Fire extinguishing agent delivery gear pump

Abstract

The utility model belongs to airborne equipment field, concretely relates to a high -efficient, long -lived fire extinguishing agent conveying gear pump. Conventional gear pump has movement friction, surface protection layer is destroyed, metal is easy to be fire extinguishing agent chemical corrosion, and the reliability of oil seal is lower. The gear shaft of driving gear and driving gear of the utility model is installed in sliding bearing, the rear cover has the rear cover liquid flow channel of intercommunication rear cover sliding bearing mounting hole and gear pump low pressure area, the front cover has the front cover liquid flow channel of intercommunication front cover sliding bearing mounting hole and gear pump low pressure area, gear shaft has gap with rear cover and front cover, sliding bearing and driving gear, driving gear clearance fit, the tooth top of driving gear, driving gear has radial clearance with casing. Avoid the movement friction of internal parts, prevent surface from being fire extinguishing agent chemical corrosion, improve the lubrication characteristic and life of sliding bearing, improve the reliability of oil seal sealing, finally realize the purpose of improving the mechanical efficiency and life of gear pump under low pressure working condition.

Description

Technical Field

[0001] This utility model belongs to the field of airborne equipment, specifically relating to a high-efficiency, long-life gear pump for delivering fire extinguishing agents. Background Technology

[0002] In the event of a fire, fire extinguishing agents and water need to be mixed in a certain proportion, and the fire extinguishing agents are injected into the water tank in a measured amount. The pipeline from the agent tank to the water tank is short and has low resistance. Therefore, the fire extinguishing agent delivery system is a low-pressure system, and the pressure difference between the pump inlet and outlet is about 0.15 to 0.2 MPa.

[0003] Fire extinguishing agents are generally delivered using vane pumps, but vane pumps have a relatively complex structure; fire extinguishing agents are corrosive, and the flexible plastic vanes are complex in shape and thin, making them difficult to process; during operation, the vanes are subjected to high-frequency cyclic stress, making them prone to fatigue damage and requiring frequent maintenance.

[0004] Gear pumps have a simple structure, but conventional gear pump designs suffer from friction between moving metal components, which damages the protective layers on the surfaces of the housing, front cover, rear cover, and sliding bearings, making the metal susceptible to chemical corrosion by fire extinguishing agents. The poor lubricity of fire extinguishing agents results in high operating resistance and low mechanical efficiency for the gear pump. Furthermore, the rubber-based skeleton oil seal has poor self-lubricating properties, resulting in high frictional resistance with the gear shaft and poor follow-through, leading to low reliability of the oil seal. Utility Model Content

[0005] To address the issue of low operating pressure in gear pumps for delivering fire extinguishing agents, a high-efficiency, long-life gear pump for delivering fire extinguishing agents is proposed.

[0006] This utility model provides a gear pump for delivering fire extinguishing agents. The pump housing contains a driven gear and a driving gear, which are enclosed by a rear cover and a front cover. Sliding bearings are installed inside the rear and front covers, and the gear shafts of the driven and driving gears are mounted within these bearings. The rear cover has a liquid flow channel connecting the sliding bearing mounting hole to the low-pressure area of ​​the gear pump, and the front cover has a liquid flow channel connecting the sliding bearing mounting hole to the low-pressure area of ​​the gear pump. The gear shafts have clearances with the rear and front covers, and the sliding bearings are in clearance fit with the driving and driven gears. The tooth tips of the driving and driven gears have radial clearances with the housing.

[0007] Advantageously or alternatively, sealing gaskets are installed on the end faces of the housing, the rear cover, and the front cover.

[0008] Advantageously or alternatively, a PTFE oil seal is mounted on the gear shaft of the drive gear.

[0009] Advantageously or alternatively, the housing also has a liquid inlet and a liquid outlet, and the interior is a gear cavity.

[0010] Advantageously or alternatively, the sliding bearing is made of high-strength, self-lubricating, corrosion-resistant engineering plastics.

[0011] Advantageously or alternatively, both the driving gear and the driven gear are made of corrosion-resistant materials.

[0012] Advantageously or alternatively, there is a gap between the end faces of the driving gear and the driven gear and the front cover and the rear cover.

[0013] Advantageously or alternatively, the tooth tips of the driving gear and driven gear have radial clearance to the housing.

[0014] Advantageously or alternatively, the driving gear, driven gear, and sliding bearing have axial clearance.

[0015] Beneficial effects: It avoids friction between moving internal parts and prevents the surface from being chemically corroded by fire extinguishing agents; it improves the lubrication characteristics and lifespan of sliding bearings; it enhances the reliability of oil seals, ultimately achieving the goal of improving the mechanical efficiency and lifespan of gear pumps under low-pressure conditions.

[0016] The features, functionalities, and advantages already discussed can be implemented independently in various examples, or combined in other examples. Further details of the examples can be seen in the following description and accompanying figures. Attached Figure Description

[0017] When read in conjunction with the accompanying drawings, the embodiments, preferred modes of use, other objects, and descriptions thereof will be best understood by referring to the following detailed description of the embodiments of the present invention, wherein:

[0018] Figure 1 This is a cross-sectional schematic diagram of a gear pump for delivering fire extinguishing agents;

[0019] Figure 2 This is a schematic diagram of the front cover structure;

[0020] Figure 3 This is a schematic diagram of the back cover structure;

[0021] Figure 4 This is a perspective view of the shell;

[0022] Figure 5 This is a schematic diagram of the internal area of ​​the gear pump for delivering fire extinguishing agents;

[0023] Figure 6 This is a schematic diagram of the working fluid circulation at the rear cover end.

[0024] Note: The working fluid circulation method is the same for the front and rear covers, so the working fluid circulation diagram for the front cover is omitted here.

[0025] 1. Rear cover; 2. Sliding bearing; 3. Sealing gasket; 4. Housing; 5. Driven gear; 6. Driving gear; 7. Front cover; 8. Oil seal; 9. Axial clearance; 10. Radial clearance; 11. Low-pressure zone of gear pump; 12. High-pressure zone of gear pump; 1-1. Rear cover sliding bearing mounting hole; 1-2. Rear cover liquid flow channel; 4-1. Liquid inlet; 4-2. Liquid outlet; 4-3. Gear cavity; 7-1. Front cover sliding bearing mounting hole; 7-2. Front cover liquid flow channel Detailed Implementation

[0026] The disclosed examples will be described more fully with reference to the accompanying drawings, in which some (but not all) of the disclosed examples are shown. In fact, many different examples may be described, and these examples should not be construed as limited to those set forth herein. Rather, these examples are described so that this disclosure will be thorough and complete, and will fully convey the scope of this disclosure to those skilled in the art.

[0027] The fire extinguishing agent delivery gear pump shown in the attached diagram mainly includes a rear cover 1, sliding bearings 2, sealing gaskets 3, a housing 4, driven gear 5, driving gear 6, a front cover 7, and an oil seal 8. The housing 4 is positioned with the front cover 7 and the rear cover 1 by cylindrical pins and connected by screws. Four sliding bearings 2 are respectively installed in the sliding bearing mounting holes 1-1 on the rear cover and 7-1 on the front cover, with clearance fit between the sliding bearings 2 and the driving gear 6 and driven gear 5. The driving gear 6 and driven gear 5 are made of corrosion-resistant materials. The driving gear 6 is connected to the motor via a splined / square shaft, and the driving gear 6 and gear shaft are integrated, as are the driven gear 5 and gear shaft. A PTFE oil seal 8 is installed on the gear shaft of the driving gear 6. This oil seal has high chemical stability, low friction, self-lubricating properties, and good following characteristics, effectively improving the reliability of the oil seal. The driving gear 6 and driven gear 5 mesh in the gear cavity 4-3 within the housing 4.

[0028] As a low-pressure gear pump, volumetric efficiency is relatively insensitive to the size of internal clearances. To improve the mechanical efficiency and service life of the gear pump, the radial clearance 10 between the tooth tips of the drive gear 6 and driven gear 5 and the housing 4 is adjusted, as is the clearance between the end faces of the drive gear 6 and driven gear 5 and the front cover 7 and rear cover 1. This avoids friction between the internal components of the gear pump, reduces the operating resistance of the gear pump, and prevents chemical corrosion of the housing 4, front cover 7, and rear cover 1, thus extending their service life. The axial clearance 9 between the end face of the sliding bearing 2 and the end faces of the drive gear 6 and driven gear 5 is adjusted to prevent the drive gear 6 and driven gear 5 from being axially jammed, reducing the operating resistance of the gear pump. The sliding bearing 2 is made of high-strength, self-lubricating, and corrosion-resistant engineering plastic, while the drive gear 6 and driven gear 5 are made of stainless steel, which effectively prevents chemical corrosion and extends their service life.

[0029] The working fluid enters the gear cavity 4-3 inside the housing through the inlet 4-1. The driven gear 5 and the driving gear 6 face the inlet 4-1 on one side as the low-pressure zone 11 of the gear pump, and the other side as the high-pressure zone 12. The low-pressure zone 11 of the gear pump is filled with low-pressure working fluid. The gear teeth squeeze the working fluid between the teeth into the high-pressure zone 12 of the gear pump, forming a certain pressure, which in turn provides energy to the working fluid, which then flows to the downstream pipeline through the outlet 4-2 of the housing 4.

[0030] When the gear pump is working, the lubrication path of the working fluid is as follows: inlet 4-1 → low-pressure zone 11 of the gear pump → liquid flow channel 7-2 of the front cover and liquid flow channel 1-2 of the rear cover → sliding bearing mounting hole 7-1 of the front cover and sliding bearing mounting hole 1-1 of the rear cover → clearance between sliding bearing 2 and driving gear 6 and driven gear 5 → low-pressure zone 11 of the gear pump, forming a circulation channel, which can provide liquid lubrication for sliding bearing 2 and improve the working efficiency of the gear pump.

[0031] The above structure effectively improves the service life and mechanical efficiency of the fire extinguishing agent delivery gear pump. Ultimately, the total power of the fire extinguishing agent delivery gear pump using this technical solution is reduced by about 20% compared to conventional technical solutions.

[0032] Example

[0033] The sliding bearing 2 has a cylindrical structure and is made of high-strength, self-lubricating, and corrosion-resistant engineering plastic. The sliding bearing 2 is clearance-fitted with the drive gear 6 and the driven gear shaft 5. The front cover 7 and rear cover 1 each have two mounting holes 7-1 and 1-1 for the sliding bearing 2, and liquid flow channels 7-2 and 1-2 are provided in the inlet working chamber. The oil seal 8 prevents working fluid leakage towards the motor and is made of PTFE material with high chemical stability, low friction, self-lubricating properties, and good follow-through, effectively improving the lifespan of the gear pump. The drive gear 6 and drive gear shaft are integrated, as are the driven gear 5 and driven gear shaft. Both the drive gear 6 and driven gear 5 are made of corrosion-resistant materials. The drive gear shaft is connected to the motor.

[0034] The axial clearance between the end faces of the drive gear 6 and driven gear 5 and the front cover 7 and rear cover 1 is adjusted to 0.3-0.45 mm, which can effectively prevent the end faces of the drive gear 6 and driven gear 5 from moving and rubbing against the front cover 7 and rear cover 1, reducing the working resistance of the gear pump and preventing the front cover 7 and rear cover 1 from being chemically corroded by fire extinguishing agents. The axial clearance of the end faces of the drive gear 6, driven gear 5, and sliding bearing 2 is reasonably set, and the end faces of the drive gear 6 and driven gear 5 are limited by the end faces of the sliding bearing 2, which can prevent the drive gear 6 and driven gear 5 from being axially jammed, reducing the working resistance of the gear pump. The radial clearance between the tooth tips of the drive gear 6 and driven gear 5 and the housing 4 is adjusted to 0.15-0.4 mm, which can effectively prevent the tooth tips of the drive gear 6 and driven gear 5 from moving and rubbing against the housing 4, while avoiding the housing 4 from being chemically corroded by fire extinguishing agents, thus improving the service life and mechanical efficiency of the gear pump.

[0035] Descriptions of various advantageous arrangements have been shown for illustrative and descriptive purposes, but such descriptions are not intended to be exclusive or limited to the disclosed forms. Many modifications and variations will be apparent to those skilled in the art. Furthermore, different advantageous examples may be described as having different advantages compared to other advantageous examples. One or more examples have been selected and described in order to best illustrate the principles and practical applications of the examples, and to enable those skilled in the art to understand that this disclosure contains various examples with various modifications suitable for the particular intended use.

Claims

1. A gear pump for delivering fire extinguishing agent, characterized in that: The gear pump housing (4) is equipped with a driven gear (5) and a driving gear (6), and is enclosed by a rear cover (1) and a front cover (7). A sliding bearing (2) is installed in the rear cover (1) and the front cover (7). The gear shafts of the driven gear (5) and the driving gear (6) are installed in the sliding bearing (2). The rear cover (1) has a rear cover liquid flow groove (1-2) that connects the rear cover sliding bearing mounting hole (1-1) and the low-pressure area (11) of the gear pump. The front cover (7) has a front cover liquid flow groove (7-2) that connects the front cover sliding bearing mounting hole (7-1) and the low-pressure area (11) of the gear pump. The gear shaft has a gap with the rear cover (1) and the front cover (7). The sliding bearing (2) is in clearance fit with the driving gear (6) and the driven gear (5). The tooth tips of the driving gear (6) and the driven gear (5) have a radial gap (10) with the housing (4).

2. The gear pump for delivering fire extinguishing agent according to claim 1, characterized in that: Sealing gaskets (3) are installed on the end faces of the housing (4), the rear cover (1), and the front cover (7).

3. The gear pump for delivering fire extinguishing agent according to claim 1, characterized in that: A PTFE oil seal (8) is installed on the gear shaft of the drive gear (6).

4. The gear pump for delivering fire extinguishing agent according to claim 1, characterized in that: The housing (4) also has a liquid inlet (4-1) and a liquid outlet (4-2), and the interior is a gear cavity (4-3).

5. The gear pump for delivering fire extinguishing agent according to claim 1, characterized in that: The sliding bearing (2) is made of high-strength, self-lubricating, and corrosion-resistant engineering plastic.

6. The gear pump for delivering fire extinguishing agent according to claim 1, characterized in that: Both the driving gear (6) and the driven gear (5) are made of corrosion-resistant materials.

7. The gear pump for delivering extinguishing agent according to any one of claims 1-6, characterized in that: There is a gap between the end faces of the driving gear (6) and driven gear (5) and the front cover (7) and the rear cover (1).

8. The gear pump for delivering fire extinguishing agent according to claim 7, characterized in that: The tooth tips of the driving gear (6) and driven gear (5) have radial clearance (10) to the housing (4).

9. The gear pump for delivering fire extinguishing agent according to claim 8, characterized in that: The driving gear (6), driven gear (5) and sliding bearing (2) have an axial clearance (9).

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