Full-freedom-degree bearing-free motor test platform
Technical Field
The invention relates to the field of motor experiments and tests, in particular to a full-freedom-degree bearingless motor test platform.
Background
The bearingless motor integrates the magnetic bearing into a motor module, realizes the stable suspension of a motor rotor by means of electromagnetic force, and does not need a mechanical bearing for supporting. Therefore, the bearingless motor has no problems of large friction loss of a rotor at a high speed, serious heating, limited service life and the like, solves the problems of difficult selection of mechanical bearing lubricating oil and the like in the high-vacuum fields of aerospace and the like, and is very suitable for the field of high cleanliness due to the absence of leakage of the mechanical bearing lubricating oil and metal debris pollution.
In addition to the rotational speed, i.e. the rotational degree of freedom of the rotor of the electric machine about the axis of rotation, which needs to be actively controlled, in bearingless electric machines it is also necessary to provide active or passive control of the remaining five degrees of freedom. The conventional scheme at present mainly comprises five types of single degree of freedom, double degree of freedom, three degrees of freedom, four degrees of freedom and full degree of freedom. However, since the bearingless motor aims to eliminate the use of the mechanical bearing, during experimental tests, attention should be paid to testing the steady-state and dynamic stability and control performance of the motor without the mechanical bearing, which requires that the motor rotor and the test platform cannot be fixed through the mechanical bearing. Meanwhile, aiming at the debugging and testing requirements of the control performance of each degree of freedom of the bearingless motor, the rack also has the functions of loading each degree of freedom and testing stress. Aiming at various possible installation modes of the bearingless motor, the test bench is required to have the function of testing the bearingless suspension performance of the motor in various installation modes of the bearingless motor.
Disclosure of Invention
Aiming at the defects or the requirement for improvement in the prior art, the invention provides a full-freedom bearing-free motor test platform. The problem that the actual performance of a bearingless motor in a state without a mechanical bearing cannot be really tested due to the existence of the mechanical bearing and the like in a traditional bearingless motor testing platform is solved.
The full-freedom-degree bearingless motor test platform provided by the invention can realize static performance test of a full-freedom-degree bearingless motor and dynamic performance test of the full-freedom-degree bearingless motor, and comprises a rotating structure, a mounting table, an L-shaped support, a pressure measurement structure and a radial loading structure, wherein the L-shaped support, the pressure measurement structure and the radial loading structure are sequentially mounted on the mounting table from inside to outside in an axial symmetry mode. The mounting table is installed on the rotating structure, and the motor performance of the full-freedom bearingless motor can be tested under different bearingless motor installation modes by controlling the mounting table and the testing equipment installed on the mounting table through the rotating structure.
Further, the rotating structure comprises a lead screw, and the lead screw is used for connecting the rotating structure base with the mounting table.
Furthermore, the pressure measurement structures are symmetrically distributed, and each pressure measurement structure comprises four radial pressure sensors and one axial pressure sensor.
Furthermore, the radial loading structures are symmetrically distributed, and the rotor rotating shaft of the bearingless motor is disturbed in the directions of various degrees of freedom by the pulleys on the radial loading structures and the smooth guide pipes.
Further, the L-shaped support is used for fixing the full-freedom-degree bearingless motor on the test platform.
When the static performance of the full-freedom bearingless motor is tested, the pressure measurement structure can be installed through applying force to a mechanical bearing fixed on a rotor shaft, the rotor is adjusted to a specified position and an angle, and the respective degree-of-freedom suspension force and the return torque applied to the rotor at the rotor position can be measured through reading data on each pressure sensor, so that the unit displacement suspension force (return torque) coefficient of the full-freedom bearingless motor can be obtained, and the variation curve of the suspension force (return torque) of each degree of freedom along with the angle of the rotor can be tested. Similarly, if different suspension currents are introduced, the unit current suspension force (recovery torque) coefficient of the full-freedom bearingless motor can be obtained, so that the design and the manufacture of the full-freedom bearingless motor are verified, and the next step of debugging of dynamic control of the full-freedom bearingless motor is guided.
When the dynamic performance test of the full-freedom bearingless motor is carried out, the control of the external force borne by the bearingless motor in the radial direction can be realized by installing the radial loading structure. The radial loading device adopts the pulley and the smooth guide pipe to ensure that the applied force does not change along the direction of the axes of the freedom degrees of the radial loading device and along the installation angle of the bearingless motor.
Compared with the prior art, the invention has the advantages that:
when the dynamic performance test of the full-freedom bearingless motor is carried out, the mechanical bearing is not used as a supporting function, and the respective freedom dynamic suspension performance of the full-freedom bearingless motor can be truly reflected and tested.
The full-freedom-degree bearingless motor test platform provided by the invention can flexibly control the external disturbance of each degree of freedom through the radial loading structure, and provides complete test conditions for testing the dynamic disturbance resistance of the full-freedom-degree bearingless motor.
The invention discloses a full-freedom bearingless motor test platform which is characterized in that a loading mode, a measuring method and a structure of the test platform are innovated, and the layout of a rack is improved, so that the angle of an installation platform can be flexibly controlled through a rotating structure, and complete test conditions are provided for testing the dynamic and static performances of the full-freedom bearingless motor in various installation modes.
Drawings
FIG. 1 is an exploded view of a full-freedom bearingless motor test platform provided by the present invention;
FIG. 2 is a static experimental configuration diagram of the full-freedom bearingless motor test platform provided by the present invention;
fig. 3 is a dynamic experimental configuration diagram of the full-freedom bearingless motor test platform provided by the invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention. In addition, the technical features involved in the embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.
The full-freedom-degree bearingless motor test platform provided by the invention can realize static performance test of a full-freedom-degree bearingless motor and dynamic performance test of the full-freedom-degree bearingless motor, and comprises a rotating structure, a mounting table, an L-shaped support, a pressure measurement structure and a radial loading structure, wherein the L-shaped support, the pressure measurement structure and the radial loading structure are sequentially mounted on the mounting table from inside to outside in an axial symmetry mode. The mounting table is installed on the rotating structure, and the motor performance of the full-freedom bearingless motor can be tested under different bearingless motor installation modes by controlling the mounting table and the testing equipment installed on the mounting table through the rotating structure.
Specifically, the rotating structure comprises a lead screw, and the lead screw is used for connecting the rotating structure base and the mounting table.
Specifically, the pressure measurement structures are symmetrically distributed, and each pressure measurement structure comprises four radial pressure sensors and one axial pressure sensor.
Specifically, the radial loading structures are symmetrically distributed, and the disturbance in each degree of freedom direction is applied to the rotor rotating shaft of the bearingless motor through the pulleys on the radial loading structures and the smooth guide pipes.
Specifically, the L-shaped bracket is used for fixing the full-freedom bearingless motor on the test platform.
When the static performance of the full-freedom bearingless motor is tested, the pressure measurement structure can be installed through applying force to a mechanical bearing fixed on a rotor shaft, the rotor is adjusted to a specified position and an angle, and the respective degree-of-freedom suspension force and the return torque applied to the rotor at the rotor position can be measured through reading data on each pressure sensor, so that the unit displacement suspension force (return torque) coefficient of the full-freedom bearingless motor can be obtained, and the variation curve of the suspension force (return torque) of each degree of freedom along with the angle of the rotor can be tested. Similarly, if different suspension currents are introduced, the unit current suspension force (recovery torque) coefficient of the full-freedom bearingless motor can be obtained, so that the design and the manufacture of the full-freedom bearingless motor are verified, and the next step of debugging of dynamic control of the full-freedom bearingless motor is guided.
When the dynamic performance test of the full-freedom bearingless motor is carried out, the control of the external force borne by the bearingless motor in the radial direction can be realized by installing the radial loading structure. The radial loading device adopts the pulley and the smooth guide pipe to ensure that the applied force does not change along the direction of the axes of the freedom degrees of the radial loading device and along the installation angle of the bearingless motor.
Fig. 1 is an exploded view of a full-freedom bearingless motor test platform provided in this embodiment. Wherein 1 and 8 are two pressure measurement structures, each pressure measurement structure comprises four radial pressure sensors and an axial pressure sensor, each pressure sensor is connected on a pressure sensor base, the radial and axial positions of the pressure sensors are controlled by a handle, the pressure sensors act on a plane formed by grinding the excircle of a mechanical bearing 5 fixed on a rotor shaft, 2 and 7 are two groups of radial loading structures, a test platform applies disturbance in each degree of freedom direction to the rotor rotating shaft through a pulley and a smooth conduit on the radial loading structure, 3 and 6 are two groups of L-shaped supports, used for fixing a full-freedom bearingless motor on a test platform, 4 is the full-freedom bearingless motor, 10 is a mounting platform, 9 is a rotating structure, the rotary structure base and the mounting table are connected through the lead screw, the angle of the mounting table can be adjusted by adjusting the length of the lead screw, and different rotor mounting modes can be simulated.
FIG. 2 is a static test configuration diagram of the test platform in the embodiment of FIG. 1. The static test of the test platform only needs to be provided with a pressure measurement structure. The motor axial direction is defined as the z-axis direction, the x-axis direction is parallel to the mounting table rotation axis, and the y-axis direction is determined according to the right-hand rule. Where Fx1-Fx4 are four x-direction pressure sensor readings, Fy1-Fy4 are four y-direction pressure sensor readings, and Fz1-Fz2 are two z-direction pressure sensor readings. The rotor can be positioned to a designated position by adjusting the handles of the pressure sensors, and at the moment, under the condition that given suspension current is introduced or not introduced, the respective degree-of-freedom suspension force and suspension moment borne by the rotor at the moment can be calculated according to the following formula by reading the readings of the pressure sensors. Wherein L1, L2 are both sides pressure measurement structure apart from motor axial midpoint length respectively, and M is rotor weight, and theta is mount table inclination.
Fx=Fx1+Fx3-Fx2-Fx4
Fy=Fy1+Fy3-Fy2-Fy4-Mg*sin(θ)
Tx=L1*(Fx1-Fx2)+L2*(Fx4-Fx3)
Ty=L1*(Fy1-Fy2)+L2*(Fy4-Fy3)
Fz=Fz1-Fz2-Mg*cos(θ)
FIG. 3 is a diagram of the dynamic test configuration of the test platform in the embodiment of FIG. 1. The dynamic experiment of the test platform only needs to install a radial loading structure. The bearing on the rotor shaft is connected with the radial loading structure through the thin wire capable of sliding freely, so that the influence of the mechanical bearing on the full-freedom bearingless motor suspension test in the dynamic test is avoided on the basis of realizing dynamic loading. The Ax1-Ax4 are four smooth guide pipes in the x direction, an external loading weight is guided by the smooth guide pipes through thin wires, external given disturbance is accurately applied to the x axis of the rotor, similarly, Ay1-Ay4 are 4 smooth guide pipes in the y direction, and pulleys are additionally arranged on Ay1 and Ay3 to achieve the conversion of the direction of the external disturbance. Similarly, the heavy matter amount corresponding to the external disturbance required by each degree of freedom can be calculated according to a formula used in a static experiment. The Z-direction disturbance is realized by adjusting the angle of the mounting table.
It will be understood by those skilled in the art that the foregoing is only a preferred embodiment of the present invention, and is not intended to limit the invention, and that any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the scope of the present invention.