JPH0727140A - Control device for thrust force pump - Google Patents

Abstract

PURPOSE:To shorten starting time of generators by reliably detecting formation of an oil film in a thrust bearing. CONSTITUTION:A control device is composed of a thrust collar 2 and thrust metal 3 to support a main shaft 4 connected directly to a generator 5, and has a thrust bearing 1 in which lubricating oil is filled, thrust shaft force pumps 6 and 8 to supply lubricating oil to the thrust bearing 1, generators 7 and 9 to drive these thrust shaft force pumps 6 and 8 and a main shaft position pickup 11 to detect a shaft directional displacement quantity of this main shaft, and has a variable resistor 12 to convert the displacement quantity outputted from the main shaft position pickup into an electric resistance quantity and a main shaft position detector 13 to compare an obtained value with a preset value corresponding to a preset proper lubricating film by converting a resistance quantity outputted from the variable resistor 12 into an electric quantity.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thrust push-up pump control device for reliably forming an oil film on a thrust bearing.

[0002]

2. Description of the Related Art A conventional thrust shaft push-up pump control device will be described with reference to the block diagram of FIG. The thrust bearing 1 is provided with a thrust collar 2 and a thrust metal 3, and is installed in a rotor of a generator 5 mounted on a main shaft 4 and a runner of a water turbine (not shown this time) connected to the generator 5 by a coupling. Supports the load. When the generator 5 is stopped, no oil film is formed between the thrust collar 2 and the thrust metal 3, and if the generator 5 is rotated in this state, the thrust bearing 1 will be burned out due to static friction. become. Therefore, prior to starting the generator 5, the thrust push-up pump 6 is started by the electric motor 7 or the thrust push-up pump 8 by the electric motor 9, and lubricating oil is sent at a high pressure between the thrust collar 2 and the thrust metal 3 of the thrust bearing 1 to form an oil film. Let This oil film forming state is the thrust lifting pump 6
Then, the pressure detector 10 attached to the pipe outlet of the thrust lifting pump 8 detects the pressure and confirms that this pressure has continued for a specified time or longer, and judges that the oil film of the thrust bearing 1 is completely formed. As a result, the activation of the generator 5 is permitted. When the discharge pressure due to the operation of the thrust lifting pump 6 is lower than the set value of the pressure detector 10, the electric motor 9 is started and the thrust lifting pump 8 is operated to keep the pressure above a predetermined value.

[0003]

In the conventional apparatus, the oil film formation on the thrust bearing 1 due to the operation of the thrust lifting pump 6 or the thrust lifting pump 8 is predicted by the establishment of the discharge pressure of the pump by the pressure detector 10 and the duration thereof. Therefore, the oil film itself was not detected. Therefore, the generator 5 is started without burning the oil film between the thrust collar 2 and the thrust metal 3 to burn out the thrust bearing 1, or it takes time for the pressure detector 10 to confirm the discharge pressure of the pressure detector. Therefore, there is a drawback that the starting time of the generator 5 becomes long and the responsiveness to the power demand of the system deteriorates. Further, in a turbine such as a Kaplan turbine whose thrust load changes at the time of starting the turbine, even if the discharge pressure of the thrust lifting pump is established, the oil film formation is insufficient and there is a risk of burning the thrust bearing.

That is, since the discharge establishing condition of the thrust lifting pump is used for detecting the oil film of the thrust bearing, there is a risk of burning the thrust bearing if the oil film is not sufficiently formed. Further, if the oil film formation confirmation time is taken sufficiently, it takes time to establish the starting condition of the generator, and there is a drawback that the starting time of the generator is prolonged. In the case of a water turbine in which the thrust load changes significantly from stop to start, it is not possible to determine whether an oil film has been formed on the thrust bearing by checking the discharge pressure of the thrust lifting pump, and the oil film formation will be insufficient. The risk was particularly high.

According to the present invention, the formation of an oil film on the thrust bearing is reliably detected, and the thrust load changes. An object of the present invention is to surely form an oil film also in a turbine generator, and to shorten the start-up time of the turbine generator without spending extra confirmation time for forming an oil film of the thrust bearing.

[0006]

SUMMARY OF THE INVENTION The present invention relates to a thrust push-up pump controller for supplying a lubricant to a thrust bearing supporting a generator and a prime mover directly connected to a main shaft to form a lubricating film, in the axial direction of the main shaft. Amount detecting means for detecting the amount of displacement of the device, resistance converting means for converting the amount of displacement output from the detecting means into an electric resistance amount, and resistance amount output from the resistance converting means into an electric amount. It is characterized by having a voltage quantity conversion means and a comparison means for comparing the quantity of electricity output from the quantity of electricity conversion means with a set value corresponding to the set proper lubricating film.

[0007]

The displacement amount detecting means detects the displacement amount of the main shaft in the axial direction. Then, this displacement amount is input to the resistance conversion means and converted into an electric resistance amount. Then, the electric resistance amount input by the electric amount conversion unit is converted into an electric amount, and the electric amount output from the electric amount conversion unit is compared with the set value corresponding to the set proper lubricating film.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the block diagram of the control device for a thrust lifting pump shown in FIG. In FIG. 1, 1 is a thrust bearing, 2 is a thrust collar, 3
Is a thrust metal, 6 is a thrust pushing pump, 8 is a thrust pushing pump, 7 is an electric motor, 9 is an electric motor, 4 is a main shaft,
Reference numeral 5 is a generator, 11 is a spindle position pickup, 12 is a variable resistor, and 13 is a spindle position detector.

The operation of this embodiment configured as described above will be described. The thrust bearing 1 is provided with a thrust collar 2 and a thrust metal 3.
The thrust metal 3 supports the full load of the main shaft 4, which is directly connected to the generator 5, the rotating part of the generator 5, and the runner (not shown this time) of the water turbine which is connected to the generator 5 by a coupling. Lubricating oil is contained in the thrust bearing 1, and the lubricating oil is pressurized by the thrust pushing pump 6 or the thrust pushing pump 8 so that the lubricating oil having a higher pressure than the hole provided in the thrust metal 3 is supplied. An oil film is formed between the thrust collar 2 and the thrust collar 2. An electric motor 7 and an electric device 9 are directly connected to the thrust push-up pump 6 and the thrust push-up pump 8, respectively, and apply a driving force to each pump.
At the time of starting the generator 5, the electric motor selected as the internal service machine of the electric motor 7 or the electric motor 9 is started to form an oil film on the thrust bearing 1. The oil film formed on the upper surface of the thrust metal 3 pushes up the thrust collar 2 and at the same time pushes up the main shaft 4. The push-up amount is interlocked with the slide portion of the variable resistor 12 by the spindle position pickup 11 to convert a small mechanical displacement amount into a variation amount of the resistance value of the variable resistor 12. Further, the amount of change in the resistance value is converted into an electric amount of voltage or current by the main shaft position detector 13, and compared with an electric amount corresponding to a preset specified main spindle lifting displacement amount, and when it becomes larger than that value, the thrust bearing It is judged that the oil film formation of No. 1 is completed.

When the formation of the oil film is completed, the generator 5 becomes rotatable, so that the water turbine (not shown) directly connected to the generator 5 is permitted to start, and the generator 9 is started. The thrust push-up pump 6 and the thrust push-up pump 8 are assigned to a normal machine and a standby machine, and in normal operation, an oil film is formed on the thrust bearing 1 by one operation.

When the thrust load changes at the time of startup due to the characteristics of the water turbine (not shown this time) directly connected to the generator 5, the load on the thrust metal 3 causes the oil film to be generated in the operation of one thrust up pump. Not formed. This state is detected by the spindle position detector 13 and the thrust lifting pump 6 or the thrust lifting pump 8 assigned to the spare machine is added to the normal machine to operate, and an oil film is formed on the thrust bearing 1 by increasing the thrust lifting capacity. . When the generator 5 is started by the formation of the oil film, the thrust load decreases, so the standby thrust-up pump is stopped.

As described above, according to the present embodiment, the oil film of the thrust bearing can be directly detected by the main shaft position detector as the amount of lift displacement of the main spindle, and the oil film formation can be reliably judged by comparing this value with a preset value. it can.

Unlike the conventional predictive formation of an oil film by continuing the discharge pressure of the thrust lifting pump, it is possible to prevent burning of the thrust bearing due to insufficient oil film. Further, it is possible to shorten the start-up time of the generator without requiring the confirmation time for establishing the discharge pressure of the thrust lifting pump for forming a sufficient oil film.

In a generator connected with a water turbine in which the thrust load changes, the thrust lifting capacity can be adjusted by the amount of displacement of the main shaft so that the oil film of the thrust bearing can be reliably formed.

In the above embodiment, each of the spindle position pickup and the variable resistor has been described as one, but a plurality of thrust metals are arranged in the thrust bearing in order to support and balance the generator that is a rotating body. In order to detect the respective oil film formation states, it is possible to perform fine detection by providing a plurality of spindle position pickups and a plurality of variable resistors.

Another embodiment will be described with reference to FIGS. The description is omitted because it has a common configuration other than the method of detecting the position of the spindle. 2 is a block configuration diagram of a method for mechanically detecting the position of the spindle, and FIG. 3 is a block configuration diagram of a method for detecting the position of the spindle by non-contact.

A second embodiment will be described with reference to FIG. 41
Is a spindle position detector, 42 is a spindle position pickup, 43 is an electromagnetic coil, 44 is a movable shaft, 45 is a spring, 46 is a fulcrum, 47
Is a contact point and 4 is a spindle.

An electromagnetic coil when the generator is stopped
Reference numeral 44 indicates non-excitation, the movable shaft 44 is pulled by the force of the spring 45, and the main shaft 4 and the main shaft position pickup 42 are in a non-contact state. When the electromagnetic coil 43 is excited prior to the operation of the generator, the movable shaft 44 is attracted toward the main shaft 4 and the main shaft position pickup 42 comes into contact with the main shaft. If the thrust lifting pump is started in this state, an oil film is formed, so that the spindle position pickup 42 is displaced upward. This displacement is the movable axis 44
The mechanical movement is amplified by the length of the movable shaft 44 from the fulcrum 46 and the fulcrum 46 to the contact point 47, and when the amount of lifting displacement of the main spindle reaches the completion of the oil film formation of the thrust bearing, the contact point is reached.
47 closes and allows the generator to start. After the start of the generator is permitted, the electromagnetic coil 43 is de-excited prior to rotation, and the spindle position pickup 42 is removed from the spindle 51 to exclude the device.

As described above, the spindle position detector 41 detects the oil film formation on the thrust bearing. A third embodiment will be described with reference to FIG. Reference numeral 48 is a ferromagnetic material, 49 is an electromagnetic pickup, 50 is a spindle position detector, and 4 is a spindle.

A ferromagnetic material 48 in a protruding state is attached to the main shaft 4 so that the main shaft 4 rotates together with the main shaft 4. The electromagnetic pickup 49 is attached to a fixed part of the generator and is arranged so as to face the ferromagnetic body 48. If a slight displacement of the spindle 4 occurs due to thrust up, the ferromagnetic body 48 enters the operating range of the electromagnetic pickup 49 and the spindle position detector 50 operates to detect the oil film formation on the thrust bearing.

In the above-mentioned embodiments, the adjustment of the thrust pushing capacity is explained by using the spare thrust pushing pump as an example.
The third embodiment shown in FIG. 4 has the same effect. Figure 4
FIG. 3 is a block configuration diagram of a thrust lifting device using an accumulator.

In FIG. 4, 52 is an electromagnetic valve, 53 is an opening / closing device, 54 is an accumulator, 55 is a thrust push-up pump, 56 is an electric motor, and 57 is a thrust bearing. When an oil film is formed on the thrust bearing 57, the electric motor 56 is started, and the thrust lifting pump 55 supplies high-pressure lubricating oil, but when the thrust load is large and the spindle displacement does not reach the preset amount, Judges that thrust thrusting capacity is insufficient, drives the opening / closing device 53, opens the solenoid valve 52, and supplies the lubricating oil in the accumulator 54 to the thrust bearing 57 to secure an oil film. As described above, also in the method using the accumulator 54, the thrust pushing capacity can be adjusted in the same manner as in the case of starting the auxiliary thrust pushing pump.

[0023]

As described above, according to the present invention, the oil film formation of the thrust bearing by the thrust lift pump can be reliably detected, and the conventional thrust lift pump operation continuation confirmation time for predicting the oil film formation is not required. The start-up time of the generator can be shortened. Further, it is possible to enhance the responsiveness of the generator in the electric power system. In a generator connected to a turbine with varying thrust load, the thrust push-up pump operated as before by adjusting the thrust push-up capacity according to the thrust load, but burnout of the thrust bearing due to insufficient oil film formation was prevented. Can be prevented.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a control device for a thrust lifting pump according to a first embodiment.

FIG. 2 is a configuration diagram of a control device for a thrust lifting pump according to a second embodiment.

FIG. 3 is a configuration diagram of a control device for a thrust lifting pump according to a third embodiment.

FIG. 4 is a configuration diagram of a control device for a thrust lifting pump according to a fourth embodiment.

FIG. 5 is a configuration diagram of a conventional thrust push-up pump controller.

[Explanation of symbols]

1 ... Thrust bearing, 2 ... Thrust collar, 3 ... Thrust metal, 4 ... Main shaft, 5 ... Generator, 6,8 ... Thrust shaft lifting pump, 7,9 ... Electric motor, 10 ... Pressure detector, 11,42 ...
Spindle position pickup, 12 ... Variable resistor, 13, 41 ... Spindle position detector, 43 ... Electromagnetic coil, 44 ... Movable shaft, 45 ... Spring, 46 ... Support point, 47 ... Contact.

Claims (1)

[Claims] 1. A displacement amount detecting a displacement amount in the axial direction of a main shaft in a control device of a thrust lifting pump for supplying a lubricant to a thrust bearing supporting a generator and a prime mover directly connected to the main shaft to form a lubricating film. A detection unit; a resistance conversion unit that converts the displacement amount output from the detection unit into an electric resistance amount; a voltage amount conversion unit that converts the resistance amount output from the resistance conversion unit into an electric amount; A control device for a thrust lift pump, comprising: a comparison unit that compares the amount of electricity output from the amount conversion unit with a set value corresponding to a set proper lubricating film.