 is inserted into a through hole 73 formed in the center of the center joint 63. Further, the edge of the upper end flange portion 71A is loosely fitted into a pin 74 bored in the revolving body 7. The outer cylinder 71 is further formed with a brake fluid supply port 75 and a circumferential groove 76 communicating with the supply port 75. On the other hand, a liquid passage 77 is bored in the inner cylinder 70, one end of which opens into the circumferential groove 76, and the other end of which is connected to a brake cylinder 78A of a brake device 78 (see FIG. 4).
The brake piping leading to is connected.

Therefore, the center joint 63 of this embodiment is used not only for the brake fluid passage 77 but also for control system oil passages such as a steering pressure oil passage and a transmission pressure oil passage for switching the transmission mechanism 65. Only an oil passage 3 for the traveling hydraulic motor 20 shown in the prior art shown in FIGS. 2 and 3 is provided.
8 and 39 have been abolished.

The fully hydraulic wheel shovel according to this embodiment has the above-described configuration, and when driving the traveling body 7, the oil discharged from the hydraulic pump 10 is supplied to the hydraulic motor 61 via the directional control valve 22. do. This rotationally drives the rotating shaft 62, and the rotation of the rotating shaft 62 is transmitted to the transmission mechanism 65 via the bevel gear 64. By driving the front wheel rotation transmission shaft 66 and the rear wheel rotation transmission shaft 67 connected to the transmission mechanism 65, the front and rear wheels 2 and 3 are rotationally driven via the front and rear axles 4 and 5. do.

However, since the hydraulic motor 61 is installed inside the rotating body 7, the hydraulic pump 10 and the hydraulic motor 61
The distance between the two becomes shorter. Therefore, not only can the piping between the hydraulic pump 10 and the hydraulic motor 61 be shortened, but also a large flow of pressure oil must be supplied to the hydraulic motor 61 for driving the travel. Since the oil passages 38 and 39 of the center joint 23 in the prior art are not formed with constricted parts, the pressure loss in the hydraulic circuit can be reduced.

Further, unlike the engine 9, the hydraulic motor has no restrictions on the installation location and can be installed vertically, and the traveling hydraulic motor 61 of this embodiment is located inside the revolving structure 7 and installed on the center joint 63. Since the rotation shaft 62 attached to the hydraulic motor 61
extends downwardly through the center joint 63 and can be directly connected to the bevel gear 64. As a result, as in the mechanical wheel shovel shown in FIG.
can be made unnecessary.

Furthermore, the center joint 63 is provided with only an oil passage for the control system, and the oil passages 38 and 3 according to the prior art are provided.
9 can be eliminated, the center joint 63 can be made smaller and can be manufactured at a lower cost.

[Effect of idea]

As described in detail above, since the fully hydraulic wheel shovel according to the present invention has the hydraulic motor for traveling the traveling body installed inside the revolving body, it has the following effects.

Since no constriction like the oil passage in the center joint is formed in the pressure oil supply line between the hydraulic pump and the hydraulic motor, pressure loss in the hydraulic circuit can be significantly reduced, allowing a large flow rate from the hydraulic pump. of pressure oil can be supplied to the hydraulic motor without reducing the pressure, and the efficiency of driving force transmission is significantly improved.

Since the hydraulic motor can be located close to the hydraulic tank, a make-up circuit is required to compensate for the pressure on the hydraulic motor, in order to prevent negative pressure in the hydraulic motor and cavitation. can be easily formed and its performance is also good.

Since the center joint is configured to have only a control system oil passage and eliminate the oil passage for the travel hydraulic motor, the number of passages in the center joint can be reduced and the center joint can be made smaller. It can be manufactured at low cost.

Since the hydraulic motor is located inside the revolving body and is provided directly above the center joint, the rotating shaft attached to the hydraulic motor can penetrate through the center joint and extend downward.
Even if the travel drive source is provided within the upper revolving body, an upper bevel gear, clutch, etc., such as in a mechanical wheel shovel, can be eliminated.

Since there is no need to provide piping for the hydraulic motor on the traveling body side, the length of the piping can be significantly shortened, and moreover, the outflow of oil when separating the rotating body and the traveling body can be reduced.

[Brief explanation of drawings]

Fig. 1 is a longitudinal sectional view of a conventional mechanical wheel shovel, Fig. 2 is a longitudinal sectional view of a conventional fully hydraulic wheel shovel, and Fig. 3 is a longitudinal sectional view of a conventional mechanical wheel shovel.
Figure 4 is a vertical cross-sectional view of the center joint installed in the wheel shovel shown in the figure, Figure 4 is a vertical cross-sectional view of the fully hydraulic wheel shovel according to the present invention, and Figure 5 is a center joint installed in the wheel shovel shown in Figure 4. FIG. 3 is a vertical sectional view of the center joint. 1... Traveling body, 7... Swivel body, 8... Swivel device, 61
... Hydraulic motor, 62 ... Rotating shaft, 63 ... Center joint, 65 ... Transmission mechanism.

Claims (1)

[Scope of utility model registration request] A traveling body that runs on wheels; a revolving body that is installed on the traveling body and has an engine inside;
A swinging device provided between the traveling body and the rotating body, and a swivel joint located on a rotation center axis in the rotating body and provided between the traveling body and the rotating body. In the fully hydraulic wheel shovel, the revolving body is provided with a hydraulic pump driven by the engine and a direction switching valve for switching the direction of pressure oil from the hydraulic pump, and the revolving body is provided with: A hydraulic motor for traveling is provided, which is located almost directly above the center joint, and is supplied with and discharged from pressure oil from a hydraulic pump via the directional switching valve, and is attached to the hydraulic motor within the swivel joint. The rotary shaft is passed through and directed downward.
A fully hydraulic wheel shovel, characterized in that the tip of the rotating shaft is connected to a transmission mechanism provided on the traveling body, and the swivel joint is provided with only an oil passage for a control system. .