JPS5910925Y2 - Piping connection device - Google Patents

Description

[Detailed description of the invention] The present invention is a piping system for supplying high-pressure oil to the sliding surface of a bearing that supports a rotating shaft that generates shaft voltage in a rotating electric machine, such as a water turbine generator, to levitate the rotating shaft from the bearing. Regarding connection devices,
In particular, the present invention relates to a piping connection device that prevents axial current from flowing.

For example, in a water turbine generator, a shaft voltage is generated by shaft linkage magnetic flux caused by non-uniform magnetic resistance in a stator side magnetic flux path.

This shaft voltage locally destroys the oil film on the bearing, causing shaft current to flow through the ground and the plurality of bearings that support both sides of the shaft voltage generating part of the rotating shaft, which may lead to a bearing burnout accident.

Therefore, the bearing must be completely insulated from the ground and must cut off the shaft current.

Therefore, not only the bracket that accommodates the bearing but also the piping attached to the bracket must be completely insulated from the ground and from each other by using a connection device using an insulating member.

As shown in FIG. 1, a conventional piping connection device installed in a slit to cut off axial current, etc. of a rotating electric machine is as shown in FIG.
A thin gasket 3 is inserted, an insulating washer 5a and a flat washer 5b are placed on one side of the head flange of the insulating bolt 4, and nuts 6 are used to tighten the bolts.

The pipe 12 is inserted into the flange 1 and welded on the outside and inside to be connected.

However, in this structure, for example, in thrust bearings, bearing lubricating oil (turbine oil) having a pressure of 110 to 150 kg/cm2 is jetted onto the bearing sliding surface in order to reduce friction torque at startup and protect oil film at startup and stop. When used in thrust piping, as shown in Fig. 2, the internal pressure 7 of lubricating oil in the pipe is applied to the insulating plate 2, and as the internal pressure 7 increases, the strength of the insulating material becomes weaker, so the insulating plate 2
However, the lubricating oil inside the pipes sometimes leaked out due to the failure of the pipes.

Furthermore, since the strength of the gasket 3 is low, the gasket 3 may not be able to withstand this internal pressure 7 in some cases.

The purpose of the present invention is to provide a piping connection device that can securely seal the part where piping for supplying high-pressure oil is connected to the bearing sliding surface of a rotating electrical machine and has excellent insulation performance to prevent shaft current. .

An embodiment of the present invention will be described below with reference to FIGS. 3 and 4.

Pipes 12 to which piping for supplying high-pressure oil to the bearing sliding surface that supports the rotating shaft that generates the shaft voltage of the rotating electrical machine should be connected.
The two flanges la and lb connected to the ends of the flange 1a are opposed to each other, and an insulating plate 2 is placed on the outer periphery of the joint surface of one flange 1a.
Annular shape for fitting (it doesn't matter if it is cut in the middle)
A groove 10 for inserting an O-ring 9 is provided near the inner periphery, and a space is provided on the outer periphery of the joint surface of the other flange 1b opposite to the flange 8 in order to maintain a space that can withstand the axial voltage. A relief 11 is provided, and a groove 10 into which the O-ring 9 is inserted is provided near the inner periphery.

The insulating plate 2 has a thickness of 2a that can withstand the axial voltage, and the flange 1a
Fit it into the overhang part 8 of.

Insert an O-ring 9 that can withstand high pressure into the groove 10 of both flanges la and lb, insert an insulating washer 5a on the head side flange 1b surface of the insulating bolt 4, and further sandwich a flat washer 5b on the outside thereof,
Tighten and connect using nuts 6.

The tube 12 is inserted into the flanges 1a and 1b, both outside and inside.
Weld and join.

According to the above structure, as shown in FIG. 4, the internal pressure 7 applied to the weak insulating plate 2 can be received by the overhanging part 8 of the flange 1a, so O-rings 9 are placed on both sides of the insulating plate 2. Coupled with the fact that it comes into contact with it, it can withstand the high pressure of lubricating oil, which is a fluid.

Also, a relief 11 is provided on the flange 1b, and both flanges la
, lb, it is possible to prevent a decrease in insulation resistance due to dirt etc., and it is possible to exhibit an excellent insulation effect.

As described above, according to the present invention, the outer periphery of the insulating plate 2 is supported by the overhanging part 8 of one flange 1a, so it is safe from high-pressure lubricating oil. In addition, since the relief 11 is provided on the outer periphery of the other flange 1b, the bearing has excellent insulation performance and supports the rotating shaft of a rotating electrical machine that generates shaft voltage. It is possible to provide a piping connection device that can supply high pressure oil to sliding surfaces and prevent shaft current with high reliability.

[Brief explanation of drawings]

Fig. 1 is a sectional view of a conventional piping connection device, Fig. 2 is a plan view showing its joint surface, Fig. 3 is a sectional view showing an embodiment of the piping connection device of the present invention, and Fig. 4 is a sectional view of a conventional piping connection device. It is a top view showing the joint surface. 1, 1 a, 1 b...flange, 2...
...Insulation plate, 4...Insulation bolt, 8...
・Protrusion part, 9...0 ring, 10...
・O-ring groove, 11... Relief, 12...
·tube.

Claims (1)

[Scope of utility model registration request] In a connection device for piping that supplies high-pressure oil to the sliding surface of a bearing that supports a rotating shaft that generates shaft voltage in a rotating electrical machine, two flanges connected to the ends of the pipes to be connected are placed opposite each other, and one The outer periphery of the joint surface of the flange is provided with an annular overhang for fitting an insulating plate, the inner periphery is provided with a groove into which an O-ring is inserted, and the outer periphery of the joint surface of the other 7 flange is provided with the above-mentioned groove. A relief is provided opposite the overhang of the flange to maintain a space that can withstand the axial voltage, a groove for inserting an O-ring is provided near the inner periphery, and a groove that is thick enough to withstand the axial voltage is provided inside the annular overhang of the flange. Insert an insulating plate with a A piping connection device characterized by applying an insulating washer to the flange surface and further inserting a washer between the insulating bolt head side and the insulating washer.