JPS59153993A - Gear pump - Google Patents

Abstract

PURPOSE:To prevent rapid change of the pressure in a gear pump by enlarging the gap between casing and gear on the discharge side gradually toward the discharge port. CONSTITUTION:The negative pressure 15b reduces gradually as going apart from the suction port 11B1. The pressure then becomes positive 16b at the point of gap 14B2 most apart from he discharge port 11B2, taking the minimum value, and this positive pressure 16b increases gradually toward the discharged port 11B2 to take the maximum value at the discharge port 11B2. Thus rapid rise 16a of the pressure at the discharge port 11A2 can be eliminated.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a gear pump for transporting liquids, particularly liquids entrained with gases.

[Background of the invention]

An example of a fluid coupling that handles a liquid containing gas is shown in FIG. After being sucked into 2, the discharge pipe 5
and the impeller 7 and runner 8 of the fluid coupling via the cooler 6.
will be supplied between. This working fluid is first applied to the impeller 7
After flowing into the runner 8 and imparting the kinetic energy to the runner 8, it flows through the pipe 10 in the rotary casing 9 and the fluid in the fluid coupling casing 1. Return to lower tank 3.

When the working fluid is exchanged between the impeller 7 and the runner 8, the dry wiping is mixed into the working fluid, and when the working fluid inside the rotating casing 9 is scooped up by the scoop pipe 10, the rotating casing 9 The air surrounding the working fluid inside is drawn into the scoop pipe 10 together. A large amount of air is mixed into the working fluid discharged from the scoop pipe 10 into the lower tank 3 in this manner.

A conventional gear pump 2 that sucks and discharges working fluid mixed with gas (air) as described above has a suction port 1 as shown in FIG.
1A, and a set of gears 12A, 13A that mesh with each other in a casing IIA having a discharge port 11A2, the casing IIA and the gears 12A, 13A
A gap 14A set to a constant value is formed between the two. The liquid sucked from the suction port 11A1 is trapped between the teeth of the -set of gears 12A and 13A, becomes high pressure, and is discharged from the discharge port 11A2.

In the above case, casing IIA and gear 1? A.

Since the gap 14A between the suction port 13A and the suction port 11A1 is set to a constant value, the liquid pressure is generally
As shown in the figure, there is a negative pressure 15a, gears 12A and 13A.
The pressure hardly rises while being conveyed by each tooth, and the pressure rises rapidly at the discharge port 11A2, like the pressure 16a. For this reason, the volume of the liquid containing air at the discharge port 11A2 rapidly decreases, and noise is generated due to pressure fluctuations on the discharge port 11A2 side and the rattling sound of the tooth surfaces of the gears 12A and 13A. There was fear.

Possible measures to prevent this noise include increasing the size of the tank so that the gas in the liquid can easily escape, or selecting a liquid with good foam-defoaming properties and providing a soundproof cover. However, with such means, there are drawbacks that not only the structure becomes complicated and the overall size increases, but also sufficient effects cannot be expected.

[Purpose of the invention]

In view of the above, it is an object of the present invention to reduce noise with a simple structure.

[Summary of the invention]

In order to achieve the above-mentioned object, the present invention provides a gear pump comprising a set of mutually meshing gears housed in a casing having a suction port and a discharge port. It is characterized in that it is formed so that it becomes gradually smaller as it moves away from the suction port, and the gear V-shaped knob between the tank and the gear on the discharge side is formed so that it becomes gradually larger as it approaches the discharge port. It is something to do.

[Embodiments of the invention]

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

In FIG. 4, 11B is the suction port 11Bl and the discharge port 11.
a casing with B2, 12B, 13B a set of intermeshed gears, 14 housed in casing IIB;
B1.14B2 is the suction port 11B1 side and the discharge port 11B
The gap between the casing 11B and the gears 12B and 13B on the two sides, one gap 14B1 is formed so as to gradually become smaller as it moves away from the suction port 11B, and the other gap 14B2 is formed so as to gradually become smaller as it moves away from the suction port 11B.
It is formed so that it gradually becomes larger as it approaches B2.

This embodiment is configured as described above. The pressure distribution inside the gear pump is shown in FIG. That is, in the portion of the gap 14B1 that is connected to the suction port 11Bl, the negative pressure 15b is at its maximum, and the negative pressure 15b is at its maximum. l:! l
The negative pressure 15b gradually becomes smaller as the distance increases. Next, in the part of the gap 14B2 farthest from the discharge port 11B2, the positive pressure 16b becomes the minimum value, but as it approaches the discharge port 11B2, the positive pressure 16b increases.
The value of b gradually increases, and the value of the positive pressure 16b becomes maximum at the discharge port 11B2. As described above, according to this embodiment, it is possible to eliminate sudden pressure fluctuations in the conventional gear pump, that is, sudden pressure fluctuations 16a at the discharge port 11A2 as shown in FIG.

〔Effect of the invention〕

As explained above, according to the present invention, by preventing sudden changes in the pressure inside the gear pump, it is possible to prevent the volume from rapidly decreasing, thereby reducing noise generation.

[Brief explanation of drawings]

Fig. 1 shows a system diagram of the working fluid of a fluid coupling, Figs. 2 and 3 show a cross-sectional view and pressure distribution diagram of a conventional gear pump, and Figs. 4 and 5 show an embodiment of the gear pump of the present invention. They are a sectional view and a pressure distribution diagram. 11B...Casing, 11Bt...Suction port, 11
B2...Discharge port, 12B, 13B...Gear, 14B
+. 14B2...Gap. ■ 1 Illustration Z Figure 3 Figure 5

Claims (1)

[Claims] A gear pump comprising a set of mutually meshing gears housed in a casing having a suction port and a discharge port, the gap between the casing and the gears on the suction port side becoming gradually smaller as the distance from the suction port increases. A gear pump characterized in that: - a gap between the casing and the gear on the side of the discharge port is formed such that it gradually becomes larger as it approaches the discharge port.