High-pressure-resistant internal gear pump

Abstract

The utility model relates to the technical field of hydraulic transmission control, in particular to a high-pressure-resistant internal gear pump which comprises a pump body, a front cover and a rear cover, an inner gear ring and a gear shaft are arranged in the pump body, and an oil high-pressure area and an oil low-pressure area are formed between the inner gear ring and the gear shaft; high-pressure oil grooves are formed in the front cover and the rear cover corresponding to the oil high-pressure area, circulation hole structures and hydraulic balance structures are arranged at the matching positions of the front cover and the gear shaft and the matching positions of the rear cover and the gear shaft, and the high-pressure oil grooves are communicated through the circulation hole structures and convey oil to the hydraulic balance structures; a front side plate and a rear side plate are arranged on the two sides, in the axial direction, of the inner gear ring correspondingly and seal the oil high-pressure area and the oil low-pressure area, and through holes are formed in the front side plate and the rear side plate correspondingly to communicate the oil high-pressure area with the high-pressure oil groove. The high-pressure oil groove structure is matched with and controls the front side plate and the rear side plate, so that the axial force of oil on the gear shaft can be reduced; the hydraulic balance structure can generate acting force which is counteracted with radial force generated by oil in the oil high-pressure area, and the stress of the gear shaft is better controlled.

Description

Technical Field

[0001] The utility model relates to the technical field of hydraulic transmission and control, in particular to a high-pressure resistant internal meshing gear pump. Background Art

[0002] Internal gear pumps are widely used in mobile machinery, petroleum, chemical industry, machine tools and other fields due to their compact structure, small flow and pressure pulsation, low noise and cheaper price than plunger pumps. Especially with the rapid development of electrification, the hydraulic system of servo-controlled variable speed motor combined with fixed displacement pump is the trend of hydraulic development. At this time, internal gear pumps show their huge performance and cost advantages.

[0003] Internal gear pumps are widely used in walking machinery to replace traditional piston pumps. They need to have good high pressure and high efficiency performance. However, due to the limitations of the structural principle of traditional internal gear pumps, as the pressure increases, the following key problems will arise: (1) axial oil leakage increases; (2) radial oil leakage increases; (3) the higher the pressure of high-pressure oil on the gear shaft and the inner gear ring.

[0004] At present, the methods to solve axial and radial oil leakage mainly include reducing the fit clearance as the oil pressure increases by setting a floating clearance supplement mechanism, and the methods to solve the excessive lateral hydraulic pressure on the gear shaft mainly include reducing the pressure area acting on the gear shaft. However, in the method of reducing the pressure area acting on the gear shaft, due to the limited effect of reducing the high-pressure area, the bearings of the gear shaft and the supporting shaft are still subjected to huge hydraulic pressure, and this hydraulic pressure increases with the increase of oil pressure. Through experiments, it was found that the gear pump prototype would have problems such as sliding bearing bite burning failure. When the pressure increased to 30MPa, the same problem also appeared in more similar products. Therefore, being able to withstand continuous high pressure without being damaged is an important indicator of the internal gear pump.

[0005] It can be seen that there is still room for improvement in the current internal gear pump structure, and adjustments and optimization should be made to improve its ability to withstand high-pressure oil. Therefore, a more reasonable technical solution needs to be proposed to solve the defects in the existing technology. Utility Model Content

[0006] In order to overcome at least one of the defects mentioned above, the utility model proposes a high-pressure resistant internal gear pump, which can offset the pressure of high-pressure oil on the gears and the inner ring by providing axial and radial auxiliary forces to the gears and the inner ring, thereby maintaining the force balance of the gears and the inner ring during operation, as well as the ability to withstand high pressure, thereby improving the service life of the pump when operating in high-pressure oil.

[0007] In order to achieve the above technical effects, the meshing gear pump disclosed in the utility model can adopt the following technical solutions:

[0008] A high-pressure resistant internal meshing gear pump comprises a pump body, an internal gear ring and a corresponding eccentrically meshing gear shaft are arranged in the pump body, a high-pressure oil zone corresponding to the oil outlet of the pump body and a low-pressure oil zone corresponding to the oil inlet of the pump body are formed between the internal gear ring and the gear shaft, and the front and rear sides of the pump body are closed by a front cover and a rear cover respectively; high-pressure oil grooves are arranged on the front cover and the rear cover corresponding to the high-pressure oil zone and are symmetrically arranged on both sides of the internal gear ring along the axial direction, the front cover and the rear cover are both matched with the gear shaft hole axis and a flow hole structure and a hydraulic balance structure are arranged at the matching position, the high-pressure oil groove is connected through the flow hole structure and the oil is transported to the hydraulic balance structure; front side plates and rear side plates are respectively arranged on both sides of the internal gear ring along the axial direction to close the high-pressure oil zone and the low-pressure oil zone, and through holes are respectively arranged on the front side plate and the rear side plate to connect the high-pressure oil zone with the high-pressure oil groove.

[0009] The internal gear pump disclosed above can realize oil suction and discharge by meshing the inner gear ring and the gear shaft in the pump body. The gear shaft drives the inner gear ring to rotate during the rotation process. A high-pressure oil tank is provided corresponding to the oil high-pressure area on the oil discharge side. The oil pressure in the high-pressure oil tank is the same as that in the oil high-pressure area. When the oil pressure increases, the front side plate or the rear side plate at the high-pressure oil tank is closer to the inner gear ring and the gear shaft, reducing the gap and improving the sealing ability, and eliminating the axial force applied by the oil to maintain axial stability; at the same time, the oil is transported to the hydraulic balance structure, which can apply a radial force to the gear shaft, and the force is opposite to the radial force applied by the oil in the oil high-pressure area and offsets it, thereby improving the radial stability of the gear shaft under high-pressure conditions, thereby realizing stable operation of the gear pump under high-pressure conditions.

[0010] Furthermore, in the present invention, the installation method of the front side plate and the rear side plate is not limited to a single method. Here, an optimization is made and one of the feasible options is proposed: the front side plate and the rear side plate are provided with a side plate center hole for matching the gear shaft, and a positioning hole for maintaining the circumferential position, and a sealing ring is provided between the front side plate front cover and between the rear side plate and the rear cover. When such a solution is adopted, the sealing ring surrounds the outer periphery of the high-pressure oil tank and forms a sealing area with the front side plate and the rear side plate. The sealing ring is made of elastic material and can undergo elastic deformation within a certain range. When the front side plate and the rear side plate are displaced along the axial direction of the gear shaft, the sealing ring can maintain the seal.

[0011] Furthermore, the flow hole structure guides the oil in the high-pressure oil tank to the hydraulic balance structure. The specific structure of the flow hole is not limited to a single one. Here, an optimization is made and one of the feasible options is proposed: the flow hole structure includes a first flow hole and a second flow hole set on both the front cover and the rear cover. The high-pressure oil tank is connected through the second flow hole and the oil is transported to the first flow hole. The first flow hole extends and transports the oil to the hydraulic balance structure. When such a solution is adopted, the first flow hole can be opened from the side of the front cover and the rear cover and extend inward, and the second flow hole can be opened from the bottom of the high-pressure oil tank and extend to the first flow hole.

[0012] Furthermore, in some other feasible solutions, the flow hole structure can be optimized. Here, another feasible option is proposed: the flow hole structure includes a flow oblique hole, and the flow oblique hole extends directly from the high-pressure oil tank to the hydraulic balance structure. When such a solution is adopted, the flow oblique hole is a straight hole and extends directly from the high-pressure oil tank to the hydraulic balance structure, which can avoid excessive resistance during the flow of oil.

[0013] Furthermore, in order to prevent the oil in the high-pressure oil tank from flowing too fast to the hydraulic balance structure, the flow hole structure can be improved. The specific improvement method is not limited to the only one. Here, optimization is made and one feasible option is proposed: the flow hole structure also includes a damping structure. When such a solution is adopted, the damping structure can use a small diameter hole section to reduce the transmission rate of the oil. In this way, the stability of the oil transmission can be maintained.

[0014] Furthermore, the hydraulic balance structure in the present invention can be constructed in a variety of forms, which are not limited to a single one. Here, an optimization is made and one of the feasible options is proposed: the front cover and the rear cover are both provided with shaft holes for matching the gear shaft, and the hydraulic balance structure includes a plurality of balance oil grooves provided on the inner wall of the shaft hole, and the balance oil grooves are opposite to the oil high pressure area and the force applied to the gear shaft is opposite. When such a scheme is adopted, the oil in the high pressure oil groove reaches the balance oil groove through the flow hole structure and applies a radial force to the gear shaft, which is opposite to the radial force applied to the gear shaft by the oil high pressure area and can offset each other, thereby reducing the radial instability of the gear shaft, making the gear shaft more stable and reliable during operation.

[0015] Furthermore, in some other feasible solutions, the setting mode of the hydraulic balance structure can also adopt other forms. Here, we optimize and propose one of the feasible options: the front cover and the rear cover are both provided with shaft holes for matching the gear shaft, and the shaft holes are provided with bearings. The hydraulic balance structure includes a balance oil groove provided on the bearing, and the balance oil groove is opposite to the oil high pressure area and the force applied to the gear shaft is opposite. When such a solution is adopted, the oil is transported from the high pressure oil groove into the balance oil groove, and the stability of the gear shaft is improved by the force applied by the bearing structure.

[0016] Furthermore, when setting the bearing, the setting position of the balancing oil groove is not limited to its surface. The balancing oil groove can be set on the outside of the bearing. The force of the oil acts on the bearing and is transmitted to the gear shaft. Optimization is performed here and one of the feasible options is proposed: the balancing oil groove is set on the outer side of the bearing that fits the shaft hole, and the balancing oil groove forms an annular groove along the circumferential outer side of the bearing.

[0017] Furthermore, when the bearing is set, the balancing oil groove can also be set on the inner side of the bearing, so that the oil directly applies force to the gear shaft. Here, an optimization is made and one of the feasible options is proposed: the balancing oil groove is set on the inner side where the bearing and the gear shaft fit together, and the balancing oil groove directly extends to the outer side of the bearing or is connected to the outer side of the bearing through an extension hole. When such a solution is adopted, if an extension hole is set on the balancing oil groove, the diameter of the extension hole is smaller than the width of the balancing oil groove.

[0018] Furthermore, when the gear shaft is supported by the hydraulic balance structure, the sealing performance and supporting performance of the hydraulic balance structure need to be satisfied. This can be achieved in a variety of ways and is not limited to the only one. Here, an optimization is made and one of the feasible options is proposed: the hydraulic balance structure also includes a sealing belt structure and a supporting belt structure, and an oil groove structure is formed on the supporting belt structure. When such a solution is adopted, the sealing belt structure can be arranged on the outside of the balancing oil groove, and the supporting belt structure can be arranged between adjacent balancing oil grooves.

[0019] Furthermore, in order to maintain the reliability of the pump body, it is necessary to avoid waste caused by leakage of oil in the hydraulic balance structure. Therefore, the hydraulic balance structure is optimized and improved, and the following feasible option is proposed: the front cover and the rear cover are both provided with a drainage cavity to store the oil leaked from the hydraulic balance structure, and the front cover and the rear cover are also provided with flushing holes, which are connected to the drainage cavity and transport the oil in the drainage cavity to the low-pressure area of ​​the oil. When such a solution is adopted, the hydraulic oil leaked from the hydraulic balance structure can be collected and redirected into the pump body, and reused by mixing it in the low-pressure area of ​​the oil.

[0020] Furthermore, in the present invention, high-pressure oil enters the corresponding positions of the front cover and the rear cover through the high-pressure oil groove to generate a force, but when the pressure of the oil is too high, it will also affect the stability of the gear shaft. Here, an optimization is made and one of the feasible options is proposed: the front cover and the rear cover are both provided with an axial hole, and an axial oil drain groove is provided in the axial hole corresponding to the high-pressure area of ​​the oil. The axial oil drain groove is connected to the low-pressure area of ​​the oil and is used to drain the high-pressure oil. When such a scheme is adopted, the front cover and the rear cover are respectively matched with the gear shaft through the axial hole, and the high-pressure oil is transported to the axial hole through the high-pressure oil groove to act on the gear shaft. When the pressure of the oil is too high, part of the oil is released outward through the oil drain groove to release the pressure.

[0021] Furthermore, the force applied to the gear shaft by the hydraulic balance structure can offset part or all of the high-pressure oil force, thereby maintaining the stability of the gear shaft. Specifically, under the same oil pressure conditions, the magnitude of the force can be controlled by different contact areas: the ratio of the radial force applied by the oil on the gear shaft through the hydraulic balance structure to the radial force applied by the gear shaft exposed to the oil high-pressure area is controlled at 0.5 to 1.5. When adopting such a solution, different forces can be controlled according to different action areas.

[0022] Compared with the prior art, some beneficial effects of the technical solution disclosed in the utility model include:

[0023] In the utility model, a high-pressure oil groove structure is set to coordinate and control the gap distance and sealing effect between the front side plate, the rear side plate and the gear shaft, thereby assisting in controlling the influence of the oil on the axial force generated by the gear shaft; the radial force acting on the gear shaft can be controlled by the hydraulic balance structure, and the radial force generated by the oil in the high-pressure area of ​​the oil can be offset, thereby better controlling the force balance of the gear shaft. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions of the embodiments of the utility model, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the utility model and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0025] Figure 1 The utility model is a schematic diagram of the structure of a high-pressure resistant internal gear pump.

[0026] Figure 2 for Figure 1 Cross-sectional view of section AA.

[0027] Figure 3 It is a structural schematic diagram of the rear end cover.

[0028] Figure 4 for Figure 3 BB section half-section of the middle and rear end covers.

[0029] Figure 5 Another structural schematic diagram of the rear end cover.

[0030] Figure 6 This is a half-section diagram of the sliding bearing structure.

[0031] Figure 7 This is a structural diagram of the rear side panel.

[0032] Figure 8 It is another structural schematic diagram of the high-pressure resistant internal gear pump in the utility model (Example 2).

[0033] Fig. 9 for Figure 8 Schematic diagram of the half-section structure of the sliding bearing.

[0034] Fig.10 It is another structural schematic diagram of the high-pressure resistant internal gear pump in the utility model (Example 3).

[0035] Fig.11 It is a structural schematic diagram of a high-pressure resistant internal gear pump without a sliding bearing in the utility model (Example 4).

[0036] In the above drawings, the meanings of the various reference numerals are as follows:

[0037] 1. Gear shaft; 2. Front cover; 3. Front side plate; 4. Inner gear ring; 5. Pump body; 6. Rear side plate; 7. Rear cover; 8. Positioning pin; 9. Crescent plate; 11. Shaft seal; 12. Front sliding bearing; 13. Gear; 14. Rear sliding bearing; 141. Annular groove; 142. Bearing balance oil groove; 21. Front cover balance oil groove; 22. Front cover first flow hole; 23. Front cover second flow hole; 24. Front cover high-pressure oil groove; 25. Front cover sealing ring; 26. Front cover flushing hole; 41. Through hole; 51. Oil inlet; 52. Oil outlet; 53. Oil high-pressure area; 54. Oil Low-pressure area; 61, center hole of side plate; 62, through hole of side plate; 63, positioning hole of side plate; 71, balancing oil groove of rear cover; 72, first through hole of rear cover; 73, second through hole of rear cover; 74, high-pressure oil groove of rear cover; 75, sealing ring of rear cover; 76, flushing hole of rear cover; 77, shaft hole; 78, damping hole; 79, axial oil drain hole; 81, positioning pin hole of rear cover; 91, crescent main plate; 92, crescent sub-plate; 93, gap of crescent plate; 94, spring piece; 95, sealing rod; 96, sealing groove; 711, inner sealing belt; 712, outer sealing belt; 713, supporting belt structure. DETAILED DESCRIPTION

[0038] The present invention will be further explained below in conjunction with the accompanying drawings and specific embodiments.

[0039] In view of the many deficiencies in the prior art, the following embodiments are optimized and overcome the defects in the prior art.

[0040] Example 1

[0041] like Figures 1-2 As shown, this embodiment provides a high-pressure resistant internal gear pump, including a gear shaft 1, a front cover 2, a pump body 5, a rear cover 7, an inner gear ring 4, a crescent plate 9 and a compensation mechanism. The two ends of the pump body 5 are fixedly connected to the front cover 2 and the rear cover 7. The gear 13 of the gear shaft 1 is meshed with the inner gear ring 4 and drives the inner gear ring 4 to rotate in the pump body 5. The compensation mechanism includes an axial clearance supplement mechanism and a radial clearance compensation mechanism.

[0042] The axial clearance compensation mechanism includes a front side plate 3 and a rear side plate 6 arranged on both sides of the gear 13 and the inner gear ring 4 of the gear shaft, a high-pressure oil groove and a seal are arranged on the front cover 2 and the rear cover 7, and the front side plate 3 and the rear side plate 6 are provided with a side plate through hole 62 to introduce high-pressure oil into the front cover high-pressure oil groove 24 and the rear cover high-pressure oil groove 74 to form axial clearance compensation, such as Figure 7 As shown, the front side plate 3 and the rear side plate 6 are also provided with a side plate center hole 61 and a side plate positioning hole 63. The front side plate 3 and the rear side plate 6 are respectively matched with the sliding clearances on both sides of the gear 13 and the inner gear ring 4. As the pressure increases, under the compensation effect of the high-pressure oil groove, the clearances between the front side plate 3 and the rear side plate 6 and the gear 13 and the inner gear ring 4 are smaller, and the oil leakage is smaller.

[0043] Preferably, the sealing member includes a front cover sealing ring 25 and a rear cover sealing ring 75 .

[0044] The radial clearance compensation mechanism includes a crescent main plate 91 and a crescent sub-plate 92 arranged between the gear 13 and the inner gear ring, a spring piece 94 and a sealing rod 95 are arranged between the crescent main plate 91 and the crescent sub-plate 92, a sealing groove 96 is arranged on the crescent main plate 91, and the spring piece 94 and the sealing rod 95 are installed on the sealing groove 96. The spring piece plays an initial sealing role, and the sealing rod 95 prevents the high-pressure oil from leaking from the crescent plate gap 93. The gap between the crescent main plate 91 and the crescent sub-plate 92 can be adjusted as the pressure changes. When the pressure increases, the high-pressure oil acts on the front end gap between the crescent main plate 91 and the crescent sub-plate 92, so that the crescent main plate 91 and the crescent sub-plate 92 are more closely fitted with the gear 13 and the inner gear ring respectively, thereby playing an adaptive radial clearance compensation role.

[0045] A shaft hole 77 is provided on the front cover 2 and the rear cover 7. Both ends of the gear shaft 1 are supported on the shaft hole 77 through sliding bearings. At least one balancing oil groove is provided on the side of the shaft hole 77 opposite to the high pressure area of ​​the gear shaft 1. A through hole is also provided on the front cover 2 and the rear cover 7. The through hole connects the high pressure oil groove and the balancing oil groove. The liquid pressure formed by the balancing oil groove offsets most or all of the force of the oil high pressure area acting on the gear shaft. It should be noted that the balancing oil groove is provided at a position opposite to the area where the oil in the oil high pressure area 53 acts on the gear shaft, such as Figure 3 As shown, area a is the area where the oil in the oil high pressure area 53 acts on the gear shaft, and area b is the area where the balancing oil groove is set. Area b can be larger or smaller than area a, depending on the width of the balancing oil groove.

[0046] Preferably, in order to maintain sealing performance, a shaft seal 11 is provided at the matching position between the gear shaft 1 and the shaft hole 77. Among them, a supporting belt structure 713 is provided between two adjacent balancing oil grooves.

[0047] Specifically, the structure of the front cover is as follows Figure 1 It can be seen that it includes a front cover balancing oil groove 21, a front cover first through-hole 22, a front cover second through-hole 23, and a front cover high-pressure oil groove 24. The front cover first through-hole 22 is punched into and connected to the front cover balancing oil groove 24 from the side, the front cover second through-hole 23 is connected to the front cover first through-hole 22, and a front cover sealing ring 25 is arranged on the periphery of the front cover high-pressure oil groove 24. High-pressure oil is drained from the high-pressure oil groove 24 to the balancing oil groove 21.

[0048] The specific structure of the back cover is as follows Figures 3-4 As shown, it includes a rear cover balancing oil groove 71, a rear cover first through hole 72, a rear cover second through hole 73, and a rear cover high-pressure oil groove 74. The rear cover first through hole 72 is punched into and connected to the rear cover balancing oil groove 71 from the side, the rear cover second through hole 73 is connected to the rear cover first through hole 72, and a rear cover sealing ring 75 is arranged on the periphery of the rear cover high-pressure oil groove 74. High-pressure oil is drained from the rear cover high-pressure oil groove 74 to the rear cover balancing oil groove 71.

[0049] The pump body 5 is arranged between the front cover 2 and the rear cover 7 and is fixedly connected by bolts. The pump body 5 is provided with an oil inlet 51 and an oil outlet 52. The oil inlet 51 and the oil outlet 52 are arranged vertically. The inner cavity of the pump body accommodates the gear shaft 1, the inner gear ring 4 and the crescent plate 9. The inner cavity of the pump body is divided into an oil high-pressure area 53 and an oil low-pressure area 54 by the gear shaft 1, the inner gear ring 4 and the crescent plate 9. The oil low-pressure area 54 is connected to the oil inlet, and the oil high-pressure area 53 is connected to the oil outlet 52. The inner gear ring 4 is provided with a through hole 41 to connect the inner and outer sides of the inner gear ring. The crescent plate 9 is connected to the front cover 2 and the rear cover 7 through a positioning pin 8 to limit the movement of the crescent plate 9.

[0050] like Figure 5As shown, another drainage structure is shown, in which the flow holes arranged on the front cover 2 and the rear cover 7 are inclined hole structures, and the inclined holes are directly connected to the balance oil tank and the high-pressure oil tank.

[0051] like Figure 3 As shown, in order to stabilize and balance the oil pressure on the oil tank, a damping hole 78 is provided on the first flow hole and / or the second flow hole. When the external load is a frequent impact pressure, the damping hole can delay the transmission time of the high-pressure oil.

[0052] In order to explain the structural details of the balance oil tank in more detail, take the rear cover structure as an example. Figure 4 As shown, an inner sealing belt 711 and an outer sealing belt 712 are provided inside and outside the rear cover balancing oil groove 71, and the inner sealing belt 711 and the outer sealing belt 712 cooperate with the outer periphery of the sliding bearing 14 or the outer periphery of the gear shaft 1 to prevent leakage of high-pressure oil in the balancing oil groove. An intermediate auxiliary support belt 713 is also provided in the area of ​​the rear cover balancing oil groove 71, and an opening (not shown) is provided on the intermediate auxiliary support belt 713, which can connect the balancing oil groove 71 separated by the intermediate auxiliary support belt 713.

[0053] like Figure 3 As shown, at least one axial oil leakage hole 79 is provided on the shaft hole 77 on the side of the gear shaft corresponding to the oil high pressure area 54, and the axial oil leakage hole 79 is connected to the pump body cavity.

[0054] A front cover flushing hole 26 and a rear cover flushing hole 76 are respectively provided on the front cover 2 and the rear cover 7. One end of the front cover flushing hole 26 and the rear cover flushing hole 76 are connected to the oil low-pressure area 54 on the pump body, and the other end is connected to the cavity of the sealing belt outside the balancing oil groove, so that the oil leaked from the front cover balancing oil groove 24 and the rear cover balancing oil groove 74 flows to the oil low-pressure area 54 on the pump body 5 through the front cover flushing hole 26 and the rear cover flushing hole 76, so as to drain the oil and lubricate.

[0055] Preferably, the rear cover 7 is also provided with a rear cover positioning pin hole 81.

[0056] like Figure 6 As shown, the structure of the front sliding bearing 12 and the rear sliding bearing 14 is shown. The front sliding bearing 12 and the rear sliding bearing 14 are interference fit with the gear shaft 1, and the outer periphery of the front sliding bearing 12 and the rear sliding bearing 14 is clearance fit with the shaft hole. At least one annular groove 141 is provided on the outer periphery of the front sliding bearing 12 and the rear sliding bearing 14 to achieve uniform lubrication.

[0057] It should be noted that if Figure 3As shown, the force exerted on the gear shaft by the oil in the high-pressure area of ​​the oil is Fa, and the total hydraulic support force generated by the front cover balance oil groove 21 and the rear cover balance oil groove 71 on the front cover 2 and the rear cover 7 is Fb. In order to extend the service life of the gear shaft, the ratio of Fb to Fa is controlled between 0.5 and 1.5.

[0058] Example 2

[0059] like Figure 8 , Fig. 9 As shown, this embodiment provides a high-pressure resistant internal gear pump, which is mainly different from the first embodiment in that the balance oil groove is arranged on the inner hole wall of the sliding bearing matched with the shaft hole. The details are as follows:

[0060] A front sliding bearing 12 and a rear sliding bearing 14 are sleeved on the axial holes arranged on the front cover 2 and the rear cover 7. At least one bearing balancing oil groove 142 is arranged on the side of the inner hole of the front sliding bearing 12 and the rear sliding bearing 14 opposite to the high-pressure area of ​​the gear shaft. Flow holes are also arranged on the front cover 2, the rear cover 7, the front sliding bearing 12 and the rear sliding bearing 14. The flow holes connect the high-pressure oil groove and the balancing oil groove. The liquid pressure formed in the balancing oil groove offsets most or all of the force of the oil in the high-pressure area acting on the gear shaft.

[0061] It should be noted that the outer periphery of the sliding bearing of this embodiment is interference fit with the shaft hole, so that the direction of the force of the front cover balance oil groove 21 and the rear cover balance oil groove 71 of the bearing remains unchanged, so as to offset the force of the high-pressure area oil on the gear shaft.

[0062] Example 3

[0063] like Fig.10 As shown, this embodiment provides a high-pressure resistant internal gear pump, which is mainly different from embodiments 1 and 2 in that the bearing balance oil groove 142 provided on the sliding bearing is a balance oil groove that runs through the inside and outside of the sliding bearing. Similarly, the outer periphery of the sliding bearing and the shaft holes of the front cover and the rear cover are interference fit, so that the direction of the force of the bearing balance oil groove 142 of the bearing remains unchanged, so as to offset the force of the oil in the high-pressure area acting on the gear shaft.

[0064] Example 4

[0065] like Fig.11 As shown, this embodiment provides a high-pressure resistant internal gear pump, which mainly differs from Embodiment 1 and Embodiment 2 in that no front sliding bearing 12 and rear sliding bearing 14 are arranged between the gear shaft 1 and the shaft holes on the front cover 2 and the rear cover 7, and the gear shaft 1 is directly supported on the shaft holes, and can offset most or all of the force of the high-pressure zone oil on the gear shaft 1 under the action of the front cover balancing oil groove 21 and the rear cover balancing oil groove 71.

[0066] It should be noted that a plurality of annular grooves (not shown) may be provided in the supporting area of ​​the gear shaft 1 corresponding to the shaft hole to achieve uniform lubrication.

[0067] The above are the implementation methods listed in this embodiment, but this embodiment is not limited to the above optional implementation methods. Those skilled in the art can arbitrarily combine the above methods to obtain other various implementation methods. Anyone can derive other various implementation methods under the inspiration of this embodiment. The above specific implementation methods should not be understood as limiting the protection scope of this embodiment. The protection scope of this embodiment should be based on the definition in the claims.

Claims

1. A high-pressure resistant internal gear pump, comprising a pump body (5), an internal gear ring (4) and a corresponding eccentrically meshed gear shaft (1) are arranged in the pump body (5), an oil high-pressure area (53) corresponding to an oil outlet (52) of the pump body (5) and an oil low-pressure area (54) corresponding to an oil inlet (51) of the pump body (5) are formed between the internal gear ring (4) and the gear shaft (1), and the front side and the rear side of the pump body (5) are respectively closed by a front cover (2) and a rear cover (7); characterized in that: The front cover (2) and the rear cover (7) are provided with high-pressure oil grooves corresponding to the oil high-pressure area (53) and are symmetrically arranged on both sides of the inner gear ring (4) along the axial direction. The front cover (2) and the rear cover (7) are both matched with the hole axis of the gear shaft (1) and a flow hole structure and a hydraulic balance structure are arranged at the matching position. The high-pressure oil groove is connected through the flow hole structure and the oil is transported to the hydraulic balance structure; the front side plate (3) and the rear side plate (6) are respectively provided on both sides of the inner gear ring (4) along the axial direction to close the oil high-pressure area (53) and the oil low-pressure area (54), and the front side plate (3) and the rear side plate (6) are respectively provided with through holes (41) to connect the oil high-pressure area (53) and the high-pressure oil groove.

2. The high pressure resistant internal gear pump according to claim 1, characterized in that: The front side plate (3) and the rear side plate (6) are provided with a side plate center hole (61) for matching the gear shaft (1), and are also provided with a positioning hole for maintaining the circumferential position. A sealing ring is provided between the front side plate (3) and the front cover (2), and between the rear side plate (6) and the rear cover (7).

3. The high pressure resistant internal gear pump according to claim 1, characterized in that: The flow hole structure comprises a first flow hole and a second flow hole (41) both provided on the front cover (2) and the rear cover (7); the high-pressure oil tank is connected via the second flow hole and delivers oil to the first flow hole; the first flow hole extends and delivers oil to the hydraulic balance structure.

4. The high pressure resistant internal gear pump according to claim 1, characterized in that: The flow hole structure comprises an inclined flow hole, and the inclined flow hole directly extends from the high-pressure oil tank to the hydraulic balance structure.

5. The high pressure resistant internal gear pump according to claim 1, 3 or 4, characterized in that: The flow hole structure also includes a damping structure.

6. The high pressure resistant internal gear pump according to claim 1, 3 or 4, characterized in that: The front cover (2) and the rear cover (7) are both provided with an axial hole (77) for matching the gear shaft (1), and the hydraulic balance structure includes a plurality of balancing oil grooves arranged on the inner wall surface of the axial hole (77), the balancing oil grooves are opposite to the oil high pressure area (53) and the direction of the force applied to the gear shaft (1) is opposite.

7. The high pressure resistant internal gear pump according to claim 1, 3 or 4, characterized in that: The front cover (2) and the rear cover (7) are both provided with an axial hole (77) for matching the gear shaft (1), and a bearing is provided in the axial hole (77). The hydraulic balance structure includes a balancing oil groove provided on the bearing, and the balancing oil groove is opposite to the oil high pressure area (53) and the direction of the force applied to the gear shaft (1) is opposite.

8. The high pressure resistant internal gear pump according to claim 7, characterized in that: The balancing oil groove is arranged on the outer side of the bearing fitting shaft hole (77), and the balancing oil groove forms an annular groove along the circumferential outer side of the bearing.

9. The high pressure resistant internal gear pump according to claim 7, characterized in that: The balancing oil groove is arranged on the inner side surface where the bearing and the gear shaft (1) are in contact, and the balancing oil groove directly extends to the outer side surface of the bearing or is connected to the outer side surface of the bearing through an extension hole.

10. The high pressure resistant internal gear pump according to claim 1, 3 or 4, characterized in that: The hydraulic balance structure further comprises a sealing belt structure and a supporting belt structure (713), and an oil groove structure is formed on the supporting belt structure (713).

11. The high pressure resistant internal gear pump according to claim 1, characterized in that: The front cover (2) and the rear cover (7) are both provided with a leakage chamber for storing oil leaked from the hydraulic balance structure. The front cover (2) and the rear cover (7) are also provided with flushing holes respectively. The flushing holes are connected to the leakage chamber and transport the oil in the leakage chamber to the oil low-pressure area (54).

12. The high pressure resistant internal gear pump according to claim 1, characterized in that: The front cover (2) and the rear cover (7) are both provided with an axial hole (77), and an axial oil drain groove is provided in the axial hole (77) corresponding to the oil high pressure area (53), and the axial oil drain groove is connected to the oil low pressure area (54) and is used to drain the high pressure oil.

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