JPH0557160B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a shaft-driven power generator, and in particular, to preventing damage to a hydraulic motor that controls constant speed operation of a generator to ensure safe control operation. This invention relates to a shaft-driven power generator.

[Prior Art] As shown in Fig. 4, a shaft-driven power generator extracts part of the engine power from a power transmission shaft 1 which is rotationally driven by a marine engine or the like and transmits the engine power through a gear train 2 or the like. It drives the generator 3 to generate electricity.

In particular, the generator 3 needs to be rotated at a constant speed in order to obtain a constant frequency, whereas in marine engines, etc., the rotation speed frequently fluctuates due to disturbances such as waves, so the generator 3 and the power transmission shaft A differential planetary gear mechanism 4 is provided between the power generator 1 and the power generator 1 for making the rotational speed transmitted to the generator 3 constant.

In the differential planetary gear mechanism 4, a differential rotation input gear 7 is meshed with external teeth 6 formed on the outer periphery of an internal gear 5. This input gear 7 increases/decelerates the internal gear 5 in order to increase/decrease the revolving speed of the planetary gear 8 which transmits power while undergoing rotational speed fluctuations, thereby making the output rotational speed of the sun gear 9 constant. The speed ratio is variably controlled by driving in forward and reverse directions.

Drive control of the input gear 7 that operates the internal gear 5 is performed by a hydraulic circuit system 10. The hydraulic circuit system 10 includes a variable displacement hydraulic pump 11 and a hydraulic motor 12 connected by a sealed circuit 13. The hydraulic pump 11 moves from the driven shaft 14 to the gear 1
It is driven by the engine power supplied through the generator 5, and the tilting angle is controlled by a servo mechanism (not shown) according to the speed of the transmission circuit to the generator 3, and a considerable amount of hydraulic oil is supplied in the forward or reverse direction. It's starting to spit out. The discharged hydraulic fluid is sent to hydraulic motor 1
2 is rotated forward or reverse at a considerable speed, and as a result, the input gear 7 is driven to provide a speed ratio for constant speed.

[Problems to be Solved by the Invention] By the way, the hydraulic motor 12 is capable of controlling the input gear 7 with high precision against minute fluctuations in the rotational speed of the power transmission shaft 1.
It is itself rotated at extremely high speeds so that it can be controlled. Further, the constant speed control of the generator 3 is set based on the engine speed during normal navigation, that is, the rotation speed of the power transmission shaft 1 during normal operation, and when the speed of the power transmission shaft 1 is increased, the hydraulic motor 12 is It is reversely rotated at high speed to shift the speed ratio in the direction of deceleration, and when it is decelerated, it is rotated forward at high speed to shift the speed ratio in the direction of speed increase.

If the power transmission shaft 1 rotates at a high speed for some reason during navigation, the hydraulic pump 11 pumps a large amount of oil in response to fluctuations in the transmission rotation speed on the generator 3 side for constant speed control. As a result, the hydraulic motor 12 was over-rotated beyond the allowable rotation speed, and as a result, there was a risk of damage.

[Object of the Invention] The present invention was devised in view of the above-mentioned problems, and its purpose is to prevent damage to the hydraulic motor that controls the constant speed operation of the generator and ensure safe control operation. The aim is to provide a shaft-driven power generation device that can be used.

[Summary of the Invention] The present invention relates to a shaft-driven power generation device that operates a generator using part of the engine power extracted from the power transmission shaft of the engine. A hydraulic motor for controlling a differential planetary gear mechanism, a rotation speed detection means for obtaining a rotation speed of the hydraulic motor, and a control means for controlling a hydraulic pump based on an output signal of the rotation speed detection means. The hydraulic pump is controlled so that the motor does not exceed its permissible rotational speed.

[Embodiments] Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 shows a first embodiment of the invention.

A configuration for extracting a part of the engine stress from the power transmission shaft of the engine 16 and applying it to the driven shaft 14 to operate the generator 3 to supply power to the load 17, as well as a structure between the engine 16 and the generator 3. The configuration of the differential planetary gear mechanism 4 and the speed of the differential planetary gear mechanism 4 are provided to smooth out the fluctuating input side rotation speed Ve of the engine 16 side and make the transmission rotation speed Vg to the generator 3 constant. The configuration of the hydraulic circuit system 10 for variable control of the ratio is the same as that of the conventional example described above.

The feature of the present invention is that the hydraulic motor 12
It is in the control system to protect the engine from overspeeding.

As shown in the figure, a speed detector 18 is provided on the output side of the differential planetary gear mechanism 4 to detect the rotational speed Vg transmitted to the generator 3. A counter 19 is connected to the speed detector 18, and the counter 19 counts the rotation detection pulses output from the speed detector 18 to determine the transmission rotation speed Ng. The obtained transmission rotation speed Ng is calculated by the counter 19.
The transmission rotation speed to the generator 3 connected in parallel with the rotation speed setting device 20 is added to the set transmission rotation speed Ns outputted from the preset rotation speed setting device 20 at an addition point 21. Then, the rotation speed difference is calculated by a calculation unit 22 such as a known PID.
This is input to the servo mechanism 25 via the speed limiter 23 and the addition point 24, and the servo mechanism 25 controls the tilt angle θ of the hydraulic pump 11 according to the input rotation speed difference. As a result, a considerable amount of hydraulic oil is supplied from the hydraulic pump 11 to the hydraulic motor 12, and the hydraulic motor 12 is driven to rotate.

The speed limiter 23 is designed to prevent the hydraulic pump 11 from being damaged due to a drastic change in the tilt angle θ when the rotational speed deviation becomes large for some reason.

By the way, if the detected transmission rotation speed Ng and the set transmission rotation speed Ns are significantly different,
The tilting angle θ that should make them coincide is angularly displaced by a large amount, and the discharge amount of the hydraulic pump 11 becomes extremely large.
As a result, the rotational speed Vm of the hydraulic motor 12 is increased, and there is a possibility that the rotational speed of the hydraulic motor 12 may exceed the allowable rotational speed and become over-rotated.

In the present invention, this hydraulic motor 12
A speed detector 26 is provided as rotation speed detection means for detecting the rotation speed Vm of the motor. In this embodiment, the rotational speed of the internal gear 5, which has a constant relationship with the rotational speed Vm of the hydraulic motor 12, is detected. An overspeed controller 28 serving as a control means is connected to the speed detector 26 via a counter 27. This controller 28 compares and calculates the detected rotation speed Nm of the hydraulic motor 12 outputted from the counter 27 and the allowable rotation speed (speed) Na stored in advance therein, and the hydraulic motor 12 calculates the allowable rotation speed Na. The hydraulic pump 11 is controlled so as not to exceed the limit. This control is performed, for example, by limiting the amount of oil discharged from the hydraulic pump 11, such as by suppressing the amount of control of the tilting angle θ by the servo mechanism 25, or by cutting off fuel to the engine 16.

With this configuration, over-rotation of the hydraulic motor 12 can be prevented and the reliability of the shaft-driven power generator can be improved.

Furthermore, in the present invention, feedforward control can be achieved by adding the rotational speed Nm of the hydraulic motor 12 to the addition point 24 through the calculator 32. That is, the inventors of the present application have determined that the speed detector 18 is based on the knowledge that the rotation speed Nm of the hydraulic motor 12 corresponds to the speed ratio of the differential planetary gear mechanism 4.
By using this as a feed forward control signal that precedes the transmission rotation speed Ng detected by , so that appropriate feed forward control can be performed. Therefore, using the rotation speed Nm of the hydraulic motor 12 as a feed forward control signal, the detected transmission rotation speed
Generator 3 along with feedback control by Ng
The accuracy of constant speed control can be further improved.

FIG. 2 shows a second embodiment of the invention.

This embodiment is similar to the first embodiment except that instead of detecting the rotation speed Vg transmitted to the generator 3, the input side rotation speed Ve of the differential planetary gear mechanism 4 is detected. It is almost the same as.

In particular, in this embodiment, the input side rotational speed Ve,
Since there is the following relationship between the transmission rotational speed Vg and the rotational speed Vm of the hydraulic motor 12 as a characteristic of the differential planetary gear mechanism 4, the input side rotational speed Ve
The transmission rotation speed Vg is determined from the rotation speed Vm of the hydraulic motor 12 and the rotation speed Vm of the hydraulic motor 12.

Vg=(ρ+1)・Ve−ρ・Vm Ng=(ρ+1)・Ne−ρ・Vm (A) Here, ρ=ZA/Zs Za: Number of teeth of internal gear Zs: Number of teeth of sun gear Specifically is the rotational speed Nm detected by the speed detectors 26 and 29 and output from the counters 27 and 30,
The arithmetic unit 31 performs arithmetic processing on Ne.

The transmitted rotational speed Ng calculated here is based on data on the input side of the differential planetary gear mechanism 4, and precedes the rotational speed Vm of the hydraulic motor 12, so it is a feed forward control signal. used as. On the other hand, the rotational speed Vm of the hydraulic motor 12 serves as a feedback control signal.

FIG. 3 shows a third embodiment of the invention.

In this embodiment, instead of directly detecting the rotational speed Vm of the hydraulic motor 12, the input side rotational speed Ve and the transmission rotational speed Vg of the differential planetary gear mechanism are detected, and the above formula (A) is calculated. The system is configured such that the rotational speed Vm of the hydraulic motor 12 is determined by performing arithmetic processing on the basis of the calculation unit 31. Then, the rotation speed Nm of the hydraulic motor 12 determined through calculation processing is inputted to the overspeed controller 28, thereby achieving prevention of over-rotation of the hydraulic motor 12. On the other hand, the rotation speed Vm of the hydraulic motor 12 and the transmission rotation speed
Vg can be used as a signal for feedback control and feedback control, respectively.

[Effects of the Invention] In summary, the present invention exhibits the following excellent effects.

(1) By providing a rotation speed detection means for obtaining the rotation speed of the hydraulic motor, and a control means for controlling the hydraulic pump so that the hydraulic motor does not exceed its permissible rotation speed based on the output signal of this detection means. , damage caused by over-rotation of the hydraulic motor can be prevented and reliability can be improved.

(2) The obtained rotational speed of the hydraulic motor can be used to control the constant speed of the rotational speed transmitted to the generator, and the equipment for rotational speed detection means can be kept to the minimum necessary, simplifying the equipment and reducing costs. .

[Brief explanation of the drawing]

FIGS. 1 to 3 are system diagrams showing preferred embodiments of the present invention, and FIG. 4 is a schematic perspective view showing the general configuration of a shaft-driven power generator. In the figure, 1 is a power transmission shaft, 3 is a generator, 4 is a differential planetary gear mechanism, 11 is a hydraulic pump, 12 is a hydraulic motor, 16 is an engine, 26 is a speed detector as a rotational speed detection means, and 28 is a control This is an overspeed controller.

Claims (1)

[Claims] 1. In a shaft-driven power generation device that operates a generator with part of the engine power extracted from the power transmission shaft of the engine, a shaft drive generator is provided between the engine and the generator to control the rotational speed transmitted to the generator at a constant speed. a differential planetary gear mechanism for controlling the operation of the differential planetary gear mechanism, a hydraulic pump driven by the engine, and a hydraulic motor supplied with hydraulic oil from the hydraulic pump to be rotationally driven and controlling the operation of the differential planetary gear mechanism. , a rotational speed detection means for obtaining the rotational speed of the hydraulic motor, and a control means for controlling the hydraulic pump so that the hydraulic motor does not exceed its permissible rotational speed based on the output signal of the rotational speed detection means. A shaft-driven power generating device characterized by comprising: