JPS63295806A - Turbine turning device - Google Patents

Abstract

PURPOSE:To permit the certain turning operation under all conditions by interlocking-connecting the output shafts of at least two torque converters through a one-way clutch. CONSTITUTION:The output shafts of torque converters 21a and 21b having different characteristics are interlocking-connected through a one-way clutch 22, and the gear 2 on the output side of the one-way clutch 22 is meshed with the gear 4 on the input side of a reduction gear group 3. When a rotor 9 revolves at a low speed, the sum of each output shaft torque of the torque converters 21a and 21b is applied onto the rotor 9 through a gear group 3, and when the speed of the rotor 9 becomes high, and the resistance reduces in comparison with a prescribed value, only one torque converter acts onto the output side by the action of the one-way clutch 22, and the torque is applied onto the gear group 3. In other words, the starting torque is increased by using two converters, and the output shaft torque having the low torque during revolution can be obtained, and the smooth turning revolution is permitted.

Description

[Detailed Description of the Invention] [Objective of the Invention] (Industrial Application Field) The present invention is provided in a rotating machine such as a steam turbine, and is used to straighten a rotor before starting or during cooling after stopping. The present invention relates to a turning device that rotates a turbine rotor at a low speed to prevent deformation of the rotor.

(Prior art) In general, in rotating machines such as turbines that use high-temperature steam, gas, etc. as a working fluid, it is necessary to minimize the bending of the turbine rotor in order to suppress vibrations during normal operation. . Therefore, when the turbine is started after being stopped for a long period of time, the turbine rotor is rotated at several revolutions per minute to correct the bending that occurred during the stoppage. In addition, since there is a risk that the turbine rotor will be permanently deformed due to residual heat immediately after it is stopped, the turbine rotor is rotated at several revolutions per minute during the cooling period, as in the case of startup. A device that rotates this turbine rotor at a low speed is a turning device.

That is, FIGS. 6 and 7 are diagrams showing a schematic configuration of a turning device used in a steam turbine, in which a gear 2 provided on the output shaft of a motor 1 is connected to a group of reduction gears 3.
The rotational force of the gear 2 is applied to the gear 4 of the reduction gear group 3. 5. 6. 7.8, the speed is sequentially reduced and transmitted to a gear 10 fixed to the turbine rotor shaft 9.

Incidentally, since the turning operation is performed only while the turbine is stopped, the gears 8 and 10 are disengaged while the turbine is in operation.

That is, FIG. 8 is an explanatory diagram of the operating mechanism of the turning device, and each gear from gear 4 to gear 8 constituting reduction gear group 3 is pivotally mounted on a carrier 11, and the carrier 11 is connected to gear 4 and gear 8. It is possible to swing up and down about the same axis O as that of No. 5. The carrier 11 is suspended by a meshing lever 12 so as not to swing downward more than necessary, and the other end of the meshing lever 12 is connected to a piston rod 13a of an air cylinder 13. Also, carrier 1
A stopper 14 is provided on the top surface of the stopper 1.
4 comes into contact with the base 15 and receives the reaction force of the rotational force of each gear, and the height can be adjusted so that the gears 8 and 10 mesh properly. On the other hand, a toggle mechanism 16 is connected to the engagement lever 12 so that the gears 8 and 10 can be engaged and disengaged accurately. The structure is such that the carrier 11 does not move unstablely due to force. Note that the reference numeral 17 in the figure is a balanced weight.

Therefore, before the turning device is activated, the carrier 11 is at the bottom dead center position as shown in FIG. 8, and the gears 8 and 10 are in a non-meshing state.

Therefore, when operating air is supplied to the air cylinder 13, the carrier 11 is pulled up by overcoming the reaction force of the toggle mechanism 16, and the gears 8 and 10 come into contact with each other.

The meshing state between the gears 8 and 10 differs depending on their relative positions, but the meshing is incomplete if the gears 8 and 10 are in contact with each other, regardless of the relative position. However, when the motor 1 is started in this state, the gear 10 does not rotate because the rotational resistance of the rotor 9 is large, and the gear 8
When only the carrier 11 rotates and the stopper 14 comes into contact with the base 15, the gears 8 and 10 are fully engaged and the gear 10 starts rotating. In this state, the reaction force of the gear 10 is always transferred to the carrier 11 via the gear 8.
When this reaction force becomes larger than the weight of the carrier 11 and the spring force of the toggle mechanism 16, the carrier 11 receives the reaction force from the stopper 14 and is maintained in the engaged position. After that, the force of the air cylinder 13 is no longer needed, so the supply of working air is stopped, and continuous turning operation begins.

If the turbine is started while in continuous turning operation,
Torque is transmitted from the rotor 9 to the gear 10, and the reaction force in the southeast 8 begins to decrease. By the way, since the motor 1 of the turning device generally uses an induction motor, when the reaction force of the gear 8 is reduced and the rotational speed of the motor 1 matches the synchronous rotational speed, the meshing between the gears 8 and 10 will be reduced. Becomes incomplete. Then, when the gear 10 is further accelerated to a speed exceeding the synchronous rotation speed of the motor 1, the gear 10 pushes the gear 8 downward, and the carrier 11 becomes the state shown in FIG.

(Problem to be solved by the invention) By the way, in a turning device, as mentioned above, the motor 1
Since an induction motor is used for this purpose, the motor 1 is accelerated to the turning speed immediately after starting. However, in the state before turning operation, the rotor 9
Since the rotor is stationary, a large-capacity motor 1 is required to overcome static friction and accelerate the rotor to a turning speed of several revolutions per minute.

On the other hand, since the resistance on the rotor 9 side during turning operation becomes dynamic friction, the 82 required of the motor 1 differs by several times or more between when the motor 1 is started and during turning operation.

Therefore, if a large-capacity motor 1 is selected, the rotor 9 will be accelerated immediately after the motor is started, and the rotation speed of the gear 10 will instantaneously exceed the synchronous rotation speed of the motor 1, causing both gears 8
, 10 becomes incomplete, resulting in the inconvenience that the meshes disengage. Moreover, since the resistance on the rotor 9 side changes depending on the operating conditions of the turbine and over time, the above-mentioned problems may become more severe.

Further, in large turbines, a hydraulic device is installed to jack up the turbine rotor to reduce rotor resistance during turning, but in such a turbine, the resistance of the turbine rotor becomes extremely small.

FIG. 9 is a diagram showing the relationship between the turning speed and the rotational resistance (torque) of the rotor. The torque when the turning speed is O, that is, the starting torque is indicated by a, and when turning starts, the rotor's rotational resistance (torque) The rotational resistance suddenly decreases, and the rotational resistance during turning operation becomes as shown by b. According to the actual measurement results, a.

Both b changes depending on the operating condition of the turbine and over time, and b may range from 110 to 1/100 of a.

However, in such a turbine, the rotor may naturally rotate beyond the turning speed due to disturbances, and it may become impossible to perform turning by meshing gears. In such a case, it is possible to set the turning speed higher than the rotor's natural rotation speed, but this would mean rotating the rotor at high speed, which has large rotor resistance and inertia. , the motor becomes larger. As the motor becomes larger in size, its output torque increases, and the accelerating force of the rotor also increases, making it more difficult to start, accelerate, and then continuously operate the rotor.

In view of these points, it is an object of the present invention to solve the problems of the above-mentioned conventional techniques and to provide a turning device in which gears can mesh with each other reliably under any conditions.

[Structure of the invention]

(Means for Solving the Problems) The present invention includes a motor, a gear group for reducing the rotation speed of the motor and transmitting power to a gear integrally fixed to the shaft end of a turbine rotor; A turbine turning device comprising a device for meshing or disengaging the output side gear of the gear group and the turbine rotor side gear,
The output shafts of at least two torque converters having different characteristics that are rotationally driven by the motor are interlocked and connected via a one-way clutch, and the gear provided on the output side of the one-way clutch is connected to the input side gear of the gear group. It is characterized by being interlocked with the

(Function) When each torque converter is started at the same time, if the rotor resistance is greater than a predetermined value, each torque converter will all work, and the sum of the output shaft torques of each torque converter will be output as output torque, and the rotor resistance will be reduced. When it becomes smaller than the predetermined value, only one torque converter acts on the output side due to the action of the one-way clutch, and the output torque of that one torque converter is applied to the gear group. In other words, by using at least two torque converters, it is possible to obtain a large starting torque and an output shaft torque with a low torque during rotation, which has characteristics that closely match the rotor resistance shown in Figure 9. It can be done.

(Example) Hereinafter, an example of the present invention will be described with reference to FIGS. 1 to 5.

In FIGS. 1 and 2, a gear 10 fixed to the shaft end of a turbine rotor 9 includes a gear 4.
The gear 8 on the output side of the gear group consisting of gears 5, 6, 7, and 8 can be engaged or disengaged.

By the way, the base 15 has motors 20a and 20, respectively.
Torque converters 21a and 21b having mutually different characteristics are supported. A one-way clutch 22 is connected to the output shaft of the torque converter 21a.
A gear 2 that meshes with a gear 4 at the input end of the gear group is fixed to the output end of the gear.

-i, chain wheels 23.24 are provided on the output shaft of the torque converter 21b and the output side of the one-way clutch 22, and both chain wheels 23.2
A Cheno 25 is wrapped between the four. The gears of the Cheno wheels 23 and 24 are determined so that the speed increasing ratio is 2 to 3 times. Further, the motors 20a and 20b are always rotated at a constant rotation speed Nla''Lb, and the rotation speed N2 of the gear 2 changes in accordance with the resistance of the rotor 9.

FIG. 3 is a diagram showing the relationship between the output shaft rotation speed N2 and the output shaft torque T of the torque converter in the above embodiment,
In this case, both torque converters are assumed to have the same capacity, and the rotation speed of the torque converter 21b is doubled by the Cheno wheel 23 and the Cheno wheel 24 of the one-way clutch 22. Here, T1 is the output shaft torque when the torque converter and gear group are directly connected,
T2 indicates the output shaft torque when the speed is doubled between the torque converter and the gear group, and T1 and T2 are inversely proportional to the speed increase ratio, and as mentioned above, when the speed increase ratio is doubled, two torque converter 21a.

When 21b are operated simultaneously, the output shaft torque T becomes T-T1 + T2 with the output from both torque converters added when the output shaft rotation speed N2 is in the range of 0 to 50%, and the starting torque is 150% of the TI torque. If this occurs and N2 becomes 50% or more, only torque T2 from torque converter 21b is output. That is, when N2 becomes 50% or more, the rotation speed on the output side of the one-way clutch 22 becomes higher than the rotation speed of the output shaft of the torque converter 21a, so the output of the torque converter 21a is transferred to the one-way clutch 22.
will no longer be transmitted to the output side. Therefore, the starting torque can be increased at the time of starting when the rotor resistance is large, and the torque can be kept low while the rotor is rotating.

FIG. 4 is a diagram showing the change in output shaft torque when the characteristics of the torque converter 21b are selected to be more optimal. When the turning device is started now, a large starting torque is required due to the static friction of the rotor 9. Therefore, the rotor 9 remains stationary and the two torque converters 21a, 21
b output shaft torque T1. When T2 rises and overcomes static friction, the rotor 9 starts rotating, and the friction of the rotor 9,
The rotor 9 is accelerated along the curve T while following the inertial force.

That is, since the torque converter 21a is connected to the gear 2 via the one-way clutch 22, if the rotation speed N2 of the output shaft of the one-way clutch 22 is smaller than the rotation speed N2a of the output shaft of the torque converter 21a, the above-mentioned One-way clutch 22 is activated, and outputs from both torque converters 21a and 21b are applied to the output shaft of one-way clutch 22.

Therefore, when N increases and reaches Na larger than N2a, the one-way clutch 22 becomes inactive, and only the output from the torque converter 21b is transmitted to the output shaft of the one-way clutch 22, and T ''
” The rotor 9 is further accelerated along the curve T2,
Continuous operation is performed at a point f where the resistance of the rotor 9 and the output shaft torque Tβ are balanced.

Note that the reduction ratio of the gear group of the turning device is set at the point e where the output shaft torque T of the torque converter becomes T-T2-aO.
, the turning rotation speed, that is, the rotation speed of the gear 10 is 2.
rpm to about 40 rpm.

On the other hand, if the resistance on the rotor 9 side changes due to disturbance or the like, the turning rotation speed changes accordingly.

In general, the turning speed of a turbine is sufficient to perform its function at a rotation speed of about 30 minutes per day, but in conventional turbines, it is set to about 1 to 5 rotations per minute due to constraints such as the size of the reduction gear. ing. However, since there are actually turbines that perform turning operations of several tens of revolutions per minute, it can be said that even if the turning speed changes as in the present invention, there is no effect on the turbine body.

Incidentally, in the above embodiment, a combination of two motors and two torque converters was shown, but as shown in FIG. 5, the motor 20a and the torque motor 21a are directly connected with one motor 20a, Motor 20a and torque converter 21b are connected to chain wheels 26, 27 and 2.
8 may be connected. In this case, the device can be made compact by simply increasing the size of the motor a little.

[Effects of the Invention] Since the present invention is configured as described above, when the rotor is at low speed, the total output of the plurality of torque converters is transmitted to the rotor via the reduction gear group, and when the rotor is at high speed, the output is transmitted to one torque converter. Only the output from the rotor is applied to the rotor, making it possible to obtain torque characteristics that match the resistance of the rotor.

Further, when the rotation speed is high, the change in the output shaft torque T2 of the torque converter can be made small, so that the acceleration of the rotor can be kept low and smooth turning rotation can be obtained. Moreover, as mentioned above, a torque characteristic that matches the rotor resistance is generated, so even if a sudden decrease in rotor resistance or a disturbance that accelerates the rotor occurs, the specified turning operation can be performed with the turning device connected. It can be continued.

[Brief explanation of the drawing]

Fig. 1 is a diagram showing the configuration of the turbine turning device of the present invention, Fig. 2 is a mechanical diagram of the same as above, and Fig. 3 is a diagram showing the change in output shaft torque with respect to the output shaft rotation speed when two torque converters are used. 4 is a characteristic diagram of the torque converter of the present invention, FIG. 5 is a mechanism diagram of another embodiment of the present invention, FIG. 6 is a diagram showing the configuration of a conventional turbine turning device, and FIG. FIG. 7 is a mechanical diagram of the same as above, FIG. 8 is an explanatory diagram showing the actuating device of the turbine turning device, and FIG. 9 is a resistance characteristic curve of the rotor. 2.4.5.6, 7.8.10...Gear, 9-o-ta, 20a, 20b...Motor, 21a. 21b...Torque converter, 22...One-way clutch, 23.24...Chain wheel, 25...
・Chen. Active 1 Artwork or middle white Number of rotations (N2) Also 3 figures 2 or axis rotation attack (N2) Delivery 4 figures also 5 figures escape 6 figures

Claims (1)

[Claims] A motor, a gear group for reducing the rotational speed of the motor and transmitting power to a gear integrally fixed to the shaft end of a turbine rotor, an output side gear of this gear group, and a gear on the turbine rotor side. and a device for engaging or disengaging the turbines, the output shafts of at least two torque converters having different characteristics that are rotationally driven by the motor are interlocked and connected via a one-way clutch, A turbine turning device characterized in that a gear provided on the output side of the one-way clutch is meshed with an input side gear of the gear group.