Experiment table for measuring fretting wear of lead
Technical Field
The invention relates to the field of power transmission accessories, in particular to an experiment table for measuring fretting wear of a lead.
Background
In the national power industry, the failure of the overhead conductor caused by vibration is mainly divided into three types: waving of the wire, subspan vibration of the wire, and breeze vibration of the wire. The aeolian vibration of the wire is frequently generated, and becomes one of the major disasters of the extra-high voltage and long-distance transmission line. The aeolian vibration is the main cause of the fatigue damage of the lead, is the most common vibration mode which endangers the safe operation of the line, is influenced by the aeolian, the overhead lead is always in the vibration, and slight slippage and friction are generated between the lead strands and between the lead and a clamp, so that continuous alternating stress is generated, and the fretting wear of the lead is caused. And because the micro-motion amplitude of the wire is small, the wire is not easy to be found by workers, and is a damaged accumulation process, and potential safety hazards are left. The lead under the micro-motion condition for a long time is easy to cause the generation and the expansion of fatigue cracks, the service life of the lead is reduced, even the lead fails, and serious safety accidents are caused seriously. Therefore, monitoring the working state of the lead and researching how to avoid fretting wear of the lead are important, and the method is a major problem to be solved by the domestic ultra-high voltage transmission line and is a key for ensuring safe, reliable and economic operation of the ultra-high voltage transmission line.
The micro-fretting wear test requires related test equipment and a workbench. The wire diameter of a high-voltage transmission wire in a real environment is often more than 20mm, the installation pretightening force at two ends of the wire is 1.5 tons, and the high-voltage transmission wire is different from the severe waving of the wire caused by strong wind, and the high-voltage transmission wire vibrates slightly in the air, the amplitude of the high-voltage transmission wire is only 1-3 mm, and the high-voltage transmission wire is continuous vibration for a long time. At present, fretting wear experimental equipment at home and abroad has different forms and different research objects, and many fretting wear experimental equipment can only measure the amplitude and the vibration frequency and cannot really simulate the working condition of the aeolian vibration of a wire.
Disclosure of Invention
Aiming at the defects of the prior art, the invention provides the experiment table for measuring the fretting wear of the wire, which can truly simulate the breeze vibration working condition of the wire.
In order to achieve the purpose, the invention designs an experimental bench for measuring the fretting wear of a lead, which is characterized in that: comprises a frame component, a power output component and a wire clamping component;
the wire clamping part is connected to the middle of a wire with two fixed ends, the wire clamping part is connected with the frame part in a sliding mode, and the power output part is connected to the bottom of the wire clamping part and used for jacking with different frequencies to enable the wire clamping part to vibrate up and down and drive the wire to simulate breeze vibration. Wherein the two ends of the lead are fixed in a hinged manner.
Further, power take off part includes motor, axle, left bearing frame, right bearing frame, shaft coupling and cam, the axle is connected with the motor to the axle both ends support respectively on left bearing frame and right bearing frame, the cam passes through the coupling joint epaxially, power take off part passes through the cam and is connected with top wire clamping part. The cam is always contacted with the clamping component to drive the clamping component to simulate the breeze vibration of the lead, and the vibration function value of the test bed is related to the outline of the cam and is easy to control.
Furthermore, an eccentric shaft sleeve is further arranged between the cam and the shaft, the cam is connected with the eccentric shaft sleeve through a first connecting key, and the eccentric shaft sleeve is connected with the shaft through a second connecting key. The cam cost is high, and processing is loaded down with trivial details, but eccentric sleeve is with low costs, and processing is convenient, changes the amplitude of vibration through changing eccentric sleeve, saves materials, and convenient processing and change.
Still further, the frame part includes frame and guide rail, the guide rail is provided with two, along frame axis symmetrical arrangement on the frame inner wall, be provided with the slider that is used for connecting wire clamping part on the guide rail. Because the guided fretting wear has small vibration, after the guide rail sliding blocks which are arranged in pairs are introduced for guiding, the guide mechanism has high precision and small clearance, and ensures the stable motion of small amplitude vibration. And the adjustment is simple and convenient, and the experimental error caused by the amplitude and the impact is reduced.
Still further, the guide rail is connected to the inner wall of the frame by a vertical mounting plate. The installation and the dismantlement are convenient.
Still further, the frame is a rectangular frame.
Still further, wire clamping part includes horizontal mounting board, U type bolt, vaulting pole and bearing roller, horizontal mounting board top surface is provided with the suspension clamp, and the bottom surface is provided with the vaulting pole, U type bolt is fixed the wire in the suspension clamp, U type bolt passes horizontal mounting board and fixes the vaulting pole in the horizontal mounting board bottom through tip lock nut, the bearing roller is connected at the vaulting pole tip and is kept in contact with the bottom cam all the time, wire clamping part passes through horizontal mounting board and fixes on the slider. Wherein, U type bolt is provided with two, adopts the fixed direction of U-shaped bolt, has guaranteed fixed reliable because, among the experimentation, owing to artificially let the wire vibrate for a long time, the fixed department of wire is not hard up easily, after not hard up, just can produce very big clearance, leads to the experiment failure.
Still further, the bearing rollers are provided with two, and are symmetrically arranged at the end part of the strut. The stress is balanced, so that the stress of the wire clamping part is balanced, and the experiment is reliable.
Still further, the horizontal mounting plate is fixed on the sliding block through an L-shaped mounting plate. The connection is convenient.
The invention has the advantages that: the middle part of the lead is connected with a clamping part, and the clamping part is jacked by a power output part to vibrate up and down, so that breeze small-amplitude vibration of the lead in the air is simulated, and fretting wear of the lead is tested. The wire clamping component is connected with the frame component in a sliding mode, so that the clamping component and the frame component are high in connection precision and small in gap, small-amplitude vibration is guaranteed to move stably, and errors caused by amplitude and impact are avoided and reduced. The vibration amplitude and the vibration frequency of the wire can be changed through the power output component, so that the condition that wind speeds and wind strengths are inconsistent in different regions and different seasons in the engineering environment is simulated, an experimental basis is provided for engineering personnel to evaluate the fatigue life and the safety condition of the wire in service, and theoretical guidance is provided for power transmission line constructors.
Drawings
FIG. 1 is a schematic structural diagram of an experimental bench for measuring fretting wear of a wire according to the present invention.
Fig. 2 is a schematic structural view of the frame member of fig. 1.
Fig. 3 is an exploded view of the power take-off of fig. 1.
Fig. 4 is a schematic view of the wire clamping member of fig. 1.
In the figure: the device comprises a frame component 1, a power output component 2, a wire clamping component 3, a frame 4, a sliding block 5, a guide rail 6, a vertical mounting plate 7, a left bearing seat 8, a cam 9, a first connecting key 10, an eccentric shaft sleeve 11, a second connecting key 12, a shaft 13, a right bearing seat 14, a coupling 15, a motor 16, a wire 17, a U-shaped bolt 18, a horizontal mounting plate 19, a suspension clamp 20, a support rod 21, a bearing roller 22 and an L-shaped mounting plate 23.
Detailed Description
The invention is described in further detail below with reference to the following figures and specific examples:
the experiment table for measuring the fretting wear of the lead wire, which is shown in the figure, comprises a frame part 1, a power output part 2 and a lead wire clamping part 3; the wire clamping part 3 is connected to the middle of a wire 17 with two fixed ends, the wire clamping part 3 is connected with the frame part 1 in a sliding mode, and the power output part 2 is connected to the bottom of the wire clamping part 3 and used for jacking the wire clamping part 3 at different frequencies to enable the wire clamping part 3 to vibrate up and down and drive the wire 17 to simulate breeze vibration.
The power output component 2 comprises a motor 16, a shaft 13, a left bearing seat 8, a right bearing seat 14, a coupler 15 and a cam 9, the shaft 13 is connected with the motor 16, two ends of the shaft 13 are respectively supported on the left bearing seat 8 and the right bearing seat 14, the cam 9 is connected onto the shaft 13 through the coupler 15, and the power output component 2 is connected with the top wire clamping component 3 through the cam 9. An eccentric shaft sleeve 11 is further arranged between the cam 9 and the shaft 13, the cam 9 is connected with the eccentric shaft sleeve 11 through a first connecting key 10, and the eccentric shaft sleeve 11 is connected with the shaft 13 through a second connecting key 12. The cam 9 is always contacted with the clamping component 3 to drive the clamping component 3 to simulate the aeolian vibration of the lead, and the vibration function value of the test bed is related to the outline of the cam and is easy to control. The vibration amplitude of the lead is changed by replacing the eccentric shaft sleeve 11, so that materials are saved, and the processing and the replacement are convenient.
The frame component 1 comprises a frame 4 and two guide rails 6, the two guide rails 6 are symmetrically arranged on two opposite inner walls of the frame 4 along the axial line of the frame 4, and the guide rails 6 are provided with sliders 5 used for connecting the wire clamping components 3. Because the guide fretting wear is small in vibration, after guide of guide rail sliding blocks arranged in pairs is introduced, the guide mechanism is high in precision and small in gap, and the small-amplitude vibration is guaranteed to be stable in motion. And the adjustment is simple and convenient, and the errors caused by amplitude and impact are reduced. Preferably, the guide rails 6 are attached to the inner wall of the frame 4 by vertical mounting plates 7, which facilitate disassembly and assembly. The frame 4 is a rectangular frame as a whole.
The wire clamping component 3 comprises a horizontal mounting plate 19, a U-shaped bolt 18, a support rod 21 and a bearing roller 22, wherein the top surface of the horizontal mounting plate 19 is provided with a suspension clamp 20, the bottom surface of the horizontal mounting plate 19 is provided with the support rod 21, the U-shaped bolt 18 fixes the wire 17 in the suspension clamp 20, the U-shaped bolt 18 penetrates through the horizontal mounting plate 19 and fixes the support rod 21 at the bottom of the horizontal mounting plate 19 through an end locking nut, the bearing roller 22 is connected at the end of the support rod 21 and always keeps contact with the bottom cam 9, and the wire clamping component 3 is fixed on the sliding block 5 through the horizontal mounting. The bearing rollers 22 are provided in two, symmetrically arranged on both sides of the end of the stay 21. The horizontal mounting plate 19 is fixed on the sliding block 5 through an L-shaped mounting plate 23, and the L-shaped mounting plate 23 is firstly connected with the horizontal mounting plate 19 through a bolt and then fixedly connected with the sliding block 5 of the frame component 1 through a bolt. The bearing roller 22 is always in contact with the cam 9 of the component 2, and in the rotating process of the cam 9, due to the eccentricity generated by the eccentric shaft sleeve 11, the bearing roller 22 drives the whole wire clamping component 3 to vertically lift and simulate the vibration of a wire in a wind blowing state. Wherein, U type bolt is provided with one for it is more firm to connect, adopts the fixed direction of U-shaped bolt 18, has guaranteed fixed reliable, because, in the experimentation, owing to artificially let the wire vibrate for a long time, the fixed department of wire is not hard up easily, after not hard up, just can produce very big clearance, leads to the experiment failure. The experiment table can simulate the breeze small-amplitude vibration condition of the wire in the air, test the fretting wear of the wire, change the vibration amplitude by replacing eccentric shaft sleeves with different eccentric distances in the experiment table, change the rotating speed of a motor and change the vibration frequency of the wire, so as to simulate the condition that the wind speed and the wind strength are inconsistent in different regions and different seasons in an engineering environment, provide an experimental basis for the engineering personnel to evaluate the fatigue life and the safety condition of the in-service wire, and provide theoretical guidance for the power transmission line constructors. In practical situation, the overhead conductor is high at two sides and concave in the middle, and the breeze vibration of the conductor is often generated near the gravity direction, so that the test bed provided by the invention is more in line with engineering practice.