CN109004807A - A kind of no linear bearing switched relutance linear motor - Google Patents

Abstract

A kind of no linear bearing switched relutance linear motor, motor are made of mover and stator, there is air gap between the two；The length of stator is greater than the length of mover；Stator includes n thrust mechanism, n+1 bearing-free mechanism, and 2n+1 " E " type mover teeth, 2n+2 biasing excitation source, n thrust coil, n+1 suspended coil and 2n+1 are every magnetic mechanism；Bearing-free mechanism includes that " E " type mover tooth, biasing excitation source a, biasing excitation source b and suspended coil, suspended coil are wound in the center tooth of " E " type mover tooth, and biasing excitation source a is opposite with biasing excitation source b excitation direction；Single thrust mechanism includes " E " type mover tooth and thrust coil, and thrust coil is wound in the center tooth of " E " type mover tooth；" E " type mover tooth of thrust mechanism and " E " type mover tooth of bearing-free mechanism are adjacent structure.The spaced design of bearing-free mechanism of the present invention and thrust mechanism realizes the decoupling of suspension magnetic Yu thrust magnetic field from mechanical structure.

Description

A Linear Bearing-less Switched Reluctance Linear Motor

technical field

The invention belongs to the field of linear motors, in particular to a linear bearing-free switched reluctance linear motor.

Background technique

With the development of industrial applications, linear motors are used more and more widely. In the case of linear drive, compared with rotary motors, linear motors directly convert electrical energy into mechanical energy for linear motion without intermediate conversion links. The structure is simple, the dynamic response is fast, the efficiency is high, and the construction cost is low. Linear motors are supported by linear bearings to ensure the size of the air gap. Linear bearings will affect the mechanical characteristics and life of linear motors. The combination of bearingless magnetic levitation technology and linear motor can solve this problem and lead to some new technologies, such as magnetic levitation trains, production conveyor lines, etc. In the selection of linear motors, permanent magnet linear motors have significant advantages in terms of efficiency, power index, power factor, etc., but in the case of long stators, permanent magnet linear motors have high engineering costs, inconvenient maintenance, and there is a risk of demagnetization of permanent magnets. Switched reluctance linear motors do not contain expensive permanent magnets, are less affected by the environment, and are suitable for use in various harsh environments.

However, the air-gap flux density harmonic content of linear switched reluctance motors is rich. If it is used as a linear motor without linear bearings, it is difficult to decouple the control of its levitation force and thrust.

Chinese Patent Application Publication Document "A Decoupling Control Method for Composite Rotor Bearingless Switched Reluctance Motor" document number: CN106655549A, publication number: CN106655549A, discloses a rotating bearingless switched reluctance motor, the torque control of the motor The method takes the output torque as the control object of the torque control link, adopts the three-phase alternate conduction control method, and obtains the output torque according to the relationship between the torque with respect to the current and the rotor position angle; according to the relationship between the suspension force with respect to the current and the rotor position angle The reference value of the levitation current is obtained, and the direct control of the levitation force and output torque is realized. This method can also be transplanted to a linear bearing-less switched reluctance linear motor. However, this structure has some major disadvantages, including the coupling between the suspension force control and the torque control, and the suspension control needs to know the position information of the rotor. These problems also exist in the corresponding switched reluctance linear motor without linear bearings, making the linear motor The grating scale not only provides position information for thrust control, but also provides position information for suspension control. At the same time, suspension force current control, thrust current control and stator position information are coupled together. The decoupling control algorithm is complicated. Once the motor is saturated, the parameters change. In severe cases, the system will become unstable.

Contents of the invention

The technical problem to be solved by the present invention is to solve the problem that the existing bearingless magnetic levitation technology is applied to the switched reluctance linear motor, which has the coupling of the levitation force magnetic field and the thrust magnetic field, the control algorithm is complicated, and the levitation force control needs to know the position information of the stator. Linear bearing-less switched reluctance linear motor, its bearingless mechanism and thrust mechanism are decoupled on the mechanical structure, through the special design of the motor structure and bearingless mechanism, the air gap permeability of the levitation coil is constant, that is, the levitation force current control Decoupled from the stator position, the levitation force does not change with the stator position.

In order to solve the above problems, the technical solution adopted in the present invention is:

A linear bearing-free switched reluctance linear motor, the motor is composed of a mover and a stator with an air gap between them; the length of the stator is greater than the length of the mover; the stator includes n thrust mechanisms, n +1 bearingless mechanism, 2n+1 "E" type mover teeth, 2n+2 bias excitation sources, n thrust coils, n+1 suspension coils and 2n+1 magnetic isolation mechanism; the bearingless mechanism It is connected with the thrust mechanism through the magnetic isolation mechanism;

The single bearingless mechanism includes an "E" type mover tooth, a bias excitation source a, a bias excitation source b, and a suspension coil. The suspension coil is wound on the middle tooth of the "E" type mover tooth. The excitation direction of bias excitation source a and bias excitation source b is opposite, and they are respectively placed on the yokes on both sides of the "E" type mover teeth;

The single thrust mechanism includes an "E" type mover tooth and a thrust coil, and the thrust coil is wound on the middle tooth of the "E" type mover tooth; the "E" type mover tooth of the thrust mechanism and all The "E" type mover teeth of the above-mentioned bearingless mechanism are adjacent structures.

Preferably, the middle tooth width of the "E" type mover tooth of the bearingless mechanism is b, the tooth width of the stator is 1/3 of b, and the pole pitch of the stator is equal to b; the "E" of the bearingless mechanism ” type mover tooth slot inner space width is 1/3 of b.

Preferably, the bias excitation source is an electric excitation winding.

Preferably, the bias excitation source is a permanent magnet.

The present invention is a linear bearing-less switched reluctance linear motor. The interval design between the bearingless mechanism and the thrust mechanism realizes the decoupling of the suspension magnetic field and the thrust magnetic field from the mechanical structure. The specific design of the stator tooth width makes the permeance of the magnetic circuit passed by the levitation magnetic field independent of the stator position, so that the levitation force does not change with the change of the stator position, that is, the levitation force control does not require stator position information, which greatly simplifies the control algorithm.

Description of drawings

Fig. 1 is a structural diagram of a linear bearing-less switched reluctance linear motor of the present invention.

Fig. 2 is the dimensional design ratio of the bearingless mechanism of the present invention.

Fig. 3 is the suspension coil inductance of the present invention.

Fig. 4 is the levitation force produced by the bearingless mechanism of the present invention.

Fig. 5 is the magnetic force lines of the levitation magnetic field and the thrust magnetic field of the present invention.

Explanation of reference numerals: In Fig. 1, 1 is the linear motor stator, 2 is the linear motor mover, 3 is the levitation coil, 4 is the bias excitation source of forward excitation, 5 is the bias excitation source of reverse excitation, 6 is "E" type mover teeth, 7 is the thrust coil, 8 is the magnetic isolation mechanism, 9 is the magnetic force line of the reasoning mechanism, and 10 is the magnetic force line of the bearingless mechanism.

Detailed ways

Below in conjunction with the accompanying drawings, when n=3, the linear bearing-less switched reluctance linear motor proposed by the present invention will be described in detail:

As shown in Figure 1, a linear bearing-free switched reluctance linear motor is composed of a mover and a stator with an air gap between them; the length of the stator is greater than the length of the mover; the stator is composed of a thrust mechanism and a bearingless mechanism , "E" type mover teeth, bias excitation source, thrust coil, suspension coil, and magnetic isolation mechanism.

There are 3 thrust mechanisms, namely No. 1 to No. 3 thrust mechanisms (numbered in sequence from left to right, the same as below); there are 4 bearingless mechanisms, which are respectively No. 1 to No. 4 bearingless mechanisms; "E" type mover There are 7 teeth, which are No. 1 to No. 7 "E" type mover teeth; there are 8 bias excitation sources, which are No. 1 to No. 8 bias excitation sources.

Wherein, the excitation direction of the odd-numbered bias excitation sources is the same, the excitation direction of the even-numbered bias excitation sources is the same, and the excitation direction of the odd-numbered bias excitation sources is opposite to that of the even-numbered bias excitation sources.

There are three thrust coils, No. 1 to No. 3 thrust coils; four suspension coils, No. 1 to No. 4 suspension coils; seven magnetic isolation mechanisms, No. 1 to No. 7 magnetic isolation mechanisms.

The No. 1 thrust mechanism is composed of the No. 1 "E" type mover tooth and the No. 1 thrust coil. The No. 1 thrust coil is wound on the middle tooth of the No. 1 "E" type mover tooth, and so on. The No. 3 thrust mechanism is composed of The No. 3 "E" type mover tooth and the No. 3 thrust coil are composed, and the No. 3 thrust coil is wound on the middle tooth of the No. 3 "E" type mover tooth.

No. 1 bearingless mechanism is composed of No. 1 "E" type mover teeth, No. 1 bias excitation source, No. 2 bias excitation source, No. 1 suspension coil, No. 1 bias excitation source and No. 2 bias excitation source excitation The direction is opposite; the No. 1 suspension coil is wound on the middle tooth of the No. 1 "E" type mover tooth, and the No. 1 bias excitation source and No. 2 bias excitation source are respectively placed on the No. 1 "E" type mover tooth. The yokes on both sides, and so on, No. 4 bearingless mechanism is composed of No. 7 "E" type mover teeth, No. 7 bias excitation source, No. 8 bias excitation source, No. 4 suspension coil, and No. 7 bias excitation source The excitation direction is opposite to that of No. 8 bias excitation source; No. 4 suspension coil is wound on the middle tooth of No. 7 "E" type mover teeth, and No. 7 bias excitation source and No. 8 bias excitation source are respectively placed on No. 7 The yokes on both sides of the "E" type mover teeth.

No. 1 bearingless mechanism is connected with No. 1 thrust mechanism through No. 1 magnetic isolation mechanism, No. 1 thrust mechanism is connected with No. 2 bearingless mechanism through No. 2 magnetic isolation mechanism, and so on, No. 3 bearingless mechanism and No. 3 thrust mechanism It is connected through No. 6 magnetic isolation mechanism, and No. 3 thrust mechanism is connected with No. 4 bearingless mechanism through No. 7 magnetic isolation mechanism.

Figure 2 is the dimensional design ratio of the bearingless mechanism of the present invention. The "E" type mover teeth of the bearingless mechanism, that is, the No. 1, No. 3, No. 5 and No. 7 "E" type mover teeth have a tooth width of b, The tooth width of the stator is 1/3 of b, and the pole pitch of the stator is equal to b; the inner space width of the "E" type mover teeth is 1/3 of b.

Fig. 3 is the inductance of the suspension coil of the bearingless mechanism of the present invention. It can be seen that, adopting the size design ratio of the bearingless mechanism provided in Fig. Variety.

Fig. 4 is the levitation force produced by the bearingless mechanism of the present invention. It can be seen that since the inductance of the levitation coil basically does not change with the position of the stator, the levitation force basically does not change with the change of the stator position, and the levitation force control and stator position information are realized. Decoupling to achieve linear control of suspension force.

Fig. 5 is the magnetic force lines of the levitation magnetic field and the thrust magnetic field of the present invention. It can be seen that due to the setting of the magnetic isolation mechanism, the magnetic force lines of the levitation magnetic field and the thrust magnetic force lines are independent, and the independent control of levitation force and thrust is realized, and the control algorithm is simple.

The above-mentioned embodiment only expresses one implementation mode of the present invention, and its description is relatively specific and detailed, but it should not be understood as limiting the patent scope of the present invention. It should be pointed out that those skilled in the art can make several modifications and improvements without departing from the concept of the present invention, and these all belong to the protection scope of the present invention.

Claims (4)

1. a kind of no linear bearing switched relutance linear motor, the motor are made of mover and stator, there is air gap between the two； The length of the stator is greater than the length of mover；It is characterized in that, the stator includes n thrust mechanism, n+1 bearing-free machine Structure, 2n+1 " E " type mover teeth, 2n+2 biasing excitation source, n thrust coil, n+1 suspended coil and 2n+1 are every magnetic mechanism；Institute Bearing-free mechanism is stated with thrust mechanism by being connected every magnetic mechanism；

The single bearing-free mechanism includes " E " type mover tooth, biasing excitation source a, biases excitation source b and suspended coil, described Suspended coil is wound in the center tooth of " E " type mover tooth, the biasing excitation source a and biasing excitation source b excitation direction on the contrary, And it is respectively placed in the both sides yoke portion of " E " type mover tooth；

The single thrust mechanism includes " E " type mover tooth and thrust coil, and the thrust coil is wound on " E " type mover tooth In center tooth；" E " type mover tooth of the thrust mechanism and " E " type mover tooth of the bearing-free mechanism are adjacent structure.

2. no linear bearing switched relutance linear motor according to claim 1, which is characterized in that bearing-free mechanism " E " type mover tooth center tooth facewidth is b, and the stator facewidth is the 1/3 of b, and the stator poles are away from equal with b；The bearing-free Spacing width is the 1/3 of b in " E " type mover tooth tooth socket of mechanism.

3. no linear bearing switched relutance linear motor according to claim 1, which is characterized in that the biasing excitation source For electrical excitation winding.

4. no linear bearing switched relutance linear motor according to claim 1, which is characterized in that the biasing excitation source For permanent magnet.