Low-noise gear pump

Abstract

The utility model relates to the technical field of gear pumps, in particular to a low-noise gear pump which comprises a base, a shell is connected to the top of the base, and a transmission shaft and a driven shaft are rotationally connected to the interior of the shell through bearings. When oil enters the cavity part, vortex flow is formed, microbubbles in the oil are gathered to the center of the cavity part through centrifugal force, the energy dissipation efficiency during bubble collapse is improved, and through the arrangement of the neck part and the cavity part, pressure pulsation drives fluid to enter the neck part, and sound energy is converted into fluid kinetic energy; fluid oscillation in the cavity part is matched with sound wave frequency, kinetic energy is converted into potential energy, so that noise is effectively reduced through the acoustic resonance dissipation principle, resonance caused when the motor is started can be effectively reduced through the arrangement of the rubber cushion block and the sound absorption cotton piece arranged at the bottom of the base, noise is reduced in multiple aspects, and the noise reduction effect is better.

Description

Technical Field

[0001] This utility model relates to the field of gear pump technology, specifically a low-noise gear pump. Background Technology

[0002] A gear pump is a rotary pump that transports or pressurizes liquids by relying on the change and movement of the working volume formed between the pump cylinder and meshing gears. It consists of two gears, a pump body, and front and rear covers forming two enclosed spaces. When the gears rotate, the volume of the space on the disengaged side increases, creating a vacuum that draws in the liquid. Conversely, the volume of the space on the meshing side decreases, forcing the liquid into the pipeline. The suction and discharge chambers are separated by the meshing line of the two gears.

[0003] The meshing characteristics of gear pumps inherently result in pulsating output flow. As the gear meshing point moves, the rate of change of the discharge chamber volume is not constant, leading to periodic fluctuations in instantaneous flow. This flow pulsation transforms into pressure pulsation, generating numerous air bubbles that are transmitted through the oil to the entire hydraulic system, inducing resonance in components such as pipes and valve blocks. Particularly when the system's natural frequency couples with the pulsating frequency, a strong noise amplification effect is created. Traditional noise reduction methods, which only add external passive noise reduction components to reduce resonance noise, have limited effectiveness. Therefore, we propose a low-noise gear pump to address these issues. Utility Model Content

[0004] The purpose of this invention is to provide a low-noise gear pump to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, this utility model provides the following technical solution: a low-noise gear pump, including a base, a housing connected to the top of the base, a drive shaft and a driven shaft rotatably connected inside the housing via bearings, the drive shaft extending outside the housing and connected to an external motor, a drive gear fixedly connected to the outside of the drive shaft, a driven gear fixedly connected to the outside of the driven shaft, the drive gear meshing with the driven gear, an oil inlet channel and an oil outlet channel respectively opened on the left and right sides of the housing, a gradually expanding flow channel provided at the oil inlet channel, a gradually converging flow channel provided at the oil outlet channel, and multiple sets of Helmholtz resonators provided inside the housing.

[0006] More preferably, the Helmholtz resonator includes a cavity and a neck, the cavity being spherical and the neck connecting the converging flow channel to the cavity.

[0007] More preferably, a spiral guide vane is fixedly connected inside the neck.

[0008] More preferably, the bottom of the cavity is provided with a resonant cavity outlet, which is connected to the oil outlet channel.

[0009] More preferably, a flow divider is fixedly connected inside the outlet of the resonant cavity, and reed valves are provided on both sides of the flow divider.

[0010] More preferably, a pump inlet flange and a pump outlet flange are fixedly connected to both sides of the housing, respectively.

[0011] More preferably, the bottom of the base is provided with a rubber pad, and the bottom of the base is provided with a hollow part, which is filled with sound-absorbing cotton sheets.

[0012] Compared with the prior art, the beneficial effects of this utility model are as follows: When in use, after the base is fixedly installed, it is connected to an external motor via a drive shaft. It is connected to a pipeline via pump inlet flanges and pump outlet flanges on both sides. The motor drives the drive shaft to rotate, which in turn drives the drive gear to rotate. The drive gear then drives the driven gear meshing with it, thereby pumping hydraulic oil in through the inlet channel and out through the outlet channel. The gradually expanding flow channel effectively reduces noise by slowing the flow rate in the inlet channel. The gradually contracting flow channel acts as a guide, reducing the impact force on the outlet channel when the hydraulic oil is pumped out, thus reducing noise. When the hydraulic oil passes through the gradually contracting flow channel, it flows into the neck through the spiral guide vanes. When the oil enters the cavity, it forms a vortex flow, reducing centrifugal force. Microbubbles in the oil are gathered at the center of the cavity to enhance the energy dissipation efficiency when the bubbles collapse. The hydraulic oil flows out through the diverter plate at the outlet of the resonant cavity. With the reed valve in place, the hydraulic oil flow causes the reed valve to open passively when the motor is working. After the motor stops working, the reed valve resets and closes the passage, thus effectively preventing impurities from entering the cavity. Through the design of the neck and the cavity, the pressure pulsation drives the fluid into the neck, converting sound energy into fluid kinetic energy. The fluid oscillation in the cavity matches the frequency of the sound wave, converting kinetic energy into potential energy. Thus, the noise is effectively reduced through the principle of acoustic resonance dissipation. The rubber pads and sound-absorbing cotton pads at the bottom of the base can effectively reduce the resonance caused by the motor starting. Therefore, noise reduction is achieved through multiple aspects, resulting in better noise reduction effect. Attached Figure Description

[0013] Figure 1 This is a front-view three-dimensional structural diagram of the present invention;

[0014] Figure 2 This is a schematic diagram of the left sectional view of the present invention;

[0015] Figure 3 This is a schematic diagram of the internal cross-sectional structure of the base of this utility model;

[0016] Figure 4 for Figure 2 Enlarged 3D structural diagram of area A in the middle.

[0017] In the diagram: 1. Base; 2. Housing; 3. Drive shaft; 4. Driven shaft; 5. Drive gear; 6. Driven gear; 7. Oil inlet channel; 8. Oil outlet channel; 9. Expanding flow channel; 10. Converging flow channel; 11. Helmholtz resonator; 12. Pump inlet flange; 13. Pump outlet flange; 14. Cavity; 15. Neck; 16. Spiral guide vane; 17. Resonance cavity outlet; 18. Flow divider; 19. Reed valve; 20. Rubber pad; 21. Sound-absorbing cotton sheet. Detailed Implementation

[0018] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model. Example

[0019] Please see Figure 1-4This utility model provides a technical solution: a low-noise gear pump, including a base 1, a housing 2 connected to the top of the base 1, a drive shaft 3 and a driven shaft 4 rotatably connected inside the housing 2 via bearings, the drive shaft 3 extending outside the housing 2 and connected to an external motor, a drive gear 5 fixedly connected to the outside of the drive shaft 3, and a driven gear 6 fixedly connected to the outside of the driven shaft 4, the drive gear 5 and the driven gear 6 meshing, an oil inlet channel 7 and an oil outlet channel 8 respectively opened on the left and right sides of the housing 2, the oil inlet channel 7 is provided with a gradually expanding flow channel 9, and the oil outlet channel 8 is provided with a gradually expanding flow channel 9. The system features a gradually narrowing flow channel 10 and multiple sets of Helmholtz resonators 11 within the housing 2. In use, after the base 1 is fixed in place, it is connected to an external motor via a drive shaft 3. The motor connects to a pipeline via pump inlet flanges 12 and pump outlet flanges 13 on both sides. The motor drives the drive shaft 3 to rotate, which in turn drives the drive gear 5. The drive gear 5 then drives the driven gear 6, which meshes with it, thus pumping hydraulic oil in through the inlet channel 7 and out through the outlet channel 8. The gradually widening flow channel 9 effectively reduces noise by slowing down the flow rate in the inlet channel 7. The converging channel 10 serves as a guide, reducing the impact force on the outlet channel 8 when the hydraulic oil is pumped out, thereby reducing noise. When the hydraulic oil passes through the converging channel 10, it flows into the neck 15 through the spiral guide vane 16. When the oil enters the cavity 14, it forms a vortex flow. Centrifugal force gathers microbubbles in the oil to the center of the cavity 14, enhancing the energy dissipation efficiency when the bubbles collapse. The hydraulic oil flows out through the diverter 18 set at the resonant cavity outlet 17. With the reed valve 19 set, the hydraulic oil flow when the motor is working causes the reed valve 19 to open passively. After the motor stops working, the reed valve 19 resets and closes the passage, thus effectively preventing impurities from entering the cavity 14. Through the setting of the neck 15 and the cavity 14, the pressure pulsation drives the fluid to enter the neck 15, and the sound energy is converted into the fluid kinetic energy. The fluid oscillation in the cavity 14 matches the sound wave frequency, and the kinetic energy is converted into potential energy. Thus, the noise is effectively reduced through the principle of acoustic resonance dissipation. The rubber pad 20 and sound-absorbing cotton sheet 21 set at the bottom of the base 1 can effectively reduce the resonance caused by the motor when starting. Thus, noise reduction is achieved through multiple aspects, and the noise reduction effect is better.

[0020] The Helmholtz resonance effect is used to convert the energy of fluid pressure pulsation into acoustic resonance energy dissipation.

[0021] Calculate the main pulsation frequency:

[0022] f0 = (z * n) / 60

[0023] z: Number of teeth

[0024] n: Rotational speed

[0025] Resonance frequency formula:

[0026] fr = c / (2 * π) * √( An / (Vc * Leq) )

[0027] c: Velocity of sound in oil (≈1400 m / s, related to oil temperature and gas content)

[0028] An: Cavity volume 14 (mm²)

[0029] Vc: Volume of the cavity section (mm³)

[0030] This allows us to deduce the volume of cavity 14 and the volume of cavity 14. By accurately calculating the cavity volume V, the neck cross-sectional area A, and the length L, we can precisely match the resonant frequency with the main pulsation frequency of the gear pump (usually 200-800Hz).

[0031] In this embodiment, specifically: the Helmholtz resonator 11 includes a cavity 14 and a neck 15. The cavity 14 is spherical, and the neck 15 connects the tapering channel 10 to the cavity 14.

[0032] In this embodiment, specifically: a spiral guide vane 16 is fixedly connected inside the neck 15. The spiral guide vane 16 is added at the inlet of the neck 15 so that when the oil enters the cavity 14, a vortex flow is formed. The centrifugal force gathers the microbubbles in the oil to the center of the cavity, thereby enhancing the energy dissipation efficiency when the bubbles collapse.

[0033] In this embodiment, specifically: a resonance cavity outlet 17 is provided at the bottom of the cavity 14, and the resonance cavity outlet 17 is connected to the oil outlet channel 8.

[0034] In this embodiment, specifically: a flow divider 18 is fixedly connected inside the resonant cavity outlet 17, and reed valves 19 are provided on both sides of the flow divider 18;

[0035] In this embodiment, specifically: a pump inlet flange 12 and a pump outlet flange 13 are fixedly connected to both sides of the housing 2, respectively;

[0036] In this embodiment, specifically: a rubber pad 20 is provided at the bottom of the base 1, and a hollow part is provided at the bottom of the base 1, which is filled with sound-absorbing cotton sheets 21.

[0037] In operation, this utility model works as follows: After the base 1 is fixedly installed, it is connected to an external motor via a drive shaft 3. It is connected to a pipeline via pump inlet flanges 12 and pump outlet flanges 13 on both sides. The motor drives the drive shaft 3 to rotate, which in turn drives the drive gear 5 to rotate. The drive gear 5 then drives the driven gear 6, which meshes with it, thus pumping hydraulic oil in through the inlet channel 7 and out through the outlet channel 8. The gradually expanding flow channel 9 effectively reduces noise by slowing the flow rate in the inlet channel 7. The gradually contracting flow channel 10 acts as a guide, reducing the impact force on the outlet channel 8 when the hydraulic oil is pumped out, thereby reducing noise. When the hydraulic oil passes through the gradually contracting flow channel 10, it flows into the neck 15 via the spiral guide vane 16. When the oil enters the cavity 14, it forms a vortex flow, and centrifugal force agglomerates the microbubbles in the oil. The hydraulic oil is concentrated in the center of the cavity 14 to enhance the energy dissipation efficiency when the bubbles collapse. The hydraulic oil flows out through the diverter plate 18 set at the outlet 17 of the resonance cavity. With the setting of the reed valve 19, the hydraulic oil flow causes the reed valve 19 to open passively when the motor is working. After the motor stops working, the reed valve 19 resets and closes the passage, thus effectively preventing impurities from entering the cavity 14. Through the setting of the neck 15 and the cavity 14, the pressure pulsation drives the fluid to enter the neck 15, and the sound energy is converted into fluid kinetic energy. The fluid oscillation in the cavity 14 matches the sound wave frequency, and the kinetic energy is converted into potential energy. Thus, the noise is effectively reduced through the acoustic resonance dissipation principle. The rubber pad 20 and the sound-absorbing cotton sheet 21 set at the bottom of the base 1 can effectively reduce the resonance caused by the motor starting. Thus, noise reduction is achieved through multiple aspects, and the noise reduction effect is better.

[0038] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A low noise gear pump comprising a base (1), characterized in that: The top of the base (1) is connected to a housing (2). Inside the housing (2), a drive shaft (3) and a driven shaft (4) are rotatably connected via bearings. The drive shaft (3) extends to the outside of the housing (2) and is connected to an external motor. A drive gear (5) is fixedly connected to the outside of the drive shaft (3), and a driven gear (6) is fixedly connected to the outside of the driven shaft (4). The drive gear (5) meshes with the driven gear (6). An oil inlet channel (7) and an oil outlet channel (8) are respectively opened on the left and right sides of the housing (2). A gradually expanding flow channel (9) is provided at the oil inlet channel (7), and a gradually contracting flow channel (10) is provided at the oil outlet channel (8). Multiple sets of Helmholtz resonators (11) are provided inside the housing (2).

2. A low noise gear pump according to claim 1, characterized in that: The Helmholtz resonator (11) includes a cavity (14) and a neck (15), the cavity (14) being spherical and the neck (15) connecting the converging channel (10) to the cavity (14).

3. A low noise gear pump according to claim 2, characterized in that: A spiral guide vane (16) is fixedly connected inside the neck (15).

4. A low-noise gear pump according to claim 3, characterized in that: The bottom of the cavity (14) is provided with a resonant cavity outlet (17), which is connected to the oil outlet channel (8).

5. A low-noise gear pump according to claim 4, characterized in that: A flow divider plate (18) is fixedly connected inside the outlet (17) of the resonant cavity, and reed valves (19) are provided on both sides of the flow divider plate (18).

6. A low-noise gear pump according to claim 5, characterized in that: The pump inlet flange (12) and pump outlet flange (13) are fixedly connected to both sides of the housing (2).

7. A low noise gear pump according to claim 6, characterised in that: The bottom of the base (1) is provided with a rubber pad (20) and a hollow part is provided at the bottom of the base (1), and the hollow part is filled with sound-absorbing cotton pads (21).

Images