JPH071031B2 - Deflector drive for Pelton turbine - Google Patents

Description

The present invention relates to a deflector drive device for a Pelton turbine using an electric servomotor.

[Conventional technology]

The Pelton turbine has a deflector between the bucket wheel and the nozzle.When the load on the turbine suddenly decreases, the deflector works to bend the direction of the jet water jet and remove it from the bucket wheel. Needle valve gradually closed to reduce running water.

This is to prevent the direct hammering of the needle valve, which causes a water hammer effect in the penstock and causes a danger due to an abnormal rise in water pressure. If the jet water jet cannot be blocked by the deflector when the load on the Pelton turbine is cut off, the bucket wheel may rotate at an unrestrained speed.
The Pelton turbine is destroyed by the excessive centrifugal force. In order to avoid such a very dangerous state, a hydraulic servomotor or an electric servomotor is conventionally used as a deflector drive device of this kind.

[Problems to be solved by the invention]

The deflector drive device using a hydraulic servomotor has a large driving force and good responsiveness, but the pump, pressure oil tank, piping,
Since a hydraulic system such as a control valve is required, there has been a problem in that maintenance and management of oil and a hydraulic system are expensive.

In addition, the deflector drive device using the electric servomotor does not use hydraulic pressure, so there is no problem of using the hydraulic servomotor and the response is good, but compressed air, springs, etc. are used as an emergency stop device at the time of power loss. Since it is used, there is a problem that the control mechanism is complicated and the device becomes expensive.

The above-mentioned conventional device is not only expensive due to its complicated structure, but also the operational reliability that it operates reliably as an emergency stop device of the Pelton turbine is an essential requirement, and in order to meet this, Requires constant maintenance and inspection, and if possible, a device with a simple and simple structure is desired.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above problems and provide a deflector drive device for a Pelton turbine that uses an electric servomotor and has a simple and simple structure and high operation reliability.

[Means for solving problems]

In order to solve the above-mentioned problems, the present invention relates to a deflector device for deflecting the direction of jet water jet from a nozzle outlet of a Pelton turbine, and an electric servomotor device for driving the deflector and having no self-braking action. A deflector drive device for a Pelton turbine, comprising: a weight device for driving the deflector in an emergency stop direction; and a shock absorber for absorbing an impact force at the operation stop end of the weight device. And

[Work]

The deflector device bends the direction of the jet water jet from the nozzle outlet of the Pelton turbine, and when the Pelton turbine is in normal driving operation during sudden load reduction or load shedding, the deflector is driven and operated by the electric servomotor device. The deflector is driven in the emergency stop direction by a weight device in an emergency when the speed governor of the Pelton turbine is lost or power is lost. The electric servomotor device connected during this emergency drive is reversely driven by an external force, but since it does not have a self-braking action, this drive is not hindered. The shock absorber absorbs the impact force at the end of the motion stop of the weight device.

〔Example〕

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

FIG. 1 shows a cross section of a Pelton turbine, in which a bucket wheel 2 having a plurality of buckets 1 mounted on the outer circumference is fixed to a main shaft 3 and is rotatably supported by a turbine housing 4. The water turbine housing 4 is provided with one or a plurality of nozzles 5, and the nozzle 5 is provided with a needle valve 7 driven in the direction of arrow 6.
The bucket 1 receives the jet of jetted water from the nozzle 5, the bucket wheel 2 rotates, and the needle valve 7 is driven in the direction of the arrow 6, so that the jetted water from the nozzle outlet 8 responds to the load variation. Adjust the amount of water in the jet.

A deflector 9 is provided between the bucket wheel 2 and the nozzle outlet 8.
Is attached to a support shaft 11 rotatably supported by a bracket 10 provided on the nozzle 5 together with a lever 12 and a lever 13.

An electric servomotor device 16 for converting the rotation of the electric motor into a linear motion in the direction of arrow 15 by means of a ball screw 14 is rotatably supported by a pedestal 18 on a foundation 17 by means of a pin joint. The tip end of the ball screw 14 is rotatably pin-joined to the lever 12, and the electric servomotor device 16 drives the deflector 9 with the support shaft 11 as a rotation shaft.

A weight device 19 is rotatably pin-joined to the lever 13, and the weight device 19 drives the deflector 9 in a clockwise direction with the support shaft 11 as a rotation axis, that is, in an emergency, in the emergency stop direction. To do.

A shock absorber 20 is provided on the foundation 17 at the end of the motion of the weight device 19, and absorbs the impact force at the end of the motion of the weight device 19.

When the ball screw 14 is driven by an external force in the direction of arrow 15 by an external force at the time of a power failure, the electric servomotor device 16 has a structure in which the electric motor idles and has no self-braking action.

During normal operation of the Pelton turbine, the power is turned on and the electric servomotor device 16 drives and holds the deflector 9 in a normal position against the drive of the weight device 19 in the emergency stop direction.

When the load on the turbine suddenly decreases, an electric servomotor device
16, the deflector 9 is actuated to deflect the jet water jet to remove it from the bucket wheel 2, while the needle valve 7 is gradually closed to reduce running water. This is because, as described above, when the direct needle valve 7 is suddenly closed, a water hammer effect is caused in the hydraulic pipe, and a danger is caused by an abnormal increase in water pressure.

If there is no weight device, the electric servomotor device
No. 16 shows that the deflector 9 remains stopped at a certain opening because the electric motor does not operate when the speed governor of the Pelton turbine is lost or the power is lost. If the jet cannot be shut off and the bucket wheel 2 rotates at an unrestrained speed, the Pelton turbine may be destroyed by an excessive centrifugal force.

In order to avoid such a very dangerous state, the present invention ensures that the deflector 9 can be in the closed position for removing the jet water jet from the bucket vehicle 2 even in such an emergency, in an emergency. Weight device 19 lever 13 when lost
The deflector 9 is reliably driven to the closed position in the emergency stop direction via. During this time, the electric servomotor device 16 is driven by an external force via the lever 12, but since it has a structure that does not have a self-braking action as described above, it does not hinder the drive in the emergency stop direction. As a result, the deflector 9 becomes a self-closing type.

Since there is no device for restraining the weight device 19 at the time of driving to the closed position, the drive operation device is subject to a large impact force when the deflector 9 is fully closed and the deflector 9 is fully closed. In order to absorb this impact force, a shock absorber 20 with which the weight device 19 engages when the deflector 9 reaches the vicinity of the fully closed state is provided, and the impact force at the end of the motion stop of the weight device 19 is absorbed. To do.

The second embodiment of the present invention is, as shown in FIG. 2, an electric servomotor device which does not have a self-braking action for driving and operating a deflector, and is attached with a deflector via a speed reducer such as a gear device driven by an electric motor. An electric device 16 'for directly rotating and operating the supported shaft is attached. When a worm gear device is used as the gear device, it is necessary to design the worm so that self-braking of the worm does not occur. Also according to the second embodiment, since the electric device 16 'does not have a self-braking action, it does not hinder the driving in the emergency stop direction, and instead of the linear motion of the first embodiment, It is possible to drive and operate a self-closing type deflector by rotating motion.

〔The invention's effect〕

The present invention relates to a deflector device for deflecting a jet water jet from a nozzle outlet of a Pelton turbine, which is an electric servomotor which does not have the self-braking action of a worm gear device or a general screw device under a certain condition. Since the deflector is driven by the device to drive the deflector in the emergency stop direction, and the weight device has a shock absorber for absorbing the impact force at the end of the motion stop of the weight device. When normal, the electric servomotor device drives and holds the deflector in a normal position.

When the load on the water turbine is suddenly reduced, the electric servomotor device activates the deflector to deflect the jet water jet. The weight device reliably drives the deflector to the closed position through the lever 13 in the emergency stop direction even in an emergency such as a failure of the speed governor of the Pelton turbine or a loss of power.

For this reason, the deflector is of a self-closing type, and the shock absorber absorbs the impact force at the end of the motion stop of the weight device.

When closing the deflector only with an emergency weight device, there is no means to control the closing operation time.However, even if the deflector closes extremely quickly, the Pelton turbine causes a water hammer effect in the penstock. The present invention is characterized by not causing an abnormal increase in water pressure or an abnormal increase in speed of the rotating part. Therefore, the present invention has a simple and simple structure and is highly reliable in operation. It is possible to provide a deflector drive device for a Pelton turbine that achieves various effects.

[Brief description of drawings]

FIG. 1 is a sectional view of a deflector driving device showing a first embodiment of the present invention, and FIG. 2 is a sectional view of a deflector driving device showing a second embodiment of the present invention. 2 ... Bucket wheel, 7 ... Needle valve, 8 ... Nozzle outlet, 9 ... Deflector, 14 ... Ball screw, 16 ... Electric servomotor device, 16 '... Electric device, 19 ... Weight device , 20 …… Shock absorber.

Claims (1)

[Claims] 1. A deflector device for deflecting a jet water jet from a nozzle outlet of a Pelton turbine, wherein the deflector is driven and operated, and an electric servomotor device having no self-braking action and a deflector are driven in an emergency stop direction. A deflector drive device for a Pelton turbine, comprising: a weight device; and a shock absorber for absorbing an impact force at the end of motion stop of the weight device.