A test apparatus for testing the connection mechanism of a FAST reflector unit

Abstract

The application relates to a test device for testing a 1# connecting mechanism of a FAST reflecting surface unit, which comprises a rotating frame support table, a fixed hinge support, a hinge shaft, a rotating frame, a weight, a weight tray, a 1# node shaft test piece, a positive pressure measuring device, a servo sliding table and the like; the device applies positive pressure to the joint bearing inner ring hole installed in the bearing seat of the 1# connecting mechanism through the fixed hinge, the rotating frame, the weight and the 1# connecting mechanism test piece shaft, so as to simulate the positive pressure applied to the 1# connecting mechanism by the gravity of the FAST reflecting surface unit. The temperature of the linear sliding bearing is measured through a temperature sensor, the friction is measured through a force sensor connected between the screw mother and the sliding table, the reciprocating linear motion of the 1# connecting mechanism is simulated through the reciprocating linear motion of the servo sliding table, so that the measurement of the friction coefficient mu of the linear sliding bearing can be realized, and the service life of the linear sliding bearing of the 1# connecting mechanism is tested through the reciprocating motion frequency of the servo sliding table.

Description

Technical Field

[0001] This invention relates to the field of radio astronomy telescope technology, and in particular to a test apparatus for testing the connection mechanism of FAST reflector unit 1#, specifically a test apparatus for testing the friction coefficient and wear life of the connection mechanism of FAST reflector unit 1#. Background Technology

[0002] The Five-hundred-meter Aperture Spherical radio Telescope (FAST) is the world's largest single-dish radio telescope, featuring three independent innovations: utilizing a natural karst depression in Guizhou as its site; an actively deformable reflector; and employing a flexible, lightweight mechanism with six parallel cables to drive the feed cabin for primary cable actuation, while the AB rotating shaft mechanism and Stewart parallel mechanism within the feed cabin enable secondary fine-tuning of the feed's attitude, achieving high-precision positioning of the feed.

[0003] The FAST reflector can instantly deform its 300-meter aperture, transforming from a spherical surface into a parabolic one. This ensures the parabolic surface always points towards the celestial object being observed, focusing the radio wave signals from that object. Simultaneously, the feed receiver at the focal point receives and processes the radio signals; this process is continuous.

[0004] The FAST reflector consists of a peripheral support structure (ring beam lattice columns), a cable net, reflector units, and hydraulic actuators. The ring beam is a spatial grid ring beam structure with an inner diameter exceeding 500 meters, a width of approximately 11 meters, and a height of approximately 5 meters. Fifty lattice columns support the ring beam. 150 ear plates are welded to the spherical nodes on the bottom surface of the inner ring beam. These ear plates are connected to 150 edge main cables of the cable net. The cable net structure supports and constrains 4450 reflector units, including 4300 triangular units and 150 quadrilateral units at the edges of the cable net.

[0005] The reflector unit consists of an aluminum alloy panel supported by a bolted ball mesh frame. The bolted ball mesh frame is located at the bottom, and the aluminum alloy panel is located at the top. A connector links the bolted ball mesh frame and the aluminum alloy panel together. At the corner points of the upper chord of the bolted ball mesh frame, the members are bolted to the node shaft ball joint of the #1 connecting structure. Each reflector unit has a different connecting mechanism at its corner points: three types: #0, #1, and #2. Connecting mechanisms #0 and #1 each include three main components: a bearing housing, a spherical bearing, and a node shaft. Connecting mechanism #2 includes four main components: a node shaft, a ball joint seat, a ball joint, and a PTFE slider fixed to the ball pin. Connecting mechanism #0 constrains three translational degrees of freedom, connecting mechanism #1 constrains two translational degrees of freedom, and connecting mechanism #2 constrains one translational degree of freedom. Three sets (three sets for triangular units) or four sets (four sets for quadrilateral units) of connection mechanisms for each reflector element are placed on the node plate of the cable net. The bearing seats of connection mechanisms #0 and #1 are fixed to the node plate supporting them by bolts. The PTFE slider of connection mechanism #2 can move freely on the node plate supporting it. This constraint connection method constrains the six degrees of freedom of the rigid reflector element, thereby ensuring that the reflector element is connected to the cable net structure in a simply supported manner, and will not cause additional internal forces due to the movement and deformation of the cable net structure itself.

[0006] The node shaft of the No. 1 connecting mechanism and the inner ring of the spherical bearing installed in the bearing housing form a linear sliding bearing. When the FAST reflector actively deforms, the relative position of the adjacent node disks will continuously change due to the active deformation of the cable net. The node shaft of the No. 1 connecting mechanism and the inner ring of the spherical bearing installed in the bearing housing form a linear sliding bearing. This linear sliding bearing can reciprocate along the axis of the node shaft to adapt to the change in the relative position of the cable net node disks.

[0007] During its long-term operation, FAST experienced intermittent malfunctions in the three connection mechanisms of the reflector unit, including deformation of the bolts connecting the bearing housing and the node disk, and deformation and breakage of the rods and bolts connecting to the ball joints of the connection mechanism. Some of these malfunctions were related to the friction coefficient μ and wear life of the linear sliding bearing in the No. 1 connection mechanism. Therefore, further testing of the friction coefficient μ and wear life of the linear sliding bearing in the No. 1 connection mechanism of the FAST reflector unit was conducted to study the variation law of its friction coefficient μ and wear life. It was found that the defects of the existing No. 1 connection mechanism are essential for its improvement. Therefore, it is necessary to design and manufacture a test device for testing the friction coefficient and wear life of the No. 1 connection mechanism of the FAST reflector unit.

[0008] The information disclosed in this background section is intended only to enhance the understanding of the general background of the invention and should not be construed as an admission or in any way implying that the information constitutes prior art known to those skilled in the art. Summary of the Invention

[0009] The purpose of this invention is to provide a test device for testing the connection mechanism of FAST reflector unit 1#, so as to solve the technical problems existing in the prior art.

[0010] To achieve the above objectives, the present invention adopts the following technical solution:

[0011] This invention provides a test apparatus for testing the connection mechanism of FAST reflector unit #1, comprising: a rotating frame support, a fixed hinge support, a hinge shaft, a rotating frame, weights, a weight tray, a #1 node shaft specimen, a positive pressure measuring device, a servo slide, and a servo slide support; the rotating frame support is provided with a fixed hinge support; the rotating frame is connected to the fixed hinge support via the hinge shaft; the node shaft connecting rod of the #1 node shaft specimen is fixedly connected to the lower chord of the rotating frame; the bearing seat specimen of the #1 node shaft specimen is mounted on the servo slide, and the servo slide is mounted on the servo slide support; the weight tray is suspended from the rotating frame, and weights are provided on the weight tray; the positive pressure measuring device is mounted on the servo slide support and is located above the bearing seat specimen.

[0012] Preferably, the node shaft connecting rod of the #1 node shaft specimen is provided with a conical recess, and the #1 node shaft specimen is fastened to the lower chord hole of the rotating bracket by a conical end set screw, and the conical end set screw 11 is pressed against the conical recess of the node shaft connecting rod.

[0013] Preferably, the positive pressure measuring device includes: a sling, a lifting eye screw, a force sensor, a force sensor connecting block, a bracket, bolts, and nuts; the force sensor connecting block is suspended on the crossbeam of the bracket by bolts and nuts, the force sensor and the force sensor connecting block are connected by threads, the lifting eye screw is connected to the lower threaded hole of the force sensor by threads, the lifting eye screw is connected to the sling, and the sling suspends the journal of the No. 1 node shaft of the No. 1 node shaft specimen at the lower No. 1 node shaft suspension point.

[0014] Preferably, the servo slide comprises a servo slide base, a linear rolling guide pair, a worktable, a ball screw pair, a synchronous pulley, a synchronous belt, a motor bracket, a servo motor, an Allen screw, a force sensor connecting washer, a force sensor, and a screw nut; the guide rail of the linear rolling guide pair is mounted on the servo slide base, the worktable is mounted on the slider of the linear rolling guide pair, the worktable slides along the guide rail of the linear rolling guide pair, and the ball screw pair is mounted on the servo slide base, with the screw of the ball screw pair connected by bearings at both ends. The servo slide base is supported by a synchronous pulley mounted on the power input end of the ball screw. A motor bracket is mounted on the servo slide base to support the servo motor. A synchronous pulley is mounted on the shaft of the servo motor 32. The ball screw pair and the synchronous pulley of the servo motor are connected by a synchronous belt. The servo motor drives the ball screw of the ball screw pair to rotate via the synchronous belt. The ball screw drives the screw nut to perform linear motion. The screw nut is connected to the worktable via a force sensor to transmit the driving force F that drives the worktable to perform linear motion, and simultaneously measures this driving force F.

[0015] Preferably, the lead screw nut and the force sensor connector are fixedly connected to the lead screw nut by screws, the force sensor is fixedly connected to the lead screw nut and the force sensor connector by a force sensor connecting washer and an internal hex screw, the worktable and the force sensor connector are fixedly connected to the worktable by bolts, and the force sensor is fixedly connected to the worktable and the force sensor connector by a force sensor connecting washer and an internal hex screw.

[0016] Preferably, a left limit switch and a right limit switch are installed on the servo slide. The brackets of the left limit switch and the right limit switch are fixed to the servo slide base by screws. The worktable reciprocates linearly between the left limit switch and the right limit switch.

[0017] Preferably, the weight tray includes: a tray, a connecting rod, and tray lifting lugs welded together in sequence.

[0018] Preferably, the lower tray of the rotating frame is suspended by a weight tray via a pin, screw, and nut. Weights are placed on the weight tray, and the weight of the weights is used to adjust the positive pressure applied by the rotating frame to the bearing housing specimen.

[0019] Preferably, the servo slide is fixed to the servo slide support by bolts, and the bearing seat specimen is fixed to the worktable of the servo slide by two flat washers, two spring washers and two hex socket screws, with the hex socket screws passing through the two bolt holes of the bearing seat of the No. 1 bearing of the No. 1 node shaft specimen.

[0020] Preferably, the #1 connecting mechanism test piece includes: a #1 node shaft test piece, a bearing housing test piece, a washer, and a bolt; the #1 node shaft test piece includes: a #1 node shaft and a node shaft connecting rod, the #1 node shaft and the node shaft connecting rod are connected, and a tapered recess is machined on the node shaft connecting rod for fixing the #1 node shaft test piece to the rotating frame; the bearing housing test piece includes: a #1 bearing housing, a spherical plain bearing, and a PTFE fabric pad, wherein the inner ring of the spherical plain bearing is fitted with a PTFE fabric pad, the #1 node shaft and the inner ring of the spherical plain bearing form a steel-PTFE friction pair, and a washer and a bolt are provided at the end of the #1 node shaft, the bolt being connected to a temperature sensor.

[0021] By adopting the above technical solution, the present invention has the following beneficial effects:

[0022] This invention simulates the connection method and positive pressure bearing method between the FAST reflector panel unit and the No. 1 connecting mechanism. Through experiments, it discovers the problems in the design and use of the No. 1 connecting mechanism and realizes the test of the friction coefficient and wear of the linear sliding bearing of the No. 1 connecting mechanism of the FAST reflector panel unit. Attached Figure Description

[0023] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0024] Figure 1 A schematic diagram of an experimental device for testing the friction coefficient and wear life of the connecting mechanism of FAST reflector unit 1#, provided by the present invention;

[0025] Figure 2 A schematic diagram of a servo slide for testing the friction coefficient and wear life of the connecting mechanism of FAST reflector unit #1, provided by this invention.

[0026] Figure 3 A schematic diagram of the normal force measurement principle of a test device for testing the friction coefficient and wear life of the connecting mechanism of FAST reflector unit 1#, provided by the present invention;

[0027] Figure 4 A schematic diagram of a normal pressure measuring device for testing the friction coefficient and wear life of the connecting mechanism of FAST reflector unit 1#, provided by the present invention;

[0028] Figure 5 A schematic diagram of a test device rotating frame for testing the friction coefficient and wear life of the connecting mechanism of FAST reflector unit 1#, provided by the present invention;

[0029] Figure 6 A schematic diagram of a weight tray for testing the friction coefficient and wear life of the connecting mechanism of FAST reflector unit 1#, provided by the present invention;

[0030] Figure 7 This is a schematic diagram of the No. 1 connecting mechanism specimen provided by the present invention;

[0031] Icons: 1—Rotating frame support; 2—Screw; 3—Fixed hinge support; 4—Hinge shaft; 5—Cotter pin; 6—Rotating frame; 7—Pin screw; 8—Nut; 9—Weight; 10—Weight tray; 11—Conical set screw; 12—No. 1 node shaft test piece; 13—Bearing seat test piece; 14—Temperature sensor; 15—Positive pressure measuring device; 16—Servo slide; 17—Bolt; 18—Servo slide support; 19—Flat washer; 20—Spring washer; 21—Hex socket screw; 22—Linear rolling guide pair; 23—Left limit switch; 24—Worktable; 25—Worktable and force sensor connection seat; 26—Right limit switch; 27—Servo slide seat; 28—Ball screw pair; 29—Synchronous pulley; 30—Synchronous belt; 31—Motor bracket; 32—Servo motor; 33—Internal... Hexagonal screw; 34—Force sensor connecting washer; 35—Force sensor; 36—Lead screw nut; 37—Lead screw nut and force sensor connecting seat; a—One-way sliding distance of the worktable; 38—Hanging point of No. 1 node shaft; 39—Lifting strap; 40—Lifting eye screw; 41—Force sensor; 42—Force sensor connecting block; 43—Bracket; 44—Bolt; 45—Nut; 46—Hinge bearing sleeve; 47—Left diagonal rod; 48—Upper chord; 49—Web rod; 50—Right diagonal rod; 51—Set screw seat; 52—Weight lifting lug; 53—Lower chord; 54—Plate; 55—Connecting lifting rod; 56—Plate lifting lug; 57—No. 1 node shaft; 58—Node shaft connecting rod; 59—Setting cone socket; 60—Spherical plain bearing; 61—PTFE fabric pad; 62—Washer; 63—Set screw; 64—No. 1 bearing seat. Detailed Implementation

[0032] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0033] The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0034] Combination Figures 1 to 7As shown, this embodiment provides a test apparatus for testing the connection mechanism of FAST reflector unit #1, which includes: a rotating frame support 1, a fixed hinge support 3, a hinge shaft 4, a rotating frame 6, weights 9, a weight tray 10, a #1 node shaft specimen 12, a positive pressure measuring device 15, a servo slide 16, and a servo slide support 18; the rotating frame support 1 is provided with a fixed hinge support 3; the rotating frame 6 is connected to the fixed hinge support 3 through the hinge shaft 4; the node shaft connecting rod 58 of the #1 node shaft specimen 12 is fixedly connected to the lower chord of the rotating frame 6; the bearing seat specimen 13 of the #1 node shaft specimen 12 is installed on the servo slide 16, and the servo slide 16 is installed on the servo slide support 18; the weight tray 10 is suspended on the rotating frame 6, and weights 9 are provided on the weight tray 10; the positive pressure measuring device 15 is installed on the servo slide support 18 and is located above the bearing seat specimen 13.

[0035] In this embodiment, preferably, the rotating frame support platform 1 and the servo slide support platform 18 support the entire test device, are fixed to the ground, and maintain a fixed position and height relationship. The fixed hinge support 3 is fixed to the rotating frame support platform 1 by bolts, and the rotating frame 6 is connected to the fixed hinge support 3 by the hinge shaft 4 to form a fixed rotating pair. The rotating support 6 can rotate around the center of the hinge shaft 4.

[0036] In this embodiment, preferably, a conical recess 59 is provided on the node shaft connecting rod 58 of the #1 node shaft specimen 12. The #1 node shaft specimen 12 is fastened to the lower chord hole of the rotating bracket 6 by a conical set screw 11. The conical set screw 11 is pressed against the conical recess 59 of the node shaft connecting rod 58, which plays a limiting role in the axial and rotational directions of the #1 node shaft specimen 12, so that the #1 node shaft specimen 12 is fixedly connected to the rotating bracket 6, completely simulating the working condition of the FAST reflector unit being fixedly connected to the #1 node shaft 57.

[0037] In this embodiment, preferably, the positive pressure measuring device 15 is fixed to the servo slide support 18 by bolts 17 and is located near the bearing housing specimen 13. It is used to measure the magnitude of the positive pressure applied to the bearing housing specimen 13 by the rotating frame. The lower tray lug 52 of the rotating frame 6 suspends the weight tray 10 by pins, screws 7 and nuts 8. Weights 9 are placed on the weight tray 10, and the magnitude of the positive pressure applied to the bearing housing specimen 13 by the weight of the weights 9 is adjusted.

[0038] In this embodiment, preferably, the positive pressure measuring device 15 includes: a sling 39, a lifting eye screw 40, a force sensor 41, a force sensor connecting block 42, a bracket 43, a bolt 44, and a nut 45; the force sensor connecting block 42 is suspended on the crossbeam of the bracket 43 by the bolt 44 and the nut 45, the force sensor 41 is connected to the force sensor connecting block 42 by threads, the lifting eye screw 40 is connected to the lower threaded hole of the force sensor 41 by threads, the lifting eye screw 40 is connected to the sling 39, and the sling 39 suspends the journal of the 1st node shaft 57 of the 1st node shaft specimen 12 at the lower 1st node shaft suspension point 38. When measuring the positive pressure, the flat washer 19, spring washer 20 and internal hex screw 21 that are fixed to the bearing housing specimen 13 and the worktable 24 are removed, the bearing housing specimen 13 is separated from the worktable 24, and when the positive pressure value is adjusted, the positive pressure measuring device 15 is completely disassembled, the flat washer 19, spring washer 20 and internal hex screw 21 are installed, and the bearing housing specimen 13 is re-fixed to the worktable 24.

[0039] In this embodiment, preferably, the servo slide 16 comprises a servo slide base 27, a linear rolling guide pair 22, a left limit switch 23, a worktable 24, a worktable-force sensor connection seat 25, a right limit switch 26, a ball screw pair 28, a synchronous pulley 29, a synchronous belt 30, a motor bracket 31, a servo motor 32, an internal hex screw 33, a force sensor connecting washer 34, a force sensor 35, a lead screw nut 36, and a lead screw nut-force sensor connection seat 37; A is the sliding distance of a single stroke of the worktable 24, which is equal to the linear sliding working distance of the 1# node shaft test piece 12 of the 1# connecting mechanism relative to the bearing seat test piece 13. The linear rolling guide assemblies 22 have their guide rails mounted on the servo slide base 27. The worktable 24 is mounted on the slider of the linear rolling guide assemblies 22 and slides along the guide rails of the linear rolling guide assemblies 22. The ball screw assembly 28 is mounted on the servo slide base 27, and the screw of the ball screw assembly 28 is supported at both ends by bearing seats. The synchronous pulley 29 is mounted on the power input end of the screw. The servo slide base 27 is equipped with a motor bracket 31 for supporting the servo motor. A servo motor 32 has a synchronous pulley 29 mounted on its shaft. The ball screw assembly 28 and the synchronous pulley 29 of the servo motor 32 are connected by a synchronous belt 30. The servo motor 32 drives the ball screw of the ball screw assembly 28 to rotate via the synchronous belt 30. The ball screw drives the screw nut 36 to perform linear motion. The screw nut 36 is connected to the worktable 24 via a force sensor 35, transmitting the driving force F that drives the worktable 24 to perform linear motion, and simultaneously measuring this driving force F. (F = F0) f+ Friction of the linear rolling guide pair. Since the coefficient of friction of the linear rolling guide pair is approximately 0.002 to 0.003, while the theoretical coefficient of friction of the steel-PTFE friction pair of the linear sliding bearing in the No. 1 connecting mechanism is 0.05, the difference is greater than 16 times. Therefore, the friction of the linear rolling guide pair can be ignored. Thus, F = F f Alternatively, without the bearing housing specimen 13 installed on the worktable 24, a weight of normal stress Fn can be applied to the worktable 24 to measure the frictional force of the linear rolling guide pair 22.

[0040] In this embodiment, preferably, the lead screw nut and the force sensor connecting seat 37 are fixedly connected to the lead screw nut 36 by screws, the force sensor 35 is fixedly connected to the lead screw nut and the force sensor connecting seat 37 by force sensor connecting washer 34 and hex socket screw 33, the worktable and the force sensor connecting seat 25 are fixedly connected to the worktable 24 by bolts, and the force sensor 35 is fixedly connected to the worktable and the force sensor connecting seat 25 by force sensor connecting washer 34 and hex socket screw 33.

[0041] In this embodiment, preferably, a left limit switch 23 and a right limit switch 26 are installed on the servo slide 16. The brackets of the left limit switch 23 and the right limit switch 26 are fixed to the servo slide base 27 by screws, and the worktable 24 reciprocates linearly between the left limit switch 23 and the right limit switch 26. Preferably, a temperature sensor 14 is installed on the servo slide 16 for measuring the temperature of the linear sliding bearing.

[0042] In this embodiment, preferably, the weight tray 10 includes: a tray 54, a connecting rod 55, and a tray lifting lug 56 welded together in sequence.

[0043] In this embodiment, preferably, the lower tray lug 52 of the rotating frame 6 suspends the weight tray 10 through the pin screw 7 and nut 8, and the weight 9 is placed on the weight tray 10. The weight of the weight 9 is used to adjust the positive pressure applied by the rotating frame 6 to the bearing seat specimen 13.

[0044] In this embodiment, preferably, the servo slide 16 is fixed to the servo slide support 18 by bolts, and the bearing seat specimen 13 is fixed to the worktable 24 of the servo slide 16 by two flat washers 19, two spring washers 20 and two hex socket screws 21. The hex socket screws 21 pass through the two bolt holes of the bearing seat 64 of the No. 1 bearing of the No. 1 node shaft specimen 12.

[0045] In this embodiment, preferably, the #1 connecting mechanism test piece includes: a #1 node shaft test piece 12, a bearing seat test piece 13, a washer 62, and a bolt 63; the #1 node shaft test piece 12 includes: a #1 node shaft 57 and a node shaft connecting rod 58, the #1 node shaft 57 and the node shaft connecting rod 58 are connected, and a conical recess 59 is machined on the node shaft connecting rod 58 for fixing the #1 node shaft test piece 12 to the rotating frame 6; the bearing seat test piece 13 includes: a #1 bearing seat 64, a spherical bearing 60, and a PTFE fabric pad 61, wherein the inner ring of the spherical bearing 60 is equipped with a PTFE fabric pad 61, the #1 node shaft 57 and the inner ring of the spherical bearing 60 form a steel-PTFE friction pair, and the end of the #1 node shaft 57 is provided with a washer 62 and a bolt 63, the bolt 63 being connected to the temperature sensor 14.

[0046] The test apparatus has a motion control device for a servo slide.

[0047] The experimental setup includes a data output device, which simultaneously performs data acquisition, display, and recording functions. It has at least five data channels, and the recorded data is shown in the table below:

[0048]

[0049] Combination Figure 4 As shown:

[0050] coefficient of friction — μ;

[0051] Friction force — F f ;

[0052] Positive pressure—F n ;

[0053] Bearing housing support reaction force — FN;

[0054] F n =F N ≈1500N (normal pressure of bearing at node #1)

[0055] μ = F f / F n

[0056] positive pressure F n Adjustment and measurement;

[0057] F N = (L2*G2+L3*G1) / L1

[0058] =1500N

[0059] F N '=(L2*G2+L3*G1) / (L1-a)

[0060] FN '—The positive pressure exerted on the bearing housing 13 at the left limit switch;

[0061] ΔF N ——F N The relative difference in size within a single stroke a;

[0062] ΔF N =(F N -F N ') / F N ;

[0063] G1 — The weight of the rotating frame 6 plus the self-weight of the test piece 12 at node 1;

[0064] G2 – The weight of weight 9 plus weight tray 10;

[0065] L1 — Design determined to ensure ΔFN does not exceed 5%;

[0066] L2 – Design finalized;

[0067] L3 is determined by the center of gravity of the rotating frame 6 plus the #1 node shaft specimen 12;

[0068] In summary, this invention provides a test apparatus for testing the friction coefficient and wear life of the FAST reflector unit #1 connecting mechanism. This apparatus consists of a rotating support platform, a fixed hinge, a rotating support, weights, a #1 connecting mechanism specimen, a servo slide, a normal pressure measuring device, a temperature sensor, a force sensor, and a servo slide support platform. The apparatus applies normal pressure to the inner ring hole of the spherical bearing installed in the bearing seat of the #1 connecting mechanism through the fixed hinge, rotating support, weights, and the shaft of the #1 connecting mechanism specimen, simulating the normal pressure applied to the #1 connecting mechanism by gravity by the FAST reflector unit. The temperature of the linear sliding bearing is measured by the temperature sensor, and the friction force is measured by the force sensor connected between the lead screw nut and the slide. The reciprocating linear motion of the servo slide simulates the reciprocating linear motion of the #1 connecting mechanism, thus enabling the measurement of the friction coefficient μ of the linear sliding bearing. The life of the linear sliding bearing of the #1 connecting mechanism is tested by the number of reciprocating motions of the servo slide.

[0069] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A test apparatus for testing the connection mechanism of FAST reflector unit #1, characterized in that, include: The rotating frame support platform (1), fixed hinge support (3), hinge shaft (4), rotating frame (6), weight (9), weight tray (10), No. 1 node shaft specimen (12), positive pressure measuring device (15), servo slide (16) and servo slide support platform (18); the rotating frame support platform (1) is provided with a fixed hinge support (3); the rotating frame (6) is connected to the fixed hinge support (3) through the hinge shaft (4); the node shaft connecting rod of the No. 1 node shaft specimen (12) (58) is fixedly connected to the lower chord of the rotating frame (6); the bearing seat specimen (13) of the No. 1 node shaft specimen (12) is installed on the servo slide (16), and the servo slide (16) is installed on the servo slide support (18); the weight tray (10) is suspended on the rotating frame (6), and the weight tray (10) is provided with weights (9); the positive pressure measuring device (15) is installed on the servo slide support (18) and is located above the bearing seat specimen (13); The node shaft connecting rod (58) of the #1 node shaft test piece (12) is provided with a conical recess (59). The #1 node shaft test piece (12) is fastened to the lower chord hole of the rotating frame (6) by a conical end set screw (11). The conical end set screw 11 is pressed against the conical recess (59) of the node shaft connecting rod (58). The positive pressure measuring device (15) includes: a sling (39), a lifting eye screw (40), a force sensor (41), a force sensor connecting block (42), a bracket (43), a bolt (44), and a nut (45); the force sensor connecting block (42) is suspended on the crossbeam of the bracket (43) by the bolt (44) and the nut (45), the force sensor (41) and the force sensor connecting block (42) are connected by threads, the lifting eye screw (40) is connected to the lower threaded hole of the force sensor (41) by threads, the lifting eye screw (40) is connected to the sling (39), and the sling (39) suspends the journal of the 1st node shaft (57) of the 1st node shaft specimen (12) at the lower 1st node shaft suspension point (38); The servo slide (16) is fixed to the servo slide support (18) by bolts. The bearing seat specimen (13) is fixed to the worktable (24) of the servo slide (16) by two flat washers (19), two spring washers (20) and two hexagon socket screws (21). The hexagon socket screws (21) pass through the two bolt holes of the bearing seat (64) of the No. 1 node shaft specimen (12). The No. 1 connecting mechanism test piece includes: No. 1 node shaft test piece (12), bearing seat test piece (13), washer (62) and bolt (63); The #1 node shaft test piece (12) includes: a #1 node shaft (57) and a node shaft connecting rod (58). The #1 node shaft (57) and the node shaft connecting rod (58) are connected. A conical recess (59) is machined on the node shaft connecting rod (58) for fixing the #1 node shaft test piece (12) to the rotating frame (6). The bearing housing specimen (13) includes: bearing housing #1 (64), spherical plain bearing (60) and PTFE fabric pad (61), wherein the inner ring of the spherical plain bearing (60) is fitted with PTFE fabric pad (61), the #1 node shaft (57) and the inner ring of the spherical plain bearing (60) form a steel-PTFE friction pair, and the end of the #1 node shaft (57) is provided with a washer (62) and a bolt (63), and the bolt (63) is connected to the temperature sensor (14).

2. The experimental apparatus according to claim 1, characterized in that, The servo slide (16) consists of a servo slide base (27), a linear rolling guide pair (22), a worktable (24), a ball screw pair (28), a synchronous pulley (29), a synchronous belt (30), a motor bracket (31), a servo motor (32), an internal hex screw (33), a force sensor connecting washer (34), a force sensor (35), and a screw nut (36). The guide rail of the linear rolling guide pair (22) is mounted on the servo slide base (27), the worktable (24) is mounted on the slider of the linear rolling guide pair (22), and the worktable (24) slides along the guide rail of the linear rolling guide pair (22). The ball screw pair (28) is mounted on the servo slide base (27), and the screw of the ball screw pair (28) is... Supported by bearing seats at both ends, the synchronous pulley (29) is installed at the power input end of the ball screw. The servo slide seat (27) is equipped with a motor bracket (31) to support the servo motor (32). The synchronous pulley (29) is installed on the shaft of the servo motor (32). The ball screw pair (28) and the synchronous pulley (29) of the servo motor (32) are connected by a synchronous belt (30). The servo motor (32) drives the ball screw of the ball screw pair (28) to rotate through the synchronous belt (30). The ball screw drives the screw nut (36) to make linear motion. The screw nut (36) is connected to the worktable (24) through a force sensor (35) to transmit the driving force F that drives the worktable (24) to make linear motion, and at the same time, the driving force F is measured.

3. The experimental apparatus according to claim 1, characterized in that, The lead screw nut and force sensor connector (37) are fixed to the lead screw nut (36) by screws. The force sensor (35) is fixed to the lead screw nut and force sensor connector (37) by force sensor connecting washer (34) and internal hex screw (33). The worktable and force sensor connector (25) are fixed to the worktable (24) by bolts. The force sensor (35) is fixed to the worktable and force sensor connector (25) by force sensor connecting washer (34) and internal hex screw (33).

4. The experimental apparatus according to claim 1, characterized in that, A left limit switch (23) and a right limit switch (26) are installed on the servo slide (16). The brackets of the left limit switch (23) and the right limit switch (26) are fixed to the servo slide base (27) by screws. The worktable (24) reciprocates linearly between the left limit switch (23) and the right limit switch (26).

5. The experimental apparatus according to claim 1, characterized in that, The weight tray (10) includes: a tray (54) welded in sequence, a connecting rod (55) and a tray lifting lug (56).

6. The experimental apparatus according to claim 1, characterized in that, The lower tray lug (52) of the rotating frame (6) suspends the weight tray (10) by the pin screw (7) and nut (8), and the weight (9) is placed on the weight tray (10). The positive pressure applied to the bearing seat specimen (13) by the rotating frame (6) is adjusted by the weight of the weight (9).

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