JP5397117B2 - Gear pump - Google Patents

Description

  The present invention relates to a gear pump that pressurizes and discharges fluid in a gap region between a gear and a casing.

Conventionally, a triple gear pump including three gears has been known as a pump for boosting and discharging a fluid.
As shown in Patent Document 1, the triple gear pump includes a gear group including three meshed gears and a casing surrounding the gear group, and a gap between each gear and the casing. The fluid is pressurized and discharged in the region.
Such a triple gear pump has four gap areas, and pressurizes the fluid in each gap area.

  The gear pump is originally a constant displacement pump that can supply a discharge flow rate proportional to the number of rotations. However, a multi-gear pump having three or more gears is stepwise rather than continuous by unloading the load of each pump element. However, when the required flow rate of the hydraulic system is small, it is desirable in terms of energy saving and heat balance design of the hydraulic system.

  On the other hand, it is widely known that a gear pump operates as a motor by flowing fuel from a suction port to a discharge port with a structure of substantially the same structure. In this case, the pressure at the suction port becomes higher than the discharge port pressure, and the magnitude of the pressure is reversed from that in the normal pump operation.

JP 2005-42627 A

  Even when the discharge flow rate required by the hydraulic system in the multi-gear pump is configured to supply the excess fuel to the minimum by unloading the load of each pump element, the resolution of the supply flow rate is gradual, and the excess flow rate This excess flow is a loss.

  In recent years, gear pumps having four or more gears have also been proposed. In particular, in such gear pumps having four or more gears, a plurality of gears are used as drive gears in order to achieve uniform power transmission. A plurality of drive shafts may be installed.

  In a gear pump in which an even number of gears are arranged in an annular shape, it is not rational to limit the number of drive shafts to one because the total load is concentrated on a specific shaft, and the load on the drive shaft is equalized. It is reasonable to have a plurality of drive shafts.

  When having a plurality of drive shafts, the surplus fuel can be recovered as torque by operating the motor as a motor by flowing fluid from the suction port to the discharge port by a hydraulic circuit to the pump element to be unloaded. It becomes possible to reduce the work.

  In addition, the above-mentioned surplus fluid is not restricted to the surplus fluid which the above-mentioned surplus fluid flows into the discharge port from the supply port supplied to the pump element to unload. For example, the main fuel pump in the fuel control mechanism of the jet engine may be operated as a motor by surplus fuel from the afterburner fuel pump to recover work.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to reduce a load on a drive source in a gear pump including a plurality of drive shafts.

  The present invention adopts the following configuration as means for solving the above-described problems.

  A first invention is a gear group composed of a plurality of continuous gears, a casing arranged to form a gap region between each gear and itself, and a plurality of fluids that supply the fluid to the gap region. And a plurality of discharge passages for discharging the fluid discharged from the gap region to the outside, the gear pump being installed for the plurality of gears and driving force from a drive source A drive shaft that transmits the gas to the gear, and any one of the inlet flow channel and the discharge flow channel that are disposed across the gap region formed by the gear in which the drive shaft is installed. The pressure of the inlet flow path is higher than the pressure of the discharge flow path disposed across the gap between the inlet flow path and the gap region, and the pressure of the inlet flow path is increased by the pressure increase means. Than rise A transmission means for transmitting torque acting on the drive shaft installed in the gear that forms the gap region between the inlet flow channel and the discharge flow channel to the other drive shaft. The configuration is adopted.

  According to a second invention, in the first invention, the pressure increasing means is an unloading means for causing the fluid in the discharge passage having the highest pressure to flow into the inlet passage among the plurality of discharge passages. The configuration is adopted.

  In a third invention, the first or second invention employs a configuration in which the transmission means is a speed reducer connected to the drive source.

According to the present invention, when the pressure in the inlet flow path is higher than the pressure in the discharge flow path, torque acting on the drive shaft is transmitted to the other drive shaft.
That is, the torque is recovered using the pressure difference when the pressure in the inlet channel is higher than the pressure in the discharge channel, and the recovered torque is used as torque for rotationally driving other gears. .
Therefore, when the pressure in the inlet channel is raised above the pressure in the discharge channel, the driving torque in the driving source can be reduced, and the load on the driving source is reduced.
Therefore, according to the present invention, it is possible to reduce the load of the drive source in a gear pump including a plurality of drive shafts.

It is sectional drawing which shows typically schematic structure of the gear pump in one Embodiment of this invention, and is sectional drawing in a surface at right angles to the axial direction of a gear. It is the sectional view on the AA line of FIG. It is a BB line arrow directional view of FIG. It is a schematic diagram for demonstrating the force which acts on a drive motor when not unloading the fluid in the gear pump in one Embodiment of this invention. It is a schematic diagram for demonstrating the force which acts on a drive motor at the time of unloading the fluid in the gear pump in one Embodiment of this invention. It is a system block diagram of a fuel system provided with the gear pump in one embodiment of the present invention.

  Hereinafter, an embodiment of a gear pump according to the present invention will be described with reference to the drawings. In the following drawings, the scale of each member is appropriately changed in order to make each member a recognizable size.

1 to 3 are cross-sectional views schematically showing a schematic configuration of the gear pump 100 of the present embodiment, FIG. 1 is a cross-sectional view in a plane perpendicular to the axial direction of the gear, and FIG. FIG. 3 is a cross-sectional view taken along line AA of FIG.
As shown in these drawings, the gear pump 100 of the present embodiment includes a gear group 1, a first casing 2, a second casing 3, an inlet flow path 4, a discharge flow path 5, and an unload device 6 ( Unloading means), fluid supply device 7, drive motor 8 (drive source), drive shaft 9, and speed reducer 10.

The gear group 1 is composed of four (even number) gears 1a to 1d that are continuous by engaging with each other and arranged in an annular shape.
In addition, in this embodiment, although each gear 1a-1d is a gear with the same diameter, the diameter of each gear 1a-1b does not necessarily need to be the same.

In the gear pump 100 of this embodiment, the gear 1b and the gear 1d are drive gears, the gear 1a and the gear 1c are driven gears, and the driving force of the drive motor 8 is applied to the gear 1b and the gear 1c. By being transmitted, the gears 1a to 1d are rotationally driven.
In the gear pump 100 of this embodiment, as shown in FIG. 1, the gear 1a and the gear 1c are rotationally driven so as to rotate clockwise in FIG. 1, and the gear 1b and the gear 1d are rotated counterclockwise in FIG. Driven by rotation.

The first casing 2 forms the outer shape of the gear pump 100 of the present embodiment and is disposed so as to surround the outer side of the gear group 1.
The first casing 2 is capable of boosting fluid in the gap region R between the gears 1a to 1d constituting the gear group 1 and itself.
In the following description, the gap region R formed between the gear group 1 and the first casing 2 is referred to as an outer gap region RA, and further, the outer gap formed between the gear 1a and the first casing 2. The region RA is referred to as a first outer clearance region RA1, the outer clearance region RA formed between the gear 1b and the first casing 2 is referred to as a second outer clearance region RA2, and between the gear 1c and the first casing 2 is defined. The outer gap area RA formed in the above is called a third outer gap area RA3, and the outer gap area RA formed between the gear 1d and the first casing 2 is called a fourth outer gap area RA4.

The second casing 3 is arranged in a central region surrounded by the gear group 1 and can pressurize the fluid in a gap region R between the gears 1a to 1d constituting the gear group 1 and itself.
In the following description, the gap region R formed between the gear group 1 and the second casing 3 is referred to as an inner gap region RB, and further, the inner gap formed between the gear 1a and the second casing 3. The region RB is referred to as a first inner clearance region RB1, the inner clearance region RB formed between the gear 1b and the second casing 3 is referred to as a second inner clearance region RB2, and between the gear 1c and the second casing 3 is defined. The inner gap area RB formed in the above is called a third inner gap area RB3, and the inner gap area RB formed between the gear 1d and the second casing 3 is called a fourth inner gap area RB4.

The inlet channel 4 is a channel for supplying a fluid from the outside of the gear pump 100 to the gap region R, and as shown in FIG. 1, four are installed in the gear pump 100 of the present embodiment.
More specifically, the inlet flow path 4 (hereinafter referred to as the first flow path 4) that can supply the fluid to the first outer gap area RA1 and the fourth outer gap area RA4 by flowing the fluid toward the area where the gear 1a and the gear 1d mesh with each other. 1 inlet channel 4a) and an inlet channel capable of supplying fluid to the second outer gap region RA2 and the third outer gap region RA3 by flowing the fluid toward the region where the gear 1b and the gear 1c mesh with each other. 4 (hereinafter referred to as the second inlet channel 4b) and the fluid flows into the region where the gear 1a and the gear 1b are separated from each other, thereby causing the fluid to flow into the first inner clearance region RB1 and the second inner clearance region RB2. The third inner clearance region RB3 and the fourth inner clearance region RB3 are formed by allowing the fluid to flow toward a region where the feedable inlet channel 4 (hereinafter referred to as the third inlet channel 4c) and the gear 1c and the gear 1d are separated from each other. Side gap region RB4 fluid can be supplied inlet channel 4 (hereinafter, referred to as a fourth inlet channel 4d) and is installed.

The discharge flow paths 5 are flow paths for discharging fluid from the gap region R, and as shown in FIG. 1, four discharge pumps 5 are installed in the gear pump 100 of the present embodiment.
More specifically, a discharge flow path 5 (hereinafter referred to as a first discharge flow path 5a) for discharging fluid discharged from the first outer gap area RA1 and the second outer gap area RA2, and a third outer gap area RA3. And the discharge flow path 5 (hereinafter referred to as the second discharge flow path 5b) for discharging the fluid discharged from the fourth outer gap area RA4 and the first inner gap area RB1 and the fourth inner gap area RB4. A discharge flow path 5 for discharging fluid (hereinafter referred to as a third discharge flow path 5c), and a discharge flow path 5 for discharging fluid discharged from the second inner gap area RB2 and the third inner gap area RB3 (hereinafter referred to as the third discharge flow path 5c) 4th discharge flow path 5d) is installed.

The unloading device 6 can connect (unload) the inlet flow path 4 and the discharge flow path 5 without the gap region R, and the flow that connects the inlet flow path 4 and the discharge flow path 5. A bypass channel 6a, which is a road, and an opening / closing adjustment unit 6b for adjusting the opening / closing of the bypass channel 6a are provided. The opening / closing adjustment unit 6b functions as a check valve.
And in the gear pump 100 of this embodiment, the location where the fluid discharged | emitted from all the discharge flow paths 5 gathers, and the 1st inlet flow path 4a are connected by the unload apparatus 6. FIG.
For convenience of explanation, in the gear pump 100 of the present embodiment, the unloading device 6 is shown to connect only the first inlet channel 4a and the third discharge channel 5c.

  The fluid supply device 7 adjusts the supply of fluid to the inlet channel 4. The fluid supply device 7 is connected to each of the first inlet channel 4a, the second inlet channel 4b, the third inlet channel 4c, and the fourth inlet channel 4d, and the first inlet channel 4a. The fluid supply to the second inlet channel 4b, the third inlet channel 4c, and the fourth inlet channel 4d can be independently adjusted.

  The drive motor 8 outputs a driving force for rotationally driving the gears 1a to 1d, and is connected to the gears 1b and 1c as drive gears via the drive shaft 9 and the speed reducer 10 as shown in FIG. Has been.

  The drive shaft 9 is installed for each of the gear 1b and the gear 1c. One end of the drive shaft 9 is connected to the speed reducer 10 and once is connected to the gears 1b and 1c. In the following description, the drive shaft 9 installed with respect to the gear 1b is referred to as a first drive shaft 9a, and the drive shaft 9 installed with respect to the gear 1c is referred to as a second drive shaft 9b.

The speed reducer 10 generates torque that allows the gears 1a to 1b to be rotationally driven by decelerating the rotational speed of the power of the drive motor 8.
Further, in the gear pump 100 of the present embodiment, the fluid in the third discharge flow path 5c is directly flowed into the first inlet flow path 4a in the unloading device 6, whereby the pressure in the first inlet flow path 4a is changed to the first pressure. When the pressure in the two discharge flow paths 5b becomes higher, torque acting on the second drive shaft 9b installed on the gear 1d is transmitted to the first drive shaft 9a.
That is, in the gear pump 100 of the present embodiment, the speed reducer 10 functions as a transmission unit of the present invention.

  The drive motor 8, the drive shaft 9, and the speed reducer 10 are fixed to the first casing 2 so as to be operable by a support mechanism (not shown).

  In the gear pump 100 of the present embodiment configured as described above, the gears 1a to 1d are rotationally driven, and the bypass flow path 6a of the unload device 6 is closed. On the other hand, when the fluid is supplied, the fluid is pressurized in each gap region R and discharged, and is discharged to the outside through the discharge channel 5.

  More specifically, as shown in FIG. 1, the fluid supplied to the first inlet channel 4a is supplied to the first outer gap region RA1 and the fourth outer gap region RA4. Then, the fluid supplied to the first outer gap region RA1 is pressurized in the first outer gap region RA1 and discharged from the first discharge flow path 5a to the outside of the gear pump 100. On the other hand, the fluid supplied to the fourth outer gap region RA4 is pressurized in the fourth outer gap region RA4 and discharged from the second discharge passage 5b to the outside of the gear pump 100.

  Further, the fluid supplied to the second inlet channel 4b is supplied to the second outer gap region RA2 and the third outer gap region RA3. Then, the fluid supplied to the second outer gap region RA2 is pressurized in the second outer gap region RA2 and discharged from the first discharge flow path 5a to the outside of the gear pump 100. On the other hand, the fluid supplied to the third outer gap region RA3 is pressurized in the third outer gap region RA3 and discharged from the second discharge passage 5b to the outside of the gear pump 100.

  Further, the fluid supplied to the third inlet channel 4c is supplied to the first inner gap region RB1 and the second inner gap region RB2. Then, the fluid supplied to the first inner clearance region RB1 is pressurized in the first inner clearance region RB1 and discharged from the third discharge flow path 5c to the outside of the gear pump 100. On the other hand, the fluid supplied to the second inner clearance region RB2 is pressurized in the second inner clearance region RB2, and discharged from the fourth discharge flow path 5d to the outside of the gear pump 100.

  Further, the fluid supplied to the fourth inlet channel 4d is supplied to the third inner gap region RB3 and the fourth inner gap region RB4. Then, the fluid supplied to the third inner clearance region RB3 is pressurized in the third inner clearance region RB3 and discharged from the fourth discharge flow path 5d to the outside of the gear pump 100. On the other hand, the fluid supplied to the fourth inner clearance region RB4 is pressurized in the fourth inner clearance region RB4 and discharged from the third discharge flow path 5c to the outside of the gear pump 100.

  Next, the case where the fluid in the discharge flow channel 5 is directly introduced into the first inlet flow channel 4a by the unload device 6 will be described.

  When the discharge flow path 5 and the first inlet flow path 4a are connected by the unloading device 6, the first outer clearance area RA1 and the fourth outer clearance area RA4 do not work, and the first discharge flow path 5a and The differential pressure in the second discharge channel 5b is reduced, and the pressure in the first inlet channel 4a is increased. At this time, since the discharge flow path 5 is connected to the first inlet flow path 4a via the opening / closing adjustment unit 6b, the discharge pressure does not change and the discharge flow rate slightly decreases.

Then, the pressure of the fluid is not increased in the fourth outer gap region RA4 formed between the gear 1d and the first casing 2, and the pressure of the first inlet channel 4a is higher than the pressure of the second discharge channel 5b. Therefore, the gear 1d is pressed from the first inlet channel 4a toward the second discharge channel 5b.
For this reason, a torque acts on the gear 1d in the direction opposite to that when the fluid is boosted, and a torque acts on the second drive shaft 9b installed with respect to the gear 1d. Torque acting on the second drive shaft 9b is transmitted to the first drive shaft 9a via the speed reducer 10.
The torque transmitted from the second drive shaft 9b to the first drive shaft 9a via the speed reducer 10 is used for rotational driving of the gear 1b. For this reason, the output of the drive motor 8 can be reduced.

That is, as shown in FIG. 4, when the pressure in the first inlet flow path 4a is lower than the pressure in the second discharge flow path 5b, the drive motor 8 causes the reaction force f1 from the gear 1d in the direction opposite to the rotation direction. And receives a reaction force f2 from the gear 1b. Therefore, the drive motor 8 needs to output torque that overcomes the reaction force f1 and the reaction force f2 in order to drive the gear pump 100.
On the other hand, as shown in FIG. 5, the fluid in the third discharge channel 5c is directly flowed into the first inlet channel 4a by the unloading device 6, so that the pressure in the first inlet channel 4a is changed to the second discharge flow. When the pressure is higher than the pressure in the path 5b, the drive motor 8 receives the torque f3 from the gear 1d in the same direction as the rotation direction, and receives the reaction force f2 from the gear 1b. Accordingly, in order to drive the gear pump 100, the drive motor 8 can drive the gear pump 100 by outputting a torque obtained by subtracting the torque f3 from the reaction force f2.

  As described above, in the gear pump 100 according to the present embodiment, the inlet channel (first inlet flow) arranged with the gap region (fourth outer gap region RA4) formed by the gear 1d provided with the second drive shaft 9b interposed therebetween. The pressure of the first inlet flow path 4a of the channel 4a) and the discharge flow path (second discharge flow path 5b) is made higher than the pressure of the second discharge flow path 5b by the unload device 6, and the first inlet flow path 4a Torque acting on the second drive shaft 9b installed in the gear 1d forming the fourth outer gap region RA4 between the first drive shaft 9a and the second discharge flow path 5b is transmitted to the first drive shaft 9a.

That is, according to the gear pump 100 of the present embodiment, the torque is recovered and recovered using the pressure difference when the pressure of the first inlet channel 4a is higher than the pressure of the second discharge channel 5b. Torque is used as torque for rotationally driving the gear 1b.
Therefore, when the pressure of the first inlet flow path 4a is increased above the pressure of the second discharge flow path 5b by the unload device 6, the drive torque in the drive motor 8 can be reduced, and the drive motor 8 Load is reduced.
Therefore, according to the gear pump 100 of this embodiment, it becomes possible to reduce the load of a drive motor in a gear pump including a plurality of drive shafts.

FIG. 6 is a system block diagram showing a schematic configuration of the fuel system 20 including the gear pump 100 of the present embodiment.
The fuel system 20 is, for example, a FADEC (Full Authority Digital Electronic Control) system that supplies fuel to an aircraft jet engine, and includes the gear pump 100, the fuel control unit 21, and the electronic control device 22 of the present embodiment. Yes.
In the fuel system 20, the gear pump 100 of this embodiment functions as a fuel pump that boosts and discharges fuel (fluid) supplied from a fuel tank or the like.
Based on a command from the electronic control unit 22, the fuel control unit 21 supplies the jet engine with an amount of fuel discharged from the gear pump 100 and returns the rest to the gear pump 100. .
The electronic control unit 22 calculates the amount of fuel to be supplied to the jet engine based on the number of revolutions of the jet engine and the instruction of the pilot of the aircraft equipped with the jet engine, and the gear pump 100 and the fuel control unit 21 based on the calculation result. To control.

At the time of takeoff of an aircraft equipped with a jet engine, the jet engine requires a large amount of fuel, and the rotational speed of the jet engine is low and the rotational speed of each gear of the gear pump 100 is low. For this reason, the fuel control unit 21 increases the work amount of the gear pump 100 by controlling the gear pump 100 of the present embodiment.
On the other hand, when cruising an aircraft equipped with a jet engine, although the fuel consumption of the jet engine is reduced, the rotational speed of the jet engine is high and the rotational speed of each gear of the gear pump 100 is high. For this reason, the fuel control part 21 reduces the work load of the gear pump 100 by using the unload apparatus of the gear pump 100 of this embodiment.

  According to the gear pump 100 provided in the fuel system 20 as described above, the torque is recovered when the work amount of the gear pump 100 is reduced by using the unload device. Therefore, according to the fuel system 20 provided in the gear pump 100 of the present embodiment, the load on the drive motor 8 can be reduced.

  As described above, the preferred embodiment of the gear pump according to the present invention has been described with reference to the accompanying drawings, but it is needless to say that the present invention is not limited to the above-described embodiment. Various shapes, combinations, and the like of the constituent members shown in the above-described embodiments are examples, and various modifications can be made based on design requirements and the like without departing from the gist of the present invention.

For example, in the above-described embodiment, the gear pump in which the four gears 1a to 1d are arranged in a ring shape has been described.
However, the present invention is not limited to this, and the present invention can be applied when a so-called triple gear pump is provided with two or more drive shafts. That is, the fluid is unloaded from the discharge passage with the highest pressure among the plurality of discharge passages of the triple gear pump to one of the inlet passages, and as a result, the torque that acts on the gear in the direction opposite to that during boosting is driven. It is also possible to adopt a configuration in which the torque is recovered via the shaft and the recovered torque is transmitted to another drive shaft.
In addition, the present invention is applied to a gear pump that includes five or more gears and further includes a plurality of drive shafts, a plurality of inlet passages, and a plurality of discharge passages, thereby reducing the load on the drive motor. Is also possible.

Moreover, in the said embodiment, the structure which makes the pressure of the inlet flow path 4 higher than the pressure of the discharge flow path 5 with the unloading apparatus 6 was demonstrated.
However, the present invention is not limited to this, and the pressure of the inlet channel 4 is set higher than the pressure of the discharge channel 5 using a pressurized fluid supply device that supplies a pressurized fluid to the inlet channel 4. May be higher.

Moreover, in the said embodiment, the structure which transmits a torque from the 2nd drive shaft 9b to the 1st drive shaft 9a with the reduction gear 10 was demonstrated.
However, the present invention is not limited to this, and torque may be transmitted from the second drive shaft 9b to the first drive shaft 9a using another mechanism.

  DESCRIPTION OF SYMBOLS 100 ... Gear pump, 1 ... Gear group, 1a-1d ... Gear, 2 ... 1st casing, 3 ... 2nd casing, 4 ... Inlet flow path, 5 ... Discharge flow path, 6 ... Ann Loading device (unloading means), 6a .. Bypass flow path, 6b..Opening / closing adjustment part, 7 ... Fluid supply part, 8 ... Drive motor (drive means), 9 ... Drive shaft, 9a ... First Drive shaft, 9b ... second drive shaft, 10 ... reduction gear (transmission means), R ... gap region, RA ... outer gap region, RB ... inner gap region, RA1 ... first outer gap region, RA2... Second outer clearance region, RA3... Third outer clearance region, RA4... Fourth outer clearance region, RB1... First inner clearance region, RB2... Second inner clearance region, RB3. Inner clearance area, RB4 ... Fourth inner clearance area

Claims (3)

A gear group composed of a plurality of three or more continuous gears, a casing arranged to form a gap region between each gear and itself, and a plurality of inlets for supplying the fluid to the gap region A gear pump comprising a flow path and a plurality of discharge flow paths for discharging the fluid discharged from the gap region to the outside,
A drive shaft that is installed for a plurality of the gears and that transmits a driving force from a driving source to the gears;
Among the inlet channel and the discharge channel arranged across the gap region formed by the gear on which the drive shaft is installed, the pressure of any one of the inlet channels is changed between the inlet channel and the discharge channel. A pressure increasing means capable of rising above the pressure of the discharge flow path disposed across the gap region;
When the pressure in the inlet channel is raised above the pressure in the discharge channel by the boosting means, the pressure sensor is installed in the gear that forms the gap region between the inlet channel and the discharge channel. Transmission gear for transmitting torque acting on the drive shaft to the other drive shaft.   2. The gear pump according to claim 1, wherein the pressure increasing unit is an unloading unit that causes the fluid in the discharge channel having the highest pressure among the plurality of discharge channels to flow into the inlet channel.   The gear pump according to claim 1, wherein the transmission unit is a reduction gear connected to the drive source.

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