An internal gear pump with more stable operation

Abstract

The present invention relates to an internal gear pump with more stable operation, including a housing provided with a cavity and a high-pressure chamber. A gear and a gear ring are rotatably arranged in the cavity, and there is a crescent plate between them. The cavity has an inner circumferential wall and an axial wall that cooperate with the gear ring. The oil guiding device between the high-pressure chamber and the cavity includes an oil inlet passage, a movable push rod, and an elastic member. The oil inlet of the oil inlet passage is connected to the high-pressure chamber, and the oil outlet is on the inner circumferential wall of the cavity. The movable push rod is arranged at the oil outlet, and there is an elastic member between it and the housing. There is an oil delivery channel inside it, and the first and second openings are respectively arranged at both ends. The oil inlet passage includes a first vertical section and a second vertical section. The movable push rod is movably inserted into the first section, and its oil delivery channel is connected to the second section through the second opening. The inner edge of the connection port of the first section cooperates with the second opening to block. This gear pump can timely adjust the pressure of the introduced oil, operate more stably, and improve the stability and adaptability under different working conditions.

Description

Technical Field

[0001] The present invention relates to an internal gear pump with more stable operation. Background Art

[0002] A Chinese invention patent application discloses an internal gear pump (CN116608121A), which features an oil inlet passage communicating with the pressure oil chamber (i.e., the high-pressure chamber) provided on the inner wall of the housing (i.e., the inner wall of the cavity). The oil inlet passage can introduce the high-pressure medium in the pressure oil chamber into the inner wall of the housing. The medium introduced by the oil inlet passage acts on the outer contour of the gear ring and applies an inward thrust to the gear ring. This pressure offsets a part of the outward thrust exerted on the inner gear ring by the high-pressure medium in the pressure oil chamber, reducing the amount of offset of the inner gear ring towards the housing during high-speed rotation, and thus reducing the noise generated during the high-speed rotation of the inner gear ring. However, it is found in actual implementation that since the oil inlet passage consists of multiple segments, has corners, and narrow segments, it is technically difficult to integrally machine the oil inlet passage on a single component.

[0003] In addition, in the above patent application solution, since the aperture size of the second segment of the oil inlet passage is fixed, the oil pressure introduced by the oil inlet passage changes with the change of the oil pressure in the pressure oil chamber, showing a certain hysteresis. When the load and operating speed of the gear pump suddenly change, it may cause the offset of the inner gear ring to intensify, resulting in increased friction with the housing and the crescent body, increased noise, and accelerated component wear. It may also cause local pressure to be too high, affecting the stable operation of the inner gear ring. Summary of the Invention

[0004] In order to overcome the defects of the above prior art, the present invention provides an internal gear pump with more stable operation, which can timely adjust the pressure of the introduced oil and improve the stability and adaptability of the gear pump under different working conditions.

[0005] The present invention provides an internal gear pump with more stable operation, including a housing. The housing includes a cavity, a high-pressure chamber connected to the cavity, and a low-pressure chamber. A gear and a gear ring are rotatably arranged in the cavity. The high-pressure chamber is arranged at both axial ends of the gear ring. A crescent plate is arranged between the gear and the gear ring. The crescent plate circumferentially divides the gap between the gear and the gear ring into a low-pressure area connected to the low-pressure chamber, a high-pressure area connected to the high-pressure chamber, and a pressure-boosting area connected between the low-pressure area and the high-pressure area. The cavity includes an inner circumferential wall that fits and contacts the outer circumferential wall of the gear ring and two axial walls that can limit the axial direction of the gear ring. A oil guiding device is arranged between the high-pressure chamber and the cavity. The oil guiding device includes an introducing oil passage arranged on the housing. The inlet of the introducing oil passage is connected to the high-pressure chamber, and the outlet of the introducing oil passage is arranged at the inner circumferential wall of the cavity, especially at a position corresponding to the high-pressure area formed between the gear and the gear ring. The oil guiding device includes a movable push rod and an elastic member. The movable push rod is movably arranged at the outlet of the introducing oil passage. An elastic member is provided between the movable push rod and the housing. The elastic member drives one end of the movable push rod to elastically abut against the outer circumferential wall of the gear ring and slidably contact and cooperate with the outer circumferential wall of the gear ring. An oil delivery channel is arranged in the movable push rod. A first opening connected to the oil delivery channel is arranged at one end of the movable push rod. A second opening connected to the oil delivery channel is arranged on the circumferential side of the other end of the movable push rod. The oil in the introducing oil passage is introduced to the cavity along the direction of the second opening, the oil delivery channel, and the first opening. The introducing oil passage includes a first section and a second section that are perpendicular to each other. The movable push rod and the first section form a movable plug-in fit. The oil delivery channel of the movable push rod is connected to the second section through the second opening at the other end of the movable push rod. The first section has a connection port that cooperates with the second section. The inner edge of the connection port and the second opening cooperate to block each other.

[0006] Due to a certain gap between the gear ring and the inner circumferential wall of the cavity, when the gear ring generates a lateral offset under the influence of the oil pressure, the movable push rod can correspondingly generate a displacement, and the relative position between the inner edge of the connection port and the second opening changes accordingly, which can change the connection diameter between the second opening and the second section of the introducing oil passage. Therefore, the pressure of the introduced oil can be adjusted in a timely manner, so that the pressure of the introduced oil counteracts the offset thrust of the gear ring, improving the stability and adaptability of the gear pump under different working conditions, and solving the problem that the fixed-diameter introducing oil passage in the prior art is prone to pressure imbalance when the working conditions change rapidly.

[0007] Further, the first section has a flared opening connected to the cavity. One end of the movable push rod includes an abutting portion. One end of the flared opening is movably connected to the abutting portion of the movable push rod. The other end of the flared opening has an annular stepped surface. The elastic member is a spring sleeved on the movable push rod. The spring is located at the flared opening. The two ends of the spring are respectively in abutting cooperation with the abutting portion and the annular stepped surface. The setting of the abutting portion can improve the contact effect with the gear ring. The setting of the flared opening can be used to accommodate the abutting portion. Only need to simply open holes on the inner peripheral wall of the cavity, and then sequentially install the spring and the movable push rod to complete the processing and assembly. Limited by the gear ring, the movable push rod will not come out of the oil inlet passage. The overall structure is simple and convenient for assembly.

[0008] Further, a third opening for connecting the oil delivery channel and the flared opening is provided on the circumferential side of one end of the movable push rod. The setting of the third opening is beneficial to ensuring the pressure balance between the flared opening and the oil delivery channel and reducing the resistance when the movable push rod displaces.

[0009] Further, the abutting portion has an arc-shaped concave surface in contact and cooperation with the outer peripheral wall of the gear ring. The first opening is provided on the arc-shaped concave surface, which can further improve the contact and cooperation effect between the abutting portion and the outer peripheral wall of the gear ring. The introduced oil flows out from the first opening and penetrates between the abutting portion and the gear ring, reducing the wear between components.

[0010] Further, the second opening is a long strip-shaped through groove, and the directions of its two ends correspond to the length direction of the movable push rod, which is convenient for the processing of the second opening and improves the oil pressure adjustment effect.

[0011] Further, there are multiple second openings, and the multiple second openings are evenly distributed along the circumferential direction of the movable push rod, improving the oil inlet effect of the oil relative to the second openings.

[0012] Further, the housing includes a first part and a second part spliced together. The inner peripheral wall of the cavity, one of the axial walls, and the oil guiding device are all provided on the first part. The other axial wall of the cavity is provided on the second part. The oil inlet passage includes a third section parallel to the first section and perpendicular to the second section. One end of the third section is connected to the high-pressure cavity, and the other end of the third section is connected to one end of the second section. A process port is provided on the splicing surface of the first part at the other end of the second section, and a plug is provided at the process port. During processing, the third section can be machined from the inner side of the high-pressure cavity, and then the second section can be machined from the splicing surface of the first part to communicate with the first section and the second section. Only need to open several straight holes on the first part of the housing to machine the oil inlet passage, and the processing is relatively convenient. And this structure has good sealing performance and is not prone to oil leakage risk.

[0013] Further, a shallow groove is provided on the splicing surface of the first part. The process port is arranged at the bottom of the shallow groove. The plug is a sealing gasket embedded in the shallow groove. The sealing gasket is pressed between the first part and the second part, which can further improve the sealing effect at the process port and prevent oil leakage. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a cross-sectional view of an embodiment of the present invention;

[0015] Figure 2 is Figure 1 a partially enlarged view;

[0016] Figure 3 It is a schematic diagram of the distribution of each pressure range of an embodiment of the present invention;

[0017] Figure 4 It is a schematic structural diagram of the movable push rod of an embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0018] An internal gear pump with more stable operation according to an embodiment of the present invention, as Figures 1-4 shown,

[0019] includes a housing. The housing includes a cavity 101, a high-pressure cavity 102 connected to the cavity 101, and a low-pressure cavity 103. A gear 2 and a gear ring 3 are rotatably arranged in the cavity 101. The high-pressure cavity 102 is arranged at both axial ends of the gear ring 3. A crescent plate 4 is arranged between the gear 2 and the gear ring 3. The crescent plate 4 circumferentially divides the gap between the gear 2 and the gear ring 3 into a low-pressure area connected to the low-pressure cavity 103, a high-pressure area connected to the high-pressure cavity 102, and a pressure-boosting area connected between the low-pressure area and the high-pressure area. Specifically, taking the lines connecting the two sides of the crescent plate 4 to the axis of the gear 2 and the lines connecting the axis and the meshing part of the gear 2 and the gear ring 3 as the boundaries (i.e., taking the three dotted lines shown in Figure 3 ), the gap is divided into three areas. The area connected to the low-pressure cavity 103 is the low-pressure area, the area connected to the high-pressure cavity 102 is the high-pressure area, and the area in the middle is the pressure-boosting area. The cavity 101 includes an inner circumferential wall 1011 that fits and contacts the outer circumferential wall of the gear ring 3 and two axial walls 1012 that can axially limit the gear ring 3. A oil guiding device is arranged between the high-pressure cavity 102 and the cavity 101. The oil guiding device includes an introducing oil passage arranged on the housing. The oil inlet of the introducing oil passage is connected to the high-pressure cavity 102, and the oil outlet of the introducing oil passage is arranged at the inner circumferential wall of the cavity 101, especially at a position corresponding to the high-pressure area formed between the gear 2 and the gear ring 3.

[0020] The oil introduction device includes a movable push rod 51 and an elastic member 52. The movable push rod 51 is movably arranged at the oil outlet of the oil introduction passage. An elastic member 52 is provided between the movable push rod 51 and the housing. The elastic member 52 drives one end of the movable push rod 51 to elastically abut against the outer peripheral wall of the gear ring 3 and is in sliding contact and fit with the outer peripheral wall of the gear ring 3. An oil delivery passage is arranged in the movable push rod 51. A first opening 511 connected to the oil delivery passage is arranged at one end of the movable push rod 51. A second opening 512 connected to the oil delivery passage is arranged on the circumferential side of the other end of the movable push rod 51. The oil in the oil introduction passage is introduced to the cavity 101 along the direction of the second opening 512, the oil delivery passage, and the first opening 511. The oil introduction passage includes a first section 531 and a second section 532 that are perpendicular to each other. The movable push rod 51 and the first section 531 form a movable plug-in fit. The oil delivery passage of the movable push rod 51 is connected to the second section 532 through the second opening 512 at its other end. The first section 531 has a connection port that is connected and matched with the second section 532. The inner edge 5311 of the connection port and the second opening 512 are matched and blocked.

[0021] Since there is a certain gap between the gear ring 3 and the inner peripheral wall of the cavity 101, when the gear ring 3 is laterally offset under the influence of the oil pressure, the movable push rod 51 can correspondingly displace. The relative position between the inner edge 5311 of the connection port and the second opening 512 changes accordingly, and the connection diameter between the second opening 512 and the second section 532 of the oil introduction passage can be changed. Therefore, the oil pressure introduced can be adjusted in time to make the introduced oil pressure resist the offset thrust of the gear ring 3, improving the stability and adaptability of the gear 2 pump under different working conditions and solving the problem of pressure imbalance that easily occurs in the prior art for the oil introduction passage with a fixed diameter when the working conditions change rapidly.

[0022] Specifically, when the movable push rod 51 is pushed by the gear ring 3 and displaces in the direction of extending into the first section 531, the shielding of the inner edge 5311 of the connection port from the second opening 512 decreases, and the pressure of the introduced oil increases. The oil pressure and the elastic force of the elastic member 52 act together on the gear ring 3 to resist the offset of the gear ring 3. When the offset thrust of the gear ring 3 decreases, the movable push rod 51 displaces towards the cavity direction, and the shielding of the inner edge 5311 from the second opening 512 increases, and the pressure of the introduced oil decreases. Therefore, the effect of balancing the pressure can be achieved.

[0023] The first section 531 has a flared opening 5312 connected to the cavity 101. One end of the movable push rod 51 includes an abutting portion 513. One end of the flared opening 5312 is movably connected to the abutting portion 513 of the movable push rod 51. The other end of the flared opening 5312 has an annular stepped surface. The elastic member 52 is a spring sleeved on the movable push rod 51. The spring is located at the flared opening 5312. The two ends of the spring are respectively in abutting cooperation with the abutting portion 513 and the annular stepped surface. The setting of the abutting portion 513 can improve the contact effect with the gear ring 3. The setting of the flared opening 5312 can be used to accommodate the abutting portion 513. Only need to simply open a hole on the inner peripheral wall of the cavity 101, and then sequentially install the spring and the movable push rod 51 to complete the processing and assembly. Limited by the gear ring 3, the movable push rod 51 will not come out of the oil inlet passage. The overall structure is simple and convenient for assembly.

[0024] On the circumferential side of one end of the movable push rod 51, a third opening 514 for connecting the oil delivery channel and the flared opening 5312 is provided. The setting of the third opening 514 is beneficial to ensuring the pressure balance between the flared opening 5312 and the oil delivery channel and reducing the resistance when the movable push rod 51 is displaced.

[0025] The abutting portion 513 has an arc-shaped concave surface 5131 in contact and cooperation with the outer peripheral wall of the gear ring 3. The first opening 511 is arranged on the arc-shaped concave surface 5131, which can further improve the contact and cooperation effect between the abutting portion 513 and the outer peripheral wall of the gear ring 3. The introduced oil flows out from the first opening 511 and penetrates between the abutting portion 513 and the gear ring 3, reducing the wear between components.

[0026] The second opening 512 is a long strip-shaped through groove, and the directions of its two ends correspond to the length direction of the movable push rod 51, which is convenient for the processing of the second opening 512 and improves the oil pressure regulation effect.

[0027] There are multiple second openings 512, and the multiple second openings 512 are evenly distributed along the circumferential direction of the movable push rod 51, improving the oil inlet effect of the oil relative to the second openings 512.

[0028] The third opening 514 preferably adopts the same structure as the second opening 512, only with different arranged positions, which can reduce the processing cost of the third opening 514.

[0029] The housing includes a first part 11 and a second part 12 that are spliced together. The inner peripheral wall of the cavity 101, one of the axial walls 1012, and the oil guiding device are all provided on the first part 11, and the other axial wall 1012 of the cavity 101 is provided on the second part 12. The introduced oil passage includes a third section 533 that is parallel to the first section 531 and perpendicular to the second section 532. One end of the third section 533 is connected to the high-pressure cavity 102, and the other end of the third section 533 is connected to one end of the second section 532. The other end of the second section 532 is provided with a process port on the splicing surface of the first part 11, and a plug 6 is provided at the process port. During processing, the third section 533 can be machined from the inner side of the high-pressure cavity 102, and then the second section 532 can be machined from the splicing surface of the first part 11 to communicate with the first section 531 and the second section 532. Only a number of straight holes need to be drilled on the first part 11 of the housing to machine the introduced oil passage, which is relatively convenient for processing. Moreover, this structure has good sealing performance and is not prone to oil leakage risks.

[0030] A shallow groove is provided on the splicing surface of the first part 11. The process port is provided at the bottom of the shallow groove. The plug 6 is a sealing gasket embedded in the shallow groove. The sealing gasket is pressed between the first part 11 and the second part 12, which can further improve the sealing effect at the process port and prevent oil leakage.

[0031] The above embodiments are only one of the preferred specific embodiments of the present invention. All ordinary changes and substitutions made by those skilled in the art within the scope of the technical solution of the present invention are included in the protection scope of the present invention.

Claims

1. An internal gear pump with more stable operation, comprising a housing, the housing comprising a cavity, a high-pressure cavity connected to the cavity, a gear and a gear ring rotatably arranged in the cavity, the high-pressure cavity being arranged at both axial ends of the gear ring, a crescent plate being arranged between the gear and the gear ring, the cavity comprising an inner circumferential wall in contact with the outer circumferential wall of the gear ring and two axial walls capable of limiting the axial position of the gear ring, an oil introduction device being arranged between the high-pressure cavity and the cavity, the oil introduction device comprising an oil introduction path arranged on the housing, the oil inlet of the oil introduction path being connected to the high-pressure cavity, and the oil outlet of the oil introduction path being arranged at the inner circumferential wall of the cavity, characterized in that: The oil introduction device includes a movable push rod and an elastic component. The movable push rod is movably arranged at the oil outlet of the oil introduction circuit. An elastic component is abutted between the movable push rod and the shell. The elastic component drives one end of the movable push rod to abut against the outer peripheral wall of the gear ring. An oil delivery channel is arranged in the movable push rod. A first opening connected to the oil delivery channel is arranged at one end of the movable push rod, and a second opening connected to the oil delivery channel is arranged on the peripheral side of the other end of the movable push rod. The oil introduction circuit includes a first section and a second section that are perpendicular to each other. The movable push rod and the first section form a movable plug-in fit. The oil delivery channel of the movable push rod is connected to the second section through the second opening at the other end thereof. The first section has a connecting port that is matched with the second section, and the inner edge of the connecting port is matched with the second opening to block.

2. An internal gear pump with more stable operation according to claim 1, characterized in that: The first section has a flared opening connected to the cavity, one end of the movable push rod includes an abutment portion, one end of the flared opening is movably connected to the abutment portion of the movable push rod, the other end of the flared opening has an annular step surface, the elastic component is a spring sleeved on the movable push rod, the spring is located at the flared opening, and both ends of the spring are respectively abutted and matched with the abutment portion and the annular step surface.

3. An internal gear pump with more stable operation according to claim 2, characterized in that: A third opening for connecting the oil delivery channel and the expansion port is arranged on the peripheral side of one end of the movable push rod.

4. An internal gear pump with more stable operation according to claim 2, characterized in that: The abutting portion has an arc-shaped concave surface that contacts and cooperates with the outer peripheral wall of the gear ring, and the first opening is arranged on the arc-shaped concave surface.

5. An internal gear pump with more stable operation according to claim 1, characterized in that: The second opening is a long strip-shaped through slot, and the directions of both ends thereof correspond to the length direction of the movable push rod.

6. An internal gear pump with more stable operation according to claim 5, characterized in that: There are multiple second openings, and the multiple second openings are evenly distributed along the circumference of the movable push rod.

7. An internal gear pump with more stable operation according to claim 1, characterized in that: The shell includes a first part and a second part which are spliced ​​together. The inner circumferential wall of the cavity and one of the axial walls and the oil introduction device are all arranged on the first part. The other axial wall of the cavity is arranged on the second part. The oil introduction circuit includes a third section which is parallel to the first section and perpendicular to the second section. One end of the third section is connected to the high-pressure chamber, and the other end of the third section is connected to one end of the second section. The other end of the second section is provided with a process port on the splicing surface of the first part, and a plug is provided at the process port.

8. An internal gear pump with more stable operation according to claim 7, characterized in that: A shallow groove is arranged on the joint surface of the first part, the process port is arranged at the bottom of the shallow groove, the plug is a sealing gasket embedded in the shallow groove, and the sealing gasket is pressed tightly between the first part and the second part.

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