Disclosure of Invention
In view of this, the present invention provides a two-dimensional tracking turntable, which is formed by combining a carbon fiber composite material with a titanium alloy insert or other metal inserts, and can ensure the condition requirement of the aerospace mechanics vibration, and further:
(1) the carbon fiber material is adopted as the main material of the turntable structure, the density of the carbon fiber is 1.8 multiplied by 103kg/m3, the specific stiffness is about 5.3 and is 2 times of that of the titanium alloy, and therefore the high characteristic frequency and excellent dynamic performance of the two-dimensional turntable can be guaranteed in the design stage.
(2) Coefficient of linear expansion of carbon fiber is 1.2X 10-6Compared with materials such as aluminum alloy and titanium alloy, the shafting can ensure normal rotation in a larger temperature range, and the working performance of the rotary table is improved.
In order to achieve the purpose, the invention provides the following technical scheme:
a two-dimensional tracking turntable comprises a base, a first frame and a second frame,
the first frame is rotatably disposed on the base along a vertical axis and the second frame is rotatably disposed on the first frame along a horizontal axis, or the first frame is rotatably disposed on the base along a horizontal axis and the second frame is rotatably disposed on the first frame along a vertical axis,
the base, the first frame and the second frame are all made of carbon fiber materials,
metal sleeves are pre-buried at the positions of the base, the first frame and the second frame, where the bearings are arranged, and the bearings are fixed in the metal sleeves.
Preferably, the first frame is a U-shaped frame, the second frame is an inner frame, the U-shaped frame is rotatably disposed on the base along a vertical axis, the inner frame is rotatably disposed on the U-shaped frame along a horizontal axis, wherein,
the base is provided with a first through hole, an outer metal sleeve is embedded in the first through hole, an inner metal sleeve is fixed in the outer metal sleeve, a first bearing is fixed in the inner metal sleeve through a first bearing pressing part, and an orientation rotating shaft is arranged in the first bearing;
the U-shaped frame comprises a horizontal frame, a first vertical frame and a second vertical frame which are arranged at the two ends of the horizontal frame, the bottom of the horizontal frame is fixedly connected with the top end of the azimuth rotating shaft,
the first vertical frame and the second vertical frame are of symmetrical structures,
a third through hole is arranged on the first vertical frame, a first metal sleeve is embedded in the third through hole, a second bearing is fixed in the first metal sleeve through a second bearing pressure-bearing part, a first pitching rotating shaft is arranged in the second bearing,
a second through hole is formed in the second vertical frame, a second metal sleeve is embedded in the second through hole, a third bearing is fixed in the second metal sleeve through a third bearing pressing part, and a second pitching rotating shaft is arranged in the third bearing;
a fourth through hole is arranged at one end of the inner frame, a third metal sleeve is pre-buried in the fourth through hole and is fixedly connected with the first pitching rotating shaft,
the other end of the inner frame is provided with a fifth through hole, a fourth metal sleeve is embedded in the fifth through hole, and the fourth metal sleeve is fixedly connected with the second pitching rotating shaft.
Preferably, the outer metal sleeve, the inner metal sleeve, the first metal sleeve, the second metal sleeve, the third metal sleeve and the fourth metal sleeve are all made of titanium alloy materials.
Preferably, the inner metal sleeve, the first metal sleeve, the second metal sleeve, the third metal sleeve and the fourth metal sleeve are all provided with an annular rib and a circular flange.
Preferably, the fundamental frequency of the base is 80.5Hz, the fundamental frequency of the U-shaped frame is 52.8Hz, and the fundamental frequency of the inner frame is 94.7 Hz.
Preferably, the base, the U-shaped frame and the inner frame are all made of cyanate ester-based carbon fiber composite materials with high elastic modulus and carbon fiber layers which are arranged in a 45-degree staggered mode.
Preferably, the outer metal sleeve and the inner metal sleeve are in threaded connection.
Preferably, the base is provided with a plurality of first fixing frames, the U-shaped frame is provided with a plurality of second fixing frames,
when the two-dimensional tracking rotary table does not work, one first fixing frame is aligned with one second fixing frame and is connected with the second fixing frame through a pin shaft, when the two-dimensional tracking rotary table works, the pin shaft is disconnected, the first fixing frame is disconnected with the second fixing frame,
the base is embedded with a plurality of first inserts, every be connected through the inner edge of screw with the first benchmark mounting panel that has the sixth through-hole on the first insert, the outer fringe of first benchmark mounting panel with the base is connected, first mount with first insert fixed connection just is located in the sixth through-hole.
Preferably, a second reference mounting plate having a seventh through hole is fixed to a side wall of the base.
Preferably, a plurality of eighth through-holes have been seted up on the above-mentioned base, built-in fifth metal sleeve that is used for fixed connection spare in the eighth through-hole, fifth metal sleeve's bottom is provided with the mounting pad.
Preferably, the second bearing is a pitch angle contact ball bearing,
the first metal sleeve is also provided with a first bearing end cover, an encoder coded disc base, a first encoder coded disc, an encoder reading head base, an encoder reading head and a pitching shaft protection end cover, wherein,
the second bearing is arranged in the first metal sleeve and is fixed through a second bearing clamping piece, the first bearing end cover is fixed on the first metal sleeve,
the encoder coded disc base is arranged on the first bearing end cover, the first encoder coded disc is fixed on the encoder coded disc base,
the encoder read head base is fixed to the U-shaped frame through the first metal sleeve, the encoder read head is mounted to the encoder read head base,
the pitch shaft protection end cover is mounted to the U-shaped frame through the first metal sleeve.
Preferably, the first bearing comprises two angular contact ball bearings and a deep groove ball bearing,
the inner metal sleeve is provided with an adapter, an azimuth rotating shaft, a second bearing end cover, an encoder code disc protective cover, a second encoder code disc, an encoder conversion unit base and an azimuth shaft protective end cover, wherein,
the first bearing is arranged in the inner layer metal sleeve and is fixed by a bearing pressing piece,
the adapter is fixedly connected with the inner layer metal sleeve, the second bearing end cover is fixedly connected with the adapter,
the second encoder coded disc and the encoder coded disc protective cover are fixed on the second bearing end cover,
the base of the encoder conversion unit is fixedly connected with the second encoder coded disc,
the azimuth axis protection end cover is fixedly connected with the adaptor.
Preferably, when the two-dimensional tracking rotary table is a polar coordinate type two-dimensional rotary table,
the pitch shaft system adopts two pairs of angular contact ball bearings to be installed face to face or back to back, and the azimuth shaft system adopts a pair of angular contact ball bearings and a deep groove ball bearing;
when the two-dimensional tracking rotary table is a rectangular coordinate type two-dimensional rotary table,
the pitching axis system and the azimuth axis system are both installed face to face or back to back by adopting two pairs of angular contact ball bearings.
The two-dimensional tracking rotary table provided by the invention is formed by combining a carbon fiber composite material with a titanium alloy insert or other metal inserts, can ensure the condition requirement of the aerospace mechanics vibration, and comprises the following components in parts by weight:
(1) the carbon fiber material is adopted as the main material of the turntable structure, the density of the carbon fiber is 1.8 multiplied by 103kg/m3, the specific stiffness is about 5.3 and is 2 times of that of the titanium alloy, and therefore the high characteristic frequency and excellent dynamic performance of the two-dimensional turntable can be guaranteed in the design stage.
(2) Coefficient of linear expansion of carbon fiber is 1.2X 10-6Compared with materials such as aluminum alloy and titanium alloy, the shafting can ensure normal rotation in a larger temperature range, and the working performance of the rotary table is improved.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
Referring to fig. 1 to 4, fig. 1 is a schematic structural diagram of a two-dimensional tracking turntable according to an embodiment of the present invention; fig. 2 is a schematic diagram of an exploded structure of a base according to an embodiment of the present invention; fig. 3 is an exploded schematic view of a U-shaped frame according to an embodiment of the present invention; fig. 4 is an exploded view of an inner frame according to an embodiment of the present invention.
The two-dimensional tracking rotary table provided by the embodiment of the invention comprises a base 10, a first frame and a second frame,
a first frame is rotatably provided on the base frame 10 along a vertical axis, and a second frame is rotatably provided on the first frame along a horizontal axis, or, a first frame is rotatably provided on the base frame 10 along a horizontal axis, and a second frame is rotatably provided on the first frame along a vertical axis,
the base 10, the first frame and the second frame are all made of carbon fiber,
metal sleeves are embedded in the positions, where the bearings are arranged, of the base 10, the first frame and the second frame, and the bearings are fixed in the metal sleeves.
The two-dimensional tracking rotary table provided by the embodiment of the invention is formed by combining a carbon fiber composite material with a titanium alloy insert or other metal inserts, can ensure the condition requirement of space mechanics vibration, and comprises the following components in parts by weight:
(1) the carbon fiber material is adopted as the main material of the turntable structure, the density of the carbon fiber is 1.8 multiplied by 103kg/m3, the specific stiffness is about 5.3 and is 2 times of that of the titanium alloy, and therefore the high characteristic frequency and excellent dynamic performance of the two-dimensional turntable can be guaranteed in the design stage.
(2) Coefficient of linear expansion of carbon fiber is 1.2X 10-6Compared with materials such as aluminum alloy and titanium alloy, the shafting can ensure normal rotation in a larger temperature range, and the working performance of the rotary table is improved.
Specifically, the first frame is a U-shaped frame 20, the second frame is an inner frame 30, the U-shaped frame 20 is rotatably disposed on the base frame 10 along a vertical axis, and the inner frame 30 is rotatably disposed on the U-shaped frame 20 along a horizontal axis, that is, the base frame 10 serves as a complete machine base of a two-dimensional tracking turntable, the U-shaped frame 20 rotates about the vertical axis with an azimuth rotational degree of freedom, the inner frame 30 rotates about the horizontal axis with a pitch rotational degree of freedom, wherein,
a first through hole is formed in the base 10, an outer-layer metal sleeve is embedded in the first through hole, an inner-layer metal sleeve 101 is fixed in the outer-layer metal sleeve, a first bearing 210 is fixed in the inner-layer metal sleeve 101 through a first bearing pressing part, and an orientation rotating shaft 212 is arranged in the first bearing 210;
the U-shaped frame 20 comprises a horizontal frame, a first vertical frame and a second vertical frame which are arranged at two ends of the horizontal frame, the bottom of the horizontal frame is fixedly connected with the top end of the azimuth rotating shaft 212,
the first vertical frame and the second vertical frame are of symmetrical structures,
a third through hole is arranged on the first vertical frame, a first metal sleeve 201 is embedded in the third through hole, a second bearing 202 is fixed in the first metal sleeve 201 through a second bearing pressure-bearing part 203, a first pitching rotating shaft 302 is arranged in the second bearing 202,
a second through hole is formed in the second vertical frame, a second metal sleeve is embedded in the second through hole, a third bearing is fixed in the second metal sleeve through a third bearing pressing part, and a second pitching rotating shaft is arranged in the third bearing;
one end of the inner frame 30 is provided with a fourth through hole, a third metal sleeve 301 is embedded in the fourth through hole, the third metal sleeve 301 is fixedly connected with a first pitching rotating shaft 302,
the other end of the inner frame 30 is provided with a fifth through hole, a fourth metal sleeve is embedded in the fifth through hole, and the fourth metal sleeve is fixedly connected with the second pitching rotating shaft.
Wherein, to the installation of position shafting, around vertical axis pivoted degree of freedom promptly, because it supports for the unipolar, consequently to the joint strength requirement of bearing junction higher, so adopt "double sleeve threaded connection" and "sleeve inserts and the pre-buried sticky" two kinds of modes of carbon fiber frame simultaneously, specifically do, pre-buried outer metal sleeve that has in the first through-hole, outer metal sleeve is threaded connection with inlayer metal sleeve 101, sets up first bearing 210 in the inlayer metal sleeve 101.
And to the every single move shafting, around the rotational degree of freedom of horizontal axis promptly, because it is for realizing the both ends installation through first grudging post and second grudging post, it is more stable from the angle of atress analysis, consequently to metal sleeve inserts and carbon fiber frame, only adopt pre-buried sticky mode just can guarantee that its joint strength satisfies operation requirements, does not use the mode of "double sleeve threaded connection".
The pre-embedding in the text means that the initial form of the carbon fiber material is a fiber filament, the fiber filament needs to be wound into a given design shape through a certain mold, so that a complete structural member is obtained, the pre-embedding process is that in the process of winding the fiber filament, an embedded part of titanium alloy, such as a metal sleeve, is firstly placed into the mold, and the fiber filament also contains the embedded part, so that a pre-embedding process is realized, and all the parts embedded into the carbon fiber need to be glued and fixed in the pre-embedding process.
Also, in a specific operation, in the process of molding the inner frame 30, the third metal sleeve 301 is pre-embedded therein, and participates in the subsequent assembly process with the inner frame 30 as a whole. The first pitching rotating shaft 302 is fixedly connected with the third metal sleeve 301, and then participates in the assembly process of the whole two-dimensional tracking rotary table as a whole.
Specifically, the outer layer metal sleeve, the inner layer metal sleeve 101, the first metal sleeve 201, the second metal sleeve, the third metal sleeve 301 and the fourth metal sleeve are all made of titanium alloy materials.
Specifically, the inner metal sleeve 101, the first metal sleeve 201, the second metal sleeve, the third metal sleeve 301 and the fourth metal sleeve are all provided with an annular rib and a circular flange.
Specifically, the fundamental frequency of the base 10 is 80.5Hz, the fundamental frequency of the U-shaped frame 20 is 52.8Hz, and the fundamental frequency of the inner frame 30 is 94.7 Hz. Meets the design index requirement of the dynamic characteristic.
Specifically, the base 10, the U-shaped frame 20 and the inner frame 30 are all made of cyanate ester-based carbon fiber composite materials with high elastic modulus and carbon fiber layers arranged in a 45-degree staggered manner.
Specifically, a plurality of first fixing frames are arranged on the base 10, a plurality of second fixing frames are arranged on the U-shaped frame,
when the two-dimensional tracking rotary table does not work, a first fixed frame is aligned with a second fixed frame and is connected with the second fixed frame through a pin shaft, when the two-dimensional tracking rotary table works, the pin shaft is disconnected, the first fixed frame is disconnected with the second fixed frame,
a plurality of first inserts 102 are embedded in the base 10, each first insert 102 is connected to an inner edge of a first reference mounting plate 103 having a sixth through hole by a screw, an outer edge of the first reference mounting plate 103 is connected to the base 10 by, for example, gluing, and a first fixing frame is fixedly connected to the first insert 102 and located in the sixth through hole.
Specifically, a second reference mounting plate 104 having a seventh through hole is fixed to the side wall of the base 10, for example, by adhesive bonding.
Specifically, a plurality of eighth through holes are formed in the base 10, a third metal sleeve 105 for fixing the connecting piece is arranged in each eighth through hole, and a mounting pad 106 is arranged at the bottom of each third metal sleeve 105.
When the above-described metal fitting, for example, the metal shim and the third metal sleeve 105 used as the reference surface outside the carbon fiber structural member such as the second reference mounting plate 104 are connected to the carbon fiber structural member, since the metal fitting is small and does not substantially receive the force, only the adhesion may be used.
Specifically, the second bearing 202 is a pitch angle contact ball bearing, and the first metal sleeve 201 is further provided with a first bearing end cap 204, an encoder code disc base 205, a first encoder code disc 206, an encoder reading head base 207, an encoder reading head 208 and a pitch axis protection end cap 209, wherein,
the second bearing is built into the first metal sleeve 201 and is fixed by means of a second bearing clamping member 203, the first bearing end cap 204 is fixed to the first metal sleeve 201, for example by means of a screw connection,
an encoder disc base 205 is mounted on a first bearing end cap 204, a first encoder disc 206 is fixed to the encoder disc base 205,
an encoder readhead base 207 is secured to the U-shaped frame 20 by a first metal sleeve 201, an encoder readhead 208 is mounted to the encoder readhead base 207,
a pitch shaft protection end cap 209 is mounted to the U-shaped frame 20 through a first metal sleeve 201.
In the assembling process of the U-shaped frame 20, the assembling of the pitch axis system is as above, specifically, first, the first metal sleeve 201 is already put in the forming process of the U-shaped frame 20, and is bonded, fixed and cured into a whole through epoxy glue; then, placing a second bearing 202, i.e. a pair of pitch angle contact ball bearings, into the first metal sleeve 201 in a face-to-face or back-to-back manner, then placing a second bearing retainer 203, and installing a first bearing end cap 204 together; secondly, mounting an encoder disc base 205 on the first bearing end cover 204, and fixing a first encoder disc 206 on the encoder disc base 205; finally, the encoder reading head base 207 is fixed to the U-shaped frame 20 through a titanium alloy insert, the encoder reading head 208 is installed on the encoder reading head base 207, and finally the pitch shaft protection end cover 209 is installed on the U-shaped frame 20 through the titanium alloy insert, so that the pitch shaft assembly is completed.
Specifically, the first bearing 210 includes two angular contact ball bearings and one deep groove ball bearing,
the inner layer metal sleeve 101 is provided with an adaptor 211, an orientation rotating shaft 212, a second bearing end cover 213, an encoder code disc protective cover 214, a second encoder code disc 215, an encoder conversion unit base 216 and an orientation shaft protective end cover 217, wherein,
the first bearing 210 is built in the inner metal sleeve 101 and fixed by a bearing pressing member,
the adaptor 211 is fixedly connected with the inner layer metal sleeve 101, the second bearing end cap 213 is fixedly connected with the adaptor 211,
a second encoder wheel 215 and an encoder wheel protective cover 214 are fixed on the second bearing end cover 213,
the encoder conversion unit base 216 is fixedly connected with the second encoder code wheel 215,
the azimuth axis protective end cap 217 is fixedly connected with the adaptor 211.
The above is the assembly for the azimuth axis.
In particular, when the two-dimensional tracking rotary table is a polar coordinate type two-dimensional rotary table,
the pitch axis system adopts 2 pairs of angular contact ball bearings to be installed face to face or back to back, and the azimuth axis system adopts 1 pair of angular contact ball bearings and a deep groove ball bearing;
when the two-dimensional tracking rotary table is a rectangular coordinate type two-dimensional rotary table,
the pitching axis system and the azimuth axis system are installed face to face or back to back by adopting 2 pairs of angular contact ball bearings.
The embodiment of the invention provides a two-dimensional tracking rotary table, which aims to meet the application requirement of aerospace/aviation on the two-dimensional tracking rotary table, and provides a design method of the two-dimensional tracking rotary table formed by combining a carbon fiber composite material with a titanium alloy insert aiming at the defects of the prior art.
The two-dimensional tracking rotary table provided by the embodiment of the invention can adopt a rectangular coordinate internal and external frame type (horizontal pitch rotation is carried out first and then vertical rotation) or a polar coordinate theodolite structural form (vertical rotation is carried out first and then horizontal pitch rotation is carried out). The rotary table has rotational freedom degrees in the azimuth direction and the pitching direction, and can point to any direction in space through a spherical coordinate system.
According to the two-dimensional tracking rotary table provided by the embodiment of the invention, titanium alloy inserts are embedded in the heavy parts such as the U-shaped frame, the inner frame, the base and the like, one part of the titanium alloy inserts are used as connecting interfaces with other mechanical parts, the titanium alloy or other metal insert components are arranged at the positions needing mechanical connection, and the other part of the titanium alloy or other metal insert components is used as a process reference for machining, detecting, installing and adjusting the heavy parts of the rotary table.
The cylindrical insert in the two-dimensional tracking rotary table provided by the embodiment of the invention is provided with the annular rib and the circular flange which are bonded, and inserts in other structural forms are connected with the carbon fiber laying layer through the screws so as to increase the embedding strength and ensure the condition requirement of the aerospace mechanics vibration.
The two-dimensional tracking turntable provided by the embodiment of the invention has the material objects that the volume is 1077mm multiplied by 755mm multiplied by 544mm, the mass is 50kg, the loading capacity is 70kg, the mechanical test environments of sinusoidal vibration, random vibration, impact and the like of an aerospace identification level are met, the operation is stable and smooth within the temperature range of-20 ℃ to +60 ℃, and the shafting shaking error is not more than 10 arc seconds.
The two-dimensional tracking rotary table provided by the embodiment of the invention is characterized in that a titanium alloy insert is arranged at a connecting part in a rotary table structural member, and the titanium alloy insert is connected with a carbon fiber layer through a back plate or a screw and is bonded by using epoxy structural adhesive. The titanium alloy inserts of the circular shaft sleeves, which are connected with the bearings in the frames, are provided with annular ribs and flanges, the embedding strength in the carbon fiber laying layer is increased in an external thread mode, and the condition requirement of the aerospace mechanics vibration is met.
According to the two-dimensional tracking rotary table provided by the embodiment of the invention, the structural member of the rotary table is provided with the processing and detecting reference surface formed by the titanium alloy insert, so that the frame made of the carbon fiber composite material can meet the index requirements of shape and position accuracy.
The two-dimensional tracking rotary table provided by the embodiment of the invention can be suitable for occasions with harsh requirements on system lightweight for aviation, aerospace, military application and the like, and can meet the requirement of the total weight index of a satellite on load.
According to the two-dimensional tracking rotary table provided by the embodiment of the invention, as the structural member is formed by combining the carbon fiber and the titanium alloy inserts, all the inserts need to be put together and adhered and fixed by using the epoxy glue in the carbon fiber forming process, and finally, each assembly is used as an independent structural member to participate in the subsequent assembly process.
The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.