A self-pressurizing gear pump with low wear and axial gap self-adjustment

Abstract

This invention discloses a low-wear, self-adjusting axial clearance self-boosting gear pump, relating to the field of hydraulic pump technology. Its main structure is as follows: The upper surface of the lower distribution plate has two lower crescent grooves a and two lower crescent grooves b. Lower crescent grooves a are connected to oil passage a through a lower damping channel a, and lower crescent grooves b are connected to oil passage b through a lower damping channel b. The lower surface of the upper distribution plate has two upper crescent grooves a and two upper crescent grooves b. Upper crescent grooves a are connected to oil passage a through an upper damping channel a, and upper crescent grooves b are connected to oil passage b through an upper damping channel b. This invention provides a low-wear, self-adjusting axial clearance self-boosting gear pump, which enables the gear to be centrally suspended between the upper and lower distribution plates, thereby effectively reducing wear between the gear end face and the upper and lower distribution plates, while also reducing pressure loss and ensuring the efficiency of the gear pump.

Description

Technical Field

[0001] This invention relates to the field of hydraulic pump technology, and more particularly to a low-wear, self-boosting gear pump with self-adjusting axial clearance. Background Technology

[0002] Gear pumps, piston pumps, and vane pumps are the three major types of hydraulic pumps in the hydraulic industry. Among them, gear pumps are the most widely used due to their advantages such as simple structure, small size, strong resistance to contamination, convenient manufacturing and maintenance, and low price. However, problems such as large flow pulsation, low operating pressure, and radial force imbalance in gear pumps greatly limit their application range. Therefore, gear pumps are mainly used in medium and low-pressure applications. However, as hydraulic systems develop towards higher response and higher power density, high speed and high pressure have become the main development trends for gear pumps.

[0003] To address this, a patent (application number: 202310102797.5) designed a self-boosting gear pump. This self-boosting gear pump effectively meets the development needs of hydraulic systems towards higher speeds and higher pressures, and possesses very strong anti-contamination capabilities. Specifically, because the self-boosting gear pump can increase pressure and output high-pressure oil through hydraulic oil compression when the closed variable volume cavity formed by gear meshing decreases, and can replenish oil by connecting to the oil inlet when the closed variable volume cavity increases, this self-boosting gear pump can achieve higher output pressure with minimal cavitation. Furthermore, because the gears in this self-boosting gear pump rotate circumferentially, it can achieve high-speed and high-overspeed operation, thereby achieving higher output flow rates. Additionally, due to the large radial clearance between the figure-eight shaped mounting cavity and the gear tooth tip circle, it also possesses very strong anti-contamination capabilities.

[0004] However, during the meshing operation of the self-boosting gear pump described in the aforementioned patent, due to manufacturing and assembly errors in the gears, as well as the influence of external interference or load changes, the end faces of the drive and driven shaft gears may come into close contact with the end faces of the upper or lower distribution plate when rotating at high speeds. This leads to rapid wear on the contact surfaces of the components, affecting their service life and creating excess material. Furthermore, because one end face of the gear is in close contact with the end face of the upper or lower distribution plate, the circumferential clearance on the other end face of the gear will inevitably increase. This will increase end-face leakage, resulting in pressure loss, which is extremely detrimental to the efficiency of the gear pump.

[0005] Therefore, there is an urgent need for a new hydraulic pump to solve the above problems. Summary of the Invention

[0006] The purpose of this invention is to provide a low-wear, self-adjusting axial clearance self-boosting gear pump, which enables the gear to be centrally suspended between the upper and lower distribution plates, thereby effectively reducing wear between the gear end face and the upper and lower distribution plates, while also reducing pressure loss and ensuring the efficiency of the gear pump.

[0007] To achieve the above objectives, the present invention provides a low-wear, self-adjusting axial clearance self-boosting gear pump, comprising a lower distribution plate, a pump housing, and an upper distribution plate arranged in a staggered manner from bottom to top. The pump housing is provided with an "8"-shaped mounting cavity for horizontally mounting a drive shaft gear and a driven shaft gear. The drive shaft gear and the driven shaft gear are engaged by involute gears, and oil passages a and b are respectively provided in the sidewalls of the "8"-shaped mounting cavity on the meshing start side and the meshing disengagement side.

[0008] The upper surface of the lower distribution plate on the meshing start side is provided with two lower crescent grooves a respectively arranged along the tooth root circles of the two gears, and the upper surface of the meshing disengagement side is provided with two lower crescent grooves b respectively arranged along the tooth root circles of the two gears. The lower crescent grooves a and b are symmetrically arranged, and the lower crescent grooves a are connected to the oil passage a through the lower damping channel a arranged in the lower distribution plate, and the lower crescent grooves b are connected to the oil passage b through the lower damping channel b arranged in the lower distribution plate.

[0009] The lower surface of the upper distribution plate on the meshing initiation side is provided with two upper crescent grooves a respectively arranged along the root circles of the two gears, and the lower surface of the meshing disengagement side is provided with two upper crescent grooves b respectively arranged along the root circles of the two gears. The upper crescent grooves a and b are symmetrically arranged, and the upper crescent grooves a are connected to the oil passage a through the upper damping channel a arranged in the upper distribution plate, and the upper crescent grooves b are connected to the oil passage b through the upper damping channel b arranged in the upper distribution plate.

[0010] As a further improvement of the present invention, the upper surface of the lower distribution plate is provided with a lower distribution waist-shaped port a communicating with the variable cavity on the engagement initiation side and a lower distribution waist-shaped port b communicating with the variable cavity on the engagement disengagement side. One end of the oil passage a is connected to the oil port a provided on the outer wall of the pump housing, and the other end is connected to the lower distribution waist-shaped port a through the lower oil passage a provided in the lower distribution plate. One end of the oil passage b is connected to the oil port b provided on the outer wall of the pump housing, and the other end is connected to the lower distribution waist-shaped port b through the lower oil passage b provided in the lower distribution plate.

[0011] The lower surface of the upper distribution plate is provided with an upper distribution waist-shaped port a communicating with the variable cavity on the engagement initiation side and an upper distribution waist-shaped port b communicating with the variable cavity on the engagement disengagement side. One end of the oil passage a is connected to the oil port a provided on the outer wall of the pump housing, and the other end is connected to the upper distribution waist-shaped port a through the upper oil passage a provided in the upper distribution plate. One end of the oil passage b is connected to the oil port b provided on the outer wall of the pump housing, and the other end is connected to the upper distribution waist-shaped port b through the upper oil passage b provided in the upper distribution plate.

[0012] As a further improvement of the present invention, one end of the lower damping channel a is connected to the lower oil passage a, and the other end is connected to the lower crescent groove a; one end of the lower damping channel b is connected to the lower oil passage b, and the other end is connected to the lower crescent groove b; one end of the upper damping channel a is connected to the upper oil passage a, and the other end is connected to the upper crescent groove a; one end of the upper damping channel b is connected to the upper oil passage b, and the other end is connected to the upper crescent groove b.

[0013] As a further improvement of the present invention, the lower damping channel a, the lower damping channel b, the upper damping channel a, and the upper damping channel b each include a first damping section disposed at both ends of the damping channel and a second damping section disposed in the middle of the damping channel, wherein the inner diameter of the first damping section is larger than the inner diameter of the second damping section.

[0014] As a further improvement of the present invention, there are two lower distribution waist-shaped ports a arranged opposite to each other, and the two lower distribution waist-shaped ports a are respectively connected to two variable cavities on the engagement initiation side; there are two lower distribution waist-shaped ports b arranged opposite to each other, and the two lower distribution waist-shaped ports b are respectively connected to two variable cavities on the engagement disengagement side.

[0015] As a further improvement of the present invention, the connection between oil passage a and lower oil passage a, and the connection between oil passage b and lower oil passage b, are all provided with flow channel sealing rings arranged along the joint.

[0016] As a further improvement of the present invention, there are two upper flow distribution waist-shaped ports a, which are arranged opposite to each other, and the two upper flow distribution waist-shaped ports a are respectively connected to two variable cavities on the engagement initiation side; there are two upper flow distribution waist-shaped ports b, which are arranged opposite to each other, and the two upper flow distribution waist-shaped ports b are respectively connected to two variable cavities on the engagement disengagement side.

[0017] As a further improvement of the present invention, the connection between oil passage a and upper oil passage a, and the connection between oil passage b and upper oil passage b, are all provided with flow channel sealing rings arranged along the joint.

[0018] As a further improvement of the present invention, the upper surface of the lower distribution plate is provided with two lower gear shaft mounting holes for mounting the drive shaft gear and the driven shaft gear, and the lower surface of the upper distribution plate is provided with two upper gear shaft mounting holes for mounting the drive shaft gear and the driven shaft gear. Both the lower gear shaft mounting holes and the upper gear shaft mounting holes are provided with bearings for rotatably mounting the gear shafts of the drive shaft gear and the driven shaft gear.

[0019] As a further improvement of the present invention, the upper gear shaft mounting hole for mounting the drive shaft gear is a through hole, and the upper part of the upper gear shaft mounting hole is provided with a retaining ring and a sealing cup that are sleeved on the gear shaft of the drive shaft gear from top to bottom.

[0020] Compared with the prior art, the advantages of the self-boosting gear pump with low wear and self-adjusting axial clearance of the present invention are as follows:

[0021] 1. During normal operation, the gear pump, through the damping channel, simultaneously introduces high-pressure oil from oil passage a into both the upper and lower crescent grooves a, and simultaneously introduces low-pressure oil from oil passage b into both the lower crescent grooves a and b. This causes the meshing initiation sides of the drive and driven gears to simultaneously bear the force of equal and opposite high-pressure oil, while the disengagement sides of the drive and driven gears simultaneously bear the force of equal and opposite low-pressure oil, thus achieving force balance on both ends of the drive and driven gears. Consequently, the drive and driven gears are positioned between the upper and lower distribution plates, and the gears are suspended by the oil pressure acting on their end faces, effectively reducing wear between the gear end faces and the upper and lower distribution plates.

[0022] 2. Because the drive and driven gears are suspended between the upper and lower distribution plates under hydraulic pressure, they achieve axial force balance in a balanced state. Therefore, neither the drive nor driven gear will experience a situation where one end face is tightly fitted to the upper / lower distribution plate while the circumferential clearance on the other end face increases. This also avoids leakage caused by increased clearance on one side of the gear end face, thus preventing pressure loss, ensuring the working efficiency of the gear pump, and improving its overall performance.

[0023] 3. When the self-boosting gear pump is affected by external interference or load changes, it can automatically adjust the pressure acting on both ends of the drive shaft gear and driven shaft gear through the set damping channels, thereby realizing the function of automatic alignment of the axial clearance of the drive shaft gear and driven shaft gear.

[0024] The invention will become clearer from the following description, taken in conjunction with the accompanying drawings, which are used to explain embodiments of the invention. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0026] Figure 1 This is an exploded view of the present invention;

[0027] Figure 2 This is a perspective view of the pump housing of the present invention;

[0028] Figure 3 This is a sectional perspective view of the pump housing of the present invention;

[0029] Figure 4 This is a perspective view of the lower distribution plate of the present invention;

[0030] Figure 5 This is a top view of the lower distribution plate of the present invention;

[0031] Figure 6 for Figure 5 Partial cross-sectional view;

[0032] Figure 7 This is a perspective view of the upper distribution plate of the present invention;

[0033] Figure 8 This is a bottom view of the upper distribution plate of the present invention;

[0034] Figure 9 for Figure 8 Partial cross-sectional view;

[0035] Figure 10 This is a diagram showing the oil pressure situation of the distribution plate when the drive shaft gear of the present invention rotates clockwise;

[0036] Figure 11 This is one of the schematic diagrams illustrating the working principle of the lower distribution plate of the present invention for realizing oil inlet and outlet;

[0037] Figure 12 This is the second schematic diagram illustrating the working principle of the lower distribution plate of the present invention for realizing oil inlet and outlet.

[0038] Figure 13 This is the third schematic diagram illustrating the working principle of the lower distribution plate of the present invention for realizing oil inlet and outlet;

[0039] Figure 14 This is the fourth schematic diagram illustrating the working principle of the lower distribution plate of the present invention for realizing oil inlet and outlet.

[0040] Wherein: 1-lower distribution plate; 11-lower gear shaft mounting hole; 12-lower oil passage a; 13-lower oil passage b; 14-lower distribution waist-shaped port a; 15-lower distribution waist-shaped port b; 16-lower crescent groove a; 17-lower crescent groove b; 18-lower damping hole a; 19-lower damping hole b; 2-pump housing; 21-figure-eight mounting cavity; 22-oil port a; 23-oil port b; 24-oil passage a; 25-oil passage b; 3-upper distribution plate; 3 1-Upper gear shaft mounting hole; 32-Upper oil passage a; 33-Upper oil passage b; 34-Upper flow distribution waist-shaped port a; 35-Upper flow distribution waist-shaped port b; 36-Upper crescent groove a; 37-Upper crescent groove b; 38-Upper damping hole a; 39-Upper damping hole b; 4-Drive shaft gear; 41-Retaining ring; 42-Sealing cup; 5-Driven shaft gear; 6-Bearing; 7-Flow channel sealing ring; 8-Edge sealing ring; 9-Positioning pin hole; 91-Threaded hole. Detailed Implementation

[0041] 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.

[0042] 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.

[0043] 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.

[0044] In the description of the embodiments of the present invention, it should be noted that if terms such as "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" are used to indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the product of the invention is usually placed during use, they are only for the convenience of describing the present invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention.

[0045] Furthermore, the use of terms such as "horizontal," "vertical," and "sag" does not imply that the component must be absolutely horizontal or suspended, but rather that it can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal relative to "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0046] In the description of the embodiments of the present invention, "multiple" means at least 3.

[0047] In the description of the embodiments of the present invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" 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; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in the present invention according to the specific circumstances.

[0048] Embodiments of the present invention will now be described with reference to the accompanying drawings.

[0049] Example

[0050] Specific embodiments of the present invention are as follows: Figure 1-3 As shown, a low-wear, self-adjusting axial clearance self-boosting gear pump includes a lower distribution plate 1, a pump housing 2, and an upper distribution plate 3 stacked sequentially from bottom to top. In this embodiment, the self-boosting gear pump composed of the lower distribution plate 1, pump housing 2, and upper distribution plate 3 has a columnar structure. The pump housing 2 has an "8"-shaped mounting cavity 21 for horizontally mounting a drive shaft gear 4 and a driven shaft gear 5. The drive shaft gear 4 and the driven shaft gear 5 are involute gears meshing, and the drive shaft gear 4 drives the driven shaft gear 5 to rotate synchronously. Simultaneously, an oil passage a24 is provided in the side wall of the "8"-shaped mounting cavity 21 on the meshing initiation side of the drive shaft gear 4 and the driven shaft gear 5, and an oil passage b25 is provided in the side wall of the "8"-shaped mounting cavity 21 on the meshing disengagement side. In this embodiment, as... Figure 2 As shown, the intersection of the two cylindrical surfaces of the figure-eight shaped mounting cavity 21 is a smooth transition, and the two smooth transition surfaces are symmetrically distributed along the plane formed by the axes of the two cylindrical holes. At the same time, neither oil passage a24 nor oil passage b25 is directly connected to the figure-eight shaped mounting cavity 21.

[0051] In this embodiment, in order to achieve pressurized oil delivery, such as Figure 4-5As shown, the upper surface of the lower distribution plate 1 is provided with a lower distribution waist-shaped port a14 communicating with the variable cavity on the engagement initiation side and a lower distribution waist-shaped port b15 communicating with the variable cavity on the engagement disengagement side. The lower distribution waist-shaped ports a14 and b15 are arranged opposite to each other. One end of the oil passage a24 is connected to the oil port a22 provided on the outer wall of the pump housing 2, and the other end is connected to the lower distribution waist-shaped port a14 through the lower oil passage a12 provided in the lower distribution plate 1. One end of the oil passage b25 is connected to the oil port b23 provided on the outer wall of the pump housing 2, and the other end is connected to the lower distribution waist-shaped port b15 through the lower oil passage b13 provided in the lower distribution plate 1. In this embodiment, there are two lower distribution waist-shaped ports a14 arranged opposite to each other, and the two lower distribution waist-shaped ports a14 are respectively connected to the two variable cavities on the engagement initiation side. There are two lower distribution waist-shaped ports b15 arranged opposite to each other, and the two lower distribution waist-shaped ports b15 are respectively connected to two variable cavities on the engagement / disengagement side.

[0052] When the drive shaft gear 4 starts to rotate, the oil port a22 located on the side where the drive shaft gear 4 and the driven shaft gear 5 begin to mesh will serve as the oil outlet, forming the pump's oil discharge chamber together with the oil passage a24, the lower oil passage a12, and the lower distribution waist-shaped port a14. The oil port b23 located on the side where the drive shaft gear 4 and the driven shaft gear 5 disengage will serve as the oil inlet, forming the pump's oil inlet chamber together with the oil passage b25, the lower oil passage b13, and the lower distribution waist-shaped port b15. Specifically, this self-boosting gear pump utilizes the rotation of the drive shaft gear 4 and the driven shaft gear 5, which are assembled in the figure-eight-shaped mounting cavity 21 and mesh with each other, to gather the oil on both sides of the figure-eight-shaped mounting cavity 21 towards the side where the meshing begins, thereby pressurizing the oil for the first time. Subsequently, in the "variable cavity" formed by the meshing of the driving shaft gear 4 and driven shaft gear 5 on the meshing initiation side, the "oil trapping" phenomenon of involute gear meshing is utilized to pressurize the oil a second time through "oil trapping" compression. The high-pressure oil is then output through the lower distribution waist-shaped port a14, oil passage a24, and oil port a22, thereby realizing the oil pressurization and high-pressure output of the gear pump. At the same time, in the "variable cavity" formed by the meshing of the driving shaft gear 4 and driven shaft gear 5 on the meshing disengagement side, the "variable cavity" gradually expands with the rotation of the driving shaft gear 4 and driven shaft gear 5, generating suction. The "variable cavity" is replenished with oil in a timely manner through the lower distribution waist-shaped port b15, oil passage b25, and oil port b23, preventing the generation of local vacuum and effectively avoiding cavitation.

[0053] Compared to existing gear pump technology, this self-boosting gear pump utilizes the continuous meshing of gears to reduce the volume of the inner wall of the figure-eight cavity 21 and the gear tooth tip circle on the meshing side, achieving the first stage of oil pressurization. Then, by utilizing the reduced volume of the variable cavity formed during continuous gear meshing, the oil is squeezed to achieve the second stage of pressurization, thereby significantly increasing its output pressure. Therefore, this self-boosting gear pump can achieve higher output pressure without the need for multi-stage gear pumps in series, thus avoiding the drawbacks of complex structure, high manufacturing cost, and difficult maintenance associated with multi-stage gear pumps. Furthermore, because the gears in this self-boosting gear pump rotate in a circular motion, high-speed and high-overspeed operation can be achieved. Therefore, compared to the poor inlet self-priming characteristics of existing plunger pumps and the poor reciprocating linear motion self-priming characteristics of plunger pumps, this self-boosting gear pump achieves a higher output flow rate through its high-speed and high-overspeed gear rotation. Furthermore, compared to existing plunger pumps, which require high precision in their mating pairs due to the small sealing clearances of the distribution plate, plunger, and slipper, this self-boosting gear pump, with its large radial clearance between the figure-eight shaped mounting cavity 21 and the gear tooth tip circle, possesses stronger resistance to contamination and better resistance to temperature rise deformation. Moreover, components such as the pump housing 2 also offer greater cost advantages in manufacturing and installation.

[0054] Not only that, such as Figure 7-8 As shown, to increase the oil flow rate, the lower surface of the upper distribution plate 3 is also provided with an upper distribution waist-shaped port a34 communicating with the variable cavity on the engagement initiation side and an upper distribution waist-shaped port b35 communicating with the variable cavity on the engagement disengagement side. The upper distribution waist-shaped port a34 and the upper distribution waist-shaped port b35 are arranged opposite to each other. One end of the oil passage a24 is connected to the oil port a22 provided on the outer wall of the pump housing 2, and the other end is connected to the upper distribution waist-shaped port a34 through the upper oil passage a32 provided in the upper distribution plate 3. One end of the oil passage b25 is connected to the oil port b23 provided on the outer wall of the pump housing 2, and the other end is connected to the upper distribution waist-shaped port b35 through the upper oil passage b33 provided in the upper distribution plate 3. In this embodiment, there are two upper distribution waist-shaped ports a34 arranged opposite to each other, and the two upper distribution waist-shaped ports a34 are respectively connected to the two variable cavities on the engagement initiation side. There are two upper flow waist-shaped ports b35 arranged opposite to each other, and the two upper flow waist-shaped ports b35 are respectively connected to two variable cavities on the engagement and disengagement side.

[0055] When the drive shaft gear 4 starts to rotate, the oil port a22 located on the side where the drive shaft gear 4 and the driven shaft gear 5 begin to mesh will serve as the oil discharge port, together with the oil passage a24, lower oil passage a12, lower distribution waist-shaped port a14, upper oil passage a32, and upper distribution waist-shaped port a34 to form the pump's oil discharge chamber. The oil port b23 located on the side where the drive shaft gear 4 and the driven shaft gear 5 disengage will serve as the oil inlet, together with the oil passage b25, lower oil passage b13, lower distribution waist-shaped port b15, upper oil passage b33, and upper distribution waist-shaped port b35 to form the pump's oil inlet chamber.

[0056] The above describes the oil delivery process of the self-boosting pump in this embodiment.

[0057] To prevent the gear pump from experiencing a situation where the gear end face might tightly rub against the end face of the upper or lower distribution plate during high-speed operation, when the drive shaft gear 4 rotates counterclockwise, as... Figure 5 , 6 As shown in Figures 8 and 9, in this type of low-wear, self-adjusting axial clearance self-boosting gear pump, the upper surface of the lower distribution plate 1 on the meshing initiation side is provided with two lower crescent grooves a16 respectively arranged along the root circles of the two gears, and the upper surface of the meshing disengagement side is provided with two lower crescent grooves b17 respectively arranged along the root circles of the two gears. The lower crescent grooves a16 and b17 are not connected and are symmetrically arranged along the plane formed by the line connecting the axes of the driving shaft gear 4 and the driven shaft gear 5. Furthermore, the lower crescent grooves a16 are connected to the oil passage a24 through the lower damping channel a18 provided in the lower distribution plate 1, and the lower crescent grooves b17 are connected to the oil passage b25 through the lower damping channel b19 provided in the lower distribution plate 1.

[0058] In this embodiment, the lower damping channel a18 and the lower damping channel b19 have the same dimensional characteristics. One end of the lower damping channel a18 is connected to the lower oil passage a12, and the other end is connected to the lower crescent groove a16. One end of the lower damping channel b19 is connected to the lower oil passage b13, and the other end is connected to the lower crescent groove b17. Both the lower damping channels a18 and b19 include a first damping section disposed at both ends of the damping channel and a second damping section disposed in the middle of the damping channel. The inner diameter of the first damping section is larger than the inner diameter of the second damping section.

[0059] When the drive shaft gear 4 rotates, the lower crescent groove a16 contains high-pressure oil overflowing from the lower oil passage a12, and the lower crescent groove b17 contains low-pressure oil overflowing from the lower oil passage b13. The high-pressure oil acts simultaneously on the end faces of the drive shaft gear 4, the driven shaft gear 5, and the lower distribution plate 1 through the lower crescent groove a16; the low-pressure oil acts simultaneously on the end faces of the drive shaft gear 4, the driven shaft gear 5, and the lower distribution plate 1 through the lower crescent groove b17.

[0060] Meanwhile, on the lower surface of the upper distribution plate 3 at the engagement initiation side, there are two upper crescent-shaped grooves a36 respectively arranged along the root circles of the two gears, and on the lower surface of the engagement disengagement side, there are two upper crescent-shaped grooves b37 respectively arranged along the root circles of the two gears. The upper crescent-shaped grooves a36 and b37 are not connected and are symmetrically arranged along the plane formed by the line connecting the axes of the driving shaft gear 4 and the driven shaft gear 5. Furthermore, the upper crescent-shaped grooves a36 are connected to the oil passage a24 through the upper damping channel a38 provided in the upper distribution plate 3, and the upper crescent-shaped grooves b37 are connected to the oil passage b25 through the upper damping channel b39 provided in the upper distribution plate 3.

[0061] In this embodiment, the upper damping channel a38 and the upper damping channel b39 have the same dimensional characteristics. One end of the upper damping channel a38 is connected to the upper oil passage a32, and the other end is connected to the upper crescent groove a36. One end of the upper damping channel b39 is connected to the upper oil passage b33, and the other end is connected to the upper crescent groove b37. Both the upper damping channels a38 and b39 include a first damping section disposed at both ends of the damping channel and a second damping section disposed in the middle of the damping channel. The inner diameter of the first damping section is larger than the inner diameter of the second damping section.

[0062] When the drive shaft gear 4 rotates, the upper crescent groove a36 contains high-pressure oil overflowing from the upper oil passage a32, and the upper crescent groove b37 contains low-pressure oil overflowing from the upper oil passage b33. The high-pressure oil acts simultaneously on the end faces of the drive shaft gear 4, the driven shaft gear 5, and the upper distribution plate 3 through the upper crescent groove a36; the low-pressure oil acts simultaneously on the end faces of the drive shaft gear 4, the driven shaft gear 5, and the upper distribution plate 3 through the upper crescent groove b37.

[0063] Specifically, when the self-boosting gear pump is in a stable operating state, on the same side of the plane formed by the axes of the two gear shafts, the contact end faces of the drive shaft gear 4 and driven shaft gear 5 with the upper distribution plate 3 and lower distribution plate 1 are respectively subjected to high-pressure oil forces of equal magnitude and opposite direction along the gear axis, achieving force balance in the gear axis direction. On the other side of the plane formed by the axes of the two gear shafts, the contact end faces of the drive shaft gear 4 and driven shaft gear 5 with the upper distribution plate 3 and lower distribution plate 1 are respectively subjected to low-pressure oil forces of equal magnitude and opposite direction along the gear axis, achieving force balance in the gear axis direction. Therefore, in a stable state, the drive shaft gear 4 and driven shaft gear 5 will be suspended between the upper distribution plate 3 and lower distribution plate 1, without contacting them, and the end faces of the gears will maintain a certain value of end face leakage, thereby effectively reducing wear and reducing the risk of excess material generated due to wear.

[0064] Furthermore, when the self-boosting gear pump experiences external interference or load changes, the axial clearance between the end faces of the drive shaft gear 4 and driven shaft gear 5 and one side of the upper distribution plate 3 or lower distribution plate 1 will decrease under the action of hydraulic force, while the axial clearance on the other side will increase. On the side with smaller axial clearance, end face leakage will decrease because the oil pressure in the crescent-shaped groove filled with high-pressure oil on that side will increase due to the damping channel, thus increasing the pressure acting on the end faces of the drive shaft gear 4 and driven shaft gear 5. Simultaneously, on the side with larger axial clearance, end face leakage will increase because the oil pressure in the crescent-shaped groove filled with high-pressure oil on that side will decrease due to the damping channel, thus decreasing the pressure acting on the end faces of the drive shaft gear 4 and driven shaft gear 5. Therefore, under the action of the high-pressure oil pressure difference, both end faces of the drive shaft gear 4 and driven shaft gear 5 will move towards the side with reduced pressure until the pressure difference between the two end faces equals 0, reaching a new equilibrium state, thereby realizing the self-adjustment function of the axial clearance of the drive shaft gear 4 and driven shaft gear 5.

[0065] In addition, such as Figure 1 As shown, the connections between oil passage a24 and lower oil passage a12, and between oil passage b25 and lower oil passage b13, are all located on the lower end face of the pump housing 2. To prevent oil leakage between oil passage a24 and lower oil passage a12, and between oil passage b25 and lower oil passage b13 during transportation, this embodiment provides flow channel sealing rings 7 along the joints at the connections between oil passage a24 and lower oil passage a12, and between oil passage b25 and lower oil passage b13. To install the flow channel sealing rings 7, sealing ring mounting grooves are provided on the lower end face of the pump housing 2 and the upper end face of the lower distribution plate 1.

[0066] The connections between oil passage a24 and upper oil passage a32, and between oil passage b25 and upper oil passage b13, are all located on the upper surface of the pump housing 2. To prevent oil leakage between oil passage a24 and upper oil passage a32, and between oil passage b25 and upper oil passage b33 during transportation, this embodiment provides flow channel sealing rings 7 along the joints at the connections between oil passage a24 and upper oil passage a32, and between oil passage b25 and upper oil passage b33. For installing the flow channel sealing rings 7, sealing ring mounting grooves are provided on the upper surface of the pump housing 2 and the lower surface of the upper distribution plate 3.

[0067] To further prevent oil leakage, edge sealing rings 8 are provided between the lower distribution plate 1 and the pump housing 2, and between the upper distribution plate 3 and the pump housing 2, respectively, along the edge of the contact surface.

[0068] In addition, such as Figure 4 and 7As shown, regarding the installation of the driving shaft gear 4 and the driven shaft gear 5, the upper surface of the lower distribution plate 1 is provided with two lower gear shaft mounting holes 11 for installing the driving shaft gear 4 and the driven shaft gear 5, and the lower surface of the upper distribution plate 3 is provided with two upper gear shaft mounting holes 31 for installing the driving shaft gear 4 and the driven shaft gear 5. Meanwhile, to ensure smooth rotation of the driving shaft gear 4 and the driven shaft gear 5, bearings 7 are provided in both the lower gear shaft mounting holes 11 and the upper gear shaft mounting holes 31 for rotatably mounting the gear shafts of the driving shaft gear 4 and the driven shaft gear 5.

[0069] In this embodiment, in order to connect the gear shaft of the drive shaft gear 4 to the drive device, the upper gear shaft mounting hole 31 for mounting the drive shaft gear 4 is a through hole, and the gear shaft at the top of the drive shaft gear 4 passes through the upper gear shaft mounting hole 31 to connect with the drive device. At the same time, in order to prevent oil leakage from the upper gear shaft mounting hole 31, a retaining ring 41 and a sealing cup 42 are also provided from top to bottom on the upper part of the upper gear shaft mounting hole 31, which are sleeved on the gear shaft of the drive shaft gear 4.

[0070] It is important to note that:

[0071] The lower distribution plate 1, pump housing 2, and upper distribution plate 3 are fixedly connected by two screws that vertically penetrate each component and two locating pins that vertically penetrate each component. Therefore, the lower distribution plate 1, pump housing 2, and upper distribution plate 3 are all provided with locating pin holes 9 and threaded holes 91. In this embodiment, the positions of the locating pin holes 9 and threaded holes 91 are as follows: Figure 2 , 4 As shown in Figures 7 and 8.

[0072] Regarding the specific operation of this device, in conjunction with Figure 8-11 The working principle of this self-boosting gear pump, which achieves two oil inlets and two oil outlets by rotating one tooth, is illustrated below using the distribution plate 1 as an example:

[0073] When the drive shaft gear 4 rotates continuously counterclockwise, oil port b23 becomes the oil inlet, and oil port a22 becomes the oil outlet. The initial critical state is defined as the position where the tip of the drive shaft gear 4, the root of the driven shaft gear 5, and the line connecting the two rotation centers coincide. Figure 11 As shown, since the overlap ratio of the two gears is greater than 1, the two gears will inevitably produce at least two meshing lines, thus forming a pattern as shown in the diagram. Figure 11 The variable cavity one is shown. Variable cavity one is a closed cavity formed by the isomorphic structure of the involute tooth surface of the driving shaft gear 4, the root circle of the driven shaft gear 5, the end face of the upper distribution plate 3, and the end face of the lower distribution plate 1. At this time, variable cavity one is in a state of maximum compression, with the highest pressure of the compressed oil. The two lower distribution slots b15 communicating with the oil inlet chamber and the two lower distribution slots a14 communicating with the oil outlet chamber are all blocked by the gear end faces.

[0074] Then, the drive shaft gear 4 rotates from the initial critical position to 1 / 4 of a tooth, that is: from Figure 11 — Figure 12 The process involves the formation of a new variable cavity, Variable Cavity II, which is a closed cavity formed by the tip circle of the driven shaft gear 5, the involute tooth surface of the driving shaft gear 4, the end face of the upper distribution plate 3, and the end face of the lower distribution plate 1. During this process, the volume of Variable Cavity I gradually increases, while the oil pressure gradually decreases. Oil is replenished to Variable Cavity I through one of the lower distribution slots (b15) connected to the oil inlet chamber. The volume of Variable Cavity I continues to increase until the gears disengage. At this point, the oil drawn from the oil inlet chamber enters the gap between the figure-eight mounting cavity 21 and the tip circle of the gear teeth through the disengaged gears. As the gears rotate, the oil is carried to the side where the gears gradually engage, completing the self-pressurization process. During this process, the volume of the variable cavity gradually decreases, and the oil pressure gradually increases due to compression. One of the lower distribution slots, a14, which communicates with the oil discharge chamber, is partially unobstructed after the gear tooth profile rotates, allowing the high-pressure oil to flow into the oil discharge chamber through this slot. Meanwhile, both the other lower distribution slot, b15, and a14 are completely blocked by the gear end face, thus completing one cycle of oil suction and discharge.

[0075] Next, the drive shaft gear 4 continues to rotate from 1 / 4 of a tooth to half a tooth, that is: from... Figure 12 — Figure 13 The process involves the following steps: During this process, the volume of the second variable cavity gradually decreases, the pressure inside the cavity gradually increases, and the oil continues to be discharged into the drain chamber through the aforementioned lower distribution waist-shaped port a14. As the gear rotates, the aforementioned lower distribution waist-shaped port b15, which communicates with the oil suction chamber, will gradually be blocked by the end face of the driven shaft gear 5 until it is completely blocked. Similarly, the unblocked portion of the aforementioned lower distribution waist-shaped port a14 will gradually decrease until it is completely blocked by the end face of the driving shaft gear 4. At this point, the volume of the second variable cavity becomes the smallest, and the first variable cavity disappears as the gears gradually disengage. During this process, the other lower distribution waist-shaped port b15 and the other lower distribution waist-shaped port a14 continue to be completely blocked. When the volume of the second variable cavity is at its smallest, both lower distribution waist-shaped ports b15 communicating with the oil inlet chamber and both lower distribution waist-shaped ports a14 communicating with the oil drain chamber are blocked by the gear end faces.

[0076] Finally, the drive shaft gear 4 continues to rotate from half a tooth to three / 4 of a tooth, that is: from Figure 13 — Figure 14The process involves the following steps: During this process, the volume of the second variable cavity gradually increases, the oil pressure inside the cavity gradually decreases, and the uncovered portion of one of the lower distribution waist-shaped ports b15, which communicates with the oil inlet cavity, gradually increases. Oil will then replenish the second variable cavity through this lower distribution waist-shaped port b15 until the gears completely disengage due to rotation, causing the second variable cavity to disappear. The oil drawn from the oil inlet cavity enters the gap between the figure-eight shaped mounting cavity 21 and the gear tooth tip circle through the disengaged gear. As the gears rotate, the oil is carried to the side where the gears gradually engage, completing self-pressurization. During this process, the third variable cavity will be reformed. The third variable cavity is a closed cavity composed of the tip circle of the driving shaft gear 4, the involute tooth surface of the driven shaft gear 5, the end face of the upper distribution plate 3, and the end face of the lower distribution plate 1. Furthermore, as the gear rotates, the volume of the variable-volume cavity three gradually decreases, and the oil pressure gradually increases. One of the lower distribution port a14, which communicates with the oil discharge chamber, gradually expands its uncovered portion, allowing high-pressure oil to be discharged into the oil discharge chamber through lower distribution port a14. During this process, both the other lower distribution port b15 and the other lower distribution port a14 are completely blocked by the gear end face, thus completing another round of oil suction and discharge.

[0077] Meanwhile, the working principle of the upper distribution waist-shaped port a34 and upper distribution waist-shaped port b35 in the upper distribution plate 3 is the same as that of the lower distribution waist-shaped port a14 and lower distribution waist-shaped port b15 in the lower distribution plate 1, and will not be repeated here. By repeating the above steps, oil can be discharged through the lower distribution waist-shaped port a14 and upper distribution waist-shaped port a34, which are connected to the oil discharge chamber. At the same time, oil can be replenished to the variable volume cavity through the lower distribution waist-shaped port b15 and upper distribution waist-shaped port b35, which are connected to the oil inlet chamber. Each time the meshing gear rotates one tooth, oil will be sucked in twice and discharged twice.

[0078] Similarly, when the drive shaft gear rotates continuously clockwise, the gear pump works on the same principle as above, which will not be repeated here. Therefore, this gear pump can also freely switch between oil discharge and oil suction directions according to the rotation direction of the drive shaft gear 4, giving the gear pump a bidirectional function.

[0079] The present invention has been described above in conjunction with the preferred embodiments, but the present invention is not limited to the embodiments disclosed above, but should cover various modifications and equivalent combinations made in accordance with the essence of the present invention.

Claims

1. A self-pressurizing gear pump with low wear and axial clearance self-adjustment, comprising a lower distribution plate (1), a pump housing (2) and an upper distribution plate (3) arranged in sequence and superposed, characterized in that, The pump housing (2) is provided with an "8"-shaped mounting cavity (21) for horizontally mounting the drive shaft gear (4) and the driven shaft gear (5). The drive shaft gear (4) and the driven shaft gear (5) are involute gear meshing. The sidewalls of the "8"-shaped mounting cavity (21) on the meshing start side and the meshing disengagement side are respectively provided with oil passage a (24) and oil passage b (25). The upper surface of the lower distribution plate (1) on the meshing start side is provided with two lower crescent grooves a (16) respectively arranged along the tooth root circles of the two gears, and the upper surface of the meshing disengagement side is provided with two lower crescent grooves b (17) respectively arranged along the tooth root circles of the two gears. The lower crescent grooves a (16) and b (17) are symmetrically arranged, and the lower crescent grooves a (16) are connected to the oil passage a (24) through the lower damping channel a (18) arranged in the lower distribution plate (1), and the lower crescent grooves b (17) are connected to the oil passage b (25) through the lower damping channel b (19) arranged in the lower distribution plate (1). The upper distribution plate (3) has two upper crescent grooves a (36) on the lower surface of the meshing start side, which are respectively arranged along the root circles of the two gears. The upper crescent grooves b (37) on the lower surface of the meshing disengagement side are respectively arranged along the root circles of the two gears. The upper crescent grooves a (36) and b (37) are arranged symmetrically. The upper crescent grooves a (36) are connected to the oil passage a (24) through the upper damping channel a (38) in the upper distribution plate (3). The upper crescent grooves b (37) are connected to the oil passage b (25) through the upper damping channel b (39) in the upper distribution plate (3). Through the damping channel, high-pressure oil in oil passage a (24) can be introduced into upper crescent groove a (36) and lower crescent groove a (16) at the same time, and low-pressure oil in oil passage b (25) can be introduced into upper crescent groove b (37) and lower crescent groove b (17) at the same time.

2. The low-wear, self-adjusting axial clearance self-boosting gear pump according to claim 1, characterized in that, The upper surface of the lower distribution plate (1) is provided with a lower distribution waist-shaped port a (14) that communicates with the variable cavity on the meshing start side and a lower distribution waist-shaped port b (15) that communicates with the variable cavity on the meshing disengagement side. One end of the oil passage a (24) is connected to the oil port a (22) provided on the outer wall of the pump housing (2), and the other end is connected to the lower distribution waist-shaped port a (14) through the lower oil passage a (12) provided in the lower distribution plate (1). One end of the oil passage b (25) is connected to the oil port b (23) provided on the outer wall of the pump housing (2), and the other end is connected to the lower distribution waist-shaped port b (15) through the lower oil passage b (13) provided in the lower distribution plate (1). The lower surface of the upper distribution plate (3) is provided with an upper distribution waist-shaped port a (34) that communicates with the variable cavity on the engagement start side and an upper distribution waist-shaped port b (35) that communicates with the variable cavity on the engagement disengagement side. One end of the oil passage a (24) is connected to the oil port a (22) provided on the outer wall of the pump housing (2), and the other end is connected to the upper distribution waist-shaped port a (34) through the upper oil passage a (32) provided in the upper distribution plate (3). One end of the oil passage b (25) is connected to the oil port b (23) provided on the outer wall of the pump housing (2), and the other end is connected to the upper distribution waist-shaped port b (35) through the upper oil passage b (33) provided in the upper distribution plate (3).

3. The low-wear, self-adjusting axial clearance self-boosting gear pump according to claim 2, characterized in that, The lower damping channel a (18) is connected to the lower oil passage a (12) at one end and to the lower crescent a (16) at the other end. The lower damping channel b (19) is connected to the lower oil passage b (13) at one end and to the lower crescent b (17) at the other end. The upper damping channel a (38) is connected to the upper oil passage a (32) at one end and to the upper crescent a (36) at the other end. The upper damping channel b (39) is connected to the upper oil passage b (33) at one end and to the upper crescent b (37) at the other end.

4. A low-wear, self-adjusting axial clearance self-boosting gear pump according to claim 1 or 3, characterized in that, The lower damping channel a (18), lower damping channel b (19), upper damping channel a (38) and upper damping channel b (39) each include a first damping section disposed at both ends of the damping channel and a second damping section disposed in the middle of the damping channel, wherein the inner diameter of the first damping section is larger than the inner diameter of the second damping section.

5. A low-wear, self-adjusting axial clearance self-boosting gear pump according to claim 2, characterized in that, There are two lower distribution waist-shaped ports a (14) arranged opposite to each other, and the two lower distribution waist-shaped ports a (14) are respectively connected to the two variable cavities on the engagement start side; there are two lower distribution waist-shaped ports b (15) arranged opposite to each other, and the two lower distribution waist-shaped ports b (15) are respectively connected to the two variable cavities on the engagement disengagement side.

6. A low-wear, self-adjusting axial clearance self-boosting gear pump according to claim 2, characterized in that, At the connection between oil passage a (24) and lower oil passage a (12), and at the connection between oil passage b (25) and lower oil passage b (13), a flow channel sealing ring (7) is provided along the joint.

7. A low-wear, self-adjusting axial clearance self-boosting gear pump according to claim 2, characterized in that, There are two upper flow distribution waist-shaped ports a (34) arranged opposite to each other, and the two upper flow distribution waist-shaped ports a (34) are respectively connected to the two variable cavities on the engagement start side; there are two upper flow distribution waist-shaped ports b (35) arranged opposite to each other, and the two upper flow distribution waist-shaped ports b (35) are respectively connected to the two variable cavities on the engagement disengagement side.

8. A low-wear, self-adjusting axial clearance self-boosting gear pump according to claim 2, characterized in that, At the connection between oil passage a (24) and upper oil passage a (32), and at the connection between oil passage b (25) and upper oil passage b (33), a flow channel sealing ring (7) is provided along the joint.

9. A low-wear, self-adjusting axial clearance self-boosting gear pump according to claim 1, characterized in that, The upper surface of the lower distribution plate (1) is provided with two lower gear shaft mounting holes (11) for mounting the drive shaft gear (4) and the driven shaft gear (5). The lower surface of the upper distribution plate (3) is provided with two upper gear shaft mounting holes (31) for mounting the drive shaft gear (4) and the driven shaft gear (5). Both the lower gear shaft mounting holes (11) and the upper gear shaft mounting holes (31) are provided with bearings for the gear shafts of the drive shaft gear (4) and the driven shaft gear (5) to be rotatably mounted.

10. A low-wear, self-adjusting axial clearance self-boosting gear pump according to claim 9, characterized in that, The upper gear shaft mounting hole (31) for mounting the drive shaft gear (4) is a through hole. The upper part of the upper gear shaft mounting hole (31) is provided with a retaining ring (41) and a sealing cup (42) that are sleeved on the gear shaft of the drive shaft gear (4) from top to bottom.

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