JP2004197573A - Fluid feeding system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fluid feeding system capable of improving the reliability by minimizing the increase in weight, miniaturizing and weight-saving thereof. <P>SOLUTION: A fuel pump 2 is made a triple gear pump having a first pressurizing part 9 and a second pressurizing part 10. A flow control unit 3 is comprised of a first flow control unit 3a for feeding a fuel of a set flow out of a fuel delivered from the first pressurizing part 9 into a burner 5 with the excess returning into the inlet side, and a second flow unit 3b for feeding the fuel of the set flow out of the fuel delivered from second pressurizing part 10 into the burner with the excess returning into the inlet side. Further, the control unit 3 is provided with a first change-over valve 40a capable of unloading the first pressurizing part 9 while the first flow control unit 3a stops, and the second change-over valve 40b capable of unloading the second pressurizing part 10 while the second flow control unit 3b stops. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a system for supplying a fluid such as fuel.
[0002]
[Prior art]
Generally, as shown in FIG. 3, a fuel supply system for a jet engine (turbofan engine) used in an aircraft or the like boosts fuel from a fuel tank 1 by a fuel pump 2 as a booster, and adjusts the position of a throttle lever and the like. Is transmitted to the combustor 5 of the jet engine, and the excess is sent back to the inlet side of the fuel pump 2.
[0003]
Here, a gear pump as shown in FIG. 3 is conventionally used as the fuel pump 2, and in this case, the rotational movement transmitted from the engine is controlled by a gear box (AGB: accession gear box) as an engine accessory. The gear pump is driven via the gears in the parentheses. Therefore, the discharge flow rate of the gear pump is substantially proportional to the engine speed.
[0004]
The flow rate control unit 3 is based on the principle that the flow rate is proportional to the opening degree of the throttle when the differential pressure is kept constant by the orifice formula,
A metering valve 301 that sets the fuel flow rate to a set flow rate by adjusting the opening degree;
A digital electronic control unit 302 that performs feedback control by capturing the opening of the metering valve 301 with a displacement meter while making the current proportional to the valve body moving speed of the metering valve 301 via a nozzle flapper mechanism by a torque motor (not shown); ,
A differential pressure sensing valve 303 for sensing a differential pressure across the metering valve 301,
A bypass valve 304 for returning a part of the fuel discharged from the fuel pump 2 to its suction side so as to keep the differential pressure before and after the metering valve 301 detected by the differential pressure sensing valve 303 constant;
It has a back pressure regulating valve 305 that always keeps the fuel pressure at the outlet of the flow control unit 3 higher than the pressure of the combustor 5 by causing a pressure loss.
[0005]
As an invention related to an aircraft fuel system, for example, there is an invention disclosed in Patent Document 1.
[0006]
[Patent Document 1]
JP-A-7-317564 (FIG. 1)
[0007]
[Problems to be solved by the invention]
By the way, the mechanical reliability of hydraulic equipment itself such as various valves (differential pressure sensing valve 303, bypass valve 304, back pressure adjusting valve 305) in the fuel pump 2 and the flow control unit 3 is relatively stable. Since the failure rate of the electric components such as the torque motor in the digital electronic control unit 302 is not stable, in a system requiring higher reliability, the fuel pump 2 and the flow rate control unit 3 are provided two by two, and the whole is provided. It is common practice to duplicate.
[0008]
However, as described above, simply duplicating the entire system increases the overall weight and also requires two gearboxes for driving the fuel pump 2, which inevitably increases the size. It is disadvantageous for a fuel supply system for an aircraft or the like, which has many restrictions in terms of space and space, and improvement has been desired.
[0009]
The present invention has been made in view of the above circumstances, and aims to provide a fluid supply system capable of minimizing an increase in weight, reducing the size and weight, and further improving the reliability.
[0010]
[Means for Solving the Problems]
The present invention provides a fluid supply system in which a fluid discharged from a pump is sent back to the device by a set flow rate by a flow rate control unit while an excess is returned to an inlet side of the pump.
The pump is a triple gear pump having a first booster and a second booster,
A first flow control unit that sends a surplus amount to the inlet side of the first booster unit of the gear pump while sending a fluid having a set flow rate to the device from the fluid discharged from the first booster unit of the gear pump; Of the fluid discharged from the second booster, a surplus is sent to the device while sending the fluid at the set flow rate to a second flow control unit that is sent back to the inlet side of the second booster of the gear pump,
A first switching valve capable of returning the fluid discharged from the first booster of the gear pump to the inlet side of the first booster when the first flow control unit is stopped and setting the first booster to an unload state,
A second switching valve capable of returning the fluid discharged from the second booster of the gear pump to the inlet side of the second booster when the second flow control unit is stopped, thereby setting the second booster in an unload state. A fluid supply system according to the present invention is characterized.
[0011]
According to the above means, the following effects can be obtained.
[0012]
During normal operation, the fluid discharged from the first booster of the triple gear pump is sent to the device by the first flow control unit by the set flow rate, and the surplus is returned to the inlet side of the first booster of the gear pump. At the same time, the fluid discharged from the second booster of the gear pump is sent to the device by the second flow control unit by the set flow rate, and the surplus is sent back to the inlet side of the second booster of the gear pump.
[0013]
On the other hand, when the first flow control unit is stopped due to failure of an electric component such as a torque motor of the first flow control unit, switching of the first switching valve causes the first booster of the gear pump to be switched. The discharged fluid is returned to the inlet side of the first booster, the first booster is in an unloaded state, and the fluid discharged from the second booster of the gear pump is supplied to the device by the second flow control unit. On the other hand, when the second flow control unit is stopped due to failure of an electric component such as a torque motor of the second flow control unit or the like, the second switching valve is switched to cause the second pressure increase of the gear pump. The fluid discharged from the section is returned to the inlet side of the second pressure rising section, the second pressure rising section is brought into the unloaded state, and the fluid discharged from the first pressure rising section of the gear pump to the device by the first flow rate control unit. Delivery continues.
[0014]
That is, by using a triple gear pump, unlike the case where the entire system is simply duplicated, the increase in the overall weight is suppressed, and not only the pump itself is made compact, but also the drive shaft and the mount are each one. It is sufficient if only one gear box is provided, and only one gear box for driving the pump is required, so that the size can be reduced. This is particularly advantageous as a fuel supply system for an aircraft or the like, which has many restrictions in terms of weight and space.
[0015]
In the fluid supply system, a first check valve is provided in the middle of a first suction line for guiding fluid to an inlet of a first booster of the gear pump, and the first switching valve is used to stop the gear pump when the first flow control unit is stopped. The fluid discharged from the first booster is configured to return to the middle of the first suction line downstream of the first check valve,
A second check valve is provided in the middle of the second suction line for branching from the middle of the first suction line on the upstream side of the first check valve and guiding the fluid to the inlet of the second booster of the gear pump. When the unit is stopped, the fluid discharged from the second booster of the gear pump by the second switching valve is configured to return to the middle of the second suction line downstream from the second check valve,
A first discharge line on the upstream side of the first switching valve and a second discharge line on the upstream side of the second switching valve are communicated by a communication line,
A high-pressure receiving surface of a movable side plate movably disposed in the axial direction of the driving bearing, the first bearing, and the second bearing rotatably supporting the driving gear, the first driven gear, and the second driven gear of the gear pump, and a communication line. And the fluid pressure of the first suction line on the downstream side of the first check valve is applied to the low pressure receiving surfaces of the driving bearing and the movable side plate of the first bearing, and the low pressure of the movable side plate of the second bearing is applied. The pressure receiving surface can be configured to apply the fluid pressure of the second suction line downstream of the second check valve,
With this configuration, when both the first booster and the second booster are operating in a normal state, the fluid pressure in the communication line is high, and the fluid pressure in the first suction line and the second suction line is Even when the pressure becomes low and one of the first booster and the second booster is in the unload state, the fluid pressure in the communication line can still be maintained at a high pressure, and the unload state is established. It is also possible to maintain the fluid pressure of the first suction line or the second suction line on the other side at a high pressure, whereby the fluid pressure on the pressure-receiving surface acting on the pressure-receiving surface of each movable side plate is reduced by the movable side plate from the gear side. It is possible to balance against the received gear side fluid pressure, the pressing force of the movable side plate against the gear side surface is always kept properly, and it is possible to avoid the occurrence of gear seizure or gaps The ability.
[0016]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0017]
FIG. 1 is an example of an embodiment of the present invention, in which parts denoted by the same reference numerals as in FIG. 3 represent the same parts, and the basic configuration is the same as that of the conventional one shown in FIG. However, as shown in FIG. 1, a feature of the illustrated example is that a fuel pump 2 as a pressure booster for a fluid such as fuel is connected to a triple pump having a first pressure booster 9 and a second pressure booster 10. Type gear pump,
The flow control unit 3 sends a surplus amount of the fuel as a fluid discharged from the first booster 9 of the gear pump to the combustor 5 as a device while feeding the fuel at a set flow rate to the inlet of the first booster 9 of the gear pump. The first flow rate control unit 3a which returns the fuel to the second pumping section of the gear pump while the fuel of a set flow rate among the fuel discharged from the second boosting section 10 of the gear pump is sent to the combustor 5 as a device. And divided into the second flow control unit 3b to be sent back to the inlet side of 10, and
A first switching valve 40a capable of returning the fuel discharged from the first booster 9 of the gear pump to the inlet side of the first booster 9 when the first flow control unit 3a is stopped so as to bring the first booster 9 into an unloaded state; ,
A second switching valve 40b capable of returning the fuel discharged from the second booster 10 of the gear pump to the inlet side of the second booster 10 when the second flow control unit 3b is stopped, thereby bringing the second booster 10 into an unloaded state; In that it has
[0018]
The fuel pump 2 as a triple gear pump is disposed at a position where a driving gear 20 that obtains a driving force by rotational motion transmitted from a driving system such as a jet engine and a position facing each other with the driving gear 20 interposed therebetween. And two driven gears (a first driven gear 21 and a second driven gear 22).
[0019]
As shown in FIG. 1, the driving gear 20, the first driven gear 21, and the second driven gear 22 are meshed with each other in a casing 23. The fuel that has flowed between the teeth is confined in the space surrounded by the adjacent teeth and the wall of the casing 23 as the gear rotates, and is pressurized, and moves to the first discharge port 26 and the second discharge port 27. And sent out. That is, the fuel pump 2 includes a first booster 9 mainly composed of the driving gear 20 and the first driven gear 21 and a second booster 10 mainly composed of the driving gear 20 and the second driven gear 22. Structure. The first driven gear 21 and the second driven gear 22 use gears of the same size, and the first booster 9 and the second booster 10 have the same discharge flow rate with respect to the rotation speed of the driving gear 20. is there. Note that the tooth profile of each gear is not limited to a spur tooth, a helical tooth, etc., and various tooth shapes such as a sine curve and a trochoid curve can be applied.
[0020]
A first suction line 28 and a second suction line 29 extending from the fuel tank 1 are respectively provided in the first suction port 24 of the first pressure rising section 9 and the second suction port 25 of the second pressure rising section 10 of the fuel pump 2. The first discharge line 30 is connected to the first discharge port 26 of the first pressure rising section 9 via the first switching valve 40a and is connected to the first flow rate control unit 3a. The second discharge port 27 is connected to the second discharge line 31 communicating with the second flow control unit 3b via the second switching valve 40b, and the first check valve 32 is provided in the middle of the first suction line 28. In the middle of the first suction line 28 on the downstream side of the first check valve 32, during normal operation, excess fuel from the first flow control unit 3a is returned and when the first flow control unit 3a is stopped, For switching the first switching valve 40a Thus, a first return line 34 for returning fuel discharged from the first booster 9 of the gear pump is connected, and a second check valve 33 is provided in the middle of the second suction line 29, In the middle of the second suction line 29 downstream of the valve 33, the excess fuel from the second flow control unit 3b is returned during normal operation, and the second switching valve 40b is switched when the second flow control unit 3b is stopped. A second return line 35 for returning fuel discharged from the second booster 10 of the gear pump is connected to the first return line 30 on the upstream side of the first switching valve 40a and on the upstream side of the second switching valve 40b. The communication line 41 communicates with the middle of the second discharge line 31 in.
[0021]
The first switching valve 40a normally guides the fuel discharged from the first booster 9 to the first flow control unit 3a and guides the surplus fuel returned from the first flow control unit 3a to the first return line 34. The position can be switched between a position N1 and an unload position U1 for guiding the fuel discharged from the first booster 9 to the first discharge line 30 to the first return line 34. A normal position N2 for guiding the fuel discharged from the second booster 10 to the second flow control unit 3b and guiding the excess fuel returned from the second flow control unit 3b to the second return line 35; To the unload position U2 for guiding the fuel discharged from the second discharge line 31 to the second return line 35.
[0022]
On the other hand, the driving gear 20, the first driven gear 21, and the second driven gear 22 are rotatably supported by a driving bearing 36 such as a journal bearing, a first bearing 37, and a second bearing 38, respectively. , 38 are fixed side plates 36a, 37a, 38a fixedly arranged on one side of each gear, and movable side plates 36b, 37b, 38b arranged axially movably on the other side of each gear. By applying the pressure of a fluid such as fuel to the high pressure receiving surfaces 36c, 37c, 38c and the low pressure receiving surfaces 36d, 37d, 38d of the movable side plates 36b, 37b, 38b, the movable side plates 36b, 37b, 38b are provided. Is pressed against the side surface of the gear to perform sealing. In the case of the illustrated example, the driving gear 20, the first driven gear 21, and the second driven gear 22 of the gear pump are rotated. The fluid in the communication line 41 is connected to the high pressure receiving surfaces 36c, 37c, 38c of the movable side plates 36b, 37b, 38b movably arranged in the axial direction of the driving bearing 36, the first bearing 37, and the second bearing 38 which are freely supported. A pressure (always high in both the normal state and the unload state) is applied, and the driving bearing 36 and the low-pressure receiving surfaces 36d and 37d of the movable side plates 36b and 37b of the first bearing 37 are located downstream of the first check valve 32. , The fluid pressure of the first suction line 28 (low pressure in the normal state and high pressure in the unloaded state) is applied to the low pressure receiving surface 38 d of the movable side plate 38 b of the second bearing 38 from the second check valve 33. The fluid pressure of the second suction line 29 on the downstream side (low pressure in a normal state and high pressure in an unloaded state) is applied, and as a result, as shown in FIG. The movable side plates 36b, 37b, 38b receive from the gears the total fluid pressure acting on the high pressure receiving surfaces 36c, 37c, 38c and the low pressure receiving surfaces 36d, 37d, 38d of the side plates 36b, 37b, 38b. The gear side fluid pressure is balanced.
[0023]
Next, the operation of the above illustrated example will be described.
[0024]
At the time of normal operation, the first switching valve 40a and the second switching valve 40b are switched to the normal positions N1 and N2, and are discharged as fluid discharged from the first booster 9 of the triple gear pump to the first discharge line 30. Is supplied to the combustor 5 by a set flow rate by the first flow control unit 3a, and the surplus is returned to the inlet side of the first booster 9 of the gear pump via the first return line 34, Fuel as a fluid discharged from the second booster unit 10 to the second discharge line 31 is sent to the combustor 5 by the second flow rate control unit 3b at a set flow rate, and the surplus is supplied to the gear pump via the second return line 35. It is sent back to the input side of the second booster 10.
[0025]
On the other hand, when the first flow control unit 3a is stopped due to failure of an electric component such as a torque motor of the first flow control unit 3a, the first switching valve 40a is switched to the unload position U1. As a result, the fuel discharged from the first booster 9 of the gear pump to the first discharge line 30 is returned to the inlet side of the first booster 9 via the first return line 34, and the first booster 9 is brought into the unloaded state. Then, the supply of the fuel discharged from the second booster 10 of the gear pump to the combustor 5 by the second flow control unit 3b is continued. On the other hand, when stopping the second flow control unit 3b due to failure of an electric component such as a torque motor of the second flow control unit 3b, the second switching valve 40b is switched to the unload position U2 by Fuel discharged from the second booster 10 of the gear pump to the second discharge line 31 is returned to the inlet side of the second booster 10 via the second return line 35, and the second booster 10 is unloaded. The supply of the fuel discharged from the first booster 9 of the gear pump to the combustor 5 by the first flow control unit 3a is continued.
[0026]
That is, by using a triple gear pump as the fuel pump 2, unlike the case where the entire system is simply duplicated, the increase in the overall weight is suppressed and the fuel pump 2 itself is not only compact, but also Only one drive shaft and one mount are required, and only one gearbox for driving the fuel pump 2 is required, which enables downsizing. In particular, a fuel supply system for an aircraft or the like, which has many restrictions in terms of weight and space. This is advantageous.
[0027]
In the illustrated example, the driving gear 20, the first driven gear 21, and the second driven gear 22 of the gear pump are rotatably supported in a driving bearing 36, a first bearing 37, and a second bearing 38 which are movable in the axial direction. The fluid pressure in the communication line 41 is applied to the high-pressure receiving surfaces 36c, 37c, and 38c of the movable side plates 36b, 37b, and 38b disposed on the movable side plates 36b, 37b, and 38b. The fluid pressure of the first suction line 28 downstream of the first check valve 32 is applied to the surfaces 36 d and 37 d, and the low pressure receiving surface 38 d of the movable side plate 38 b of the second bearing 38 is applied to the surfaces 36 d and 37 d by the second check valve 33. The fluid pressure of the second suction line 29 on the downstream side is applied. In this case, when both the first pressure increasing unit 9 and the second pressure increasing unit 10 are operated in the normal state, the communication line 4 Is high, the fluid pressure in the first suction line 28 and the second suction line 29 is low, and either one of the first booster 9 or the second booster 10 is in the unloaded state. However, the fluid pressure in the communication line 41 can also be maintained at a high pressure, and the fluid pressure in the first suction line 28 or the second suction line 29 on the unloaded state can also be maintained at a high pressure. As a result, as shown in FIG. 2, the total fluid pressure acting on the high-pressure receiving surfaces 36c, 37c, 38c and the low-pressure receiving surfaces 36d, 37d, 38d of the movable side plates 36b, 37b, 38b is reduced. It becomes possible to balance the fluid pressure received by the movable side plates 36b, 37b, 38b from the gear side, and to push the movable side plates 36b, 37b, 38b against the gear side surfaces. Force is always properly maintained, it becomes possible avoid seizure of gear or cause occurs or or gap.
[0028]
Thus, reliability can be further improved while minimizing weight increase and miniaturization and weight reduction.
[0029]
In addition, the fluid supply system of the present invention is not limited to the illustrated example described above, and is applicable not only to a fuel supply system of a jet engine used for an aircraft or the like but also to a supply system that handles various fluids. Of course, various changes can be made without departing from the spirit of the present invention.
[0030]
【The invention's effect】
As described above, according to the fluid supply system of the present invention, it is possible to achieve an excellent effect that the reliability can be further improved while minimizing weight increase, miniaturization and weight reduction.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram of an example of an embodiment of the present invention.
FIG. 2 is an enlarged view of a portion II in FIG.
FIG. 3 is a schematic configuration diagram of a conventional example.
[Explanation of symbols]
2 Fuel pump (pump)
3 Flow control unit 3a First flow control unit 3b Second flow control unit 5 Combustor (equipment)
9 First booster 10 Second booster 20 Drive gear 21 First driven gear 22 Second driven gear 28 First suction line 29 Second suction line 30 First discharge line 31 Second discharge line 32 First check valve 33 Second check valve 34 First return line 35 Second return line 36 Drive bearing 36a Fixed side plate 36b Movable side plate 36c High pressure receiving surface 36d Low pressure receiving surface 37 First bearing 37b Movable side plate 37c High pressure receiving surface 37d Low pressure receiving surface 38 Second Bearing 38b Movable side plate 38c High pressure receiving surface 38d Low pressure receiving surface 40a First switching valve 40b Second switching valve 41 Communication line N1 Normal position N2 Normal position U1 Unload position U2 Unload position

Claims (2)

In a fluid supply system in which the fluid discharged from the pump is sent to the device by the flow rate control unit by the set flow rate and the surplus is returned to the inlet side of the pump,
The pump is a triple gear pump having a first booster and a second booster,
A first flow control unit that sends a surplus amount to the inlet side of the first booster unit of the gear pump while sending a fluid having a set flow rate to the device from the fluid discharged from the first booster unit of the gear pump; Of the fluid discharged from the second booster, a surplus is sent to the device while sending the fluid at the set flow rate to a second flow control unit that is sent back to the inlet side of the second booster of the gear pump,
A first switching valve capable of returning the fluid discharged from the first booster of the gear pump to the inlet side of the first booster when the first flow control unit is stopped and setting the first booster to an unload state,
And a second switching valve capable of returning the fluid discharged from the second booster of the gear pump to the inlet side of the second booster when the second flow control unit is stopped, thereby bringing the second booster into an unload state. Characterized fluid supply system. A first check valve is provided in the middle of the first suction line for guiding fluid to the inlet of the first booster of the gear pump, and is discharged from the first booster of the gear pump by the first switching valve when the first flow control unit is stopped. Fluid to return to the middle of the first suction line downstream of the first check valve,
A second check valve is provided in the middle of the second suction line for branching from the middle of the first suction line on the upstream side of the first check valve and guiding the fluid to the inlet of the second booster of the gear pump, and the second flow control is performed. When the unit is stopped, the fluid discharged from the second booster of the gear pump by the second switching valve is configured to return to the middle of the second suction line downstream of the second check valve,
A first discharge line on the upstream side of the first switching valve and a second discharge line on the upstream side of the second switching valve are communicated by a communication line,
A high-pressure receiving surface of a movable side plate movably disposed in the axial direction of the driving bearing, the first bearing, and the second bearing rotatably supporting the driving gear, the first driven gear, and the second driven gear of the gear pump, and a communication line. And the fluid pressure of the first suction line on the downstream side of the first check valve is applied to the low pressure receiving surfaces of the driving bearing and the movable side plate of the first bearing, and the low pressure of the movable side plate of the second bearing is applied. The fluid supply system according to claim 1, wherein a fluid pressure of a second suction line downstream of the second check valve is applied to the pressure receiving surface.

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