阅读说明：本技术 一种泵及其带轮箍可调速的诱导轮 (Pump and inducer with adjustable speed of belt wheel hoop thereof ) 是由 朱荣生 王芮 付强 陈一鸣 王秀礼 李广朋 于 2020-12-11 设计创作，主要内容包括：本发明提供了一种泵及其带轮箍可调速的诱导轮,属于流体机械领域。本发明的诱导轮包括同轴设置的叶轮和诱导轮,叶轮的进口直口环与诱导轮轮箍之间安装有调速装置,调速装置为两组啮合的齿轮组,通过设置齿轮之间的传动比,使得诱导轮在与叶轮同轴旋转的同时,根据齿轮组的不同传动比,实现诱导轮与叶轮的转速不同,有效地改善因进口流速变化而产生的空化现象；本发明的诱导轮带有轮箍,用于解决诱导轮运行过程中存在的叶顶间隙空化和叶顶间隙泄漏流的问题；本发明还可以实现诱导轮与叶轮的转向相反,进一步的提高泵的抗空化性能。(The invention provides a pump and an inducer with a belt wheel hoop capable of adjusting speed thereof, belonging to the field of fluid machinery. The inducer comprises an impeller and an inducer which are coaxially arranged, a speed regulating device is arranged between an inlet straight opening ring of the impeller and an inducer wheel hoop, the speed regulating device is two groups of meshed gear sets, and the inducer rotates coaxially with the impeller by setting the transmission ratio between the gears, so that the rotating speeds of the inducer and the impeller are different according to different transmission ratios of the gear sets, and the cavitation phenomenon caused by the change of the inlet flow speed is effectively improved; the inducer is provided with the wheel rim and used for solving the problems of blade top gap cavitation and blade top gap leakage flow in the operation process of the inducer; the invention can also realize the reverse rotation of the inducer and the impeller, and further improve the anti-cavitation performance of the pump.)

1. The inducer with the wheel band capable of regulating speed is characterized by comprising an impeller (4) and an inducer (8) which are coaxially arranged on a pump shaft (6);

an inlet straight-mouth ring (401) is integrally formed on a front cover plate of the impeller (4), an inducer wheel hoop (801) is arranged on the outer side of a blade of the inducer (8), and a speed regulating device (3) is arranged between the inducer wheel hoop (801) and the inlet straight-mouth ring (401);

the speed regulating device (3) comprises a first gear (801a), a second gear (301) and a third gear (401a), the first gear (801a) is arranged at the section of the outer edge 1/3 of the outlet of the inducer wheel hoop (801), the third gear (401a) is arranged at the inner edge of the outlet of the inlet straight opening ring (401), and the second gear (301) is installed on the inlet pipe (1); the second gear (301) is meshed with the first gear (801a) and the third gear (401a), respectively.

2. The inducer with the belt pulley and the hoop capable of regulating speed according to claim 1, characterized in that the pump shaft (6) is processed into a stepped shaft, one end of the pump shaft (6) close to the inlet pipe (1) is small in diameter, one end far away from the inlet pipe (1) is large in diameter, the impeller (4) is fixed on the section of the pump shaft (6) with the large diameter, and the inducer (8) is fixed on the section of the pump shaft (6) with the small diameter.

3. The inducer with the adjustable speed of the belt wheel hoop according to claim 2, characterized in that a hub bearing A (9a) and a hub bearing B (9B) are respectively installed at two ends of the pump shaft (6) with the small diameter.

4. The inducer with the belt pulley and the hoop adjustable in speed according to claim 2, characterized in that the front end of the pump shaft (6) is provided with a conical or hemispherical water guide cone (7).

5. The inducer with the band clamp capable of regulating speed according to claim 3, characterized in that an inducer hub (802) is arranged on the inner side of a blade of the inducer (8), a gland A (10a) and a gland B (10B) which are in clearance fit with a pump shaft (6) are respectively fixed at two ends of the inducer hub (802), and oil seals are respectively arranged inside the gland A (10a) and the gland B (10B); the inner wall of the inducer hub (802) is matched with the outer rings of the hub bearing A (9a) and the hub bearing B (9B).

6. The inducer of speed regulation according to claim 1, characterized in that said first gear (801a) and second gear (301) are both external gears and third gear (401a) is an internal gear.

7. The inducer of speed regulation of a pulley band according to claim 6, characterized in that said third gear (401a) is the same length as the first gear (801 a).

8. The inducer of speed regulation of a pulley band according to claim 6, characterized in that the number of said second gears (301) is at least 3.

9. The inducer of speed regulation of a belt pulley hoop according to claim 1, characterized in that the diameter of the inlet straight-mouth ring (401) is greater than or equal to the inlet diameter of the impeller (4).

10. A pump comprising a band-adjustable inducer according to claims 1-9.

Technical Field

The invention relates to the field of fluid machinery, in particular to an inducer with a belt wheel hoop capable of adjusting speed for a pump.

Background

When the pump is in actual operation, cavitation is easy to occur, and the main reasons for generating the cavitation include the following aspects: the backflow height is insufficient, so that the effective cavitation allowance is reduced; air enters the pump; the sealing gap is large, so that gap cavitation is caused; the blade is deviated from the designed working condition for long time to operate, so that the internal flow velocity of the blade is too high; the pump runs in overload; the pressure and the flow are unevenly distributed, and bubbles are generated; improper operation mode, etc. When the water quantity of the pump greatly exceeds a design value, the speed of the inlet of the impeller is increased due to the large flow, so that the pressure from the inlet of the pump to the impeller and the pressure drop in an inlet pipeline are increased, the cavitation limit is exceeded, and severe cavitation is generated. There are many ways to prevent or reduce cavitation, such as changing the inlet structure of the vanes, changing the inlet flow passage structure, or adding auxiliary devices.

At present, an inducer is added at an inlet, which is one of the most effective methods for improving the cavitation performance of the centrifugal pump and is a more common method. The inducer is used for improving the suction performance of the centrifugal pump, the inlet attack angle is small, the number of blades is small, the blade load is low, the density of the blade cascade is high, the self-cavitation performance is good, and the inlet fluid energy of the centrifugal wheel can be increased; in addition, when the cavitation allowance of the device is insufficient, the service life of the flow passage components such as the impeller, the pump body, the cover plate and the like can be prolonged.

The prior art discloses a centrifugal pump with contra-rotating inducer, which is driven by a gear set to rotate in opposite rotating directions, and the rotating speed of the inducer can realize different rotating speeds according to different transmission ratios of the gear set, so that the design of the inducer can be further optimized, and the cavitation performance of the centrifugal pump is improved. However, the device does not consider the cavitation generated by the blade top gap and cannot meet the requirements of certain occasions.

The prior art discloses a short-distance inducer without blade top gap cavitation, which solves the problems of blade top gap cavitation and blade top gap leakage flow in the operation process of an inducer by uniformly arranging a circle of axial flow type blades in the circumferential direction of an inducer wheel hub body, coaxially arranging a wheel rim ring sleeve on the outer edge of each axial flow type blade, and fixedly connecting the axial flow type blades and the inner surface of the wheel rim ring sleeve into a whole. However, the technology cannot effectively solve the problem of serious cavitation of the pump caused by the increase of the impeller inlet speed due to large flow.

Disclosure of Invention

Aiming at the defects in the prior art, the invention provides the inducer with the speed adjustable belt wheel hoop for the pump, which effectively improves the cavitation phenomenon generated due to the change of the inlet flow speed, simultaneously solves the problems of blade top gap cavitation and blade top gap leakage flow in the operation process of the inducer, and can further improve the anti-cavitation performance of the pump.

The present invention achieves the above-described object by the following technical means.

A speed-adjustable inducer with a belt wheel hoop for a pump comprises an impeller and an inducer which are coaxially arranged on a pump shaft;

an inlet straight-mouth ring is integrally formed on a front cover plate of the impeller, an inducer wheel band is arranged on the outer side of a blade of the inducer, and a speed regulating device is arranged between the inducer wheel band and the inlet straight-mouth ring;

the speed regulating device comprises a first gear, a second gear and a third gear, the first gear is arranged at the section of the outer edge 1/3 of the outlet of the inducer wheel band, the third gear is arranged at the inner edge of the outlet of the inlet straight-mouth ring, and the second gear is arranged on the inlet pipe; the second gear is respectively meshed with the first gear and the third gear.

Among the above-mentioned technical scheme, the pump shaft processing is the step shaft, and the pump shaft is less than the one end diameter of keeping away from the import pipe near the one end diameter of import pipe, fixes the impeller on the big one section pump shaft of diameter, fixes the inducer on the little one section pump shaft of diameter.

In the technical scheme, the hub bearing A and the hub bearing B are respectively arranged at two ends of the pump shaft with the small diameter.

In the technical scheme, the front end of the pump shaft is provided with a conical or hemispherical water guide cone.

In the technical scheme, an inducer hub is arranged on the inner side of an inducer blade, a gland A and a gland B which are in clearance fit with a pump shaft are respectively fixed at two ends of the inducer hub, and oil seals are respectively arranged inside the gland A and the gland B; the inner wall of the inducer hub is matched with the outer rings of the hub bearing A and the hub bearing B.

In the above technical solution, the first gear and the second gear are both external gears, and the third gear is an internal gear.

In the above technical solution, the third gear and the first gear have the same length.

In the above technical solution, the number of the second gears is at least 3.

In the technical scheme, the diameter of the inlet straight opening ring is larger than or equal to the diameter of the impeller inlet.

A pump comprises the inducer with the belt wheel hoop capable of adjusting speed.

The invention has the beneficial effects that:

the speed regulating device is arranged between the inlet straight-mouth ring of the impeller and the inducer wheel rim, the speed regulating device is two sets of meshed gear sets, and the inducer rotates coaxially with the impeller by setting the transmission ratio between the gears, and the rotating speeds of the inducer and the impeller are different according to different transmission ratios of the gear sets, so that the cavitation phenomenon generated due to the change of the inlet flow speed is effectively improved; meanwhile, the inducer with the wheel rim can solve the problems of blade top gap cavitation and blade top gap leakage flow in the operation process of the inducer.

In addition, the gear of the inducer wheel band is an external gear, the gear of the inlet straight-mouth ring is an internal gear, and the gear meshed with the gear of the inducer wheel band and the gear of the inlet straight-mouth ring is an external gear, so that the relative rotation of the inducer and the impeller is realized, and the anti-cavitation performance of the pump is further improved. The inducer with the belt wheel hoop capable of adjusting speed for the pump is simple in structure and convenient to install, and guarantees stable and safe operation of an impeller.

Drawings

FIG. 1 is a schematic diagram of an inducer with adjustable speed of a belt wheel hoop for a pump according to the present invention;

FIG. 2 is a schematic structural view of a pulley band inducer;

FIG. 3 is an enlarged view of a portion A of FIG. 1;

in the figure: 1-an inlet pipe; 2-a pump housing; 3-a speed regulating device; 301-a second gear; 4-an impeller; 401-inlet straight mouth ring; 401 a-third gear; 5-impeller nut; 6-a pump shaft; 7-a water guide cone; 8-inducer; 801-inducer rim; 802-inducer hub; 801 a-first gear; 9 a-hub bearing a; 9B-hub bearing B; 10 a-gland a; 10B-gland B; 11-gear bearings; 12-bolt.

Detailed Description

The invention will be further described with reference to the following figures and specific examples, but the scope of the invention is not limited thereto.

As shown in fig. 1 and 2, the inducer with a speed-adjustable pulley band for a pump according to the present invention includes an inlet tube 1, a pump housing 2, a speed-adjusting device 3, a second gear 301, an impeller 4, an inlet straight-mouth ring 401, a third gear 401a, an impeller nut 5, a pump shaft 6, a water guide cone 7, an inducer 8, an inducer band 801, a first gear 801a, an inducer hub 802, a hub bearing A9a, a hub bearing B9B, a gland a10a, a gland B10B, a gear bearing 11, and a bolt 12.

The inlet pipe 1 is fixed at the front end of the pump shell 2 through a bolt 12, the impeller 4, the pump shaft 6 and the inducer 8 are all positioned in the pump shell 2, and the impeller 4 and the inducer 8 are coaxially arranged; the pump shaft 6 is processed into a stepped shaft, the diameter of one end, close to the inlet pipe 1, of the pump shaft 6 is small, the diameter of one end, far away from the inlet pipe 1, of the pump shaft 6 is large, one section, with the large diameter, of the pump shaft 6 is fixedly connected with the impeller 4 through an impeller nut 5, the inlet straight-mouth ring 401 is located at the front end of the impeller 4, the inlet straight-mouth ring 401 and a front cover plate of the impeller 4 are integrally formed, and the diameter of the inlet straight-mouth ring 401 is; the two ends of the small-diameter section of the pump shaft 6 are respectively provided with a hub bearing A9a and a hub bearing B9B, the foremost end of the pump shaft 6 is provided with a water guide cone 7, and the water guide cone 7 is conical or hemispherical.

The inducer 8 is a complete wheel rim type inducer, an inducer wheel rim 801 is arranged on the outer side of the blade of the inducer 8, and the speed regulating device 3 is installed between the inducer wheel rim 801 and the inlet straight opening ring 401. 8 blade inboards of inducer are inducer hub 802, and inducer hub 802 inner wall sets up to cascaded, specifically is: the inner wall of the inducer hub 802 is processed into a shape with a thick middle part and thin two sides, two ends of the inner wall of the inducer hub 802 are respectively matched with an outer ring of a hub bearing A9a and an outer ring of a hub bearing B9B, two ends of the inducer hub 802 are respectively provided with a gland A10a and a gland B10B, the gland A10a and the gland B10B are in clearance fit with the pump shaft 6, and oil seals are arranged inside the gland A10a and the gland B10B and used for sealing the hub bearing A9a and the hub bearing B9B.

A first gear 801a is machined on the outer edge 1/3 section of the inducer wheel rim 801 at the outlet, and the first gear 801a is an external gear; the inlet straight-mouth ring 401 extends to be flush with the inducer wheel band 801 along the inlet direction, a third gear 401a is machined on the inner edge of the outlet of the inlet straight-mouth ring 401, the third gear 401a is an internal gear, and the length of the third gear 401a is the same as that of the first gear 801 a.

The speed regulating device 3 comprises a first gear 801a, a second gear 301 and a third gear 401a, the second gear 301 is an external gear, is fixedly arranged on the inlet pipe 1 through a bearing 11 and does not affect transmission, and the second gear 301 is respectively meshed with the first gear 801a and the third gear 401 a; according to actual working conditions, transmission ratios among the second gear 301, the first gear 801a and the third gear 401a are set respectively, and speed adjustment of the inducer 8 and the impeller 4 is achieved.

As shown in fig. 3, the second gears 301 are distributed along the circumferential direction, and the number of the second gears is at least 3; the working principle is as follows: the impeller 4 rotates along with the pump shaft 6, the inlet straight-mouth ring 401 rotates along with the impeller 4, the third gear 401a at the front end of the inlet straight-mouth ring 401 also rotates along with the impeller 4, the second gear 301 is driven to rotate, and the second gear 301 is meshed with the first gear 801a, so that the inducer 8 is driven to rotate; at this time, the inducer 8 and the impeller 4 rotate relative to each other, and the speed of the inducer 8 and the impeller 4 is adjusted by setting the transmission ratio between the gears.

The present invention is not limited to the above-described embodiments, and any obvious improvements, substitutions or modifications can be made by those skilled in the art without departing from the spirit of the present invention.