CN117212023A

CN117212023A - Volumetric hydraulic turbine for driving foam pump and foam proportion mixing device

Info

Publication number: CN117212023A
Application number: CN202311280403.1A
Authority: CN
Inventors: 吴海卫; 贺源
Original assignee: Shanghai Pudong Special Fire Fighting Equipment Co ltd
Current assignee: Shanghai Pudong Special Fire Fighting Equipment Co ltd
Priority date: 2023-09-28
Filing date: 2023-09-28
Publication date: 2023-12-12

Abstract

The invention provides a positive displacement hydraulic turbine for driving a foam pump and a foam proportion mixing device, wherein the hydraulic turbine comprises: the engine body, the output shaft, the synchronous shaft, the rotor and the synchronous gear are provided with a fire water inlet and a mixed liquid outlet which are arranged oppositely; the synchronous shaft and the output shaft synchronously rotate and are arranged in the machine body in parallel with each other; the rotors are respectively arranged on the output shaft and the synchronous shaft, the rotors have helical angles with equal sizes and opposite directions, and normal surface molded lines of the rotors are mutually conjugate curves; the synchronous gears are respectively arranged at the end parts of the same side of the synchronous shaft and the output shaft and are meshed with each other, so that the synchronous shaft and the output shaft synchronously rotate; the fire water inlet and the mixed liquid outlet of the machine body are both provided with enveloping baffles, and the enveloping baffles can shield the flow channel in the rotation process of the rotor, so that a complete enveloping space is formed among the rotor, the machine body and the enveloping baffles. The invention has high strength, high overspeed resistance, impurity resistance, relatively easy processing and very low noise and vibration.

Description

Volumetric hydraulic turbine for driving foam pump and foam proportion mixing device

Technical Field

The invention relates to the field of foam fire extinguishing systems, in particular to a positive displacement hydraulic turbine for driving a foam pump and a foam proportion mixing device.

Background

The foam fire extinguishing system is a fire extinguishing system which takes foam liquid as a fire extinguishing agent. According to the classification of the component parts, the foam liquid storage device, the foam liquid and water mixing device according to the proportion and the terminal spraying foaming device can be divided. The fire-extinguishing system can be divided into a fixed foam fire-extinguishing system (such as a foam water spraying system, a tank area foam spraying covering system and a foam gun fire-extinguishing system) and a movable foam fire-extinguishing system according to application modes. The foam fire extinguishing systems can be classified into low-multiple, medium-multiple and high-multiple foam fire extinguishing systems according to different foaming times. In foam system applications, the core component is a device that mixes the foam concentrate with water in a proportional manner.

Among the numerous foam proportioning devices, the mechanical pumped proportioning device is a flow balanced proportioning device. The fire water flowing in the pipeline is used as driving force, and the foam liquid pump is driven by the water turbine to pump foam liquid in the normal pressure tank, and the foam liquid is pumped into the fire main pipeline. Through the matching of the internal structural parameters of the hydraulic turbine and the foam liquid pump, the flow of water and the flow of foam liquid are balanced, and the constant-proportion mixing is realized.

The mechanical pump type proportion mixing device has small volume, small occupied area, accurate mixing ratio control, no water source loss, no need of externally providing power supply or diesel engine, and is a product with excellent performance and advanced technology. And the most central structure of the mechanical pump-in type proportional mixing device is a non-discharge water turbine for driving a foam pump.

In fire-fighting foam fire-extinguishing systems, it is generally necessary to inject foam concentrate into fire-fighting water in a certain proportion to form foam mixture for fire-fighting. The volumetric foam pump is used for conveying foam concentrate in a common mode, the driving mode of the volumetric foam pump comprises a motor, a diesel engine, a water turbine and the like, and the water turbine is used as an intrinsically safe power source, so that the volumetric foam pump has the advantages of being simple in system, safe, reliable and the like, and is very suitable for being used as a power source of the foam pump. The water turbine is generally arranged on a fire water main pipeline, the flow of the water turbine is the flow of fire water, and the fire water drives the water turbine to work so as to generate a certain pressure difference. Because the power of the foam pump is generally smaller, the pressure difference generated after the fire water turbine is driven is also not large, and the normal water supply of the fire protection system is not greatly influenced by the pressure difference which is generally about 0.2 MPa.

The current water turbines mainly comprise a sliding vane type water turbine and a screw type water turbine.

Fig. 1A shows a sliding vane water turbine. The sliding vane turbine generally has the following disadvantages:

1. the strength is weaker, so that the rotating speed is not easy to be too fast, generally not more than 1500r/min, and when the flow is too high, the water turbine is easy to damage due to the higher rotating speed (the rotating speed is positively related to the flow).

2. Is sensitive to medium, has relatively high requirement on water quality, is easy to be seized in water containing impurities, and has poor working reliability.

3. The structure is complex, the precision requirement of the part manufacturing is higher, and therefore the price is higher.

4. When the rotation speed is large, the noise and vibration of the equipment are large.

Fig. 1B shows a screw turbine. Screw-type hydraulic turbines have the following disadvantages:

1. the processing difficulty is high, the manufacturing cost is high, and the price is high.

2. The noise and vibration of the equipment are large.

3. Because the internal structure of twin-screw is comparatively complicated, need professional to carry out accurate maintenance.

4. Is relatively sensitive to the medium.

In view of the above, the present inventors devised a volumetric water turbine and a foam proportional mixing device for driving a foam pump in order to overcome the above-mentioned problems.

Disclosure of Invention

The invention aims to overcome the defects of low strength, intolerance to overspeed, intolerance to impurities, high processing difficulty, high working noise and high vibration of a water turbine in the prior art, and provides a volumetric water turbine for driving a foam pump and a foam proportion mixing device.

The invention solves the technical problems by the following technical proposal:

the invention provides a positive displacement hydraulic turbine for driving a foam pump, which is characterized in that the hydraulic turbine comprises: the engine comprises an engine body, an output shaft, a synchronizing shaft, at least two rotors and a pair of synchronizing gears, wherein a group of fire water inlets and mixed liquid outlets which are arranged oppositely are arranged on the engine body; the synchronous shaft and the output shaft are arranged in the machine body in parallel, and the synchronous shaft and the output shaft synchronously rotate; the rotors are respectively arranged on the output shaft and the synchronous shaft, the rotors have spiral angles with equal sizes and opposite directions, and normal surface molded lines of the rotors are mutually conjugate curves; the synchronous gears are respectively arranged at the same side end parts of the synchronous shaft and the output shaft and are meshed with each other, so that the synchronous shaft and the output shaft synchronously rotate; the fire-fighting water inlet and the mixed liquid outlet of the machine body are both provided with enveloping baffles, and the enveloping baffles can shield a runner in the rotation process of the rotor, so that a complete enveloping space is formed among the rotor, the machine body and the enveloping baffles.

According to one embodiment of the invention, the rotor is a torsional gear rotor, and the phase difference between two end surfaces of the rotor is 170-190 degrees.

According to one embodiment of the invention, the rotor is a torsional gear rotor, and the phase difference between two end surfaces of the rotor is 80-100 degrees.

According to one embodiment of the invention, the envelope baffles are staggered, the envelope baffles at the fire water inlet of the machine body being arranged close to the first end of the rotor; the enveloping baffle at the mixed liquid outlet of the machine body is arranged at the second end part close to the rotor, so that two adjacent teeth of the rotor can be not communicated with the fire-fighting water inlet and the mixed liquid outlet together with a cavity formed between the machine body and the enveloping baffle, thereby forming a complete enveloping space and ensuring that the water turbine has accurate displacement.

According to one embodiment of the invention, the envelope baffle is a V-shaped baffle.

According to one embodiment of the invention, the formation angle of the two sides of the V-shaped baffle plate is smaller than or equal to the sum of the helix angles of the rotors at the two sides.

According to one embodiment of the invention, the envelope baffle is a U-shaped baffle.

According to one embodiment of the invention, the rotor has at least four teeth.

According to one embodiment of the invention, the rotor has a crest factor of 1.0-1.25 and a roof clearance factor of 0.25-0.

According to one embodiment of the invention, an end face compensation plate is arranged between the end part of the rotor and the inner wall surface of the bearing body of the machine body, and an elastic compensation structure is arranged on a first end face of the end face compensation plate, wherein the first end face faces the inner wall surface of the bearing body of the machine body.

According to one embodiment of the invention, the elastic compensation structure is a wave spring.

According to one embodiment of the invention, the ratio of the tooth width of the rotor to the center distance of the rotor is 2.5, and the ratio of the shaft diameter of the rotor to the center distance of the rotor is between 0.3 and 0.4.

According to one embodiment of the invention, the tooth width of the rotor is 175-625 mm, the center distance of the rotor is 70-250 mm, and the shaft diameter of the rotor is 28-75 mm.

According to one embodiment of the invention, the tooth width of the rotor is 175mm, the center distance of the rotor is 70mm, and the shaft diameter of the rotor is 28mm.

According to one embodiment of the invention, the tooth width of the rotor is 220mm, the center distance of the rotor is 88mm, and the shaft diameter of the rotor is 33mm.

According to one embodiment of the invention, the tooth width of the rotor is 275mm, the center distance of the rotor is 110mm, and the shaft diameter of the rotor is 38mm.

According to one embodiment of the invention, the tooth width of the rotor is 330mm, the center distance of the rotor is 132mm, and the shaft diameter of the rotor is 43mm.

According to one embodiment of the invention, the tooth width of the rotor is 400mm, the center distance of the rotor is 160mm, and the shaft diameter of the rotor is 53mm.

According to one embodiment of the invention, the tooth width of the rotor is 500mm, the center distance of the rotor is 200mm, and the shaft diameter of the rotor is 63mm.

According to one embodiment of the invention, the tooth width of the rotor is 625mm, the center distance of the rotor is 250mm, and the shaft diameter of the rotor is 75mm.

According to one embodiment of the invention, the hydraulic turbine is further provided with a speed change gear box body, a connecting shaft, a first speed change gear and a second speed change gear, the connecting shaft is provided with the first speed change gear, the output shaft is provided with the second speed change gear, the first speed change gear is meshed with the second speed change gear so as to transmit the power of the output shaft to the connecting shaft, the speed change gear box body is arranged on the opposite side of the machine body, the synchronous gear side is arranged on the machine body, the connecting shaft is movably connected to the speed change gear box body, and the first speed change gear and the second speed change gear are arranged in the speed change gear box body.

The invention also provides a foam proportion mixing device which is characterized by comprising a foam pump, a foam liquid pipeline and a flushing pipeline, and the positive displacement hydraulic turbine which comprises a connecting shaft and a speed change gear structure and is used for driving the foam pump, wherein the outlet of the foam pump is connected with the mixed liquid outlet of the hydraulic turbine through the foam liquid pipeline, the inlet of the foam pump is connected with the fire water inlet of the hydraulic turbine through the flushing pipeline, and the main shaft of the foam pump is connected with the connecting shaft of the hydraulic turbine, so that the power generated by the hydraulic turbine is transmitted to the foam pump.

The invention also provides another foam proportion mixing device which is characterized by comprising a foam pump, a foam liquid pipeline and a flushing pipeline, and a positive displacement hydraulic turbine which does not comprise a connecting shaft and a speed change gear structure and is used for driving the foam pump, wherein the outlet of the foam pump is connected with the mixed liquid outlet of the hydraulic turbine through the foam liquid pipeline, the inlet of the foam pump is connected with the fire water inlet of the hydraulic turbine through the flushing pipeline, and the main shaft of the foam pump is connected with the output shaft of the hydraulic turbine, so that the power generated by the hydraulic turbine is transmitted to the foam pump.

The invention has the positive progress effects that:

the positive displacement hydraulic turbine and the foam proportion mixing device for driving the foam pump have the following advantages:

1. the strength is high, the overspeed and impurity resistance is realized, the processing is relatively easy, and the noise and vibration are very small;

2. a complete enveloping space can be formed between the rotor and the machine body of the positive displacement water turbine, so that the accurate displacement of the water turbine is ensured;

3. the two rotors are free from friction, so that the rotors can be ensured to run more safely, permanently and reliably;

4. the foam proportion mixing device can adjust the ratio of the foam concentrate to the fire water, so that foam mixed liquids with different mixing ratios are obtained, and different places and project requirements are met.

Drawings

The above and other features, properties and advantages of the present invention will become more apparent from the following description of embodiments taken in conjunction with the accompanying drawings in which like reference characters designate like features throughout the drawings, and in which:

fig. 1A is a schematic structural view of a prior art sliding vane water turbine.

Fig. 1B is a schematic structural view of a screw turbine in the prior art.

Fig. 2 is a schematic perspective view of a positive displacement hydraulic turbine for driving a foam pump according to the present invention.

Fig. 3 is a schematic cross-sectional view of a positive displacement hydraulic turbine for driving a foam pump according to the present invention.

Fig. 4 is a schematic diagram showing a double rotor structure of a positive displacement hydraulic turbine for driving a foam pump according to the present invention.

Fig. 5A is a schematic view of the undercut phenomenon of the gear.

Fig. 5B is a schematic diagram of gerotor volume utilization calculation.

Fig. 6A is a schematic diagram of a design structure of a gear rotor with seven teeth.

Fig. 6B is a schematic diagram of a design structure of a gear rotor with six teeth.

Fig. 6C is a schematic diagram of a design structure of a gear rotor with five teeth.

Fig. 6D is a schematic diagram of a design structure of a gear rotor with four teeth.

Fig. 6E is a schematic diagram of a design structure of a gear rotor with three teeth.

Fig. 7A is a schematic front view of a 180 degree out of phase rotor of a positive displacement turbine for driving a foam pump according to the present invention.

Fig. 7B is a perspective view of a rotor having a phase difference of 180 degrees in a positive displacement turbine for driving a foam pump according to the present invention.

Fig. 8 is a perspective view showing a rotor having a phase difference of 90 degrees in a positive displacement turbine for driving a foam pump according to the present invention.

Fig. 9A is a schematic diagram of the relationship between the tooth top coefficient and the tooth profile.

Fig. 9B is a schematic view showing a gap between a rotor and a body in a positive displacement turbine for driving a foam pump according to the present invention.

Fig. 9C is a schematic diagram of the top gap of the prior art design when the gears are engaged.

Fig. 9D is a schematic diagram of the head space of the positive displacement turbine of the present invention for driving a foam pump when the two rotors are mated.

Fig. 10A is a schematic view showing a V-shaped baffle plate provided at the outlet side of a mixed liquid in a volumetric water turbine for driving a foam pump according to the present invention.

Fig. 10B is a schematic view of a V-shaped baffle plate provided on the water inlet side of the hydro-fire turbine for driving a foam pump according to the present invention.

Fig. 11A is a schematic perspective view showing the movement structure of the volumetric water turbine for driving the foam pump according to the present invention.

Fig. 11B is a schematic sectional view showing the movement structure of the volumetric water turbine for driving the foam pump according to the present invention.

Fig. 12 is a schematic view of a U-shaped baffle in a positive displacement turbine for driving a foam pump according to the present invention.

Fig. 13 is a schematic view showing the structure of the end face compensation plate and the wave spring in the positive displacement turbine for driving the foam pump according to the present invention.

Fig. 14A is a schematic view showing engagement of a first speed change gear and a second speed change gear of a volumetric turbine when the foam mixing apparatus of the present invention outputs a foam mixture of 1% mixing ratio.

Fig. 14B is a schematic view showing engagement of the first speed change gear and the second speed change gear of the volumetric turbine when the foam mixing device of the present invention outputs a foam mixture of 3% mixing ratio.

Fig. 14C is a schematic view showing engagement of the first speed change gear and the second speed change gear of the volumetric turbine when the foam mixing device of the present invention outputs a foam mixture of 6% mixing ratio.

FIG. 15A is a schematic cross-sectional view of a positive displacement hydraulic turbine when the foam proportioning device of the present invention outputs a foam mixture at a 1% mixing ratio.

FIG. 15B is a schematic cross-sectional view of a positive displacement hydraulic turbine when the foam proportioning device of the present invention outputs a foam mixture at a 3% mixing ratio.

FIG. 15C is a schematic cross-sectional view of a positive displacement hydraulic turbine when the foam proportioning device of the present invention outputs a foam mixture at a mixing ratio of 6%.

Fig. 16 is a perspective view showing engagement of a first speed gear and a second speed gear in a positive displacement hydraulic turbine for driving a foam pump according to the present invention.

Fig. 17 is a schematic cross-sectional view of an embodiment of the volumetric water turbine for driving a foam pump of the present invention without a connecting shaft and a ratio gear structure.

Fig. 18 is a schematic perspective view of a foam proportioning device of the present invention having a connecting shaft and a ratio gear structure.

Fig. 19 is a schematic perspective view of a foam proportioning device of the present invention having only one foam pump connected to the output shaft of a hydraulic turbine without a connecting shaft and a ratio gear structure.

Fig. 20 is a schematic perspective view of a foam proportioning device of the present invention having one foam pump connected to each side of the output shaft of a hydraulic turbine without a connecting shaft and a ratio gear structure.

[ reference numerals ]

Body 100

Fire water inlet 110

Mixed liquor outlet 120

Envelope baffle 130

Bearing body 140

Outer casing 150

Movement 160

Output shaft 200

Synchronizing shaft 300

Rotor 400

Flow channel 410

First end 420

Second end 430

Synchronous gear 500

End face compensation plate 600

First end face 610

Elasticity compensation structure 700

Speed change gear case 800

Connecting shaft 900

First variable-speed gear 1000

Second ratio gear 1100

Foam pump 11

Foam liquid pipeline 12

Flushing line 13

Detailed Description

In order to make the above objects, features and advantages of the present invention more comprehensible, embodiments accompanied with figures are described in detail below.

Embodiments of the present invention will now be described in detail with reference to the accompanying drawings. Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts.

Furthermore, although terms used in the present invention are selected from publicly known and commonly used terms, some terms mentioned in the present specification may be selected by the applicant at his or her discretion, the detailed meanings of which are described in relevant parts of the description herein.

Furthermore, it is required that the present invention is understood, not simply by the actual terms used but by the meaning of each term lying within.

As shown in fig. 2, 3 and 16, the present invention provides a positive displacement hydraulic turbine for driving a foam pump, the hydraulic turbine comprising: the machine body 100, the output shaft 200, the synchronizing shaft 300, at least two rotors 400, and a pair of synchronizing gears 500. The machine body 100 is provided with a set of fire water inlet 110 and mixed liquor outlet 120 which are arranged oppositely. The synchronizing shaft 300 and the output shaft 200 are disposed in parallel with each other in the machine body 100, and the synchronizing shaft 300 rotates in synchronization with the output shaft 200. The two rotors 400 are respectively mounted on the output shaft 200 and the synchronizing shaft 300, the two rotors 400 have equal and opposite spiral angles, and the normal surface molded lines of the two rotors 400 are mutually conjugate curves. The synchronizing gears 500 are provided at the same side ends of the synchronizing shaft 300 and the output shaft 200, respectively, and intermesh so that the synchronizing shaft 300 and the output shaft 200 rotate synchronously.

As shown in fig. 10A and 10B, the fire water inlet 110 and the mixed liquor outlet 120 of the machine body 100 are both provided with an envelope baffle 130, and the envelope baffle 130 can cover the flow passage 410 in the rotation process of the rotor 400, so that a complete envelope space is formed among the rotor 400, the machine body 100 and the envelope baffle 130.

Preferably, the body 100 includes an outer case 150, a deck 160, and a bearing body 140, the deck 160 surrounding the outer case 150, the bearing body 140 being disposed at both sides of the deck 160 and the outer case 150. The output shaft 200 and the synchronizing shaft 300 are fixed to the machine body 100 through bearings in the bearing body 140 so that they can freely rotate. Meanwhile, lip seals are also provided at both sides of the output shaft 200 and the synchronizing shaft 300, thereby preventing leakage. The synchronizing gear 500 is disposed on the non-output side of the turbine.

In the use process of the positive displacement water turbine, the pair of synchronous gears 500 are meshed, so that friction generated by contact between the two rotors 400 is effectively avoided, the rotors 400 can be protected, the rotors 400 can be ensured to run more safely, permanently and reliably, and the equipment can run more permanently, stably and with high performance.

As shown in fig. 4, the end surface profile of the rotor 400 is preferably formed of involute type, and a certain helix angle is selected to generate a left-handed and a right-handed rotor 400, respectively, for engagement. In operation, the pair of rotors 400 are rotated in different directions by the action of the liquid pressure. Although the rotors 400 are intermeshed, the two rotors 400 are independent of each other and do not contact each other. So that there is zero, no load, no interaction, and no energy transfer between the rotor 400 and the tooth face forces. Wear does not occur in the rotation process of equal rotation speed and equal torque, and the service life is greatly prolonged. And the rotor 400 adopts a spiral type, so that the non-uniformity of liquid delivery can be improved, and the pulsation of instantaneous flow can be reduced. Because the flow pulsation is small, and the two rotors 400 have equal rotating speeds and equal torque, the vibration and the noise are low when the water turbine operates, and the pressure loss is reduced to a certain extent. Therefore, the rotor 400 adopts a form with a spiral angle, so that pressure pulsation generated by fluid in the running process is effectively reduced, and the equipment runs more stably.

Because the fire water inlet 110 and the mixed liquid outlet 120 of the body 100 of the volumetric water turbine are both provided with the envelope baffle 130, a complete envelope space is formed among the rotor 400, the body 100 and the envelope baffle 130, so that the constant displacement of the water turbine can be effectively ensured. The displacement, i.e. the volume of fluid displaced in one revolution of the device.

As shown in fig. 4, 7A and 7B, as a preferred embodiment of the volumetric water turbine for driving a foam pump according to the present invention, the rotor 400 is a twist type gerotor 400, and a phase difference between both end surfaces of the rotor 400 is preferably 170 degrees to 190 degrees.

Further, the phase difference of both end surfaces of the rotor 400 may be preferably 180 degrees. The inner wall of the body 100 and the grooves of the rotor 400 together form an enclosed space having a certain fixed volume therein, which is called an overflow chamber of the water turbine. The fluid in the space is a single volume divided into successive fluids by the rotor 400. A number of spiral cavities of known volume are formed between the spiral rotor 400 mounted in the body 100 and the body 100. Under the action of water flow, the two spiral rotors 400 with the same geometric dimension and opposite rotation directions are pushed to be meshed and rotated by the pressure difference of the inlet and the outlet, and the flow rate flowing through the water turbine is in direct proportion to the rotation speed of the rotors 400.

Since the rotor 400 is a 180 degree spiral, the force of the water flow is the same at any angle of rotation. Therefore, although the pair of conjugate rotors 400 are meshed with each other like gears, there is no interaction force, the tooth surface force between the rotors 400 is zero, no energy transmission is generated, abrasion does not occur in the rotation process of constant speed and equal torque, and the service life is prolonged. In one cross-section, the liquid acts perpendicularly to the contour of the rotor 400. As for the whole of the rotor 400, the pair of rotors 400 are rotated in different directions by the action of the liquid pressure. The rotor 400 has the characteristics of stable rotation, low noise and no pulsation.

When the roots rotor, the cam rotor, etc. are selected, the water flow pressure received by each rotor is different at different rotation positions, and the output torque is periodically changed from zero to the maximum, which inevitably generates vibration. Torsional gerotors vibrate relatively little when in operation and are therefore a preferred option.

The surfaces of the two rotors 400 designed in the present invention are not in contact but maintain a minute fixed gap, and thus, the normal surface profile of the rotors 400 is a pair of curves conjugate to each other, typically composed of a combination of an arc, an involute and a cycloid.

As shown in fig. 8, as a preferred embodiment of the positive displacement turbine for driving the foam pump of the present invention, the rotor 400 is a twist type gerotor 400, and the phase difference between both end surfaces of the rotor 400 is 80 degrees to 100 degrees.

Further, the phase difference of both end surfaces of the rotor 400 may be preferably 90 degrees. Similar to the rotor 400 having a phase difference of 180 degrees, the rotor 400 having a phase difference of 90 degrees is rotated at an arbitrary rotation angle, and the force of the water flow is the same. Therefore, no interaction force exists between the pair of conjugated rotors 400, the tooth surface force between the rotors 400 is zero, and no energy transmission is realized. The structure can ensure that the rotor 400 is not worn in the rotation process of constant speed and equal torque, and the service life is prolonged.

In the prior art study on a bevel gear pump, the following conclusion is drawn: under the condition that the helical gear pump works normally, the tooth width is fixed, and the flow non-uniformity coefficient of the helical gear pump and the helical angle are in a linear inverse relation. That is, as the helix angle increases, the flow non-uniformity coefficient gradually decreases; the larger the helix angle (the larger the phase difference), the smaller the pressure pulsation.

According to the above conclusion: because the rotor 400 with a 90-degree phase difference has a smaller spiral angle than the rotor 400 with a 180-degree phase difference, the flow non-uniformity coefficient is larger, and the pressure pulsation is larger.

Therefore, a rotor 400 having a phase difference of 180 degrees is a preferable solution compared to a rotor 400 having a phase difference of 90 degrees, and a rotor 400 having a phase difference of 90 degrees is a suboptimal solution. That is, the phase difference of the rotor 400 is more preferably in the range of 170 degrees to 190 degrees, and the phase difference of the rotor 400 is less preferably in the range of 80 degrees to 100 degrees. As shown in fig. 10A to 11B, as a preferred embodiment of the volumetric water turbine for driving a foam pump of the present invention, envelope baffles 130 are staggered,

the envelope baffle 130 at the fire water inlet 110 of the machine body 100 is disposed near the first end 420 of the rotor 400; the envelope baffle 130 of the mixed liquor outlet 120 of the body 100 is disposed proximate the second end 430 of the rotor 400,

so that the adjacent two teeth of the rotor 400 can not be communicated with the cavity formed between the machine body 100 and the enveloping baffle 130, the fire water inlet 110 and the mixed liquid outlet 120, thereby forming a complete enveloping space and ensuring that the water turbine has accurate displacement.

The arrangement of the envelope baffle 130 ensures that a complete envelope space can be formed between the rotor 400 and the machine body 100 and between the rotor 400 and the envelope baffle 130, namely, when the rotor 400 rotates to a certain position, cavities formed by two adjacent teeth of the rotor 400 and the machine body 100 and the envelope baffle 130 are not communicated with the inlet and the outlet, so that the water turbine is ensured to have accurate displacement, namely, the flow rate of each rotation is the same.

Without the envelope baffle 130, a complete envelope space cannot be formed, and even a rotor with a 90 degree phase difference cannot form a complete envelope flow path. And rotors with the envelope baffles 130, 90 degrees and 180 degrees phase difference can form a complete envelope flow path.

As shown in fig. 10A to 11B, as a preferred embodiment of the positive displacement turbine for driving a foam pump of the present invention, the envelope baffle 130 preferably adopts a V-shaped baffle.

The V-shaped baffle structure can be designed to fit the spiral angles of the rotors 400 on both sides as much as possible, so that the material is saved and the positive displacement turbine equipment is light. The V-shaped baffle structure is preferably provided on the movement 160. The V-shaped baffle structure cooperates with the machine body 100 and the rotor 400 to form a complete envelope space, ensuring accurate displacement of the turbine.

As shown in fig. 10A to 11B, as a preferred embodiment of the positive displacement turbine for driving a foam pump of the present invention, both sides of the V-shaped baffle plate are formed to have an angle less than or equal to the sum of the helix angles α of the both side rotors 400.

The calculation formula of the helix angle alpha is as follows: tan α= (pi×d×phase angle/360 °)/L;

where D represents the pitch circle diameter (center-to-center distance) and L represents the tooth width.

TABLE 1 relation between the body structure and the rotor structure of various products of the volumetric water turbine of the present invention

As shown in table 1 above, for example, when the helix angle of each type of product rotor 400 is 32.25 °, the angles formed by the two sides of the V-shaped baffle are preferably equal to the sum of the helix angles of the two side rotors 400 (64.5=32.25+32.25). If the angles of the two sides of the V-shaped baffle are too large, a complete enveloping space cannot be formed, the performance of the water turbine is affected, and if the angles of the two sides of the V-shaped baffle are too small, the area of the flow passage 410 is reduced, and the pressure loss is increased.

As shown in fig. 12, as a preferred embodiment of the positive displacement turbine for driving a foam pump of the present invention, the envelope baffle 130 may also preferably employ a U-shaped baffle.

Similar to the V-shaped baffle, the U-shaped baffle structure can be designed to fit the spiral angles of the rotors 400 on both sides as much as possible, so that the material can be saved and the weight can be reduced, and the strength of the U-shaped baffle is relatively high. The U-shaped baffle structure is preferably provided on the movement 160. The U-shaped baffle structure cooperates with the machine body 100 and the rotor 400 to form a complete envelope space, ensuring accurate displacement of the water turbine.

As shown in fig. 5A to 6E, as a preferred embodiment of the positive displacement turbine for driving a foam pump of the present invention, the rotor 400 has at least four teeth.

As shown in fig. 5A, the undercut phenomenon occurs when the number of gear teeth is small, and the lower the number of teeth is, the more serious the undercut phenomenon is, that is, the larger the undercut region U1 is. The undercut phenomenon weakens the bending strength of the gears and is very disadvantageous for gear transmission, but the undercut phenomenon increases the volume utilization rate of the rotor 400, effectively increasing the displacement of the water turbine.

As shown in fig. 5B, volume utilization= (area s2+area s3+area s4+area s5)/(area s1+area s2+area s3+area s4+area S5)

Table 2 volume utilization of rotors with different teeth numbers

Tooth number	Volume utilization (%)
		3	61
4	53
		5	47
6	42
		7	37

As can be seen from table 2 above, the greater the number of teeth, the lower the volume utilization of the rotor 400. Therefore, on the premise of ensuring the strength of the rotor 400, the rotor 400 with the least number of teeth can be selected as much as possible to improve the flow of the water turbine.

As shown in fig. 6A to 6E, when the number of teeth of the rotor 400 is three, a serious undercut phenomenon (the fewer the number of teeth, the more serious the undercut phenomenon) has occurred, and the whole rotor 400 is cut into three parts, so that the three-tooth scheme is not preferable. When the four-tooth rotor 400 is adopted, the undercut phenomenon is not caused to split the rotor 400, and the larger volume utilization rate can be ensured. Thus, four teeth are the best solution for the number of teeth of rotor 400 in aggregate.

As shown in fig. 9A to 9D, as a preferred embodiment of the positive displacement turbine for driving a foam pump of the present invention, the tip height coefficient of the rotor 400 is 1.0 to 1.25 and the tip clearance coefficient is 0.25 to 0.

The coefficient of the tooth top of the standard involute gear is 1, and the coefficient of the tooth top is properly improved in order to improve the displacement of the water turbine.

As shown in fig. 9A, a represents a tooth form having a tooth top coefficient of 1, B represents a tooth form having a tooth top coefficient of 1.1, and C represents a tooth form having a tooth top coefficient of 1.2. As shown in table 3 below, when the coefficient of the tooth top height increases, the outer diameter of the rotor 400 increases, and the turbine displacement increases, but the width of the tooth top circle decreases at the same time. Since the present invention is to reduce friction loss between the rotor 400 and the machine body 100, a gap D exists between the rotor 400 and the machine body 100 as shown in fig. 9B. Too small a tip width will increase the leakage and affect the performance of the turbine. Therefore, the coefficient of the addendum circle needs to be improved on the premise of ensuring the width of the addendum circle.

TABLE 3 relationship of addendum circle width and addendum coefficient

Coefficient of tooth top	Tip circle width/standard tip circle width
		1	1
1.1	0.8
		1.25	0.3125

As shown in fig. 9C, a certain radial gap should be left when the gears are meshed, which is called a top gap, and the top gap is E, so that the top gap is used to ensure that the gears are not blocked when the gears are meshed, and lubricating oil can be stored, and the coefficient of the top gap is generally 0.25.

As shown in fig. 9D, the two rotors 400 of the present apparatus are independent of each other, and there is no seizing and lubrication required, so the head clearance between the two rotors 400 is set to zero, and the head clearance is F. This minimizes the amount of leakage between the two rotors 400 and improves the performance of the turbine.

As shown in fig. 3, 13 and 17, as a preferred embodiment of the volumetric water turbine for driving a foam pump according to the present invention, an end face compensation plate 600 is provided between an end of a rotor 400 and an inner wall face of a bearing body 140 of a machine body 100, and an elastic compensation structure 700 is provided on a first end face 610 of the end face compensation plate 600, the first end face 610 facing the inner wall face of the bearing body 140 of the machine body 100.

The bearing body 140 is positioned at both sides of the body 100, and abuts against the elastic compensation structure 700 and the end compensation plate 600 at the outer sides of both end surfaces of the rotor 400.

The cooperation of the end face compensation plate 600 and the elastic compensation structure 700 can ensure accurate displacement of the hydraulic turbine by always supporting the end of the rotor 400 when, for example, the rotor 400 expands due to heat or contracts due to cold, and improving the tightness of the runner 410 during the rotation of the rotor 400. The resilient compensation structure 700 herein may preferably be a wave spring, an O-ring or a generally cylindrical compression spring.

As shown in fig. 12, as a preferred embodiment of the positive displacement hydraulic turbine for driving a foam pump of the present invention, the elastic compensating structure 700 is preferably a wave spring. The axial distance of the wave spring structure is very short, and the integral structure of the positive displacement water turbine of the invention is not influenced.

When an O-ring is used as the elastic compensating structure 700, its compensating force is inferior to that of a wave spring due to a material problem of the O-ring.

When a general cylindrical compression spring is used as the elastic compensating structure 700, the overall structure of the positive displacement turbine of the present invention is affected due to the excessively long axial distance of the cylindrical compression spring.

Therefore, the wave spring is better as an elastic compensation structure 700 than an O-ring and a general cylindrical compression spring.

As a preferred embodiment of the positive displacement water turbine for driving a foam pump according to the present invention, the ratio of the tooth width of the rotor 400 to the center distance of the rotor 400 is 2.5, and the ratio of the shaft diameter of the rotor 400 to the center distance of the rotor 400 is between 0.3 and 0.4.

If the tooth width is low, the displacement is small, namely the flow per revolution is small, so that the flow of the water turbine is small. If the tooth width is too large, the strength is insufficient, so that the rotor 400 and the shaft deform, larger noise and vibration are generated, and the stable operation of the water turbine is adversely affected.

The rotor 400 designed by the ratio has good running performance when applied to the positive displacement water turbine of the invention. The following table 4 lists several data on center distance, tooth width, and rotor shaft diameter for a rotor designed using the above ratios.

TABLE 4 center distance, tooth width and rotor shaft diameter of rotors of various products of positive displacement water turbine of the invention

As shown in Table 4 above, as a preferred embodiment of the positive displacement water turbine for driving a foam pump of the present invention, the tooth width of the rotor 400 is 175mm to 625mm, the center distance of the rotor 400 is 70mm to 250mm, and the shaft diameter of the rotor 400 is 28mm to 75mm.

Further preferably, the tooth width of the rotor 400 is 175mm, the center distance of the rotor 400 is 70mm, and the shaft diameter of the rotor 400 is 28mm.

Further preferably, the tooth width of the rotor 400 is 220mm, the center distance of the rotor 400 is 88mm, and the shaft diameter of the rotor 400 is 33mm.

Further preferably, the tooth width of the rotor 400 is 275mm, the center distance of the rotor 400 is 110mm, and the shaft diameter of the rotor 400 is 38mm.

Further preferably, the tooth width of the rotor 400 is 330mm, the center distance of the rotor 400 is 132mm, and the shaft diameter of the rotor 400 is 43mm.

Further preferably, the tooth width of the rotor 400 is 400mm, the center distance of the rotor 400 is 160mm, and the shaft diameter of the rotor 400 is 53mm.

Further preferably, the tooth width of the rotor 400 is 500mm, the center distance of the rotor 400 is 200mm, and the shaft diameter of the rotor 400 is 63mm.

Further preferably, the tooth width of the rotor 400 is 625mm, the center distance of the rotor 400 is 250mm, and the shaft diameter of the rotor 400 is 75mm.

As shown in fig. 3 and 14A to 15C, as a preferred embodiment of the volumetric water turbine for driving the foam pump 11 of the present invention, a speed change gear housing 800, a connection shaft 900, a first speed change gear 1000 and a second speed change gear 1100 are further provided on the water turbine, the first speed change gear 1000 is provided on the connection shaft 900, the second speed change gear 1100 is provided on the output shaft 200, the first speed change gear 1000 is engaged with the second speed change gear 1100 so as to transmit the power of the output shaft 200 to the connection shaft 900, the speed change gear housing 800 is provided on the opposite side of the machine body 100 where the synchronous gear 500 is provided, the connection shaft 900 is movably connected to the speed change gear housing 800, and the first speed change gear 1000 and the second speed change gear 1100 are provided in the speed change gear housing 800.

Preferably, the connection shaft 900 is movably coupled to the speed change gear housing 800 through a bearing so that the connection shaft 900 can freely rotate. A speed regulating mechanism comprising a first speed change gear 1000 and a second speed change gear 1100 is arranged at the output end of the water turbine.

After the positive displacement hydraulic turbine is connected with the main shaft of the foam pump 11 through the connecting shaft 900, the flow ratio of the foam pump 11 to the hydraulic turbine is changed by replacing the first variable speed gear 1000 and the second variable speed gear 1100 with different speed ratios, so that mixed liquid with different mixing ratios (0.5%, 1%, 3% and 6%) can be accurately obtained, and different places and different project requirements can be met. The mixing ratio is the volume fraction ratio of the foam liquid output by the foam pump in the foam mixed liquid (the fire water output by the hydraulic turbine is mixed with the foam liquid).

As shown in fig. 14A and 15A, the second change gear 1100 having the number of teeth 15 and the first change gear 1000 having the number of teeth 45 are replaced, and after the hydraulic turbine is connected to the foam pump 11, the mixture of 1% mixing ratio can be outputted.

As shown in fig. 14B and 15B, the second speed gear 1100 having the number of teeth of 30 and the first speed gear 1000 having the number of teeth of 30 are replaced, and after the hydraulic turbine is connected to the foam pump 11, the mixture of 3% mixing ratio can be outputted.

As shown in fig. 14C and 15C, the second speed gear 1100 having the number of teeth 40 and the first speed gear 1000 having the number of teeth 20 are replaced, and after the hydraulic turbine is connected to the foam pump 11, the mixed liquid of 6% mixing ratio can be outputted.

In summary, the positive displacement hydraulic turbine for driving the foam pump 11 has high strength, high overspeed resistance, high impurity resistance, relatively easy processing and low noise and vibration. The complete envelope space can be formed between the rotor 400 and the body 100 of the volumetric water turbine of the present invention, thereby ensuring that the water turbine has accurate displacement; no friction exists between the two rotors 400, so that safer, longer and reliable operation of the rotors 400 can be ensured.

After the positive displacement hydraulic turbine and the foam pump 11 are connected, the ratio of the foam concentrate to the fire water can be accurately adjusted, so that foam mixed liquid with different mixing ratios can be obtained, and different places and project requirements can be met.

As shown in fig. 18, the present invention also provides a preferred embodiment of a foam proportioning device, which includes a foam pump 11, a foam liquid pipe 12 and a flushing pipe 13, and the above-mentioned positive displacement hydraulic turbine provided with a speed change gear housing 800, a connecting shaft 900, a first speed change gear 1000 and a second speed change gear 1100 for driving the foam pump 11, wherein an outlet of the foam pump 11 is connected with a mixed liquid outlet 120 of the hydraulic turbine through the foam liquid pipe 12, an inlet of the foam pump 11 is connected with a fire water inlet 110 of the hydraulic turbine through the flushing pipe 13, and a main shaft of the foam pump 11 is connected with the connecting shaft 900 of the hydraulic turbine, thereby transmitting power of the hydraulic turbine to the foam pump 11.

The hydraulic turbine of the invention is of a positive displacement type, and the foam pump 11 driven by the hydraulic turbine is of a positive displacement type, and because the flow rates of the positive displacement foam pump 11 and the hydraulic turbine are in direct proportion to the rotating speed, the displacement of the foam pump 11 and the displacement of the hydraulic turbine are well matched according to the required proportion. In operation, the ratio of foam to water is theoretically constant no matter how the flow rate and the pressure of the fire fighting water for driving are changed, and the characteristic is very in line with the requirement of a fire fighting foam ratio mixing device, so that the fire fighting foam ratio mixing device is ideal fire fighting foam ratio mixing equipment.

According to the foam proportion mixing device, due to the adoption of the positive displacement water turbine with the speed change gear structure, the water turbine changes the flow ratio of the foam pump 11 to the water turbine by changing the first speed change gear 1000 and the second speed change gear 1100 with different speed ratios, so that mixed liquids with different mixing ratios can be obtained, and different places and different project requirements can be met.

As shown in fig. 19 and 20, the present invention also provides another preferred embodiment of the foam proportioning device, which includes a foam pump 11, a foam liquid pipe 12 and a flushing pipe 13, and a positive displacement hydraulic turbine for driving the foam pump 11 without a connecting shaft 900 and a speed change gear structure, the outlet of the foam pump 11 is connected with the mixed liquid outlet 120 of the hydraulic turbine through the foam liquid pipe 12, the inlet of the foam pump 11 is connected with the fire water inlet 110 of the hydraulic turbine through the flushing pipe 13, and the main shaft of the foam pump 11 is connected with the output shaft 200 of the hydraulic turbine, thereby transmitting the power of the hydraulic turbine to the foam pump 11.

As shown in fig. 17, in the positive displacement hydraulic turbine without the speed change gear structure used in the present embodiment, since the positive displacement hydraulic turbine has no connecting shaft 900 and no speed change gear structure, the power of the foam pump 11 is directly provided by the output shaft 200 of the hydraulic turbine, and both sides of the output shaft 200 of the hydraulic turbine in fig. 16 may be connected to the main shaft of the foam pump 11, that is, both sides of the output shaft 200 of the hydraulic turbine may be connected to one foam pump 11, or only one side of the output shaft 200 may be connected to one foam pump 11. When one foam pump 11 is connected to each of both sides of the output shaft, the mixing ratio of the mixed liquid output from the foam ratio mixing device is twice that when only one foam pump 11 is connected to one side of the output shaft 200, that is, by adjusting the number of connected foam pumps 11, mixed liquids of different mixing ratios are obtained. The foam proportion mixing device of the scheme can be suitable for fire-fighting foam fire extinguishing systems with low selection requirements on the mixing ratio of foam mixed liquids (only two fixed mixing ratios are enough).

As shown in fig. 19, only one foam proportioning device of the foam pump 11 is connected to the output shaft 200 of the hydraulic turbine.

As shown in fig. 20, a foam ratio mixing device of a foam pump 11 is connected to both sides of an output shaft 200 of a hydraulic turbine.

As described above, the positive displacement hydraulic turbine used by the foam proportion mixing device provided by the invention has the advantages of high strength, overspeed resistance, impurity resistance, relatively easy processing and very low noise and vibration. A complete envelope space can be formed between the rotor 400 of the turbine and the body 100, thereby ensuring that the turbine has an accurate displacement. The friction-free between the two rotors 400 of the positive displacement turbine used can ensure safer, longer and more reliable operation of the rotors 400. Thereby also guaranteeing the service performance of the foam proportion mixing device.

The foam proportion mixing device provided by the invention can adjust the ratio of the foam concentrate to the fire water, so that foam mixed liquids with different mixing ratios are obtained, and different places and project requirements are met.

The design development process of the positive displacement water turbine rotor for driving the foam pump is as follows:

since the positive displacement turbine works on a similar principle as a hydraulic motor, its displacement is much greater than that of hydraulic pressure Ma Dada. According to the use requirement, a positive displacement water turbine with the following advantages needs to be designed:

1. the flow per revolution, i.e. the displacement, is as large as possible with the same housing size.

2. The pressure loss is as small as possible.

3. Stable operation, low noise and small vibration.

The first step of design: the tooth width of the rotor 400 is first determined

The choice of tooth width is initial data, and if the width is low, then the displacement (per turn flow) is small, resulting in a smaller turbine flow. If the tooth width is too large, the strength is insufficient, so that the rotor 400 and the shaft deform, larger noise and vibration are generated, and the stable operation of the water turbine is adversely affected.

The tooth width selection value of each type of positive displacement turbine rotor 400 as in table 4 above was determined, and the ratio of the tooth width to the center distance=2.5 was determined, thereby determining the selection value of the center distance of the rotor 400.

The ratio of the shaft diameter of the rotor 400 to the center distance of the rotor 400 is determined to be between 0.3 and 0.4, and the larger the specification is, the smaller the ratio is, but not lower than 0.3, so that the shaft diameter of the rotor 400 is determined.

To this end, the center distances, tooth widths, and shaft diameters of the rotors 400 of the positive displacement water turbine rotors 400 of different models in table 4 were obtained.

Designing a second step: determining the number of teeth of rotor 400

As shown in FIG. 5A, undercut occurs when the number of teeth of the gear is small, and the less the number of teeth, the more severe the undercut, i.e., the larger the undercut region. The undercut phenomenon weakens the bending strength of the gears and is very disadvantageous for gear transmission, but the undercut phenomenon increases the volume utilization rate of the rotor 400, effectively increasing the displacement of the water turbine.

As shown in table 2 above, the greater the number of teeth, the lower the volume utilization of the rotor 400. Therefore, on the premise of ensuring the strength of the rotor 400, the rotor 400 with the least number of teeth can be selected as much as possible to improve the flow of the water turbine.

And a third step of design: determining phase difference (helix angle) of rotor 400

Let F (x) be the sum of the torques applied to the rotor 400 and F (x) be the torque applied to the rotor 400 at any point along the length of the rotor. F (x) is therefore the original function of F (x).

Then

∵f(x+T)＝f(x)

I.e. F (X+T) =F (X)

The middle part of the above formulaIn this case, the torque (sum of torques) applied to the rotor 400 is always constant. The rotor 400 is optimally stable during rotation.

For a four tooth rotor 400: the minimum period t=360/4 (number of teeth) =90°, so that the phase difference across the rotor 400 can only be a minimum period or a multiple of a minimum period, such as one-time period 90 °, two-time period 180 °, three-time period 270 °, four-time period 360 °, etc., to ensure zero integration.

When the rotors 400 with three-time period 270 °, four-time period 360 ° and larger phase difference are selected, the projection angle of the runner 410 formed between the two rotors 400 in the normal direction is too large due to the too large phase difference between the two end surfaces of the rotors 400, so that the whole runner 410 cannot be enveloped, a complete enveloping space cannot be formed between the rotors 400 and the machine body 100 of the water turbine, and the inlet and outlet of the runner 410 in the rotation process of the rotors 400 are communicated, so that the water turbine does not have accurate displacement, and the service performance of the water turbine is affected.

Thus, a rotor 400 with a phase difference of one cycle of 90 ° and two cycles of 180 ° is a preferred solution.

In the research of the oblique gear pump in the prior art, the following conclusion is drawn: under the condition that the helical gear pump works normally, the tooth width is fixed, and the flow non-uniformity coefficient of the helical gear pump and the helical angle are in a linear inverse relation. That is, as the helix angle increases, the flow non-uniformity coefficient gradually decreases. The larger the helix angle (the larger the phase difference), the smaller the pressure pulsation.

Therefore, a rotor 400 having a phase difference of 180 degrees is a preferable solution compared to a rotor 400 having a phase difference of 90 degrees, and a rotor 400 having a phase difference of 90 degrees is a suboptimal solution.

Meanwhile, the inventor also sets a enveloping baffle 130 which is preferably V-shaped on the body 100 of the water turbine.

Without the envelope baffle 130, a complete envelope space cannot be formed between the rotor 400 of the water turbine and the machine body 100 (even if the rotor 400 with a phase difference of 90 degrees still cannot form a complete envelope flow passage), and the rotor 400 with the phase differences of 90 degrees and 180 degrees can form a complete envelope flow passage. The V-shaped envelope baffle 130 does not work for rotors with phase differences above 270 degrees.

And a fourth step of design: tooth form optimization of rotor 400

As shown in fig. 9A, a represents a tooth form having a tooth top coefficient of 1, B represents a tooth form having a tooth top coefficient of 1.1, and C represents a tooth form having a tooth top coefficient of 1.2. As shown in table 3 above, when the coefficient of the tooth top height increases, the outer diameter of the rotor 400 becomes larger, the turbine displacement increases, but the width of the tooth top circle decreases at the same time. Since the present invention is to reduce friction loss between the rotor 400 and the machine body 100, a gap D exists between the rotor 400 and the machine body 100 as shown in fig. 9B. Too small a tip width will increase the leakage and affect the performance of the turbine. Therefore, the coefficient of the addendum circle needs to be improved on the premise of ensuring the width of the addendum circle.

As shown in fig. 9D, the two rotors 400 of the present apparatus are independent of each other, and there is no seizing and lubrication required, so the head clearance between the two rotors 400 is set to zero, and the head clearance is F. This minimizes the amount of leakage between the two rotors 400 and further improves the performance of the turbine.

The design and research steps of the positive displacement hydraulic turbine rotor for driving the foam pump are the above steps.

As shown in fig. 7A and 7B, in order to design a rotor 400 of a superior positive displacement turbine through the above steps, the tooth width (rotor length) L of the rotor 400 may reach 1/2 of the lead, and the length is large. At this time, the phase difference between the two end faces of the rotor 400 is 180 degrees, and as shown in fig. 7A, the position G1 of the same tooth of the rotor 400 on the right end face is located at the top, and the position G2 on the left end face is located at the bottom. The 180 degree phase difference ensures that the rotor 400 is subjected to a steady and constant torque. The tooth width (rotor length) is in direct proportion to the flow, the larger tooth width can ensure that the water turbine achieves higher flow, meanwhile, the outer diameter of the rotor 400 can be reduced by enlarging the tooth width, the linear speed of the tooth top of the rotor 400 is reduced, and the hydraulic turbine has obvious effect on reducing pressure loss.

The end surface profile of the rotor 400 designed through the above steps is based on a standard involute equation profile, but is different from a general involute equation, and has the following characteristics compared with a tooth profile generated by the general involute equation: the tooth top coefficient is larger, the top gap is zero, the number of teeth is smaller (the minimum number of teeth is 4), the tooth width is larger (1/2 lead), and the torsion phase difference is larger (180 degrees).

By adjusting these parameters, the resulting turbine rotor is provided with: high accuracy, stable rotation, low noise, no pulsation, large flow, long service life, etc.

In summary, the positive displacement hydraulic turbine and the foam proportional mixing device for driving the foam pump have the following advantages:

3. the friction between the two rotors is avoided, so that the rotors can be ensured to run more safely, permanently and reliably;

While specific embodiments of the invention have been described above, it will be appreciated by those skilled in the art that these are by way of example only, and the scope of the invention is defined by the appended claims. Various changes and modifications to these embodiments may be made by those skilled in the art without departing from the principles and spirit of the invention, but such changes and modifications fall within the scope of the invention.

Claims

1. A positive displacement hydraulic turbine for driving a foam pump, the hydraulic turbine comprising:

the fire-fighting water inlet and the mixed liquid outlet are arranged on the machine body in a group of opposite arrangement;

the output shaft and the synchronizing shaft are arranged in the machine body in parallel, and the synchronizing shaft and the output shaft synchronously rotate;

the rotors are respectively arranged on the output shaft and the synchronous shaft, the rotors are provided with spiral angles with equal magnitudes and opposite directions, and normal surface molded lines of the rotors are curves which are conjugate with each other;

a pair of synchronizing gears which are respectively provided at the same side ends of the synchronizing shaft and the output shaft and are engaged with each other so that the synchronizing shaft and the output shaft are rotated synchronously;

The fire-fighting water inlet and the mixed liquid outlet of the machine body are both provided with enveloping baffles, and the enveloping baffles can shield a runner in the rotation process of the rotor, so that a complete enveloping space is formed among the rotor, the machine body and the enveloping baffles.

2. The positive-displacement hydraulic turbine for driving a foam pump according to claim 1, wherein the rotor is a twisted gear rotor, and the phase difference between both end surfaces of the rotor is 170 degrees to 190 degrees.

3. The positive-displacement hydraulic turbine for driving a foam pump according to claim 1, wherein the rotor is a twisted gear rotor, and the phase difference between both end surfaces of the rotor is 80 degrees to 100 degrees.

4. The positive-displacement water turbine for driving a foam pump as claimed in claim 2, wherein said envelope baffles are staggered,

the enveloping baffle at the fire water inlet of the machine body is arranged near the first end of the rotor; the envelope baffle at the mixed liquor outlet of the machine body is arranged near the second end of the rotor,

the two adjacent teeth of the rotor are not communicated with the fire water inlet and the mixed liquid outlet, so that a complete enveloping space is formed, and accurate displacement of the water turbine is ensured.

5. The positive-displacement hydraulic turbine for driving a foam pump as recited in claim 4, wherein said envelope barrier is a V-shaped barrier.

6. The positive-displacement hydraulic turbine for driving a foam pump as recited in claim 5, wherein the included angle of both sides of the V-shaped baffle is less than or equal to the sum of both side rotor helix angles.

7. The positive-displacement hydraulic turbine for driving a foam pump as recited in claim 4, wherein said envelope barrier is a U-shaped barrier.

8. The positive-displacement hydraulic turbine for driving a foam pump as recited in claim 2, wherein said rotor has at least four teeth.

9. The positive-displacement hydraulic turbine for driving a foam pump according to claim 8, wherein the rotor has a tip height coefficient of 1.0 to 1.25 and a tip clearance coefficient of 0.25 to 0.

10. The volumetric water turbine for driving a foam pump according to claim 1, wherein an end face compensation plate is provided between an end of the rotor and an inner wall face of the bearing body of the machine body, and an elastic compensation structure is provided on a first end face of the end face compensation plate, the first end face facing the inner wall face of the bearing body of the machine body.

11. The positive displacement hydraulic turbine for driving a foam pump as recited in claim 10, wherein said resilient compensation structure is a wave spring.

12. The positive-displacement hydraulic turbine for driving a foam pump as recited in claim 4, wherein the ratio of the tooth width of said rotor to the center distance of said rotor is 2.5 and the ratio of the shaft diameter of said rotor to the center distance of said rotor is between 0.3 and 0.4.

13. A positive-displacement hydraulic turbine for driving a foam pump as claimed in claim 12, wherein the tooth width of the rotor is 175mm to 625mm, the center distance of the rotor is 70mm to 250mm, and the shaft diameter of the rotor is 28mm to 75mm.

14. The positive-displacement hydraulic turbine for driving a foam pump as recited in claim 13, wherein said rotor has a tooth width of 175mm, a center-to-center distance of 70mm, and a shaft diameter of 28mm.

15. The positive-displacement hydraulic turbine for driving a foam pump as recited in claim 13, wherein the rotor has a tooth width of 220mm, a center-to-center distance of 88mm, and a shaft diameter of 33mm.

16. The positive-displacement hydraulic turbine for driving a foam pump as recited in claim 13, wherein said rotor has a tooth width of 275mm, a center-to-center distance of 110mm, and a shaft diameter of 38mm.

17. The positive-displacement hydraulic turbine for driving a foam pump according to claim 13, wherein the tooth width of the rotor is 330mm, the center distance of the rotor is 132mm, and the shaft diameter of the rotor is 43mm.

18. The positive-displacement hydraulic turbine for driving a foam pump according to claim 13, wherein the tooth width of the rotor is 400mm, the center distance of the rotor is 160mm, and the shaft diameter of the rotor is 53mm.

19. The positive-displacement hydraulic turbine for driving a foam pump according to claim 13, wherein the tooth width of the rotor is 500mm, the center distance of the rotor is 200mm, and the shaft diameter of the rotor is 63mm.

20. The positive-displacement hydraulic turbine for driving a foam pump as recited in claim 13, wherein the rotor has a tooth width of 625mm, a center-to-center distance of 250mm, and a shaft diameter of 75mm.

21. A positive-displacement water turbine for driving a foam pump as claimed in any one of claims 1 to 20, further comprising a speed change gear housing, a connecting shaft, a first speed change gear and a second speed change gear, wherein the connecting shaft is provided with the first speed change gear, the output shaft is provided with the second speed change gear, the first speed change gear is meshed with the second speed change gear, thereby transmitting the power of the output shaft to the connecting shaft, the speed change gear housing is arranged on the opposite side of the housing where the synchronizing gear is arranged, the connecting shaft is movably connected to the speed change gear housing, and the first speed change gear and the second speed change gear are arranged in the speed change gear housing.

22. A foam proportioning device, characterized in that the foam proportioning device comprises a foam pump, a foam liquid pipeline and a flushing pipeline, and a positive displacement hydraulic turbine for driving the foam pump according to any one of claims 21, wherein an outlet of the foam pump is connected with a mixed liquid outlet of the hydraulic turbine through the foam liquid pipeline, an inlet of the foam pump is connected with a fire water inlet of the hydraulic turbine through the flushing pipeline, and a main shaft of the foam pump is connected with a connecting shaft of the hydraulic turbine, so that power generated by the hydraulic turbine is transmitted to the foam pump.

23. A foam proportioning device, characterized in that the foam proportioning device comprises a foam pump, a foam liquid pipeline and a flushing pipeline, and a positive displacement hydraulic turbine for driving the foam pump according to any one of claims 1-20, wherein an outlet of the foam pump is connected with a mixed liquid outlet of the hydraulic turbine through the foam liquid pipeline, an inlet of the foam pump is connected with a fire water inlet of the hydraulic turbine through the flushing pipeline, and a main shaft of the foam pump is connected with an output shaft of the hydraulic turbine, so that power generated by the hydraulic turbine is transmitted to the foam pump.