Highly oil-absorbing external gear pump

Abstract

An external gear pump with high oil absorption efficiency, a front end cover (1) and a pump body (3) are positioned by a positioning pin (2), connected by a bolt (13), and end face sealing is realized by a sealing ring (11); a sliding bearing (8) is arranged in the shaft sleeve and the floating shaft sleeve mounting hole of the pump body (3), and the sliding bearing (8) supports a driving gear shaft (9) and a driven gear shaft (10) together; a sealing surface (7-5) of a floating side plate (7) is attached to a gear end face, an upper fan-shaped groove (4-1) and a lower fan-shaped groove (12-2) are in communication with each other and are aligned with an axial flow distribution groove (7-2) of the floating side plate (7); an axial oil absorption blocking plate (7-1) in the floating side plate (7) and a radial oil absorption blocking plate (3-2) in the pump body (3) form a radial oil distribution groove (16), the radial oil distribution groove (16) is aligned with a gear disengagement meshing area; a driving shaft sleeve (4), a driven shaft sleeve (12) and an oil guide plane (3-3) of the pump body (3) form an oil guide cavity (17), and an oil absorption cavity (3-1) in the pump body (3) is communicated with a right circular arc groove (1-3) of the front end cover (1).

Description

Technical Field

[0001] This invention relates to the field of external gear pump technology, and is particularly applicable to external gear pumps operating at high speeds. Background Technology

[0002] External gear pumps, due to their simple structure and low manufacturing cost, are often used as the power source for hydraulic systems in mobile machinery. Their efficiency is crucial to the energy utilization efficiency of fluid transmission systems. The volumetric efficiency loss of external gear pumps can generally be attributed to two parts: leakage loss and oil suction efficiency loss. Oil suction efficiency loss can be further divided into two categories: one is due to the internal structure of the flow channel affecting oil flow, generating local vortices, and increasing gear suction resistance; the other is that when the external gear pump disengages, under the action of centrifugal force, the oil is thrown out of the gear cavity, thus reducing the filling rate in the gear cavity. Currently, there are two methods to improve gear oil suction efficiency. One is to optimize the flow channel structure of the diffuser section of the pump body's suction cavity, reducing local vortices during the flow process to reduce suction flow resistance. Its disadvantage is that it cannot solve the problem of suction resistance caused by gear centrifugal force. The other method is to install a suction booster device before the hydraulic pump, which increases the inlet pressure of the gear pump, thereby increasing the filling rate of the gear cavity. Its disadvantages are that the series structure is limited by the installation method, the manufacturing cost increases, and it cannot eliminate the oil suction resistance of the gear pump. Summary of the Invention

[0003] The purpose of this invention is to provide a high-efficiency external gear pump for oil suction.

[0004] This invention is a high-efficiency external gear pump for oil suction, comprising a front cover 1, a positioning pin 2, a pump body 3, a drive shaft sleeve 4, a polytetrafluoroethylene seal 5, a rubber seal 6, a floating side plate 7, a sliding bearing 8, a drive gear shaft 9, a driven gear shaft 10, a sealing ring 11, a driven shaft sleeve 12, a bolt 13, a lip seal 14, and a retaining ring 15 for the bore. The front cover 1 and the pump body 3 are positioned by the positioning pin 2, connected by the bolt 13, and sealed at the end face by the sealing ring 11. A sliding bearing 8 is provided inside the sleeve and in the mounting hole of the floating sleeve of the pump body 3, jointly supporting the drive gear shaft 9 and the driven gear shaft 10. The sealing surface 7-5 of the floating side plate 7 is in contact with the gear end face, and a rubber seal 6 is provided on the back. The PTFE seal 5 and the axial distribution groove 7-2 are aligned with the irregular polygon 3-1A of the oil suction chamber 3-1; the main positioning plane 4-2 of the drive shaft sleeve 4 is installed opposite to the driven positioning plane 12-1 of the driven shaft sleeve 12, the main sector groove 4-1 and the driven sector groove 12-2 are interconnected and aligned with the axial distribution groove 7-2 of the floating side plate 7; the axial oil suction baffle 7-1 in the floating side plate 7 and the radial oil suction baffle 3-2 in the pump body 3 form a radial oil distribution groove 16, which is aligned with the gear disengagement area; the drive shaft sleeve 4, the driven shaft sleeve 12 and the oil guide plane 3-3 of the pump body 3 form an oil guide chamber 17, which connects the oil suction chamber 3-1 in the pump body 3 with the right arc groove 1-3 of the front end cover 1.

[0005] The advantages of this invention are: the radial oil suction baffle 3-2 of the pump body 3 and the axial oil suction baffle 7-1 of the floating side plate 7 prevent the oil in the gear cavity from being thrown out under the action of centrifugal force; the axial distribution groove 7-2 enhances the oil suction capacity at the gear root and replenishes the oil thrown out at the tooth root; the axial oil suction design of the oil suction chamber 3-1 and the scanning mixing flow channel design from a circle to an irregular polygon 3-1A greatly reduce the flow resistance of the oil flow process. This invention has the advantages of convenient installation, small size, and high oil suction efficiency. Attached Figure Description

[0006] Figure 1 This is a full sectional view of the present invention. Figure 2 It is a complete three-dimensional sectional view. Figure 3 This is a schematic diagram of the front cover structure. Figure 4 This is the main sectional view of the pump body. Figure 5 This is a BB cross-sectional view of the pump body. Figure 6 This is a quarter section view of the pump body. Figure 7 This is a schematic diagram of an irregular polygon shape. Figure 8 This is a 3D schematic diagram of the floating side plate. Figure 9 It is a floating two-dimensional main view. Figure 10 This is a front 3D schematic diagram of the drive shaft bushing. Figure 11 This is a 3D schematic diagram of the reverse side of the drive shaft bushing. Figure 12This is a frontal 3D schematic diagram of the driven shaft bushing. Figure 13 This is a 3D schematic diagram of the reverse side of the driven shaft sleeve. The reference numerals and names are as follows: Front end cover 1, Upper transition hole 1-1, Left circular arc groove 1-2, Right circular arc groove 1-3, Lower transition hole 1-4, End cover oil reservoir hole 1-5, Positioning pin 2, Pump body 3, Oil suction chamber 3-1, Radial oil suction baffle plate 3-2, Oil guide plane 3-3, Axial positioning surface 3-4, Sealing groove 3-5, Oil discharge chamber 3-6, Connecting groove 3-7, Pump body oil reservoir hole 3-8, Bearing mounting hole 3-9, Pump chamber 3-10, Drive shaft sleeve 4, Main sector groove 4-1, Main positioning plane 4-2, Main bearing mounting hole 4-3, Main bearing mounting hole 4-4, Main sector groove 4-1, Main positioning plane 4-2, Main bearing mounting hole 4-5, Main sector groove 4-1, Main positioning plane 4-2, Main bearing mounting hole 4-3, Main sector groove 4-1, Main sector groove 4-2, Main bearing mounting hole 4-3, Main sector groove 4-1, Main sector groove 4-2, Main bearing mounting hole 4-3, Main sector groove 4-1, Main sector groove 4-2, Main sector groove ...3, Main sector groove 4-4, Main sector groove 4-3, Main sector groove 4-4, Main sector groove 4-3, Main sector groove 4-4, Main sector groove 4-3, Main sector groove 4-4, Main sector groove 4-3, Main sector groove 4-4, Main sector groove 4-3, Main sector groove 4- 4-3 mounting hole, 4-4 main boss, 5 PTFE seal, 6 rubber seal, 7 floating side plate, 7-1 axial oil suction baffle, 7-2 axial flow distribution groove, 7-3 oil suction unloading groove, 7-4 oil discharge unloading groove, 7-5 sealing surface, 8 sliding bearing, 9 driving gear shaft, 10 driven gear shaft, 11 sealing ring, 12 driven shaft sleeve, 12-1 positioning plane, 12-2 sector groove, 12-3 bearing mounting hole, 12-4 boss, 13 bolt, 14 lip seal, 15 elastic retaining ring for hole. Detailed Implementation

[0007] This invention is a high-efficiency external gear pump for oil suction, comprising a front cover 1, a positioning pin 2, a pump body 3, a drive shaft sleeve 4, a polytetrafluoroethylene (PTFE) seal 5, a rubber seal 6, a floating side plate 7, a sliding bearing 8, a drive gear shaft 9, a driven gear shaft 10, a sealing ring 11, a driven shaft sleeve 12, a bolt 13, a lip seal 14, and a retaining ring 15 for the bore. The front cover 1 and the pump body 3 are positioned by the positioning pin 2, connected by the bolt 13, and sealed at the end face by the sealing ring 11. A sliding bearing 8 is provided inside the sleeve and in the mounting hole of the floating sleeve of the pump body 3, jointly supporting the gear shafts (9, 10). The sealing surface 7-5 of the floating side plate 7 is in contact with the gear end face, and a rubber seal 6 and a polytetrafluoroethylene (PTFE) seal are provided on the back. The fluoroethylene seal 5, the axial distribution groove 7-2 and the irregular polygon 3-1A of the oil suction chamber 3-1 are aligned; the main positioning plane 4-2 of the drive shaft sleeve 4 and the driven positioning plane 12-1 of the driven shaft sleeve 12 are installed opposite each other, the main sector groove 4-1 and the driven sector groove 12-2 are interconnected and aligned with the axial distribution groove 7-2 of the floating side plate 7; the axial oil suction baffle 7-1 in the floating side plate 7 and the radial oil suction baffle 3-2 in the pump body 3 form a radial oil distribution groove 16, which is aligned with the gear disengagement area; the drive shaft sleeve 4, the driven shaft sleeve 12 and the oil guide plane 3-3 of the pump body 3 form an oil guide chamber 17, which connects the oil suction chamber 3-1 in the pump body 3 with the right arc groove 1-3 of the front end cover 1.

[0008] The high-efficiency external gear pump described above has a pump body 3 equipped with an oil suction chamber 3-1, a radial oil suction baffle 3-2, an oil guide plane 3-3, an axial positioning surface 3-4, a sealing groove 3-5, an oil discharge chamber 3-6, a connecting groove 3-7, a pump body oil storage hole 3-8, a bearing mounting hole 3-9, and a pump chamber 3-10. The oil suction chamber 3-1 is parallel to the gear shaft axis, with a circular inlet and an irregular polygonal shape 3-1A extending to the axial positioning surface 3-4.

[0009] Furthermore, the irregular polygon 3-1A has a horizontal line 3-1A-1, two axisymmetric flow distribution arcs 3-1A-2, two axisymmetric flow distribution vertical lines 3-1A-3, and a flow distribution semicircle 3-1A-4. The radius of the flow distribution arc 3-1A-2 is the same as the radius of the gear tooth root circle, and it intersects with the horizontal line 3-1A-1; the flow distribution vertical line 3-1A-3 intersects with the flow distribution arc 3-1A-2; and the flow distribution semicircle 3-1A-4 is tangent to the flow distribution vertical line 3-1A-3.

[0010] Furthermore, the radial oil suction baffle 3-2 is arc-shaped, with a width equal to or greater than the gear tooth width, and is integrated with the pump cavity 3-10. It is divided in the middle by rectangular cross-sections, forming an "eight" shape, and is symmetrical about the central plane. It has an upper arc-shaped surface 3-2-1 and a lower arc-shaped surface 3-2-2, wherein the radius of the upper arc-shaped surface 3-2-1 is greater than or equal to the tooth tip circle radius of the gear.

[0011] The high-efficiency oil-suction external gear pump described above has a floating side plate 7 equipped with an axial oil suction baffle 7-1, an axial flow distribution groove 7-2, an oil suction unloading groove 7-3, an oil discharge unloading groove 7-4, and a sealing surface 7-5.

[0012] Furthermore, the axial oil suction baffle 7-1 is provided with two axisymmetric lower distribution arc surfaces 7-1-1, a lower distribution transverse surface 7-1-2, a transverse surface 7-1-3, two axisymmetric lower arc surfaces 7-1-4, an outer positioning surface 7-1-5, and two axisymmetric mounting arc surfaces 7-1-6. The radius of the lower distribution arc surface 7-1-1 is the same as the base circle radius of the gear and is aligned with the distribution arc line 3-1A-2; the lower distribution transverse surface 7-1-2 is located outside the oil suction unloading groove 7-3; the radius of the lower arc surface 7-1-4 is equal to the radius of the lower arc surface 3-2-2 of the radial oil suction baffle (3-2) and is aligned with it; the outer positioning surface 7-1-5 is flush with the sealing surface 7-5 or is in the form of a groove at a distance from the sealing surface 7-5; the mounting arc surface 7-1-6 has the same radius as the distribution semicircle line 3-1A-4 and is installed concentrically with it.

[0013] Furthermore, the axial distribution groove 7-2 is composed of an upper distribution transverse surface 7-2-1, two axisymmetric upper distribution arc surfaces 7-2-2, two axisymmetric upper distribution vertical surfaces 7-2-3, and two lower distribution arc surfaces 7-1-1 and lower distribution transverse surface 7-1-2 of the axial oil suction baffle 7-1. The upper distribution transverse surface 7-2-1 is located within the oil suction unloading groove and is aligned with the distribution transverse line 3-1A-1; the upper distribution arc surface 7-2-2 has the same radius as the gear tooth root circle and is aligned with the distribution arc line 3-1A-2; the upper distribution vertical surface 7-2-3 is aligned with the distribution vertical line 3-1A-3.

[0014] Furthermore, both the axial oil suction plate 7-1 and the axial distribution groove 7-2 are in the shape of "π".

[0015] Furthermore, the sealing surface 7-5 is coated with a wear-resistant coating.

[0016] The high-efficiency oil-suction external gear pump described above has a main sector groove 4-1, a main positioning plane 4-2, a main bearing mounting hole 4-3, and a main boss 4-4 on the drive shaft sleeve 4.

[0017] Furthermore, the main sector groove 4-1 is connected to the axial distribution groove 7-2, and is provided with a main vertical surface 4-1-1, a main arc surface 4-1-2, and a main transverse surface 4-1-3. The main vertical surface 4-1-1 is aligned with the upper distribution vertical surface 7-2-3; the main arc surface 4-1-2 has the same radius as the tooth root circle and is aligned with the upper distribution arc surface 7-2-2; the main transverse surface 4-1-3 is aligned with the upper distribution transverse surface 7-2-1.

[0018] The high-efficiency oil-suction external gear pump described above has a driven shaft sleeve 12 with a positioning plane 12-1, a sector groove 12-2, a bearing mounting hole 12-3, and a boss 12-4.

[0019] Furthermore, the fan-shaped groove 12-2 is connected to the axial distribution groove 7-2, and is provided with a transverse surface 12-2-1, a circular arc surface 12-2-2, and a vertical surface 12-2-3. The transverse surface 12-2-1 is aligned with the upper distribution transverse surface 7-2-1; the circular arc surface 12-2-2 has the same radius as the tooth root circle and is aligned with the upper distribution circular arc surface 7-2-2; the vertical surface 12-2-3 is aligned with the upper distribution vertical surface 7-2-3.

[0020] The principles and features of the present invention will now be further described with reference to the accompanying drawings. The examples given are for illustrative purposes only and are not intended to limit the scope of the invention.

[0021] like Figures 1-3 , Figure 6 , Figure 8 , Figure 10 , Figure 12As shown, the main structure includes a front cover 1, a positioning pin 2, a pump body 3, a drive shaft sleeve 4, a polytetrafluoroethylene seal 5, a rubber seal 6, a floating side plate 7, a sliding bearing 8, a drive gear shaft 9, a driven gear shaft 10, a sealing ring 11, a driven shaft sleeve 12, a bolt 13, a lip seal 14, and a retaining ring 15 for the bore. The front cover 1 and the pump body 3 are positioned by the positioning pin 2, connected by the bolt 13, and sealed at the end face by the sealing ring 11. Sliding bearings 8 are provided inside the sleeve and in the mounting hole of the floating sleeve of the pump body 3, which together support the drive gear shaft 9 and the driven gear shaft 10. The sealing surface 7-5 of the floating side plate 7 is in contact with the gear end face, and a rubber seal 6 and a polytetrafluoroethylene seal are provided on the back. Seal 5, axial distribution groove 7-2 is aligned with the irregular polygon 3-1A of oil suction chamber 3-1; the main positioning plane 4-2 of drive shaft sleeve 4 is installed opposite to the driven positioning plane 12-1 of driven shaft sleeve 12, the main sector groove 4-1 and the driven sector groove 12-2 are interconnected and aligned with the axial distribution groove 7-2 of floating side plate 7; the axial suction oil baffle 7-1 in floating side plate 7 and the radial suction oil baffle 3-2 in pump body 3 form radial oil distribution groove 16, which is aligned with the gear disengagement area; drive shaft sleeve 4, driven shaft sleeve 12 and oil guide plane 3-3 of pump body 3 form oil guide chamber 17, which connects the oil suction chamber 3-1 in pump body 3 with the right arc groove 1-3 of front end cover 1.

[0022] like Figure 3 As shown, the front end cover 1 is provided with an upper transition hole 1-1, a left circular arc groove 1-2, a right circular arc groove 1-3, a lower transition hole 1-4, and an end cover oil storage hole 1-5. The left circular arc groove 1-2 and the right circular arc groove 1-3 connect the upper transition hole 1-1 and the lower transition hole 1-4.

[0023] like Figures 4-7As shown, the pump body 3 is provided with an oil suction chamber 3-1, a radial oil suction baffle 3-2, an oil guide plane 3-3, an axial positioning surface 3-4, a sealing groove 3-5, an oil discharge chamber 3-6, a connecting groove 3-7, a pump body oil storage hole 3-8, a bearing mounting hole 3-9, and a pump chamber 3-10. The oil suction chamber 3-1 is parallel to the gear shaft axis, with a circular inlet and an irregular polygon 3-1A extending to the axial positioning surface 3-4. The irregular polygon 3-1A includes a horizontal line 3-1A-1, two axisymmetric distribution arc lines 3-1A-2, two axisymmetric distribution vertical lines 3-1A-3, and a distribution semicircle line 3-1A-4. The radius of the flow distribution arc 3-1A-2 is the same as the root circle radius of the gear teeth, intersecting the transverse line 3-1A-1; the vertical flow distribution line 3-1A-3 intersects the flow distribution arc 3-1A-2; the semicircular flow distribution line 3-1A-4 is tangent to the vertical flow distribution line 3-1A-3. The radial oil suction baffle 3-2 is arc-shaped, with a width equal to or greater than the gear tooth width, and is integral with the pump cavity 3-10, separated by rectangular cross-sections in the middle, forming an "eight" shape, symmetrical about the central plane. It has an upper arc-shaped surface 3-2-1 and a lower arc-shaped surface 3-2-2, wherein the radius of the upper arc-shaped surface 3-2-1 is greater than or equal to the tip circle radius of the gear teeth.

[0024] like Figure 8 , Figure 9As shown, the floating side plate 7 is provided with an axial oil suction baffle 7-1, an axial flow distribution groove 7-2, an oil suction unloading groove 7-3, an oil discharge unloading groove 7-4, and a sealing surface 7-5. The axial oil suction baffle 7-1 is provided with two axisymmetric lower flow distribution arc surfaces 7-1-1, a lower flow distribution transverse surface 7-1-2, a transverse surface 7-1-3, two axisymmetric lower arc surfaces 7-1-4, an outer positioning surface 7-1-5, and two axisymmetric mounting arc surfaces 7-1-6. The lower distribution arc surface 7-1-1 has a radius equal to the base circle radius of the gear and is aligned with the distribution arc line 3-1A-2. The lower distribution transverse surface 7-1-2 is located outside the oil suction unloading groove 7-3. The lower arc surface 7-1-4 has a radius equal to and aligned with the lower arc surface 3-2-2 of the radial oil suction baffle 3-2. The outer positioning surface 7-1-5 is flush with the sealing surface 7-5 or is in the form of a groove at a distance from the sealing surface 7-5. The mounting arc surface 7-1-6 has the same radius as the distribution semicircle line 3-1A-4 and is installed concentrically with it. The axial distribution groove 7-2 is composed of the upper distribution transverse surface 7-2-1, two axially symmetrical upper distribution arc surfaces 7-2-2, two axially symmetrical upper distribution vertical surfaces 7-2-3, and the two lower distribution arc surfaces 7-1-1 and lower distribution transverse surfaces 7-1-2 of the axial oil suction baffle 7-1. The upper distribution transverse surface 7-2-1 is located within the oil suction and unloading groove and is aligned with the distribution transverse line 3-1A-1; the upper distribution arc surface 7-2-2 has the same radius as the gear tooth root circle and is aligned with the distribution arc line 3-1A-2; the upper distribution vertical surface 7-2-3 is aligned with the distribution vertical line 3-1A-3. Both the axial oil suction baffle 7-1 and the axial distribution groove 7-2 are π-shaped. The sealing surface 7-5 is coated with a wear-resistant coating.

[0025] like Figure 10 , Figure 11 As shown, the drive shaft sleeve 4 is provided with a main sector groove 4-1, a main positioning plane 4-2, a main bearing mounting hole 4-3, and a main boss 4-4. The main sector groove 4-1 is connected to the axial distribution groove 7-2 and is provided with a main vertical surface 4-1-1, a main arc surface 4-1-2, and a main transverse surface 4-1-3. The main vertical surface 4-1-1 is aligned with the upper distribution vertical surface 7-2-3; the main arc surface 4-1-2 has the same radius as the tooth root circle and is aligned with the upper distribution arc surface 7-2-2; the main transverse surface 4-1-3 is aligned with the upper distribution transverse surface 7-2-1.

[0026] like Figure 12 , Figure 13As shown, the driven shaft sleeve 12 is provided with a positioning plane 12-1, a sector groove 12-2, a bearing mounting hole 12-3, and a boss 12-4. The sector groove 12-2 communicates with the axial distribution groove 7-2 and is provided with a transverse surface 12-2-1, an arc surface 12-2-2, and a vertical surface 12-2-3. The transverse surface 12-2-1 is aligned with the upper distribution transverse surface 7-2-1; the arc surface 12-2-2 has the same radius as the tooth root circle and is aligned with the upper distribution arc surface 7-2-2; the vertical surface 12-2-3 is aligned with the upper distribution vertical surface 7-2-3.

[0027] The working process of this invention is as follows: When the gear pump starts to rotate, the oil flows through the gear disengagement area and is simultaneously drawn in from the axial distribution groove 7-2 and the radial distribution groove 16. After being squeezed to form high-pressure oil, the oil is discharged through the discharge chamber 3-6. In this process, the design of the oil suction chamber 3-1 and the scanning mixing channel, which is from a circle to an irregular polygon 3-1A and is parallel to the axis of the driving gear shaft 9 and the driven gear shaft 10, can slow down the oil flow rate and increase the pressure; the radial oil suction baffle 3-2 of the pump body 3 and the axial oil suction baffle 7-1 of the floating side plate 7 can prevent the oil in the gear cavity from being thrown out under the action of centrifugal force; the axial distribution groove 7-2 can enhance the oil suction capacity of the gear root and further replenish the oil thrown out by centrifugal force at the gear root; the main sector groove 4-1 and the secondary sector groove 12-2 of the driving shaft sleeve 4 and the driven shaft sleeve 12 can increase the axial oil suction depth and reduce the local flow resistance; the driving shaft sleeve 4 and the driven shaft sleeve 12 can increase the axial oil suction depth and reduce the local flow resistance. Sleeve 12 indirectly compresses rubber seal 6 by extruding polytetrafluoroethylene seal 5, generating axial sealing force of high-pressure oil on the back of sealing floating side plate 7; the connecting groove 3-7 of pump body 3 connects pump body oil storage hole 3-8 with oil suction chamber 3-1, preventing the accumulation of leaking oil from sliding bearing 8 in bearing mounting hole 3-9 and the accumulation of heat generated by dynamic friction; left arc groove 1-2 and right arc groove 1-3 connect upper transition hole 1-1 and lower transition hole 1-4 of end cover 1, wherein oil guide chamber 17 connects right arc groove 1-3 with oil suction chamber 3-1, which can prevent the accumulation of leaking oil from sliding bearing 8 in drive shaft sleeve 4 and driven shaft sleeve 12 and the accumulation of heat generated by dynamic friction.

Claims

1. A high-efficiency oil-suction external gear pump, comprising: The pump body (3) comprises a front cover (1), a positioning pin (2), a pump body (3), a drive shaft sleeve (4), a polytetrafluoroethylene seal (5), a rubber seal (6), a floating side plate (7), a sliding bearing (8), a drive gear shaft (9), a driven gear shaft (10), a sealing ring (11), a driven shaft sleeve (12), a bolt (13), a lip seal (14), and a hole elastic retaining ring (15). The pump body (3) is characterized by having an oil suction chamber (3-1) and a radial oil suction baffle (3-2). The radial oil suction baffle (3-2) is arc-shaped. The width of the radial oil suction baffle (3-2) is equal to or greater than the gear tooth width. It is integral with the pump chamber (3-10), separated by rectangular sections in the middle, forming an "eight" shape, symmetrical about the central plane. It has an upper arc surface (3-2-1) and a lower arc surface (3-2-2), wherein the radius of the upper arc surface (3-2-1) is greater than or equal to the gear tooth tip circle radius. The floating side plate (7) is provided with an axial oil suction baffle (7-1), an axial flow distribution groove (7-2), an oil suction unloading groove (7-3), an oil discharge unloading groove (7-4), and a sealing surface (7-5); The drive shaft sleeve (4) is provided with a main sector groove (4-1), which is connected to the axial distribution groove (7-2); The driven shaft sleeve (12) is provided with a sector-shaped groove (12-2); The front cover (1) and the pump body (3) are positioned by a positioning pin (2), connected by bolts (13), and sealed at the end face by a sealing ring (11); sliding bearings (8) are provided in the bushing and the floating bushing mounting hole of the pump body (3) to jointly support the drive gear shaft (9) and the driven gear shaft (10); the sealing surface (7-5) of the floating side plate (7) is in contact with the end face of the gear, and a rubber seal (6) and a polytetrafluoroethylene seal (5) are provided on the back; the axial distribution groove (7-2) is aligned with the irregular polygon (3-1A) of the oil suction chamber (3-1); the main positioning plane (4-2) of the drive shaft bushing (4) is aligned with the driven shaft bushing (10). 2) The main fan groove (4-1) and the secondary fan groove (12-2) are connected to each other and aligned with the axial distribution groove (7-2) of the floating side plate (7); the axial oil suction plate (7-1) in the floating side plate (7) and the radial oil suction plate (3-2) in the pump body (3) form a radial oil distribution groove (16), and the radial oil distribution groove (16) is aligned with the gear disengagement area; the drive shaft sleeve (4), the driven shaft sleeve (12) and the oil guide plane (3-3) of the pump body (3) form an oil guide cavity (17), which connects the oil suction cavity (3-1) in the pump body (3) with the right arc groove (1-3) of the front end cover (1).

2. The high-efficiency oil-suction external gear pump according to claim 1, characterized in that: The pump body (3) is provided with an oil guide plane (3-3), an axial positioning surface (3-4), a sealing groove (3-5), an oil discharge chamber (3-6), a connecting groove (3-7), a pump body oil storage hole (3-8), a bearing mounting hole (3-9), and a pump chamber (3-10). The oil suction chamber (3-1) is parallel to the gear shaft axis, with a circular inlet and an irregular polygon (3-1A) at the axial positioning surface (3-4). The irregular polygon (3-1A) has a horizontal line (3-1A-1), two axisymmetric distribution arcs (3-1A-2), two axisymmetric distribution vertical lines (3-1A-3), and a distribution semicircle (3-1A-4). The radius of the distribution arc (3-1A-2) is the same as the root circle radius of the gear, and it intersects with the horizontal line (3-1A-1). The distribution vertical line (3-1A-3) intersects with the distribution arc (3-1A-2). The distribution semicircle (3-1A-4) is tangent to the distribution vertical line (3-1A-3).

3. The high-efficiency oil-suction external gear pump according to claim 1, characterized in that: The axial oil suction baffle (7-1) is provided with two axisymmetric lower distribution arc surfaces (7-1-1), a lower distribution transverse surface (7-1-2), a transverse surface (7-1-3), two axisymmetric lower arc surfaces (7-1-4), an outer positioning surface (7-1-5), and two axisymmetric mounting arc surfaces (7-1-6); wherein the radius of the lower distribution arc surface (7-1-1) is the base circle radius of the gear and is aligned with the distribution arc line (3-1A-2); the lower distribution... The transverse flow surface (7-1-2) is located outside the oil suction unloading groove (7-3); the radius of the lower arc surface (7-1-4) is equal to the radius of the lower arc surface (3-2-2) of the radial oil suction baffle (3-2), and is aligned with it; the outer positioning surface (7-1-5) is flush with the sealing surface (7-5) or is in the form of a groove at a distance from the sealing surface (7-5); the installation arc surface (7-1-6) has the same radius as the distribution semicircle line (3-1A-4), and is installed concentrically with it; The axial distribution groove (7-2) is composed of an upper distribution transverse surface (7-2-1), two axisymmetric upper distribution arc surfaces (7-2-2), two axisymmetric upper distribution vertical surfaces (7-2-3), and two lower distribution arc surfaces (7-1-1) and lower distribution transverse surface (7-1-2) of the axial oil suction baffle plate (7-1). The upper distribution transverse surface (7-2-1) is inside the oil suction unloading groove and is aligned with the distribution transverse line (3-1A-1). The upper distribution arc surface (7-2-2) has the same radius as the root circle of the gear teeth and is aligned with the distribution arc line (3-1A-2). The upper distribution vertical plane (7-2-3) is aligned with the distribution vertical line (3-1A-3); The axial oil suction baffle (7-1) and the axial distribution groove (7-2) are both in the shape of "π". The sealing surface (7-5) is coated with a wear-resistant coating.

4. The high-efficiency oil-suction external gear pump according to claim 1, characterized in that: The drive shaft sleeve (4) is provided with a main positioning plane (4-2), a main bearing mounting hole (4-3), and a main boss (4-4). The main sector groove (4-1) is provided with a main vertical surface (4-1-1), a main arc surface (4-1-2), and a main transverse surface (4-1-3); the main vertical surface (4-1-1) is aligned with the upper distribution vertical surface (7-2-3); the main arc surface (4-1-2) has the same radius as the tooth root circle and is aligned with the upper distribution arc surface (7-2-2); the main transverse surface (4-1-3) is aligned with the upper distribution transverse surface (7-2-1).

5. The high-efficiency oil-suction external gear pump according to claim 1, characterized in that: The driven shaft sleeve (12) is provided with a positioning plane (12-1), a bearing mounting hole (12-3), and a boss (12-4). The fan-shaped groove (12-2) is connected to the axial distribution groove (7-2), and is provided with a transverse surface (12-2-1), a circular arc surface (12-2-2), and a vertical surface (12-2-3). The transverse surface (12-2-1) is aligned with the upper distribution transverse surface (7-2-1); the circular arc surface (12-2-2) has the same radius as the tooth root circle and is aligned with the upper distribution circular arc surface (7-2-2); the vertical surface (12-2-3) is aligned with the upper distribution vertical surface (7-2-3).

6. The high-efficiency oil-suction external gear pump according to claim 1, characterized in that: The front end cover (1) is provided with an upper transition hole (1-1), a left circular arc groove (1-2), a right circular arc groove (1-3), a lower transition hole (1-4), and an end cover oil storage hole (1-5), wherein the left circular arc groove (1-2) and the right circular arc groove (1-3) connect the upper transition hole (1-1) and the lower transition hole (1-4).

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