KR20160002685U - Gear pump - Google Patents

Gear pump Download PDF

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Publication number
KR20160002685U
KR20160002685U KR2020150000562U KR20150000562U KR20160002685U KR 20160002685 U KR20160002685 U KR 20160002685U KR 2020150000562 U KR2020150000562 U KR 2020150000562U KR 20150000562 U KR20150000562 U KR 20150000562U KR 20160002685 U KR20160002685 U KR 20160002685U
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KR
South Korea
Prior art keywords
gear
fluid
end portion
approximately
teeth
Prior art date
Application number
KR2020150000562U
Other languages
Korean (ko)
Inventor
서정세
성홍석
박인성
하임규
이병수
Original Assignee
경상대학교산학협력단
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 경상대학교산학협력단 filed Critical 경상대학교산학협력단
Priority to KR2020150000562U priority Critical patent/KR20160002685U/en
Publication of KR20160002685U publication Critical patent/KR20160002685U/en

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Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
    • F04C13/00—Adaptations of machines or pumps for special use, e.g. for extremely high pressures
    • F04C13/001—Pumps for particular liquids
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
    • F04C2/00—Rotary-piston machines or pumps
    • F04C2/08—Rotary-piston machines or pumps of intermeshing-engagement type, i.e. with engagement of co-operating members similar to that of toothed gearing
    • F04C2/12—Rotary-piston machines or pumps of intermeshing-engagement type, i.e. with engagement of co-operating members similar to that of toothed gearing of other than internal-axis type
    • F04C2/14—Rotary-piston machines or pumps of intermeshing-engagement type, i.e. with engagement of co-operating members similar to that of toothed gearing of other than internal-axis type with toothed rotary pistons

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Rotary Pumps (AREA)

Abstract

A gear pump is disclosed. The disclosed gear pump includes a drive source; A first gear which receives power from the driving source and has a plurality of gears formed of involute curves; A second gear that receives power from the first gear and has the same shape as the first gear; And a housing including a gear chamber in which the first gear and the second gear are disposed, an inlet through which the fluid flows, and a outlet through which the introduced fluid is discharged, wherein a sum of the lengths of the end portions of the first gear teeth Is 1.33% ~ 1.38% of the circumference of the end connecting the end of the first gear tooth.

Description

Gear Pump {GEAR PUMP}

The present invention relates to a gear pump, and more particularly to a gear pump with improved fluid transfer efficiency.

A gear pump is a type of rotary pump that transfers fluid by the engagement of two gears. Specifically, the gear pump mounts two gears meshing with each other in the housing, and rotates the gear to transfer the fluid through a gap between the groove of the gear tooth and the inner wall of the housing.

These gear pumps are suitable for transporting highly viscous homogeneous liquids. In addition, the gear pump is light in weight, low in cost, and simple in construction, used to feed hydraulic machinery and small amounts of oil. These gear pumps include external gear pumps and internal gear pumps.

The external gear pump is rotated by engaging two gears in the housing and the fluid is introduced into the space between the gears when the engagement part falls and the fluid introduced into the space is transferred to the discharge part along the inner wall of the housing.

The internal gear pump has the same principle as that of the external gear pump, but has a structure in which two gears engage with each other, and a crescent-shaped partition plate is further provided.

In such a conventional gear pump, a backward flow occurs at a minute gap formed in a portion where the end portion of the housing or the partition plate and the gear teeth are adjacent to each other. As a result, the fluid to be conveyed is turbulent, and the fluid can not be efficiently transferred according to the rotation of the gear.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above problems and provide a gear pump capable of reducing back flow generated in a gap between an end portion of a gear and an inner wall of a housing to increase the amount of fluid discharged.

In order to achieve the above object, A first gear which receives power from the driving source and has a plurality of gears formed of involute curves; A second gear that receives power from the first gear and has the same shape as the first gear; And a housing including a gear chamber in which the first gear and the second gear are disposed, an inlet through which the fluid flows, and a outlet through which the introduced fluid is discharged, wherein a sum of the lengths of the end portions of the first gear teeth Provides 1.33% ~ 1.38% of the circumference of the end connecting the end of the first gear tooth.

Here, the number of the first gears is eight, the radius of the end connecting the end of the first gear is 18.285 mm, and the radius of the base circle of the involute curve is 13.156 mm.

The two starting points of the involute curve where the base circle of the involute curve and the involute curve meet meet at an angle of 27.4 ° to 27.6 ° with respect to the center of the first gear Lt; / RTI >

Furthermore, the distance between the inner wall of the gear chamber and the end of the first gear can be 0.04 mm.

In addition, the fluid may be viscous.

According to the gear pump according to an embodiment of the present invention having the above structure, the back flow generated in the gap between the end portion of the gear and the inner wall of the housing is reduced during the transfer of the fluid, The discharge flow rate increases.

1 is a sectional view showing a gear pump according to an embodiment of the present invention.
Fig. 2 is a plan view showing the first gear shown in Fig. 1. Fig.
3 is a schematic view showing a result of numerical analysis of a flow of fluid occurring between a conventional gear and an inner wall of a gear chamber.
FIG. 4 is a schematic view showing a result of a numerical analysis of a fluid flow occurring between a gear having a reduced length of the end portion of the gear and the inner wall of the gear chamber as compared with the prior art.
FIGS. 5 and 6 are schematic views showing a result of numerical analysis of a fluid flow occurring between a gear and an inner wall of a gear chamber, the length of which gradually increases from the end of the gear tooth, as compared with the prior art.

Hereinafter, an embodiment of the gear pump 1 according to the present invention will be described with reference to the accompanying drawings. In the following description of the present invention, detailed description and specific examples are omitted when it is determined that a detailed description of related functions or components may unnecessarily obscure the gist of the present invention. In addition, for ease of understanding of the design, the attached drawings are not drawn to scale, but the dimensions of some of the elements may be exaggerated.

In the following description, the gear pump 1 according to one embodiment of the present invention has been described as being manufactured to a predetermined size, but such a dimension is determined by maintaining the ratio according to the present invention in correspondence with the size of the gear pump 1 being changed. Of course, can be changed.

Referring to FIG. 1, a gear pump 1 according to an embodiment of the present invention includes a housing 100, a gear portion 200, and a driving portion 300.

The housing 100 has a transfer path for fluid to be introduced into the low pressure side to discharge the fluid to the high pressure side and includes an inlet portion 110, a gear chamber 120, and a discharge portion 130.

The inlet 110 is provided at one side of the housing 100 and is formed in the shape of a pipe having a hollow through which the fluid is transferred. However, although the cross section is shown as circular in FIG. 1, the cross section may be formed in an elliptical shape or a polygonal shape depending on the application. The inlet portion 110 receives the fluid on the low-pressure side by driving the gear portion 200 and transfers the fluid to the gear chamber 120.

The gear chamber 120 is formed in such a manner that the first gear 210 and the second gear 220 can be engaged with each other where the gear unit 200 is mounted. The radius of the circle drawn by the inner wall 121 of the gear chamber 120 in this embodiment is approximately 18.325 mm.

The inner wall 121 of the gear chamber 120 is connected to the end portion of the first gear tooth 212 forming the end of the first gear 210, 212a of the second gear 222 and the end portion 222a of the second gear 222 forming the end of the second gear 220. The gap between the inner wall 121 of the gear chamber 120 and the end portion 212a of the first gear tooth 212 and the end portion 222a of the second gear tooth 222 in this embodiment is approximately 0.04 mm .

The discharge part 130 is provided on the other side of the housing 100 and is formed in the shape of a pipe having a hollow through which the fluid is transferred, similar to the inflow part 110. However, although the cross section is shown as circular in FIG. 1, the cross section may be formed in an elliptical shape or a polygonal shape depending on the application. The discharge unit 130 discharges the fluid transferred by the gear unit 200 driven in the gear chamber 120 to the outside of the housing 100.

The gear portion 200 is disposed in the gear chamber 120 and transfers the fluid introduced from the inlet portion 110 to be discharged through the outlet portion 130. The gear portion 200 includes a first gear 210 and a second gear 220.

Referring to FIG. 2, the first gear 210 includes a first rotating shaft insertion hole 211 and a plurality of first gears 212, which are rotated by receiving power from a driving unit 300 to be described later.

The first rotation shaft insertion hole 211 is formed in a substantially central portion of the first gear 210 and connects the driving unit 300 and the first gear 210 so that the first gear 210 can transmit power from the driving unit 300 To be delivered.

The plurality of first gears 212 is configured to be rotatable with respect to the first gears 210 by being engaged with the second gears 220. In the present embodiment, It is also possible to form ten or more. However, in response, the following limited figures should be changed.

It is also preferable that the first gear tooth 212 has the shape of an involute curve drawn based on the base circle Cb. Accordingly, the first gear 212 according to the present invention can be easily machined, and the speed ratio can be maintained constant even if the distance between the centers of the first and second gears is slightly changed. Also, the durability of the inner portion of the first gear teeth 212 is increased.

In this embodiment, the involute curves are formed on the basis of the base circle Cb having a radius of approximately 13.156 mm. The starting point 212b of the two involute curves located on the base circle Cb is larger than the conventional angle? Of the angle? Of about 26 占 with respect to the center C1 of the first gear 210 ). Specifically, the start point 212b of the involute curve has an angle (?) Of approximately 27.4 DEG to approximately 27.6 DEG with respect to the center C1 of the first gear 210. Here, when the angle? Of approximately 27.6 占 is exceeded, since the size of the first gear 212 is not driven to engage with the second gear 222, approximately 27.6 占 is the upper limit.

If an involute curve is formed after the angle? Of the start point 212b of the involute curve with respect to the center C of the first gear 210 is made wider than that of the prior art, The length L of the end portion 212a of the end portion 212a is longer than that of the prior art. That is, the size of the first gear teeth 212 is large while the space 213 between the first gear teeth 212 is small.

In this embodiment, the start point 212b of the involute curve is determined so as to have an angle? Of approximately 27.4 to approximately 27.6 relative to the center C1 of the first gear 210, (212). Specifically, conventionally, the length L of the end portion 212a of the first gear 212 is approximately 1.08 mm, while in the present embodiment, the length L is approximately 1.53 mm to approximately 1.59 mm. The length L of the end portion 212a of the first gear tooth 212 is set so as to correspond to the angle? Of the start point 212b of the involute curve with respect to the center C1 of the first gear 210, Is approximately 1.59 mm, the gear is not driven, so approximately 1.59 mm is the upper limit.

This length L may also be expressed as a ratio of the circumference of the addendum circle Cu connecting the end portion 212a of the first gear 212. [ That is, in the present embodiment, since the end portion Cu has a radius of approximately 18.285 mm, when the length L of the end portion 212a of the conventional first gear tooth 212 is approximately 1.08 mm, Approximately 0.94% of the periphery of the copper (Cu) is adjacent to the inner wall 121 of the gear chamber 120 at a minute interval.

Alternatively, in the present invention, when the length L of the end portion 212a of the first gear tooth 212 is approximately 1.53 mm, approximately 1.33% of the circumference of the end tooth Cu is approximately 1.33% When the length L of the end portion 212a of the first gear tooth 212 is approximately 1.59 mm, approximately 1.38% of the circumference of the end tooth Cu is adjacent to the gear chamber 121 120 adjacent to each other at a minute interval. That is, the length L of the end portion 212a of the first gear teeth 212 adjacent to the inner wall 121 of the gear chamber 120 at a small interval is increased. Accordingly, the present invention increases the viscous friction in the gap between the inner wall 121 of the gear chamber 120 and the end portion 212a of the first gear teeth 212 as compared with the prior art, .

That is, although the space 213 between the first gear teeth 212 is reduced as the size of the first gear teeth 212 is increased, the gear pump 1 according to the embodiment of the present invention is not limited to the gear chambers The area of the end portion 212a of the first gear teeth 212 that meets the inner wall 121 of the first gear teeth 120 is increased compared with the conventional one and the flow loss due to the reverse flow is reduced. Therefore, the effect of increasing the flow rate as a whole can be obtained.

The second gear 220 receives power from the first gear 210 and rotates and includes a second rotation shaft insertion hole 221 and a plurality of second gears 222 in the same manner as the first gear 210 described above do.

The second rotation shaft insertion hole 221 serves as a center of rotation of the second gear 220 and does not receive power from the driving source as the first gear 210. [

Since the size and shape of the second gear 220 are substantially the same as those of the first gear 210, detailed description thereof will be omitted.

The driving unit 300 supplies power to the gear unit 200 to rotate the gear unit 200 and includes a driving source 310 and a shaft 320. The driving unit 300 may be disposed outside or inside the housing 100 and is intercepted from the gear chamber 120 so that the fluid to be transferred is not introduced into the driving unit 300 when the driving unit 300 is disposed inside the housing 100 .

The driving source 310 may be a motor that generates power to be transmitted to the gear unit 200.

The shaft 320 connects the driving source 310 and the first gear 210 to transmit the power generated by the driving source 310 to the first gear 210.

Hereinafter, the fluid transfer process of the gear pump 1 according to one embodiment of the present invention will be described.

Referring to FIG. 1, the gear pump 1 according to an embodiment of the present invention is configured such that the driving source 310 transmits power to the first gear 210 to start rotation of the first gear 210, The second gear 220 also starts rotating in the engaged state.

When the first gear 210 and the second gear 220 are rotated, the fluid at the low-pressure side flows through the inlet portion 110 of the housing. The fluid that has passed through the inlet 110 is transferred to the gear chamber 120.

The fluid transferred to the gear chamber 120 is separated from the spaces 213 and 214 between the first and second gears 212 and 222 that are opened as the meshing of the first gear 210 and the second gear 220 is released, 223). The fluid transferred to the spaces 213 and 223 between the first and second gears 212 and 222 is then transferred toward the discharge port 130 as the first and second gears 210 and 220 rotate .

At this time, the smooth rotation of the first and second gears 210 and 220 between the end portions 212a and 222a of the first and second gears 212 and 222 and the inner wall 121 of the gear chamber 120 Since the width of the end portions 212a and 222a of the first and second gears 212 and 222 of the present invention is wider than that of the prior art, The reverse flow hardly occurs between the inner wall 121 and the end portions 212a and 222a of the first and second gears 212 and 222.

The fluid transferred to the discharge port 130 side is discharged to the outside of the housing 100 which is a high-pressure side.

3 to 6, when the length L of the end portions 212a and 222a of the first and second gears 212 and 222 increases, the inner wall 121 of the gear chamber 120 and the first And the amount of fluid flowing backward between the ends 212a and 222a of the second gear teeth 212 and 222 increases. Here, the diameter of the base circle Cb forming the involute curve, the diameter of the end circle Cu of the first and second gears 212 and 222, and the diameter of the first and second gears 212 and 222 The numbers are all set to be the same.

The second gear 220 has the same shape as the first gear 210 and has the same fluid flow, so that a detailed description thereof will be omitted.

The results of the numerical analysis of the conventional first gear will be described with reference to FIG.

The conventional first gear has an angle of about 26 占 at two starting points of the involute curve with respect to the center of the first gear and the length of the end portion 1212a of the first gear tooth 1212 thus formed is about 1.08 mm to be. In addition, the sum of the lengths of the end portions 1212a of the first gear teeth 1212 occupies approximately 0.94% of the circumference of this end circle Cu.

The results of the numerical analysis of the conventional first gear will be described with respect to the advancing direction A of the fluid in the gap between the end portion 1212a of the first gear 1212 and the inner wall 121 of the gear chamber 120 It can be confirmed that a backward flowing fluid is generated.

The numerical analysis result in the case where the length of the end portion 2212a of the first gear tooth 2212 is reduced as compared with that of the prior art will be described with reference to FIG.

When the length of the end portion 2212a of the first gear tooth 2212 is reduced compared to the conventional one, the angle of the two starting points of the involute curve with respect to the center of the first gear is approximately 24 占, The length of the end portion 2212a of the tooth 2212 is approximately 0.45 mm. In addition, the sum of the lengths of the end portions 2212a of the first gear teeth 2212 occupies approximately 0.39% of the circumference of this end (Cu).

The end portion 2212a of the first gear 2212 and the end portion 2212a of the gear chamber 120 are formed in the same manner as in the first embodiment. It can be seen that the fluid flowing backward in the direction of flow A of the fluid at the gap between the first and second gears 121 is larger than that of the conventional first gear. That is, when the length of the end portion 2212a of the first gear 2212 is reduced compared with the conventional one, the end portion 2212a of the first gear 2212 is larger than the end portion 2212a of the gear chamber 120 ), The viscous friction becomes small, and therefore the amount of loss due to the back flow increases.

However, as the size of the first gear 2212 becomes smaller, the space for transferring the fluid between the first gear 2212 becomes larger, so that the total flow rate discharged through the discharge portion 130 becomes larger, 1 gear.

The results of numerical analysis in the case where the length of the end portion 3212a of the first gear tooth 3212 is reduced as compared with the prior art will be described with reference to FIG.

The angle of the two starting points of the involute curve with respect to the center of the first gear is approximately 27.4 DEG when the end portion 3212a of the first gear 3212 is reduced as compared with the conventional one, The length of the end portion 3212a is approximately 1.53 mm. In addition, the sum of the lengths of the end portions 3212a of the first gear teeth 3212 occupies approximately 1.33% of the circumference of this end (Cu).

The end portion 3212a of the first gear tooth 3212 and the end portion 3212a of the gear chamber 120 are formed in the same manner as in the first embodiment. It can be seen that there is almost no fluid flowing backward with respect to the flow direction A of the fluid in the gap between the fluid flow paths 121 and a small amount of turbulent flow is generated in the direction perpendicular to the flow direction of the fluid. That is, when the length of the end portion 3212a of the first gear 3212 is increased as compared with the conventional one, the end portion 3212a of the first gear 3212 is connected to the inner wall 121 of the gear chamber 120 Since the adjacent length is formed to be long, the viscous friction becomes large, and therefore the amount of loss due to the back flow is reduced.

In addition, as the size of the first gear 3212 increases, the space for transferring the fluid between the first gears 3212 decreases, but the loss of the fluid due to the reverse flow decreases, The total discharge flow rate is increased compared with the case where the length of the end portion 2212a of the first gear 2212 is reduced as compared with the conventional one.

With reference to FIG. 6, a numerical analysis result obtained when the length of the end portion 4212a of the first gear tooth 4212 is increased more than the length of the end portion 3212a of the first gear tooth 3212 of FIG. 5 Explain.

When the length of the end portion 4212a of the first gear tooth 4212 is increased more than the length of the end portion 3212a of the first gear tooth 3212 in Fig. 5, an involute curve of the center of the first gear The angle of the two starting points is approximately 27.6 占 and the length of the end portion 4212a of the first gear tooth 4212 thus formed is approximately 1.59mm. In addition, the sum of the lengths of the end portions 4212a of the first gear teeth 4212 occupies approximately 1.38% of the circumference of this end circle Cu.

As a result of numerical analysis in the case where the length of the end portion 4212a of the first gear tooth 4212 is increased more than the length of the end portion 3212a of the first gear tooth 3212 in FIG. 5, It can be seen that there is no fluid flowing backward in the direction of flow A in the gap between the end 4212a of the gear 4212 and the inner wall 121 of the gear chamber 120. That is, when the sum of the lengths of the end portions 4212a of the first gear teeth 4212 is set to be approximately 1.38% of the circumference of the end teeth Cu, the end portions 4212a of the first gear teeth 4212 Since the length adjacent to the inner wall 121 of the gear chamber 120 is the longest, the viscous friction becomes the largest, and the amount of loss due to the reverse flow is almost zero.

Also, as the size of the first gear 4212 is increased, the space for transferring the fluid between the first gear 4212 is reduced, but the loss of the fluid due to the backward flow is reduced, The total discharged flow rate was the largest in comparison with the above-mentioned models.

However, when the angle of the two starting points of the involute curve with respect to the center of the first gear exceeds approximately 27.6 degrees, the first gear is unable to rotate due to engagement with the second gear. Therefore, when the radius of the end of the first gear (Cu) is approximately 18.285 mm, the first gear is driven with the minimum amount of back flow generated in the gap between the end of the first gear and the inner wall of the gear chamber, The maximum length of the tip of the gear teeth is approximately 1.59 mm.

At this time, the sum of the lengths of the ends of the first gear teeth occupies approximately 1.38% of the circumference of the end teeth. This ratio is applicable even if the size of the first gear is changed.

As described above, although the present invention has been described with reference to certain exemplary embodiments and drawings, it is to be understood that the present invention is not limited thereto and that various changes and modifications may be made without departing from the spirit and scope of the present invention by those skilled in the art. It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention.

100; housing
210; The first gear
212, 1212, 2212, 3212, 4212; The first gear
212a 1212a, 2212a, 3212a, 4212a; The tip of the first gear teeth
213; The space between the first gears
220; The second gear
222; The second gear
222a; The end of the second gear teeth
223; The space between the second gears
300; The driving unit

Claims (5)

A driving source;
A first gear which receives power from the driving source and has a plurality of gears formed of involute curves;
A second gear that receives power from the first gear and has the same shape as the first gear; And
And a housing including a gear chamber in which the first gear and the second gear are disposed, an inlet through which the fluid flows, and a outlet through which the introduced fluid is discharged,
Wherein the sum of the lengths of the end portions of the first gear teeth is 1.33% to 1.38% of the circumference of the end teeth connecting the end portions of the first gear teeth. The method according to claim 1,
The number of the first gear teeth is eight,
The radius of the end connecting the end of the first gear is 18.285 mm,
Wherein the base circle of the involute curve has a radius of 13.156 mm. 3. The method of claim 2,
Wherein the two starting points of the involute curve where the base circle of the involute curve meets the involute curve and the starting point of the involute curve are in the range of 27.4 ° to 27.6 ° with respect to the center of the first gear Features a gear pump. 3. The method of claim 2,
Wherein an interval between an inner wall of the gear chamber and an end portion of the first gear is 0.04 mm. The method according to claim 1,
Wherein said fluid has a viscosity.
KR2020150000562U 2015-01-23 2015-01-23 Gear pump KR20160002685U (en)

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20200141765A (en) * 2019-06-11 2020-12-21 울산대학교 산학협력단 Calculation method of circular tooth profile of silenced gear pump and gear calculated by the same

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20200141765A (en) * 2019-06-11 2020-12-21 울산대학교 산학협력단 Calculation method of circular tooth profile of silenced gear pump and gear calculated by the same

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