WALKING DEVICE WITH SELF-ADAPTIVE TRACK GAUGE AND WHEEL PRESSURE FOR PREVENTING RAIL GNAWING
20220297980 · 2022-09-22
Inventors
Cpc classification
B66C7/08
PERFORMING OPERATIONS; TRANSPORTING
B66C9/16
PERFORMING OPERATIONS; TRANSPORTING
International classification
B66C9/16
PERFORMING OPERATIONS; TRANSPORTING
B66C7/08
PERFORMING OPERATIONS; TRANSPORTING
Abstract
A walking device with a self-adaptive track gauge and wheel pressure for preventing rail gnawing comprises a first rail, a second rail parallel to the first rail, a driving trolley disposed on the first rail, a driven trolley disposed on the second rail, two beams connected between the driving trolley and the driven trolley and each of which having a sliding groove, and an electric hoist disposed on the two beams. The driving trolley is hung on the first rail through a first bearing wheel, and the driven trolley is hung on the second rail through a second bearing wheel. The driving trolley is connected with a driving motor, and the driving trolley is configured to drive the driven trolley to synchronously move along length directions of the first rail and the second rail through the two beams, so that the electric hoist is driven to synchronously move.
Claims
1. A walking device with a self-adaptive track gauge and wheel pressure for preventing rail gnawing, comprising: a first rail, a second rail parallel to the first rail, a driving trolley disposed on the first rail, a driven trolley disposed on the second rail, two beams connected between the driving trolley and the driven trolley, each of which has a sliding groove, and an electric hoist disposed on the two beams, wherein: the driving trolley is hung on the first rail through a first bearing wheel, the driven trolley is hung on the second rail through a second bearing wheel, the driving trolley is fixedly connected to hole grooves of the two beams through a first bolt group, the driven trolley is movably connected to the sliding groove of each of the two beams through a double-headed bolt group, the electric hoist is fixed on a sliding frame through a second bolt group, the sliding frame is connected with a T-shaped bolt group and is slidingly connected to the sliding groove of each of the two beams through the T-shaped bolt group, the driving trolley is connected with a driving motor, and the driving trolley is configured to drive the driven trolley to synchronously move along length directions of the first rail and the second rail through the two beams so that the electric hoist is driven to synchronously move.
2. The walking device with the self-adaptive track gauge and wheel pressure for preventing rail gnawing according to claim 1, wherein: the driving trolley comprises a first left frame, a first right frame, a third bolt group, a fourth bolt group, the driving motor, a transmission gear box, a first bearing wheel, a first rail side balance wheel group, and a first rail bottom balance wheel group, the first left frame and the first right frame are connected to each other through the third bolt group for limiting a frame distance between the first left frame and the first right frame and the fourth bolt group for connecting the first left frame and the first right frame, the driving motor and the transmission gear box are connected to the first left frame and the first right frame through a sixth bolt group, the first bearing wheel is respectively supported on the first left frame and the first right frame through bearings and shafts, the first rail side balance wheel group is connected to the first left frame and the first right frame through a first support frame and a fifth bolt group, and the first rail bottom balance wheel group is connected to the first left frame and the first right frame through a balance wheel base and a sixth bolt group.
3. The walking device with the self-adaptive track gauge and wheel pressure for preventing rail gnawing according to claim 2, wherein: the driven trolley comprises a second left frame, a second right frame, a seventh bolt group, an eighth bolt group, a second bearing wheel, a second rail side balance wheel group, and a second rail bottom balance wheel group, the second left frame and the second right frame are connected to each other through the seventh bolt group for limiting a frame distance between the second left frame and the second right frame and the eighth bolt group for connecting the second left frame and the second right frame, the second bearing wheel is respectively supported on the second left frame and the second right frame through bearings and shafts, the second rail side balance wheel group is connected to the second left frame and the second right frame through a second support frame and a ninth bolt group, the second rail bottom balance wheel group is connected to the second left frame and the second right frame through the balance wheel base and a tenth bolt group.
4. The walking device with the self-adaptive track gauge and wheel pressure for preventing rail gnawing according to claim 3, wherein: the first rail side balance wheel group comprises four first rail side balance wheels, the second rail side balance wheel group comprises four second rail side balance wheels, the first rail bottom balance wheel group comprises two first rail bottom balance wheels, and the second rail bottom balance wheel group comprises two second rail bottom balance wheels.
5. The walking device with the self-adaptive track gauge and wheel pressure for preventing rail gnawing according to claim 4, wherein: a structure of each of the four first rail side balance wheels is the same as a structure of each of the four second rail side balance wheels, each of the four first rail side balance wheels comprises the first support frame, a first balance wheel base, a first balance wheel limit adjusting bolt, a first balance wheel support, a first balance wheel, a first guide rod bolt group, and a first compression spring, the first balance wheel base is connected to the first support frame through the first guide rod bolt group, the first guide rod bolt group sequentially passes through the first balance wheel base, the first support frame, the first compression spring, and the first balance wheel support to enable the first compression spring, the first balance wheel support, and the first guide rod bolt group to be connected together, the first compression spring presses the first balance wheel against a side of the first rail through the first balance wheel support, and the first balance wheel limit adjusting bolt defines a retracted location at which the first balance wheel support is configured to be located along a first guide rod through a first nut which is fixedly connected at a middle location of the first balance wheel base, so as to define a maximum offset distance of the driving trolley and the driven trolley along a direction vertical to the side of the first rail and a side of the second rail.
6. The walking device with the self-adaptive track gauge and wheel pressure for preventing rail gnawing according to claim 5, wherein: a structure of each of the two first rail bottom balance wheels is the same as a structure of each of the two second rail bottom balance wheels, each of the two second rail bottom balance wheels comprises the balance wheel base, a second balance wheel limit adjusting bolt, a second balance wheel support, a second balance wheel, a second compression spring, a second guide rod bolt group, and the tenth bolt group, the balance wheel base is connected to the second left frame and the second right frame through the tenth bolt group, the second guide rod bolt group is connected to the balance wheel base through a nut fixed on the balance wheel base, the second guide rod bolt group sequentially passes through the balance wheel base, the second left frame, the second right frame, the second compression spring, and the second balance wheel support to enable the second compression spring, the second balance wheel support, and the second guide rod bolt group to be connected together, the second compression spring presses the second balance wheel against a bottom of the second rail through the second balance wheel support, and the second balance wheel limit adjusting bolt defines a retracted location at which the second balance wheel support is configured to be located along a second guide rod through a second nut which is fixedly connected at a middle location of the balance wheel base, so as to define a maximum jumping distance of the driven trolley along a direction vertical to the bottom of the second rail.
7. The walking device with the self-adaptive track gauge and wheel pressure for preventing rail gnawing according to claim 6, wherein: the first bearing wheel comprises a first left bearing wheel and a first right bearing wheel, the second bearing wheel comprises a second left bearing wheel and a second right bearing wheel, the first left bearing wheel, the second left bearing wheel, and the second right bearing wheel are driven wheels, the first right bearing wheel is connected to the driving motor, the first right bearing wheel is a driving wheel, and the driving motor is configured to transmit power to the driving wheel so as to drive the driven wheels to move along the first rail and the second rail.
8. The walking device with the self-adaptive track gauge and wheel pressure for preventing rail gnawing according to claim 7, wherein: a track gauge between the first rail and the second rail is represented by L.sub.rail, an axle distance between the first left bearing wheel and the first right bearing wheel is represented by L.sub.axle, an axle distance between two of the four first rail side balance wheels that are located on a same side of the first rail is represented by L.sub.wheel, a distance between a driving force F.sub.driving of the driving wheel and a friction force F.sub.5 on a first of the driven wheels is represented by L.sub.driving, a distance between friction forces F.sub.6, F.sub.7 on a second and third of the driven wheels is represented by L.sub.driven, an acting force of the first rail acting on the driving wheel is the driving force F.sub.driving whose direction is the same as a moving direction of the walking device, rolling frictions applied by the second rail to the driven wheels are resistance forces represented by F.sub.1, F.sub.2, F.sub.3, F.sub.4, F.sub.5, F.sub.6, and F.sub.7, the driving force F.sub.driving applied on the driving wheel and the rolling frictions F.sub.1, F.sub.2, F.sub.3, F.sub.4, F.sub.5, F.sub.6, F.sub.7 applied on the driven wheels are configured to generate a deflection torque around a center O of the walking device so that a respective two of the four first rail side balance wheels that are arranged on two sides of the first rail and a respective two of the four second rail side balance wheels that are arranged on two sides of the second rail are respectively pressed onto the two sides of the first rail and the two sides of the second rail to generate four rail side pressures F.sub.N1, F.sub.N2, F.sub.N3, and F.sub.N4, the four rail side pressures F.sub.N1, F.sub.N2, F.sub.N3, and F.sub.N4 are configured to generate a torque that balances the deflection torque, an equilibrium equation between force and moment is shown as follow:
F.sub.driving=F.sub.2+F.sub.3+F.sub.4+F.sub.5+F.sub.6+F.sub.7 (1),
F.sub.N1+F.sub.N3=F.sub.N2+F.sub.N4 (2),
(F.sub.driving+F.sub.5)×L.sub.driving+(F.sub.6−F.sub.7)×L.sub.driven+(F.sub.3+F.sub.4−F.sub.1−F.sub.2)×L.sub.rail=L.sub.wheel×(F.sub.N1+F.sub.N2+F.sub.N3+F.sub.N4) (3), a rail width of the first rail and the second rail is negligible relative to the track gauge L.sub.rail, so that L.sub.driving=L.sub.driven=L.sub.rail, the formulas (1) and (2) are substituted into the formula (3) to obtain the formula (4):
(F.sub.3+F.sub.4+F.sub.5+F.sub.6)×L.sub.rail=(F.sub.N1+F.sub.N3)×L.sub.wheel (4), rolling friction coefficients of the driving wheel and the driven wheels are considered as f.sub.roll, so that F.sub.N1=F.sub.N2=F.sub.N3=F.sub.N4=F.sub.N, F.sub.3+F.sub.4=(F.sub.N3+F.sub.N4)×f.sub.roll=2×F.sub.N'f.sub.roll, and F.sub.5+F.sub.6=F.sub.weight×f.sub.roll, wherein the F.sub.weight is a total weight borne by the second bearing wheel of the driven trolley, the above formulas are substituted into formula (4) to obtain the formulas (5) and (6):
9. The walking device with the self-adaptive track gauge and wheel pressure for preventing rail gnawing according to claim 8, wherein: the hole grooves of each of the two beams is divided into a first hole groove and a second hole groove, the driving trolley is fixedly connected with the first hole groove and the second hole groove through the first bolt group, a length of an unthreaded part of a double-headed bolt of the double-headed bolt group is greater than a sum of a thicknesses of a corresponding one of the second left frame or the second right frame and each of the two beams at a junction of the corresponding one of the second left frame and the second right frame and each of the two beams, when a distance between the first rail and the second rail is changed, the driven trolley and the double-headed bolt group slide along the sliding groove so as to adapt different track gauges, a gravity center of the driving trolley is marked as O, F.sub.G is a gravity of the driving trolley, F.sub.bearing 1 and F.sub.bearing 2 are positive pressures which are respectively applied to the first left bearing wheel and the first right bearing wheel by the first rail, F.sub.N5 and F.sub.N6 are positive pressures which are respectively applied by the first rail to the two first rail bottom balance wheels, which are separated from each other in a front-rear direction, F.sub.beam 1 and F.sub.beam 2 are downward pulling forces which are applied by the two beams to the first left frame and the first right frame of the driving trolley, an equilibrium equation for force and moment is shown as follow,
F.sub.bearing 1+F.sub.bearing 2=F.sub.G+F.sub.N5+F.sub.N6+F.sub.beam 1+F.sub.beam 2 (7),
(F.sub.bearing 1−F.sub.bearing 2)×L.sub.axle=(F.sub.N5−F.sub.N6)×L.sub.wheel+(F.sub.beam 1−F.sub.beam 2)×L.sub.beam (8), L.sub.beam is a distance between the two beams, when F.sub.beam 1=F.sub.beam 2, F.sub.bearing 1=F.sub.bearing 2 and the first left bearing wheel and the first right bearing wheel are stressed evenly, the positive pressures F.sub.N5 and F.sub.N6 which are applied by the first rail to the two first rail bottom balance wheels are ignored, when a stress on the two beams is unbalanced and the F.sub.beam 1 is larger than the F.sub.beam 2, the driving trolley is subjected to a counterclockwise turning moment around the gravity center O, let F.sub.beam 2=0 and F.sub.N5=0, then:
(F.sub.bearing 1−F.sub.bearing 2)×L.sub.axle=F.sub.beam 1×L.sub.beam−F.sub.N6×L.sub.wheel (9), from the above formula, when
10. The walking device with the self-adaptive track gauge and wheel pressure for preventing rail gnawing according to claim 9, wherein: when a direction of a trolley body and a direction of the rail deviate from each other and the four first rail side balance wheels and the four second rail side balance wheels reach a maximum retraction distance b due to a limitation of a limit adjusting bolt: a deflection angle is a maximum deflection angle α, a diameter of each of the four first rail side balance wheels is set as d.sub.1, diameters of a first bearing wheel and a second bearing wheel are set as d.sub.2, a width of the rail is set as w, a wall thickness of the rail is set as s, then
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0034]
[0035]
[0036]
[0037]
[0038]
[0039]
[0040]
[0041]
[0042]
[0043]
[0044]
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0045] The present disclosure will be further described below in combination with the accompanying drawings and embodiments.
[0046] Referring to
[0047] The driving trolley 3 is hung on the first rail 1 through a first bearing wheel, and the driven trolley 4 is hung on the second rail 2 through a second bearing wheel. The driving trolley 3 is fixedly connected to hole grooves of the two beams through a first bolt group 11, and the driven trolley 4 is movably connected to the sliding groove 64 of each of the two beams through a double-headed bolt group 12. The electric hoist 7 is fixed on a sliding frame 8 through a second bolt group 10. The sliding frame 8 is connected with a T-shaped bolt group 9, and the sliding frame 8 is slidingly connected to the sliding groove 64 of each of the two beams through the T-shaped bolt group 9. The driving trolley 3 is connected with a driving motor 13, and the driving trolley 3 drives the driven trolley 4 to synchronously move along length directions of the first rail 1 and the second rail 2 through the two beams, so that the electric hoist 7 is driven to synchronously move.
[0048] Specifically, the first bearing wheel comprises a first left bearing wheel 23 and a first right bearing wheel 24, and the second bearing wheel comprises a second left bearing wheel 37 and a second right bearing wheel 38. The first left bearing wheel 23, the second left bearing wheel 37, and the second right bearing wheel 38 are driven wheels. The first right bearing wheel 24 is connected to the driving motor 13, and the first right bearing wheel 24 is a driving wheel. The driving motor 13 transmits power to the driving wheel, thereby driving the driven wheels to move along the first rail 1 and the second rail 2.
[0049] The driving trolley 3 comprises a first left frame 25, a first right frame 26, a third bolt group 27, a fourth bolt group 28, the driving motor 13, a transmission gear box 14, the first bearing wheel, a first rail side balance wheel group 19, and a first rail bottom balance wheel group 22. The first left frame 25 and the first right frame 26 are connected to each other through the third bolt group 27 for limiting a frame distance between the first left frame 25 and the first right frame 26 and the fourth bolt group 28 for connecting the first left frame 25 and the first right frame 26. The driving motor 13 and the transmission gear box 14 are also connected to the first left frame 25 and the first right frame 26 through a sixth bolt group 131. The first left bearing wheel 23 and the first right bearing wheel 24 are respectively supported on the first left frame 25 and the first right frame 26 through bearings and shafts. The first rail side balance wheel group 19 is connected to the first left frame 25 and the first right frame 26 through a first support frame and a fifth bolt group 51. The first rail bottom balance wheel group 22 is connected to the first left frame 25 and the first right frame 26 through a balance wheel base 52 and a tenth bolt group 58. Specifically, the first rail bottom balance wheel group 22 comprises two first rail bottom balance wheels 20, 21.
[0050] The driven trolley 4 comprises a second left frame 39, a second right frame 40, a seventh bolt group 41, an eighth bolt group 42, the second bearing wheel, a second rail side balance wheel group 33, and a second rail bottom balance wheel group 36. The second left frame 39 and the second right frame 40 are connected by the seventh bolt group 41 for limiting a frame distance between the second left frame 39 and the second right frame 40 and the eighth bolt group 42 for connecting the second left frame 39 and the second right frame 40. The second left bearing wheel 37 and the second right bearing wheel 38 are respectively supported on the second left frame 39 and the second right frame 40 through bearings and shafts. The second rail side balance wheel group 33 is connected to the second left frame 39 and the second right frame 40 through a second support frame 321 and a ninth bolt group 322. The second rail bottom balance wheel group 36 is connected to the second left frame 39 and the second right frame 40 through the balance wheel base 52 and the tenth bolt group 58. Specifically, the second rail bottom balance wheel group 36 comprises two second rail bottom balance wheels 34, 35.
[0051] The first rail side balance wheel group 19 comprises four first rail side balance wheels 15, 16, 17, 18. The second rail side balance wheel group 33 comprises four second rail side balance wheels 29, 30, 31, 32. The first rail bottom balance wheel group 22 comprises the two first rail bottom balance wheels 20, 21. The second rail bottom balance wheel group 36 comprises the two second rail bottom balance wheels 34, 35.
[0052] A structure of each of the four first rail side balance wheels 15, 16, 17, 18 is the same as a structure of each of the four second rail side balance wheels 29, 30, 31, 32. Each of the four first rail side balance wheels 15, 16, 17, 18 comprises the first support frame, a first balance wheel base 45, a first balance wheel limit adjusting bolt 46, a first balance wheel support 47, a first balance wheel 48, a first guide rod bolt group 49, and a first compression spring 50. The first support frame is divided into two support frame 43, 44. The first balance wheel base 45 is connected to the first support frame through the first guide rod bolt group 49. The first guide rod bolt group 49 sequentially passes through the first balance wheel base 45, the first support frame, the first compression spring 50, and the first balance wheel support 47 to enable the first compression spring 50, the first balance wheel support 47, and the first guide rod bolt group 49 to be connected together. The first compression spring 50 presses the first balance wheel 48 tightly against a side of the first rail 1 through the first balance wheel support 47. The first balance wheel limit adjusting bolt 46 defines a retracted location at which the first balance wheel support 47 is configured to be located along a first guide rod 461 through a first nut 462 which is fixedly connected at a middle location of the first balance wheel base 45, so as to define a maximum offset distance of the driving trolley 3 and the driven trolley 4 along a direction vertical to the side of the first rail 1 and a side of the second rail 2.
[0053] A structure of each of the two first rail bottom balance wheels 20, 21 is the same as a structure of each of the two second rail bottom balance wheels 34, 35. Each of the two second rail bottom balance wheels 34, 35 comprises the balance wheel base 52, a second balance wheel limit adjusting bolt 53, a second balance wheel support 54, a second balance wheel 55, a second compression spring 56, a second guide rod bolt group 57, and the tenth bolt group 58. The balance wheel base 52 is connected to the second left frame 39 and the second right frame 40 through the tenth bolt group 58. The second guide rod bolt group 57 is connected to the balance wheel base 52 through a nut fixed on the balance wheel base 52. The second guide rod bolt group 57 sequentially passes through the balance wheel base 52, the second left frame 39, the second right frame 40, the second compression spring 56, and the second balance wheel support 54 to enable the second compression spring 56, the second balance wheel support 54, and the second guide rod bolt group 57 to be connected together. The second compression spring 56 presses the second balance wheel 55 tightly against a bottom of the second rail 2 through the second balance wheel support 54. The second balance wheel limit adjusting bolt 53 defines a retracted location at which the second balance wheel support 54 is configured to be located along a second guide rod 531 through a second nut 532 which is fixedly connected at a middle location of the balance wheel base 52, so as to define a maximum jumping distance of the driven trolley 4 along a direction vertical to the bottom of the second rail 2.
[0054] A track gauge between the first rail 1 and the second rail 2 is represented by L.sub.rail, an axle distance between the first left bearing wheel 23 and the first right bearing wheel 24 is represented by L.sub.axle, an axle distance between two of the four first rail side balance wheels 15, 16, 17, 18 that are located on the same side of the first rail 1 is represented by L.sub.wheel, a distance between a driving force F.sub.driving of the driving wheel and a friction force F.sub.5 on one of the driven wheels that is symmetrically arranged with respect to the driving wheel on two sides of the Z axis is represented by L.sub.driving, and a distance between friction forces F.sub.6, F.sub.7 on the other two of driven wheels is represented by L.sub.driven. An acting force of the first rail 1 acting on the driving wheel is the driving force F.sub.driving whose direction is the same as a moving direction of the walking device. Rolling frictions applied by the second rail 2 to the driven wheels are resistance forces represented by F.sub.1, F.sub.2, F.sub.3, F.sub.4, F.sub.5, F.sub.6, and F.sub.7 (the forces of the driven wheels acting on the first rail bottom balance wheels 20, 21 and the second rail bottom balance wheels 34, 35 are not taken into account). The driving force F.sub.driving applied on the driving wheel and the rolling frictions F.sub.1, F.sub.2, F.sub.3, F.sub.4, F.sub.5, F.sub.6, F.sub.7 applied on the driven wheels generate a deflection torque around a center O of the walking device, so that a respective two of the four first rail side balance wheels 15, 16, 17, 18 that are arranged on two sides of the first rail 1, and a respective two of the four second rail side balance wheels 29, 30, 31, 32 that are arranged on two sides of the second rail 2 are respectively pressed onto the two sides of the first rail 1 and the two sides of the second rail 2 to generate four rail side pressures F.sub.N1, F.sub.N2, F.sub.N3, and F.sub.N4. The four rail side pressures F.sub.N1, F.sub.N2, F.sub.N3, and F.sub.N4 will create a torque that balances the deflection torque, and an equilibrium equation between force and moment is shown as follow.
F.sub.driving=F.sub.1+F.sub.2+F.sub.3+F.sub.4+F.sub.5+F.sub.6+F.sub.7 (1);
F.sub.N1+F.sub.N3=F.sub.N2+F.sub.N4 (2);
(F.sub.driving+F.sub.5)×L.sub.driving+(F.sub.6−F.sub.7)×L.sub.driven+(F.sub.3+F.sub.4−F.sub.1−F.sub.2)×L.sub.rail=L.sub.wheel×(F.sub.N1+F.sub.N2+F.sub.N3+F.sub.N4) (3).
[0055] A rail width of the first rail 1 and the second rail 2 is negligible relative to a track gauge, so that L.sub.driving is equal to L.sub.driven, is equal to L.sub.rail; the formulas (1) and (2) are substituted into the formula (3) to obtain the formula (4).
(F.sub.3+F.sub.4+F.sub.5+F.sub.6)×L.sub.rail=(F.sub.N1+F.sub.N3)×L.sub.wheel (4).
[0056] Rolling friction coefficients of the driving wheel and the driven wheels are considered as f.sub.roll, so that F.sub.N1=F.sub.N2=F.sub.N3=F.sub.N4=F.sub.N, F.sub.3+F.sub.4=(F.sub.N3+F.sub.N4)×f.sub.roll=2×F.sub.N×f.sub.roll, and F.sub.5+F.sub.6=F.sub.weight×L.sub.roll, wherein the F.sub.weight is a total weight borne by the second bearing wheel of the driven trolley. The above formulas are substituted into formula (4) to obtain the formulas (5) and (6).
[0057] The formula (5) illustrates a relationship among the F.sub.N, the f.sub.roll, the L.sub.wheel, the L.sub.rail, and the F.sub.weight. Under a condition that other parameters are fixed, the f.sub.roll is positively correlated with the F.sub.N; the L.sub.wheel is negatively correlated with the F.sub.N; the L.sub.rail is positively correlated with the F.sub.N; the F.sub.weight is positively correlated with the F.sub.N. The formula (6) illustrates a method for setting the axle distance relative to the track gauge: the method comprises: (1) determining a limit value F.sub.side limit of the rail side pressure F.sub.N according to an ultimate stress of a rail material; (2) substituting the F.sub.side limit into the formula (6) to obtain a lowest limit value of the L.sub.wheel, and (3) selecting a proper value of the L.sub.wheel according to the lowest limit value of the L.sub.wheel.
[0058] The hole grooves of each of the two beams is divided into a first hole groove 62 and a second hole groove 63. Frames (i.e., the first left frame 25, the first right frame 26, the second left frame 39, and the second right frame 40) of the walking device comprise through grooves 59 for being connected with the first compression spring 50 and the second compression spring 56. The frames of the walking device comprise fixing grooves 60 and holes 61 for being connected with the balance wheel base 52. The driving trolley 3 is fixedly connected with the first hole groove 62 and the second hole groove 63 through the first bolt group 11. A length of an unthreaded part of a double-headed bolt of the double-headed bolt group 12 is greater than a sum of a thickness of the frame (i.e., the first left frame 25 or first right frame 26) and each of the two beams at a junction of the frame and each of the two beams. When a distance between the first rail 1 and the second rail 2 is changed, the driven trolley 4 and the double-headed bolt group 12 slide along the sliding groove 64, so as to adapt to different track gauges. Referring to
F.sub.bearing 1+F.sub.bearing 2=F.sub.G+F.sub.N5+F.sub.N6+F.sub.beam 1+F.sub.beam 2 (7);
(F.sub.bearing 1−F.sub.bearing 2)×L.sub.axle=(F.sub.N5−F.sub.N6)×L.sub.wheel+(F.sub.beam 1−F.sub.beam 2)L.sub.beam (8);
[0059] When the F.sub.beam 1 is equal to the F.sub.beam 2, the F.sub.bearing 1 is equal to the F.sub.bearing 2, the bearing wheels (i.e., the first bearing wheel and the second bearing wheel) are stressed evenly, and the positive pressures F.sub.N5 and F.sub.N6 which are applied by the rail to the rail bottom balance wheels are ignored. When a stress on the two beams is unbalanced and the F.sub.beam 1 is far larger than the F.sub.beam 2, the driving trolley 3 is subjected to a counterclockwise turning moment around the gravity center O. When F.sub.beam 2=0 and F.sub.N5=0, then:
(F.sub.bearing 1−F.sub.bearing 2)×L.sub.axle=F.sub.beam 1×L.sub.beam−F.sub.N6×L.sub.wheel (9);
[0060] From the above formula, when
that is, the bearing wheels are still stressed in balance. The formula (9) shows that when the stress on the two beams is unbalanced, the rail bottom balance wheels 20, 21, 34, 35 help to reduce an unbalanced degree of the stress on the bearing wheels.
[0061] The present disclosure forms a rail holding system by the bearing wheels, the rail side balance wheels, and the rail bottom balance wheels vertical to the rail side balance wheels, thereby effectively avoiding an occurrence of gnawing rail and derailing. The rail bottom balance wheels can prevent the trolleys (i.e., the driving trolley 3 and the driven trolley 4) from overturning forwards and backwards. The rail side balance wheels define a maximum deflection angle between a trolley body (i.e., a trolley body of the driving trolley 3 or the driven trolley 4) and the rail (i.e., the first rail 1 and the second rail 2), and prevent the rail from being gnawed. In order to prevent gnawing rail, after the trolleys are installed on the rail, a minimum gap value between an edge of the bearing wheels (i.e., the first bearing wheel or the second bearing wheel) and an edge of the rail, a maximum retracted distance (i.e., the maximum retracted position) of the rail side balance wheels on the side of the rail and a deflection angle between the trolley and the rail need to meet a certain constraint relation. The following provides a method for setting the maximum retracted distance of the rail side balance wheels and the minimum gap value for preventing the rail from being gnawed. Referring to
[0062] As can be seen from formula (10), the larger the maximum retraction distance b, the larger the maximum deflection angle α. When b is determined, the maximum deflection angle α is also determined. The gnawing rail does not occur when projection straight lines EF, GH of rail edge of the rail projected on a rail plane do not intersect with sides AB, DC of a circumscribed rectangle ABCD projected by the bearing wheels on the rail plane, then:
[0063] BC=w+c is set, wherein c is the minimum gap value which should be reserved between the edge of the bearing wheels and the edge of the rail after the trolleys are installed on the rails; then:
[0064] The minimum gap value c between the edge of the bearing wheels and the edge of the rail is adjusted through a frame spacing limiting bolt group and a frame connecting bolt group (i.e., the third bolt group 27, the fourth bolt group 28, the seventh bolt group 41, and the eighth bolt group 42), and the maximum retraction distance b is adjusted through a balance wheel limit adjusting bolt (i.e., the first balance wheel limit adjusting bolt 46 or the second balance wheel limit adjusting bolt 53). According to the formulas (10) and (12), when the gap value c is given, the maximum deflection angle α of the rail and the maximum retraction distance b of rail side balance wheels which are set to prevent rail gnawing can be calculated. When the maximum retraction distance b of rail side balance wheels is given, the maximum deflection angle α of the rail and the minimum gap value c at which no track gnawing occurs can be calculated.
[0065] The present disclosure can adjust the frame distance between the first left frame 25 and the first right frame 26, and is suitable for rails of different types or widths. The frame distance between the first left frame 25 and the first right frame 26 is adjusted in the same method as the frame distance between the second left frame 39 and the second right frame 40. The adjustment method is to tighten the fourth bolt group 28 to decrease the frame distance between the first left frame 25 and the first right frame 26, or to loosen the fourth bolt group 28 to increase the frame distance between the first left frame 25 and the first right frame 26. When the frame distance between the first left frame 25 and the first right frame 26 reaches a set value, the third bolt group 27 is tightened to maintain the frame distance at the set value. In order to adjust the rail bottom balance wheels and the two beams to adapt to the space between the frames, the through grooves are arranged on the first left frame 25, the first right frame 26, and the two beams.
[0066] In addition, this embodiment is a double rail embodiment. When the two beams have been removed, the electric hoist can be installed below the driving trolley 3 to achieve a monorail motion.
[0067] The aforementioned embodiments are merely some embodiments of the present disclosure, and the scope of the disclosure is not limited thereto. Thus, it is intended that the present disclosure cover any modifications and variations of the presently presented embodiments provided they are made without departing from the appended claims and the specification of the present disclosure.