What are the advantages of single acting vane pumps, and why are single acting vane pumps variable d

Easy flow regulation and long service life.

Because there are two kinds of vane pumps in history, according to the different types: first) specifically refers to the sliding vane pump in the positive displacement pump. 2) Refers to the three pumps (centrifugal pumps) of the power pump.

Mixed-flow pumps, axial flow pumps.

or other special pumps.

This type of pump product is generally not called a vane pump. However, as a monograph, vane pumps almost all refer to centrifugal pumps, mixed-flow pumps, axial flow pumps, etc. According to whether its theoretical displacement per revolution is a fixed value or a variable value, it can be divided into vane variable pump and vane fixed pump.

In addition to preventing dry rotation and overload, preventing suction air and excessive suction vacuum, the management points of vane pumps should also pay attention to:

1. If the steering of the pump changes, the direction of suction and discharge also changes, and the vane pump has a specified steering and is not allowed to reverse. Because the rotor leaf groove is sloped, the blades are chamfered.

The bottom of the blade is connected with the oil discharge chamber, and the throttle groove and suction and discharge ports on the oil distribution plate are designed according to the established steering. Reversible vane pumps must be specifically designed.

2 Vane pump assembly with oil pan and stator.

Correct positioning with positioning pin, blades, rotor, oil distribution pan are not installed in reverse, the inner surface of the stator suction area part is the most easy to wear, if necessary, it can be flipped and installed, so that the original suction area becomes the discharge area and continues to be used.

3 Disassembly and assembly Pay attention to the cleanliness of the working surface, and the oil should be well filtered when working.

4.If the gap between the blades in the blade groove is too large, the leakage will increase, and if it is too small, the blades will not be able to expand and contract freely, which will lead to abnormal work.

5 The axial clearance of the vane pump has a great influence on v. 1) Small pumps, medium pumps.

6. The temperature and viscosity of the oil should not exceed 55, and the viscosity is required to be between 17 and 37mm2 s. If the viscosity is too large, it is difficult to absorb oil; If the viscosity is too small, the leakage will be serious. As a pump product, vane pumps refer more to sliding vane pumps. Vane pumps are almost exclusively referred to as sliding vane pumps.

Easy flow regulation and long service life.

Variable displacement pumps can be single-acting vane, radial piston or axial piston pumps. Gear pumps and double-acting vane pumps are generally fixed displacement pumps.

The variable pump structure is complex and high; The variable piston pump controls the angle of the swash plate by the outlet pressure feedback mechanism, so as to control the stroke of the plunger and achieve the purpose of controlling the flow; The variable vane pump relies on the outlet pressure feedback mechanism to control the eccentricity of the eccentric ring to achieve the purpose of controlling the flow; In other words, when the variable piston swash plate is vertical, the flow rate is zero, and the same is true for vane pumps.

The main differences are as follows:

1. Single-acting vane pumps are generally variable displacement pumps (such as pressure-limiting variable vane pumps);

2. The double-acting vane pump can only be used as a quantitative vane pump;

3. There is also a difference in the inclination angle of the blade: "single front and double rear".

The existence of microplastics also means that plastics have officially entered the human body to create offside tactics to disintegrate the opponent's strength.

The working principle of a double-acting vane pump is as follows:

The double-acting vane pump is also composed of a stator, a rotor, a vane and an oil distribution pan. The center of the rotor and stator coincide, and the inner surface of the stator is approximately elliptical, which is composed of two long radius r, two short radius r and four transition curves.

When the rotor rotates, the blade moves radially in the rotor groove and presses to the inner surface of the stator under the action of centrifugal force and root pressure, and forms a number of sealing spaces between the blade, the inner surface of the stator, the surface of the rotor and the oil distribution plate on both sides, when the rotor rotates in the direction shown in the figure, the sealing space on the small arc moves to the large arc through the transition curve, and the capacity of the sealing space of the leaf rises to increase, forming a local vacuum, and the oil to suck people.

In the process of moving from the large arc transition curve to the small arc, the blades are gradually pressed into the groove by the inner wall of the stator, the sealing space volume becomes smaller, the oil is squeezed, and the oil is pressed out of the oil pressure port.

Therefore, when the rotary Jane is rotated every week, each working space needs to complete two oil suction and oil pressure, so it is called double-acting vane pump, this vane pump has two oil suction chambers and two oil chambers, and the angle between their centers is symmetrical, so the oil pressure acting on the rotor is balanced with each other, so the double-acting vane pump is also called the unloading vane pump, in order to balance the radial force, the sealing space (that is, the number of blades) should be a double number. Since the stator and rotor are concentric, the double-acting vane pump is a fixed displacement pump.

(1) The bottom of the blade is at the top of the blade in the oil pressure cavity will be affected by the pressure oil, which will push the blade into the blade groove. In order to make the top of the blade reliably contact with the inner surface of the stator, the bottom of the blade on one side of the oil pressure chamber should be communicated with the oil pressure cavity through a special groove, and the bottom of the blade on one side of the oil suction chamber should be communicated with the oil suction cavity, so that the hydraulic pressure of the blade up and down is balanced, and is conducive to reducing the wear between the blade and the stator.

2) The blades of the single-acting vane pump have an inclination angle opposite to the direction of rotation, which is called the backward inclination angle, which is conducive to the blades to stretch outward under the action of centrifugal force, and the backward inclination angle is generally 24°.

3) The number of blades in the single-acting vane pump has pulsation, the more blades in the pump, the smaller the flow rate ripples. The pulsation rate of odd-numbered vane pumps is smaller than that of even-numbered vane pumps, so the number of blades of single-acting vane pumps is odd, generally 13 or 15.

The main differences are as follows:

1. Single-acting vane pumps are generally variable displacement pumps (such as pressure-limiting variable vane pumps);

2. The double-acting vane pump can only be used as a quantitative vane pump;

3. There is also a difference in the inclination angle of the blade: "single front and double rear".

There are two oil suction ports and two oil pressure ports for double acting, the rotor rotates for one week, the oil is suction and pressed twice, the stator and the rotor are installed concentrically, the stator is oval, imvariable, the pressure pulsation is small, and there is no radial force. There is only one oil suction port and one oil pressure port for single action, the rotor rotates for a week, the oil is suction and pressed once, the stator and the rotor are eccentricly installed, the stator is circular, variable, the size of the eccentricity determines the size of the variable, the pressure fluctuation is larger than the double action, and there is a radial force.

View the original post

There are several distinct differences between a single-acting vane pump and a double-acting vane pump described above:

The inner surface curve of the stator for single-acting vane pumps is circular, while for double-acting vane pumps it is oval.

Single-acting vane pumps have only two windows on the pan, while double-acting vane pumps have four. For each revolution of the rotor, the single-acting vane pump only completes one oil suction and one oil pressing, while the double-acting vane pump rotor completes two oil suction and two oil pressure per revolution.

There is an eccentricity in the center of the stator and rotor of a single-acting vane pump. Due to the existence of eccentricity, it lays the foundation for making variable vane pumps, that is, single-acting vane pumps can be made into variable vane pumps; The double-acting vane pump can only be used as a quantitative vane pump.

Because the oil suction chamber and the oil discharge chamber of the single-acting vane pump occupy one side each, the rotor is subjected to the force of the oil in the oil pressure chamber, resulting in the unbalanced radial force of the rotor; The double-acting vane pump has two suction chambers and two pressure chambers, and is symmetrically distributed on the rotating shaft, and the pressure is balanced by the radial force acting on the bearing.

The double-acting vane pump not only acts on the rotor with balanced radial force, smooth operation, uniform oil transfer and low noise, but also has a compact structure and small volume because it is a double-acting pump, which increases the flow rate. The disadvantages of double-acting vane pumps are that they have complex structure, poor oil absorption characteristics, and are more sensitive to oil pollution. Double-acting vane pumps are widely used in a variety of medium and low pressure hydraulic systems.

on your Mac, complete a medium load of work.

Compared with double-acting vane pumps, single-acting vane pumps have complex structures, large dimensions, radial unbalanced force, large noise, volumetric efficiency and mechanical efficiency.

All are low, the flow pulsation and oil trapping phenomenon become more serious, but it is easy to achieve flow adjustment, often used in fast and slow moving hydraulic systems, can reduce power loss, reduce oil heating.

Simplify the oil circuit and save hydraulic components.

When the rotor of the vane pump rotates, the tip of the vane is attached to the inner surface of the stator under the action of centrifugal force and pressure oil. In this way, the working volume of the two blades and the inner surface of the rotor and stator is first absorbed from small to large, and then drained from large to small, and when the blades rotate for one week, the oil absorption and oil discharge are completed once.

The difference is only that the stator surface is composed of eight parts: two long radius arcs, two short radius arcs and four transition curves, and the stator and rotor are concentric. The volume of the sealing working cavity gradually increases at the upper left corner and the lower right corner, which is the oil absorption area, and gradually decreases at the lower left corner and the upper right corner, which is the oil pressure area; There is an oil sealing zone between the suction zone and the pressurized zone to separate them.

The rotor of this pump rotates once and each sealed working chamber completes oil suction and oil pressure twice, so it is called a double-acting vane pump. The two suction zones and the two pressurized zones of the pump are radially symmetrical, and the hydraulic force acting on the rotor is radially balanced, so it is also called a balanced vane pump.

Physical explanation: the working principle and common faults of vane pumps.

It is composed of rotor, stator, blade and oil distribution pan. The rotor has radial chutes, equipped with blades, and the oil distribution pans are installed on both sides of the rotor, and the action of inertia and oil pressure makes the blades close to the stator when rotating, so that it forms a plurality of sealing spaces. The oil distribution pan has an oil suction window and an oil pressure window, which is the blade when working, and the sealing volume increases into a vacuum to absorb oil from the oil suction window, and the blade is gradually pressed in, and the oil comes out from the oil pressure window.

1. From the setting of the bottom oil groove and the oil suction chamber, in the pressure-limiting variable vane pump, the oil groove at the bottom of the blade on one side of the oil pressure chamber is connected with the oil pressure cavity, and the oil groove at the bottom of the blade on one side of the oil suction chamber is connected with the oil suction cavity, so that the hydraulic pressure at the bottom and the top of the blade is balanced. This avoids the problem of severe wear on the inner surface of the stator in the suction zone of the double-acting vane pump.

2. From the perspective of the inclination angle of the blades, the inclination direction of the blades of the pressure-limiting variable vane pump is just opposite to that of the double-acting vane pump, because the upper and lower pressure of the blades of the pressure-limiting variable vane pump is balanced, and the outward movement of the blades in the oil suction area mainly depends on the centrifugal inertia when it rotates, according to the mechanical analysis, such an inclination reversal is more conducive to the blades to stretch out outward under the action of centrifugal inertia.

3. From the perspective of volumetric efficiency and mechanical efficiency, the pressure-limiting variable vane pump has a complex structure, large leakage, unbalanced radial force, high noise, volumetric efficiency and mechanical efficiency are not as high as double-acting vane pumps, and the highest setting pressure is generally about 7MPa. However, it can automatically adjust the flow rate according to the load size, and the power is used reasonably, which can reduce oil heating.

The main differences are as follows: 1. Single-acting vane pumps are generally variable vane pumps (such as pressure-limiting variable vane pumps); 2. The double-acting vane pump can only be used as a quantitative vane pump; 3. There is also a difference in the inclination angle of the blade: "single front and double rear".

This is because vane pumps with inclination angles are not allowed to be reversed, and the direction of the vanes must correspond to the direction of rotation of the rotor.

In the process of working, the blade is subjected to centrifugal force and the pressure oil at the root of the blade, so that the blade and the stator are in close contact.

When the blade is turned to the oil pressure zone, the inner surface of the stator forces the blade to push towards the center of the rotor, and its working situation is similar to that of the cam, the blade and the inner surface of the stator contact have a pressure angle, and the magnitude is variable (the law of change is the same as the radial velocity of the blade - that is, it gradually increases from zero to maximum, and gradually decreases from maximum to zero).

Therefore, in the double-acting vane pump, the blades are tilted forward at a certain angle along the rotor rotation direction to reduce the pressure angle, so that the lateral force can be reduced, the blades can move flexibly in the groove, and the wear can be reduced. When the blades have a placement angle, the vane pump is not allowed to reverse.

The steering mark of the vane pump is on the pump body, and when its rotor is loaded into the pump body, the position of the oil distribution port should be confirmed, that is, there should be a fixed relationship between the oil distribution pan and the housing, and the upper pin of the oil distribution plate and the hole on the pump body are generally used to cooperate and position, so that the cooperation of the pump body oil port, the oil distribution plate oil port and the stator working section of the pump body is realized.

The blade forward tilt of the double-acting vane pump is mainly to reduce the pressure angle, so as to reduce the force imbalance of the blade when it rotates with the rotor of the hydraulic pump. The blade tilt of the single-acting vane pump is mainly conducive to the ejection of the blades during operation (the inner surface of the stator of the single-acting vane pump is round, while the stator of the double-acting vane pump is elliptical composed of an eight-segment arc).

According to the inner surface curve of the stator in the vane pump, the resultant force of the stator on the blade and the centrifugal force on the blade of the single-acting vane pump is just one direction of backward inclination, while the resultant force of the two of the double-acting vane pump on the vane is one direction of forward inclination. And the resultant force of these two forces happens to be in the same direction as the blade protruding.

In order to reduce the side pressure, the double-acting vane pump makes the blades move flexibly in the groove and reduce friction, but the acting vane pump is conducive to the ejection of the blades when working.

There is pressure oil acting on the top of the blade in the pressure zone, and it is not difficult for the blade to retract, while the top of the blade in the oil suction zone is in a vacuum oil absorption state. After setting the blade rake angle, the pressure angle in the suction zone increases, and not all models of double-acting vane pumps have a vane rake angle.

In order to reduce the angle between the blade and the normal of the stator curve, so as to reduce the vertical component of the contact reaction force between the inner surface of the stator transition curve and the blade head, so as to reduce the friction between the blade and the inner wall of the blade groove and ensure the free sliding of the blade.