JPH0152597B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] "Industrial Application Field" The present invention relates to a blade angle control device for a fluid machine equipped with movable blades.

"Problems to be Solved by Prior Art and the Invention" Conventionally, in fluid machines equipped with rotary blades, the blades are made movable and the pitch of the blades is changed to adapt to the flow rate in order to improve efficiency.

FIG. 1 is an example of a vertical sectional view of a movable vane pump. The shaft coupling 20 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 the operating shaft 2 for controlling the blade angle by a pin i. A device for moving the blade angle control operating shaft 2 in the axial direction is housed in the blade angle control device a.

When the blade angle control operating shaft 2 moves in the axial direction, the crosshead j moves together, and the link h rotates the arm f 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 is provided with a blade angle control operating shaft for driving the movable blade in a rotary shaft on which a movable blade of a fluid machine is attached so that the blade angle control operation shaft can be moved in the axial direction. There are those in which the operating force is supported by the rotating shaft and those in which the operating force is supported by a stationary object outside the rotating shaft.

If the movable blade is operated by supporting the blade angle operating force with a stationary object, this acting force will move between the rotating shaft and the stationary object, so this force will be applied to the thrust bearing that supports the rotating shaft. The disadvantage is that a larger capacity thrust bearing is required due to the additional acting force. On the other hand, in the case where the blade angle control force is supported by the rotary shaft, the blade angle control force is not applied to the thrust bearing that supports the rotary shaft because the rotary shaft is equipped with a means for operating the blade angle control control shaft. .

Conventionally, as a means for operating a blade angle control operating shaft on a rotating shaft, a hydraulic cylinder is generally provided on the rotating shaft concentrically with the rotating shaft, and the piston of the hydraulic cylinder and the blade angle controlling operating shaft are connected. It had been taken. However, in the case of such a hydraulic drive device, it is necessary to include a hydraulic supply device, a feedback mechanism for controlling the blade angle, etc., making the device large and complicated.
There was also a problem with the hydraulic seal.

Therefore, mechanical drive devices are often used to control the blade angle of relatively small fluid machines.

An invention disclosed in Japanese Patent Application Laid-open No. 30517/1983 is a blade angle control device for a fluid machine having a movable blade having a mechanical operating means for supporting the blade angle control force on a rotating shaft. This conventional example includes a piece provided around a rotating shaft so as to be rotatable relative to the rotating shaft, a rotor of an electric motor fixed to the outer periphery of the piece, a stator of the electric motor fixed with a space between the rotor and the above-mentioned rotor. A reduction gear supported on a rotating shaft decelerates the rotation of the piece, and a nut provided on the output side of the reduction gear engages with a threaded part provided on the blade angle control shaft.Rotary motion is converted into axial motion on the rotating shaft. It is characterized by the provision of means.

However, in this conventional example, since the nut on the output side of the reduction gear is engaged with the threaded portion of the blade angle operating shaft, it is not possible to extend the rotating shaft beyond the nut. Therefore, in this conventional example, the main engine driving electric motor that drives the rotary shaft has to have a special type with a hollow shaft, which makes the main engine driving electric motor expensive. Furthermore, when an existing fixed-blade pump, for example, is to be modified into a movable-blade pump, an existing solid-shaft electric motor for driving the main engine must be used, and this conventional example cannot be modified.

In order to eliminate the above-mentioned drawbacks in a blade angle control device for a fluid machine equipped with movable blades, the present invention does not use hydraulic pressure and is equipped with a mechanical actuation means structured to support the blade angle control force on a rotating shaft. An object of the present invention is to provide a blade angle control device that can use a general-purpose rotary machine and can convert a fixed-wing fluid machine into a fluid machine with movable wings.

[Structure of the invention]

"Means for Solving the Problems" The present invention provides a blade angle control operating shaft penetrating the hollow rotating shaft of a fluid machine equipped with movable blades, and moves the operating shaft in the axial direction. In a device for controlling the blade angle, a piece is provided on a rotating shaft so as to be rotatable without moving in the axial direction with respect to the rotating shaft, a rotor of an electric motor fixed to the outer periphery of the piece, and a gap between the rotor and an air gap. A stator of an electric motor fixed with a
The sliding ring comprises a screw cut into a piece and coaxial with the rotating shaft, and a sliding ring that has a screw that engages with the screw and is slid into the rotating shaft so that it cannot rotate relative to the rotating shaft and is movable in the axial direction. The ring is a blade angle control device for a fluid machine equipped with movable blades, and the output side of the ring is connected to a blade angle control operation shaft.

``Operation'' When the stator of the motor is energized, the rotor is energized. When the rotation speed of the rotor is made faster or slower than the rotation axis, the pieces rotate relative to the rotation axis. Relative rotation of this piece with respect to the rotation axis moves the sliding ring by the screw of the piece and the screw of the sliding ring, and the movement of the sliding ring drives the blade angle control operating shaft to change the blade angle. If the rotor is made to rotate at the same rotational speed as the rotation axis, the blade angle remains unchanged.

"Example" An example of the present invention will be described according to the drawings. Second
The figure is a longitudinal sectional view of an embodiment of the invention. A blade angle control operating shaft 2 is inserted into a hollow rotary shaft 1 of a fluid machine equipped with movable blades so as to be movable in the axial direction. Although not shown, a direct operating member connected to the movable wing at the bottom of the figure is engaged with this blade angle control operating shaft 2. The blade angle control operating shaft 2 is fitted into a disk-shaped crosshead 3 and is fixed by a shaft nut 4 screwed into the blade angle control operating shaft 2. A plurality of connecting rods 5 are fitted into axial holes on the circumference of the crosshead 3, and are fixed by nuts 6 screwed into the connecting rods 5. The connecting rod 5 passes axially displaceably through the coupling ring 15 and is connected to a sliding ring 7 which is slid onto the rotary shaft 1 so as to be axially displaceable. The sliding ring 7 has a male thread 7S cut concentrically with the rotating shaft 1 on its outer periphery, and is engaged with a female thread 8S cut on the inner periphery of the bridge 8.
The distance piece 11 is fitted into the rotating shaft 1 with its end touching the stepped portion 26 of the rotating shaft 1, the ball bearing 9 is fitted into the rotating shaft 1 with its end touching the distance piece 11,
The ball bearing 9 and the distance piece 11 are fixed by a shaft nut 10 screwed into the rotating shaft 1. A piece 8 is fitted and fixed into the outer ring of the ball bearing 9, and the piece 8 is mounted on the rotating shaft 1 via the ball bearing 9 so as to be immovable in the axial direction and rotatable relative to the rotating shaft 1. A rotor 12 is fixed to the outer periphery of the piece 8 so as to rotate together with the piece 8. A stator 13 is fixed to the inner periphery of the casing 18 with a gap between the rotor 12 and the stator 13 . The coupling ring 15 is fitted onto the rotating shaft 1 via a key 19, and is axially closed and fixed to the rotating shaft 1 by a shaft nut 14 screwed into the rotating shaft 1, and transmits main power. ing. A pair of coupling rings 16 is fixed to the coupling ring 15, and a power transmission shaft 17 is fixed to the coupling ring 16, so that the rotating shaft 1 and the power transmission shaft 17 are connected.

The center part of a piece 21 having a crank-shaped radial cross section and a disk-shaped outer diameter side is fixed to the sliding ring 7 by a connecting rod 5, and the outer periphery of the piece 21 is connected to the inner cylindrical part of the casing 18 via a key 22. It slides into the groove of the sliding piece 23, which is slid in so as to be freely movable in the axial direction. A detection rod 24 inserted through the casing 18 and protruding outside is fixed to the sliding piece 23, and the detection rod 24 is fixed to the sliding piece 23.
The structure is such that a detection rod 24 transmits the blade angle to a position detector 25 fixed to the casing 18 outside.

The stator coil of the stator 13 is guided outside the machine and wired to a control device. The pair of stator 13 and rotor 12 constitutes a variable speed electric motor.

Next, the operation of the blade angle control device of the present invention will be explained. During operation of a fluid machine with movable blades, the rotating shaft 1, couplings 15, 16, and power transmission shaft 1 are always connected.
7, the blade angle control operating shaft 2, shaft nut 4, crosshead 3, connecting rod 5, nut 6, sliding ring 7, etc. rotate together. When the blade angle is kept constant, the electric motor composed of the rotor 12 and the stator 13 is rotated at the same rotation speed as the rotating shaft 1.
That is, no relative rotation is caused between the rotating shaft 1 and the piece 8. When changing the blade angle, the rotor 12
A motor consisting of a stator 13 and a rotary shaft 1
Set the rotation speed so that it is not synchronized with the rotation of the shaft (faster or slower than the rotation speed of the rotating shaft). As a result, relative rotation occurs between the rotating shaft 1 and the piece 8, and the rotating shaft 1
The relative rotation of the piece 8 with respect to the rotating shaft 1 is caused by the axial movement of the sliding ring 7 due to the threaded pair of the male thread 7S cut on the outer periphery of the sliding ring 7 and the female thread 8S cut on the inner periphery of the piece 8, which rotate together with the piece 8. is converted to This axial movement is transmitted to the blade angle control operating shaft 2 via the connecting rod 5, crosshead 3, etc., and the blade angle changes.

The axial thrust as the blade angle operating force is the female thread 8 of the piece 8.
It is transmitted to and supported by the rotating shaft 1 by the screwing surface of S and the male thread 7S of the sliding ring 7, the ball bearing 9, the shaft nut 10, or the distance piece 11. Therefore, the blade angle operating force is supported inside the rotating shaft 1.

The position of the sliding ring 7 corresponds to the blade angle.
With the piece 21 moving together with the sliding ring 7,
The sliding piece 23 moves, the detection rod 24 is displaced, and the position of the blade angle control operating shaft 2 is detected by the position detector 25, thereby determining the current value of the blade angle.

In the example of a pump, the torsional direction of the male thread 7S of the sliding ring and the female thread 8S of the bridge is determined by the direction in which the bridge 8 is rotated by the inertial force of the rotor 12, etc. carried by the bridge 8 at startup or stop. If the blade angle is set in the direction where the blade angle increases, and the blade angle is set in the direction where the blade angle curves when stopped, there will be no problem as this matches the actual driving operation method.

In the embodiment of the present invention, the pieces are arranged around the rotating shaft so as to rotate relative to the rotating shaft, and the rotor is fixed on the outer periphery of the piece, and the stator is fixed with a space between the rotor and the rotor. The control device is carried on the rotating shaft and rotates without contacting the drive side of the blade angle control, and there is no friction loss due to the blade angle control device except during the blade angle control operation.

Considering this fact from the fact that in actual operating conditions, the steady-state operation time in which the blade pitch is kept constant occupies most of the time, this effect is significant. Since this does not occur, there is no wear and tear, resulting in extremely high durability. The operating force when controlling the blade angle acts uniformly on the entire circumference of the rotating shaft as a rotational moment (positive and negative), so the force in a direction other than the axial direction of the rotating shaft is used as an external force for controlling the blade angle on the rotating shaft system. I will not give it to you. Further, since the speed and torque (forward and reverse) of the rotor can be freely changed by the electric control device, the blade angle control operation time can be freely changed, and optimal control can be performed.

The rotor is fixed to a piece that is rotatably supported so that it does not move in the axial direction of the rotating shaft, so the rotor does not move in the axial direction of the rotating shaft and the rotor and stator are connected like a normal electric motor. can be arranged.

Relative rotation of the rotor with respect to the rotation axis is converted from mechanical rotary motion to linear motion conversion means, and as part of the movement conversion means, the female thread of the piece centered on the rotation axis is rotated integrally with the rotation axis. Since the male screw of the sliding ring that fits into the rotating shaft is engaged so that it can move freely in the axial direction of the rotating shaft, even if the operating shaft for controlling the blade angle is subjected to force due to the fluid force applied to the blades, the operating shaft for controlling the blade angle cannot be operated. The axis never moves. Since the blade angle control device is carried on the rotary shaft, the thrust bearing of the rotary shaft is not affected by the force applied to the blade angle control operating shaft for blade angle operation, so the thrust bearing can be made smaller. Furthermore, when converting an existing fixed-blade pump into a movable-blade pump, there is no need to change the thrust bearing that carries the thrust of the movable blade.

〔Effect of the invention〕

The present invention includes a screw coaxial with a rotating shaft cut into a piece,
a sliding ring having a thread that engages with the screw and slidingly inserted into the rotating shaft so as to be non-rotatable relative to the rotating shaft and movable in the axial direction; the sliding ring has an output side connected to an operating shaft for controlling the blade angle Since it is possible to provide an electric motor or a generator coaxially with the rotating shaft on an extension of the rotating shaft, the shafts of these rotating machines can be solid, and general-purpose rotating machines can be used. Therefore, the rotating machine does not become particularly expensive. Furthermore, it is possible to modify a fixed-wing fluid machine into a fluid machine with movable wings.

[Brief explanation of drawings]

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...Rotation axis, 2...Operation axis for blade angle control, 3...
...Crosshead, a...Blade angle control device, b...Suction casing, c...Movable blade body, d...Blade,
e...axis, f...arm, g, i...pin, h...
...Link, j...Head, 4...Shaft nut, 5...
...Connecting rod, 6...Nut, 7...Sliding ring, 7
S...male thread, 8...piece, 8S...female thread, 9...
... ball bearing, 10 ... shaft nut, 11 ... distance piece, 12 ... rotor, 13 ... stator,
14... Shaft nut, 15, 16... Coupling, 17... Power transmission shaft, 18... Casing,
19...Key, 20...Shaft coupling, 21...Piece, 22...Key, 23...Sliding piece, 24...Detection rod, 25...Position detector, 26...Step part.

Claims (1)

[Claims] 1. In a device for controlling a blade angle by providing a blade angle control operating shaft extending through a hollow rotating shaft of a fluid machine equipped with movable blades and moving the operating shaft in the axial direction, the rotating shaft a piece provided on the top so that it does not move in the axial direction with respect to the rotating shaft and is rotatable;
It has a rotor of an electric motor fixed to the outer periphery of the piece, a stator of the electric motor fixed with a gap between the rotor and the rotor, a screw cut into the piece that is concentric with the rotating shaft, and a screw that engages with the screw. A movable wing comprising: a sliding ring that cannot rotate relative to the rotating shaft but is movable in the axial direction; the sliding ring has an output side connected to an operating shaft for controlling the blade angle. A blade angle control device for fluid machinery equipped with