Quasi-real friction test bench for friction pair of radial plunger tilt cylinder hydraulic motor

Abstract

The invention discloses a quasi-real friction test bench of a radial plunger tilt cylinder hydraulic motor friction pair, which comprises a hydraulic loading system and a rack, and also comprises an eccentric shaft and a first servo motor which are arranged on the rack, and the eccentric shaft comprises an upper end fixing shaft and a lower end fixing shaft which are connected to the rack through respective rolling bearings; the lower end fixing shaft is coaxially connected with the first servo motor, the upper end fixing shaft and the lower end fixing shaft are coaxial, and the eccentric shaft further comprises an adjustable eccentric shaft with the distance between the axis and the axis of the fixing shaft adjustable. Two tilt cylinders needing to be subjected to a real friction test are symmetrically arranged on the rack; the device further comprises a micro swing angle generating mechanism used for simulating reciprocating swing friction between a radial plunger swing cylinder hydraulic motor crank and the swing cylinder. The quasi-real friction test bed is high in pertinence, can perform a quasi-real friction test on the radial plunger tilt cylinder hydraulic motor friction pair for a long time, and can obtain related data of friction performance of the radial plunger tilt cylinder hydraulic motor friction pair under different working conditions.

Description

Technical Field

[0001] The invention relates to the technical field of radial piston motor friction pair testing, in particular to a simulated friction test bench for radial piston swing cylinder hydraulic motor friction pairs. Background Art

[0002] The radial piston swing cylinder hydraulic motor of the prior art, such as the five-star swing cylinder hydraulic motor, uses the oil pressure to keep the oil cylinder close to the surface of the crankshaft eccentric wheel, and the oil pressure drives the eccentric shaft to rotate. The radial piston swing cylinder hydraulic motor is widely used in engineering machinery, ships, mining equipment and other fields due to its compact structure, high efficiency and strong load-bearing capacity. The radial piston swing cylinder hydraulic friction pair in the radial piston swing cylinder hydraulic motor is a key component.

[0003] In the prior art, in order to analyze the friction characteristics and influencing factors and provide a scientific basis for optimizing the design and use of radial piston swing cylinder hydraulic motors, it is necessary to conduct a friction test on the friction pair of the radial piston swing cylinder hydraulic motor.

[0004] The friction pair test bench in the prior art has a common friction pair form of line contact instead of the surface contact of the present application. This form is generally only suitable for the study of the characteristics of the inner curve hydraulic motor plunger friction pair, and the positive pressure is loaded by the linear telescopic piston cylinder instead of the swing cylinder or swing piston cylinder of the present application. The friction pair test bench is not suitable for the friction test of the friction pair of the radial piston swing cylinder hydraulic motor of the present invention, and cannot solve the technical problem to be solved by the present application, nor does it have the technical effect to be achieved by the present application.

[0005] The prior art discloses a measuring device for the friction pair of a radial piston swing cylinder hydraulic motor, but what is tested is the single dynamic friction characteristics of the radial piston swing cylinder hydraulic motor after the running-in is completed. In particular, the measuring device only measures the data and parameter of the friction force of the eccentric shaft of the cylinder, and in order to eliminate the interference and influence of the piston extension and swing on the measurement of the friction force of the eccentric shaft of the cylinder, the eccentric shaft is changed into a concentric shaft. This makes it impossible to perform a simulated friction test on the friction pair of the radial piston swing cylinder hydraulic motor, and it is even more impossible to obtain the friction performance-related data of the friction pair of the radial piston swing cylinder hydraulic motor under different working conditions. Summary of the invention

[0006] The technical problem to be solved by the present invention is to provide a simulated friction test bench for the friction pair of a radial piston swing cylinder hydraulic motor, which is highly targeted and can carry out simulated working condition friction tests on the friction pair of a radial piston swing cylinder hydraulic motor for a long time, and can obtain friction performance related data of the friction pair of the radial piston swing cylinder hydraulic motor under different working conditions.

[0007] The technical solution of the present invention is to provide a simulated friction test bench for the friction pair of a radial piston swing cylinder hydraulic motor, including a hydraulic loading system and a frame.

[0008] It also includes an eccentric shaft and a first motor mounted on the frame, the eccentric shaft includes an upper fixed shaft and a lower fixed shaft connected to the frame via respective rolling bearings, the lower fixed shaft is coaxially connected to the motor, the upper fixed shaft is coaxial with the lower fixed shaft, the eccentric shaft also includes an adjustable eccentric shaft whose axis is at an adjustable distance from the axis of the fixed shaft, the adjustable eccentric shaft includes a core shaft and a sleeve, a radial convex ring friction arc surface is provided on the outer circumference of the sleeve, and the core shaft and the sleeve are rotatably connected by respective needle roller parts of a plurality of needle roller bearings;

[0009] Two swing cylinders to be tested in simulated friction are symmetrically arranged on the frame. The hydraulic loading system is connected to the hydraulic chambers in the two swing cylinders. The friction end faces of the pistons of the respective swing cylinders are always in contact with the radial convex ring friction arc surface and lubricated by the oil seeping from the center hole of the piston.

[0010] The simulated friction test bench for the friction pair of the radial piston swing cylinder hydraulic motor of the present invention also includes a micro-swing angle generating mechanism for simulating the reciprocating swing friction between the crank of the radial piston swing cylinder hydraulic motor and the swing cylinder. The micro-swing angle generating mechanism is arranged on the frame, connected to the sleeve of the adjustable eccentric shaft, and is controlled by the second servo motor to repeatedly rotate forward and reverse for several tens of degrees.

[0011] After adopting the above structure, the simulated friction test bench of the radial piston swing cylinder hydraulic motor friction pair of the present invention has the following advantages:

[0012] The simulated friction test bench for the friction pair of the radial piston swing cylinder hydraulic motor of the present invention is highly targeted and can carry out the simulated friction test of the friction pair of the radial piston swing cylinder hydraulic motor for a long time, and can obtain the friction performance related data of the friction pair of the radial piston swing cylinder hydraulic motor under different working conditions, so as to evaluate the friction performance, working efficiency and service life of the radial piston swing cylinder hydraulic motor.

[0013] The eccentricity of the eccentric shaft in the present invention is adjustable, and can adapt to the simulated friction test of the friction pair of the radial piston swing cylinder hydraulic motor with different eccentricities, so that the test range is wide and the versatility is strong.

[0014] Symmetrically arranging two of the five swivel cylinders of a swivel cylinder motor, such as the inner five-star motor, on the simulated friction test bench can reduce radial load, vibration and noise caused by uneven load, avoid unnecessary mechanical stress and internal loss, and increase the mechanical rigidity of the entire test bench.

[0015] It is not difficult to understand that the radial piston swing cylinder hydraulic motor, such as the inner five-star motor, has five swing cylinders that move in coordination under real working conditions. Under the joint action of the five swing cylinders, a small-angle rotational friction swing will be generated between the piston and the crank, which is equivalent to the sleeve. This angle is referred to as the micro-swing angle. Another outstanding advantage of the present invention is that by setting a micro-swing angle generating mechanism, the relative friction angle between the crank and the inner friction surface of the swing cylinder can be simulated. During the test, the micro-swing angle generating mechanism controlled by the second servo motor drives the sleeve of the adjustable eccentric shaft to repeatedly rotate forward and reverse by a corresponding angle, which can be 5°-20°, such as 20 degrees forward, 20 degrees reverse, 20 degrees forward again, and 20 degrees reverse again..., and the cycle of 20 degrees forward and reverse each time constitutes repeated swinging; at the same time, because the first servo motor continuously rotates to drive the upper fixed shaft and the lower fixed shaft to rotate 360° around their own axes, because the axis of the fixed shaft is close to the adjustable eccentric shaft The axis of the core shaft has an eccentric distance of such as 2-5 cm, so the core shaft axis of the adjustable eccentric shaft is always in a state of swinging around the fixed shaft axis, that is, the motor shaft axis; in this way, under the joint action of the hydraulic loading system, the friction of the two swing cylinders and the spherical friction pair of the eccentric shaft and the micro-swing angle generating mechanism, the real friction effect of the friction pair of the radial piston swing cylinder hydraulic motor of multiple swing cylinders such as five swing cylinders is simulated to the greatest extent. It is not difficult to understand that the real inner five-star motor is hydraulically driven friction and then output by the crank shaft rotation, while this test bench is rotation input friction, the direction is opposite, but the friction effect is equivalent, and its simulation effect is particularly obvious and prominent.

[0016] Furthermore, the structure of the micro-swing angle generating mechanism is as follows: the second servo motor is arranged on the frame, a driving sprocket is coaxially fixed on the rotating shaft of the second servo motor, a driven sprocket is coaxially fixed on the sleeve of the adjustable eccentric shaft, an annular chain is meshed on the driving sprocket and the driven sprocket, and the two outer sides of the middle section of the annular chain are fixed on the frame respectively for always tensioning the annular chain. After the micro-swing angle generating mechanism adopts the above specific structure, the micro-swing angle generating mechanism is driven by the second motor to rotate the driving sprocket, the chain, and the driven sprocket, thereby driving the sleeve and the core shaft of the adjustable eccentric shaft fixed to the center hole of the driven sprocket to undergo a slight swing angle change to complete the micro-swing angle action; in order to prevent the chain from swinging due to the change of tensioning force, two spring tensioners symmetrically arranged in the middle section of the chain are used to automatically adjust the tensioning force of the chain at any time to prevent the chain from being dislocated and swinging, thereby ensuring the stability of the chain transmission. The chain-sprocket type micro-swing angle generating mechanism has outstanding advantages: the meshing transmission of the chain and the sprocket can ensure the accuracy of the transmission ratio, can transmit a large power, and has a strong overload capacity. It has good applicability in various working conditions in harsh environments such as high temperature, dust, and pollution. And due to the eccentric rotation of the eccentric shaft, the chain-sprocket mechanism is selected as the implementation method of the micro-swing angle movement of the eccentric shaft. There is no elastic sliding and slipping phenomenon, and high transmission efficiency can be achieved. In the case of friction and wear tests, the micro-swing generating mechanism can continue to rotate forward and reverse repeatedly for a long time, and the chain-sprocket mechanism transmission can always maintain its stability and reliability.

[0017] Furthermore, the passive sprocket is fixed by screwing two half sprockets through a plurality of threaded fasteners. With the above structure, it is more convenient to install. When the test conditions change and the test parts need to be replaced, the passive sprocket and chain can be directly disassembled and installed without disassembling other parts associated with the test bench.

[0018] Furthermore, the structure of the adjustable eccentric shaft is as follows: the upper fixed shaft and the lower fixed shaft both include a circular shaft neck and a circular disk fixed at the inner end of the circular shaft neck, and the inner end surface of the circular disk is fixed with two symmetrical vertical connection blocks, and each adjustment bolt is screwed in sequence with a threaded hole of a vertical connection block, a threaded hole provided on the diameter line of one end of the adjustable eccentric shaft, and a threaded hole of the other vertical connection block, so as to synchronously adjust the eccentricity between the axis of the adjustable eccentric shaft and the axis of the fixed shaft in radial direction up and down; the adjustable eccentric shaft also includes a fixing structure to prevent the adjustment bolt from rotating automatically after adjustment. After adopting the above structure, as long as two wrenches are used to clamp the hexagonal column of the bolt or insert the hexagonal hole and rotate the bolt up and down in the same direction at the same time, the eccentricity can be increased or decreased, and the adjustment is flexible, stable, accurate and reliable.

[0019] Furthermore, two pairs of first transverse elongated through holes are symmetrically arranged on both sides of the center hole for passing the eccentric shaft on the upper horizontal plate of the frame, and two symmetrically arranged sway cylinder mounting seats are fixed by bolts passing through the bolt holes and the first transverse elongated through holes and matching nuts. Each sway cylinder mounting seat has a vertical guide rail on the inner side surface, and an L-shaped upper sway cylinder mounting block and a lower sway cylinder mounting block are slidably fitted on the vertical guide rail. Each sway cylinder mounting seat has a plurality of first vertical elongated through holes on the vertical plate, and the upper and lower L-shaped sway cylinder mounting blocks are respectively fixed by a plurality of threaded fasteners passing through the respective through holes on the sway cylinder mounting blocks and the first vertical elongated through holes. The upper sway cylinder mounting block and the lower sway cylinder mounting block are respectively provided with through holes fixed to the outer rings of the first rolling bearings, and the top column and the bottom column of each sway cylinder are fixed to the inner rings of the respective first rolling bearings. After adopting the above structure, the distance between the two symmetrical swing cylinder mounting seats and the eccentric shaft, the height position of the upper swing cylinder mounting block and the height position of the lower swing cylinder mounting block can be adjusted, making it more convenient and faster to install or disassemble the swing cylinder for testing, and can adapt to the simulated friction test of the friction pair of swing cylinders and radial piston swing cylinder hydraulic motors of different specifications, making the test range wider and more versatile. After being fixed with bolts, its stability and position accuracy can be guaranteed.

[0020] Furthermore, a pair of second transverse elongated through holes which are 90° to each other with respect to the first transverse elongated through hole are provided on the outer side of the center hole for passing the eccentric shaft on the upper transverse plate of the frame, and an upper fixed shaft mounting seat is fixed by screwing through bolts passing through the bolt through holes and the second transverse elongated through holes and matching nuts, and a vertical guide rail is provided on the inner side surface of the upper fixed shaft mounting seat, and a T-shaped upper fixed shaft mounting block is slidably fitted on the vertical guide rail, and a plurality of second vertical elongated through holes are provided on the vertical plate of the upper fixed shaft mounting seat, and the T-shaped upper fixed shaft mounting block is screwed and fixed to the upper fixed shaft mounting seat by threaded fasteners passing through a plurality of through holes and the second vertical elongated through holes on the upper fixed shaft mounting block, and a through hole which is fixed to the outer ring of a second rolling bearing is provided on the upper fixed shaft mounting block, and the circular shaft neck of the upper fixed shaft is aligned with the inner ring of the second rolling bearing Fixed; a pair of third transverse elongated through holes are arranged parallel to the second transverse elongated through hole on the outer side of the center hole for passing the rotating shaft of the first servo motor on the lower horizontal plate of the frame, and a lower fixed shaft mounting seat is fixed by bolts passing through the bolt through holes and the third transverse elongated through holes and matching nuts, and a vertical guide rail is provided on the inner side surface of the lower fixed shaft mounting seat, and a T-shaped lower fixed shaft mounting block is slidably fitted on the vertical guide rail, and a plurality of third vertical elongated through holes are provided on the vertical plate of the lower fixed shaft mounting seat, and the T-shaped lower fixed shaft mounting block is fixed by screwing and fastening with threads passing through a plurality of through holes on the lower fixed shaft mounting block and the third vertical elongated through hole, and a through hole fixed to the outer ring of a third rolling bearing is provided on the lower fixed shaft mounting block, and the circular shaft neck of the lower fixed shaft is fixed to the inner ring of the third rolling bearing. After the upper fixed shaft and the lower fixed shaft and the frame adopt the above installation structure, the distance between the two symmetrical swing cylinder mounting seats and the adjustable eccentric shaft, the height position of the upper swing cylinder mounting block and the height position of the lower swing cylinder mounting block are all adjustable, making it more convenient and faster to install or disassemble the swing cylinder for testing, and can adapt to the simulated friction test of the friction pair of swing cylinders and radial piston swing cylinder hydraulic motors of different specifications, making the test range wider and more versatile. After being fixed with bolts, its stability and position accuracy can be guaranteed.

[0021] Furthermore, the frame has an annular oil receiving basin located below the friction arc surface and connected to the oil tank through an oil return pipe, and a truncated cone-shaped oil guide cover with a small top and a large bottom is fixed and liquid-sealed at the lower part of the outer circumference of the shaft sleeve and is used to guide the oil flowing down from the friction arc surface into the annular oil receiving basin. With the above structure, the good lubrication of the friction arc surface can be ensured, and the used oil can be recovered to reduce waste and ensure that other parts below are dry and clean. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 The structure of the preferred embodiment of the simulated friction test bench of the present invention is shown in FIG. Figure 1 ( Figure 1-Figure 9 The fastening screws, bolts and nuts are not shown).

[0023] Figure 2 yes Figure 1 Schematic diagram of the explosion structure with some parts exploded.

[0024] Figure 3 yes Figure 2 Schematic diagram of the enlarged structure of A.

[0025] Figure 4 yes Figure 2 Schematic diagram of the exploded structure from a different angle with some components exploded out.

[0026] Figure 5 The structure of the preferred embodiment of the simulated friction test bench of the present invention is shown in FIG. Figure 2

[0027] Figure 6 yes Figure 5 Schematic diagram of the enlarged structure of B.

[0028] Figure 7 It is a schematic structural diagram (enlarged) of the passive sprocket in the preferred embodiment of the simulated friction test bench of the present invention.

[0029] Figure 8 It is a structural schematic diagram of the preferred embodiment of the simulated friction test bench of the present invention, highlighting the mounting seat, the eccentric shaft and the swing cylinder (the bushing is exploded).

[0030] Fig. 9 yes Figure 8 Schematic diagram of the enlarged structure of the exploded sleeve.

[0031] Fig.10 It is a connection diagram of the hydraulic loading system in the preferred embodiment in the loading state.

[0032] Fig.11 It is a connection diagram of the hydraulic loading system in the preferred embodiment in the unloading state.

[0033] As shown in the figure:

[0034] 1. frame, 11. upper transverse plate, 111. first center hole, 112. first transverse long through hole, 113. second transverse long through hole, 114. first transverse dovetail guide rail, 115. second transverse dovetail guide rail, 12. lower transverse plate, 121. third transverse dovetail guide rail, 13. column;

[0035] 2. eccentric shaft, 21. first servo motor, 22. fastening nut, 23. upper fixed shaft, 231. circular journal, 232. circular disk, 233. vertical connecting block, 2331. second threaded hole, 24. lower fixed shaft, 25. adjustable eccentric shaft, 251. core shaft, 2511. third threaded hole, 252. bushing, 2521. radial convex ring friction arc surface, 253. needle roller, 254. cage, 26. adjusting bolt, 27. semicircular block, 28. fourth rolling bearing;

[0036] 3. Swing cylinder, 31. Piston, 311. Friction end surface, 32. Top column, 321. Oil inlet joint, 33. Bottom column, 331. Plug;

[0037] 4. micro-swing angle generating mechanism, 41. second servo motor, 42. motor bracket, 43. driving sprocket, 44. driven sprocket, 441. right half sprocket, 4411. first screw through hole, 442. left half sprocket, 4421. first threaded hole, 45. endless chain, 46. spring tensioner;

[0038] 5. Swing cylinder mounting seat, 51. Swing cylinder mounting seat base plate, 511. First bolt through hole, 512. First vertical guide rail, 52. First transverse dovetail groove, 53. Upper swing cylinder mounting block, 531. First vertical slide groove, 54. Lower swing cylinder mounting block, 541. Second vertical slide groove, 542. Bolt through hole, 55. First vertical elongated through hole, 56. First rolling bearing, 57. First through hole;

[0039] 6. upper fixed shaft mounting seat, 61. upper fixed shaft mounting seat base plate, 611. second bolt through hole, 612. second vertical guide rail, 613. second vertical elongated through hole, 62. second transverse dovetail groove, 63. upper fixed shaft mounting block, 631. outer half hoop, 632. inner half hoop, 64. second through hole, 65. second rolling bearing;

[0040] 7. Lower end fixed shaft mounting seat, 71. Third transverse dovetail groove;

[0041] 8. Hydraulic loading system, 81. Oil tank, 82. Hydraulic pump, 83. Overflow valve, 84. Two-position three-way solenoid valve, 85. Throttle valve, 86. Pressure reducing valve, 87. Oil pipe, 88. Circular oil receiving basin. DETAILED DESCRIPTION

[0042] The specific embodiments of the present invention are further described below in conjunction with the accompanying drawings. It should be noted that the description of these specific embodiments is used to help understand the present invention, but does not constitute a limitation of the present invention. In addition, the technical features involved in each specific embodiment of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0043] like Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 , Figure 6 , Figure 7 , Figure 8 , Fig. 9 , Fig.10 and Fig.11 shown.

[0044] The simulated friction test bench of the radial piston swing cylinder hydraulic motor friction pair in the preferred embodiment of the present invention includes a hydraulic loading system 8 and a frame 1. The simulated friction test bench also includes a controller, such as an MCU, also called a micro control unit, or a single chip microcomputer. The simulated friction test bench also includes a power on button, a power off button, the pressure sensor, temperature sensor, hydraulic pump 82 described below, etc. The power on button, power off button, pressure sensor, temperature sensor, hydraulic pump 82 such as the relay of the hydraulic pump 82, etc. are all electrically connected to the controller. The above is the prior art.

[0045] The simulated friction test bench of the friction pair of the radial piston swing cylinder hydraulic motor of the preferred embodiment of the present invention also includes an eccentric shaft 2 and a first servo motor 21 mounted on the frame 1. The eccentric shaft 2 includes an upper fixed shaft 23 and a lower fixed shaft 24 connected to the frame 1 via respective rolling bearings such as the second rolling bearing 65. The lower fixed shaft 24 is coaxially connected to the first servo motor 21. For example, the first servo motor 21 can be fixed such as being screwed to the bottom surface of the lower cross plate 12 via a plurality of screws. The rotating shaft of the first servo motor 21 passes upward through the center hole of the lower cross plate 12 such as the second center hole, and is coaxially connected to the circular journal of the lower fixed shaft 24 via a coupling 29. The circular journal 231 of the upper fixed shaft 23 is coaxial with the circular journal of the lower fixed shaft 24. The eccentric shaft 2 also includes an adjustable eccentric shaft 25 whose axis is adjustable to the axis of the fixed shaft. It is not difficult to understand that here, it means that the distance between the axis of the adjustable eccentric shaft 25 and the axis of the upper and lower fixed shafts is adjustable. The adjustable eccentric shaft 25 includes a core shaft 251 and a sleeve 252. The sleeve 252 has a radial convex ring friction arc surface 2521 on its outer circumference. The core shaft 251 and the sleeve 252 are rotatably connected by the respective needle roller parts of a plurality of needle roller bearings. Figure 7 The three needle roller bearings shown have three sets of needle roller parts, each set of needle roller parts may include a plurality of needle rollers 253 evenly distributed in a ring shape, and may also be provided with a retaining frame 254 or a bearing frame for the needle rollers 253. The eccentric shaft 2 may also be called an eccentric shaft assembly.

[0046] The frame 1 includes an upper cross plate 11, a lower cross plate 12 and four columns 13. Two swing cylinders 3 that need to be simulated friction tests are symmetrically arranged on the frame 1 as on the upper cross plate 11. The hydraulic loading system 8 is connected to the hydraulic chambers in the two swing cylinders 3. The friction end faces 311 of the pistons 31 of the respective swing cylinders 3 are always in contact with the radial convex ring friction arc surface 2521 and are lubricated by the oil seeping out of the center hole of the piston 31. The center hole of the piston 31 is also called the center oil hole, and its diameter is generally 1-2 mm. The radial convex ring friction arc surface 2521 can also be called a friction spherical surface. It is not difficult to understand that the symmetry is that the structure is exactly the same, but the direction is exactly opposite. For example, the shape of the radial convex ring friction arc surface 2521 is consistent with the shape of the friction pair of the eccentric shaft of the real radial piston swing cylinder hydraulic motor, the surface morphology is consistent, the surface roughness is consistent, the surface hardness is consistent, and the material is consistent. The two swivel cylinders 3 are both swivel cylinders 3 that are actually used in the internal five-star swivel cylinder motor and need to be tested. Each swivel cylinder 3 has a top column 32 and a bottom column 33 .

[0047] The simulated friction test bench for the friction pair of the radial piston swing cylinder hydraulic motor in the preferred embodiment of the present invention also includes a micro-swing angle generating mechanism 4 for simulating the reciprocating swing friction between the crank of the radial piston swing cylinder hydraulic motor and the swing cylinder. The micro-swing angle generating mechanism 4 is arranged on the frame 1, connected to the sleeve 252 of the adjustable eccentric shaft 25, and controlled by the second servo motor 41 to repeatedly rotate forward and reverse for several tens of degrees, which can be between 5° and 20°, such as 20° for forward and reverse rotation.

[0048] The preferred embodiment of the structure of the micro-swing angle generating mechanism 4 is as follows: the second servo motor 41 is arranged on the frame 1, such as being fixed on the lower horizontal plate 12 via a motor bracket 42, a driving sprocket 43 is coaxially fixed on the rotating shaft of the second servo motor 41, a driven sprocket 44 is coaxially fixed on the shaft sleeve 252 of the adjustable eccentric shaft 25, and an annular chain 45 is meshed with the driving sprocket 43 and the driven sprocket 44. It is not difficult to understand that the annular chain 45 is meshed with the teeth of the driving sprocket 43 and the teeth of the driven sprocket 44. The two outer sides of the middle section of the annular chain 45 are fixed on the frame 1, such as the bottom surface of the lower horizontal plate 12, respectively, for always tensioning the annular chain 45. The micro-swing angle generating mechanism 4 can also be called a micro-swing angle generating mechanism. The driven sprocket 44 is also called a driven sprocket. The spring tensioner 46 is a commercially available spring tensioner.

[0049] The driven sprocket 44 can be fixed by screwing two sprocket halves via a plurality of threaded fasteners, see Figure 6 For example, one half of the sprocket, such as the right half sprocket 441, has two screw holes, such as two first screw holes 4411, and one half of the sprocket, such as the left half sprocket 442, has two corresponding threaded holes, such as first threaded holes 4421. Two screws pass through their respective first screw holes 4411 and are tightened in their respective first threaded holes 4421. The first screw holes 4411 may be countersunk holes.

[0050] The structure of the adjustable eccentric shaft 25 is preferably as follows: the upper fixed shaft 23 and the lower fixed shaft 24 both include a circular journal 231 and a circular disk 232 fixed to the inner end of the circular journal 231, and the inner end surface of the circular disk 232 is fixed with two symmetrical vertical connecting blocks 233, and each adjusting bolt 26 is screwed in sequence with a threaded hole of a vertical connecting block 233, a threaded hole provided on the diameter line of one end of the adjustable eccentric shaft 25, and a threaded hole of another vertical connecting block 233, such as the second threaded hole 2331, so as to synchronously and radially adjust the eccentric distance between the axis of the adjustable eccentric shaft 25 and the axis of the fixed shaft up and down. It is not difficult to understand that the circular journal 231 of the upper fixed shaft 23 is above the circular disk 232, and the circular journal of the lower fixed shaft 24 is below the circular disk, the two vertical connecting blocks 233 of the upper fixed shaft 23 are below the circular disk 232, and the two vertical connecting blocks of the lower fixed shaft 24 are above the circular disk. Figure 2 and Figure 3 As shown, the two vertical connecting blocks 233 may be connected by a hollow semicircular block 27 to increase strength. The adjusting bolt 26 here can also be called a screw with a large head with an external hexagon or a round large head with an internal hexagon hole, and the large head is convenient for a wrench to engage. Figure 2 , the adjusting bolt 26 can also be rotated by one end of the big head through a rolling bearing such as the fourth rolling bearing 28 to fit in a through hole of a vertical connection block 233, while the middle section of the adjusting bolt 26 is still screwed into each end of the core shaft 251, such as the third threaded hole 2511 at the upper end and the third threaded hole at the lower end, and the free end of the adjusting bolt 26 is still screwed into the threaded hole of another vertical connection block, such as the second threaded hole 2331. The adjustable eccentric shaft 25 also includes a fixing structure to prevent the adjusting bolt 26 from automatically rotating after adjustment, such as a fastening nut 22 can be provided on the free end of the adjusting bolt 26 to lock with a vertical connection block 233. The vertical connection block 233 can also be called a vertical connection plate. The semicircular block 27 can also be called a semicircular plate. The distance between the axis of the core shaft 251 of the eccentric shaft 2 and the axis of the upper fixed shaft 23 and the axis of the lower fixed shaft 24, i.e., the axis of the motor shaft, can be 2-5 cm.

[0051] The upper horizontal plate 11 of the frame 1 has two pairs of first transverse long through holes 112 symmetrically arranged on both sides of the center hole for the eccentric shaft 2, such as the first center hole 111. The two symmetrically arranged swing cylinder mounting seats 5 are fixed by bolts passing through bolt holes, such as the first bolt through hole 511 and the first transverse long through hole 112, and the matching nuts are screwed together, that is, the bottom plate of the swing cylinder mounting seat base plate 51 is provided with a first transverse long through hole 112, and the inner side surface of the vertical plate of each swing cylinder mounting seat base plate 51 is provided with a vertical guide rail, such as the first vertical guide rail 512, and the first vertical guide rail 512 is slidably matched with an L-shaped The upper swing cylinder mounting block 53 and the lower swing cylinder mounting block 54 are not difficult to understand. The L-shaped upper swing cylinder mounting block 53 and the lower swing cylinder mounting block 54 are both provided with vertical slide grooves such as the first vertical slide groove 531 and the second vertical slide groove 541 that are slidably matched with the first vertical guide rail 512. Each swing cylinder mounting seat 5 has a plurality of vertical plates such as two first vertical elongated through holes 55. The upper and lower L-shaped swing cylinder mounting blocks are both fixed by a plurality of threaded fasteners such as bolts that pass through respective bolt through holes 542 or bolt through holes and the first vertical elongated through holes 55 on the swing cylinder mounting blocks and are screwed and fixed with nuts. The upper swing cylinder mounting block 53 and the lower swing cylinder mounting block 54 are both provided with through holes such as the first through holes 57 that are fixed with the outer rings of the respective first rolling bearings 56 such as interference fit. The top column 32 and the bottom column 33 of each swing cylinder 3 are both fixed with the inner rings of the respective first rolling bearings 56 such as interference fit. In order to align the axes of the pistons 31 of the two swing cylinders 3 after installation with the axis of the core shaft 251, a first transverse dovetail guide rail 114 and a first transverse dovetail groove 52 are provided on the bottom surface of the swing cylinder mounting seat 5 and the top surface of the upper transverse plate 11, and the width bisectors of the first transverse dovetail guide rail 114 and the first transverse dovetail groove 52 are on the same vertical plane as the width bisectors of the vertical guide rail and the vertical slide groove. It is not difficult to understand that the first transverse dovetail guide rail 114 is provided on the upper transverse plate 11, and the first transverse dovetail groove 52 is provided on the bottom surface of the swing cylinder mounting seat 5.

[0052] The center hole for passing the eccentric shaft 2 on the upper horizontal plate 11 of the frame 1, such as the first center hole 111, has a pair of second transverse elongated through holes 113 at 90 degrees to the first transverse elongated through hole 112 on the outer side, and an upper fixed shaft mounting seat 6 is screwed and fixed by bolts and matching nuts passing through bolt through holes, such as the second bolt through holes 611 provided on the bottom plate of the upper fixed shaft mounting seat base plate 61 and the second transverse elongated through holes 113. The inner side surface of the vertical plate of the upper fixed shaft mounting seat base plate 61 of the upper fixed shaft mounting seat 6 is provided with a vertical guide rail such as the second vertical guide rail 612, and the second vertical guide rail 612 is slidably matched with an upper fixed shaft mounting block 63 with a vertical slide groove and in a T shape, and the vertical plate of the upper fixed shaft mounting seat 6 is provided with multiple, such as four, second vertical elongated through holes 613, and the T-shaped upper fixed shaft mounting block 63 is screwed and fixed to the upper fixed shaft mounting seat 6 by threaded fasteners passing through multiple through holes and the second vertical elongated through holes 613 on the upper fixed shaft mounting block, and the upper fixed shaft mounting block 63 is provided with a second through hole 64 fixed to the outer ring of a second rolling bearing 65, and the circular shaft neck 231 of the upper fixed shaft 24 is fixed to the inner ring of the second rolling bearing 65 such as by interference fit.

[0053] It is not difficult to understand that the structure and connection relationship of the lower end fixed shaft mounting seat 7 are the same as those of the upper end fixed shaft mounting seat 6, so some parts are not shown or marked: the lower cross plate 12 of the frame 1 has a center hole for passing the rotating shaft of the first servo motor 21, such as a pair of third transverse elongated through holes arranged vertically parallel to the second transverse elongated through hole 113 on the outer side of the second center hole, and the lower end fixed shaft mounting seat 7 is fixed by the bolt through hole of the bottom plate of the lower fixed seat substrate and the bolt and the matching nut of the third transverse elongated through hole through the lower end, and the lower end fixed A vertical guide rail is provided on the inner side surface of the vertical plate of the lower fixed seat substrate of the shaft mounting seat 7, and a T-shaped lower fixed shaft mounting block is slidably fitted on the vertical guide rail. A plurality of third vertical elongated through holes are provided on the vertical plate of the lower fixed shaft mounting seat 7, and the T-shaped lower fixed shaft mounting block is fixed by screwing through a plurality of through holes on the lower fixed shaft mounting block and the third vertical elongated through holes, and a through hole is provided on the lower fixed shaft mounting block for fixing the outer ring of a third rolling bearing, and the circular shaft neck of the lower fixed shaft is fixed to the inner ring of the third rolling bearing as if by interference fit.

[0054] A second transverse dovetail guide rail 115 and a second transverse dovetail groove 62 are provided on the bottom surface of the upper fixed shaft mounting seat 6 and the top surface of the upper horizontal plate 11, and the extension line of the second transverse dovetail guide rail 115 and the extension line of the first transverse dovetail guide rail 114 are mutually 90 degrees. It is not difficult to understand that the second transverse dovetail guide rail 115 is provided on the upper horizontal plate 11. A third transverse dovetail guide rail 121 and a third transverse dovetail groove 71 are provided on the bottom surface of the lower fixed shaft mounting seat 7 and the top surface of the lower horizontal plate 12, and the width bisector of the second transverse dovetail guide rail 115 and the width bisector of the third transverse dovetail guide rail 121 are on the same vertical plane, so that the axis of the circular journal 231 of the upper fixed shaft 23 after installation and the axis of the circular journal of the lower fixed shaft 24 are on the same vertical line. For easy installation, the second through hole 64 at the end of the transverse plate of the T-shaped upper fixed shaft mounting block 63 and the through hole at the end of the transverse plate of the T-shaped lower fixed shaft mounting block can be composed of two semicircular holes, and can be fixed by multiple screws. For example, each outer half clamp 631 has two screw holes, which can be countersunk holes, and each inner half clamp 632 can have two corresponding threaded holes. A screw passes through each screw hole and is tightened in each threaded hole. The bolt holes on the above-mentioned mounting seat can be waist-shaped holes to increase the double adjustment range. The rolling bearings generally use ball bearings.

[0055] like Figure 1-11 shown.

[0056] The hydraulic loading device can basically adopt the original radial piston swing cylinder hydraulic motor such as the five-star swing cylinder hydraulic motor, such as the swing cylinder 3 and the piston 31 therein are any two of the original five swing cylinders, and the diameter of the oil hole that longitudinally passes through the center of the piston 31 is still 1-2 mm. However, in order to adapt to this test bench, some corresponding improvements have been made. For example, the oil inlet holes of the two swing cylinders 3 can be set on the top column 32 and connected with the inner cavity of the swing cylinder 3. The oil inlet hole is provided with an oil inlet joint 321 connected to the oil pipe 87; the bottom column 33 can be provided with an oil outlet, and the oil outlet hole is provided with a plug 331. After the test is completed, before the swing cylinder 3 on the test bench is removed, the plug 331 is unscrewed to release the oil in the swing cylinder 3 and then the plug 331 is tightened, so that it can be installed on the five-star swing cylinder hydraulic motor later and then injected with clean oil. The hydraulic loading device 8 can also be called a hydraulic system.

[0057] The frame 1 has an annular oil collecting basin 88 located below the radial convex ring friction arc surface 2521 and connected to the oil tank 81 by an oil return pipe 87. The lower part of the outer circumference of the sleeve 252 is fixed and liquid-sealed with a truncated cone-shaped oil guide cover (not shown in the figure) which is small at the top and large at the bottom and is used to guide the oil flowing down from the radial convex ring friction arc surface 2521 into the annular oil collecting basin 88.

[0058] It is not difficult to understand that in order to express the intuition in the figure, Fig.10 and Fig.11The fuel tanks 81 in the figure are drawn as multiple, but there is actually only one large fuel tank.

[0059] The hydraulic pump 82 is connected to the two-position three-way solenoid valve 84 and the overflow valve 83. The overflow valve 83 and the two-position three-way solenoid valve 84 are respectively connected to the oil tank 81. The two-position three-way solenoid valve 84 is connected to the throttle valve 85, also known as the steady flow valve 85. The throttle valve 85 is connected to the pressure reducing valve 86. The pressure reducing valve 86 is connected to both the swing cylinders 3 through the oil inlet connector 321. The pressure reducing valve 86 is also connected to the oil tank 81. The connections are all connected through the oil pipe 87. It is not difficult to understand that the pressure reducing valve 86, the two-position three-way valve 84 and the overflow valve 83 are all electrically connected to the controller, and the relay of the hydraulic pump 82 is also electrically connected to the controller.

[0060] The oil pressure can be 10MPa. The hydraulic pump 82 can use the commercially available A7V250 plunger pump, the displacement of which can be 250mL / r, the maximum speed is 1500r / min, and the flow rate is 375L / min. In order to detect relevant indicators, the simulated friction test bench can be provided with a pressure sensor, such as one that can be installed at the oil inlet joint 321 to measure the inlet pressure input to the friction test bench swing cylinder 3. A temperature sensor can be provided, such as one that can be installed at the return oil end of the oil pipe 87 of the oil tank 81 to grasp the change of oil temperature.

[0061] The rotation speed and torque of the first servo motor 21 can be directly read from the driver of the motor.

[0062] Simulation can also be understood as restoration as much as possible. Coaxial means coaxial lines. Threaded fasteners such as screws or bolts and nuts. The adjustable eccentric shaft 25 refers to the axis of the core shaft 251 and the axis of the fixed shaft, which are adjustable. The fixed shaft is the upper fixed shaft 23 and the lower fixed shaft 24. The friction pair can also be called a transmission friction pair or a transmission pair. The core shaft 251 and the multiple needle rollers 253 and the sleeve 252 distributed in an annular shape, the core shaft 251 can be regarded as the inner ring extended at both ends, the sleeve 252 can be regarded as the outer ring extended at both ends, and the multiple needle rollers 253 distributed in an annular shape can be regarded as the needle rollers 253 of the needle bearing and the retaining frame 254 or the bearing frame part. The radial convex ring friction arc surface 2521 can also be called a friction spherical surface. The first servo motor 21 can be 7.5kw and the rated speed can be 1500r / min.

[0063] When it is necessary to test the two swing cylinders 3 in the inner five-star swing cylinder hydraulic motor, first select the swing cylinders 3 to be tested, mark the two swing cylinders 3, and then install them on the simulated friction test bench of the friction pair of the radial piston swing cylinder hydraulic motor. Connect the oil inlet joints 321 of the two swing cylinders 3 with the oil pipe 87, so that the friction end faces 311 of the pistons 31 of the two symmetrically arranged swing cylinders 3 are both under the pressure of the hydraulic oil of the hydraulic loading system 8. The radial convex ring friction On the arc surface 2521; according to the test requirements, pre-adjust the flow of the throttle valve 85 and the pressure of the pressure reducing valve 86; then press the power on button, the controller controls the first servo motor 21, the second servo motor 41 and the hydraulic pump to start and run, and at the same time conducts the two-position three-way solenoid valve 84 and the pressure reducing valve 86; during the operation, the controller controls the on and off of the overflow valve 83 to return the oil exceeding the predetermined flow and predetermined pressure to the oil tank 81, and the oil in the annular oil receiving basin 88 also returns to the oil tank 81 due to the position difference. The speed, torque of the first servo motor 21 and the oil pressure and temperature of the hydraulic loading system 8 can be detected during the test and displayed on the display screen; after the test is completed, press the power off button; at this time, the two-position three-way solenoid valve 84 is switched to the oil return state by the controller, and the oil in the oil pipe 87 returns to the oil tank 81 through the position difference, such as the controller controls the pressure reducing valve 86 and the two-position three-way solenoid valve 84 to return oil to the oil tank 81. After the test is completed, the friction pair can be disassembled, and the plug 331 can be loosened above the oil tank 81 to release the test oil in the swing cylinder 3. The surface properties of the radial convex ring friction arc surface 2521 and the friction end surface 311 of the piston 31 are measured on the test instrument, such as using a surface roughness instrument, an optical measuring instrument, etc. to measure the surface roughness and surface morphology of the friction and wear surface, and using a scanning electron microscope to measure the migration amount of elements on the friction and wear surface, such as measuring the migration of copper elements to the steel surface at the copper / steel friction pair interface, and then analyzing and evaluating the changes in the friction and wear interface, and obtaining the friction loss and friction coefficient related data of the radial piston swing cylinder hydraulic motor friction pair under different working conditions. The plunger in the radial piston swing cylinder is also called a piston.

[0064] The above unmarked parts, structures or quantities are not shown in the figures, and some parts shown in the figures are not marked in the text. The drawings are only for reference. If there is any inconsistency between the drawings and the text description or between the drawings, the text description shall prevail.

[0065] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A simulated friction test bench for a radial piston swing cylinder hydraulic motor friction pair, comprising a hydraulic loading system and a frame, characterized in that: It also includes an eccentric shaft and a first servo motor installed on the frame, the eccentric shaft includes an upper fixed shaft and a lower fixed shaft connected to the frame via respective rolling bearings, the lower fixed shaft is coaxially connected to the first servo motor, the upper fixed shaft is coaxial with the lower fixed shaft, the eccentric shaft also includes an adjustable eccentric shaft whose axis is at an adjustable distance from the axis of the fixed shaft, the adjustable eccentric shaft includes a core shaft and a sleeve, a radial convex ring friction arc surface is provided on the outer circumference of the sleeve, and the core shaft and the sleeve are rotatably connected by respective needle roller parts of a plurality of needle roller bearings; Two swing cylinders to be tested in simulated friction are symmetrically arranged on the frame. The hydraulic loading system is connected to the hydraulic chambers in the two swing cylinders. The friction end faces of the pistons of the respective swing cylinders are always in contact with the radial convex ring friction arc surface and lubricated by the oil seeping from the center hole of the piston. It also includes a micro-swing angle generating mechanism for simulating the reciprocating swing friction between the crank of the radial piston swing cylinder hydraulic motor and the swing cylinder. The micro-swing angle generating mechanism is arranged on the frame, connected to the sleeve of the adjustable eccentric shaft, and is controlled by the second servo motor to repeatedly rotate forward and reverse for dozens of degrees.

2. The simulated friction test bench for the friction pair of the radial piston swing cylinder hydraulic motor according to claim 1 is characterized in that: The structure of the micro-swing angle generating mechanism is as follows: the second servo motor is arranged on the frame, a driving sprocket is coaxially fixed on the rotating shaft of the second servo motor, a passive sprocket is coaxially fixed on the sleeve of the adjustable eccentric shaft, an annular chain is meshed on the driving sprocket and the passive sprocket, and two outer sides of the middle section of the annular chain are respectively provided with a spring tensioner fixed on the frame for always tensioning the annular chain.

3. The simulated friction test bench for the friction pair of the radial piston swing cylinder hydraulic motor according to claim 2 is characterized in that: The driven sprocket is fixed by screwing two half sprockets via a plurality of threaded fasteners.

4. The simulated friction test bench for the friction pair of the radial piston swing cylinder hydraulic motor according to claim 1 is characterized in that: The structure of the adjustable eccentric shaft is as follows: the upper fixed shaft and the lower fixed shaft both include a circular shaft neck and a circular disk fixed at the inner end of the circular shaft neck, and the inner end surface of the circular disk is fixed with two symmetrical vertical connecting blocks, each with an adjusting bolt which is screwed in sequence with a threaded hole of a vertical connecting block, a threaded hole arranged on the diameter line of one end of the adjustable eccentric shaft and a threaded hole of the other vertical connecting block, so as to synchronously and radially adjust the eccentric distance between the axis of the adjustable eccentric shaft and the axis of the fixed shaft up and down; the adjustable eccentric shaft also includes a fixing structure for preventing the adjusting bolt from rotating on its own after adjustment.

5. The simulated friction test bench for the friction pair of radial piston swing cylinder hydraulic motor according to claim 1 is characterized in that: Two pairs of first transverse elongated through holes are symmetrically arranged on both sides of the center hole for the eccentric shaft to pass through. Two symmetrically arranged sway cylinder mounting seats are fixed by bolts passing through the bolt holes and the first transverse elongated through holes and matching nuts. There is a vertical guide rail on the inner side of each sway cylinder mounting seat, and an L-shaped upper sway cylinder mounting block and a lower sway cylinder mounting block are slidably fitted on the vertical guide rail. There are multiple first vertical elongated through holes on the vertical plate of each sway cylinder mounting seat. The upper and lower L-shaped sway cylinder mounting blocks are fixed by screwing through their respective through holes and the first vertical elongated through holes with their respective multiple threaded fasteners. The upper sway cylinder mounting block and the lower sway cylinder mounting block are both provided with through holes fixed to their respective first rolling bearing outer rings, and the top column and bottom column of each sway cylinder are fixed to their respective first rolling bearing inner rings.

6. The simulated friction test bench for the friction pair of the radial piston swing cylinder hydraulic motor according to claim 5 is characterized in that: A pair of second transverse elongated through holes which are 90° to each other with respect to the first transverse elongated through hole are arranged on the outer side of the center hole for passing the eccentric shaft on the upper transverse plate of the frame; an upper fixed shaft mounting seat is fixed by bolts passing through the bolt through holes and the second transverse elongated through holes and matching nuts; a vertical guide rail is arranged on the inner side surface of the upper fixed shaft mounting seat; a T-shaped upper fixed shaft mounting block is slidably matched on the vertical guide rail; a plurality of second vertical elongated through holes are arranged on the vertical plate of the upper fixed shaft mounting seat; the T-shaped upper fixed shaft mounting block is fixed by screwing with the upper fixed shaft mounting seat by threaded fasteners passing through a plurality of through holes and the second vertical elongated through holes on the upper fixed shaft mounting block; a through hole which is fixed to the outer ring of a second rolling bearing is arranged on the upper fixed shaft mounting block; and a circular journal of the upper fixed shaft is fixed to the inner ring of the second rolling bearing; A pair of third transverse elongated through holes are arranged parallel to the second transverse elongated through hole on the outer side of the center hole for the rotating shaft of the first servo motor passing through the lower horizontal plate of the frame, and a lower fixed shaft mounting seat is fixed by bolts passing through the bolt through holes and the third transverse elongated through holes and matching nuts, and a vertical guide rail is provided on the inner side surface of the lower fixed shaft mounting seat, and a T-shaped lower fixed shaft mounting block is slidably fitted on the vertical guide rail, and a plurality of third vertical elongated through holes are provided on the vertical plate of the lower fixed shaft mounting seat, and the T-shaped lower fixed shaft mounting block is fixed by threaded fasteners passing through a plurality of through holes on the lower fixed shaft mounting block and the third vertical elongated through hole, and a through hole fixed to the outer ring of a third rolling bearing is provided on the lower fixed shaft mounting block, and the circular shaft neck of the lower fixed shaft is fixed to the inner ring of the third rolling bearing.

7. The simulated friction test bench for the friction pair of radial piston swing cylinder hydraulic motor according to claim 1 is characterized in that: The frame is provided with an annular oil collecting basin which is located below the friction arc surface and connected to the oil tank by an oil return pipe. The lower part of the outer circumference of the sleeve is fixed and liquid-sealed with a truncated cone-shaped oil guide cover which is small at the top and large at the bottom and is used to guide the oil flowing down the friction arc surface into the annular oil collecting basin.

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