JP2021116714A - Multiple gear pump and pump system - Google Patents

Abstract

To suppress deterioration in capacity efficiency while ensuring loading capability of a bearing more than before.SOLUTION: A multiple gear pump includes three or more gears respectively including a rotation shaft and engaging each other in a row to form two or more fluid pressure boosting parts, where a rotation shaft not positioned in each end of the row is a drive shaft. A bearing for the drive shaft is connected to a low-pressure side of a pair of liquid input/output ports connected to the fluid pressure boosting parts.SELECTED DRAWING: Figure 1

Description

The present invention relates to multiple gear pumps and pump systems.

Patent Document 1 below discloses a double gear pump for series-parallel switching. This double gear pump for series-parallel switching includes a triple-barrel gear pump having a first booster and a second booster, and the first booster and the second booster are connected in parallel by switching the external flow path. It switches between (normal mode) and a state in which the first booster and the second booster are connected in series (half mode). The half mode is an operation mode in which a fluid having a flow rate about half that of the normal mode is discharged.

Japanese Unexamined Patent Publication No. 2003-328598

By the way, in the above background technique, the force acting on the bearings of the three gears changes between the normal mode (parallel operation mode) and the half mode (series operation mode). In addition, static pressure bearings are often used in the above triple-barrel gear pumps, and in the parallel operation mode, the load capacity of the static pressure bearings is increased by supplying a part of the relatively high-pressure discharge fluid to each static pressure bearing. (Load capacity) is secured.

However, consuming the discharge fluid in order to secure the load capacity of the hydrostatic bearing is nothing but reducing the capacitance efficiency of the multiple gear pump such as the triple gear pump.

The present invention has been made in view of the above circumstances, and an object of the present invention is to suppress a decrease in capacity efficiency as compared with the conventional case while ensuring a load capacity of a bearing.

In order to achieve the above object, in the present invention, as a first solution for a multiple gear pump, three drive shafts are arranged so as to be parallel to each other and not located at the end of the arrangement. The above-mentioned rotating shaft, three or more bearings that support the rotating shaft, and three or more gears that are mounted on the rotating shaft and mesh with each other in a row to form two or more fluid boosters. The bearing of the drive shaft is connected to the low pressure side of the pair of liquid input / output ports communicating with the fluid booster.

In the present invention, as the second solution for the multi-series gear pump, in the first solution, a plain bearing provided with a static pressure pad is adopted.

In the present invention, as the third solution means for the multiple gear pump, the means that the number of the rotating shaft, the bearing, and the gear is three is adopted in the first or second solution. ..

In the present invention, as a solution according to the pump system, a multiple gear pump according to any one of the first to third solutions and a switching flow path for switching the connection relationship of the fluid booster unit between parallel connection and series connection. The bearing is connected to the liquid input / output port which is on the low pressure side when the fluid boosting unit is connected in parallel and on the high pressure side when the fluid boosting unit is connected in series. Is adopted.

According to the present invention, it is possible to suppress a decrease in capacity efficiency as compared with the conventional case while ensuring the load capacity of the bearing.

It is a piping system diagram which shows the structure of the multiple gear pump and a pump system which concerns on one Embodiment of this invention. It is a schematic diagram which shows the operating state in the parallel operation mode of the pump system which concerns on one Embodiment of this invention. It is a schematic diagram which shows the operating state in the series operation mode of the pump system which concerns on one Embodiment of this invention.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
As shown in FIG. 1, the pump system according to the present embodiment includes a triple-barrel gear pump 1, an inflow pipe 2, an outflow pipe 3, first to fifth connection pipes 4 to 8, a check valve 9, and a flow rate control valve 10. I have. In this pump system, a predetermined fluid (liquid) received from the outside is boosted and sent out to the outside. The fluid (liquid) to be pressurized is, for example, a fuel.

Here, among these components, the triple-barrel gear pump 1 is the multiple-barrel gear pump according to the present embodiment. Further, the inflow pipe 2, the outflow pipe 3, the first to fifth connection pipes 4 to 8, the check valve 9, and the flow rate control valve 10 form a switching flow path in the present embodiment. That is, the switching flow path switches the connection relationship between the first fluid boosting unit S1 and the second fluid boosting unit S2, which will be described later, to parallel connection or series connection.

In the triple gear pump 1, the predetermined casing 1a, the first to third gears 1b to 1d which are housed in the casing 1a and mesh with each other in a row, and the first to third gears 1b to 1d are fixed. The first to third rotary shafts 1e to 1g and the first to third rotary shafts 1h to 1j that rotatably support the first to third rotary shafts 1e to 1g with respect to the casing 1a are provided. Of the first to third rotation shafts 1e to 1g, the second rotation shaft 1f is a drive shaft that is rotationally driven by a drive source (not shown).

In the triple-barrel gear pump 1, the casing 1a is a metal housing that accommodates the first to third gears 1b to 1d, the first to third rotating shafts 1e to 1g, and the first to third bearings 1h to 1j. .. The casing 1a includes first to fourth input / output ports P1 to P4 (liquid input / output ports) for inputting / outputting fluid to / from the outside. Of the first to fourth input / output ports P1 to P4, the first input / output port P1, the second input / output port P2, and the third input / output port P3 communicate with the first fluid booster unit S1 as shown. Further, the second input / output port P2, the third input / output port P3, and the fourth input / output port P4 communicate with the second fluid boosting unit S2.

As shown in the figure, the first to third gears 1b to 1d are disk-shaped members having a predetermined number of teeth formed on the outer periphery, and by engaging with each other in a continuous manner, the first fluid boosting unit S1 and the second fluid boosting unit S2 To form. The first fluid boosting unit S1 is a portion that boosts the pressure-pressed liquid by rotating the first gear 1b and the second gear 1c in mesh with each other. Further, the second fluid boosting unit S2 is a portion that boosts the pressure-pressed liquid by rotating the second gear 1c and the third gear 1d in mesh with each other.

Of the first to third gears 1b to 1d, the first gear 1b is rotatably supported with respect to the casing 1a via the first rotating shaft 1e and the first bearing 1h. The second gear 1c is rotatably supported with respect to the casing 1a via the second rotating shaft 1f and the second bearing 1i. Further, the third gear 1d is rotatably supported with respect to the casing 1a via the third rotating shaft 1g and the third bearing 1j.

The first to third rotation shafts 1e to 1g are rod-shaped members to which the first to third gears 1b to 1d are mounted coaxially. The first to third rotation shafts 1e to 1g are arranged so as to be parallel to each other, and the second rotation shaft 1f not located at the end of the arrangement is the drive shaft. For example, the first rotating shaft 1e is mounted in a posture in which the first gear 1b is orthogonal to the rotating surface of the first gear 1b. The second rotating shaft 1f is mounted in a posture in which the second gear 1c is orthogonal to the rotating surface of the second gear 1c. The third rotating shaft 1g is mounted in a posture in which the third gear 1d is orthogonal to the rotating surface of the third gear 1d.

A pair of first to third bearings 1h to 1j are provided on both sides of the first to third gears 1b to 1d in the direction of the central axis of the first to third rotating shafts 1e to 1g. For example, a pair of first bearings 1h are provided on both sides of the first gear 1b in the central axis direction of the first rotating shaft 1e, and a second bearing 1i is provided on both sides of the second gear 1c in the central axis direction of the second rotating shaft 1f. A pair of third bearings 1j are provided on both sides, and a pair of third bearings 1j are provided on both sides of the third gear 1d in the direction of the central axis of the third rotating shaft 1g.

Such first to third bearings 1h to 1j rotatably support the first to third rotating shafts 1e to 1g, and are, for example, slide bearings. That is, in the first to third bearings 1h to 1j, the lubricant is inserted into the wedge-shaped gap formed between the first to third rotating shafts 1e to 1g and the first to third bearings 1h to 1j. By generating fluid pressure (flubrication with a lubricant), the first to third bearings 1h to 1j can be rotated while supporting the radial load acting from the first to third rotating shafts 1e to 1g. Is. It is known that the slide bearing is provided with a static pressure pad between the slide bearing and the rotating shaft. For the first to third bearings 1h to 1j, a slide bearing provided with a static pressure pad may be adopted.

Such first to third bearings 1h to 1j (slide bearings) use a liquid to be pressurized as a lubricant. That is, the first to third bearings 1h to 1j are connected to any of the first to fourth input / output ports P1 to P4 in order to receive the pressurized liquid as a lubricant.

For example, the first bearing 1h is connected to the second input / output port P2. Further, the connection portion of the first bearing 1h with the second input / output port P2 is a portion where the pressure of the pressurized liquid acting on the first gear 1b is relatively low. This relatively low-voltage portion is a region in the vicinity of the first input / output port P1 in the first gear 1b.

The second bearing 1i is connected to the fourth input / output port P4. Further, the connection portion of the second bearing 1i with the first input / output port P1 is a region near the first input / output port P1 where the pressure of the pressure-pressed liquid acting on the second gear 1c is relatively low.

Further, the third bearing 1j is connected to the third input / output port P3. Further, the connection portion of the third bearing 1j with the third input / output port P3 is a region near the fourth input / output port P4.

Such triple gear pumps 1 are arranged so as to be parallel to each other, and the first to third rotation shafts 1e to 1g in which the second rotation shaft 1f not located at the end of the arrangement is the drive shaft and the said one. The first to third bearings 1h to 1j that rotatably support the first to third rotating shafts 1e to 1g and the first to third rotating shafts 1e to 1g are respectively mounted and meshed with each other. The second bearing 1i provided with the first to third gears 1b to 1d forming the fluid boosting unit S1 and the second fluid boosting unit S2 and supporting the second rotating shaft 1f (drive shaft) is the second fluid boosting unit. Of the third input / output port P3 and the fourth input / output port P4 communicating with S2, this is a type of multiple gear pump connected to the fourth input / output port P4 on the low pressure side.

The inflow pipe 2 is a pipe in which one end is connected to the first input / output port P1 and the other end is connected to an external liquid supply source. The inflow pipe 2 distributes the pressurized liquid received from the liquid supply source to the triple-barrel gear pump 1. The outflow pipe 3 is a pipe in which one end is connected to the second input / output port P2 and the other end is connected to an external liquid demand destination. The outflow pipe 3 distributes the boosted liquid discharged by the triple-barrel gear pump 1 to the liquid demand destination.

The first connection pipe 4 is a pipe that connects the inflow pipe 2 and the first input / output port of the check valve 9. The second connection pipe 5 is a pipe that connects the second input / output port of the check valve 9 and the first input / output port of the flow rate control valve 10. The third connection pipe 6 is a pipe that connects the second input / output port of the flow rate control valve 10 and the third input / output port P3 of the triple-barrel gear pump 1. The fourth connection pipe 7 is a pipe that connects the second input / output port of the flow rate control valve 10 and the second input / output port P2 of the triple-barrel gear pump 1. The fifth connection pipe 8 is a pipe that connects the second input / output port of the check valve 9 and the fourth input / output port P4 of the triple-barrel gear pump 1.

The check valve 9 is provided between the first connection pipe 4, the second connection pipe 5, and the fifth connection pipe 8, and includes a pair of input / output ports, that is, a first input / output port and a second input / output port. There is. The check valve 9 prevents the liquid to be pressurized from conducting and blocking the conduction between the first input / output port and the second input / output port according to the differential pressure between the first input / output port and the second input / output port. It is a valve that automatically switches.

The flow rate control valve 10 is provided between the second connection pipe 5, the third connection pipe 6, and the fourth connection pipe 7, and includes a pair of input / output ports, that is, a first input / output port and a second input / output port. There is. The flow rate control valve 10 is a control valve capable of adjusting the flow rate (passing flow rate) of the pressurized liquid flowing between the first input / output port and the second input / output port.

Next, the operation of the multiple gear pump and the pump system according to the present embodiment will be described in detail with reference to FIGS. 2A and 2B.

First, the basic operation will be described. In the pump system according to the present embodiment, the two operation modes as shown in FIGS. 2A and 2B can be switched by adjusting the flow rate control valve 10. That is, in the pump system according to the present embodiment, by setting the flow rate control valve 10 to the closed state, the first and second fluid boosters S1 and S2 of the triple-barrel gear pump 1 are connected in parallel as shown in FIG. 2A. The parallel operation mode is set in the set state.

Further, in the pump system according to the present embodiment, by setting the flow rate control valve 10 to the open state, the first and second fluid boosters S1 and S2 are connected in series as shown in FIG. 2B. Become a mode. In addition, in FIGS. 2A and 2B, the part where the relatively low pressure liquid to be pressurized (low pressure liquid) flows and the part where the relatively high pressure liquid to be pressurized (high pressure liquid) flows are compared in different modes, that is, the low pressure liquid is compared. It is thin and draws a high-pressure liquid relatively thickly.

Explaining the parallel operation mode first, the low-pressure liquid supplied from the inflow pipe 2 to the first input / output port P1 of the triple gear pump 1 rotates in the direction shown by the second rotating shaft 1f (drive shaft). The first gear 1b and the second gear 1c are rotationally driven in opposite directions. As a result, the low-pressure liquid of the first input / output port P1 is boosted by the first fluid boosting unit S1 and discharged as the high-pressure liquid to the second input / output port P2 and the third input / output port P3.

That is, due to the pressurizing action of the first fluid boosting unit S1, the low-pressure liquid becomes a high-pressure liquid by the first fluid boosting unit S1 and is sent out to the second input / output port P2 and the third input / output port P3. Then, the high-pressure liquid of the second input / output port P2 is supplied to the liquid demand destination via the outflow pipe 3. The high-pressure liquid of the third input / output port P3 is supplied to the liquid demand destination via the fourth connection pipe 7 and the outflow pipe 3.

Further, in this parallel operation mode, since the flow rate control valve 10 is set to the closed state, the differential pressure acting on the check valve 9 is relatively small. That is, in the parallel operation mode, the check valve 9 is in a conductive state. Therefore, a part of the low-pressure liquid supplied from the liquid supply source to the inflow pipe 2 is not only the first input / output port P1 of the triple-barrel gear pump 1, but also the first connection pipe 4, the check valve 9, and the fifth connection pipe. It is also supplied to the fourth input / output port P4 of the triple-barrel gear pump 1 via 8.

Then, the low-pressure liquid supplied to the fourth input / output port P4 is boosted by the second fluid boosting unit S2 by rotating the second gear 1c and the third gear 1d in the direction shown in the drawing, and enters the second high-pressure liquid as a high-pressure liquid. It is discharged to the output port P2 and the third input / output port P3. The high-pressure liquid of the second input / output port P2 is supplied to the liquid demand destination via the outflow pipe 3. The high-pressure liquid of the third input / output port P3 flows to the outflow pipe 3 via the third connection pipe 6 and the fourth connection pipe 7, and is supplied to the liquid demand destination.

In this way, in the parallel operation mode, the first and second fluid boosters S1 and S2 provided in the triple-barrel gear pump 1 are connected in parallel in the flow direction of the liquid to be boosted, that is, in the direction from the inflow pipe 2 to the outflow pipe 3. It will be in the state of being. That is, in the parallel operation mode, the high-pressure liquid boosted by the first fluid boosting unit S1 and the high-pressure liquid boosted by the second fluid boosting unit S2 are discharged from the triple gear pump 1. Therefore, in this parallel operation mode, a high-pressure liquid having a flow rate of about twice the discharge amount of the first fluid boosting unit S1 is supplied to the liquid demand destination.

On the other hand, in the series operation mode, the low-pressure liquid supplied from the inflow pipe 2 to the first input / output port P1 is boosted by the first fluid boosting unit S1 to be a high-pressure liquid, which is the second input / output port P2 and the third input / output port. It is discharged to P3. Then, the high-pressure liquid of the second input / output port P2 is supplied to the liquid demand destination via the outflow pipe 3. The high-pressure liquid of the third input / output port P3 is supplied to the liquid demand destination via the fourth connection pipe 7 and the outflow pipe 3.

However, in this series operation mode, since the flow rate control valve 10 is set to the open state, a part of the high-pressure liquid of the third input / output port P3 passes through the flow rate control valve 10 in the check valve 9 in the initial state. It is supplied to the second input / output port. That is, in the series operation mode, the differential pressure acting on the check valve 9 becomes relatively large, so that the check valve 9 is in an outrageous state.

As a result, a part of the high-pressure liquid discharged to the third input / output port P3 is supplied to the second input / output port P2 via the fifth connection pipe 8 in addition to the flow rate control valve 10. Then, this high-pressure liquid is discharged to the second input / output port P2 via the second fluid boosting unit S2. Then, the high-pressure liquid flows through the outflow pipe 3 and is supplied to the liquid demand destination.

In such a series operation mode, the first and second fluid boosters S1 and S2 of the triple-barrel gear pump 1 are connected in series in the flow direction of the liquid to be boosted, that is, in the direction from the inflow pipe 2 to the outflow pipe 3. It becomes. That is, in the series operation mode, the high-pressure liquid boosted by the first fluid boosting unit S1 is discharged from the triple-barrel gear pump 1.

Here, focusing on the second rotating shaft 1f (driving shaft) in the parallel operation mode, as shown in FIG. 2A, the pressure of the liquid to be pressurized acting on the second gear 1c is balanced in the circumferential direction, whereby the first The radial load acting on the two rotating shafts 1f (drive shaft) is offset.

That is, the radial load (radial load) acting from the second rotating shaft 1f is relatively small on the second bearing 1i that rotatably supports the second rotating shaft 1f (driving shaft). Therefore, since the load acting from the second rotating shaft 1f is relatively small, the second bearing 1i does not require a high-pressure liquid for a high load as a lubricant.

In such a multiple gear pump and pump system according to the present embodiment, the second bearing 1i is provided by considering a relatively small radial load acting on the second rotating shaft 1f (drive shaft) and the second bearing 1i. It is connected to the fourth input / output port P4 through which the low-pressure liquid flows. That is, in the present embodiment, since the high pressure liquid is not consumed as a lubricant in the second bearing 1i, the reduction in capacity efficiency due to the consumption of the high pressure liquid as a lubricant while ensuring the load capacity of the second bearing 1i is conventionally achieved. It is possible to suppress more than.

Regarding the first rotating shaft 1e other than the second rotating shaft 1f (drive shaft), as shown in FIG. 2A, the pressure of the liquid to be pressurized acting on the first gear 1b is unbalanced in the circumferential direction, and the radial load. However, in the first gear 1b, the pressure of the liquid to be pressurized is relatively low, that is, in the first bearing 1h, the high pressure liquid is supplied from the second input / output port P2 to the region near the first input / output port P1. NS. Therefore, the first bearing 1h can sufficiently cope with the radial load.

Further, regarding the third rotating shaft 1g, the pressure of the liquid to be pressurized acting on the third gear 1d is unbalanced in the circumferential direction as in the case of the first rotating shaft 1e, and the radial load is relatively large, but the third gear In 1d, the pressure of the liquid to be pressurized is relatively low, that is, in the third bearing 1j, the high pressure liquid is supplied from the third input / output port P3 to the region near the fourth input / output port P4. Therefore, the third bearing 1j can sufficiently cope with the radial load.

On the other hand, in the series operation mode, as shown in FIG. 2B, the pressure of the pressurized liquid acting on the second gear 1c is unbalanced in the circumferential direction. Therefore, the radial load acting on the second bearing 1i that supports the second rotating shaft 1f is relatively large. On the other hand, the second bearing 1i is connected to the fourth input / output port P4 through which the high-pressure liquid flows, and the pressure-pressed liquid acting on the second gear 1c has a relatively low pressure of the first input / output port P1. High-pressure liquid is supplied from the fourth input / output port P4 to the region in the vicinity of. Therefore, the second bearing 1i can sufficiently cope with the radial load.

Here, the fourth input / output port P4 is on the low pressure side in the parallel operation mode, that is, when the connection relationship between the first fluid booster unit S1 and the second fluid booster unit S2 is parallel connection, and is in the series operation mode, that is, the first fluid booster unit. When the connection relationship between S1 and the second fluid booster S2 is a series connection, it is a liquid input / output port on the high pressure side. In the present embodiment, two operation modes, a parallel operation mode and a series operation mode, are switched by a switching flow path, so that the second bearing 1i that supports the second rotation shaft 1f (drive shaft) is connected from the fourth input / output port P4. Supply the liquid to be pressurized (lubricant).

Further, with respect to the first rotating shaft 1e, as shown in FIG. 2B, the pressure of the pressure-pressed liquid acting on the first gear 1b is unbalanced in the circumferential direction, and the radial load is relatively large. However, in the first bearing 1h that supports the first rotating shaft 1e, the pressure of the liquid to be pressurized acting on the first gear 1b is secondly inserted in the region near the first input / output port P1 where the pressure is relatively low. High-pressure liquid is supplied from the output port P2. Therefore, the first bearing 1h can sufficiently cope with the radial load.

Further, with respect to the third rotating shaft 1g, the pressure of the pressure-pressed liquid acting on the third gear 1d is balanced in the circumferential direction, and the radial load is relatively small. Since the third bearing 1j that supports the third rotating shaft 1g is connected from the third input / output port P3 of the high-pressure liquid to the vicinity of the fourth input / output port P4 of the high-pressure liquid, the high-pressure liquid can be used. It is possible to sufficiently cope with a radial load without consuming it as a lubricant.

According to this embodiment, the high pressure liquid is not supplied to the second bearing 1i as a lubricant in the parallel operation mode, that is, the high pressure liquid is not consumed in the second bearing 1i, so that the high pressure is applied only to the first bearing 1h and the third bearing 1j. Consume liquid. Therefore, according to the present embodiment, it is possible to suppress a decrease in capacitance efficiency in the parallel operation mode as compared with the conventional case, while ensuring the load capacity of the first to third bearings 1h to 1j.

The present invention is not limited to the above embodiment, and for example, the following modifications can be considered.
(1) In the above embodiment, the parallel operation mode and the series operation mode are switched by providing the switching flow path, but the present invention is not limited to this. For example, the external flow path of the triple-barrel gear pump 1 may be formed so that the operation mode is fixed to either the parallel operation mode or the series operation mode.

(2) In the above embodiment, the input / output port of the triple-barrel gear pump 1, that is, the fourth input / output port P4, which changes from the low pressure liquid to the high pressure liquid in the parallel operation mode and the series operation mode, is connected to the second bearing 1i. , The present invention is not limited to this. For example, when operating only in the parallel operation mode, the first input / output port P1 through which the low-pressure liquid flows may be connected to the second bearing 1i in the same manner as the fourth input / output port P4.

(3) In the above embodiment, the triple-barrel gear pump 1 is adopted, but the present invention is not limited thereto. The present invention can also be applied to a multi-series gear pump having a larger number of stations, for example, a five-series gear pump. That is, the number of rotating shafts, bearings, and gears in the present invention may be three or more, that is, the number of fluid boosters in the present invention may be two or more.

1 Triple-barrel gear pump (multiple-barrel gear pump)
1a Casing 1b 1st gear 1c 2nd gear 1d 3rd gear 1e 1st rotary shaft 1f 2nd rotary shaft 1g 3rd rotary shaft 1h 1st bearing 1i 2nd bearing 1j 3rd bearing 2 Inflow pipe 3 Outflow pipe 4 1st Connection piping 5 2nd connection piping 6 3rd connection piping 7 4th connection piping 8 5th connection piping 9 Check valve 10 Flow control valve P1 1st input / output port (liquid input / output port)
P2 2nd input / output port (liquid input / output port)
P3 3rd input / output port (liquid input / output port)
P4 4th input / output port (liquid input / output port)
S1 1st fluid booster S2 2nd fluid booster

Claims (4)

Arranged so as to be parallel to each other, and three or more rotating shafts whose drive shafts are not located at the ends of the arrangement,
Three or more bearings that support each of the rotating shafts,
Each of the rotating shafts is equipped with three or more gears which are mounted in a row and mesh with each other to form two or more fluid boosting portions.
A multi-communicated gear pump characterized in that the bearing of the drive shaft is connected to the low pressure side of a pair of liquid input / output ports communicating with the fluid booster. The multiple gear pump according to claim 1, wherein the bearing is a slide bearing provided with a static pressure pad. The multiple gear pump according to claim 1 or 2, wherein the number of the rotating shaft, the bearing, and the gear is three. The multiple gear pump according to any one of claims 1 to 3 and
It is provided with a switching flow path for switching the connection relationship of the fluid booster unit between parallel connection and series connection.
The bearing is connected to the liquid input / output port on the low pressure side when the fluid boosting unit is connected in parallel and on the high pressure side when the fluid boosting unit is connected in series. system.

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