Internal gear pump
By adopting a two-stage combined structure and optimized shaft hole design, the problems of traditional internal meshing gear pumps are solved in high-speed and high-pressure conditions and poor sealing performance, achieving a more stable flow output and a longer service life.
Patent Information
- Application Number
- CN202520288867.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-02-24
- Publication Date
- 2025-03-25
- Estimated Expiration
- 2035-02-24
AI Technical Summary
When the traditional internal meshing gear pump is operated under high-speed and high-pressure impact conditions, the micro-moving of the front cover and the rear cover causes the gear shaft to jump, affecting the stability, service life and sealing performance of the flow output.
A two-stage combination structure of the end cover and the pump body is adopted to reduce the number of parts and assembly gaps. By setting up a reamer and sealing assembly at the shaft hole, a low-pressure oil cavity is formed to balance the oil pressure, and a recess and sealing ring are provided on the axial end wall to achieve high-pressure sealing.
It improves component assembly accuracy, reduces the jump of gear shaft under high-speed and high-pressure conditions, enhances the sealing effect, improves the stability and service life of flow output, and reduces the number of parts and processing costs.
Smart Images
Figure CN222668375U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to an internal meshing gear pump. Background Art
[0002] The structure of a traditional internal gear pump is as follows: Figure 1 As shown, it includes a pump body 11, a front cover 12, and a rear cover 13. The front cover 12 and the rear cover 13 are respectively limited at both ends of the pump body 11 by pins. The pump body 11, the front cover 12, and the rear cover 13 are spliced to form a working chamber 10 for accommodating a gear ring and a gear. The working chamber 10 is formed by two axial end walls corresponding to the two ends of the pump body 11 and a circumferential side wall corresponding to the side direction of the pump body 11. The two axial end walls of the working chamber 10 are respectively arranged on the front cover 12 and the rear cover 13, and the circumferential side wall of the working chamber 10 is arranged on the pump body. 11, the front cover 12 and the rear cover 13 are both provided with an axial hole 15 for penetrating and connecting the gear shaft 14, the axial hole 15 on the front cover 12 is a through hole, and the axial hole 15 on the rear cover 13 is a blind hole, a bearing matched with the gear shaft 14 is also provided in the axial hole 15, a sealing structure is also provided between the outer end of the axial hole 15 of the front cover 12 and the gear shaft 14, a low-pressure oil chamber 16 is formed at the outer end of the axial hole 15 of the front cover 12 and the inner end of the axial hole 15 of the rear cover 13, and a connecting hole 17 is provided between the low-pressure oil chamber 16 and the low-pressure area of the working chamber 10. In addition, two side plates 18 are installed in the working chamber 10, one side of the two side plates 18 is respectively abutted against the two ends of the gear and the gear ring, and the other sides of the two side plates 18 are respectively abutted against the axial end walls arranged on the front cover 12 and the rear cover 13. A sealing ring is sandwiched between the inner side of the front cover 12 and the rear cover 13 and the side plates 18 to form a high-pressure oil chamber connected to the high-pressure area of the working chamber 10. The inner sides of the front cover 12 and the rear cover 13 are both provided with a concave platform for constituting the high-pressure oil chamber, and the concave platform is surrounded by an annular groove 19 for embedding and positioning the sealing ring.
[0003] The above-mentioned traditional internal meshing gear pump structure adopts a three-section combined structure consisting of a front cover 12, a pump body 11 and a rear cover 13. The front cover 12, the pump body 11 and the rear cover 13 are three relatively independent components, which are connected and fixed together by pins. The relevant structural features used to form the low-pressure oil chamber 16 and the high-pressure oil chamber need to be processed and formed on the front cover 12 and the rear cover 13 respectively. Due to the limitations of manufacturing process precision, installation methods and other reasons, there is inevitably a gap between the front cover 12 and the pump body 11, and between the pump body 11 and the rear cover 13. When the gear pump is running under high-speed and high-pressure impact conditions, the front cover 12 and the rear cover 13 will produce micro-motion relative to the pump body 11 as the internal parts run at high speed. This micro-motion of the front cover 12 and the rear cover 13 will increase the beating generated when the gear shaft 14 is running, thereby affecting the stability of the flow output, service life and sealing performance of the gear pump. Utility Model Content
[0004] In order to overcome the above-mentioned defects of the prior art, the utility model provides an internal gear pump which has a simpler structure, is convenient to assemble, and has better working stability and service life.
[0005] The utility model discloses an internal meshing gear pump, comprising a pump body and an end cover. The pump body and the end cover are spliced to form a working chamber for accommodating a gear ring and a gear. The gear ring and the gear mesh in the working chamber for transmission. The working chamber is enclosed by two axial end walls corresponding to the two end directions of the pump body and a circumferential side wall corresponding to the side direction of the pump body. The end cover is connected to the end of the pump body. A first axial hole for connecting the gear shaft is provided on the end cover. A second axial hole for connecting the gear shaft is provided on the pump body. One of the axial end walls of the working chamber is integrally formed on the end cover and is located on the inner side of the end cover. The other axial end wall and the circumferential side wall of the working chamber are integrally formed on the pump body. The other axial end wall of the working chamber is connected to the second axial hole. The side of the pump body is provided with an oil inlet channel and an oil outlet channel connected to the working chamber. The oil inlet channel and the oil outlet channel are radially arranged along the center of the working chamber.
[0006] In one preferred solution, the end cover is arranged at an end corresponding to the power input end of the gear shaft relative to the pump body, one end of the first shaft hole is connected to the working chamber, a reaming hole connected to the other end of the first shaft hole is arranged on the outer side of the end cover, the inner diameter of the reaming hole is larger than the inner diameter of the first shaft hole, the gear shaft is also connected in the reaming hole, an annular step is formed at the connection between the reaming hole and the first shaft hole, a sealing assembly is arranged in the reaming hole, the sealing assembly is used to seal the gap between the inner wall of the reaming hole and the gear shaft, a first low-pressure oil chamber is formed between the inner wall of the reaming hole, the sealing assembly and the annular step, a first connecting hole for connecting the first low-pressure oil chamber and the working chamber is arranged on the end cover; the pump body is provided with a concave cavity, one end of the second shaft hole is connected to the working chamber, the other end of the second shaft hole is connected to the concave cavity, a second low-pressure oil chamber is formed between the concave cavity and the gear shaft, and a second connecting hole for connecting the second low-pressure oil chamber and the working chamber is arranged on the pump body. The first connecting hole and the second connecting hole extend to the low-pressure area of the working chamber, which can achieve the effect of balancing the oil pressure.
[0007] In another preferred embodiment, the end cover is arranged at an end corresponding to the output end of the gear shaft relative to the pump body, the end cover is provided with a concave cavity, one end of the first shaft hole is connected to the working cavity, the other end of the first shaft hole is connected to the concave cavity, a first low-pressure oil cavity is formed between the concave cavity and the gear shaft, and a first connecting hole for connecting the first low-pressure oil cavity and the working cavity is arranged on the end cover; one end of the second shaft hole is connected to the working cavity, an expansion hole connected to the other end of the second shaft hole is arranged on the outside of the pump body, the inner diameter of the expansion hole is larger than the inner diameter of the second shaft hole, and an annular step is formed at the connection between the expansion hole and the second shaft hole, a sealing component is arranged in the expansion hole, the sealing component is used to seal the gap between the inner wall of the expansion hole and the gear shaft, a second low-pressure oil cavity is formed between the inner wall of the expansion hole, the sealing component and the annular step, and a second connecting hole for connecting the second low-pressure oil cavity and the working cavity is arranged on the end cover. Similarly, the first connecting hole and the second connecting hole extend to the low-pressure area formed when the gear and the gear ring are matched, which can play the effect of balancing the oil pressure.
[0008] Furthermore, the two axial end walls of the working chamber are provided with concave platforms correspondingly, and the concave platforms of the two axial end walls are provided with annular grooves for embedding the positioning sealing rings, that is, the two concave platforms and the two annular grooves are respectively provided on the end cover and the pump body. The axial end wall is abutted against the side plate through the sealing ring embedded in the annular groove, so that a high-pressure oil chamber connected to the high-pressure area of the working chamber can be formed between the side plate and the axial end wall. When the gear pump is running, the fluid pressure is introduced into the high-pressure oil chamber, which can press the side plate to the end of the gear and the gear ring, so as to realize the axial sealing of the high-pressure fluid.
[0009] Furthermore, a positioning rod is inserted between the two axial end walls for cooperating with the side plate and the crescent plate for positioning.
[0010] Furthermore, the end cover and the pump body form a plug-in fit, and a sealing ring is provided at the plug-in fit to prevent oil from leaking from the connection between the end cover and the pump body. The end cover and the pump body are connected by pins in the plug-in direction, which can further improve the connection effect between the end cover and the pump body.
[0011] The beneficial effects of the utility model are as follows: compared with the traditional three-stage combination structure of the front cover, pump body and rear cover, the internal gear pump of the utility model adopts a two-stage combination structure of the end cover and pump body, with fewer parts and fewer assembly gaps, simpler structure and more convenient assembly, which can not only improve the assembly accuracy between parts and reduce the vibration of the gear shaft under high-speed and high-pressure impact conditions, but also improve the sealing effect of the product and improve the stability and service life of the flow output of the gear pump. Reducing the number of parts, optimizing the processing procedures, and reducing processing costs bring cost advantages. BRIEF DESCRIPTION OF THE DRAWINGS
[0012] Figure 1It is a cross-sectional view of an internal gear pump in the prior art;
[0013] Figure 2 A cross-sectional view of an embodiment of the utility model;
[0014] Figure 3 for Figure 2 Sectional view along AA;
[0015] Figure 4 It is a schematic diagram of another axial end wall of the pump body of the utility model embodiment;
[0016] Figure 5 for Figure 2 A magnified view of part B;
[0017] Figure 6 It is a cross-sectional view of another embodiment of the utility model. DETAILED DESCRIPTION
[0018] An internal gear pump according to an embodiment of the utility model, such as Figure 2-5 As shown, it includes a pump body 21 and an end cover 22. The pump body 21 and the end cover 22 are spliced to form a working chamber 20 for accommodating a gear ring 31 and a gear. The gear ring 31 and the gear are meshed and driven in the working chamber 20. The working chamber 20 is enclosed by two axial end walls corresponding to the two ends of the pump body 21 and a circumferential side wall 201 corresponding to the side direction of the pump body 21. The end cover 22 is connected to the end of the pump body 21. The end cover 22 is provided with a first shaft hole 221 for connecting the gear shaft 33. The pump body 21 is provided with a first shaft hole 221 for connecting the gear shaft The second axial hole 211 of 33, one of the axial end walls 202 of the working chamber 20 is integrally formed on the end cover 22 and is located on the inner side of the end cover 22, the other axial end wall 203 of the working chamber 20 and the circumferential side wall 201 are integrally formed on the pump body 21, the other axial end wall 203 of the working chamber 20 is connected to the second axial hole 211, and the side of the pump body 21 is provided with an oil inlet channel 212 and an oil outlet channel 213 connected to the working chamber 20, and the oil inlet channel 212 and the oil outlet channel 213 are arranged along the center radial direction of the working chamber 20.
[0019] In this embodiment, the end cover 22 is arranged at an end corresponding to the power input end of the gear shaft 33 relative to the pump body 21, one end of the first shaft hole 221 is connected to the working chamber 20, and an expansion hole 41 connected to the other end of the first shaft hole 221 is arranged on the outer side of the end cover 22, and the inner diameter of the expansion hole 41 is larger than the inner diameter of the first shaft hole 221. The gear shaft 33 is also penetrated and connected in the expansion hole 41, and an annular step surface 42 is formed at the connection between the expansion hole 41 and the first shaft hole 221. A sealing component 43 is arranged in the expansion hole 41, and the sealing component 43 is used to seal the inner wall of the expansion hole 41 and the gear shaft 33. The gap is sealed, and a first low-pressure oil chamber 44 is formed between the inner wall of the expansion hole 41, the sealing assembly 43 and the annular step surface 42. The end cover 22 is provided with a first connecting hole 45 for connecting the first low-pressure oil chamber 44 and the working chamber 20; the pump body 21 is provided with a concave cavity 46, one end of the second shaft hole 211 is connected to the working chamber 20, and the other end of the second shaft hole 211 is connected to the concave cavity 46. A second low-pressure oil chamber 47 is formed between the concave cavity 46 and the gear shaft 33, and the pump body 21 is provided with a second connecting hole 48 for connecting the second low-pressure oil chamber 47 and the working chamber 20. The first connecting hole 45 and the second connecting hole 48 extend to the low-pressure area of the working chamber 20, which can balance the oil pressure and prevent the leakage of hydraulic oil.
[0020] like Figure 5 As shown, the two axial end walls of the working chamber 20 are correspondingly provided with concave platforms 49, and the concave platforms 49 of the two axial end walls are surrounded by annular grooves 50 for embedding the positioning sealing rings 51, that is, the two concave platforms 49 and the two annular grooves 50 are respectively provided on the end cover 22 and the pump body 21. The axial end wall is abutted against the side plate 52 through the sealing ring 51 embedded in the annular groove 50, so that a high-pressure oil chamber connected to the high-pressure area of the working chamber 20 can be formed between the side plate 52 and the axial end wall. When the gear pump is running, the fluid pressure is introduced into the high-pressure oil chamber, which can press the side plate 52 to the end of the gear and the gear ring 31, so as to realize the axial sealing of the high-pressure fluid.
[0021] A positioning rod 54 for cooperating with the side plate 52 and the crescent plate assembly 53 is inserted between the two axial end walls. The side plate 52 is sleeved on the positioning rod 54 through the connecting hole. The crescent plate assembly 53 is composed of the main crescent plate, the auxiliary crescent plate, the leaf spring, the sealing rod and other components. The axial end wall includes a positioning slot 55 for cooperating with the positioning rod 54. During assembly, one end of the positioning rod 54 is first inserted into the positioning slot 55 of the other axial end wall 203 of the pump body 21 of the end cover 22, and then after the side plate 52, the gear ring 31, the gear, the crescent plate assembly 53 and other components are assembled, the pump body 21 and the end cover 22 are connected, and at the same time, the other end of the positioning rod 54 is inserted into the positioning slot of one of the axial end walls 202 of the pump body 21, so that the assembly is more convenient.
[0022] The end cover 22 and the pump body 21 form a plug-in fit, and a sealing ring is provided at the plug-in fit to prevent oil from leaking from the connection between the end cover 22 and the pump body 21. The end cover 22 and the pump body 21 are connected by a pin 57 in the plug-in direction, which can further improve the connection effect between the end cover 22 and the pump body 21.
[0023] In another embodiment, if Figure 6 As shown, the difference from the above embodiment is that the end cover 22 is arranged at the end corresponding to the output end of the gear shaft 33 relative to the pump body 21, and the concave cavity 46, the second low-pressure oil chamber 47, the second connecting hole 48, the expansion hole 41, the annular step surface 42, the sealing assembly 43, the first low-pressure oil chamber 44, and the first connecting hole 45 are all arranged on the pump body 21.
[0024] The above embodiment is only one of the preferred specific embodiments of the present invention. Common changes and substitutions made by those skilled in the art within the technical solution of the present invention are all included in the protection scope of the present invention.
Claims
1. An internal gear pump, comprising a pump body and an end cover, wherein the pump body and the end cover are spliced to form a working chamber for accommodating a gear ring and a gear, wherein the working chamber is enclosed by two axial end walls corresponding to the two ends of the pump body and a circumferential side wall corresponding to the side of the pump body, wherein the end cover is connected to the end of the pump body, and a first shaft hole for connecting a gear shaft is provided on the end cover, wherein: One of the axial end walls of the working chamber is integrally formed on the end cover and is located on the inner side of the end cover, the other axial end wall and the circumferential side wall of the working chamber are integrally formed on the pump body, a second axial hole for connecting the gear shaft is provided on the pump body, the other axial end wall of the working chamber is connected to the second axial hole, and an oil inlet channel and an oil outlet channel connected to the working chamber are provided on the side of the pump body, and the oil inlet channel and the oil outlet channel are arranged radially along the center of the working chamber.
2. An internal gear pump according to claim 1, characterized in that: One end of the first axial hole is connected to the working chamber, and a reaming hole connected to the other end of the first axial hole is arranged on the outer side of the end cover, the inner diameter of the reaming hole is larger than the inner diameter of the first axial hole, and an annular step surface is formed at the connection between the reaming hole and the first axial hole, and a sealing assembly is arranged in the reaming hole, which is used to seal the gap between the inner wall of the reaming hole and the gear shaft, and a first low-pressure oil chamber is formed between the inner wall of the reaming hole, the sealing assembly and the annular step surface, and a first connecting hole for connecting the first low-pressure oil chamber and the working chamber is arranged on the end cover; the pump body is provided with a concave cavity, one end of the second axial hole is connected to the working chamber, and the other end of the second axial hole is connected to the concave cavity, a second low-pressure oil chamber is formed between the concave cavity and the gear shaft, and a second connecting hole for connecting the second low-pressure oil chamber and the working chamber is arranged on the pump body.
3. An internal gear pump according to claim 1, characterized in that: The end cover is provided with a concave cavity, one end of the first axial hole is connected to the working cavity, and the other end of the first axial hole is connected to the concave cavity, a first low-pressure oil cavity is formed between the concave cavity and the gear shaft, and the end cover is provided with a first connecting hole for connecting the first low-pressure oil cavity and the working cavity; one end of the second axial hole is connected to the working cavity, and an expanded hole connected to the other end of the second axial hole is provided on the outside of the pump body, the inner diameter of the expanded hole is larger than the inner diameter of the second axial hole, and an annular step surface is formed at the connection between the expanded hole and the second axial hole, a sealing assembly is provided in the expanded hole, the sealing assembly is used to seal the gap between the inner wall of the expanded hole and the gear shaft, a second low-pressure oil cavity is formed between the inner wall of the expanded hole, the sealing assembly and the annular step surface, and the end cover is provided with a second connecting hole for connecting the second low-pressure oil cavity and the working cavity.
4. An internal gear pump according to claim 1, characterized in that: Concave platforms are correspondingly arranged on the two axial end walls of the working chamber, and annular grooves for embedding positioning sealing rings are arranged around the concave platforms of the two axial end walls.
5. An internal gear pump according to claim 1, characterized in that: A positioning rod for cooperating with the side plate and the crescent plate assembly for positioning is inserted between the two axial end walls, and the axial end wall includes a positioning slot for inserting and positioning with the positioning rod.
6. An internal gear pump according to claim 1, characterized in that: The end cover and the pump body form a plug-in fit, and a sealing ring is arranged at the plug-in fit position. The end cover and the pump body are connected by a pin in the plug-in direction.