A hydraulic-mechanical compound drive cable fatigue testing machine

Abstract

The present invention discloses a hydraulic-mechanical compound drive cable fatigue testing machine, which includes a longitudinal excitation unit and a transverse excitation unit. The longitudinal excitation unit includes a first hydraulic motor, a first coupling, a first main shaft, a first bearing, a first flywheel, a second bearing, a first crank, a first connecting rod, and a first matching component. The transverse excitation unit includes a second hydraulic motor, a second coupling, a second main shaft, a third bearing, a second flywheel, a fourth bearing, a second crank, a second connecting rod, and a second matching component. The longitudinal and transverse excitation units can respectively perform periodic excitation on the cable under test along the vertical and horizontal directions. The excitation frequency is steplessly adjustable, and the excitation amplitude value is adjustable in grades, so as to achieve the purpose of fatigue testing. Through the design of vertical double guide rails, the excitation in two directions does not interfere with each other and will not cause additional damage to the cable under test. By adopting the hydraulic-mechanical compound drive mode, the installed power requirement of the fatigue testing machine for the hydraulic pump station is greatly reduced.

Description

Technical Field

[0001] The present invention relates to a fatigue testing machine, and more particularly to a cable fatigue testing machine with a hydraulic-mechanical composite drive. Background Art

[0002] In the fatigue life test of a certain type of cable, a certain tensile force needs to be applied to the cable under test first, and then a fatigue testing machine is used to apply periodic excitation to the cable under test in two mutually perpendicular directions. It is required that the maximum excitation frequency in a single direction is not less than 10 Hz, the frequency accuracy is controlled within ±0.5 Hz, the maximum excitation amplitude is not less than 7.5 cm, and the amplitude accuracy is controlled within ±0.5 cm. Due to the relatively heavy self-weight of the cable under test, the maximum excitation force generated by the high-frequency excitation in a single direction can reach 15 tons. In the prior art, an electro-hydraulic servo system is usually used to design such a fatigue testing machine because the electro-hydraulic servo system can conveniently adjust the amplitude and frequency of excitation. However, the electro-hydraulic servo system has low efficiency, which results in a huge installed power and high cost; in addition, the electronic control system of the electro-hydraulic servo system is also relatively complex.

[0003] The invention application with the application number CN200610146975.0 discloses a multi-parameter adjustable cable micro-motion fatigue device, which is composed of a vibration source device, a tensioning device, a fixed groove seat, a vertical positioning device, a suspension clamp, a wire, a vibration measuring instrument, a stress and strain measuring instrument, etc. The vibration source device is composed of a variable-speed motor speed regulator and an eccentric wheel. The vibration is excited by the relative movement between the eccentric wheel installed on the motor shaft and the rolling docking wheel below the suspension clamp fixed in the middle of the wire. A motor speed regulator is installed on the variable-speed motor to adjust the vibration frequency of the wire, and the adjustment range is 0-35 HZ. There is an eccentric wheel on the motor to control the bending amplitude through the eccentricity of the eccentric wheel, so that the wire generates micro-motion, and the amplitude is adjusted by using different eccentricities of the designed eccentric wheel. The amplitude parameter range is 0-6 mm. The tensioning device is composed of a fine-thread screw, a nut and a positioning spring, and is connected by the wires to adjust the tensile load of the wire by adjusting the thread-spring tensioning system at the end. The load is applied to the wire through this system, and the wire load is measured by the stress and strain measuring instrument and the strain gauge at the end of the screw. The vertical positioning device is composed of a positioning guide rod and a sleeve. The sleeve is fixed to the ground by a rigid structural member, and the longitudinal movement of the vibration is ensured through the vertical positioning device to prevent deviation.

[0004] The invention application with the application number CN202111174110.6 discloses a digital large-range high-precision multi-functional crankshaft fatigue testing machine, including: a mechanical mainframe for fixedly supporting a three-dimensional motion lifting mechanism, a swing arm mechanism, a load calibration mechanism, and a vibration table; a three-dimensional motion lifting mechanism for adjusting the stroke space of the swing arm mechanism in the up, down, left, and right directions and realizing the 90° suspension of the swing arm mechanism; a swing arm mechanism for clamping and loosening the specimen; a hydraulic control system for controlling the clamping and loosening of the specimen by the swing arm mechanism; a load calibration mechanism for statically loading the stress of the specimen in the swing arm mechanism; and an electromagnetic vibration control system for dynamically loading the stress of the specimen in the swing arm mechanism to make the stress level of the dynamic loading consistent with the stress data of the static calibration.

[0005] However, the testing machines in the above-mentioned prior art either have the defects of large equipment power, complex structure, and high cost, or will damage the cables during the test. In short, at present, there is an urgent need to develop a new cable fatigue testing machine to solve the defects existing in the prior art. Summary of the Invention

[0006] Aiming at the deficiencies of the prior art, the purpose of the present invention is to provide a hydraulic-mechanical composite drive cable fatigue testing machine, which can effectively complete the fatigue life test of the cable, greatly reduce the installed power and cost of such equipment, and greatly simplify the electronic control system.

[0007] The technical solution adopted by the present invention to solve the technical problems is: a hydraulic-mechanical composite drive cable fatigue testing machine, mainly including a longitudinal excitation unit and a transverse excitation unit. The longitudinal excitation unit mainly consists of a first hydraulic motor, a first coupling, a first main shaft, a first bearing, a first flywheel, a second bearing, a first crank, a first connecting rod, a first matching component, etc. The transverse excitation unit mainly consists of a second hydraulic motor, a second coupling, a second main shaft, a third bearing, a second flywheel, a fourth bearing, a second crank, a second connecting rod, a second matching component, etc.; the longitudinal excitation unit and the transverse excitation unit can respectively perform periodic excitation on the cable under test in the vertical direction and the horizontal direction, the excitation frequency is steplessly adjustable, and the excitation amplitude value is adjustable in grades, so as to achieve the purpose of fatigue testing of the cable under test.

[0008] Furthermore, the longitudinal excitation unit of the present invention further includes a first hydraulic control valve group, and the first hydraulic control valve group mainly functions to limit the maximum pressure difference between the two chambers of the first hydraulic motor, control the first hydraulic motor to cut the free wheel, and release the hot oil in the low-pressure chamber of the first hydraulic motor; the transverse excitation unit further includes a second hydraulic control valve group, and the second hydraulic control valve group mainly functions to limit the maximum pressure difference between the two chambers of the second hydraulic motor, control the second hydraulic motor to cut the free wheel, and release the hot oil in the low-pressure chamber of the second hydraulic motor.

[0009] Further, the longitudinal excitation unit of the present invention further includes a first displacement sensor for real-time detection of the displacement of the first mating component during the excitation process; the transverse excitation unit further includes a second displacement sensor for real-time detection of the displacement of the second mating component during the excitation process.

[0010] Further, both the first mating component and the second mating component of the present invention adopt a vertical double-guide rail design, so that the excitation of the longitudinal excitation unit and the transverse excitation unit is completely independent and does not interfere with each other, and will not cause additional damage to the cable under test.

[0011] Further, the first mating component mainly includes a first split frame, a first cable clamping mechanism, a first transverse moving slider, a first transverse moving guide rail, a first longitudinal moving slider and a first longitudinal moving guide rail; the second mating component mainly includes a second split frame, a second cable clamping mechanism, a second longitudinal moving slider, a second longitudinal moving guide rail, a second transverse moving slider and a second transverse moving guide rail.

[0012] Further, the first longitudinal moving slider is fixed on the first split frame and can move vertically along the first longitudinal moving guide rail fixed on the mechanical frame; the first transverse moving slider is fixed together with the first cable clamping mechanism and can move horizontally along the first transverse moving guide rail fixed inside the first split frame.

[0013] Further, the second transverse moving slider is fixed on the second split frame and can move horizontally along the second transverse moving guide rail fixed on the mechanical frame; the second longitudinal moving slider is fixed together with the second cable clamping mechanism and can move vertically along the second longitudinal moving guide rail fixed inside the second split frame.

[0014] Further, both the longitudinal excitation unit and the transverse excitation unit of the present invention adopt a hydraulic-mechanical composite drive mode of a hydraulic motor - flywheel, which greatly reduces the installed power requirement of the vibration fatigue testing machine for the hydraulic pump station.

[0015] The beneficial effects of the present invention are as follows: Compared with the prior art, the cable fatigue testing machine with a hydraulic-mechanical composite drive provided by the present invention has the following advantages:

[0016] 1) Both the longitudinal excitation unit and the transverse excitation unit adopt a hydraulic-mechanical composite drive mode of a hydraulic motor - flywheel, which greatly reduces the installed power requirement of the vibration fatigue testing machine for the hydraulic pump station.

[0017] 2) The matching component adopts a vertical double-rail design, enabling the excitation of the longitudinal excitation unit and the transverse excitation unit to be completely independent and non-interfering with each other, and will not cause additional damage to the cable under test.

[0018] 3) The electrical control of the fatigue testing machine is greatly simplified. By controlling the rotational speed of the hydraulic motor, the excitation frequency can be steplessly adjusted, and the excitation amplitude is completely determined by the length of the crank without electrical control. Description of the Drawings

[0019] Figure 1 It is a schematic structural diagram of an embodiment of the present invention.

[0020] Figure 2 It is a schematic structural diagram of an embodiment of the first matching component.

[0021] Figure 3 It is a schematic structural diagram of an embodiment of the second matching component.

[0022] Figure 1 In the figure: 1. First hydraulic motor, 2. First coupling, 3. First main shaft, 4. First bearing, 5. First flywheel, 6. Second bearing, 7. First crank, 8. First connecting rod, 9. First matching component, 10. First hydraulic control valve group, 11. First displacement sensor, 12. Second hydraulic motor, 13. Second coupling, 14. Second main shaft, 15. Third bearing, 16. Second flywheel, 17. Fourth bearing, 18. Second crank, 19. Second connecting rod, 20. Second matching component, 21. Second hydraulic control valve group, 22. Second displacement sensor.

[0023] Figure 2 In the figure: 101. First split frame, 102. First cable clamping mechanism, 103. First transverse moving slider, 104. First transverse moving guide rail, 105. First longitudinal moving slider, 106. First longitudinal moving guide rail.

[0024] Figure 3 In the figure: 201. Second split frame, 202. Second cable clamping mechanism, 203. Second longitudinal moving slider, 204. Second longitudinal moving guide rail, 205. Second transverse moving slider, 206. Second transverse moving guide rail. Detailed Embodiment

[0025] The present invention will be further described below through specific embodiments. However, these embodiments are only used to illustrate the present invention and not to limit the scope of the present invention.

[0026] Embodiment

[0027] See Figure 1, as an embodiment of the present invention, the present invention mainly includes a longitudinal excitation unit and a transverse excitation unit. The longitudinal excitation unit mainly consists of a first hydraulic motor 1, a first coupling 2, a first main shaft 3, a first bearing 4, a first flywheel 5, a second bearing 6, a first crank 7, a first connecting rod 8, a first matching component 9, etc. The transverse excitation unit mainly consists of a second hydraulic motor 12, a second coupling 13, a second main shaft 14, a third bearing 15, a second flywheel 16, a fourth bearing 17, a second crank 18, a second connecting rod 19, a second matching component 20, etc. The output shaft of the first hydraulic motor 1 is coaxial with the first main shaft 3, and the output shaft of the first hydraulic motor 1 is connected to the input end of the first main shaft 3 through the first coupling 2. The first main shaft 3 is jointly supported by the first bearing 4 and the second bearing 6. The first flywheel 5 is connected to the first main shaft 3 through a flat key or a spline and is installed between the first bearing 4 and the second bearing 6. The output end of the first main shaft 3 is connected to the input end of the first crank 7 through a flat key or a spline. The output end of the first crank 7 is connected to the input end of the first connecting rod 8 through a connecting shaft. The output end of the first connecting rod 8 is connected to the driving end of the first matching component 9 through a connecting shaft. The output shaft of the second hydraulic motor 12 is coaxial with the second main shaft 14, and the output shaft of the second hydraulic motor 12 is connected to the input end of the second main shaft 14 through the second coupling 13. The second main shaft 14 is jointly supported by the third bearing 15 and the fourth bearing 17. The second flywheel 16 is connected to the second main shaft 14 through a flat key or a spline and is installed between the third bearing 15 and the fourth bearing 17. The output end of the second main shaft 14 is connected to the input end of the second crank 18 through a flat key or a spline. The output end of the second crank 18 is connected to the input end of the second connecting rod 19 through a connecting shaft. The output end of the second connecting rod 19 is connected to the driving end of the second matching component 20 through a connecting shaft.

[0028] See Figure 1, as an embodiment of the present invention, the cable fatigue testing machine further includes a first hydraulic control valve group 10 and a second hydraulic control valve group 21. The two output oil ports of the first hydraulic control valve group 10 are connected to the two main oil ports of the first hydraulic motor 1 through pipelines. The two input oil ports of the first hydraulic control valve group 10 need to be connected to a hydraulic pump station. Generally, it is recommended that the hydraulic pump station use one closed hydraulic pump to be connected to the first hydraulic control valve group 10 and drive the first hydraulic motor 1. The two output oil ports of the second hydraulic control valve group 21 are connected to the two main oil ports of the second hydraulic motor 12 through pipelines. The two input oil ports of the second hydraulic control valve group 21 need to be connected to a hydraulic pump station. Generally, it is recommended that the hydraulic pump station use one closed hydraulic pump to be connected to the second hydraulic control valve group 21 and drive the second hydraulic motor 12. Among them, the first hydraulic control valve group 10 mainly functions to limit the maximum pressure difference between the two chambers of the first hydraulic motor 1, control the first hydraulic motor 1 to cut the free wheel, release the hot oil in the low-pressure chamber of the first hydraulic motor 1, etc.; the second hydraulic control valve group 21 mainly functions to limit the maximum pressure difference between the two chambers of the second hydraulic motor 12, control the second hydraulic motor 12 to cut the free wheel, release the hot oil in the low-pressure chamber of the second hydraulic motor 12, etc.

[0029] See Figure 1 , as an embodiment of the present invention, the cable fatigue testing machine further includes a first displacement sensor 11 and a second displacement sensor 22. The first displacement sensor 11 is used to detect the displacement of the first mating component 9 during the vibration excitation process in real time, and the second displacement sensor 22 is used to detect the displacement of the second mating component 20 during the vibration excitation process in real time.

[0030] See Figure 2 , the first mating component 9 is mainly composed of a first split frame 101, a first cable clamping mechanism 102, a first transverse moving slider 103, a first transverse moving guide rail 104, a first longitudinal moving slider 105, a first longitudinal moving guide rail 106, etc. Among them: the first longitudinal moving slider 105 is fixed on the first split frame 101 and can move vertically along the first longitudinal moving guide rail 106 fixed on the machine frame; further, the first transverse moving slider 103 is fixed together with the first cable clamping mechanism 102 and can move horizontally along the first transverse moving guide rail 104 fixed inside the first split frame 101.

[0031] See Figure 3, the second matching component 20 mainly consists of a second split-frame 201, a second cable clamping mechanism 202, a second longitudinal moving slider 203, a second longitudinal moving guide rail 204, a second transverse moving slider 205, a second transverse moving guide rail 206, etc. Among them: The second transverse moving slider 205 is fixed on the second split-frame 201 and can move horizontally along the second transverse moving guide rail 206 fixed on the machine frame; further, the second longitudinal moving slider 203 is fixed together with the second cable clamping mechanism 202 and can move vertically along the second longitudinal moving guide rail 204 fixed inside the second split-frame 201.

[0032] Through the vertical double-guide rail design of the above-mentioned matching components, the excitation of the longitudinal excitation unit and the transverse excitation unit can be completely independent and non-interfering, and no additional damage will be caused to the cable under test. The specific implementation is as follows: The first hydraulic motor 1 drives the first main shaft 3 and the first flywheel 5 to rotate at a certain fixed speed, and through the "crank-slider structure" of the first crank 7, the first connecting rod 8 and the first matching component 9, the rotational motion is converted into the linear motion of the first matching component 9 in the longitudinal direction, that is, the longitudinal excitation of the cable under test is realized. By changing the speed of the first hydraulic motor 1, the frequency of the longitudinal excitation is changed, and the amplitude of the longitudinal excitation is completely determined by the structure of the first crank 7 without electrical control; The second hydraulic motor 12 drives the second main shaft 14 and the second flywheel 16 to rotate at a certain fixed speed, and through the "crank-slider structure" of the second crank 18, the second connecting rod 19 and the second matching component 20, the rotational motion is converted into the linear motion of the second matching component 20 in the transverse direction, that is, the transverse excitation of the cable under test is realized. By changing the speed of the second hydraulic motor 12, the frequency of the transverse excitation is changed, and the amplitude of the transverse excitation is completely determined by the structure of the second crank 18 without electrical control; further, since the first cable clamping mechanism 102 inside the first matching component 9 can slide freely along the first transverse moving guide rail 104, its displacement in the horizontal direction has nothing to do with the longitudinal excitation and only depends on the transverse excitation unit, that is, the first cable clamping mechanism 102 follows the motion of the transverse excitation unit in the horizontal direction; similarly, the displacement of the second cable clamping mechanism 202 inside the second matching component 20 in the vertical direction has nothing to do with the transverse excitation and only depends on the longitudinal excitation unit, that is, the second cable clamping mechanism 202 follows the motion of the longitudinal excitation unit in the vertical direction.

[0033] The above embodiments are only used to illustrate the present invention and are not intended to limit the present invention. Those of ordinary skill in the relevant technical fields can also make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, all equivalent technical solutions also belong to the scope of the present invention, and the patent protection scope of the present invention should be defined by the claims.

Claims

1. A cable fatigue testing machine with a hydraulic-mechanical composite drive, characterized in that: The cable fatigue testing machine mainly includes a longitudinal excitation unit and a transverse excitation unit. The longitudinal excitation unit includes a first hydraulic motor (1), a first coupling (2), a first main shaft (3), a first bearing (4), a first flywheel (5), a second bearing (6), a first crank (7), a first connecting rod (8), and a first matching component (9); the transverse excitation unit includes a second hydraulic motor (12), a second coupling (13), a second main shaft (14), a third bearing (15), a second flywheel (16), a fourth bearing (17), a second crank (18), a second connecting rod (19), and a second matching component (20); the longitudinal excitation unit and the transverse excitation unit can respectively perform periodic excitation on the cable under test in the vertical direction and the horizontal direction, the excitation frequency is steplessly adjustable, and the excitation amplitude value is adjustable in grades, so as to achieve the purpose of fatigue testing on the cable under test; Both the first matching component (9) and the second matching component (20) adopt a vertical double-rail design, so that the excitation of the longitudinal excitation unit and the transverse excitation unit is completely independent and does not interfere with each other, and will not cause additional damage to the cable under test; The first matching component (9) mainly includes a first split frame (101), a first cable clamping mechanism (102), a first transverse moving slider (103), a first transverse moving guide rail (104), a first longitudinal moving slider (105), and a first longitudinal moving guide rail (106); the second matching component (20) mainly includes a second split frame (201), a second cable clamping mechanism (202), a second longitudinal moving slider (203), a second longitudinal moving guide rail (204), a second transverse moving slider (205), and a second transverse moving guide rail (206); Both the longitudinal excitation unit and the transverse excitation unit adopt a hydraulic-mechanical composite drive mode of hydraulic motor-flywheel, which greatly reduces the installed power demand of the vibration fatigue testing machine for the hydraulic pump station.

2. The cable fatigue testing machine with a hydraulic-mechanical composite drive according to claim 1, characterized in that: The longitudinal excitation unit further includes a first hydraulic control valve group (10), and the first hydraulic control valve group (10) is mainly used to limit the maximum pressure difference between the two chambers of the first hydraulic motor (1), control the first hydraulic motor (1) to cut the free wheel, and release the hot oil in the low-pressure chamber of the first hydraulic motor (1); the transverse excitation unit further includes a second hydraulic control valve group (21), and the second hydraulic control valve group (21) is mainly used to limit the maximum pressure difference between the two chambers of the second hydraulic motor (12), control the second hydraulic motor (12) to cut the free wheel, and release the hot oil in the low-pressure chamber of the second hydraulic motor (12).

3. The cable fatigue testing machine with a hydraulic-mechanical composite drive according to claim 1, characterized in that: The longitudinal excitation unit further includes a first displacement sensor (11), and the first displacement sensor (11) is used to detect the displacement of the first matching component (9) during excitation in real time; the transverse excitation unit further includes a second displacement sensor (22), and the second displacement sensor (22) is used to detect the displacement of the second matching component (20) during excitation in real time.

4. The cable fatigue testing machine with a hydraulic-mechanical composite drive according to claim 1, characterized in that: The first longitudinal moving slider (105) is fixed on the first split frame (101) and can move vertically along the first longitudinal moving guide rail (106) fixed on the machine frame; the first transverse moving slider (103) is fixed together with the first cable clamping mechanism (102) and can move horizontally along the first transverse moving guide rail (104) fixed inside the first split frame (101).

5. The cable fatigue testing machine with a hydraulic-mechanical composite drive according to claim 1, characterized in that: The second transverse moving slider (205) is fixed on the second split frame (201) and can move horizontally along the second transverse moving guide rail (206) fixed on the machine frame; the second longitudinal moving slider (203) is fixed together with the second cable clamping mechanism (202) and can move vertically along the second longitudinal moving guide rail (204) fixed inside the second split frame (201).

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