JPS5830153Y2 - gear pump - Google Patents

Description

[Detailed description of the invention] The present invention relates to a gear pump, and in particular, includes a pressure balance mechanism to form a high-performance gear pump with low noise and high pressure, and a structure that can completely separate high-pressure oil and low-pressure oil. This invention relates to a gear pump equipped with a gear pump.

A gear pump equipped with a conventional pressure balance mechanism uses the pressure brought to the discharge side to guide high-pressure oil from the gap formed when the bearing and side plate of the gear pump are pressed against the suction side to the back of the bearing. A configuration was adopted that balanced the pressure and kept the axial clearance constant.

However, when such structure e is adopted, a part of the high-pressure oil inevitably flows into the low-pressure region, that is, the suction side, resulting in a drawback that the performance of the gear pump is degraded.

In view of this drawback, in order to eliminate this drawback, the present applicant proposed a gear pump in Japanese Patent Application No. 128636/1982 (Japanese Patent Publication No. 14322/1989), and this gear pump has two bearings located on both sides of the gear. balance things.

This is a so-called double-sided balanced gear pump.

Although this double-sided balanced gear pump is completely satisfactory in terms of performance, the purpose of this invention is to simplify the structure by balancing only one side of the bearings located on both sides of the gear. Reduced price.

The aim is to provide a popular gear pump.

According to the present invention, like the above-mentioned double-sided balanced gear pump, it has a structure that can completely separate high-pressure oil from low-pressure oil so that they do not mix, and the bearing member is equipped with pressure oil that balances the pressure. The gap in the axial direction is maintained constant by having a configuration in which the oil is guided to the back surface of the member through a through-hole.

A gear pump with low noise and high pressure is provided.

An embodiment of the present invention will be described below with reference to the drawings.

Referring to FIG. 1, there is shown a partially sectional side view of a gear pump according to the present invention.

FIG. 2 is a front view seen from the line ``--'' in FIG. 1, and shows a state with the cover 3 removed.

FIG. 3 shows a front view of the cover 3 as seen from the line ■--■ in FIG.

Here, a casing 1 of the gear pump is provided with a hollow part 2.

The hollow part 2 is formed by a pair of gears 5°5' that mesh with each other.
It consists of a hollow section with an elongated cross section that accommodates the.

The cover 3 constitutes a part of the casing 1. It is liquid-tightly fixed to both ends of the casing via seals 4.

The shaft 6 of the gear 5 and the shaft 6' of the gear 5' are bearing members 7, 7 and 7', respectively.

7″′ is rotatably supported.

6 is a driving shaft, and 6' is a driven shaft.

One end of a drive shaft 6 extending outside the cover 3 of the casing 1 receives power to mesh and rotate the gears 5, 5'.

Thus, when the gears 5 and 5' are meshed and rotated in the direction of the arrow in FIG. 2, liquid flows in from the suction port 8 provided in the casing 1 and is discharged from the discharge port 9.

Between the axial end surfaces of the bearing members 7, 7' and the cover 3,
4 flexible 7-rules 10° 11; 10', 11'
is provided.

Referring to FIG. 4, the shapes of seals 10 and 11 are shown enlarged.

1, 2 and 4, such a seal ensures that the axial end face of the bearing member 7,7' and the cover 3
It will be understood that there are a total of two rooms between them.

That is. Chamber 0 between seals 10 and 11: seals 10' and 1
The chambers P between 1' are each surrounded by two seals and are formed in a sealed state.

The arrangement of the seals 11 and 11' is slightly shifted toward the suction port 8 as shown in FIG. 2. Note that in the case shown in FIG. However, it goes without saying that it can be provided on the cover 3 depending on the size of the pump, etc.

These seals provided on the axial end face of the bearing member are
It serves to completely separate the high pressure side and the low pressure side.

FIG. 5 is a cross-sectional view of FIG. 4 taken along the line -V.

As shown in FIGS. 1, 2, 4, and 5, one through oil hole 12, 12' is bored in the bearing members 7, 7'.

A through oil hole 13 is also formed in the axially central portion of the driven shaft 6'.

FIG. 6 is a rear view of the bearing member 7' seen from the rear direction of FIG. 4, and as shown here, it communicates with the suction port 8 and the discharge port 9, respectively.

The bearing members 7', 7 are provided with notches i and V.

These notches i and V are also provided at similar positions on the right bearing members 7 and 7''.

The arrangement of the through oil holes 12, 12' is shown in FIGS. 1 and 2.

As is clear from FIGS. 4 and 5, a hole is provided in the axial direction of the bearing member in the center between the suction port 81 and the discharge port 9v of the pump.

These penetrating oil holes are each communicated with the chamber O1P.

Referring to FIGS. 1 and 3, the drive shaft 6. The cover 3 has an oil hole 14 (3
Individual).

14a (one piece) is provided.

This oil hole 14a is a stepped hole 14 provided in the cover 3.
The inner end of the sealing member 141 is positioned in contact with the shoulder of the hole 140 and the outer peripheral surface of the drive shaft 6.

One of the covers 3 is provided with a communication pipe 15 near the suction port, which communicates with the oil hole 14 via an oil drain hole 16, as shown in FIG.

In the other cover 3, the oil hole 14a and the oil hole 14 are communicated with each other through an oil drain hole 16a (FIG. 1).

The communication pipe 15 is connected to a recovery hole 17 provided near the suction port 8 at the outer end of the casing 1 .

The recovery hole 17 communicates with the suction port 8.

Next, the operation of the gear pump configured as described above will be explained.

When the drive shaft 6 receives rotational power and the gears 5 and 5' mesh and rotate in the direction of the arrow in FIG. The liquid is carried along the inner circumference of the casing 1 to the discharge port 9, and is pushed out by the meshing of the gears.

As both gears 5, 5' rotate, fluid is trapped between the teeth and gradually compressed, and is discharged to the discharge port 9 at high pressure.

FIG. 8 is a diagram showing the relationship between the distance L between the suction port 81 and the discharge port 9v (the distance between the teeth and the inner circumference of the case song) and the oil pressure P. It can be seen that the value increases almost linearly from 0-)P1 to P2.

Approximately at the midpoint of the raised high-pressure oil, that is, at the small point -L in FIG. 8, there is a through oil hole 12, as described above.
12' is provided.

Therefore, the liquid at intermediate pressure P□ is introduced into the chamber O9P surrounded by the seal described above.

The thickness of the oil film between the thrust surface of the gear and the thrust surface of the bearing member is maintained uniformly, thereby serving to prevent bearing wear and reduce gap leakage.

The seal 11.11' prevents high pressure oil from leaking from the gap formed between the cover 3 and the bearing members 7, 7', and also prevents leakage from the gap 7.7' (see FIG. 2). Note that 10 and 10' are flattened and matched as shown in Figure 1).

Similarly, seal 10a. 10d prevents leakage from gaps formed between the other cover 3 and the bearing members 7//, 7///.

on the other hand. The low pressure oil used for lubricating the bearing passes through the oil drain hole 16° 16a and the through oil hole 13, and is collected from the communication pipe 15 through the collection hole 17 to the suction port 8.

Note that this low-pressure oil never mixes with high-pressure oil due to the seal 18 attached to the connecting pipe 15, and always flows through the suction port 8.
will be collected.

Looking at FIG. 7, the above-mentioned oil flow path is illustrated by arrows.

first. Through holes 12, 12 provided in bearing members 7, 7'
' is filled with oil at intermediate pressure P1 (see arrow e), and each of the above-mentioned chambers 0. It is confined by P and acts on the bearing member as one reaction force.

At this time, the reaction force (indicated by arrow W1) is obtained by multiplying the area (denoted by a) of each chamber O9P by the oil pressure (denoted by P).

On the other hand, the pressure generated in the gears 5, 5' causes the gears and bearings 7, 7 to
A force that acts to widen the gap between ′ (assumed to be W2)
is the product of the area of the side surface of the gear (denoted as a') and the discharge pressure P2.

P That is, W2-a'×i''.

Here, in order to balance the pressure of the guest, aXP=a
It is necessary that 'X'', that is, W1yr-W2.

In order to meet this demand, it is possible to provide the seals 10, 10', 11° and 11' by considering their area.

In this way, the gap between the side surface of the gear and the bearing member 7,7' and the gap between the side surface of the bearing member and the cover can be kept constant.

The oil removal necessary to achieve the above-mentioned balance does not escape from this, and since the bearing member itself is movable, the above-mentioned gap can always be maintained constant.

Next, the flow of oil used for lubrication can be clearly understood in FIG. 7 by the unmarked arrows.

That is, from the gear to the shafts 6, 6' and the bearing member 7s
7', 7tt, and 7ttt to reach 14 and 14a, and the oil that entered 14 of the left cover (in Fig. 7) passes through 16 and reaches the recovery hole 17 via the communication pipe 15. and is collected into the suction port 8.

The oil that has entered 14a of the right cover in FIG. 7 passes through 16a and reaches 14, and from 14 it passes through the through oil hole 13 for collecting lubricating oil provided in the shaft 6' and reaches 14 of the left cover. This is why it flows.

It will be seen that the lubricating oil recovery circuit is a lubricating path in which a flow is forced toward the suction port.

Regarding the positions of the through-oil holes 12 and 12' of the present invention, when considering the results of numerous experiments, it is preferable to provide them approximately at the center between the suction port 81 and the discharge port 9v, that is, at the -L position. It was found that the bearing temperature and bearing thrust surface wear were stable.

In addition, by slightly shifting the position of the seals 11 and 11' toward the suction port (see Figure 2), it is possible to automatically adjust and improve the inclination of the thrust surface caused by the pressure difference between the suction side and the discharge side. It turned out that it was possible and gave good results.

FIG. 9 is another embodiment of the embodiment shown in FIG.
In the embodiment shown in FIG. 9, the arrangement of the bearing members 7, 7' and 7", 7"' in the embodiment shown in FIG. 1 is reversed.

That is, in the embodiment shown in FIG. 9, chamber 0 is defined by seals 10 and 11 on the right, chamber P is defined by seals 10' and 11', and the bearing member on the right is balanced. The other operations are the same as those of the embodiment shown in FIG. 1, so they will not be repeated.

In addition, the configuration of the casing and casing cover is also
Instead of having covers on both sides of the casing as shown in FIG. 9, the cover 3 on the right or left side is formed integrally with the casing 1 as shown in FIGS. 10 and 11, The casing 1 is made into a cup-shaped piece 1'
It may be done as follows.

FIG. 12 shows the seal 10 of the bearing member 7' shown in FIG.
This is an explanation of an operating state in which oil is introduced into the chamber 0 between 11 and 11 through the through oil hole 12', and the bearing member moves slightly to the right.

The state in which chamber 0 is formed can be clearly understood.

As explained above, when one invention is used.

The internally generated pressure of the gear pump is extracted through the bearing.

Uniform pressure balance can be brought about over the entire thrust surface of one bearing, and the high-pressure part and low-pressure part can be completely separated, making it possible to obtain a high-performance, low-noise, high-pressure gear pump.

The gear pump of the present invention not only improves the volumetric efficiency of the pump, but also directs a large amount of lubricant to each part of the bearing, lowering the bearing temperature.

It can also improve its durability, making it extremely useful industrially.

As is clear from the above, one patent application was made in 1973.
The structure is simpler than the double-balanced gear pump described in Japanese Patent Publication No. 9-128636 (Japanese Patent Publication No. 54-14322), and the cost can therefore be reduced. , it is possible to obtain a corresponding effect.

[Brief explanation of the drawing]

Fig. 1 is a side view showing a partial cross section of a gear pump which is an embodiment of the present invention, Fig. 2 is a front view taken from the line ■-■ in Fig. 1, and Fig. 3 is the same as that shown in Fig. 1. Fig. 4 is a front view showing an enlarged view of the seal and the bearing member, Fig. 5 is a sectional view taken from line -■ in Fig. 4, and Fig. 6 is a front view of the cover as seen from the line The figure is a rear view of Figure 4 seen from the rear direction, Figure 7 is an explanatory diagram to explain the flow of lubricant, and Figure 8 is the inner surface of the casing and tooth grooves from the suction port to the discharge port. FIG. 9 is a diagram showing the rising state of the lubricating fluid pressure that occurs between the two bearings, and FIG. An example is shown. Figures 10 and 11 are surface diagrams showing modified examples of the casing and casing cover used in the gear pump of the present invention, and Figure 12 shows the operating state of Figure 5, with one through oil hole. The oil led to chamber 0 through bearing member 7'
This figure shows the state in which the chamber 0 is being pressed to the right (this shows the state in which chamber 0 is formed). The same reference numerals indicate the same or corresponding parts throughout the drawings. 1 is a casing, 3 is a cover, 4. ．． 10,11゜10
', 11', 10a, 10'd, 1B are seals, 12.12' are through oil holes, 13 are through holes for lubricating oil recovery, 14, 14a are oil holes, 15 are connecting pipes, 16, 1
6a is an oil drain hole, and 17 is a recovery hole. 6 is the drive shaft, 6' is the driven shaft, 7.7's 7〃t7
'' is a bearing member, 8 is a suction port, 9 is a discharge port, and 0°P is a liquid-tightly isolated chamber.

Claims (1)

[Claims for Utility Model Registration] A casing 1 having both open ends, and a hollow portion 2 inside the casing when each of the open ends is closed.
first and second covers (3 and 3) defining a . A pair of mutually meshing gears (5
and 5'). A drive shaft 6 provided on one gear 5 of the pair of gears and protruding from both sides of the one gear, and a drive shaft 6 provided on the other gear 5' of the pair of gears and protruding from both sides of the one gear 5. and a driven shaft 6' protruding from both sides of the gear. The drive shaft 6 is arranged on both sides of the one gear 50.
A first pair of bearing members (7 and 7) supporting the driven shaft 6' and a second pair of bearing members (7' and 7) disposed on both sides of the other gear 5' and supporting the driven shaft 6'. ″′
) and has. In a gear pump configured to suck oil from a suction port 8 and discharge it to a pump outlet 9. Equipped with a pressure equalization device and a lubricating oil recovery device. The pressure equalization device. The first cover 3 and the first pair of bearing members (7
and 7), one of the bearing members 7 on the side adjacent to the first cover, and one of the second pair of bearing members (7' and 7'') adjacent to the first cover. A first double seal member (10' and 11') and a second double seal member (10' and 11') are arranged only between the respective outer end surfaces of one of the side bearing members 7'. 10 and 11),
The first double seal member is provided to contain the drive shaft 6, and defines a first chamber P that is fluid-tightly isolated between the first double seal member. and the outer seal member 10 of the first double seal member.
' is disposed in a concentric relationship with the drive shaft, and the inner seal member 11' of the first double seal member is shifted toward the suction port 8 and is aligned with respect to the drive shaft. The second double seal member (1
0 and 11) are provided to enclose the driven shaft 6' and define one second chamber O that is fluid-tightly isolated between the second double sealing member, and The outer seal member 10 of the two double seal members is arranged concentrically with the driven shaft, and the inner seal member 11 of the second double seal members is arranged in a concentric relationship with the driven shaft. A first double seal member (10' and 11
) and a second double seal member (10 and 11). In order to guide oil under an intermediate pressure at a substantially central portion between the suction port 8 and the discharge port 9 from the tooth groove of the one gear 5 to the first chamber P, A through hole 12 is provided to penetrate in the axial direction of the one bearing member TVc of the bearing members (7 and 7). In order to guide oil under an intermediate pressure at a substantially central portion between the suction port 8 and the discharge port 9 to the second chamber 0 from both sides of the other gear 5', A through oil hole 12' is provided to penetrate in the axial direction in one of the front bearing members 7' of the bearing members (7' and 7'');
has. The lubricating oil recovery device. The drive shaft and the first pair of bearing members are provided in portions of the first and second covers (3 and 3) facing both ends of the drive shaft 6 and both ends of the driven shaft 6', respectively. (
7 and 7") and between the driven shaft 6' and the second pair of bearing members (7' and 7"'). ), a communication pipe 15 provided on one cover 3 of the first and second covers and communicated with the suction port 8, and a communication pipe 15 provided on the one cover and communicated with the suction port 8; an oil drain hole 16 for communicating the oil holes (14 and 14) provided in the connecting pipe 15 with the communication pipe 15; A lubricating oil recovery penetrating oil hole 13 that connects the opposed oil holes (14 and 14) with each other. The oil hole (
14 and 14a) & an oil drain hole 16a that communicates with each other.