Heavy duty stacker

Abstract

The application provides a heavy load stacking machine, and belongs to the field of logistics sorting and automatic equipment. A new type of lifting mechanism capable of being applied to heavy cargo lifting operation is configured. The lifting mechanism adopts a combination scheme of an R type speed reducer motor and a chain transmission mechanism, so as to reduce the torque peak value borne by the motor, disperse the force flow transmission path, inhibit the impact load transmission, optimize the stiffness matching of the transmission system, and reduce the requirements on the motor specifications. The whole frame composed of a lower cross beam, an upper cross beam and two groups of columns runs between the overhead rail and the ground rail. The lifting drive assembly drives the cargo platform assembly along the guide rail to reciprocate to vertically convey the cargo through the steel wire rope transmission between the lower cross beam and the upper cross beam. The pulley assembly for guiding the steel wire rope is arranged at the top of the column.

Description

Technical Field

[0001] This application belongs to the field of logistics sorting and automation equipment, and specifically relates to a heavy-duty stacker crane that has a novel lifting mechanism that is suitable for transporting heavy goods. Background Technology

[0002] With the rapid development of automated logistics transportation technology at home and abroad, automated warehousing has become widely popular. The stacker cranes currently in use operate at high speeds and are core handling equipment, which can effectively improve the efficiency of transportation operations.

[0003] Existing stacker cranes generally have a tall and narrow overall structure. The lifting transmission system of stacker cranes typically uses a KA-type geared motor directly connected to the drum to drive the loading platform for lifting and lowering goods. This approach has the following main drawbacks in terms of mechanical performance and cost: 1. The instantaneous peak torque on the motor is too high; under heavy-load lifting conditions, the dynamic load generated by the swaying of the goods will cause the motor output shaft to directly bear more than 1.5 times the peak load torque. According to the proportional relationship between shear stress and torque in material mechanics, excessively high instantaneous torque causes the motor shaft to be in a high-stress state for a long time, significantly increasing the risk of fatigue fracture and reducing the service life of the motor. 2. Concentrated force transmission leads to excessive local stress; when the geared motor directly drives the drum, the drum only bears force through one end of the bearing housing. The load reaction force is concentrated on a single bearing, and the radial force can reach tens of thousands of Newtons, easily causing plastic deformation of the bearing outer ring and the housing hole mating surface; at the same time, the connecting key between the motor shaft and the drum bears a large shear force, and stress concentration cracks are prone to appear at the keyway, affecting the structural integrity of the transmission components. 3. Lack of buffering leads to direct transmission of impact loads; rigid connections allow impact loads from cargo braking or center of gravity shift to be transmitted to the motor rotor without attenuation, resulting in instantaneous radial forces between the rotor and stator. Over time, this increases motor bearing clearance, causing abnormal noises and excessive vibration, reducing the stability of the mechanism. 4. Inappropriate stiffness matching in the existing transmission system: The rigid connection between the motor and the drum results in high overall system stiffness. At specific lifting speeds, its resonant frequency easily approaches the natural frequency of the lifting platform, causing resonance, accelerating component fatigue damage, and affecting the long-term reliable operation of the lifting mechanism. 5. High drive system cost: Because the geared motor must directly bear the entire load torque, a large-size model must be selected to meet heavy-load lifting requirements. However, large-size geared motors have higher manufacturing costs, increasing the overall cost of the equipment.

[0004] In view of the above, this patent application is hereby filed. Summary of the Invention

[0005] The heavy-duty stacker crane described in this application aims to address the problems and shortcomings of the existing technology by proposing a new type of lifting mechanism suitable for lifting heavy goods. This lifting mechanism adopts a combination of an R-type geared motor and a chain drive mechanism to reduce the peak torque on the motor, disperse the force flow transmission path, suppress the transmission of impact loads, optimize the stiffness matching of the transmission system, and reduce the requirements for motor specifications.

[0006] To achieve the above design objectives, the heavy-duty stacker crane includes an integral frame consisting of a lower crossbeam, an upper crossbeam, and two sets of columns, which runs between the overhead rail and the ground rail. Between the lower and upper crossbeams, a lifting drive assembly drives a loading platform assembly to reciprocate along the guide rail via a wire rope to vertically transport goods. A pulley assembly is provided at the top of the columns to guide the wire rope. The lifting drive assembly includes an R-type geared motor, with a motor end sprocket mounted on the drive shaft of the geared motor. A drum sprocket is mounted on a drum mounted on the side of the column through the drive mechanism bracket. A wire rope is wound on the drive drum, and the chain runs in a closed loop between the motor end sprocket and the drum sprocket.

[0007] Furthermore, the motor end sprocket is located vertically below the drum sprocket, and the angle between the line connecting their centers and the horizontal plane is 4° to 6°.

[0008] Furthermore, the pulley assembly includes two sets of fixed pulleys arranged in parallel via an anti-jump rope bracket and mounted on the top of the column.

[0009] Furthermore, the loading platform assembly is equipped with a fork drive motor, guide wheels, and a movable pulley mounted on the loading platform anti-jump rope bracket on its loading platform body; the wire rope passes around the movable pulley and is tied to the top of the column through a wire rope fixing device; the guide wheel runs inside the groove on the side of the guide rail; the drive end of the fork drive motor is connected to the telescopic fork to realize the grabbing and placement of goods.

[0010] Furthermore, a wire rope fixing assembly is provided on the side of the column. The wire rope fixing device includes a fixing block that is rigidly connected to the loading platform body. The wire rope tie rod passes through the fixing block and is connected to the wire rope through a wire rope wedge joint. A disc spring is sleeved on the wire rope tie rod and locked and compressed to the top of the fixing block by a nut. A slack rope detection switch is connected to the wire rope tie rod, and its trigger end contacts the fixing block to monitor the rope tension in real time.

[0011] As mentioned above, the heavy-duty stacker crane proposed in this application has the following advantages and beneficial effects:

[0012] 1. This application can effectively reduce the torque load of the motor and extend its service life. Through the chain drive structure with an n:1 transmission ratio, the output torque of the R-type geared motor is only 1 / n of that of the existing KA-type motor. Even with a dynamic load of 1.5 times, the instantaneous torque peak value is significantly reduced. According to the principles of materials mechanics, the shear stress of the motor shaft is reduced simultaneously, the risk of fatigue fracture is greatly reduced, and the service life of the motor can be extended.

[0013] 2. This application can effectively disperse the force flow and reduce local stress; the chain drive mechanism makes the bearing seats at both ends of the drum uniformly stressed, and the radial force of a single bearing is reduced to less than 1 / 2 of the prior art; the double fixed pulleys can distribute the tension of the wire rope to the two pulleys, and the moving pulley further disperses the load, avoiding plastic deformation or cracks of the components caused by excessive local stress, and improving the structural integrity of the transmission components.

[0014] 3. This application can enhance the buffering capacity and improve the operational stability; the flexible transmission characteristics of the chain can absorb some of the impact energy, and with the buffering effect of the disc spring in the wire rope fixing device, the impact load generated by the braking of the cargo or the shift of the center of gravity is attenuated and then transmitted to the motor, which can reduce the phenomenon of increased motor bearing clearance, reduce abnormal noise and vibration during operation, and improve the stability of the mechanism.

[0015] 4. This application optimizes stiffness matching and avoids resonance damage; the flexibility of chain drive reduces the overall stiffness of the system, causing the resonance frequency of the transmission system to deviate from the natural frequency of the lifting of the loading platform, effectively avoiding resonance, reducing fatigue damage to components, and improving the long-term reliable operation capability of the mechanism.

[0016] 5. This application can significantly reduce costs; the manufacturing cost of the R-type geared motor is lower than that of the KA-type motor of the same power level, and due to the reduced torque requirement, a smaller specification model can be selected, which can significantly reduce the overall cost of the drive system; at the same time, the extended component life reduces the frequency of maintenance and replacement, further reducing the cost of use. Attached Figure Description

[0017] The present application will now be further illustrated with reference to the following figures.

[0018] Figure 1 This is a structural schematic diagram of the heavy-duty stacker crane described in this application;

[0019] Figure 2 This is a schematic diagram of the fixed pulley assembly;

[0020] Figure 3 This is a schematic diagram of the lifting drive mechanism;

[0021] Figure 4 This is a structural diagram of the loading platform assembly;

[0022] Figure 5 This is a structural schematic diagram of a wire rope fixing assembly;

[0023] In the above attached figures, 1 is the pulley assembly; 2 is the wire rope; 3 is the column; 4 is the lifting drive assembly; 5 is the loading platform assembly; 6 is the wire rope fixing assembly; and 7 is the guide rail.

[0024] 11. Fixed pulley; 12. Anti-jump rope bracket;

[0025] 41. Drive mechanism bracket; 42. Drum; 43. Drum sprocket; 44. Chain; 45. Motor end sprocket; 46. Drive shaft bracket; 47. Gear motor;

[0026] 51. Guide wheel; 52. Movable pulley; 53. Telescopic fork; 54. Anti-jump rope bracket for loading platform; 55. Loading platform body; 56. Fork drive motor; 57. Cargo;

[0027] 61. Slack rope detection switch; 62. Fixing block; 63. Wire rope tie rod; 64. Wire rope wedge joint; 65. Disc spring. Detailed Implementation

[0028] Example 1, as Figures 1 to 5 As shown, a novel heavy-duty stacker crane includes an integral frame consisting of a lower crossbeam, an upper crossbeam, and two sets of columns 3, which runs between the overhead rail and the ground rail. Between the lower and upper crossbeams, a lifting drive assembly 4 drives a loading platform assembly 5 to reciprocate along a guide rail 7 via a wire rope 2 to vertically transport goods. A pulley assembly 1 is provided at the top of the column 3 to guide the wire rope 2, and a wire rope fixing assembly 6 is provided on the side of the column 3. The following innovative transmission structure design achieves a balance between reducing the overall cost and ensuring performance.

[0029] The lifting drive assembly 4 includes an R-type geared motor 47 to replace the KA-type geared motor commonly used in the prior art. A motor end sprocket 45 is mounted on the drive shaft of the geared motor 47. A drum sprocket 43 is sleeved on a drum 42 mounted on the side of the column 3 via the drive mechanism bracket 41. A steel wire rope 2 is wound on the drive drum 42. A chain 44 runs in a closed loop between the motor end sprocket 45 and the drum sprocket 43, forming a chain drive mechanism with a transmission ratio of n:1. That is, this chain drive mechanism can amplify the output torque of the R-type geared motor 47 to n times (ignoring transmission losses), thus effectively reducing the torque requirements of the motor itself.

[0030] The motor end sprocket 45 is located vertically below the drum sprocket 43, and the angle between the line connecting their centers and the horizontal plane is 4° to 6°, which can reduce the influence of the sag of the chain 44.

[0031] The pulley assembly 1 includes two sets of fixed pulleys 11 arranged in parallel through the anti-jump rope bracket 12 and mounted on the top of the column 3. This double fixed pulley structure can distribute the force through the steel wire rope 2.

[0032] The loading platform assembly 5 is provided with a fork drive motor 56, a guide wheel 51, and a movable pulley 52 that is driven by the anti-jump rope bracket 54 on its loading platform body 55. The wire rope 2 passes around the movable pulley 52 and is tied to the top of the column 3 by the wire rope fixing device 6. The guide wheel 51 runs in the groove on the side of the guide rail 7. The column 3 provides stable support for the vertical operation of the loading platform assembly 5. The drive end of the fork drive motor 56 is connected to the telescopic fork 53 to realize the grabbing and placement operation of the goods 57.

[0033] During operation, the geared motor 47 drives the drum 42 to rotate via a chain drive mechanism. Under the winding and unwinding action of the drum 42, and guided by the pulley assembly 1 and the movable pulley 52, the wire rope 2 reciprocates vertically along the guide rail 7 to lift the loading platform assembly 5. This structure, while meeting the cargo lifting requirements, allows for the use of a smaller R-type geared motor 47 to effectively reduce costs and component fatigue damage, thereby improving the long-term reliable operation of the loading platform assembly 5.

[0034] The wire rope fixing device 6 includes a fixing block 62 rigidly connected to the loading platform body 55. The wire rope rod 63 passes through the fixing block 62 and is connected to the wire rope 2 through the wire rope wedge joint 64. The disc spring 65 is sleeved on the wire rope rod 63 and locked and compressed to the top of the fixing block 62 by a nut, thereby providing continuous pretension force to the wire rope 2 and preventing the rope from slack. The slack rope detection switch 61 is connected to the wire rope rod 63, and its trigger end contacts the fixing block 62 to monitor the rope tension in real time.

[0035] In summary, the embodiments shown in the accompanying drawings are merely preferred solutions. Those skilled in the art can draw inspiration from these embodiments and directly derive other alternative structures that conform to the design concept of this invention, which should also fall within the scope of the present invention.

Claims

1. A heavy-duty stacker crane, characterized in that: It includes an overall frame consisting of a lower crossbeam, an upper crossbeam, and two sets of columns that run between the overhead rail and the ground rail. Between the lower and upper crossbeams, the loading platform assembly is driven by a lifting drive component to reciprocate along the guide rail to vertically transport goods. A pulley assembly is installed at the top of the columns to guide the wire rope. The lifting drive assembly includes an R-type geared motor, a motor end sprocket mounted on the drive shaft of the geared motor, a drum sprocket mounted on a drum mounted on the side of the column, and a steel wire rope wound on the drive drum. The chain runs in a closed loop between the motor end sprocket and the drum sprocket.

2. The heavy-duty stacker crane according to claim 1, characterized in that: The motor end sprocket is located vertically below the drum sprocket, and the angle between the line connecting their centers and the horizontal plane is 4° to 6°.

3. The heavy-duty stacker crane according to claim 1 or 2, characterized in that: The pulley assembly includes two sets of fixed pulleys arranged in parallel via an anti-jump rope bracket and mounted on the top of a column.

4. The heavy-duty stacker crane according to claim 1, characterized in that: The loading platform assembly includes a fork drive motor, guide wheels, and a movable pulley mounted on the loading platform anti-jump rope bracket. The wire rope passes around the movable pulley and is then tied to the top of the column via a wire rope fixing device. The guide wheel runs inside the groove on the side of the guide rail. The drive end of the fork drive motor is connected to the telescopic forks to realize the grabbing and placement of goods.

5. The heavy-duty stacker crane according to claim 4, characterized in that: A wire rope fixing assembly is installed on the side of the column. The wire rope fixing device includes a fixing block that is rigidly connected to the loading platform body. The wire rope tie rod passes through the fixing block and is connected to the wire rope through a wire rope wedge joint. The disc spring is sleeved on the wire rope tie rod and locked and compressed to the top of the fixed block by a nut. The slack rope detection switch is connected to the wire rope tie rod, and its trigger end is in contact with the fixed block to monitor the rope tension in real time.

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