A helical gear pump with a multi-tooth asymmetric same module involute tooth profile
By designing a multi-tooth-count asymmetric involute helical gear pump with the same module, the problems of flow pulsation, vibration, noise, and axial force in high-pressure gear oil pumps are solved, achieving more stable fluid delivery and higher reliability.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- FUXIN BEIXINXING HYDRAULIC CO LTD
- Filing Date
- 2025-06-23
- Publication Date
- 2026-06-23
AI Technical Summary
Existing high-pressure gear oil pumps suffer from problems such as large flow pulsation, large vibration and impact, high noise, the need for complex axial force compensation devices, high cost, and poor reliability.
The design adopts a helical gear with asymmetric involute tooth profile and multiple teeth. The driving helical gear and the driven helical gear have 4-6 more teeth under the same tip circle diameter. The meshing side adopts a positive involute with a large pressure angle, and the non-meshing side adopts a negative involute with a small pressure angle. The helix angle is 4°-6°, which simplifies the structure and reduces the axial force component.
It effectively reduces flow pulsation and noise, simplifies the structure, reduces manufacturing costs, improves reliability, enhances anti-fouling ability, and ensures gear strength and operational stability.
Smart Images
Figure CN224396686U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of helical gear pump technology, and in particular to a helical gear pump with a multi-tooth number asymmetric involute tooth profile of the same module. Background Technology
[0002] Currently, high-pressure gear oil pumps on the market are divided into spur gear pumps, helical gear pumps, and spiral circular arc helical gear pumps.
[0003] The drawback of using a spur gear pump is that the contact line of the spur gear is parallel to the axis, and the teeth enter and disengage simultaneously during operation, resulting in large flow pulsation, significant vibration and impact, and high noise levels. In contrast, using a helical gear pump involves a gradual engagement process where the contact line on the tooth surfaces first lengthens and then shortens again until disengagement. Under the same conditions, the engagement process of helical gears is longer than that of spur gears, reducing the load on each pair of gears, resulting in smoother transmission and effective noise control. Although helical gear pumps are superior to spur gear pumps in noise reduction, the inherent limitations of helical gears... The presence of the helix angle (usually β > 20°) of the gear results in a certain axial force during meshing transmission. To overcome this axial force, a complex axial compensation device is required, which is costly and has poor reliability. Although the oil pump uses a helical arc gear pump, which is the most effective in reducing noise, has no oil trapping zone, and has small flow pulsation, the presence of the helix angle (usually β > 20°) of the helical arc gear results in a certain axial force during meshing transmission. To overcome this axial force, a complex axial compensation device is required, which is costly to manufacture. In addition, because the helical arc helical gear pump has no side clearance or top clearance during transmission, it has poor resistance to contamination.
[0004] Therefore, there is an urgent need to develop a helical gear pump with a multi-tooth number, asymmetric involute tooth profile to solve the above-mentioned technical problems. Utility Model Content
[0005] This utility model provides a helical gear pump with a multi-tooth number asymmetric involute tooth profile, which adopts the following technical solution, including: a rear cover, a positioning pin, a floating sleeve, a driving helical gear, a driven helical gear, a high-pressure sealing assembly, a sealing ring, a front cover, a rotating lip skeleton oil seal, a hole retaining ring, bolts, and a pump body.
[0006] The driving helical gear and the driven helical gear are multi-tooth asymmetric involute helical gears with the same module, and the number of teeth is 4-6 more than that of the standard helical gear under the same tip circle diameter.
[0007] The rear cover is positioned and installed with the pump body by the positioning pin. The high-pressure sealing assembly is installed in the sealing grooves corresponding to the rear cover and the front cover. The sealing ring is installed in the sealing grooves corresponding to the front and rear end faces of the pump body. The floating sleeve is inserted into the pump body.
[0008] The driving helical gear meshes with the driven helical gear and is installed in the gear hole of the pump body, and the shafts of the driving helical gear and the driven helical gear are installed in the bearing hole corresponding to the floating sleeve;
[0009] The front cover is positioned and installed with the pump body via the positioning pin. The rotating lip skeleton oil seal and the hole snap ring are sequentially installed into the opening of the front cover to fix the active helical gear.
[0010] The front cover, the pump body, and the rear cover are fixedly connected by the bolts.
[0011] Furthermore, the tooth profiles of the driving helical gear and the driven helical gear with the multi-tooth number asymmetric same module involute tooth profile are asymmetric structures; the meshing side has a positive involute large pressure angle, with a normal pressure angle α of 27°-32°; the non-meshing side has a negative involute small pressure angle, with a normal pressure angle α of 15°-20°.
[0012] Furthermore, the helix angle β of the multi-tooth asymmetric involute gear with the same module is 4°-6°.
[0013] In summary, this utility model has the following beneficial technical effects:
[0014] 1. The tooth profile of this utility model adopts a positive involute with a large pressure angle (normal pressure angle α is 27° to 32°) on the working side, which enhances the gear strength and ensures a certain overlap coefficient; the non-working side adopts a negative involute with a small pressure angle (normal pressure angle α is 15° to 20°), which can increase the number of teeth by 4 to 6 under the same standard helical gear addendum circle diameter. The multiple tooth design makes the gear meshing tighter, reduces flow pulsation, and thus effectively reduces noise.
[0015] 2. The helix angle β of this invention is set at 4°-6° to ensure an effective overlap coefficient. Multiple teeth participate in meshing, resulting in less impact and smoother meshing, further reducing noise during operation. Due to the small helix angle, the axial force generated during meshing is very small, thus eliminating the need for a complex axial force compensation device. This not only simplifies the overall structure of the pump but also reduces manufacturing costs and improves pump reliability.
[0016] 3. The asymmetrical involute tooth profile with the same module increases the tooth thickness while leaving room for rotation at the tooth tip, ensuring the strength and stability of the gear. Attached Figure Description
[0017] Figure 1 This is a schematic diagram of the structure of this utility model;
[0018] Figure 2 This is the utility model Figure 1 BB (sectional view);
[0019] Figure 3 This is a structural schematic diagram of the driving helical gear and the driven helical gear of this utility model;
[0020] Figure 4 This is a diagram of the end face tooth profile of the driving helical gear and the driven helical gear of this utility model.
[0021] Explanation of reference numerals in the attached drawings: 1. Rear cover; 2. Locating pin; 3. Floating sleeve; 4. Driving helical gear; 5. Driven helical gear; 6. High-pressure sealing assembly; 7. Sealing ring; 8. Front cover; 9. Rotary lip skeleton oil seal; 10. Hole retaining ring; 11. Bolt; 12. Pump body; 13. Pitch circle; 14. Intersection point; 15. Tangent; 16. Normal; 17. Spiral schematic line.
[0022] Where α is the normal pressure angle and β is the helix angle. Detailed Implementation
[0023] The present invention will be further described in detail below with reference to the accompanying drawings.
[0024] like Figures 1 to 4 A specific embodiment of a helical gear pump with a multi-tooth asymmetric involute tooth profile of the same module is shown, comprising: a rear cover 1, a positioning pin 2, a floating sleeve 3, a driving helical gear 4, a driven helical gear 5, a high-pressure sealing assembly 6, a sealing ring 7, a front cover 8, a rotary lip skeleton oil seal 9, a retaining ring for the hole 10, bolts 11, and a pump body 12; the driving helical gear 4 and the driven helical gear 5 are multi-tooth asymmetric involute tooth profile helical gears of the same module, with 4-6 more teeth than a standard helical gear for the same tip circle diameter; the rear cover 1 is positioned and installed on the pump body 12 by the positioning pin 2, and the high-pressure sealing assembly 6 is installed on the rear cover 1 and the front cover 8 respectively. In the sealing groove, the sealing ring 7 is installed in the sealing grooves corresponding to the front and rear end faces of the pump body 12, and the floating sleeve 3 is installed in the pump body 12; the driving helical gear 4 and the driven helical gear 5 are meshed and installed in the gear hole of the pump body 12, and the shafts of the driving helical gear 4 and the driven helical gear 5 are installed in the bearing hole corresponding to the floating sleeve 3; the front cover 8 is positioned and installed with the pump body 12 by the positioning pin 2, and the rotating lip skeleton oil seal 9 and the hole snap ring 10 are sequentially installed in the opening position of the front cover 8 to fix the driving helical gear 4; the front cover 8, the pump body 12 and the rear cover 1 are fixedly connected by the bolts 11.
[0025] Specifically, the driving helical gear 4 and driven helical gear 5 in this invention adopt a multi-tooth asymmetric involute tooth profile with the same module, increasing the number of teeth by 4-6 compared to a standard helical gear under the same tip circle diameter. This multi-tooth meshing reduces flow pulsation, making fluid delivery smoother and reducing vibration and noise caused by flow fluctuations. Furthermore, the increased number of teeth involved in meshing improves sealing performance, reduces fluid leakage, increases pump volumetric efficiency, and enhances self-priming capability, making it suitable for applications requiring high precision and efficiency in fluid transmission.
[0026] Specifically, the rear cover 1 and the pump body 12, and the front cover 8 and the pump body 12 are positioned by the positioning pin 2 and fixed by the bolt 11, to ensure gear meshing accuracy, reduce operational failures caused by assembly errors, and improve overall reliability.
[0027] Specifically, the high-pressure sealing assembly 6 is installed in the sealing grooves of the rear cover 1 and the front cover 8, and the sealing ring 7 is installed in the sealing grooves of the front and rear end faces of the pump body 12, forming a multi-layer sealing structure to prevent high-pressure fluid leakage and ensure stable operation of the pump under high-pressure conditions. The opening of the front cover 8 is fitted with a rotary lip skeleton oil seal 9 and a hole retaining spring 10, which not only fixes the drive helical gear 4 but also prevents external dust and impurities from entering the pump body, protects the gear transmission system, and enhances the pump's anti-fouling ability and environmental adaptability.
[0028] In other preferred embodiments, the tooth profiles of the multi-tooth asymmetric involute gear 4 and driven helical gear 5 with the same module are asymmetric; the meshing side has a positive involute large pressure angle, with a normal pressure angle α of 27°-32°; the non-meshing side has a negative involute small pressure angle, with a normal pressure angle α of 15°-20°; and the helix angle β of the multi-tooth asymmetric involute gear 4 and driven helical gear 5 with the same module is 4°-6°.
[0029] Specifically, such as Figure 3 As shown, the normal pressure angle α is the angle between the tangent and the normal at the intersection of the gear pitch circle and the tooth, and the helix angle β is the angle between the axis of the gear shaft and the schematic line of the helix.
[0030] Specifically, the meshing side adopts a positive involute with a large pressure angle (α=27°-32°), resulting in a steeper tooth profile, increased tooth root thickness, and significantly improved gear bending strength. This allows the gear to withstand greater loads and reduces the risk of tooth surface wear and fracture under high-pressure conditions. Simultaneously, the large pressure angle ensures a sufficient overlap coefficient, enabling multiple gear pairs to mesh simultaneously, resulting in a more uniform load distribution, reduced transmission impact, and smoother operation.
[0031] Specifically, the non-meshing side adopts a reverse involute with a small pressure angle (α=15°-20°), resulting in a smoother tooth profile. Under the same tooth tip circle diameter, the tooth thickness can be increased, further enhancing the tooth body strength. At the same time, the small pressure angle leaves more rotation space at the tooth tip, avoiding interference between the gear and the pump body when rotating, and ensuring structural reliability.
[0032] Specifically, the asymmetrical tooth profile and small pressure angle design allow for 4-6 more teeth to be added with the same tip circle diameter, resulting in a denser gear mesh. With multiple teeth meshing, the fluid is divided into smaller units, making the pump's suction and discharge process more continuous and significantly reducing flow pulsation.
[0033] Specifically, the helix angle β = 4°-6° ensures the necessary overlap coefficient, guaranteeing the continuity of multi-tooth meshing; on the other hand, it significantly reduces the axial force, avoiding vibration and noise caused by excessive axial force. Simultaneously, the small helix angle shortens the gear meshing line, reducing meshing impact. Furthermore, due to the small helix angle, the axial force generated during meshing is minimal, eliminating the need for the complex axial compensation device found in traditional helical gear pumps, thus simplifying the pump body structure.
[0034] Specifically, the driving helical gear 4 and the driven helical gear 5 are designed with the same module, ensuring that they have a consistent tooth pitch during meshing. Furthermore, the same module design allows the driving helical gear 4 and the driven helical gear 5 to be machined using the same set of molds, reducing mold costs.
[0035] The above are all preferred embodiments of this utility model, and are not intended to limit the scope of protection of this utility model. Therefore, all equivalent changes made to the structure, shape and principle of this utility model should be included within the scope of protection of this utility model.
Claims
1. A helical gear pump with a multi-tooth-count asymmetric involute tooth profile of the same module, characterized in that, Includes rear cover, locating pin, floating sleeve, driving helical gear, driven helical gear, high-pressure sealing assembly, sealing ring, front cover, rotary lip skeleton oil seal, hole retaining ring, bolts and pump body; The driving helical gear and the driven helical gear are multi-tooth asymmetric involute helical gears with the same module, and the number of teeth is 4-6 more than that of the standard helical gear under the same tip circle diameter. The rear cover is positioned and installed with the pump body by the positioning pin. The high-pressure sealing assembly is installed in the sealing grooves corresponding to the rear cover and the front cover. The sealing ring is installed in the sealing grooves corresponding to the front and rear end faces of the pump body. The floating sleeve is inserted into the pump body. The driving helical gear meshes with the driven helical gear and is installed in the gear hole of the pump body, and the shafts of the driving helical gear and the driven helical gear are installed in the bearing hole corresponding to the floating sleeve; The front cover is positioned and installed with the pump body via the positioning pin. The rotating lip skeleton oil seal and the hole snap ring are sequentially installed into the opening of the front cover to fix the active helical gear. The front cover, the pump body, and the rear cover are fixedly connected by the bolts.
2. A helical gear pump with an asymmetric involute tooth profile of multiple tooth count and same module according to claim 1, characterized in that, The tooth profiles of the driving and driven helical gears with multi-tooth asymmetric involute tooth profiles of the same module are asymmetric; the meshing side has a positive involute with a large pressure angle, and the normal pressure angle α is 27°-32°; the non-meshing side has a negative involute with a small pressure angle, and the normal pressure angle α is 15°-20°.
3. A helical gear pump with an asymmetric involute tooth profile of multiple tooth count and same module according to claim 2, characterized in that, The helix angle β of the driving and driven helical gears with multi-tooth asymmetric involute tooth profiles of the same module is 4°-6°.