CN210404981U

CN210404981U - Magnetic suspension bearing and high-performance servo motor

Info

Publication number: CN210404981U
Application number: CN201920945923.2U
Authority: CN
Inventors: 李月芹
Original assignee: Daguo Zhongqi Automation Equipment Shandong Co ltd
Current assignee: Daguo Zhongqi Automation Equipment Shandong Co ltd
Priority date: 2019-06-23
Filing date: 2019-06-23
Publication date: 2020-04-24
Anticipated expiration: 2029-06-23

Abstract

The magnetic suspension bearing comprises a shell and is characterized by further comprising a fixing ring arranged in the shell and a plurality of magnetic rollers arranged on the periphery of the fixing ring along the circumferential direction, wherein the fixing ring comprises four concentric rings which are sequentially nested, and the four rings are sequentially provided with a rare earth metal ring, a Teflon ring, a permanent magnet ring and a copper ring from inside to outside; the magnetic roller at least comprises a permanent magnet, and the polarity of the permanent magnet ring on the fixed ring is opposite to that of the permanent magnet of the magnetic roller. Used the utility model provides a magnetic suspension bearing's servo motor, control circuit is simple, longe-lived, and the rotational speed is fast.

Description

Magnetic suspension bearing and high-performance servo motor

Technical Field

The utility model relates to a magnetic suspension bearing and high performance servo motor belongs to motor technical field.

Background

The servo motor provided by the prior art is a motor of a mechanical bearing, and comprises a stator and a rotor, wherein a winding for rotation is arranged in a slot of the stator, and the rotor rotates in the mechanical bearing when current is applied to the winding.

SUMMERY OF THE UTILITY MODEL

In order to overcome the defects of the prior art, the invention aims to provide a magnetic suspension bearing and a high-performance servo motor.

In order to achieve the purpose, the utility model provides a magnetic suspension bearing, which comprises a shell and is characterized by also comprising a fixing ring arranged in the shell and a plurality of magnetic rollers arranged on the periphery of the fixing ring along the circumferential direction, wherein the fixing ring comprises four concentric rings which are nested in sequence, and the four rings are sequentially provided with a rare earth metal ring, a Teflon ring, a permanent magnet ring and a copper ring from inside to outside; the magnetic roller at least comprises a permanent magnet, and the polarity of the permanent magnet ring on the fixed ring is opposite to that of the permanent magnet of the magnetic roller.

Preferably, the magnetic roller is a magnetic roller which is sequentially provided with a rare earth metal ring, a Teflon ring, a permanent magnet ring and a copper ring from inside to outside.

Preferably, the rare earth metal is neodymium.

Preferably, the housing includes at least a shielding layer for isolating interference of a magnetic field generated by the fixed ring and the magnetic roller with the outside.

For realizing the utility model discloses the purpose, the utility model discloses still provide a servo motor, it includes motor and driver, the motor sets up the rotor shaft movably on the support through foretell magnetic suspension bearing.

Compared with the prior art, the utility model provides a magnetic suspension bearing simple structure does not need extra power supply to produce the holding power, and utility model provides a servo motor need not overcome mechanical bearing's resistance when the rotor is rotatory owing to make rotor magnetism suspension on the base, and mechanical friction is little, consequently, longe-lived, and the rotational speed is high and output is big.

Drawings

Fig. 1 is a schematic composition diagram of a magnetic suspension bearing provided by the present invention;

fig. 2 is a block diagram of the power supply circuit of the servo motor provided by the present invention;

fig. 3 is a working state diagram of the servo motor provided by the present invention;

fig. 4 is a block diagram showing a modified example of the power supply circuit for the servo motor according to the present invention;

fig. 5 is a block diagram showing another modification of the servo motor power supply circuit according to the present invention.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below by referring to the drawings are exemplary, and the illustrated embodiments are only for explaining the present invention, and should not be construed as limiting the present invention.

As used herein, the singular forms "a", "an", "the" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and/or "comprising," when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. It will be understood that when an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. As used herein, the term "and/or" includes all or any element and all combinations of one or more of the associated listed items.

It will be understood by those within the art that all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. It will be further understood that terms used in the specification should be interpreted as having a meaning that is consistent with their prior art and will not be interpreted in an extreme sense unless specifically defined herein.

Fig. 1 is the utility model provides a magnetic suspension bearing' S composition sketch map, as shown in fig. 1, the utility model provides a magnetic suspension bearing includes shell 5, still including setting up solid fixed ring in shell 5 and a plurality of setting at solid fixed ring outer magnetic roller Ro1-Ro8 of arranging along circumference, gu fixed ring includes concentric setting and four rings nested in proper order, four rings are rare earth metal ring 1, teflon ring 2, permanent magnet ring 3 and copper ring 4 from inside to outside in proper order, 3 upper ends of permanent magnet are the N polarity, and the lower extreme is the S polarity. The magnetic roller at least comprises a permanent magnet, preferably, the magnetic roller is a magnetic roller, the magnetic roller Ro sequentially comprises a rare earth metal ring, a Teflon ring, a permanent magnet ring and a copper ring from inside to outside, the upper end of the permanent magnet is an S pole, and the lower end of the permanent magnet is an N pole. Preferably, the rare earth metal is neodymium. The housing 5 preferably comprises a magnetic shielding material for preventing interference of the magnetic field generated by the stationary ring and the magnetic rollers with the outside. Although the present invention is exemplified by 8 magnetic rollers, any number of magnetic rollers may be used.

When the rotor shaft AX is driven to rotate by a rotating magnetic field generated by a stator of the servo motor, the fixed ring also rotates, and magnetic levitation is generated between the fixed ring and magnetic rollers arranged around the fixed ring, so that frictionless sliding is realized, and the magnetic rollers rotate.

The following describes the utility model provides a servo motor's supply circuit.

Fig. 2 is the utility model provides a servo motor's supply circuit's component block diagram, as shown in fig. 2, control system includes boost circuit, and it is used for stepping up the alternating current electric energy that alternating current power supply 201 provided to convert direct current electric energy, boost circuit includes inductance 202, electric energy converter 203 and wave filter 204, and alternating current power supply 201 connects in electric energy converter 203 through inductance 202, and electric energy converter 203 converts alternating current electric energy into direct current electric energy and steps up, then exchanges the composition through wave filter 204 filtering.

The output of the power converter 203 is connected to an energy storage 209 and provides dc power to the current inverter 206. The energy storage 209 may use a rechargeable battery, a large-capacity capacitor, an electric double layer capacitor, or the like.

A capacitor 207 is also provided on the dc side of the inverter 206. The ac side of the inverter 206 is connected to an ac motor M for supplying ac current to the motor M to generate a rotating magnetic field. The rotational speed and the rotational position of the alternating-current motor M are detected by the encoder 211. A command for the rotational speed of the motor M is output from the rotational speed command unit 221.

The speed control unit 222 operates based on the speed command from the rotational speed command unit 221 and the feedback signals from the encoder 211 and the current detector 223, and performs speed control, current control, and PWM control of the ac motor M and PWM control of the inverter 206 based on the output. Since this control is well known, a detailed description is omitted.

The utility model provides a power supply circuit still includes the instruction arithmetic unit, including current detection unit 234, speed instruction unit 221, energy storage detecting element 231, current instruction arithmetic unit 232 and current control unit 233, wherein, current detection unit 234 is used for detecting the current value of boost circuit input; the energy storage detection unit 231 is used for detecting the amount of electricity stored in the energy storage 209; the speed command unit 221 calculates the required electric energy for driving the motor M according to the rotational speed pattern; the current instruction arithmetic unit 232 calculates the proportion of the electric energy supplied to the motor from the booster circuit and the energy storage 209 according to the instruction of the rotating speed instruction unit 221 and the electric energy supplied by the energy storage 209 provided by the energy storage detection unit 231; the current control unit 233 controls the booster circuit to supply electric energy according to a ratio to be supplied, in accordance with the instruction of the current instruction operation unit 232 and the supply current supplied from the current detection unit 234. In the present example, the speed command is issued from the rotational speed command unit 221, but the position command may be issued and the position control, speed control, current control, and PWM control of the ac motor M may be performed by the speed control unit 222

On the other hand, the energy charging state of the energy storage 209 is detected by the energy charging detection unit 231. In addition, the required electric energy of the ac motor M is calculated by the rotational speed command unit 221. The detected value of the energy storage detecting means 231 and the required electric energy from the rotational speed command means 221 are inputted to the current command calculating means 232, and the output current of the booster circuit 205 is calculated in the current command calculating means 232. That is, when the power factor of the ac power supply 201 is 1, the magnitude of the current of the ac power supply 201 is indicated. The current control unit 233 operates based on the output of the current command operation unit 232, the voltage of the ac power supply 201, and the signal from the current detector 234, and performs current control and PWM control of the ac power supply 201 and PWM operation of the power converter 203

The operation of the booster circuit 205 is described below. The instantaneous electric energy required by the alternating-current motor M, that is, the electric energy required to drive the motor M according to the rotational speed pattern is calculated in the rotational speed command unit 221. The required electric energy is obtained from the product of the speed command and the torque command according to the rotational speed mode. The speed command is obtained as a rotational speed pattern of the robot, that is, a speed command of the ac motor, and the torque command is obtained from a torque command when the test robot moves.

The electric energy required for the ac motor M is supplied from the energy storage 209 and the booster circuit 205. The current command operation unit 232 determines the supply ratio of the two. The stored energy detection unit 231 calculates an output and a storable power from the stored amount. The current command operation means 232 operates the electric energy output from the booster circuit 205, that is, the current command value corresponding to the electric energy, based on the electric energy required for the motor from the rotational speed command means 221 and the detection value from the stored energy detection means 231. The electric energy required by the motor from the current command unit 221 may be output at any time including the current time and the value after the current time, or may be output to the current command operation unit 232 in advance for one cycle of the rotational speed pattern. The amount of storage of the energy storage 209 may be calculated based on the voltage and current in and out of the energy storage 209. Alternatively, the calculation may be performed from only one of the voltage and the current. In addition, the accumulated energy detection means 231 may detect the accumulated amount itself based on the electric energy flowing into or out of the accumulator 209 without detecting the accumulated amount.

In this way, the current command operation unit 232 operates the current command in consideration of the electric energy required by the motor corresponding to the rotation speed mode and the stored energy stored in the accumulator. Current control section 233 controls booster circuit 205 so that the power supply current corresponding to the current command value flows from ac power supply 201 to booster circuit 205. With this configuration, the power supply current can be controlled to be sinusoidal and the power factor can be controlled to be 1. As described above, the current command value supplied to current control section 233 can be controlled not only to have a power factor of 1 but also to have a control other than a power factor = 1.

Fig. 3 is a diagram showing an example of controlling the operation state of the booster circuit according to the rotation speed mode, fig. 3 (a) is a waveform diagram of the rotation speed of the motor, fig. 3 (b) is the torque required by the motor, fig. 3 (c) is the electric energy required by the motor, fig. 3 (d) is the output of the booster circuit, fig. 3 (e) is the output of the accumulator, fig. 3 (f) is the stored electric energy stored in the accumulator, and the horizontal axis is a common time axis. As shown in fig. 3, at time t0, the motor rotates at a high speed. From time t1 to time t2, the deceleration state is entered. The work is performed while accelerating from time t2 to time t3, and after the work is completed from time t3 to time t4, the motor is accelerated and then the rotational speed is increased from time t 5. The above process is repeated thereafter.

In the example shown in fig. 3, the motor requires deceleration torque from time t1 to time t2, requires torque for work from time t2 to time t3, and requires acceleration torque from time t3 to time t 4. The torque of the rotational speed is obtained in advance from the results of the simulation calculation or the test rotational speed according to the work content. The electric power required by the motor is determined by the product of the motor rotational speed and the required torque, and therefore, a large amount of electric power is required from t2 to t3 at the time of operation, and further, a large amount of energy is required as time integration. In order to cope with such a large energy at the time of work, the current output value is set as follows. In fig. 3, a command for obtaining a predetermined output current is output to the booster circuit from time t 1. From time t1 to time t2, the voltage-boosting circuit causes electric energy to be output from the ac power supply 201 to the voltage-boosting circuit, although the motor performs the regenerative operation. As a result, as shown in fig. 3 (e), from time t1 to time t2, the regenerative electric power from the motor and the electric power from the power supply flow into the energy storage. From time t2, power from both the energy storage and the power source flows to the motor for time t 4. Then, a current command for causing the accumulator to perform the charging operation is issued while the charging state is detected, and the current command is returned to zero at time t 41. Thus, the required electric energy required is calculated according to the operation mode, and when the current command is determined, the required energy can be supplied to the motor even if the conversion capacity of the booster circuit or the energy storage capacity of the energy storage device is small.

Fig. 4 is a block diagram showing a power supply circuit according to another embodiment of the present invention. In fig. 4, the same components as those in fig. 2 are denoted by the same reference numerals. The embodiment is characterized in that the instruction operation unit comprises a voltage detection unit 253, a speed instruction unit 221, an energy storage detection unit 231, a voltage instruction operation unit 251 and a voltage control unit 252, wherein the voltage detection unit 253 is used for detecting the voltage value at the input end of the voltage boost circuit; the energy storage detection unit 231 is used for detecting the amount of electricity stored in the energy storage device; the rotational speed instruction unit 221 calculates the required electric energy for driving the motor according to the operation mode; the voltage instruction operation unit 251 calculates the proportion of the electric energy supplied to the motor from the booster circuit and the energy storage 209 according to the instruction of the rotating speed instruction unit 221 and the electric energy supplied by the energy storage provided by the energy storage detection unit 231; the voltage control unit 252 controls the booster circuit to supply electric energy according to the ratio it should supply, according to the instruction of the voltage instruction operation unit and the supply voltage of the voltage supplied by the voltage detection unit 253. In this way, the voltage command is changed according to the rotational speed command and the energy storage state, and a voltage command corresponding to the voltage command is obtained, so that the booster circuit 205 is operated. Since the voltage of the energy storage 209 differs depending on the energy storage state, the command value of the dc voltage is changed depending on the rotational speed command and the energy storage state. This also enables the utility model to be implemented.

Fig. 5 is a block diagram of another power supply circuit with a modified column according to the present invention, and the same parts as those of the power supply circuit shown in fig. 2 as shown in fig. 5 are not repeated, and only different parts will be described below. The power supply circuit shown in fig. 5 further includes a current limit operation unit 261 for supplying the voltage boost circuit 205, which calculates the voltage command output by the voltage boost circuit 205 and calculates the maximum limit current value thereof according to the energy storage information of the energy storage 209 provided by the energy storage detection unit and the command provided by the speed command unit 221. The voltage instruction unit 262 provides an instruction to the voltage control unit 263 according to the instruction from the current limit operation unit 261. The voltage control unit 263 gives the current limiting unit 264 a supply current command value according to the direct current voltage command, information provided by the voltage detection unit 253 for detecting the voltage at the input terminal of the booster circuit 205, and information provided by the voltage detection unit 265 for detecting the voltage at the output terminal of the booster circuit 205. The current limiting unit 264 determines a limit value of the current of the power supply 201 according to the signal of the current limit operation unit 261 and the instruction provided by the voltage control unit 263, thereby limiting the current flowing from the alternating-current power supply 201. Since the voltage command value and the current limit value are variably controlled according to the rotation speed command and the stored energy, the capacities of the boost 205 and the accumulator 209 can be further reduced.

The utility model provides a control system can provide control signal for a plurality of motors, provides the electric energy by all motors of accumulator or boost circuit supply. Each motor has its own inverter. The dc bus sides of the motor inverters are commonly connected and then connected to the output terminal of the booster circuit 205.

It should be noted that the language used in the specification has been principally selected for readability and instructional purposes, and may not have been selected to delineate or circumscribe the inventive subject matter. Accordingly, many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the appended claims. The disclosure of the present invention is intended to be illustrative, but not limiting, of the scope of the invention, which is set forth in the following claims.

Claims

1. The magnetic suspension bearing comprises a shell and is characterized by further comprising a fixing ring arranged in the shell and a plurality of magnetic rollers arranged on the periphery of the fixing ring along the circumferential direction, wherein the fixing ring comprises four concentric rings which are sequentially nested, and the four rings are sequentially provided with a rare earth metal ring, a Teflon ring, a permanent magnet ring and a copper ring from inside to outside; the magnetic roller at least comprises a permanent magnet, and the polarity of the permanent magnet ring on the fixed ring is opposite to that of the permanent magnet of the magnetic roller.

2. The magnetic suspension bearing according to claim 1, wherein the magnetic rollers are magnetic rollers which are a rare earth metal ring, a teflon ring, a permanent magnet ring and a copper ring in sequence from inside to outside.

3. Magnetic bearing according to claim 2, characterized in that the rare earth metal is neodymium.

4. Magnetic bearing according to claim 3, characterized in that the housing comprises at least a shielding layer for isolating disturbances of the magnetic field generated by the stator ring and the magnetic rollers from the outside.

5. A servo motor comprising an electric motor and a drive, said electric motor movably mounting a rotor shaft on a support via a magnetic bearing according to any of claims 1-4.