JPH0542585B2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to a method for supplying lateral pressure oil to a shaft sealing portion of a rotating electric machine shaft oil sealing device.

[Conventional technology]

Conventionally, a hydrogen-cooled rotating electric machine is provided with a shaft oil sealing device to prevent leakage of hydrogen gas from the surface of the rotating shaft. This shaft sealing device includes a shaft sealing portion inside a bearing portion of a rotating electric machine main body, and a shaft sealing oil ring support and a shaft sealing oil ring are provided on this shaft sealing portion. There is a narrow space between the shaft seal oil ring and the rotating shaft, and pressure oil higher than the in-machine gas pressure is flowed here to keep the space filled with shaft seal oil and prevent the in-machine gas from leaking out. Regarding the shaft oil sealing device mentioned above, for example, see the Institute of Electrical Engineers of Japan University Lecture “Synchronous Machines” (published by the Institute of Electrical Engineers of Japan in October 1985).
Although described on pages 86 to 87, another example of the shaft seal portion in this type of shaft seal oil device is shown in FIG. 2. In FIG. 2, a cylindrical shaft seal oil ring support 12 with an upper and lower split structure has an annular shaft seal oil chamber 17 formed on the inner diameter side, and is attached to the bearing bracket of the rotating machine body with packings 13 and 14 in between. 15 with bolts 23. The shaft seal oil ring 16 includes a white metal 19 in a portion facing the rotating shaft 11, and is arranged in the shaft seal oil chamber 17 so that it does not rotate in the circumferential direction but can freely move in the radial direction. . The left side of the shaft seal oil ring support 12 in the figure is the hydrogen side, and the right side is the air side. The shaft seal oil ring 16 includes a plurality of shaft seal oil holes 20 that penetrate in the radial direction, and these shaft seal oil holes 20 are annular shaft seal oil holes that are formed so as to open toward the rotating shaft 11. It communicates with the groove 21. On the other hand, the shaft seal oil ring support 12 has a shaft seal oil chamber 17.
A radial shaft seal oil hole 22 communicating with the shaft seal oil hole 22 is provided, and a shaft seal oil pipe (not shown) is connected to this hole through a shaft seal oil supply hole 24 . Further, an annular side pressure oil groove 18 is formed in the air side side wall of the shaft seal oil chamber 17, and a side pressure oil pipe (not shown) is connected to this. In such a shaft seal part, the shaft seal oil supply hole 24
The shaft sealing oil sent to the shaft passes through the shaft sealing oil hole 22 and accumulates in the shaft sealing oil chamber 17, and further flows through the shaft sealing oil groove 21 through the shaft sealing oil hole 20 of the shaft sealing oil ring, and then flows through the shaft sealing oil groove 21 to the rotating shaft 11. It is divided into an air side and a hydrogen side at the surface. In addition, a part of the shaft seal oil accumulated in the shaft seal oil chamber 17 passes through the space between the shaft seal oil ring support 12 and the shaft seal oil ring 16 on both the hydrogen side and the air side of the rotating shaft 11. flows to the surface. By supplying the shaft seal oil in this manner, leakage of hydrogen from the surface of the rotating shaft 11 is prevented. The oil coming out of the shaft seal is transferred to the shaft seal oil ring support 12.
is collected from a housing (not shown) surrounding the Furthermore, side pressure oil is supplied to the side pressure oil groove 18,
Side pressure is applied to the shaft seal oil ring 16 to maintain its axial position approximately at the center of the shaft oil chamber 17. This is because hydrogen gas pressure is higher than air pressure, so if there is no side pressure oil, the shaft seal oil ring 16 will be pushed toward the air side due to the hydrogen gas pressure acting on the side, and will come into contact with the shaft seal oil ring support 12. It is from. Conventionally, this side pressure oil is supplied from an oil pump through a needle valve to the side pressure oil groove 18, and from there is supplied between the shaft seal oil ring 16 and the shaft seal oil ring support 12. was. Note that this side pressure oil is recovered together with the shaft seal oil.

[Problem to be solved by the invention]

However, since the needle valve is a throttle valve, if the pressure difference before and after the throttle changes, the flow rate on the discharge side will change, and the pressure of the oil sent from the oil pump may change due to some reason such as pulsation, or the pressure of hydrogen gas inside the machine may change. When this changes, the flow rate on the discharge side of the needle valve changes and the supply flow rate of lateral pressure oil changes. Therefore, when the supply flow rate of the lateral pressure oil is insufficient and the lateral pressure decreases as a result, the position of the shaft seal oil ring 16 in the shaft seal section moves toward the air side, and the shaft seal oil ring support 12 and the shaft seal oil ring 16
The distance between the two is larger on the hydrogen side than on the air side. As a result, the balance between the amount of shaft seal oil flowing to the air side and the amount of shaft seal oil flowing to the hydrogen side is disrupted, and the amount of shaft seal oil flowing to the hydrogen side increases compared to the air side, and the amount of hydrogen dissolved in the shaft seal oil increases. As a result, there was a problem that hydrogen consumption increased. By the way, the hydrogen dissolved in the shaft seal oil flows out from the shaft seal part along with the shaft seal oil, passes through an intermediate tank, and is accumulated in a vacuum tank, where the hydrogen that is degassed from the shaft seal oil by a vacuum pump is released into the atmosphere. released. Furthermore, if the position of the shaft seal oil ring 16 moves extremely toward the air side, the shaft seal oil ring 16 comes into contact with the shaft seal oil ring support 12 and becomes difficult to float. There was a problem in that the vibration of the rotating shaft 11 increased because it was hit and restrained.

[Purpose of the invention]

In view of the above-mentioned problems, an object of the present invention is to maintain the shaft sealing oil ring at a predetermined position by keeping the flow rate of lateral pressure oil supplied to the shaft sealing part constant, thereby making the lateral pressure applied to the shaft sealing oil ring constant. shall be.

[Means to solve the problem]

The oil discharged from the shaft seal of the rotating electric machine is collected in a vacuum tank via an intermediate tank, the oil stored in this vacuum tank is sucked out by an oil pump, and sent to an oil cooler while adjusting the flow rate with a control valve. In the shaft seal device, the cooled oil is cleaned with a filter and oil pressure is adjusted with a differential pressure regulating valve, and then oil is supplied to the shaft sealing portion. The above object is achieved by providing a constant flow valve in parallel and supplying the oil purified by the filter as side pressure oil to the shaft sealing portion of the shaft sealing oil device through the constant flow valve. .

[Effect]

In this invention, since a constant flow valve is provided in parallel with the differential pressure regulating valve between the shaft sealing part of the filter, the flow rate of the side pressure oil supplied to the shaft sealing part is kept constant, and the side pressure applied to the shaft sealing oil ring is maintained. can be controlled at a constant level, and the position of the shaft sealing oil ring can be kept constant.

【Example】

FIG. 1 is a system diagram of a rotating electromagnetic shaft oil sealing device which is an embodiment of the present invention, in which oil discharged from the shaft sealing portion _O1 of a rotating electric machine O passes through an intermediate tank 1 and is accumulated in a vacuum tank 2. . In consideration of the possibility of failure of the intermediate tank system, some oil is collected in the vacuum tank 2 by direct vacuuming from the shaft seal _O1 . 3 is a vacuum pump for keeping the vacuum tank 2 in a vacuum state at all times. The oil stored in the vacuum tank 2 is sucked out by the oil pump 4 ₁ and its flow rate is adjusted by the control valve 5 ₁ to keep the oil pressure at a predetermined value and sent to the oil coolers 6 ₁ and 6 ₂ . In consideration of the failure of the vacuum tank system, the oil stored in the intermediate tank 1 and the oil in the shaft seal O ₁ are sucked out directly by the oil feed pump 4 ₂ and the flow rate is adjusted by the control valve 5 ₂ for oil cooling. A system for sending oil to the containers 6 ₁ and 6 ₂ is also provided. Oil cooler 6 ₁ , 6 ₂
The cooled oil is cleaned by filters 7 ₁ and 7 ₂ in the next step, and the pressure is adjusted by differential pressure regulating valves 8 ₁ and 8 ₂ before being supplied to the shaft seals O ₁ and O ₂ . Two of each device are connected in parallel in case of failure. The embodiment of this invention includes filters 7 ₁ and 7 ₂ and a shaft sealing portion.
Constant flow valves 9 ₁ and 9 ₂ were provided in parallel with differential pressure regulating valves 8 ₁ and 8 ₂ between O ₁ and O ₂ . The constant flow valves 9 ₁ and 9 ₂ are equipped with a pressure compensation mechanism such as a diaphragm that adjusts the restriction according to the pressure difference between the inlet side and the outlet side, and the discharge flow rate is maintained regardless of changes in the inlet side pressure or the outlet side pressure. is held at a predetermined value. That is, as shown by the thick line, the side pressure oil cleaned by the filters 7 ₁ and 7 ₂ is sent through the constant flow valves 9 ₁ and 9 ₂ , and the oil is sent through the constant flow valves 9 _{1 and 9 2} .
Even if the pressure of the oil flowing into 9 ₂ or the pressure of the in-machine hydrogen gas changes, a constant flow rate of side pressure oil is supplied to the shaft seals O ₁ and O ₂ on the discharge side of the constant flow valve, respectively. In this invention, by supplying a constant flow of lateral pressure oil to the shaft seal parts O ₁ and O ₂ , a constant lateral pressure is applied to the shaft seal oil ring, and the position of the shaft seal oil ring can be maintained at a fixed position.

【Effect of the invention】

According to this invention, a constant flow valve is provided between the filter and the shaft seal part in parallel with the differential pressure regulating valve, and a constant flow rate of side pressure oil is supplied to apply a constant side pressure to the shaft seal oil ring. The axial position of the oil sealing ring can be kept constant. As a result, the amount of shaft seal oil that flows out from between the shaft seal oil ring and the rotating shaft to the air side and the amount of shaft seal oil that flows to the hydrogen side are balanced, so the increase in shaft seal oil that flows out to the hydrogen side is suppressed. To prevent an increase in the amount of hydrogen dissolved in shaft seal oil, and to prevent an increase in vibration of the rotating shaft by making the shaft seal oil ring float well and eliminating the restriction of the rotating shaft by the shaft seal oil ring. I can do it.

[Brief explanation of the drawing]

FIG. 1 is a system diagram for explaining a side pressure oil supply method for a rotary electric machine shaft oil sealing device which is an embodiment of the present invention, and FIG. 2 is a longitudinal sectional view showing the configuration of a shaft sealing portion. O: Rotating electric machine, O ₁ , O ₂ : Shaft seal, 1: Intermediate tank, 2: Vacuum tank, 4 ₁ , 4 ₂ : Oil pump,
5 ₁ , 5 ₂ : Control valve, 6 ₁ , 6 ₂ : Oil cooler, 7 ₁ , 7 ₂ : Filter, 8 ₁ , 8 ₂ : Differential pressure regulating valve, 9 ₁ , 9 ₂ : Constant flow valve, 12 : Shaft seal oil ring support, 16: Shaft seal oil ring.

Claims (1)

[Claims] 1. The oil discharged from the shaft seal of the rotating electric machine is collected in a vacuum tank via an intermediate tank, and the oil stored in this vacuum tank is sucked out with an oil feed pump and sent to an oil cooler while adjusting the flow rate with a control valve. ,
In the shaft seal oil device, the cooled oil is cleaned with a filter, the oil pressure is adjusted with a differential pressure regulating valve, and then oil is supplied to the shaft sealing section. A rotary electric machine shaft seal oil, characterized in that a constant flow valve is provided in parallel, and the oil purified by the filter is supplied as side pressure oil to the shaft seal portion of the shaft seal oil device through the constant flow valve. Side pressure oil supply method for equipment.