JPS5899593A - Swivel joint - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] The present invention relates to hydraulic working machines such as hydraulic excavators and hydraulic cranes,
The present invention relates to a swivel joint that allows pressure oil to flow between a fixed body and a revolving body that constitute other hydraulic machines.

For example, as shown in FIG. 1, a hydraulic excavator as a working machine has a lower traveling body 1 as a fixed body, a revolving body 2 provided on the upper part of the lower traveling body 1, and a rotating body 2 that rotates with respect to the lower traveling body 1. It is generally composed of a turning device 3 that supports the body 2 so as to be able to turn. The lower running body l has running crawler tracks 4 on its left and right sides.
A and 4B are provided, and hydraulic motors 5A and 5B as actuators are attached to each layer band 4A and 4B, respectively, so that the left and right crawler tracks 4A and 4B can be driven independently. On the other hand, hydraulic pumps 6A and 6B as hydraulic power sources are installed on the revolving structure 2 side. Each of the hydraulic motors 5A, 5B is driven by a hydraulic pump 6A, 6B, and for this reason, a swivel joint 7 for pressure oil circulation is provided at the center of rotation of the swing device 3.

Conventionally, as this type of swivel joint 7, those shown in FIGS. 2 and 3 are known.

The swivel joint 7 is composed of a rotor 8 fixed to the lower traveling body 1 and a housing 9 fixed to the revolving body 2. The housing 9 is formed into a cylindrical shape with a lid, and the rotor 8 is formed into a cylindrical shape.
is fitted into the housing 9, and the housing 9 slides along the outer periphery of the rotor 8 as the rotating body 2 rotates.

Thus, a pair of hydraulic motors 5A provided on the lower traveling body 1,
5B are hydraulic pumps 6A provided on the revolving body 2,
Since the swivel joint 7 is independently driven by the swivel joint 6B via a directional control valve (not shown), it is necessary to provide four pressure oil supply/discharge passages to the swivel joint 7. For this reason, the housing 9 has flow passages 10A and IIA connected to the - direction switching valves vertically along the axial direction of the rotating axis O-0 of the rotating body 2,
Flow paths 10B and 11B are bored to be connected to other directional switching valves. Also, the rotor 8 includes passages 12A and 13A connected to one hydraulic motor 5A, and the other hydraulic motor 5.
A flow path 12B connected to B.

13B are drilled in each case. Since the rotor 8 and the housing 9 are rotatably fitted, the flow paths 10A and 12A, IOB and 12B, and 11A and 13A are connected regardless of the rotation angle.

11B and 13B must be kept in constant communication. For this purpose, the sliding surfaces of the rotor 8 and the housing 9 are provided with circumferential grooves 14A, 14B, and 15A.

15B is formed. Reference numerals 16 and 16 denote bearings provided at upper and lower positions between the rotor 8 and the housing 9, and each bearing 16 allows the housing 9 to rotate smoothly with respect to the rotor 8.

The swivel joint 7 according to the prior art has the above-mentioned configuration, including circumferential grooves 14A and 14B.

15A and 15B are disposed vertically along the rotation axis O-O, so the rotor 8 becomes longer in the axial direction, and the flow paths 12A,
12B, 13A, and 13B are also longer.

Moreover, since each flow path 12A, 12B, 13A, 13B is arranged in the direction of the rotation axis O-O, the circumferential groove 14A
, '14B, 15A, and 15B, the flow path must be curved in an L-shape. In this way, the flow path provided in the swivel joint 7 has a long flow path length,
Because of the bent portion, the pressure loss increases, and the efficiency of the hydraulic motors 5A and 5B increases rapidly.Moreover, this pressure loss causes the oil temperature to rise, so there is a drawback that the capacity of the oil cooler must also be increased. Moreover, the flow path 10A.

Since 10B, 11A, and IIB are also disposed in a direction perpendicular to the rotation axis o-o'ff, it is also difficult to attach a switching valve or the like to the upper part of the housing 9. Furthermore, since the swivel joint 7 is vertically long, the unbalanced load due to the unbalance of the housing 9 is large. Therefore, in order to avoid this unbalanced load, the bearing 16 is placed between the outer 111 surface of the rotor 8 and the inner surface of the housing 9. Since it is necessary to provide the swivel joint 7 in the upper and lower positions, there is a drawback that the swivel joint 7 becomes expensive.

The present invention improves the drawbacks of the prior art as described above, and is characterized in that a circumferential groove that communicates the housing side passage and the rotor side passage is formed on the sliding surface perpendicular to the rotation axis. It is something.

The swivel joint of the present invention will be explained together with the embodiment shown in FIGS. 4 and 5.

In the figure, the same components as in FIGS. 1 to 3 are given the same reference numerals, and their explanations will be omitted. Reference numeral 20 denotes a swivel joint provided in the swing device 3, and the swivel joint 20 is a disc-shaped rotor 2 fixedly provided on the lower traveling body 1.
1 and a housing 22 fixed to the revolving body 2 (5).

The housing 22 has a flat surface portion 22A that is in sliding contact with the upper surface of the rotor 21, and a circumferential body portion 22B formed by extending the peripheral edge portion downward, and is formed by the inner wall of the flat portion 22A and the circumferential body portion 22B. rotor 2 in the recess.
1 is fitted. The rotor 21 has a flow passage 23 in the vertical direction.
A, 24A.

23B and 24B, and the housing 22 also has flow passages 25A, 26A, 25B, and 26B vertically bored therein. Here, the flow paths 23A and 24A are hydraulic pumps A
, the flow paths 23B and 24B communicate with the hydraulic pump 6B, and the flow paths 25A and 26A communicate with the hydraulic motor 5A, the flow path 25B,
26B communicates with the hydraulic motor 5B. The flow path 23A is provided on the sliding surface between the rotor 21 and the housing 22.
and 25A.

Circumferential grooves 27A, 28A, which allow constant communication between 24A and 26A, 23B and 25B, and 24B and 26B,
27B.

28B is formed. Moreover, each flow path 23A.

24A, 23B, 24B and channels 25A, 26A.

25B, 26B and circumferential grooves 27A, 28A, 27B.

(6) The opening portion of 28B is located between each flow path 23A of the rotor 21 and the housing 22 when the rotating body 2 is running normally, that is, when the lower traveling body l and the rotating body 2 are parallel to each other in the longitudinal direction. 2
5A, 24A and 26 A, 23B and 25B, 24
B and 26B are arranged in a straight line. Further, a bearing 29 is installed only at the negative position between the circumferential trunk portion 22B of the housing 22 and the outer circumferential portion of the rotor 21.

The swivel joint 20 according to the present invention is configured as described above, and in a hydraulic excavator, the hydraulic motor 5A,
During normal running when it is necessary to maximize the output of 5B, that is, in the non-swinging position of the revolving structure 2, the flow paths 23A and 2
5A, 24A and 26A.

2'3B and 25B, 24B and 26B are straight lines, and there are no bends Fm, and their lengths are short, so even if a large amount of pressure oil flows through the hydraulic pumps 6A, 6B or the hydraulic motors 5A, 5B. Almost no pressure loss occurs.

In addition, flow paths 23A, 24A, 23B on the housing 22 side
, 24B are disposed parallel to the rotation axis 0-0, so it is easy to add switching valves 30A and 30B to the upper part of the housing 22 constituting the swivel joint 20 as shown by the imaginary line in FIG. , which can give more freedom in design. Also, when supplying and discharging pressure oil, circumferential grooves 27A and 27B are used.
, 28A, 28B are subjected to heavy hydraulic pressure in the vertical direction, but since bearings 29 are disposed on their outer peripheries,
The load 1. can be effectively absorbed. Moreover, since the length of the rotation axis O-O of the swivel joint 20 consisting of the rotor 21 and the housing 22 is short,
There is no risk of receiving side loads, and it is sufficient to provide the bearing 29 only at the lower position.

On the actual flow side, the flow path 25A on the rotor 21 side,
25B, 26A, 26B, flow path 23 on the housing 22 side
A, 23B, 24. A, 24B'f1: Although the number is four each, the number is not limited to this, and for example, brake piping or the like may be provided, and the number may be five or six each. Furthermore, if the flow path 31 is provided in the portion indicated by the imaginary line in FIG. . Although it has been described that the hydraulic power sources 6A and 6B are provided on the revolving body 2 and the actuators 5A and 5B are provided on the fixed body 1, conversely, the hydraulic power sources may be provided on the fixed body and the actuators may be provided on the revolving body.

Furthermore, although the swivel join 20 has been described as being used in a hydraulic excavator, it is needless to say that it is not limited to this, and may be used in working machines such as hydraulic cranes and other swinging hydraulic machines.

The swivel joint according to the present invention has been described in detail above, and has the following effects.

■ The rotor and housing that make up the swivel joint are provided with flow paths leading to the hydraulic source and the actuator, and each flow path on the housing side is provided on the sliding surface perpendicular to the rotation axis of the rotating body between the housing and rotor. By forming circumferential grooves that communicate with each flow path on the rotor side, each flow path is short, and when the rotating body is at a predetermined angle with respect to the fixed body, the flow path is straight. Therefore, the pressure loss of the oil flowing in the flow path is reduced, and no extra load is applied to the hydraulic power source.

(9) ■ Since the axial length of the swivel joint can be shortened, the swivel joint will not receive uneven loads, and it is sufficient to install the bearing between the rotor and the housing only in the lower position. .

- Since the housing-side flow path can be provided parallel to the pivot axis, the directional switching valve can be disposed on the housing.

■ In relation to item 0 above, because the oil pressure loss is small,
The oil temperature does not rise and only requires a small oil cooler piece.

[Brief explanation of drawings]

Fig. 1 is an external view of a hydraulic excavator equipped with a swivel joint i according to the prior art, Fig. 2 is a longitudinal cross-sectional view of the swivel joint in Fig. 1, and Fig. 3 is a 1[-1 arrow 4 is a longitudinal sectional view of the swivel joint according to the present invention, and FIG. 5 is a sectional view taken along the line V--■ in FIG. 4. 1... Lower traveling body (fixed body), 2... Swivel body, 5A
. 5B...Hydraulic motor (actuator), 6A. 6B... Hydraulic pump (hydraulic source), 21... Rotor,
22(lO)...Housing, 23A, 23B, 24A, 24B. 25A, 25B, 26A, 26B...channel, 27A. 27B, 28A, 28B...circumferential groove. (11) Figure 1 480-e method

Claims (1)

[Claims] It has a fixed body and a rotating body that is rotatably provided with respect to the fixed body, a housing and a rotor that fits in the housing are provided between the fixed body and the rotating body, and the housing and the rotor are connected to each other. are each provided with a flow path leading to a hydraulic power source or an actuator, and each flow path on the housing side and each flow path on the rotor side are provided on a sliding surface perpendicular to the rotation axis of the rotating body between the housing and the rotor. A swivel joint formed with a circumferential groove that communicates with the flow path.