Air suspension radial bearing and high-speed fan
By setting up an electromagnet and an energized coil on the aerodynamic pressure bearing, suction force is generated to reduce friction, and the wear problem caused by insufficient dynamic pressure during the start and stop phase of the aerodynamic pressure bearing is solved, and the reliability and life of the bearing are improved.
Patent Information
- Application Number
- CN202421527512.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-07-01
- Publication Date
- 2025-02-07
- Estimated Expiration
- 2034-07-01
AI Technical Summary
Inadequate dynamic pressure of aerodynamic bearings during the start and stop stage causes wear of the rotor and the inner wall of the bearing, affecting the reliability and life of the bearing.
An air-suspended radial bearing is designed. By installing an electromagnet on the bearing, current is sent to the energized coil during the start and stop stage, an upward suction force is generated, which reduces the force of the aerodynamic bearing and reduces the friction between the rotor and the inner wall of the bearing.
It effectively provides additional rotor support, reduces friction, and improves the reliability and life of aerodynamic bearings. At the same time, the structure is simple, the cost is not much increased, and maintenance-free.
Smart Images
Figure CN222436855U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of high-speed fan equipment, in particular to an air suspension radial bearing and a high-speed fan. Background Art
[0002] In the application scenarios of sewage treatment, fish pond oxygen supply, particle transportation, etc., the traditional Roots blower is replaced by the more advanced high-speed blower, which is more efficient, quieter and more compact. High-speed blowers have the advantages of high speed, high efficiency, high-speed frequency conversion control, integration of multiple intelligent algorithms, and remote control, and are the key development direction of high-efficiency blowers.
[0003] In high-speed fans, the efficient impeller rotates at high speed (more than 20,000 rpm) driven by the shaft to throw out the gas, and the high-speed rotating shaft needs to be supported by bearings to ensure the rotation accuracy. Traditional rolling bearings are generally composed of four parts: inner ring, outer ring, rolling element and cage. Obviously, such a structure has a lot of extra weight involved in the rotation, which is not conducive to the high-speed rotation of this level of high-speed fans. Rolling bearing failures caused by rolling element slippage, fatigue, wear, etc. often occur. Once the rolling bearing fails, it will lead to reduced system accuracy, sharp increase in vibration, wear, and even shaft sticking and breaking. Therefore, high-speed fans currently generally use magnetic suspension bearings and air bearings that are suitable for high-speed rotation.
[0004] Magnetic bearings use magnetic force to suspend the rotor in the air, so that there is no mechanical contact between the rotor and the stator. Magnetic bearings are composed of four parts: rotor, sensor, controller and actuator, of which the actuator includes two parts: electromagnet and power amplifier. Assuming that the rotor is subjected to a downward disturbance at the reference position, it will deviate from its reference position. At this time, the sensor detects the displacement of the rotor from the reference point, and the microprocessor as the controller converts the detected displacement into a control signal. The power amplifier then converts this control signal into a control current, which generates magnetic force in the actuator magnet, thereby driving the rotor back to its original equilibrium position. Therefore, no matter whether the rotor is subjected to downward or upward disturbance, the rotor can always be in a stable equilibrium state. The advantages of magnetic bearings are high rotation accuracy and strong bearing capacity, but the production and installation are complicated and the price is high.
[0005] Air bearings (also known as air bearings) refer to sliding bearings that use gas (usually air, but it may also be other gases) as lubricant. Air is less viscous than oil, resistant to high temperatures, and pollution-free, so it can be used in high-speed machines, instruments, and radioactive devices. Air dynamic pressure bearings, also known as self-acting bearings, no longer require an external air supply system compared to gas static pressure bearings. Instead, they work on the principle of dynamic pressure effect. The two relatively moving surfaces form a certain convergence gap. The high-speed movement of the moving surfaces brings viscous air into the wedge gap to generate pressure rise, and then generates a bearing capacity acting on the rotor. The bearing capacity increases with the increase in speed. The wedge gap, the thickness of the lubricating gas film, and the viscosity of the gas are the key conditions for the formation of the dynamic pressure effect. Because it is free from dependence on the air supply system, the gas dynamic pressure bearing has a simple structure, does not require maintenance, and has a lower cost. However, when the speed is low and the dynamic pressure effect is weak during the start-stop stage, it is not enough to generate a supporting force acting on the rotor, resulting in contact between the rotor and the inner wall of the bearing, resulting in severe friction and wear, which directly affects the life of the bearing. Utility Model Content
[0006] The utility model aims to solve the problem of insufficient dynamic pressure of air bearings during the start-stop phase, which causes contact wear between the rotor and the inner wall of the bearing. The utility model provides an air suspension radial bearing, which provides additional rotor support force on the bearing, reduces the friction between the rotor and the inner wall of the bearing, and improves the reliability and life of the air dynamic pressure bearing. The utility model has a simple structure, little additional cost, and is maintenance-free.
[0007] In order to achieve the above purpose, the technical solution adopted by the utility model is:
[0008] An air suspension radial bearing, characterized in that it comprises a radial bearing, an air dynamic pressure bearing, a radial bearing sleeve, a radial bearing iron core, and a radial bearing magnetic pole;
[0009] The air dynamic pressure bearing and the radial bearing sleeve contain section notches, and the air dynamic pressure bearing is installed between the radial bearing and the radial bearing sleeve; the radial bearing iron core and the radial bearing magnetic pole are installed in the section notch of the radial bearing sleeve, on the outside of the radial bearing iron core, and an energized coil is wound on the iron core.
[0010] During the start-stop stage of the air bearing, due to the low rotation speed and weak dynamic pressure effect, an electromagnet is arranged above the bearing in the utility model, and current is passed through the energized coil during the start-stop stage of the air bearing to generate upward suction, thereby reducing the force on the air dynamic pressure bearing, reducing the friction between the rotor and the inner wall of the bearing, and improving the reliability and life of the air dynamic pressure bearing.
[0011] Preferably, the radial bearing pole is made of magnetically conductive material.
[0012] Preferably, the material of the radial bearing pole is any one of DT4 electrical pure iron, 2Cr13, and 17-4 stainless steel.
[0013] Preferably, the radial bearing core and the radial bearing pole are made of the same material.
[0014] The wire diameter of the energized coil on the radial bearing core (5-1) is 0.4-0.7 mm; it is single strand or multi-strand, with 80-150 turns.
[0015] When the radial bearing (5) bears a weight of 15-20 kg, the current flowing through the energized coil (6) is 3-6 A.
[0016] When the weight borne by the radial bearing (5) is greater than 20kg and less than 40kg, the current flowing through the energized coil (6) is 6-9A.
[0017] The utility model also provides a high-speed fan, comprising the air suspension radial bearing.
[0018] Preferably, the high-speed fan further comprises a volute, a casing, a stator and a rotating shaft; the two large impellers, the thrust plate and the small impeller are fixed on both ends of the shaft body, and together constitute the rotating shaft; the rotating shaft is limited to a predetermined position by a thrust bearing and two radial bearings, the two radial bearings are mounted on the casing, and the two volutes are respectively mounted on both sides of the casing;
[0019] The air dynamic pressure bearing and the radial bearing sleeve contain section notches, and the air dynamic pressure bearing is installed between the radial bearing and the radial bearing sleeve; the radial bearing iron core and the radial bearing magnetic pole are installed in the section notch of the radial bearing sleeve, on the outside of the radial bearing iron core, and an energized coil is wound on the iron core.
[0020] Compared with the prior art, the utility model has the following beneficial effects:
[0021] (1) The utility model effectively generates additional rotor support force on the bearing by arranging an electromagnet on the air dynamic pressure bearing, thereby reducing the friction between the rotor and the inner wall of the bearing, and improving the reliability and life of the air dynamic pressure bearing.
[0022] (2) The improved air bearing structure of the utility model is simple in structure and has low additional cost, which increases the service life of the air dynamic pressure bearing and reduces the overall operation and maintenance costs. BRIEF DESCRIPTION OF THE DRAWINGS
[0023] Figure 1 This is a cross-sectional view of a high-speed fan according to an embodiment of the utility model.
[0024] Figure 2 It is an overall schematic diagram of an air suspension radial bearing according to an embodiment of the utility model.
[0025] Figure 3 This is an exploded view of an air suspension radial bearing according to an embodiment of the utility model.
[0026] Figure 4 It is a side sectional view of an air suspension radial bearing according to an embodiment of the utility model.
[0027] Figure 5 The front view (a), side view (b) and top view (c) of the air suspension radial bearing of the embodiment of the utility model are shown. DETAILED DESCRIPTION
[0028] In order to make the purpose, technical solution and advantages of the utility model clearer, the utility model is further described in detail in conjunction with the embodiments below. It should be understood that the specific embodiments described herein are only used to explain the utility model and are not used to limit the utility model. Those skilled in the art who make modifications or equivalent substitutions based on their understanding of the technical solution of the utility model without departing from the spirit and scope of the technical solution of the utility model should be included in the protection scope of the utility model.
[0029] Example 1
[0030] like Figure 1 As shown, this embodiment provides a high-speed fan, including a volute 1, a casing 2, a stator 3, a rotating shaft 4 and an air suspension radial bearing.
[0031] The two large impellers 4-1, the thrust plate 4-2 and the small impeller 4-3 are all fixed on the shaft body 4-4, and together constitute the rotating shaft 4. The rotating shaft 4 is restricted in a predetermined position by the thrust bearing 2-1 and the radial bearing 5. The two volutes 1 are respectively installed on both sides of the casing 2.
[0032] like Figure 2-5 As shown, Figure 5 (a) is a front view of the air suspension radial bearing, (b) is a side view, and (c) is a top view. The air dynamic pressure bearing 5-4 and the radial bearing sleeve 5-3 contain a cut-out notch, and the air dynamic pressure bearing 5-4 is installed between the radial bearing 5 and the radial bearing sleeve 5-3; the radial bearing core 5-1 and the radial bearing pole 5-2 are fixedly installed in the cut-out notch of the radial bearing sleeve 5-3 by screws, and the radial bearing core 5-1 is outside, and the energized coil 6 is wound on the core.
[0033] The material of the radial bearing pole 5-2 is DT4 electrical pure iron, 2Cr13 or 17-4 stainless steel, and the radial bearing core 5-1 and the radial bearing pole 5-2 are made of the same material.
[0034] According to the principle of aerodynamic bearings, when the rotor starts, there will be a process where the rotor contacts the inner wall of the bearing and then separates from the inner wall of the bearing. In this process, one of the most important key points is the rotor speed. The lowest speed that can separate the rotor from the inner wall of the bearing is called the takeoff speed. Generally speaking, when other conditions remain unchanged, the lower the rotor weight, the lower the takeoff speed.
[0035] In the experiment, 110 turns of double-strand 0.5 diameter enameled wire were wound around the radial bearing cores 5-1 on the two radial bearings 5, and a current of 4A was passed through both. The electromagnets generated suction, reducing the pressure of the rotor on the inner wall of the bearing. The fan was then started according to the normal process, and the take-off speed was reduced by 2000r / min compared to when the radial bearings 5 were not energized.
[0036] In contrast, the rotating shaft 4 is driven by the magnetic field generated by the stator 3 being energized. The greater the current flowing through the stator 3, the greater the magnetic field generated, and the greater the driving force on the rotating shaft 4. When the rotating shaft 4 is controlled to accelerate to the rated speed according to the set angular acceleration, the maximum current required by the stator 3 is called the starting current. In the experiment, 110 turns of double-strand enameled wire with a wire diameter of 0.5 were wound on the radial bearing cores 5-1 on the two radial bearings 5, and a current of 4A was passed through both. The electromagnet generated suction, which in disguise reduced the pressure of the rotor on the inner wall of the bearing, and also reduced the friction at the air dynamic pressure bearing. The starting current was reduced by 15% relative to when the radial bearing 5 was not energized.
[0037] In this embodiment, electromagnetic force is generated inside the radial bearing core 5-1, and through the two radial bearing poles 5-2 connected thereto, the rotating shaft 4 is subjected to an upward suction force, thereby reducing the force on the air dynamic pressure bearing 5-4, thereby reducing the friction between the rotor and the inner wall of the bearing, and increasing the life (number of starts) of the air dynamic pressure bearing from 100,000 times to 300,000 times.
Claims
1. An air suspension radial bearing, characterized in that: It comprises a radial bearing (5), an air dynamic pressure bearing (5-4), a radial bearing sleeve (5-3), a radial bearing iron core (5-1), and a radial bearing magnetic pole (5-2); The air dynamic pressure bearing (5-4) and the radial bearing sleeve (5-3) contain a section notch, and the air dynamic pressure bearing (5-4) is installed between the radial bearing (5) and the radial bearing sleeve (5-3); the radial bearing iron core (5-1) and the radial bearing magnetic pole (5-2) are installed in the section notch of the radial bearing sleeve (5-3), outside the radial bearing iron core (5-1), and an energized coil (6) is wound around the iron core.
2. The air suspension radial bearing according to claim 1, characterized in that: The radial bearing magnetic pole (5-2) is made of magnetic conductive material.
3. The air suspension radial bearing according to claim 1, characterized in that: The material of the radial bearing magnetic pole (5-2) is any one of DT4 electrical pure iron, 2Cr13 and 17-4 stainless steel.
4. The air suspension radial bearing according to claim 1, characterized in that: The radial bearing iron core (5-1) and the radial bearing magnetic pole (5-2) are made of the same material.
5. The air suspension radial bearing according to claim 1, characterized in that: The wire diameter of the energized coil on the radial bearing core (5-1) is 0.4-0.7 mm, single strand or multiple strands, and the number of winding turns is 80-150.
6. The air suspension radial bearing according to claim 1, characterized in that: When the radial bearing (5) bears a weight of 15-20 kg, the current flowing through the energized coil (6) is 3-6 A.
7. The air suspension radial bearing according to claim 1, characterized in that: When the weight borne by the radial bearing (5) is greater than 20kg and less than 40kg, the current flowing through the energized coil (6) is 6-9A.
8. A high-speed fan, characterized in that: The invention comprises the air suspension radial bearing according to any one of claims 1 to 7.
9. The high-speed blower according to claim 8, characterized in that: It also includes a volute (1), a casing (2), a stator (3) and a rotating shaft (4); The two large impellers (4-1), the thrust plate (4-2) and the small impeller (4-3) are all fixed on both ends of the shaft body (4-4), and together form a rotating shaft (4); The rotating shaft (4) is restricted at a predetermined position by a thrust bearing (2-1) and two radial bearings (5), the two radial bearings (5) are mounted on the casing (2), and the two volutes (1) are respectively mounted on both sides of the casing (2); The air dynamic pressure bearing (5-4) and the radial bearing sleeve (5-3) contain a section notch, and the air dynamic pressure bearing (5-4) is installed between the radial bearing (5) and the radial bearing sleeve (5-3); the radial bearing iron core (5-1) and the radial bearing magnetic pole (5-2) are installed in the section notch of the radial bearing sleeve (5-3), outside the radial bearing iron core (5-1), and an energized coil (6) is wound around the iron core.