Planetary gear train type efficient rotary jet pump

Abstract

The planetary gear train type efficient rotary spraying pump comprises a shell, a main shaft is installed in the front end of the shell through a bearing and a bearing box, and the main shaft is provided with a water inlet body; a rotor cavity is formed in the shell and is formed by a rotary shell and a rotary shell cover; an impeller is fixed at the front end in the rotor cavity; a cover plate is arranged at the rear end of the shell; the cover plate contains a water outlet body; the collecting pipe is connected with the rotary shell cover through a mechanical sealing assembly; the tail end of the spindle is connected with the front end of the rotor cavity; the rotary shell and the impeller are provided with liquid medium channels which are communicated with the water inlet body of the main shaft; a planetary gear train is arranged on the outer side of the rear end of the rotor cavity and comprises a planet carrier, an inner gear arranged on the outer side of the rear end of the rotary shell cover, a double-planet-gear assembly and a center gear, the planet carrier is fixed to the collecting pipe, the center gear is fixed to the cover plate, and the planetary gear train is used for changing the rotating direction and the rotating speed of the collecting pipe. By changing the state of the collecting pipe of the rotary jet pump, the efficiency of the novel rotary jet pump is improved.

Description

Technical Field

[0001] The invention provides a planetary gear train type high-efficiency rotary jet pump, belonging to the technical field of rotary jet pumps. Background Art

[0002] The rotary jet pump is a low specific speed centrifugal pump. Its most prominent features among pump products are high efficiency, stable operation and long service life. Since the rotary jet pump involves many fields and requires a wide range of flow rates, it is naturally required to be able to adapt well to the working conditions of small flow and high head.

[0003] The rotary jet pump is mainly composed of three parts: impeller, rotor cavity and manifold. The liquid medium enters the suction chamber from the water inlet and then enters the impeller; the liquid medium obtains energy in the impeller, then enters the rotor cavity from the impeller outlet; and finally is output to the pump outlet through the manifold. The liquid medium in the impeller and rotor cavity rotates with the rotor cavity, and the impeller has no disc friction loss. The entire cavity is rotating, so the rotational torque is large when rotating.

[0004] The theoretical head of the rotary jet pump is closely related to the geometric structure and rotation speed of the impeller, the physical properties of the fluid medium, the structure and working state of the pump. The increase in the rotation speed of the rotary shell can increase the head of the rotary jet pump, but the method of increasing the liquid energy by driving the liquid to rotate rapidly by the inner wall surface will lead to a decrease in pump efficiency. Therefore, the rotation speed of the rotary shell is limited to a certain range.

[0005] For ordinary rotary jet pumps, since the impeller rotates with the rotor cavity, the degree of intense friction between the impeller, liquid medium and the inner wall of the rotor cavity is reduced. Therefore, compared with other centrifugal pumps, the efficiency of rotary jet pumps is higher. At present, the highest efficiency of rotary jet pumps is about 40% to 58%, and there is still room for further improvement. Summary of the invention

[0006] In view of the above technical problems, the present invention provides a planetary gear train type high-efficiency rotary jet pump, comprising a housing, a main shaft installed in the front end of the housing through a bearing and a bearing box, and a water inlet body is provided on the main shaft; an oil ring assembly is provided on the inner side of the bearing;

[0007] A rotor cavity is provided in the outer shell, and the rotor cavity is formed by a rotary shell and a rotary shell cover; an impeller is fixed at the front end of the rotor cavity;

[0008] A cover plate is provided at the rear end of the housing. The collecting pipe is connected to the rotating shell cover through a mechanical seal assembly to ensure that the collecting pipe rotates independently relative to the rotating shell cover. The collecting pipe is connected to the cover plate through a bearing and a bearing end cover to ensure that the collecting pipe rotates independently relative to the cover plate.

[0009] The end of the main shaft is connected to the front end of the rotor cavity through a driving disk; a liquid medium channel is provided on the rotary casing and the impeller and is connected to the water inlet of the main shaft;

[0010] After the power is input by the diesel engine or electric motor, the rotor cavity and impeller are driven to rotate through the main shaft, and finally the liquid medium entering the rotor cavity through the inner hole of the main shaft is driven to rotate.

[0011] A planetary gear train is provided on the outer side of the rear end of the rotor cavity, and the planetary gear train includes a planetary carrier, an internal gear provided on the outer side of the rear end of the rotary shell cover, a double planetary gear assembly and a center wheel. The rotary shell cover serves as an input component of the planetary gear train, the planetary carrier is fixed on the collector, and the center wheel is fixed on the cover plate. The planetary gear train is used to change the rotation direction and speed of the collector.

[0012] The technical solution of the present invention improves the efficiency of the novel rotary jet pump by changing the state of the manifold of the rotary jet pump, that is, selecting the appropriate direction and speed of the manifold through the tooth matching of each gear of the planetary gear train. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a schematic cross-sectional structure diagram of a planetary gear train type high-efficiency rotary jet pump of the present invention;

[0014] Figure 2 It is an enlarged view of the planetary gear system of the present invention;

[0015] Figure 3 It is a schematic diagram of the first embodiment of the planetary gear mechanism of the present invention;

[0016] Figure 4 This is a schematic diagram of the second planetary gear mechanism scheme of the present invention. DETAILED DESCRIPTION

[0017] The specific technical solution of the present invention is described in conjunction with the accompanying drawings.

[0018] like Figure 1 As shown, a planetary gear train type high-efficiency rotary jet pump comprises a housing 11, a main shaft 3 is installed in the front end of the housing 11 through a bearing 1 and a bearing box 4, and the main shaft 3 is provided with a water inlet; an oil ring assembly 2 is provided inside the bearing 1;

[0019] The housing 11 is provided with a rotor cavity, which is formed by a rotary shell 6 and a rotary shell cover 10; an impeller 7 is fixed at the front end of the rotor cavity;

[0020] A cover plate 15 is provided at the rear end of the housing 11. The manifold 8 is connected to the rotary shell cover 10 through a mechanical seal assembly 9 to ensure that the manifold 8 rotates independently relative to the rotary shell cover 10. The manifold 8 is connected to the cover plate 15 through a bearing and a bearing end cover 16 to ensure that the manifold 8 rotates independently relative to the cover plate 15.

[0021] The end of the main shaft 3 is connected to the front end of the rotor cavity through the driving disk 5; the swirl casing 6 and the impeller 7 are provided with a liquid medium channel connected to the water inlet of the main shaft 3;

[0022] After the power is input by the diesel engine or the electric motor, the main shaft 3 drives the rotor cavity and the impeller 7 to rotate, and finally drives the liquid medium entering the rotor cavity through the inner hole of the main shaft 3 to rotate.

[0023] A planetary gear train is provided on the outer side of the rear end of the rotor chamber, and the planetary gear train includes a planetary carrier 12, an internal gear provided on the outer side of the rear end of the rotary shell cover 10, a double planetary gear assembly 13 and a center wheel 14. The rotary shell cover 10 serves as an input component of the planetary gear train, the planetary carrier 12 is fixed on the collecting pipe 8, and the center wheel 14 is fixed on the cover plate 15. The planetary gear train is used to change the rotation direction and speed of the collecting pipe 8.

[0024] The biggest differences between the planetary gear train type high-efficiency rotary jet pump provided by the present invention and the existing rotary jet pump are as follows:

[0025] First, the planetary gear type high-efficiency rotary jet pump adds a set of planetary gears at the rear end of the rotor cavity, that is, the internal gear 10 rotates with the rotor cavity, the planet carrier 12 is fixed to the manifold 8, and the center wheel 14 is fixed to the cover plate 15. For this planetary gear, the input of the internal gear 10 will inevitably cause the rotation of the planet carrier 12, and then cause the manifold 8 to rotate.

[0026] Secondly, the main shaft 3 and the impeller 7 are installed on the front outer side and the front inner side of the rotor cavity respectively.

[0027] like Figure 1 As shown, the power is provided by a diesel engine or an electric motor, input from the main shaft 3, and driven by the drive disc 5 to rotate the rotor cavity composed of the swirl shell 6 and the swirl shell cover 10, the impeller 7, and the fluid medium. In addition, for the planetary gear train, the swirl shell cover 10 rotates and the central wheel 14 is stationary, which will inevitably cause the planet carrier 12 to rotate and output, while the manifold 8 is fixed to the planet carrier 12. Therefore, the manifold 8 must rotate with the planet carrier 12 of the planetary gear train. Designing the manifold 8 with a suitable direction and speed will inevitably increase the amount of fluid medium in the rotor cavity entering the manifold, and ultimately show the improvement of the efficiency of the new rotary jet pump.

[0028] Compared with ordinary rotary jet pumps, the present invention uses an additional set of planetary gear trains to realize the rotation of the manifold 8. At the same time, if the original arrangement of the left side of the water inlet is adopted, it will inevitably cause the water inlet to flush the planetary frame when entering the rotor cavity, causing the planetary frame to be subjected to axial force. More importantly, some areas of the planetary gear train are very likely to be soaked by the water inlet, increasing the resistance to movement and even suffering corrosion. In order to reduce the interference of the water inlet on the movement of the planetary gear train, and to ensure the reasonable structural layout of the whole machine, the technical solution arranges the water inlet on the main shaft 1, and the impeller 7 is arranged on the right inner side of the rotor cavity to realize the diversion of the water inlet into the rotor cavity.

[0029] Figure 2It is an enlarged view of the planetary gear train assembly at a ratio of 2:1, in which the planet carrier 12 is connected to the double planetary gear assembly 13, wherein the double planetary gear is provided to change the rotation direction of the manifold 8. The rotation speed of the manifold 8 can be changed by different tooth matching between the internal gear 10 of the planetary gear train assembly, the double planetary gear assembly 13, and the center wheel 14.

[0030] In the planetary gear train, the gears of the rotating shell cover 10, the planet carrier 12, the double planetary gear assembly 13, the center wheel 14, and the structural form of the planetary gear assembly 13 will directly affect the rotation direction and speed of the manifold. Therefore, the structural form of the planetary gear train will be discussed below.

[0031] Planetary gear train scheme 1:

[0032] like Figure 3 As shown, for the convenience of description in subsequent formulas, the rotating shell cover 10 is represented by the inner ring gear a, the planet carrier 12 is represented by the planet carrier h, the center wheel 14 is represented by the center wheel b, and the planetary wheel assembly 13 is represented by c.

[0033] According to the mechanical principle, the planetary gear train belongs to the 2K-H differential gear train. Assume that the speeds of gears a, b and planet carrier h are n respectively. a 、n b and n h , the number of teeth of gears a, b, and c is z a 、z b 、z c The conversion mechanism transmission ratio obtained by fixing the planet carrier h in the 2K-H type differential gear train is:

[0034]

[0035] Since the center wheel 14 in the planetary gear type high-efficiency rotary jet pump technical solution is fixed on the cover plate 15 and the rotation speed is zero, it is necessary to set n in formula (1) b =0. Then we can obtain from formula (1):

[0036]

[0037] According to the above fixing of the manifold 8 and the planet carrier h, the speed of the manifold 8 is n h If we assume that the speed of the fluid medium at the nozzle in the rotor cavity is approximately equal to the speed of the rotating shell cover 10, n a The same, then the speed n of the manifold 8 at the manifold nozzle relative to the rotor cavity ha Expressed as:

[0038]

[0039] From formula (3), we can know that the speed n of the collector nozzle relative to the rotor cavity is ha Expressed as Then the relative speed of the collector nozzle 8 relative to the rotor cavity is for:

[0040]

[0041] according to Figure 3 The structure of z a >z b , so formula (4) can be further determined as:

[0042]

[0043] Planetary gear train scheme 2:

[0044] like Figure 4 As shown, similarly, for the convenience of description in subsequent formulas, the rotating shell cover 10 is represented by the inner ring a, the planet carrier 12 is represented by the planet carrier h, the center wheel 14 is represented by the center wheel b, and the planetary wheel assembly 13 is represented by c1 and c2.

[0045] According to the mechanical principle, the planetary gear train belongs to the 2K-H differential gear train. Assume that the speeds of gears a, b and planet carrier h are n respectively. a 、n b and n h , the number of teeth of gears a, b, c1, c2 is z a 、z b 、z c1 、z c2 The conversion mechanism transmission ratio obtained by fixing the planet carrier h in the 2K-H type differential gear train is:

[0046]

[0047] Since the center wheel 14 in the planetary gear type high-efficiency rotary jet pump technical solution is fixed on the cover plate 15 and the rotation speed is zero, it is necessary to set n in formula (6) b =0. Then we can obtain from formula (6):

[0048]

[0049] According to the above fixing of the manifold 8 and the planet carrier h, the speed of the manifold 8 is n h If we assume that the speed of the fluid at the nozzle in the rotor cavity is approximately equal to the speed of the rotating shell cover 10, n a The same, then the speed n of the manifold 8 at the manifold nozzle relative to the rotor cavity ha Expressed as:

[0050]

[0051] From formula (8), we can know that the velocity at the nozzle of the manifold 8 relative to the rotor cavity is expressed as Then the relative speed of the collector nozzle 8 relative to the rotor cavity is for:

[0052]

[0053] according to Figure 4 The structure of z a >z b , it can be seen from formula (9) that a reasonable choice of z a 、z b Values ​​can reach

[0054] Comparison of the relative rotational speed of the collector nozzle 8 relative to the rotor cavity in the planetary gear train scheme 1 and scheme 2 It can be determined that option 2 is more reasonable.

[0055] In order to ensure that the mechanical efficiency of the rotary jet pump designed by the technical solution adopted in the present invention is higher than that of ordinary rotary jet pumps on the market, it is necessary to require that formula (9) is greater than 1, that is:

[0056]

[0057] Simplifying formula (10) yields:

[0058]

[0059] That is, the planetary gear train adopts a 2K-H type differential gear train with a double planetary gear train, such as Figure 4 , and the gear matching of gears a and b satisfies If the conditions are met, the double planetary gear train mechanism is combined with the aforementioned rotary jet pump components to ensure the high mechanical efficiency of the planetary gear train type rotary jet pump from a design perspective.

Claims

1. A planetary gear type high-efficiency rotary jet pump, comprising a housing (11), a main shaft (3) mounted in the front end of the housing (11) via a bearing (1) and a bearing box (4), and a water inlet body provided on the main shaft (3); It is characterized in that A rotor cavity is provided in the outer shell (11), and the rotor cavity is formed by a rotary shell (6) and a rotary shell cover (10); an impeller (7) is fixed at the front end of the rotor cavity; A cover plate (15) is provided at the rear end of the housing (11); the collecting pipe (8) is connected to the rotating shell cover (10) via a mechanical seal assembly (9); the collecting pipe (8) rotates independently relative to the rotating shell cover (10); the collecting pipe (8) is connected to the cover plate (15) via a bearing and a bearing end cover (16); the collecting pipe (8) rotates independently relative to the cover plate (15); The end of the main shaft (3) is connected to the front end of the rotor cavity through a driving disk (5); a liquid medium channel is provided on the rotary shell (6) and the impeller (7) and is connected to the water inlet of the main shaft (3); after the power is input from the diesel engine or the electric motor, the main shaft (3) drives the rotor cavity and the impeller (7) to rotate, and finally drives the liquid medium entering the rotor cavity through the inner hole of the main shaft (3) to rotate; A planetary gear train is arranged outside the rear end of the rotor cavity, the planetary gear train comprising a planetary carrier (12), an internal gear arranged outside the rear end of a rotary shell cover (10), a double planetary gear assembly (13) and a center wheel (14); the rotary shell cover (10) serves as an input component of the planetary gear train, the planetary carrier (12) is fixed on a collector (8), and the center wheel (14) is fixed on a cover plate (15); the planetary gear train is used to change the rotation direction and rotation speed of the collector (8).

2. A planetary gear type high-efficiency rotary jet pump according to claim 1, characterized in that: An oil ring assembly (2) is provided on the inner side of the bearing (1).

3. A planetary gear type high-efficiency rotary jet pump according to claim 1, characterized in that: The collecting pipe (8) is connected to the rotary shell cover (10) via a mechanical sealing assembly (9).

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