KR101486255B1

KR101486255B1 - Micro gear pump

Info

Publication number: KR101486255B1
Application number: KR1020140112069A
Authority: KR
Inventors: 김경수; 장용석; 이상민; 최성호
Original assignee: 주식회사 마르센
Priority date: 2014-08-27
Filing date: 2014-08-27
Publication date: 2015-01-27
Also published as: WO2016032063A1

Abstract

The present invention relates to a micro-gear pump improved in structure so as to maintain a pressure of a working fluid below a reference pressure. The micro gear pump according to the present invention is a micro gear pump having a pump main body in which a working fluid flow path is formed, and a pair of impellers connected to the motor to rotate the working fluid, A check valve installed in the pump main body to open or shut off the flow path by hydraulic pressure of a working fluid formed by rotation of the impeller; And a relief valve for discharging the working fluid to the outside such that the pressure inside the pump body is lowered.

Description

Micro gear pump

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a micro-gear pump, and more particularly, to a micro-gear pump used in a VRC system for controlling piping in an offshore plant or various ships.

A typical gear pump is a pump that puts two gears that mesh with each other into a case circumscribing it and rotates the gear to flow the fluid through a space between the groove of the tooth and the peripheral wall. Regarding this, Registration No. 10-1413694 has been disclosed.

The structure and operation principle of the gear pump will be described with reference to Figs. 1 to 3. First, the gear housing is provided with a bearing housing 1 forming an outer tube, and a gear box 2 And a casing 3 is coupled to the other side of the bearing housing 1. [

A first reduction gear 5 connected to a motor 4 via a motor (not shown) and rotated by receiving a driving force of the motor, and a second reduction gear 5 rotated in a state of being engaged with the first reduction gear. A second reduction gear 6 having a diameter larger than the diameter of the first reduction gear 5 is incorporated so that the first reduction gear 5 and the second reduction gear 6 are rotated in opposite directions .

The bearing housing 1 is provided with a first rotary gear 7 axially connected to the first reduction gear 5 and rotated by the first reduction gear 5 and a second rotary gear 7 engaged with the first rotary gear 7, A second rotary gear 8 rotating according to the rotation of the rotary gear 7 is incorporated and the first rotary gear 7 and the second rotary gear 8 are rotated in opposite directions.

A first lobe gear impeller 9 which is connected to the first rotary gear 7 and connected to the first rotary gear 7 and rotates by receiving the rotational force of the first rotary gear 7, And a second lobe gear impeller 10 engaged with the first lobe gear impeller 9 and rotatable by receiving the rotational force of the second rotary gear 8. The first lobe gear impeller 9 is rotatably supported by the first lobe gear impeller 9, And the second lobe gear impeller 10 are rotated in directions opposite to each other, and the fluid is transferred in accordance with the rotation of the first and second gear impellers 9 and 10.

A bearing that supports the shaft and smoothly rotates the shaft is coupled to the shaft of the motor and the shaft that connects the gears. A fluid from a shaft portion rotating at high speed under a high temperature and a high pressure is introduced between the first rotary gear 7 and the first lobe gear impeller 9 and between the second rotary gear 8 and the second lobe gear impeller 10 A mechanical seal 11 is coupled to prevent leakage of the fluid.

An inlet 12 having a fluid flow path or a circular inlet hole 13 is formed on the outside of the casing 3 so as to allow the fluid to flow into the casing 3, A discharging portion 14 having a fluid passage or a circular discharge hole 15 for discharging the fluid from the inside of the casing 3 to the outside is formed on the outer side of the casing 3 as a position, And a flange portion 16 to which a pipe is coupled is formed at an end portion of the inflow portion 12 and the discharge portion 14,

In such a conventional gear pump, a power is applied to generate a rotational force while a motor (not shown) is driven to rotate the shaft 4 connected to the motor, and the rotation shaft 4 rotates the shaft 4 in the reducer box 2 The installed first reduction gear 5 is rotated.

The second reduction gear 6 engaged with the first reduction gear 5 is rotated in the direction opposite to the first reduction gear 5 in accordance with the rotation of the first reduction gear 5, The rotation speed (rpm) of the first reduction gear 5 is reduced by the second reduction gear 6 as the diameter of the first reduction gear 5 is larger than the diameter of the first reduction gear 5. The first rotary gear 7 which is installed in the bearing housing 1 and is connected to the second reduction gear 6 in a state in which the number of rotations is reduced by the second reduction gear 6, And is rotated by receiving the rotational force.

At the same time, the second rotary gear 8 engaged with the first rotary gear 7 is also rotated along the rotating first rotary gear 7. The second rotary gear 8 is rotated by the first rotary gear 7, The first and second rotary gears 7 and 8 are rotated in opposite directions to each other.

Also, the first and second gear impellers 9 and 10, which are installed in the casing 3 and are respectively connected to the first and second rotary gears 7 and 8, are also rotated. That is, The second rotary gear 8 is axially connected to the first lobe gear impeller 9 while being axially connected to the second lobe gear impeller 10 and the first lobe gear impeller 9 and the second lobe gear impeller 10, The first lobe gear impeller 9 and the second lobe gear impeller 10 are rotated together with the first and second rotating gears 7 and 8 to be rotated, As shown in Fig.

Therefore, the fluid introduced into the casing 3 through the inflow hole 13 formed in the inflow portion 12 of the casing 3 flows into the first and second gear impellers 9 and 10, which are rotated in the meshed state, And is transported in a direction opposite to the inflow portion 12 while flowing through a space formed between the outer circumferential surface and the inner surface of the casing 3. [

The fluid transferred along the space formed between the inner surface of the casing 3 and the outer peripheral surface of the first and second gear impellers 9 and 10 is sent to the discharge hole 15 of the discharge portion 14, And is discharged to the outside of the gear pump through the discharge hole 15 while being pushed by the fluid conveyed by the first and second gear impellers 9 and 10 to be rotated.

On the other hand, the working pressure in the above-mentioned gear pump (i.e., the pressure of the fluid) is determined by the rotational speed of the gear, which is generally set at a very high pressure (170 bar) Lt; / RTI > Therefore, excessive pressure is applied to the actuator, which may easily damage or malfunction the actuator. To solve this problem, it is possible to add a separate pressure reducing device, but in this case, additional cost is incurred and the structure of the device becomes complicated.

Korean Patent No. 10-1413694

SUMMARY OF THE INVENTION It is an object of the present invention to provide a micro gear pump improved in structure to maintain a working fluid pressure below a reference pressure.

The micro gear pump according to the present invention is a micro gear pump having a pump main body in which a working fluid flow path is formed, and a pair of impellers connected to the motor to rotate the working fluid, A check valve installed in the pump main body to open or shut off the flow path by hydraulic pressure of a working fluid formed by rotation of the impeller; And a relief valve for discharging the working fluid to the outside such that the pressure inside the pump body is lowered.

According to the present invention, the relief valve includes a relief valve body coupled to the pump body and having a discharge passage communicated with the passage of the pump body, and a relief valve body disposed inside the relief valve body, And a relief valve spring that moves the relief valve ball in a blocking position to block the discharge passage and a relief valve spring that elastically biases the relief valve ball to the blocking position .

According to the present invention, when the pressure of the working fluid is higher than the reference pressure, the working fluid is discharged through the discharge passage, thereby preventing the pressure inside the pump body from increasing beyond the reference pressure.

1 to 3 are views for explaining the structure and operation principle of a conventional gear pump.
4 is a photograph of a micro gear pump according to an embodiment of the present invention in a separated state.
FIG. 5 is a schematic view showing a state where a check valve and a relief valve are coupled to a pump body, FIG. 6 is a view showing a separated pump body, a check valve and a relief valve, FIG. 7 is an enlarged view of a portion A of FIG. FIG. 8 is a view of a relief valve body, and FIG. 9 is a hydraulic circuit diagram of a whole product to which a micro gear pump is applied.

Hereinafter, a micro gear pump according to a preferred embodiment of the present invention will be described with reference to the accompanying drawings.

4 is a photograph of a micro gear pump according to an embodiment of the present invention in a separated state.

4, the micro gear pump 1000 according to the present embodiment includes a pump body 100, a check valve 200, a relief valve 300, an impeller 400, and a motor 500 .

At this time, the impeller 400 and the motor 500 have been described in the background. The pump main body 100, the check valve 200, and the relief valve 300 will be described below, since the structure of the present invention is such that the fluid is automatically discharged when the pressure of the pump main body becomes equal to or higher than the reference pressure.

FIG. 5 is a schematic view showing a state where a check valve and a relief valve are coupled to a pump body, FIG. 6 is a view showing a separated pump body, a check valve and a relief valve, FIG. 7 is an enlarged view of a portion A of FIG. FIG. 8 is a view of a relief valve body, and FIG. 9 is a hydraulic circuit diagram of a whole product to which a micro gear pump is applied.

A flow path through which the working fluid flows is formed inside the pump main body 100.

The check v / v 200 is for opening or closing the flow path of the pump main body. In this embodiment, the check valve 200 is composed of a check valve ball 210 and a check valve spring 220. The check valve ball 210 is formed in a ball shape and is movably disposed between a position for closing the flow path of the pump body (hereinafter referred to as a first position) and a position for opening the flow path of the pump body (hereinafter referred to as a second position) do. The check valve spring 220 is coupled to the check valve ball 210 and resiliently biases the check valve ball 210 to the first position.

The operation of the check valve will be briefly described. When the impeller rotates, pressure is generated inside the pump body, and the check valve spring 220 contracts due to the pressure, so that the check valve ball 210 moves to the second position . For reference, there are two check valves in this embodiment, and one of the two check valves is opened and the other one is closed in accordance with the direction in which the impeller is rotated.

The relief valve 300 relieves the pressure of the pump main body (that is, the hydraulic pressure of the working fluid) by discharging a part of the working fluid to the outside when the hydraulic pressure of the working fluid in the pump main body becomes the reference pressure or more To maintain the pressure below the reference pressure.

The relief valve 300 according to the present embodiment includes a relief valve ring 310, a relief valve body 320, a relief valve ball 330, a relief valve holder 340, a relief valve spring 350, A relief valve nut 360, and a relief valve bolt 370.

The relief valve ring 310 is formed in a ring shape and is sandwiched between the pump body 100 and the relief valve body 320 to function as a sealing member.

One end portion 321 of the relief valve body 320 is formed in the shape of a male screw (that is, an acid is formed on the outer peripheral surface) and screwed to the pump body 100. The other end 322 of the relief valve body has a larger diameter than one end of the relief valve body. The other end portion 322 has a female thread structure, that is, a groove portion having an inner peripheral surface formed with a thread, so that a relief valve bolt 370 described later can be screwed. A relief valve body is formed with a discharge passage. 8, the discharge passage is formed so as to pass through one end portion 321 and the other end portion 322. At this time, a part of the discharge passage (that is, the area A1 in FIG. 8) .

The relief valve ball 330 is for opening or closing the discharge passage. The relief valve ball 330 is disposed in the discharge passage of the relief valve body, more specifically, in the region A2 of FIG. When the relief valve ball is brought into close contact with the area A1, the discharge flow passage is blocked. When the relief valve ball is released from the area A1, the discharge flow passage is bagged. For reference, a check valve spring 220 is inserted and supported in the area A3 of the relief valve body.

The relief valve holder 340 is disposed inside the region A2 of the relief valve body 320 and the relief valve ball 330 is mounted on the relief valve holder 340.

The relief valve spring 350 is coupled to the relief valve holder 340 and elastically biases the relief valve ball 330, which is mounted on the relief valve holder, to the shutoff position.

The relief valve bolt 370 is screwed to the other end (i.e., female threaded portion) of the relief valve body. One end of the relief valve spring 350 described above is supported by the relief valve bolt 370. Accordingly, the elastic force (that is, the compressed strength) of the relief valve spring 350 can be adjusted according to the tightness of the relief valve bolt 370.

The relief valve nut 360 serves as a washer to prevent the relief valve bolt from being released.

In the micro gear pump constructed as described above, when the micro gear pump is driven, the check valve is opened or blocked according to the hydraulic pressure of the working fluid. At this time, when the check valve is opened, that is, when the check valve spring 220 is compressed, if the flow path is opened, the pressure of the working fluid flows through the discharge flow passage A3 region formed at one end of the relief valve body to the relief valve ball 330 .

In this case, when the pressure of the working fluid is smaller than the reference pressure (that is, the elastic force of the relief valve spring), the relief valve ball 330 is kept in the blocking position while maintaining the state in which the discharge passage is shut off. On the other hand, when the pressure of the working fluid exceeds the reference pressure, the relief valve spring 350 is contracted by the pressure of the working fluid, and accordingly, the discharge flow path is opened and part of the working fluid is discharged through the discharge flow path. As a result, the pressure inside the pump main body (i.e., the pressure of the working fluid) is lowered to the reference pressure.

For reference, the working fluid discharged through the discharge passage flows back to the working fluid storage tank.

As described above, according to the present invention, it is possible to prevent the pressure of the working fluid from exceeding the reference pressure, and as a result, the micro-gear pump or the actuator connected thereto can be prevented from malfunctioning or being damaged by excessive pressure.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is clearly understood that the same is by way of illustration and example only and is not to be taken by way of limitation in the embodiment in which said invention is directed. It will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the scope of the appended claims.

1000 ... Micro Gear Pump
100 ... Pump body 200 ... Check valve
210 ... check valve ball 220 ... check valve spring
300 ... Relief valve 310 ... Relief valve ring
320 ... Relief valve body 330 ... Relief valve ball
340 ... Relief valve holder 350 ... Relief valve spring
360 ... Relief valve nut 370 ... Relief valve bolt

Claims

1. A micro gear pump comprising: a pump main body having a flow path through which a working fluid flows; and a pair of impellers connected to the motor to rotate the working fluid along the flow path,
A check valve installed in the pump body to open or shut off the flow path by hydraulic pressure of a working fluid formed by rotation of the impeller,
And a relief valve for discharging the working fluid to the outside such that the pressure inside the pump body is lowered when the hydraulic pressure of the working fluid in the pump body becomes equal to or higher than a reference pressure,
The relief valve includes:
A relief valve body provided at one end thereof with a discharge flow passage threaded to the pump body and communicating with the flow passage of the pump body and having a groove formed at the other end thereof along an inner peripheral surface thereof,
A relief valve ball disposed in a groove portion of the relief valve body and moved in an open position for opening the discharge flow passage and a shutoff position for blocking the discharge flow passage so that the working fluid is discharged through the discharge flow passage,
A relief valve spring disposed in the groove of the relief valve body for elastically biasing the relief valve ball to the shutoff position,
And a relief valve bolt screwed to the groove of the relief valve body to support one end of the relief valve spring and adjust an elastic force of the relief valve spring according to a degree of screwing the relief valve body into a groove of the relief valve body A micro gear pump.

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