CN104196719A - Multi-stage internal meshing aircraft fuel gear pump - Google Patents

Abstract

The invention discloses a multistage internal meshing aviation fuel gear pump. The multistage internal meshing gear pump is driven by a single shaft, and the drive shaft is fixedly connected to the external drive. The three stage gear pumps are connected in series and rotate through the drive shaft. The end plate of the pump body is fixed between the first-stage casing and the second-stage casing, which is used to transition the fuel oil of the first-stage and second-stage gear pumps, and controls the opening of the oil outlet tank and the oil inlet tank to form a common area. There are oil inlet grooves and oil outlet grooves respectively. The oil passages of the gear pumps at all levels are located on the upper and lower edges of the casing to form a straight channel for communication. The oil port and the oil inlet are installed at different positions on the same side; the first-stage gear pump, the second-stage gear pump, the third-stage gear pump, and the casing tail cover are fixedly connected by bolts. The gear pump can improve the front and rear pressurization capacity of the fuel pump under high flow rate, and reduce the pressure pulsation of the fuel pump; the gear pump has a compact structure, which can reduce the leakage between each stage of the fuel pump.

Description

A multi-stage internal meshing aviation fuel gear pump

technical field

The invention relates to an aviation propulsion system fuel pump, in particular to a multistage internal meshing aviation fuel gear pump.

Background technique

In the existing aviation propulsion system, various commonly used pumps, such as plunger pumps, gear pumps and some centrifugal pumps, can meet high pressure requirements, but the structure of the plunger pump is complicated. With the increase of the maximum flow rate, the pump volume and The weight increases a lot, and the flow rate is generally below 10000kg/h, which is difficult to meet the requirements of large flow rate. The centrifugal pump has high speed, large flow rate, high reliability, simple structure and light weight, but at low speed, it cannot provide the required pressure for the engine oil supply device, that is, it cannot meet the requirements of the starting speed. The gear pump is simple in structure, compact in size, small in size and high in reliability, but it is difficult to increase the outlet pressure of the gear pump; as the pressure difference between the inlet and outlet increases, the leakage of the gear pump will increase, resulting in a decrease in volumetric efficiency; the large pressure difference makes The radial force of the driven shaft increases, which increases the wear of the bearing and reduces the life of the pump; the wear of the floating side plate and the end face is large, the mechanical efficiency of the gear pump will be reduced, and the life of the gear pump will also be reduced. The further increase of gear pump pressure is limited.

In the prior art, multi-stage parallel gear pumps and multi-stage series external gear pumps are proposed, which only achieve the purpose of boosting and increasing fuel efficiency. Designed with high-efficiency features. Invention patent CN 202493425 U discloses a "multi-stage internal gear pump". The fuel utilization rate and pressure pulsation characteristics of the stage pump. In the literature "Research on the design method of multi-stage aviation fuel gear pump", the design method and force analysis of the internal meshing cycloid gear pump are proposed, but the volumetric efficiency of the pump is not considered.

Contents of the invention

In order to avoid the defects of the prior art and overcome the problems of insufficient pressure supply of the fuel pump, large pressure pulsation, and large losses of the multi-stage pump, the present invention proposes a multi-stage internal meshing aviation fuel gear pump. The purpose is to improve the front and rear pressurization capacity of the fuel pump under high flow rate and reduce the pressure pulsation of the fuel pump; the compact structure reduces the leakage between each stage of the fuel pump.

The technical solution adopted by the present invention to solve the technical problem is: comprising a first-stage gear pump, a second-stage gear pump, a third-stage gear pump, a first-stage casing, a second-stage casing, a third-stage casing, First-stage inner rotor, second-stage inner rotor, third-stage inner rotor, first-stage outer rotor, second-stage outer rotor, third-stage outer rotor, driving shaft, oil inlet, oil outlet, pump body end The plate, the shell tail cover, and the multi-stage internal meshing gear pump are driven by a single shaft. Cycloid internal meshing, and form the first-stage gear pump with the first-stage casing, the second-stage inner rotor and second-stage outer rotor are pancycloid internal meshing, and form the second-stage gear pump with the second-stage casing , the third-stage inner rotor and the third-stage outer rotor are pancycloidally meshed, and form a third-stage gear pump with the third-stage housing. The three-stage gear pumps are connected in series and rotate through the drive shaft. The end plate of the pump body is located Between the first-stage housing and the second-stage housing, it is used to transition the fuel of the first- and second-stage gear pumps, and control the opening of the oil outlet tank and the oil inlet tank to form a common area. The third-stage gear pump housings have oil inlet tanks and outlets respectively. The oil tank, the gear pump oil circuit of each stage is located on the upper and lower edges of the casing to form a straight channel to communicate with each other. There is an oil inlet on the outside of the first stage casing, and an oil outlet on the outside of the third stage casing, which is on the same side as the oil inlet. Off-site installation, installation holes are provided at the four corners of the housing tail cover.

The first stage gear pump, the second stage gear pump, the third stage gear pump, the central axis of the casing tail cover coincides with the axis of the driving shaft.

Beneficial effect

Compared with external meshing multistage pumps and parallel gear pumps, the multistage internal meshing aviation fuel gear pump proposed by the present invention has reduced volume and weight, more compact structure, and improved transmission efficiency and power utilization. Due to the oil circuit connection between each stage, the fuel leakage between each stage of the pump body is smaller than that of other multi-stage oil pumps and combined pumps.

The end plate of the pump body is provided in the multi-stage internal meshing aviation fuel gear pump of the present invention, which can more effectively reduce leakage, and form a unique "one"-shaped oil circuit of the multi-stage pump, so as to achieve the purpose of increasing fuel utilization. In the meshing connection of the inner and outer rotors, the pancycloid inner meshing connection method is used more effectively on the aviation fuel pump. Compared with the external meshing multistage gear pump, the multistage internal meshing aviation fuel gear pump has a larger working range and smaller pressure pulsation. Under all operating conditions, it can meet the technical requirements.

Description of drawings

A multi-stage internal meshing aviation fuel gear pump of the present invention will be further described in detail below in conjunction with the drawings and embodiments.

Fig. 1 is a schematic structural diagram of a multi-stage internal meshing aviation fuel gear pump of the present invention.

Fig. 2 is a front view of the multi-stage internal meshing aviation fuel gear pump of the present invention.

Fig. 3 is a sectional view of the multi-stage internal meshing aviation fuel gear pump of the present invention.

Fig. 4a is an axial sectional view of the end plate of the pump body of the multi-stage internal meshing aviation fuel gear pump of the present invention.

Fig. 4b is a radial sectional view of the end plate of the pump body of the multi-stage internal meshing aviation fuel gear pump of the present invention.

Fig. 5a is an axial cross-sectional view of the third-stage housing of the multi-stage internal meshing aviation fuel gear pump of the present invention.

Fig. 5b is a radial cross-sectional view of the third-stage housing of the multi-stage internal meshing aviation fuel gear pump of the present invention.

In the picture:

1. First stage gear pump 2. Second stage gear pump 3. Third stage gear pump 4. First stage casing 5. Second stage casing 6. Third stage casing 7. First stage inner rotor 8 .Second stage inner rotor 9.Third stage inner rotor 10.First stage outer rotor 11.Second stage outer rotor 12.Third stage outer rotor 13.Drive shaft 14.Oil inlet 15.Oil outlet 16. Pump body end plate 17. Shell tail cover

Detailed ways

This embodiment is a multistage internal meshing aviation fuel gear pump.

Refer to Figures 1 to 5. The multi-stage internal meshing aviation fuel gear pump in this embodiment consists of a first-stage gear pump 1, a second-stage gear pump 2, a third-stage gear pump 3, a first-stage housing 4, and a second-stage gear pump. Stage housing 5, third stage casing 6, first stage inner rotor 7, second stage inner rotor 8, third stage inner rotor 9, first stage outer rotor 10, second stage outer rotor 11, third stage The outer rotor 12, the driving shaft 13, the oil inlet 14, the oil outlet 15, the pump body end plate 16, and the tail cover housing 17; wherein, the gear pump housings of all levels are equipped with oil inlet grooves and oil outlet grooves at various levels. To form an inherent "one" type oil circuit.

The three-stage internal meshing aviation fuel gear pump is connected in series by the first-stage gear pump 1, the second-stage gear pump 2, and the third-stage gear pump 3. The pump body of the three-stage gear pump is driven to rotate by the driving shaft 13, which meets the single The stress range that the shaft bears, the driving shaft 13 is fixedly connected with the first stage casing 4, the pump body end plate 16, the second stage casing 5, the third stage casing 6 and the tail cover casing 17 respectively. An oil inlet 14 is provided on the outer side of the first-stage housing 1 , and an oil outlet 15 is provided on the outer side of the third-stage housing.

The external dimensions of the second-stage casing 6 and the third-stage casing 7 are the same as those of the pump body end plate 16, and the external dimensions of the first-stage casing 5 and the tail cover casing 17 are the same to ensure the compactness of the pump body. The drive shaft 13 is located at the center of the gear pump housings at all levels to ensure that the forces on the gear pumps are symmetrical and balanced to achieve overall stability. The oil inlet 14 and the oil outlet 15 are installed at different positions on the same side to meet the overall oil circuit of the three-stage gear pump and realize the fuel utilization rate of the gear pump. The multi-stage internal meshing gear pump is driven by a single shaft, and the gear pumps of all stages are connected in series by the driving shaft 13, and the length of the driving shaft 13 is relatively long. The outlet pressure of the gear pump is relatively high, and the driving gear shaft 13 bears a large acting moment. Its strength and rigidity meet the requirements through simulation experiment analysis, and it is not easy to be damaged during use.

A type flat key is arranged on the top of the driving shaft 13 to realize the connection with the external drive, and is connected with the first stage housing 6 through the bearing cover and the bearing. The first-stage inner rotor 7 and the first-stage outer rotor 10 are pancycloid internal meshes and form the first-stage gear pump 1 with the first-stage housing 4; the second-stage inner rotor 8 and the second-stage outer rotor 11 are pancycloid Cycloid internal meshing and second-stage gear pump 2 with the second-stage casing 5; third-stage casing 6, third-stage inner rotor 9 and third-stage outer rotor 12 are pancycloid internal meshing and third-stage The first-stage casing 6 forms the third-stage gear pump 3; the three-stage gear pumps are connected in series, and the three-stage gear pump is connected and rotated through the driving shaft 13, and the casing end plate 16 is installed between the first-stage casing 4 and the second-stage casing 5 Between the first and second gear pumps, it is used to transition the fuel oil of the first and second gear pumps, and controls the opening of the oil outlet tank and the oil inlet tank to form a common area. The oil passages are located on the upper and lower edges of the casing to form a straight channel for communication. The design of the inner and outer rotors includes the design of the number of teeth, eccentricity, radius and arc of the created circle. The connection form of the inner and outer rotors is internal meshing to achieve large flow, small leakage, and no undercutting. The three-stage internal and external rotor structure includes the design of the first-stage inner rotor 7, the second-stage inner rotor 8, and the third-stage inner rotor 9. The pancycloid motion equation is derived by using the pancycloid formation principle, and combined with the UG expression function, it can be directly drawn The tooth profile curve of the inner rotor is obtained, and the solid model of the inner rotor is obtained by stretching. This improves accuracy and saves modeling man-hours. The first-stage outer rotor 10, the second-stage outer rotor 11, and the third-stage outer rotor 12 are all arc-shaped, and their tooth profiles are arcs with the same number of teeth, and the centers of the arcs are evenly distributed on the created circle.

In order to realize the tightness of the three-stage gear pumps in series, the oil inlet grooves and oil outlet grooves of the pumps of each stage are formed on the shells of each stage in the way of "one"-shaped channel. Each gear pump oil circuit of the three-stage internal gear pump is communicated with the inlet and outlet located at the upper and lower edges of the first-stage casing 4 , the second-stage casing 5 , and the third-stage casing 6 . Among them, on the connecting end plates of each stage, the eccentricity of the first-stage outer rotor 10, the second-stage outer rotor 11, and the third-stage outer rotor 12 are reversed by the front and rear external gears to make the outlet of the previous stage and the rear one. The inlet of the stage is on the same side of the shaft, that is, the outlet of the first-stage oil outlet and the inlet of the second-stage oil inlet, the outlet of the second-stage oil outlet and the outlet of the third-stage oil inlet are on the same side of the shaft, and the front and rear oil grooves The public area is opened, and the liquid can directly flow into the next level. In each pump body, the first-stage oil outlet tank and the second-stage oil inlet tank have a common overlapping area. When the common area is opened, the oil is discharged from the first-stage gear pump 1 and directly enters the second-stage gear pump 2 to continue pressurization. The oil inlet of the multi-stage gear pump is formed on the right side of the first-stage gear pump, and the oil outlet of the first-stage gear pump is formed on the left side of the rear cover plate of the first-stage gear pump 1 to allow the oil to flow smoothly into the next stage. The second-stage oil inlet on the left side of the front cover of the second-stage gear pump 2, the oil flows out from the second-stage oil outlet on the right side of the rear cover of the second-stage gear pump 2, and enters the third-stage gear The third-stage oil inlet on the right side of the front cover of the pump 3 finally flows out of the oil outlet 15 on the left side of the tail cover housing. The end plate 16 of the pump body is arranged between the first-stage casing 4 and the second-stage casing 5, and forms an oil passage through which the oil passages of the first and second pumps communicate, so as to obtain good oil filling performance. In order to obtain good sealing performance, the second-stage housing 5 and the third-stage housing 6 are integrated with the end plate to prevent leakage caused by the tight connection between the end plate and the eccentric sleeve housing. The oil inlet tank of the latter stage gear pump is still connected.

Claims (2)

1. A multi-stage internal meshing aviation fuel gear pump is characterized in that: comprising a first-stage gear pump, a second-stage gear pump, a third-stage gear pump, a first-stage housing, a second-stage housing, a third Stage casing, first stage inner rotor, second stage inner rotor, third stage inner rotor, first stage outer rotor, second stage outer rotor, third stage outer rotor, drive shaft, oil inlet, oil outlet , pump body end plate, casing tail cover, multi-stage internal meshing gear pump adopts single-shaft drive, the driving shaft is fixedly connected with the external drive, and is connected with the first-stage casing through bearings, the first-stage inner rotor and the first-stage The outer rotor is a pancycloid internal mesh, and forms the first-stage gear pump with the first-stage casing, the second-stage inner rotor and the second-stage outer rotor are pancycloid internal mesh, and forms the second-stage gear pump with the second-stage casing. Two-stage gear pump, the third-stage inner rotor and the third-stage outer rotor are pancycloid internally meshed, and form the third-stage gear pump with the third-stage housing. The three-stage gear pumps are connected in series and rotate through the drive shaft. The body end plate is located between the first-stage shell and the second-stage shell, and is used to transition the fuel oil of the first-stage and second-stage gear pumps, and controls the opening of the oil outlet tank and the oil inlet tank to form a common area. The oil inlet groove and the oil outlet groove, the oil passages of the gear pumps at all levels are located on the upper and lower edges of the casing to form a straight channel to communicate with each other. The oil port is installed in different positions on the same side, and the four corners of the tail cover of the housing are provided with installation holes. 2. The multi-stage internal meshing aviation fuel gear pump according to claim 1, characterized in that: the first-stage gear pump, the second-stage gear pump, the third-stage gear pump, the central axis of the housing tail cover and the axis of the drive shaft coincide.