Leakage problem of stainless steel gear pump
Leakage problem of stainless steel gear pump
Leakage during installation static test, in which the inner rotor of the stainless steel gear pump is the driving wheel, and the outer rotor is the driven theory. Since the teeth of the inner and outer rotors have one tooth difference, there is a secondary meshing in the meshing process and several independent The enclosed liquid chamber. With the rotation of the inner and outer rotors, the volume of each liquid chamber changes differently: When the liquid chamber volume changes from small to large, a partial vacuum is generated in the liquid chamber, under the action of atmospheric pressure, Liquid through the inlet pipe and the annular groove on the pump cover, into the pump chamber to start the liquid, when the volume of the liquid chamber reaches the maximum. The end of the aspiration process; when the volume in the liquid chamber is greatly changed. The liquid in the liquid chamber is pressed out of the other annular groove, which is the discharge process of the pump. When the internal gear pump is in operation, the internal and external rotors must run in the same direction at different speeds around the mutually parallel two axes. Relative movement. This movement creates a constantly changing space between the inner and outer rotors, and is connected to the liquid suction and drainage channels to achieve the purpose of suction and drainage.
Stainless steel gear pump noise caused by the following situations
(1) The phenomenon of "cavitation" and the phenomenon of "air-breathing"
The "cavitation" phenomenon and "vacuuming" phenomenon are one of the major causes of excessive noise in stainless steel gear pumps. In flowing liquids, the pressure at a certain point is lower than the air separation pressure and generates bubbles, known as "gas." "The phenomenon of hole" phenomenon. These air is bound to form a large number of bubbles, causing the original continuous oil into a discontinuous state. At the same time, these bubbles will enter the high pressure chamber with the oil from the low-pressure chamber of the gear pump, and the impact of pressure oil. Under rapid rupture, this process occurs instantaneously and can cause local hydraulic shocks. Where the bubble condenses, the pressure and temperature rise sharply, causing strong vibration and noise. When the “cavitation†phenomenon occurs, it often accompanies There is whistling and fluctuates the pressure of the system, causing the equipment to sometimes not work properly. At this time, if the suction pipe joints and shaft oil seals are not sealed properly, the oil inlet pipe is blocked, the liquid level in the oil tank is too low, and the oil viscosity is low. If it is too high, the degree of vacuum at the suction port of the gear oil pump will be too high, so that the air will infiltrate, resulting in a phenomenon of “sucking emptyâ€. When these infiltrated air bubbles enter the high pressure chamber of the stainless steel gear pump, “cavitation†phenomenon will also occur, causing Vibration and noise. The usual measures are: 1 Select the larger diameter oil suction pipe according to the actual flow of the gear pump, the pipeline layout is as reasonable as possible to reduce the local resistance of the pipeline, to ensure that the flow rate of the stainless steel gear pump suction pipe oil is 2-3 m/s. If the viscosity of the hydraulic oil is too high, replace the hydraulic oil and clean the pipeline regularly; 2 check whether the seal at the suction pipe joint is reliable, whether the oil seal at the shaft extension is worn or deformed, or replace the seal; 3 adopt a large-capacity oil filter, And try to install in the lower part of the tank to ensure the oil filter capacity, regular cleaning of the oil filter; 4 regular inspection of the oil surface, add hydraulic oil, so that the liquid level in the tank is higher than the gear pump suction port.
(2) Excessive wear of parts generates noise
During the use of the stainless steel gear pump, due to internal parts wear and tear, excessive clearance, damage to the seal ring, etc., can cause a large internal leakage of the gear pump (high and low pressure chambers connected) pump flow and pressure changes, resulting in vibration and Noise. The solutions include: 1 Check whether the clearance between the gear pump sliding bearing and the gear journal is normal. Otherwise, replace it. 2 Check whether the sleeve (or the side plate) and the gear mating surface are damaged. If abnormality is found, according to the specific situation Take the side of the grinding gear, the sleeve end face and the housing end face or replace the parts. To ensure the best clearance of 0.12-0.18mm, reduce the internal leakage of the stainless steel gear pump and reduce the noise.
(3) Tooth error noise
If the surface roughness of the gear is poor, the tooth profile error is large, and the tooth deformation causes the uneven meshing of the gears and causes noise. The usual methods are: 1 For the gear pump with large displacement and high load, in order to improve the wheel The tooth profile accuracy of the tooth is usually a tooth grinding process, which not only can correct the tooth shape error caused by the heat treatment deformation of the gear, but also can improve the roughness of the tooth surface, meet the requirements of meshing precision, and reduce the noise; 2 For medium and small displacement gear oil pumps, If the tooth grinding process is not used, the gear pump noise can be reduced by improving the precision of gear cutters and processing equipment and reducing the tooth profile error without changing the tooth profile; The gear tooth profile method achieves a good effect of "low noise". The general measure adopted for the gear pump vibration is to install an accumulator and a muffler at the outlet of the gear pump to reduce the noise. Stainless steel gear pump If the rotational speed of the pump is too high, resonance will occur. When the fundamental frequency of the pump and its resonance frequency are in agreement with the mechanical or hydraulic natural frequency, the noise will be greatly increased. If the fluid is not properly selected, the viscosity is too high, the hydraulic pump The oil absorption resistance increases, resulting in noise. The cross section of the flow passage in the pump suddenly expands and contracts, and the sharp bends. The passage cross section is too small and the like can cause turbulent flow of the oil, whirlpools and jets, which increase the noise. Others such as improper bearing assembly, damage The excessive coaxiality of the pump shaft and the ancillary equipment during installation will also increase the noise. It should be checked in time and replaced if necessary.
Leakage during installation static test, in which the inner rotor of the stainless steel gear pump is the driving wheel, and the outer rotor is the driven theory. Since the teeth of the inner and outer rotors have one tooth difference, there is a secondary meshing in the meshing process and several independent The enclosed liquid chamber. With the rotation of the inner and outer rotors, the volume of each liquid chamber changes differently: When the liquid chamber volume changes from small to large, a partial vacuum is generated in the liquid chamber, under the action of atmospheric pressure, Liquid through the inlet pipe and the annular groove on the pump cover, into the pump chamber to start the liquid, when the volume of the liquid chamber reaches the maximum. The end of the aspiration process; when the volume in the liquid chamber is greatly changed. The liquid in the liquid chamber is pressed out of the other annular groove, which is the discharge process of the pump. When the internal gear pump is in operation, the internal and external rotors must run in the same direction at different speeds around the mutually parallel two axes. Relative movement. This movement creates a constantly changing space between the inner and outer rotors, and is connected to the liquid suction and drainage channels to achieve the purpose of suction and drainage.
Stainless steel gear pump noise caused by the following situations
(1) The phenomenon of "cavitation" and the phenomenon of "air-breathing"
The "cavitation" phenomenon and "vacuuming" phenomenon are one of the major causes of excessive noise in stainless steel gear pumps. In flowing liquids, the pressure at a certain point is lower than the air separation pressure and generates bubbles, known as "gas." "The phenomenon of hole" phenomenon. These air is bound to form a large number of bubbles, causing the original continuous oil into a discontinuous state. At the same time, these bubbles will enter the high pressure chamber with the oil from the low-pressure chamber of the gear pump, and the impact of pressure oil. Under rapid rupture, this process occurs instantaneously and can cause local hydraulic shocks. Where the bubble condenses, the pressure and temperature rise sharply, causing strong vibration and noise. When the “cavitation†phenomenon occurs, it often accompanies There is whistling and fluctuates the pressure of the system, causing the equipment to sometimes not work properly. At this time, if the suction pipe joints and shaft oil seals are not sealed properly, the oil inlet pipe is blocked, the liquid level in the oil tank is too low, and the oil viscosity is low. If it is too high, the degree of vacuum at the suction port of the gear oil pump will be too high, so that the air will infiltrate, resulting in a phenomenon of “sucking emptyâ€. When these infiltrated air bubbles enter the high pressure chamber of the stainless steel gear pump, “cavitation†phenomenon will also occur, causing Vibration and noise. The usual measures are: 1 Select the larger diameter oil suction pipe according to the actual flow of the gear pump, the pipeline layout is as reasonable as possible to reduce the local resistance of the pipeline, to ensure that the flow rate of the stainless steel gear pump suction pipe oil is 2-3 m/s. If the viscosity of the hydraulic oil is too high, replace the hydraulic oil and clean the pipeline regularly; 2 check whether the seal at the suction pipe joint is reliable, whether the oil seal at the shaft extension is worn or deformed, or replace the seal; 3 adopt a large-capacity oil filter, And try to install in the lower part of the tank to ensure the oil filter capacity, regular cleaning of the oil filter; 4 regular inspection of the oil surface, add hydraulic oil, so that the liquid level in the tank is higher than the gear pump suction port.
(2) Excessive wear of parts generates noise
During the use of the stainless steel gear pump, due to internal parts wear and tear, excessive clearance, damage to the seal ring, etc., can cause a large internal leakage of the gear pump (high and low pressure chambers connected) pump flow and pressure changes, resulting in vibration and Noise. The solutions include: 1 Check whether the clearance between the gear pump sliding bearing and the gear journal is normal. Otherwise, replace it. 2 Check whether the sleeve (or the side plate) and the gear mating surface are damaged. If abnormality is found, according to the specific situation Take the side of the grinding gear, the sleeve end face and the housing end face or replace the parts. To ensure the best clearance of 0.12-0.18mm, reduce the internal leakage of the stainless steel gear pump and reduce the noise.
(3) Tooth error noise
If the surface roughness of the gear is poor, the tooth profile error is large, and the tooth deformation causes the uneven meshing of the gears and causes noise. The usual methods are: 1 For the gear pump with large displacement and high load, in order to improve the wheel The tooth profile accuracy of the tooth is usually a tooth grinding process, which not only can correct the tooth shape error caused by the heat treatment deformation of the gear, but also can improve the roughness of the tooth surface, meet the requirements of meshing precision, and reduce the noise; 2 For medium and small displacement gear oil pumps, If the tooth grinding process is not used, the gear pump noise can be reduced by improving the precision of gear cutters and processing equipment and reducing the tooth profile error without changing the tooth profile; The gear tooth profile method achieves a good effect of "low noise". The general measure adopted for the gear pump vibration is to install an accumulator and a muffler at the outlet of the gear pump to reduce the noise. Stainless steel gear pump If the rotational speed of the pump is too high, resonance will occur. When the fundamental frequency of the pump and its resonance frequency are in agreement with the mechanical or hydraulic natural frequency, the noise will be greatly increased. If the fluid is not properly selected, the viscosity is too high, the hydraulic pump The oil absorption resistance increases, resulting in noise. The cross section of the flow passage in the pump suddenly expands and contracts, and the sharp bends. The passage cross section is too small and the like can cause turbulent flow of the oil, whirlpools and jets, which increase the noise. Others such as improper bearing assembly, damage The excessive coaxiality of the pump shaft and the ancillary equipment during installation will also increase the noise. It should be checked in time and replaced if necessary.
Chenille Embroidery Machine,Multi-Head Chenille Embroidery Machine,632 Chenille Machine
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