JP2903641B2 - Water turbine bearing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial applications]

The present invention relates to a bearing device provided with a main bearing pad for guiding a collar integrally formed with a main shaft of a vertical shaft turbine in an oil tank, and a bearing support for supporting the main bearing pad.

[Prior art]

Conventionally, a bearing device provided with a main bearing pad configured to guide a collar integrally formed with a main shaft of a vertical shaft turbine and a bearing support for supporting the main bearing pad circulates lubricating oil in an oil tank housing the bearing device. There is a method in which an electric pump is provided outside the oil tank to circulate the oil, and circulation is performed by the electric pump. In addition, a method is used in which a radial hole is made in the collar of the main shaft, and oil is circulated by generating hydraulic pressure by a pump action utilizing centrifugal force due to the speed difference between the outer diameter and the inner diameter of the collar hole accompanying the rotation of the collar. There is.

[Problems to be solved by the invention]

The above-mentioned conventional method using an electric pump requires an electric pump to be connected to a separate cooler as power, which complicates equipment such as piping, valves, and electric pumps, increases the cost of equipment, and increases the cost of these equipment. Space is also needed to place the equipment. Further, when the motor or the pump breaks down, the circulation of the oil stops, the temperature of the lubricating oil rises, and it becomes impossible to sufficiently cool the bearing, and there is a safety problem. On the other hand, the method using a centrifugal pump uses oil pressure determined by the diameter of the collar and the number of revolutions of the main shaft, so if the oil cooler is installed separately, the resistance value of the pipe loss of the lubricating oil pipe and oil cooler There is a limit. Therefore, it is difficult to apply to a small-capacity, low-speed water turbine. An object of the present invention is to circulate the lubricating oil in the oil tank at a large discharge pressure and discharge amount when a cooler is separately installed because the space of the oil tank is narrow and it is difficult to incorporate a cooler. .

[Means for Solving the Problems]

In order to solve the above-mentioned problem, the present invention extends a collar integrally formed with a main shaft of a vertical water turbine, and forms an annular floating metal having an inner peripheral surface that is in sliding contact with an outer peripheral surface of the extended portion. Along with being provided on the bearing support so as to float in accordance with the lateral movement and inclination of the main shaft, a circumferential groove whose depth changes along the rotation direction of the main shaft is formed on the inner peripheral surface thereof, One end is provided with an oil suction hole communicating with the oil tank, and the other end is provided with an oil feed groove communicating with an oil cooler separately disposed outside the oil tank to constitute a viscous pump,
The lubricating oil in the oil tank is circulated through the oil cooler by the pump action of the viscous pump accompanying the rotation of the main shaft.

[Action]

According to the present invention, a floating metal constituting a viscous pump is provided using an extension of a main spindle collar, and lubricating oil in an oil tank is circulated through an oil cooler by a pump action of the viscous pump. The viscous pump uses the viscosity of oil to generate a pump action by a laminar friction effect accompanying rotation of the main shaft, and can obtain a large discharge pressure and a large discharge amount. Therefore, sufficient oil circulation can be realized even if the loss of the separate oil cooler and the pipeline is large, and the separate oil cooler can be applied to a small-capacity, low-speed water turbine. on the other hand,
Since the floating metal supported in a floating manner can freely follow the horizontal movement and inclination of the main shaft, even if the main shaft receives a lateral load during the operation of the water turbine, it can escape from the movement of the main shaft and avoid damage.

【Example】

An embodiment of the present invention will be described below with reference to the drawings. First
FIG. 1 is a longitudinal sectional view showing a water turbine bearing device according to an embodiment of the present invention. In FIG. 1, a collar 1a integrally formed with a main shaft 1 for connecting a runner (not shown) has a bearing support 7.
The collar 1a is provided with an extended portion 1b which is guided by a main bearing pad 2 in an oil tank 10 attached to the oil tank 10 and extends downward. Supports 4 and 5 are attached below the bearing support 7, and the floating metal 3 that slides in contact with the outer periphery of the collar 1 a is loosely sandwiched and supported between the supports 4 and 5. The pins 6 mounted upright at several places are loosely fitted into the cylindrical holes 5a of the upper support 5 and are prevented from rotating. A bearing cover 8 is provided above the bearing support 7.
The floating metal 3, the bearing support 7, and the bearing covers 8, 9 form a bearing chamber 7a surrounding the main bearing pad 2. The bearing chamber 7a is connected to an oil cooler (not shown) via an oil feed pipe 11, and a return oil pipe (not shown) from the oil cooler opens on the oil tank 10. In the floating metal 3, a circumferential groove 12 whose depth changes along the rotation direction of the main shaft 1 is formed on an inner peripheral surface of the floating metal 3 which is in contact with the outer peripheral surface of the collar extension 1 b. However, it has a constant length in the circumferential direction of the inner peripheral surface of the floating metal 3, and the peripheral grooves 12 are arranged at equal pitches, for example, at three to four locations on the inner peripheral surface. ),
At one end, an oil suction hole 13 communicating with the oil tank 10 is provided downward, and at the other end, an oil feed groove 14 communicating with the bearing chamber 7a is provided. The floating metal 3 forms a viscous pump with the collar extension 1b. That is, when the main shaft 1 rotates, the oil in the circumferential groove 12 is carried by the viscosity in the rotating direction of the collar extension 1b and is gradually compressed, and the pressure increases to increase the oil supply groove 14
From the bearing chamber 7a. Accordingly, the oil is sucked into the circumferential groove 12 through the oil suction hole 13 in the oil tank 10, and a pump action is generated by the continuous action. Part of the oil flowing as indicated by the arrows due to this pumping action is
The lubricating oil passes through a gap 14 between the main bearing pad 2 and the other, and is collected in an oil feed pipe 11 after passing behind the main bearing pad 2 and cooled by an oil cooler (not shown). Circulation returning to the oil tank 10 via the oil pipe is performed. On the other hand, the main shaft 1 receives a lateral load during operation of the turbine, and
In the case where the floating metal 3 is tilted or moved in the horizontal direction, the floating metal 3 is loosened in the vertical direction in the supports 4, 5 and the cylindrical hole 5 is loosened.
Due to the looseness of the pin 6 in the horizontal plane within a, the pin 6 follows the movement of the main shaft 1 and floats, so that the movement of the main shaft 1 is not restricted, and there is no danger of the floating metal 3 being damaged by the movement.

【The invention's effect】

According to the present invention, a large discharge pressure and a large discharge amount can be obtained by forming the viscous pump with the floating metal opposed to the collar extension portion of the main shaft, so that the separate pump type is not restricted by the pipe loss resistance. The lubricating oil can be sufficiently cooled using the oil cooler. In this case, by supporting the floating metal in a floating manner, the pump mechanism can freely follow the movement of the main shaft caused by the lateral load.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a longitudinal sectional view of a main part of a bearing device of a water turbine showing an embodiment of the present invention. 1: Main shaft, 1a: Collar, 1b: Extension, 2: Main bearing pad, 3: Floating metal, 7: Bearing support, 7a: Bearing chamber, 10: Oil bath, 12: Peripheral groove, 13: Oil suction hole, 14 : Oil groove.

Claims (1)

(57) [Claims] 1. A bearing device comprising: a main bearing pad for guiding a collar formed integrally with a main shaft of a vertical shaft turbine in an oil tank; and a bearing support for supporting the main bearing pad, wherein the collar is extended downward. An annular floating metal having an inner peripheral surface that is in slidable contact with the outer peripheral surface of the extension portion is supported by the bearing support so as to float in accordance with the lateral movement and inclination of the main shaft. An oil groove formed on a peripheral surface of which a circumferential groove whose depth changes along the rotation direction of the main shaft is provided at one end thereof with an oil suction hole communicating with the oil tank, and an oil cooler separately provided at the other end outside the oil tank; A viscous pump is formed by providing an oil feed groove communicating with the main shaft, and the lubricating oil in the oil tank is circulated through the oil cooler by a pump action of the viscous pump accompanying rotation of the main shaft. Bearing mounting Place.