JPH0322555Y2 - - Google Patents

Description

[Detailed description of the invention] (Field of industrial application) The present invention relates to a movable blade fluid machine that enables reliable servo control of the axial position of a blade angle operating shaft that adjusts the angle of a movable blade. be.

(Prior art) A vertical cross-sectional view of an example of a conventional movable blade fluid machine is shown in Fig. 4.
As shown in the figure. In FIG. 4, a rotating shaft 1 is hollow, and a blade angle operating shaft 2 is inserted into the rotating shaft 1 so as to be movable in the axial direction. An impeller boss 3 is fixed to the tip of the rotating shaft 1, and movable blades 4, 4, . . . are arranged radially on the impeller boss 3. Furthermore, the arms 6, 6... provided on the mounting shafts 5, 5... of these movable blades 4, 4... are connected to the crosshead 7 provided at the tip of the blade angle operating shaft 2 and the links 8, 8... The movable blades 4, 4, .

Further, a servo cylinder 9 is provided at the other end (upper end in FIG. 4) of the rotating shaft 1, and a servo piston 10 connected to the blade angle operating shaft 2 is housed within the servo cylinder 9. The servo cylinder 9 is
It is connected by a joint 12 to the shaft of an electric motor (not shown) that is placed and fixed on a motor stand 11 . Then, an oil supply ring 14 fixed to the foundation 13 is fitted to the outer periphery of the rotating shaft 1, and one of the two pressure oil guide holes 15 and 16 provided in the oil supply ring 14 connects the rotating shaft 1 and the servo cylinder 9. The inside of the servo cylinder 9 is divided into two chambers (the fourth
The other chamber communicates with the other chamber (the lower chamber in FIG. 4) in the servo cylinder 9 through a hole 18 passing through the rotating shaft 1. and,
Pressure oil guide holes 15 and 16 communicate with a pressure oil source 20 via a four-way switching valve 19.

Further, a connecting rod 21 is axially movable and sealingly penetrates the upper wall of the servo cylinder 9, one end of which is fixed to the servo piston 10, and the other end is axially movable on the outside of the rotating shaft 1. It is fixed to a movable annular follower wheel 22. A swinging end of a lever 24 swingably provided on the shaft 23 is engaged with the follower wheel 22 . This shaft 23 is provided with an output signal generator (not shown), and an output signal corresponding to the rotation angle of the shaft 23 is output. and,
This output signal and the setting signal set and outputted by the blade angle setting device 25 are given to a comparison amplifier 26, and the four-way switching valve 19 is switched and controlled by the output of the comparison amplifier 26 so that the output signal and the setting signal match. .

In such a configuration, when the electric motor is rotationally driven, the rotating shaft 1 rotates via the joint 12, and the movable blades 4, 4, .
It rotates around the axis to generate lift.

Here, if the output signal output from the output signal generator and the setting signal set and output by the blade angle setting device 25 match, the comparator amplifier 26 does not generate an output, and the pressure oil guide hole 15, Pressure oil is not introduced into any of the servo pistons 16 and the servo piston 10 does not move in the axial direction. The blade angle operating shaft 2 rotates together with the rotary shaft 1, and the angles of the movable blades 4, 4, . . . do not change.

By the way, if the output signal output from the output signal generator and the setting signal output from the blade angle setting device 25 do not match, the comparison amplifier 26 switches the four-way switching valve 19 to adjust the pressure oil guide holes 15 and 16. The servo piston 10 is moved in the axial direction by introducing pressure oil into one of the pistons and draining the oil from the other. As the servo piston 10 moves, the lever 24 swings, and when the output signal from the output signal generator provided on the shaft 23 changes and matches the set signal, the output from the comparator amplifier 26 disappears and The switching valve 19 is switched and the servo piston 1
0's axial movement stops. As a result, the blade angle operating shaft 2 connected to the servo piston 10 is servo-controlled in accordance with the setting signal set by the blade angle setting device 25. Then, by the axial movement of the blade angle operating shaft 2, the mounting shafts 5, 5... are rotated via the crosshead 7, links 8, 8... and arms 6, 6..., and the movable blades 4, 4... The angle is adjusted.

(Problem to be solved by the invention) By the way, in the above-mentioned conventional movable blade fluid machine, the position of the servo piston 10 is set to the connecting rod 21.
However, the following wheel 22 is rotated together with the rotating shaft 1, and if the following wheel 22 is not rotated on a plane perpendicular to the axis of the rotating shaft 1, the lever The swing end of the shaft 24 swings, and the rotation angle of the shaft 23 is not constant. For this reason, the output signal generator does not output an output signal that accurately corresponds to the axial position of the blade angle control shaft 2, making accurate servo control difficult. For this reason, the follower wheel 22 must be accurately assembled on a plane perpendicular to the axis of the rotary shaft 1, which poses a problem in that a skilled worker requires a lot of work time. Furthermore, even when the rotating shaft 1 undergoes center runout due to hydrodynamic excitation force due to switching of operating conditions or excitation force due to earthquakes, the swing end of the lever 24 swings and the output signal generator is turned off. There is a problem that the output signal tends to change.

Note that a technique for detecting the axial position of a metal disk corresponding to the follower wheel 22 using a single magnetic proximity sensor is disclosed in Japanese Utility Model Application Publication No. 60-90987; However, there is a problem in that the metal disk must be reliably assembled on a plane perpendicular to the axis of the rotating shaft, making the assembly work difficult. If the metal disk is not assembled perpendicular to the rotation axis, the signal detected by the magnetic proximity sensor will contain pulsations. Furthermore, in this conventional technology, the axial movement of the metal disc is detected as a change in axial distance using a magnetic proximity sensor, and in the case of large movable blade fluid machines, the blade angle is controlled. The axial movement of the axis is 100mm.
Magnetic proximity sensors that can measure such large changes in distance are special and expensive, making the entire device expensive.

The purpose of the present invention was to solve the above-mentioned problems of conventional movable blade fluid machines. An object of the present invention is to provide a movable blade fluid machine in which the axial position of the blade can be reliably servo controlled.

(Means for Solving the Problem) In order to achieve the above object, the movable blade fluid machine of the present invention includes a blade angle operating shaft that is movable in the axial direction and is provided within the rotating shaft, and the blade angle operating shaft is moved. In the movable blade fluid machine that adjusts the angle of a movable blade provided at the tip of the rotating shaft, an annular interlocking member that moves in the axial direction in conjunction with the blade angle operating shaft is disposed outside the rotating shaft. A plurality of non-contact sensors are installed on the outer periphery of the annular interlocking member at positions equally divided concentrically from the direction perpendicular to the axis, and the output signal changes by detecting the axial movement of the annular interlocking member from the direction perpendicular to the axis. A type position detector is provided, and the output signals of the plurality of non-contact type position detectors are provided to a computing unit to generate a computed output signal corresponding to the sum of the output signals, and the computed output signal and the blade angle are The blade angle control shaft is configured to be servo-controlled by a setting signal output from a setting device.

(Function) An annular interlocking member that moves in the axial direction in conjunction with the blade angle operating shaft is provided, and a plurality of non-contact members are placed on the outer periphery of the annular interlocking member at positions equally divided on a concentric circle, facing from a direction perpendicular to the axis. Since a contact type position detector is installed and a calculation output signal corresponding to the sum of these output signals is output from the calculation unit, the axis of the annular interlocking member does not coincide with the axis of the rotating shaft. Even if there is a sideways shake, etc.,
The sum of the output signals from the plurality of non-contact position detectors is approximately constant, and a stable calculation output signal can be obtained from the calculation unit according to the axial position of the blade angle operation axis. In addition, since the non-contact position detector is arranged facing the outer periphery of the annular interlocking member from the direction perpendicular to the axis,
A large amount of displacement in the axial movement of this annular interlocking member can be converted into a change amount in a small range and measured.

(Description of Embodiments) Hereinafter, embodiments of the present invention will be described with reference to FIG. FIG. 1 is a longitudinal sectional view of a main part showing a mechanism for detecting the axial position of a blade angle operating shaft of a movable blade fluid machine according to the present invention. In FIG. 1, the same members as those in FIG. 4 are given the same reference numerals and redundant explanations will be omitted.

In FIG. 1, a plurality of connecting rods 21, 21 are movable in the axial direction of the upper wall of the servo cylinder 9, are hermetically penetrated at positions symmetrical to the axis of the rotating shaft 1, and one end of each rod is axially movable. It is fixed to the servo piston 10, and its other end is fixed to an annular interlocking member 30 which is movable in the axial direction outside the rotating shaft 1 and is made of a tapered ferromagnetic metal cylinder whose outer periphery widens downward. ing. Further, two magnetic proximity sensors 31, 31 as non-contact type position detectors are disposed on the outer periphery of the annular interlocking member 30 in positions symmetrical to the axis of the rotating shaft 1, facing from a direction perpendicular to the axis. These magnetic proximity sensors 3
A calculation unit 32 calculates an addition value or an average value of the output signals output from the output signals 1 and 31, and outputs the resultant value as a calculation output signal. The comparator output signal and the setting signal output from the blade angle setter 25 are compared by a comparator amplifier 26, and the four-way switching valve 19 is controlled.

In this configuration, the axial position of the annular interlocking member 30 changes in conjunction with the axial position of the blade angle operation shaft 2, and the distance from the magnetic proximity sensors 31, 31 changes due to the taper of the outer periphery of the annular interlocking member 30. The output signal changes. In addition, magnetic proximity sensor 3
Reference numerals 1 and 31 are equipped with high-frequency coils whose inductance changes due to the eddy current effect using the annular interlocking member 30 as a sensitive piece, and the output voltage changes due to the change in inductance.

Here, if the axis of the annular interlocking member 30 is misaligned or tilted with respect to the axis of the rotating shaft 1, the two magnetic proximity sensors 31, 31 are alternately connected to each other, compared to a case where the axes are aligned. One output signal becomes small and the other output signal becomes large. However, since the two magnetic proximity sensors 31, 31 are arranged at symmetrical positions, as the output signal of one becomes smaller, the output signal of the other becomes larger.
The calculation output signal, which is an added value or an average value, output from the calculation unit 32 is approximately constant.

This calculated output signal accurately corresponds to the axial position of the blade angle operating shaft 2 and is stable, allowing accurate servo control of the axial position of the blade angle operating shaft 2.

Further, a large amount of displacement in the axial direction of the annular interlocking member 30 is converted into a small amount of change in the distance between the annular interlocking member 30 and the magnetic proximity sensors 31, 31, depending on the taper angle of the outer periphery of the annular interlocking member 30.
Therefore, by appropriately setting the angle of the taper, a large amount of displacement in the axial direction of the annular interlocking member 30 can be controlled by a distance in the direction perpendicular to the axis in a small range corresponding to the measurement range of the magnetic proximity sensors 31, 31. It can be converted into a change amount, and a commercially available inexpensive magnetic proximity sensor can be used even when measuring a large movable blade fluid machine.

FIGS. 2 and 3 show other embodiments in which an optical sensor is used as a non-contact position detector for a movable blade fluid machine according to the present invention. FIG. 2 is a longitudinal sectional view of a main part, and FIG. 3 is a view taken along arrow A in FIG.

In Figures 2 and 3, connecting rods 21, 2
The annular interlocking member 40 fixed to 1 has a cylindrical shape, and has triangular windows 41, 4 on the side that expand to one side in the axial direction.
1 are drilled axially symmetrically, and these triangular windows 41, 41
Photosensors 42, 42, in which a light receiving element and a light emitting element are arranged in such a way as to sandwich the light receiving element and the light emitting element, are arranged symmetrically about the axis of the rotating shaft 1. The amount of light received by the light receiving element changes depending on the axial position of the annular interlocking member 40, and the impedance of the light receiving element is appropriately converted into a voltage or the like and used as an output signal.

In such a configuration, even if the axis of the annular interlocking member 40 is deviated from or tilted from the axis of the rotating shaft 1,
The sum or average value of the output signals from the symmetrically arranged optical sensors 42, 42 is approximately constant.
Further, due to the shape of the triangular windows 41, 41 of the annular interlocking member 40, the amount of displacement in the axial direction of the annular interlocking member 40 can be converted into a change in the amount of light received by the optical sensors 42, 42 within an appropriate range.

In the above embodiment, two magnetic proximity sensors 31, 31 and two optical sensors 42, 42 as non-contact position detectors are arranged symmetrically with respect to the rotation axis 1. Not limited to 2
It is also possible to arrange more than one non-contact type position detector at equally divided positions on a concentric circle, and have the arithmetic unit 32 output the sum or average value of these output signals as a calculated output signal. In addition, the optical sensors 42, 42
The sensor is not limited to the transmission type as in the above embodiment, but may be a reflection type.Furthermore, the non-contact position detector is not limited to the above embodiment, but may be constructed using a Hall element or the like. The annular interlocking members 30 and 40 as sensitive pieces are not limited to cylinders, but may be disk-shaped. Furthermore, the movable blade fluid machine of the present invention can be applied not only to pumps but also to water turbines, wind turbines, headwind machines, and the like. Further, the blade angle operating shaft 2 may be mechanically moved in the axial direction.

(Effect of the invention) As explained above, according to the movable blade fluid machine of the invention, even if the axis of the annular interlocking member is deviated from or tilted from the axis of the rotating shaft, the blade angle It is possible to obtain a stable calculation output signal that accurately corresponds to the axial position of the operating shaft, and accurate servo control is possible, so assembly errors in the annular interlocking member are tolerated, making assembly and maintenance inspection easy. In addition, a stable calculation output signal can be obtained even with respect to center runout of the rotating shaft, and servo control can be performed accurately. In addition, it is possible to convert the amount of displacement of the axial movement of the annular interlocking member that is linked to the axial movement of the blade angle operation shaft into an appropriate amount of change according to the measurement range of the non-contact position detector. This has an excellent effect in that inexpensive non-contact position detectors that are commercially available in large quantities can be used, and the entire device can be made inexpensive.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal cross-sectional view of the main part of the mechanism for detecting the axial position of the blade angle operating axis of the movable blade fluid machine of the present invention, and FIG. FIG. 3 is a vertical sectional view of a main part of another embodiment using an optical sensor as a non-contact position detector, FIG. 3 is a view taken in the direction of arrow A in FIG. 2, and FIG. FIG. 2 is a vertical cross-sectional view of an example of a fluid machine. DESCRIPTION OF SYMBOLS 1... Rotation axis, 2... Blade angle operation axis, 4... Movable blade, 25... Blade angle setter, 30, 40... Annular interlocking member, 31... Magnetic proximity sensor, 32... Arithmetic unit, 42...Light sensor.

Claims (1)

[Claims for Utility Model Registration] (1) A blade angle operating shaft is provided within the rotating shaft so as to be movable in the axial direction, and movement of the blade angle operating shaft allows the movable blade provided at the tip of the rotating shaft to be moved. In a movable blade fluid machine that adjusts an angle, an annular interlocking member that moves in the axial direction in conjunction with the blade angle operating shaft is disposed outside the rotating shaft, and the outer periphery of the annular interlocking member is faced from a direction perpendicular to the axis. A plurality of non-contact type position detectors that detect the axial movement of the annular interlocking member from a direction perpendicular to the axis and change the output signal are arranged at positions equally divided on a concentric circle by the plurality of non-contact type position detectors. The output signal of the shape position detector is given to a calculation unit to generate a calculation output signal according to the sum of the output signals, and the blade angle is controlled by this calculation output signal and the setting signal output from the blade angle setting device. A movable wing fluid machine characterized in that the axis is configured to be servo controlled. (2) The movable wing according to claim 1, wherein the annular interlocking member is a cylindrical body with a tapered outer periphery, and the non-contact position detector is a magnetic proximity sensor. Fluid machinery.