Radial symmetric type double-acting internal gear pump
By designing a radially symmetrical double-acting internal meshing gear pump, the problems of unstable and noisy oil output by the existing pump are solved, the stability of oil flow and noise reduction are achieved, and the performance and life of the pump are improved.
Patent Information
- Application Number
- CN202421303880.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-06-07
- Publication Date
- 2025-02-11
- Estimated Expiration
- 2034-06-07
AI Technical Summary
The existing internal meshing gear pumps have problems such as unstable oil output, high noise and obvious pulsation flow, which affects the life of the pump and product quality.
A radially symmetrical double-acting internal meshing gear pump is designed. By improving the structural design, changing the fluid movement path, and using four symmetrical oil chambers and oil passages to ensure the stability and symmetry of oil flow.
It achieves smooth oil flow, reduces noise and pulsating flow, improves the load adaptability and performance of the pump, and extends the life of the pump.
Smart Images
Figure CN222457754U_ABST
Abstract
Description
Technical Field
[0001] The utility model belongs to the technical field of internal gear pumps, and in particular relates to a radially symmetrical double-acting internal gear pump. Background Art
[0002] like Figure 1 As shown, in the existing internal gear pump, it includes a front cover 3 and a housing 22, the housing 22 and the rear cover 4 are fixedly connected by screws 7, the housing 22 and the end faces of the front cover 3 and the rear cover 4 are provided with sealing rings 6, and the transmission shaft 8 is provided at the center of the housing 22, the transmission shaft drives the inner rotor 10 to mesh with the outer rotor 11, when the inner rotor 10 rotates with the transmission shaft 8, two sealed working chambers are formed between the inner rotor 10 and the outer rotor 11, and the sealing chamber is eccentrically placed on one side of the shaft. The pressure oil deviated to one side generates a unilateral radial force on the transmission, so that the shaft moves to the side of the sliding bearing 9, the transmission shaft is subjected to the radial force and produces flexural deformation, which weakens the bearing capacity, and causes the two ends of the bearing to have local contact with the shaft, aggravating wear and directly affecting the life of the pump.
[0003] like Figure 1 As shown, increasing the pressure of the internal gear pump directly increases the machining accuracy of the housing 22, the inner rotor 10, and the outer rotor 11, which places high demands on the equipment and is not conducive to reducing costs and increasing efficiency. At the same time, the single-acting internal gear pump has only one eccentricity, and the radial output flow unevenness coefficient is too large, resulting in large flow pressure pulsation, unstable pressure oil, and forming a pressure source. The hydraulic oil reacts on the wall, forming a reflected wave that is transmitted to the pressure source, and the pulsations are superimposed on each other to produce more harmful standing waves, and the output oil is unstable. Reducing the noise of the internal gear pump and reducing the pulsating flow have become urgent tasks, and product quality continues to improve. Utility Model Content
[0004] The utility model overcomes the shortcomings of the prior art and provides a radially symmetrical double-acting internal gear pump, which solves the problem of unstable oil output of the current single-acting internal gear pump.
[0005] In order to achieve the above purpose, the utility model is implemented through the following technical solutions.
[0006] A radially symmetrical double-acting internal gear pump comprises a front housing and a rear housing, wherein the rear end face of the front housing butts against the front end face of the rear housing, a front cover is arranged at the front end opening of the front housing, and a rear cover is arranged at the rear end opening of the rear housing; a cylindrical front side mounting groove is arranged on the rear end face of the front housing, and a cylindrical rear side mounting groove is arranged on the rear end face of the rear housing, a transmission shaft is connected and inserted in the front cover, the front housing, the rear housing and the rear cover, the transmission shaft passes through the front side mounting groove and the rear side mounting groove in sequence, and the front side mounting groove and the rear side mounting groove are both arranged in the interior thereof. An inner rotor and an outer rotor are provided, the inner rotor is sleeved on the outer side of the transmission shaft, the outer rotor is fixed on the inner walls of the front mounting groove and the rear mounting groove, and a crescent plate is provided between the inner rotor and the outer rotor; a front oil outlet chamber is provided on the left side of the bottom surface of the front mounting groove, a front oil inlet chamber is provided on the right side of the bottom surface of the front mounting groove, a front oil inlet chamber is provided on the left side of the bottom surface of the rear mounting groove, a rear oil outlet chamber is provided on the right side of the bottom surface of the rear mounting groove, an oil passage is provided on the rear shell body, and the front oil outlet chamber and the rear oil inlet chamber are connected through the oil passage.
[0007] Furthermore, the front cover and the front shell are positioned by positioning pins, the front shell and the rear shell are positioned by positioning pins, and the rear shell and the rear cover are positioned by positioning pins.
[0008] Furthermore, the front screws pass through the front cover and the front shell and are screwed to the rear shell, and the rear screws pass through the rear cover and the rear shell and are screwed to the front shell, thereby fixing the front cover, the front shell, the rear shell and the rear cover together.
[0009] Furthermore, sealing rings are provided between the front cover and the front shell, between the front shell and the rear shell, and between the rear shell and the rear cover.
[0010] Furthermore, the axis of the transmission shaft is parallel to the axes of the front mounting groove and the rear mounting groove, and the axis of the front mounting groove is located above the axis of the transmission shaft, and the axis of the rear mounting groove is located below the axis of the transmission shaft.
[0011] Furthermore, the axes of the front and rear inner rotors coincide with the axis of the transmission shaft, the axis of the front outer rotor coincides with the axis of the front mounting groove, and the axis of the rear outer rotor coincides with the axis of the rear mounting groove.
[0012] Furthermore, the crescent plates are fixedly arranged inside the front mounting groove and the rear mounting groove respectively, the crescent plate inside the front mounting groove is located above the inner rotor, and the crescent plate inside the rear mounting groove is located below the inner rotor; the crescent plates are respectively in contact with the outer meshing teeth of the inner rotor and the inner meshing teeth of the outer rotor.
[0013] Furthermore, an oil inlet is provided on the front cover, an oil outlet is provided on the rear cover, the front oil inlet chamber is connected to the oil inlet on the front cover, and the rear oil outlet chamber is connected to the oil outlet on the rear cover.
[0014] Furthermore, in the front mounting groove, the area between the crescent plate and the inner meshing teeth of the outer rotor in contact is a low-pressure transition chamber; in the rear mounting groove, the area between the crescent plate and the inner meshing teeth of the outer rotor in contact is a high-pressure transition chamber.
[0015] Furthermore, the front oil inlet chamber and the rear oil inlet chamber are symmetrically arranged relative to the axis center of the transmission shaft, and the front oil outlet chamber and the rear oil outlet chamber are symmetrically arranged relative to the axis center of the transmission shaft.
[0016] The beneficial effects of the utility model compared with the prior art are:
[0017] The utility model provides a radially symmetrical double-acting internal gear pump, which changes the fluid movement path by improving the structural design, stabilizes the pressure flow fluctuation, improves the load adaptability, improves the noise, improves the performance test of the internal gear pump, increases the production efficiency, and promotes the growth of corporate benefits. BRIEF DESCRIPTION OF THE DRAWINGS
[0018] The utility model is further described in detail below in conjunction with the accompanying drawings:
[0019] Figure 1 It is a structural schematic diagram of an existing internal gear pump;
[0020] Figure 2 It is a schematic diagram of the overall structure of the utility model;
[0021] Figure 3 yes Figure 2 The CC cross-sectional view in the figure shows that the pink area represents the oil inside the front oil outlet cavity, and the blue area represents the area inside the front oil inlet cavity;
[0022] Figure 4 yes Figure 2 The DD cross-sectional view in the figure shows that the pink area represents the oil inside the rear oil inlet chamber, and the red area represents the oil inside the rear oil outlet chamber;
[0023] Figure 5 It is a schematic diagram of the relative positions of the front oil inlet chamber, the front oil outlet chamber, the rear oil inlet chamber, the rear oil outlet chamber, and the oil passage;
[0024] Figure 6 It is a schematic diagram of the positions of the inner rotor, outer rotor and crescent plate on the front and rear sides relative to the transmission shaft;
[0025] Among them, 1 is the front housing, 2 is the rear housing, 3 is the front cover, 4 is the rear cover, 5 is the positioning pin, 6 is the sealing ring, 7 is the screw, 8 is the transmission shaft, 9 is the sliding bearing, 10 is the inner rotor, 11 is the outer rotor, 12 is the crescent plate, 13 is the oil inlet, 14 is the oil outlet, 15 is the front oil inlet chamber, 16 is the front oil outlet chamber, 17 is the low-pressure transition chamber, 18 is the rear oil inlet chamber, 19 is the rear oil outlet chamber, 20 is the high-pressure transition chamber, and 21 is the oil passage. DETAILED DESCRIPTION
[0026] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention is further described in detail in combination with the embodiments and the accompanying drawings. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention. The technical solution of the present invention is described in detail below in combination with the embodiments and the accompanying drawings, but the scope of protection is not limited thereto.
[0027] like Figure 2-6 As shown, the utility model provides a radially symmetrical double-acting internal gear pump, including a front cover 3, a rear cover 4, a front housing 1, and a rear housing 2. The rear end face of the front housing 1 and the front end face of the rear housing 2 are butted against each other. The front cover 3 is arranged at the front end opening of the front housing 1, and the rear cover 4 is arranged at the rear end opening of the rear housing 2. The front cover 3 and the front housing 1 are positioned by a positioning pin 5, the front housing 1 and the rear housing 2 are positioned by a positioning pin 5, and the rear housing 2 and the rear cover 4 are positioned by a positioning pin 5. The screw 7 on the front side passes through the front cover 3 and the front housing 1 and is screwed to the rear housing 2, and the screw 7 on the rear side passes through the rear cover 4 and the rear housing 2 and is screwed to the front housing 1, so that the front cover 3, the front housing 1, the rear housing 2, and the rear cover 4 are fixedly connected. A sealing ring 6 is arranged between the front cover 3 and the front housing 1, between the front housing 1 and the rear housing 2, and between the rear housing 2 and the rear cover 4, and the sealing of the connection is ensured by the sealing ring 6.
[0028] A cylindrical front mounting groove is provided on the rear end surface of the front housing 1, and a cylindrical rear mounting groove is provided on the rear end surface of the rear housing 2. A transmission shaft 8 is connected and inserted in the front cover 3, the front housing 1, the rear housing 2, and the rear cover 4. The transmission shaft 8 passes through the front mounting groove and the rear mounting groove in sequence. The axis of the transmission shaft 8 is parallel to the axis of the front mounting groove and the rear mounting groove, and the axis of the front mounting groove is located above the axis of the transmission shaft 8, and the axis of the rear mounting groove is located below the axis of the transmission shaft 8.
[0029] Sliding bearings 9 are provided between the outer side surface of the transmission shaft 8 and the inner wall of the front housing 1 , between the outer side surface of the transmission shaft 8 and the inner wall of the rear housing 2 , and between the outer side surface of the transmission shaft 8 and the rear cover 4 .
[0030] An inner rotor 10 is arranged inside the front mounting groove. The inner rotor 10 is sleeved on the outer side of the transmission shaft 8. The axis of the inner rotor 10 coincides with the axis of the transmission shaft 8. The number of external meshing teeth on the inner rotor 10 is 10. The inner rotor 10 and the transmission shaft 8 are keyed so that the transmission shaft 8 drives the inner rotor 10 to rotate. An outer rotor 11 is fixedly arranged on the inner wall of the front mounting groove. The axis of the outer rotor 11 coincides with the axis of the front mounting groove. The number of external meshing teeth on the outer rotor 11 is 13. A crescent plate 12 is arranged between the inner rotor 10 and the outer rotor 11. The crescent plate 12 is located above the inner rotor 10. The crescent plate 12 is fixed inside the front mounting groove. The crescent plate 12 contacts the external meshing teeth of the inner rotor 10 and the internal meshing teeth of the outer rotor 11 respectively.
[0031] An inner rotor 10 is arranged inside the rear mounting groove. The inner rotor 10 is sleeved on the outer side of the transmission shaft 8. The axis of the inner rotor 10 coincides with the axis of the transmission shaft 8. The number of external meshing teeth on the inner rotor 10 is 10. The inner rotor 10 and the transmission shaft 8 are keyed so that the transmission shaft 8 drives the inner rotor 10 to rotate. An outer rotor 11 is fixedly arranged on the inner wall of the rear mounting groove. The axis of the outer rotor 11 coincides with the axis of the rear mounting groove. The number of external meshing teeth on the outer rotor 11 is 13. A crescent plate 12 is arranged between the inner rotor 10 and the outer rotor 11. The crescent plate 12 is located below the inner rotor 10. The crescent plate 12 is fixedly arranged inside the rear mounting groove. The crescent plate 12 contacts the external meshing teeth of the inner rotor 10 and the internal meshing teeth of the outer rotor 11 respectively.
[0032] An oil inlet 13 is provided on the front cover 3 , and an oil outlet 14 is provided on the rear cover 4 .
[0033] A front oil outlet cavity 16 is provided on the left side of the bottom surface of the front mounting groove, and a front oil inlet cavity 15 is provided on the right side of the bottom surface of the front mounting groove. The front oil inlet cavity 15 and the front oil outlet cavity 16 are respectively located at the two ends of the front crescent plate 12, and the front oil inlet cavity 15 is connected to the oil inlet port 13 on the front cover 3. In the front mounting groove, the area between the crescent plate 12 and the inner meshing teeth of the outer rotor 11 in contact therewith is a low-pressure transition cavity 17.
[0034] A front oil inlet chamber 15 is provided on the left side of the bottom surface of the rear mounting groove, and a rear oil outlet chamber 19 is provided on the right side of the bottom surface of the rear mounting groove. The rear oil inlet chamber 18 and the rear oil outlet chamber 19 are respectively located at the two ends of the rear crescent plate 12, and the rear oil outlet chamber 19 is connected to the oil outlet 14 on the rear cover 4. In the rear mounting groove, the area between the crescent plate 12 and the inner meshing teeth of the outer rotor 11 in contact therewith is a high-pressure transition chamber 20.
[0035] An oil passage 21 is provided on the rear housing 2 , the axis of the oil passage 21 is parallel to the axis of the transmission shaft 8 , and the front oil outlet chamber 16 and the rear oil inlet chamber 18 are communicated with each other through the oil passage 21 .
[0036] The front oil inlet chamber 15 and the rear oil inlet chamber 18 are symmetrically arranged relative to the axis center of the transmission shaft 8 , and the front oil outlet chamber 16 and the rear oil outlet chamber 19 are symmetrically arranged relative to the axis center of the transmission shaft 8 .
[0037] The working principle of the utility model is:
[0038] When the rotating shaft rotates, the front and rear inner rotors 10 are driven to rotate together, and the front inner rotor 10, outer rotor 11, and crescent plate 12 cooperate with each other to suck oil from the oil inlet 13 and the front oil inlet chamber 15, and discharge it from the front oil outlet chamber 16. The oil discharged from the front oil outlet chamber 16 enters the rear oil inlet chamber 18 through the oil passage 21, and the rear inner rotor 10, outer rotor 11, and crescent plate 12 cooperate with each other to discharge the oil from the rear oil outlet chamber 19 and the oil outlet 14 to the outside.
[0039] The front oil inlet chamber 15, the front oil outlet chamber 16, the low-pressure transition chamber 17 and the rear oil inlet chamber 18, the rear oil outlet chamber 19, and the height transition chamber are symmetrically arranged relative to the axis center of the transmission shaft 8. More than half of the oil in the front oil inlet chamber 15 and the front oil outlet chamber 16 is located above the axis of the transmission shaft 8, so that the oil has a downward component force on the transmission shaft 8, and the transmission shaft 8 has a tendency to move downward. More than half of the oil in the rear oil inlet chamber 18 and the rear oil outlet chamber 19 is located below the axis of the transmission shaft 8, so that the oil has an upward component force on the transmission shaft 8, and the transmission shaft 8 has a tendency to move upward. Overall, the upper and lower force components are equal in size and opposite in direction, and the external resultant force is zero. The transmission shaft 8 is evenly stressed along the circumferential direction, reducing the problems of reduced load capacity and local wear caused by the tilt of the transmission shaft 8 in the bearing.
[0040] The single-acting oil pump is one that completes one oil suction and oil discharge cycle per rotation of the inner rotor 10, and the double-acting oil pump is one that completes two oil suction and oil discharge cycles per rotation of the inner rotor 10. The oil in the oil tank enters the front oil inlet chamber 15 inside the front housing 1 through the front cover 3, passes through the low-pressure transition chamber 17, and finally is distributed from the front oil outlet chamber 16. The front inner rotor 10 completes one oil suction and oil discharge cycle per rotation. Similarly, the rear inner rotor 10 also completes one oil suction and oil distribution cycle per rotation of the rear inner rotor 10. In order to transform the transmission shaft 8 so that it completes two oil suction and discharge cycles in one rotation, the front oil inlet chamber 15, the front oil outlet chamber 16, the rear oil inlet chamber 18 and the rear oil outlet chamber 19 are designed to be symmetrical structures relative to the axis center of the transmission shaft 8, and then the front oil outlet chamber 16 is connected to the rear oil inlet chamber 18 through the oil passage 21, and the oil flowing out of the front oil outlet chamber 16 enters the rear oil inlet chamber 18. The four chambers are paired in pairs, and the number of high-pressure transition chambers 20 and low-pressure transition chambers 17 is equal and even. The oil passes through the front oil inlet chamber 15, the front oil outlet chamber 16, the rear oil inlet chamber 18 and the rear oil outlet chamber 19 in the flow direction. Overall, the transmission shaft 8 completes two front and rear oil suction and discharge cycles in one rotation, so it can be defined as a double-acting oil pump. The double-acting oil pump has good flow uniformity and the radial liquid pressure on the rotor body is basically balanced.
[0041] The usual method of increasing the pressure of the oil pump is to improve the machining accuracy of the workpiece, and to increase the pressure p once. The utility model is designed with a front pump pressure of p / 2, and the rear pump pressure is increased from p / 2 to p. The specific implementation method is that the front housing 1 and the rear housing 2 are provided with an oil passage 21, connecting the front oil outlet chamber 16 and the rear oil inlet chamber 18. During the meshing process of the inner rotor 10 and the outer rotor 11, an initial pressure oil p / 2 is formed at the front oil outlet chamber 16 of the front housing 1, and flows through the oil passage 21 into the rear oil inlet chamber 18 of the rear housing 2. The rear pump p / 2 oil is pressurized to p again, and the pressure oil p flows out of the oil pump from the rear oil outlet chamber 19. The precision of the parts is determined by the pressure difference. Compared with increasing the pressure p once, increasing the pressure twice significantly reduces the precision requirements of the parts, and the difficulty of processing the parts is significantly reduced.
[0042] The volume of the oil inlet chamber changes from small to large, and the volume of the oil outlet chamber changes from large to small, completing an oil suction and oil pressure cycle. The radial velocity and acceleration of the oil in the oil chamber change area change as small as possible. The sudden change of radial velocity will make the radial acceleration infinite, forming a "hard impact". The oil has a certain compressibility, storing energy when under pressure and releasing energy when depressurized. The pressure gradient is the source of noise. The transmission shaft 8 rotates, and the periodic pressure pulsation depends on the number and layout of the high and low oil chambers at the instantaneous position. The flow pressure pulsation of the even-numbered chamber is low.
[0043] The oil in the oil outlet cavity generates a tiny vibration, which reacts to the wall to form a reflected wave, which interacts with the vibration source to generate a more harmful standing wave. After the oil is connected through the oil passage 21, the oil in the four oil chambers arranged symmetrically at the center is connected to each other, and the reflected waves offset and absorb each other, so that no waveform is generated to the outside, and the pulsation of the output oil is reduced. At the same time, the transmission shaft 8 is well lubricated, the load is evenly distributed, the inner and outer rotors 11 run smoothly, the noise reduction effect is greatly improved, and the work is more reliable.
[0044] It is obvious to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the present invention can be implemented in other specific forms without departing from the spirit or essential features of the present invention. Therefore, the embodiments should be regarded as exemplary and non-restrictive from any point of view, and the scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims be included in the present invention. Any reference numeral in a claim should not be regarded as limiting the claim to which it relates.
Claims
1. A radially symmetrical double-acting internal gear pump, characterized in that: The invention comprises a front housing (1) and a rear housing (2), wherein the rear end surface of the front housing (1) and the front end surface of the rear housing (2) are butted against each other, a front cover (3) is arranged at the front end opening of the front housing (1), and a rear cover (4) is arranged at the rear end opening of the rear housing (2); a cylindrical front side mounting groove is arranged on the rear end surface of the front housing (1), and a cylindrical rear side mounting groove is arranged on the rear end surface of the rear housing (2); a transmission shaft (8) is connected and inserted in the front cover (3), the front housing (1), the rear housing (2), and the rear cover (4), and the transmission shaft (8) passes through the front side mounting groove and the rear side mounting groove in sequence; an inner rotor (10) and an outer rotor are arranged in the front side mounting groove and the rear side mounting groove. The inner rotor (10) is sleeved on the outer side of the transmission shaft (8), the outer rotor (11) is fixed on the inner walls of the front mounting groove and the rear mounting groove, and a crescent plate (12) is provided between the inner rotor (10) and the outer rotor (11); a front oil outlet chamber (16) is provided on the left side of the bottom surface of the front mounting groove, a front oil inlet chamber (15) is provided on the right side of the bottom surface of the front mounting groove, a front oil inlet chamber (15) is provided on the left side of the bottom surface of the rear mounting groove, and a rear oil outlet chamber (19) is provided on the right side of the bottom surface of the rear mounting groove; an oil passage (21) is provided on the rear housing (2), and the front oil outlet chamber (16) and the rear oil inlet chamber (18) are connected through the oil passage (21).
2. A radially symmetrical double-acting internal gear pump according to claim 1, characterized in that: The front cover (3) and the front housing (1) are positioned by a positioning pin (5), the front housing (1) and the rear housing (2) are positioned by a positioning pin (5), and the rear housing (2) and the rear cover (4) are positioned by a positioning pin (5).
3. A radially symmetrical double-acting internal gear pump according to claim 1, characterized in that: The front screw (7) passes through the front cover (3) and the front shell (1) and is screwed to the rear shell (2); the rear screw (7) passes through the rear cover (4) and the rear shell (2) and is screwed to the front shell (1), thereby fixing the front cover (3), the front shell (1), the rear shell (2) and the rear cover (4) together.
4. A radially symmetrical double-acting internal gear pump according to claim 1, characterized in that: Sealing rings (6) are provided between the front cover (3) and the front shell (1), between the front shell (1) and the rear shell (2), and between the rear shell (2) and the rear cover (4).
5. A radially symmetrical double-acting internal gear pump according to claim 1, characterized in that: The axis of the transmission shaft (8) is parallel to the axes of the front mounting groove and the rear mounting groove, and the axis of the front mounting groove is located above the axis of the transmission shaft (8), while the axis of the rear mounting groove is located below the axis of the transmission shaft (8).
6. A radially symmetrical double-acting internal gear pump according to claim 5, characterized in that: The axes of the two front and rear inner rotors (10) coincide with the axis of the transmission shaft (8), the axis of the front outer rotor (11) coincides with the axis of the front mounting groove, and the axis of the rear outer rotor (11) coincides with the axis of the rear mounting groove.
7. A radially symmetrical double-acting internal gear pump according to claim 6, characterized in that: The crescent plate (12) is fixedly arranged in the front mounting groove and the rear mounting groove, respectively; the crescent plate (12) in the front mounting groove is located above the inner rotor (10), and the crescent plate (12) in the rear mounting groove is located below the inner rotor (10); the crescent plate (12) is in contact with the outer meshing teeth of the inner rotor (10) and the inner meshing teeth of the outer rotor (11), respectively.
8. A radially symmetrical double-acting internal gear pump according to claim 1, characterized in that: An oil inlet (13) is provided on the front cover (3), and an oil outlet (14) is provided on the rear cover (4); a front oil inlet chamber (15) is connected to the oil inlet (13) on the front cover (3), and a rear oil outlet chamber (19) is connected to the oil outlet (14) on the rear cover (4).
9. A radially symmetrical double-acting internal gear pump according to claim 1, characterized in that: In the front mounting groove, the area between the crescent plate (12) and the inner meshing teeth of the contacting outer rotor (11) is a low-pressure transition chamber (17); in the rear mounting groove, the area between the crescent plate (12) and the inner meshing teeth of the contacting outer rotor (11) is a high-pressure transition chamber (20).
10. The radially symmetrical double-acting internal gear pump according to claim 1, characterized in that: The front oil inlet chamber (15) and the rear oil inlet chamber (18) are symmetrically arranged relative to the axis center of the transmission shaft (8), and the front oil outlet chamber (16) and the rear oil outlet chamber (19) are symmetrically arranged relative to the axis center of the transmission shaft (8).