JPS6338558B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a blade angle control device for a fluid machine equipped with movable blades.

Conventionally, in fluid machines equipped with rotary blades, efficiency has been improved by making the blades movable and changing the pitch of the blades to adapt to the flow rate.

FIG. 1 is an example of a vertical sectional view of a movable vane pump. The shaft coupling 13 is fixed to one end of the rotating shaft,
The rotating shaft 1 enters the suction casing b via a blade angle control device a fixed to the suction casing b in a sealed manner, and a spindle-shaped movable blade main body c is fixed to the rotating shaft 1. A radial axis e is pivotally connected to the rotation axis 1 of the blade d at c, and the other end of a link h, which is pivotally attached to the end of arm f fixed to axis e by a pin g, is inserted through the rotation axis 1. It is pivotally connected to a crosshead j fixed to a tension rod 2 by a pin i. A device for moving the tension rod 2 in the axial direction is housed in the blade angle control device a. When the tension rod 2 moves in the axial direction, the crosshead j moves together, and the arm f is rotated by the link h to change the pitch of the blade d. The figure shows an example of a horizontal type, but there is also a vertical type, and the same example exists for water turbines.

Such a blade angle control device has a tension rod for driving a movable blade movable in the axial direction on a rotating shaft to which a movable blade of a fluid machine is attached, and the blade angle control force acting on the tension rod is supported by the rotating shaft. Some are supported by a stationary object outside the axis of rotation. If the movable blade is operated by supporting the blade angle operating force acting on the tension rod with a rotating shaft, this acting force acts between the rotating shaft and the tension rod, and therefore the thrust bearing that supports the rotating shaft is required. Since this acting force is added to
The disadvantage is that a thrust bearing with a larger capacity must be used. On the other hand, the stationary object that supports the blade angle operating force acting on the tension rod has means for operating the tension rod on the stationary object, so the reaction force of the force applied to the tension rod acts on the thrust bearing that supports the rotating shaft. do not have.

Conventional operating means generally have a construction in which a hydraulic cylinder is arranged on a rotating shaft and coaxial with the rotating shaft, and a piston of the hydraulic cylinder and a tension rod are connected. However, in the case of such a hydraulic system, it is necessary to have a hydraulic source, a hydraulic servo mechanism for controlling the position of the tension rod, etc., making the device large and complex, and the thrust bearing that supports the rotating shaft must have a large capacity. Therefore, it is desirable to provide a mechanical actuation means on the stationary object that does not use hydraulic pressure.

In addition, in the case of a hydraulic type, it is necessary to constantly control the position of the tension rod while the rotating shaft is rotating, and power is always required to keep the blade angle constant.

An invention disclosed in Japanese Patent Application Laid-open No. 30517/1984 uses an electric motor concentric with the rotating shaft without using hydraulic pressure. However, this conventional example requires complicated control in that the relative rotational speeds of the two motors, the motor for driving the tension rod and the motor for driving the rotating shaft, must be controlled, and it is difficult to keep the blade angle constant. However, the electric motor for driving the tension rod must be kept rotating, which is uneconomical, and it is difficult to convert a fixed-blade fluid machine to a movable-blade machine later on.

The present invention supports a blade angle control force acting on a tension rod in a blade angle control device for a fluid machine equipped with movable blades by a stationary object outside the rotation axis, and
It is an object of the present invention to provide a means for operating a tension rod that requires operating power only when changing the blade angle.

The present invention relates to a blade angle control device for a fluid machine equipped with a movable blade having a hollow rotating shaft and a tension rod passing through the rotating shaft, including a piece rotatably provided around the rotating shaft on a stationary casing; A rotor of the electric motor fixed to the outer periphery of the piece, a stator of the electric motor fixed with a gap from the rotor, and a member that supports the piece, is connected to the tension rod, and is fixed to the rotating shaft. A blade of a fluid machine equipped with a movable blade, characterized in that the blade has a sliding ring movably slid in the axial direction of the shaft, and the piece and the stationary casing are connected by a pair of screws concentric with the rotating shaft. It is an angle control device.

Embodiments of the present invention will be described below with reference to the drawings. FIG. 2 is a longitudinal sectional view. A tension rod 2 is inserted through the center of a hollow rotating shaft 1 of a fluid machine equipped with movable blades (not shown) so as to be movable in the axial direction. Although not shown in the drawings, the tension rod 2 is engaged with an operating member immediately after being connected to the movable wing. A disk-shaped disk 4 is fitted into the tension rod 2 via a key 3, and is fixed to the tension rod 2 so as not to move in the axial direction or rotationally with respect to the tension rod 2. One end of a plurality of operating rods 6 is fitted into an axial hole on the circumference of the disk 4, and a nut 7 is screwed into the operating rod 6 to fix the disk 4 and the operating rod 6. The operating rod 6 is fitted into the rotating shaft 1 through a key 8, and is tightened in the axial direction by a nut 9 screwed into the rotating shaft 1, and the rotating shaft is attached to a bush 12 press-fitted into a coupling ring 11 fixed to the rotating shaft 1. It slides in so that it can move freely in the same direction as the axial direction of 1.

A shaft coupling 13 at the end of a driving shaft (if the fluid machine is a pump) or a driven shaft (if the fluid machine is a water turbine) is fitted into the coupling 11, and the two are connected by a coupling bolt and nut 14.

A sliding ring 16 is fitted into the coupling ring 11 via a key 15 so as to be movable in the axial direction of the rotating shaft 1.
A male screw 24a on the boss 24b of the end plate 24A of the casing 24, which is divided into a cylindrical outer circumference 24B and an end plate 24A and fixed together, has a male thread 24a coaxial with the rotating shaft 1. A female thread 18a is screwed in. The piece 18 is supported via a bearing 17 so as not to move axially but rotatably relative to the sliding ring 16. That is, the bearing 17 is a face-to-face angular contact bearing, and the step 18b of the bearing house of the piece 18 and the bolt 1
The outer ring of the bearing 17 is held down by the collar 21 with a collar attached to the piece 18 by 9, and the sliding ring 1 is held on the side of the inner ring.
6 stages 16a are held between them.

Sliding ring 1 of the output side member of the mechanical motion converting means that converts the rotational motion of the piece 18 into linear motion.
6 and tension rod 2 are connected. That is, the other end of the operating rod 6 is screwed and fixed to the sliding ring 16.

A rotor 22 of a motor is fixed to the outer periphery of the piece 18, and a stator 23 is fixed to a casing 24 with a gap between the rotor 22 and the stator 23.

One end of a crank-shaped piece 26 is fixed to the piece 18 by a bolt 20, and the other end of the piece 26 is fitted with a sliding ring 28 that is slid into the inner cylindrical portion of the casing 24 via a key 27 so as to be movable in the axial direction. It slides into the inner circumferential groove. The casing 2 is attached to the sliding ring 28.
A pointer 29 that is inserted through the blade 4 in the axial direction is fixed, and the blade angle is transmitted to a blade angle detection device 25 fixed to the casing 24 outside the casing 24.

The stator coil of the stator 23 is guided outside the machine and wired to a control device via a terminal block 31. Stator 2
3. The pair of rotors 22 constitutes a motor.

When the rotating shaft 1 is rotating, the coupling 1 is rotationally rigid relative to the rotating shaft 1.
1. The shaft joint 13, sliding ring 16, operating rod 6, disk 4, tension rod 2, etc. always rotate integrally. Since the piece 18 does not rotate when the stator 23 is not energized, the screws 24a, 1
Since the tension rod 8a does not move relative to each other, the axial position of the tension rod 2 does not change and the blade angle remains constant. Further, at this time, the pointer 29 remains stationary.

Now rotate the rotor 22. That is, stator 2
3, the rotor 22 and stator 23 become motors, and the rotor 22 receives torque and rotates the piece 18. This rotation of the piece 18 causes the female thread 18 of the piece to
a and the male screw 24a of the casing rotate relative to each other, and the piece 18 moves in the axial direction, so the sliding ring 16 is urged in the axial direction via the bearing 17.
slides on the coupling 11, moves the operating rod 6, moves the tension rod 2 connected by the disk 4 in the axial direction, and changes the blade angle. Since the piece 26 moves in the axial direction while rotating together with the piece 18, the sliding ring 28 moves in the axial direction, and the pointer 29 moves in the axial direction.
transmits the position of the tension rod 2 to the blade angle sensing device 25, which also indicates the current state of the blade angle and inputs this signal to the feedback circuit if necessary. At this time, the rotor 22 moves in the axial direction, but the axial movement is slow and the axial movement is not hindered by the induced electric power.

When the rotor 22 is rotated in the opposite direction, the piece 18 also rotates in the opposite direction, and the piece 18 is moved in the axial direction by the male screw 24a of the casing and the female screw 18a of the piece, and the sliding ring is moved through the bearing 17. 16 is slid on the coupling ring 11, and the operating rod 6, disk 4, and tension rod 2 move together with the sliding ring 16, and the blade angle moves in the opposite direction.

Casing male thread 24a and bridge female thread 18a
In the example of a pump, when the pieces 18 and 18 are rotated by the inertial force of the object they are carrying when starting or stopping, the direction in which the blade angle is increased is the direction in which the blade angle is increased when starting, and the blade angle is increased when stopped. If you set it in the direction in which it bends, there will be no problem since it matches the actual driving operation method.

A motor consisting of a rotor 22 and a stator 23 used in such a device is, for example, a step motor,
It is appropriate to configure it as a low frequency multi-pole motor, etc.
It is preferable to use a pulse motor and perform numerical control.

The present invention relates to a blade angle control device for a fluid machine equipped with a movable blade having a hollow rotating shaft and a tension rod passing through the rotating shaft, including a piece rotatably provided around the rotating shaft on a stationary casing; A rotor of the electric motor fixed to the outer periphery of the piece, a stator of the electric motor fixed with a gap from the rotor, and a member that supports the piece, is connected to the tension rod, and is fixed to the rotating shaft. A blade of a fluid machine equipped with a movable blade, characterized in that the blade has a sliding ring movably slid in the axial direction of the shaft, and the piece and the stationary casing are connected by a pair of screws concentric with the rotating shaft. Since it is an angle control device, even if the tension rod receives axial force due to the fluid force applied to the blades, the piece will not rotate due to the friction of the screw. In other words, no power is required to keep the blade angle constant except during the blade angle control operation.

Considering this fact from the fact that in actual operating conditions, the steady operation time in which the blade pitch is kept constant occupies most of the time, this effect is very large.
In addition, since the speed and torque (forward and reverse) of the rotor can be freely changed by the electric control device without being affected by the rotational speed of the rotating shaft, it is possible to freely change the blade angle control operation time and achieve the optimal Easy to control. Since the blade angle control device is carried on the casing, the force applied to the tension rod for controlling the blade angle does not act on the thrust bearing of the rotating shaft, so that the thrust bearing can be made smaller. The torque of the rotor of the electric motor for driving the tension rod is not applied to the rotating shaft and has no effect on the rotating shaft. A pair of screws concentric with the rotating shaft of the mechanical motion converting means that converts the rotational motion of the rotor into linear motion is provided between the casing and the piece and is separated from the rotating shaft, so that the blade angle control device part that drives the tension rod is separated from the rotating shaft. can be installed in the middle of the rotating shaft, allowing an existing fluid machine with fixed blades to be modified into a fluid machine with movable blades.

[Brief explanation of the drawing]

FIG. 1 is a vertical cross-sectional view for explaining blade angle control of a fluid machine equipped with movable blades, and FIG. 2 is a vertical cross-sectional view of an embodiment of the present invention. 1...Rotating shaft, 2...Tension rod, 3...Key, 4...Disc, 6...Operation rod, 7...Nut, 8
...key, 9...nut, 11...coupling, 12
...Bush, 13...Shaft coupling, 14...Coupling bolt nut, 15...Key, 16...Sliding ring,
16a, 18b...step, 18...piece, 18a...female thread, 19, 20...bolt, 21...collar with collar,
22...Rotor, 23...Stator, 24...Casing, 24A...End plate part, 24B...Cylindrical outer peripheral part, 24
a...male thread, 24b...boss, 25...blade angle detection device, 26...piece, 27...key, 28...sliding ring,
29... Pointer, 31... Terminal block, a... Blade angle control device,
b...Suction casing, c...Movable blade body, d...Blade, e...Shaft, f...Arm, g...Pin, h...Ring, i...Pin, j...Crosshead.

Claims (1)

[Scope of Claims] 1. In a blade angle control device for a fluid machine equipped with a movable blade having a hollow rotating shaft and a tension rod passing through the rotating shaft, the blade angle control device is provided rotatably around the rotating shaft on a stationary casing. a rotor of the electric motor fixed to the outer periphery of the bridge; a stator of the electric motor fixed with a space between the rotor and the rotor; a sliding ring slidably inserted into a member that is movable in the axial direction of the rotating shaft, and the bridge and the stationary casing are connected by a pair of screws concentric with the rotating shaft. Blade angle control device for fluid machinery. 2. Blade angle control of a fluid machine equipped with a movable blade according to claim 1, comprising a female thread with a threaded pair cut into the bridge and a male thread cut into the casing that engages with the female thread. Device.