Water-based gear pump device and hydraulic system

Abstract

The application belongs to the technical field of water-based gear pump, and discloses a water-based gear pump device and a hydraulic system, which comprise a motor, a gear pump, a motor shaft seal, a gear pump shaft seal and a limiting heat dissipation module. One end of the gear pump is provided with a motor pump shaft connecting cavity and is provided with a gear pump shaft. The bottom surface of the motor pump shaft connecting cavity is provided with a gear pump shaft seal mounting hole. The limiting heat dissipation module is arranged in the motor pump shaft connecting cavity to dissipate heat of the motor pump shaft connecting cavity. One end of the motor is arranged in the motor pump shaft connecting cavity, and the end of the motor in the motor pump shaft connecting cavity is provided with a motor shaft. The motor shaft seal is embedded in the end of the motor in the motor pump shaft connecting cavity and is sleeved on the motor shaft. One end of the gear pump shaft penetrates through the gear pump shaft seal and extends into the limiting heat dissipation module to be connected with the motor shaft. The gear pump shaft seal is arranged in the gear pump shaft seal mounting hole, and opposite ends of the gear pump shaft seal are respectively provided with a second main lip and a second secondary lip. The application improves the sealing performance and durability.

Description

Technical Field

[0001] This invention belongs to the technical field of water-based gear pumps, and more specifically, relates to a water-based gear pump device and hydraulic system. Background Technology

[0002] A gear pump is a positive displacement pump that works by periodically changing the working volume when gears mesh to transport liquid. When the gears disengage, the gear teeth move out of the space between them, increasing the sealed volume of the suction chamber and creating a partial vacuum. Liquid, under atmospheric pressure, flows through the pipes and into the space between the teeth. As the gears rotate, the liquid drawn into the space between the teeth is carried to the other side and into the discharge chamber. At this point, the gears re-engage, causing the sealed volume of the discharge chamber to gradually decrease, forcing out some of the liquid between the gears, thus completing the pump's pressure process.

[0003] The drive gear shaft of a gear pump extends outwards and connects to the motor shaft, thus transmitting power. Currently, the seals on the extended portion of the main shaft of water-based gear pumps typically employ mechanical seals or magnetic coupling-type static seals. However, both of these sealing methods require a certain space and are not conducive to the lightweight design of gear pumps. Although using a skeleton-type water seal offers significant advantages in lightweight design, the sealing performance and durability issues of the water seal become increasingly prominent, requiring further improvement. Summary of the Invention

[0004] In view of the above-mentioned defects or improvement needs of the prior art, the present invention provides a water-based gear pump device and hydraulic system, which aims to solve the problems of poor sealing performance and durability of existing water-based gear pumps.

[0005] To achieve the above objectives, according to one aspect of the present invention, a water-based gear pump device is provided. The water-based gear pump device includes a motor, a gear pump, a motor shaft seal, a gear pump shaft seal, and a limiting and heat dissipation module. One end of the gear pump has a motor-pump shaft connection cavity and a gear pump shaft is disposed thereon. The bottom surface of the motor-pump shaft connection cavity has a gear pump shaft seal mounting hole. The limiting and heat dissipation module is disposed within the motor-pump shaft connection cavity to dissipate heat from the motor-pump shaft connection cavity. One end of the motor is disposed within the motor-pump shaft connection cavity, and the motor is located... A motor shaft is provided at one end of the motor-pump shaft connecting cavity; the motor shaft seal is embedded in the end of the motor located in the motor-pump shaft connecting cavity and is sleeved on the motor shaft, and the motor shaft seal is in contact with the motor shaft; one end of the gear pump shaft passes through the gear pump shaft seal and extends into the limiting heat dissipation module to connect with the motor shaft; the gear pump shaft seal is provided in the gear pump shaft seal mounting hole, and its opposite ends are respectively provided with a second main lip and a second secondary lip, both of which are in contact with the gear pump shaft.

[0006] Furthermore, the gear pump shaft seal includes a gear pump shaft seal base, which has a through second hole. The second main lip and the second secondary lip are respectively disposed at opposite ends of the second through hole, which is used for the gear pump shaft to pass through. One end of the gear pump shaft seal base has a second main lip pressure chamber, and the other end has a secondary lip pressure chamber. Both the second main lip pressure chamber and the secondary lip pressure chamber are located outside the second through hole. The motor pump shaft connecting cavity is filled with hydraulic lubricating oil.

[0007] Furthermore, the gear pump shaft seal also includes a second fastening spring, which is disposed on the cavity wall of the second main lip pressure chamber adjacent to the second through hole.

[0008] Furthermore, the gear pump shaft seal also includes a third sealing ring, which is embedded on the outer circumferential surface of the gear pump shaft seal base and fits against the wall of the gear pump shaft seal mounting hole.

[0009] Furthermore, the motor shaft seal includes a motor shaft seal base and a first fastening spring. The motor shaft seal base has a through first hole, through which it is sleeved on the motor shaft. A first main lip and a first secondary lip are respectively provided at both ends of the first through hole, and both the first main lip and the first secondary lip are in contact with the motor shaft. A first main lip pressure chamber is provided at one end of the motor shaft seal base, and an annular first fastening spring groove is provided on the cavity wall of the first main lip pressure chamber adjacent to the first through hole. The first fastening spring is disposed in the first fastening spring groove.

[0010] Furthermore, a first sealing ring groove is formed on the outer periphery of the end of the motor shaft seal base away from the first main lip pressure chamber, and a first sealing ring is provided in the first sealing ring groove; the motor shaft seal base and the gear pump shaft seal base are made of PTFE material.

[0011] Furthermore, the motor includes a motor base and a stop connected to one end of the motor base. The stop is disposed in the motor pump shaft connecting cavity, and one end of the stop has a motor shaft seal mounting groove. The bottom surface of the motor shaft seal mounting groove has a first groove. One end of the motor shaft is disposed in the first groove, and the other end protrudes from the motor shaft seal mounting groove and is connected to the gear pump shaft. The motor shaft seal is disposed in the motor shaft seal mounting groove.

[0012] Furthermore, the gear pump includes a gear pump base and a protrusion connected to one end of the gear pump base. One end of the gear pump shaft is connected to the gear pump base, and the other end is located inside the protrusion. The motor pump shaft connecting cavity is opened at the end of the protrusion away from the gear pump base. A first oil inlet / outlet port and a second oil inlet / outlet port are respectively opened on the opposite sides of the protrusion. Both the first oil inlet / outlet port and the second oil inlet / outlet port are connected to the motor pump shaft connecting cavity. The first oil inlet / outlet port and the second oil inlet / outlet port are threadedly connected to the first plug and the second plug, respectively.

[0013] Furthermore, the two opposite ends of the limiting heat dissipation module are respectively fitted to the motor shaft seal and the gear pump shaft seal; the limiting heat dissipation module is annular, including an inner peripheral wall and an outer peripheral wall, the inner peripheral wall is provided with heat dissipation fins, the heat dissipation fins form a through hole, the through hole is used to accommodate part of the motor shaft and the gear pump shaft; a first annular groove is formed on the outer peripheral wall, and the limiting heat dissipation module is also provided with an oil passage hole, the oil passage hole connecting the through hole and the first annular groove.

[0014] The present invention also provides a hydraulic system comprising the water-based gear pump device as described above.

[0015] In summary, compared with the prior art, the water-based gear pump device and hydraulic system provided by the present invention have the following advantages: 1. The motor shaft seal is fitted with the motor shaft to form a seal. Both the second main lip and the second secondary lip are fitted with the gear pump shaft to form a seal. The motor shaft seal and the gear pump shaft seal simultaneously provide a sealing function. The gear pump shaft seal uses a series connection of the second main lip and the second secondary lip. The second main lip bears the main water pressure, while the second secondary lip acts as a redundant barrier, maintaining a seal even if a single layer fails. The motor shaft seal provides the final sealing barrier for the motor. Simultaneously, the limiting heat dissipation block absorbs the heat generated during the rotation of the gear pump shaft and conducts the heat away through its own wall surface, preventing excessive pressure buildup within the motor pump shaft connection cavity due to temperature rise. Therefore, this invention improves the sealing performance and durability of the water-based gear pump device.

[0016] 2. After the failure of the second main lip and second auxiliary lip of the gear pump shaft seal, the rate at which water enters the motor pump shaft connection cavity can still be suppressed, while simultaneously achieving resealing of the second auxiliary lip. Specifically, when the second main lip of the gear pump shaft seal fails, the second auxiliary lip of the gear pump shaft seal assumes the main water pressure sealing function. Unlike the second main lip, the second auxiliary lip faces a working condition where one side is water medium and the other side is oil medium. Therefore, compared with the working environment of the second main lip where one side is water medium and the other side is air, the working environment of the second auxiliary lip is better, and its service life is longer. When leakage begins to occur in the second auxiliary lip, water enters the motor pump shaft connection cavity. Due to the incompressibility of oil, the pressure in the motor pump shaft connection cavity will rapidly rise to the water pressure pressure. This pressure will act on the pressure chamber of the auxiliary lip, and ultimately on the second auxiliary lip, providing sealing force and further achieving a seal. In this state, the rate at which water enters the motor pump shaft connection cavity is suppressed, thereby improving the sealing performance and durability of the water-based gear pump.

[0017] 3. The second fastening spring of the gear pump shaft seal can provide the required initial sealing force. When the water pressure increases further, the water pressure in the second main lip pressure chamber will act on the second main lip to further provide sealing force, thereby achieving a reliable seal under 1MPa pressure.

[0018] 4. When the gear pump unit is working, the motor shaft drives the gear pump shaft to rotate. The second main lip of the gear pump shaft seal will face water pressure from inside the gear pump. Since the viscosity of water is much less than that of oil, the lubrication performance of water is poor. However, the gear pump shaft seal base is made of PTFE material, which has a self-lubricating effect and can provide good lubrication conditions for the second main lip.

[0019] 5. The motor shaft seal adopts a main and auxiliary lip configuration. The first main lip bears the oil pressure, and the first auxiliary lip blocks impurities inside the motor, preventing impurities from wearing down the first main lip and causing it to fail.

[0020] 6. The first plug and the second plug are installed in the first oil inlet and the second oil inlet and the second oil inlet respectively by threaded connection to prevent external water from entering the motor pump shaft connection cavity; the two ends of the limiting heat dissipation module are tightly fitted with the motor shaft seal and the gear pump shaft seal respectively, realizing the axial limiting of the shaft seal. Attached Figure Description

[0021] Figure 1 This is a cross-sectional view of a water-based gear pump device provided in an embodiment of the present invention; Figure 2 (a) and (b) in the text are respectively Figure 1 A three-dimensional structural diagram of the first plug of the water-based gear pump device and a cross-sectional view of the plug base of the first plug; Figure 3 yes Figure 1A cross-sectional view of the gear pump in the water-based gear pump unit; Figure 4 (a) and (b) in the text are respectively Figure 1 A three-dimensional structural diagram of the motor shaft seal of the water-based gear pump device and a cross-sectional view of the motor shaft seal base; Figure 5 (a) and (b) in the text are respectively Figure 1 A three-dimensional structural diagram of the first plug of the water-based gear pump device and a cross-sectional view of the plug base of the first plug; Figure 6 yes Figure 1 A three-dimensional schematic diagram of the limiting heat dissipation module in the middle; Figure 7 (a) and (b) in the text are respectively Figure 1 A three-dimensional schematic diagram of the gear pump shaft seal of the water-based gear pump device and a cross-sectional view of the gear pump shaft seal base.

[0022] In all the accompanying drawings, the same reference numerals are used to denote the same elements or structures, wherein: 1-motor, 11-motor base, 12-stop, 13-first sealing groove, 14-motor shaft seal mounting groove, 15-motor shaft, 2-gear pump, 21-gear pump base, 22-motor pump shaft connecting cavity, 23-gear pump shaft, 24-gear pump shaft seal mounting hole, 25-first oil inlet / outlet port, 26-second oil inlet / outlet port, 3-motor shaft seal, 31-motor shaft seal base, 311-first main lip, 312-first secondary lip, 313-first main lip pressure chamber, 314-first fastening spring groove, 315-first sealing ring groove, 32-first sealing ring, 3 3-First fastening spring, 4-First plug, 41-Plug base, 411-Second sealing groove, 412-Relief groove, 413-External thread, 414-Internal hexagonal hole, 42-Second sealing ring, 5-Limiting heat dissipation module, 51-Outer peripheral wall, 52-Inner peripheral wall, 53-Heat dissipation fins, 54-Oil passage hole, 55-First annular groove, 6-Second plug, 7-Gear pump shaft seal, 71-Gear pump shaft seal base, 711-Second main lip, 712-Second secondary lip, 713-Second fastening spring groove, 714-Secondary lip pressure chamber, 715-Second main lip pressure chamber, 716-Second sealing ring groove, 72-Third sealing ring, 73-Second fastening spring. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0024] Please see Figure 1 This invention provides a water-based gear pump device that, within a limited space (where mechanical seals and magnetic coupling seals are not applicable), improves the sealing performance and durability of the water-based gear pump's main shaft, achieving a lightweight design for the water-based gear pump.

[0025] The device includes a motor 1, a motor shaft seal 3, a gear pump 2, a first plug 4, a second plug 6, a gear pump shaft seal 7, and a limiting and heat dissipation module 5. The motor 1 includes a motor shaft 15, the gear pump includes a gear pump shaft, and the gear pump 2 includes a gear pump shaft 23. One end of the gear pump has a motor pump shaft connecting cavity 22, and the bottom surface of the motor pump shaft connecting cavity 22 has a gear pump shaft seal mounting hole 24. The limiting and heat dissipation module 5 is disposed in the motor pump shaft connecting cavity 22 and is simultaneously sleeved on the motor shaft 15 and the gear pump shaft. One end of the motor has a motor shaft seal mounting groove 14, and the motor shaft seal is installed in the motor shaft seal mounting groove 14. The motor shaft seal is sleeved on the motor shaft, and its opposite ends respectively form a first main lip 311 and a first secondary lip 312, which are both attached to the motor shaft to form a seal. The gear pump shaft seal is disposed within the gear pump shaft seal mounting hole 24 and is sleeved on the gear pump shaft. A second main lip 711 and a second secondary lip 712 are respectively formed at opposite ends of the gear pump shaft seal, and the second main lip 711 and the second secondary lip 712 fit against the gear pump shaft to form a seal. The gear pump is connected to the motor shaft, and the motor shaft seal is located within the motor pump shaft connecting cavity 22.

[0026] The motor-pump shaft connecting cavity 22 is filled with hydraulic lubricating oil to improve the frictional environment of the motor shaft seal and the gear pump shaft seal. Simultaneously, the hydraulic lubricating oil filling the motor-pump shaft connecting cavity 22 allows for the suppression of water ingress into the motor-pump shaft connecting cavity 22 when both the main and auxiliary lips of the gear pump fail, thereby achieving resealing of the auxiliary lip. The limiting and heat dissipation module 5 absorbs the heat generated by the hydraulic lubricating oil during gear pump shaft rotation and conducts the heat away through its wall surface, suppressing the pressure rise caused by temperature within the motor-pump shaft connecting cavity 22, while also providing axial limiting for the motor shaft seal and the gear pump shaft seal.

[0027] The first plug 4 and the second plug 6 are respectively threaded to one end of the gear pump; both the first plug 4 and the second plug 6 are M8×1.5 plugs.

[0028] Please see Figure 2The motor includes a motor base 11, a motor shaft connected to the motor base 11, and a stop 12 connected to one end of the motor base 11. One end of the stop 12 has a motor shaft seal mounting groove 14. The bottom surface of the motor shaft seal mounting groove 14 has a first groove. One end of the motor shaft is disposed in the first groove, and the other end protrudes from the motor shaft seal mounting groove and has a first receiving groove. A first sealing groove 13 is formed on the outer periphery of the stop 12.

[0029] Please see Figure 3 The gear pump includes a gear pump base 21, a gear pump shaft, and a protrusion connected to one end of the gear pump base 21. One end of the gear pump shaft is connected to the gear pump base 21, and the other end is located inside the protrusion.

[0030] The protrusion away from the gear pump base 21 has a motor pump shaft connecting cavity 22. The bottom surface of the motor pump shaft connecting cavity 22 has a gear pump shaft seal mounting hole 24. One end of the gear pump shaft passes through the gear pump shaft seal mounting hole 24 and extends into the motor pump shaft connecting cavity 22. The end of the gear pump shaft located in the motor pump shaft connecting cavity 22 is received in the first receiving hole, thus connecting the gear pump shaft to the motor shaft. A first oil inlet / outlet port 25 and a second oil inlet / outlet port 26 are respectively provided on opposite sides of the protrusion. Both the first oil inlet / outlet port 25 and the second oil inlet / outlet port 26 are connected to the motor pump shaft connecting cavity 22. Both the first oil inlet / outlet port 25 and the second oil inlet / outlet port 26 are provided with internal threads, forming threaded connections with the first plug 4 and the second plug 6 respectively through these internal threads.

[0031] Please see Figure 4 The motor shaft seal is disposed within the motor shaft seal mounting groove 14 and is in contact with the limiting heat dissipation module 5. The motor shaft seal includes a motor shaft seal base 31, a first sealing ring 32, and a first fastening spring 33. The first sealing ring 32 is partially disposed within the first sealing groove 13, located between the motor shaft seal and the groove wall of the motor shaft seal mounting groove 14. The first fastening spring 33 is disposed within the motor shaft seal base 31.

[0032] The motor shaft seal base 31 has a through hole, through which it is fitted onto the motor shaft. A first main lip 311 and a first secondary lip 312 are respectively provided at both ends of the first through hole. A first main lip pressure chamber 313 is provided at one end of the motor shaft seal base 31, and an annular first fastening spring groove 314 is provided on the cavity wall of the first main lip pressure chamber 313 adjacent to the first through hole. The first through hole is located within the first main lip pressure chamber 313, and their central axes coincide. The first fastening spring is disposed within the first fastening spring groove 314. A first sealing ring groove 315 is provided on the outer periphery of the other end of the motor shaft seal base 31, and the first sealing ring groove 315 is used to accommodate a portion of the first sealing ring. In this embodiment, the central axis of the first through hole coincides with the central axis of the motor shaft seal base 31; the first main lip and the first main lip pressure chamber 313 are located at the same end of the motor shaft seal; the first main lip and the first secondary lip 312 are tightly fitted with the motor shaft to form a seal; when the motor shaft seal is installed, the orientation of the first main lip pressure chamber 313 is consistent with the direction in which the motor shaft extends; the motor shaft seal adopts a main and secondary lip configuration, the first main lip bears oil pressure, and the first secondary lip blocks impurities inside the motor, preventing impurities from wearing down the first main lip and causing failure.

[0033] Please see Figure 5 The first plug 4 includes a plug base 41 and a second sealing ring 42 disposed on the plug base 41. The plug base 41 is stepped, and a second sealing groove 411 is formed on the stepped surface. One end of the first plug 4 with the second sealing groove 411 has an internal hexagonal hole 414, and the outer peripheral surface of the other end has an external thread 413. The external thread 413 engages with the internal thread, so that the first plug 4 is threadedly connected to the first oil inlet / outlet port 25. A relief groove 412 is formed between the end of the first plug 4 with the external thread 413 and the stepped surface. The second sealing ring 42 is close to the end face of the first oil inlet / outlet port 25 to form an end face seal. The first oil inlet / outlet port 25 and the second oil inlet / outlet port 26 are inlets and outlets for periodically changing lubricating oil. The structure of the first plug 4 is the same as that of the second plug 6.

[0034] Please see Figure 6The limiting heat dissipation module 5 is disposed within the motor-pump shaft connecting cavity 22, with its opposite sides contacting the motor shaft seal and the gear pump shaft seal, respectively. The limiting heat dissipation module 5 is annular, comprising an inner peripheral wall 52 and an outer peripheral wall 51. The inner peripheral wall 52 is provided with heat dissipation fins 53 forming a through hole, which accommodates a portion of the motor shaft and the gear pump shaft. The outer peripheral wall 51 has a first annular groove 55. The limiting heat dissipation module 5 also has an oil passage hole 54, which connects the through hole and the first annular groove 55. The heat dissipation fins 53 effectively absorb the heat generated by the hydraulic lubricating oil during gear pump shaft rotation, while the outer peripheral wall 51 is tightly fitted to the inner wall of the motor-pump shaft connecting cavity 22, conducting the heat away and thus suppressing the pressure rise caused by temperature within the motor-pump shaft connecting cavity 22. Simultaneously, the limiting heat dissipation module 5 provides axial limiting for the motor shaft seal and the gear pump shaft seal.

[0035] Please see Figure 7 The gear pump shaft seal includes a gear pump shaft seal base 71, a third sealing ring 72, and a second fastening spring 73. The gear pump shaft seal base 71 has a second through hole that penetrates the gear pump shaft seal. A second main lip 711 and a second secondary lip 712 are formed at opposite ends of the second through hole, respectively, and the second main lip and the second secondary lip 712 are tightly fitted onto the gear pump shaft to form a seal. A second main lip pressure chamber 715 is formed at one end of the gear pump shaft seal base 71, located outside the second through hole. A second fastening spring groove 713 is formed on the cavity wall of the second main lip pressure chamber 715 adjacent to the second through hole. The second main lip and the second main lip pressure chamber 715 are located at the same end of the gear pump shaft seal base 71, and a secondary lip pressure chamber 714 is formed at the other end of the gear pump shaft seal base 71, located outside the second through hole. A second sealing ring groove 716 is formed on the outer periphery of the gear pump shaft seal base 71, and a third sealing ring 72 is disposed in the second sealing ring groove 716. In this embodiment, the first sealing ring, the second sealing ring, and the third sealing ring 72 are all O-rings.

[0036] When installing the gear pump shaft seal, the orientation of the second main lip pressure chamber 715 is opposite to the direction in which the gear pump shaft extends. The gear pump shaft seal adopts a series connection of main and auxiliary lips. The main lip bears the main water pressure, and the auxiliary lip acts as a redundant barrier, maintaining a seal even if a single layer fails.

[0037] The motor shaft seal base 31 and the gear pump shaft seal base 71 are made of PTFE material, and the first and second fastening springs are helical springs or V-shaped springs.

[0038] During installation, the gear pump shaft is directly connected to the motor shaft by inserting it into the motor shaft. The stop is inserted into the motor pump shaft connection cavity 22, and the first sealing ring on the first sealing groove 13 forms a radial seal with the inner wall of the motor pump shaft connection cavity 22, preventing external water from entering the motor pump shaft connection cavity 22. The motor shaft seal is installed in the motor shaft seal mounting groove 14, and the gear pump shaft seal is installed in the gear pump shaft seal mounting hole 24. During shaft seal installation, the orientation of the first main lip pressure chamber 313 of the motor shaft seal is consistent with the direction of the motor shaft extension; the orientation of the second main lip pressure chamber 715 of the gear pump shaft seal is opposite to the direction of the gear pump shaft extension. The limiting heat dissipation module 5 is installed between the motor shaft seal and the gear pump shaft seal, with its two end faces tightly fitted to the motor shaft seal and the gear pump shaft seal respectively, achieving axial limiting of the shaft seal. Furthermore, the outer peripheral wall 51 of the limiting heat dissipation module 5 is fitted to the inner wall of the motor pump shaft connection cavity 22, achieving efficient heat conduction and thus suppressing the pressure rise caused by temperature within the motor pump shaft connection cavity 22. The first plug 4 and the second plug 6 are installed in the first oil inlet / outlet 25 and the second oil inlet / outlet 26 respectively through threaded connection to prevent external water from entering the motor pump shaft connecting cavity 22.

[0039] When the gear pump unit is operating, the motor shaft drives the gear pump shaft to rotate. The second main lip of the gear pump shaft seal faces water pressure from inside the gear pump. Since the viscosity of water is much lower than that of oil, water has poor lubrication performance. However, the gear pump shaft seal base 71, made of PTFE material, has a self-lubricating effect, providing excellent lubrication for the second main lip. The second retaining spring on the second main lip provides the necessary initial sealing force. As the water pressure increases further, the water pressure in the pressure chamber 715 of the second main lip acts on the second main lip, further providing sealing force, thus achieving a reliable seal at 1 MPa pressure. When the second main lip of the gear pump shaft seal fails, the second auxiliary lip 712 of the gear pump shaft seal assumes the main water pressure sealing function. Unlike the second main lip, the second auxiliary lip 712 faces a working condition where one side is water and the other side is oil. Therefore, compared to the working environment of the second main lip, where one side is water and the other side is air, the working environment of the second auxiliary lip 712 is better, and its service life is longer. When leakage begins in the second auxiliary lip 712, water enters the motor-pump shaft connection cavity 22. Due to the incompressibility of oil, the pressure inside the motor-pump shaft connection cavity 22 rapidly increases to the water pressure. This pressure acts on the auxiliary lip pressure cavity 714, and ultimately on the second auxiliary lip 712, providing sealing force and further achieving a seal. In this state, the rate at which water enters the motor-pump shaft connection cavity 22 is suppressed, thereby improving the sealing performance and durability of the water-based gear pump.

[0040] The present invention also provides a hydraulic system comprising the water-based gear pump device as described above.

[0041] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A water-based gear pump device, characterized in that: The water-based gear pump device includes a motor (1), a gear pump (2), a motor shaft seal (3), a gear pump shaft seal (7), and a limiting heat dissipation module (5). One end of the gear pump (2) has a motor pump shaft connecting cavity (22) and a gear pump shaft (23). The bottom surface of the motor pump shaft connecting cavity (22) has a gear pump shaft seal mounting hole (24). The limiting heat dissipation module (5) is disposed in the motor pump shaft connecting cavity (22) to dissipate heat from the motor pump shaft connecting cavity (22). One end of the motor (1) is disposed in the motor pump shaft connecting cavity (22), and the end of the motor (1) located in the motor pump shaft connecting cavity (22) is provided with a motor shaft (13). 5); The motor shaft seal (3) is embedded in one end of the motor (1) located in the motor pump shaft connecting cavity (22) and sleeved on the motor shaft (15). The motor shaft seal (3) is in contact with the motor shaft (15); one end of the gear pump shaft (23) passes through the gear pump shaft seal (7) and extends into the limiting heat dissipation module (5) to connect with the motor shaft (15); the gear pump shaft seal (7) is set in the gear pump shaft seal mounting hole (24), and its opposite ends are respectively provided with a second main lip (711) and a second secondary lip (712). The second main lip (711) and the second secondary lip (712) are both in contact with the gear pump shaft (23).

2. The water-based gear pump device as described in claim 1, characterized in that: The gear pump shaft seal (7) includes a gear pump shaft seal base (71), which has a through second through hole. The second main lip (711) and the second secondary lip (712) are respectively located at opposite ends of the second through hole. The second through hole is used for the gear pump shaft (23) to pass through. One end of the gear pump shaft seal base (71) has a second main lip pressure chamber (715), and the other end has a secondary lip pressure chamber (714). The second main lip pressure chamber (715) and the secondary lip pressure chamber (714) are both located outside the second through hole. The motor pump shaft connecting cavity (22) is filled with hydraulic lubricating oil.

3. The water-based gear pump device as described in claim 2, characterized in that: The gear pump shaft seal (7) also includes a second fastening spring (73), which is disposed on the cavity wall of the second main lip pressure chamber (715) adjacent to the second through hole.

4. The water-based gear pump device as described in claim 3, characterized in that: The gear pump shaft seal (7) also includes a third sealing ring (72), which is embedded on the outer circumferential surface of the gear pump shaft seal base (71) and fits against the hole wall of the gear pump shaft seal mounting hole (24).

5. The water-based gear pump device according to any one of claims 1-4, characterized in that: The motor shaft seal (3) includes a motor shaft seal base (31) and a first fastening spring (33). The motor shaft seal base (31) has a through hole, which is sleeved on the motor shaft (15) through the through hole. A first main lip (311) and a first secondary lip (312) are respectively provided at both ends of the first through hole. The first main lip (311) and the first secondary lip (312) are both in contact with the motor shaft (15). A first main lip pressure cavity (313) is provided at one end of the motor shaft seal base (31). An annular first fastening spring groove (314) is provided on the cavity wall of the first main lip pressure cavity (313) adjacent to the first through hole. The first fastening spring (33) is disposed in the first fastening spring groove (314).

6. The water-based gear pump device as described in claim 5, characterized in that: The motor shaft seal base (31) has a first sealing ring groove (315) on the outer periphery of the end away from the first main lip pressure chamber (313), and a first sealing ring (32) is provided in the first sealing ring groove (315); the motor shaft seal base (31) and the gear pump shaft seal base (71) are made of PTFE material.

7. The water-based gear pump device as described in claim 5, characterized in that: The motor (1) includes a motor base (11) and a stop (12) connected to one end of the motor base (11). The stop (12) is located in the motor pump shaft connecting cavity (22). One end of the stop is provided with a motor shaft seal mounting groove (14). The bottom surface of the motor shaft seal mounting groove (14) is provided with a first groove. One end of the motor shaft (15) is located in the first groove, and the other end protrudes from the motor shaft seal mounting groove (14) and is connected to the gear pump shaft (23). The motor shaft seal (3) is located in the motor shaft seal mounting groove (14).

8. The water-based gear pump device as described in claim 7, characterized in that: The gear pump (2) includes a gear pump base (21) and a protrusion connected to one end of the gear pump base (21). One end of the gear pump shaft (23) is connected to the gear pump base (21), and the other end is located inside the protrusion. The motor pump shaft connecting cavity (22) is opened at the end of the protrusion away from the gear pump base (21). A first oil inlet / outlet port (25) and a second oil inlet / outlet port (26) are respectively opened on the opposite sides of the protrusion. The first oil inlet / outlet port (25) and the second oil inlet / outlet port (26) are both connected to the motor pump shaft connecting cavity (22), and the first oil inlet / outlet port (25) and the second oil inlet / outlet port (26) are respectively threaded to the first plug (4) and the second plug (6).

9. The water-based gear pump device according to any one of claims 1-4, characterized in that: The two opposite ends of the limiting heat dissipation module (5) are respectively attached to the motor shaft seal (3) and the gear pump shaft seal (7); the limiting heat dissipation module (5) is annular, including an inner peripheral wall (52) and an outer peripheral wall (51). The inner peripheral wall (52) is provided with heat dissipation fins (53), and the heat dissipation fins (53) form a through hole. The through hole is used to accommodate part of the motor shaft (15) and the gear pump shaft (23); the outer peripheral wall (51) is provided with a first annular groove (55), and the limiting heat dissipation module (5) is also provided with an oil passage hole (54). The oil passage hole (54) connects the through hole and the first annular groove (55).

10. A hydraulic system, characterized in that: The hydraulic system includes the water-based gear pump device according to any one of claims 1-9.

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