An external gear oil pump of a shaftless plane driven gear

Abstract

The utility model relates to a kind of external engagement gear oil pump of shaftless plane driven gear in the field of micro gear pump, including pump body, pump cover, driving gear and passive gear, the driving gear and passive gear are engaged with each other and are housed in the pump cavity surrounded by the pump body and pump cover, the passive gear is the flat disc structure of no central driven gear shaft or shaft hole, its two end faces are plane, and directly slide fit with the plane of the inner side of the pump body and the plane of the inner side of the pump cover respectively.The utility model passive gear uses the flat disc structure of no central shaft or shaft hole, saves the traditional driven gear shaft, bearing or bushing etc. parts, while reducing the machining requirement of shaft hole in pump body and pump cover, not only simplify the overall structure, also significantly reduce material and manufacturing cost, while also make assembly process more simple, fast, improve production efficiency and maintenance convenience.

Description

Technical Field

[0001] This utility model relates to the field of micro gear pump technology, and in particular to an external meshing gear oil pump without a shaft and a planar driven gear. Background Technology

[0002] Gear pumps, as a common fluid transport device, are widely used in various hydraulic and lubrication systems. Their basic working principle involves a pair of meshing gears (one driving gear and one driven gear) rotating within the pump chamber, creating a volume change to draw in and discharge fluid.

[0003] In existing miniature gear oil pump designs, the driven gear typically employs a structure with a central shaft or shaft hole. This driven gear shaft requires dedicated bearings or bushings for support and is installed in corresponding shaft holes machined into the pump body and pump cover to achieve rotation. This traditional structure has the following main drawbacks: 1. The increase in parts such as the driven gear shaft, bearings, or bushings leads to an increase in the overall number of pump parts, making the structure more complex. Simultaneously, the pump body and pump cover require high-precision shaft holes, demanding high-precision manufacturing processes and increasing material and manufacturing costs. Furthermore, during assembly, the driven gear shaft needs to be precisely aligned and installed into the shaft holes of the pump body and pump cover, resulting in numerous assembly steps and low efficiency. 2. In miniature pump applications, the diameter of the driven gear shaft is usually small. Its mating parts with the key are prone to jamming due to small dimensions, improper tolerances, or foreign object intrusion, leading to pump failure and requiring improved operational reliability.

[0004] Therefore, there is an urgent need in this field for a new type of gear oil pump structure that is simpler in structure, lower in cost, easier to assemble, and more reliable in operation, in order to overcome the above-mentioned shortcomings of the prior art. Utility Model Content

[0005] In order to overcome the shortcomings of the prior art, this utility model discloses an external meshing gear oil pump with a shaftless planar driven gear.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] An external meshing gear oil pump with a shaftless planar driven gear includes a pump body, a pump cover, a driving gear, and a driven gear. The driving gear and the driven gear mesh with each other and are housed in a pump cavity enclosed by the pump body and the pump cover. The driven gear is a flat disc structure without a center driven gear shaft or shaft hole, and its two end faces are both planes, which directly slide in contact with the plane inside the pump body and the plane inside the pump cover, respectively.

[0008] Furthermore, the passive gear achieves rotational drive through the meshing of its teeth with the active gear, and achieves radial positioning in conjunction with the inner wall of the pump body.

[0009] Furthermore, the passive gear is fitted into the inner wall of the pump body.

[0010] Furthermore, a wear-resistant and friction-reducing layer is provided on the inner wall of the pump body near the driven gear.

[0011] Furthermore, the flat end face of the passive gear and / or the inner surface of the pump body and pump cover that mate with it are provided with a wear-resistant and friction-reducing layer.

[0012] Furthermore, an oil storage chamber is provided in the middle of the plane on the inner side of the pump body and pump cover that mate with the end face of the passive gear.

[0013] Furthermore, several guide grooves are evenly distributed circumferentially on the outer side of the oil storage cavity.

[0014] Furthermore, the guide groove gradually shifts radially from the outside to the inside of the oil storage cavity towards the direction of rotation of the driven gear.

[0015] Furthermore, the driving gear is a shaft gear, with its short end rotatably inserted into the mounting groove on the inner side of the pump cover, and its long end sealingly rotating through the through hole of the pump body, used to drive the connection to the drive source.

[0016] Furthermore, the through hole is a stepped hole with the large diameter section located axially outside the small diameter section. The large diameter section of the stepped hole is provided with a bushing or packing and a pressure cap in sequence along the axial direction. The bushing or packing and pressure cap are rotatably sleeved on the shaft body of the drive gear shaft. The outer end of the through hole has a protrusion, and the protrusion is threaded with a clamping nut.

[0017] Compared with the prior art, the beneficial effects of this utility model are:

[0018] 1. The driven gear adopts a flat disc structure without a central shaft or shaft hole, which eliminates the traditional driven gear shaft, bearing or bushing and other parts. At the same time, it reduces the machining requirements of the shaft hole in the pump body and pump cover. This not only simplifies the overall structure, but also significantly reduces material and manufacturing costs. It also makes the assembly process simpler and faster, and improves production efficiency and maintenance convenience.

[0019] 2. Axial support and sealing are achieved through the direct sliding fit between the flat end face of the driven gear and the inner plane of the pump body and pump cover. The wear-resistant and friction-reducing layer set on the mating surface effectively reduces frictional resistance and wear, thereby improving the volumetric efficiency and service life of the oil pump.

[0020] 3. An oil storage chamber is set in the middle of the inner plane of the pump body and pump cover, combined with circumferentially evenly distributed guide grooves. The guide grooves gradually shift radially from the outside to the inside towards the direction of rotation of the driven gear, which helps the lubricating oil to be evenly distributed and form an oil film during rotation, further reducing friction and temperature rise, and improving the lubrication effect.

[0021] 4. This utility model has a compact structure and is suitable for the field of micro gear pumps. Due to the simplification of parts, maintenance and replacement are more convenient, thus reducing the cost of use. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the structure of this utility model;

[0023] Figure 2 This is a cross-sectional view of the present invention;

[0024] Figure 3 This is a cross-sectional view of the present invention from another angle;

[0025] Figure 4 This is a front view of the pump body in this utility model;

[0026] Figure 5 This is the front view of the pump cover in this utility model.

[0027] In the diagram: 1. Pump body; 11. Through hole; 12. Protrusion; 2. Pump cover; 21. Assembly groove; 3. Drive gear; 4. Driven gear; 5. Oil reservoir; 6. Guide groove; 7. Shaft sleeve or packing; 8. Pressure cap; 9. Pressure nut. Detailed Implementation

[0028] The present invention will be explained in detail through the following embodiments. The purpose of disclosing the present invention is to protect all technical improvements within the scope of the present invention. In the description of the present invention, it should be understood that if terms such as "upper", "lower", "front", "rear", "left", "right" indicate orientation or positional relationship, they are only corresponding to the drawings of this application for the convenience of describing the present invention. It should be understood that if terms such as "end", "side", "end portion", "side part", "lateral", "longitudinal", etc. indicate orientation or positional relationship, they are only corresponding to the length and width of the corresponding component. That is, "end" indicates the head and tail area in the length direction of the corresponding component, and "side part" indicates the head and tail area in the width direction of the corresponding component. They are used for the convenience of describing the present invention and do not indicate or imply that the device or element referred to must have a specific orientation.

[0029] Example 1, in conjunction with Appendix Figure 1-5A shaftless planar driven gear external gear oil pump includes a pump body 1, a pump cover 2, a driving gear 3, and a driven gear 4. The driving gear 3 and the driven gear 4 mesh with each other and are housed in a pump cavity enclosed by the pump body 1 and the pump cover 2. The driven gear 4 is a flat disc structure without a center driven gear shaft or shaft hole, with both end faces being planes, and directly slidingly engaging with the inner planes of the pump body 1 and the pump cover 2, respectively. This design not only eliminates the traditional shaft or shaft hole structure of the driven gear, as well as the machining of the shaft holes of the pump body 1 and the pump cover 2, but also effectively simplifies assembly, reduces costs, and essentially eliminates the technical defect in the prior art where the shaft diameter of the driven gear 4 is too small, making it prone to jamming when engaged with a key.

[0030] The driven gear 4 achieves rotational drive through the meshing of its teeth with the driving gear 3, and achieves radial positioning by cooperating with the inner wall of the pump body 1; specifically, the driven gear 4 is correspondingly fitted to the inner wall of the pump body 1 to ensure sealing and stability. To reduce friction and wear, a wear-resistant and friction-reducing layer (such as a polytetrafluoroethylene coating or a ceramic coating) is provided on the inner wall of the pump body 1 near the driven gear 4. Similarly, a wear-resistant and friction-reducing layer can also be provided on the flat end face of the driven gear 4 and / or the inner surface of the pump body 1 and pump cover 2 that it mates with.

[0031] An oil reservoir 5 is located in the center of the inner plane of the pump body 1 and pump cover 2, which mate with the end face of the driven gear 4, to store lubricating oil and improve lubrication conditions. Several guide grooves 6 are evenly distributed circumferentially on the outer side of the oil reservoir 5, and these guide grooves 6 gradually shift radially from the outside to the inside towards the rotation direction of the driven gear 4. This design helps the lubricating oil to distribute evenly during rotation, forming an oil film and further reducing friction and temperature rise.

[0032] The driving gear 3 is a shaft gear. Its short end rotates and inserts into the mounting groove 21 on the inner side of the pump cover 2, while its long end seals and rotates through the through hole 11 of the pump body 1, used to drive and connect to an external drive source. The through hole 11 is a stepped hole with the large diameter section located axially outside the small diameter section. Along the axial direction, the large diameter section of the stepped hole is provided with a bushing or packing 7 and a pressure cap 8. The bushing or packing 7 and the pressure cap 8 are rotatably fitted onto the shaft body of the driving gear 3. The outer end of the through hole 11 has a protrusion 12, and the protrusion 12 is threaded with a clamping nut 9, used to clamp the bushing or packing 7 to ensure sealing and axial positioning.

[0033] If the bushing or packing 7 is a packing material, its material is preferably one or a combination of flexible graphite, polytetrafluoroethylene, carbon fiber woven material, aramid fiber woven material or rubber (such as nitrile rubber).

[0034] Working principle: When the drive source rotates the driving gear 3, the driving gear 3 drives the driven gear 4 to rotate through meshing. Since the driven gear 4 is a shaftless flat disc structure, its end face directly slides with the inner plane of the pump body 1 and the pump cover 2, achieving radial positioning through meshing. The oil reservoir 5 and the guide groove 6 provide continuous lubrication, reducing friction and wear, thereby improving the pump's efficiency and lifespan.

[0035] The parts of this utility model not described in detail are prior art. It is obvious to those skilled in the art that this utility model is not limited to the details of the above exemplary embodiments, and that this utility model can be implemented in other specific forms without departing from the spirit or basic characteristics of this utility model. Therefore, the above embodiments should be regarded as exemplary and non-limiting in all respects. The scope of this utility model is defined by the appended claims rather than the foregoing description. Therefore, it is intended to include all changes that fall within the meaning and scope of the equivalents of the claims in this utility model, and no reference numerals in the claims should be regarded as limiting the content of the claims.

Claims

1. A shaftless planar driven gear external gear oil pump, comprising a pump body (1), a pump cover (2), a driving gear (3) and a driven gear (4), wherein the driving gear (3) and the driven gear (4) mesh with each other and are housed in a pump cavity enclosed by the pump body (1) and the pump cover (2), characterized in that: The passive gear (4) is a flat disc structure with no center driven gear shaft or shaft hole. Both of its end faces are planes and are directly slidingly engaged with the plane inside the pump body (1) and the plane inside the pump cover (2), respectively.

2. The external meshing gear oil pump with a shaftless planar driven gear according to claim 1, characterized in that: The passive gear (4) achieves rotational drive by meshing its teeth with the active gear (3), and achieves radial positioning by cooperating with the inner wall of the pump body (1).

3. The external meshing gear oil pump with a shaftless planar driven gear according to claim 1, characterized in that: The passive gear (4) is fitted to the inner wall of the pump body (1).

4. The external meshing gear oil pump with a shaftless planar driven gear according to claim 3, characterized in that: The inner wall of the pump body (1) near the passive gear (4) is provided with a wear-resistant and friction-reducing layer.

5. The external meshing gear oil pump with a shaftless planar driven gear according to claim 1, characterized in that: The flat end face of the passive gear (4) and / or the inner surface of the pump body (1) and pump cover (2) that cooperate with it are provided with a wear-resistant and friction-reducing layer.

6. The external meshing gear oil pump with a shaftless planar driven gear according to claim 1, characterized in that: An oil storage chamber (5) is provided in the middle of the plane of the pump body (1) and pump cover (2) that are in contact with the end face of the passive gear (4).

7. The external meshing gear oil pump with a shaftless planar driven gear according to claim 6, characterized in that: The oil storage cavity (5) has several guide grooves (6) evenly distributed around its outer side in the circumferential direction.

8. The external meshing gear oil pump with a shaftless planar driven gear according to claim 7, characterized in that: The guide groove (6) gradually shifts radially from the outside to the inside towards the rotation direction of the driven gear (4) along the oil storage cavity (5).

9. The external meshing gear oil pump with a shaftless planar driven gear according to claim 1, characterized in that: The drive gear (3) is a shaft gear. Its short end rotates and inserts into the mounting groove (21) on the inner side of the pump cover (2), and its long end seals and rotates through the through hole (11) of the pump body (1) to drive the connection to the drive source.

10. A shaftless planar driven gear external meshing gear oil pump according to claim 9, characterized in that: The through hole (11) is a stepped hole with the large diameter section located on the outer side of the small diameter section. The large diameter section of the stepped hole is provided with a bushing or packing (7) and a pressure cap (8) in sequence along the axial direction. The bushing or packing (7) and the pressure cap (8) are rotatably sleeved on the shaft of the drive gear (3). The outer end of the through hole (11) has a protrusion (12), and the protrusion (12) is threaded with a clamping nut (9).

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