A sealing structure of a double gear pump with clearance compensation function

Abstract

The invention discloses a double gear pump sealing structure with a clearance compensation function, comprising a front pump cover, a pump body and a rear pump cover which are assembled in sequence, a rear driving gear and a rear driven gear are installed in a pump cavity formed by the pump body and the rear pump cover; a floating side plate is provided on the front end face of the rear driving gear and the front end face of the rear driven gear, a rubber sealing ring is provided between the floating side plate and the end face of the pump body; the rubber sealing ring comprises an outer sealing ring body on the outer periphery and an inner sealing ring body integrally connected to the inner side of the outer sealing ring body; the outer sealing ring body is pressed between the pump body and the rear pump cover to achieve the seal between the pump body and the rear pump cover, and the inner sealing ring body is pressed between the floating side plate and the end face of the pump body to provide a pressing force for the floating side plate and isolate the low-pressure area from the high-pressure area of ​​the pump. The invention has a simple structure, is economical and practical, and has a good sealing effect, and can achieve automatic compensation of the end face clearance between the front end face of the gear and the pump body without introducing pressure oil.

Description

Technical Field

[0001] The invention relates to the technical field of hydraulic pumps, in particular to a sealing structure of a double gear pump with a clearance compensation function. Background Art

[0002] Among the parts that constitute the closed volume of the gear pump, the end face clearance between the gear end face and the front and rear cover plates is the most susceptible to leakage under the action of the pump suction and pressure oil pressure difference. Due to the limitations of processing and assembly technology, the end face clearance value cannot be made very small at present, especially after use and wear, the clearance will become larger and larger, resulting in increased leakage. In order to keep the end face clearance value small after wear, the gap compensation method is currently used to achieve automatic compensation of the end face clearance, but the traditional method requires the introduction of pressure oil from the pressure oil chamber to use the pressure of the pressure oil to keep the floating element close to the gear end face. This method requires the introduction of pressure oil and the structure is relatively complex. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide a sealing structure of a double gear pump with a clearance compensation function, which has a simple structure, good sealing effect, and can realize automatic compensation of end face clearance without introducing pressure oil, in view of the current status of the above-mentioned prior art.

[0004] The technical solution adopted by the present invention to solve the above technical problems is:

[0005] A double gear pump sealing structure with a clearance compensation function comprises a front pump cover, a pump body and a rear pump cover which are assembled in sequence, wherein a meshing rear driving gear and a rear driven gear are rotatably mounted in a pump cavity formed by the pump body and the rear pump cover; a floating side plate for reducing the end face clearance between the front end face of the gear and the pump body is provided on the front end face of the rear driving gear and the front end face of the rear driven gear, and a rubber sealing ring which can use the compression force generated by the elastic deformation force to force the floating side plate to always be close to the front end face of the gear to realize automatic compensation of the end face clearance is provided between the floating side plate and the end face of the pump body; the rubber sealing ring comprises an outer sealing ring body on the outer periphery and an inner sealing ring body integrally connected to the inner side of the outer sealing ring body; the outer sealing ring body is pressed between the pump body and the rear pump cover to realize the sealing between the pump body and the rear pump cover, and the inner sealing ring body is pressed between the floating side plate and the end face of the pump body to provide compression force for the floating side plate and isolate the low-pressure area from the high-pressure area of ​​the pump.

[0006] To optimize the above technical solutions, the specific measures taken also include:

[0007] The end surface of the pump body is formed with a sealing groove for positioning and installing the rubber sealing ring, and the sealing groove includes an outer sealing groove located at the outer periphery and an inner sealing groove located in the area surrounded by the outer sealing groove; the inner sealing groove divides the area inside the outer sealing groove into a low-pressure area and a high-pressure area of ​​the pump; the outer sealing ring body of the rubber sealing ring is positioned and mounted in the outer sealing groove, and the inner sealing ring body is positioned and mounted in the inner sealing groove.

[0008] The end surface of the pump body is formed with an oil inlet hole, a first shaft hole for rotatably supporting the rear driving gear, and a second shaft hole for rotatably supporting the rear driven gear in the low-pressure area of ​​the pump; the end surface of the pump body is formed with an oil outlet in the high-pressure area of ​​the pump.

[0009] The above-mentioned rear pump cover is formed with a gear mounting cavity which constitutes the pump cavity body, and the bottom surface of the gear mounting cavity is formed with a third axial hole corresponding to the first axial hole and a fourth axial hole corresponding to the second axial hole, and the cover plate surface of the rear pump cover is formed with an oil inlet channel for connecting the oil inlet hole and the gear mounting cavity and an oil outlet channel for connecting the oil outlet and the gear mounting cavity.

[0010] A driving gear shaft is formed on the above-mentioned rear driving gear, the front end of which is rotatably supported in the first shaft hole of the pump body, and the rear end of which is rotatably supported in the third shaft hole of the rear pump cover; a driven gear shaft is formed on the rear driven gear, the front end of which is rotatably supported in the second shaft hole of the pump body, and the rear end of which is rotatably supported in the fourth shaft hole of the rear pump cover.

[0011] The front and rear ends of the driving gear shaft and the front and rear ends of the driven gear shaft are both equipped with wear-resistant oil-free bearings.

[0012] The floating side plate is an "8" shaped gasket with a main shaft hole and a driven shaft hole. The main shaft hole matches the driving gear shaft sleeve of the rear driving gear, and the driven shaft hole matches the driven gear shaft sleeve of the rear driven gear.

[0013] The floating side plate is composed of a base steel plate at the bottom and a wear-resistant alloy plate composited on the base steel plate.

[0014] The front pump cover, pump body and rear pump cover are fixedly connected into one body by four long bolts. The front pump cover, pump body and rear pump cover are all processed with bolt holes for the long bolts to pass through.

[0015] Two first locating pin holes are symmetrically processed on the end surface of the pump body and located outside the formed sealing groove. The first locating pin holes are installed with locating pins. Correspondingly, the rear cover plate is processed with a second locating pin hole for plugging and matching with the locating pin.

[0016] Compared with the prior art, the present invention provides a floating side plate on the front end face of the rear driving gear and the front end face of the rear driven gear, and a rubber sealing ring is provided between the floating side plate and the end face of the pump body. The present invention directly uses the elastic deformation force generated by the press-fitting of the rubber sealing ring to provide a clamping force for the floating side plate. The floating side plate can not only reduce the end face gap between the front end face of the gear and the pump body, but also when the floating side plate is worn, the floating side plate can also keep the floating side plate close to the front end face of the gear under the elastic deformation force of the rubber sealing ring, thereby realizing automatic compensation of the end face gap. The present invention uses the deformation force of the rubber sealing ring to provide a clamping force for the floating side plate, which not only plays a role in sealing between the pump body and the rear cover plate, but also replaces the introduction of traditional pressure oil, thereby simplifying the structure of the traditional gear pump.

[0017] The invention has a simple structure, is economical and practical, and has a good sealing effect, and can realize automatic compensation of the end face gap between the front end face of the gear and the pump body without introducing pressure oil. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the assembly structure of the pump body and the rear pump cover of the present invention;

[0019] Figure 2 It is a structural diagram of the pump body of the present invention;

[0020] Figure 3 yes Figure 2 Cross-sectional structural diagram;

[0021] Figure 4 yes Figure 1 Schematic diagram of the structure of the rubber sealing ring;

[0022] Figure 5 yes Figure 1 Schematic diagram of the structure of the middle floating side plate;

[0023] Figure 6 yes Figure 5 Cross-sectional structural diagram;

[0024] Figure 7 It is a structural schematic diagram of the rear pump cover of the present invention;

[0025] Figure 8 yes Figure 7 Cross-sectional structural diagram;

[0026] Fig. 9 It is a schematic diagram of the structure of the present invention;

[0027] Fig.10 yes Fig. 9 Right view of . DETAILED DESCRIPTION

[0028] The embodiments of the present invention are further described in detail below in conjunction with the accompanying drawings.

[0029] Figures 1 to 10 It is a structural schematic diagram of the present invention.

[0030] The accompanying drawings are marked as follows: low-pressure area D, high-pressure area G, pump cavity K, gear mounting cavity K1, bolt hole L, front pump cover 1, pump body 2, oil inlet hole 2a, first shaft hole 2b, second shaft hole 2c, oil outlet 2d, first positioning pin hole 2e, outer sealing groove 21, inner sealing groove 22, rear pump cover 3, oil inlet channel 3a, third shaft hole 3b, fourth shaft hole 3c, oil outlet channel 3d, second positioning pin hole 3e, rear driving gear 4, driving gear shaft 41, rear driven gear 5, driven gear shaft 51, floating side plate 6, main shaft hole 6a, driven shaft hole 6b, base steel plate 61, wear-resistant alloy plate 62, rubber sealing ring 7, outer sealing ring body 71, inner sealing ring body 72, oil-free bearing 8, positioning pin 9.

[0031] like Figure 1 and Fig.10 As shown, the present invention discloses a double gear pump sealing structure with clearance compensation function, including a front pump cover 1, a pump body 2 and a rear pump cover 3 which are sequentially assembled by bolts, the pump body 2 and the rear pump cover 3 are covered to form a pump chamber K, two meshing gears are rotatably installed in the pump chamber K, the two gears include a rear driving gear 4 and a rear driven gear 5, and the pump chamber K is sealed by two gears to form an oil suction chamber and an oil pressure chamber. The oil suction chamber is formed by the increase of the closed volume of the cavity on the side where the two gears exit the meshing in the pump chamber K, and the oil pressure chamber is formed by the decrease of the closed volume of the cavity on the side where the two gears mesh in the pump chamber K. In the prior art, more than 80% of the oil leakage of the double gear pump is from the end face gap between the front end face of the gear and the pump body, especially when the end face gap increases due to end face wear after the pump is used for a long time, the leakage will also increase. In order to reduce the end face clearance and achieve clearance compensation even after wear, the present invention provides a floating side plate 6 for reducing the end face clearance between the front end face of the gear and the pump body 2 on the front end face of the two gears, i.e., the front end face of the rear driving gear 4 and the front end face of the rear driven gear 5, and an elastic rubber sealing ring 7 is provided between the floating side plate 6 and the end face of the pump body 2. The rubber sealing ring 7 forms a pressing force on the floating side plate 6 by the elastic deformation force generated by pressure, forcing the floating side plate 6 to always be close to the front end face of the gear, thereby reducing the clearance between the end faces, and realizing automatic compensation of the end face clearance even after the floating side plate 6 is worn.

[0032] like Figure 4As shown, the rubber seal ring 7 of the present invention is a special-shaped rubber ring, which is composed of an outer seal ring body 71 on the outer periphery and an inner seal ring body 72 integrally connected to the inner side of the outer seal ring body 71. The outer seal ring body 71 is pressed between the pump body 2 and the rear pump cover 3 to achieve the seal between the pump body 2 and the rear pump cover 3. The inner seal ring body 72 is pressed between the floating side plate 6 and the end face of the pump body 2 to provide a pressing force for the floating side plate 6 so that the floating side plate 6 is close to the front end face of the gear. At the same time, the inner seal ring body 72 is also used to isolate the low-pressure area D from the high-pressure area G of the pump.

[0033] In the embodiment, in order to facilitate the positioning and installation of the rubber sealing ring 7 and prevent the rubber sealing ring 7 from borrowing position, as shown in FIG. Figure 2 As shown, the end surface of the pump body 2 of the present invention is formed with a sealing groove for positioning and installing the rubber sealing ring 7. The sealing groove is an inner groove processed on the end surface of the pump body 2, which includes an outer sealing groove 21 located at the outer periphery and an inner sealing groove 22 located in the area surrounded by the outer sealing groove 21. The inner sealing groove 22 divides the area inside the outer sealing groove 21 into a low-pressure area D and a high-pressure area G of the pump; the outer sealing ring body 71 of the rubber sealing ring 7 is positioned and clamped in the outer sealing groove 21, and the inner sealing ring body 72 is positioned and clamped in the inner sealing groove 22.

[0034] In the embodiment, please continue to refer to Figure 2 The end surface of the pump body 2 of the present invention is formed with an oil inlet hole 2a, a first shaft hole 2b for rotationally supporting the rear driving gear 4, and a second shaft hole 2c for rotationally supporting the rear driven gear 5 in the low-pressure area D of the pump; the end surface of the pump body 2 is formed with an oil outlet 2d in the high-pressure area G of the pump. The oil inlet hole 2a is used to provide hydraulic oil to the oil suction chamber of the pump, and the oil outlet 2d is used to discharge the high-pressure oil in the pressure oil chamber. Therefore, the high-pressure area G of the pump and the low-pressure area D of the pump are separated by the inner sealing ring body 72, which can prevent oil leakage between the oil inlet hole 2a and the oil outlet 2d.

[0035] In the examples, see Figure 7 and Figure 8 In the present invention, a gear installation cavity K1 with a front opening is formed in the rear pump cover 3, and the gear installation cavity K1 constitutes the main part of the pump cavity K. The pump body 2 seals the front opening of the gear installation cavity K1 to form the above-mentioned pump cavity K. A third axial hole 3b corresponding to the first axial hole 2b and a fourth axial hole 3c corresponding to the second axial hole 2c are formed on the bottom surface of the gear installation cavity K1. In addition, an oil inlet channel 3a for connecting the oil inlet hole 2a and the gear installation cavity K1 and an oil outlet channel 3d for connecting the oil outlet 2d and the gear installation cavity K1 are formed on the cover plate surface of the rear pump cover 3.

[0036] In the embodiment Figure 1As shown, a driving gear shaft 41 is formed on the rear driving gear 4 of the present invention, and the front end of the driving gear shaft 41 is rotatably supported in the first shaft hole 2b of the pump body 2, and the rear end of the driving gear shaft 41 is rotatably supported in the third shaft hole 3b of the rear pump cover 3. It can also be seen from the figure that the front end of the driven gear shaft 41 is also connected to a coupling sleeve, so that the power drives the rear driving gear 4 through the coupling sleeve to drive the rear driven gear 5 to rotate. A driven gear shaft 51 is formed on the rear driven gear 5 of the present invention, and the front end of the driven gear shaft 51 is rotatably supported in the second shaft hole 2c of the pump body 2, and the rear end of the driven gear shaft 51 is rotatably supported in the fourth shaft hole 3c of the rear pump cover 3.

[0037] In the embodiment, in order to ensure smooth rotation of the gears and increase the service life of the gears, the front and rear ends of the driving gear shaft 41 and the front and rear ends of the driven gear shaft 51 of the present invention are both equipped with wear-resistant oil-free bearings 8.

[0038] like Figure 5 and Figure 6 As shown, the floating side plate 6 of the present invention is a gasket with an "8"-shaped structure. The floating side plate 6 is processed with a main shaft hole 6a and a driven shaft hole 6b. The main shaft hole 6a is fitted with the driving gear shaft 41 of the rear driving gear 4, and the driven shaft hole 6b is fitted with the driven gear shaft 51 of the rear driven gear 5. The floating side plate 6 is fitted on the gear shaft of the gear through the processed main shaft hole 6a and driven shaft hole 6b, so that the gear shaft can provide a guide for the floating of the floating side plate 6 and prevent the floating side plate 6 from deviating left and right.

[0039] In order to further improve the wear resistance of the floating side plate 6 and reduce the manufacturing cost of the floating side plate 6 , the floating side plate 6 is made of two composite materials, including a base steel plate 61 located at the bottom and a wear-resistant alloy plate 62 composited on the base steel plate 61 .

[0040] In the embodiment, the front pump cover 1, the pump body 2 and the rear pump cover 3 of the present invention are fixedly connected as a whole by four long bolts, and the front pump cover 1, the pump body 2 and the rear pump cover 3 are all processed with bolt holes L for the long bolts to pass through.

[0041] Two first locating pin holes 2e are symmetrically processed on the end face of the pump body 2 and located outside the formed sealing groove. The locating pins 9 are installed in the first locating pin holes 2e. Correspondingly, the rear cover plate 3 is processed with second locating pin holes 3e for plugging with the locating pins 9.

[0042] Compared with the prior art, the present invention utilizes the deformation force of the rubber sealing ring to provide a pressing force for the floating side plate, which not only plays a sealing role between the pump body and the rear cover plate, but also replaces the introduction of traditional pressure oil, thereby simplifying the structure of the traditional gear pump.

[0043] The best embodiment of the present invention has been described, and various changes or modifications made by those skilled in the art will not depart from the scope of the present invention.

Claims

1. A double gear pump sealing structure with clearance compensation function, comprising a front pump cover, a pump body and a rear pump cover which are assembled in sequence, wherein a rear driving gear and a rear driven gear which mesh with each other are rotatably mounted in a pump cavity formed by the pump body and the rear pump cover; wherein: A floating side plate for reducing the end face gap between the front face of the gear and the pump body is provided on the front face of the rear driving gear and the front face of the rear driven gear, and a rubber sealing ring is provided between the floating side plate and the end face of the pump body, which can use the compression force generated by the elastic deformation force to force the floating side plate to always be close to the front face of the gear to realize automatic compensation of the end face gap; the rubber sealing ring includes an outer sealing ring body on the outer periphery and an inner sealing ring body integrally connected to the inner side of the outer sealing ring body; the outer sealing ring body is pressed between the pump body and the rear pump cover to realize the sealing between the pump body and the rear pump cover, and the inner sealing ring body is pressed between the floating side plate and the end face of the pump body to provide compression force for the floating side plate and isolate the low-pressure area from the high-pressure area of ​​the pump; The end surface of the pump body is formed with a sealing groove for positioning and installing a rubber sealing ring, and the sealing groove includes an outer sealing groove located at the outer periphery and an inner sealing groove located in the area surrounded by the outer sealing groove; the inner sealing groove divides the area in the outer sealing groove into a low-pressure area and a high-pressure area of ​​the pump; the outer sealing ring body of the rubber sealing ring is positioned and clamped in the outer sealing groove, and the inner sealing ring body is positioned and clamped in the inner sealing groove; The end surface of the pump body is formed with an oil inlet hole, a first shaft hole for rotatably supporting the rear driving gear, and a second shaft hole for rotatably supporting the rear driven gear in the low-pressure area of ​​the pump; the end surface of the pump body is formed with an oil outlet in the high-pressure area of ​​the pump; The rear pump cover is formed with a gear installation cavity constituting a pump cavity body, the bottom surface of the gear installation cavity is formed with a third axial hole corresponding to the first axial hole and a fourth axial hole corresponding to the second axial hole, and the cover plate surface of the rear pump cover is formed with an oil inlet channel for connecting the oil inlet hole and the gear installation cavity and an oil outlet channel for connecting the oil outlet and the gear installation cavity; The rear driving gear is formed with a driving gear shaft, the front end of which is rotatably supported in the first shaft hole of the pump body, and the rear end of which is rotatably supported in the third shaft hole of the rear pump cover; the rear driven gear is formed with a driven gear shaft, the front end of which is rotatably supported in the second shaft hole of the pump body, and the rear end of which is rotatably supported in the fourth shaft hole of the rear pump cover; The floating side plate is an "8" shaped gasket with a main shaft hole and a driven shaft hole. The main shaft hole matches with the driving gear shaft sleeve of the rear driving gear, and the driven shaft hole matches with the driven gear shaft sleeve of the rear driven gear. The floating side plate is composed of a base steel plate at the bottom and a wear-resistant alloy plate composited on the base steel plate.

2. The double gear pump sealing structure with clearance compensation function according to claim 1 is characterized in that: The front and rear ends of the driving gear shaft and the front and rear ends of the driven gear shaft are both covered with wear-resistant oil-free bearings.

3. The double gear pump sealing structure with clearance compensation function according to claim 2 is characterized in that: The front pump cover, pump body and rear pump cover are fixedly connected into one body by four long bolts, and the front pump cover, pump body and rear pump cover are all processed with bolt holes for the long bolts to pass through.

4. The double gear pump sealing structure with clearance compensation function according to claim 3 is characterized in that: The end surface of the pump body is symmetrically processed with two first positioning pin holes located outside the formed sealing groove, and positioning pins are installed in the first positioning pin holes. Correspondingly, the rear pump cover is processed with a second positioning pin hole for plugging and cooperating with the positioning pin.

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