Engine base for pump and oil pump

Abstract

The invention belongs to the technical field of electronic oil pumps, and provides a pump base and an oil pump, the pump base comprises a gear mounting cavity, the gear mounting cavity is configured to mount an inner gear and an outer gear which are rotationally meshed with each other, the inner gear is arranged in the outer gear, and the inner gear and the outer gear are eccentrically arranged; the inner gear and the outer gear are meshed and can form a maximum volume cavity; an oil discharge groove is formed in the bottom of the gear mounting cavity, and oil in the maximum-volume cavity is discharged to the oil discharge groove; a first extending groove communicated with the oil discharging groove is formed in the end, close to the maximum volume cavity, of the oil discharging groove.

Description

Technical Field

[0001] This invention belongs to the field of electronic oil pump technology, and particularly relates to a pump base and an oil pump. Background Technology

[0002] like Figure 1 and Figure 2 As shown, existing electronic oil pumps have different designs for the suction groove 10' and the discharge groove 20'. Practice has shown that simply optimizing the pump's rotor parameters has limited effect on improving the volumetric efficiency of the electronic oil pump; the structure of the suction groove 10' and the discharge groove 20' is the key factor determining the volumetric efficiency.

[0003] Conventional oil suction grooves 10' and oil discharge grooves 20' are mainly divided into two types: parallel groove type ( Figure 1 ) and angled groove type ( Figure 2 ).

[0004] Analysis revealed that when the two types of crescent-shaped oil cavities form a closed line at the same meshing point W, the area of ​​the angled oil cavity is slightly larger than that of the parallel oil cavity.

[0005] In addition, when the oil inlet chamber is completely closed, the oil suction groove 10' and the oil discharge groove 20' are angled grooves of the electronic oil pump, and the opening cross-sectional area of ​​its oil chamber is larger than that of the oil chamber of the electronic oil pump with parallel grooves 10' and 20'. This helps to reduce flow loss and improve oil inlet efficiency.

[0006] In the initial stage of oil discharge, the oil suction groove 10' and the oil discharge groove 20' are angled groove-type electronic oil pumps, and their oil chambers have a larger opening cross-sectional area. Similarly, due to the weakening of the throttling effect, they are more conducive to oil discharge.

[0007] In summary, the angled oil chamber structure outperforms the parallel oil chamber in terms of volumetric efficiency. Therefore, most manufacturers adopt the angled design for their oil suction groove 10' and oil discharge groove 20'.

[0008] However, in both of the above designs, when the inlet chamber is completely closed during operation and oil is being discharged into the drain sump 20', the pressure in the inlet chamber drops too much, resulting in a large impact and noise when the electronic oil pump is working. Summary of the Invention

[0009] In view of the shortcomings of the existing technology, the purpose of this invention is to provide a pump base for opening reasonable oil suction grooves and oil discharge grooves on the pump casing, so as to reduce the operating noise of the electronic oil pump while ensuring the volumetric efficiency of the electronic oil pump.

[0010] Another object of the present invention is to provide an oil pump that, by utilizing the above-mentioned pump base, can reduce the operating noise of the electronic oil pump while ensuring the pumping efficiency of the electronic oil pump.

[0011] To achieve this objective, the present invention adopts the following technical solution: A pump base includes a gear mounting cavity, which is configured to mount an internal gear and an external gear that rotate and mesh with each other. The internal gear is disposed inside the external gear and is eccentrically disposed with respect to the external gear. The internal gear and the external gear mesh together to form a maximum volume cavity. An oil groove is provided at the bottom of the gear mounting cavity, and oil is transferred between the oil groove and the maximum volume cavity; An extension groove communicating with the oil groove is provided at one end of the oil groove near the maximum volume cavity, and the extension groove is located within the projection range of the maximum volume cavity at the bottom of the gear mounting cavity.

[0012] As a preferred option, The oil trough includes an oil drain trough formed at the bottom of the gear mounting cavity; The oil draining trough is provided with a first extension trough that communicates with the oil draining trough at one end near the maximum volume cavity; The oil in the largest volume chamber is discharged into the oil draining tank.

[0013] Preferably, the oil groove further includes an oil suction groove formed at the bottom of the gear mounting cavity, and a second extension groove is formed at one end of the oil suction groove near the maximum volume cavity; The oil suction groove and the oil discharge groove are arranged circumferentially, and the maximum volume cavity is located between the oil suction groove and the oil discharge groove; the oil in the oil suction groove is sucked into the maximum volume cavity.

[0014] Preferably, the first extension groove is located in the projection area of ​​the first closed area formed by the root circle of the internal gear, the root circle of the external gear, the first contour line, and the second contour line at the bottom of the gear mounting cavity. The center line connecting the internal gear and the external gear is the first center line. When the internal gear and the external gear mesh to form the maximum volume cavity, the first contour line is parallel to the first center line, and the first contour line is tangent to the tooth of the external gear that forms the maximum volume cavity. The first contour line is relative to the second contour line and is located on the side closer to the oil suction groove. When the internal gear and the external gear mesh to form the maximum volume cavity, the second contour line is the line connecting the meshing point of the teeth of the internal gear and the teeth of the external gear that form the maximum volume cavity with the center of the internal gear, and the second contour line is located on the side close to the oil drain groove. And / or, the second extended groove is located in the projection area of ​​the second closed region formed by the root circle of the internal gear, the root circle of the external gear, the third profile line, and the fourth profile line at the bottom of the gear mounting cavity, the third profile line being relative to the fourth profile line, the third profile line being located on the side closer to the oil drain groove. The center line connecting the internal gear and the external gear is the first center line. When the internal gear and the external gear mesh to form the maximum volume cavity, the third contour line is parallel to the first center line, and the third contour line is tangent to the tooth of the external gear that forms the maximum volume cavity. When the internal gear and the external gear mesh to form the maximum volume cavity, the fourth contour line is the line connecting the meshing point of the teeth of the internal gear and the teeth of the external gear that form the maximum volume cavity with the center of the internal gear, and the fourth contour line is located on the side close to the oil suction groove.

[0015] Preferably, the outline of the first extended groove coincides with the outline of the projection area of ​​the first closed region at the bottom of the gear mounting cavity. And / or, the outline of the second extended groove coincides with the outline of the projection area of ​​the second closed region at the bottom of the gear mounting cavity.

[0016] Preferably, the first extension groove further includes a seventh profile line, which coincides with the projection of the pitch circles of the internal gear and the external gear onto the bottom of the gear mounting cavity; One end of the seventh contour line is connected to the projection of the second contour line at the bottom of the gear mounting cavity, and the other end is connected to the projection of the first contour line at the bottom of the gear mounting cavity. And / or, the second extension groove further includes an eighth profile line, which coincides with the projection of the pitch circles of the internal gear and the external gear onto the bottom of the gear mounting cavity; One end of the eighth contour line is connected to the projection of the fourth contour line at the bottom of the gear mounting cavity, and the other end is connected to the projection of the third contour line at the bottom of the gear mounting cavity.

[0017] Preferably, the projection of the root circle of the internal gear at the bottom of the gear mounting cavity and the projection of the second contour line at the bottom of the gear mounting cavity are connected by a first arc portion. And / or, the projection of the second contour line at the bottom of the gear mounting cavity and the projection of the pitch circle of the meshing internal gear and the external gear at the bottom of the gear mounting cavity are connected by a second arc portion. And / or, the projection of the internal gear at the bottom of the gear mounting cavity and the pitch circle of the external gear meshing are connected to the projection of the first profile line at the bottom of the gear mounting cavity via a third arc portion. And / or, the projection of the root circle of the external gear at the bottom of the gear mounting cavity and the projection of the first contour line at the bottom of the gear mounting cavity are connected by a fourth arc portion.

[0018] Preferably, the outer contour of the oil drain groove is located within the projection area of ​​the bottom of the gear mounting cavity of the area enclosed by the root circle of the internal gear, the root circle of the external gear, the second contour line, and the fifth contour line. The outer contour of the oil suction groove is located in the projection area at the bottom of the gear mounting cavity of the area enclosed by the root circle of the internal gear, the root circle of the external gear, the fourth contour line, and the sixth contour line. When the internal gear and the external gear mesh to form the minimum volume cavity, the meshing point of the teeth of the external gear and the teeth of the internal gear forming the minimum volume cavity and the center point of the internal gear respectively form a first line and a second line, with the first line located on the side closer to the oil drain groove. Both the fifth contour line and the sixth contour line are located within the area between the first connecting line and the second connecting line.

[0019] Preferably, the fifth contour line coincides with the first connecting line, and the sixth contour line coincides with the second connecting line.

[0020] An oil pump, including the aforementioned pump base.

[0021] Compared with the prior art, the present invention has the following advantages: In the present invention, an internal gear and an external gear are installed in the gear mounting cavity. During the rotation and meshing of the internal and external gears, a maximum volume cavity is formed, thereby absorbing and discharging oil. An oil drain groove is provided at the bottom of the gear mounting cavity. As the internal and external gears continue to rotate, the oil in the maximum volume cavity is discharged into the oil drain groove.

[0022] A first extension groove is provided at one end of the oil drain groove near the maximum volume chamber. The first extension groove is located within the projection range of the maximum volume chamber at the bottom of the gear mounting cavity.

[0023] When the internal and external gears mesh to form the maximum volume cavity, if the internal and external gears continue to rotate and disengage, the oil pressure inside will drop too quickly, resulting in a large pressure change and an impact. When the pump is working, an impact noise will occur.

[0024] The first extension groove effectively increases the space of the maximum volume chamber. As the internal and external gears continue to rotate, they begin to release the oil from the maximum volume chamber into the first extension groove. In this way, the capacity of the maximum volume chamber increases, reducing the pressure within the maximum volume chamber. During oil discharge, it acts as a buffer, preventing a large impact when the internal and external gears disengage, and reducing the pump's flow pulsation rate.

[0025] Meanwhile, the addition of the first extension groove increases the volume of the maximum volume chamber, but the structure still has superior oil absorption capacity even when negative pressure is formed at the inlet. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the parallel groove type structure of the inlet and outlet oil tanks of the pump in the background art; Figure 2 This is a schematic diagram of the angled groove structure of the inlet and outlet oil tanks of a pump in the background art; Figure 3 This is a front view of the base in this invention; Figure 4 For the present invention Figure 3 A magnified view of point I; Figure 5 This is a schematic diagram of the base structure in this invention; Figure 6 This is a front view of the base, internal gear, and external gear in this invention; Figure 7 This is a schematic diagram of the structure of the base and the tooth profiles of the internal and external gears in this invention; Figure 8 This is a schematic diagram of the first angle of the end cap in this invention; Figure 9 This is a schematic diagram of the second angle of the end cap in this invention. Figure 10 This is a schematic diagram of the end cap at the third angle in this invention.

[0027] Among them, 10' is the oil inlet chamber; 20' is the oil outlet chamber; 1. Gear mounting cavity; 11. Oil suction groove; 12. Oil discharge groove; 13. First connecting line; 14. Second connecting line; 2. Internal gear; 3. External gear; 411. First contour line; 412. Second contour line; 413. Third contour line; 414. Fourth contour line; 43. Fifth contour line; 44. Sixth contour line; 45. First arc portion; 46. Second arc portion; 47. Third arc portion; 48. Fourth arc portion; 100. Maximum volume cavity; 120. Minimum volume cavity; 417. Seventh contour line; 418. Eighth contour line; 8. First extension groove; 9. Second extension groove; 10. First center line; 16. End cap; 161. Oil suction groove; 162. Oil discharge groove. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0029] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0030] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0031] In the description of this invention, it should be noted that the terms "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of this invention is in use. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0032] In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set" and "connection" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0033] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0034] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0035] like Figures 3-10 As shown, this embodiment provides a pump base, including a gear mounting cavity 1. The gear mounting cavity 1 is configured to mount an internal gear 2 and an external gear 3 that rotate and mesh with each other. The internal gear 2 is disposed inside the external gear 3 and is eccentrically disposed with respect to the external gear 3. The internal gear 2 and the external gear 3 mesh together and can form a maximum volume cavity 100 during the meshing process. During the rotational meshing process of the internal gear 2 and the external gear 3, oil is sucked in and oil is discharged.

[0036] An oil groove is provided at the bottom of the gear mounting cavity 1, and the oil is transferred between the oil groove and the maximum volume cavity 100.

[0037] An extension groove communicating with the oil drain groove 12 is provided at one end of the oil sump near the maximum volume cavity 100. The extension groove is located within the projection range of the maximum volume cavity 100 at the bottom of the gear mounting cavity 1.

[0038] In this embodiment, an internal gear 2 and an external gear 3 are installed in the gear mounting cavity 1. During the rotation and meshing of the internal gear 2 and the external gear 3, a maximum volume cavity 100 is formed, thereby absorbing and discharging oil.

[0039] An extension groove communicating with the oil tank is provided at one end of the oil tank near the maximum volume chamber 100. This extension groove effectively increases the oil-accommodating space and reduces the pressure within the maximum volume chamber 100 while maintaining the same oil intake. Thus, when the internal gear 2 and external gear 3 mesh to form the maximum volume chamber 100, and then disengage as they rotate, the rapid pressure change during oil discharge prevents large pressure fluctuations and impacts caused by the rapid transition of oil pressure from the low-pressure zone to the high-pressure zone within the maximum volume chamber. Consequently, no impact noise occurs during pump operation.

[0040] Preferably, the oil tank includes an oil draining groove 12 formed at the bottom of the gear mounting cavity 1. A first extension groove 8 communicating with the oil draining groove 12 is provided at one end near the maximum volume cavity 100. Specifically, the first extension groove 8 is located within the projection range of the maximum volume cavity 100 at the bottom of the gear mounting cavity 1. Oil in the maximum volume cavity 100 is drained into the oil draining groove 12.

[0041] In this embodiment, an oil drain groove 12 is provided at the bottom of the gear mounting cavity 1. As the internal gear 2 and external gear 3 continue to rotate, the oil in the maximum volume cavity 100 is discharged into the oil drain groove 12.

[0042] Specifically, an end cover 16 is installed at the port of the pump body base. The end cover 16 has an oil drain port that communicates with the oil drain trough 12, through which oil is drained to the pump outlet. More specifically, the area of ​​the oil drain port covers the area of ​​the oil drain trough.

[0043] When the internal gear 2 and the external gear 3 mesh to form the maximum volume cavity 100, when the internal gear 2 and the external gear 3 continue to rotate and disengage, the oil pressure in the maximum volume cavity will change too quickly from the low pressure area to the high pressure area, resulting in a large pressure change and impact. When the pump is working, an impact noise will occur.

[0044] The first extension groove 8 effectively increases the space of the maximum volume chamber 100. When the internal gear 2 and external gear 3 continue to rotate, some of the oil in the maximum volume chamber 100 will be released into the first extension groove 8. This effectively increases the capacity of the maximum volume chamber 100, reduces the pressure within the maximum volume chamber 100, and acts as a buffer during oil discharge. When the internal gear 2 and external gear 3 disengage, there will be no significant impact, reducing the pump's flow pulsation rate.

[0045] Meanwhile, the addition of the first extension groove 8 increases the volume of the maximum volume chamber 100, but the structure still has superior oil suction capacity even when negative pressure is formed at the inlet.

[0046] Preferably, the oil tank further includes an oil suction groove 11 formed at the bottom of the gear mounting cavity 1. The oil suction groove 11 and the oil discharge groove 12 are circumferentially spaced apart. A second extension groove 9 is formed at one end of the oil suction groove 11 near the maximum volume cavity 100. The oil suction groove 11 and the oil discharge groove 12 are circumferentially spaced apart, and the maximum volume cavity 100 is located between the oil suction groove 11 and the oil discharge groove 12. The oil in the oil suction groove 11 is sucked into the maximum volume cavity 100.

[0047] The second extension groove 9 is located within the projection range of the maximum volume cavity 100 at the bottom of the gear mounting cavity 1, so as to ensure that the accommodating space of the maximum volume cavity 100 is increased by the space of the first extension groove 8 and the second extension groove 9. This ensures that the maximum volume cavity 100 can gradually detach from the oil suction groove 11, and also improves the situation of sudden pressure change during oil discharge when the oil discharge begins, further reducing the impact noise generated by the pump during operation.

[0048] Regarding the specific structure of the first extension groove 8 and the second extension groove 9, preferably, the first extension groove 8 is located in the projection area of ​​the first closed area formed by the root circle of the internal gear 2, the root circle of the external gear 3, the first contour line 411 and the second contour line 412 at the bottom of the gear mounting cavity 1.

[0049] The center line connecting the internal gear 2 and the external gear 3 is the first center line 10. When the internal gear 2 and the external gear 3 mesh to form the maximum volume cavity 100, the first contour line 411 is parallel to the first center line 10, and the first contour line 411 is tangent to the teeth of the external gear 3 that forms the maximum volume cavity 100. The position of the first contour line 411 relative to the second contour line 412 is that the first contour line 411 is located on the side close to the oil suction groove 11.

[0050] When the internal gear 2 and the external gear 3 mesh to form the maximum volume cavity 100, the second contour line 412 is the line connecting the meshing point of the teeth of the internal gear 2 and the teeth of the external gear 3 that form the maximum volume cavity 100 with the center of the internal gear 2. Compared with the position of the first contour line 411, the second contour line 412 is located on the side closer to the oil drain groove 12.

[0051] And / or, the second extension groove 9 is located in the projection area of ​​the second closed area formed by the root circle of the internal gear 2, the root circle of the external gear 3, the third contour line 413 and the fourth contour line 414 at the bottom of the gear mounting cavity 1, the position of the third contour line 413 relative to the fourth contour line 414, the third contour line 413 is located on the side close to the oil drain groove 12.

[0052] The center line connecting the internal gear 2 and the external gear 3 is the first center line 10. When the internal gear 2 and the external gear 3 mesh to form the maximum volume cavity 100, the third contour line 413 is parallel to the first center line 10, and the third contour line 413 is tangent to the tooth of the external gear 3 that forms the maximum volume cavity 100.

[0053] When the internal gear 2 and the external gear 3 mesh to form the maximum volume cavity 100, the fourth contour line 414 is the line connecting the meshing point of the teeth of the internal gear 2 and the teeth of the external gear 3 that form the maximum volume cavity 100 with the center of the internal gear 2. Compared with the position of the third contour line 413, the fourth contour line 414 is located on the side closer to the oil suction groove 11.

[0054] In this embodiment, the structures of the first extension groove 8 and the second extension groove 9 can be different. Because the boundary region of the aforementioned maximum volume cavity 100 is within the space between the root circle of the internal gear 2 and the root circle of the external gear 3, see... Figure 6 That is, the closed space area formed by the meshing of two adjacent teeth of the external gear 3 and the internal gear 2. Therefore, the outline of the first extension groove 8 is the projection of the root circle of the internal gear 2, the root circle of the external gear 3, the first outline 411, and the second outline 412 onto the bottom of the gear mounting cavity 1.

[0055] Similarly, the outline of the second extension groove 9 is the projection of the root circle of the internal gear 2, the root circle of the external gear 3, the third outline 413, and the fourth outline 414 onto the bottom of the gear mounting cavity 1.

[0056] In an internal gear pump, when the internal gear 2 and external gear 3 rotate to a specific position, a closed maximum volume chamber 100 is formed. The maximum volume chamber 100 is filled with oil brought from the suction zone. Subsequently, as the gears continue to rotate, this closed chamber suddenly connects with the discharge groove 12. The first extension groove 8 effectively establishes a buffer zone between the maximum volume chamber 100 and the discharge groove 12, allowing for pre-pressure relief.

[0057] In this embodiment, a second extension groove 9 is also provided. That is, when the maximum volume chamber 100 discharges oil into the oil discharge groove 12, the maximum volume chamber 100 is still connected to the low-pressure oil suction zone 11 through the second extension groove 9. In other words, when the oil in the maximum volume chamber 100 enters the oil discharge groove 12, it can still experience partial and small-scale pressure relief and buffering in the low-pressure oil suction zone 11. That is, the second extension groove 9 can further reduce the pressure in the maximum volume chamber 100, preventing noise caused by impact during pump operation.

[0058] The boundary line of the first extension groove 8 is the projection of the first contour line 411 onto the bottom of the gear mounting cavity 1. The first contour line 411 is parallel to the first center line 10 and tangent to the teeth of the external gear 3 that forms the maximum volume cavity 100. The first center line 10 is the line connecting the centers of the internal gear 2 and the external gear 3.

[0059] The reason for setting the first contour line 411 in the above manner is that the tangent point between the first contour line 411 and the external gear 3 can accurately determine the start of the oil discharge process. When the internal and external gears 3 rotate to the boundary of the maximum volume cavity 100 just crosses the first contour line 411, the oil in the cavity begins to flow into the first extension groove 8 and enter the oil discharge groove 12.

[0060] Before the maximum volume chamber 100 is formed, the cavity formed between the internal gear and the external gear is still in the oil suction or closed compression stage. If the first extension groove 8 continues to extend towards the side closer to the oil suction groove 11, that is, the first extension groove 8 exceeds the first contour line 411, for example, the position of the first contour line 411 is closer to the first center line 10, the oil will leak back to the low pressure area too much, resulting in a decrease in the volumetric efficiency of the pump, and the oil sucked into the cavity will leak back to the oil suction area 11 too much.

[0061] If the position of the first contour line 411 is closer to the oil drain 12 and farther away from the first center line 10, the buffering effect of the first extension groove 8 will decrease, the pressure of the oil draining into the oil drain 12 will still be relatively high, and there will be a situation where it is released instantly, which will still produce impact and abnormal noise.

[0062] Therefore, setting the first contour line 411 at a position where it is tangent to the teeth of the external gear 3 and parallel to the first center line 10 in the formed maximum volume cavity 100 is the best balance point between avoiding premature pressure release and ensuring timely buffering. It ensures that the oil discharge action occurs just when the cavity formed by the meshing of the internal and external gears reaches the maximum volume cavity 100.

[0063] Similarly, the boundary line of the second extension groove 9 is selected as the projection of the third contour line 413 on the bottom of the gear mounting cavity 1, so that when the maximum volume cavity 100 gradually separates from the oil suction area, it gradually and smoothly separates along the second extension groove 9, reducing the area of ​​the connected oil suction area.

[0064] The oil suction groove 11 to the second extension groove 9 provides a smooth transition for the oil in the oil suction volume chamber, eliminates pressure sudden changes, and makes the process of forming the sealed maximum volume chamber 100 smooth, effectively preventing the oil from being squeezed back into the oil suction groove 11, and also avoiding cavitation caused by sealing too quickly.

[0065] The first contour line 411 and the third contour line 413 mentioned above are determined by the geometric relationship of the meshing of the internal gear 2 and the external gear 3. The sealing time of the maximum volume cavity 100 corresponds to the position of the gear transmission, ensuring that each oil suction process ends at the same position in the meshing cycle, thus guaranteeing the consistency, reliability and high efficiency of the pump operation.

[0066] Preferably, the first extension groove 8 further includes a seventh contour line 417, which coincides with the projection of the pitch circles of the internal gear 2 and the external gear 3 at the bottom of the gear mounting cavity 1.

[0067] One end of the seventh contour line 417 is connected to the projection of the second contour line 412 on the bottom of the gear mounting cavity 1, and the other end is connected to the projection of the first contour line 411 on the bottom of the gear mounting cavity 1.

[0068] And / or, the second extension groove 9 also includes an eighth profile line 418, which coincides with the projection of the pitch circles of the internal gear 2 and the external gear 3 onto the bottom of the gear mounting cavity 1. One end of the eighth profile line 418 is connected to the projection of the fourth profile line 414 onto the bottom of the gear mounting cavity 1, and the other end is connected to the projection of the third profile line 413 onto the bottom of the gear mounting cavity 1.

[0069] The seventh contour line 417 is set to coincide with the projection of the pitch circle of the inner and outer gears 3, that is, the boundary of the first extended groove 8 is consistent with the motion trend when the gears are meshing.

[0070] With the addition of the seventh contour line 417, the area formed by the first extension groove 8 provides a smooth and low-resistance flow path for the high-pressure oil in the maximum volume chamber 100 to flow out of the maximum volume chamber 100 and into the oil discharge groove 12. The direction in which the oil is pushed by the gear teeth is approximately tangential to the boundary direction of the extension groove, avoiding drastic changes in direction. By using a curve with coincident pitch circles to connect the first contour line 411 and the second contour line 412, a smoother transition flow channel can be formed within the area of ​​the first extension groove 8, further reducing flow resistance. During the rotation of the inner and outer gears 3, more energy is used for effective oil discharge, resulting in a higher output oil flow rate under the same conditions, thus ensuring the pump's pumping efficiency. Furthermore, due to the first extension groove 8, the oil flow within it is smoother, which helps reduce vibration and noise during the oil discharge process.

[0071] The principle of the eighth contour line 418 is completely symmetrical to that of the seventh contour line 417 and serves the same purpose, except that it is applied to the second extension groove 9 on the oil suction side. During the oil suction stage, the oil is drawn into the maximum volume cavity 100 of the second extension groove 9 by vacuum. The eighth contour line 418 coincides with the projection of the pitch circle, providing a smooth guiding space for the oil, allowing it to smoothly and with less resistance enter the gradually increasing oil suction cavity, gradually forming the maximum volume cavity 100.

[0072] Especially at high speeds or when the oil viscosity is high, the oil's fluidity is poor. The second extension groove 9 reduces the vacuum requirement of the cavity formed by the meshing of the internal and external gears during oil suction, improving the pump's suction capacity and reducing cavitation problems. Further optimization of the second extension groove 9 improves the oil suction path and increases pump efficiency. Furthermore, the smooth flow of oil within the suction groove 11 and the second extension groove 9 reduces the possibility of vacuum eddies. This ensures the cavity is filled with oil during high-speed operation of the internal and external gears 3, guaranteeing operational efficiency.

[0073] Preferably, when the internal gear 2 and the external gear 3 mesh to form the maximum volume cavity 100, the second contour line 412 and the fourth contour line 414 both coincide with the line connecting the meshing point of the teeth of the internal gear 2 and the teeth of the external gear 3 that form the maximum volume cavity 100 and the center line of the internal gear 2.

[0074] The second contour line 412 is the boundary line of the oil discharge groove 12, and the fourth contour line 414 is the boundary line of the oil suction groove 11. When the engagement point rotates to coincide with the second contour line 412 and the fourth contour line 414, the maximum volume cavity 100 is formed.

[0075] Because the working cycle of a gear pump requires that the positions of the oil suction and discharge actions be the same for each rotation, in order to ensure stable flow output and reliable operation.

[0076] If the second profile line 412 and the fourth profile line 414 are set in other positions, such as an angle earlier or later, then the moment when the maximum volume chamber 100 disengages from the oil suction groove or connects to the oil discharge groove will deviate from the phase of gear engagement. This deviation will cause the volume to be slightly different in each cycle, increase flow pulsation, and cause unstable sealing shocks.

[0077] The alignment of the line connecting the meshing point ensures that the sealing action and gear transmission are synchronized. Each time the gear rotates, it completes the oil suction sealing and begins the oil discharge buffering at the same meshing point, which ensures the pump operates at high efficiency.

[0078] Preferably, the outline of the first extension groove 8 coincides with the outline of the projection area of ​​the first closed region at the bottom of the gear mounting cavity 1.

[0079] And / or the outline of the second extension groove 9 coincides with the outline of the projection area of ​​the second closed region at the bottom of the gear mounting cavity 1.

[0080] The outline of the largest region of the first extension groove 8 can only coincide with the outline of the projection of the first closed region onto the bottom of the gear mounting cavity 1. Similarly, the outline of the largest region of the second extension groove 9 can only coincide with the outline of the projection of the second closed region onto the bottom of the gear mounting cavity 1.

[0081] If the first extension groove 8 extends beyond the first closed area and / or the second extension groove 9 extends beyond the second closed area, causing the soon-to-be-formed maximum volume chamber 100 to connect with the oil drain groove 12, during the rotation of the gear, high-pressure oil will leak into the low-pressure area through the channel of the extended area, or the high and low pressure areas will be directly connected. This will cause the pump's volumetric efficiency to drop significantly and fail to meet the pump's design requirements.

[0082] Preferably, the projection of the root circle of the internal gear 2 on the bottom of the gear mounting cavity 1 and the projection of the second contour line 412 on the bottom of the gear mounting cavity 1 are connected by a first arc portion 45. And / or, the projection of the second contour line 412 on the bottom of the gear mounting cavity 1 and the projection of the pitch circle of the meshing internal gear 2 and external gear 3 on the bottom of the gear mounting cavity 1 are connected by the second arc portion 46. And / or, the projection of the internal gear 2 at the bottom of the gear mounting cavity 1 and the pitch circle of the meshing external gear 3 are connected by a third arc portion 47 between them and the projection of the first contour line 411 at the bottom of the gear mounting cavity 1. And / or, the projection of the tooth root circle of the external gear 3 at the bottom of the gear mounting cavity 1 and the projection of the first contour line 411 at the bottom of the gear mounting cavity 1 are connected by a fourth arc portion 48.

[0083] The aforementioned arrangement of the first arc portion 45, the second arc portion 46, the third arc portion 47, and the fourth arc portion 48 facilitates machining, simplifies the processing technology, and reduces production costs. Furthermore, it optimizes the structure of the first extension groove 8 and the second extension groove 9 to the greatest extent possible. When oil passes through sharp corners, eddies, flow separation, and turbulence are generated, leading to significant pressure losses. This arrangement reduces the flow resistance of the oil within these areas and optimizes the hydrodynamic performance.

[0084] Furthermore, sharp corners are prone to cracking in components subjected to cyclic loads, which can significantly reduce the fatigue strength of the parts.

[0085] Preferably, the outer contour of the oil drain groove 12 is located in the area enclosed by the root circle of the internal gear 2, the root circle of the external gear 3, the second contour line 412, and the fifth contour line 43 within the projection area at the bottom of the gear mounting cavity 1.

[0086] The outer contour of the oil suction groove 11 is located in the area enclosed by the root circle of the internal gear 2, the root circle of the external gear 3, the fourth contour line 414 and the sixth contour line 44, which is within the projection area at the bottom of the gear mounting cavity 1.

[0087] When the internal gear 2 and the external gear 3 mesh to form the minimum volume cavity 120, the meshing point of the teeth of the external gear 3 and the teeth of the internal gear 2 forming the minimum volume cavity 120 and the center point of the internal gear 2 respectively form the first connecting line 13 and the second connecting line 14. The first connecting line 13 is located on the side close to the oil drain groove 12.

[0088] The fifth contour line 43 and the sixth contour line 44 are both located in the area between the first connecting line 13 and the second connecting line 14 within the projection area at the bottom of the gear mounting cavity 1.

[0089] The above settings define the boundary contours of the oil suction groove 11 and the oil discharge groove 12. The fifth contour line 43 and the sixth contour line 44 define the boundaries of the oil suction groove 11 and the oil discharge groove 12, respectively. These boundaries control the range of the oil suction area and the oil discharge area. If the contour lines are not designed correctly, the oil discharge groove 12 may be cut off too early, or the oil suction groove 11 may be connected too late, resulting in oil trapping.

[0090] When the internal and external gears 3 mesh to form the maximum volume cavity 100, they gradually rotate and begin to discharge oil into the oil drain groove 12. When the internal and external gears 3 reach the position of the minimum volume cavity 120, the oil in the cavity should be completely discharged. If the sixth contour line 44 exceeds the second connecting line 14, that is, is closer to the oil drain side, it means that the oil drain groove 12 separates too early. When the minimum volume cavity 120 is compressed to its minimum, it has already separated from the oil drain groove 12, and the high-pressure oil cannot be discharged to the oil drain groove 12, which will inevitably lead to trapped oil compression.

[0091] If it can cover the area between the first connection 13 and the second connection 14, it provides a channel for the high-pressure oil to always be connected to the oil drain groove 12 throughout the compression process, thus avoiding pressure peaks. When the minimum volume cavity 120 begins to increase, that is, when oil suction begins, a vacuum will be formed inside it. At this time, oil can be drawn from the low-pressure oil suction groove 11 through the oil suction groove 11 (that is, the inner boundary defined by the fifth contour line 434) to replenish it, preventing the formation of vacuum and cavitation.

[0092] If the fifth contour line 43 extends beyond the first connecting line 13, i.e., is closer to the oil suction side, it indicates that the size range of the oil suction groove 11 is small. When the minimum volume cavity 120 needs to be replenished with oil, it has not yet come into contact with the oil suction groove 11 and cannot suck in the oil, which will inevitably lead to cavitation.

[0093] Preferably, the fifth contour line 43 coincides with the first connecting line 13, and the sixth contour line 44 coincides with the second connecting line 14.

[0094] The first extension groove 8 and the second extension groove 9, as described above, were further optimized by varying their dimensions and using simulation results obtained from Pumplinx simulation software to determine a suitable parallel boundary. Pumplinx simulation results show that this scheme achieves better optimization in volumetric efficiency and flow pulsation rate compared to conventional oil trough structures. Furthermore, this structure exhibits superior oil suction capacity when negative pressure is generated at the inlet.

[0095] Preferably, this embodiment also provides a pump, including the pump base described above. This pump has low operating noise, low vibration, and can ensure high volumetric efficiency.

[0096] This pump is suitable for applications with high noise requirements, such as electric drive oil cooling systems for new energy vehicles, battery oil cooling systems, high-end hydraulic systems, medical fields, laboratory equipment, and indoor machinery.

[0097] Furthermore, this pump can output greater flow rate and pressure while consuming the same amount of power. This reduces the energy consumption of the equipment, especially for pumps that need to operate continuously for extended periods, resulting in significant energy savings.

[0098] The pump outputs a very stable oil flow rate with minimal fluctuations. It can smoothly draw in and discharge oil, avoiding sudden changes in flow rate.

[0099] Furthermore, this pump boasts a low failure rate and long service life. Eliminating pressure shocks and oil trapping significantly reduces alternating stress on gears, bearings, and their internal components, minimizing fatigue damage. It also prevents cavitation, protecting the surfaces of gears and the pump body from corrosion. The rounded transition design eliminates stress concentration points, enhancing the structural strength of the pump base and thus reducing maintenance costs and downtime, improving overall durability. This makes it particularly suitable for use in critical, difficult-to-replace, or harsh operating conditions.

[0100] Preferably, the oil pump further includes an end cover 16, on which an oil suction groove 161 corresponding to the position of the oil suction groove 11 is provided. After the end cover 16 is installed on the pump base, the oil suction groove 161 and the oil suction groove 11 form an oil suction receiving cavity, which is used to receive low-pressure oil.

[0101] Preferably, the end cap 16 is further provided with an oil drain groove 162 corresponding to the oil drain groove 12. The oil drain groove 162 is directly opposite to the oil drain groove 12, and the two form an oil drain cavity. The oil drain cavity is provided with an outlet, such as... Figure 8 The outlet shown at point A, the oil drain groove 162, can discharge the oil squeezed into the maximum accommodating cavity into the oil drain groove 162 to the outside of the pump body.

[0102] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A pump base, characterized in that, Includes a gear mounting cavity (1), which is configured to mount an internal gear (2) and an external gear (3) that rotate and mesh with each other. The internal gear (2) is disposed inside the external gear (3) and is eccentrically disposed with respect to the external gear (3). The internal gear (2) and the external gear (3) mesh together and can form a maximum volume cavity (100). An oil groove is provided at the bottom of the gear mounting cavity (1), and oil is transferred between the oil groove and the maximum volume cavity (100); An extension groove communicating with the oil groove is provided at one end of the oil groove near the maximum volume cavity (100), and the extension groove is located within the projection range of the maximum volume cavity (100) at the bottom of the gear mounting cavity (1).

2. The pump base according to claim 1, characterized in that, The oil trough includes an oil drain trough (12) opened at the bottom of the gear mounting cavity (1); The oil draining groove (12) is provided with a first extension groove (8) communicating with the oil draining groove (12) at one end near the maximum volume cavity (100); The oil in the maximum volume chamber (100) is discharged into the oil draining tank (12).

3. The pump base according to claim 2, characterized in that, The oil tank also includes an oil suction groove (11) at the bottom of the gear mounting cavity (1), and a second extension groove (9) is provided at one end of the oil suction groove (11) near the maximum volume cavity (100). The oil suction groove (11) and the oil discharge groove (12) are arranged circumferentially, and the maximum volume chamber (100) is located between the oil suction groove (11) and the oil discharge groove (12); the oil in the oil suction groove (11) is sucked into the maximum volume chamber (100).

4. The pump base according to claim 3, characterized in that, The first extension groove (8) is located in the projection area of ​​the bottom of the gear mounting cavity (1) formed by the root circle of the internal gear (2), the root circle of the external gear (3), the first contour line (411), and the second contour line (412). The center line connecting the internal gear (2) and the external gear (3) is the first center line (10). When the internal gear (2) and the external gear (3) mesh to form the maximum volume cavity (100), the first contour line (411) is parallel to the first center line (10), and the first contour line (411) is tangent to the teeth of the external gear (3) that forms the maximum volume cavity (100). The first contour line (411) is relative to the second contour line (412), and the first contour line (411) is located on the side close to the oil suction groove (11). When the internal gear (2) and the external gear (3) mesh to form the maximum volume cavity (100), the second contour line (412) is the line connecting the meshing point of the teeth of the internal gear (2) and the teeth of the external gear (3) that form the maximum volume cavity (100) with the center of the internal gear (2). The second contour line (412) is located on the side close to the oil drain groove (12). And / or, the second extension groove (9) is located in the projection area of ​​the bottom of the gear mounting cavity (1) formed by the root circle of the internal gear (2), the root circle of the external gear (3), the third profile line (413) and the fourth profile line (414), the third profile line (413) being relative to the fourth profile line (414), the third profile line (413) being located on the side closer to the oil drain groove (12); The center line connecting the internal gear (2) and the external gear (3) is the first center line (10). When the internal gear (2) and the external gear (3) mesh to form the maximum volume cavity (100), the third contour line (413) is parallel to the first center line (10), and the third contour line (413) is tangent to the teeth of the external gear (3) that forms the maximum volume cavity (100). When the internal gear (2) and the external gear (3) mesh to form the maximum volume cavity (100), the fourth contour line (414) is the line connecting the meshing point of the teeth of the internal gear (2) and the teeth of the external gear (3) that form the maximum volume cavity (100) with the center of the internal gear (2). The fourth contour line (414) is located on the side close to the oil suction groove (11).

5. The pump base according to claim 4, characterized in that, The outline of the first extension groove (8) coincides with the outline of the projection area of ​​the first closed region at the bottom of the gear mounting cavity (1). And / or, the outline of the second extension groove (9) coincides with the outline of the projection area of ​​the second closed region at the bottom of the gear mounting cavity (1).

6. The pump base according to claim 4, characterized in that, The first extension groove (8) also includes a seventh profile line (417), which coincides with the projection of the pitch circles of the internal gear and the external gear at the bottom of the gear mounting cavity (1). One end of the seventh contour line (417) is connected to the projection of the second contour line (412) at the bottom of the gear mounting cavity (1), and the other end is connected to the projection of the first contour line (411) at the bottom of the gear mounting cavity (1). And / or, the second extension groove (9) further includes an eighth profile line (418) that coincides with the projection of the pitch circles of the internal gear and the external gear onto the bottom of the gear mounting cavity (1); One end of the eighth contour line (418) is connected to the projection of the fourth contour line (414) at the bottom of the gear mounting cavity (1), and the other end is connected to the projection of the third contour line (413) at the bottom of the gear mounting cavity (1).

7. The pump base according to claim 4, characterized in that, The projection of the root circle of the internal gear (2) onto the bottom of the gear mounting cavity (1) and the projection of the second contour line (412) onto the bottom of the gear mounting cavity (1) are connected by a first arc portion (45). And / or, the projection of the second profile line (412) at the bottom of the gear mounting cavity (1) and the projection of the pitch circle of the meshing internal gear (2) and the external gear (3) at the bottom of the gear mounting cavity (1) are transitioned and connected by the second arc portion (46). And / or, the projection of the internal gear (2) at the bottom of the gear mounting cavity (1) and the pitch circle of the meshing external gear (3) are connected by a third arc portion (47) between the projection of the first profile line (411) at the bottom of the gear mounting cavity (1). And / or, the projection of the root circle of the external gear (3) onto the bottom of the gear mounting cavity (1) and the projection of the first contour line (411) onto the bottom of the gear mounting cavity (1) are connected by a fourth arc portion (48).

8. The pump base according to claim 4, characterized in that, The outer contour of the oil drain groove (12) is located in the area enclosed by the root circle of the internal gear (2), the root circle of the external gear (3), the second contour line (412), and the fifth contour line (43) within the projection area at the bottom of the gear mounting cavity (1). The outer contour of the oil suction groove (11) is located in the area enclosed by the root circle of the internal gear (2), the root circle of the external gear (3), the fourth contour line (414), and the sixth contour line (44) within the projection area at the bottom of the gear mounting cavity (1). When the internal gear (2) and the external gear (3) mesh to form the minimum volume cavity (120), the meshing point of the teeth of the external gear (3) and the teeth of the internal gear (2) forming the minimum volume cavity (120) and the center point of the internal gear (2) respectively form a first connecting line (13) and a second connecting line (14), and the first connecting line (13) is located on the side close to the oil drain groove (12); The fifth contour line (43) and the sixth contour line (44) are both located in the area between the first connecting line (13) and the second connecting line (14).

9. The pump base according to claim 8, characterized in that, The fifth contour line (43) coincides with the first connecting line (13), and the sixth contour line (44) coincides with the second connecting line (14).

10. An oil pump, characterized in that, Includes the pump base as described in any one of claims 1-9.

Images