JPH0663660U - Slewing joint for electro-hydraulic of electric excavator excavator - Google Patents

Abstract

(57) [Abstract] [Purpose] It is possible to supply electric power for powering an electric excavator excavator with an electrohydraulic swivel joint. [Structure] A shaft 41 having a cable insertion hole 40 in the axial direction and a tubular body 43 rotatable relative to the shaft 41 are provided, and the electric circuits 18, 19 and the hydraulic circuits 25, 26, 29, 30 are provided. The hydraulic connection portion 8 of the electrohydraulic swivel joint 2 to be connected is provided with body-side hydraulic ports 45 and 46, shaft-side hydraulic ports 48 and 49, and oil passages 51 and 52 that connect both side hydraulic ports, At the electrical connection portion 9, the slip ring 6 is provided on the outer periphery of the shaft 40.
5, the wiring 66 is led out from the inside of the cable insertion hole 40 through the wiring hole 67 and connected to the slip ring 65, and the body 43 is made into a housing shape and holds the brush 71 slidably contacting the slip ring 65.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a structure of an electrohydraulic swivel joint that connects an electric circuit and a hydraulic circuit between an upper revolving structure and a lower traveling structure of an electric excavator excavator.

[0002]

[Prior art]

 Generally, excavator excavators are hydraulically driven, and most of the prime movers of hydraulic pumps use internal combustion engines. However, the use of an internal combustion engine causes a large amount of exhaust gas and noise, and it is not preferable to use the engine in a narrow pit. Therefore, it is desirable to use an electric excavator excavator that uses an electric motor as the prime mover of the hydraulic pump for underground work.

Conventionally, in an electric excavator excavator, an electric motor and a hydraulic pump are installed in an upper swing body, a power cable is directly connected to the electric motor, and the hydraulic pump drives a lower traveling body. In order to supply the pressure oil for use, a hydraulic swing joint that connects a hydraulic circuit was provided between the upper swing body and the lower traveling body. However, if the power cable is directly connected to the electric motor on the upper revolving structure that revolves 360 °, the power cable is swung around as the upper revolving structure revolves, which hinders the work. To prevent this, connect the power cable to the lower traveling body side, but to connect the power cable to the lower traveling body side, connect the power cable between the upper revolving structure and the lower traveling structure. Slewing joints for electric-hydraulics must be provided which can be connected to the electric circuit and hydraulic circuit respectively.

As an electrohydraulic swivel joint to which an electric circuit and a hydraulic circuit can be connected, a tubular body installed at the swivel center of the upper swivel body and a tubular body coaxial with the swivel center of the upper swivel body in the body It has a spindle accommodated therein and locked to the lower traveling body, a hydraulic circuit is connected through a port formed on the body side and the spindle side, and a slip ring and a brush are provided on the upper end of the body. The lower traveling body has a body, the upper revolving body has a spindle, the lower end of the body has a slip ring and a brush, the lower traveling body has a body, the upper revolving body has a spindle, and the upper end of the body has a slip ring and a brush. Some are provided (see Japanese Patent Laid-Open No. 4-366233).

However, in these electro-hydraulic swivel joints, the slip ring and the brush are provided at the upper end portion or the lower end portion of the body. In both cases, the contact area between the slip ring and the brush is small, and the control signal or the like is small. It is good if it is an electric current, but it is not suitable for supplying a large electric current for power.

[0006]

[Problems to be solved by the device]

 The present invention solves such a problem in an electric excavator excavator, which can supply electric power for power, and by connecting a power cable to the lower traveling body side, It is an object of the present invention to provide an electrohydraulic swivel joint capable of preventing a power cable from being swung around during swiveling and improving the work efficiency of an electric excavator excavator.

[0007]

[Means for Solving the Problems]

 In order to solve the above problems in an electric excavator excavator, the present invention comprises a shaft having a cable insertion hole in the axial direction and a tubular body rotatable relative to the shaft. At the hydraulic connection part of the electrohydraulic swivel joint that connects the electric circuit and hydraulic circuit at the swivel section with the undercarriage, connect the hydraulic port on the body side, the hydraulic port on the shaft side, and the hydraulic ports on both sides. An oil passage for connection is provided, and at the electrical connection part, a slip ring is provided on the outer circumference of the shaft to lead out the wire from the inside of the cable insertion hole through the wiring hole and connect it to the slip ring. A brush is provided that makes sliding contact with the slip ring.

[0008]

[Action]

 During excavation work, electric power is sent from the power cable connected to the undercarriage through the electrical connection of the electrohydraulic swivel joint to the electric motor installed in the upper swivel. The electric motor drives a hydraulic pump, and the generated pressure oil is supplied to the actuators of the work equipment of the upper swing body. When traveling, the driving hydraulic oil is supplied to the lower traveling body through the hydraulic connection portion of the electrohydraulic swing joint.

[0009]

【Example】

 1 is an explanatory view of the structure of an electric excavator excavator provided with an electrohydraulic swivel joint, which is an embodiment of the present invention, FIG. 2 is a vertical cross-sectional view of the electrohydraulic swivel joint, and FIG. 3 is shown in FIG. Fig. 3 is a sectional view taken along line 3-3, Fig. 4 is a lower end view of an electrohydraulic swivel joint, Fig. 5 is a sectional view taken along line 5-5 of Fig. 4, Fig. 6 is a sectional view taken along line 6-6 of Fig. 4, and Fig. 7 is FIG. 7 is a sectional view taken along line 7-7 of FIG. 4.

In this embodiment, the electric excavator excavator 1 is provided with an upper swing body 12 on a lower traveling body 11, and an electric motor 13 and a hydraulic pump 14 are installed on the upper swing body 12. . An excavation work device (not shown) including a shovel and a boom that supports the shovel is attached to a front portion of the upper swing body 12. A cable reel 15 is provided at the rear part of the lower traveling body 11 to connect a cable 17 for power from a power source. An electrohydraulic swing joint 2 is provided between the upper swing body 12 and the lower traveling body 11 coaxially with the swing axis of the upper swing body 12. The cable 18 on the side of the lower traveling body 11 connected to the cable reel 15 and the cable 19 on the side of the upper rotating body 12 connected to the electric motor 13 are connected via the electro-hydraulic swing joint 2.

The discharge pipe line 20 of the hydraulic pump 14 is, via a hydraulic control valve 21, a drive pipe line 23 to a hydraulic cylinder for an excavation work machine and a swing hydraulic motor (not shown) for the upper swing body 12. 24, as well as the traveling hydraulic pipes 25 and 26 and the pilot pipe 27. The traveling hydraulic pipes 25 and 26 and the pilot pipe 27 are also connected to the traveling hydraulic motor 28 via the electrohydraulic swivel joint 2 and the traveling hydraulic pipes 29 and 30 and the pilot pipe on the side of the lower traveling body 11 are connected. It is connected with 31.

The electro-hydraulic swivel joint 2 includes a shaft 41 having a cable insertion hole 40 in the axial direction and a tubular body 43 rotatably attached to the shaft 41 via a bearing 42. The hydraulic connection 8 is located below the intermediate spacer 44, and the electrical connection 9 is located above the spacer 44. On the body 43 side of the hydraulic connection portion 8, hydraulic ports 45, 46, 47 to which the traveling hydraulic pipes 25, 26 and the pilot pipe 27 are connected are provided vertically separated from each other. On the shaft 41 side, hydraulic ports 48, 49 and 50 to which the traveling hydraulic pipes 29 and 30 and the pilot pipe 31 are connected are provided so as to be circumferentially separated from each other. Further, oil passages 51, 52, 53 and annular grooves 54, 55, 56 for connecting the hydraulic ports 45, 46, 47 to the hydraulic ports 48, 49, 50 are formed.

At the electrical connection portion 9, a disc 64, which is held by bolts 63 and is separated from each other by a collar 62, is attached between the upper and lower flanges 60, 61 on the outer periphery of the shaft 41. A slip ring 65 is fixed to the. The shaft 41 is provided with a wiring hole 67 for leading out the wiring 66 at the end of the cable 18 from the inside of the cable insertion hole 40, and the wiring 66 led out from the wiring hole 67 is connected to the slip ring 65. Has been done. The body 43 has a housing-like shape, and a bracket 68 is attached to the inside thereof, and a pole 70 for holding a brush holder 69 is fixed to the bracket 68. At the tip of the brush holder 69, a brush 71 that is in sliding contact with the slip ring 65 is provided. The brush 71 is connected to the cable 19.

During excavation work, electric power is connected to the cable reel 15 of the lower traveling body 11 from the power cable 17 to the electrical connection of the electrohydraulic swivel joint 2 via the cable 18 on the lower traveling body 11 side. It is sent to the electric motor 13 installed on the upper swing body 12 through the section 9. The electric motor 13 drives a hydraulic pump 14, and the generated pressure oil is supplied via a hydraulic control valve 21 to a hydraulic cylinder for an excavation work device and a swing hydraulic motor for the upper swing body 12. When traveling, the driving hydraulic oil is supplied to the traveling hydraulic motor 28 of the lower traveling body 11 through the hydraulic connecting portion 8 of the electrohydraulic swivel joint 2.

Since the slip ring 65 is provided on the outer circumference of the shaft 41 in this way, a large-sized slip ring 65 can be used, and the contact area between the slip ring 65 and the brush 71 is large, which is large. Electric power for motive power, which is an electric current, can be supplied. Also, unlike the conventional one, by increasing the number of slip rings 65, it is possible to connect a large number of lines.

[0016]

[Effect of device]

 As described above, according to the present invention, it is possible to supply power for power, and by connecting the power cable to the lower traveling body side, the power cable is swung around by the swing of the upper swing structure. Can be prevented and the work efficiency of the electric excavator excavator can be improved.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of a configuration of an electric excavator excavator having an electrohydraulic swivel joint according to an embodiment of the present invention.

FIG. 2 is a vertical cross-sectional view of an electrohydraulic swivel joint.

FIG. 3 is a sectional view taken along line 3-3 of FIG.

FIG. 4 is a bottom view of a swivel joint for electrohydraulics.

5 is a sectional view taken along line 5-5 of FIG.

6 is a sectional view taken along line 6-6 of FIG.

7 is a sectional view taken along line 7-7 of FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Electric excavator excavator 2 Swivel joint for electrohydraulic 8 Hydraulic connection 9 Electric connection 11 Lower traveling body 12 Upper revolving body 13 Electric motor 14 Hydraulic pump 18 Cable 19 Cable 25 Running hydraulic piping 26 Running hydraulic piping 28 Running Hydraulic motor 29 Traveling hydraulic piping 30 Traveling hydraulic piping 40 Cable insertion hole 41 Shaft 43 Body 45 Hydraulic port 46 Hydraulic port 51 Oil passage 52 Oil passage 65 Slip ring 66 Wiring 67 Wiring hole 71 Brush

Claims (1)

[Scope of utility model registration request] 1. An electric excavator excavator, which is an electrohydraulic swivel joint for connecting an electric circuit and a hydraulic circuit at a swivel portion between an upper revolving structure and a lower traveling structure, and a cable extending in an axial direction. A shaft having an insertion hole and a tubular body rotatable relative to the shaft, and the hydraulic connection portion includes an oil passage connecting the hydraulic port on the body side, the hydraulic port on the shaft side, and the hydraulic ports on both sides. Is provided
In the electrical connection part, a slip ring is provided on the outer circumference of the shaft, and the wire is led out from the inside of the cable insertion hole through the wiring hole and connected to the slip ring, and the body has a housing shape and is in sliding contact with the slip ring. A swivel joint for electro-hydraulics of an electric excavator excavator characterized by being provided with.