Motor and method of operating the same

Abstract

The present invention discloses a motor and an operation method thereof, wherein the motor comprises: a rotating shaft; a gas bearing, the gas bearing comprising an inner ring and an outer ring; a first stator into which direct current is supplied to form a uniform magnetic field; a first rotor arranged in the first stator; a second stator; a second rotor arranged in the second stator; the first stator comprises at least four electromagnets; the first stator is switched to connect three-phase alternating current to rotate the first rotor. Compared with the prior art, the present invention improves the control accuracy of the motor by using the first stator as a magnetic field transition in the start-stop stage of the motor, and avoids the strong friction between the inner and outer rings of the gas bearing due to the instability of the air film between the inner and outer rings of the gas bearing in the start-stop stage of the motor.

Description

Technical Field

[0001] The present invention relates to the field of motor design and manufacturing, and in particular to a motor capable of effectively reducing internal friction of a bearing and an operating method thereof. Background Art

[0002] At present, most motor bearings use rolling bearings and sliding bearings. With the advancement of science and technology, magnetic bearings are gradually used to replace the existing bearing system in some special fields. However, magnetic bearings require a series of sensors, controllers and actuators to use with them and are expensive. Therefore, air bearing technology came into being. Especially in the field of high-speed motors, air bearings have broad application prospects.

[0003] Existing air suspension bearings all use the aerodynamic force generated by the motor when it rotates to provide a pressure difference, thereby achieving air intake and exhaust in the bearing gap. The principle is: the gas enters from the bearing pores, passes through the bearing gap, and finally exits from both ends of the bearing, forming a layer of air film between the inner and outer rings of the bearing to achieve the purpose of air pressure suspension. However, when the motor is started and stopped, friction will occur between the inner and outer rings of the bearing due to the lack of aerodynamic force, which greatly affects the service life of the bearing. Summary of the invention

[0004] The present invention provides a motor and an operating method thereof, which solve the technical problem in the prior art that a motor using an air suspension bearing has severe friction inside the bearing when starting and stopping.

[0005] The technical solution adopted by the present invention is: a motor, including a rotating shaft and a gas bearing arranged on the rotating shaft, the gas bearing including an inner ring and an outer ring, and also including: a first stator into which direct current is passed to form a uniform magnetic field, and a first rotor arranged in the first stator; the rotating shaft is installed in the first rotor, and the first rotor is suspended in the uniform magnetic field to drive the inner ring to be suspended in the outer ring.

[0006] Furthermore, the motor also includes a second stator and a second rotor disposed in the second stator, and the rotating shaft is installed in the second rotor to rotate with the second rotor.

[0007] Furthermore, the first stator includes at least four electromagnets uniformly surrounding the rotating shaft.

[0008] Furthermore, the first stator is switched to connect three-phase alternating current to rotate the first rotor.

[0009] A method for operating a motor, wherein the motor is the above-mentioned motor, and the motor includes a gas bearing. The method for operating the motor includes: before driving the rotating shaft to rotate, first supplying direct current to the first stator to suspend the rotating shaft, and before the rotating shaft stops rotating, supplying direct current to the first stator to suspend the rotating shaft.

[0010] Further, when the time for which direct current is supplied to the first stator reaches a first preset time T1, the second stator is energized to drive the rotating shaft to rotate.

[0011] Further, when the rotation time of the rotating shaft reaches a second preset time T2, the first stator switches on the three-phase alternating current to drive the rotating shaft to rotate.

[0012] Furthermore, the first stator is switched to direct current, and then the power supply of the second stator is cut off to stop driving the rotating shaft.

[0013] Furthermore, when the rotating shaft is stationary, the power supply of the first stator is cut off.

[0014] Compared with the prior art, the present invention uses the first stator as the magnetic field transition during the start-stop stage of the motor, thereby improving the control accuracy of the motor and avoiding strong friction between the inner and outer rings of the gas bearing due to the instability of the air film between the inner and outer rings of the gas bearing during the start-stop stage of the motor, thereby greatly increasing the service life of the gas bearing. At the same time, the present application also has the characteristics of simple structure and fast motor operation speed. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0016] Figure 1 It is a schematic diagram of the installation structure of the rotating shaft and one surface of the gas bearing in the present invention;

[0017] Figure 2 It is a schematic diagram of the installation structure of the rotating shaft and the other surface of the gas bearing in the present invention;

[0018] Figure 3 It is a schematic diagram showing part of the structure of the motor in the present invention. DETAILED DESCRIPTION

[0019] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0020] The present invention provides a motor, which comprises a shell and a rotating shaft arranged in the shell. The shell is provided with a bearing chamber, the bearing chamber is provided with a gas bearing, and the rotating shaft is installed in the gas bearing.

[0021] like Figure 1 , 2 As shown, the gas bearing 2 includes an inner ring 21 and an outer ring 22, with a gap between the inner ring 21 and the outer ring 22, and an air vent 221 is provided on the outer ring 22. The rotating shaft 1 is fixedly installed with the inner ring 21. When the rotating shaft 1 rotates at a high speed, aerodynamic force is generated inside the gas bearing 2 to provide a pressure difference. The gas enters from the air vent 221 and fills the annular gap between the inner ring 21 and the outer ring 22. The gas is discharged from both ends of the gas bearing 2 to form a gas film between the inner ring 21 and the outer ring 22, so that the rotating shaft 1 is in a completely suspended state.

[0022] like Figure 3 As shown, the motor in the present application includes a first stator 4 and a first rotor 41. The first stator 4 is arranged inside the shell, the first rotor 41 is matched with the first stator 4, and the shaft 1 is fixedly installed in the first rotor 41. Direct current is connected to the first stator 4, so that a uniform and stable electromagnetic field is generated between the first stators 4. Under the action of magnetic force, the first rotor 41 drives the shaft 1 to float in the first stator 4, so that the inner ring 21 is also suspended in the outer ring 22, thereby reducing the contact friction between the inner ring 21 and the outer ring 22.

[0023] Furthermore, a second stator 3 and a second rotor 31 are provided in the motor housing. The second stator 3 and the second rotor 31 are power elements for driving the rotating shaft 1 to rotate, that is, the second rotor 31 is fixedly mounted on the rotating shaft 1. When a three-phase AC power supply is connected to the second stator 3, a periodically changing magnetic field is generated in the second stator 3, and the second rotor 31 drives the rotating shaft 1 to rotate rapidly in the second stator 3.

[0024] In one embodiment, the first stator 4 is four electromagnets evenly arranged around the rotating shaft 1, so as to ensure that the first rotor 41 is subjected to uniform force, so that the inner ring 21 is located as close to the center of the outer ring 22 as possible, and the inner and outer rings of the gas bearing do not contact each other.

[0025] Furthermore, the three-phase AC power supply can also be switched on the first stator 4 to generate a changing magnetic field force to drive the first rotor 41 to drive the rotating shaft 1 to rotate, thereby achieving the same function as the second stator 3 .

[0026] The present application also proposes a motor operation method based on the motor proposed in the present application, which is specifically:

[0027] Before starting the motor: first pass direct current into the first stator 4, the first stator 4 is energized to generate a uniformly changing magnetic field, so that the shaft 1 is suspended therein, and then the shaft 1 drives the inner ring 21 of the gas bearing 2 to be suspended in the outer ring 22, so that a gap is generated between the inner and outer rings.

[0028] Start the motor: When the time for energizing the first stator 4 reaches the first preset time T 1 After that, three-phase AC power is supplied to the second stator 3 to drive the second rotor 31 to drive the shaft 1 to start rotating. Since there is a gap between the inner and outer rings of the gas bearing 2 at this time, the inner ring 21 does not rub dryly with the outer ring 22 when rotating.

[0029] After starting the motor: the shaft 1 starts to rotate T 2 After a period of time, the motor shaft 1 has started to run stably. At this time, the first stator 4 is not needed to provide a uniform magnetic field. At this time, the first stator 4 cuts off the DC power and connects the three-phase AC power supply. At this time, the first stator 4 and the second stator 3 have the same function and can generate a changing magnetic field to drive the first rotor 41 to rotate. The first stator 4 and the second stator 3 work at the same time to drive the motor shaft 1 to rotate faster, thereby making the shaft 1 run at high speed.

[0030] When shutdown is required: first cut off the three-phase AC power supply of the first stator 4, and connect the DC power supply, so that the first stator 4 generates a uniform and stable magnetic field again. At this time, since only the second stator 3 drives the motor shaft 1 to rotate, the speed of the shaft 1 will decrease, and then cut off the three-phase AC power of the second stator 3, so that the shaft 1 is no longer rotated by force, and the shaft 1 continues to rotate only under the action of inertia. The shaft 1 is suspended in the magnetic field generated by the first stator 4, and the inner and outer rings of the gas bearing 2 will not have contact friction. Finally, when the shaft 1 completely stops rotating and reaches a stationary state, the first stator 4 is powered off to make the shaft 2 fall smoothly and slowly, that is, there will be no friction between the inner and outer rings of the gas bearing 2 when it stops.

[0031] In this way, the strong friction between the inner and outer rings of the gas bearing 2 due to the instability of the air film between the inner and outer rings of the gas bearing 2 during the start and stop stages of the motor is avoided, thereby greatly increasing the service life of the gas bearing 2; at the same time, since the first stator 4 is used as the magnetic field transition during the start and stop stages of the motor, the control accuracy of the motor is improved; in addition, the present application also has the characteristics of simple structure and fast motor operation speed.

[0032] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A motor, comprising a rotating shaft and a gas bearing arranged on the rotating shaft, wherein the gas bearing comprises an inner ring and an outer ring, and is characterized in that: Also includes: A first stator is supplied with direct current to form a uniform magnetic field, and a first rotor is arranged in the first stator; the rotating shaft is installed in the first rotor, the first rotor is suspended in the uniform magnetic field to drive the inner ring to be suspended in the outer ring, and the first stator is switched to connect three-phase alternating current to rotate the first rotor; The motor further includes a second stator and a second rotor disposed in the second stator, and the rotating shaft is installed in the second rotor to rotate with the second rotor.

2. The motor according to claim 1, characterized in that The first stator includes at least four electromagnets uniformly surrounding the rotating shaft.

3. A method for operating a motor, characterized in that: The motor is a motor according to any one of claims 1 to 2, the motor comprises a gas bearing, and the operating method of the motor comprises: Before driving the rotating shaft to rotate, direct current is supplied to the first stator to make the rotating shaft suspended, and before the rotating shaft stops rotating, direct current is supplied to the first stator to make the rotating shaft suspended; When the time for which the first stator is supplied with direct current reaches a first preset time T1, the second stator is energized to drive the rotating shaft to rotate; When the rotation time of the rotating shaft reaches a second preset time T2, the first stator switches on the three-phase alternating current to drive the rotating shaft to rotate; Before the rotating shaft stops, the first stator is switched to direct current, and then the power supply of the second stator is cut off to stop driving the rotating shaft.

4. The method for operating a motor according to claim 3, characterized in that: When the shaft is stationary, the power supply of the first stator is cut off.

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