Axial pressure compensation structure of internal gear pump

Abstract

The utility model discloses an axial pressure compensation structure of an internal gear pump, which comprises a shell, the shell comprises an accommodating cavity for accommodating a gear and a gear ring, the accommodating cavity comprises two axial side walls, a compensation sheet is arranged between the gear ring and the two axial side walls, concave platforms are arranged on the axial side walls, and the concave platforms are arranged on the inner side walls of the shell. An annular groove is formed in the periphery of the concave table in a surrounding mode, an annular sealing piece is embedded in the groove, the groove and the sealing piece are integrally in a crescent shape, the compensation piece is in contact sealing fit with one end of the sealing piece, a pressure cavity is formed among the compensation piece, the concave table and the sealing piece, and the compensation piece is provided with a hole connected with the pressure cavity. And a channel through which oil can flow is arranged between the pressure cavity and the groove, one end of the channel is arranged at the surface of the concave platform, and the other end of the channel is arranged at the position, corresponding to the other end of the sealing piece, of the groove. The pressure compensation device is simple in structure, convenient to machine and capable of providing a better pressure compensation effect.

Description

TECHNICAL FIELD

[0001] The utility model relates to an axial pressure compensation structure of an internal meshing gear pump. BACKGROUND

[0002] The gear and the gear ring of the internal meshing gear pump will generate axial force when discharging oil and rotating, which will cause the displacement of the gear ring in the axial direction and increase the gap between the two sides of the gear ring and the compensation sheet, resulting in the decrease of the volumetric efficiency of the pump, aggravating the wear between the components, and also increasing the noise during operation.

[0003] A kind of axial pressure compensation structure for hydraulic device is disclosed in Chinese utility model patent (CN202971169U), its characteristics are that sealed cavity is formed between compensation sheet and the front cover, rear cover of pump by sealing element, hole is arranged on compensation sheet, when pump is running, oil with certain pressure will enter containing space through hole, then fill the entire sealed cavity, oil pressure in containing space will provide the pressure of compensation sheet towards the direction of gear ring, the gap between driven wheel and compensation sheet can be kept in reasonable range, effectively reduce the loss of energy efficiency, improve efficiency.

[0004] In the above patent, the sealing element is usually embedded in the special-shaped groove of the front cover and the rear cover for positioning, and the sealing element is in elastic contact with the compensation sheet. However, due to component wear, aging, poor machining precision and other reasons, a gap may be generated between the compensation sheet and the sealing element when the compensation sheet is displaced, and the oil in the containing space may seep out from the gap, affecting the axial pressure compensation effect. SUMMARY

[0005] In order to overcome the defects of the above-mentioned prior art, the utility model provides an axial pressure compensation structure of an internal meshing gear pump, which has better axial pressure compensation effect.

[0006] The utility model discloses an axial pressure compensation structure of internal meshing gear pump, including the shell, in three -section type shell structure, the shell can be formed by the splicing of front cover, rear cover and pump body, the shell includes the accommodation cavity of accommodating gear and gear ring, and the gear and gear ring mesh in transmission in the accommodation cavity, the accommodation cavity includes two axial side walls, namely the side wall of corresponding gear and gear ring's two axial ends, and the compensation sheet is arranged between gear ring and two axial side walls, be provided with the recessed platform on the axial side wall, and the recessed platform is surrounded with annular recess around, and the annular sealing element is embedded in the recess, and the recess and sealing element are integral crescent, and one end of compensation sheet and sealing element contact seal cooperation, and the pressure cavity is formed between compensation sheet, recess and sealing element, and the compensation sheet is provided with the hole connected with pressure cavity, and the oil enters into the pressure cavity along the hole when the pump works, can push the compensation sheet and press tightly on gear ring, and the channel that can supply oil liquid to flow is arranged between pressure cavity and recess, and one end of the channel is arranged at the mesa of recessed platform, and the other end of the channel is arranged at the position corresponding to the other end of sealing element of recess, and the oil pressure in pressure cavity also can enter the other end position of sealing element along the channel, provides the thrust of sealing element to the direction of compensation piece, can make sealing element press tightly on compensation sheet better, makes the oil liquid in pressure cavity not easy to seep from the contact place of sealing element and compensation sheet, guarantees good compensation effect.

[0007] Further, the recess includes an annular inner side wall, an annular outer side wall, and a bottom inner wall connected between the inner side wall and the outer side wall, the other end of the sealing element includes an annular recessed portion and an annular protruding portion, the protruding portion abuts against and is limited by the bottom inner wall of the recess, a gap is left between the recessed portion of the sealing element and the bottom inner wall of the recessed platform, the other end of the channel communicates with the gap, and the gap allows the oil in the pressure cavity to enter, so that the oil pressure can act on the other end of the sealing element.

[0008] Further, the recessed portion is arranged at a position close to the recessed platform, and the channel is an opening formed between the mesa of the recessed platform and the inner side wall of the recess, the opening has an inclined bottom inner wall, and the channel structure formed by the opening is convenient to manufacture, and the oil can easily enter the gap at the other end of the sealing element through the opening.

[0009] Further, the channel is multiple and is arranged in a uniform distribution along the circumference of the recess, so that different positions of the sealing element can be balancedly pressed.

[0010] The utility model discloses the beneficial effect is: the utility model discloses simple structure, convenient production and processing, can solve the problem of the seepage of oil between compensation sheet and sealing element simply, guarantee that pressure cavity has better sealing property, guarantee good pressure compensation effect. BRIEF DESCRIPTION OF DRAWINGS

[0011] Figure 1This is a cross-sectional view of an embodiment of the present utility model;

[0012] Figure 2 for Figure 1 Enlarged view of section A;

[0013] Figure 3 This is a schematic diagram showing the distribution of the notches in an embodiment of the present utility model. Detailed Implementation

[0014] An axial pressure compensation structure for an internal gear pump according to an embodiment of this utility model, such as... Figures 1-3 The device includes a housing. In this embodiment, a three-section housing structure is adopted. The housing includes a front cover 11, a rear cover 12, and a pump body 13 that are spliced ​​together. The housing includes a cavity 10 for accommodating a gear 21 and a gear ring 22. The gear 21 and the gear ring 22 mesh and drive in the cavity 10. The cavity 10 includes two axial sidewalls 101, which are the sidewalls corresponding to the two axial ends of the gear 21 and the gear ring 22. In this embodiment, the two axial sidewalls 101 are respectively provided on the front cover 11 and the rear cover 12. A compensation piece 3 is provided between the gear ring 22 and the two axial sidewalls 101. A recess 102 is provided on the axial sidewall 101. An annular groove 103 is provided around the recess 102. An annular sealing element 4 is embedded in the groove 103. The groove 103 and the sealing element 4 are crescent-shaped as a whole. The compensation piece 3 and the sealing element 4... A pressure chamber 5 is formed between the compensating plate 3, the recess 102, and the sealing element 4, with one end in contact with a sealing fit. The compensating plate 3 is provided with a hole connected to the pressure chamber 5. When the pump is working, the oil enters the pressure chamber 5 along the hole, which can push the compensating plate 3 to press against the gear ring 22. A channel for oil to flow is provided between the pressure chamber 5 and the recess 103. One end of the channel is located at the platform of the recess 102, and the other end of the channel is located at the position of the recess 103 corresponding to the other end of the sealing element 4. The oil pressure in the pressure chamber 5 will also enter the other end of the sealing element 4 along the channel, providing the sealing element 4 with a thrust towards the compensating element, which can make the sealing element 4 press better against the compensating plate 3, so that the oil in the pressure chamber 5 is not easy to leak out from the contact point between the sealing element 4 and the compensating plate 3, ensuring a good compensation effect.

[0015] The groove 103 includes an annular inner wall, an annular outer wall, and a bottom inner wall connecting the inner wall and the outer wall. The other end of the seal 4 includes an annular recess 41 and an annular protrusion 42. The protrusion 42 and the bottom inner wall of the groove 103 abut and limit each other. A gap is left between the recess 41 of the seal 4 and the bottom inner wall of the recess 102. The other end of the channel is connected to the gap. The gap allows the oil in the pressure chamber 5 to enter into it, so that the oil pressure can act on the other end of the seal 4.

[0016] The recessed portion 41 is located close to the recessed platform 102, that is, the recessed portion 41 is located radially inside the protrusion 42. The channel is a notch 6 formed between the platform surface of the recessed platform 102 and the inner wall of the groove 103. The notch 6 has an inclined bottom inner wall. The channel structure formed by the notch 6 is easy to process and manufacture. Oil can easily enter the gap at the other end of the seal 4 through the notch 6.

[0017] like Figure 3 As shown, there are multiple channels, which are evenly distributed along the circumference of the groove 103, so that different positions of the seal 4 can be evenly pressurized.

[0018] The above embodiments are merely one preferred embodiment of the present utility model. Ordinary changes and substitutions made by those skilled in the art within the scope of the present utility model's technical solution are all included within the protection scope of the present utility model.

Claims

1. An axial pressure compensation structure for an internal gear pump, comprising a housing, the housing including a cavity for accommodating a gear and a gear ring, the cavity including two axial sidewalls, a compensation plate disposed between the gear ring and the two axial sidewalls, a recessed platform disposed on the axial sidewalls, an annular groove surrounding the recessed platform, an annular sealing element embedded in the groove, the groove and the sealing element being crescent-shaped in whole, one end of the compensation plate and the sealing element contacting and sealingly fitting, a pressure chamber being formed between the compensation plate, the recessed platform and the sealing element, the compensation plate having a hole connected to the pressure chamber, characterized in that: A channel for oil to flow is provided between the pressure chamber and the groove. One end of the channel is located on the platform of the recess, and the other end of the channel is located in the groove at a position corresponding to the other end of the seal.

2. The axial pressure compensation structure for an internal gear pump according to claim 1, characterized in that: The groove includes an annular inner wall, an annular outer wall, and a bottom inner wall connecting the inner wall and the outer wall. The other end of the seal includes an annular recess and an annular protrusion. The protrusion and the bottom inner wall of the groove abut and limit each other. A gap is left between the recess of the seal and the bottom inner wall of the recess. The other end of the channel is connected to the gap.

3. The axial pressure compensation structure for an internal gear pump according to claim 2, characterized in that: The recessed portion is located close to the recessed platform, and the channel is a notch formed between the platform surface and the inner wall of the groove.

4. The axial pressure compensation structure for an internal gear pump according to claim 3, characterized in that: The notch has a sloping inner wall.

5. An axial pressure compensation structure for an internal gear pump according to any one of claims 1 to 4, characterized in that: The channels are multiple and are evenly distributed along the circumference of the groove.

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