阅读说明：本技术 软硬配合的大螺旋角极少齿斜齿轮副及其应用 (Hard-soft matched helical gear pair with large helical angle and few teeth and application thereof ) 是由 侯国祥 于 2021-04-25 设计创作，主要内容包括：本发明先涉及一种软硬配合的大螺旋角极少齿斜齿轮副,主动齿轮与从动齿轮的齿形轮廓相同,旋向相反,所述主动齿轮为金属材质,所述从动齿轮为金属内芯、并在金属内芯外包覆一层弹性体材料。接着提供包括上述斜齿轮副的极少齿斜齿轮水泵,尤其适合船用。本发明首先在从动齿轮表面包覆一层弹性体,实现主从动齿轮的软硬接触和过盈配合能够有效提升水泵的效率以及运行过程中的振动与噪声；中心对称的泵体结构和全对称的斜齿轮副能够实现双向工作；大包角极少齿的设计能够保证在低转速下获得大的流量,保证输出的可靠性,与泵体结构相配合的卸荷槽,能减小进出流阻力,解决困油现象,降低高转速下的噪声。(The invention relates to a large helix angle few teeth helical gear pair with soft and hard matching, wherein the tooth profiles of a driving gear and a driven gear are the same, the rotation directions are opposite, the driving gear is made of metal, the driven gear is a metal inner core, and a layer of elastomer material is coated outside the metal inner core. Next, a helical gear water pump with few teeth comprising the above-mentioned helical gear pair is provided, which is particularly suitable for ships. According to the invention, firstly, the surface of the driven gear is coated with a layer of elastomer, so that the soft and hard contact and interference fit of the driving gear and the driven gear are realized, and the efficiency of the water pump and the vibration and noise in the operation process can be effectively improved; the centrosymmetric pump body structure and the full-symmetric bevel gear pair can realize bidirectional work; the design of the large wrap angle and few teeth can ensure that large flow can be obtained at low rotating speed, the reliability of output is ensured, and the unloading groove matched with the pump body structure can reduce the inflow and outflow resistance, solve the oil trapping phenomenon and reduce the noise at high rotating speed.)

1. The helical gear pair with the large helical angle and few teeth in soft-hard matching comprises a driving gear and a driven gear, and is characterized in that the tooth profiles of the driving gear and the driven gear are the same, and the rotation directions are opposite, the driving gear is made of metal, the driven gear is a metal inner core, and a layer of elastomer material is coated outside the metal inner core.

2. The large helix angle few teeth helical gear set of claim 1, wherein said elastomeric material is polyurethane.

3. The large helix angle few teeth helical gear set of claim 1, wherein the number of gears for said drive and driven gears is four, the helix angle is 38.15 °, and the wrap angle is 180 °.

4. Use of a large helix angle few teeth helical gear set as claimed in any one of claims 1 to 3 in a hydraulic water pump.

5. A low speed, high flow, very small tooth, helical gear pump comprising housing means, functional components and sealing means, said functional components comprising a high helix angle, very small tooth, helical gear pair as claimed in any one of claims 1 to 3.

6. The helical gear water pump as claimed in claim 5, wherein said housing means comprises an upper cover plate, a pump body housing, a lower cover plate, a bottom cover, a driven bearing cap and a driving bearing cap; the functional components comprise driving gears, driving gear shafts, driven gears and driven gear shafts; the sealing device comprises a mechanical seal, a polytetrafluoroethylene elastic side plate and a tapered roller bearing.

7. The helical gear water pump with few teeth as claimed in claim 6, wherein the pump body housing is a centrosymmetric structure, and the water suction port and the water discharge port with the same geometric structure are arranged on both sides of the pump body housing, and are matched with the upper helical gear pair, so that the water pump can work in two directions.

8. The helical gear water pump as claimed in claim 6, wherein said mechanical seal comprises O-ring seals grooved into the upper and lower cover plates; the polytetrafluoroethylene elastic side plates are arranged between the upper cover plate and the gear end face and between the lower cover plate and the gear end face; the tapered roller bearing is arranged among the gear end face, the upper cover plate, the lower cover plate, the driving gear shaft and the shaft body of the driven gear shaft, and is sealed by mechanical seal.

9. The helical gear water pump with few teeth as claimed in claim 6 or 8, wherein the teflon elastic side plate is further provided with relief grooves along the meshing direction, and the relief grooves are arranged one on each side.

10. The use of the helical gear pump with few teeth according to any of claims 5 to 9 for marine applications.

Technical Field

The invention relates to a helical gear pair structure, in particular to a soft and hard matched helical gear pair with a large helical angle and few teeth and application thereof.

Background

The few-tooth helical gear pump is one kind of external gear pump, and it is a rotary positive displacement pump, and it is used to convey liquid by means of the volume change of the tooth space of the gear. When the gear pump works, the driving gear rotates along with the motor and drives the driven gear to rotate along with the motor. When the meshing teeth on one side of the suction chamber are gradually separated, the meshing cavity is gradually enlarged to form partial vacuum, so that a self-suction effect can be generated, and liquid in the pipe is sucked into the pump; the suction liquid is pushed to the discharge chamber by the gear in the tooth grooves in two paths. After the liquid enters the discharge chamber, the liquid is discharged into the pipe by the extrusion effect formed by the gradual reduction of the meshing cavity due to the continuous meshing of the gear teeth of the two gears.

However, when transporting low viscosity fluids such as water, positive displacement pumps place higher demands on leakage; furthermore, water is more sensitive to oil trapping because it is less compressible than oil. When the general gear pump is used as a water pump, the effect of large flow and high pressure head is difficult to obtain.

Disclosure of Invention

In order to overcome the technical defects, the invention firstly provides a helical gear pair with a large helical angle and few teeth, which is matched with hardness and hardness, and comprises a driving gear and a driven gear, wherein the tooth profiles of the driving gear and the driven gear are the same, the rotation directions of the driving gear and the driven gear are opposite, the driving gear is made of metal, the driven gear is a metal inner core, and a layer of elastomer material is coated outside the metal inner core. Preferably, the elastomeric material is polyurethane.

When the driving gear and the driven gear are used, the driving gear and the driven gear are driven by the driving gear shaft and the driven gear shaft respectively. During processing, the driving gear and the driving gear shaft can be integrally processed, namely, the driving gear and the driving gear shaft are processed by a single metal material. The driven gear and the driven gear shaft are manufactured by firstly processing a metal inner core which has the opposite rotation direction with the driving gear and is strictly similar to the shape and the size, then manufacturing a die, coating a layer of elastomer material (preferably polyurethane material) outside the inner core, and processing to ensure that the final driven gear is consistent with the geometric shape of the driving gear. According to the invention, the surface of the driven gear is coated with a layer of elastomer (preferably polyurethane elastomer, which has good tensile strength, tear strength, impact resistance, wear resistance, weather resistance, hydrolysis resistance and oil resistance) so that the bevel gear pair is a combination of hard and soft, and three benefits can be brought. Firstly, do benefit to and realize zero clearance, reduce and leak the raise the efficiency, secondly meshing time increases and does benefit to and reduces the meshing impact and reduce vibrations, thirdly rotor inertia reduces, does benefit to the input demand that reduces energy and torque, reduces reaction time.

Furthermore, the helical gear pair with the large helical angle and few teeth has four gears of the driving gear and the driven gear, the helical angle is 38.15 degrees, and the wrap angle is 180 degrees. The gear has only four teeth but a large helix angle of 38.15 deg. which causes the four tooth helical gear to have three teeth in mesh at each instant, thereby smoothing the operation of the pump. The driving gear and the driven gear are both few-tooth helical gears, the wrap angle is 180 degrees, liquid in the pump directly flows to an outlet when being extruded, contact time of impurities in the liquid and the gears is reduced, the pump is insensitive to solid impurities, and abrasion of helical teeth of the gears is greatly reduced. The area utilization rate of the gear molded line is close to 50%, large flow can be obtained at low rotating speed, and favorable conditions for reducing vibration and noise can be created at low rotating speed. Therefore, the helical gear pair with large helix angle and few teeth is particularly suitable for hydraulic water pumps, and can bring the technical effects of improving the working efficiency of the water pump, reducing the operation noise and quickly realizing the role switching of water injection and drainage.

The invention further provides a low-speed large-flow water pump with few-teeth helical gear, which comprises a shell device, a functional part and a sealing device, wherein the functional part comprises the helical gear pair with large helical angle and few teeth. The driving gear and the driven gear of the water pump are mutually meshed and are mutually matched with the pump body shell to form a cylindrical cavity. The driving gear and the driven gear are both provided with a few-tooth helical gear wrap angle of 180 degrees, liquid inside the pump directly flows to an outlet when being extruded, contact time of impurities inside the liquid and the gear is shortened, the pump is insensitive to solid impurities, and abrasion of helical teeth of the gear is greatly reduced. The number of teeth of the bevel gear pair is 4, the helix angle is 38.15 degrees, and the tooth width of the bevel gear is 2-2.5 times of the center distance of the gear pair; the small number of teeth can ensure the rigidity and the strength of the gear teeth and improve the area utilization rate; the large helical angle enables the helical gear with four teeth to have three teeth in a meshing state at each moment, so that the pump runs stably and pulsation is reduced; the large tooth width can reduce the bending amount of the teeth, which is beneficial to reducing noise, and can also ensure that the pump can obtain large flow at a lower rotating speed, thereby creating conditions for reducing noise.

Preferably, the housing device comprises an upper cover plate, a pump body housing, a lower cover plate, a bottom cover, a driven bearing cover and a driving bearing cover; the functional components comprise driving gears, driving gear shafts, driven gears and driven gear shafts; the sealing device comprises a mechanical seal, a polytetrafluoroethylene elastic side plate and a tapered roller bearing.

The pump body shell is of a centrosymmetric structure, the two sides of the pump body shell are provided with a water suction port and a water discharge port which have the same geometric structure, and the pump body shell is matched with an upper bevel gear pair, so that the bidirectional work of the water pump can be realized.

The mechanical seal comprises O-shaped sealing strips arranged on the upper cover plate and the lower cover plate in a groove mode; the polytetrafluoroethylene elastic side plates are arranged between the upper cover plate and the gear end face and between the lower cover plate and the gear end face; the tapered roller bearing is arranged among the gear end face, the upper cover plate, the lower cover plate, the driving gear shaft and the shaft body of the driven gear shaft, and is sealed by mechanical seal.

And the polytetrafluoroethylene elastic side plate is also provided with unloading grooves along the meshing direction, and the unloading grooves are arranged on one side.

The technical effect that above-mentioned technical scheme can realize:

the driving gear and the driven gear divide the inner cavity of the pump body into a suction cavity and a discharge cavity, and the two sides of the pump body are provided with a water suction port and a water discharge port which have the same geometric structures, so that the flowing characteristics of water are kept unchanged after the pump completes the role conversion of water injection and water discharge. The driving gear shaft and the driving gear as well as the driven gear shaft and the driven gear are integrally machined into a whole rod. The driving gear shaft is connected with the mute permanent magnet motor through the elastic pin tooth type coupler, the rotating speed of the driving gear shaft is consistent with the designed rotating speed of the pump, the weight of a speed reducer is saved, and meanwhile, the vibration level and the noise of the motor are greatly reduced; the relative speed between the rotor and the liquid drops rapidly and the flow-induced noise is correspondingly reduced. The pump can be fixed with the motor base, the motor and the bracket part through the upper cover plate by adopting the inner hexagon screws. The polytetrafluoroethylene elastic side plates arranged between the upper cover plate and the gear end face and between the lower cover plate and the gear end face compensate for the end face gap, so that the end face leakage can be reduced, and the efficiency of the pump is improved; a group of unloading grooves matched with the gear teeth and the water suction and discharge ports are formed in the polytetrafluoroethylene elastic side plate, so that inflow and outflow resistance can be reduced, the oil trapping phenomenon of the gear pump can be eliminated, and vibration noise is reduced. O-shaped sealing strips are arranged on the upper cover plate and the lower cover plate in a groove-cutting mode, so that sealing between the pump body and the cover can be effectively guaranteed, and external leakage is reduced. The tapered roller bearings are arranged among the gear end face, the upper cover plate, the lower cover plate, the driving gear shaft and the driven gear shaft, can bear larger axial load caused by a large helical angle, and can operate under the condition of heavy load.

In sum, the helical gear water pump with few teeth provided by the invention is particularly suitable for ships. The requirements of high flow, high lift and low vibration noise operation can be met. According to the invention, firstly, the surface of the driven gear is coated with a layer of polyurethane, so that the soft-hard contact and interference fit of the driving gear and the driven gear are realized, and the efficiency of the water pump and the vibration and noise in the operation process can be effectively improved; the centrosymmetric pump body structure and the full-symmetric bevel gear pair can realize bidirectional work; the design of the large wrap angle and few teeth can ensure that large flow can be obtained at low rotating speed, the reliability of output is ensured, and the unloading groove matched with the pump body structure can reduce the inflow and outflow resistance, solve the oil trapping phenomenon and reduce the noise at high rotating speed.

Drawings

FIG. 1 is a polyurethane coated driven gear;

FIG. 2 is a schematic external view of the water pump according to the embodiment;

FIG. 3 is a schematic view of the internal structure of the water pump according to the embodiment;

FIG. 4 is a front view of the water pump of the embodiment;

FIG. 5 is a cross-sectional view of FIG. 4;

FIG. 6 illustrates the operation of the water pump of the embodiment;

FIG. 7 is a schematic structural view of an unloading groove on a polytetrafluoroethylene elastic side plate.

The parts and their corresponding numbers in the figures are: 1. the pump comprises an upper cover plate, 2, a pump body shell, 3, a lower cover plate, 4, a bottom cover, 5, a driving bearing cover, 6, a mechanical seal, 7, a driving gear shaft, 8, a driven bearing cover, 9, a driven gear shaft, 10, a tapered roller bearing, 11, a polytetrafluoroethylene elastic side plate, 12, a water suction port, 13, a water discharge port, 14, a suction cavity, 15, a discharge cavity, 16 and an unloading groove.

Detailed Description

Embodiments of the present invention are described below with reference to the drawings. Elements and features depicted in one drawing or one embodiment of the invention may be combined with elements and features shown in one or more other drawings or embodiments. It should be noted that the figures and description omit representation and description of components or processes that are not relevant to the present invention and that are known to those of ordinary skill in the art for the sake of clarity.

The invention firstly provides a large helix angle few teeth helical gear pair with soft and hard matching, which comprises a driving gear and a driven gear, wherein the tooth profiles of the driving gear and the driven gear are the same, the rotation directions are opposite, the driving gear is made of metal, the driven gear is made of metal inner core, and a layer of elastomer material is coated outside the metal inner core. Preferably, the elastomeric material is polyurethane. When the driving gear and the driven gear are used, the driving gear shaft and the driven gear shaft drive the driving gear and the driven gear respectively. During processing, the driving gear and the driving gear shaft can be integrally processed, namely, the driving gear and the driving gear shaft are processed by a single metal material. The driven gear and the driven gear shaft are manufactured by firstly processing a metal inner core which has the opposite rotation direction with the driving gear and is strictly similar to the shape and the size, then manufacturing a die, coating a layer of elastomer material (preferably polyurethane material) outside the inner core, and processing to ensure that the final driven gear is consistent with the geometric shape of the driving gear. Fig. 1 is a schematic view showing a driven gear.

Further, the invention provides a low-speed large-flow helical gear water pump with few teeth, as shown in fig. 2-5, which comprises a shell device, a functional component and a sealing device, wherein the shell device comprises an upper cover plate 1, a pump body shell 2, a lower cover plate 3, a bottom cover 4, a driven bearing cover 8 and a driving bearing cover 5; the functional components comprise a driving gear, a driving gear shaft 7, a driven gear and a driven gear shaft 9 to form a pump body; the sealing device comprises a mechanical seal 6, a polytetrafluoroethylene elastic side plate 11 and a tapered roller bearing 10.

The pump body shell is of a central symmetrical structure, a water suction port 12 and a water discharge port 13 which have the same geometric structure are arranged on two sides of the pump body shell, and the pump body shell is matched with an upper bevel gear pair, so that the bidirectional work of the pump can be realized.

The mechanical seal 6 comprises O-shaped sealing strips which are arranged on the upper cover plate and the lower cover plate in a groove cutting way; the polytetrafluoroethylene elastic side plate 11 is arranged between the upper cover plate and the gear end face and between the lower cover plate and the gear end face; the tapered roller bearing 10 is arranged among the gear end face, the upper cover plate, the lower cover plate, the driving gear shaft and the shaft body of the driven gear shaft, and is sealed by mechanical seal. The teflon elastic side plate 11 is further provided with relief grooves 16 (as shown in fig. 7) along the engagement direction, and the relief grooves are arranged one on each side.

The water pump uses the coupler to assemble the part of the driving gear shaft 7 extending out with the motor, the driving gear is driven by the motor, and a mute permanent magnet motor can be selected as the optimal choice. Because the helical angle of the helical gear of the water pump is larger, a larger axial force can be generated in the meshing process, tapered roller bearings 10 capable of bearing combined loads of the radial direction and the axial direction need to be installed on the driving shaft and the driven shaft, 4 mechanical seals 6 are installed on the driving shaft and the driven shaft between the upper cover plate and the lower cover plate, the corrosion of the bearings caused by the fact that working fluid enters the bearings is prevented, and in addition, a driving bearing cover 5 and a driven bearing cover 8 are installed above the driving gear shaft 7 and the driven gear shaft 9 at the upper end of the pump to protect the bearings and prevent dust. O-shaped sealing rings are arranged among the upper cover plate 1, the pump body shell 2 and the lower cover plate 3, and all parts of the shell are fixedly positioned by bolts. The driving gear and the driven gear are meshed with each other to divide the internal working chamber of the pump body shell 2 into a suction cavity 14 and a discharge cavity 15, and the suction opening 12 and the water discharge opening 13 are respectively arranged. A polytetrafluoroethylene elastic side plate 11 is arranged between the rotor and the upper cover plate 1 and the lower cover plate 3, and a load and unload groove 16 is arranged on the side plate.

When the pump works, the motor drives the driving shaft to rotate according to the arrow direction shown in figure 6, the driving gear shaft 5 drives the driven gear shaft 9 to rotate, the gears in the suction cavity 14 are disengaged, the volume is increased, the pressure intensity is reduced, liquid is sucked from the water suction port 12 under the action of pressure difference and is gradually conveyed to the discharge cavity 15 along the outer side along with the rotation of the gears, the gears in the discharge cavity are gradually engaged, the volume is reduced, and the liquid is extruded out and is discharged into a pipeline through the water discharge port 13. However, part of liquid enters the meshing dead zone along with the gear to generate an oil trapping phenomenon, so that the unloading groove matched with the inlet and the outlet is formed in the polytetrafluoroethylene elastic side plate, the inlet and outlet flow area can be increased, the inlet and outlet flow resistance can be reduced, the oil trapping phenomenon of the bevel gear can be solved, and the running noise can be reduced.

Although the present invention and its advantages have been described in detail, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the invention as defined by the appended claims. Moreover, the scope of the present application is not intended to be limited to the particular embodiments of the process, machine, means, methods and steps described in the specification. As one of ordinary skill in the art will readily appreciate from the disclosure of the present invention, processes, machines, means, methods, or steps, presently existing or later to be developed that perform substantially the same function or achieve substantially the same result as the corresponding embodiments described herein may be utilized according to the present invention. Accordingly, the appended claims are intended to include within their scope such processes, devices, means, methods, or steps.