Two-dimensional pointing mechanism with bearing and vibration isolation capabilitiesTechnical Field
The invention relates to the field of high-precision directional control of space optical loads, in particular to a two-dimensional directional mechanism with bearing and vibration isolation capabilities.
Background
With the continuous development of the field of space application, future space optical loading (investigation photographic satellites, astronomical telescopes, etc.) technology will be developed towards higher pointing accuracy. The existing two-dimensional pointing mechanism has no vibration isolation capability, a vibration isolation platform is additionally arranged between the two-dimensional pointing mechanism and the star body to ensure that micro vibration generated on the star body is transmitted to optical load, so that the complexity of a system is increased, or the existing two-dimensional pointing mechanism has no bearing capability, and the upper platform and the lower platform of the two-dimensional pointing mechanism are locked by a locking mechanism in the transmitting stage to unlock in space, so that the structural weight and the structural complexity are increased.
Disclosure of Invention
In order to solve the problems in the prior art, the invention aims to provide a two-dimensional pointing mechanism with bearing and vibration isolation capabilities, which has static bearing capability and dynamic vibration isolation capability, so that locking is not required in a transmitting stage, vibration isolation can be realized in space, influence of star micro-vibration on optical load is weakened, and the two-dimensional pointing precision of the optical load is improved.
In order to achieve the above purpose, the invention adopts the following technical scheme:
The two-dimensional pointing mechanism with the bearing and vibration isolation capabilities comprises an upper platform 1 and a lower platform 2, a voice coil motor 3 and a high-static low-motion actuator 4 which are arranged between the upper platform 1 and the lower platform 2, wherein the high-static low-motion actuator 4 is arranged in the middle, and the voice coil motor 3 is symmetrically arranged on the circumference of the high-static low-motion actuator 4;
the voice coil motor 3 comprises a stator 8, a rotor 9 and an exciting coil 10, wherein the exciting coil 10 is wound on the rotor 9;
The high-static low-dynamic actuator 4 comprises an adjustable bottom cover 11, a shell 12, an upper cover 13, a screw 14, a spring 15, a compression joint screw sleeve 16, an outer permanent magnet 17, a sleeve 18, an inner permanent magnet 19, a gland 20 and a screw 21, wherein the adjustable bottom cover 11 is connected with the shell 12 in a threaded manner, the adjustment of the spring 15 is realized according to the weight of an upper platform 1, the outer permanent magnet 17 is embedded in the shell 12, the upper cover 13 is connected with the shell 12 through the screw 14, the compression of the outer permanent magnet 17 is realized, the inner permanent magnet 19 is placed in the sleeve 18, compressed by the gland 20 and then sleeved on the screw 21, and then the compression joint screw sleeve 16 is connected with the screw 21 through threads, and simultaneously compresses the gland 20, the spring 15 is sleeved on the screw 21 and is compressed and adjusted through the compression joint screw sleeve 16 and the adjustable bottom cover 11, and the screw 21 is in clearance fit with the upper cover 13;
the two opposite-angle voice coil motors 3 are driven by current in opposite directions to realize a two-dimensional pointing function, the high-static low-motion actuator 4 has the capacity of carrying large mass due to the positive stiffness of the spring 15 in a static state, and the high-static low-motion actuator 4 can generate the function of quasi-zero stiffness under the combined action of the positive stiffness of the spring 15 and the negative stiffness formed by the outer permanent magnet 17 and the inner permanent magnet 19 in dynamic load transmission when external disturbance acts on the lower platform 2, so that the high-frequency part of the dynamic load transmitted by the lower platform 2 is isolated, and the dynamic vibration isolation function is realized.
The voice coil motors 3 are distributed at 90-degree intervals to form a two-dimensional directional decoupling structure. Except for the inner permanent magnet 19 and the outer permanent magnet 17, other parts of the two-dimensional pointing mechanism are made of non-magnetic materials.
The inner permanent magnet 19 and the outer permanent magnet 17 are both magnetized by radiation, and the magnetizing directions are opposite.
The stator 8, the rotor 9 and the exciting coil 10 are in non-connection contact, so that a force transmission path between an upper platform and a lower platform of the whole two-dimensional pointing mechanism can only be transmitted through the high-static low-motion actuator 4.
The voice coil motor 3 is connected with the upper platform 1 through a connecting piece 5 and a first flexible hinge 6, and the high-static low-dynamic actuator 4 is connected with the upper platform 1 through a second flexible hinge 7.
Compared with the prior art, the invention has the following advantages:
1) According to the invention, the center parts of the upper table top and the lower table top are connected by adopting the high-static low-dynamic actuator, so that the two-dimensional pointing mechanism has the bearing capacity in static state and the vibration isolation capacity in the disturbance state of the lower platform.
2) According to the invention, the bottom cover of the high-static low-moving actuator is connected with the shell in a threaded mode, and the relative position between the bottom cover and the shell can be adjusted according to the mass of the upper platform so as to adapt to the change of the relative position of the inner permanent magnet and the outer permanent magnet caused by the mass change of the upper platform, and the middle sections of the inner permanent magnet and the outer permanent magnet are adjusted to coincide.
Drawings
FIG. 1 is a schematic diagram of a two-dimensional pointing mechanism with both carrying and pointing capabilities according to the present invention.
FIG. 2 is a side view of a two-dimensional pointing mechanism of the present invention having both load and pointing capabilities.
Fig. 3 is a sectional view showing the internal structure of the voice coil motor.
Fig. 4 is a sectional view of the internal structure of the high-static low-dynamic actuator.
Detailed Description
The invention is described in further detail below with reference to the drawings and the detailed description.
As shown in fig. 1 and 2, the two-dimensional pointing mechanism with bearing and vibration isolation capabilities comprises an upper platform 1, a lower platform 2, a voice coil motor 3, a high-static low-motion actuator 4, a connecting piece 5, a first flexible hinge 6 and a second flexible hinge 7. Wherein voice coil motor 3 and high quiet low moves actuator 4 setting between upper platform 1 and lower platform 2, and high quiet low moves actuator 4 setting is in the middle part, and voice coil motor 3 symmetry sets up at high quiet low moves actuator 4 circumference circle, and voice coil motor 3 passes through connecting piece 5 and first flexible hinge 6 and connects upper platform 1, and high quiet low moves actuator 4 passes through second flexible hinge 7 and connects upper platform 1.
As shown in fig. 3, the voice coil motor 3 includes a stator 8, a mover 9, and an exciting coil 10, and the exciting coil 10 is wound around the mover 9.
As shown in FIG. 4, the high-static low-dynamic actuator 4 comprises an adjustable bottom cover 11, a shell 12, an upper cover 13, a screw 14, a spring 15, a compression screw sleeve 16, an outer permanent magnet 17, a sleeve 18, an inner permanent magnet 19, a gland 20 and a screw 21, wherein the adjustable bottom cover 11 is connected with the shell 12 in a threaded mode, the adjustment of the spring 15 is realized according to the weight of the upper platform 1, the outer permanent magnet 17 is embedded in the shell 12, the upper cover 13 is connected with the shell 12 through the screw 14, the compression of the outer permanent magnet 17 is realized, the inner permanent magnet 19 is placed in the sleeve 18, compressed by the gland 20 and then sleeved on the screw 21, the compression screw sleeve 16 is connected with the screw 21 through threads, the compression screw 21 is compressed, the spring 15 is sleeved on the screw 21, the compression screw sleeve 16 and the adjustable bottom cover 11 are compressed and adjusted through the compression screw 21 and the upper cover 13 in a small clearance fit.
As a preferred embodiment of the present invention, there is no connection contact between the stator 8 and the mover 9 and the exciting coil 10, so that the force transmission path between the upper and lower stages of the entire two-dimensional pointing mechanism can pass through only the high-static low-dynamic actuator 4.
As a preferred embodiment of the invention, the voice coil motor 3 is connected with the upper table top 1 through the connecting piece 5 and the first flexible hinge 6, the high-static low-dynamic actuator 4 is connected with the upper table top 1 through the second flexible hinge 7, and the flexible hinge can eliminate idle stroke and mechanical friction in the two-dimensional pointing process, so that ultra-high precision displacement resolution is obtained.
As the preferred embodiment of the invention, other parts of the high-static low-dynamic actuator are made of non-magnetic conductive materials except the inner permanent magnet 19 and the outer permanent magnet 17, so that the loss of magnetic flux between the inner permanent magnet 19 and the outer permanent magnet 17 can be reduced.
As a preferred embodiment of the invention, the inner permanent magnet 19 and the outer permanent magnet 17 are magnetized by radiation, and the magnetizing directions are opposite, so that mutual attraction is formed, and the formation of magnetic negative rigidity between the inner permanent magnet 19 and the outer permanent magnet 17 is facilitated.
The two-dimensional directional vibration isolation mechanism has the working principle that the voice coil motor is distributed at 90-degree intervals to form a two-dimensional directional decoupling structure, the two-dimensional directional function can be realized by driving the opposite-angle voice coil motor in opposite directions through current, the force transmission path between the upper platform and the lower platform of the whole two-dimensional directional mechanism can only pass through the high static low-motion actuator 4 due to no connection contact between the stator 8, the rotor 9 and the exciting coil 10, when the two-dimensional directional mechanism is in a static balance state, the voice coil motor part does not have bearing capacity, the middle sections of the inner permanent magnet 19 and the outer permanent magnet 17 coincide, the magnetic force of the outer permanent magnet 17 on the inner permanent magnet 19 in the axial direction is zero, so that the static bearing capacity of the spring 15 is not influenced, the two-dimensional directional bearing function is realized, when external disturbance acts on the lower platform 2, the voice coil motor 3 does not have dynamic force transmission capacity, dynamic force can only be transmitted through the high static low-motion actuator 4, the rigidity of the magnetic spring formed by the inner permanent magnet 19 and the outer permanent magnet 17, the rigidity is very low in the natural rigidity of the system load balance position, the system frequency is close to zero, the dynamic load frequency is very low, the dynamic load isolation function of the two-dimensional directional vibration isolation mechanism is realized, and the dynamic load isolation function is realized.