Novel electric chain hoist load limiting device

Abstract

The invention relates to the technical field of hoisting machinery, in particular to a novel electric chain hoist load limiting device. Some load limiting mechanisms are directly installed in motors, dust and heat generated after operation of the motors can influence the correct degree of load limiting, time and labor are wasted during replacement and adjustment, and efficiency is low. A traditional mechanical load limiting structure is simple in design, inaccurate in load limiting capacity and difficult to meet the requirement for high-precision operation. A novel electric chain hoist load limiting device is characterized in that a gear shaft is arranged on a gearbox body, a load limiting mechanism on the outer side of the gear shaft and an adjusting mechanism arranged in the gear shaft are included, a power source is connected to the load limiting mechanism and inputs power, and shafts of the gear shaft, the load limiting mechanism, the adjusting mechanism and the power source are coaxial; the adjusting mechanism abuts against the load limiting mechanism to adjust the friction force of the load limiting mechanism. The device is reasonable and compact in structure, the adjusting mechanism is arranged in the gear shaft, and the change of axial force cannot be caused.

Description

Technical Field

[0001] This invention relates to the field of lifting machinery technology, and more specifically to a novel load limiting device for electric chain hoists. Background Technology

[0002] In various fields such as stage construction, factories, mines, ports, and wind turbine generators, there is a need for lifting parts, which requires the use of cranes or electric hoists. Electric hoists are more widely used due to their unique advantages.

[0003] Electric hoists are widely used in industrial production, but existing load limiting devices have many shortcomings. Some load limiting components use electronic sensors, which are easily affected by environmental interference, impacting accuracy and exhibiting poor reliability under complex working conditions. For example, some load limiting mechanisms are directly installed inside the motor; dust and heat generated by the motor's operation can affect the accuracy of load limiting. Furthermore, replacing or adjusting the load limiting mechanism requires opening the motor's interior for related operations, and after completion, the positions of all parts must be reinstalled and adjusted, which is time-consuming, labor-intensive, and inefficient.

[0004] Other traditional mechanical load limiting structures have simple designs and imprecise load limiting capacity, making it difficult to meet the needs of high-precision operations. When overloaded, they cannot effectively stop the electric hoist from continuing to lift, posing safety hazards and easily damaging the equipment, reducing its service life and increasing maintenance costs. Summary of the Invention

[0005] The purpose of this invention is to address the shortcomings of existing technologies by providing a novel load limiting device for electric chain hoists. This device overcomes the defects of existing load limiting devices, ensures that the electric hoist operates within a safe load range, improves the stability and safety of equipment operation, and extends the service life of the equipment.

[0006] A novel load-limiting device for an electric chain hoist includes a gearbox housing with a gear shaft. The device comprises a load-limiting mechanism on the outside of the gear shaft and an adjustment mechanism inside the gear shaft. The gear shaft is hollow. A power source is connected to the load-limiting mechanism, providing power input. The shafts of the gear shaft, load-limiting mechanism, adjustment mechanism, and power source are coaxial. The adjustment mechanism abuts against the load-limiting mechanism to adjust its friction. This invention has a reasonable and compact structure, reducing space requirements. The adjustment mechanism is located inside the gear shaft, ensuring that adjustment does not affect the bearings mounted on the shaft and does not cause changes in axial force.

[0007] As a further improvement and supplement to the above solution, the present invention also includes the following additional technical features: The adjustment mechanism includes a load-limiting rod and a load-limiting spring seat, both with a clearance fit, located inside the gear shaft cavity. The load-limiting rod abuts against the load-limiting mechanism, and the end faces of the load-limiting spring seat and the load-limiting rod are aligned coaxially. A load-limiting spring is sleeved on the load-limiting spring seat, a load-limiting spring washer on the outside of the load-limiting spring for pressing, an adjustment pin, and a load-limiting tightening sleeve for positioning. Adjustment is convenient and quick, the structure is reasonable, the accuracy of load limit setting and adjustment is high, and the consistency of repeated load limit adjustments is good. This ensures the electric hoist operates within a safe load range, improves the stability, reliability, and safety of equipment operation, and extends the equipment's service life.

[0008] The load-limiting mechanism includes a load-limiting friction plate seat A and a load-limiting friction plate seat B, with a load-limiting friction plate located in the middle. The structure is reasonable, and disassembly and replacement are convenient.

[0009] The power source is an electric motor, which operates stably.

[0010] One end of the pin has a hexagonal structure, making it easy to install, disassemble, and adjust.

[0011] The following beneficial effects can be achieved by using this invention: This invention incorporates an adjustment mechanism within the gear shaft. Adjustment does not affect the bearings mounted on the shaft and does not cause changes in axial force. Furthermore, adjustment only requires adjusting the pin and pressing the load-limiting spring to adjust the friction force between the load-limiting rod and the load-limiting friction plate seat B. The load-limiting rod evenly contacts and engages with the load-limiting friction plate seat B, resulting in uniform axial pressure distribution. Therefore, this limiting device offers high load-limiting stability, high accuracy in setting and adjusting the load limit, and good consistency in repeated adjustments. This ensures the electric hoist operates within a safe load range, improving equipment stability, reliability, and safety, and extending equipment lifespan. It effectively prevents overload and reduces equipment failure rate. Attached Figure Description

[0012] Figure 1 This is the front view of the present invention.

[0013] Figure 2 This is a bottom view of the present invention.

[0014] Figure 3 This is a schematic diagram of the structure of the pin 13 in this invention.

[0015] In the picture: 1. Gearbox housing; 3. Motor; 4. Load-limiting friction plate seat A; 5. Load-limiting friction plate; 6. Load-limiting friction plate seat B; 7. Gear shaft; 8. Load-limiting push rod; 9. Load-limiting spring seat; 10. Load-limiting spring washer; 11. Nut; 12. Load-limiting tightening sleeve; 13. Pin; 14. Load-limiting spring; 15. Snap ring. Detailed Implementation

[0016] The specific embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0017] like Figure 1-3 As shown, the present invention is a novel load limiting device for electric chain hoists.

[0018] The novel chain electric hoist load limiting device described in this embodiment includes a gearbox housing 1, which has a gear shaft 7. The gear shaft 7 is hollow. The novel chain electric hoist load limiting device includes a load limiting mechanism on the outside of the gear shaft 7 and an adjustment mechanism inside the gear shaft 7. A power source is connected to the load limiting mechanism, and the power source inputs power. The shafts of the gear shaft 7, the load limiting mechanism, the adjustment mechanism, and the power source are all on the same axis. The power source drives the load limiting mechanism, which in turn drives the gear shaft 7 to rotate, thereby driving other transmission components inside the gearbox housing 1. The adjustment mechanism abuts against the load limiting mechanism to adjust the friction of the load limiting mechanism.

[0019] Furthermore, the adjustment mechanism includes a load-limiting rod 8 and a load-limiting spring seat 9 disposed within the inner cavity of the gear shaft 7 with a clearance fit. The load-limiting rod 8 abuts against the load-limiting mechanism, and the end faces of the load-limiting spring seat 9 and the load-limiting rod 8 are aligned with the coaxial axis. The load-limiting spring seat 9 has a boss for the load-limiting spring 14 sleeved on the load-limiting spring seat 9, a load-limiting spring washer 10 on the outside of the load-limiting spring 14 for pressing, a pin 13 for adjustment, and a load-limiting tightening sleeve 12 for positioning. The load-limiting tightening sleeve 12 is fixed inside the gear shaft 7 by a snap ring 15 to limit the position of the load-limiting spring 14 and the load-limiting spring washer 10. The load-limiting tightening sleeve 12 is threadedly connected to the pin 13, and the pin 13 is fixed by a nut 11 on the outside of the snap ring 15.

[0020] Furthermore, the load-limiting mechanism includes a load-limiting friction plate seat A4 and a load-limiting friction plate seat B6. Both seats have a double-step structure, with a load-limiting friction plate 5 positioned in the middle. The load-limiting friction plate seat A4 is connected to the motor shaft of the motor 3. A load-limiting top rod 8 is fitted onto the load-limiting friction plate seat B6. The load-limiting friction plate seat B6 is in contact with one step of the gear shaft 7, with the far end of the gear shaft 7 extending into the load-limiting friction plate seat B6, and a gap is provided between them.

[0021] Furthermore, the power source is motor 3. Motor 3 drives the load-limiting friction plate seat A 4, which in turn drives the load-limiting friction plate 5 and the load-limiting friction plate seat B 6, which in turn drives the gear shaft 7 to rotate.

[0022] Furthermore, one end of the pin 13 is provided with a hexagonal structure, and the exposed end of the pin 13 is provided with an inner angle structure for adjusting the position of the pin 13.

[0023] When this new type of electric chain hoist load limiting device is used, After installing the parts, adjust the pin and lock it with the nut. Simply adjust the position of the pin and press down the load-limiting spring 14. The load-limiting spring presses inward, adjusting the friction force between the load-limiting rod and the load-limiting friction plate seat B. The further inward the pin is positioned, the greater the friction force, resulting in a greater lifting force and a higher lifting multiplier. Adjust the load-limiting multiplier as required, such as 1.2 times. Exceeding this value will cause the load-limiting friction plate 5 and the load-limiting friction plate seat B 6 to slip, preventing the gear shaft 7 from rotating and power transmission. In this case, the load cannot be lifted, thus achieving load limiting. Because the adjusted pin has a fixed position, and the load-limiting rod evenly contacts and engages with the load-limiting friction plate seat B, the axial positive pressure is evenly distributed. Therefore, this limiting device has high load-limiting stability, high accuracy in setting and adjusting the load limit value, and good consistency in repeated adjustments of the load limit value.

[0024] The above are preferred embodiments of the present invention and do not limit the scope of protection of the present invention. Any modifications and improvements made by those skilled in the art based on the design concept of the present invention should be considered within the scope of protection of the present invention.

Claims

1. A novel load limiting device for an electric chain hoist, comprising a gear box body (1), the gear box body (1) being provided with a gear shaft (7), characterized in that: The novel chain electric hoist load limiting device comprises a load limiting mechanism on the outside of a gear shaft (7) and an adjustment mechanism arranged inside the gear shaft (7); the load limiting mechanism is connected to a power source, the power source inputs power, the gear shaft (7) is a hollow structure, and the gear shaft (7), the load limiting mechanism, the adjustment mechanism and the axis of the power source are coaxial; the adjustment mechanism abuts against the load limiting mechanism to adjust the friction force of the load limiting mechanism.

2. The new type of chain electric hoist load limiting device as claimed in claim 1 is characterized in that: The adjustment mechanism comprises a load-limiting push rod (8) and a load-limiting spring seat (9) which are arranged in the inner cavity of the gear shaft (7) and have clearance fit, the load-limiting push rod (8) abutting against the load-limiting mechanism, and the end faces of the load-limiting spring seat (9) and the load-limiting push rod (8) are arranged in contact with the same axis; a load-limiting spring (14) sleeved on the load-limiting spring seat (9), a load-limiting spring gasket (10) for pressing the outer side of the load-limiting spring (14), a pin shaft (13) for adjustment, and a load-limiting top tight sleeve (12) for limiting position.

3. The new type of chain electric hoist load limiting device as claimed in claim 1 is characterized in that: The load limiting mechanism comprises a load limiting friction plate seat A (4) and a load limiting friction plate seat B (6), with a load limiting friction plate (5) arranged in the middle.

4. The new type of chain electric hoist load limiting device as claimed in claim 1 is characterized in that: The power source is a motor (3).

5. The new type of chain electric hoist load limiting device as claimed in claim 2 is characterized in that: One end of the pin shaft (13) is provided with a hexagonal structure.

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