JPH08100774A - Externally attached type gear type fluid feeder - Google Patents

Abstract

PURPOSE: To define a multitude of independent pumping elements via an extremely simple and economical method that offers appreciably reduced overall device dimensions. CONSTITUTION: A hollow body 2 acts as a casing closed off axially at one end by a cover 4 and at the opposite end by a flange 3. The hollow body 2 has a cavity 5 in the form of two opposing lobes in which are coupled rotationally pairs of driving gearwheels 9 and 9a and driven gearwheels that mesh with the driving gearwheels 9 and 9a. The driving gearwheels 9 and 9a are coupled to driving means. The hollow body 2 is fitted with positionable partitioning means 11 that divides the cavity 5 into at least two independent pumping chambers 13.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a positive displacement external gear type fluid feeder. This pump includes a hollow cylindrical body that acts as a case with one end in the axial direction closed by a cover and the other end closed by a flange, and this cylindrical body is composed of two drive gears and a driven gear that are rotatably connected to each other. A seat, which is a lobe, has a driving gear and a driven gear meshing with each other, and the driving gear is connected to the driving means.

[0002]

2. Description of the Related Art In the above conventional gear pump, a hollow body is obtained by extruding a high-strength aluminum or casting a metal material such as special cast iron. In an extrusion pump, a shaft to which the gear is keyed is rotatably connected to a shaft. The shaft is installed in a two lobe cavity in which the gear is located. Therefore, the gears are necessarily arranged coaxially with the lobes of the cavity.

If two or more independent pump elements with the same displacement are required, they are connected in series so that the drive shafts of a pair of gears of one pump element are connected via a coupling. And is connected in series to the drive shaft of the next pump element. As a result, the axial dimension is
It is the sum of the axial length of the main body of each pump element, and the thickness of the cover and the thickness of the flange. The axial length of the coupling is added to the axial length of the main body.

In pumps where the body is obtained by casting, the support of the shaft of each pump element is provided in the cover or in the flange and therefore centering pins are used to bring these supports to the body. Since positioning is required, high cost is required because high processing accuracy is required. If more than one pump element is required, the pump body is divided into several parts in order to insert a rotation-transmitting coupling between the shaft of one pump element and the next shaft connected to it.

[0005]

If this is done, it is difficult to perform further processing, the cost becomes considerably high, and the overall size becomes large. As an alternative, a special casting with two separate pump chambers must be designed, at least if only two pump elements that are hydrodynamically independent of each other are required. Such devices are oversized, and there are severe restrictions on the use of these pumps,
There are many problems when installing. For example, for small fluid excavators, the space available is very limited, requiring a large number of independent fluid circuits. The prior art device as described above needs to be improved to eliminate the above-mentioned problems.

[0006]

The problem to be solved by the present invention is to simplify the manufacture of fluidic devices such as gear motors or pumps, in a very simple and economical way and in overall dimensions. The objective is to create a large number of independent pumping elements with a large drop.

This object can be achieved by employing a gear motor or pump of the type described above, which is provided in the casting containing a lobe-shaped case. The case comprises positionable partitioning means dividing the lobe-like cavity into at least two separate, independent chambers.

Each chamber has an inlet and a corresponding outlet, which is particularly convenient when it is desired to use the fluid system as a bidirectional gear motor or pump. This room is
It may have a common inlet and a different outlet,
It is particularly convenient when it is desired to use the fluid system as a unidirectional gear motor shunt. In the case of a unidirectional gear motor type flow dividing device, particularly when it is desired to be used as a high-low pump, a check valve may be interposed between the discharge ports.

In a particularly preferred embodiment, the positionable partitioning means may consist of at least one divider plate which can be axially arranged in a cavity with two opposing lobes. The lobes of the gears in a lateral plane perpendicular to the axis of the cavity.

One of the advantages of the present invention is that when at least two independent pump or motor elements are required,
By adopting the above configuration, the overall size is reduced.

Another advantage is that by adopting the same pump body or motor body having a predetermined length and changing the axial position where the dividing plate is set during assembly,
The point is that the pump chamber can be moved variously within a certain range. As a result, the number of spare parts to be stocked can be reduced and the manufacturing process can be greatly simplified. Further, the above-described configuration is suitable for both the pump made by extrusion and the pump of the main body obtained by casting.

In this regard, it is preferred that the divider be made of a low friction, wear resistant material suitable for connecting to the ends of the gear. Such a construction is not possible with conventional pumps, especially casting-type pumps in which the pump body is made of one type of material, and extrusion-type pumps in which the structural elements cannot be formed in a plane perpendicular to the extrusion axis. You can realize what was possible.

In a particularly preferred arrangement, it has a single inlet through the pump body, which body is divided into two parts by a dividing plate below the inlet, into two pump chambers. The fluids are made to flow separately, and the flow rate of the fluids is preferably proportional to the discharge amount of each pump chamber.

For this reason, the divider plate may be centrally located with respect to said intake or may be off-center, ie along the axis of the cavity, towards one pump chamber side. Displace.

In this respect, the dividing plate is positioned and the pump chamber of each pump element is used in a very simple manner without using a complicated external intake manifold as used in the prior art. It is particularly advantageous because it supplies the fluid in an optimum way.

In another preferred embodiment, the axial length of the divider, ie, the dimension parallel to the axis of the cavity with two opposing lobes, is the axial direction of the end support. Less than total length. The length is reduced by approximately 30% to 50%.

Thus, when the ratio of the discharge amounts of the adjacent pump chambers is a constant value, there is an advantage that the axial dimension of the pump body is further reduced.

The reduction in the axial length of the divider plate allows the pump usage to be taken into account to optimize the amount of material needed for production, eliminating the nuisance waste resulting from overdesign. It can be lost.

The addition of supports to each of the drive and driven shafts at the split plate provides a synergistic effect from the perspective of load distribution.
This effect cannot be obtained by using the coupling to connect the pumps in series as in the prior art.

In yet another preferred embodiment, the divider plate comprises:
There is a plane of symmetry parallel to the axis of the cavity with two opposite lobes, which is divided into two parts at the point of said plane of symmetry. For example, using a semi-finished product made by machining from a round bar by using casting, forging, or a normal machine tool, machining symmetrically in the axial direction is performed by dividing each of two parts obtained by dividing the dividing plate. As a result, the advantage is obtained that the division plate is particularly simple to manufacture.

In yet another preferred embodiment, the divider plate has a first recess located on the side corresponding to the intake,
Thereby, the pump chambers are axially communicated with each other to improve the fluid filling. On the side facing the outlet, the divider may have a second recess, which is similar to said first recess and which protrudes from the surface forming the cavity and is lobe-shaped. It is connected to a plug element of the same shape that extends inward at a position corresponding to the connection portion between them. This prevents the pump chambers from connecting to each other on the outlet side.

In addition, the divider plate may be symmetrical with respect to a plane perpendicular to the axis of the cavity with the two opposed lobes of the pump body. This has the additional advantage of being quick to assemble. Rapid assembly is essential to facilitate automation of the manufacturing process of such pumps.

[0023]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A fluid feeding apparatus of the present invention includes a body 2 including a gear pump 1 formed by, for example, an extrusion process, a cover 4 is fitted to the body 2 in the axial direction of the body, and the opposite side of the cover 4 is provided. Is provided with a flange 3 for connecting to a driving means (not shown). The main body 2 has a cavity 5,
This cavity preferably has two opposite symmetrical lobes. Drive gears 9 and 9 into this lobe
The drive shaft 7 and the driven shaft 8 that are connected to each other via a are inserted into the support portions 6 at the two pairs of ends in a sealed state so as not to leak liquid. Drive shaft 7
And the driven shaft 8 are engaged with each other by driving gears 9 and 9a keyed to the drive shaft 7 to form a pair with driven gears 10 and 10a, which are corresponding gear pairs keyed to the driven shaft 8. It is connected. This support 6 is a bush 6b for rotatably connecting to the shafts 7 and 8.
The bush 6b is fitted in the corresponding axial hole 6a of the support portion 6. The cover 4 and the flange 3 are locked to the main body 2 by the pull rod 10c, and the front peripheral seals 2a are arranged between the main body 2 and the cover 4 and between the main body 2 and the cover 4, respectively. .
The flange 3 has a through hole 10d through which the shaft 7 passes, and the through hole 10d is provided with a rotary sealing element 10e that rides on the shaft 7. There is a dividing plate 11 near the center of each of the shafts 7 and 8.
Has a pair of through holes 12, and the shafts 7 and 8 are rotatably connected to each other through the bushes 11a between the through hole 12 and the shaft 7 and between the through hole 12 and the shaft 8, respectively. ing. Inside the cavity 5 of the main body 2 which acts as a seat for the drive gears 9, 10 and the driven gears 9a, 10a and has the shape of two opposed lobes, a dividing plate 11 divides the cavity 5 to form an axial direction. Two separate pump chambers 13 are formed between the split plate and each support 6. Drive gears 9, 10 and driven gear 9
Note that a and 10a are in sliding contact with the split plate 11 on one side and in sliding contact with the end support 6 on the other side. Thereby, it is possible to obtain a discharge amount within a certain range having a predetermined ratio between both pump chambers by using a gear having an appropriate axial dimension as shown in FIG.

If the dividing plate 11 is manufactured separately from the main body 2 and is inserted into an appropriate axial position in the cavity 5 during assembly, one pump main body 2 can be used to separate each other. The same or different pump chambers 13 can be defined. The positioning and fixing of the divider plate in place is preferably done by an interference fit, preferably by heating the body 2 and cooling the divider plate 11.

In the case of an aluminum pump, the main body should be
The split plate may be heated to 250 ° C. and cooled to approximately −20 ° C. These temperature values are equivalent to those suitable for cast iron pumps. A known assembly manipulator may be used as the device used to insert the dividing plate into the body 2 at a predetermined axial position.

Normally, the intake port A for taking in a fluid such as oil comprises a through hole 14 provided at a position in the main body 2 corresponding to the position of the dividing plate 11, and supplies the fluid to both pump chambers at an appropriate ratio. I am trying to do it. The shape of the through hole 14 viewed from the front may be a circle, an elongated rectangle with rounded ends, a combination thereof (FIGS. 6 and 7), or any other suitable shape. Also, intakes A and 1
4 may be a portion where the oil flow rate is constant, or may be a variable flow rate portion that expands as it approaches the pump chamber. In this embodiment, in order to make it easy to completely fill the pump chamber, especially when the pump chamber extends in the axial direction, the side wall of the intake port 14 is preferably formed as in the embodiment of FIGS. 4 and 5. There are stretches 14a that expand inwardly of the body 2. When the intake port 14 is configured in this way, for example, even when the dividing plate 11 is extended in the axial direction for the reason of strength, the pump chamber 13 can be optimally filled with the fluid. Figure 7
As shown in FIG. 6, or at a position corresponding to the axis of symmetry of the intake port 14 as shown in FIG. If it is off center, the position of the intake must be determined according to a function of the ratio between the displacements of the pump chambers 13, but if it is at the position of the axis of symmetry, the positioning is essentially that of the dividing plate 11. Regardless of position.

1, 3 and 4 show how to provide the end connecting means on the side opposite to the end of the drive shaft 7 connected to the drive means. For example, shank 7a and key 7
Means may be provided for driving the drive shaft of another pump connected in series with pump 1 via b. The driving means may include a spline 7.

In FIG. 4, a pair of gears 15 meshing with each other is housed inside each pump chamber 13, each gear has two ring gears 15a, and a spacer ring 16 is provided between these ring gears 15a. 1 shows an example of a pump arranged. Each ring gear 15a is offset from the other ring gear 15a inserted in the same pump chamber 13 by an angle corresponding to a value of 1 pitch or less, and is 1 / l of the pitch between the teeth of each gear. 2 is preferred. This reduces the noise level of the pump.

The carry-out port M is formed of a through hole 17 provided in the main body 2, and each pump chamber 13 is connected to the downstream fluid circulation path by the corresponding discharge port M. This outlet M
Ha. FIG. 5 shows a hollow body 18 similar to the body 2.
An example in which the cover 19 and the flange 20 are connected to each other by manufacturing by casting is shown. In this embodiment, the supporting portion 6 is integrally formed with the flange and the cover, and each has a pair of bushes 6a. At the ends of the drive gears 9 and 9a and the driven gears 10 and 10a, the side close to the inside of the cover 4 tee 5 is in direct slidable contact with the split plate 11, and the side close to the outside of the cover 4 tee 5 is located. The cover 19 and the flange 20 are slidably in contact with each other via the friction reducing plate 21. The friction reducing plate 21 is made of a material having a low friction coefficient. Since the division plate 11 is made of a wear resistant material having a low friction coefficient, if the division plate 11 is formed separately from the main body 18, the drive gears 9 and 9a and the driven gears 0 and 10a are formed.
It should be noted that a plate for reducing friction between the partition plate 11 and the partition plate 11 is not necessary, and the manufacturing cost can be saved.

8 to 10 show two possible embodiments of the dividing plate 11. The outer surface of the divider plate is provided with two opposing lobes 22 to cover both lobes and the axial cover 4.
It must be assembled such that the inner surface of the tee 5 and the lobe shape of the tee 5 match each other correctly. On the intake side A, the split plate is provided with the first recessed portion 23 so that the pump chamber 13
Ensure that the fluid is well filled.

On the same side, the dividing plate has a pair of grooves 23a, and the grooves 23a allow the through holes 12 to communicate with each other and prevent the occurrence of cavitation. A second concave portion 26 corresponding to the first concave portion 23 is provided on the discharge port side M,
It may be provided on the side facing the first recess 23. Inside the cavity 5, a plug element 27 is arranged between the second recess 26 and the cavity 5 to prevent the pump chambers 13 from communicating with each other on the outlet side. are doing. The plug element 27 may be integrally formed with the body of the hydraulic device 1 or may be formed by an appendix protruding inward of the lobe-shaped cavity 5. On the side where the second concave portion 26 is provided, it is preferable to provide two pairs of opposed grooves 24 each having a V shape in the dividing plate, and these grooves 24 allow the position of the pump chamber where the pressure is the highest. At corresponding positions, oil is drained more slowly from the pump chamber formed by the mating teeth to reduce noise levels.

The dividing plate is symmetrical about a first plane parallel to the axis of the hole 12, ie parallel to the cavity 5,
This dividing plate is divided along the symmetry plane S as in the embodiment of FIG.
It may be divided into two parts and the relative position may be determined by a positioning pin at the time of assembly, or may be made of a single member as in the embodiment of FIG. Furthermore, as shown in FIGS. 9 and 11,
It is preferable that the dividing plate is also symmetrical in the third plane of symmetry that is perpendicular to the axis of the hole 12. The support portion 6 and the friction reducing plate 21 are
Drive gears 9, 9 of shafts 7 and 8 which occur in the prior art
Note that it is intended to compensate for axial thrust on the ends of a and the driven gears 10, 10a.

Although not shown, in another embodiment, both the drive shaft 7 and the driven shaft 8 may be rotatably connected to one of the supports 6 and the split plate, whereby a further support is provided. 6 is an axial balancing plate
only acts as e). As shown in FIG. 12, the fluid device may be composed of a bidirectional gear motor, that is, a pump 1a. In the drawing, when the gears 9 and 9a are driven clockwise, the intake port A is connected to the discharge port M. When rotated counterclockwise, the intake port A1 is connected to the discharge port M1.

Each pump chamber 13 has intakes A, A1, 14
b and outlets M, M1 which are located in the body 2 of the motor or pump 1a. In order to separate the pump chambers 13 from each other, the outer contour of the dividing plate 11b must be joined to the inner contour of the cavity 5.
This is preferably performed by providing the dividing plate 11b which is also symmetrical with respect to the second plane of symmetry passing through the axis of the hole 12. In particular, the partition plate 11b has a pair of opposed second recesses 26 that can engage with the corresponding protrusions 27 of the cavity 5. Each second recess 26 has a V-shaped groove 24.

As shown in FIG. 15, a fluid high-low pump 1c guides a check valve 31 and a sequence valve 33, and a pilot line 32.
There are outlets connected to each other by a connection channel 30 having the above, and the sequence valve 33 is inserted into a bypass line 34 of one pump chamber 13.

FIG. 16 shows a gear motor shunt 1d. This scaler includes a first recess 23 and a second recess 2
6 is provided, and a V-shaped groove 24 is provided in both concave portions. This gear motor shunt 1d
Has a pair of opposed covers 4 and has a shaft 7d
The connecting means 7c are provided at both ends of the. In practice, various modifications may be made in the material, in the dimensions, and in the details of the embodiments, without departing from the scope of the invention.

[Brief description of drawings]

FIG. 1 is a first embodiment in which two pump chambers having the same discharge amount are separated by a dividing plate placed in the middle of both pump chambers, and a longitudinal direction of a unidirectional gear pump formed by extrusion. FIG.

FIG. 2 is a sectional view taken along line II-II of FIG.

FIG. 3 is a sectional view taken along the line III-III in FIG. 2, showing an embodiment having pump chambers with different discharge amounts.

FIG. 4 is a vertical cross-sectional view similar to FIG. 1, showing an embodiment with dual ring gears to reduce noise levels.

5 is a longitudinal section similar to that of FIG. 1, but for an embodiment in which the body is cast.

FIG. 6 is a partially enlarged plan view of FIG. 2, showing an embodiment in which the dividing plate is at the center position of the intake port.

FIG. 7 is a view similar to FIG. 6, showing an embodiment in which the dividing plate is off the center of the intake.

FIG. 8 is an elevational view of a divider plate separating two adjacent pump chambers of a pump according to the invention, for example two separate symmetrical parts placed side by side with each other, made of a round bar. An example including is shown.

9 is a diagram viewed from the right in FIG.

FIG. 10 is a view similar to FIG. 8 and shows an embodiment having an integral solid dividing plate, for example made by casting.

11 is a diagram viewed from the right of FIG.

FIG. 12 is a longitudinal cross-sectional view of yet another example bidirectional gear motor or pump of which the body is extruded, with substantially equal emissions and intermediate splits. Figure 3 shows a pump with two pump chambers separated by a plate.

13 is a sectional view taken along line XIII-XIII in FIG.

14 shows a split plate insertable in the middle of the cavity of the gear motor or pump shown in FIG.

FIG. 15 is a longitudinal cross-sectional view of a high-low pump provided with a positionable dividing plate.

FIG. 16 is a longitudinal sectional view of a bidirectional gear motor shunt with two pump chambers provided by a positionable divider.

FIG. 17 is a front view of a partition plate positionable in a lobe-shaped cavity of the gear distributor shown in FIG.

[Explanation of symbols]

 4 cover 5 capacity 6, 6a support 8 drive shaft 9, 9a drive gear 10, 10a driven gear 11 split plate 12 through hole 13 pump chamber 14 intake 15, 15a drive gear 16 spacer ring 23 recessed portion 27 plug element

Claims (18)

[Claims] 1. A body (2) which is axially closed by a closing means (3, 4; 19, 20) and has two opposing lobe-shaped cavities (5), said cavities (5). ) To a pair of gears (9, 9a, 1
0,10a, 15,15a) are rotatably connected so that the gears (9,9a, 10,10a, 15,15a) mesh with each other, the main body (2) has a cavity (5). At least two independent pump chambers (1
An external gear-type fluid feed device fitted to a partitioning means (11) which can be divided into 3) and which can be positioned. 2. Each pump chamber (13) has an intake (A, 1).
4, 14a) and independent outlets (M, M1, 17), each inlet (A, 14, 14a) corresponding to another inlet (A, 14) in another pump chamber (13). , 14a). The external gear type fluid feed device according to claim 1, wherein the fluid feed device is external. 3. Each pump chamber (13) has an independent outlet (M, M1, 14b, 17) and an independent inlet (A, A).
1, 14, 14b, 17), and the external gear type fluid feeder according to claim 1. 4. The partition means (11) capable of positioning
But at least one split plate (11, 11b, 11c)
The partition plate is axially arranged inside the cavity (5) in a lateral plane perpendicular to the axis of the cavity (5), and the partition plate (11, 11b,
11c) has a pair of through holes (12), and a drive shaft (7) and a drive shaft (8) are rotatably connected to the respective through holes, and these shafts have the gear (9). , 9a, 10, 10a, 15, 15a) are provided, and the external type gear type fluid feeding device according to claim 1. 5. A single intake (14) is provided so as to pass through the body (2) of the pump, and the intake is divided into two parts by a dividing plate (11) below this intake. The external gear type fluid feed device according to claim 2, wherein the external fluid feed device is divided. 6. The pump chamber (1) is provided with the intake (14a).
The external gear type fluid feed device according to any one of claims 1 to 5, further comprising a side wall forming a flow path that widens toward (3). 7. The position of the dividing plate (11) with respect to the pump chamber (13) is determined so that the flow of the liquid entering each pump chamber (13) is proportional to the discharge amount of each chamber. The external gear type fluid feed device according to claim 5, which is characterized. 8. The linear dimension of the dividing plate (11) in the direction parallel to the axis of the cavity (5) is smaller than the sum of the axial dimensions of the supporting portions (6, 6a) for supporting the end portions. The external geared fluid feeder of claim 1, wherein the reduction in length is from about 30% up to 50%. 9. The partition plate (11, 11c) has a first recess (23) located on the side corresponding to the intake (14, 14a), and the first recess (23). The external gear type fluid feed device according to claim 4, wherein the pump chambers (13) communicate with each other to facilitate filling with a fluid. 10. The dividing plate (11) has a contour matching the inner surface of the cavity (5) on the side facing the outlet (17), so that the pump chambers (13) are mutually connected. The gear pump according to claim 4, wherein the gear pump prevents the communication. 11. The partition plate (11) is made to form a seal with a plug element (27) projecting from the cavity (5) at a position corresponding to the connection point between the lobes. The external gear type fluid feed device according to claim 9, further comprising a second concave portion (26). 12. The dividing plate (11) has two pairs of grooves (23a) which are bidirectional and opposite to each other, and these grooves connect the through hole (12) with the through hole (12). The external gear type fluid feed device according to claim 4, wherein 13. The dividing plates (11, 11b, 11c)
External gear type fluid feed according to claim 4, characterized in that it has two pairs of V-shaped bidirectionally opposed grooves (24) on the side of the outlet (17). apparatus. 14. The dividing plates (11, 11b, 11c)
Has a plane of symmetry (S) parallel to the axis of the cavity (5), the external gear type fluid feeder according to claim 4. 15. The partition plate (11b) has a through hole (1).
The gear pump according to claim 4, which has a second plane of symmetry that passes through the axis of 2). 16. The dividing plate (11, 11b, 11c)
The external gear type fluid feed device according to claim 4, wherein is symmetrical with respect to a third plane of symmetry perpendicular to the axis of the hole (12). 17. The dividing plate (11, 11b, 11c)
Is obtained by molding a wear-resistant material having a low coefficient of friction, and the external gear type fluid feed device according to claim 4, wherein 18. Each gear (10, 10a, 15, 15)
a) has two ring gears (10a, 15a), and a spacer ring (16) is arranged between the two ring gears so that the ring gears have teeth that are offset from each other. The external gear type fluid feed device according to claim 1, wherein the external gear feed device is provided.