Impact of rotating blades on cylinder wall

If the design, manufacturing, or use of materials are improper, resulting in poor sliding of the rotary blades, or due to the presence of exhaust dead gaps and incompressible oil, the head of the rotary blades cannot always run tightly against the cylinder wall, it will cause the rotary blades to strike and sound against the cylinder wall. Therefore, it is advisable to adopt a structure with a circular arc surface separating the intake and exhaust ports. Use exhaust guide grooves to eliminate dead gaps.

When using a line separation structure, the distance from the exhaust endpoint to the tangent point should be minimized as much as possible. For rotary vane gear pumps below 70L/s, considering the actual thickness of the rotary vane, it is recommended to take 7-lOmm, and for large gear gear pumps, the larger value should be taken. When too close, due to the presence of the rotor blade groove and only a narrow strip in contact with the blade head, if the sealing effect is not good when the blade is turned to the tangential position, it will affect the pumping speed and even limit the pressure of the gear pump. It can be seen that this structure cannot completely eliminate exhaust dead gaps, limiting the level of noise reduction.

It should be pointed out that excessive clearance between the rotor and groove can reduce performance. Therefore, it is necessary to ensure reasonable tolerance fits and geometric tolerance values, pay attention to the thermal expansion of the rotor, avoid galling between the rotor and the groove, pay attention to the cold oil viscosity of the oil, and design sufficient spring force for the rotor. When using circular arc surface separation, the additional eccentricity value of the rotor center should not be too large. Otherwise, if the rotating blade passes through two circular arcs, there will be a tendency to detach from the cylinder wall at the intersection, which will instead cause impact noise. Generally, 0.20~0.25mm is sufficient for small gear pumps, while larger gear pumps can be appropriately increased. The sound produced by the pressure oil in the exhaust dead gap and the pressure oil in the residual volume. When the gear pump reaches the limit pressure, the pressure oil at two places will shoot at high speed into the vacuum chamber when connected to it, and collide with the rotor and cylinder wall to make a sound. The size and location of the two volumes are related to noise.

The impact noise of the valve disc on the valve seat and supporting parts sucks in a large amount of gas

The more circulating oil in a gear pump, the greater the noise of the valve disc, the higher the valve jump, the larger the valve area, and the greater the noise of the valve disc. The material of the valve disc also has a certain impact. The noise of rubber valve discs should be better than that of steel discs or laminated plates. To this end, it is necessary to control the oil intake, and the valve plate should be closed in a timely and tight manner. Pay attention to the material selection and structure of the valve.

When the amount of echo and bubble rupture sound inside the box increases, this noise will increase

Therefore, this noise will significantly increase when the gas is turned on or when the atmosphere is open. If the gas balance is adjustable, the gas balance can be adjusted reasonably.

The noise emitted when a large amount of gas and oil is discharged and impacts components such as oil baffles

If the rigidity of the parts is insufficient or not tightened, vibration and collision will occur, which will increase the noise. Therefore, the oil baffle should not only have sufficient stiffness and fastening, but also use the method of clamping rubber to avoid collision noise caused by vibration and improve the oil baffle effect when it needs to come into contact with other parts (such as the fuel tank).