JPH06336998A - Motor-driven runner vane servo-motor - Google Patents

Abstract

PURPOSE:To reduce the capacity and rotational friction loss of thrust bearings by connecting plural planetary reduction gears to a driving motor, connecting a case to the main shaft of a hydraulic turbine or the like, and connecting the operating rod of a movable vane to the output shaft of one planetary reduction gear by a lift nut. CONSTITUTION:In order to change the vane angle of a movable vane 1, a screw shaft 9 is rotated normally or reversely. At this time, thrust does not act upon thrust bearings 6a, 6b because of being offset by the tension or compression of a main shaft 5. The capacity and rotational friction loss of a main bearing 6 can be thereby reduced. In order to rotate the screw shaft 9 normally or reversely, the rotation of a variable speed motor 11 is increased or reduced to produce relative rotational difference between the output shaft 12b of a secondary planetary reduction gear 12, that is, the screw shaft 9, and the main shaft 5, that is, an extended part 12B. When the relative rotational difference is plus, for instance, a lift nut 7 moves axially by the specified stroke S so as to move an operating rod 4 in a direction (b), thus changing the vane angle of the movable vane 1 in a direction (d).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric runner vane servomotor for electrically changing the angle of a movable blade in response to a change in flow rate of a water turbine or a pump.

[0002]

2. Description of the Related Art As a means for changing the angle of a movable blade, a conventional hydraulic cylinder type or an electric lever type in which an electric actuator is separately installed and a lever is used is generally used.

[0003]

In the case of the conventional hydraulic cylinder type, in addition to requiring a large-scale pressure oil device, maintenance and initial cost including oil for operation,
There is a drawback that running costs are high.

Unlike the hydraulic cylinder type in the electric lever type shown in FIG. 3, the large driving force required to change the blade angle of the movable blade 1 in the forward and reverse directions is generated from the electric actuator 2 to the lever 3 and the operating rod. 4 and turbine or pump 1
00 and the motor or generator 200 are connected to the thrust bearings 6a and 6b of the main bearing 6 through the main shaft 5. Therefore, in addition to the capacity of the main bearing 6 increasing by the amount of this thrust, the rotational friction loss due to the thrust also causes thrust bearings 6a and 6b.
And the efficiency of the turbine or pump 100 is significantly reduced.

It is an object of the present invention to provide an electric runner vane servomotor which eliminates the problems associated with the thrust generated when changing the blade angle.

[0006]

According to the present invention, primary and secondary planetary speed reducers are connected to a drive motor, and a case of the secondary planetary speed reducer is connected to a main shaft of a water turbine or a pump. Alternatively, the operating rod of the movable blade of the pump is connected to the output shaft of the secondary planetary speed reducer via a lift nut.

It is preferable that the lift nut is screwed into a trapezoidal screw portion of a screw shaft provided on the output shaft of the secondary planetary speed reducer.

[0008]

In the electric runner vane servomotor configured as described above, the rotation of the drive motor is accelerated or decelerated to cause a relative rotation difference between the screw shaft and the spindle, and the lift nut is axially moved. It moves and changes the wing angle of the movable wing via the operation rod. The thrust generated at this time is applied to the thrust bearing that supports the screw shaft, and the reaction force pulls or compresses the main shaft, and is canceled within the main shaft. Therefore, the conventional problem related to the thrust is eliminated.

[0009]

Embodiments of the present invention will be described below with reference to the drawings.

In FIG. 1, a sun gear shaft 13a of a primary planetary speed reducer 13 is connected to an output shaft 11a of a variable speed motor 11. On the output shaft 13b of the speed reducer 13,
The sun gear shaft 12a supported by the radial bearing 14 of the secondary planetary speed reducer 12 is connected. The output shaft 12b of the speed reducer 12 is connected to a screw shaft 9 having a trapezoidal screw portion a. Further, an extension 12B is integrally connected to the case 12A of the speed reducer 12, and the extension 12B is
One end of the main shaft 5 is flanged. This spindle 5
Is a power shaft of the motor or generator 200, is supported by the radial bearing 15 and the thrust bearings 6a and 6b of the main bearing 6, and is connected to the other end by a water turbine or a pump lunge.

The water turbine or pump 100 is provided with a plurality of movable vanes 1 so that the vane angle can be changed forward and backward by the forward and backward movement of the operating rod 4.

The distal end of the operating rod 4 is fixedly mounted in the extension portion 12B with a lift nut 7 and locked by the spline guide 8 in the rotational direction with respect to the extension portion 12B and supported slidably in the axial direction. ing. Then, the screw portion a of the screw shaft 9 is screwed into the lift nut 7. Reference numerals 10a and 10b in the drawing denote thrust bearings that sandwich the disk portion 9a of the screw shaft 9.

Next, the operation will be described.

To change the blade angle of the movable blade 1, the screw shaft 9 is rotated in the forward or reverse direction. The thrust generated at that time is applied to the thrust bearing 10a or 10b, and the reaction force pulls or compresses the main shaft 5. That is, the thrust required to change the blade angle of the movable blade 1 is canceled inside the main shaft 5 and does not act on the thrust bearings 6a and 6b. Therefore, the capacity of the main bearing 6 can be reduced by this amount, and the rotational friction loss can be reduced.

In order to rotate the screw shaft 9 in the forward or reverse direction, the rotation of the variable speed motor 11 is accelerated or decelerated, and the output shaft 12b of the secondary planetary speed reducer 12, that is, the screw shaft 9 and the main shaft 5. That is, a relative rotation difference is generated between the extension 12B. Accordingly, for example, when the relative rotation difference is positive, the lift nut 7 moves in the axial direction by the stroke S, the operation rod 4 moves in the arrow b direction, and the blade angle of the movable blade 1 changes in the arrow d direction. Let When the relative rotation difference is negative, the operating rod 4 moves in the direction of arrow c and changes in the direction of arrow e. When the relative rotation difference is zero, the blade angle does not change. That is, the variable speed motor 11 is in an unloaded state, and the turbine or pump 1
It is idling by the power of 00. When such a relative rotation difference is zero, even if thrust is applied to the operating rod 4 by the water surface acting on the blade, the screw portion a is a trapezoidal screw and the screw gradient is small, so Since the screw shaft 9 does not rotate, the lift nut 7
Does not move, so the wing angle retains its position.

The maximum rotation speed of the variable speed motor 11 is generally about 2400 r / m, and it is economical to set the rotation speed as high as possible and increase the reduction ratio so that the reduction speed is small. On the other hand, the rotation speed of the water turbine or pump 100 is low in the case of a large machine. For example, the rotation speed of the water turbine is 20
Assuming 0 r / m, when the variable speed motor 11 is directly connected to the secondary planetary speed reducer 12 without providing the primary planetary speed reducer 13 as shown in FIG. Rotate without load at the same speed of 200 rpm. When a load is applied to the motor 11 based on this no-load rotation speed to accelerate or decelerate the blade angle,
Deceleration width is 200r / m from 200r / m to 0r / m
There is nothing. However, the acceleration range is from 200r / m to 2400
There is a case where the difference up to r / m is 2200 r / m, the shift width is unbalanced, and the change speed of the blade angle cannot be properly controlled.

On the other hand, in the present embodiment shown in FIG. 1, when the primary planetary speed reducer 13 is provided and the reduction ratio thereof is set to, for example, 1/6, the no-load rotation speed of the motor 11 is the rotation speed 2 of the water turbine.
It is 1200 r / m, which is six times 00 r / m. Since this rotation speed is an intermediate rotation speed of the maximum rotation speed 2400 r / m of the motor 11, the acceleration width and the deceleration width are the same, and the blade blade change speed setting can be widened. Further, by changing the reduction ratio of the primary planetary speed reducer 13 arbitrarily, the magnitude of the acceleration width and the deceleration width of the variable speed motor 11 can be determined, so that the opening / closing speed of the blades can be set arbitrarily. .

[0018]

EFFECTS OF THE INVENTION Since the present invention is constructed as described above, it is possible to suppress an increase in the capacity of the thrust bearing and an increase in the rotational friction loss associated with the thrust generated when the blade angle is changed, and to improve the efficiency of the pump or the turbine. Can be greatly improved. Further, since the opening / closing speed of the blade angle can be arbitrarily set, the water hammer can be limited.

[Brief description of drawings]

FIG. 1 is a side sectional view showing an embodiment of the present invention.

FIG. 2 is a drawing showing a state in which a primary planetary speed reducer is omitted from FIG.

FIG. 3 is a side sectional view showing an electric lever type device.

[Explanation of symbols]

 1 ... Movable wing 2 ... Electric actuator 3 ... Lever 4 ... Operation rod 5 ... Main shaft 6 ... Main bearing 6a, 6b, 10a, 10b ... Thrust bearing 7 ... Lift nut 8 ... Spline guide 9 ... Screw shaft 9a ... Disk part 11 ... Variable speed motor 11a ... Output shaft 12 ... Secondary planetary reducer 12a, 13a ... Sun gear Shaft 12b, 13b ... Output shaft 12A ... Case 12B ... Extension 13 ... Primary planetary reducer 14, 15 ... Radial bearing 100 ... Water turbine or pump 200 ... Motor or power generation Machine a: Trapezoidal thread S: Stroke

Claims (1)

[Claims] 1. A primary and secondary planetary speed reducer is connected to a drive motor, a case of the secondary planetary speed reducer is connected to a main shaft of a water turbine or a pump, and an operating rod of a movable blade of the water turbine or the pump is connected to the drive shaft. An electric runner vane servomotor characterized by being connected to the output shaft of a secondary planetary reducer via a lift nut.